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Sample records for random phase encoding

  1. Review of Random Phase Encoding in Volume Holographic Storage

    Directory of Open Access Journals (Sweden)

    Wei-Chia Su

    2012-09-01

    Full Text Available Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holographic storage. We then review an image encryption system based on random phase encoding. The alignment of phase key for decryption of the encoded image stored in holographic memory is analyzed and discussed. In the latter part of the review, an all-optical sensing system implemented by random phase encoding and holographic interconnection is presented.

  2. Encoding plaintext by Fourier transform hologram in double random phase encoding using fingerprint keys

    Science.gov (United States)

    Takeda, Masafumi; Nakano, Kazuya; Suzuki, Hiroyuki; Yamaguchi, Masahiro

    2012-09-01

    It has been shown that biometric information can be used as a cipher key for binary data encryption by applying double random phase encoding. In such methods, binary data are encoded in a bit pattern image, and the decrypted image becomes a plain image when the key is genuine; otherwise, decrypted images become random images. In some cases, images decrypted by imposters may not be fully random, such that the blurred bit pattern can be partially observed. In this paper, we propose a novel bit coding method based on a Fourier transform hologram, which makes images decrypted by imposters more random. Computer experiments confirm that the method increases the randomness of images decrypted by imposters while keeping the false rejection rate as low as in the conventional method.

  3. Encoding plaintext by Fourier transform hologram in double random phase encoding using fingerprint keys

    International Nuclear Information System (INIS)

    Takeda, Masafumi; Nakano, Kazuya; Suzuki, Hiroyuki; Yamaguchi, Masahiro

    2012-01-01

    It has been shown that biometric information can be used as a cipher key for binary data encryption by applying double random phase encoding. In such methods, binary data are encoded in a bit pattern image, and the decrypted image becomes a plain image when the key is genuine; otherwise, decrypted images become random images. In some cases, images decrypted by imposters may not be fully random, such that the blurred bit pattern can be partially observed. In this paper, we propose a novel bit coding method based on a Fourier transform hologram, which makes images decrypted by imposters more random. Computer experiments confirm that the method increases the randomness of images decrypted by imposters while keeping the false rejection rate as low as in the conventional method. (paper)

  4. 3D Multisource Full‐Waveform Inversion using Dynamic Random Phase Encoding

    KAUST Repository

    Boonyasiriwat, Chaiwoot; Schuster, Gerard T.

    2010-01-01

    We have developed a multisource full‐waveform inversion algorithm using a dynamic phase encoding strategy with dual‐randomization—both the position and polarity of simultaneous sources are randomized and changed every iteration. The dynamic dual

  5. Security enhancement of double random phase encoding using rear-mounted phase masking

    Science.gov (United States)

    Chen, Junxin; Zhang, Yu; Li, Jinchang; Zhang, Li-bo

    2018-02-01

    In this paper, a security enhancement for double random phase encoding (DRPE) by introducing a rear-mounted phase masking procedure is presented. Based on exhaustively studying the cryptanalysis achievements of DRPE and its variants, invalidation of the second lens, which plays a critical role in cryptanalyzing processes, is concluded. The improved system can exploit the security potential of the second lens and consequently strengthen the security of DRPE. Experimental results and security analyses are presented in detail to demonstrate the security potential of the proposed cryptosystem.

  6. Key management of the double random-phase-encoding method using public-key encryption

    Science.gov (United States)

    Saini, Nirmala; Sinha, Aloka

    2010-03-01

    Public-key encryption has been used to encode the key of the encryption process. In the proposed technique, an input image has been encrypted by using the double random-phase-encoding method using extended fractional Fourier transform. The key of the encryption process have been encoded by using the Rivest-Shamir-Adelman (RSA) public-key encryption algorithm. The encoded key has then been transmitted to the receiver side along with the encrypted image. In the decryption process, first the encoded key has been decrypted using the secret key and then the encrypted image has been decrypted by using the retrieved key parameters. The proposed technique has advantage over double random-phase-encoding method because the problem associated with the transmission of the key has been eliminated by using public-key encryption. Computer simulation has been carried out to validate the proposed technique.

  7. Enhancing Security of Double Random Phase Encoding Based on Random S-Box

    Science.gov (United States)

    Girija, R.; Singh, Hukum

    2018-06-01

    In this paper, we propose a novel asymmetric cryptosystem for double random phase encoding (DRPE) using random S-Box. While utilising S-Box separately is not reliable and DRPE does not support non-linearity, so, our system unites the effectiveness of S-Box with an asymmetric system of DRPE (through Fourier transform). The uniqueness of proposed cryptosystem lies on employing high sensitivity dynamic S-Box for our DRPE system. The randomness and scalability achieved due to applied technique is an additional feature of the proposed solution. The firmness of random S-Box is investigated in terms of performance parameters such as non-linearity, strict avalanche criterion, bit independence criterion, linear and differential approximation probabilities etc. S-Boxes convey nonlinearity to cryptosystems which is a significant parameter and very essential for DRPE. The strength of proposed cryptosystem has been analysed using various parameters such as MSE, PSNR, correlation coefficient analysis, noise analysis, SVD analysis, etc. Experimental results are conferred in detail to exhibit proposed cryptosystem is highly secure.

  8. A novel attack method about double-random-phase-encoding-based image hiding method

    Science.gov (United States)

    Xu, Hongsheng; Xiao, Zhijun; Zhu, Xianchen

    2018-03-01

    By using optical image processing techniques, a novel text encryption and hiding method applied by double-random phase-encoding technique is proposed in the paper. The first step is that the secret message is transformed into a 2-dimension array. The higher bits of the elements in the array are used to fill with the bit stream of the secret text, while the lower bits are stored specific values. Then, the transformed array is encoded by double random phase encoding technique. Last, the encoded array is embedded on a public host image to obtain the image embedded with hidden text. The performance of the proposed technique is tested via analytical modeling and test data stream. Experimental results show that the secret text can be recovered either accurately or almost accurately, while maintaining the quality of the host image embedded with hidden data by properly selecting the method of transforming the secret text into an array and the superimposition coefficient.

  9. 3D Multisource Full‐Waveform Inversion using Dynamic Random Phase Encoding

    KAUST Repository

    Boonyasiriwat, Chaiwoot

    2010-10-17

    We have developed a multisource full‐waveform inversion algorithm using a dynamic phase encoding strategy with dual‐randomization—both the position and polarity of simultaneous sources are randomized and changed every iteration. The dynamic dual‐randomization is used to promote the destructive interference of crosstalk noise resulting from blending a large number of common shot gathers into a supergather. We compare our multisource algorithm with various algorithms in a numerical experiment using the 3D SEG/EAGE overthrust model and show that our algorithm provides a higher‐quality velocity tomogram than the other methods that use only monorandomization. This suggests that increasing the degree of randomness in phase encoding should improve the quality of the inversion result.

  10. Efficient Text Encryption and Hiding with Double-Random Phase-Encoding

    Directory of Open Access Journals (Sweden)

    Mohammad S. Alam

    2012-10-01

    Full Text Available In this paper, a double-random phase-encoding technique-based text encryption and hiding method is proposed. First, the secret text is transformed into a 2-dimensional array and the higher bits of the elements in the transformed array are used to store the bit stream of the secret text, while the lower bits are filled with specific values. Then, the transformed array is encoded with double-random phase-encoding technique. Finally, the encoded array is superimposed on an expanded host image to obtain the image embedded with hidden data. The performance of the proposed technique, including the hiding capacity, the recovery accuracy of the secret text, and the quality of the image embedded with hidden data, is tested via analytical modeling and test data stream. Experimental results show that the secret text can be recovered either accurately or almost accurately, while maintaining the quality of the host image embedded with hidden data by properly selecting the method of transforming the secret text into an array and the superimposition coefficient. By using optical information processing techniques, the proposed method has been found to significantly improve the security of text information transmission, while ensuring hiding capacity at a prescribed level.

  11. Optical image transformation and encryption by phase-retrieval-based double random-phase encoding and compressive ghost imaging

    Science.gov (United States)

    Yuan, Sheng; Yang, Yangrui; Liu, Xuemei; Zhou, Xin; Wei, Zhenzhuo

    2018-01-01

    An optical image transformation and encryption scheme is proposed based on double random-phase encoding (DRPE) and compressive ghost imaging (CGI) techniques. In this scheme, a secret image is first transformed into a binary image with the phase-retrieval-based DRPE technique, and then encoded by a series of random amplitude patterns according to the ghost imaging (GI) principle. Compressive sensing, corrosion and expansion operations are implemented to retrieve the secret image in the decryption process. This encryption scheme takes the advantage of complementary capabilities offered by the phase-retrieval-based DRPE and GI-based encryption techniques. That is the phase-retrieval-based DRPE is used to overcome the blurring defect of the decrypted image in the GI-based encryption, and the CGI not only reduces the data amount of the ciphertext, but also enhances the security of DRPE. Computer simulation results are presented to verify the performance of the proposed encryption scheme.

  12. Information hiding based on double random-phase encoding and public-key cryptography.

    Science.gov (United States)

    Sheng, Yuan; Xin, Zhou; Alam, Mohammed S; Xi, Lu; Xiao-Feng, Li

    2009-03-02

    A novel information hiding method based on double random-phase encoding (DRPE) and Rivest-Shamir-Adleman (RSA) public-key cryptosystem is proposed. In the proposed technique, the inherent diffusion property of DRPE is cleverly utilized to make up the diffusion insufficiency of RSA public-key cryptography, while the RSA cryptosystem is utilized for simultaneous transmission of the cipher text and the two phase-masks, which is not possible under the DRPE technique. This technique combines the complementary advantages of the DPRE and RSA encryption techniques and brings security and convenience for efficient information transmission. Extensive numerical simulation results are presented to verify the performance of the proposed technique.

  13. Biometrics based key management of double random phase encoding scheme using error control codes

    Science.gov (United States)

    Saini, Nirmala; Sinha, Aloka

    2013-08-01

    In this paper, an optical security system has been proposed in which key of the double random phase encoding technique is linked to the biometrics of the user to make it user specific. The error in recognition due to the biometric variation is corrected by encoding the key using the BCH code. A user specific shuffling key is used to increase the separation between genuine and impostor Hamming distance distribution. This shuffling key is then further secured using the RSA public key encryption to enhance the security of the system. XOR operation is performed between the encoded key and the feature vector obtained from the biometrics. The RSA encoded shuffling key and the data obtained from the XOR operation are stored into a token. The main advantage of the present technique is that the key retrieval is possible only in the simultaneous presence of the token and the biometrics of the user which not only authenticates the presence of the original input but also secures the key of the system. Computational experiments showed the effectiveness of the proposed technique for key retrieval in the decryption process by using the live biometrics of the user.

  14. Fractional Fourier domain optical image hiding using phase retrieval algorithm based on iterative nonlinear double random phase encoding.

    Science.gov (United States)

    Wang, Xiaogang; Chen, Wen; Chen, Xudong

    2014-09-22

    We present a novel image hiding method based on phase retrieval algorithm under the framework of nonlinear double random phase encoding in fractional Fourier domain. Two phase-only masks (POMs) are efficiently determined by using the phase retrieval algorithm, in which two cascaded phase-truncated fractional Fourier transforms (FrFTs) are involved. No undesired information disclosure, post-processing of the POMs or digital inverse computation appears in our proposed method. In order to achieve the reduction in key transmission, a modified image hiding method based on the modified phase retrieval algorithm and logistic map is further proposed in this paper, in which the fractional orders and the parameters with respect to the logistic map are regarded as encryption keys. Numerical results have demonstrated the feasibility and effectiveness of the proposed algorithms.

  15. A multispectral photon-counting double random phase encoding scheme for image authentication.

    Science.gov (United States)

    Yi, Faliu; Moon, Inkyu; Lee, Yeon H

    2014-05-20

    In this paper, we propose a new method for color image-based authentication that combines multispectral photon-counting imaging (MPCI) and double random phase encoding (DRPE) schemes. The sparsely distributed information from MPCI and the stationary white noise signal from DRPE make intruder attacks difficult. In this authentication method, the original multispectral RGB color image is down-sampled into a Bayer image. The three types of color samples (red, green and blue color) in the Bayer image are encrypted with DRPE and the amplitude part of the resulting image is photon counted. The corresponding phase information that has nonzero amplitude after photon counting is then kept for decryption. Experimental results show that the retrieved images from the proposed method do not visually resemble their original counterparts. Nevertheless, the original color image can be efficiently verified with statistical nonlinear correlations. Our experimental results also show that different interpolation algorithms applied to Bayer images result in different verification effects for multispectral RGB color images.

  16. A Multispectral Photon-Counting Double Random Phase Encoding Scheme for Image Authentication

    Directory of Open Access Journals (Sweden)

    Faliu Yi

    2014-05-01

    Full Text Available In this paper, we propose a new method for color image-based authentication that combines multispectral photon-counting imaging (MPCI and double random phase encoding (DRPE schemes. The sparsely distributed information from MPCI and the stationary white noise signal from DRPE make intruder attacks difficult. In this authentication method, the original multispectral RGB color image is down-sampled into a Bayer image. The three types of color samples (red, green and blue color in the Bayer image are encrypted with DRPE and the amplitude part of the resulting image is photon counted. The corresponding phase information that has nonzero amplitude after photon counting is then kept for decryption. Experimental results show that the retrieved images from the proposed method do not visually resemble their original counterparts. Nevertheless, the original color image can be efficiently verified with statistical nonlinear correlations. Our experimental results also show that different interpolation algorithms applied to Bayer images result in different verification effects for multispectral RGB color images.

  17. Steganographic optical image encryption system based on reversible data hiding and double random phase encoding

    Science.gov (United States)

    Chuang, Cheng-Hung; Chen, Yen-Lin

    2013-02-01

    This study presents a steganographic optical image encryption system based on reversible data hiding and double random phase encoding (DRPE) techniques. Conventional optical image encryption systems can securely transmit valuable images using an encryption method for possible application in optical transmission systems. The steganographic optical image encryption system based on the DRPE technique has been investigated to hide secret data in encrypted images. However, the DRPE techniques vulnerable to attacks and many of the data hiding methods in the DRPE system can distort the decrypted images. The proposed system, based on reversible data hiding, uses a JBIG2 compression scheme to achieve lossless decrypted image quality and perform a prior encryption process. Thus, the DRPE technique enables a more secured optical encryption process. The proposed method extracts and compresses the bit planes of the original image using the lossless JBIG2 technique. The secret data are embedded in the remaining storage space. The RSA algorithm can cipher the compressed binary bits and secret data for advanced security. Experimental results show that the proposed system achieves a high data embedding capacity and lossless reconstruction of the original images.

  18. Phase-Image Encryption Based on 3D-Lorenz Chaotic System and Double Random Phase Encoding

    Science.gov (United States)

    Sharma, Neha; Saini, Indu; Yadav, AK; Singh, Phool

    2017-12-01

    In this paper, an encryption scheme for phase-images based on 3D-Lorenz chaotic system in Fourier domain under the 4f optical system is presented. The encryption scheme uses a random amplitude mask in the spatial domain and a random phase mask in the frequency domain. Its inputs are phase-images, which are relatively more secure as compared to the intensity images because of non-linearity. The proposed scheme further derives its strength from the use of 3D-Lorenz transform in the frequency domain. Although the experimental setup for optical realization of the proposed scheme has been provided, the results presented here are based on simulations on MATLAB. It has been validated for grayscale images, and is found to be sensitive to the encryption parameters of the Lorenz system. The attacks analysis shows that the key-space is large enough to resist brute-force attack, and the scheme is also resistant to the noise and occlusion attacks. Statistical analysis and the analysis based on correlation distribution of adjacent pixels have been performed to test the efficacy of the encryption scheme. The results have indicated that the proposed encryption scheme possesses a high level of security.

  19. Cryptanalysis and improvement of an optical image encryption scheme using a chaotic Baker map and double random phase encoding

    International Nuclear Information System (INIS)

    Chen, Jun-Xin; Fu, Chong; Zhu, Zhi-Liang; Zhang, Li-Bo; Zhang, Yushu

    2014-01-01

    In this paper, we evaluate the security of an enhanced double random phase encoding (DRPE) image encryption scheme (2013 J. Lightwave Technol. 31 2533). The original system employs a chaotic Baker map prior to DRPE to provide more protection to the plain image and hence promote the security level of DRPE, as claimed. However, cryptanalysis shows that this scheme is vulnerable to a chosen-plaintext attack, and the ciphertext can be precisely recovered. The corresponding improvement is subsequently reported upon the basic premise that no extra equipment or computational complexity is required. The simulation results and security analyses prove its effectiveness and security. The proposed achievements are suitable for all cryptosystems under permutation and, following that, the DRPE architecture, and we hope that our work can motivate the further research on optical image encryption. (paper)

  20. Cryptanalysis and improvement of an optical image encryption scheme using a chaotic Baker map and double random phase encoding

    Science.gov (United States)

    Chen, Jun-Xin; Zhu, Zhi-Liang; Fu, Chong; Zhang, Li-Bo; Zhang, Yushu

    2014-12-01

    In this paper, we evaluate the security of an enhanced double random phase encoding (DRPE) image encryption scheme (2013 J. Lightwave Technol. 31 2533). The original system employs a chaotic Baker map prior to DRPE to provide more protection to the plain image and hence promote the security level of DRPE, as claimed. However, cryptanalysis shows that this scheme is vulnerable to a chosen-plaintext attack, and the ciphertext can be precisely recovered. The corresponding improvement is subsequently reported upon the basic premise that no extra equipment or computational complexity is required. The simulation results and security analyses prove its effectiveness and security. The proposed achievements are suitable for all cryptosystems under permutation and, following that, the DRPE architecture, and we hope that our work can motivate the further research on optical image encryption.

  1. Information verification cryptosystem using one-time keys based on double random phase encoding and public-key cryptography

    Science.gov (United States)

    Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

    2016-08-01

    A novel image encryption system based on double random phase encoding (DRPE) and RSA public-key algorithm is proposed. The main characteristic of the system is that each encryption process produces a new decryption key (even for the same plaintext), thus the encryption system conforms to the feature of the one-time pad (OTP) cryptography. The other characteristic of the system is the use of fingerprint key. Only with the rightful authorization will the true decryption be obtained, otherwise the decryption will result in noisy images. So the proposed system can be used to determine whether the ciphertext is falsified by attackers. In addition, the system conforms to the basic agreement of asymmetric cryptosystem (ACS) due to the combination with the RSA public-key algorithm. The simulation results show that the encryption scheme has high robustness against the existing attacks.

  2. Image security based on iterative random phase encoding in expanded fractional Fourier transform domains

    Science.gov (United States)

    Liu, Zhengjun; Chen, Hang; Blondel, Walter; Shen, Zhenmin; Liu, Shutian

    2018-06-01

    A novel image encryption method is proposed by using the expanded fractional Fourier transform, which is implemented with a pair of lenses. Here the centers of two lenses are separated at the cross section of axis in optical system. The encryption system is addressed with Fresnel diffraction and phase modulation for the calculation of information transmission. The iterative process with the transform unit is utilized for hiding secret image. The structure parameters of a battery of lenses can be used for additional keys. The performance of encryption method is analyzed theoretically and digitally. The results show that the security of this algorithm is enhanced markedly by the added keys.

  3. Performance analysis of spectral-phase-encoded optical code-division multiple-access system regarding the incorrectly decoded signal as a nonstationary random process

    Science.gov (United States)

    Yan, Meng; Yao, Minyu; Zhang, Hongming

    2005-11-01

    The performance of a spectral-phase-encoded (SPE) optical code-division multiple-access (OCDMA) system is analyzed. Regarding the incorrectly decoded signal (IDS) as a nonstationary random process, we derive a novel probability distribution for it. The probability distribution of the IDS is considered a chi-squared distribution with degrees of freedom r=1, which is more reasonable and accurate than in previous work. The bit error rate (BER) of an SPE OCDMA system under multiple-access interference is evaluated. Numerical results show that the system can sustain very low BER even when there are multiple simultaneous users, and as the code length becomes longer or the initial pulse becomes shorter, the system performs better.

  4. Cryptographic analysis on the key space of optical phase encryption algorithm based on the design of discrete random phase mask

    Science.gov (United States)

    Lin, Chao; Shen, Xueju; Li, Zengyan

    2013-07-01

    The key space of phase encryption algorithm using discrete random phase mask is investigated by numerical simulation in this paper. Random phase mask with finite and discrete phase levels is considered as the core component in most practical optical encryption architectures. The key space analysis is based on the design criteria of discrete random phase mask. The role of random amplitude mask and random phase mask in optical encryption system is identified from the perspective of confusion and diffusion. The properties of discrete random phase mask in a practical double random phase encoding scheme working in both amplitude encoding (AE) and phase encoding (PE) modes are comparably analyzed. The key space of random phase encryption algorithm is evaluated considering both the encryption quality and the brute-force attack resistibility. A method for enlarging the key space of phase encryption algorithm is also proposed to enhance the security of optical phase encryption techniques.

  5. Multiple-stage pure phase encoding with biometric information

    Science.gov (United States)

    Chen, Wen

    2018-01-01

    In recent years, many optical systems have been developed for securing information, and optical encryption/encoding has attracted more and more attention due to the marked advantages, such as parallel processing and multiple-dimensional characteristics. In this paper, an optical security method is presented based on pure phase encoding with biometric information. Biometric information (such as fingerprint) is employed as security keys rather than plaintext used in conventional optical security systems, and multiple-stage phase-encoding-based optical systems are designed for generating several phase-only masks with biometric information. Subsequently, the extracted phase-only masks are further used in an optical setup for encoding an input image (i.e., plaintext). Numerical simulations are conducted to illustrate the validity, and the results demonstrate that high flexibility and high security can be achieved.

  6. Theory of multisource crosstalk reduction by phase-encoded statics

    KAUST Repository

    Schuster, Gerard T.

    2011-03-01

    Formulas are derived that relate the strength of the crosstalk noise in supergather migration images to the variance of time, amplitude and polarity shifts in encoding functions. A supergather migration image is computed by migrating an encoded supergather, where the supergather is formed by stacking a large number of encoded shot gathers. Analysis reveals that for temporal source static shifts in each shot gather, the crosstalk noise is exponentially reduced with increasing variance of the static shift and the square of source frequency. This is not too surprising because larger time shifts lead to less correlation between traces in different shot gathers, and so should tend to reduce the crosstalk noise. Analysis also reveals that combining both polarity and time statics is a superior encoding strategy compared to using either polarity statics or time statics alone. Signal-to-noise (SNR) estimates show that for a standard migration image and for an image computed by migrating a phase-encoded supergather; here, G is the number of traces in a shot gather, I is the number of stacking iterations in the supergather and S is the number of encoded/blended shot gathers that comprise the supergather. If the supergather can be uniformly divided up into Q unique sub-supergathers, then the resulting SNR of the final image is, which means that we can enhance image quality but at the expense of Q times more cost. The importance of these formulas is that they provide a precise understanding between different phase encoding strategies and image quality. Finally, we show that iterative migration of phase-encoded supergathers is a special case of passive seismic interferometry. We suggest that the crosstalk noise formulas can be helpful in designing optimal strategies for passive seismic interferometry and efficient extraction of Green\\'s functions from simulated supergathers. © 2011 The Authors Geophysical Journal International © 2011 RAS.

  7. Simultaneous transmission for an encrypted image and a double random-phase encryption key

    Science.gov (United States)

    Yuan, Sheng; Zhou, Xin; Li, Da-Hai; Zhou, Ding-Fu

    2007-06-01

    We propose a method to simultaneously transmit double random-phase encryption key and an encrypted image by making use of the fact that an acceptable decryption result can be obtained when only partial data of the encrypted image have been taken in the decryption process. First, the original image data are encoded as an encrypted image by a double random-phase encryption technique. Second, a double random-phase encryption key is encoded as an encoded key by the Rivest-Shamir-Adelman (RSA) public-key encryption algorithm. Then the amplitude of the encrypted image is modulated by the encoded key to form what we call an encoded image. Finally, the encoded image that carries both the encrypted image and the encoded key is delivered to the receiver. Based on such a method, the receiver can have an acceptable result and secure transmission can be guaranteed by the RSA cipher system.

  8. Synthesis and nanoscale thermal encoding of phase-change nanowires

    International Nuclear Information System (INIS)

    Sun Xuhui; Yu Bin; Meyyappan, M.

    2007-01-01

    Low-dimensional phase-change nanostructures provide a valuable research platform for understanding the phase-transition behavior and thermal properties at nanoscale and their potential in achieving superdense data storage. Ge 2 Sb 2 Te 5 nanowires have been grown using a vapor-liquid-solid technique and shown to exhibit distinctive properties that may overcome the present data storage scaling barrier. Local heating of an individual nanowire with a focused electron beam was used to shape a nano-bar-code on a Ge 2 Sb 2 Te 5 nanowire. The data encoding on Ge 2 Sb 2 Te 5 nanowire may promote novel device concepts to implement ultrahigh density, low energy, high speed data storage using phase-change nanomaterials with diverse thermal-programing strategies

  9. A randomized phase II study of immunization with dendritic cells modified with poxvectors encoding CEA and MUC1 compared with the same poxvectors plus GM-CSF for resected metastatic colorectal cancer.

    Science.gov (United States)

    Morse, Michael A; Niedzwiecki, Donna; Marshall, John L; Garrett, Christopher; Chang, David Z; Aklilu, Mebea; Crocenzi, Todd S; Cole, David J; Dessureault, Sophie; Hobeika, Amy C; Osada, Takuya; Onaitis, Mark; Clary, Bryan M; Hsu, David; Devi, Gayathri R; Bulusu, Anuradha; Annechiarico, Robert P; Chadaram, Vijaya; Clay, Timothy M; Lyerly, H Kim

    2013-12-01

    To determine whether 1 of 2 vaccines based on dendritic cells (DCs) and poxvectors encoding CEA (carcinoembryonic antigen) and MUC1 (PANVAC) would lengthen survival in patients with resected metastases of colorectal cancer (CRC). Recurrences after complete resections of metastatic CRC remain frequent. Immune responses to CRC are associated with fewer recurrences, suggesting a role for cancer vaccines as adjuvant therapy. Both DCs and poxvectors are potent stimulators of immune responses against cancer antigens. Patients, disease-free after CRC metastasectomy and perioperative chemotherapy (n = 74), were randomized to injections of autologous DCs modified with PANVAC (DC/PANVAC) or PANVAC with per injection GM-CSF (granulocyte-macrophage colony-stimulating factor). Endpoints were recurrence-free survival overall survival, and rate of CEA-specific immune responses. Clinical outcome was compared with that of an unvaccinated, contemporary group of patients who had undergone CRC metastasectomy, received similar perioperative therapy, and would have otherwise been eligible for the study. Recurrence-free survival at 2 years was similar (47% and 55% for DC/PANVAC and PANVAC/GM-CSF, respectively) (χ P = 0.48). At a median follow-up of 35.7 months, there were 2 of 37 deaths in the DC/PANVAC arm and 5 of 37 deaths in the PANVAC/GM-CSF arm. The rate and magnitude of T-cell responses against CEA was statistically similar between study arms. As a group, vaccinated patients had superior survival compared with the contemporary unvaccinated group. Both DC and poxvector vaccines have similar activity. Survival was longer for vaccinated patients than for a contemporary unvaccinated group, suggesting that a randomized trial of poxvector vaccinations compared with standard follow-up after metastasectomy is warranted. (NCT00103142).

  10. Latency Performance of Encoding with Random Linear Network Coding

    DEFF Research Database (Denmark)

    Nielsen, Lars; Hansen, René Rydhof; Lucani Rötter, Daniel Enrique

    2018-01-01

    the encoding process can be parallelized based on system requirements to reduce data access time within the system. Using a counting argument, we focus on predicting the effect of changes of generation (number of original packets) and symbol size (number of bytes per data packet) configurations on the encoding...... latency on full vector and on-the-fly algorithms. We show that the encoding latency doubles when either the generation size or the symbol size double and confirm this via extensive simulations. Although we show that the theoretical speed gain of on-the-fly over full vector is two, our measurements show...

  11. Beyond the random phase approximation

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian S.

    2013-01-01

    We assess the performance of a recently proposed renormalized adiabatic local density approximation (rALDA) for ab initio calculations of electronic correlation energies in solids and molecules. The method is an extension of the random phase approximation (RPA) derived from time-dependent density...... functional theory and the adiabatic connection fluctuation-dissipation theorem and contains no fitted parameters. The new kernel is shown to preserve the accurate description of dispersive interactions from RPA while significantly improving the description of short-range correlation in molecules, insulators......, and metals. For molecular atomization energies, the rALDA is a factor of 7 better than RPA and a factor of 4 better than the Perdew-Burke-Ernzerhof (PBE) functional when compared to experiments, and a factor of 3 (1.5) better than RPA (PBE) for cohesive energies of solids. For transition metals...

  12. Micro-Texture Synthesis by Phase Randomization

    Directory of Open Access Journals (Sweden)

    Bruno Galerne

    2011-09-01

    Full Text Available This contribution is concerned with texture synthesis by example, the process of generating new texture images from a given sample. The Random Phase Noise algorithm presented here synthesizes a texture from an original image by simply randomizing its Fourier phase. It is able to reproduce textures which are characterized by their Fourier modulus, namely the random phase textures (or micro-textures.

  13. Artificial neural networks using complex numbers and phase encoded weights.

    Science.gov (United States)

    Michel, Howard E; Awwal, Abdul Ahad S

    2010-04-01

    The model of a simple perceptron using phase-encoded inputs and complex-valued weights is proposed. The aggregation function, activation function, and learning rule for the proposed neuron are derived and applied to Boolean logic functions and simple computer vision tasks. The complex-valued neuron (CVN) is shown to be superior to traditional perceptrons. An improvement of 135% over the theoretical maximum of 104 linearly separable problems (of three variables) solvable by conventional perceptrons is achieved without additional logic, neuron stages, or higher order terms such as those required in polynomial logic gates. The application of CVN in distortion invariant character recognition and image segmentation is demonstrated. Implementation details are discussed, and the CVN is shown to be very attractive for optical implementation since optical computations are naturally complex. The cost of the CVN is less in all cases than the traditional neuron when implemented optically. Therefore, all the benefits of the CVN can be obtained without additional cost. However, on those implementations dependent on standard serial computers, CVN will be more cost effective only in those applications where its increased power can offset the requirement for additional neurons.

  14. Encoding Sequential Information in Semantic Space Models: Comparing Holographic Reduced Representation and Random Permutation

    Directory of Open Access Journals (Sweden)

    Gabriel Recchia

    2015-01-01

    Full Text Available Circular convolution and random permutation have each been proposed as neurally plausible binding operators capable of encoding sequential information in semantic memory. We perform several controlled comparisons of circular convolution and random permutation as means of encoding paired associates as well as encoding sequential information. Random permutations outperformed convolution with respect to the number of paired associates that can be reliably stored in a single memory trace. Performance was equal on semantic tasks when using a small corpus, but random permutations were ultimately capable of achieving superior performance due to their higher scalability to large corpora. Finally, “noisy” permutations in which units are mapped to other units arbitrarily (no one-to-one mapping perform nearly as well as true permutations. These findings increase the neurological plausibility of random permutations and highlight their utility in vector space models of semantics.

  15. Security of BB84 with weak randomness and imperfect qubit encoding

    Science.gov (United States)

    Zhao, Liang-Yuan; Yin, Zhen-Qiang; Li, Hong-Wei; Chen, Wei; Fang, Xi; Han, Zheng-Fu; Huang, Wei

    2018-03-01

    The main threats for the well-known Bennett-Brassard 1984 (BB84) practical quantum key distribution (QKD) systems are that its encoding is inaccurate and measurement device may be vulnerable to particular attacks. Thus, a general physical model or security proof to tackle these loopholes simultaneously and quantitatively is highly desired. Here we give a framework on the security of BB84 when imperfect qubit encoding and vulnerability of measurement device are both considered. In our analysis, the potential attacks to measurement device are generalized by the recently proposed weak randomness model which assumes the input random numbers are partially biased depending on a hidden variable planted by an eavesdropper. And the inevitable encoding inaccuracy is also introduced here. From a fundamental view, our work reveals the potential information leakage due to encoding inaccuracy and weak randomness input. For applications, our result can be viewed as a useful tool to quantitatively evaluate the security of a practical QKD system.

  16. The Implications of Encoder/Modulator/ Phased Array Designs for Future Broadband LEO Communications

    Science.gov (United States)

    Vanderaar, Mark; Jensen, Chris A.; Terry, John D.

    1997-01-01

    In this paper we summarize the effects of modulation and channel coding on the design of wide angle scan, broadband, phased army antennas. In the paper we perform several trade studies. First, we investigate the amplifier back-off requirement as a function of variability of modulation envelope. Specifically, we contrast constant and non-constant envelope modulations, as well as single and multiple carrier schemes. Additionally, we address the issues an(f concerns of using pulse shaping filters with the above modulation types. Second, we quantify the effects of beam steering on the quality of data, recovery using selected modulation techniques. In particular, we show that the frequency response of the array introduces intersymbol interference for broadband signals and that the mode of operation for the beam steering controller may introduce additional burst or random errors. Finally, we show that the encoder/modulator design must be performed in conjunction with the phased array antenna design.

  17. Distributed-phase OCDMA encoder-decoders based on fiber Bragg gratings

    OpenAIRE

    Zhang, Zhaowei; Tian, C.; Petropoulos, P.; Richardson, D.J.; Ibsen, M.

    2007-01-01

    We propose and demonstrate new optical code-division multiple-access (OCDMA) encoder-decoders having a continuous phase-distribution. With the same spatial refractive index distribution as the reconfigurable optical phase encoder-decoders, they are inherently suitable for the application in reconfigurable OCDMA systems. Furthermore, compared with conventional discrete-phase devices, they also have additional advantages of being more tolerant to input pulse width and, therefore, have the poten...

  18. Known-plaintext attack on the double phase encoding and its implementation with parallel hardware

    Science.gov (United States)

    Wei, Hengzheng; Peng, Xiang; Liu, Haitao; Feng, Songlin; Gao, Bruce Z.

    2008-03-01

    A known-plaintext attack on the double phase encryption scheme implemented with parallel hardware is presented. The double random phase encoding (DRPE) is one of the most representative optical cryptosystems developed in mid of 90's and derives quite a few variants since then. Although the DRPE encryption system has a strong power resisting to a brute-force attack, the inherent architecture of DRPE leaves a hidden trouble due to its linearity nature. Recently the real security strength of this opto-cryptosystem has been doubted and analyzed from the cryptanalysis point of view. In this presentation, we demonstrate that the optical cryptosystems based on DRPE architecture are vulnerable to known-plain text attack. With this attack the two encryption keys in the DRPE can be accessed with the help of the phase retrieval technique. In our approach, we adopt hybrid input-output algorithm (HIO) to recover the random phase key in the object domain and then infer the key in frequency domain. Only a plaintext-ciphertext pair is sufficient to create vulnerability. Moreover this attack does not need to select particular plaintext. The phase retrieval technique based on HIO is an iterative process performing Fourier transforms, so it fits very much into the hardware implementation of the digital signal processor (DSP). We make use of the high performance DSP to accomplish the known-plaintext attack. Compared with the software implementation, the speed of the hardware implementation is much fast. The performance of this DSP-based cryptanalysis system is also evaluated.

  19. Time domain spectral phase encoding/DPSK data modulation using single phase modulator for OCDMA application.

    Science.gov (United States)

    Wang, Xu; Gao, Zhensen; Kataoka, Nobuyuki; Wada, Naoya

    2010-05-10

    A novel scheme using single phase modulator for simultaneous time domain spectral phase encoding (SPE) signal generation and DPSK data modulation is proposed and experimentally demonstrated. Array- Waveguide-Grating and Variable-Bandwidth-Spectrum-Shaper based devices can be used for decoding the signal directly in spectral domain. The effects of fiber dispersion, light pulse width and timing error on the coding performance have been investigated by simulation and verified in experiment. In the experiment, SPE signal with 8-chip, 20GHz/chip optical code patterns has been generated and modulated with 2.5 Gbps DPSK data using single modulator. Transmission of the 2.5 Gbps data over 34km fiber with BEROCDMA) and secure optical communication applications. (c) 2010 Optical Society of America.

  20. Wireless, Passive Encoded Saw Sensors and Communication Links, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — There are several objectives of this Phase I proposal. One major objective is to investigate SAW sensor embodiments for pressure and acceleration. Two approaches...

  1. Fully phase-encoded MRI near metallic implants using ultrashort echo times and broadband excitation.

    Science.gov (United States)

    Wiens, Curtis N; Artz, Nathan S; Jang, Hyungseok; McMillan, Alan B; Koch, Kevin M; Reeder, Scott B

    2018-04-01

    To develop a fully phase-encoded MRI method for distortion-free imaging near metallic implants, in clinically feasible acquisition times. An accelerated 3D fully phase-encoded acquisition with broadband excitation and ultrashort echo times is presented, which uses a broadband radiofrequency pulse to excite the entire off-resonance induced by the metallic implant. Furthermore, fully phase-encoded imaging is used to prevent distortions caused by frequency encoding, and to obtain ultrashort echo times for rapidly decaying signal. Phantom and in vivo acquisitions were used to describe the relationship among excitation bandwidth, signal loss near metallic implants, and T 1 weighting. Shorter radiofrequency pulses captured signal closer to the implant by improving spectral coverage and allowing shorter echo times, whereas longer pulses improved T 1 weighting through larger maximum attainable flip angles. Comparisons of fully phase-encoded acquisition with broadband excitation and ultrashort echo times to T 1 -weighted multi-acquisition with variable resonance image combination selective were performed in phantoms and subjects with metallic knee and hip prostheses. These acquisitions had similar contrast and acquisition efficiency. Accelerated fully phase-encoded acquisitions with ultrashort echo times and broadband excitation can generate distortion free images near metallic implants in clinically feasible acquisition times. Magn Reson Med 79:2156-2163, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  2. Phase behavior of random copolymers in quenched random media

    International Nuclear Information System (INIS)

    Chakraborty, A.K.; Shakhnovich, E.I.

    1995-01-01

    In this paper, we consider the behavior of random heteropolymers in a quenched disordered medium. We develop a field theory and obtain a mean-field solution that allows for replica symmetry breaking. The presence of an external disorder leads to the formation of compact states; a homopolymeric effect. We compute the phase diagram for two classes of problems. First, we consider the situation wherein the bare heteropolymer prefers like segments to segregate, and second, we examine cases where the bare heteropolymer prefers unlike segments to mix. For the first class of systems, we find a phase diagram characterized by a replica symmetry broken phase that exists below a particular temperature. This temperature grows with the strength of the external disorder. In the second class of situations, the phase diagram is much richer. Here we find two replica symmetry broken phases with different patterns separated by a reentrant phase. The reentrant phase and one of the two replica symmetry broken phases are induced by interactions with the external disorder. The dependence of the location of the phase boundaries on the strength of the external disorder are elucidated. We discuss our results from a physical standpoint, and note the testable experimental consequences of our findings. copyright 1995 American Institute of Physics

  3. Spectral phase encoding of ultra-short optical pulse in time domain for OCDMA application.

    Science.gov (United States)

    Wang, Xu; Wada, Naoya

    2007-06-11

    We propose a novel reconfigurable time domain spectral phase encoding (SPE) scheme for coherent optical code-division-multiple-access application. In the proposed scheme, the ultra-short optical pulse is stretched by dispersive device and the SPE is done in time domain using high speed phase modulator. The time domain SPE scheme is robust to wavelength drift of the light source and is very flexible and compatible with the fiber optical system. Proof-of-principle experiments of encoding with 16-chip, 20 GHz/chip binary-phase-shift-keying codes and 1.25 Gbps data transmission have been successfully demonstrated together with an arrayed-wave-guide decoder.

  4. Quasilinear theory without the random phase approximation

    International Nuclear Information System (INIS)

    Weibel, E.S.; Vaclavik, J.

    1980-08-01

    The system of quasilinear equations is derived without making use of the random phase approximation. The fluctuating quantities are described by the autocorrelation function of the electric field using the techniques of Fourier analysis. The resulting equations posses the necessary conservation properties, but comprise new terms which hitherto have been lost in the conventional derivations

  5. Random-phase metasurfaces at optical wavelengths

    DEFF Research Database (Denmark)

    Pors, Anders; Ding, Fei; Chen, Yiting

    2016-01-01

    , with statistics obeying the theoretical predictions. We foresee the use of random-phase metasurfaces for camouflage applications and as high-quality reference structures in dark-field microscopy, while the control of the statistics for polarised and unpolarised light might find usage in security applications...

  6. Polarization states encoded by phase modulation for high bit rate quantum key distribution

    International Nuclear Information System (INIS)

    Liu Xiaobao; Tang Zhilie; Liao Changjun; Lu Yiqun; Zhao Feng; Liu Songhao

    2006-01-01

    We present implementation of quantum cryptography with polarization code by wave-guide type phase modulator. At four different low input voltages of the phase modulator, coder encodes pulses into four different polarization states, 45 o , 135 o linearly polarized or right, left circle polarized, while the decoder serves as the complementary polarizers

  7. Phase modulated high density collinear holographic data storage system with phase-retrieval reference beam locking and orthogonal reference encoding.

    Science.gov (United States)

    Liu, Jinpeng; Horimai, Hideyoshi; Lin, Xiao; Huang, Yong; Tan, Xiaodi

    2018-02-19

    A novel phase modulation method for holographic data storage with phase-retrieval reference beam locking is proposed and incorporated into an amplitude-encoding collinear holographic storage system. Unlike the conventional phase retrieval method, the proposed method locks the data page and the corresponding phase-retrieval interference beam together at the same location with a sequential recording process, which eliminates piezoelectric elements, phase shift arrays and extra interference beams, making the system more compact and phase retrieval easier. To evaluate our proposed phase modulation method, we recorded and then recovered data pages with multilevel phase modulation using two spatial light modulators experimentally. For 4-level, 8-level, and 16-level phase modulation, we achieved the bit error rate (BER) of 0.3%, 1.5% and 6.6% respectively. To further improve data storage density, an orthogonal reference encoding multiplexing method at the same position of medium is also proposed and validated experimentally. We increased the code rate of pure 3/16 amplitude encoding method from 0.5 up to 1.0 and 1.5 using 4-level and 8-level phase modulation respectively.

  8. Random matrix models for phase diagrams

    International Nuclear Information System (INIS)

    Vanderheyden, B; Jackson, A D

    2011-01-01

    We describe a random matrix approach that can provide generic and readily soluble mean-field descriptions of the phase diagram for a variety of systems ranging from quantum chromodynamics to high-T c materials. Instead of working from specific models, phase diagrams are constructed by averaging over the ensemble of theories that possesses the relevant symmetries of the problem. Although approximate in nature, this approach has a number of advantages. First, it can be useful in distinguishing generic features from model-dependent details. Second, it can help in understanding the 'minimal' number of symmetry constraints required to reproduce specific phase structures. Third, the robustness of predictions can be checked with respect to variations in the detailed description of the interactions. Finally, near critical points, random matrix models bear strong similarities to Ginsburg-Landau theories with the advantage of additional constraints inherited from the symmetries of the underlying interaction. These constraints can be helpful in ruling out certain topologies in the phase diagram. In this Key Issues Review, we illustrate the basic structure of random matrix models, discuss their strengths and weaknesses, and consider the kinds of system to which they can be applied.

  9. Random-phase approximation and broken symmetry

    International Nuclear Information System (INIS)

    Davis, E.D.; Heiss, W.D.

    1986-01-01

    The validity of the random-phase approximation (RPA) in broken-symmetry bases is tested in an appropriate many-body system for which exact solutions are available. Initially the regions of stability of the self-consistent quasiparticle bases in this system are established and depicted in a 'phase' diagram. It is found that only stable bases can be used in an RPA calculation. This is particularly true for those RPA modes which are not associated with the onset of instability of the basis; it is seen that these modes do not describe any excited state when the basis is unstable, although from a formal point of view they remain acceptable. The RPA does well in a stable broken-symmetry basis provided one is not too close to a point where a phase transition occurs. This is true for both energies and matrix elements. (author)

  10. Fiber Bragg grating for spectral phase optical code-division multiple-access encoding and decoding

    Science.gov (United States)

    Fang, Xiaohui; Wang, Dong-Ning; Li, Shichen

    2003-08-01

    A new method for realizing spectral phase optical code-division multiple-access (OCDMA) coding based on step chirped fiber Bragg gratings (SCFBGs) is proposed and the corresponding encoder/decoder is presented. With this method, a mapping code is introduced for the m-sequence address code and the phase shift can be inserted into the subgratings of the SCFBG according to the mapping code. The transfer matrix method together with Fourier transform is used to investigate the characteristics of the encoder/decoder. The factors that influence the correlation property of the encoder/decoder, including index modulation and bandwidth of the subgrating, are identified. The system structure is simple and good correlation output can be obtained. The performance of the OCDMA system based on SCFBGs has been analyzed.

  11. GPU accelerated iterative SENSE reconstruction of radial phase encoded whole-heart MRI

    DEFF Research Database (Denmark)

    Sørensen, Thomas Sangild; Prieto, Claudia; Atkinson, David

    2010-01-01

    Isotropic whole-heart imaging has become an important protocol in simplifying cardiac MRI. The acquisition time can however be a prohibiting factor. To reduce acquisition times a 3D scheme combining Cartesian sampling in the readout direction with radial sampling in the phase encoding plane was r...... time can be brought to a clinically acceptable level using commodity graphics hardware (GPUs)....

  12. Generalized Encoding CRDSA: Maximizing Throughput in Enhanced Random Access Schemes for Satellite

    Directory of Open Access Journals (Sweden)

    Manlio Bacco

    2014-12-01

    Full Text Available This work starts from the analysis of the literature about the Random Access protocols with contention resolution, such as Contention Resolution Diversity Slotted Aloha (CRDSA, and introduces a possible enhancement, named Generalized Encoding Contention Resolution Diversity Slotted Aloha (GE-CRDSA. The GE-CRDSA aims at improving the aggregated throughput when the system load is less than 50%, playing on the opportunity of transmitting an optimal combination of information and parity packets frame by frame. This paper shows the improvement in terms of throughput, by performing traffic estimation and adaptive choice of information and parity rates, when a satellite network undergoes a variable traffic load profile.

  13. Key-space analysis of double random phase encryption technique

    Science.gov (United States)

    Monaghan, David S.; Gopinathan, Unnikrishnan; Naughton, Thomas J.; Sheridan, John T.

    2007-09-01

    We perform a numerical analysis on the double random phase encryption/decryption technique. The key-space of an encryption technique is the set of possible keys that can be used to encode data using that technique. In the case of a strong encryption scheme, many keys must be tried in any brute-force attack on that technique. Traditionally, designers of optical image encryption systems demonstrate only how a small number of arbitrary keys cannot decrypt a chosen encrypted image in their system. However, this type of demonstration does not discuss the properties of the key-space nor refute the feasibility of an efficient brute-force attack. To clarify these issues we present a key-space analysis of the technique. For a range of problem instances we plot the distribution of decryption errors in the key-space indicating the lack of feasibility of a simple brute-force attack.

  14. Encoding atlases by randomized classification forests for efficient multi-atlas label propagation.

    Science.gov (United States)

    Zikic, D; Glocker, B; Criminisi, A

    2014-12-01

    We propose a method for multi-atlas label propagation (MALP) based on encoding the individual atlases by randomized classification forests. Most current approaches perform a non-linear registration between all atlases and the target image, followed by a sophisticated fusion scheme. While these approaches can achieve high accuracy, in general they do so at high computational cost. This might negatively affect the scalability to large databases and experimentation. To tackle this issue, we propose to use a small and deep classification forest to encode each atlas individually in reference to an aligned probabilistic atlas, resulting in an Atlas Forest (AF). Our classifier-based encoding differs from current MALP approaches, which represent each point in the atlas either directly as a single image/label value pair, or by a set of corresponding patches. At test time, each AF produces one probabilistic label estimate, and their fusion is done by averaging. Our scheme performs only one registration per target image, achieves good results with a simple fusion scheme, and allows for efficient experimentation. In contrast to standard forest schemes, in which each tree would be trained on all atlases, our approach retains the advantages of the standard MALP framework. The target-specific selection of atlases remains possible, and incorporation of new scans is straightforward without retraining. The evaluation on four different databases shows accuracy within the range of the state of the art at a significantly lower running time. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Static correlation beyond the random phase approximation

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian Sommer

    2014-01-01

    derived from Hedin's equations (Random Phase Approximation (RPA), Time-dependent Hartree-Fock (TDHF), Bethe-Salpeter equation (BSE), and Time-Dependent GW) all reproduce the correct dissociation limit. We also show that the BSE improves the correlation energies obtained within RPA and TDHF significantly...... and confirms that BSE greatly improves the RPA and TDHF results despite the fact that the BSE excitation spectrum breaks down in the dissociation limit. In contrast, second order screened exchange gives a poor description of the dissociation limit, which can be attributed to the fact that it cannot be derived...

  16. Phase-encoded measurement device independent quantum key distribution without a shared reference frame

    Science.gov (United States)

    Zhuo-Dan, Zhu; Shang-Hong, Zhao; Chen, Dong; Ying, Sun

    2018-07-01

    In this paper, a phase-encoded measurement device independent quantum key distribution (MDI-QKD) protocol without a shared reference frame is presented, which can generate secure keys between two parties while the quantum channel or interferometer introduces an unknown and slowly time-varying phase. The corresponding secret key rate and single photons bit error rate is analysed, respectively, with single photons source (SPS) and weak coherent source (WCS), taking finite-key analysis into account. The numerical simulations show that the modified phase-encoded MDI-QKD protocol has apparent superiority both in maximal secure transmission distance and key generation rate while possessing the improved robustness and practical security in the high-speed case. Moreover, the rejection of the frame-calibrating part will intrinsically reduce the consumption of resources as well as the potential security flaws of practical MDI-QKD systems.

  17. Combining Fourier phase encoding and broadband inversion toward J-edited spectra

    Science.gov (United States)

    Lin, Yulan; Guan, Quanshuai; Su, Jianwei; Chen, Zhong

    2018-06-01

    Nuclear magnetic resonance (NMR) spectra are often utilized for gathering accurate information relevant to molecular structures and composition assignments. In this study, we develop a homonuclear encoding approach based on imparting a discrete phase modulation of the targeted cross peaks, and combine it with a pure shift experiments (PSYCHE) based J-modulated scheme, providing simple 2D J-edited spectra for accurate measurement of scalar coupling networks. Chemical shifts and J coupling constants of protons coupled to the specific protons are demonstrated along the F2 and F1 dimensions, respectively. Polychromatic pulses by Fourier phase encoding were performed to simultaneously detect several coupling networks. Proton-proton scalar couplings are chosen by a polychromatic pulse and a PSYCHE element. Axis peaks and unwanted couplings are complete eradicated by incorporating a selective COSY block as a preparation period. The theoretical principles and the signal processing procedure are laid out, and experimental observations are rationalized on the basis of theoretical analyses.

  18. Phase recovering algorithms for extended objects encoded in digitally recorded holograms

    Directory of Open Access Journals (Sweden)

    Peng Z.

    2010-06-01

    Full Text Available The paper presents algorithms to recover the optical phase of digitally encoded holograms. Algorithms are based on the use of a numerical spherical reconstructing wave. Proof of the validity of the concept is performed through an experimental off axis digital holographic set-up. Two-color digital holographic reconstruction is also investigated. Application of the color set-up and algorithms concerns the simultaneous two-dimensional deformation measurement of an object submitted to a mechanical loading.

  19. Least-squares reverse time migration of marine data with frequency-selection encoding

    KAUST Repository

    Dai, Wei; Huang, Yunsong; Schuster, Gerard T.

    2013-01-01

    The phase-encoding technique can sometimes increase the efficiency of the least-squares reverse time migration (LSRTM) by more than one order of magnitude. However, traditional random encoding functions require all the encoded shots to share

  20. Stimulus number, duration and intensity encoding in randomly connected attractor networks with synaptic depression

    Directory of Open Access Journals (Sweden)

    Paul eMiller

    2013-05-01

    Full Text Available Randomly connected recurrent networks of excitatory groups of neurons can possess a multitude of attractor states. When the internal excitatory synapses of these networks are depressing, the attractor states can be destabilized with increasing input. This leads to an itinerancy, where with either repeated transient stimuli, or increasing duration of a single stimulus, the network activity advances through sequences of attractor states. We find that the resulting network state, which persists beyond stimulus offset, can encode the number of stimuli presented via a distributed representation of neural activity with non-monotonic tuning curves for most neurons. Increased duration of a single stimulus is encoded via different distributed representations, so unlike an integrator, the network distinguishes separate successive presentations of a short stimulus from a single presentation of a longer stimulus with equal total duration. Moreover, different amplitudes of stimulus cause new, distinct activity patterns, such that changes in stimulus number, duration and amplitude can be distinguished from each other. These properties of the network depend on dynamic depressing synapses, as they disappear if synapses are static. Thus short-term synaptic depression allows a network to store separately the different dynamic properties of a spatially constant stimulus.

  1. Random phase approximation in relativistic approach

    International Nuclear Information System (INIS)

    Ma Zhongyu; Yang Ding; Tian Yuan; Cao Ligang

    2009-01-01

    Some special issues of the random phase approximation(RPA) in the relativistic approach are reviewed. A full consistency and proper treatment of coupling to the continuum are responsible for the successful application of the RPA in the description of dynamical properties of finite nuclei. The fully consistent relativistic RPA(RRPA) requires that the relativistic mean filed (RMF) wave function of the nucleus and the RRPA correlations are calculated in a same effective Lagrangian and the consistent treatment of the Dirac sea of negative energy states. The proper treatment of the single particle continuum with scattering asymptotic conditions in the RMF and RRPA is discussed. The full continuum spectrum can be described by the single particle Green's function and the relativistic continuum RPA is established. A separable form of the paring force is introduced in the relativistic quasi-particle RPA. (authors)

  2. Temporal lobe cortical electrical stimulation during the encoding and retrieval phase reduces false memories.

    Directory of Open Access Journals (Sweden)

    Paulo S Boggio

    Full Text Available A recent study found that false memories were reduced by 36% when low frequency repetitive transcranial magnetic stimulation (rTMS was applied to the left anterior temporal lobe after the encoding (study phase. Here we were interested in the consequences on a false memory task of brain stimulation throughout the encoding and retrieval task phases. We used transcranial direct current stimulation (tDCS because it has been shown to be a useful tool to enhance cognition. Specifically, we examined whether tDCS can induce changes in a task assessing false memories. Based on our preliminary results, three conditions of stimulation were chosen: anodal left/cathodal right anterior temporal lobe (ATL stimulation ("bilateral stimulation"; anodal left ATL stimulation (with a large contralateral cathodal electrode--referred as "unilateral stimulation" and sham stimulation. Our results showed that false memories were reduced significantly after the two active conditions (unilateral and bilateral stimulation as compared with sham stimulation. There were no significant changes in veridical memories. Our findings show that false memories are reduced by 73% when anodal tDCS is applied to the anterior temporal lobes throughout the encoding and retrieval stages, suggesting a possible strategy for improving certain aspects of learning.

  3. Collaborative Random Faces-Guided Encoders for Pose-Invariant Face Representation Learning.

    Science.gov (United States)

    Shao, Ming; Zhang, Yizhe; Fu, Yun

    2018-04-01

    Learning discriminant face representation for pose-invariant face recognition has been identified as a critical issue in visual learning systems. The challenge lies in the drastic changes of facial appearances between the test face and the registered face. To that end, we propose a high-level feature learning framework called "collaborative random faces (RFs)-guided encoders" toward this problem. The contributions of this paper are three fold. First, we propose a novel supervised autoencoder that is able to capture the high-level identity feature despite of pose variations. Second, we enrich the identity features by replacing the target values of conventional autoencoders with random signals (RFs in this paper), which are unique for each subject under different poses. Third, we further improve the performance of the framework by incorporating deep convolutional neural network facial descriptors and linking discriminative identity features from different RFs for the augmented identity features. Finally, we conduct face identification experiments on Multi-PIE database, and face verification experiments on labeled faces in the wild and YouTube Face databases, where face recognition rate and verification accuracy with Receiver Operating Characteristic curves are rendered. In addition, discussions of model parameters and connections with the existing methods are provided. These experiments demonstrate that our learning system works fairly well on handling pose variations.

  4. Effect of phase-encoding direction on group analysis of resting-state functional magnetic resonance imaging.

    Science.gov (United States)

    Mori, Yasuo; Miyata, Jun; Isobe, Masanori; Son, Shuraku; Yoshihara, Yujiro; Aso, Toshihiko; Kouchiyama, Takanori; Murai, Toshiya; Takahashi, Hidehiko

    2018-05-17

    Echo-planar imaging is a common technique used in functional magnetic resonance imaging (fMRI), however it suffers from image distortion and signal loss because of large susceptibility effects that are related to the phase-encoding direction of the scan. Despite this relationship, the majority of neuroimaging studies have not considered the influence of phase-encoding direction. Here, we aimed to clarify how phase-encoding direction can affect the outcome of an fMRI connectivity study of schizophrenia. Resting-state fMRI using anterior to posterior (A-P) and posterior to anterior (P-A) directions was used to examine 25 patients with schizophrenia (SC) and 37 matched healthy controls (HC). We conducted a functional connectivity analysis using independent component analysis and performed three group comparisons: A-P vs. P-A (all participants), SC vs. HC for the A-P and P-A datasets, and the interaction between phase-encoding direction and participant group. The estimated functional connectivity differed between the two phase-encoding directions in areas that were more extensive than those where signal loss has been reported. Although functional connectivity in the SC group was lower than that in the HC group for both directions, the A-P and P-A conditions did not exhibit the same specific pattern of differences. Further, we observed an interaction between participant group and the phase-encoding direction in the left temporo-parietal junction and left fusiform gyrus. Phase-encoding direction can influence the results of functional connectivity studies. Thus, appropriate selection and documentation of phase-encoding direction will be important in future resting-state fMRI studies. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Estimating Accurate Target Coordinates with Magnetic Resonance Images by Using Multiple Phase-Encoding Directions during Acquisition.

    Science.gov (United States)

    Kim, Minsoo; Jung, Na Young; Park, Chang Kyu; Chang, Won Seok; Jung, Hyun Ho; Chang, Jin Woo

    2018-06-01

    Stereotactic procedures are image guided, often using magnetic resonance (MR) images limited by image distortion, which may influence targets for stereotactic procedures. The aim of this work was to assess methods of identifying target coordinates for stereotactic procedures with MR in multiple phase-encoding directions. In 30 patients undergoing deep brain stimulation, we acquired 5 image sets: stereotactic brain computed tomography (CT), T2-weighted images (T2WI), and T1WI in both right-to-left (RL) and anterior-to-posterior (AP) phase-encoding directions. Using CT coordinates as a reference, we analyzed anterior commissure and posterior commissure coordinates to identify any distortion relating to phase-encoding direction. Compared with CT coordinates, RL-directed images had more positive x-axis values (0.51 mm in T1WI, 0.58 mm in T2WI). AP-directed images had more negative y-axis values (0.44 mm in T1WI, 0.59 mm in T2WI). We adopted 2 methods to predict CT coordinates with MR image sets: parallel translation and selective choice of axes according to phase-encoding direction. Both were equally effective at predicting CT coordinates using only MR; however, the latter may be easier to use in clinical settings. Acquiring MR in multiple phase-encoding directions and selecting axes according to the phase-encoding direction allows identification of more accurate coordinates for stereotactic procedures. © 2018 S. Karger AG, Basel.

  6. Cardiac magnetic resonance: is phonocardiogram gating reliable in velocity-encoded phase contrast imaging?

    International Nuclear Information System (INIS)

    Nassenstein, Kai; Schlosser, Thomas; Orzada, Stephan; Ladd, Mark E.; Maderwald, Stefan; Haering, Lars; Czylwik, Andreas; Jensen, Christoph; Bruder, Oliver

    2012-01-01

    To assess the diagnostic accuracy of phonocardiogram (PCG) gated velocity-encoded phase contrast magnetic resonance imaging (MRI). Flow quantification above the aortic valve was performed in 68 patients by acquiring a retrospectively PCG- and a retrospectively ECG-gated velocity-encoded GE-sequence at 1.5 T. Peak velocity (PV), average velocity (AV), forward volume (FV), reverse volume (RV), net forward volume (NFV), as well as the regurgitant fraction (RF) were assessed for both datasets, as well as for the PCG-gated datasets after compensation for the PCG trigger delay. PCG-gated image acquisition was feasible in 64 patients, ECG-gated in all patients. PCG-gated flow quantification overestimated PV (Δ 3.8 ± 14.1 cm/s; P = 0.037) and underestimated FV (Δ -4.9 ± 15.7 ml; P = 0.015) and NFV (Δ -4.5 ± 16.5 ml; P = 0.033) compared with ECG-gated imaging. After compensation for the PCG trigger delay, differences were only observed for PV (Δ 3.8 ± 14.1 cm/s; P = 0.037). Wide limits of agreement between PCG- and ECG-gated flow quantification were observed for all variables (PV: -23.9 to 31.4 cm/s; AV: -4.5 to 3.9 cm/s; FV: -35.6 to 25.9 ml; RV: -8.0 to 7.2 ml; NFV: -36.8 to 27.8 ml; RF: -10.4 to 10.2 %). The present study demonstrates that PCG gating in its current form is not reliable enough for flow quantification based on velocity-encoded phase contrast gradient echo (GE) sequences. (orig.)

  7. Phase-only asymmetric optical cryptosystem based on random modulus decomposition

    Science.gov (United States)

    Xu, Hongfeng; Xu, Wenhui; Wang, Shuaihua; Wu, Shaofan

    2018-06-01

    We propose a phase-only asymmetric optical cryptosystem based on random modulus decomposition (RMD). The cryptosystem is presented for effectively improving the capacity to resist various attacks, including the attack of iterative algorithms. On the one hand, RMD and phase encoding are combined to remove the constraints that can be used in the attacking process. On the other hand, the security keys (geometrical parameters) introduced by Fresnel transform can increase the key variety and enlarge the key space simultaneously. Numerical simulation results demonstrate the strong feasibility, security and robustness of the proposed cryptosystem. This cryptosystem will open up many new opportunities in the application fields of optical encryption and authentication.

  8. Experimental phase diagram for random laser spectra

    International Nuclear Information System (INIS)

    El-Dardiry, Ramy G S; Mooiweer, Ronald; Lagendijk, Ad

    2012-01-01

    We systematically study the presence of narrow spectral features in a wide variety of random laser samples. Less gain or stronger scattering are shown to lead to a crossover from spiky to smooth spectra. A decomposition of random laser spectra into a set of Lorentzians provides unprecedented detail in the analysis of random laser spectra. We suggest an interpretation in terms of mode competition that enables an understanding of the observed experimental trends. In this interpretation, smooth random laser spectra are a consequence of competing modes for which the loss and gain are proportional. Spectral spikes are associated with modes that are uncoupled from the mode competition in the bulk of the sample. (paper)

  9. Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

    Science.gov (United States)

    Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

    2012-07-30

    A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

  10. Hacking on decoy-state quantum key distribution system with partial phase randomization

    Science.gov (United States)

    Sun, Shi-Hai; Jiang, Mu-Sheng; Ma, Xiang-Chun; Li, Chun-Yan; Liang, Lin-Mei

    2014-04-01

    Quantum key distribution (QKD) provides means for unconditional secure key transmission between two distant parties. However, in practical implementations, it suffers from quantum hacking due to device imperfections. Here we propose a hybrid measurement attack, with only linear optics, homodyne detection, and single photon detection, to the widely used vacuum + weak decoy state QKD system when the phase of source is partially randomized. Our analysis shows that, in some parameter regimes, the proposed attack would result in an entanglement breaking channel but still be able to trick the legitimate users to believe they have transmitted secure keys. That is, the eavesdropper is able to steal all the key information without discovered by the users. Thus, our proposal reveals that partial phase randomization is not sufficient to guarantee the security of phase-encoding QKD systems with weak coherent states.

  11. Hacking on decoy-state quantum key distribution system with partial phase randomization.

    Science.gov (United States)

    Sun, Shi-Hai; Jiang, Mu-Sheng; Ma, Xiang-Chun; Li, Chun-Yan; Liang, Lin-Mei

    2014-04-23

    Quantum key distribution (QKD) provides means for unconditional secure key transmission between two distant parties. However, in practical implementations, it suffers from quantum hacking due to device imperfections. Here we propose a hybrid measurement attack, with only linear optics, homodyne detection, and single photon detection, to the widely used vacuum + weak decoy state QKD system when the phase of source is partially randomized. Our analysis shows that, in some parameter regimes, the proposed attack would result in an entanglement breaking channel but still be able to trick the legitimate users to believe they have transmitted secure keys. That is, the eavesdropper is able to steal all the key information without discovered by the users. Thus, our proposal reveals that partial phase randomization is not sufficient to guarantee the security of phase-encoding QKD systems with weak coherent states.

  12. Choice of optical system is critical for the security of double random phase encryption systems

    Science.gov (United States)

    Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Cassidy, Derek; Zhao, Liang; Ryle, James P.; Healy, John J.; Sheridan, John T.

    2017-06-01

    The linear canonical transform (LCT) is used in modeling a coherent light-field propagation through first-order optical systems. Recently, a generic optical system, known as the quadratic phase encoding system (QPES), for encrypting a two-dimensional image has been reported. In such systems, two random phase keys and the individual LCT parameters (α,β,γ) serve as secret keys of the cryptosystem. It is important that such encryption systems also satisfy some dynamic security properties. We, therefore, examine such systems using two cryptographic evaluation methods, the avalanche effect and bit independence criterion, which indicate the degree of security of the cryptographic algorithms using QPES. We compared our simulation results with the conventional Fourier and the Fresnel transform-based double random phase encryption (DRPE) systems. The results show that the LCT-based DRPE has an excellent avalanche and bit independence characteristics compared to the conventional Fourier and Fresnel-based encryption systems.

  13. MR imaging of ore for heap bioleaching studies using pure phase encode acquisition methods

    Science.gov (United States)

    Fagan, Marijke A.; Sederman, Andrew J.; Johns, Michael L.

    2012-03-01

    Various MRI techniques were considered with respect to imaging of aqueous flow fields in low grade copper ore. Spin echo frequency encoded techniques were shown to produce unacceptable image distortions which led to pure phase encoded techniques being considered. Single point imaging multiple point acquisition (SPI-MPA) and spin echo single point imaging (SESPI) techniques were applied. By direct comparison with X-ray tomographic images, both techniques were found to be able to produce distortion-free images of the ore packings at 2 T. The signal to noise ratios (SNRs) of the SESPI images were found to be superior to SPI-MPA for equal total acquisition times; this was explained based on NMR relaxation measurements. SESPI was also found to produce suitable images for a range of particles sizes, whereas SPI-MPA SNR deteriorated markedly as particles size was reduced. Comparisons on a 4.7 T magnet showed significant signal loss from the SPI-MPA images, the effect of which was accentuated in the case of unsaturated flowing systems. Hence it was concluded that SESPI was the most robust imaging method for the study of copper ore heap leaching hydrology.

  14. Ultrasonic backscatter imaging by shear-wave-induced echo phase encoding of target locations.

    Science.gov (United States)

    McAleavey, Stephen

    2011-01-01

    We present a novel method for ultrasound backscatter image formation wherein lateral resolution of the target is obtained by using traveling shear waves to encode the lateral position of targets in the phase of the received echo. We demonstrate that the phase modulation as a function of shear wavenumber can be expressed in terms of a Fourier transform of the lateral component of the target echogenicity. The inverse transform, obtained by measurements of the phase modulation over a range of shear wave spatial frequencies, yields the lateral scatterer distribution. Range data are recovered from time of flight as in conventional ultrasound, yielding a B-mode-like image. In contrast to conventional ultrasound imaging, where mechanical or electronic focusing is used and lateral resolution is determined by aperture size and wavelength, we demonstrate that lateral resolution using the proposed method is independent of the properties of the aperture. Lateral resolution of the target is achieved using a stationary, unfocused, single-element transducer. We present simulated images of targets of uniform and non-uniform shear modulus. Compounding for speckle reduction is demonstrated. Finally, we demonstrate image formation with an unfocused transducer in gelatin phantoms of uniform shear modulus.

  15. WE-DE-206-03: MRI Image Formation - Slice Selection, Phase Encoding, Frequency Encoding, K-Space, SNR

    International Nuclear Information System (INIS)

    Lin, C.

    2016-01-01

    Magnetic resonance imaging (MRI) has become an essential part of clinical imaging due to its ability to render high soft tissue contrast. Instead of ionizing radiation, MRI use strong magnetic field, radio frequency waves and field gradients to create diagnostic useful images. It can be used to image the anatomy and also functional and physiological activities within the human body. Knowledge of the basic physical principles underlying MRI acquisition is vitally important to successful image production and proper image interpretation. This lecture will give an overview of the spin physics, imaging principle of MRI, the hardware of the MRI scanner, and various pulse sequences and their applications. It aims to provide a conceptual foundation to understand the image formation process of a clinical MRI scanner. Learning Objectives: Understand the origin of the MR signal and contrast from the spin physics level. Understand the main hardware components of a MRI scanner and their purposes Understand steps for MR image formation including spatial encoding and image reconstruction Understand the main kinds of MR pulse sequences and their characteristics.

  16. WE-DE-206-03: MRI Image Formation - Slice Selection, Phase Encoding, Frequency Encoding, K-Space, SNR

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C. [Indiana University School of Medicine (United States)

    2016-06-15

    Magnetic resonance imaging (MRI) has become an essential part of clinical imaging due to its ability to render high soft tissue contrast. Instead of ionizing radiation, MRI use strong magnetic field, radio frequency waves and field gradients to create diagnostic useful images. It can be used to image the anatomy and also functional and physiological activities within the human body. Knowledge of the basic physical principles underlying MRI acquisition is vitally important to successful image production and proper image interpretation. This lecture will give an overview of the spin physics, imaging principle of MRI, the hardware of the MRI scanner, and various pulse sequences and their applications. It aims to provide a conceptual foundation to understand the image formation process of a clinical MRI scanner. Learning Objectives: Understand the origin of the MR signal and contrast from the spin physics level. Understand the main hardware components of a MRI scanner and their purposes Understand steps for MR image formation including spatial encoding and image reconstruction Understand the main kinds of MR pulse sequences and their characteristics.

  17. Multiple-image authentication with a cascaded multilevel architecture based on amplitude field random sampling and phase information multiplexing.

    Science.gov (United States)

    Fan, Desheng; Meng, Xiangfeng; Wang, Yurong; Yang, Xiulun; Pan, Xuemei; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

    2015-04-10

    A multiple-image authentication method with a cascaded multilevel architecture in the Fresnel domain is proposed, in which a synthetic encoded complex amplitude is first fabricated, and its real amplitude component is generated by iterative amplitude encoding, random sampling, and space multiplexing for the low-level certification images, while the phase component of the synthetic encoded complex amplitude is constructed by iterative phase information encoding and multiplexing for the high-level certification images. Then the synthetic encoded complex amplitude is iteratively encoded into two phase-type ciphertexts located in two different transform planes. During high-level authentication, when the two phase-type ciphertexts and the high-level decryption key are presented to the system and then the Fresnel transform is carried out, a meaningful image with good quality and a high correlation coefficient with the original certification image can be recovered in the output plane. Similar to the procedure of high-level authentication, in the case of low-level authentication with the aid of a low-level decryption key, no significant or meaningful information is retrieved, but it can result in a remarkable peak output in the nonlinear correlation coefficient of the output image and the corresponding original certification image. Therefore, the method realizes different levels of accessibility to the original certification image for different authority levels with the same cascaded multilevel architecture.

  18. Nonlinear diffuse scattering of the random-phased wave

    International Nuclear Information System (INIS)

    Kato, Yoshiaki; Arinaga, Shinji; Mima, Kunioki.

    1983-01-01

    First experimental observation of the nonlinear diffuse scattering is reported. This new effect was observed in the propagation of the random-phased wave through a nonlinear dielectric medium. This effect is ascribed to the diffusion of the wavevector of the electro-magnetic wave to the lateral direction due to the randomly distributed nonlinear increase in the refractive index. (author)

  19. Revealing novel quantum phases in quantum antiferromagnets on random lattices

    Directory of Open Access Journals (Sweden)

    R. Yu

    2009-01-01

    Full Text Available Quantum magnets represent an ideal playground for the controlled realization of novel quantum phases and of quantum phase transitions. The Hamiltonian of the system can be indeed manipulated by applying a magnetic field or pressure on the sample. When doping the system with non-magnetic impurities, novel inhomogeneous phases emerge from the interplay between geometric randomness and quantum fluctuations. In this paper we review our recent work on quantum phase transitions and novel quantum phases realized in disordered quantum magnets. The system inhomogeneity is found to strongly affect phase transitions by changing their universality class, giving the transition a novel, quantum percolative nature. Such transitions connect conventionally ordered phases to unconventional, quantum disordered ones - quantum Griffiths phases, magnetic Bose glass phases - exhibiting gapless spectra associated with low-energy localized excitations.

  20. Effect of Phase-Encoding Reduction on Geometric Distortion and BOLD Signal Changes in fMRI

    Directory of Open Access Journals (Sweden)

    Golestan karami

    2013-03-01

    Full Text Available Introduction Echo-planar imaging (EPI is a group of fast data acquisition methods commonly used in fMRI studies. It acquires multiple image lines in k-space after a single excitation, which leads to a very short scan time. A well-known problem with EPI is that it is more sensitive to distortions due to the used encoding scheme. Source of distortion is inhomogeneity in the static B0 field that causes more geometric distortion in phase encoding direction. This inhomogeneity is induced mainly by the magnetic susceptibility differences between various structures within the object placed inside the scanner, often at air-tissue or bone-tissue interfaces. Methods of reducing EPI distortion are mainly based on decreasing steps of the phase encoding. Reducing steps of phase encoding can be applied by reducing field of view, slice thickness, and/or the use of parallel acquisition technique. Materials and Methods We obtained three data acquisitions with different FOVs including: conventional low resolution, conventional high resolution, and zoomed high resolution EPIs. Moreover we used SENSE technique for phase encoding reduction. All experiments were carried out on three Tesla scanners (Siemens, TIM, and Germany equipped with 12 channel head coil. Ten subjects participated in the experiments. Results The data were processed by FSL software and were evaluated by ANOVA. Distortion was assessed by obtaining low displacement voxels map, and calculated from a field map image. Conclusion We showed that image distortion can be reduced by decreasing slice thickness and phase encoding steps. Distortion reduction in zoomed technique resulted the lowest level, but at the cost of signal-to-noise loss. Moreover, the SENSE technique was shown to decrease the amount of image distortion, efficiently.

  1. Phase reconstruction from velocity-encoded MRI measurements – A survey of sparsity-promoting variational approaches

    KAUST Repository

    Benning, Martin; Gladden, Lynn; Holland, Daniel; Schö nlieb, Carola-Bibiane; Valkonen, Tuomo

    2014-01-01

    for the reconstruction of phase-encoded magnetic resonance velocity images from sub-sampled k-space data. We are particularly interested in regularisers that correctly treat both smooth and geometric features of the image. These features are common to velocity imaging

  2. Phase stability of random brasses: pseudopotential theory revisited

    International Nuclear Information System (INIS)

    Rahman, S.M.M.

    1987-06-01

    We review the theoretical development concerning the phase stability of random brasses. The introductory discussion of the subject embraces the rules of metallurgy in general, but we emphasize on the roles of electron-per-atom ratio in the major bulk of our discussion. Starting from the so-called rigid-band model the discussion goes up to the recent higher-order pseudopotential theory. The theoretical refinements within the pseudopotential framework are discussed briefly. The stability criteria of the random phases are analysed both in the static lattice and dynamic lattice approximations. (author). 71 refs, figs and tabs

  3. Ultrafast quantum random number generation based on quantum phase fluctuations.

    Science.gov (United States)

    Xu, Feihu; Qi, Bing; Ma, Xiongfeng; Xu, He; Zheng, Haoxuan; Lo, Hoi-Kwong

    2012-05-21

    A quantum random number generator (QRNG) can generate true randomness by exploiting the fundamental indeterminism of quantum mechanics. Most approaches to QRNG employ single-photon detection technologies and are limited in speed. Here, we experimentally demonstrate an ultrafast QRNG at a rate over 6 Gbits/s based on the quantum phase fluctuations of a laser operating near threshold. Moreover, we consider a potential adversary who has partial knowledge on the raw data and discuss how one can rigorously remove such partial knowledge with postprocessing. We quantify the quantum randomness through min-entropy by modeling our system and employ two randomness extractors--Trevisan's extractor and Toeplitz-hashing--to distill the randomness, which is information-theoretically provable. The simplicity and high-speed of our experimental setup show the feasibility of a robust, low-cost, high-speed QRNG.

  4. Quantum phase transitions in random XY spin chains

    International Nuclear Information System (INIS)

    Bunder, J.E.; McKenzie, R.H.

    2000-01-01

    Full text: The XY spin chain in a transverse field is one of the simplest quantum spin models. It is a reasonable model for heavy fermion materials such as CeCu 6-x Au x . It has two quantum phase transitions: the Ising transition and the anisotropic transition. Quantum phase transitions occur at zero temperature. We are investigating what effect the introduction of randomness has on these quantum phase transitions. Disordered systems which undergo quantum phase transitions can exhibit new universality classes. The universality class of a phase transition is defined by the set of critical exponents. In a random system with quantum phase transitions we can observe Griffiths-McCoy singularities. Such singularities are observed in regions which have no long range order, so they are not classified as critical regions, yet they display phenomena normally associated with critical points, such as a diverging susceptibility. Griffiths-McCoy phases are due to rare regions with stronger than! average interactions and may be present far from the quantum critical point. We show how the random XY spin chain may be mapped onto a random Dirac equation. This allows us to calculate the density of states without making any approximations. From the density of states we can describe the conditions which should allow a Griffiths-McCoy phase. We find that for the Ising transition the dynamic critical exponent, z, is not universal. It is proportional to the disorder strength and inversely proportional to the energy gap, hence z becomes infinite at the critical point where the energy gap vanishes

  5. Variational random phase approximation for the anharmonic oscillator

    International Nuclear Information System (INIS)

    Dukelsky, J.; Schuck, P.

    1990-04-01

    The recently derived Variational Random Phase Approximation is examined using the anharmonic oscillator model. Special attention is paid to the ground state RPA wave function and the convergence of the proposed truncation scheme to obtain the diagonal density matrix. Comparison with the standard Coupled Cluster method is made

  6. Atomic structure calculations using the relativistic random phase approximation

    International Nuclear Information System (INIS)

    Cheng, K.T.; Johnson, W.R.

    1981-01-01

    A brief review is given for the relativistic random phase approximation (RRPA) applied to atomic transition problems. Selected examples of RRPA calculations on discrete excitations and photoionization are given to illustrate the need of relativistic many-body theories in dealing with atomic processes where both relativity and correlation are important

  7. Double random phase spread spectrum spread space technique for secure parallel optical multiplexing with individual encryption key

    Science.gov (United States)

    Hennelly, B. M.; Javidi, B.; Sheridan, J. T.

    2005-09-01

    A number of methods have been recently proposed in the literature for the encryption of 2-D information using linear optical systems. In particular the double random phase encoding system has received widespread attention. This system uses two Random Phase Keys (RPK) positioned in the input spatial domain and the spatial frequency domain and if these random phases are described by statistically independent white noises then the encrypted image can be shown to be a white noise. Decryption only requires knowledge of the RPK in the frequency domain. The RPK may be implemented using a Spatial Light Modulators (SLM). In this paper we propose and investigate the use of SLMs for secure optical multiplexing. We show that in this case it is possible to encrypt multiple images in parallel and multiplex them for transmission or storage. The signal energy is effectively spread in the spatial frequency domain. As expected the number of images that can be multiplexed together and recovered without loss is proportional to the ratio of the input image and the SLM resolution. Many more images may be multiplexed with some loss in recovery. Furthermore each individual encryption is more robust than traditional double random phase encoding since decryption requires knowledge of both RPK and a lowpass filter in order to despread the spectrum and decrypt the image. Numerical simulations are presented and discussed.

  8. Saccades phase-locked to alpha oscillations in the occipital and medial temporal lobe enhance memory encoding

    OpenAIRE

    Noachtar, Soheyl; Doeller, Christian; Jensen, Ole; Hartl, Elisabeth; Staudigl, Tobias

    2017-01-01

    Efficient sampling of visual information requires a coordination of eye movements and ongoing brain oscillations. Using intracranial and MEG recordings, we show that saccades are locked to the phase of visual alpha oscillations, and that this coordination supports mnemonic encoding of visual scenes. Furthermore, parahippocampal and retrosplenial cortex involvement in this coordination reflects effective vision-to-memory mapping, highlighting the importance of neural oscillations for the inter...

  9. Choosing the polarity of the phase-encoding direction in diffusion MRI: Does it matter for group analysis?

    OpenAIRE

    Kennis, M.; van Rooij, S.J.H.; Kahn, R.S.; Geuze, E.; Leemans, A.

    2016-01-01

    Notorious for degrading diffusion MRI data quality are so-called susceptibility-induced off-resonance fields, which cause non-linear geometric image deformations. While acquiring additional data to correct for these distortions alleviates the adverse effects of this artifact drastically – e.g., by reversing the polarity of the phase-encoding (PE) direction – this strategy is often not an option due to scan time constraints. Especially in a clinical context, where patient comfort and safety ar...

  10. Enhanced wavefront reconstruction by random phase modulation with a phase diffuser

    DEFF Research Database (Denmark)

    Almoro, Percival F; Pedrini, Giancarlo; Gundu, Phanindra Narayan

    2011-01-01

    propagation in free space. The presentation of this technique is carried out using two setups. In the first setup, a diffuser plate is placed at the image plane of a metallic test object. The benefit of randomizing the phase of the object wave is the enhanced intensity recording due to high dynamic range...... of the diffusely scattered beam. The use of demagnification optics will also allow the investigations of relatively large objects. In the second setup, a transparent object is illuminated using a wavefront with random phase and constant amplitude by positioning the phase diffuser close to the object. The benefit...

  11. Phase conjugation with random fields and with deterministic and random scatterers

    International Nuclear Information System (INIS)

    Gbur, G.; Wolf, E.

    1999-01-01

    The theory of distortion correction by phase conjugation, developed since the discovery of this phenomenon many years ago, applies to situations when the field that is conjugated is monochromatic and the medium with which it interacts is deterministic. In this Letter a generalization of the theory is presented that applies to phase conjugation of partially coherent waves interacting with either deterministic or random weakly scattering nonabsorbing media. copyright 1999 Optical Society of America

  12. Reduced randomness in quantum cryptography with sequences of qubits encoded in the same basis

    International Nuclear Information System (INIS)

    Lamoureux, L.-P.; Cerf, N. J.; Bechmann-Pasquinucci, H.; Gisin, N.; Macchiavello, C.

    2006-01-01

    We consider the cloning of sequences of qubits prepared in the states used in the BB84 or six-state quantum cryptography protocol, and show that the single-qubit fidelity is unaffected even if entire sequences of qubits are prepared in the same basis. This result is only valid provided that the sequences are much shorter than the total key. It is of great importance for practical quantum cryptosystems because it reduces the need for high-speed random number generation without impairing on the security against finite-size cloning attacks

  13. A random-key encoded harmony search approach for energy-efficient production scheduling with shared resources

    Science.gov (United States)

    Garcia-Santiago, C. A.; Del Ser, J.; Upton, C.; Quilligan, F.; Gil-Lopez, S.; Salcedo-Sanz, S.

    2015-11-01

    When seeking near-optimal solutions for complex scheduling problems, meta-heuristics demonstrate good performance with affordable computational effort. This has resulted in a gravitation towards these approaches when researching industrial use-cases such as energy-efficient production planning. However, much of the previous research makes assumptions about softer constraints that affect planning strategies and about how human planners interact with the algorithm in a live production environment. This article describes a job-shop problem that focuses on minimizing energy consumption across a production facility of shared resources. The application scenario is based on real facilities made available by the Irish Center for Manufacturing Research. The formulated problem is tackled via harmony search heuristics with random keys encoding. Simulation results are compared to a genetic algorithm, a simulated annealing approach and a first-come-first-served scheduling. The superior performance obtained by the proposed scheduler paves the way towards its practical implementation over industrial production chains.

  14. Divided attention can enhance early-phase memory encoding: the attentional boost effect and study trial duration.

    Science.gov (United States)

    Mulligan, Neil W; Spataro, Pietro

    2015-07-01

    Divided attention during encoding typically produces marked reductions in later memory. The attentional boost effect (ABE) is a surprising variation on this phenomenon. In this paradigm, each study stimulus (e.g., a word) is presented along with a target or a distractor (e.g., different colored circles) in a detection task. Later memory is better for stimuli co-occurring with targets. The present experiments indicate that the ABE arises during an early phase of memory encoding that involves initial stimulus perception and comprehension rather than at a later phase entailing controlled, elaborative rehearsal. Experiment 1 demonstrated that the ABE was robust at a short study duration (700 ms) and did not increase with increasing study trial durations (1,500 ms and 4,000 ms). Furthermore, the target condition is boosted to the level of memory performance in a full-attention condition for the short duration but not the long duration. Both results followed from the early-phase account. This account also predicts that for very short study times (limiting the influence of late-phase controlled encoding and thus minimizing the usual negative effect of divided attention), the target condition will produce better memory than will the full-attention condition. Experiment 2 used a study time of 400 ms and found that words presented with targets lead to greater recognition accuracy than do either words presented with distractors or words in the full-attention condition. Consistent with the early-phase account, a divided attention condition actually produced superior memory than did the full-attention condition, a very unusual but theoretically predicted result. (c) 2015 APA, all rights reserved.

  15. Geometrically undistorted MRI in the presence of field inhomogeneities using compressed sensing accelerated broadband 3D phase encoded turbo spin-echo imaging

    International Nuclear Information System (INIS)

    Van Gorp, Jetse S; Bakker, Chris J G; Bouwman, Job G; Zijlstra, Frank; Seevinck, Peter R; Smink, Jouke

    2015-01-01

    In this study, we explore the potential of compressed sensing (CS) accelerated broadband 3D phase-encoded turbo spin-echo (3D-PE-TSE) for the purpose of geometrically undistorted imaging in the presence of field inhomogeneities. To achieve this goal 3D-PE-SE and 3D-PE-TSE sequences with broadband rf pulses and dedicated undersampling patterns were implemented on a clinical scanner. Additionally, a 3D multi-spectral spin-echo (ms3D-SE) sequence was implemented for reference purposes. First, we demonstrated the influence of susceptibility induced off-resonance effects on the spatial encoding of broadband 3D-SE, ms3D-SE, 3D-PE-SE and 3D-PE-TSE using a grid phantom containing a titanium implant (Δχ = 182 ppm) with x-ray CT as a gold standard. These experiments showed that the spatial encoding of 3D-PE-(T)SE was unaffected by susceptibility induced off-resonance effects, which caused geometrical distortions and/or signal hyper-intensities in broadband 3D-SE and, to a lesser extent, in ms3D-SE frequency encoded methods. Additionally, an SNR analysis was performed and the temporally resolved signal of 3D-PE-(T)SE sequences was exploited to retrospectively decrease the acquisition bandwidth and obtain field offset maps. The feasibility of CS acceleration was studied retrospectively and prospectively for the 3D-PE-SE sequence using an existing CS algorithm adapted for the reconstruction of 3D data with undersampling in all three phase encoded dimensions. CS was combined with turbo-acceleration by variable density undersampling and spherical stepwise T 2 weighting by randomly sorting consecutive echoes in predefined spherical k-space layers. The CS-TSE combination resulted in an overall acceleration factor of 60, decreasing the original 3D-PE-SE scan time from 7 h to 7 min. Finally, CS accelerated 3D-PE-TSE in vivo images of a titanium screw were obtained within 10 min using a micro-coil demonstrating the feasibility of geometrically undistorted MRI near severe

  16. Analysis of double random phase encryption from a key-space perspective

    Science.gov (United States)

    Monaghan, David S.; Situ, Guohai; Ryle, James; Gopinathan, Unnikrishnan; Naughton, Thomas J.; Sheridan, John T.

    2007-09-01

    The main advantage of the double random phase encryption technique is its physical implementation however to allow us to analyse its behaviour we perform the encryption/decryption numerically. A typically strong encryption scheme will have an extremely large key-space, which will make the probable success of any brute force attack on that algorithm miniscule. Traditionally, designers of optical image encryption systems only demonstrate how a small number of arbitrary keys cannot decrypt a chosen encrypted image in their system. We analyse this algorithm from a key-space perspective. The key-space of an encryption algorithm can be defined as the set of possible keys that can be used to encode data using that algorithm. For a range of problem instances we plot the distribution of decryption errors in the key-space indicating the lack of feasibility of a simple brute force attack.

  17. Profilometry of discontinuous solids by means of co-phased demodulation of projected fringes with RGB encoding

    Science.gov (United States)

    Padilla, J. M.; Servin, M.; Garnica, G.

    2015-05-01

    Here we describe a 2-projectors and 1-camera setup for profilometry of discontinuous solids by means of co-phased demodulation of projected fringes and red, green, and blue (RGB) multichannel operation. The dual projection configuration for this profilometer is proposed to solve efficiently specular regions and self-occluding shadows due to discontinuities, which are the main drawbacks for a 1-projector 1-camera configuration. This is because the regions where shadows and specular reflections are generated, and the fringe contrast drops to zero, are in general different for each projection direction; thus, the resulting fringe patterns will have complementary phase information. Multichannel RGB operation allows us to work simultaneously with both projectors and to record independently the complementary fringe patterns phase-modulated by the 3D profile of the object under study. In other words, color encoding/decoding reduces the acquisition time respect to one-at-a-time grayscale operation and, in principle, enables the study of dynamic phenomena. The co-phased demodulation method implemented in this work benefits from the complex (analytic) nature of the output signals estimated with most phase demodulation methods (such as the Fourier method, and temporal phaseshifting algorithms). This allowed us to straightforwardly generate a single phase-map well-defined for the entire area of interest. Finally we assessed our proposed profilometry setup by measuring a fractured spherical cap made of (uncoated) expanded polystyrene. The results were satisfactory but in the authors' opinion this must be considered a preliminary report.

  18. Accelerated three-dimensional cine phase contrast imaging using randomly undersampled echo planar imaging with compressed sensing reconstruction.

    Science.gov (United States)

    Basha, Tamer A; Akçakaya, Mehmet; Goddu, Beth; Berg, Sophie; Nezafat, Reza

    2015-01-01

    The aim of this study was to implement and evaluate an accelerated three-dimensional (3D) cine phase contrast MRI sequence by combining a randomly sampled 3D k-space acquisition sequence with an echo planar imaging (EPI) readout. An accelerated 3D cine phase contrast MRI sequence was implemented by combining EPI readout with randomly undersampled 3D k-space data suitable for compressed sensing (CS) reconstruction. The undersampled data were then reconstructed using low-dimensional structural self-learning and thresholding (LOST). 3D phase contrast MRI was acquired in 11 healthy adults using an overall acceleration of 7 (EPI factor of 3 and CS rate of 3). For comparison, a single two-dimensional (2D) cine phase contrast scan was also performed with sensitivity encoding (SENSE) rate 2 and approximately at the level of the pulmonary artery bifurcation. The stroke volume and mean velocity in both the ascending and descending aorta were measured and compared between two sequences using Bland-Altman plots. An average scan time of 3 min and 30 s, corresponding to an acceleration rate of 7, was achieved for 3D cine phase contrast scan with one direction flow encoding, voxel size of 2 × 2 × 3 mm(3) , foot-head coverage of 6 cm and temporal resolution of 30 ms. The mean velocity and stroke volume in both the ascending and descending aorta were statistically equivalent between the proposed 3D sequence and the standard 2D cine phase contrast sequence. The combination of EPI with a randomly undersampled 3D k-space sampling sequence using LOST reconstruction allows a seven-fold reduction in scan time of 3D cine phase contrast MRI without compromising blood flow quantification. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Modified random phase approximation for multipole excitations at finite temperature

    International Nuclear Information System (INIS)

    Nguyen Dinh Dang

    1991-01-01

    The modified finite temperature random phase approximation (modified FT-RPA) has been constructed with taking the influence of thermostat on the structure of quansiparticles into account. The modified FT-RPA linear response for electric quadrupole (λ π = 2 + ) and octupole (λ π = 3 - ) excitations in 5 8Ni has been calculated as a function of the nuclear temperature. As compared to the conventional FT-RPA the modified FT-RPA has given a stronger spreading for the strength distribution of quandrupole excitations at finite temperature T ≤ 3MeV. (author). 22 refs; 4 figs; 2 tabs

  20. Magnetic transitions and phases in random-anisotropy magnets

    International Nuclear Information System (INIS)

    Sellmyer, D.J.; Nafis, S.; O'Shea, M.J.

    1988-01-01

    The generality and universality of the Ising spin-glass-like phase transitions observed in several rare-earth, random-anisotropy magnets are discussed. Some uncertainties and practical problems in determining critical exponents are considered, and a comparison is made to insulating spin glasses and crystalline spin glasses where an apparent anisotropy-induced crossover from Heisenberg to Ising-like behavior is seen. The observation of a reentrant transition in a weak anisotropy system and its correlation with the theory of Chudnovsky, Saslow, and Serota [Phys. Rev. B 33, 251 (1986)] for the correlated spin glass is discussed

  1. Magnetic transitions and phases in random-anisotropy magnets

    Science.gov (United States)

    Sellmyer, D. J.; Nafis, S.; O'Shea, M. J.

    1988-04-01

    The generality and universality of the Ising spin-glass-like phase transitions observed in several rare-earth, random-anisotropy magnets are discussed. Some uncertainties and practical problems in determining critical exponents are considered, and a comparison is made to insulating spin glasses and crystalline spin glasses where an apparent anisotropy-induced crossover from Heisenberg to Ising-like behavior is seen. The observation of a reentrant transition in a weak anisotropy system and its correlation with the theory of Chudnovsky, Saslow, and Serota [Phys. Rev. B 33, 251 (1986)] for the correlated spin glass is discussed.

  2. Relativistic quasiparticle random phase approximation in deformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pena Arteaga, D.

    2007-06-25

    Covariant density functional theory is used to study the influence of electromagnetic radiation on deformed superfluid nuclei. The relativistic Hartree-Bogolyubov equations and the resulting diagonalization problem of the quasiparticle random phase approximation are solved for axially symmetric systems in a fully self-consistent way by a newly developed parallel code. Three different kinds of high precision energy functionals are investigated and special care is taken for the decoupling of the Goldstone modes. This allows the microscopic investigation of Pygmy and scissor resonances in electric and magnetic dipole fields. Excellent agreement with recent experiments is found and new types of modes are predicted for deformed systems with large neutron excess. (orig.)

  3. Random phase approximation: from Giant to Intra-doublet resonances

    International Nuclear Information System (INIS)

    Amusia, M.Ya.

    2004-01-01

    We discuss here the history and current achievements of one of the most powerful approaches of 20th century physics--the random phase approximation (RPA) that permits us to study collective or multiparticle effects in atoms, nuclei, molecules and clusters, as well as in quantum liquids. We concentrate on RPA application to studies of isolated atoms where it permits one to disclose the collective multielectron nature of so-called Giant resonances and predict a number of others, like Interference and Intra-doublet resonances. We present general theory as well as results of concrete calculations for a number of atoms

  4. Random phase approximation: from Giant to Intra-doublet resonances

    Energy Technology Data Exchange (ETDEWEB)

    Amusia, M.Ya. E-mail: amusia@vms.huji.ac.il

    2004-06-01

    We discuss here the history and current achievements of one of the most powerful approaches of 20th century physics--the random phase approximation (RPA) that permits us to study collective or multiparticle effects in atoms, nuclei, molecules and clusters, as well as in quantum liquids. We concentrate on RPA application to studies of isolated atoms where it permits one to disclose the collective multielectron nature of so-called Giant resonances and predict a number of others, like Interference and Intra-doublet resonances. We present general theory as well as results of concrete calculations for a number of atoms.

  5. Photons in dense nuclear matter: Random-phase approximation

    Science.gov (United States)

    Stetina, Stephan; Rrapaj, Ermal; Reddy, Sanjay

    2018-04-01

    We present a comprehensive and pedagogic discussion of the properties of photons in cold and dense nuclear matter based on the resummed one-loop photon self-energy. Correlations among electrons, muons, protons, and neutrons in β equilibrium that arise as a result of electromagnetic and strong interactions are consistently taken into account within the random phase approximation. Screening effects, damping, and collective excitations are systematically studied in a fully relativistic setup. Our study is relevant to the linear response theory of dense nuclear matter, calculations of transport properties of cold dense matter, and investigations of the production and propagation of hypothetical vector bosons such as the dark photons.

  6. Relationship of activity in ascending paths with phase encoding in the lumbar spinal cord

    Directory of Open Access Journals (Sweden)

    O. O. Shugurov

    2012-02-01

    Full Text Available We studied the relationship of discharges phase characteristics in ascending column of spinal cord (SC and specificity of activation of neurones, which generate negative components of evoked potentials of SC. The discharges was recorded from SC at a level of a presence of dorsal column (DC, spinocervical and dorsal spinocerebellar tract in upper lumbar and thoracic segments at a stimulation of a nerve or DC. It is shown, that the phase of the discharges depends on the quantity of synaptic delays in generating chain of such signals. Thus, the phase of a signal can carry the additional information on specificity of activation of the sensory elements in CNS.

  7. Regularly incremented phase encoding - MR fingerprinting (RIPE-MRF) for enhanced motion artifact suppression in preclinical cartesian MR fingerprinting.

    Science.gov (United States)

    Anderson, Christian E; Wang, Charlie Y; Gu, Yuning; Darrah, Rebecca; Griswold, Mark A; Yu, Xin; Flask, Chris A

    2018-04-01

    The regularly incremented phase encoding-magnetic resonance fingerprinting (RIPE-MRF) method is introduced to limit the sensitivity of preclinical MRF assessments to pulsatile and respiratory motion artifacts. As compared to previously reported standard Cartesian-MRF methods (SC-MRF), the proposed RIPE-MRF method uses a modified Cartesian trajectory that varies the acquired phase-encoding line within each dynamic MRF dataset. Phantoms and mice were scanned without gating or triggering on a 7T preclinical MRI scanner using the RIPE-MRF and SC-MRF methods. In vitro phantom longitudinal relaxation time (T 1 ) and transverse relaxation time (T 2 ) measurements, as well as in vivo liver assessments of artifact-to-noise ratio (ANR) and MRF-based T 1 and T 2 mean and standard deviation, were compared between the two methods (n = 5). RIPE-MRF showed significant ANR reductions in regions of pulsatility (P Reson Med 79:2176-2182, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  8. A random walk rule for phase I clinical trials.

    Science.gov (United States)

    Durham, S D; Flournoy, N; Rosenberger, W F

    1997-06-01

    We describe a family of random walk rules for the sequential allocation of dose levels to patients in a dose-response study, or phase I clinical trial. Patients are sequentially assigned the next higher, same, or next lower dose level according to some probability distribution, which may be determined by ethical considerations as well as the patient's response. It is shown that one can choose these probabilities in order to center dose level assignments unimodally around any target quantile of interest. Estimation of the quantile is discussed; the maximum likelihood estimator and its variance are derived under a two-parameter logistic distribution, and the maximum likelihood estimator is compared with other nonparametric estimators. Random walk rules have clear advantages: they are simple to implement, and finite and asymptotic distribution theory is completely worked out. For a specific random walk rule, we compute finite and asymptotic properties and give examples of its use in planning studies. Having the finite distribution theory available and tractable obviates the need for elaborate simulation studies to analyze the properties of the design. The small sample properties of our rule, as determined by exact theory, compare favorably to those of the continual reassessment method, determined by simulation.

  9. Intrinsically stable phase-modulated polarization encoding system for quantum key distribution

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiaobao [Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China); Liao Changjun [Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China)], E-mail: chliao@scnu.edu.cn; Mi Jinglong; Wang Jindong; Liu Songhao [Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China)

    2008-12-22

    We demonstrate experimentally an intrinsically stable polarization coding and decoding system composed of optical-fiber Sagnac interferometers with integrated phase modulators for quantum key distribution. An interference visibility of 98.35% can be kept longtime during the experiment without any efforts of active compensation for coding all four desired polarization states.

  10. Random signal tomographical analysis of two-phase flow

    International Nuclear Information System (INIS)

    Han, P.; Wesser, U.

    1990-01-01

    This paper reports on radiation tomography which is a useful tool for studying the internal structures of two-phase flow. However, general tomography analysis gives only time-averaged results, hence much information is lost. As a result, it is sometimes difficult to identify the flow regime; for example, the time-averaged picture does not significantly change as an annual flow develops from a slug flow. A two-phase flow diagnostic technique based on random signal tomographical analysis is developed. It extracts more information by studying the statistical variation of the measured signal with time. Local statistical parameters, including mean value, variance, skewness and flatness etc., are reconstructed from the information obtained by a general tomography technique. More important information are provided by the results. Not only the void fraction can be easily calculated, but also the flow pattern can be identified more objectively and more accurately. The experimental setup is introduced. It consisted of a two-phase flow loop, an X-ray system, a fan-like five-beam detector system and a signal acquisition and processing system. In the experiment, for both horizontal and vertical test sections (aluminum and steel tube with Di/Do = 40/45 mm), different flow situations are realized by independently adjusting air and water mass flow. Through a glass tube connected with the test section, some typical flow patterns are visualized and used for comparing with the reconstruction results

  11. Isoscalar compression modes in relativistic random phase approximation

    International Nuclear Information System (INIS)

    Ma, Zhong-yu; Van Giai, Nguyen.; Wandelt, A.; Vretenar, D.; Ring, P.

    2001-01-01

    Monopole and dipole compression modes in nuclei are analyzed in the framework of a fully consistent relativistic random phase approximation (RRPA), based on effective mean-field Lagrangians with nonlinear meson self-interaction terms. The large effect of Dirac sea states on isoscalar strength distribution functions is illustrated for the monopole mode. The main contribution of Fermi and Dirac sea pair states arises through the exchange of the scalar meson. The effect of vector meson exchange is much smaller. For the monopole mode, RRPA results are compared with constrained relativistic mean-field calculations. A comparison between experimental and calculated energies of isoscalar giant monopole resonances points to a value of 250-270 MeV for the nuclear matter incompressibility. A large discrepancy remains between theoretical predictions and experimental data for the dipole compression mode

  12. Laser-beam apodization with a graded random phase window

    Energy Technology Data Exchange (ETDEWEB)

    Haas, R.A.; Summers, M.A.; Linford, G.J.

    1986-10-01

    Experiments and analysis indicate that graded random phase modulation can be usesd to apodize a laser beam. In the case of an obscuration or a hard edge it can prevent the formation of Fresnel-diffraction ripples. For example, here the interaction of a 1-..mu..m-wavelength laser beam with a central obscuration of half-width a -- 100 ..mu..m is studied theoretically. It is found that if the exit surface of a window, placed immediately downstream of the obstacle, is randomly modulated with a Gaussian amplitude transverse correlation length l -- 50..mu..m and a mean-square amplitude that decreases exponentially from a peak height of --1..mu..m/sup 2/ away from the center of the obscuration with transverse scale length L -- 500 ..mu..m, then the Fresenel-diffraction ripples normally produced by the obscuration are elimated. The scaling of these results is also discussed. The calculations are in general agreement with experimental results.

  13. Laser-beam apodization with a graded random phase window

    International Nuclear Information System (INIS)

    Haas, R.A.; Summers, M.A.; Linford, G.J.

    1986-01-01

    Experiments and analysis indicate that graded random phase modulation can be usesd to apodize a laser beam. In the case of an obscuration or a hard edge it can prevent the formation of Fresnel-diffraction ripples. For example, here the interaction of a 1-μm-wavelength laser beam with a central obscuration of half-width a -- 100 μm is studied theoretically. It is found that if the exit surface of a window, placed immediately downstream of the obstacle, is randomly modulated with a Gaussian amplitude transverse correlation length l -- 50μm and a mean-square amplitude that decreases exponentially from a peak height of --1μm 2 away from the center of the obscuration with transverse scale length L -- 500 μm, then the Fresenel-diffraction ripples normally produced by the obscuration are elimated. The scaling of these results is also discussed. The calculations are in general agreement with experimental results

  14. Topical tofacitinib for atopic dermatitis: a phase IIa randomized trial.

    Science.gov (United States)

    Bissonnette, R; Papp, K A; Poulin, Y; Gooderham, M; Raman, M; Mallbris, L; Wang, C; Purohit, V; Mamolo, C; Papacharalambous, J; Ports, W C

    2016-11-01

    Despite unmet need, 15 years have passed since a topical therapy with a new mechanism of action for atopic dermatitis (AD) has been approved. Janus kinase (JAK) inhibitor treatment effect via topical application in patients with AD is unknown. Tofacitinib, a small-molecule JAK inhibitor, was investigated for the topical treatment of AD. In this 4-week, phase IIa, randomized, double-blind, vehicle-controlled study (NCT02001181), 69 adults with mild-to-moderate AD were randomized 1:1 to 2% tofacitinib or vehicle ointment twice daily. Percentage change from baseline (CFB) in Eczema Area and Severity Index (EASI) score at week 4 was the primary end point. Secondary efficacy end points included percentage CFB in body surface area (BSA), CFB in EASI Clinical Signs Severity Sum Score, proportion of patients with Physician's Global Assessment (PGA) response and CFB in patient-reported pruritus. Safety, local tolerability and pharmacokinetics were monitored. The mean percentage CFB at week 4 in EASI score was significantly greater (P tofacitinib (-81·7%) vs. vehicle (-29·9%). Patients treated with tofacitinib showed significant (P tofacitinib. Tofacitinib ointment showed significantly greater efficacy vs. vehicle across end points, with early onset of effect and comparable safety/local tolerability to vehicle. JAK inhibition through topical delivery is potentially a promising therapeutic target for AD. © 2016 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

  15. Excitations and phase transitions in random anti-ferromagnets

    International Nuclear Information System (INIS)

    Cowley, R.A.; Birgeneau, R.J.; Shirane, G.

    1979-01-01

    Neutron scattering techniques can be used to study the magnetic excitations and phase transitions in the randomly mixed transition metal fluorides. The results for the excitations of samples with two different types of magnetic ions show two bands of excitations; each associated with excitations propagating largely on one type of ion. In the diluted salts the spectra show a complex line shape and greater widths. These results are in good accord with computer simulations showing that linear spin wave theory can be used, but have not been described satisfactorily using the coherent potential approximation. The phase transitions in these materials are always smeared, but it is difficult to ascertain if this smearing is due to macroscopic fluctuations in the concentration or of an intrinsic origin. Studies of these systems close to the percolation point have shown that the thermal disorder is associated with the one-dimensional weak links of the large clusters. Currently theory and experiment are in accord for the two-dimensional Ising system but features are still not understood in Heisenberg systems in both two and three dimensions

  16. Statistics of light deflection in a random two-phase medium

    International Nuclear Information System (INIS)

    Sviridov, A P

    2007-01-01

    The statistics of the angles of light deflection during its propagation in a random two-phase medium with randomly oriented phase interfaces is considered within the framework of geometrical optics. The probabilities of finding a randomly walking photon in different phases of the inhomogeneous medium are calculated. Analytic expressions are obtained for the scattering phase function and the scattering phase matrix which relates the Stokes vector of the incident light beam with the Stokes vectors of deflected beams. (special issue devoted to multiple radiation scattering in random media)

  17. Utilisation of ISA Reverse Genetics and Large-Scale Random Codon Re-Encoding to Produce Attenuated Strains of Tick-Borne Encephalitis Virus within Days.

    Science.gov (United States)

    de Fabritus, Lauriane; Nougairède, Antoine; Aubry, Fabien; Gould, Ernest A; de Lamballerie, Xavier

    2016-01-01

    Large-scale codon re-encoding is a new method of attenuating RNA viruses. However, the use of infectious clones to generate attenuated viruses has inherent technical problems. We previously developed a bacterium-free reverse genetics protocol, designated ISA, and now combined it with large-scale random codon-re-encoding method to produce attenuated tick-borne encephalitis virus (TBEV), a pathogenic flavivirus which causes febrile illness and encephalitis in humans. We produced wild-type (WT) and two re-encoded TBEVs, containing 273 or 273+284 synonymous mutations in the NS5 and NS5+NS3 coding regions respectively. Both re-encoded viruses were attenuated when compared with WT virus using a laboratory mouse model and the relative level of attenuation increased with the degree of re-encoding. Moreover, all infected animals produced neutralizing antibodies. This novel, rapid and efficient approach to engineering attenuated viruses could potentially expedite the development of safe and effective new-generation live attenuated vaccines.

  18. (3+1)-dimensional topological phases and self-dual quantum geometries encoded on Heegaard surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Bianca [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada)

    2017-05-22

    We apply the recently suggested strategy to lift state spaces and operators for (2+1)-dimensional topological quantum field theories to state spaces and operators for a (3+1)-dimensional TQFT with defects. We start from the (2+1)-dimensional Turaev-Viro theory and obtain a state space, consistent with the state space expected from the Crane-Yetter model with line defects. This work has important applications for quantum gravity as well as the theory of topological phases in (3+1) dimensions. It provides a self-dual quantum geometry realization based on a vacuum state peaked on a homogeneously curved geometry. The state spaces and operators we construct here provide also an improved version of the Walker-Wang model, and simplify its analysis considerably. We in particular show that the fusion bases of the (2+1)-dimensional theory lead to a rich set of bases for the (3+1)-dimensional theory. This includes a quantum deformed spin network basis, which in a loop quantum gravity context diagonalizes spatial geometry operators. We also obtain a dual curvature basis, that diagonalizes the Walker-Wang Hamiltonian. Furthermore, the construction presented here can be generalized to provide state spaces for the recently introduced dichromatic four-dimensional manifold invariants.

  19. Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase-II: A Phase II Randomized Trial.

    Science.gov (United States)

    Okonkwo, David O; Shutter, Lori A; Moore, Carol; Temkin, Nancy R; Puccio, Ava M; Madden, Christopher J; Andaluz, Norberto; Chesnut, Randall M; Bullock, M Ross; Grant, Gerald A; McGregor, John; Weaver, Michael; Jallo, Jack; LeRoux, Peter D; Moberg, Dick; Barber, Jason; Lazaridis, Christos; Diaz-Arrastia, Ramon R

    2017-11-01

    A relationship between reduced brain tissue oxygenation and poor outcome following severe traumatic brain injury has been reported in observational studies. We designed a Phase II trial to assess whether a neurocritical care management protocol could improve brain tissue oxygenation levels in patients with severe traumatic brain injury and the feasibility of a Phase III efficacy study. Randomized prospective clinical trial. Ten ICUs in the United States. One hundred nineteen severe traumatic brain injury patients. Patients were randomized to treatment protocol based on intracranial pressure plus brain tissue oxygenation monitoring versus intracranial pressure monitoring alone. Brain tissue oxygenation data were recorded in the intracranial pressure -only group in blinded fashion. Tiered interventions in each arm were specified and impact on intracranial pressure and brain tissue oxygenation measured. Monitors were removed if values were normal for 48 hours consecutively, or after 5 days. Outcome was measured at 6 months using the Glasgow Outcome Scale-Extended. A management protocol based on brain tissue oxygenation and intracranial pressure monitoring reduced the proportion of time with brain tissue hypoxia after severe traumatic brain injury (0.45 in intracranial pressure-only group and 0.16 in intracranial pressure plus brain tissue oxygenation group; p injury after severe traumatic brain injury based on brain tissue oxygenation and intracranial pressure values was consistent with reduced mortality and increased proportions of patients with good recovery compared with intracranial pressure-only management; however, the study was not powered for clinical efficacy. Management of severe traumatic brain injury informed by multimodal intracranial pressure and brain tissue oxygenation monitoring reduced brain tissue hypoxia with a trend toward lower mortality and more favorable outcomes than intracranial pressure-only treatment. A Phase III randomized trial to assess

  20. Communication: Random phase approximation renormalized many-body perturbation theory

    International Nuclear Information System (INIS)

    Bates, Jefferson E.; Furche, Filipp

    2013-01-01

    We derive a renormalized many-body perturbation theory (MBPT) starting from the random phase approximation (RPA). This RPA-renormalized perturbation theory extends the scope of single-reference MBPT methods to small-gap systems without significantly increasing the computational cost. The leading correction to RPA, termed the approximate exchange kernel (AXK), substantially improves upon RPA atomization energies and ionization potentials without affecting other properties such as barrier heights where RPA is already accurate. Thus, AXK is more balanced than second-order screened exchange [A. Grüneis et al., J. Chem. Phys. 131, 154115 (2009)], which tends to overcorrect RPA for systems with stronger static correlation. Similarly, AXK avoids the divergence of second-order Møller-Plesset (MP2) theory for small gap systems and delivers a much more consistent performance than MP2 across the periodic table at comparable cost. RPA+AXK thus is an accurate, non-empirical, and robust tool to assess and improve semi-local density functional theory for a wide range of systems previously inaccessible to first-principles electronic structure calculations

  1. Relativistic continuum random phase approximation in spherical nuclei

    International Nuclear Information System (INIS)

    Daoutidis, Ioannis

    2009-01-01

    Covariant density functional theory is used to analyze the nuclear response in the external multipole fields. The investigations are based on modern functionals with zero range and density dependent coupling constants. After a self-consistent solution of the Relativistic Mean Field (RMF) equations for the nuclear ground states multipole giant resonances are studied within the Relativistic Random Phase Approximation (RRPA), the small amplitude limit of the time-dependent RMF. The coupling to the continuum is treated precisely by calculating the single particle Greens-function of the corresponding Dirac equation. In conventional methods based on a discretization of the continuum this was not possible. The residual interaction is derived from the same RMF Lagrangian. This guarantees current conservation and a precise decoupling of the Goldstone modes. For nuclei with open shells pairing correlations are taken into account in the framework of BCS theory and relativistic quasiparticle RPA. Continuum RPA (CRPA) presents a robust method connected with an astonishing reduction of the numerical effort as compared to conventional methods. Modes of various multipolarities and isospin are investigated, in particular also the newly discovered Pygmy modes in the vicinity of the neutron evaporation threshold. The results are compared with conventional discrete RPA calculations as well as with experimental data. We find that the full treatment of the continuum is essential for light nuclei and the study of resonances in the neighborhood of the threshold. (orig.)

  2. Relativistic continuum random phase approximation in spherical nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Daoutidis, Ioannis

    2009-10-01

    Covariant density functional theory is used to analyze the nuclear response in the external multipole fields. The investigations are based on modern functionals with zero range and density dependent coupling constants. After a self-consistent solution of the Relativistic Mean Field (RMF) equations for the nuclear ground states multipole giant resonances are studied within the Relativistic Random Phase Approximation (RRPA), the small amplitude limit of the time-dependent RMF. The coupling to the continuum is treated precisely by calculating the single particle Greens-function of the corresponding Dirac equation. In conventional methods based on a discretization of the continuum this was not possible. The residual interaction is derived from the same RMF Lagrangian. This guarantees current conservation and a precise decoupling of the Goldstone modes. For nuclei with open shells pairing correlations are taken into account in the framework of BCS theory and relativistic quasiparticle RPA. Continuum RPA (CRPA) presents a robust method connected with an astonishing reduction of the numerical effort as compared to conventional methods. Modes of various multipolarities and isospin are investigated, in particular also the newly discovered Pygmy modes in the vicinity of the neutron evaporation threshold. The results are compared with conventional discrete RPA calculations as well as with experimental data. We find that the full treatment of the continuum is essential for light nuclei and the study of resonances in the neighborhood of the threshold. (orig.)

  3. Relativistic quasiparticle random phase approximation with a separable pairing force

    International Nuclear Information System (INIS)

    Tian Yuan; Ma Zhongyu; Ring Peter

    2009-01-01

    In our previous work, we introduced a separable pairing force for relativistic Hartree-Bogoliubov calculations. This force was adjusted to reproduce the pairing properties of the Gogny force in nuclear matter. By using the well known techniques of Talmi and Moshinsky it can be expanded in a series of separable terms and converges quickly after a few terms. It was found that the pairing properties can be depicted on almost the same footing as the original pairing interaction, not only in nuclear matter, but also in finite nuclei. In this study, we construct a relativistic quasiparticle random phase approximation (RQRPA) with this separable pairing interaction and calculate the excitation energies of the first excited 2 + states and reduced B(E2; 0 + →2 + ) transition rates for a chain of Sn isotopes in RQRPA. Compared with the results of the full Gogny force, we find that this simple separable pairing interaction can describe the pairing properties of the excited vibrational states as well as the original pairing interaction. (authors)

  4. Separable pairing force for relativistic quasiparticle random-phase approximation

    International Nuclear Information System (INIS)

    Tian Yuan; Ma Zhongyu; Ring, Peter

    2009-01-01

    We have introduced a separable pairing force, which was adjusted to reproduce the pairing properties of the Gogny force in nuclear matter. This separable pairing force is able to describe in relativistic Hartree-Bogoliubov (RHB) calculations the pairing properties in the ground state of finite nuclei on almost the same footing as the original Gogny interaction. In this work we investigate excited states using the Relativistic Quasiparticle Random-Phase Approximation (RQRPA) with the same separable pairing force. For consistency the Goldstone modes and the convergence with various cutoff parameters in this version of RQRPA are studied. The first excited 2 + states for the chain of Sn isotopes with Z=50 and the chain of isotones with N=82 isotones are calculated in RQRPA together with the 3 - states of Sn isotopes. By comparing our results with experimental data and with the results of the original Gogny force we find that this simple separable pairing interaction is very successful in depicting the pairing properties of vibrational excitations.

  5. Three Phase Power Imbalance Decomposition into Systematic Imbalance and Random Imbalance

    DEFF Research Database (Denmark)

    Kong, Wangwei; Ma, Kang; Wu, Qiuwei

    2017-01-01

    Uneven load allocations and random load behaviors are two major causes for three-phase power imbalance. The former mainly cause systematic imbalance, which can be addressed by low-cost phase swapping; the latter contribute to random imbalance, which requires relatively costly demand...... minimum phase, or both. Then, this paper proposes a new method to decompose three-phase power series into a systematic imbalance component and a random imbalance component as the closed-form solutions of quadratic optimization models that minimize random imbalance. A degree of power imbalance...... is calculated based on the systematic imbalance component to guide phase swapping. Case studies demonstrate that 72.8% of 782 low voltage substations have systematic imbalance components. The degree of power imbalance results reveal the maximum need for phase swapping and the random imbalance components reveal...

  6. Note: An absolute X-Y-Θ position sensor using a two-dimensional phase-encoded binary scale

    Science.gov (United States)

    Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan

    2018-04-01

    This Note presents a new absolute X-Y-Θ position sensor for measuring planar motion of a precision multi-axis stage system. By analyzing the rotated image of a two-dimensional phase-encoded binary scale (2D), the absolute 2D position values at two separated points were obtained and the absolute X-Y-Θ position could be calculated combining these values. The sensor head was constructed using a board-level camera, a light-emitting diode light source, an imaging lens, and a cube beam-splitter. To obtain the uniform intensity profiles from the vignette scale image, we selected the averaging directions deliberately, and higher resolution in the angle measurement could be achieved by increasing the allowable offset size. The performance of a prototype sensor was evaluated in respect of resolution, nonlinearity, and repeatability. The sensor could resolve 25 nm linear and 0.001° angular displacements clearly, and the standard deviations were less than 18 nm when 2D grid positions were measured repeatedly.

  7. Phase reconstruction from velocity-encoded MRI measurements – A survey of sparsity-promoting variational approaches

    KAUST Repository

    Benning, Martin

    2014-01-01

    In recent years there has been significant developments in the reconstruction of magnetic resonance velocity images from sub-sampled k-space data. While showing a strong improvement in reconstruction quality compared to classical approaches, the vast number of different methods, and the challenges in setting them up, often leaves the user with the difficult task of choosing the correct approach, or more importantly, not selecting a poor approach. In this paper, we survey variational approaches for the reconstruction of phase-encoded magnetic resonance velocity images from sub-sampled k-space data. We are particularly interested in regularisers that correctly treat both smooth and geometric features of the image. These features are common to velocity imaging, where the flow field will be smooth but interfaces between the fluid and surrounding material will be sharp, but are challenging to represent sparsely. As an example we demonstrate the variational approaches on velocity imaging of water flowing through a packed bed of solid particles. We evaluate Wavelet regularisation against Total Variation and the relatively recent second order Total Generalised Variation regularisation. We combine these regularisation schemes with a contrast enhancement approach called Bregman iteration. We verify for a variety of sampling patterns that Morozov\\'s discrepancy principle provides a good criterion for stopping the iterations. Therefore, given only the noise level, we present a robust guideline for setting up a variational reconstruction scheme for MR velocity imaging. © 2013 Elsevier Inc. All rights reserved.

  8. Optical pulse coupling in a photorefractive crystal, propagation of encoded pulses in an optical fiber, and phase conjugate optical interconnections

    Energy Technology Data Exchange (ETDEWEB)

    Yao, X.S.

    1992-01-01

    In Part I, the author presents a theory to describe the interaction between short optical pulses in a photorefractive crystal. This theory provides an analytical framework for pulse coherence length measurements using a photorefractive crystal. The theory also predicts how a pulse changes its temporal shape due to its coupling with another pulse in a photorefractive crystal. The author describes experiments to demonstrate how photorefractive coupling alters the temporal shape and the frequency spectrum of an optical pulse. The author describes a compact optical field correlator. Using this correlator, the author measured the field cross-correlation function of optical pulses using a photorefractive crystal. The author presents a more sophisticated theory to describe the photorefractive coupling of optical pulses that are too short for the previous theory to be valid. In Part II of this dissertation, the author analyzes how the group-velocity dispersion and the optical nonlinearity of an optical fiber ruin an fiberoptic code-division multiple-access (CDMA) communication system. The author treats the optical fiber's nonlinear response with a novel approach and derives the pulse propagation equation. Through analysis and numerically simulations, the author obtains the maximum and the maximum allowed peak pulse power, as well as the minimum and the maximum allowed pulse width for the communication system to function properly. The author simulates how the relative misalignment between the encoding and the decoding masks affects the system's performance. In Part III the author demonstrates a novel optical interconnection device based on a mutually pumped phase conjugator. This device automatically routes light from selected information-sending channels to selected information-receiving channels, and vice versa. The phase conjugator eliminates the need for critical alignment. It is shown that a large number of optical channels can be interconnected using this

  9. Surface wake in the random-phase approximation

    International Nuclear Information System (INIS)

    Garcia de Abajo, F.J.; Echenique, P.M.

    1993-01-01

    The scalar-electric-potential distribution set up by an ion traveling in the vicinity of a plane solid-vacuum interface, that is, the surface-wake potential, is investigated with the specular-reflection model to describe the response of the surface and with the random-phase approximation for the dielectric function of the bulk material. This permits us to address the study of the low-velocity surface wake: the static potential is found to have a dip at the position of the ion; that dip is shifted towards the direction opposite to the velocity vector for velocities smaller than the threshold of creation of plasmons (∼1.3v F ). Extensive numerical calculations are presented for an ion both inside and outside aluminum. Comparison to the results obtained with the plasmon-pole dielectric function indicates excellent agreement for velocities larger than ∼1.3v F . On the other side, the possibility of surface-wake riding is suggested, by analogy with bulk-wake riding postulated in the past. In it, the electron would be bound in the first trough of the surface-wake potential set up when the ion describes a grazing trajectory. The main feature introduced by the surface with respect to the bulk consists of allowing the use of ions of higher charge, reducing in this way the relative importance of the electron self-energy, and in addition, giving rise to larger binding energies. When the ion beam is directed along a special direction of an oriented crystal surface, the mechanism of resonant coherent excitation could provide a way for experimentally detecting this phenomenon through the emission of the bound electron with well-defined energy and around a preferential direction

  10. Deep learning the quantum phase transitions in random two-dimensional electron systems

    International Nuclear Information System (INIS)

    Ohtsuki, Tomoki; Ohtsuki, Tomi

    2016-01-01

    Random electron systems show rich phases such as Anderson insulator, diffusive metal, quantum Hall and quantum anomalous Hall insulators, Weyl semimetal, as well as strong/weak topological insulators. Eigenfunctions of each matter phase have specific features, but owing to the random nature of systems, determining the matter phase from eigenfunctions is difficult. Here, we propose the deep learning algorithm to capture the features of eigenfunctions. Localization-delocalization transition, as well as disordered Chern insulator-Anderson insulator transition, is discussed. (author)

  11. Shaping the spectrum of random-phase radar waveforms

    Science.gov (United States)

    Doerry, Armin W.; Marquette, Brandeis

    2017-05-09

    The various technologies presented herein relate to generation of a desired waveform profile in the form of a spectrum of apparently random noise (e.g., white noise or colored noise), but with precise spectral characteristics. Hence, a waveform profile that could be readily determined (e.g., by a spoofing system) is effectively obscured. Obscuration is achieved by dividing the waveform into a series of chips, each with an assigned frequency, wherein the sequence of chips are subsequently randomized. Randomization can be a function of the application of a key to the chip sequence. During processing of the echo pulse, a copy of the randomized transmitted pulse is recovered or regenerated against which the received echo is correlated. Hence, with the echo energy range-compressed in this manner, it is possible to generate a radar image with precise impulse response.

  12. Number-conserving random phase approximation with analytically integrated matrix elements

    International Nuclear Information System (INIS)

    Kyotoku, M.; Schmid, K.W.; Gruemmer, F.; Faessler, A.

    1990-01-01

    In the present paper a number conserving random phase approximation is derived as a special case of the recently developed random phase approximation in general symmetry projected quasiparticle mean fields. All the occurring integrals induced by the number projection are performed analytically after writing the various overlap and energy matrices in the random phase approximation equation as polynomials in the gauge angle. In the limit of a large number of particles the well-known pairing vibration matrix elements are recovered. We also present a new analytically number projected variational equation for the number conserving pairing problem

  13. Thermal behavior for a nanoscale two ferromagnetic phase system based on random anisotropy model

    International Nuclear Information System (INIS)

    Muraca, D.; Sanchez, F.H.; Pampillo, L.G.; Saccone, F.D.

    2010-01-01

    Advances in theory that explain the magnetic behavior as function of temperature for two phase nanocrystalline soft magnetic materials are presented. The theory developed is based on the well known random anisotropy model, which includes the crystalline exchange stiffness and anisotropy energies in both amorphous and crystalline phases. The phenomenological behavior of the coercivity was obtained in the temperature range between the amorphous phase Curie temperature and the crystalline phase one.

  14. (Non-) Gibbsianness and Phase Transitions in Random Lattice Spin Models

    NARCIS (Netherlands)

    Külske, C.

    1999-01-01

    We consider disordered lattice spin models with finite-volume Gibbs measures µΛ[η](dσ). Here σ denotes a lattice spin variable and η a lattice random variable with product distribution P describing the quenched disorder of the model. We ask: when will the joint measures limΛ↑Zd P(dη)µΛ[η](dσ) be

  15. Ultra-fast quantum randomness generation by accelerated phase diffusion in a pulsed laser diode.

    Science.gov (United States)

    Abellán, C; Amaya, W; Jofre, M; Curty, M; Acín, A; Capmany, J; Pruneri, V; Mitchell, M W

    2014-01-27

    We demonstrate a high bit-rate quantum random number generator by interferometric detection of phase diffusion in a gain-switched DFB laser diode. Gain switching at few-GHz frequencies produces a train of bright pulses with nearly equal amplitudes and random phases. An unbalanced Mach-Zehnder interferometer is used to interfere subsequent pulses and thereby generate strong random-amplitude pulses, which are detected and digitized to produce a high-rate random bit string. Using established models of semiconductor laser field dynamics, we predict a regime of high visibility interference and nearly complete vacuum-fluctuation-induced phase diffusion between pulses. These are confirmed by measurement of pulse power statistics at the output of the interferometer. Using a 5.825 GHz excitation rate and 14-bit digitization, we observe 43 Gbps quantum randomness generation.

  16. Smoothing by spectral dispersion using random phase modulation for inertial confinement fusion

    International Nuclear Information System (INIS)

    Rothenberg, J.E.

    1995-01-01

    Numerical simulations of beam smoothing using random phase modulation and grating dispersion are presented. Spatial spectra of the target illumination show that significantly improved smoothing at low spatial frequency is achieved while maintaining uniform intensity in the laser amplifier

  17. Phase diagram and tricritical behavior of an metamagnet in uniform and random fields

    International Nuclear Information System (INIS)

    Liang Yaqiu; Wei Guozhu; Xu Xiaojuan; Song Guoli

    2010-01-01

    A two-sublattice Ising metamagnet in both uniform and random fields is studied within the mean-field approach based on Bogoliubov's inequality for the Gibbs free energy. We show that the qualitative features of the phase diagrams are dependent on the parameters of the model and the uniform field values. The tricritical point and reentrant phenomenon can be observed on the phase diagram. The reentrance is due to the competition between uniform and random interactions.

  18. Nonequilibrium phase transition in directed small-world-Voronoi-Delaunay random lattices

    International Nuclear Information System (INIS)

    Lima, F.W.S.

    2016-01-01

    On directed small-world-Voronoi-Delaunay random lattices in two dimensions with quenched connectivity disorder we study the critical properties of the dynamics evolution of public opinion in social influence networks using a simple spin-like model. The system is treated by applying Monte Carlo simulations. We show that directed links on these random lattices may lead to phase diagram with first- and second-order social phase transitions out of equilibrium. (paper)

  19. Photoabsorption for helium, lithium, and beryllium atoms in the random-phase approximation with exchange

    International Nuclear Information System (INIS)

    Amusia, M.Y.; Cherepkov, N.A.; Zivanovic, D.; Radojevic, V.

    1976-01-01

    The photoionization cross sections and the oscillator strengths for helium, lithium, and beryllium atoms are calculated in the framework of the random-phase approximation with exchange. The energy-level shift for discrete transitions is taken into account consistently in this approximation. The results are compared with other many-body calculations and with experimental data. The comparison shows that the random-phase approximation with exchange can even be used for systems with a small number of particles

  20. Phase transitions in random uniaxial systems with dipolar interactions

    International Nuclear Information System (INIS)

    Schuster, H.G.

    1977-01-01

    The critical behaviour of random uniaxial ferromagnetic (ferroelectric) systems with both short range and long range dipolar interactions is investigated, using the field theoretic renormalization method of Brezin et al. for the free energy above and below transition point Tsub(c). The randomness is due to externally introduced fluctuations in the short range interactions (quenched case) or (and) magneto-elastic coupling to the lattice (annealed case). Strong deviations in the critical behaviour with respect to the pure systems are found. In the quenched case, e.g., the specific heat C and the coefficient f 2 (of M 3 in the equation of state, where M is the magnetization) change from C proportional to abs ln abs t abs abssup(1/3), f 2 proportional to abs ln abs t abs abs sup(1/3), f 2 proportional to abs ln abs t abs abs -1 in the pure system to C = A+- + C+-exp[-4√ 3 106 abs ln abs t abs abs], f 2 proportional to abs ln abs t abs abs sup(-1/2) (where t = (T-Tsub(c)) / Tsub(c) is the reduced temperature and A+-, C+- are constants) in the random situation. (orig.) [de

  1. Coherent-phase or random-phase acceleration of electron beams in solar flares

    Science.gov (United States)

    Aschwanden, Markus J.; Benz, Arnold O.; Montello, Maria L.

    1994-01-01

    Time structures of electron beam signatures at radio wavelengths are investigated to probe correlated versus random behavior in solar flares. In particular we address the issue whether acceleration and injection of electron beams is coherently modulated by a single source, or whether the injection is driven by a stochastic (possibly spatially fragmented) process. We analyze a total of approximately = 6000 type III bursts observed by Ikarus (Zurich) in the frequency range of 100-500 MHz, during 359 solar flares with simultaneous greater than or = 25 keV hard X-ray emission, in the years 1890-1983. In 155 flares we find a total of 260 continuous type III groups, with an average number of 13 +/- 9 bursts per group, a mean duration of D = 12 +/- 14 s, a mean period of P = 2.0 +/- 1.2 s, with the highest burst rate at a frequency of nu = 310 +/- 120 MHz. Pulse periods have been measured between 0.5 and 10 s, and can be described by an exponential distribution, i.e., N(P) varies as e (exp -P/1.0s). The period shows a frequency dependence of P(nu)=46(exp-0.6)(sub MHz)s for different flares, but is invariant during a particular flare. We measure the mean period P and its standard deviation sigma (sub p) in each type III group, and quantify the degree of periodicity (or phase-coherence) by the dimensionless parameter sigma (sub p)P. The representative sample of 260 type III burst groups shows a mean periodicity of sigma (sub p/P) = 0.37 +/- 0.12, while Monte Carlo simulations of an equivalent set of truly random time series show a distinctly different value of sigma (sub p)P = 0.93 +/- 0.26. This result indicates that the injection of electron beams is coherently modulated by a particle acceleration source which is either compact or has a global organization on a timescale of seconds, in contrast to an incoherent acceleration source, which is stochastic either in time or space. We discuss the constraints on the size of the acceleration region resulting from electron beam

  2. Divided Attention Can Enhance Early-Phase Memory Encoding: The Attentional Boost Effect and Study Trial Duration

    Science.gov (United States)

    Mulligan, Neil W.; Spataro, Pietro

    2015-01-01

    Divided attention during encoding typically produces marked reductions in later memory. The attentional boost effect (ABE) is a surprising variation on this phenomenon. In this paradigm, each study stimulus (e.g., a word) is presented along with a target or a distractor (e.g., different colored circles) in a detection task. Later memory is better…

  3. Efficacy of double arterial phase dynamic magnetic resonance imaging with the sensitivity encoding technique versus dynamic multidetector-row helical computed tomography for detecting hypervascular hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Kumano, Seishi; Okada, Masahiro; Murakami, Takamichi; Uemura, Masahiko; Haraikawa, Toyoaki; Hirata, Masaaki; Kikuchi, Keiichi; Mochizuki, Teruhito; Kim, Tonsok

    2009-01-01

    The aim of this study was to evaluate the efficacy of double arterial phase dynamic magnetic resonance imaging (MRI) with the sensitivity encoding technique (SENSE dynamic MRI) for detection of hypervascular hepatocellular carcinoma (HCC) in comparison with double arterial phase dynamic multidetector-row helical computed tomography (dynamic MDCT). A total of 28 patients with 66 hypervascular HCCs underwent both double arterial SENSE dynamic MRI and dynamic MDCT. The diagnosis of HCC was based on surgical resection (n=7), biopsy (n=10), or a combination of CT during arterial portography (CTAP), CT during hepatic arteriography (CTA), and/or the 6-month follow-up CT (n=49). Based on alternative-free response receiving operating characteristic (ROC) analysis, the diagnostic performance for detecting HCC was compared between double arterial phase SENSE dynamic MRI and double arterial phase dynamic MDCT. The mean sensitivity, positive predictive value, and mean A Z values for hypervascular HCCs were 72%, 80%, and 0.79, respectively, for SENSE dynamic MRI and 66%, 92%, and 0.78, respectively, for dynamic MDCT. The mean sensitivity for double arterial phase SENSE dynamic MRI was higher than that for double arterial phase dynamic MDCT, but the difference was not statistically significant. Double arterial phase SENSE dynamic MRI is as valuable as double arterial phase dynamic MDCT for detecting hypervascular HCCs. (author)

  4. Mathematic model analysis of Gaussian beam propagation through an arbitrary thickness random phase screen.

    Science.gov (United States)

    Tian, Yuzhen; Guo, Jin; Wang, Rui; Wang, Tingfeng

    2011-09-12

    In order to research the statistical properties of Gaussian beam propagation through an arbitrary thickness random phase screen for adaptive optics and laser communication application in the laboratory, we establish mathematic models of statistical quantities, which are based on the Rytov method and the thin phase screen model, involved in the propagation process. And the analytic results are developed for an arbitrary thickness phase screen based on the Kolmogorov power spectrum. The comparison between the arbitrary thickness phase screen and the thin phase screen shows that it is more suitable for our results to describe the generalized case, especially the scintillation index.

  5. Exosomes released in vitro from Epstein-Barr virus (EBV)-infected cells contain EBV-encoded latent phase mRNAs.

    Science.gov (United States)

    Canitano, Andrea; Venturi, Giulietta; Borghi, Martina; Ammendolia, Maria Grazia; Fais, Stefano

    2013-09-01

    EBV is a human herpesvirus associated with a number of malignancies. Both lymphoblastoid cell lines (LCLs), and EBV-infected nasopharyngeal carcinoma (NPC) cells have been demonstrated to release exosomes containing the EBV-encoded latent membrane protein 1 (LMP1), and mature micro-RNAs (EBV-miRNAs). Here we analyze the EBV protein and nucleic acid content of exosomes from different EBV-infected cells (LCL, 721 and Daudi) and we show for the first time that exosomes released from LCLs and 721 also contain EBV-encoded latent phase mRNAs. This confirms and strengthens exosomes pathogenetic potential, and might provide insights for development of novel diagnostic and therapeutic strategies. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Minocycline in Acute Cerebral Hemorrhage: An Early Phase Randomized Trial.

    Science.gov (United States)

    Fouda, Abdelrahman Y; Newsome, Andrea S; Spellicy, Samantha; Waller, Jennifer L; Zhi, Wenbo; Hess, David C; Ergul, Adviye; Edwards, David J; Fagan, Susan C; Switzer, Jeffrey A

    2017-10-01

    Minocycline is under investigation as a neurovascular protective agent for stroke. This study evaluated the pharmacokinetic, anti-inflammatory, and safety profile of minocycline after intracerebral hemorrhage. This study was a single-site, randomized controlled trial of minocycline conducted from 2013 to 2016. Adults ≥18 years with primary intracerebral hemorrhage who could have study drug administered within 24 hours of onset were included. Patients received 400 mg of intravenous minocycline, followed by 400 mg minocycline oral daily for 4 days. Serum concentrations of minocycline after the last oral dose and biomarkers were sampled to determine the peak concentration, half-life, and anti-inflammatory profile. A total of 16 consecutive eligible patients were enrolled, with 8 randomized to minocycline. Although the literature supports a time to peak concentration (T max ) of 1 hour for oral minocycline, the T max was estimated to be at least 6 hours in this cohort. The elimination half-life (available on 7 patients) was 17.5 hours (SD±3.5). No differences were observed in inflammatory biomarkers, hematoma volume, or perihematomal edema. Concentrations remained at neuroprotective levels (>3 mg/L) throughout the dosing interval in 5 of 7 patients. In intracerebral hemorrhage, a 400 mg dose of minocycline was safe and achieved neuroprotective serum concentrations. However, oral administration led to delayed absorption in these critically ill patients and should not be used when rapid, high concentrations are desired. Given the safety and pharmacokinetic profile of minocycline in intracerebral hemorrhage and promising data in the treatment of ischemic stroke, intravenous minocycline is an excellent candidate for a prehospital treatment trial. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01805895. © 2017 American Heart Association, Inc.

  7. Randomly displaced phase distribution design and its advantage in page-data recording of Fourier transform holograms.

    Science.gov (United States)

    Emoto, Akira; Fukuda, Takashi

    2013-02-20

    For Fourier transform holography, an effective random phase distribution with randomly displaced phase segments is proposed for obtaining a smooth finite optical intensity distribution in the Fourier transform plane. Since unitary phase segments are randomly distributed in-plane, the blanks give various spatial frequency components to an image, and thus smooth the spectrum. Moreover, by randomly changing the phase segment size, spike generation from the unitary phase segment size in the spectrum can be reduced significantly. As a result, a smooth spectrum including sidebands can be formed at a relatively narrow extent. The proposed phase distribution sustains the primary functions of a random phase mask for holographic-data recording and reconstruction. Therefore, this distribution is expected to find applications in high-density holographic memory systems, replacing conventional random phase mask patterns.

  8. Phase correction for three-dimensional (3D) diffusion-weighted interleaved EPI using 3D multiplexed sensitivity encoding and reconstruction (3D-MUSER).

    Science.gov (United States)

    Chang, Hing-Chiu; Hui, Edward S; Chiu, Pui-Wai; Liu, Xiaoxi; Chen, Nan-Kuei

    2018-05-01

    Three-dimensional (3D) multiplexed sensitivity encoding and reconstruction (3D-MUSER) algorithm is proposed to reduce aliasing artifacts and signal corruption caused by inter-shot 3D phase variations in 3D diffusion-weighted echo planar imaging (DW-EPI). 3D-MUSER extends the original framework of multiplexed sensitivity encoding (MUSE) to a hybrid k-space-based reconstruction, thereby enabling the correction of inter-shot 3D phase variations. A 3D single-shot EPI navigator echo was used to measure inter-shot 3D phase variations. The performance of 3D-MUSER was evaluated by analyses of point-spread function (PSF), signal-to-noise ratio (SNR), and artifact levels. The efficacy of phase correction using 3D-MUSER for different slab thicknesses and b-values were investigated. Simulations showed that 3D-MUSER could eliminate artifacts because of through-slab phase variation and reduce noise amplification because of SENSE reconstruction. All aliasing artifacts and signal corruption in 3D interleaved DW-EPI acquired with different slab thicknesses and b-values were reduced by our new algorithm. A near-whole brain single-slab 3D DTI with 1.3-mm isotropic voxel acquired at 1.5T was successfully demonstrated. 3D phase correction for 3D interleaved DW-EPI data is made possible by 3D-MUSER, thereby improving feasible slab thickness and maximum feasible b-value. Magn Reson Med 79:2702-2712, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  9. Effects of systematic phase errors on optimized quantum random-walk search algorithm

    International Nuclear Information System (INIS)

    Zhang Yu-Chao; Bao Wan-Su; Wang Xiang; Fu Xiang-Qun

    2015-01-01

    This study investigates the effects of systematic errors in phase inversions on the success rate and number of iterations in the optimized quantum random-walk search algorithm. Using the geometric description of this algorithm, a model of the algorithm with phase errors is established, and the relationship between the success rate of the algorithm, the database size, the number of iterations, and the phase error is determined. For a given database size, we obtain both the maximum success rate of the algorithm and the required number of iterations when phase errors are present in the algorithm. Analyses and numerical simulations show that the optimized quantum random-walk search algorithm is more robust against phase errors than Grover’s algorithm. (paper)

  10. Large leptonic Dirac CP phase from broken democracy with random perturbations

    Science.gov (United States)

    Ge, Shao-Feng; Kusenko, Alexander; Yanagida, Tsutomu T.

    2018-06-01

    A large value of the leptonic Dirac CP phase can arise from broken democracy, where the mass matrices are democratic up to small random perturbations. Such perturbations are a natural consequence of broken residual S3 symmetries that dictate the democratic mass matrices at leading order. With random perturbations, the leptonic Dirac CP phase has a higher probability to attain a value around ± π / 2. Comparing with the anarchy model, broken democracy can benefit from residual S3 symmetries, and it can produce much better, realistic predictions for the mass hierarchy, mixing angles, and Dirac CP phase in both quark and lepton sectors. Our approach provides a general framework for a class of models in which a residual symmetry determines the general features at leading order, and where, in the absence of other fundamental principles, the symmetry breaking appears in the form of random perturbations.

  11. Gene encoding gamma-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kaur, Simarjot; Mishra, Mukti N; Tripathi, Anil K

    2010-07-04

    Carbonic anhydrase (CA) is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (gamma-CAs) are widespread in prokaryotes but their physiological roles remain elusive. At present, only gamma-CA of Methanosarcina thermophila (Cam) has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one beta-CA and two gamma-CAs. One of the putative gamma-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-gamma-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1). Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a gamma-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized gamma-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration.

  12. The random phase transducer in ultrasonic NDT of coarse grain stainless steel

    International Nuclear Information System (INIS)

    Bordier, J.M.; Fink, M.; Le Brun, A.; Cohen-Tenoudji, F.

    1993-11-01

    Ultrasonic NDT of cast stainless steel is known to be difficult due to a huge loss of focussing of the ultrasonic beam, and to a high level speckle noise generated by the coarse grain structure. In this paper, we describe the principle of the ultrasonic random phase transducer. Experimental results are compared with those obtained with a standard spatial compound technique. We show that the random phase transducer is a good tool to characterize the multiple scattering process generated by these materials. (authors). 7 figs., 11 refs

  13. Phase transitions in the random field Ising model in the presence of a transverse field

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, A.; Chakrabarti, B.K. [Saha Institute of Nuclear Physics, Bidhannagar, Calcutta (India); Stinchcombe, R.B. [Saha Institute of Nuclear Physics, Bidhannagar, Calcutta (India); Department of Physics, Oxford (United Kingdom)

    1996-09-07

    We have studied the phase transition behaviour of the random field Ising model in the presence of a transverse (or tunnelling) field. The mean field phase diagram has been studied in detail, and in particular the nature of the transition induced by the tunnelling (transverse) field at zero temperature. Modified hyper-scaling relation for the zero-temperature transition has been derived using the Suzuki-Trotter formalism and a modified 'Harris criterion'. Mapping of the model to a randomly diluted antiferromagnetic Ising model in uniform longitudinal and transverse field is also given. (author)

  14. Displacement encoder

    International Nuclear Information System (INIS)

    Hesketh, T.G.

    1983-01-01

    In an optical encoder, light from an optical fibre input A is encoded by means of the encoding disc and is subsequently collected for transmission via optical fibre B. At some point in the optical path between the fibres A and B, the light is separated into component form by means of a filtering or dispersive system and each colour component is associated with a respective one of the coding channels of the disc. In this way, the significance of each bit of the coded information is represented by a respective colour thereby enabling the components to be re-combined for transmission by the fibre B without loss of information. (author)

  15. Performance Analysis of Spectral-Phase-Encoded Optical CDMA System Using Two-Photon-Absorption Receiver Structure for Asynchronous and Slot-Level Synchronous Transmitters

    Science.gov (United States)

    Jamshidi, Kambiz; Salehi, Jawad A.

    2007-06-01

    In this paper, we analyze the performance of a nonlinear two-photon-absorption (TPA) receiver and compare its performance with that of a single-photon-absorption (SPA) receiver in the context of spectral-phase-encoded optical code-division multiple access (CDMA) technique. The performances for the above systems are evaluated for two different transmission scenarios, namely, asynchronous and slot-level synchronous transmitters. Performance evaluation includes different sources of degradation such as multiple-access interference, noise due to optical amplification, shot noise, and thermal noise. In obtaining the performance, the mean and variance of the received signal in each of the above techniques are derived, and bit error rate is obtained using Gaussian approximation. In general, it is shown that TPA receivers are superior in performance with respect to SPA receivers when the receiver employs a much slower photodetector in comparison with the laser's transmitted pulse duration. This, indeed, is the reason behind the choice of nonlinear receivers, such as TPA, in most spectral-phase-encoded optical CDMA systems.

  16. Deterministic matrices matching the compressed sensing phase transitions of Gaussian random matrices

    OpenAIRE

    Monajemi, Hatef; Jafarpour, Sina; Gavish, Matan; Donoho, David L.; Ambikasaran, Sivaram; Bacallado, Sergio; Bharadia, Dinesh; Chen, Yuxin; Choi, Young; Chowdhury, Mainak; Chowdhury, Soham; Damle, Anil; Fithian, Will; Goetz, Georges; Grosenick, Logan

    2012-01-01

    In compressed sensing, one takes samples of an N-dimensional vector using an matrix A, obtaining undersampled measurements . For random matrices with independent standard Gaussian entries, it is known that, when is k-sparse, there is a precisely determined phase transition: for a certain region in the (,)-phase diagram, convex optimization typically finds the sparsest solution, whereas outside that region, it typically fails. It has been shown empirically that the same property—with the ...

  17. Does quasi-long-range order in the two-dimensional XY model really survive weak random phase fluctuations?

    International Nuclear Information System (INIS)

    Mudry, Christopher; Wen Xiaogang

    1999-01-01

    Effective theories for random critical points are usually non-unitary, and thus may contain relevant operators with negative scaling dimensions. To study the consequences of the existence of negative-dimensional operators, we consider the random-bond XY model. It has been argued that the XY model on a square lattice, when weakly perturbed by random phases, has a quasi-long-range ordered phase (the random spin wave phase) at sufficiently low temperatures. We show that infinitely many relevant perturbations to the proposed critical action for the random spin wave phase were omitted in all previous treatments. The physical origin of these perturbations is intimately related to the existence of broadly distributed correlation functions. We find that those relevant perturbations do enter the Renormalization Group equations, and affect critical behavior. This raises the possibility that the random XY model has no quasi-long-range ordered phase and no Kosterlitz-Thouless (KT) phase transition

  18. Deterministic matrices matching the compressed sensing phase transitions of Gaussian random matrices

    Science.gov (United States)

    Monajemi, Hatef; Jafarpour, Sina; Gavish, Matan; Donoho, David L.; Ambikasaran, Sivaram; Bacallado, Sergio; Bharadia, Dinesh; Chen, Yuxin; Choi, Young; Chowdhury, Mainak; Chowdhury, Soham; Damle, Anil; Fithian, Will; Goetz, Georges; Grosenick, Logan; Gross, Sam; Hills, Gage; Hornstein, Michael; Lakkam, Milinda; Lee, Jason; Li, Jian; Liu, Linxi; Sing-Long, Carlos; Marx, Mike; Mittal, Akshay; Monajemi, Hatef; No, Albert; Omrani, Reza; Pekelis, Leonid; Qin, Junjie; Raines, Kevin; Ryu, Ernest; Saxe, Andrew; Shi, Dai; Siilats, Keith; Strauss, David; Tang, Gary; Wang, Chaojun; Zhou, Zoey; Zhu, Zhen

    2013-01-01

    In compressed sensing, one takes samples of an N-dimensional vector using an matrix A, obtaining undersampled measurements . For random matrices with independent standard Gaussian entries, it is known that, when is k-sparse, there is a precisely determined phase transition: for a certain region in the (,)-phase diagram, convex optimization typically finds the sparsest solution, whereas outside that region, it typically fails. It has been shown empirically that the same property—with the same phase transition location—holds for a wide range of non-Gaussian random matrix ensembles. We report extensive experiments showing that the Gaussian phase transition also describes numerous deterministic matrices, including Spikes and Sines, Spikes and Noiselets, Paley Frames, Delsarte-Goethals Frames, Chirp Sensing Matrices, and Grassmannian Frames. Namely, for each of these deterministic matrices in turn, for a typical k-sparse object, we observe that convex optimization is successful over a region of the phase diagram that coincides with the region known for Gaussian random matrices. Our experiments considered coefficients constrained to for four different sets , and the results establish our finding for each of the four associated phase transitions. PMID:23277588

  19. Interaction between local parameters of two-phase flow and random forces on a cylinder

    International Nuclear Information System (INIS)

    Sylviane Pascal-Ribot; Yves Blanchet; Franck Baj; Phillippe Piteau

    2005-01-01

    Full text of publication follows: In the frame of assessments of steam generator tube bundle vibrations, a study was conducted in order to investigate the effects of an air/water flow on turbulent buffeting forces induced on a cylinder. The main purpose is to relate the physical parameters characterizing an air/water two-phase crossflow with the structural loading of a fixed cylindrical tube. In this first approach, the experiments are carried out in a rectangular acrylic test section supplied with a vertical upward bubbly flow. This flow is transversally impeded by a fixed rigid 12,15 mm diameter cylinder. Different turbulence grids are used in order to modify two-phase characteristics such as bubble diameter, void fraction profile, fluctuation parameters. Preliminarily, a dimensional analysis of fluid-structure interaction under two-phase turbulent solicitations has enabled to identify a list of physically relevant variables which must be measured to evaluate the random forces. The meaning of these relevant parameters as well as the effect of flow patterns are discussed. Direct measurements of two-phase flow parameters are performed simultaneously with measurements of forces exerted on the cylinder. The main descriptive parameters of a two-phase flow are measured using a bi-optical probe, in particular void fraction profiles, interfacial velocities, bubble diameters, void fraction fluctuations. In the same time, the magnitude of random forces caused by two-phase flow is measured with a force transducer. A thorough analysis of the experimental data is then undertaken in order to correlate physical two-phase mechanisms with the random forces exerted on the cylinder. The hypotheses made while applying the dimensional analysis are verified and their pertinence is discussed. Finally, physical parameters involved in random buffeting forces applied on a transverse tube are proposed to scale the spectral magnitude of these forces and comparisons with other authors

  20. Optimized random phase approximation for the structure of liquid alkali metals as electron-ion plasmas

    International Nuclear Information System (INIS)

    Senatore, G.; Tosi, M.P.; Trieste Univ.

    1981-08-01

    The purpose of this letter is to stress that the way towards an unconventional optimized-random-phase-approximation (ORPA) approach to the structure of liquid metals is indicated, and in fact already a good first-order solution for such an approach is provided

  1. Calculation of thermodynamic properties using the random-phase approximation: alpha-N2

    NARCIS (Netherlands)

    Jansen, A.P.J.; Schoorl, R.

    1988-01-01

    The random-phase approximation (RPA) for molecular crystals is extended in order to calculate thermodynamic properties. A recursion formula for thermodynamic averages of products of mean-field excitation and deexcitation operators is derived. With this formula the thermodynamic average of any

  2. First-order corrections to random-phase approximation GW calculations in silicon and diamond

    NARCIS (Netherlands)

    Ummels, R.T.M.; Bobbert, P.A.; van Haeringen, W.

    1998-01-01

    We report on ab initio calculations of the first-order corrections in the screened interaction W to the random-phase approximation polarizability and to the GW self-energy, using a noninteracting Green's function, for silicon and diamond. It is found that the first-order vertex and self-consistency

  3. Nanostructure-property relations for phase-change random access memory (PCRAM) line cells

    NARCIS (Netherlands)

    Kooi, B. J.; Oosthoek, J. L. M.; Verheijen, M. A.; Kaiser, M.; Jedema, F. J.; Gravesteijn, D. J.

    2012-01-01

    Phase-change random access memory (PCRAM) cells have been studied extensively using electrical characterization and rather limited by detailed structure characterization. The combination of these two characterization techniques has hardly been exploited and it is the focus of the present work.

  4. The generation of 68 Gbps quantum random number by measuring laser phase fluctuations

    International Nuclear Information System (INIS)

    Nie, You-Qi; Liu, Yang; Zhang, Jun; Pan, Jian-Wei; Huang, Leilei; Payne, Frank

    2015-01-01

    The speed of a quantum random number generator is essential for practical applications, such as high-speed quantum key distribution systems. Here, we push the speed of a quantum random number generator to 68 Gbps by operating a laser around its threshold level. To achieve the rate, not only high-speed photodetector and high sampling rate are needed but also a very stable interferometer is required. A practical interferometer with active feedback instead of common temperature control is developed to meet the requirement of stability. Phase fluctuations of the laser are measured by the interferometer with a photodetector and then digitalized to raw random numbers with a rate of 80 Gbps. The min-entropy of the raw data is evaluated by modeling the system and is used to quantify the quantum randomness of the raw data. The bias of the raw data caused by other signals, such as classical and detection noises, can be removed by Toeplitz-matrix hashing randomness extraction. The final random numbers can pass through the standard randomness tests. Our demonstration shows that high-speed quantum random number generators are ready for practical usage

  5. Deep Learning the Quantum Phase Transitions in Random Electron Systems: Applications to Three Dimensions

    Science.gov (United States)

    Ohtsuki, Tomi; Ohtsuki, Tomoki

    2017-04-01

    Three-dimensional random electron systems undergo quantum phase transitions and show rich phase diagrams. Examples of the phases are the band gap insulator, Anderson insulator, strong and weak topological insulators, Weyl semimetal, and diffusive metal. As in the previous paper on two-dimensional quantum phase transitions [J. Phys. Soc. Jpn. 85, 123706 (2016)], we use an image recognition algorithm based on a multilayered convolutional neural network to identify which phase the eigenfunction belongs to. The Anderson model for localization-delocalization transition, the Wilson-Dirac model for topological insulators, and the layered Chern insulator model for Weyl semimetal are studied. The situation where the standard transfer matrix approach is not applicable is also treated by this method.

  6. The phase diagrams of a ferromagnetic thin film in a random magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Zaim, N.; Zaim, A., E-mail: ah_zaim@yahoo.fr; Kerouad, M., E-mail: m.kerouad@fs-umi.ac.ma

    2016-10-07

    In this paper, the magnetic properties and the phase diagrams of a ferromagnetic thin film with a thickness N in a random magnetic field (RMF) are investigated by using the Monte Carlo simulation technique based on the Metropolis algorithm. The effects of the RMF and the surface exchange interaction on the critical behavior are studied. A variety of multicritical points such as tricritical points, isolated critical points, and triple points are obtained. It is also found that the double reentrant phenomenon can appear for appropriate values of the system parameters. - Highlights: • Phase diagrams of a ferromagnetic thin film are examined by the Monte Carlo simulation. • The effect of the random magnetic field on the magnetic properties is studied. • Different types of the phase diagrams are obtained. • The dependence of the magnetization and susceptibility on the temperature are investigated.

  7. Arbitrary-step randomly delayed robust filter with application to boost phase tracking

    Science.gov (United States)

    Qin, Wutao; Wang, Xiaogang; Bai, Yuliang; Cui, Naigang

    2018-04-01

    The conventional filters such as extended Kalman filter, unscented Kalman filter and cubature Kalman filter assume that the measurement is available in real-time and the measurement noise is Gaussian white noise. But in practice, both two assumptions are invalid. To solve this problem, a novel algorithm is proposed by taking the following four steps. At first, the measurement model is modified by the Bernoulli random variables to describe the random delay. Then, the expression of predicted measurement and covariance are reformulated, which could get rid of the restriction that the maximum number of delay must be one or two and the assumption that probabilities of Bernoulli random variables taking the value one are equal. Next, the arbitrary-step randomly delayed high-degree cubature Kalman filter is derived based on the 5th-degree spherical-radial rule and the reformulated expressions. Finally, the arbitrary-step randomly delayed high-degree cubature Kalman filter is modified to the arbitrary-step randomly delayed high-degree cubature Huber-based filter based on the Huber technique, which is essentially an M-estimator. Therefore, the proposed filter is not only robust to the randomly delayed measurements, but robust to the glint noise. The application to the boost phase tracking example demonstrate the superiority of the proposed algorithms.

  8. Gene encoding γ-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7

    Science.gov (United States)

    2010-01-01

    Background Carbonic anhydrase (CA) is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (γ-CAs) are widespread in prokaryotes but their physiological roles remain elusive. At present, only γ-CA of Methanosarcina thermophila (Cam) has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one β-CA and two γ-CAs. Results One of the putative γ-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-γ-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1). Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. Conclusions This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a γ-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized γ-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration. PMID:20598158

  9. Gene encoding γ-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7

    Directory of Open Access Journals (Sweden)

    Mishra Mukti N

    2010-07-01

    Full Text Available Abstract Background Carbonic anhydrase (CA is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (γ-CAs are widespread in prokaryotes but their physiological roles remain elusive. At present, only γ-CA of Methanosarcina thermophila (Cam has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one β-CA and two γ-CAs. Results One of the putative γ-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-γ-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1. Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. Conclusions This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a γ-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized γ-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration.

  10. Lensless digital holography with diffuse illumination through a pseudo-random phase mask.

    Science.gov (United States)

    Bernet, Stefan; Harm, Walter; Jesacher, Alexander; Ritsch-Marte, Monika

    2011-12-05

    Microscopic imaging with a setup consisting of a pseudo-random phase mask, and an open CMOS camera, without an imaging objective, is demonstrated. The pseudo random phase mask acts as a diffuser for an incoming laser beam, scattering a speckle pattern to a CMOS chip, which is recorded once as a reference. A sample which is afterwards inserted somewhere in the optical beam path changes the speckle pattern. A single (non-iterative) image processing step, comparing the modified speckle pattern with the previously recorded one, generates a sharp image of the sample. After a first calibration the method works in real-time and allows quantitative imaging of complex (amplitude and phase) samples in an extended three-dimensional volume. Since no lenses are used, the method is free from lens abberations. Compared to standard inline holography the diffuse sample illumination improves the axial sectioning capability by increasing the effective numerical aperture in the illumination path, and it suppresses the undesired so-called twin images. For demonstration, a high resolution spatial light modulator (SLM) is programmed to act as the pseudo-random phase mask. We show experimental results, imaging microscopic biological samples, e.g. insects, within an extended volume at a distance of 15 cm with a transverse and longitudinal resolution of about 60 μm and 400 μm, respectively.

  11. Disorder Induced Dynamic Equilibrium Localization and Random Phase Steps of Bose—Einstein Condensates

    International Nuclear Information System (INIS)

    Duan Ya-Fan; Xu Zhen; Qian Jun; Sun Jian-Fang; Jiang Bo-Nan; Hong Tao

    2011-01-01

    We numerically analyze the dynamic behavior of Bose—Einstein condensate (BEC) in a one-dimensional disordered potential before it completely loses spatial quantum coherence. We find that both the disorder statistics and the atom interactions produce remarkable effects on localization. We also find that the single phase of the initial condensate is broken into many small pieces while the system approaches localization, showing a counter-intuitive step-wise phase but not a thoroughly randomized phase. Although the condensates as a whole show less flow and expansion, the currents between adjacent phase steps retain strong time dependence. Thus we show explicitly that the localization of a finite size Bose—Einstein condensate is a dynamic equilibrium state. (general)

  12. Role of an encapsulating layer for reducing resistance drift in phase change random access memory

    Directory of Open Access Journals (Sweden)

    Bo Jin

    2014-12-01

    Full Text Available Phase change random access memory (PCRAM devices exhibit a steady increase in resistance in the amorphous phase upon aging and this resistance drift phenomenon directly affects the device reliability. A stress relaxation model is used here to study the effect of a device encapsulating layer material in addressing the resistance drift phenomenon in PCRAM. The resistance drift can be increased or decreased depending on the biaxial moduli of the phase change material (YPCM and the encapsulating layer material (YELM according to the stress relationship between them in the drift regime. The proposed model suggests that the resistance drift can be effectively reduced by selecting a proper material as an encapsulating layer. Moreover, our model explains that reducing the size of the phase change material (PCM while fully reset and reducing the amorphous/crystalline ratio in PCM help to improve the resistance drift, and thus opens an avenue for highly reliable multilevel PCRAM applications.

  13. Impulse attack-free four random phase mask encryption based on a 4-f optical system.

    Science.gov (United States)

    Kumar, Pramod; Joseph, Joby; Singh, Kehar

    2009-04-20

    Optical encryption methods based on double random phase encryption (DRPE) have been shown to be vulnerable to different types of attacks. The Fourier plane random phase mask (RPM), which is the most important key, can be cracked with a single impulse function attack. Such an attack is viable because the Fourier transform of a delta function is a unity function. Formation of a unity function can be avoided if RPMs are placed in front of both lenses in a 4-f optical setup, thereby protecting the DRPE from an impulse attack. We have performed numerical simulations to verify the proposed scheme. Resistance of this scheme is checked against the brute force and the impulse function attacks. The experimental results validate the feasibility of the scheme.

  14. Reduction of Musical Noise in Spectral Subtraction Method Using Subframe Phase Randomization

    Energy Technology Data Exchange (ETDEWEB)

    Seok, J.W.; Bae, K.S. [Kyungpook National University, Taegu (Korea)

    1999-06-01

    The Subframe phase randomization method is applied to the spectral subtraction method to reduce the musical noise in nonvoicing region after speech enhancement. The musical noise in the spectral subtraction method is the result of the narrowband tonal components that appearing somewhat periodically in the spectrogram of unvoiced and silence regions. Thus each synthesis frame in nonvoicing region is divided into several subframes to broaden the narrowband spectrum, and then phases of silence and unvoiced regions are randomized to eliminate the tonal components in the spectrum while keeping the shape of the amplitude spectrum. Performance assessments based on visual inspection of spectrogram, objective measure, and informal subjective listening tests demonstrate the superiority of the proposed algorithm. (author). 7 refs., 5 figs.

  15. Beyond the Random Phase Approximation for the Electron Correlation Energy: The Importance of Single Excitations

    OpenAIRE

    Ren, Xinguo; Rinke, Patrick; Tkatchenko, Alexandre; Scheffler, Matthias

    2010-01-01

    The random-phase approximation (RPA) for the electron correlation energy, combined with the exact-exchange (EX) energy, represents the state-of-the-art exchange-correlation functional within density-functional theory. However, the standard RPA practice-evaluating both the EX and the RPA correlation energies using Kohn-Sham (KS) orbitals from local or semilocal exchange-correlation functionals-leads to a systematic underbinding of molecules and solids. Here we demonstrate that this behavior ca...

  16. Improved light extraction from white organic light-emitting devices using a binary random phase array

    Energy Technology Data Exchange (ETDEWEB)

    Inada, Yasuhisa, E-mail: inada.yasuhisa@jp.panasonic.com; Nishiwaki, Seiji; Hirasawa, Taku; Nakamura, Yoshitaka; Hashiya, Akira; Wakabayashi, Shin-ichi; Suzuki, Masa-aki [R and D Division, Panasonic Corporation, 1006 Kadoma, Kadoma City, Osaka 571-8501 (Japan); Matsuzaki, Jumpei [Device Development Center, Eco Solutions Company, Panasonic Corporation, 1048 Kadoma, Osaka 571-8686 Japan (Japan)

    2014-02-10

    We have developed a binary random phase array (BRPA) to improve the light extraction performance of white organic light-emitting devices (WOLEDs). We demonstrated that the scattering of incoming light can be controlled by employing diffraction optics to modify the structural parameters of the BRPA. Applying a BRPA to the substrate of the WOLED leads to enhanced extraction efficiency and suppression of angle-dependent color changes. Our systematic study clarifies the effect of scattering on the light extraction of WOLEDs.

  17. Calculating beta decay in the deformed self-consistent quasiparticle random phase approximation

    Energy Technology Data Exchange (ETDEWEB)

    Engel, Jonathan, E-mail: engelj@physics.unc.edu [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Mustonen, M. T., E-mail: mika.mustonen@yale.edu [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06052 (United States)

    2016-06-21

    We discuss a recent global calculation of beta-decay rates in the self-consistent Skyrme quasiparticle random phase approximation (QRPA), with axially symmetric nuclear deformation treated explicitly. The calculation makes makes use of the finite-amplitude method, first proposed by Nakatsukasa and collaborators, to reduce computation time. The results are comparable in quality to those of several other global QRPA calculations. The QRPA may have reached the limit of its accuracy.

  18. Improved light extraction from white organic light-emitting devices using a binary random phase array

    International Nuclear Information System (INIS)

    Inada, Yasuhisa; Nishiwaki, Seiji; Hirasawa, Taku; Nakamura, Yoshitaka; Hashiya, Akira; Wakabayashi, Shin-ichi; Suzuki, Masa-aki; Matsuzaki, Jumpei

    2014-01-01

    We have developed a binary random phase array (BRPA) to improve the light extraction performance of white organic light-emitting devices (WOLEDs). We demonstrated that the scattering of incoming light can be controlled by employing diffraction optics to modify the structural parameters of the BRPA. Applying a BRPA to the substrate of the WOLED leads to enhanced extraction efficiency and suppression of angle-dependent color changes. Our systematic study clarifies the effect of scattering on the light extraction of WOLEDs

  19. Neutrino-nucleus reaction rates based on the relativistic quasiparticle random phase approximation

    International Nuclear Information System (INIS)

    Paar, N.; Vretenar, D.; Marketin, T.; Ring, P.

    2008-01-01

    Neutrino-nucleus cross sections are described in a novel theoretical framework where the weak interaction of leptons with hadrons is expressed in the standard current-current form, the nuclear ground state is described in the relativistic Hartree-Bogoliubov model, and the relevant transitions to excited states are calculated in the relativistic quasiparticle random phase approximation. The model is employed in studies of neutrino-nucleus reactions in several test cases

  20. Development of hydrogel TentaGel shell-core beads for ultrahigh throughput solution-phase screening of encoded OBOC combinatorial small molecule libraries.

    Science.gov (United States)

    Baek, Hyoung Gee; Liu, Ruiwu; Lam, Kit S

    2009-01-01

    The one-bead one-compound (OBOC) combinatorial library method enables the rapid generation and screening of millions of discrete chemical compounds on beads. Most of the OBOC screening methods require the library compounds to remain tethered to the bead during screening process. Methods have also been developed to release library compounds from immobilized beads for in situ solution phase or "lawn" assays. However, this latter approach, while extremely powerful, is severely limited by the lack of suitable solid supports for such assays. Here, we report on the development of a novel hydrogel TentaGel shell-core (HTSC) bead in which hydrogel is grafted onto the polystyrene-based TentaGel (TG) bead as an outer shell (5-80 mum thick) via free radical surface-initiated polymerization. This novel shell-core bilayer resin enables the preparation of encoded OBOC combinatorial small molecule libraries, such that the library compounds reside on the highly hydrophilic outer layer and the coding tags reside in the polystyrene-based TG core. Using fluorescein as a model small molecule compound, we have demonstrated that fluorescein molecules that have been linked covalently to the hydrogel shell via a disulfide bond could readily diffuse out of the hydrogel layer into the bead surrounding after reduction with dithiothreitol. In contrast, under identical condition, the released fluorescein molecules remained bound to unmodified TG bead. We have prepared an encoded OBOC small molecule library on the novel shell-core beads and demonstrated that the beads can be readily decoded.

  1. Phase Diagram in a Random Mixture of Two Antiferromagnets with Competing Spin Anisotropies. I

    Science.gov (United States)

    Someya, Yoshiko

    1981-12-01

    The phase diagram of a random mixture of two antiferromagnets with competing spin anisotropies (A1-xBx) has been analyzed by extending the theory of Matsubara and Inawashiro, and Oguchi and Ishikawa. In the model assumed, the anisotropy energies are expressed by the anisotropic exchange interactions. According to this formulation, it has been shown that the concentration dependence of TN becomes a function of \\includegraphics{dummy.eps}, where P, Q=A, B; SP is a magnitude of P-spin, and JPQη is a η component of exchange integral between P- and Q-spin). Further, the phase boundary between an AF phase and an OAF (oblique antiferromagnetic) phase at T{=}0 K has been shown to be determined by α({\\equiv}SB/SA), if \\includegraphics{dummy.eps} are given. The obtained phase diagrams for Fe1-xCoxCl2, K2Mn1-xFexF4 and Fe1-xCoxCl2\\cdot2H2O are compared with the experimental ones.

  2. Ga-doped indium oxide nanowire phase change random access memory cells

    International Nuclear Information System (INIS)

    Jin, Bo; Lee, Jeong-Soo; Lim, Taekyung; Ju, Sanghyun; Latypov, Marat I; Kim, Hyoung Seop; Meyyappan, M

    2014-01-01

    Phase change random access memory (PCRAM) devices are usually constructed using tellurium based compounds, but efforts to seek other materials providing desirable memory characteristics have continued. We have fabricated PCRAM devices using Ga-doped In 2 O 3 nanowires with three different Ga compositions (Ga/(In+Ga) atomic ratio: 2.1%, 11.5% and 13.0%), and investigated their phase switching properties. The nanowires (∼40 nm in diameter) can be repeatedly switched between crystalline and amorphous phases, and Ga concentration-dependent memory switching behavior in the nanowires was observed with ultra-fast set/reset rates of 80 ns/20 ns, which are faster than for other competitive phase change materials. The observations of fast set/reset rates and two distinct states with a difference in resistance of two to three orders of magnitude appear promising for nonvolatile information storage. Moreover, we found that increasing the Ga concentration can reduce the power consumption and resistance drift; however, too high a level of Ga doping may cause difficulty in achieving the phase transition. (paper)

  3. Dasatinib or imatinib in newly diagnosed chronic-phase chronic myeloid leukemia : 2-year follow-up from a randomized phase 3 trial (DASISION)

    NARCIS (Netherlands)

    Kantarjian, Hagop M.; Shah, Neil P.; Cortes, Jorge E.; Baccarani, Michele; Agarwal, Mohan B.; Soledad Undurraga, Maria; Wang, Jianxiang; Kassack Ipina, Juan Julio; Kim, Dong-Wook; Ogura, Michinori; Pavlovsky, Carolina; Junghanss, Christian; Milone, Jorge H.; Nicolini, Franck E.; Robak, Tadeusz; Van Droogenbroeck, Jan; Vellenga, Edo; Bradley-Garelik, M. Brigid; Zhu, Chao; Hochhaus, Andreas

    2012-01-01

    Dasatinib is a highly potent BCR-ABL inhibitor with established efficacy and safety in imatinib-resistant/-intolerant patients with chronic myeloid leukemia (CML). In the phase 3 DASISION trial, patients with newly diagnosed chronic-phase (CP) CML were randomized to receive dasatinib 100 mg (n =

  4. Dispersive and Covalent Interactions between Graphene and Metal Surfaces from the Random Phase Approximation

    DEFF Research Database (Denmark)

    Olsen, Thomas; Yan, Jun; Mortensen, Jens Jørgen

    2011-01-01

    We calculate the potential energy surfaces for graphene adsorbed on Cu(111), Ni(111), and Co(0001) using density functional theory and the random phase approximation (RPA). For these adsorption systems covalent and dispersive interactions are equally important and while commonly used approximations...... for exchange-correlation functionals give inadequate descriptions of either van der Waals or chemical bonds, RPA accounts accurately for both. It is found that the adsorption is a delicate competition between a weak chemisorption minimum close to the surface and a physisorption minimum further from the surface....

  5. Finite-temperature random-phase approximation for spectroscopic properties of neon plasmas

    International Nuclear Information System (INIS)

    Colgan, J.; Collins, L. A.; Fontes, C. J.; Csanak, G.

    2007-01-01

    A finite-temperature random-phase approximation (FTRPA) is applied to calculate oscillator strengths for excitations in hot and dense plasmas. Application of the FTRPA provides a convenient, self-consistent method with which to explore coupled-channel effects of excited electrons in a dense plasma. We present FTRPA calculations that include coupled-channel effects. The inclusion of these effects is shown to cause significant differences in the oscillator strength for a prototypical case of 1 P excitation in neon when compared with single-channel and with average-atom calculations. Trends as a function of temperature and density are also discussed

  6. Color image encryption using random transforms, phase retrieval, chaotic maps, and diffusion

    Science.gov (United States)

    Annaby, M. H.; Rushdi, M. A.; Nehary, E. A.

    2018-04-01

    The recent tremendous proliferation of color imaging applications has been accompanied by growing research in data encryption to secure color images against adversary attacks. While recent color image encryption techniques perform reasonably well, they still exhibit vulnerabilities and deficiencies in terms of statistical security measures due to image data redundancy and inherent weaknesses. This paper proposes two encryption algorithms that largely treat these deficiencies and boost the security strength through novel integration of the random fractional Fourier transforms, phase retrieval algorithms, as well as chaotic scrambling and diffusion. We show through detailed experiments and statistical analysis that the proposed enhancements significantly improve security measures and immunity to attacks.

  7. Reconstruction of photon number conditioned states using phase randomized homodyne measurements

    International Nuclear Information System (INIS)

    Chrzanowski, H M; Assad, S M; Bernu, J; Hage, B; Lam, P K; Symul, T; Lund, A P; Ralph, T C

    2013-01-01

    We experimentally demonstrate the reconstruction of a photon number conditioned state without using a photon number discriminating detector. By using only phase randomized homodyne measurements, we reconstruct up to the three photon subtracted squeezed vacuum state. The reconstructed Wigner functions of these states show regions of pronounced negativity, signifying the non-classical nature of the reconstructed states. The techniques presented allow for complete characterization of the role of a conditional measurement on an ensemble of states, and might prove useful in systems where photon counting still proves technically challenging. (paper)

  8. Random projections and the optimization of an algorithm for phase retrieval

    International Nuclear Information System (INIS)

    Elser, Veit

    2003-01-01

    Iterative phase retrieval algorithms typically employ projections onto constraint subspaces to recover the unknown phases in the Fourier transform of an image, or, in the case of x-ray crystallography, the electron density of a molecule. For a general class of algorithms, where the basic iteration is specified by the difference map, solutions are associated with fixed points of the map, the attractive character of which determines the effectiveness of the algorithm. The behaviour of the difference map near fixed points is controlled by the relative orientation of the tangent spaces of the two constraint subspaces employed by the map. Since the dimensionalities involved are always large in practical applications, it is appropriate to use random matrix theory ideas to analyse the average-case convergence at fixed points. Optimal values of the γ parameters of the difference map are found which differ somewhat from the values previously obtained on the assumption of orthogonal tangent spaces

  9. Statistical properties of laser hot spots produced by a random phase plate

    International Nuclear Information System (INIS)

    Rose, H.A.; DuBois, D.F.

    1993-01-01

    A quantitative theory of laser hot spots, which control plasma instabilities in real laser--plasma interactions, is presented in the case of random phase plate (RPP) optics. It is shown that the probability density of intense hot spots with intensity I, P hot (I), is given by P hot (I)∼(I/I 0 2 )exp(-I/I 0 ) where I 0 is the average intensity, and that the detailed amplitude and phase variation of the laser field in the vicinity of an intense hot spot is uniquely specified by the optics and is deterministic. These hot spots may be the source of below threshold stimulated Raman scattering (SRS) and its variation with I 0 is shown to be super exponential. A brief preview of a quantitative nonlinear theory of hot-spot-induced laser filamentation is presented

  10. Workshop on Strategic Behavior and Phase Transitions in Random and Complex Combinatorial Structures : Extended Abstracts

    CERN Document Server

    Kirousis, Lefteris; Ortiz-Gracia, Luis; Serna, Maria

    2017-01-01

    This book is divided into two parts, the first of which seeks to connect the phase transitions of various disciplines, including game theory, and to explore the synergies between statistical physics and combinatorics. Phase Transitions has been an active multidisciplinary field of research, bringing together physicists, computer scientists and mathematicians. The main research theme explores how atomic agents that act locally and microscopically lead to discontinuous macroscopic changes. Adopting this perspective has proven to be especially useful in studying the evolution of random and usually complex or large combinatorial objects (like networks or logic formulas) with respect to discontinuous changes in global parameters like connectivity, satisfiability etc. There is, of course, an obvious strategic element in the formation of a transition: the atomic agents “selfishly” seek to optimize a local parameter. However, up to now this game-theoretic aspect of abrupt, locally triggered changes had not been e...

  11. High energy X-ray phase and dark-field imaging using a random absorption mask.

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Cai, Biao; Sawhney, Kawal

    2016-07-28

    High energy X-ray imaging has unique advantage over conventional X-ray imaging, since it enables higher penetration into materials with significantly reduced radiation damage. However, the absorption contrast in high energy region is considerably low due to the reduced X-ray absorption cross section for most materials. Even though the X-ray phase and dark-field imaging techniques can provide substantially increased contrast and complementary information, fabricating dedicated optics for high energies still remain a challenge. To address this issue, we present an alternative X-ray imaging approach to produce transmission, phase and scattering signals at high X-ray energies by using a random absorption mask. Importantly, in addition to the synchrotron radiation source, this approach has been demonstrated for practical imaging application with a laboratory-based microfocus X-ray source. This new imaging method could be potentially useful for studying thick samples or heavy materials for advanced research in materials science.

  12. Effects of the randomly distributed magnetic field on the phase diagrams of the Ising Nanowire II: Continuous distributions

    International Nuclear Information System (INIS)

    Akıncı, Ümit

    2012-01-01

    The effect of the random magnetic field distribution on the phase diagrams and ground state magnetizations of the Ising nanowire has been investigated with effective field theory with correlations. Gaussian distribution has been chosen as a random magnetic field distribution. The variation of the phase diagrams with that distribution parameters has been obtained and some interesting results have been found such as disappearance of the reentrant behavior and first order transitions which appear in the case of discrete distributions. Also for single and double Gaussian distributions, ground state magnetizations for different distribution parameters have been determined which can be regarded as separate partially ordered phases of the system. - Highlights: ► We give the phase diagrams of the Ising nanowire under the continuous randomly distributed magnetic field. ► Ground state magnetization values obtained. ► Different partially ordered phases observed.

  13. A random phased array device for delivery of high intensity focused ultrasound

    International Nuclear Information System (INIS)

    Hand, J W; Shaw, A; Sadhoo, N; Rajagopal, S; Dickinson, R J; Gavrilov, L R

    2009-01-01

    Randomized phased arrays can offer electronic steering of a single focus and simultaneous multiple foci concomitant with low levels of secondary maxima and are potentially useful as sources of high intensity focused ultrasound (HIFU). This work describes laboratory testing of a 1 MHz random phased array consisting of 254 elements on a spherical shell of radius of curvature 130 mm and diameter 170 mm. Acoustic output power and efficiency are measured for a range of input electrical powers, and field distributions for various single- and multiple-focus conditions are evaluated by a novel technique using an infrared camera to provide rapid imaging of temperature changes on the surface of an absorbing target. Experimental results show that the array can steer a single focus laterally to at least ±15 mm off axis and axially to more than ±15 mm from the centre of curvature of the array and patterns of four and five simultaneous foci ±10 mm laterally and axially whilst maintaining low intensity levels in secondary maxima away from the targeted area in good agreement with linear theoretical predictions. Experiments in which pork meat was thermally ablated indicate that contiguous lesions several cm 3 in volume can be produced using the patterns of multiple foci.

  14. A random phased array device for delivery of high intensity focused ultrasound.

    Science.gov (United States)

    Hand, J W; Shaw, A; Sadhoo, N; Rajagopal, S; Dickinson, R J; Gavrilov, L R

    2009-10-07

    Randomized phased arrays can offer electronic steering of a single focus and simultaneous multiple foci concomitant with low levels of secondary maxima and are potentially useful as sources of high intensity focused ultrasound (HIFU). This work describes laboratory testing of a 1 MHz random phased array consisting of 254 elements on a spherical shell of radius of curvature 130 mm and diameter 170 mm. Acoustic output power and efficiency are measured for a range of input electrical powers, and field distributions for various single- and multiple-focus conditions are evaluated by a novel technique using an infrared camera to provide rapid imaging of temperature changes on the surface of an absorbing target. Experimental results show that the array can steer a single focus laterally to at least +/-15 mm off axis and axially to more than +/-15 mm from the centre of curvature of the array and patterns of four and five simultaneous foci +/-10 mm laterally and axially whilst maintaining low intensity levels in secondary maxima away from the targeted area in good agreement with linear theoretical predictions. Experiments in which pork meat was thermally ablated indicate that contiguous lesions several cm(3) in volume can be produced using the patterns of multiple foci.

  15. Multi-kW coherent combining of fiber lasers seeded with pseudo random phase modulated light

    Science.gov (United States)

    Flores, Angel; Ehrehreich, Thomas; Holten, Roger; Anderson, Brian; Dajani, Iyad

    2016-03-01

    We report efficient coherent beam combining of five kilowatt-class fiber amplifiers with a diffractive optical element (DOE). Based on a master oscillator power amplifier (MOPA) configuration, the amplifiers were seeded with pseudo random phase modulated light. Each non-polarization maintaining fiber amplifier was optically path length matched and provides approximately 1.2 kW of near diffraction-limited output power (measured M2polarization control. A low power sample of the combined beam after the DOE provided an error signal for active phase locking which was performed via Locking of Optical Coherence by Single-Detector Electronic-Frequency Tagging (LOCSET). After phase stabilization, the beams were coherently combined via the 1x5 DOE. A total combined output power of 4.9 kW was achieved with 82% combining efficiency and excellent beam quality (M2splitter loss was 5%. Similarly, losses due in part to non-ideal polarization, ASE content, uncorrelated wavefront errors, and misalignment errors contributed to the efficiency reduction.

  16. Correlated random-phase approximation from densities and in-medium matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Trippel, Richard; Roth, Robert [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)

    2016-07-01

    The random-phase approximation (RPA) as well as the second RPA (SRPA) are established tools for the study of collective excitations in nuclei. Addressing the well known lack of correlations, we derived a universal framework for a fully correlated RPA based on the use of one- and two-body densities. We apply densities from coupled cluster theory and investigate the impact of correlations. As an alternative approach to correlations we use matrix elements transformed via in-medium similarity renormalization group (IM-SRG) in combination with RPA and SRPA. We find that within SRPA the use of IM-SRG matrix elements leads to the disappearance of instabilities of low-lying states. For the calculations we use normal-ordered two- plus three-body interactions derived from chiral effective field theory. We apply different Hamiltonians to a number of doubly-magic nuclei and calculate electric transition strengths.

  17. Random-phase approximation and its extension for the O(2) anharmonic oscillator

    International Nuclear Information System (INIS)

    Aouissat, Z.; Martin, C.

    2004-01-01

    We apply the random-phase approximation (RPA) and its extension called renormalized RPA to the quantum anharmonic oscillator with an O(2) symmetry. We first obtain the equation for the RPA frequencies in the standard and in the renormalized RPAs using the equation-of-motion method. In the case where the ground state has a broken symmetry, we check the existence of a zero frequency in the standard and in the renormalized RPAs. Then we use a time-dependent approach where the standard-RPA frequencies are obtained as small oscillations around the static solution in the time-dependent Hartree-Bogolyubov equation. We draw the parallel between the two approaches. (orig.)

  18. Random phase approximations for the screening function in high Tc superconductors

    International Nuclear Information System (INIS)

    Lopez-Aguilar, F.; Costa-Quintana, J.; Sanchez, A.; Puig, T.; Aurell, M.T.; Martinez, L.M.; Munoz, J.S.

    1990-01-01

    This paper reports on the electronic transferences from the CuO 2 sheets toward the CuO 3 linear chain, which locate electrons in the orbitals p y /p z of O4/O1 and d z 2 -y 2 of Cu1, and holes in the orbitals d x 2 -y 2 - P z /p y of Cu2 - P2/O3. These holes states present large interatomic overlapping. In this paper, we determine the screening function within the random phase approximation applied to the high-T c superconductors. This screening function is vanishing for determined values of the frequency which correspond to renormalized plasmon frequencies. These frequencies depends on the band parameters and their knowledge is essential for determining the self energy. This self energy is deduced and it contain independent terms for each of the channels for the localization

  19. Finite nucleus Dirac mean field theory and random phase approximation using finite B splines

    International Nuclear Information System (INIS)

    McNeil, J.A.; Furnstahl, R.J.; Rost, E.; Shepard, J.R.; Department of Physics, University of Maryland, College Park, Maryland 20742; Department of Physics, University of Colorado, Boulder, Colorado 80309)

    1989-01-01

    We calculate the finite nucleus Dirac mean field spectrum in a Galerkin approach using finite basis splines. We review the method and present results for the relativistic σ-ω model for the closed-shell nuclei 16 O and 40 Ca. We study the convergence of the method as a function of the size of the basis and the closure properties of the spectrum using an energy-weighted dipole sum rule. We apply the method to the Dirac random-phase-approximation response and present results for the isoscalar 1/sup -/ and 3/sup -/ longitudinal form factors of 16 O and 40 Ca. We also use a B-spline spectral representation of the positive-energy projector to evaluate partial energy-weighted sum rules and compare with nonrelativistic sum rule results

  20. Thermodynamics and structure of liquid metals from a consistent optimized random phase approximation

    International Nuclear Information System (INIS)

    Akinlade, O.; Badirkhan, Z.; Pastore, G.

    2000-05-01

    We study thermodynamics and structural properties of several liquid metals to assess the validity of the generalized non-local model potential (GNMP) of Li et. al. [J.Phys. F16,309 (1986)]. By using a new thermodynamically consistent version of the optimized random phase approximation (ORPA), especially adapted to continuous reference potentials, we improve our previous results obtained within the variational approach based on the Gibbs - Bogoliubov inequality. Hinging on the unified and very accurate evaluation of structure factors and thermodynamic quantities provided by the ORPA, we find that the GNMP yields satisfactory results for the alkali metals, however, those for the polyvalent metals point to a substantial inadequacy of the GNMP for high valence systems. (author)

  1. Toward a consistent random phase approximation based on the relativistic Hartree approximation

    International Nuclear Information System (INIS)

    Price, C.E.; Rost, E.; Shepard, J.R.; McNeil, J.A.

    1992-01-01

    We examine the random phase approximation (RPA) based on a relativistic Hartree approximation description for nuclear ground states. This model includes contributions from the negative energy sea at the one-loop level. We emphasize consistency between the treatment of the ground state and the RPA. This consistency is important in the description of low-lying collective levels but less important for the longitudinal (e,e') quasielastic response. We also study the effect of imposing a three-momentum cutoff on negative energy sea contributions. A cutoff of twice the nucleon mass improves agreement with observed spin-orbit splittings in nuclei compared to the standard infinite cutoff results, an effect traceable to the fact that imposing the cutoff reduces m * /m. Consistency is much more important than the cutoff in the description of low-lying collective levels. The cutoff model also provides excellent agreement with quasielastic (e,e') data

  2. Collective excitations in the Penson-Kolb model: A generalized random-phase-approximation study

    International Nuclear Information System (INIS)

    Roy, G.K.; Bhattacharyya, B.

    1997-01-01

    The evolution of the superconducting ground state of the half-filled Penson-Kolb model is examined as a function of the coupling constant using a mean-field approach and the generalized random phase approximation (RPA) in two and three dimensions. On-site singlet pairs hop to compete against single-particle motion in this model, giving the coupling constant a strong momentum dependence. There is a pronounced bandwidth enhancement effect that converges smoothly to a finite value in the strong-coupling (Bose) regime. The low-lying collective excitations evaluated in generalized RPA show a linear dispersion and a gradual crossover from the weak-coupling (BCS) limit to the Bose regime; the mode velocity increases monotonically in sharp contrast to the attractive Hubbard model. Analytical results are derived in the asymptotic limits. copyright 1997 The American Physical Society

  3. Large-Scale Cubic-Scaling Random Phase Approximation Correlation Energy Calculations Using a Gaussian Basis.

    Science.gov (United States)

    Wilhelm, Jan; Seewald, Patrick; Del Ben, Mauro; Hutter, Jürg

    2016-12-13

    We present an algorithm for computing the correlation energy in the random phase approximation (RPA) in a Gaussian basis requiring [Formula: see text] operations and [Formula: see text] memory. The method is based on the resolution of the identity (RI) with the overlap metric, a reformulation of RI-RPA in the Gaussian basis, imaginary time, and imaginary frequency integration techniques, and the use of sparse linear algebra. Additional memory reduction without extra computations can be achieved by an iterative scheme that overcomes the memory bottleneck of canonical RPA implementations. We report a massively parallel implementation that is the key for the application to large systems. Finally, cubic-scaling RPA is applied to a thousand water molecules using a correlation-consistent triple-ζ quality basis.

  4. Importance of self-consistency in relativistic continuum random-phase approximation calculations

    International Nuclear Information System (INIS)

    Yang Ding; Cao Ligang; Tian Yuan; Ma Zhongyu

    2010-01-01

    A fully consistent relativistic continuum random phase approximation (RCRPA) is constructed, where the contribution of the continuum spectrum to nuclear excitations is treated exactly by the single-particle Green's function technique. The full consistency of the calculations is achieved that the same effective Lagrangian is adopted for the ground state and the excited states. The negative energy states in the Dirac sea are also included in the single-particle Green's function in the no-sea approximation. The currents from the vector meson and photon exchanges and the Coulomb interaction in RCRPA are treated exactly. The spin-orbit interaction is included naturally in the relativistic frame. Numerical results of the RCRPA are checked with the constrained relativistic mean-field theory. We study the effects of the inconsistency, particularly the currents and Coulomb interaction in various collective multipole excitations.

  5. Random phase plate hot spots and their effect on stimulated Brillouin backscatter and self-focusing

    International Nuclear Information System (INIS)

    Rose, H.A.

    1995-01-01

    Laser hot spots, as determined by Random Phase Plate (RPP) hot spots, control the critical value of the average intensity, I c , at which there is a rapid onset of stimulated scatter in the strongly damped convective regime of three wave parametric instabilities. For the case of stimulated Brillouin backscatter in a long scale length plasma, nascent hot spot ponderomotive self-focusing is shown to reduce the value of I c in the regime of very strongly damped acoustic waves. RPP hot spots have two, intrinsically nonlinear, thresholds for ponderomotive self-focusing. Large intensity amplifications occur in the hot spot neighborhood when the hot spot power exceeds a certain critical power, P c , which is independent of the optic's f number, F. When the second, F-dependent, hot spot power threshold is exceeded, a filament emerges from the far side of the hot spot, whose extent grows erratically in time

  6. Insight into organic reactions from the direct random phase approximation and its corrections

    Energy Technology Data Exchange (ETDEWEB)

    Ruzsinszky, Adrienn [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Zhang, Igor Ying; Scheffler, Matthias [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany)

    2015-10-14

    The performance of the random phase approximation (RPA) and beyond-RPA approximations for the treatment of electron correlation is benchmarked on three different molecular test sets. The test sets are chosen to represent three typical sources of error which can contribute to the failure of most density functional approximations in chemical reactions. The first test set (atomization and n-homodesmotic reactions) offers a gradually increasing balance of error from the chemical environment. The second test set (Diels-Alder reaction cycloaddition = DARC) reflects more the effect of weak dispersion interactions in chemical reactions. Finally, the third test set (self-interaction error 11 = SIE11) represents reactions which are exposed to noticeable self-interaction errors. This work seeks to answer whether any one of the many-body approximations considered here successfully addresses all these challenges.

  7. Insight into organic reactions from the direct random phase approximation and its corrections

    International Nuclear Information System (INIS)

    Ruzsinszky, Adrienn; Zhang, Igor Ying; Scheffler, Matthias

    2015-01-01

    The performance of the random phase approximation (RPA) and beyond-RPA approximations for the treatment of electron correlation is benchmarked on three different molecular test sets. The test sets are chosen to represent three typical sources of error which can contribute to the failure of most density functional approximations in chemical reactions. The first test set (atomization and n-homodesmotic reactions) offers a gradually increasing balance of error from the chemical environment. The second test set (Diels-Alder reaction cycloaddition = DARC) reflects more the effect of weak dispersion interactions in chemical reactions. Finally, the third test set (self-interaction error 11 = SIE11) represents reactions which are exposed to noticeable self-interaction errors. This work seeks to answer whether any one of the many-body approximations considered here successfully addresses all these challenges

  8. Beyond the random-phase approximation for the electron correlation energy: the importance of single excitations.

    Science.gov (United States)

    Ren, Xinguo; Tkatchenko, Alexandre; Rinke, Patrick; Scheffler, Matthias

    2011-04-15

    The random-phase approximation (RPA) for the electron correlation energy, combined with the exact-exchange (EX) energy, represents the state-of-the-art exchange-correlation functional within density-functional theory. However, the standard RPA practice--evaluating both the EX and the RPA correlation energies using Kohn-Sham (KS) orbitals from local or semilocal exchange-correlation functionals--leads to a systematic underbinding of molecules and solids. Here we demonstrate that this behavior can be corrected by adding a "single excitation" contribution, so far not included in the standard RPA scheme. A similar improvement can also be achieved by replacing the non-self-consistent EX total energy by the corresponding self-consistent Hartree-Fock total energy, while retaining the RPA correlation energy evaluated using KS orbitals. Both schemes achieve chemical accuracy for a standard benchmark set of noncovalent intermolecular interactions.

  9. Extended random-phase approximation with three-body ground-state correlations

    International Nuclear Information System (INIS)

    Tohyama, M.; Schuck, P.

    2008-01-01

    An extended random-phase approximation (ERPA) which contains the effects of ground-state correlations up to a three-body level is applied to an extended Lipkin model which contains an additional particle-scattering term. Three-body correlations in the ground state are necessary to preserve the hermiticity of the Hamiltonian matrix of ERPA. Two approximate forms of ERPA which neglect the three-body correlations are also applied to investigate the importance of three-body correlations. It is found that the ground-state energy is little affected by the inclusion of the three-body correlations. On the contrary, three-body correlations for the excited states can become quite important. (orig.)

  10. Random phase approximation applied to solids, molecules, and graphene-metal interfaces

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian S.

    2013-01-01

    The random phase approximation (RPA) is attracting renewed interest as a universal and accurate method for first-principles total energy calculations. The RPA naturally accounts for long-range dispersive forces without compromising accuracy for short-range interactions making the RPA superior...... to semilocal and hybrid functionals in systems dominated by weak van der Waals or mixed covalent-dispersive interactions. In this work, we present plane-wave-based RPA calculations for a broad collection of systems with bond types ranging from strong covalent to van der Waals. Our main result is the RPA...... the RPA captures both the weak covalent and dispersive forces, which are equally important for these systems. We benchmark our implementation in the GPAW electronic structure code by calculating cohesive energies of graphite and a range of covalently bonded solids and molecules as well as the dissociation...

  11. Random-phase approximation and its extension for the O(2) anharmonic oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Aouissat, Z. [Institut fuer Kernphysik, Technische Hochschule Darmstadt, Schlossgarten 9, D-64289, Darmstadt (Germany); Martin, C. [Groupe de Physique Theorique, Institut de Physique Nucleaire, F-91406, Orsay Cedex (France)

    2004-02-01

    We apply the random-phase approximation (RPA) and its extension called renormalized RPA to the quantum anharmonic oscillator with an O(2) symmetry. We first obtain the equation for the RPA frequencies in the standard and in the renormalized RPAs using the equation-of-motion method. In the case where the ground state has a broken symmetry, we check the existence of a zero frequency in the standard and in the renormalized RPAs. Then we use a time-dependent approach where the standard-RPA frequencies are obtained as small oscillations around the static solution in the time-dependent Hartree-Bogolyubov equation. We draw the parallel between the two approaches. (orig.)

  12. Extending the random-phase approximation for electronic correlation energies: the renormalized adiabatic local density approximation

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian S.

    2012-01-01

    The adiabatic connection fluctuation-dissipation theorem with the random phase approximation (RPA) has recently been applied with success to obtain correlation energies of a variety of chemical and solid state systems. The main merit of this approach is the improved description of dispersive forces...... while chemical bond strengths and absolute correlation energies are systematically underestimated. In this work we extend the RPA by including a parameter-free renormalized version of the adiabatic local-density (ALDA) exchange-correlation kernel. The renormalization consists of a (local) truncation...... of the ALDA kernel for wave vectors q > 2kF, which is found to yield excellent results for the homogeneous electron gas. In addition, the kernel significantly improves both the absolute correlation energies and atomization energies of small molecules over RPA and ALDA. The renormalization can...

  13. Relativistic Random-Phase Approximation with Density-dependent Meson-nucleon Couplings at Finite Temperature

    International Nuclear Information System (INIS)

    Niu, Y.; Paar, N.; Vretenar, D.; Meng, J.

    2009-01-01

    The fully self-consistent relativistic random-phase approximation (RRPA) framework based on effective interactions with a phenomenological density dependence is extended to finite temperatures. The RRPA configuration space is built from the spectrum of single-nucleon states at finite temperature obtained by the temperature dependent relativistic mean field (RMF-T) theory based on effective Lagrangian with density dependent meson-nucleon vertex functions. As an illustration, the dependence of binding energy, radius, entropy and single particle levels on temperature for spherical nucleus 2 08P b is investigated in RMF-T theory. The finite temperature RRPA has been employed in studies of giant monopole and dipole resonances, and the evolution of resonance properties has been studied as a function of temperature. In addition, exotic modes of excitation have been systematically explored at finite temperatures, with an emphasis on the case of pygmy dipole resonances.(author)

  14. A randomized placebo-controlled phase III trial of oral laquinimod for multiple sclerosis

    DEFF Research Database (Denmark)

    Vollmer, T L; Sorensen, P S; Selmaj, K

    2014-01-01

    The phase III placebo-controlled BRAVO study assessed laquinimod effects in patients with relapsing-remitting MS (RRMS), and descriptively compared laquinimod with interferon beta (IFNβ)-1a (Avonex(®) reference arm). RRMS patients age 18-55 years with Expanded Disability Status Scale (EDSS) scores...... months. The primary endpoint was annualized relapse rate (ARR); secondary endpoints included percent brain volume change (PBVC) and 3-month confirmed disability worsening. In all, 1,331 patients were randomized: laquinimod (n = 434), placebo (n = 450), and IFNβ-1a (n = 447). ARR was not significantly...... reduced with laquinimod [-18 %, risk ratio (RR) = 0.82, 95 % CI 0.66-1.02; p = 0.075] vs. placebo. Laquinimod significantly reduced PBVC (28 %, p change in confirmed disability worsening with laquinimod measured...

  15. LETTER TO THE EDITOR: Phase transition in a random fragmentation problem with applications to computer science

    Science.gov (United States)

    Dean, David S.; Majumdar, Satya N.

    2002-08-01

    We study a fragmentation problem where an initial object of size x is broken into m random pieces provided x > x0 where x0 is an atomic cut-off. Subsequently, the fragmentation process continues for each of those daughter pieces whose sizes are bigger than x0. The process stops when all the fragments have sizes smaller than x0. We show that the fluctuation of the total number of splitting events, characterized by the variance, generically undergoes a nontrivial phase transition as one tunes the branching number m through a critical value m = mc. For m mc they are anomalously large and non-Gaussian. We apply this general result to analyse two different search algorithms in computer science.

  16. Quantum mechanics of the fractional-statistics gas: Random-phase approximation

    International Nuclear Information System (INIS)

    Dai, Q.; Levy, J.L.; Fetter, A.L.; Hanna, C.B.; Laughlin, R.B.

    1992-01-01

    A description of the fractional-statistics gas based on the complete summation of Hartree, Fock, ladder and bubble diagrams is presented. The superfluid properties identified previously in the random-phase-approximation (RPA) calculation of Fetter, Hanna, and Laughlin [Phys. Rev. B 39, 9679 (1989)] are substantially confirmed. The discrepancy between the RPA sound speed and the Hartree-Fock bulk modulus is found to be eliminated. The unusual Hall-effect behavior is found to vanish for the Bose gas test case but not for the fractional-statistics gas, implying that it is physically correct. Excellent agreement is obtained with the collective-mode dispersion obtained numerically by Xie, He, and Das Sarma [Phys. Rev. Lett. 65, 649 (1990)

  17. β-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation

    International Nuclear Information System (INIS)

    Niksic, T.; Marketin, T.; Vretenar, D.; Paar, N.; Ring, P.

    2004-01-01

    The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of β-decay half-lives of neutron-rich nuclei in the N∼50 and N∼82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogolyubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains, but overestimate the lifetimes of Ni isotopes and predict a stable 132 Sn. (orig.)

  18. β-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation

    International Nuclear Information System (INIS)

    Niksic, T.; Marketin, T.; Vretenar, D.; Paar, N.; Ring, P.

    2005-01-01

    The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of β-decay half-lives of neutron-rich nuclei in the N≅50 and N≅82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogoliubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains but overestimate the lifetimes of Ni isotopes and predict a stable 132 Sn

  19. Relativistic quasiparticle random-phase approximation calculation of total muon capture rates

    International Nuclear Information System (INIS)

    Marketin, T.; Paar, N.; Niksic, T.; Vretenar, D.

    2009-01-01

    The relativistic proton-neutron quasiparticle random phase approximation (pn-RQRPA) is applied in the calculation of total muon capture rates on a large set of nuclei from 12 C to 244 Pu, for which experimental values are available. The microscopic theoretical framework is based on the relativistic Hartree-Bogoliubov (RHB) model for the nuclear ground state, and transitions to excited states are calculated using the pn-RQRPA. The calculation is fully consistent, i.e., the same interactions are used both in the RHB equations that determine the quasiparticle basis, and in the matrix equations of the pn-RQRPA. The calculated capture rates are sensitive to the in-medium quenching of the axial-vector coupling constant. By reducing this constant from its free-nucleon value g A =1.262 by 10% for all multipole transitions, the calculation reproduces the experimental muon capture rates to better than 10% accuracy.

  20. {beta}-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation

    Energy Technology Data Exchange (ETDEWEB)

    Niksic, T.; Marketin, T.; Vretenar, D. [Zagreb Univ. (Croatia). Faculty of Science, Physics Dept.; Paar, N. [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik; Ring, P. [Technische Univ. Muenchen, Garching (Germany). Physik-Department

    2004-12-08

    The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of {beta}-decay half-lives of neutron-rich nuclei in the N{approx}50 and N{approx}82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogolyubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains, but overestimate the lifetimes of Ni isotopes and predict a stable {sup 132}Sn. (orig.)

  1. SPIRIT: A seamless phase I/II randomized design for immunotherapy trials.

    Science.gov (United States)

    Guo, Beibei; Li, Daniel; Yuan, Ying

    2018-06-07

    Immunotherapy-treatments that enlist the immune system to battle tumors-has received widespread attention in cancer research. Due to its unique features and mechanisms for treating cancer, immunotherapy requires novel clinical trial designs. We propose a Bayesian seamless phase I/II randomized design for immunotherapy trials (SPIRIT) to find the optimal biological dose (OBD) defined in terms of the restricted mean survival time. We jointly model progression-free survival and the immune response. Progression-free survival is used as the primary endpoint to determine the OBD, and the immune response is used as an ancillary endpoint to quickly screen out futile doses. Toxicity is monitored throughout the trial. The design consists of two seamlessly connected stages. The first stage identifies a set of safe doses. The second stage adaptively randomizes patients to the safe doses identified and uses their progression-free survival and immune response to find the OBD. The simulation study shows that the SPIRIT has desirable operating characteristics and outperforms the conventional design. Copyright © 2018 John Wiley & Sons, Ltd.

  2. Random excitation forces in tube bundles subjected to two-phase cross-flow

    International Nuclear Information System (INIS)

    Taylor, C.E.; Pettigrew, M.J.; Currie, I.G.

    1996-01-01

    Data from two experimental programs have been analyzed to determine the characteristics of the random excitation forces associated with two-phase cross-flow in tube bundles. Large-scale air-water flow loops in France and Canada were used to generate the data. Tests were carried out on cantilevered, clamped-pinned, and clamped-clamped tubes in normal-square, parallel-triangular, and normal-triangular configurations. Either strain gages or force transducers were used to measure the vibration response of a centrally located tube as the tue array was subjected to a wide range of void fractions and flow rates. Power spectra were analyzed to determine the effect of parameters such as tube diameter, frequency, flow rate, void fraction, and flow regime on the random excitation forces. Normalized expressions for the excitation force power spectra were found to be flow-regime dependent. In the churn flow regime, flow rate and void fraction had very little effect on the magnitude of the excitation forces. In the bubble-plug flow regime, the excitation forces increased rapidly with flow rate and void fraction

  3. Local Treatment of Unresectable Colorectal Liver Metastases: Results of a Randomized Phase II Trial.

    Science.gov (United States)

    Ruers, Theo; Van Coevorden, Frits; Punt, Cornelis J A; Pierie, Jean-Pierre E N; Borel-Rinkes, Inne; Ledermann, Jonathan A; Poston, Graeme; Bechstein, Wolf; Lentz, Marie-Ange; Mauer, Murielle; Folprecht, Gunnar; Van Cutsem, Eric; Ducreux, Michel; Nordlinger, Bernard

    2017-09-01

    Tumor ablation is often employed for unresectable colorectal liver metastases. However, no survival benefit has ever been demonstrated in prospective randomized studies. Here, we investigate the long-term benefits of such an aggressive approach. In this randomized phase II trial, 119 patients with unresectable colorectal liver metastases (n  38%) was met. We now report on long-term OS results. All statistical tests were two-sided. The analyses were according to intention to treat. At a median follow up of 9.7 years, 92 of 119 (77.3%) patients had died: 39 of 60 (65.0%) in the combined modality arm and 53 of 59 (89.8%) in the systemic treatment arm. Almost all patients died of progressive disease (35 patients in the combined modality arm, 49 patients in the systemic treatment arm). There was a statistically significant difference in OS in favor of the combined modality arm (hazard ratio [HR] = 0.58, 95% confidence interval [CI] = 0.38 to 0.88, P = .01). Three-, five-, and eight-year OS were 56.9% (95% CI = 43.3% to 68.5%), 43.1% (95% CI = 30.3% to 55.3%), 35.9% (95% CI = 23.8% to 48.2%), respectively, in the combined modality arm and 55.2% (95% CI = 41.6% to 66.9%), 30.3% (95% CI = 19.0% to 42.4%), 8.9% (95% CI = 3.3% to 18.1%), respectively, in the systemic treatment arm. Median OS was 45.6 months (95% CI = 30.3 to 67.8 months) in the combined modality arm vs 40.5 months (95% CI = 27.5 to 47.7 months) in the systemic treatment arm. This phase II trial is the first randomized study demonstrating that aggressive local treatment can prolong OS in patients with unresectable colorectal liver metastases. © The Author 2017. Published by Oxford University Press.

  4. Collapse of the random-phase approximation: Examples and counter-examples from the shell model

    International Nuclear Information System (INIS)

    Johnson, Calvin W.; Stetcu, Ionel

    2009-01-01

    The Hartree-Fock approximation to the many-fermion problem can break exact symmetries, and in some cases by changing a parameter in the interaction one can drive the Hartree-Fock minimum from a symmetry-breaking state to a symmetry-conserving state (also referred to as a 'phase transition' in the literature). The order of the transition is important when one applies the random-phase approximation (RPA) to the of the Hartree-Fock wave function: if first order, RPA is stable through the transition, but if second-order, then the RPA amplitudes become large and lead to unphysical results. The latter is known as 'collapse' of the RPA. While the difference between first- and second-order transitions in the RPA was first pointed out by Thouless, we present for the first time nontrivial examples of both first- and second-order transitions in a uniform model, the interacting shell-model, where we can compare to exact numerical results.

  5. Long-Term Improvements After Multimodal Rehabilitation in Late Phase After Stroke: A Randomized Controlled Trial.

    Science.gov (United States)

    Bunketorp-Käll, Lina; Lundgren-Nilsson, Åsa; Samuelsson, Hans; Pekny, Tulen; Blomvé, Karin; Pekna, Marcela; Pekny, Milos; Blomstrand, Christian; Nilsson, Michael

    2017-07-01

    Treatments that improve function in late phase after stroke are urgently needed. We assessed whether multimodal interventions based on rhythm-and-music therapy or horse-riding therapy could lead to increased perceived recovery and functional improvement in a mixed population of individuals in late phase after stroke. Participants were assigned to rhythm-and-music therapy, horse-riding therapy, or control using concealed randomization, stratified with respect to sex and stroke laterality. Therapy was given twice a week for 12 weeks. The primary outcome was change in participants' perception of stroke recovery as assessed by the Stroke Impact Scale with an intention-to-treat analysis. Secondary objective outcome measures were changes in balance, gait, grip strength, and cognition. Blinded assessments were performed at baseline, postintervention, and at 3- and 6-month follow-up. One hundred twenty-three participants were assigned to rhythm-and-music therapy (n=41), horse-riding therapy (n=41), or control (n=41). Post-intervention, the perception of stroke recovery (mean change from baseline on a scale ranging from 1 to 100) was higher among rhythm-and-music therapy (5.2 [95% confidence interval, 0.79-9.61]) and horse-riding therapy participants (9.8 [95% confidence interval, 6.00-13.66]), compared with controls (-0.5 [-3.20 to 2.28]); P =0.001 (1-way ANOVA). The improvements were sustained in both intervention groups 6 months later, and corresponding gains were observed for the secondary outcomes. Multimodal interventions can improve long-term perception of recovery, as well as balance, gait, grip strength, and working memory in a mixed population of individuals in late phase after stroke. URL: http//www.ClinicalTrials.gov. Unique identifier: NCT01372059. © 2017 American Heart Association, Inc.

  6. Tradeoff between insensitivity to depth-induced spherical aberration and resolution of 3D fluorescence imaging due to the use of wavefront encoding with a radially symmetric phase mask

    Science.gov (United States)

    Doblas, Ana; Dutta, Ananya; Saavedra, Genaro; Preza, Chrysanthe

    2018-02-01

    Previously, a wavefront encoded (WFE) imaging system implemented using a squared cubic (SQUBIC) phase mask has been verified to reduce the sensitivity of the imaging system to spherical aberration (SA). The strength of the SQUBIC phase mask and, as consequence, the performance of the WFE system are controlled by a design parameter, A. Although the higher the A-value, the more tolerant the WFE system is to SA, this is accomplished at the expense of the effective imaging resolution. In this contribution, we investigate this tradeoff in order to find an optimal A-value to balance the effect of SA and loss of resolution.

  7. TU-AB-BRA-09: A Novel Method of Generating Ultrafast Volumetric Cine MRI (VC-MRI) Using Prior 4D-MRI and On-Board Phase-Skipped Encoding Acquisition for Radiotherapy Target Localization

    International Nuclear Information System (INIS)

    Wang, C; Yin, F; Harris, W; Cai, J; Chang, Z; Ren, L

    2016-01-01

    Purpose: To develop a technique generating ultrafast on-board VC-MRI using prior 4D-MRI and on-board phase-skipped encoding k-space acquisition for real-time 3D target tracking of liver and lung radiotherapy. Methods: The end-of-expiration (EOE) volume in 4D-MRI acquired during the simulation was selected as the prior volume. 3 major respiratory deformation patterns were extracted through the principal component analysis of the deformation field maps (DFMs) generated between EOE and all other phases. The on-board VC-MRI at each instant was considered as a deformation of the prior volume, and the deformation was modeled as a linear combination of the extracted 3 major deformation patterns. To solve the weighting coefficients of the 3 major patterns, a 2D slice was extracted from VC-MRI volume to match with the 2D on-board sampling data, which was generated by 8-fold phase skipped-encoding k-space acquisition (i.e., sample 1 phase-encoding line out of every 8 lines) to achieve an ultrafast 16–24 volumes/s frame rate. The method was evaluated using XCAT digital phantom to simulate lung cancer patients. The 3D volume of end-ofinhalation (EOI) phase at the treatment day was used as ground-truth onboard VC-MRI with simulated changes in 1) breathing amplitude and 2) breathing amplitude/phase change from the simulation day. A liver cancer patient case was evaluated for in-vivo feasibility demonstration. Results: The comparison between ground truth and estimated on-board VC-MRI shows good agreements. In XCAT study with changed breathing amplitude, the volume-percent-difference(VPD) between ground-truth and estimated tumor volumes at EOI was 6.28% and the Center-of-Mass-Shift(COMS) was 0.82mm; with changed breathing amplitude and phase, the VPD was 8.50% and the COMS was 0.54mm. The study of liver patient case also demonstrated a promising in vivo feasibility of the proposed method Conclusion: Preliminary results suggest the feasibility to estimate ultrafast VC-MRI for on

  8. TU-AB-BRA-09: A Novel Method of Generating Ultrafast Volumetric Cine MRI (VC-MRI) Using Prior 4D-MRI and On-Board Phase-Skipped Encoding Acquisition for Radiotherapy Target Localization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C; Yin, F; Harris, W; Cai, J; Chang, Z; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: To develop a technique generating ultrafast on-board VC-MRI using prior 4D-MRI and on-board phase-skipped encoding k-space acquisition for real-time 3D target tracking of liver and lung radiotherapy. Methods: The end-of-expiration (EOE) volume in 4D-MRI acquired during the simulation was selected as the prior volume. 3 major respiratory deformation patterns were extracted through the principal component analysis of the deformation field maps (DFMs) generated between EOE and all other phases. The on-board VC-MRI at each instant was considered as a deformation of the prior volume, and the deformation was modeled as a linear combination of the extracted 3 major deformation patterns. To solve the weighting coefficients of the 3 major patterns, a 2D slice was extracted from VC-MRI volume to match with the 2D on-board sampling data, which was generated by 8-fold phase skipped-encoding k-space acquisition (i.e., sample 1 phase-encoding line out of every 8 lines) to achieve an ultrafast 16–24 volumes/s frame rate. The method was evaluated using XCAT digital phantom to simulate lung cancer patients. The 3D volume of end-ofinhalation (EOI) phase at the treatment day was used as ground-truth onboard VC-MRI with simulated changes in 1) breathing amplitude and 2) breathing amplitude/phase change from the simulation day. A liver cancer patient case was evaluated for in-vivo feasibility demonstration. Results: The comparison between ground truth and estimated on-board VC-MRI shows good agreements. In XCAT study with changed breathing amplitude, the volume-percent-difference(VPD) between ground-truth and estimated tumor volumes at EOI was 6.28% and the Center-of-Mass-Shift(COMS) was 0.82mm; with changed breathing amplitude and phase, the VPD was 8.50% and the COMS was 0.54mm. The study of liver patient case also demonstrated a promising in vivo feasibility of the proposed method Conclusion: Preliminary results suggest the feasibility to estimate ultrafast VC-MRI for on

  9. Global mean-field phase diagram of the spin-1 Ising ferromagnet in a random crystal field

    Science.gov (United States)

    Borelli, M. E. S.; Carneiro, C. E. I.

    1996-02-01

    We study the phase diagram of the mean-field spin-1 Ising ferromagnet in a uniform magnetic field H and a random crystal field Δi, with probability distribution P( Δi) = pδ( Δi - Δ) + (1 - p) δ( Δi). We analyse the effects of randomness on the first-order surfaces of the Δ- T- H phase diagram for different values of the concentration p and show how these surfaces are affected by the dilution of the crystal field.

  10. Validation of the k-filtering technique for a signal composed of random-phase plane waves and non-random coherent structures

    Directory of Open Access Journals (Sweden)

    O. W. Roberts

    2014-12-01

    Full Text Available Recent observations of astrophysical magnetic fields have shown the presence of fluctuations being wave-like (propagating in the plasma frame and those described as being structure-like (advected by the plasma bulk velocity. Typically with single-spacecraft missions it is impossible to differentiate between these two fluctuations, due to the inherent spatio-temporal ambiguity associated with a single point measurement. However missions such as Cluster which contain multiple spacecraft have allowed for temporal and spatial changes to be resolved, using techniques such as k filtering. While this technique does not assume Taylor's hypothesis it requires both weak stationarity of the time series and that the fluctuations can be described by a superposition of plane waves with random phases. In this paper we test whether the method can cope with a synthetic signal which is composed of a combination of non-random-phase coherent structures with a mean radius d and a mean separation λ, as well as plane waves with random phase.

  11. Randomized placebo-controlled phase II trial of autologous mesenchymal stem cells in multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Sara Llufriu

    Full Text Available Uncontrolled studies of mesenchymal stem cells (MSCs in multiple sclerosis suggested some beneficial effect. In this randomized, double-blind, placebo-controlled, crossover phase II study we investigated their safety and efficacy in relapsing-remitting multiple sclerosis patients. Efficacy was evaluated in terms of cumulative number of gadolinium-enhancing lesions (GEL on magnetic resonance imaging (MRI at 6 months and at the end of the study.Patients unresponsive to conventional therapy, defined by at least 1 relapse and/or GEL on MRI scan in past 12 months, disease duration 2 to 10 years and Expanded Disability Status Scale (EDSS 3.0-6.5 were randomized to receive IV 1-2×10(6 bone-marrow-derived-MSCs/Kg or placebo. After 6 months, the treatment was reversed and patients were followed-up for another 6 months. Secondary endpoints were clinical outcomes (relapses and disability by EDSS and MS Functional Composite, and several brain MRI and optical coherence tomography measures. Immunological tests were explored to assess the immunomodulatory effects.At baseline 9 patients were randomized to receive MSCs (n = 5 or placebo (n = 4. One patient on placebo withdrew after having 3 relapses in the first 5 months. We did not identify any serious adverse events. At 6 months, patients treated with MSCs had a trend to lower mean cumulative number of GEL (3.1, 95% CI = 1.1-8.8 vs 12.3, 95% CI = 4.4-34.5, p = 0.064, and at the end of study to reduced mean GEL (-2.8±5.9 vs 3±5.4, p = 0.075. No significant treatment differences were detected in the secondary endpoints. We observed a non-significant decrease of the frequency of Th1 (CD4+ IFN-γ+ cells in blood of MSCs treated patients.Bone-marrow-MSCs are safe and may reduce inflammatory MRI parameters supporting their immunomodulatory properties. ClinicalTrials.gov NCT01228266.

  12. A Phase Ib open label, randomized, safety study of SANGUINATE™ in patients with sickle cell anemia

    Directory of Open Access Journals (Sweden)

    Hemant Misra

    Full Text Available Abstract Background: Treatment of sickle cell anemia is a challenging task and despite the well understood genetic and biochemical pathway of sickle hemoglobin, current therapy continues to be limited to the symptomatic treatment of pain, supplemental oxygen, antibiotics, red blood cell transfusions and hydroxyurea. SANGUINATE is a carbon monoxide releasing molecule and oxygen transfer agent under clinical development for the treatment of sickle cell anemia and comorbidities. Methods: An open-label randomized Phase Ib study was performed in adult sickle cell anemia patients. Two dose levels of SANGUINATE were compared to hydroxyurea in 24 homozygotes for Hb SS. Twelve subjects received either a low dose (160 mg/kg of SANGUINATE or 15 mg/kg hydroxyurea. Another 12 subjects received either a high dose (320 mg/kg of SANGUINATE or 15 mg/kg hydroxyurea. The primary endpoint was the safety of SANGUINATE versus hydroxyurea in sickle cell anemia patients. Secondary endpoints included determination of the plasma pharmacokinetics and assessment of hematologic measurements. Results: Musculoskeletal related adverse events were the most common. Transient troponin I levels increased in three patients, one of whom had an increase in tricuspid regurgitant velocity; however, no clinical signs were noted. Following an assessment of vital signs, tricuspid regurgitant velocity, electrocardiogram, serum biochemistry, hematology, urinalysis, and analysis of reported adverse events, SANGUINATE was found to be safe in stable sickle cell anemia patients. Conclusions: The clinical trial met its primary objective of demonstrating an acceptable safety profile for SANGUINATE in patients with sickle cell anemia. This trial established the safety of SANGUINATE at both dose levels and permitted its advance to Phase II trials.

  13. Self-consistent random phase approximation - application to systems of strongly correlated fermions

    International Nuclear Information System (INIS)

    Jemai, M.

    2004-07-01

    In the present thesis we have applied the self consistent random phase approximation (SCRPA) to the Hubbard model with a small number of sites (a chain of 2, 4, 6,... sites). Earlier SCRPA had produced very good results in other models like the pairing model of Richardson. It was therefore interesting to see what kind of results the method is able to produce in the case of a more complex model like the Hubbard model. To our great satisfaction the case of two sites with two electrons (half-filling) is solved exactly by the SCRPA. This may seem a little trivial but the fact is that other respectable approximations like 'GW' or the approach with the Gutzwiller wave function yield results still far from exact. With this promising starting point, the case of 6 sites at half filling was considered next. For that case, evidently, SCRPA does not any longer give exact results. However, they are still excellent for a wide range of values of the coupling constant U, covering for instance the phase transition region towards a state with non zero magnetisation. We consider this as a good success of the theory. Non the less the case of 4 sites (a plaquette), as indeed all cases with 4n sites at half filling, turned out to have a problem because of degeneracies at the Hartree Fock level. A generalisation of the present method, including in addition to the pairs, quadruples of Fermions operators (called second RPA) is proposed to also include exactly the plaquette case in our approach. This is therefore a very interesting perspective of the present work. (author)

  14. The new INRIM rotating encoder angle comparator (REAC)

    International Nuclear Information System (INIS)

    Pisani, Marco; Astrua, Milena

    2017-01-01

    A novel angle comparator has been built and tested at INRIM. The device is based on a double air bearing structure embedding a continuously rotating encoder, which is read by two heads: one fixed to the base of the comparator and a second fixed to the upper moving part of the comparator. The phase measurement between the two heads’ signals is proportional to the relative angle suspended between them (and, therefore, the angle between the base and the upper, movable part of the comparator). The advantage of this solution is to reduce the encoder graduation errors and to cancel the cyclic errors due to the interpolation of the encoder lines. By using only two pairs of reading heads, we have achieved an intrinsic accuracy of  ±0.04″ (rectangular distribution) that can be reduced through self-calibration. The residual cyclic errors have shown to be less than 0.01″ peak-to-peak. The random fluctuations are less than 0.01″ rms on a 100 s time interval. A further advantage of the rotating encoder is the intrinsic knowledge of the absolute position without the need of a zeroing procedure. Construction details of the rotating encoder angle comparator (REAC), characterization tests, and examples of practical use are given. (paper)

  15. A randomized phase II dose-response exercise trial among colon cancer survivors: Purpose, study design, methods, and recruitment results.

    Science.gov (United States)

    Brown, Justin C; Troxel, Andrea B; Ky, Bonnie; Damjanov, Nevena; Zemel, Babette S; Rickels, Michael R; Rhim, Andrew D; Rustgi, Anil K; Courneya, Kerry S; Schmitz, Kathryn H

    2016-03-01

    Observational studies indicate that higher volumes of physical activity are associated with improved disease outcomes among colon cancer survivors. The aim of this report is to describe the purpose, study design, methods, and recruitment results of the courage trial, a National Cancer Institute (NCI) sponsored, phase II, randomized, dose-response exercise trial among colon cancer survivors. The primary objective of the courage trial is to quantify the feasibility, safety, and physiologic effects of low-dose (150 min·week(-1)) and high-dose (300 min·week(-1)) moderate-intensity aerobic exercise compared to usual-care control group over six months. The exercise groups are provided with in-home treadmills and heart rate monitors. Between January and July 2015, 1433 letters were mailed using a population-based state cancer registry; 126 colon cancer survivors inquired about participation, and 39 were randomized onto the study protocol. Age was associated with inquiry about study participation (Pclinical, or geographic characteristics were associated with study inquiry or randomization. The final trial participant was randomized in August 2015. Six month endpoint data collection was completed in February 2016. The recruitment of colon cancer survivors into an exercise trial is feasible. The findings from this trial will inform key design aspects for future phase 2 and phase 3 randomized controlled trials to examine the efficacy of exercise to improve clinical outcomes among colon cancer survivors. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. The use of odd random phase electrochemical impedance spectroscopy to study lithium-based corrosion inhibition by active protective coatings

    NARCIS (Netherlands)

    Meeusen, M.; Visser, P.; Fernández Macía, L.; Hubin, A.; Terryn, H.A.; Mol, J.M.C.

    2018-01-01

    In this work, the study of the time-dependent behaviour of lithium carbonate based inhibitor technology for the active corrosion protection of aluminium alloy 2024-T3 is presented. Odd random phase electrochemical impedance spectroscopy (ORP-EIS) is selected as the electrochemical tool to study

  17. Dielectric Matrix Formulation of Correlation Energies in the Random Phase Approximation: Inclusion of Exchange Effects.

    Science.gov (United States)

    Mussard, Bastien; Rocca, Dario; Jansen, Georg; Ángyán, János G

    2016-05-10

    Starting from the general expression for the ground state correlation energy in the adiabatic-connection fluctuation-dissipation theorem (ACFDT) framework, it is shown that the dielectric matrix formulation, which is usually applied to calculate the direct random phase approximation (dRPA) correlation energy, can be used for alternative RPA expressions including exchange effects. Within this famework, the ACFDT analog of the second order screened exchange (SOSEX) approximation leads to a logarithmic formula for the correlation energy similar to the direct RPA expression. Alternatively, the contribution of the exchange can be included in the kernel used to evaluate the response functions. In this case, the use of an approximate kernel is crucial to simplify the formalism and to obtain a correlation energy in logarithmic form. Technical details of the implementation of these methods are discussed, and it is shown that one can take advantage of density fitting or Cholesky decomposition techniques to improve the computational efficiency; a discussion on the numerical quadrature made on the frequency variable is also provided. A series of test calculations on atomic correlation energies and molecular reaction energies shows that exchange effects are instrumental for improvement over direct RPA results.

  18. Collective nuclear excitations with Skyrme-second random-phase approximation

    International Nuclear Information System (INIS)

    Gambacurta, D.; Catara, F.; Grasso, M.

    2010-01-01

    Second random-phase approximation (RPA) calculations with a Skyrme force are performed to describe both high- and low-lying excited states in 16 O. The coupling between one particle-one hole and two particle-two hole as well as that between two particle-two hole configurations among themselves are fully taken into account, and the residual interaction is never neglected; we do not resort therefore to a generally used approximate scheme where only the first kind of coupling is considered. The issue of the rearrangement terms in the matrix elements beyond the standard RPA will be considered in detail in a forthcoming paper. Two approximations are employed here for these rearrangement terms: they are either neglected or evaluated with the RPA procedure. As a general feature of second RPA results, a several-MeV shift of the strength distribution to lower energies is systematically found with respect to RPA distributions. A much more important fragmentation of the strength is also naturally provided by the second RPA owing to the huge number of two particle-two hole configurations. A better description of the excitation energies of the low-lying 0 + and 2 + states is obtained with the second RPA than with the RPA.

  19. Self-consistent Random Phase Approximation applied to a schematic model of the field theory

    International Nuclear Information System (INIS)

    Bertrand, Thierry

    1998-01-01

    The self-consistent Random Phase Approximation (SCRPA) is a method allowing in the mean-field theory inclusion of the correlations in the ground and excited states. It has the advantage of not violating the Pauli principle in contrast to RPA, that is based on the quasi-bosonic approximation; in addition, numerous applications in different domains of physics, show a possible variational character. However, the latter should be formally demonstrated. The first model studied with SCRPA is the anharmonic oscillator in the region where one of its symmetries is spontaneously broken. The ground state energy is reproduced by SCRPA more accurately than RPA, with no violation of the Ritz variational principle, what is not the case for the latter approximation. The success of SCRPA is the the same in case of ground state energy for a model mixing bosons and fermions. At the transition point the SCRPA is correcting RPA drastically, but far from this region the correction becomes negligible, both methods being of similar precision. In the deformed region in the case of RPA a spurious mode occurred due to the microscopical character of the model.. The SCRPA may also reproduce this mode very accurately and actually it coincides with an excitation in the exact spectrum

  20. Restricted second random phase approximations and Tamm-Dancoff approximations for electronic excitation energy calculations

    International Nuclear Information System (INIS)

    Peng, Degao; Yang, Yang; Zhang, Peng; Yang, Weitao

    2014-01-01

    In this article, we develop systematically second random phase approximations (RPA) and Tamm-Dancoff approximations (TDA) of particle-hole and particle-particle channels for calculating molecular excitation energies. The second particle-hole RPA/TDA can capture double excitations missed by the particle-hole RPA/TDA and time-dependent density-functional theory (TDDFT), while the second particle-particle RPA/TDA recovers non-highest-occupied-molecular-orbital excitations missed by the particle-particle RPA/TDA. With proper orbital restrictions, these restricted second RPAs and TDAs have a formal scaling of only O(N 4 ). The restricted versions of second RPAs and TDAs are tested with various small molecules to show some positive results. Data suggest that the restricted second particle-hole TDA (r2ph-TDA) has the best overall performance with a correlation coefficient similar to TDDFT, but with a larger negative bias. The negative bias of the r2ph-TDA may be induced by the unaccounted ground state correlation energy to be investigated further. Overall, the r2ph-TDA is recommended to study systems with both single and some low-lying double excitations with a moderate accuracy. Some expressions on excited state property evaluations, such as 〈S ^2 〉 are also developed and tested

  1. Application of the resonating Hartree-Fock random phase approximation to the Lipkin model

    International Nuclear Information System (INIS)

    Nishiyama, S.; Ishida, K.; Ido, M.

    1996-01-01

    We have applied the resonating Hartree-Fock (Res-HF) approximation to the exactly solvable Lipkin model by utilizing a newly developed orbital-optimization algorithm. The Res-HF wave function was superposed by two Slater determinants (S-dets) which give two corresponding local energy minima of monopole ''deformations''. The self-consistent Res-HF calculation gives an excellent ground-state correlation energy. There exist excitations due to small vibrational fluctuations of the orbitals and mixing coefficients around their stationary values. They are described by a new approximation called the resonating Hartree-Fock random phase approximation (Res-HF RPA). Matrices of the second-order variation of the Res-HF energy have the same structures as those of the Res-HF RPA's matrices. The quadratic steepest descent of the Res-HF energy in the orbital optimization is considered to include certainly both effects of RPA-type fluctuations up to higher orders and their mode-mode couplings. It is a very important and interesting task to apply the Res-HF RPA to the Lipkin model with the use of the stationary values and to prove the above argument. It turns out that the Res-HF RPA works far better than the usual HF RPA and the renormalized one. We also show some important features of the Res-HF RPA. (orig.)

  2. Linear-scaling implementation of the direct random-phase approximation

    International Nuclear Information System (INIS)

    Kállay, Mihály

    2015-01-01

    We report the linear-scaling implementation of the direct random-phase approximation (dRPA) for closed-shell molecular systems. As a bonus, linear-scaling algorithms are also presented for the second-order screened exchange extension of dRPA as well as for the second-order Møller–Plesset (MP2) method and its spin-scaled variants. Our approach is based on an incremental scheme which is an extension of our previous local correlation method [Rolik et al., J. Chem. Phys. 139, 094105 (2013)]. The approach extensively uses local natural orbitals to reduce the size of the molecular orbital basis of local correlation domains. In addition, we also demonstrate that using natural auxiliary functions [M. Kállay, J. Chem. Phys. 141, 244113 (2014)], the size of the auxiliary basis of the domains and thus that of the three-center Coulomb integral lists can be reduced by an order of magnitude, which results in significant savings in computation time. The new approach is validated by extensive test calculations for energies and energy differences. Our benchmark calculations also demonstrate that the new method enables dRPA calculations for molecules with more than 1000 atoms and 10 000 basis functions on a single processor

  3. Roles of antinucleon degrees of freedom in the relativistic random phase approximation

    Science.gov (United States)

    Kurasawa, Haruki; Suzuki, Toshio

    2015-11-01

    The roles of antinucleon degrees of freedom in the relativistic random phase approximation (RPA) are investigated. The energy-weighted sum of the RPA transition strengths is expressed in terms of the double commutator between the excitation operator and the Hamiltonian, as in nonrelativistic models. The commutator, however, should not be calculated in the usual way in the local field theory, because, otherwise, the sum vanishes. The sum value obtained correctly from the commutator is infinite, owing to the Dirac sea. Most of the previous calculations take into account only some of the nucleon-antinucleon states, in order to avoid divergence problems. As a result, RPA states with negative excitation energy appear, which make the sum value vanish. Moreover, disregarding the divergence changes the sign of nuclear interactions in the RPA equation that describes the coupling of the nucleon particle-hole states with the nucleon-antinucleon states. Indeed, the excitation energies of the spurious state and giant monopole states in the no-sea approximation are dominated by these unphysical changes. The baryon current conservation can be described without touching the divergence problems. A schematic model with separable interactions is presented, which makes the structure of the relativistic RPA transparent.

  4. Restricted second random phase approximations and Tamm-Dancoff approximations for electronic excitation energy calculations

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Degao; Yang, Yang; Zhang, Peng [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Yang, Weitao, E-mail: weitao.yang@duke.edu [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2014-12-07

    In this article, we develop systematically second random phase approximations (RPA) and Tamm-Dancoff approximations (TDA) of particle-hole and particle-particle channels for calculating molecular excitation energies. The second particle-hole RPA/TDA can capture double excitations missed by the particle-hole RPA/TDA and time-dependent density-functional theory (TDDFT), while the second particle-particle RPA/TDA recovers non-highest-occupied-molecular-orbital excitations missed by the particle-particle RPA/TDA. With proper orbital restrictions, these restricted second RPAs and TDAs have a formal scaling of only O(N{sup 4}). The restricted versions of second RPAs and TDAs are tested with various small molecules to show some positive results. Data suggest that the restricted second particle-hole TDA (r2ph-TDA) has the best overall performance with a correlation coefficient similar to TDDFT, but with a larger negative bias. The negative bias of the r2ph-TDA may be induced by the unaccounted ground state correlation energy to be investigated further. Overall, the r2ph-TDA is recommended to study systems with both single and some low-lying double excitations with a moderate accuracy. Some expressions on excited state property evaluations, such as 〈S{sup ^2}〉 are also developed and tested.

  5. Chiral NNLOsat descriptions of nuclear multipole resonances within the random-phase approximation

    Science.gov (United States)

    Wu, Q.; Hu, B. S.; Xu, F. R.; Ma, Y. Z.; Dai, S. J.; Sun, Z. H.; Jansen, G. R.

    2018-05-01

    We study nuclear multipole resonances in the framework of the random-phase approximation by using the chiral potential NNLOsat. This potential includes two- and three-body terms that have been simultaneously optimized to low-energy nucleon-nucleon scattering data and selected nuclear structure data. Our main focuses have been the isoscalar monopole, isovector dipole, and isoscalar quadrupole resonances of the closed-shell nuclei, 4He, O 16 ,22 ,24 , and Ca,4840. These resonance modes have been widely observed in experiment. In addition, we use a renormalized chiral potential Vlow-k, based on the N3LO two-body potential by Entem and Machleidt [Phys. Rev. C 68, 041001 (2011), 10.1103/PhysRevC.68.041001]. This introduces a dependency on the cutoff parameter used in the normalization procedure as reported in previous works by other groups. While NNLOsat can reasonably reproduce observed multipole resonances, it is not possible to find a single cutoff parameter for the Vlow-k potential that simultaneously describes the different types of resonance modes. The sensitivity to the cutoff parameter can be explained by missing induced three-body forces in the calculations. Our results for neutron-rich O,2422 show a mixing nature of isoscalar and isovector resonances in the dipole channel at low energies. We predict that 22O and 24O have low-energy isoscalar quadrupole resonances at energies lower than 5 MeV.

  6. Reference Determinant Dependence of the Random Phase Approximation in 3d Transition Metal Chemistry.

    Science.gov (United States)

    Bates, J E; Mezei, P D; Csonka, G I; Sun, J; Ruzsinszky, A

    2017-01-10

    Without extensive fitting, accurate prediction of transition metal chemistry is a challenge for semilocal and hybrid density funcitonals. The Random Phase Approximation (RPA) has been shown to yield superior results to semilocal functionals for main group thermochemistry, but much less is known about its performance for transition metals. We have therefore analyzed the behavior of reaction energies, barrier heights, and ligand dissociation energies obtained with RPA and compare our results to several semilocal and hybrid functionals. Particular attention is paid to the reference determinant dependence of RPA. We find that typically the results do not vary much between semilocal or hybrid functionals as a reference, as long as the fraction of exact exchange (EXX) mixing in the hybrid functional is small. For large fractions of EXX mixing, however, the Hartree-Fock-like nature of the determinant can severely degrade the performance. Overall, RPA systematically reduces the errors of semilocal functionals and delivers excellent performance from a single reference determinant for inherently multireference reactions. The behavior of dual hybrids that combine RPA correlation with a hybrid exchange energy was also explored, but ultimately did not lead to a systematic improvement compared to traditional RPA for these systems. We rationalize this conclusion by decomposing the contributions to the reaction energies, and briefly discuss the possible implications for double-hybrid functionals based on RPA. The correlation between EXX mixing and spin-symmetry breaking is also discussed.

  7. Broadband diffuse terahertz wave scattering by flexible metasurface with randomized phase distribution.

    Science.gov (United States)

    Zhang, Yin; Liang, Lanju; Yang, Jing; Feng, Yijun; Zhu, Bo; Zhao, Junming; Jiang, Tian; Jin, Biaobing; Liu, Weiwei

    2016-05-26

    Suppressing specular electromagnetic wave reflection or backward radar cross section is important and of broad interests in practical electromagnetic engineering. Here, we present a scheme to achieve broadband backward scattering reduction through diffuse terahertz wave reflection by a flexible metasurface. The diffuse scattering of terahertz wave is caused by the randomized reflection phase distribution on the metasurface, which consists of meta-particles of differently sized metallic patches arranged on top of a grounded polyimide substrate simply through a certain computer generated pseudorandom sequence. Both numerical simulations and experimental results demonstrate the ultralow specular reflection over a broad frequency band and wide angle of incidence due to the re-distribution of the incident energy into various directions. The diffuse scattering property is also polarization insensitive and can be well preserved when the flexible metasurface is conformably wrapped on a curved reflective object. The proposed design opens up a new route for specular reflection suppression, and may be applicable in stealth and other technology in the terahertz spectrum.

  8. The time-dependent relativistic mean-field theory and the random phase approximation

    International Nuclear Information System (INIS)

    Ring, P.; Ma, Zhong-yu; Van Giai, Nguyen; Vretenar, D.; Wandelt, A.; Cao, Li-gang

    2001-01-01

    The Relativistic Random Phase Approximation (RRPA) is derived from the Time-Dependent Relativistic Mean-Field (TD RMF) theory in the limit of small amplitude oscillations. In the no-sea approximation of the RMF theory, the RRPA configuration space includes not only the usual particle-hole ph-states, but also αh-configurations, i.e. pairs formed from occupied states in the Fermi sea and empty negative-energy states in the Dirac sea. The contribution of the negative-energy states to the RRPA matrices is examined in a schematic model, and the large effect of Dirac-sea states on isoscalar strength distributions is illustrated for the giant monopole resonance in 116 Sn. It is shown that, because the matrix elements of the time-like component of the vector-meson fields which couple the αh-configurations with the ph-configurations are strongly reduced with respect to the corresponding matrix elements of the isoscalar scalar meson field, the inclusion of states with unperturbed energies more than 1.2 GeV below the Fermi energy has a pronounced effect on giant resonances with excitation energies in the MeV region. The influence of nuclear magnetism, i.e. the effect of the spatial components of the vector fields is examined, and the difference between the nonrelativistic and relativistic RPA predictions for the nuclear matter compression modulus is explained

  9. Assessment of correlation energies based on the random-phase approximation

    International Nuclear Information System (INIS)

    Paier, Joachim; Ren, Xinguo; Rinke, Patrick; Scheffler, Matthias; Scuseria, Gustavo E; Grüneis, Andreas; Kresse, Georg

    2012-01-01

    The random-phase approximation to the ground state correlation energy (RPA) in combination with exact exchange (EX) has brought the Kohn-Sham (KS) density functional theory one step closer towards a universal, ‘general purpose first-principles method’. In an effort to systematically assess the influence of several correlation energy contributions beyond RPA, this paper presents dissociation energies of small molecules and solids, activation energies for hydrogen transfer and non-hydrogen transfer reactions, as well as reaction energies for a number of common test sets. We benchmark EX + RPA and several flavors of energy functionals going beyond it: second-order screened exchange (SOSEX), single-excitation (SE) corrections, renormalized single-excitation (rSE) corrections and their combinations. Both the SE correction and the SOSEX contribution to the correlation energy significantly improve on the notorious tendency of EX + RPA to underbind. Surprisingly, activation energies obtained using EX + RPA based on a KS reference alone are remarkably accurate. RPA + SOSEX + rSE provides an equal level of accuracy for reaction as well as activation energies and overall gives the most balanced performance, because of which it can be applied to a wide range of systems and chemical reactions. (paper)

  10. Least-squares reverse time migration of marine data with frequency-selection encoding

    KAUST Repository

    Dai, Wei

    2013-06-24

    The phase-encoding technique can sometimes increase the efficiency of the least-squares reverse time migration (LSRTM) by more than one order of magnitude. However, traditional random encoding functions require all the encoded shots to share the same receiver locations, thus limiting the usage to seismic surveys with a fixed spread geometry. We implement a frequency-selection encoding strategy that accommodates data with a marine streamer geometry. The encoding functions are delta functions in the frequency domain, so that all the encoded shots have unique nonoverlapping frequency content, and the receivers can distinguish the wavefield from each shot with a unique frequency band. Because the encoding functions are orthogonal to each other, there will be no crosstalk between different shots during modeling and migration. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is comparable to conventional RTM for the Marmousi2 model and a marine data set recorded in the Gulf of Mexico. With more iterations, the LSRTM image quality is further improved by suppressing migration artifacts, balancing reflector amplitudes, and enhancing the spatial resolution. We conclude that LSRTM with frequency-selection is an efficient migration method that can sometimes produce more focused images than conventional RTM. © 2013 Society of Exploration Geophysicists.

  11. Optimal scheme of postoperative chemoradiotherapy in rectal cancer: phase III prospective randomized trial

    International Nuclear Information System (INIS)

    Kim, Young Seok; Kim, Jong Hoon; Choi, Eun Kyung

    2002-01-01

    To determine the optimal scheme of postoperative chemoradiotherapy in rectal cancer by comparing survival, patterns of failure, toxicities in early and late radiotherapy groups using a phase III randomized prospective clinical trial. From January 1996 to March 1999, 307 patients with curatively resected AJCC stage II and III rectal cancer were assigned randomly to an 'early (151 patients, arm I)' or a 'late (156 patients, arm II)' and were administered combined chemotherapy (5-FU 375 mg/m 2 /day, leucovorin 20 mg/m 2 , IV bolus daily, for 3 days with RT, 5 days without RT, 8 cycles with 4 weeks interval) and radiation therapy (whole pelvis with 45 Gy/25 fractions/5 weeks). Patients of arm I received radiation therapy from day 1 of the first cycle of chemotherapy and those of arm II from day 57 with a third cycle of chemotherapy. The median follow-up period of living patients was 40 months. Of the 307 patients enrolled, fifty patients did not receive scheduled radiation therapy or chemotherapy. The overall survival rate and disease free survival rate at 5 years were 78.3% and 68.7% in arm I, and 78.4% and 67.5% in arm II. The local recurrence rate was 6.6% and 6.4% (ρ = 0.46) in arms I and II, respectively, no significant difference was observed between the distant metastasis rates of the two arms (23.8% and 29.5%, ρ = 0.16). During radiation therapy, grade 3 diarrhea or more, by the NCI common toxicity criteria, was observed in 63.0% and 58.2% of the respective arms (ρ = N.S.), but most were controlled with supportive care. Hematologic toxicity (leukopenia) greater than RTOG grade 2 was found in only 1.3% and 2.6% of patients in each respective arm. There was no significant difference in survival, patterns of failure or toxicities between the early and late radiation therapy arms. Postoperative adjuvant chemoradiation was found to be a relatively safe treatment but higher compliance is needed

  12. Trunk Exercises Improve Gait Symmetry in Parkinson Disease: A Blind Phase II Randomized Controlled Trial.

    Science.gov (United States)

    Hubble, Ryan P; Naughton, Geraldine; Silburn, Peter A; Cole, Michael H

    2018-03-01

    Deficits in step-to-step symmetry and trunk muscle activations have been linked to falls in Parkinson disease. Given such symptoms are poorly managed with anti-parkinsonian medications, alternate therapies are needed. This blind phase II randomized controlled trial sought to establish whether exercise can improve step-to-step symmetry in Parkinson disease. Twenty-four Parkinson disease patients with a falls history completed baseline assessments of symptom severity, balance confidence, mobility, and quality of life. Step-to-step symmetry was assessed by deriving harmonic ratios from three-dimensional accelerations collected for the head and trunk. Patients were randomly assigned to either 12 wks of exercise and falls prevention education or falls prevention education only. Both groups repeated the baseline tests 12 and 24 wks after the initial assessment. The Australian and New Zealand Clinical Trials Registry number is ACTRN12613001175763. At 12 wks, the exercise group had statistically significant and clinically relevant improvements in anterior-posterior step-to-step trunk symmetry. In contrast, the education group recorded statistically significant and clinically meaningful reductions in medial-lateral and vertical step-to-step trunk symmetry at 12 wks. Given that step-to-step symmetry improved for the exercise group and declined for the education group after intervention, active interventions seem more suited to increasing independence and quality of life for people with Parkinson disease. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to do the following: (1) Describe the effect deficits in trunk muscle function have on gait in individuals with Parkinson disease; (2) Identify the benefits of targeted trunk exercises on step-to-step symmetry; and (3) Discuss the benefits of improving step-to-step symmetry in individuals with Parkinson

  13. Sunitinib versus sorafenib in advanced hepatocellular cancer: results of a randomized phase III trial.

    Science.gov (United States)

    Cheng, Ann-Lii; Kang, Yoon-Koo; Lin, Deng-Yn; Park, Joong-Won; Kudo, Masatoshi; Qin, Shukui; Chung, Hyun-Cheol; Song, Xiangqun; Xu, Jianming; Poggi, Guido; Omata, Masao; Pitman Lowenthal, Susan; Lanzalone, Silvana; Yang, Liqiang; Lechuga, Maria Jose; Raymond, Eric

    2013-11-10

    Open-label, phase III trial evaluating whether sunitinib was superior or equivalent to sorafenib in hepatocellular cancer. Patients were stratified and randomly assigned to receive sunitinib 37.5 mg once per day or sorafenib 400 mg twice per day. Primary end point was overall survival (OS). Early trial termination occurred for futility and safety reasons. A total of 1,074 patients were randomly assigned to the study (sunitinib arm, n = 530; sorafenib arm, n = 544). For sunitinib and sorafenib, respectively, median OS was 7.9 versus 10.2 months (hazard ratio [HR], 1.30; one-sided P = .9990; two-sided P = .0014); median progression-free survival (PFS; 3.6 v 3.0 months; HR, 1.13; one-sided P = .8785; two-sided P = .2286) and time to progression (TTP; 4.1 v 3.8 months; HR, 1.13; one-sided P = .8312; two-sided P = .3082) were comparable. Median OS was similar among Asian (7.7 v 8.8 months; HR, 1.21; one-sided P = .9829) and hepatitis B-infected patients (7.6 v 8.0 months; HR, 1.10; one-sided P = .8286), but was shorter with sunitinib in hepatitis C-infected patients (9.2 v 17.6 months; HR, 1.52; one-sided P = .9835). Sunitinib was associated with more frequent and severe adverse events (AEs) than sorafenib. Common grade 3/4 AEs were thrombocytopenia (29.7%) and neutropenia (25.7%) for sunitinib; hand-foot syndrome (21.2%) for sorafenib. Discontinuations owing to AEs were similar (sunitinib, 13.3%; sorafenib, 12.7%). OS with sunitinib was not superior or equivalent but was significantly inferior to sorafenib. OS was comparable in Asian and hepatitis B-infected patients. OS was superior in hepatitis C-infected patients who received sorafenib. Sunitinib-treated patients reported more frequent and severe toxicity.

  14. Phase II prospective randomized trial of weight loss prior to radical prostatectomy.

    Science.gov (United States)

    Henning, Susanne M; Galet, Colette; Gollapudi, Kiran; Byrd, Joshua B; Liang, Pei; Li, Zhaoping; Grogan, Tristan; Elashoff, David; Magyar, Clara E; Said, Jonathan; Cohen, Pinchas; Aronson, William J

    2017-12-04

    Obesity is associated with poorly differentiated and advanced prostate cancer and increased mortality. In preclinical models, caloric restriction delays prostate cancer progression and prolongs survival. We sought to determine if weight loss (WL) in men with prostate cancer prior to radical prostatectomy affects tumor apoptosis and proliferation, and if WL effects other metabolic biomarkers. In this Phase II prospective trial, overweight and obese men scheduled for radical prostatectomy were randomized to a 5-8 week WL program consisting of standard structured energy-restricted meal plans (1200-1500 Kcal/day) and physical activity or to a control group. The primary endpoint was apoptotic index in the radical prostatectomy malignant epithelium. Secondary endpoints were proliferation (Ki67) in the radical prostatectomy tissue, body weight, body mass index (BMI), waist to hip ratio, body composition, and serum PSA, insulin, triglyceride, cholesterol, testosterone, estradiol, leptin, adiponectin, interleukin 6, interleukin 8, insulin-like growth factor 1, and IGF binding protein 1. In total 23 patients were randomized to the WL intervention and 21 patients to the control group. Subjects in the intervention group had significantly more weight loss (WL:-3.7 ± 0.5 kg; Control:-1.6 ± 0.5 kg; p = 0.007) than the control group and total fat mass was significantly reduced (WL:-2.1 ± 0.4; Control: 0.1 ± 0.3; p = 0.015). There was no significant difference in apoptotic or proliferation index between the groups. Among the other biomarkers, triglyceride, and insulin levels were significantly decreased in the WL compared with the control group. In summary, this short-term WL program prior to radical prostatectomy resulted in significantly more WL in the intervention vs. the control group and was accompanied by significant reductions in body fat mass, circulating triglycerides, and insulin. However, no significant changes were observed in malignant

  15. Pharmacokinetics and Safety of Amenamevir in Healthy Subjects: Analysis of Four Randomized Phase 1 Studies.

    Science.gov (United States)

    Kusawake, Tomohiro; Keirns, James J; Kowalski, Donna; den Adel, Martin; Groenendaal-van de Meent, Dorien; Takada, Akitsugu; Ohtsu, Yoshiaki; Katashima, Masataka

    2017-12-01

    Amenamevir (ASP2151) is a nonnucleoside antiherpesvirus compound available for the treatment of varicella-zoster virus infections. In this article we summarize the findings of four phase 1 studies in healthy participants. Four randomized phase 1 studies investigated the safety and pharmacokinetics of single and multiple doses of amenamevir, including the assessment of age group effect (nonelderly vs elderly), food effect, and the relative bioavailability of two formulations. Amenamevir was administered orally at various doses as a single dose (5-2400 mg) or daily (300 or 600 mg/day) for 7 days. Following single and multiple oral doses, amenamevir demonstrated a less than dose proportional increase in the pharmacokinetic parameters area under the plasma drug concentration versus time curve from time zero to infinity (AUC inf ) and C max . After single and multiple oral 300-mg doses of amenamevir, no apparent differences in pharmacokinetics were observed between nonelderly and elderly participants. In contrast, with the amenamevir 600-mg dose both the area under the plasma drug concentration versus time curve from time zero to 24 h and C max were slightly increased and renal clearance was decreased in elderly participants. The pharmacokinetics of amenamevir was affected by food, with AUC inf increased by about 90%. In the bioavailability study, AUC inf and C max were slightly lower following tablet versus capsule administration (decreased by 14 and 12%, respectively), with relative bioavailability of 86%. The different amenamevir doses and formulations were safe and well tolerated; no deaths or serious adverse events were reported. Amenamevir had less than dose proportional pharmacokinetic characteristics. Age may have an influence on amenamevir pharmacokinetics; however, the effect was considered minimal. The pharmacokinetics of amenamevir were affected by food, with AUC inf almost doubling when amenamevir was administered with food. The concentration versus

  16. Exchange-correlation energy from pairing matrix fluctuation and the particle-particle random phase approximation.

    Science.gov (United States)

    van Aggelen, Helen; Yang, Yang; Yang, Weitao

    2014-05-14

    Despite their unmatched success for many applications, commonly used local, semi-local, and hybrid density functionals still face challenges when it comes to describing long-range interactions, static correlation, and electron delocalization. Density functionals of both the occupied and virtual orbitals are able to address these problems. The particle-hole (ph-) Random Phase Approximation (RPA), a functional of occupied and virtual orbitals, has recently known a revival within the density functional theory community. Following up on an idea introduced in our recent communication [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)], we formulate more general adiabatic connections for the correlation energy in terms of pairing matrix fluctuations described by the particle-particle (pp-) propagator. With numerical examples of the pp-RPA, the lowest-order approximation to the pp-propagator, we illustrate the potential of density functional approximations based on pairing matrix fluctuations. The pp-RPA is size-extensive, self-interaction free, fully anti-symmetric, describes the strong static correlation limit in H2, and eliminates delocalization errors in H2(+) and other single-bond systems. It gives surprisingly good non-bonded interaction energies--competitive with the ph-RPA--with the correct R(-6) asymptotic decay as a function of the separation R, which we argue is mainly attributable to its correct second-order energy term. While the pp-RPA tends to underestimate absolute correlation energies, it gives good relative energies: much better atomization energies than the ph-RPA, as it has no tendency to underbind, and reaction energies of similar quality. The adiabatic connection in terms of pairing matrix fluctuation paves the way for promising new density functional approximations.

  17. Exchange-correlation energy from pairing matrix fluctuation and the particle-particle random phase approximation

    International Nuclear Information System (INIS)

    Aggelen, Helen van; Yang, Yang; Yang, Weitao

    2014-01-01

    Despite their unmatched success for many applications, commonly used local, semi-local, and hybrid density functionals still face challenges when it comes to describing long-range interactions, static correlation, and electron delocalization. Density functionals of both the occupied and virtual orbitals are able to address these problems. The particle-hole (ph-) Random Phase Approximation (RPA), a functional of occupied and virtual orbitals, has recently known a revival within the density functional theory community. Following up on an idea introduced in our recent communication [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)], we formulate more general adiabatic connections for the correlation energy in terms of pairing matrix fluctuations described by the particle-particle (pp-) propagator. With numerical examples of the pp-RPA, the lowest-order approximation to the pp-propagator, we illustrate the potential of density functional approximations based on pairing matrix fluctuations. The pp-RPA is size-extensive, self-interaction free, fully anti-symmetric, describes the strong static correlation limit in H 2 , and eliminates delocalization errors in H 2 + and other single-bond systems. It gives surprisingly good non-bonded interaction energies – competitive with the ph-RPA – with the correct R −6 asymptotic decay as a function of the separation R, which we argue is mainly attributable to its correct second-order energy term. While the pp-RPA tends to underestimate absolute correlation energies, it gives good relative energies: much better atomization energies than the ph-RPA, as it has no tendency to underbind, and reaction energies of similar quality. The adiabatic connection in terms of pairing matrix fluctuation paves the way for promising new density functional approximations

  18. Application of the random phase approximation to some atoms with ns2 ground state configurations

    International Nuclear Information System (INIS)

    Wright, L.A.

    1975-01-01

    Atomic bound state properties such as excitation energies and oscillator strengths were calculated by the Random Phase Approximation (RPA), also known as the Time Dependent Hartree-Fock Approximation (TDHFA). The RPA is equivalent to describing excited states as the creation of particle-hole pairs and the application to atoms is important for two reasons: the wide range of densities in an atom will cause the physical interpretation and mathematical approximations to be much different than with a uniform density system, such as an electron gas; this method could detect the existence of collective states in atoms similar to those responsible for the giant dipole resonances in nuclei. The method is shown to be superior to the H-F method in three basic ways: (1) The RPA contains explicit correlations between the excited and ground states. These are not included in the H-F theory. One can apply this method to large atoms since only these correlations are explicitly included. (2) The RPA calculates excitation energies directly without recourse to highly correlated ground state wavefunctions. This is in contrast to the method of configuration mixing which is known to have slow convergence properties. (3) Oscillator strengths and photoionization cross sections can be calculated by finding the eigenvectors corresponding excitation energy eigenvalues. The strength of the RPA is that the excitation energies and oscillator strengths, which are relative quantities, are calculated directly. The results for the oscillator strengths show an improvement of up to 45 percent over the H-F values and an improvement over the RPA done with Hartree wavefunctions by as much as 65 percent. The work was limited to atoms with an ns 2 ground state configuration. These atoms were He, Be, Mg and Ca

  19. Benchmark tests and spin adaptation for the particle-particle random phase approximation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Steinmann, Stephan N.; Peng, Degao [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Aggelen, Helen van, E-mail: Helen.VanAggelen@UGent.be [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Department of Inorganic and Physical Chemistry, Ghent University, 9000 Ghent (Belgium); Yang, Weitao, E-mail: Weitao.Yang@duke.edu [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2013-11-07

    The particle-particle random phase approximation (pp-RPA) provides an approximation to the correlation energy in density functional theory via the adiabatic connection [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)]. It has virtually no delocalization error nor static correlation error for single-bond systems. However, with its formal O(N{sup 6}) scaling, the pp-RPA is computationally expensive. In this paper, we implement a spin-separated and spin-adapted pp-RPA algorithm, which reduces the computational cost by a substantial factor. We then perform benchmark tests on the G2/97 enthalpies of formation database, DBH24 reaction barrier database, and four test sets for non-bonded interactions (HB6/04, CT7/04, DI6/04, and WI9/04). For the G2/97 database, the pp-RPA gives a significantly smaller mean absolute error (8.3 kcal/mol) than the direct particle-hole RPA (ph-RPA) (22.7 kcal/mol). Furthermore, the error in the pp-RPA is nearly constant with the number of atoms in a molecule, while the error in the ph-RPA increases. For chemical reactions involving typical organic closed-shell molecules, pp- and ph-RPA both give accurate reaction energies. Similarly, both RPAs perform well for reaction barriers and nonbonded interactions. These results suggest that the pp-RPA gives reliable energies in chemical applications. The adiabatic connection formalism based on pairing matrix fluctuation is therefore expected to lead to widely applicable and accurate density functionals.

  20. Application of the random phase approximation to complex problems in materials science

    International Nuclear Information System (INIS)

    Schimka, L.

    2012-01-01

    This thesis is devoted to the assessment and application of the random phase approximation (RPA) in the adiabatic-connection fluctuation-dissipation (ACFD) framework in solid state physics. The first part presents a review of density functional theory (DFT) and the ACFD theorem in the RPA. This includes an introduction to the many-body problem as well as a description of the implementation of the RPA in the Vienna Ab-initio Simulation Package (VASP). In the results part, the quality of the RPA is assessed and its performance compared to three (beyond) DFT functionals. The experimental values are corrected for the effect of phonon zero-point vibrational energies which were calculated at the DFT level from ab-initio. We find that the RPA describes all bonding situations very accurately, making it a promising candidate for more complex problems in solid state physics. In light of these findings, we investigate the carbon-water interaction in two specific cases: the adsorption of water on benzene and the adsorption of water on a graphene layer. We compare our results to a different correlated method: diffusion Monte Carlo (DMC). We find very good agreement and thus believe that our values can serve as a benchmark for the development of other DFT functionals to treat water-carbon interfaces. The highlight of this thesis is the successful application of the RPA to the long-standing and (at DFT level) unsolved CO adsorption puzzle. We show results for CO adsorption on Cu, late 4d metals and Pt. RPA is at present the only ab-initio method that describes adsorption and surface energies accurately at the same time and predicts the correct adsorption site in every single case. (author) [de

  1. Accurate and Efficient Parallel Implementation of an Effective Linear-Scaling Direct Random Phase Approximation Method.

    Science.gov (United States)

    Graf, Daniel; Beuerle, Matthias; Schurkus, Henry F; Luenser, Arne; Savasci, Gökcen; Ochsenfeld, Christian

    2018-05-08

    An efficient algorithm for calculating the random phase approximation (RPA) correlation energy is presented that is as accurate as the canonical molecular orbital resolution-of-the-identity RPA (RI-RPA) with the important advantage of an effective linear-scaling behavior (instead of quartic) for large systems due to a formulation in the local atomic orbital space. The high accuracy is achieved by utilizing optimized minimax integration schemes and the local Coulomb metric attenuated by the complementary error function for the RI approximation. The memory bottleneck of former atomic orbital (AO)-RI-RPA implementations ( Schurkus, H. F.; Ochsenfeld, C. J. Chem. Phys. 2016 , 144 , 031101 and Luenser, A.; Schurkus, H. F.; Ochsenfeld, C. J. Chem. Theory Comput. 2017 , 13 , 1647 - 1655 ) is addressed by precontraction of the large 3-center integral matrix with the Cholesky factors of the ground state density reducing the memory requirements of that matrix by a factor of [Formula: see text]. Furthermore, we present a parallel implementation of our method, which not only leads to faster RPA correlation energy calculations but also to a scalable decrease in memory requirements, opening the door for investigations of large molecules even on small- to medium-sized computing clusters. Although it is known that AO methods are highly efficient for extended systems, where sparsity allows for reaching the linear-scaling regime, we show that our work also extends the applicability when considering highly delocalized systems for which no linear scaling can be achieved. As an example, the interlayer distance of two covalent organic framework pore fragments (comprising 384 atoms in total) is analyzed.

  2. Hindrance Velocity Model for Phase Segregation in Suspensions of Poly-dispersed Randomly Oriented Spheroids

    Science.gov (United States)

    Faroughi, S. A.; Huber, C.

    2015-12-01

    Crystal settling and bubbles migration in magmas have significant effects on the physical and chemical evolution of magmas. The rate of phase segregation is controlled by the force balance that governs the migration of particles suspended in the melt. The relative velocity of a single particle or bubble in a quiescent infinite fluid (melt) is well characterized; however, the interplay between particles or bubbles in suspensions and emulsions and its effect on their settling/rising velocity remains poorly quantified. We propose a theoretical model for the hindered velocity of non-Brownian emulsions of nondeformable droplets, and suspensions of spherical solid particles in the creeping flow regime. The model is based on three sets of hydrodynamic corrections: two on the drag coefficient experienced by each particle to account for both return flow and Smoluchowski effects and a correction on the mixture rheology to account for nonlocal interactions between particles. The model is then extended for mono-disperse non-spherical solid particles that are randomly oriented. The non-spherical particles are idealized as spheroids and characterized by their aspect ratio. The poly-disperse nature of natural suspensions is then taken into consideration by introducing an effective volume fraction of particles for each class of mono-disperse particles sizes. Our model is tested against new and published experimental data over a wide range of particle volume fraction and viscosity ratios between the constituents of dispersions. We find an excellent agreement between our model and experiments. We also show two significant applications for our model: (1) We demonstrate that hindered settling can increase mineral residence time by up to an order of magnitude in convecting magma chambers. (2) We provide a model to correct for particle interactions in the conventional hydrometer test to estimate the particle size distribution in soils. Our model offers a greatly improved agreement with

  3. Focusing of high intensity ultrasound through the rib cage using a therapeutic random phased array

    Science.gov (United States)

    Bobkova, Svetlana; Gavrilov, Leonid; Khokhlova, Vera; Shaw, Adam; Hand, Jeffrey; #, ||

    2010-01-01

    A method for focusing high intensity ultrasound through a rib cage that aims to minimize heating of the ribs whilst maintaining high intensities at the focus (or foci) is proposed and tested theoretically and experimentally. Two approaches, one based on geometric acoustics and the other accounting for diffraction effects associated with propagation through the rib cage, are investigated theoretically for idealized source conditions. It is shown that for an idealized radiator the diffraction approach provides a 23% gain in peak intensity and results in significantly less power losses on the ribs (1% versus 7.5% of the irradiated power) compared with the geometric one. A 2D 1-MHz phased array with 254 randomly distributed elements, tissue mimicking phantoms, and samples of porcine rib cages are used in experiments; the geometric approach is used to configure how the array is driven. Intensity distributions are measured in the plane of the ribs and in the focal plane using an infra-red camera. Theoretical and experimental results show that it is possible to provide adequate focusing through the ribs without overheating them for a single focus and several foci, including steering at ± 10–15 mm off and ± 20 mm along the array axis. Focus splitting due to the periodic spatial structure of ribs is demonstrated both in simulations and experiments; the parameters of splitting are quantified. The ability to produce thermal lesions with a split focal pattern in ex vivo porcine tissue placed beyond the rib phantom is also demonstrated. The results suggest that the method is potentially useful for clinical applications of HIFU for which the rib cage lies between the transducer(s) and the targeted tissue. PMID:20510186

  4. Phase diagrams of a spin-1/2 transverse Ising model with three-peak random field distribution

    International Nuclear Information System (INIS)

    Bassir, A.; Bassir, C.E.; Benyoussef, A.; Ez-Zahraouy, H.

    1996-07-01

    The effect of the transverse magnetic field on the phase diagrams structures of the Ising model in a random longitudinal magnetic field with a trimodal symmetric distribution is investigated within a finite cluster approximation. We find that a small magnetizations ordered phase (small ordered phase) disappears completely for a sufficiently large value of the transverse field or/and large value of the concentration of the disorder of the magnetic field. Multicritical behaviour and reentrant phenomena are discussed. The regions where the tricritical, reentrant phenomena and the small ordered phase persist are delimited as a function of the transverse field and the concentration p. Longitudinal magnetizations are also presented. (author). 33 refs, 6 figs

  5. Scandium doping brings speed improvement in Sb2Te alloy for phase change random access memory application.

    Science.gov (United States)

    Chen, Xin; Zheng, Yonghui; Zhu, Min; Ren, Kun; Wang, Yong; Li, Tao; Liu, Guangyu; Guo, Tianqi; Wu, Lei; Liu, Xianqiang; Cheng, Yan; Song, Zhitang

    2018-05-01

    Phase change random access memory (PCRAM) has gained much attention as a candidate for nonvolatile memory application. To develop PCRAM materials with better properties, especially to draw closer to dynamic random access memory (DRAM), the key challenge is to research new high-speed phase change materials. Here, Scandium (Sc) has been found it is helpful to get high-speed and good stability after doping in Sb 2 Te alloy. Sc 0.1 Sb 2 Te based PCRAM cell can achieve reversible switching by applying even 6 ns voltage pulse experimentally. And, Sc doping not only promotes amorphous stability but also improves the endurance ability comparing with pure Sb 2 Te alloy. Moreover, according to DFT calculations, strong Sc-Te bonds lead to the rigidity of Sc centered octahedrons, which may act as crystallization precursors in recrystallization process to boost the set speed.

  6. The Kubo-Greenwood formula as a result of the random phase approximation for the electrons of the metal

    Science.gov (United States)

    Ivliev, S. V.

    2017-12-01

    For calculation of short laser pulse absorption in metal the imaginary part of permittivity, which is simply related to the conductivity, is required. Currently to find the static and dynamic conductivity the Kubo-Greenwood formula is most commonly used. It describes the electromagnetic energy absorption in the one-electron approach. In the present study, this formula is derived directly from the expression for the permittivity expression in the random phase approximation, which in fact is equivalent to the method of the mean field. The detailed analysis of the role of electron-electron interaction in the calculation of the matrix elements of the velocity operator is given. It is shown that in the one-electron random phase approximation the single-particle conductive electron wave functions in the field of fixed ions should be used. The possibility of considering the exchange and correlation effects by means of an amendment to a local function field is discussed.

  7. A randomized trial of microdose leuprolide acetate protocol versus luteal phase ganirelix protocol in predicted poor responders.

    Science.gov (United States)

    DiLuigi, Andrea J; Engmann, Lawrence; Schmidt, David W; Benadiva, Claudio A; Nulsen, John C

    2011-06-30

    We performed a randomized trial to compare IVF outcomes in 54 poor responder patients undergoing a microdose leuprolide acetate (LA) protocol or a GnRH antagonist protocol incorporating a luteal phase E(2) patch and GnRH antagonist in the preceding menstrual cycle. Cancellation rates, number of oocytes retrieved, clinical pregnancy rates (PR), and ongoing PRs were similar between the two groups. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  8. Studies of Ionic Photoionization Using Relativistic Random Phase Approximation and Relativistic Multichannel Quantum Defect Theory

    Science.gov (United States)

    Haque, Ghousia Nasreen

    The absorption of electromagnetic radiation by positive ions is one of the fundamental processes of nature which occurs in every intensely hot environment. Due to the difficulties in producing sufficient densities of ions in a laboratory, there are very few measurements of ionic photoabsorption parameters. On the theoretical side, some calculations have been made of a few major photoionization parameters, but generally speaking, most of the work done so far has employed rather simple single particle models and any theoretical work which has adequately taken into account intricate atomic many-body and relativistic effects is only scanty. In the present work, several complex aspects of atomic/ionic photoabsorption parameters have been studied. Non -resonant photoionization in neon and argon isonuclear as well as isoelectronic sequences has been studied using a very sophisticated technique, namely the relativistic random phase approximation (RRPA). This technique takes into account relativistic effects as well as an important class of major many-body effects on the same footing. The present calculations confirmed that gross features of photoionization parameters calculated using simpler models were not an artifact of the simple model. Also, the present RRPA calculations on K^+ ion and neutral Ar brought out the relative importance of various many-body effects such the inter-channel coupling. Inter-channel coupling between discrete bound state photoexcitation channels from an inner atomic/ionic level and photoionization continuum channels from an outer atomic/ionic level leads to the phenomena of autoionization resonances in the photoionization process. These resonances lead to very complex effects in the atomic/ionic photoabsorption spectra. These resonances have been calculated and studied in the present work in the neon and magnesium isoelectronic sequences using the relativistic multi-channel quantum defect theory (RMQDT) within the framework of the RRPA. The

  9. Least-squares reverse time migration of marine data with frequency-selection encoding

    KAUST Repository

    Dai, Wei

    2013-08-20

    The phase-encoding technique can sometimes increase the efficiency of the least-squares reverse time migration (LSRTM) by more than one order of magnitude. However, traditional random encoding functions require all the encoded shots to share the same receiver locations, thus limiting the usage to seismic surveys with a fixed spread geometry. We implement a frequency-selection encoding strategy that accommodates data with a marine streamer geometry. The encoding functions are delta functions in the frequency domain, so that all the en- coded shots have unique non-overlapping frequency content, and the receivers can distinguish the wavefield from each shot with a unique frequency band. Since the encoding functions are orthogonal to each other, there will be no crosstalk between different shots during modeling and migration. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is compara- ble to conventional RTM for both the Marmousi2 model and a marine data set recorded in the Gulf of Mexico. With more iterations, the LSRTM image quality is further improved. We conclude that LSRTM with frequency-selection is an efficient migration method that can sometimes produce more focused images than conventional RTM.

  10. Optimal dose selection accounting for patient subpopulations in a randomized Phase II trial to maximize the success probability of a subsequent Phase III trial.

    Science.gov (United States)

    Takahashi, Fumihiro; Morita, Satoshi

    2018-02-08

    Phase II clinical trials are conducted to determine the optimal dose of the study drug for use in Phase III clinical trials while also balancing efficacy and safety. In conducting these trials, it may be important to consider subpopulations of patients grouped by background factors such as drug metabolism and kidney and liver function. Determining the optimal dose, as well as maximizing the effectiveness of the study drug by analyzing patient subpopulations, requires a complex decision-making process. In extreme cases, drug development has to be terminated due to inadequate efficacy or severe toxicity. Such a decision may be based on a particular subpopulation. We propose a Bayesian utility approach (BUART) to randomized Phase II clinical trials which uses a first-order bivariate normal dynamic linear model for efficacy and safety in order to determine the optimal dose and study population in a subsequent Phase III clinical trial. We carried out a simulation study under a wide range of clinical scenarios to evaluate the performance of the proposed method in comparison with a conventional method separately analyzing efficacy and safety in each patient population. The proposed method showed more favorable operating characteristics in determining the optimal population and dose.

  11. Dynamical replica analysis of processes on finitely connected random graphs: II. Dynamics in the Griffiths phase of the diluted Ising ferromagnet

    International Nuclear Information System (INIS)

    Mozeika, A; Coolen, A C C

    2009-01-01

    We study the Glauber dynamics of Ising spin models with random bonds, on finitely connected random graphs. We generalize a recent dynamical replica theory with which to predict the evolution of the joint spin-field distribution, to include random graphs with arbitrary degree distributions. The theory is applied to Ising ferromagnets on randomly diluted Bethe lattices, where we study the evolution of the magnetization and the internal energy. It predicts a prominent slowing down of the flow in the Griffiths phase, it suggests a further dynamical transition at lower temperatures within the Griffiths phase, and it is verified quantitatively by the results of Monte Carlo simulations

  12. Phase structure of the O(n) model on a random lattice for n > 2

    DEFF Research Database (Denmark)

    Durhuus, B.; Kristjansen, C.

    1997-01-01

    We show that coarse graining arguments invented for the analysis of multi-spin systems on a randomly triangulated surface apply also to the O(n) model on a random lattice. These arguments imply that if the model has a critical point with diverging string susceptibility, then either γ = +1....../2 or there exists a dual critical point with negative string susceptibility exponent, γ̃, related to γ by γ = γ̃/γ̃-1. Exploiting the exact solution of the O(n) model on a random lattice we show that both situations are realized for n > 2 and that the possible dual pairs of string susceptibility exponents are given...... by (γ̃, γ) = (-1/m, 1/m+1), m = 2, 3, . . . We also show that at the critical points with positive string susceptibility exponent the average number of loops on the surface diverges while the average length of a single loop stays finite....

  13. Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

    Science.gov (United States)

    Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

    2016-03-29

    Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

  14. Phase-space diffusion in turbulent plasmas: The random acceleration problem revisited

    DEFF Research Database (Denmark)

    Pécseli, H.L.; Trulsen, J.

    1991-01-01

    Phase-space diffusion of test particles in turbulent plasmas is studied by an approach based on a conditional statistical analysis of fluctuating electrostatic fields. Analytical relations between relevant conditional averages and higher-order correlations, , and triple...

  15. The impact of luteal phase support on endometrial estrogen and progesterone receptor expression: a randomized control trial

    Directory of Open Access Journals (Sweden)

    Brezina Paul R

    2012-02-01

    Full Text Available Abstract Background To assess the impact of luteal phase support on the expression of estrogen receptor (ER alpha and progesterone receptors B (PR-B on the endometrium of oocyte donors undergoing controlled ovarian hyperstimulation (COH. Methods A prospective, randomized study was conducted in women undergoing controlled ovarian hyperstimulation for oocyte donation. Participants were randomized to receive no luteal support, vaginal progesterone alone, or vaginal progesterone plus orally administered 17 Beta estradiol. Endometrial biopsies were obtained at 4 time points in the luteal phase and evaluated by tissue microarray for expression of ER alpha and PR-B. Results One-hundred and eight endometrial tissue samples were obtained from 12 patients. No differences were found in expression of ER alpha and PR-B among all the specimens with the exception of one sample value. Conclusions The administration of progesterone during the luteal phase of COH for oocyte donor cycles, either with or without estrogen, does not significantly affect the endometrial expression of ER alpha and PR.

  16. Efficacy of extended-release tramadol for treatment of prescription opioid withdrawal: A two-phase randomized controlled trial*

    Science.gov (United States)

    Lofwall, Michelle R.; Babalonis, Shanna; Nuzzo, Paul A.; Siegel, Anthony; Campbell, Charles; Walsh, Sharon L.

    2013-01-01

    Background Tramadol is an atypical analgesic with monoamine and modest mu opioid agonist activity. The purpose of this study was to evaluate: 1) the efficacy of extended-release (ER) tramadol in treating prescription opioid withdrawal and 2) whether cessation of ER tramadol produces opioid withdrawal. Methods Prescription opioid users with current opioid dependence and observed withdrawal participated in this inpatient, two-phase double blind, randomized placebo-controlled trial. In Phase 1 (days 1-7), participants were randomly assigned to matched oral placebo or ER tramadol (200 or 600 mg daily). In Phase 2 (days 8-13), all participants underwent double blind crossover to placebo. Breakthrough withdrawal medications were available for all subjects. Enrollment continued until 12 completers/group was achieved. Results Use of breakthrough withdrawal medication differed significantly (popioid withdrawal. Mild opioid withdrawal occurred after cessation of treatment with 600 mg tramadol. These data support the continued investigation of tramadol as a treatment for opioid withdrawal. PMID:23755929

  17. Efficacy of extended-release tramadol for treatment of prescription opioid withdrawal: a two-phase randomized controlled trial.

    Science.gov (United States)

    Lofwall, Michelle R; Babalonis, Shanna; Nuzzo, Paul A; Siegel, Anthony; Campbell, Charles; Walsh, Sharon L

    2013-11-01

    Tramadol is an atypical analgesic with monoamine and modest mu opioid agonist activity. The purpose of this study was to evaluate: (1) the efficacy of extended-release (ER) tramadol in treating prescription opioid withdrawal and (2) whether cessation of ER tramadol produces opioid withdrawal. Prescription opioid users with current opioid dependence and observed withdrawal participated in this inpatient, two-phase double blind, randomized placebo-controlled trial. In Phase 1 (days 1-7), participants were randomly assigned to matched oral placebo or ER tramadol (200 or 600 mg daily). In Phase 2 (days 8-13), all participants underwent double blind crossover to placebo. Breakthrough withdrawal medications were available for all subjects. Enrollment continued until 12 completers/group was achieved. Use of breakthrough withdrawal medication differed significantly (popioid withdrawal. Mild opioid withdrawal occurred after cessation of treatment with 600 mg tramadol. These data support the continued investigation of tramadol as a treatment for opioid withdrawal. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  18. Quasi-Coherent Noise Jamming to LFM Radar Based on Pseudo-random Sequence Phase-modulation

    Directory of Open Access Journals (Sweden)

    N. Tai

    2015-12-01

    Full Text Available A novel quasi-coherent noise jamming method is proposed against linear frequency modulation (LFM signal and pulse compression radar. Based on the structure of digital radio frequency memory (DRFM, the jamming signal is acquired by the pseudo-random sequence phase-modulation of sampled radar signal. The characteristic of jamming signal in time domain and frequency domain is analyzed in detail. Results of ambiguity function indicate that the blanket jamming effect along the range direction will be formed when jamming signal passes through the matched filter. By flexible controlling the parameters of interrupted-sampling pulse and pseudo-random sequence, different covering distances and jamming effects will be achieved. When the jamming power is equivalent, this jamming obtains higher process gain compared with non-coherent jamming. The jamming signal enhances the detection threshold and the real target avoids being detected. Simulation results and circuit engineering implementation validate that the jamming signal covers real target effectively.

  19. Strong disorder real-space renormalization for the many-body-localized phase of random Majorana models

    Science.gov (United States)

    Monthus, Cécile

    2018-03-01

    For the many-body-localized phase of random Majorana models, a general strong disorder real-space renormalization procedure known as RSRG-X (Pekker et al 2014 Phys. Rev. X 4 011052) is described to produce the whole set of excited states, via the iterative construction of the local integrals of motion (LIOMs). The RG rules are then explicitly derived for arbitrary quadratic Hamiltonians (free-fermions models) and for the Kitaev chain with local interactions involving even numbers of consecutive Majorana fermions. The emphasis is put on the advantages of the Majorana language over the usual quantum spin language to formulate unified RSRG-X rules.

  20. Accurate Quasiparticle Spectra from the T-Matrix Self-Energy and the Particle-Particle Random Phase Approximation.

    Science.gov (United States)

    Zhang, Du; Su, Neil Qiang; Yang, Weitao

    2017-07-20

    The GW self-energy, especially G 0 W 0 based on the particle-hole random phase approximation (phRPA), is widely used to study quasiparticle (QP) energies. Motivated by the desirable features of the particle-particle (pp) RPA compared to the conventional phRPA, we explore the pp counterpart of GW, that is, the T-matrix self-energy, formulated with the eigenvectors and eigenvalues of the ppRPA matrix. We demonstrate the accuracy of the T-matrix method for molecular QP energies, highlighting the importance of the pp channel for calculating QP spectra.

  1. Low-lying dipole response in the stable 40,48Ca nuclei within the second random-phase approximation

    International Nuclear Information System (INIS)

    Gambacurta, D.; Grasso, M.; Catara, F.

    2012-01-01

    The low-lying dipole strength distributions of 40 CaCa and 48 Ca, in the energy region between 5 and 10 MeV, are studied within the second random phase approximation (RPA) with Skyrme interaction. Standard RPA models do not usually predict any presence of strength in this energy region, while experimentally a significant amount of strength is found. The inclusion of the 2 particle −2 hole configurations allows to obtain a description in a rather good agreement with the experimental data. The properties of the most collective state are analyzed in terms of its 1 particle −1 hole nature and its transition densities.

  2. Low-lying dipole response in the stable 40,48Ca nuclei within the second random-phase approximation

    Science.gov (United States)

    Gambacurta, D.; Grasso, M.; Catara, F.

    2012-10-01

    The low-lying dipole strength distributions of 40CaCa and 48Ca, in the energy region between 5 and 10 MeV, are studied within the second random phase approximation (RPA) with Skyrme interaction. Standard RPA models do not usually predict any presence of strength in this energy region, while experimentally a significant amount of strength is found. The inclusion of the 2 particle -2 hole configurations allows to obtain a description in a rather good agreement with the experimental data. The properties of the most collective state are analyzed in terms of its 1 particle -1 hole nature and its transition densities.

  3. SANS [small-angle neutron scattering] evaluation of the RPA [random phase approximation] theory for binary homopolymer mixtures

    International Nuclear Information System (INIS)

    Bates, F.S.; Koehler, W.C.; Wignall, G.D.; Fetters, L.J.

    1986-12-01

    A well characterized binary mixture of normal (protonated) and perdeuterated monodisperse 1,2 polybutenes has been studied by small-angle neutron scattering (SANS). For scattering wavevectors q greater than the inverse radius-of-gyration R/sub g/ -1 , the SANS intensity is quantitatively predicted by the random phase approximation (RPA) theory of deGennes over all measured values of the segment-segment interaction parameter Chi. In the region (Chi s-Chi)Chi s -1 > 0.5 the interaction parameter determined using the RPA theory for q > R/sub g/ -1 is greater than that calculated from the zero-angle intensity based on an Ornstein-Zernike plot, where Chi s represents the limit of single phase stability. These findings indicate a correlation between the critical fluctuation length ξ and R/sub g/ which is not accounted for by the RPA theory

  4. Hubbard-U corrected Hamiltonians for non-self-consistent random-phase approximation total-energy calculations

    DEFF Research Database (Denmark)

    Patrick, Christopher; Thygesen, Kristian Sommer

    2016-01-01

    In non-self-consistent calculations of the total energy within the random-phase approximation (RPA) for electronic correlation, it is necessary to choose a single-particle Hamiltonian whose solutions are used to construct the electronic density and noninteracting response function. Here we...... investigate the effect of including a Hubbard-U term in this single-particle Hamiltonian, to better describe the on-site correlation of 3d electrons in the transitionmetal compounds ZnS, TiO2, and NiO.We find that the RPA lattice constants are essentially independent of U, despite large changes...... in the underlying electronic structure. We further demonstrate that the non-selfconsistent RPA total energies of these materials have minima at nonzero U. Our RPA calculations find the rutile phase of TiO2 to be more stable than anatase independent of U, a result which is consistent with experiments...

  5. Safety profile, efficacy, and biodistribution of a bicistronic high-capacity adenovirus vector encoding a combined immunostimulation and cytotoxic gene therapy as a prelude to a phase I clinical trial for glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Puntel, Mariana [Department of Neurosurgery, The University of Michigan School of Medicine, MSRB II, RM 4570C, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5689 (United States); Department of Cell and Developmental Biology, The University of Michigan School of Medicine, MSRB II, RM 4570C, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5689 (United States); Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048 (United States); Ghulam, Muhammad A.K.M. [Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048 (United States); Farrokhi, Catherine [Department of Psychiatry and Behavioral Neurosciences, Cedars Sinai Medical Center, Los Angeles, CA 90048 (United States); VanderVeen, Nathan; Paran, Christopher; Appelhans, Ashley [Department of Neurosurgery, The University of Michigan School of Medicine, MSRB II, RM 4570C, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5689 (United States); Department of Cell and Developmental Biology, The University of Michigan School of Medicine, MSRB II, RM 4570C, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5689 (United States); Kroeger, Kurt M.; Salem, Alireza [Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048 (United States); Lacayo, Liliana [Department of Psychiatry and Behavioral Neurosciences, Cedars Sinai Medical Center, Los Angeles, CA 90048 (United States); Pechnick, Robert N. [Department of Psychiatry and Behavioral Neurosciences, Cedars Sinai Medical Center, Los Angeles, CA 90048 (United States); Department of Psychiatry and Behavioral Neurosciences, David Geffen School of Medicine, University of California, Los Angeles, CA (United States); Kelson, Kyle R.; Kaur, Sukhpreet; Kennedy, Sean [Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048 (United States); Palmer, Donna; Ng, Philip [Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030 (United States); and others

    2013-05-01

    Adenoviral vectors (Ads) are promising gene delivery vehicles due to their high transduction efficiency; however, their clinical usefulness has been hampered by their immunogenicity and the presence of anti-Ad immunity in humans. We reported the efficacy of a gene therapy approach for glioma consisting of intratumoral injection of Ads encoding conditionally cytotoxic herpes simplex type 1 thymidine kinase (Ad-TK) and the immunostimulatory cytokine fms-like tyrosine kinase ligand 3 (Ad-Flt3L). Herein, we report the biodistribution, efficacy, and neurological and systemic effects of a bicistronic high-capacity Ad, i.e., HC-Ad-TK/TetOn-Flt3L. HC-Ads elicit sustained transgene expression, even in the presence of anti-Ad immunity, and can encode large therapeutic cassettes, including regulatory elements to enable turning gene expression “on” or “off” according to clinical need. The inclusion of two therapeutic transgenes within a single vector enables a reduction of the total vector load without adversely impacting efficacy. Because clinically the vectors will be delivered into the surgical cavity, normal regions of the brain parenchyma are likely to be transduced. Thus, we assessed any potential toxicities elicited by escalating doses of HC-Ad-TK/TetOn-Flt3L (1 × 10{sup 8}, 1 × 10{sup 9}, or 1 × 10{sup 10} viral particles [vp]) delivered into the rat brain parenchyma. We assessed neuropathology, biodistribution, transgene expression, systemic toxicity, and behavioral impact at acute and chronic time points. The results indicate that doses up to 1 × 10{sup 9} vp of HC-Ad-TK/TetOn-Flt3L can be safely delivered into the normal rat brain and underpin further developments for its implementation in a phase I clinical trial for glioma. - Highlights: ► High capacity Ad vectors elicit sustained therapeutic gene expression in the brain. ► HC-Ad-TK/TetOn-Flt3L encodes two therapeutic genes and a transcriptional switch. ► We performed a dose escalation study at

  6. A recombinant modified vaccinia ankara vaccine encoding Epstein-Barr Virus (EBV) target antigens: a phase I trial in UK patients with EBV-positive cancer.

    Science.gov (United States)

    Taylor, Graham S; Jia, Hui; Harrington, Kevin; Lee, Lip Wai; Turner, James; Ladell, Kristin; Price, David A; Tanday, Manjit; Matthews, Jen; Roberts, Claudia; Edwards, Ceri; McGuigan, Lesley; Hartley, Andrew; Wilson, Steve; Hui, Edwin P; Chan, Anthony T C; Rickinson, Alan B; Steven, Neil M

    2014-10-01

    Epstein-Barr virus (EBV) is associated with several cancers in which the tumor cells express EBV antigens EBNA1 and LMP2. A therapeutic vaccine comprising a recombinant vaccinia virus, MVA-EL, was designed to boost immunity to these tumor antigens. A phase I trial was conducted to demonstrate the safety and immunogenicity of MVA-EL across a range of doses. Sixteen patients in the United Kingdom (UK) with EBV-positive nasopharyngeal carcinoma (NPC) received three intradermal vaccinations of MVA-EL at 3-weekly intervals at dose levels between 5 × 10(7) and 5 × 10(8) plaque-forming units (pfu). Blood samples were taken at screening, after each vaccine cycle, and during the post-vaccination period. T-cell responses were measured using IFNγ ELISpot assays with overlapping EBNA1/LMP2 peptide mixes or HLA-matched epitope peptides. Polychromatic flow cytometry was used to characterize functionally responsive T-cell populations. Vaccination was generally well tolerated. Immunity increased after vaccination to at least one antigen in 8 of 14 patients (7/14, EBNA1; 6/14, LMP2), including recognition of epitopes that vary between EBV strains associated with different ethnic groups. Immunophenotypic analysis revealed that vaccination induced differentiation and functional diversification of responsive T-cell populations specific for EBNA1 and LMP2 within the CD4 and CD8 compartments, respectively. MVA-EL is safe and immunogenic across diverse ethnicities and thus suitable for use in trials against different EBV-positive cancers globally as well as in South-East Asia where NPC is most common. The highest dose (5 × 10(8) pfu) is recommended for investigation in current phase IB and II trials. ©2014 American Association for Cancer Research.

  7. Electric dipole strength and dipole polarizability in 48Ca within a fully self-consistent second random-phase approximation

    Science.gov (United States)

    Gambacurta, D.; Grasso, M.; Vasseur, O.

    2018-02-01

    The second random-phase-approximation model corrected by a subtraction procedure designed to cure double counting, instabilities, and ultraviolet divergences, is employed for the first time to analyze the dipole strength and polarizability in 48Ca. All the terms of the residual interaction are included, leading to a fully self-consistent scheme. Results are illustrated with two Skyrme parametrizations, SGII and SLy4. Those obtained with the SGII interaction are particularly satisfactory. In this case, the low-lying strength below the neutron threshold is well reproduced and the giant dipole resonance is described in a very satisfactory way especially in its spreading and fragmentation. Spreading and fragmentation are produced in a natural way within such a theoretical model by the coupling of 1 particle-1 hole and 2 particle-2 hole configurations. Owing to this feature, we may provide for the electric polarizability as a function of the excitation energy a curve with a similar slope around the centroid energy of the giant resonance compared to the corresponding experimental results. This represents a considerable improvement with respect to previous theoretical predictions obtained with the random-phase approximation or with several ab-initio models. In such cases, the spreading width of the excitation cannot be reproduced and the polarizability as a function of the excitation energy displays a stiff increase around the predicted centroid energy of the giant resonance.

  8. Dietary Soy Supplement on Fibromyalgia Symptoms: A Randomized, Double-Blind, Placebo-Controlled, Early Phase Trial

    Science.gov (United States)

    Wahner-Roedler, Dietlind L.; Thompson, Jeffrey M.; Luedtke, Connie A.; King, Susan M.; Cha, Stephen S.; Elkin, Peter L.; Bruce, Barbara K.; Townsend, Cynthia O.; Bergeson, Jody R.; Eickhoff, Andrea L.; Loehrer, Laura L.; Sood, Amit; Bauer, Brent A.

    2011-01-01

    Most patients with fibromyalgia use complementary and alternative medicine (CAM). Properly designed controlled trials are necessary to assess the effectiveness of these practices. This study was a randomized, double-blind, placebo-controlled, early phase trial. Fifty patients seen at a fibromyalgia outpatient treatment program were randomly assigned to a daily soy or placebo (casein) shake. Outcome measures were scores of the Fibromyalgia Impact Questionnaire (FIQ) and the Center for Epidemiologic Studies Depression Scale (CES-D) at baseline and after 6 weeks of intervention. Analysis was with standard statistics based on the null hypothesis, and separation test for early phase CAM comparative trials. Twenty-eight patients completed the study. Use of standard statistics with intent-to-treat analysis showed that total FIQ scores decreased by 14% in the soy group (P = .02) and by 18% in the placebo group (P fibromyalgia treatment program, provide a decrease in fibromyalgia symptoms. Separation between the effects of soy and casein (control) shakes did not favor the intervention. Therefore, large-sample studies using soy for patients with fibromyalgia are probably not indicated. PMID:18990724

  9. Spatial short-term memory in children with nonverbal learning disabilities: impairment in encoding spatial configuration.

    Science.gov (United States)

    Narimoto, Tadamasa; Matsuura, Naomi; Takezawa, Tomohiro; Mitsuhashi, Yoshinori; Hiratani, Michio

    2013-01-01

    The authors investigated whether impaired spatial short-term memory exhibited by children with nonverbal learning disabilities is due to a problem in the encoding process. Children with or without nonverbal learning disabilities performed a simple spatial test that required them to remember 3, 5, or 7 spatial items presented simultaneously in random positions (i.e., spatial configuration) and to decide if a target item was changed or all items including the target were in the same position. The results showed that, even when the spatial positions in the encoding and probe phases were similar, the mean proportion correct of children with nonverbal learning disabilities was 0.58 while that of children without nonverbal learning disabilities was 0.84. The authors argue with the results that children with nonverbal learning disabilities have difficulty encoding relational information between spatial items, and that this difficulty is responsible for their impaired spatial short-term memory.

  10. Phase I/II randomized trial of aerobic exercise in Parkinson disease in a community setting.

    Science.gov (United States)

    Uc, Ergun Y; Doerschug, Kevin C; Magnotta, Vincent; Dawson, Jeffrey D; Thomsen, Teri R; Kline, Joel N; Rizzo, Matthew; Newman, Sara R; Mehta, Sonya; Grabowski, Thomas J; Bruss, Joel; Blanchette, Derek R; Anderson, Steven W; Voss, Michelle W; Kramer, Arthur F; Darling, Warren G

    2014-07-29

    To (1) investigate effects of aerobic walking on motor function, cognition, and quality of life in Parkinson disease (PD), and (2) compare safety, tolerability, and fitness benefits of different forms of exercise intervention: continuous/moderate intensity vs interval/alternating between low and vigorous intensity, and individual/neighborhood vs group/facility setting. Initial design was a 6-month, 2 × 2 randomized trial of different exercise regimens in independently ambulatory patients with PD. All arms were required to exercise 3 times per week, 45 minutes per session. Randomization to group/facility setting was not feasible because of logistical factors. Over the first 2 years, we randomized 43 participants to continuous or interval training. Because preliminary analyses suggested higher musculoskeletal adverse events in the interval group and lack of difference between training methods in improving fitness, the next 17 participants were allocated only to continuous training. Eighty-one percent of 60 participants completed the study with a mean attendance of 83.3% (95% confidence interval: 77.5%-89.0%), exercising at 46.8% (44.0%-49.7%) of their heart rate reserve. There were no serious adverse events. Across all completers, we observed improvements in maximum oxygen consumption, gait speed, Unified Parkinson's Disease Rating Scale sections I and III scores (particularly axial functions and rigidity), fatigue, depression, quality of life (e.g., psychological outlook), and flanker task scores (p improvements on the flanker task and quality of life (p improves aerobic fitness, motor function, fatigue, mood, executive control, and quality of life in mild to moderate PD. This study provides Class IV evidence that in patients with PD, an aerobic exercise program improves aerobic fitness, motor function, fatigue, mood, and cognition. © 2014 American Academy of Neurology.

  11. Periodically driven random quantum spin chains: real-space renormalization for Floquet localized phases

    Science.gov (United States)

    Monthus, Cécile

    2017-07-01

    When random quantum spin chains are submitted to some periodic Floquet driving, the eigenstates of the time-evolution operator over one period can be localized in real space. For the case of periodic quenches between two Hamiltonians (or periodic kicks), where the time-evolution operator over one period reduces to the product of two simple transfer matrices, we propose a block-self-dual renormalization procedure to construct the localized eigenstates of the Floquet dynamics. We also discuss the corresponding strong disorder renormalization procedure, that generalizes the RSRG-X procedure to construct the localized eigenstates of time-independent Hamiltonians.

  12. Randomized phase III trial of regorafenib in metastatic colorectal cancer: analysis of the CORRECT Japanese and non-Japanese subpopulations.

    Science.gov (United States)

    Yoshino, Takayuki; Komatsu, Yoshito; Yamada, Yasuhide; Yamazaki, Kentaro; Tsuji, Akihito; Ura, Takashi; Grothey, Axel; Van Cutsem, Eric; Wagner, Andrea; Cihon, Frank; Hamada, Yoko; Ohtsu, Atsushi

    2015-06-01

    In the international, phase III, randomized, double-blind CORRECT trial, regorafenib significantly prolonged overall survival (OS) versus placebo in patients with metastatic colorectal cancer (mCRC) that had progressed on all standard therapies. This post hoc analysis evaluated the efficacy and safety of regorafenib in Japanese and non-Japanese subpopulations in the CORRECT trial. Patients were randomized 2 : 1 to regorafenib 160 mg once daily or placebo for weeks 1-3 of each 4-week cycle. The primary endpoint was OS. Outcomes were assessed using descriptive statistics. One hundred Japanese and 660 non-Japanese patients were randomized to regorafenib (n = 67 and n = 438) or placebo (n = 33 and n = 222). Regorafenib had a consistent OS benefit in the Japanese and non-Japanese subpopulations, with hazard ratios of 0.81 (95 % confidence interval [CI] 0.43-1.51) and 0.77 (95 % CI 0.62-0.94), respectively. Regorafenib-associated hand-foot skin reaction, hypertension, proteinuria, thrombocytopenia, and lipase elevations occurred more frequently in the Japanese subpopulation than in the non-Japanese subpopulation, but were generally manageable. Regorafenib appears to have comparable efficacy in Japanese and non-Japanese subpopulations, with a manageable adverse-event profile, suggesting that this agent could potentially become a standard of care in patients with mCRC.

  13. Randomized Phase III and Extension Studies of Naldemedine in Patients With Opioid-Induced Constipation and Cancer.

    Science.gov (United States)

    Katakami, Nobuyuki; Harada, Toshiyuki; Murata, Toru; Shinozaki, Katsunori; Tsutsumi, Masakazu; Yokota, Takaaki; Arai, Masatsugu; Tada, Yukio; Narabayashi, Masaru; Boku, Narikazu

    2017-12-01

    Purpose Opioid-induced constipation (OIC) is a frequent and debilitating adverse effect (AE) of opioids-common analgesics for cancer pain. We investigated the efficacy and safety of a peripherally acting μ-opioid receptor antagonist, naldemedine (S-297995), for OIC, specifically in patients with cancer. Patients and Methods This phase III trial consisted of a 2-week, randomized, double-blind, placebo-controlled study (COMPOSE-4) and an open-label, 12-week extension study (COMPOSE-5). In COMPOSE-4, eligible adults with OIC and cancer were randomly assigned on a 1:1 basis to receive once-daily oral naldemedine 0.2 mg or placebo. The primary end point was the proportion of spontaneous bowel movement (SBM) responders (≥ 3 SBMs/week and an increase of ≥ 1 SBM/week from baseline). The primary end point of COMPOSE-5 was safety. Results In COMPOSE-4, 193 eligible patients were randomly assigned to naldemedine (n = 97) or placebo (n = 96). The proportion of SBM responders in COMPOSE-4 was significantly greater with naldemedine than with placebo (71.1% [69 of 97 patients] v 34.4% [33 of 96 patients]; P opioid withdrawal and had no notable impact on opioid-mediated analgesia. Conclusion Once-daily oral naldemedine 0.2 mg effectively treated OIC and was generally well tolerated in patients with OIC and cancer.

  14. Phase III Randomized Clinical Trial Comparing Tremelimumab With Standard-of-Care Chemotherapy in Patients With Advanced Melanoma

    Science.gov (United States)

    Ribas, Antoni; Kefford, Richard; Marshall, Margaret A.; Punt, Cornelis J.A.; Haanen, John B.; Marmol, Maribel; Garbe, Claus; Gogas, Helen; Schachter, Jacob; Linette, Gerald; Lorigan, Paul; Kendra, Kari L.; Maio, Michele; Trefzer, Uwe; Smylie, Michael; McArthur, Grant A.; Dreno, Brigitte; Nathan, Paul D.; Mackiewicz, Jacek; Kirkwood, John M.; Gomez-Navarro, Jesus; Huang, Bo; Pavlov, Dmitri; Hauschild, Axel

    2013-01-01

    Purpose In phase I/II trials, the cytotoxic T lymphocyte–associated antigen-4–blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients with advanced melanoma treated with tremelimumab or standard-of-care chemotherapy. Patients and Methods Patients with treatment-naive, unresectable stage IIIc or IV melanoma were randomly assigned at a ratio of one to one to tremelimumab (15 mg/kg once every 90 days) or physician's choice of standard-of-care chemotherapy (temozolomide or dacarbazine). Results In all, 655 patients were enrolled and randomly assigned. The test statistic crossed the prespecified futility boundary at second interim analysis after 340 deaths, but survival follow-up continued. At final analysis with 534 events, median OS by intent to treat was 12.6 months (95% CI, 10.8 to 14.3) for tremelimumab and 10.7 months (95% CI, 9.36 to 11.96) for chemotherapy (hazard ratio, 0.88; P = .127). Objective response rates were similar in the two arms: 10.7% in the tremelimumab arm and 9.8% in the chemotherapy arm. However, response duration (measured from date of random assignment) was significantly longer after tremelimumab (35.8 v 13.7 months; P = .0011). Diarrhea, pruritus, and rash were the most common treatment-related adverse events in the tremelimumab arm; 7.4% had endocrine toxicities. Seven deaths in the tremelimumab arm and one in the chemotherapy arm were considered treatment related by either investigators or sponsor. Conclusion This study failed to demonstrate a statistically significant survival advantage of treatment with tremelimumab over standard-of-care chemotherapy in first-line treatment of patients with metastatic melanoma. PMID:23295794

  15. Stereotactic ablative radiotherapy for comprehensive treatment of oligometastatic tumors (SABR-COMET): Study protocol for a randomized phase II trial

    International Nuclear Information System (INIS)

    Palma, David A; Griffioen, GwendolynHMJ; Gaede, Stewart; Slotman, Ben; Senan, Suresh; Haasbeek, Cornelis J A; Rodrigues, George B; Dahele, Max; Lock, Michael; Yaremko, Brian; Olson, Robert; Liu, Mitchell; Panarotto, Jason

    2012-01-01

    Stereotactic ablative radiotherapy (SABR) has emerged as a new treatment option for patients with oligometastatic disease. SABR delivers precise, high-dose, hypofractionated radiotherapy, and achieves excellent rates of local control. Survival outcomes for patients with oligometastatic disease treated with SABR appear promising, but conclusions are limited by patient selection, and the lack of adequate controls in most studies. The goal of this multicenter randomized phase II trial is to assess the impact of a comprehensive oligometastatic SABR treatment program on overall survival and quality of life in patients with up to 5 metastatic cancer lesions, compared to patients who receive standard of care treatment alone. After stratification by the number of metastases (1-3 vs. 4-5), patients will be randomized between Arm 1: current standard of care treatment, and Arm 2: standard of care treatment + SABR to all sites of known disease. Patients will be randomized in a 1:2 ratio to Arm 1:Arm 2, respectively. For patients receiving SABR, radiotherapy dose and fractionation depends on the site of metastasis and the proximity to critical normal structures. This study aims to accrue a total of 99 patients within four years. The primary endpoint is overall survival, and secondary endpoints include quality of life, toxicity, progression-free survival, lesion control rate, and number of cycles of further chemotherapy/systemic therapy. This study will provide an assessment of the impact of SABR on clinical outcomes and quality of life, to determine if long-term survival can be achieved for selected patients with oligometastatic disease, and will inform the design of a possible phase III study. Clinicaltrials.gov identifier: NCT01446744

  16. Phase III randomized clinical trial comparing tremelimumab with standard-of-care chemotherapy in patients with advanced melanoma.

    Science.gov (United States)

    Ribas, Antoni; Kefford, Richard; Marshall, Margaret A; Punt, Cornelis J A; Haanen, John B; Marmol, Maribel; Garbe, Claus; Gogas, Helen; Schachter, Jacob; Linette, Gerald; Lorigan, Paul; Kendra, Kari L; Maio, Michele; Trefzer, Uwe; Smylie, Michael; McArthur, Grant A; Dreno, Brigitte; Nathan, Paul D; Mackiewicz, Jacek; Kirkwood, John M; Gomez-Navarro, Jesus; Huang, Bo; Pavlov, Dmitri; Hauschild, Axel

    2013-02-10

    In phase I/II trials, the cytotoxic T lymphocyte-associated antigen-4-blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients with advanced melanoma treated with tremelimumab or standard-of-care chemotherapy. Patients with treatment-naive, unresectable stage IIIc or IV melanoma were randomly assigned at a ratio of one to one to tremelimumab (15 mg/kg once every 90 days) or physician's choice of standard-of-care chemotherapy (temozolomide or dacarbazine). In all, 655 patients were enrolled and randomly assigned. The test statistic crossed the prespecified futility boundary at second interim analysis after 340 deaths, but survival follow-up continued. At final analysis with 534 events, median OS by intent to treat was 12.6 months (95% CI, 10.8 to 14.3) for tremelimumab and 10.7 months (95% CI, 9.36 to 11.96) for chemotherapy (hazard ratio, 0.88; P = .127). Objective response rates were similar in the two arms: 10.7% in the tremelimumab arm and 9.8% in the chemotherapy arm. However, response duration (measured from date of random assignment) was significantly longer after tremelimumab (35.8 v 13.7 months; P = .0011). Diarrhea, pruritus, and rash were the most common treatment-related adverse events in the tremelimumab arm; 7.4% had endocrine toxicities. Seven deaths in the tremelimumab arm and one in the chemotherapy arm were considered treatment related by either investigators or sponsor. This study failed to demonstrate a statistically significant survival advantage of treatment with tremelimumab over standard-of-care chemotherapy in first-line treatment of patients with metastatic melanoma.

  17. Differential benefits of amoxicillin-metronidazole in different phases of periodontal therapy in a randomized controlled crossover clinical trial.

    Science.gov (United States)

    Mombelli, Andrea; Almaghlouth, Adnan; Cionca, Norbert; Courvoisier, Delphine S; Giannopoulou, Catherine

    2015-03-01

    The specific advantage of administering systemic antibiotics during initial, non-surgical therapy or in the context of periodontal surgery is unclear. This study assesses the differential outcomes of periodontal therapy supplemented with amoxicillin-metronidazole during either the non-surgical or the surgical treatment phase. This is a single-center, randomized placebo-controlled crossover clinical trial with a 1-year follow-up. Eighty participants with Aggregatibacter actinomycetemcomitans-associated moderate to advanced periodontitis were randomized into two treatment groups: group A, antibiotics (500 mg metronidazole plus 375 mg amoxicillin three times per day for 7 days) during the first, non-surgical phase of periodontal therapy (T1) and placebo during the second, surgical phase (T2); and group B, placebo during T1 and antibiotics during T2. The number of sites with probing depth (PD) >4 mm and bleeding on probing (BOP) per patient was the primary outcome. A total of 11,212 sites were clinically monitored on 1,870 teeth. T1 with antibiotics decreased the number of sites with PD >4 mm and BOP per patient significantly more than without (group A: from 34.5 to 5.7, 84%; group B: from 28.7 to 8.7, 70%; P antibiotics, but only eight treated with placebo, achieved a 10-fold reduction of diseased sites (P = 0.007). Consequently, fewer patients of group A needed additional therapy, the mean number of surgical interventions was lower, and treatment time in T2 was shorter. Six months after T2, the mean number of residual pockets (group A: 2.8 ± 5.2; group B: 2.2 ± 5.0) was not significantly different and was sustained over 12 months in both groups. Giving the antibiotics during T1 or T2 yielded similar long-term outcomes, but antibiotics in T1 resolved the disease quicker and thus reduced the need for additional surgical intervention.

  18. Landscape encodings enhance optimization.

    Directory of Open Access Journals (Sweden)

    Konstantin Klemm

    Full Text Available Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state.

  19. Landscape Encodings Enhance Optimization

    Science.gov (United States)

    Klemm, Konstantin; Mehta, Anita; Stadler, Peter F.

    2012-01-01

    Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states) of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state. PMID:22496860

  20. Rocksalt or cesium chloride: Investigating the relative stability of the cesium halide structures with random phase approximation based methods

    Science.gov (United States)

    Nepal, Niraj K.; Ruzsinszky, Adrienn; Bates, Jefferson E.

    2018-03-01

    The ground state structural and energetic properties for rocksalt and cesium chloride phases of the cesium halides were explored using the random phase approximation (RPA) and beyond-RPA methods to benchmark the nonempirical SCAN meta-GGA and its empirical dispersion corrections. The importance of nonadditivity and higher-order multipole moments of dispersion in these systems is discussed. RPA generally predicts the equilibrium volume for these halides within 2.4% of the experimental value, while beyond-RPA methods utilizing the renormalized adiabatic LDA (rALDA) exchange-correlation kernel are typically within 1.8%. The zero-point vibrational energy is small and shows that the stability of these halides is purely due to electronic correlation effects. The rAPBE kernel as a correction to RPA overestimates the equilibrium volume and could not predict the correct phase ordering in the case of cesium chloride, while the rALDA kernel consistently predicted results in agreement with the experiment for all of the halides. However, due to its reasonable accuracy with lower computational cost, SCAN+rVV10 proved to be a good alternative to the RPA-like methods for describing the properties of these ionic solids.

  1. Using a short-pulse diffraction-limited laser beam to probe filamentation of a random phase plate smoothed beam

    International Nuclear Information System (INIS)

    Kline, J. L.; Montgomery, D. S.; Flippo, K. A.; Johnson, R. P.; Rose, H. A.; Shimada, T.; Williams, E. A.

    2008-01-01

    A short pulse (few picoseconds) laser probe provides high temporal resolution measurements to elucidate details of fast dynamic phenomena not observable with typical longer laser pulse probes and gated diagnostics. Such a short pulse laser probe (SPLP) has been used to measure filamentation of a random phase plate (RPP) smoothed laser beam in a gas-jet plasma. The plasma index of refraction due to driven density and temperature fluctuations by the RPP beam perturbs the phase front of a SPLP propagating at a 90 deg. angle with respect to the RPP interaction beam. The density and temperature fluctuations are quasistatic on the time scale of the SPLP (∼2 ps). The transmitted near-field intensity distribution from the SPLP provides a measure of the phase front perturbation. At low plasma densities, the transmitted intensity pattern is asymmetric with striations across the entire probe beam in the direction of the RPP smoothed beam. As the plasma density increases, the striations break up into smaller sizes along the direction of the RPP beam propagation. The breakup of the intensity pattern is consistent with self-focusing of the RPP smoothed interaction beam. Simulations of the experiment using the wave propagation code, PF3D, are in qualitative agreement demonstrating that the asymmetric striations can be attributed to the RPP driven density fluctuations. Quantification of the beam breakup measured by the transmitted SPLP could lead to a new method for measuring self-focusing of lasers in underdense plasmas.

  2. Using a short-pulse diffraction-limited laser beam to probe filamentation of a random phase plate smoothed beam.

    Science.gov (United States)

    Kline, J L; Montgomery, D S; Flippo, K A; Johnson, R P; Rose, H A; Shimada, T; Williams, E A

    2008-10-01

    A short pulse (few picoseconds) laser probe provides high temporal resolution measurements to elucidate details of fast dynamic phenomena not observable with typical longer laser pulse probes and gated diagnostics. Such a short pulse laser probe (SPLP) has been used to measure filamentation of a random phase plate (RPP) smoothed laser beam in a gas-jet plasma. The plasma index of refraction due to driven density and temperature fluctuations by the RPP beam perturbs the phase front of a SPLP propagating at a 90 degree angle with respect to the RPP interaction beam. The density and temperature fluctuations are quasistatic on the time scale of the SPLP (approximately 2 ps). The transmitted near-field intensity distribution from the SPLP provides a measure of the phase front perturbation. At low plasma densities, the transmitted intensity pattern is asymmetric with striations across the entire probe beam in the direction of the RPP smoothed beam. As the plasma density increases, the striations break up into smaller sizes along the direction of the RPP beam propagation. The breakup of the intensity pattern is consistent with self-focusing of the RPP smoothed interaction beam. Simulations of the experiment using the wave propagation code, PF3D, are in qualitative agreement demonstrating that the asymmetric striations can be attributed to the RPP driven density fluctuations. Quantification of the beam breakup measured by the transmitted SPLP could lead to a new method for measuring self-focusing of lasers in underdense plasmas.

  3. A randomized controlled Phase Ib trial of the malaria vaccine candidate GMZ2 in African children

    DEFF Research Database (Denmark)

    Bélard, Sabine; Issifou, Saadou; Hounkpatin, Aurore B

    2011-01-01

    GMZ2 is a fusion protein of Plasmodium falciparum merozoite surface protein 3 (MSP3) and glutamate rich protein (GLURP) that mediates an immune response against the blood stage of the parasite. Two previous phase I clinical trials, one in naïve European adults and one in malaria-exposed Gabonese ...... adults showed that GMZ2 was well tolerated and immunogenic. Here, we present data on safety and immunogenicity of GMZ2 in one to five year old Gabonese children, a target population for future malaria vaccine efficacy trials....

  4. Amplitude and phase fluctuations of Van der Pol oscillator under external random forcing

    Science.gov (United States)

    Singh, Aman K.; Yadava, R. D. S.

    2018-05-01

    The paper presents an analytical study of noise in Van der Pol oscillator output subjected to an external force noise assumed to be characterized by delta function (white noise). The external fluctuations are assumed to be small in comparison to the average response of the noise free system. The autocorrelation function and power spectrum are calculated under the condition of weak nonlinearity. The latter ensures limit cycle oscillations. The total spectral power density is dominated by the contributions from the phase fluctuations. The amplitude fluctuations are at least two orders of magnitude smaller. The analysis is shown to be useful to interpretation microcantilever based biosensing data.

  5. Donepezil for Irradiated Brain Tumor Survivors: A Phase III Randomized Placebo-Controlled Clinical Trial.

    Science.gov (United States)

    Rapp, Stephen R; Case, L Doug; Peiffer, Ann; Naughton, Michelle M; Chan, Michael D; Stieber, Volker W; Moore, Dennis F; Falchuk, Steven C; Piephoff, James V; Edenfield, William J; Giguere, Jeffrey K; Loghin, Monica E; Shaw, Edward G

    2015-05-20

    Neurotoxic effects of brain irradiation include cognitive impairment in 50% to 90% of patients. Prior studies have suggested that donepezil, a neurotransmitter modulator, may improve cognitive function. A total of 198 adult brain tumor survivors ≥ 6 months after partial- or whole-brain irradiation were randomly assigned to receive a single daily dose (5 mg for 6 weeks, 10 mg for 18 weeks) of donepezil or placebo. A cognitive test battery assessing memory, attention, language, visuomotor, verbal fluency, and executive functions was administered before random assignment and at 12 and 24 weeks. A cognitive composite score (primary outcome) and individual cognitive domains were evaluated. Of this mostly middle-age, married, non-Hispanic white sample, 66% had primary brain tumors, 27% had brain metastases, and 8% underwent prophylactic cranial irradiation. After 24 weeks of treatment, the composite scores did not differ significantly between groups (P = .48); however, significant differences favoring donepezil were observed for memory (recognition, P = .027; discrimination, P = .007) and motor speed and dexterity (P = .016). Significant interactions between pretreatment cognitive function and treatment were found for cognitive composite (P = .01), immediate recall (P = .05), delayed recall (P = .004), attention (P = .01), visuomotor skills (P = .02), and motor speed and dexterity (P < .001), with the benefits of donepezil greater for those who were more cognitively impaired before study treatment. Treatment with donepezil did not significantly improve the overall composite score, but it did result in modest improvements in several cognitive functions, especially among patients with greater pretreatment impairments. © 2015 by American Society of Clinical Oncology.

  6. A phase 3 randomized placebo-controlled trial of tadalafil for Duchenne muscular dystrophy.

    Science.gov (United States)

    Victor, Ronald G; Sweeney, H Lee; Finkel, Richard; McDonald, Craig M; Byrne, Barry; Eagle, Michelle; Goemans, Nathalie; Vandenborne, Krista; Dubrovsky, Alberto L; Topaloglu, Haluk; Miceli, M Carrie; Furlong, Pat; Landry, John; Elashoff, Robert; Cox, David

    2017-10-24

    To conduct a randomized trial to test the primary hypothesis that once-daily tadalafil, administered orally for 48 weeks, lessens the decline in ambulatory ability in boys with Duchenne muscular dystrophy (DMD). Three hundred thirty-one participants with DMD 7 to 14 years of age taking glucocorticoids were randomized to tadalafil 0.3 mg·kg -1 ·d -1 , tadalafil 0.6 mg·kg -1 ·d -1 , or placebo. The primary efficacy measure was 6-minute walk distance (6MWD) after 48 weeks. Secondary efficacy measures included North Star Ambulatory Assessment and timed function tests. Performance of Upper Limb (PUL) was a prespecified exploratory outcome. Tadalafil had no effect on the primary outcome: 48-week declines in 6MWD were 51.0 ± 9.3 m with placebo, 64.7 ± 9.8 m with low-dose tadalafil ( p = 0.307 vs placebo), and 59.1 ± 9.4 m with high-dose tadalafil ( p = 0.538 vs placebo). Tadalafil also had no effect on secondary outcomes. In boys >10 years of age, total PUL score and shoulder subscore declined less with low-dose tadalafil than placebo. Adverse events were consistent with the known safety profile of tadalafil and the DMD disease state. Tadalafil did not lessen the decline in ambulatory ability in boys with DMD. Further studies should be considered to confirm the hypothesis-generating upper limb data and to determine whether ambulatory decline can be slowed by initiation of tadalafil before 7 years of age. NCT01865084. This study provides Class I evidence that tadalafil does not slow ambulatory decline in 7- to 14-year-old boys with Duchenne muscular dystrophy. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  7. Equilibrium phases of dipolar lattice bosons in the presence of random diagonal disorder

    Science.gov (United States)

    Zhang, C.; Safavi-Naini, A.; Capogrosso-Sansone, B.

    2018-01-01

    Ultracold gases offer an unprecedented opportunity to engineer disorder and interactions in a controlled manner. In an effort to understand the interplay between disorder, dipolar interactions, and quantum degeneracy, we study two-dimensional hard-core dipolar lattice bosons in the presence of on-site bound disorder. Our results are based on large-scale path-integral quantum Monte Carlo simulations by the worm algorithm. We study the ground-state phase diagram at a fixed half-integer filling factor for which the clean system is either a superfluid at a lower dipolar interaction strength or a checkerboard solid at a larger dipolar interaction strength. We find that, even for weak dipolar interactions, superfluidity is destroyed in favor of a Bose glass at a relatively low disorder strength. Interestingly, in the presence of disorder, superfluidity persists for values of the dipolar interaction strength for which the clean system is a checkerboard solid. At a fixed disorder strength, as the dipolar interaction is increased, superfluidity is destroyed in favor of a Bose glass. As the interaction is further increased, the system eventually develops extended checkerboard patterns in the density distribution. Due to the presence of disorder, though, grain boundaries and defects, responsible for a finite residual compressibility, are present in the density distribution. Finally, we study the robustness of the superfluid phase against thermal fluctuations.

  8. A phase II randomized trial of Observation versus stereotactic ablative RadiatIon for OLigometastatic prostate CancEr (ORIOLE).

    Science.gov (United States)

    Radwan, Noura; Phillips, Ryan; Ross, Ashley; Rowe, Steven P; Gorin, Michael A; Antonarakis, Emmanuel S; Deville, Curtiland; Greco, Stephen; Denmeade, Samuel; Paller, Channing; Song, Daniel Y; Diehn, Maximilian; Wang, Hao; Carducci, Michael; Pienta, Kenneth J; Pomper, Martin G; DeWeese, Theodore L; Dicker, Adam; Eisenberger, Mario; Tran, Phuoc T

    2017-06-29

    We describe a randomized, non-blinded Phase II interventional study to assess the safety and efficacy of stereotactic ablative radiotherapy (SABR) for hormone-sensitive oligometastatic prostate adenocarcinoma, and to describe the biology of the oligometastatic state using immunologic, cellular, molecular, and functional imaging correlates. 54 men with oligometastatic prostate adenocarcinoma will be accrued. The primary clinical endpoint will be progression at 6 months from randomization with the hypothesis that SABR to all metastases will forestall progression by disrupting the metastatic process. Secondary clinical endpoints will include local control at 6 months post-SABR, toxicity and quality of life, and androgen deprivation therapy (ADT)-free survival (ADT-FS). Further fundamental analysis of the oligometastatic state with be achieved through correlation with investigational 18 F-DCFPyL PET/CT imaging and measurement of circulating tumor cells, circulating tumor DNA, and circulating T-cell receptor repertoires, facilitating an unprecedented opportunity to characterize, in isolation, the effects of SABR on the dynamics of and immunologic response to oligometastatic disease. Patients will be randomized 2:1 to SABR or observation with minimization to balance assignment by primary intervention, prior hormonal therapy, and PSA doubling time. Progression after 6 months will be compared using Fisher's exact test. Hazard ratios and Kaplan-Meier estimates of progression free survival (PFS), ADT free survival (ADT-FS), time to locoregional progression (TTLP) and time to distant progression (TTDP) will be calculated based on an intention-to-treat. Local control will be assessed using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria. Withdrawal from the study prior to 6 months will be counted as progression. Adverse events will be summarized by type and grade. Quality of life pre- and post- SABR will be measured by Brief Pain Inventory. The ORIOLE

  9. Ursodeoxycholic acid in advanced polycystic liver disease: A phase 2 multicenter randomized controlled trial.

    Science.gov (United States)

    D'Agnolo, Hedwig M A; Kievit, Wietske; Takkenberg, R Bart; Riaño, Ioana; Bujanda, Luis; Neijenhuis, Myrte K; Brunenberg, Ellen J L; Beuers, Ulrich; Banales, Jesus M; Drenth, Joost P H

    2016-09-01

    Ursodeoxycholic acid (UDCA) inhibits proliferation of polycystic human cholangiocytes in vitro and hepatic cystogenesis in a rat model of polycystic liver disease (PLD) in vivo. Our aim was to test whether UDCA may beneficially affect liver volume in patients with advanced PLD. We conducted an international, multicenter, randomized controlled trial in symptomatic PLD patients from three tertiary referral centers. Patients with PLD and total liver volume (TLV) ⩾2500ml were randomly assigned to UDCA treatment (15-20mg/kg/day) for 24weeks, or to no treatment. Primary endpoint was proportional change in TLV. Secondary endpoints were change in symptoms and health-related quality of life. We performed a post-hoc analysis of the effect of UDCA on liver cyst volume (LCV). We included 34 patients and were able to assess primary endpoint in 32 patients, 16 with autosomal dominant polycystic kidney disease (ADPKD) and 16 with autosomal dominant polycystic liver disease (ADPLD). Proportional TLV increased by 4.6±7.7% (mean TLV increased from 6697ml to 6954ml) after 24weeks of UDCA treatment compared to 3.1±3.8% (mean TLV increased from 5512ml to 5724ml) in the control group (p=0.493). LCV was not different after 24weeks between controls and UDCA treated patients (p=0.848). However, UDCA inhibited LCV growth in ADPKD patients compared to ADPKD controls (p=0.049). UDCA administration for 24weeks did not reduce TLV in advanced PLD, but UDCA reduced LCV growth in ADPKD patients. Future studies might explore whether ADPKD and ADPLD patients respond differently to UDCA treatment. Current therapies for polycystic liver disease are invasive and have high recurrence risks. Our trial showed that the drug, ursodeoxycholic acid, was not able to reduce liver volume in patients with polycystic liver disease. However, a subgroup analysis in patients that have kidney cysts as well showed that liver cyst volume growth was reduced in patients who received ursodeoxycholic acid in comparison

  10. Blind encoding into qudits

    International Nuclear Information System (INIS)

    Shaari, J.S.; Wahiddin, M.R.B.; Mancini, S.

    2008-01-01

    We consider the problem of encoding classical information into unknown qudit states belonging to any basis, of a maximal set of mutually unbiased bases, by one party and then decoding by another party who has perfect knowledge of the basis. Working with qudits of prime dimensions, we point out a no-go theorem that forbids 'shift' operations on arbitrary unknown states. We then provide the necessary conditions for reliable encoding/decoding

  11. An encoding device and a method of encoding

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to an encoding device, such as an optical position encoder, for encoding input from an object, and a method for encoding input from an object, for determining a position of an object that interferes with light of the device. The encoding device comprises a light source...... in the area in the space and may interfere with the light, which interference may be encoded into a position or activation....

  12. A randomized, double-blind, phase 3 study of fospropofol disodium for sedation during colonoscopy.

    Science.gov (United States)

    Cohen, Lawrence B; Cattau, Edward; Goetsch, Allen; Shah, Atul; Weber, John R; Rex, Douglas K; Kline, Jacqueline M

    2010-01-01

    This double-blind, multicenter study evaluated the safety and efficacy of intravenous fospropofol (6.5 mg/kg vs. 2 mg/kg) for moderate sedation in patients undergoing colonoscopy. In all, 314 patients >or=18 years (American Society of Anesthesiologists PS1 to PS3) were randomized to receive fospropofol 2 mg/kg, fospropofol 6.5- mg/kg, or midazolam 0.02 mg/kg, after pretreatment with intravenous fentanyl 50 mcg. Supplemental doses of study medication were permitted to achieve a Modified Observer's Assessment of Alertness/Sedation scale score sedation success, recovery, memory retention, physician satisfaction, and safety. Sedation success was higher in the fospropofol 6.5 mg/kg versus 2 mg/kg group (87% vs. 26%; Pmemory retention (70% and 82% for the 6.5 mg/kg and 2 mg/kg groups, respectively) compared with 41% for the midazolam group. Mean physician satisfaction scores were higher in the fospropofol 6.5-mg/kg group (7.7) than the 2-mg/kg group (4.5), Psedation during colonoscopy and was associated with higher rates of sedation success, memory retention, and physician satisfaction than the fospropofol 2-mg/kg dose.

  13. Dynamic and static correlation functions in the inhomogeneous Hartree-Fock-state approach with random-phase-approximation fluctuations

    International Nuclear Information System (INIS)

    Lorenzana, J.; Grynberg, M.D.; Yu, L.; Yonemitsu, K.; Bishop, A.R.

    1992-11-01

    The ground state energy, and static and dynamic correlation functions are investigated in the inhomogeneous Hartree-Fock (HF) plus random phase approximation (RPA) approach applied to a one-dimensional spinless fermion model showing self-trapped doping states at the mean field level. Results are compared with homogeneous HF and exact diagonalization. RPA fluctuations added to the generally inhomogeneous HF ground state allows the computation of dynamical correlation functions that compare well with exact diagonalization results. The RPA correction to the ground state energy agrees well with the exact results at strong and weak coupling limits. We also compare it with a related quasi-boson approach. The instability towards self-trapped behaviour is signaled by a RPA mode with frequency approaching zero. (author). 21 refs, 10 figs

  14. Continuum random-phase approximation study of the incoherent μ--e- conversion rate and its spurious 1- admixture

    International Nuclear Information System (INIS)

    Papakonstantinou, P.; Wambach, J.; Kosmas, T.S.; Faessler, A.

    2006-01-01

    The incoherent transition strength of the exotic μ - -e - conversion in the 208 Pb nucleus is investigated by utilizing the continuum random-phase-approximation method, appropriate for the evaluation of the rate that goes to the continuum of the nuclear spectrum. We find that the contribution of resonances lying high in the continuum is not negligible. Special attention is paid to the detailed study of the pronounced 1 - contribution that according to previous calculations, dominates the overall incoherent rate in about all the nuclear targets. The spurious center-of-mass admixture to the partial rate originating from the 1 - excitations is explored, and its elimination is performed by correcting properly the dipole operators. The results found this way show that the greatest portion of the total 1 - contribution to the incoherent rate is spurious

  15. Assessing the performance of the random phase approximation for exchange and superexchange coupling constants in magnetic crystalline solids

    DEFF Research Database (Denmark)

    Olsen, Thomas

    2017-01-01

    The random phase approximation (RPA) for total energies has previously been shown to provide a qualitatively correct description of static correlation in molecular systems, where density functional theory (DFT) with local functionals are bound to fail. This immediately poses the question of whether...... the RPA is also able to capture the correct physics of strongly correlated solids such asMott insulators. Due to strong electron localization, magnetic interactions in such systems are dominated by superexchange, which in the simplest picture can be regarded as the analog of static correlation...... for molecules. In this paper, we investigate the performance of the RPA for evaluating both superexchange and direct exchange interactions in the magnetic solids NiO, MnO, Na3Cu2SbO6, Sr2CuO3, Sr2CuTeO6, and a monolayer of CrI3, which were chosen to represent a broad variety of magnetic interactions...

  16. Vanishing-Overhead Linear-Scaling Random Phase Approximation by Cholesky Decomposition and an Attenuated Coulomb-Metric.

    Science.gov (United States)

    Luenser, Arne; Schurkus, Henry F; Ochsenfeld, Christian

    2017-04-11

    A reformulation of the random phase approximation within the resolution-of-the-identity (RI) scheme is presented, that is competitive to canonical molecular orbital RI-RPA already for small- to medium-sized molecules. For electronically sparse systems drastic speedups due to the reduced scaling behavior compared to the molecular orbital formulation are demonstrated. Our reformulation is based on two ideas, which are independently useful: First, a Cholesky decomposition of density matrices that reduces the scaling with basis set size for a fixed-size molecule by one order, leading to massive performance improvements. Second, replacement of the overlap RI metric used in the original AO-RPA by an attenuated Coulomb metric. Accuracy is significantly improved compared to the overlap metric, while locality and sparsity of the integrals are retained, as is the effective linear scaling behavior.

  17. High-K precession modes: Axially symmetric limit of wobbling motion in the cranked random-phase approximation description

    International Nuclear Information System (INIS)

    Shimizu, Yoshifumi R.; Matsuzaki, Masayuki; Matsuyanagi, Kenichi

    2005-01-01

    The rotational band built on the high-K multi-quasiparticle state can be interpreted as a multi-phonon band of the precession mode, which represents the precessional rotation about the axis perpendicular to the direction of the intrinsic angular momentum. By using the axially symmetric limit of the random-phase approximation (RPA) formalism developed for the nuclear wobbling motion, we study the properties of the precession modes in 178 W: the excitation energies, B(E2) and B(M1) values. We show that the excitations of such a specific type of rotation can be well described by the RPA formalism, which gives new insight into the wobbling motion in the triaxial superdeformed nuclei from a microscopic viewpoint

  18. Lowest lying 2+ and 3- vibrational states in Pb, Sn, and Ni isotopes in relativistic quasiparticle random-phase approximation

    International Nuclear Information System (INIS)

    Ansari, A.; Ring, P.

    2006-01-01

    The excitation energies and electric multipole decay rates of the lowest lying 2 + and 3 - vibrational states in Pb, Sn, and Ni nuclei are calculated following relativistic quasiparticle random-phase approximation formalism based on the relativistic Hartree-Bogoliubov mean field. Two sets of Lagrangian parameters, NL1 and NL3, are used to investigate the effect of the nuclear force. Overall there is good agreement with the available experimental data for a wide range of mass numbers considered here, and the NL3 set seems to be a better choice. However, strictly speaking, these studies point toward the need of a new set of force parameters that could produce more realistic single-particle levels, at least in vicinity of the Fermi surface, of a wide range of nuclear masses

  19. Description of excited states in the nucleus using the Quasiparticle Random-Phase Approximation and the Gogny interaction

    International Nuclear Information System (INIS)

    Lechaftois, Francois

    2016-01-01

    This thesis presents three aspects centered around the QRPA (Quasiparticle Random Phase Approximation). The first consists in the use of an axial code to confront computed data with experimental results and to feed a microscopic reaction code. This step is a chance to analyse low-energy spectroscopy (few tens of MeV) of some nuclei, and more precisely (but not exclusively) the tin isotopic chain (Z=50). The second one relies on the improvement of the formalism to calculate multipolar electromagnetic transition operators, and a method to consolidate the computation of these operators, allowing to ease the programming by unifying the code for different multipolarities. Finally, in order to overcome the axial symmetry constraint, a new triaxial code has been developed. Its assets and development are presented, followed by the first batch of results. (author) [fr

  20. Random-phase-approximation approach to optical and magnetic excitations in the two-dimensional multiband Hubbard model

    International Nuclear Information System (INIS)

    Yonemitsu, K.; Bishop, A.R.

    1992-01-01

    As a convenient qualitative approach to strongly correlated electronic systems, an inhomogeneous Hartree-Fock plus random-phase approximation is applied to response functions for the two-dimensional multiband Hubbard model for cuprate superconductors. A comparison of the results with those obtained by exact diagonalization by Wagner, Hanke, and Scalapino [Phys. Rev. B 43, 10 517 (1991)] shows that overall structures in optical and magnetic particle-hole excitation spectra are well reproduced by this method. This approach is computationally simple, retains conceptual clarity, and can be calibrated by comparison with exact results on small systems. Most importantly, it is easily extended to larger systems and straightforward to incorporate additional terms in the Hamiltonian, such as electron-phonon interactions, which may play a crucial role in high-temperature superconductivity

  1. Density functional formulation of the random-phase approximation for inhomogeneous fluids: Application to the Gaussian core and Coulomb particles.

    Science.gov (United States)

    Frydel, Derek; Ma, Manman

    2016-06-01

    Using the adiabatic connection, we formulate the free energy in terms of the correlation function of a fictitious system, h_{λ}(r,r^{'}), in which interactions λu(r,r^{'}) are gradually switched on as λ changes from 0 to 1. The function h_{λ}(r,r^{'}) is then obtained from the inhomogeneous Ornstein-Zernike equation and the two equations constitute a general liquid-state framework for treating inhomogeneous fluids. The two equations do not yet constitute a closed set. In the present work we use the closure c_{λ}(r,r^{'})≈-λβu(r,r^{'}), known as the random-phase approximation (RPA). We demonstrate that the RPA is identical with the variational Gaussian approximation derived within the field-theoretical framework, originally derived and used for charged particles. We apply our generalized RPA approximation to the Gaussian core model and Coulomb charges.

  2. Single exposure optically compressed imaging and visualization using random aperture coding

    Energy Technology Data Exchange (ETDEWEB)

    Stern, A [Electro Optical Unit, Ben Gurion University of the Negev, Beer-Sheva 84105 (Israel); Rivenson, Yair [Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer-Sheva 84105 (Israel); Javidi, Bahrain [Department of Electrical and Computer Engineering, University of Connecticut, Storrs, Connecticut 06269-1157 (United States)], E-mail: stern@bgu.ac.il

    2008-11-01

    The common approach in digital imaging follows the sample-then-compress framework. According to this approach, in the first step as many pixels as possible are captured and in the second step the captured image is compressed by digital means. The recently introduced theory of compressed sensing provides the mathematical foundation necessary to combine these two steps in a single one, that is, to compress the information optically before it is recorded. In this paper we overview and extend an optical implementation of compressed sensing theory that we have recently proposed. With this new imaging approach the compression is accomplished inherently in the optical acquisition step. The primary feature of this imaging approach is a randomly encoded aperture realized by means of a random phase screen. The randomly encoded aperture implements random projection of the object field in the image plane. Using a single exposure, a randomly encoded image is captured which can be decoded by proper decoding algorithm.

  3. Everolimus for Previously Treated Advanced Gastric Cancer: Results of the Randomized, Double-Blind, Phase III GRANITE-1 Study

    Science.gov (United States)

    Ohtsu, Atsushi; Ajani, Jaffer A.; Bai, Yu-Xian; Bang, Yung-Jue; Chung, Hyun-Cheol; Pan, Hong-Ming; Sahmoud, Tarek; Shen, Lin; Yeh, Kun-Huei; Chin, Keisho; Muro, Kei; Kim, Yeul Hong; Ferry, David; Tebbutt, Niall C.; Al-Batran, Salah-Eddin; Smith, Heind; Costantini, Chiara; Rizvi, Syed; Lebwohl, David; Van Cutsem, Eric

    2013-01-01

    Purpose The oral mammalian target of rapamycin inhibitor everolimus demonstrated promising efficacy in a phase II study of pretreated advanced gastric cancer. This international, double-blind, phase III study compared everolimus efficacy and safety with that of best supportive care (BSC) in previously treated advanced gastric cancer. Patients and Methods Patients with advanced gastric cancer that progressed after one or two lines of systemic chemotherapy were randomly assigned to everolimus 10 mg/d (assignment schedule: 2:1) or matching placebo, both given with BSC. Randomization was stratified by previous chemotherapy lines (one v two) and region (Asia v rest of the world [ROW]). Treatment continued until disease progression or intolerable toxicity. Primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), overall response rate, and safety. Results Six hundred fifty-six patients (median age, 62.0 years; 73.6% male) were enrolled. Median OS was 5.4 months with everolimus and 4.3 months with placebo (hazard ratio, 0.90; 95% CI, 0.75 to 1.08; P = .124). Median PFS was 1.7 months and 1.4 months in the everolimus and placebo arms, respectively (hazard ratio, 0.66; 95% CI, 0.56 to 0.78). Common grade 3/4 adverse events included anemia, decreased appetite, and fatigue. The safety profile was similar in patients enrolled in Asia versus ROW. Conclusion Compared with BSC, everolimus did not significantly improve overall survival for advanced gastric cancer that progressed after one or two lines of previous systemic chemotherapy. The safety profile observed for everolimus was consistent with that observed for everolimus in other cancers. PMID:24043745

  4. Dietary Soy Supplement on Fibromyalgia Symptoms: A Randomized, Double-Blind, Placebo-Controlled, Early Phase Trial

    Directory of Open Access Journals (Sweden)

    Dietlind L. Wahner-Roedler

    2011-01-01

    Full Text Available Most patients with fibromyalgia use complementary and alternative medicine (CAM. Properly designed controlled trials are necessary to assess the effectiveness of these practices. This study was a randomized, double-blind, placebo-controlled, early phase trial. Fifty patients seen at a fibromyalgia outpatient treatment program were randomly assigned to a daily soy or placebo (casein shake. Outcome measures were scores of the Fibromyalgia Impact Questionnaire (FIQ and the Center for Epidemiologic Studies Depression Scale (CES-D at baseline and after 6 weeks of intervention. Analysis was with standard statistics based on the null hypothesis, and separation test for early phase CAM comparative trials. Twenty-eight patients completed the study. Use of standard statistics with intent-to-treat analysis showed that total FIQ scores decreased by 14% in the soy group (P = .02 and by 18% in the placebo group (P < .001. The difference in change in scores between the groups was not significant (P = .16. With the same analysis, CES-D scores decreased in the soy group by 16% (P = .004 and in the placebo group by 15% (P = .05. The change in scores was similar in the groups (P = .83. Results of statistical analysis using the separation test and intent-to-treat analysis revealed no benefit of soy compared with placebo. Shakes that contain soy and shakes that contain casein, when combined with a multidisciplinary fibromyalgia treatment program, provide a decrease in fibromyalgia symptoms. Separation between the effects of soy and casein (control shakes did not favor the intervention. Therefore, large-sample studies using soy for patients with fibromyalgia are probably not indicated.

  5. Vandetanib in patients with locally advanced or metastatic medullary thyroid cancer: a randomized, double-blind phase III trial.

    Science.gov (United States)

    Wells, Samuel A; Robinson, Bruce G; Gagel, Robert F; Dralle, Henning; Fagin, James A; Santoro, Massimo; Baudin, Eric; Elisei, Rossella; Jarzab, Barbara; Vasselli, James R; Read, Jessica; Langmuir, Peter; Ryan, Anderson J; Schlumberger, Martin J

    2012-01-10

    There is no effective therapy for patients with advanced medullary thyroid carcinoma (MTC). Vandetanib, a once-daily oral inhibitor of RET kinase, vascular endothelial growth factor receptor, and epidermal growth factor receptor signaling, has previously shown antitumor activity in a phase II study of patients with advanced hereditary MTC. Patients with advanced MTC were randomly assigned in a 2:1 ratio to receive vandetanib 300 mg/d or placebo. On objective disease progression, patients could elect to receive open-label vandetanib. The primary end point was progression-free survival (PFS), determined by independent central Response Evaluation Criteria in Solid Tumors (RECIST) assessments. Between December 2006 and November 2007, 331 patients (mean age, 52 years; 90% sporadic; 95% metastatic) were randomly assigned to receive vandetanib (231) or placebo (100). At data cutoff (July 2009; median follow-up, 24 months), 37% of patients had progressed and 15% had died. The study met its primary objective of PFS prolongation with vandetanib versus placebo (hazard ratio [HR], 0.46; 95% CI, 0.31 to 0.69; P < .001). Statistically significant advantages for vandetanib were also seen for objective response rate (P < .001), disease control rate (P = .001), and biochemical response (P < .001). Overall survival data were immature at data cutoff (HR, 0.89; 95% CI, 0.48 to 1.65). A final survival analysis will take place when 50% of the patients have died. Common adverse events (any grade) occurred more frequently with vandetanib compared with placebo, including diarrhea (56% v 26%), rash (45% v 11%), nausea (33% v 16%), hypertension (32% v 5%), and headache (26% v 9%). Vandetanib demonstrated therapeutic efficacy in a phase III trial of patients with advanced MTC (ClinicalTrials.gov NCT00410761).

  6. DNA priming for seasonal influenza vaccine: a phase 1b double-blind randomized clinical trial.

    Directory of Open Access Journals (Sweden)

    Julie E Ledgerwood

    Full Text Available The efficacy of current influenza vaccines is limited in vulnerable populations. DNA vaccines can be produced rapidly, and may offer a potential strategy to improve vaccine immunogenicity, indicated by studies with H5 influenza DNA vaccine prime followed by inactivated vaccine boost.Four sites enrolled healthy adults, randomized to receive 2011/12 seasonal influenza DNA vaccine prime (n=65 or phosphate buffered saline (PBS (n=66 administered intramuscularly with Biojector. All subjects received the 2012/13 seasonal inactivated influenza vaccine, trivalent (IIV3 36 weeks after the priming injection. Vaccine safety and tolerability was the primary objective and measurement of antibody response by hemagglutination inhibition (HAI was the secondary objective.The DNA vaccine prime-IIV3 boost regimen was safe and well tolerated. Significant differences in HAI responses between the DNA vaccine prime and the PBS prime groups were not detected in this study.While DNA priming significantly improved the response to a conventional monovalent H5 vaccine in a previous study, it was not effective in adults using seasonal influenza strains, possibly due to pre-existing immunity to the prime, unmatched prime and boost antigens, or the lengthy 36 week boost interval. Careful optimization of the DNA prime-IIV3 boost regimen as related to antigen matching, interval between vaccinations, and pre-existing immune responses to influenza is likely to be needed in further evaluations of this vaccine strategy. In particular, testing this concept in younger age groups with less prior exposure to seasonal influenza strains may be informative.ClinicalTrials.gov NCT01498718.

  7. A Phase III Randomized Trial of the Timing of Meloxicam With Iodine-125 Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Crook, Juanita; Patil, Nikhilesh; Wallace, Kris; Borg, Jette; Zhou, David; Ma, Clement; Pond, Greg

    2010-01-01

    Purpose: Nonsteroidal anti-inflammatory medication is used to reduce prostate edema and urinary symptoms following prostate brachytherapy. We hypothesized that a cyclooxygenase-2 (COX-2) inhibitor regimen started 1 week prior to seed implant might diminish the inflammatory response, thus reducing edema, retention rates, and symptom severity. Methods and Materials: From March 2004 to February 2008, 316 men consented to an institutional review board-approved randomized study of a 4-week course of meloxicam, 7.5 mg orally twice per day, starting either on the day of implant or 1 week prior to implant. Brachytherapy was performed using iodine-125 seeds and was preplanned and performed under transrectal ultrasound (TRUS) and fluoroscopic guidance. Prostate volume obtained by MR imaging at 1 month was compared to baseline prostate volume obtained by TRUS planimetry and expressed as an edema factor. The trial endpoints were prostate edema at 1 month, International Prostate Symptom Score (IPSS) questionnaire results at 1 and 3 months, and any need for catheterization. Results: Results for 300 men were analyzed. Median age was 61 (range, 45-79 years), and median TRUS prostate volume was 35.7 cc (range, 18.1-69.5 cc). Median IPSS at baseline was 5 (range, 0-24) and was 15 at 1 month, 16 at 3 months, and 10 at 6 months. Catheterization was required for 7% of patients (6.2% day 0 arm vs. 7.9% day -7 arm; p = 0.65). The median edema factor at 1 month was 1.02 (range, 0.73-1.7). 1.01 day 0 arm vs. 1.05 day -7 arm. Baseline prostate volume remained the primary predictor of postimplant urinary retention. Conclusions: Starting meloxicam 1 week prior to brachytherapy compared to starting immediately after the procedure did not reduce 1-month edema, improve IPSSs at 1 or 3 months, or reduce the need for catheterization.

  8. Iodixanol in cerebral computed tomography: a randomized, double-blind, phase-III, parallel study with iodixanol and iohexol

    International Nuclear Information System (INIS)

    Doerfler, A.; Wanke, I.; Forsting, M.; Fiebach, J.; Sartor, K.; Henseke, P.

    1999-01-01

    Iodixanol is a new nonionic dimer, isotonic with blood at all clinically relevant concentrations. Iodixanol (270 mg I/ml) was compared in a double-blind, randomized, parallel-group, phase-III study to the monomeric nonionic iohexol (300 mg I/ml) for evaluation of safety, tolerability and radiographic efficacy during cerebral CT. One hundred adult patients scheduled to undergo contrast-enhanced cerebral CT were randomly allocated to receive either iodixanol or iohexol. All completed the trial. Safety was evaluated by recording discomfort and other adverse events, tolerance by assessing intensity and incidence of discomfort. Radiographic efficacy was assessed from the diagnostic information and the radiographic density. No serious adverse events occurred. One patient (2 %) in the iodixanol group and one patient (2 %) in the iohexol group experienced a transient reddening at the neck and lower neck-line, respectively. Both contrast agents were well tolerated. One patient (2 %) in the iodixanol group and two patients (4 %) in the iohexol group experienced a sensation of warmth (discomfort) in connection with the injection. No difference between the two contrast media were noted radiographically. This comparison between iodixanol and iohexol showed both contrast media to be safe, well-tolerated and efficacious for use in cerebral CT. (orig.)

  9. A phase 2 randomized trial of ELND005, scyllo-inositol, in mild to moderate Alzheimer disease

    Science.gov (United States)

    Sperling, R.; Keren, R.; Porsteinsson, A.P.; van Dyck, C.H.; Tariot, P.N.; Gilman, S.; Arnold, D.; Abushakra, S.; Hernandez, C.; Crans, G.; Liang, E.; Quinn, G.; Bairu, M.; Pastrak, A.; Cedarbaum, J.M.

    2011-01-01

    Objective: This randomized, double-blind, placebo-controlled, dose-ranging phase 2 study explored safety, efficacy, and biomarker effects of ELND005 (an oral amyloid anti-aggregation agent) in mild to moderate Alzheimer disease (AD). Methods: A total of 353 patients were randomized to ELND005 (250, 1,000, or 2,000 mg) or placebo twice daily for 78 weeks. Coprimary endpoints were the Neuropsychological Test Battery (NTB) and Alzheimer's Disease Cooperative Study–Activities of Daily Living (ADCS-ADL) scale. The primary analysis compared 250 mg (n =84) to placebo (n =82) after an imbalance of infections and deaths led to early discontinuation of the 2 higher dose groups. Results: The 250 mg dose demonstrated acceptable safety. The primary efficacy analysis at 78 weeks revealed no significant differences between the treatment groups on the NTB or ADCS-ADL. Brain ventricular volume showed a small but significant increase in the overall 250 mg group (p =0.049). At the 250 mg dose, scyllo-inositol concentrations increased in CSF and brain and CSF Aβx-42 was decreased significantly compared to placebo (p =0.009). Conclusions: Primary clinical efficacy outcomes were not significant. The safety and CSF biomarker results will guide selection of the optimal dose for future studies, which will target earlier stages of AD. Classification of evidence: Due to the small sample sizes, this Class II trial provides insufficient evidence to support or refute a benefit of ELND005. PMID:21917766

  10. Safety of a silicone elastomer vaginal ring as potential microbicide delivery method in African women: A Phase 1 randomized trial.

    Science.gov (United States)

    Nel, Annaléne; Martins, Janine; Bekker, Linda-Gail; Ramjee, Gita; Masenga, Gileard; Rees, Helen; van Niekerk, Neliëtte

    2018-01-01

    Women in sub-Saharan Africa are in urgent need of female-initiated human immunodeficiency virus (HIV) preventative methods. Vaginal rings are one dosage form in development for delivery of HIV microbicides. However, African women have limited experience with vaginal rings. This Phase I, randomized, crossover trial assessed and compared the safety, acceptability and adherence of a silicone elastomer placebo vaginal ring, intended as a microbicide delivery method, inserted for a 12-week period in healthy, HIV-negative, sexually active women in South Africa and Tanzania. 170 women, aged 18 to 35 years were enrolled with 88 women randomized to Group A, using a placebo vaginal ring for 12 weeks followed by a 12-week safety observation period. 82 women were randomized to Group B and observed for safety first, followed by a placebo vaginal ring for 12 weeks. Safety was assessed by clinical laboratory assessments, pelvic/colposcopy examinations and adverse events. Possible carry-over effect was addressed by ensuring no signs or symptoms of genital irritation at crossover. No safety concerns were identified for any safety variables assessed during the trial. No serious adverse events were reported considered related to the placebo vaginal ring. Vaginal candidiasis was the most common adverse event occurring in 11% of participants during each trial period. Vaginal discharge (2%), vaginal odour (2%), and bacterial vaginitis (2%) were assessed as possibly or probably related to the vaginal ring. Thirty-four percent of participants had sexually transmitted infections (STIs) at screening, compared to 12% of participants who tested positive for STIs at crossover and the final trial visit. Three participants (2%) tested HIV positive during the trial. The silicone elastomer vaginal ring had no safety concerns, demonstrating a profile favorable for further development for topical release of antiretroviral-based microbicides.

  11. Self-consistent random phase approximation - application to systems of strongly correlated fermions; Approximation des phases aleatoires self-consistante - applications a des systemes de fermions fortement correles

    Energy Technology Data Exchange (ETDEWEB)

    Jemai, M

    2004-07-01

    In the present thesis we have applied the self consistent random phase approximation (SCRPA) to the Hubbard model with a small number of sites (a chain of 2, 4, 6,... sites). Earlier SCRPA had produced very good results in other models like the pairing model of Richardson. It was therefore interesting to see what kind of results the method is able to produce in the case of a more complex model like the Hubbard model. To our great satisfaction the case of two sites with two electrons (half-filling) is solved exactly by the SCRPA. This may seem a little trivial but the fact is that other respectable approximations like 'GW' or the approach with the Gutzwiller wave function yield results still far from exact. With this promising starting point, the case of 6 sites at half filling was considered next. For that case, evidently, SCRPA does not any longer give exact results. However, they are still excellent for a wide range of values of the coupling constant U, covering for instance the phase transition region towards a state with non zero magnetisation. We consider this as a good success of the theory. Non the less the case of 4 sites (a plaquette), as indeed all cases with 4n sites at half filling, turned out to have a problem because of degeneracies at the Hartree Fock level. A generalisation of the present method, including in addition to the pairs, quadruples of Fermions operators (called second RPA) is proposed to also include exactly the plaquette case in our approach. This is therefore a very interesting perspective of the present work. (author)

  12. Phase I randomized safety study of twice daily dosing of acidform vaginal gel: candidate antimicrobial contraceptive.

    Directory of Open Access Journals (Sweden)

    Marla J Keller

    Full Text Available BACKGROUND: Acidform gel, an acid-buffering product that inactivates spermatozoa, may be an effective topical non-hormonal contraceptive. This study was designed to evaluate the safety of vaginal dosing and effects of Acidform on mucosal immune mediators, antimicrobial properties of genital secretions, and vaginal microbiota. METHODS: Thirty-six sexually abstinent U.S. women were randomized to apply Acidform or hydroxyethylcellulose (HEC placebo gel twice daily for 14 consecutive days. Safety was assessed by symptoms and pelvic examination. The impact of gel on mucosal immunity was assessed by quantifying cytokines, chemokines, antimicrobial proteins and antimicrobial activity of genital secretions collected by cervicovaginal lavage (CVL at screening, 2 hours after gel application, and on days 7, 14 and 21. Vaginal microbiota was characterized at enrollment and day 14 using species-specific quantitative PCR assays. RESULTS: The median vaginal and cervical pH was significantly lower 2 hours after application of Acidform and was associated with an increase in the bactericidal activity of CVL against E. coli. However, 65% of women who received Acidform had at least one local adverse event compared with 11% who received placebo (p = 0.002. While there was no increase in inflammatory cytokines or chemokines, CVL concentrations of lactoferrin and interleukin-1 receptor antagonist (IL-1ra, an anti-inflammatory protein, were significantly lower following Acidform compared to HEC placebo gel application. There were no significant changes in Lactobacillus crispatus or Lactobacillus jensenii in either group but there was a decrease in Gardnerella vaginalis in the Acidform group (p = 0.08. CONCLUSIONS: Acidform gel may augment mucosal defense as evidenced by an increase in bactericidal activity of genital secretions against E. coli and a decrease in Gardnerella vaginalis colonization. However, Acidform was associated with more irritation than

  13. Phase I Randomized Safety Study of Twice Daily Dosing of Acidform Vaginal Gel: Candidate Antimicrobial Contraceptive

    Science.gov (United States)

    Keller, Marla J.; Carpenter, Colleen A.; Lo, Yungtai; Einstein, Mark H.; Liu, Congzhou; Fredricks, David N.; Herold, Betsy C.

    2012-01-01

    Background Acidform gel, an acid-buffering product that inactivates spermatozoa, may be an effective topical non-hormonal contraceptive. This study was designed to evaluate the safety of vaginal dosing and effects of Acidform on mucosal immune mediators, antimicrobial properties of genital secretions, and vaginal microbiota. Methods Thirty-six sexually abstinent U.S. women were randomized to apply Acidform or hydroxyethylcellulose (HEC) placebo gel twice daily for 14 consecutive days. Safety was assessed by symptoms and pelvic examination. The impact of gel on mucosal immunity was assessed by quantifying cytokines, chemokines, antimicrobial proteins and antimicrobial activity of genital secretions collected by cervicovaginal lavage (CVL) at screening, 2 hours after gel application, and on days 7, 14 and 21. Vaginal microbiota was characterized at enrollment and day 14 using species-specific quantitative PCR assays. Results The median vaginal and cervical pH was significantly lower 2 hours after application of Acidform and was associated with an increase in the bactericidal activity of CVL against E. coli. However, 65% of women who received Acidform had at least one local adverse event compared with 11% who received placebo (p = 0.002). While there was no increase in inflammatory cytokines or chemokines, CVL concentrations of lactoferrin and interleukin-1 receptor antagonist (IL-1ra), an anti-inflammatory protein, were significantly lower following Acidform compared to HEC placebo gel application. There were no significant changes in Lactobacillus crispatus or Lactobacillus jensenii in either group but there was a decrease in Gardnerella vaginalis in the Acidform group (p = 0.08). Conclusions Acidform gel may augment mucosal defense as evidenced by an increase in bactericidal activity of genital secretions against E. coli and a decrease in Gardnerella vaginalis colonization. However, Acidform was associated with more irritation than placebo and lower levels

  14. Tofacitinib attenuates pathologic immune pathways in patients with psoriasis: A randomized phase 2 study.

    Science.gov (United States)

    Krueger, James; Clark, James D; Suárez-Fariñas, Mayte; Fuentes-Duculan, Judilyn; Cueto, Inna; Wang, Claire Q; Tan, Huaming; Wolk, Robert; Rottinghaus, Scott T; Whitley, Maryann Z; Valdez, Hernan; von Schack, David; O'Neil, Shawn P; Reddy, Padmalatha S; Tatulych, Svitlana

    2016-04-01

    Tofacitinib is an oral Janus kinase inhibitor being investigated for psoriasis. We sought to elucidate the molecular mechanisms underlying the clinical efficacy of tofacitinib in patients with psoriasis. Twelve patients with plaque psoriasis were randomized (3:1) to receive 10 mg of tofacitinib or placebo twice daily for 12 weeks. Biopsy specimens were taken from nonlesional (baseline) and lesional (baseline, days 1 and 3, and weeks 1, 2, 4, and 12) skin. Biopsy specimens were examined for psoriatic epidermal features (thickness, Ki67(+) keratinocytes and keratin 16 [KRT16] mRNA expression, and phosphorylated signal transducer and activator of transcription [pSTAT](+) nuclei) and T-cell and dendritic cell (DC) subsets by using immunohistochemistry, and mRNA transcripts were quantified by using a microarray. In lesional skin keratinocyte pSTAT1 and pSTAT3 staining was increased at baseline but reduced after 1 day of tofacitinib (baseline, median of 1290 pSTAT1(+) cells/μm(2); day 1, median of 332 pSTAT1(+) cells/μm(2); and nonlesional, median of 155 pSTAT1(+) cells/μm(2)). Epidermal thickness and KRT16 mRNA expression were significantly and progressively reduced after days 1 and 3 of tofacitinib administration, respectively (eg, KRT16 decreased 2.74-fold, day 3 vs baseline, P = .016). Decreases in DC and T-cell numbers were observed after weeks 1 and 2, respectively. At week 4, significant decreases in IL-23/TH17 pathways were observed that persisted through week 12. Improvements in clinical and histologic features were strongly associated with changes in expression of psoriasis-related genes and reduction in IL-17 gene expression. Tofacitinib has a multitiered response in patients with psoriasis: (1) rapid attenuation of keratinocyte Janus kinase/STAT signaling; (2) removal of keratinocyte-induced cytokine signaling, leading to reductions in pathologic DC and T-cell numbers to nonlesional levels; and (3) inhibition of the IL-23/TH17 pathway. Copyright © 2016

  15. Serelaxin as a potential treatment for renal dysfunction in cirrhosis: Preclinical evaluation and results of a randomized phase 2 trial.

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    Victoria K Snowdon

    2017-02-01

    Full Text Available Chronic liver scarring from any cause leads to cirrhosis, portal hypertension, and a progressive decline in renal blood flow and renal function. Extreme renal vasoconstriction characterizes hepatorenal syndrome, a functional and potentially reversible form of acute kidney injury in patients with advanced cirrhosis, but current therapy with systemic vasoconstrictors is ineffective in a substantial proportion of patients and is limited by ischemic adverse events. Serelaxin (recombinant human relaxin-2 is a peptide molecule with anti-fibrotic and vasoprotective properties that binds to relaxin family peptide receptor-1 (RXFP1 and has been shown to increase renal perfusion in healthy human volunteers. We hypothesized that serelaxin could ameliorate renal vasoconstriction and renal dysfunction in patients with cirrhosis and portal hypertension.To establish preclinical proof of concept, we developed two independent rat models of cirrhosis that were characterized by progressive reduction in renal blood flow and glomerular filtration rate and showed evidence of renal endothelial dysfunction. We then set out to further explore and validate our hypothesis in a phase 2 randomized open-label parallel-group study in male and female patients with alcohol-related cirrhosis and portal hypertension. Forty patients were randomized 1:1 to treatment with serelaxin intravenous (i.v. infusion (for 60 min at 80 μg/kg/d and then 60 min at 30 μg/kg/d or terlipressin (single 2-mg i.v. bolus, and the regional hemodynamic effects were quantified by phase contrast magnetic resonance angiography at baseline and after 120 min. The primary endpoint was the change from baseline in total renal artery blood flow. Therapeutic targeting of renal vasoconstriction with serelaxin in the rat models increased kidney perfusion, oxygenation, and function through reduction in renal vascular resistance, reversal of endothelial dysfunction, and increased activation of the AKT

  16. Selumetinib in Combination With Dacarbazine in Patients With Metastatic Uveal Melanoma: A Phase III, Multicenter, Randomized Trial (SUMIT).

    Science.gov (United States)

    Carvajal, Richard D; Piperno-Neumann, Sophie; Kapiteijn, Ellen; Chapman, Paul B; Frank, Stephen; Joshua, Anthony M; Piulats, Josep M; Wolter, Pascal; Cocquyt, Veronique; Chmielowski, Bartosz; Evans, T R Jeffry; Gastaud, Lauris; Linette, Gerald; Berking, Carola; Schachter, Jacob; Rodrigues, Manuel J; Shoushtari, Alexander N; Clemett, Delyth; Ghiorghiu, Dana; Mariani, Gabriella; Spratt, Shirley; Lovick, Susan; Barker, Peter; Kilgour, Elaine; Lai, Zhongwu; Schwartz, Gary K; Nathan, Paul

    2018-04-20

    Purpose Uveal melanoma is the most common primary intraocular malignancy in adults with no effective systemic treatment option in the metastatic setting. Selumetinib (AZD6244, ARRY-142886) is an oral, potent, and selective MEK1/2 inhibitor with a short half-life, which demonstrated single-agent activity in patients with metastatic uveal melanoma in a randomized phase II trial. Methods The Selumetinib (AZD6244: ARRY-142886) (Hyd-Sulfate) in Metastatic Uveal Melanoma (SUMIT) study was a phase III, double-blind trial ( ClinicalTrial.gov identifier: NCT01974752) in which patients with metastatic uveal melanoma and no prior systemic therapy were randomly assigned (3:1) to selumetinib (75 mg twice daily) plus dacarbazine (1,000 mg/m 2 intravenously on day 1 of every 21-day cycle) or placebo plus dacarbazine. The primary end point was progression-free survival (PFS) by blinded independent central radiologic review. Secondary end points included overall survival and objective response rate. Results A total of 129 patients were randomly assigned to receive selumetinib plus dacarbazine (n = 97) or placebo plus dacarbazine (n = 32). In the selumetinib plus dacarbazine group, 82 patients (85%) experienced a PFS event, compared with 24 (75%) in the placebo plus dacarbazine group (median, 2.8 v 1.8 months); the hazard ratio for PFS was 0.78 (95% CI, 0.48 to 1.27; two-sided P = .32). The objective response rate was 3% with selumetinib plus dacarbazine and 0% with placebo plus dacarbazine (two-sided P = .36). At 37% maturity (n = 48 deaths), analysis of overall survival gave a hazard ratio of 0.75 (95% CI, 0.39 to 1.46; two-sided P = .40). The most frequently reported adverse events (selumetinib plus dacarbazine v placebo plus dacarbazine) were nausea (62% v 19%), rash (57% v 6%), fatigue (44% v 47%), diarrhea (44% v 22%), and peripheral edema (43% v 6%). Conclusion In patients with metastatic uveal melanoma, the combination of selumetinib plus dacarbazine had a tolerable safety

  17. Phase 2 Randomized, Dose-Ranging Study of Oxymetazoline Cream for Treatment of Persistent Facial Erythema Associated With Rosacea.

    Science.gov (United States)

    DuBois, Janet; Dover, Jeffrey S; Jones, Terry M; Weiss, Robert A; Berk, David R; Ahluwalia, Gurpreet

    2018-03-01

    Rosacea is a chronic dermatologic condition with limited treatment options. This phase 2 study evaluated the optimal oxymetazoline dosing regimen in patients with moderate to severe persistent facial erythema of rosacea. Patients were randomly assigned to oxymetazoline cream, 0.5%, 1.0%, or 1.5%, or vehicle, administered once daily (QD) or twice daily (BID) for 28 consecutive days. The primary efficacy endpoint was the proportion of patients with ≥2-grade improvement from baseline on the Clinician Erythema Assessment (CEA) and the Subject Self-Assessment of erythema (SSA-1) on day 28. Safety assessments included treatment-emergent adverse events and dermal tolerability. A total of 356 patients were treated (mean age, 50.0 years; 80.1% female). The proportions of patients achieving the primary endpoint were significantly higher with oxymetazoline 0.5% QD (P=0.049), 1.0% QD (P=0.006), 1.5% QD (P=0.012), 1.0% BID (P=0.021), and 1.5% BID (P=0.006) versus their respective vehicles. For both QD and BID dosing, the efficacy of oxymetazoline 1.0% was greater than the 0.5% dose and comparable to the 1.5% dose. Safety and application-site tolerability were similar across groups. Short-term treatment period. Oxymetazoline 1.0% QD provided the optimal dosing regimen and was selected for evaluation in phase 3 clinical studies. J Drugs Dermatol. 2018;17(3):308-316.

  18. Microstructure of two-phase random media. II. The Mayer--Montroll and Kirkwood--Salsburg hierarchies

    International Nuclear Information System (INIS)

    Torquato, S.; Stell, G.

    1983-01-01

    It is shown that the Mayer--Montroll (MM) and Kirkwood--Salsburg (KS) hierarchies of equilibrium statistical mechanics for a binary mixture under certain limits become equations for the n-point matrix probability functions S/sub n/ associated with two-phase random media. The MM representation proves to be identical to the S/sub n/ expression derived by us in a previous paper, whereas the KS representation is different and new. These results are shown to illuminate our understanding of the S/sub n/ from both a physical and quantitative point of view. In particular rigorous upper and lower bounds on the S/sub n/ are obtained for a two-phase medium formed so as to be in a state of thermal equilibrium. For such a medium consisting of impenetrable-sphere inclusions in a matrix, a new exact expression is also given for S/sub n/ in terms of a two-body probability distribution function rho/sub 2/ as well as new expressions for S/sub 3/ in terms of rho/sub 2/ and rho/sub 3/, a three-body distribution function. Physical insight into the nature of these results is given by extending some geometrical arguments originally put forth by Boltzmann

  19. Aortoiliac stenooculusive disease and aneurysms. Screening with non-contrast enhanced two-dimensional cardiac gated cine phase contrast MR angiography with multiple velocity encoded values and cardiac gated two-dimensional time-of-flight MR angiography

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Koshikawa, Tokiko; Kato, Katsuhiko

    2001-01-01

    To evaluate the performance of two-dimensional cine phase contrast MRA with multi-velocity encoded values (multi-VENC cine PC) and ECG-gated two-dimensional time-of-flight MRA (ECG-2D-TOF) for the detection of stenoocclusive lesions and aneurysms in the aortoiliac area, when each method was used individually and when the two methods were used together. Forty-one patients were included in this study. Multi-VENC cine PC and ECG-2D-TOF were obtained first, then contrast enhanced three-dimensional magnetic resonance angiography (CE-3D-MRA) was performed as the standard of reference. Two observers reviewed the images separately without knowledge of patients' symptoms or histories. Sensitivities and specificities were obtained separately for stenooclusive lesions and aneurysms by two reviewers. When the two methods were applied together, high sensitivities (93.0 by observer 1 and 91.9% by observer 2) and adequate specificities (87.6 and 82.3%) were obtained for stenoocclusive lesions. For aneurysms, moderate to high sensitivities (91.1 and 71.1%) and high specificities (98.8 and 99.4%) were obtained. These results suggest that the performance of two non-contrast enhanced MRA techniques may be valuable as a screening tool when the two methods are applied together. (author)

  20. Multichannel compressive sensing MRI using noiselet encoding.

    Directory of Open Access Journals (Sweden)

    Kamlesh Pawar

    Full Text Available The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS. In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  1. HIV-DNA Given with or without Intradermal Electroporation Is Safe and Highly Immunogenic in Healthy Swedish HIV-1 DNA/MVA Vaccinees: A Phase I Randomized Trial.

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    Charlotta Nilsson

    Full Text Available We compared safety and immunogenicity of intradermal (ID vaccination with and without electroporation (EP in a phase I randomized placebo-controlled trial of an HIV-DNA prime HIV-MVA boost vaccine in healthy Swedish volunteers.HIV-DNA plasmids encoding HIV-1 genes gp160 subtypes A, B and C; Rev B; Gag A and B and RTmut B were given ID at weeks 0, 6 and 12 in a dose of 0.6 mg. Twenty-five volunteers received vaccine using a needle-free device (ZetaJet with (n=16 or without (n=9 ID EP (Dermavax. Five volunteers were placebo recipients. Boosting with recombinant MVA-CMDR expressing HIV-1 Env, Gag, Pol of CRF01_AE (HIV-MVA or placebo was performed at weeks 24 and 40. Nine of the vaccinees received a subtype C CN54 gp140 protein boost together with HIV-MVA.The ID/EP delivery was very well tolerated. After three HIV-DNA immunizations, no statistically significant difference was seen in the IFN-γ ELISpot response rate to Gag between HIV-DNA ID/EP recipients (5/15, 33% and HIV-DNA ID recipients (1/7, 14%, p=0.6158. The first HIV-MVA or HIV-MVA+gp140 vaccination increased the IFN-γ ELISpot response rate to 18/19 (95%. CD4+ and/or CD8+ T cell responses to Gag or Env were demonstrable in 94% of vaccinees. A balanced CD4+ and CD8+ T cell response was noted, with 78% and 71% responders, respectively. IFN-γ and IL-2 dominated the CD4+ T cell response to Gag and Env. The CD8+ response to Gag was broader with expression of IFN-γ, IL-2, MIP-1β and/or CD107. No differences were seen between DNA vaccine groups. Binding antibodies were induced after the second HIV-MVA+/-gp140 in 93% of vaccinees to subtype C Env, with the highest titers among EP/gp140 recipients.Intradermal electroporation of HIV-DNA was well tolerated. Strong cell- and antibody-mediated immune responses were elicited by the HIV-DNA prime and HIV-MVA boosting regimen, with or without intradermal electroporation use.International Standard Randomised Controlled Trial Number (ISRCTN 60284968.

  2. HIV-DNA Given with or without Intradermal Electroporation Is Safe and Highly Immunogenic in Healthy Swedish HIV-1 DNA/MVA Vaccinees: A Phase I Randomized Trial.

    Science.gov (United States)

    Nilsson, Charlotta; Hejdeman, Bo; Godoy-Ramirez, Karina; Tecleab, Teghesti; Scarlatti, Gabriella; Bråve, Andreas; Earl, Patricia L; Stout, Richard R; Robb, Merlin L; Shattock, Robin J; Biberfeld, Gunnel; Sandström, Eric; Wahren, Britta

    2015-01-01

    We compared safety and immunogenicity of intradermal (ID) vaccination with and without electroporation (EP) in a phase I randomized placebo-controlled trial of an HIV-DNA prime HIV-MVA boost vaccine in healthy Swedish volunteers. HIV-DNA plasmids encoding HIV-1 genes gp160 subtypes A, B and C; Rev B; Gag A and B and RTmut B were given ID at weeks 0, 6 and 12 in a dose of 0.6 mg. Twenty-five volunteers received vaccine using a needle-free device (ZetaJet) with (n=16) or without (n=9) ID EP (Dermavax). Five volunteers were placebo recipients. Boosting with recombinant MVA-CMDR expressing HIV-1 Env, Gag, Pol of CRF01_AE (HIV-MVA) or placebo was performed at weeks 24 and 40. Nine of the vaccinees received a subtype C CN54 gp140 protein boost together with HIV-MVA. The ID/EP delivery was very well tolerated. After three HIV-DNA immunizations, no statistically significant difference was seen in the IFN-γ ELISpot response rate to Gag between HIV-DNA ID/EP recipients (5/15, 33%) and HIV-DNA ID recipients (1/7, 14%, p=0.6158). The first HIV-MVA or HIV-MVA+gp140 vaccination increased the IFN-γ ELISpot response rate to 18/19 (95%). CD4+ and/or CD8+ T cell responses to Gag or Env were demonstrable in 94% of vaccinees. A balanced CD4+ and CD8+ T cell response was noted, with 78% and 71% responders, respectively. IFN-γ and IL-2 dominated the CD4+ T cell response to Gag and Env. The CD8+ response to Gag was broader with expression of IFN-γ, IL-2, MIP-1β and/or CD107. No differences were seen between DNA vaccine groups. Binding antibodies were induced after the second HIV-MVA+/-gp140 in 93% of vaccinees to subtype C Env, with the highest titers among EP/gp140 recipients. Intradermal electroporation of HIV-DNA was well tolerated. Strong cell- and antibody-mediated immune responses were elicited by the HIV-DNA prime and HIV-MVA boosting regimen, with or without intradermal electroporation use. International Standard Randomised Controlled Trial Number (ISRCTN) 60284968.

  3. Encoding negative events under stress: high subjective arousal is related to accurate emotional memory despite misinformation exposure.

    Science.gov (United States)

    Hoscheidt, Siobhan M; LaBar, Kevin S; Ryan, Lee; Jacobs, W Jake; Nadel, Lynn

    2014-07-01

    Stress at encoding affects memory processes, typically enhancing, or preserving, memory for emotional information. These effects have interesting implications for eyewitness accounts, which in real-world contexts typically involve encoding an aversive event under stressful conditions followed by potential exposure to misinformation. The present study investigated memory for a negative event encoded under stress and subsequent misinformation endorsement. Healthy young adults participated in a between-groups design with three experimental sessions conducted 48 h apart. Session one consisted of a psychosocial stress induction (or control task) followed by incidental encoding of a negative slideshow. During session two, participants were asked questions about the slideshow, during which a random subgroup was exposed to misinformation. Memory for the slideshow was tested during the third session. Assessment of memory accuracy across stress and no-stress groups revealed that stress induced just prior to encoding led to significantly better memory for the slideshow overall. The classic misinformation effect was also observed - participants exposed to misinformation were significantly more likely to endorse false information during memory testing. In the stress group, however, memory accuracy and misinformation effects were moderated by arousal experienced during encoding of the negative event. Misinformed-stress group participants who reported that the negative slideshow elicited high arousal during encoding were less likely to endorse misinformation for the most aversive phase of the story. Furthermore, these individuals showed better memory for components of the aversive slideshow phase that had been directly misinformed. Results from the current study provide evidence that stress and high subjective arousal elicited by a negative event act concomitantly during encoding to enhance emotional memory such that the most aversive aspects of the event are well remembered and

  4. Safety and immunogenicity of inactivated poliovirus vaccine made from Sabin strains: a phase II, randomized, positive-controlled trial.

    Science.gov (United States)

    Liao, Guoyang; Li, Rongcheng; Li, Changgui; Sun, Mingbo; Li, Yanping; Chu, Jiayou; Jiang, Shude; Li, Qihan

    2012-01-15

    The production of Sabin inactivated poliovirus vaccine (IPV) can reduce biosafety requirements in the posteradication/post-oral poliovirus vaccine (OPV) era. We conducted a phase II, randomized, positive-controlled trial to assess the safety and immunogenicity of Sabin IPV. The test groups (A, B, and C) received 3 doses of high, middle, and low D antigen (D Ag) of Sabin IPV at ages 2, 3, and 4 months, respectively. Infants in 2 control groups, group D and group E, received 3 doses of trivalent OPV and conventional IPV (cIPV), respectively, on the same schedule as that of groups A, B, and C. Serum samples were collected before and 30 days after the administration of the third dose. In total, 500 infants were randomly assigned to 5 groups, and 449 infants completed the vaccine series. No serious adverse events were associated with vaccinations. After 3 doses, the seroconversion rates in groups A, B, C, D, and E were 100%, 97.8%, 96.6%, 100%, and 90.1%, respectively, for type 1 poliovirus; 97.7%, 95.7%, 78.7%, 100%, and 90.1%, respectively, for type 2; and 98.8%, 98.9%, 93.3%, 100%, and 97.8%, respectively, for type 3. Sabin IPV has good safety characteristics. The seroconversion rates for type 1 poliovirus (most appropriate concentration, 15 D Ag units [DU]), type 2 (32 DU), and type 3 (45 DU) Sabin IPV were similar to those of the OPV and cIPV control groups. NCT01056705.

  5. Comparison of Iohexol-380 and Iohexol-350 for coronary CT angiography: A multicenter, randomized, double-blind phase 3 trial

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun Ah; Lee, Whal [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kang, Doo Kyoung [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); and others

    2016-06-15

    This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine.

  6. Comparison of Iohexol-380 and Iohexol-350 for coronary CT angiography: A multicenter, randomized, double-blind phase 3 trial

    International Nuclear Information System (INIS)

    Park, Eun Ah; Lee, Whal; Kang, Doo Kyoung

    2016-01-01

    This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine

  7. Comparison of two approaches in achieving smoking abstinence among patients in an outpatient clinic: a phase 2 randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Ka Yan Ho

    2018-03-01

    Full Text Available Background Having a disease and requiring medical attention present an excellent 'teachable moment' for smoking cessation interventions. However, nicotine is addictive and quitting is difficult, with a high rate of relapse, particularly among chronic smokers. Our previous smoking cessation projects in the community have revealed that many smokers who are reluctant to quit are interested in reducing the number of cigarettes they smoke per day. Therefore, smoking reduction may be an important alternative strategy for promoting smoking cessation. This Phase 2 randomized controlled trial of smokers who had medical follow-ups in an outpatient clinic compared the effectiveness of two approaches to smoking cessation: quitting immediately and cutting down to quit. Methods A total of 100 subjects were randomized into two groups, 50 in the quit immediately group, who received an intervention on abruptly quitting, and 50 in the cut down to quit group, who received an intervention on gradual reduction. All subjects were followed up at 6 and 12 months via telephone, and their smoking status was assessed. The primary outcomes were self-reported 7-day point prevalence of abstinence at 6 and 12 months. Intention-to-treat analysis was employed. Results On average, subjects had smoked 11.31 cigarettes per day over 37 years and 96% had mild nicotine dependence. At the 6-month follow-up, the self-reported quit rate of subjects in the quit immediately group was significantly higher than in the cut down to quit group (18.0% vs. 4.0%, p = 0.04. However, this difference was not significant at the 12-month follow-up (12.0% vs. 4.0%, p = 0.16. Conclusions These data suggest that quitting immediately might be more effective than cutting down to quit in smokers who need to quit sooner, such as those with diseases requiring medical attention. Nevertheless, the effectiveness of the cut down to quit approach requires further testing.

  8. A randomized phase II feasibility trial of a multimodal intervention for the management of cachexia in lung and pancreatic cancer.

    Science.gov (United States)

    Solheim, Tora S; Laird, Barry J A; Balstad, Trude Rakel; Stene, Guro B; Bye, Asta; Johns, Neil; Pettersen, Caroline H; Fallon, Marie; Fayers, Peter; Fearon, Kenneth; Kaasa, Stein

    2017-10-01

    Cancer cachexia is a syndrome of weight loss (including muscle and fat), anorexia, and decreased physical function. It has been suggested that the optimal treatment for cachexia should be a multimodal intervention. The primary aim of this study was to examine the feasibility and safety of a multimodal intervention (n-3 polyunsaturated fatty acid nutritional supplements, exercise, and anti-inflammatory medication: celecoxib) for cancer cachexia in patients with incurable lung or pancreatic cancer, undergoing chemotherapy. Patients receiving two cycles of standard chemotherapy were randomized to either the multimodal cachexia intervention or standard care. Primary outcome measures were feasibility assessed by recruitment, attrition, and compliance with intervention (>50% of components in >50% of patients). Key secondary outcomes were change in weight, muscle mass, physical activity, safety, and survival. Three hundred and ninety-nine were screened resulting in 46 patients recruited (11.5%). Twenty five patients were randomized to the treatment and 21 as controls. Forty-one completed the study (attrition rate 11%). Compliance to the individual components of the intervention was 76% for celecoxib, 60% for exercise, and 48% for nutritional supplements. As expected from the sample size, there was no statistically significant effect on physical activity or muscle mass. There were no intervention-related Serious Adverse Events and survival was similar between the groups. A multimodal cachexia intervention is feasible and safe in patients with incurable lung or pancreatic cancer; however, compliance to nutritional supplements was suboptimal. A phase III study is now underway to assess fully the effect of the intervention. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  9. Phase I Randomized Study of a Tetravalent Dengue Purified Inactivated Vaccine in Healthy Adults from Puerto Rico.

    Science.gov (United States)

    Diaz, Clemente; Lin, Leyi; Martinez, Luis J; Eckels, Kenneth H; Campos, Maribel; Jarman, Richard G; De La Barrera, Rafael; Lepine, Edith; Toussaint, Jean-François; Febo, Irma; Innis, Bruce L; Thomas, Stephen J; Schmidt, Alexander C

    2018-05-01

    The safety and immunogenicity of four adjuvanted formulations of an investigational tetravalent dengue purified inactivated vaccine (DPIV) were evaluated in a predominantly dengue-primed population in Puerto Rico. In this placebo-controlled, randomized, observer-blind, phase I trial, 100 healthy adults were randomized 1:1:1:1:1 to receive DPIV at Day (D)0 and D28 (1 μg per dengue virus [DENV] type 1-4 adjuvanted with either alum, AS01 E or AS03 B , or 4 μg per DENV type adjuvanted with alum) or saline placebo. Functional antibody responses were assessed using a microneutralization assay at D56, Month (M)7, and M13. All DPIV formulations were well tolerated and no safety signals were identified through M13. The M13 according-to-protocol (ATP) immunogenicity cohort included 83 participants. The ATP analysis of immunogenicity was performed only on the 78 subjects seropositive for ≥ 1 DENV type at baseline: 69 tetravalent, three trivalent, two bivalent, and four monovalent. In all DPIV groups, geometric mean antibody titers (GMTs) increased from D0 to D56 and waned modestly through M13, while remaining well above prevaccination levels. The 4 μg + alum and the AS01 E - and AS03 B -adjuvanted formulations were highly immunogenic, with M13-neutralizing antibody GMTs against all four DENV types above 1,000. M13/D0 GMT ratios were highest in the 1 μg + AS03 B group (ranging 3.2-3.7 depending on the DENV type). These results encourage continued clinical development of DPIV (ClinicalTrials.gov: NCT01702857).

  10. Fearful contextual expression impairs the encoding and recognition of target faces: an ERP study

    Directory of Open Access Journals (Sweden)

    Huiyan eLin

    2015-09-01

    Full Text Available Previous event-related potential (ERP studies have shown that the N170 to faces is modulated by the emotion of the face and its context. However, it is unclear how the encoding of emotional target faces as reflected in the N170 is modulated by the preceding contextual facial expression when temporal onset and identity of target faces are unpredictable. In addition, no study as yet has investigated whether contextual facial expression modulates later recognition of target faces. To address these issues, participants in the present study were asked to identify target faces (fearful or neutral that were presented after a sequence of fearful or neutral contextual faces. The number of sequential contextual faces was random and contextual and target faces were of different identities so that temporal onset and identity of target faces were unpredictable. Electroencephalography (EEG data was recorded during the encoding phase. Subsequently, participants had to perform an unexpected old/new recognition task in which target face identities were presented in either the encoded or the non-encoded expression. ERP data showed a reduced N170 to target faces in fearful as compared to neutral context regardless of target facial expression. In the later recognition phase, recognition rates were reduced for target faces in the encoded expression when they had been encountered in fearful as compared to neutral context. The present findings suggest that fearful compared to neutral contextual faces reduce the allocation of attentional resources towards target faces, which results in limited encoding and recognition of target faces.

  11. Safety and immunogenicity of an AMA1 malaria vaccine in Malian children: results of a phase 1 randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Mahamadou A Thera

    2010-02-01

    Full Text Available The objective was to evaluate the safety and immunogenicity of the AMA1-based malaria vaccine FMP2.1/AS02(A in children exposed to seasonal falciparum malaria.A Phase 1 double blind randomized controlled dose escalation trial was conducted in Bandiagara, Mali, West Africa, a rural town with intense seasonal transmission of Plasmodium falciparum malaria. The malaria vaccine FMP2.1/AS02(A is a recombinant protein (FMP2.1 based on apical membrane antigen 1 (AMA1 from the 3D7 clone of P. falciparum, formulated in the Adjuvant System AS02(A. The comparator vaccine was a cell-culture rabies virus vaccine (RabAvert. One hundred healthy Malian children aged 1-6 years were recruited into 3 cohorts and randomized to receive either 10 microg FMP2.1 in 0.1 mL AS02(A, or 25 microg FMP2.1 in 0.25 mL AS02(A, or 50 microg FMP2.1 50 microg in 0.5 mL AS02(A, or rabies vaccine. Three doses of vaccine were given at 0, 1 and 2 months, and children were followed for 1 year. Solicited symptoms were assessed for 7 days and unsolicited symptoms for 30 days after each vaccination. Serious adverse events were assessed throughout the study. Transient local pain and swelling were common and more frequent in all malaria vaccine dosage groups than in the comparator group, but were acceptable to parents of participants. Levels of anti-AMA1 antibodies measured by ELISA increased significantly (at least 100-fold compared to baseline in all 3 malaria vaccine groups, and remained high during the year of follow up.The FMP2.1/AS02(A vaccine had a good safety profile, was well-tolerated, and induced high and sustained antibody levels in malaria-exposed children. This malaria vaccine is being evaluated in a Phase 2 efficacy trial in children at this site.ClinicalTrials.gov NCT00358332 [NCT00358332].

  12. A Randomized Controlled Trial of Cognitive-Behavior Therapy Plus Bright Light Therapy for Adolescent Delayed Sleep Phase Disorder

    Science.gov (United States)

    Gradisar, Michael; Dohnt, Hayley; Gardner, Greg; Paine, Sarah; Starkey, Karina; Menne, Annemarie; Slater, Amy; Wright, Helen; Hudson, Jennifer L.; Weaver, Edward; Trenowden, Sophie

    2011-01-01

    Objective: To evaluate cognitive-behavior therapy plus bright light therapy (CBT plus BLT) for adolescents diagnosed with delayed sleep phase disorder (DSPD). Design: Randomized controlled trial of CBT plus BLT vs. waitlist (WL) control with comparisons at pre- and post-treatment. There was 6-month follow-up for the CBT plus BLT group only. Setting: Flinders University Child & Adolescent Sleep Clinic, Adelaide, South Australia. Patients: 49 adolescents (mean age 14.6 ± 1.0 y, 53% males) diagnosed with DSPD; mean chronicity 4 y 8 months; 16% not attending school. Eighteen percent of adolescents dropped out of the study (CBT plus BLT: N = 23 vs WL: N = 17). Interventions: CBT plus BLT consisted of 6 individual sessions, including morning bright light therapy to advance adolescents' circadian rhythms, and cognitive restructuring and sleep education to target associated insomnia and sleep hygiene. Measurements and Results: DSPD diagnosis was performed via a clinical interview and 7-day sleep diary. Measurements at each time-point included online sleep diaries and scales measuring sleepiness, fatigue, and depression symptoms. Compared to WL, moderate-to-large improvements (d = 0.65-1.24) were found at post-treatment for CBT plus BLT adolescents, including reduced sleep latency, earlier sleep onset and rise times, total sleep time (school nights), wake after sleep onset, sleepiness, and fatigue. At 6-month follow-up (N = 15), small-to-large improvements (d = 0.24-1.53) continued for CBT plus BLT adolescents, with effects found for all measures. Significantly fewer adolescents receiving CBT plus BLT met DPSD criteria at post-treatment (WL = 82% vs. CBT plus BLT = 13%, P sleep and daytime impairments in the immediate and long-term. Studies evaluating the treatment effectiveness of each treatment component are needed. Clinical Trial Information: Australia – New Zealand Trials Registry Number: ACTRN12610001041044. Citation: Gradisar M; Dohnt H; Gardner G; Paine S; Starkey

  13. Safety and immunogenicity of an AMA-1 malaria vaccine in Malian adults: results of a phase 1 randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Mahamadou A Thera

    2008-01-01

    Full Text Available The objective was to evaluate the safety, reactogenicity and immunogenicity of the AMA-1-based blood-stage malaria vaccine FMP2.1/AS02A in adults exposed to seasonal malaria.A phase 1 double blind randomized controlled dose escalation trial was conducted in Bandiagara, Mali, West Africa, a rural town with intense seasonal transmission of Plasmodium falciparum malaria. The malaria vaccine FMP2.1/AS02A is a recombinant protein (FMP2.1 based on apical membrane antigen-1 (AMA-1 from the 3D7 clone of P. falciparum, adjuvanted with AS02A. The comparator vaccine was a cell-culture rabies virus vaccine (RabAvert. Sixty healthy, malaria-experienced adults aged 18-55 y were recruited into 2 cohorts and randomized to receive either a half dose or full dose of the malaria vaccine (FMP2.1 25 microg/AS02A 0.25 mL or FMP2.1 50 microg/AS02A 0.5 mL or rabies vaccine given in 3 doses at 0, 1 and 2 mo, and were followed for 1 y. Solicited symptoms were assessed for 7 d and unsolicited symptoms for 30 d after each vaccination. Serious adverse events were assessed throughout the study. Titers of anti-AMA-1 antibodies were measured by ELISA and P. falciparum growth inhibition assays were performed on sera collected at pre- and post-vaccination time points. Transient local pain and swelling were common and more frequent in both malaria vaccine dosage groups than in the comparator group. Anti-AMA-1 antibodies increased significantly in both malaria vaccine groups, peaking at nearly 5-fold and more than 6-fold higher than baseline in the half-dose and full-dose groups, respectively.The FMP2.1/AS02A vaccine had a good safety profile, was well-tolerated, and was highly immunogenic in malaria-exposed adults. This malaria vaccine is being evaluated in Phase 1 and 2 trials in children at this site.

  14. Randomized Phase II Trial of Gemcitabine Plus TH-302 Versus Gemcitabine in Patients With Advanced Pancreatic Cancer.

    Science.gov (United States)

    Borad, Mitesh J; Reddy, Shantan G; Bahary, Nathan; Uronis, Hope E; Sigal, Darren; Cohn, Allen L; Schelman, William R; Stephenson, Joe; Chiorean, E Gabriela; Rosen, Peter J; Ulrich, Brian; Dragovich, Tomislav; Del Prete, Salvatore A; Rarick, Mark; Eng, Clarence; Kroll, Stew; Ryan, David P

    2015-05-01

    TH-302 is an investigational hypoxia-activated prodrug that releases the DNA alkylator bromo-isophosphoramide mustard in hypoxic settings. This phase II study (NCT01144455) evaluated gemcitabine plus TH-302 in patients with previously untreated, locally advanced or metastatic pancreatic cancer. Patients were randomly assigned 1:1:1 to gemcitabine (1,000 mg/m(2)), gemcitabine plus TH-302 240 mg/m(2) (G+T240), or gemcitabine plus TH-302 340 mg/m(2) (G+T340). Randomized crossover after progression on gemcitabine was allowed. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), tumor response, CA 19-9 response, and safety. Two hundred fourteen patients (77% with metastatic disease) were enrolled between June 2010 and July 2011. PFS was significantly longer with gemcitabine plus TH-302 (pooled combination arms) compared with gemcitabine alone (median PFS, 5.6 v 3.6 months, respectively; hazard ratio, 0.61; 95% CI, 0.43 to 0.87; P = .005; median PFS for metastatic disease, 5.1 v 3.4 months, respectively). Median PFS times for G+T240 and G+T340 were 5.6 and 6.0 months, respectively. Tumor response was 12%, 17%, and 26% in the gemcitabine, G+T240, and G+T340 arms, respectively (G+T340 v gemcitabine, P = .04). CA 19-9 decrease was greater with G+T340 versus gemcitabine (-5,398 v -549 U/mL, respectively; P = .008). Median OS times for gemcitabine, G+T240, and G+T340 were 6.9, 8.7, and 9.2 months, respectively (P = not significant). The most common adverse events (AEs) were fatigue, nausea, and peripheral edema (frequencies similar across arms). Skin and mucosal toxicities (2% grade 3) and myelosuppression (55% grade 3 or 4) were the most common TH-302-related AEs but were not associated with treatment discontinuation. PFS, tumor response, and CA 19-9 response were significantly improved with G+TH-302. G+T340 is being investigated further in the phase III MAESTRO study (NCT01746979). © 2014 by American Society of

  15. Substitution of ethambutol with linezolid during the intensive phase of treatment of pulmonary tuberculosis: study protocol for a prospective, multicenter, randomized, open-label, phase II trial.

    Science.gov (United States)

    Lee, Ji Yeon; Kim, Deog Kyeom; Lee, Jung-Kyu; Yoon, Ho Il; Jeong, Ina; Heo, Eunyoung; Park, Young Sik; Lee, Jae Ho; Park, Sung Soo; Lee, Sang-Min; Lee, Chang-Hoon; Lee, Jinwoo; Choi, Sun Mi; Park, Jong Sun; Joh, Joon-Sung; Cho, Young-Jae; Lee, Yeon Joo; Kim, Se Joong; Hwang, Young Ran; Kim, Hyeonjeong; Ki, Jongeun; Choi, Hyungsook; Han, Jiyeon; Ahn, Heejung; Hahn, Seokyung; Yim, Jae-Joon

    2017-02-13

    Linezolid, an oxazolidinone, substantially improves treatment outcomes of multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis. We started a trial to test whether the use of linezolid instead of ethambutol could increase the rate of sputum culture conversion as of 8 weeks of treatment in patients with drug-susceptible tuberculosis. This is a phase II, multicenter, randomized study with three arms. We are enrolling patients with pulmonary tuberculosis without rifampicin resistance screened by the Xpert MTB/RIF® assay. The standard treatment arm uses isoniazid (6 months), rifampicin (6 months), pyrazinamide (2 months), and ethambutol (2 months). Experimental arm 1 uses linezolid (600 mg/day) for 4 weeks instead of ethambutol. Experimental arm 2 uses linezolid (600 mg/day) for 2 weeks instead of ethambutol. The primary outcome is the sputum culture conversion rate on liquid media after 2 months of treatment. Secondary outcomes include the sputum culture conversion rate on solid media after 2 months of treatment, time to sputum culture conversion on liquid and solid media, cure rate, and treatment success rate. The frequencies of total adverse events (AEs) and serious AEs will be described and documented. Based on an α = 0.05 level of significance, a power of 85%, a 15% difference in the culture conversion rate after 2 months between the control arm and experimental arm 1 (75% vs. 90%), a 10% default (loss to follow-up) rate, and a 10% culture failure, the required number per arm was calculated to be 143 (429 in total). This trial will reveal the effectiveness and safety of 2 or 4 weeks of use of linezolid instead of ethambutol for patients with drug-susceptible pulmonary tuberculosis. If a new regimen including linezolid shows a higher culture conversion rate by week 8, and is safe, it could be tested as a 4-month antituberculosis treatment regimen in the future. ClincalTrials.gov, NCT01994460 . Registered on 13 November 2013.

  16. Noise level and MPEG-2 encoder statistics

    Science.gov (United States)

    Lee, Jungwoo

    1997-01-01

    Most software in the movie and broadcasting industries are still in analog film or tape format, which typically contains random noise that originated from film, CCD camera, and tape recording. The performance of the MPEG-2 encoder may be significantly degraded by the noise. It is also affected by the scene type that includes spatial and temporal activity. The statistical property of noise originating from camera and tape player is analyzed and the models for the two types of noise are developed. The relationship between the noise, the scene type, and encoder statistics of a number of MPEG-2 parameters such as motion vector magnitude, prediction error, and quant scale are discussed. This analysis is intended to be a tool for designing robust MPEG encoding algorithms such as preprocessing and rate control.

  17. Safety and immunogenicity of three different formulations of an adjuvanted varicella-zoster virus subunit candidate vaccine in older adults: a phase II, randomized, controlled study

    NARCIS (Netherlands)

    Chlibek, Roman; Smetana, Jan; Pauksens, Karlis; Rombo, Lars; van den Hoek, J. Anneke R.; Richardus, Jan H.; Plassmann, Georg; Schwarz, Tino F.; Ledent, Edouard; Heineman, Thomas C.

    2014-01-01

    This study investigated the safety and immunogenicity of different formulations and schedules of a candidate subunit herpes zoster vaccine containing varicella-zoster virus glycoprotein E (gE) with or without the adjuvant system AS01B. In this phase II, single-blind, randomized, controlled study,

  18. The FINISH-3 Trial : A Phase 3, International, Randomized, Single-Blind, Controlled Trial of Topical Fibrocaps in Intraoperative Surgical Hemostasis

    NARCIS (Netherlands)

    Bochicchio, Grant V.; Gupta, Navyash; Porte, Robert J.; Renkens, Kenneth L.; Pattyn, Piet; Topal, Baki; Troisi, Roberto Ivan; Muir, William; Chetter, Ian; Gillen, Daniel L.; Zuckerman, Linda A.; Frohna, Paul A.

    BACKGROUND: This Phase 3, international, randomized, single-blind, controlled trial (FINISH-3) compared the efficacy and safety of Fibrocaps, a ready-to-use, dry-powder fibrin sealant containing human plasma-derived thrombin and fibrinogen, vs gelatin sponge alone for use as a hemostat for surgical

  19. Multicenter prospective randomized phase II study of antimicrobial prophylaxis in low-risk patients undergoing colon surgery.

    Science.gov (United States)

    Shimizu, Junzo; Ikeda, Kimimasa; Fukunaga, Mutsumi; Murata, Kohei; Miyamoto, Atsushi; Umeshita, Koji; Kobayashi, Tetsuro; Monden, Morito

    2010-10-01

    Postoperative antimicrobial therapy is generally administered as standard prophylaxis against postoperative infection, despite a lack of sufficient evidence for its usefulness. This study was a phase II study to evaluate the necessity of postoperative antibiotic prophylaxis in patients undergoing a colectomy. Patients received 1 g cefmetazole or flomoxef immediately after anesthetic induction, every 3 h during surgery, and then later once again on the next day. They were randomly assigned to receive either cefmetazole or flomoxef. Ninety-one patients were enrolled in the study. A surgical site infection (SSI) occurred in 7.7% (7/91) of patients. All cases were superficial incisional infections. When comparing the two drugs, SSI occurred in 8.3% (4/48) of patients treated with cefmetazole and in 7.0% (3/43) treated with flomoxef, showing no significant difference (P > 0.99). Antimicrobial prophylaxis was well tolerated when used on the day of a colectomy and once again on the next day.

  20. A phase II randomized trial comparing radiotherapy with concurrent weekly cisplatin or weekly paclitaxel in patients with advanced cervical cancer

    International Nuclear Information System (INIS)

    Geara, Fady B; Shamseddine, Ali; Khalil, Ali; Abboud, Mirna; Charafeddine, Maya; Seoud, Muhieddine

    2010-01-01

    This is a prospective comparison of weekly cisplatin to weekly paclitaxel as concurrent chemotherapy with standard radiotherapy for locally advanced cervical carcinoma. Between May 2000 and May 2004, 31 women with FIGO stage IB2-IVA cervical cancer or with postsurgical pelvic recurrence were enrolled into this phase II study and randomized to receive on a weekly basis either 40 mg/m 2 Cisplatin (group I; 16 patients) or 50 mg/m 2 paclitaxel (group II; 15 patients) concurrently with radiotherapy. Median total dose to point A was 74 Gy (range: 66-92 Gy) for group I and 66 Gy (range: 40-98 Gy) for group II. Median follow-up time was 46 months. Patient and tumor characteristics were similar in both groups. The mean number of chemotherapy cycles was also comparable with 87% and 80% of patients receiving at least 4 doses in groups I and II, respectively. Seven patients (44%) of group I and 8 patients (53%) of group II developed tumor recurrence. The Median Survival time was not reached for Group I and 53 months for group II. The proportion of patients surviving at 2 and 5 years was 78% and 54% for group I and 73% and 43% for group II respectively. This small prospective study shows that weekly paclitaxel does not provide any clinical advantage over weekly cisplatin for concurrent chemoradiation for advanced carcinoma of the cervix

  1. Plasmon response in K, Na and Li clusters: systematics using the separable random-phase approximation with pseudo-Hamiltonians

    International Nuclear Information System (INIS)

    Kleinig, W.; Nesterenko, V.O.; Reinhard, P.-G.; Serra, Ll.

    1998-01-01

    The systematics of the plasmon response in spherical K, Na and Li clusters in a wide size region (8≤N≤440) is studied. We have considered two simplifying approximations whose validity has been established previously. First, a separable approach to the random-phase approximation is used. This involves an expansion of the residual interaction into a sum of separable terms until convergence is reached. Second, the electron-ion interaction is modelled by using the pseudo-Hamiltonian jellium model (MHJM) which includes nonlocal effects by means of realistic atomic pseudo-Hamiltonians. In cases where nonlocal effects are negligible the Structure Averaged Jellium Model (SAJM) has been used. Good agreement with available experimental data is achieved for K, Na (using the SAJM) and small Li clusters (invoking the PHJM). The trends for peak position and width are generally well reproduced, even up to details of the Landau fragmentation in several clusters. Less good agreement, however, is found for large Li clusters. This remains an open question

  2. Molecular Excitation Energies from Time-Dependent Density Functional Theory Employing Random-Phase Approximation Hessians with Exact Exchange.

    Science.gov (United States)

    Heßelmann, Andreas

    2015-04-14

    Molecular excitation energies have been calculated with time-dependent density-functional theory (TDDFT) using random-phase approximation Hessians augmented with exact exchange contributions in various orders. It has been observed that this approach yields fairly accurate local valence excitations if combined with accurate asymptotically corrected exchange-correlation potentials used in the ground-state Kohn-Sham calculations. The inclusion of long-range particle-particle with hole-hole interactions in the kernel leads to errors of 0.14 eV only for the lowest excitations of a selection of three alkene, three carbonyl, and five azabenzene molecules, thus surpassing the accuracy of a number of common TDDFT and even some wave function correlation methods. In the case of long-range charge-transfer excitations, the method typically underestimates accurate reference excitation energies by 8% on average, which is better than with standard hybrid-GGA functionals but worse compared to range-separated functional approximations.

  3. Safety and preliminary immunogenicity of Cuban pneumococcal conjugate vaccine candidate in healthy children: a randomized phase I clinical trial.

    Science.gov (United States)

    Dotres, Carlos P; Puga, Rinaldo; Ricardo, Yariset; Broño, Carmen R; Paredes, Beatriz; Echemendía, Vladimir; Rosell, Sandra; González, Nadezhda; García-Rivera, Dagmar; Valdés, Yury; Goldblatt, David; Vérez-Bencomo, Vicente

    2014-09-15

    A new heptavalent conjugate vaccine (PCV7-TT) is under development in Cuba. PCV7-TT contains 2 μg of serotypes 1, 5, 14, 18C, 19F, 23F and 4 μg of 6B, each one conjugated to tetanus toxoid (TT). This vaccine was designed with the serotypes that cause most invasive pneumococcal diseases (IPD) worldwide. In the present study, we investigated the safety and explored the immunogenicity of PCV7-TT during a controlled, randomized and double blind clinical trial phase I in 4-5-year-old children. PCV7-TT was well tolerated and as safe as Synflorix used as control vaccine. Following a single-dose vaccination, all individual serotypes included in PCV7-TT induced statistically significant increase of IgG GMC and OPA GMT. These are the first clinical results of PCV7-TT in children and they pave the way toward next clinical trials in children and infants. This clinical trial was published in the Cuban Public Register of Clinical Trials with code RPCEC00000173. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. A randomized placebo-controlled phase 3 trial of an antisense oligonucleotide, drisapersen, in Duchenne muscular dystrophy.

    Science.gov (United States)

    Goemans, Nathalie; Mercuri, Eugenio; Belousova, Elena; Komaki, Hirofumi; Dubrovsky, Alberto; McDonald, Craig M; Kraus, John E; Lourbakos, Afrodite; Lin, Zhengning; Campion, Giles; Wang, Susanne X; Campbell, Craig

    2018-01-01

    This 48-week, randomized, placebo-controlled phase 3 study (DMD114044; NCT01254019) evaluated efficacy and safety of subcutaneous drisapersen 6 mg/kg/week in 186 ambulant boys aged ≥5 years, with Duchenne muscular dystrophy (DMD) resulting from an exon 51 skipping amenable mutation. Drisapersen was generally well tolerated, with injection-site reactions and renal events as most commonly reported adverse events. A nonsignificant treatment difference (P = 0.415) in the change from baseline in six-minute walk distance (6MWD; primary efficacy endpoint) of 10.3 meters in favor of drisapersen was observed at week 48. Key secondary efficacy endpoints (North Star Ambulatory Assessment, 4-stair climb ascent velocity, and 10-meter walk/run velocity) gave consistent findings. Lack of statistical significance was thought to be largely due to greater data variability and subgroup heterogeneity. The increased standard deviation alone, due to less stringent inclusion/exclusion criteria, reduced the statistical power from pre-specified 90% to actual 53%. Therefore, a post-hoc analysis was performed in 80 subjects with a baseline 6MWD 300-400 meters and ability to rise from floor. A statistically significant improvement in 6MWD of 35.4 meters (P = 0.039) in favor of drisapersen was observed in this subpopulation. Results suggest that drisapersen could have benefit in a less impaired population of DMD subjects. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Effect of sacrum-perineum heat therapy on active phase labor pain and client satisfaction: a randomized, controlled trial study.

    Science.gov (United States)

    Taavoni, Simin; Abdolahian, Somayeh; Haghani, Hamid

    2013-09-01

    Reduction of labor pain is one of the most important aspects of obstetric care. Heat therapy, typically applied to the woman's back, lower abdomen, groin, and/or perineum during last stage of labor, is an easy pain relief method that does not require highly skilled care. The effectiveness of heat therapy applied to the perineum during the first stage of labor has not been evaluated. This study aimed to evaluate the effectiveness of heat therapy for pain and woman's satisfaction during physiological labor. Sixty primiparous women aged 18-35 years old were randomly assigned to heat therapy and control groups. Pain and satisfaction scores were measured by visual analog scale. The measurements of satisfaction were accomplished after birth. Data were analyzed by using the t-test and chi-square Mean pain scores in the heat therapy group were significantly lower than the control group (P heat therapy group was significantly higher than in the control group (P Heat therapy, an inexpensive complementary treatment with low risk, can reduce the intensity of pain and increase mothers' satisfaction with care during the active phase of labor. Wiley Periodicals, Inc.

  6. Inclusive charged-current neutrino-nucleus reactions calculated with the relativistic quasiparticle random-phase approximation

    International Nuclear Information System (INIS)

    Paar, N.; Vretenar, D.; Marketin, T.; Ring, P.

    2008-01-01

    Inclusive neutrino-nucleus cross sections are calculated using a consistent relativistic mean-field theoretical framework. The weak lepton-hadron interaction is expressed in the standard current-current form, the nuclear ground state is described with the relativistic Hartree-Bogoliubov model, and the relevant transitions to excited nuclear states are calculated in the relativistic quasiparticle random-phase approximation. Illustrative test calculations are performed for charged-current neutrino reactions on 12 C, 16 O, 56 Fe, and 208 Pb, and results compared with previous studies and available data. Through the use of the experimental neutrino fluxes, the averaged cross sections are evaluated for nuclei of interest for neutrino detectors. We analyze the total neutrino-nucleus cross sections and the evolution of the contribution of the different multipole excitations as a function of neutrino energy. The cross sections for reactions of supernova neutrinos on 16 O and 208 Pb target nuclei are analyzed as functions of the temperature and chemical potential

  7. Modular verification of chemical reaction network encodings via serializability analysis

    Science.gov (United States)

    Lakin, Matthew R.; Stefanovic, Darko; Phillips, Andrew

    2015-01-01

    Chemical reaction networks are a powerful means of specifying the intended behaviour of synthetic biochemical systems. A high-level formal specification, expressed as a chemical reaction network, may be compiled into a lower-level encoding, which can be directly implemented in wet chemistry and may itself be expressed as a chemical reaction network. Here we present conditions under which a lower-level encoding correctly emulates the sequential dynamics of a high-level chemical reaction network. We require that encodings are transactional, such that their execution is divided by a “commit reaction” that irreversibly separates the reactant-consuming phase of the encoding from the product-generating phase. We also impose restrictions on the sharing of species between reaction encodings, based on a notion of “extra tolerance”, which defines species that may be shared between encodings without enabling unwanted reactions. Our notion of correctness is serializability of interleaved reaction encodings, and if all reaction encodings satisfy our correctness properties then we can infer that the global dynamics of the system are correct. This allows us to infer correctness of any system constructed using verified encodings. As an example, we show how this approach may be used to verify two- and four-domain DNA strand displacement encodings of chemical reaction networks, and we generalize our result to the limit where the populations of helper species are unlimited. PMID:27325906

  8. The random phase approximation

    International Nuclear Information System (INIS)

    Schuck, P.

    1985-01-01

    RPA is the adequate theory to describe vibrations of the nucleus of very small amplitudes. These vibrations can either be forced by an external electromagnetic field or can be eigenmodes of the nucleus. In a one dimensional analogue the potential corresponding to such eigenmodes of very small amplitude should be rather stiff otherwise the motion risks to be a large amplitude one and to enter a region where the approximation is not valid. This means that nuclei which are supposedly well described by RPA must have a very stable groundstate configuration (must e.g. be very stiff against deformation). This is usually the case for doubly magic nuclei or close to magic nuclei which are in the middle of proton and neutron shells which develop a very stable groundstate deformation; we take the deformation as an example but there are many other possible degrees of freedom as, for example, compression modes, isovector degrees of freedom, spin degrees of freedom, and many more

  9. A randomized phase II study of gemcitabine and carboplatin with or without cediranib as first-line therapy in advanced non-small-cell lung cancer: North Central Cancer Treatment Group Study N0528.

    Science.gov (United States)

    Dy, Grace K; Mandrekar, Sumithra J; Nelson, Garth D; Meyers, Jeffrey P; Adjei, Araba A; Ross, Helen J; Ansari, Rafat H; Lyss, Alan P; Stella, Philip J; Schild, Steven E; Molina, Julian R; Adjei, Alex A

    2013-01-01

    The purpose of this study was to assess the safety and efficacy of gemcitabine and carboplatin with (arm A) or without (arm B) daily oral cediranib as first-line therapy for advanced non-small-cell lung cancer. A lead-in phase to determine the tolerability of gemcitabine 1000 mg/m on days 1 and 8, and carboplatin on day 1 at area under curve 5 administered every 21 days with cediranib 45 mg once daily was followed by a 2 (A):1 (B) randomized phase II study. The primary end point was confirmed overall response rate (ORR) with 6-month progression-free survival (PFS6) rate in arm A as secondary end point. Polymorphisms in genes encoding cediranib targets and transport were correlated with treatment outcome. On the basis of the safety assessment, cediranib 30 mg daily was used in the phase II portion. A total of 58 and 29 evaluable patients were accrued to arms A and B. Patients in A experienced more grade 3+ nonhematologic adverse events, 71% versus 45% (p = 0.01). The ORR was 19% (A) versus 20% (B) (p = 1.0). PFS6 in A was 48% (95% confidence interval: 35%-62%), thus meeting the protocol-specified threshold of at least 40%. The median overall survival was 12.0 versus 9.9 months (p = 0.10). FGFR1 rs7012413, FGFR2 rs2912791, and VEGFR3 rs11748431 polymorphisms were significantly associated with decreased overall survival (hazard ratio 2.78-5.01, p = 0.0002-0.0095). The trial did not meet its primary end point of ORR but met its secondary end point of PFS6. The combination with cediranib 30 mg daily resulted in increased toxicity. Pharmacogenetic analysis revealed an association of FGFR and VEGFR variants with survival.

  10. a permutation encoding te algorithm solution of reso tation encoding

    African Journals Online (AJOL)

    eobe

    Keywords: Genetic algorithm, resource constrained. 1. INTRODUCTION. 1. .... Nigerian Journal of Technology. Vol. 34, No. 1, January 2015. 128 ... 4. ENCODING OF CHROMOSOME. ENCODING OF CHROMOSOME .... International Multi conference of Engineers and ... method”, Naval Research Logistics, vol 48, issue 2,.

  11. Phase II study of metformin for reduction of obesity-associated breast cancer risk: a randomized controlled trial protocol

    International Nuclear Information System (INIS)

    Martinez, Jessica A.; Chalasani, Pavani; Thomson, Cynthia A.; Roe, Denise; Altbach, Maria; Galons, Jean-Philippe; Stopeck, Alison; Thompson, Patricia A.; Villa-Guillen, Diana Evelyn; Chow, H-H. Sherry

    2016-01-01

    Two-thirds of U.S. adult women are overweight or obese. High body mass index (BMI) and adult weight gain are risk factors for a number of chronic diseases, including postmenopausal breast cancer. The higher postmenopausal breast cancer risk in women with elevated BMI is likely to be attributable to related metabolic disturbances including altered circulating sex steroid hormones and adipokines, elevated pro-inflammatory cytokines, and insulin resistance. Metformin is a widely used antidiabetic drug that has demonstrated favorable effects on metabolic disturbances and as such may lead to lower breast cancer risk in obese women. Further, the anti-proliferative effects of metformin suggest it may decrease breast density, an accepted biomarker of breast cancer risk. This is a Phase II randomized, double-blind, placebo-controlled trial of metformin in overweight/obese premenopausal women who have elements of metabolic syndrome. Eligible participants will be randomized to receive metformin 850 mg BID (n = 75) or placebo (n = 75) for 12 months. The primary endpoint is change in breast density, based on magnetic resonance imaging (MRI) acquired fat-water features. Secondary outcomes include changes in serum insulin levels, serum insulin-like growth factor (IGF)-1 to insulin-like growth factor binding protein (IGFBP)-3 ratio, serum IGF-2 levels, serum testosterone levels, serum leptin to adiponectin ratio, body weight, and waist circumference. Exploratory outcomes include changes in metabolomic profiles in plasma and nipple aspirate fluid. Changes in tissue architecture as well as cellular and molecular targets in breast tissue collected in a subgroup of participants will also be explored. The study will evaluate whether metformin can result in favorable changes in breast density, select proteins and hormones, products of body metabolism, and body weight and composition. The study should help determine the potential breast cancer preventive activity of metformin in a

  12. A Phase 2 Randomized Trial of a Rifapentine plus Moxifloxacin-Based Regimen for Treatment of Pulmonary Tuberculosis.

    Directory of Open Access Journals (Sweden)

    Marcus B Conde

    Full Text Available The combination of rifapentine and moxifloxacin administered daily with other anti-tuberculosis drugs is highly active in mouse models of tuberculosis chemotherapy. The objective of this phase 2 clinical trial was to determine the bactericidal activity, safety, and tolerability of a regimen comprised of rifapentine, moxifloxacin, isoniazid, and pyrazinamide administered daily during the first 8 weeks of pulmonary tuberculosis treatment.Adults with sputum smear-positive pulmonary tuberculosis were randomized to receive either rifapentine (approximately 7.5 mg/kg plus moxifloxacin (investigational arm, or rifampin (approximately 10 mg/kg plus ethambutol (control daily for 8 weeks, along with isoniazid and pyrazinamide. The primary endpoint was sputum culture status at completion of 8 weeks of treatment.121 participants (56% of accrual target were enrolled. At completion of 8 weeks of treatment, negative cultures using Löwenstein-Jensen (LJ medium occurred in 47/60 (78% participants in the investigational arm vs. 43/51 (84%, p = 0.47 in the control arm; negative cultures using liquid medium occurred in 37/47 (79% in the investigational arm vs. 27/41 (66%, p = 0.23 in the control arm. Time to stable culture conversion was shorter for the investigational arm vs. the control arm using liquid culture medium (p = 0.03, but there was no difference using LJ medium. Median rifapentine area under the concentration-time curve (AUC0-24 was 313 mcg*h/mL, similar to recent studies of rifapentine dosed at 450-600 mg daily. Median moxifloxacin AUC0-24 was 28.0 mcg*h/mL, much lower than in trials where rifapentine was given only intermittently with moxifloxacin. The proportion of participants discontinuing assigned treatment for reasons other than microbiological ineligibility was higher in the investigational arm vs. the control arm (11/62 [18%] vs. 3/59 [5%], p = 0.04 although the proportions of grade 3 or higher adverse events were similar (5/62 [8%] in the

  13. PREVENTION OF CONVERSION TO ABNORMAL TCD WITH HYDROXYUREA IN SICKLE CELL ANEMIA: A PHASE III INTERNATIONAL RANDOMIZED CLINICAL TRIAL

    Science.gov (United States)

    Hankins, Jane S.; McCarville, M. Beth; Rankine-Mullings, Angela; Reid, Marvin E.; Lobo, Clarisse L.C.; Moura, Patricia G.; Ali, Susanna; Soares, Deanne; Aldred, Karen; Jay, Dennis W.; Aygun, Banu; Bennett, John; Kang, Guolian; Goldsmith, Jonathan C.; Smeltzer, Matthew P.; Boyett, James M.; Ware, Russell E.

    2015-01-01

    Children with sickle cell anemia (SCA) and conditional transcranial Doppler (TCD) ultrasound velocities (170-199 cm/sec) may develop stroke. However, with limited available clinical data, the current standard of care for conditional TCD velocities is observation. The efficacy of hydroxyurea in preventing conversion from conditional to abnormal TCD (≥200 cm/sec), which confers a higher stroke risk, has not been studied prospectively in a randomized trial. Sparing Conversion to Abnormal TCD Elevation (SCATE #NCT01531387) was an NHLBI-funded Phase III multicenter international clinical trial comparing alternative therapy (hydroxyurea) to standard care (observation) to prevent conversion from conditional to abnormal TCD velocity in children with SCA. SCATE enrolled 38 children from the United States, Jamaica, and Brazil [HbSS (36), HbSβ0-thalassemia (1), and HbSD (1), median age 5.4 years (range, 2.7-9.8)]. Due to slow patient accrual and administrative delays, SCATE was terminated early. In an intention-to-treat analysis, the cumulative incidence of abnormal conversion was 9% (95% CI 0 to 35%) in the hydroxyurea arm and 47% (95% CI 6 to 81%) in observation arm at 15 months (p=0.16). In post-hoc analysis according to treatment received, significantly fewer children on hydroxyurea converted to abnormal TCD velocities, compared to observation (0% versus 50%, p=0.02). After a mean of 10.1 months, a significant change in mean TCD velocity was observed with hydroxyurea treatment (−15.5 versus +10.2 cm/sec, p=0.02). No stroke events occurred in either arm. Hydroxyurea reduces TCD velocities in children with SCA and conditional velocities. PMID:26414435

  14. Prevention of conversion to abnormal transcranial Doppler with hydroxyurea in sickle cell anemia: A Phase III international randomized clinical trial.

    Science.gov (United States)

    Hankins, Jane S; McCarville, Mary Beth; Rankine-Mullings, Angela; Reid, Marvin E; Lobo, Clarisse L C; Moura, Patricia G; Ali, Susanna; Soares, Deanne P; Aldred, Karen; Jay, Dennis W; Aygun, Banu; Bennett, John; Kang, Guolian; Goldsmith, Jonathan C; Smeltzer, Matthew P; Boyett, James M; Ware, Russell E

    2015-12-01

    Children with sickle cell anemia (SCA) and conditional transcranial Doppler (TCD) ultrasound velocities (170-199 cm/sec) may develop stroke. However, with limited available clinical data, the current standard of care for conditional TCD velocities is observation. The efficacy of hydroxyurea in preventing conversion from conditional to abnormal TCD (≥200 cm/sec), which confers a higher stroke risk, has not been studied prospectively in a randomized trial. Sparing Conversion to Abnormal TCD Elevation (SCATE #NCT01531387) was a National Heart, Lung, and Blood Institute-funded Phase III multicenter international clinical trial comparing alternative therapy (hydroxyurea) to standard care (observation) to prevent conversion from conditional to abnormal TCD velocity in children with SCA. SCATE enrolled 38 children from the United States, Jamaica, and Brazil [HbSS (36), HbSβ(0) -thalassemia (1), and HbSD (1), median age = 5.4 years (range, 2.7-9.8)]. Because of the slow patient accrual and administrative delays, SCATE was terminated early. In an intention-to-treat analysis, the cumulative incidence of abnormal conversion was 9% (95% CI = 0-35%) in the hydroxyurea arm and 47% (95% CI = 6-81%) in observation arm at 15 months (P = 0.16). In post hoc analysis according to treatment received, significantly fewer children on hydroxyurea converted to abnormal TCD velocities when compared with observation (0% vs. 50%, P = 0.02). After a mean of 10.1 months, a significant change in mean TCD velocity was observed with hydroxyurea treatment (-15.5 vs. +10.2 cm/sec, P = 0.02). No stroke events occurred in either arm. Hydroxyurea reduces TCD velocities in children with SCA and conditional velocities. © 2015 Wiley Periodicals, Inc.

  15. Design and initial results of a multi-phase randomized trial of ceftriaxone in amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    James D Berry

    Full Text Available Ceftriaxone increases expression of the astrocytic glutamate transporter, EAAT2, which might protect from glutamate-mediated excitotoxicity. A trial using a novel three stage nonstop design, incorporating Phases I-III, tested ceftriaxone in ALS. Stage 1 determined the cerebrospinal fluid pharmacokinetics of ceftriaxone in subjects with ALS. Stage 2 evaluated safety and tolerability for 20-weeks. Analysis of the pharmacokinetics, tolerability, and safety was used to determine the ceftriaxone dosage for Stage 3 efficacy testing.In Stage 1, 66 subjects at ten clinical sites were enrolled and randomized equally into three study groups receiving intravenous placebo, ceftriaxone 2 grams daily or ceftriaxone 4 grams daily divided BID. Participants provided serum and cerebrospinal fluid for pharmacokinetic analysis on study day 7. Participants continued their assigned treatment in Stage 2. The Data and Safety Monitoring Board (DSMB reviewed the data after the last participants completed 20 weeks on study drug.Stage 1 analysis revealed linear pharmacokinetics, and CSF trough levels for both dosage levels exceeding the pre-specified target trough level of 1 µM (0.55 µg/mL. Tolerability (Stages 1 and 2 results showed that ceftriaxone at dosages up to 4 grams/day was well tolerated at 20 weeks. Biliary adverse events were more common with ceftriaxone but not dose-dependent and improved with ursodeoxycholic (ursodiol therapy.The goals of Stages 1 and 2 of the ceftriaxone trial were successfully achieved. Based on the pre-specified decision rules, the DSMB recommended the use of ceftriaxone 4 g/d (divided BID for Stage 3, which recently closed.ClinicalTrials.gov NCT00349622.

  16. Fast computation of molecular random phase approximation correlation energies using resolution of the identity and imaginary frequency integration

    Science.gov (United States)

    Eshuis, Henk; Yarkony, Julian; Furche, Filipp

    2010-06-01

    The random phase approximation (RPA) is an increasingly popular post-Kohn-Sham correlation method, but its high computational cost has limited molecular applications to systems with few atoms. Here we present an efficient implementation of RPA correlation energies based on a combination of resolution of the identity (RI) and imaginary frequency integration techniques. We show that the RI approximation to four-index electron repulsion integrals leads to a variational upper bound to the exact RPA correlation energy if the Coulomb metric is used. Auxiliary basis sets optimized for second-order Møller-Plesset (MP2) calculations are well suitable for RPA, as is demonstrated for the HEAT [A. Tajti et al., J. Chem. Phys. 121, 11599 (2004)] and MOLEKEL [F. Weigend et al., Chem. Phys. Lett. 294, 143 (1998)] benchmark sets. Using imaginary frequency integration rather than diagonalization to compute the matrix square root necessary for RPA, evaluation of the RPA correlation energy requires O(N4 log N) operations and O(N3) storage only; the price for this dramatic improvement over existing algorithms is a numerical quadrature. We propose a numerical integration scheme that is exact in the two-orbital case and converges exponentially with the number of grid points. For most systems, 30-40 grid points yield μH accuracy in triple zeta basis sets, but much larger grids are necessary for small gap systems. The lowest-order approximation to the present method is a post-Kohn-Sham frequency-domain version of opposite-spin Laplace-transform RI-MP2 [J. Jung et al., Phys. Rev. B 70, 205107 (2004)]. Timings for polyacenes with up to 30 atoms show speed-ups of two orders of magnitude over previous implementations. The present approach makes it possible to routinely compute RPA correlation energies of systems well beyond 100 atoms, as is demonstrated for the octapeptide angiotensin II.

  17. A randomized, controlled, phase 2 study of AMG 317, an IL-4Ralpha antagonist, in patients with asthma.

    Science.gov (United States)

    Corren, Jonathan; Busse, William; Meltzer, Eli O; Mansfield, Lyndon; Bensch, George; Fahrenholz, John; Wenzel, Sally E; Chon, Yun; Dunn, Meleana; Weng, Haoling H; Lin, Shao-Lee

    2010-04-15

    IL-4 and IL-13 share many biological functions important in the development of allergic airway inflammation and are implicated in the pathogenesis of asthma. AMG 317 is a fully human monoclonal antibody to IL-4Ralpha that blocks both IL-4 and IL-13 pathways. To evaluate efficacy and safety of AMG 317 in patients with moderate to severe asthma. In this phase 2, randomized, double-blind, placebo-controlled study, patients received weekly subcutaneous injections of placebo or AMG 317 (75-300 mg) for 12 weeks, followed by a 4-week follow-up period. The primary endpoint was change from baseline at Week 12 in Asthma Control Questionnaire (ACQ) symptom score. Mean ACQ change (SE) was -0.49 (0.09) in placebo (n = 74), and -0.43 (0.11), -0.58 (0.12), and -0.70 (0.09) in the AMG 317 75 mg (n = 73), 150 mg (n = 73), and 300 mg (n = 74) groups, respectively (treatment effect P = 0.25). No statistically significant differences were observed in the secondary endpoints. Numerical decreases in number of and time to exacerbations were noted in patients receiving AMG 317 150 mg and 300 mg. Preplanned analyses by tertile of baseline ACQ revealed that patients with higher baseline ACQ scores (>or=2.86) were more likely to respond to AMG 317. Serious adverse events were reported in three patients, each noted as not related to study drug. AMG 317 did not demonstrate clinical efficacy across the overall group of patients. Clinically significant improvements were observed in several outcome measures in patients with higher baseline ACQ scores. AMG 317 was safe and well tolerated in this study population. Clinical trial registered with www.clinicaltrials.gov (NCT 00436670).

  18. Parallel encoders for pixel detectors

    International Nuclear Information System (INIS)

    Nikityuk, N.M.

    1991-01-01

    A new method of fast encoding and determining the multiplicity and coordinates of fired pixels is described. A specific example construction of parallel encodes and MCC for n=49 and t=2 is given. 16 refs.; 6 figs.; 2 tabs

  19. Use of incidentally encoded memory from a single experience in cats.

    Science.gov (United States)

    Takagi, Saho; Tsuzuki, Mana; Chijiiwa, Hitomi; Arahori, Minori; Watanabe, Arii; Saito, Atsuko; Fujita, Kazuo

    2017-08-01

    We examined whether cats could retrieve and utilize incidentally encoded information from a single past event in a simple food-exploration task previously used for dogs (Fujita et al., 2012). In Experiment 1, cats were led to four open, baited containers and allowed to eat from two of them (Exposure phase). After a 15-min delay during which the cats were absent and all containers were replaced with empty ones, the cats were unexpectedly returned to the room and allowed to explore the containers (Test phase). Although the cats' first choice of container to visit was random, they explored containers from which they had not previously eaten for longer than those from which they did previously eat. In the Exposure phase of Experiment 2, two containers held food, one held a nonedible object, and the fourth was empty. Cats were allowed to eat from one of them. In the post-delay Test phase, the cats first visited the remaining baited-uneaten container significantly more often than chance and they spent more time exploring this container. Because the cats' behavior in the Test phase cannot be explained by association of the container with a pleasant experience (eating), the results suggest that cats retrieved and utilized "what" and "where" information from an incidentally encoded memory from a single experience. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Phase III Randomized Study of SB5, an Adalimumab Biosimilar, Versus Reference Adalimumab in Patients With Moderate‐to‐Severe Rheumatoid Arthritis

    OpenAIRE

    Weinblatt, Michael E.; Baranauskaite, Asta; Niebrzydowski, Jaroslaw; Dokoupilova, Eva; Zielinska, Agnieszka; Jaworski, Janusz; Racewicz, Artur; Pileckyte, Margarita; Jedrychowicz‐Rosiak, Krystyna; Cheong, Soo Yeon; Ghil, Jeehoon; Sokolovic, S.; Mekic, M.; Prodanovic, N.; Gajic, B.

    2017-01-01

    Objective SB5 is a biosimilar agent for adalimumab (ADA). The aim of this study was to evaluate the efficacy, pharmacokinetics (PK), safety, and immunogenicity of SB5 in comparison with reference ADA in patients with rheumatoid arthritis (RA). Methods In this phase III, randomized, double‐blind, parallel‐group study, patients with moderately to severely active RA despite treatment with methotrexate were randomized 1:1 to receive SB5 or reference ADA at a dosage of 40 mg subcutaneously every o...

  1. Tensor hypercontracted ppRPA: Reducing the cost of the particle-particle random phase approximation from O(r 6) to O(r 4)

    International Nuclear Information System (INIS)

    Shenvi, Neil; Yang, Yang; Yang, Weitao; Aggelen, Helen van

    2014-01-01

    In recent years, interest in the random-phase approximation (RPA) has grown rapidly. At the same time, tensor hypercontraction has emerged as an intriguing method to reduce the computational cost of electronic structure algorithms. In this paper, we combine the particle-particle random phase approximation with tensor hypercontraction to produce the tensor-hypercontracted particle-particle RPA (THC-ppRPA) algorithm. Unlike previous implementations of ppRPA which scale as O(r 6 ), the THC-ppRPA algorithm scales asymptotically as only O(r 4 ), albeit with a much larger prefactor than the traditional algorithm. We apply THC-ppRPA to several model systems and show that it yields the same results as traditional ppRPA to within mH accuracy. Our method opens the door to the development of post-Kohn Sham functionals based on ppRPA without the excessive asymptotic cost of traditional ppRPA implementations

  2. Defect-mediated relaxation in the random tiling phase of a binary mixture: Birth, death and mobility of an atomic zipper

    Energy Technology Data Exchange (ETDEWEB)

    Tondl, Elisabeth; Ramsay, Malcolm; Harrowell, Peter; Widmer-Cooper, Asaph [School of Chemistry, University of Sydney, Sydney, NSW 2006 (Australia)

    2014-03-14

    This paper describes the mechanism of defect-mediated relaxation in a dodecagonal square-triangle random tiling phase exhibited by a simulated binary mixture of soft discs in 2D. We examine the internal transitions within the elementary mobile defect (christened the “zipper”) that allow it to move, as well as the mechanisms by which the zipper is created and annihilated. The structural relaxation of the random tiling phase is quantified and we show that this relaxation is well described by a model based on the distribution of waiting times for each atom to be visited by the diffusing zipper. This system, representing one of the few instances where a well defined mobile defect is capable of structural relaxation, can provide a valuable test case for general theories of relaxation in complex and disordered materials.

  3. Defect-mediated relaxation in the random tiling phase of a binary mixture: Birth, death and mobility of an atomic zipper

    International Nuclear Information System (INIS)

    Tondl, Elisabeth; Ramsay, Malcolm; Harrowell, Peter; Widmer-Cooper, Asaph

    2014-01-01

    This paper describes the mechanism of defect-mediated relaxation in a dodecagonal square-triangle random tiling phase exhibited by a simulated binary mixture of soft discs in 2D. We examine the internal transitions within the elementary mobile defect (christened the “zipper”) that allow it to move, as well as the mechanisms by which the zipper is created and annihilated. The structural relaxation of the random tiling phase is quantified and we show that this relaxation is well described by a model based on the distribution of waiting times for each atom to be visited by the diffusing zipper. This system, representing one of the few instances where a well defined mobile defect is capable of structural relaxation, can provide a valuable test case for general theories of relaxation in complex and disordered materials

  4. Efficacy and Safety of Axitinib Versus Sorafenib in Metastatic Renal Cell Carcinoma: Subgroup Analysis of Japanese Patients from the Global Randomized Phase 3 AXIS Trial

    OpenAIRE

    Ueda, Takeshi; Uemura, Hirotsugu; Tomita, Yoshihiko; Tsukamoto, Taiji; Kanayama, Hiroomi; Shinohara, Nobuo; Tarazi, Jamal; Chen, Connie; Kim, Sinil; Ozono, Seiichiro; Naito, Seiji; Akaza, Hideyuki

    2013-01-01

    Objective Axitinib is a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors 1, 2 and 3. The efficacy and safety of axitinib in Japanese patients with metastatic renal cell carcinoma were evaluated. Methods A subgroup analysis was conducted in Japanese patients enrolled in the randomized Phase III trial of axitinib versus sorafenib after failure of one prior systemic therapy for metastatic renal cell carcinoma. Results Twenty-five (of 361) and 29 (o...

  5. Tofacitinib with conventional synthetic disease‐modifying antirheumatic drugs in Chinese patients with rheumatoid arthritis: Patient‐reported outcomes from a Phase 3 randomized controlled trial

    OpenAIRE

    Li, Zhanguo; An, Yuan; Su, Houheng; Li, Xiangpei; Xu, Jianhua; Zheng, Yi; Li, Guiye; Kwok, Kenneth; Wang, Lisy; Wu, Qizhe

    2018-01-01

    Abstract Aim Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We assess the effect of tofacitinib + conventional synthetic disease‐modifying anti rheumatic drugs (csDMARDs) on patient‐reported outcomes in Chinese patients with RA and inadequate response to DMARDs. Methods This analysis of data from the Phase 3 study ORAL Sync included Chinese patients randomized 4 : 4 : 1 : 1 to receive tofacitinib 5 mg twice daily, tofacitinib 10 mg twice daily, p...

  6. Spin-adapted open-shell random phase approximation and time-dependent density functional theory. I. Theory.

    Science.gov (United States)

    Li, Zhendong; Liu, Wenjian

    2010-08-14

    The spin-adaptation of single-reference quantum chemical methods for excited states of open-shell systems has been nontrivial. The primary reason is that the configuration space, generated by a truncated rank of excitations from only one component of a reference multiplet, is spin-incomplete. Those "missing" configurations are of higher ranks and can, in principle, be recaptured by a particular class of excitation operators. However, the resulting formalisms are then quite involved and there are situations [e.g., time-dependent density functional theory (TD-DFT) under the adiabatic approximation] that prevent one from doing so. To solve this issue, we propose here a tensor-coupling scheme that invokes all the components of a reference multiplet (i.e., a tensor reference) rather than increases the excitation ranks. A minimal spin-adapted n-tuply excited configuration space can readily be constructed by tensor products between the n-tuple tensor excitation operators and the chosen tensor reference. Further combined with the tensor equation-of-motion formalism, very compact expressions for excitation energies can be obtained. As a first application of this general idea, a spin-adapted open-shell random phase approximation is first developed. The so-called "translation rule" is then adopted to formulate a spin-adapted, restricted open-shell Kohn-Sham (ROKS)-based TD-DFT (ROKS-TD-DFT). Here, a particular symmetry structure has to be imposed on the exchange-correlation kernel. While the standard ROKS-TD-DFT can access only excited states due to singlet-coupled single excitations, i.e., only some of the singly excited states of the same spin (S(i)) as the reference, the new scheme can capture all the excited states of spin S(i)-1, S(i), or S(i)+1 due to both singlet- and triplet-coupled single excitations. The actual implementation and computation are very much like the (spin-contaminated) unrestricted Kohn-Sham-based TD-DFT. It is also shown that spin-contaminated spin

  7. A randomized, phase 1/2 trial of the safety, tolerability, and immunogenicity of bivalent rLP2086 meningococcal B vaccine in healthy infants.

    Science.gov (United States)

    Martinon-Torres, Federico; Gimenez-Sanchez, Francisco; Bernaola-Iturbe, Enrique; Diez-Domingo, Javier; Jiang, Qin; Perez, John L

    2014-09-08

    Neisseria meningitidis serogroup B (MnB) is a major cause of invasive meningococcal disease in infants. A conserved, surface-exposed lipoprotein, LP2086 (a factor H-binding protein [fHBP]), is a promising MnB vaccine target. A bivalent, recombinant vaccine targeting the fHBP (rLP2086) of MnB was developed. This phase 1/2 clinical study was designed to assess the immunogenicity, safety, and tolerability of a 4-dose series of the rLP2086 vaccine at 20-, 60-, 120-, or 200-μg dose levels in vaccine-naive infants when given with routine childhood vaccines. The study was to consist of two phases: a single-blind sentinel phase and an open-label full enrollment phase. During the sentinel phase, randomization of subjects to the next higher dose was delayed pending a 14-day safety review of dose 1 of the preceding dose cohort. The full enrollment phase was to occur after completion of the sentinel phase. Local reactions were generally mild and adverse events infrequent; however, after only 46 infants were randomized into the study, fever rates were 64% and 90% in subjects receiving one 20- or 60-μg rLP2086 dose, respectively. Most fevers were group and 1 subject in the 60-μg group experienced fevers >39.0°C; no fevers were >40.0°C. Due to these high fever rates, the study was terminated early. No immunogenicity data were collected. This report discusses the safety and acceptability of rLP2086 in infants after one 20- or 60-μg dose. Due to the high fever rate experienced in the 20- and 60-μg groups, rLP2086 in the current formulation may not be acceptable for infants. Copyright © 2014. Published by Elsevier Ltd.

  8. Efficacy, Safety, and Dose of Pafuramidine, a New Oral Drug for Treatment of First Stage Sleeping Sickness, in a Phase 2a Clinical Study and Phase 2b Randomized Clinical Studies.

    Directory of Open Access Journals (Sweden)

    Christian Burri

    2016-02-01

    Full Text Available Sleeping sickness (human African trypanosomiasis [HAT] is caused by protozoan parasites and characterized by a chronic progressive course, which may last up to several years before death. We conducted two Phase 2 studies to determine the efficacy and safety of oral pafuramidine in African patients with first stage HAT.The Phase 2a study was an open-label, non-controlled, proof-of-concept study where 32 patients were treated with 100 mg of pafuramidine orally twice a day (BID for 5 days at two trypanosomiasis reference centers (Angola and the Democratic Republic of the Congo [DRC] between August 2001 and November 2004. The Phase 2b study compared pafuramidine in 41 patients versus standard pentamidine therapy in 40 patients. The Phase 2b study was open-label, parallel-group, controlled, randomized, and conducted at two sites in the DRC between April 2003 and February 2007. The Phase 2b study was then amended to add an open-label sequence (Phase 2b-2, where 30 patients received pafuramidine for 10 days. The primary efficacy endpoint was parasitologic cure at 24 hours (Phase 2a or 3 months (Phase 2b after treatment completion. The primary safety outcome was the rate of occurrence of World Health Organization Toxicity Scale Grade 3 or higher adverse events. All subjects provided written informed consent.Pafuramidine for the treatment of first stage HAT was comparable in efficacy to pentamidine after 10 days of dosing. The cure rates 3 months post-treatment were 79% in the 5-day pafuramidine, 100% in the 7-day pentamidine, and 93% in the 10-day pafuramidine groups. In Phase 2b, the percentage of patients with at least 1 treatment-emergent adverse event was notably higher after pentamidine treatment (93% than pafuramidine treatment for 5 days (25% and 10 days (57%. These results support continuation of the development program for pafuramidine into Phase 3.

  9. Efficacy, Safety, and Dose of Pafuramidine, a New Oral Drug for Treatment of First Stage Sleeping Sickness, in a Phase 2a Clinical Study and Phase 2b Randomized Clinical Studies.

    Science.gov (United States)

    Burri, Christian; Yeramian, Patrick D; Allen, James L; Merolle, Ada; Serge, Kazadi Kyanza; Mpanya, Alain; Lutumba, Pascal; Mesu, Victor Kande Betu Ku; Bilenge, Constantin Miaka Mia; Lubaki, Jean-Pierre Fina; Mpoto, Alfred Mpoo; Thompson, Mark; Munungu, Blaise Fungula; Manuel, Francisco; Josenando, Théophilo; Bernhard, Sonja C; Olson, Carol A; Blum, Johannes; Tidwell, Richard R; Pohlig, Gabriele

    2016-02-01

    Sleeping sickness (human African trypanosomiasis [HAT]) is caused by protozoan parasites and characterized by a chronic progressive course, which may last up to several years before death. We conducted two Phase 2 studies to determine the efficacy and safety of oral pafuramidine in African patients with first stage HAT. The Phase 2a study was an open-label, non-controlled, proof-of-concept study where 32 patients were treated with 100 mg of pafuramidine orally twice a day (BID) for 5 days at two trypanosomiasis reference centers (Angola and the Democratic Republic of the Congo [DRC]) between August 2001 and November 2004. The Phase 2b study compared pafuramidine in 41 patients versus standard pentamidine therapy in 40 patients. The Phase 2b study was open-label, parallel-group, controlled, randomized, and conducted at two sites in the DRC between April 2003 and February 2007. The Phase 2b study was then amended to add an open-label sequence (Phase 2b-2), where 30 patients received pafuramidine for 10 days. The primary efficacy endpoint was parasitologic cure at 24 hours (Phase 2a) or 3 months (Phase 2b) after treatment completion. The primary safety outcome was the rate of occurrence of World Health Organization Toxicity Scale Grade 3 or higher adverse events. All subjects provided written informed consent. Pafuramidine for the treatment of first stage HAT was comparable in efficacy to pentamidine after 10 days of dosing. The cure rates 3 months post-treatment were 79% in the 5-day pafuramidine, 100% in the 7-day pentamidine, and 93% in the 10-day pafuramidine groups. In Phase 2b, the percentage of patients with at least 1 treatment-emergent adverse event was notably higher after pentamidine treatment (93%) than pafuramidine treatment for 5 days (25%) and 10 days (57%). These results support continuation of the development program for pafuramidine into Phase 3.

  10. Designing the selenium and bladder cancer trial (SELEBLAT, a phase lll randomized chemoprevention study with selenium on recurrence of bladder cancer in Belgium

    Directory of Open Access Journals (Sweden)

    Goossens Maria E

    2012-03-01

    Full Text Available Abstract Background In Belgium, bladder cancer is the fifth most common cancer in males (5.2% and the sixth most frequent cause of death from cancer in males (3.8%. Previous epidemiological studies have consistently reported that selenium concentrations were inversely associated with the risk of bladder cancer. This suggests that selenium may also be suitable for chemoprevention of recurrence. Method The SELEBLAT study opened in September 2009 and is still recruiting all patients with non-invasive transitional cell carcinoma of the bladder on TURB operation in 15 Belgian hospitals. Recruitment progress can be monitored live at http://www.seleblat.org. Patients are randomly assigned to selenium yeast (200 μg/day supplementation for 3 years or matching placebo, in addition to standard care. The objective is to determine the effect of selenium on the recurrence of bladder cancer. Randomization is stratified by treatment centre. A computerized algorithm randomly assigns the patients to a treatment arm. All study personnel and participants are blinded to treatment assignment for the duration of the study. Design The SELEnium and BLAdder cancer Trial (SELEBLAT is a phase III randomized, placebo-controlled, academic, double-blind superior trial. Discussion This is the first report on a selenium randomized trial in bladder cancer patients. Trial registration ClinicalTrials.gov identifier: NCT00729287

  11. [Vitex agnus castus extract in the treatment of luteal phase defects due to latent hyperprolactinemia. Results of a randomized placebo-controlled double-blind study].

    Science.gov (United States)

    Milewicz, A; Gejdel, E; Sworen, H; Sienkiewicz, K; Jedrzejak, J; Teucher, T; Schmitz, H

    1993-07-01

    The efficacy of a Vitex agnus castus preparation (Strotan capsules) was investigated in a randomized double blind study vs. placebo. This clinical study involved 52 women with luteal phase defects due to latent hyperprolactinaemia. The daily dose was one capsule (20 mg) Vitex agnus castus preparation and placebo, respectively. Aim of the study was to prove whether the elevated pituitary prolactin reserve can be reduced and deficits in luteal phase length and luteal phase progesterone synthesis be normalized. Blood for hormonal analysis was taken at days 5-8 and day 20 of the menstrual cycle before and after three month of therapy. Latent hyperprolactinaemia was analysed by monitoring the prolactin release 15 and 30 min after i.v. injection of 200 micrograms TRH. 37 complete case reports (placebo: n = 20, verum: n = 17) after 3 month of therapy were statistically evaluated. The prolactin release was reduced after 3 months, shortened luteal phases were normalised and deficits in the luteal progesterone synthesis were eliminated. These changes were significant and occurred only in the verum group. All other hormonal parameters did not change with the exception of 17 beta-estradiol which rouse up in the luteal phase in patients receiving verum. Side effects were not seen, two women treated with the Vitex agnus castus preparation got pregnant. The tested preparation is thought to be an efficient medication in the treatment of luteal phase defects due to latent hyperprolactinaemia.

  12. Selecting Operations for Assembler Encoding

    Directory of Open Access Journals (Sweden)

    Tomasz Praczyk

    2010-04-01

    Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
    The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

  13. Phase III randomized clinical trial comparing tremelimumab with standard-of-care chemotherapy in patients with advanced melanoma

    NARCIS (Netherlands)

    Ribas, Antoni; Kefford, Richard; Marshall, Margaret A.; Punt, Cornelis J. A.; Haanen, John B.; Marmol, Maribel; Garbe, Claus; Gogas, Helen; Schachter, Jacob; Linette, Gerald; Lorigan, Paul; Kendra, Kari L.; Maio, Michele; Trefzer, Uwe; Smylie, Michael; McArthur, Grant A.; Dreno, Brigitte; Nathan, Paul D.; Mackiewicz, Jacek; Kirkwood, John M.; Gomez-Navarro, Jesus; Huang, Bo; Pavlov, Dmitri; Hauschild, Axel

    2013-01-01

    In phase I/II trials, the cytotoxic T lymphocyte-associated antigen-4-blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients with

  14. Phase III randomized clinical trial comparing tremelimumab with standard-of-care chemotherapy in patients with advanced melanoma.

    NARCIS (Netherlands)

    Ribas, A.; Kefford, R.; Marshall, Martin; Punt, C.J.A.; Haanen, J.B.; Marmol, M.; Garbe, C.; Gogas, H.; Schachter, J.; Linette, G.; Lorigan, P.; Kendra, K.L.; Maio, M.; Trefzer, U.; Smylie, M.; McArthur, G.A.; Dreno, B.; Nathan, P.D.; Mackiewicz, J.; Kirkwood, J.M.; Gomez-Navarro, J.; Huang, B.; Pavlov, D.; Hauschild, A.

    2013-01-01

    PURPOSE: In phase I/II trials, the cytotoxic T lymphocyte-associated antigen-4-blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients

  15. Closed-form solution for the Wigner phase-space distribution function for diffuse reflection and small-angle scattering in a random medium.

    Science.gov (United States)

    Yura, H T; Thrane, L; Andersen, P E

    2000-12-01

    Within the paraxial approximation, a closed-form solution for the Wigner phase-space distribution function is derived for diffuse reflection and small-angle scattering in a random medium. This solution is based on the extended Huygens-Fresnel principle for the optical field, which is widely used in studies of wave propagation through random media. The results are general in that they apply to both an arbitrary small-angle volume scattering function, and arbitrary (real) ABCD optical systems. Furthermore, they are valid in both the single- and multiple-scattering regimes. Some general features of the Wigner phase-space distribution function are discussed, and analytic results are obtained for various types of scattering functions in the asymptotic limit s > 1, where s is the optical depth. In particular, explicit results are presented for optical coherence tomography (OCT) systems. On this basis, a novel way of creating OCT images based on measurements of the momentum width of the Wigner phase-space distribution is suggested, and the advantage over conventional OCT images is discussed. Because all previous published studies regarding the Wigner function are carried out in the transmission geometry, it is important to note that the extended Huygens-Fresnel principle and the ABCD matrix formalism may be used successfully to describe this geometry (within the paraxial approximation). Therefore for completeness we present in an appendix the general closed-form solution for the Wigner phase-space distribution function in ABCD paraxial optical systems for direct propagation through random media, and in a second appendix absorption effects are included.

  16. Oral tetrahydrouridine and decitabine for non-cytotoxic epigenetic gene regulation in sickle cell disease: A randomized phase 1 study.

    Directory of Open Access Journals (Sweden)

    Robert Molokie

    2017-09-01

    Full Text Available Sickle cell disease (SCD, a congenital hemolytic anemia that exacts terrible global morbidity and mortality, is driven by polymerization of mutated sickle hemoglobin (HbS in red blood cells (RBCs. Fetal hemoglobin (HbF interferes with this polymerization, but HbF is epigenetically silenced from infancy onward by DNA methyltransferase 1 (DNMT1.To pharmacologically re-induce HbF by DNMT1 inhibition, this first-in-human clinical trial (NCT01685515 combined 2 small molecules-decitabine to deplete DNMT1 and tetrahydrouridine (THU to inhibit cytidine deaminase (CDA, the enzyme that otherwise rapidly deaminates/inactivates decitabine, severely limiting its half-life, tissue distribution, and oral bioavailability. Oral decitabine doses, administered after oral THU 10 mg/kg, were escalated from a very low starting level (0.01, 0.02, 0.04, 0.08, or 0.16 mg/kg to identify minimal doses active in depleting DNMT1 without cytotoxicity. Patients were SCD adults at risk of early death despite standard-of-care, randomized 3:2 to THU-decitabine versus placebo in 5 cohorts of 5 patients treated 2X/week for 8 weeks, with 4 weeks of follow-up. The primary endpoint was ≥ grade 3 non-hematologic toxicity. This endpoint was not triggered, and adverse events (AEs were not significantly different in THU-decitabine-versus placebo-treated patients. At the decitabine 0.16 mg/kg dose, plasma concentrations peaked at approximately 50 nM (Cmax and remained elevated for several hours. This dose decreased DNMT1 protein in peripheral blood mononuclear cells by >75% and repetitive element CpG methylation by approximately 10%, and increased HbF by 4%-9% (P < 0.001, doubling fetal hemoglobin-enriched red blood cells (F-cells up to approximately 80% of total RBCs. Total hemoglobin increased by 1.2-1.9 g/dL (P = 0.01 as reticulocytes simultaneously decreased; that is, better quality and efficiency of HbF-enriched erythropoiesis elevated hemoglobin using fewer reticulocytes. Also

  17. Safety and hemostatic efficacy of fibrin pad in partial nephrectomy: Results of an open-label Phase I and a randomized, standard-of-care-controlled Phase I/II study

    Directory of Open Access Journals (Sweden)

    Nativ Ofer

    2012-11-01

    Full Text Available Abstract Background Bleeding severity, anatomic location, tissue characteristics, and visibility are common challenges encountered while managing intraoperative bleeding, and conventional hemostatic measures (suture, ligature, and cautery may sometimes be ineffective or impractical. While topical absorbable hemostats (TAH are useful hemostatic adjuvants, each TAH has associated disadvantages. Methods We evaluated the safety and hemostatic efficacy of a new advanced biologic combination product―fibrin pad―to potentially address some gaps associated with TAHs. Fibrin pad was assessed as adjunctive hemostat in open partial nephrectomy in single-center, open-label, Phase I study (N = 10, and as primary hemostat in multicenter, single-blind, randomized, standard-of-care (SOC-controlled Phase I/II study (N = 7 in Israel. It was used to control mild-to-moderate bleeding in Phase I and also spurting arterial bleeding in Phase I/II study. Phase I study assessed safety and Phase I/II study, proportion of successes at 10 min following randomization, analyzed by Fisher exact tests at 5% significance level. Results Phase I (N = 10: All patients completed the study. Hemostasis was achieved within 3–4 min (average = 3.1 min of a single application in all patients. Fibrin pad was found to be safe for human use, with no product-related adverse events reported. Phase I/II (N = 7: Hemostatic success at 10 min (primary endpoint was achieved in 3/4 patients treated with fibrin pad versus 0/3 patients treated with SOC. No clinically significant change in laboratory or coagulation parameters was recorded, except a case of post-procedural hemorrhage with fibrin pad, which was considered serious and related to the fibrin pad treatment, and required re-operation. Although Data Safety Monitoring Board authorized trial continuation, the sponsor decided against proceeding toward an indication for primary treatment of severe arterial

  18. Asymmetric synthesis using chiral-encoded metal

    Science.gov (United States)

    Yutthalekha, Thittaya; Wattanakit, Chularat; Lapeyre, Veronique; Nokbin, Somkiat; Warakulwit, Chompunuch; Limtrakul, Jumras; Kuhn, Alexander

    2016-08-01

    The synthesis of chiral compounds is of crucial importance in many areas of society and science, including medicine, biology, chemistry, biotechnology and agriculture. Thus, there is a fundamental interest in developing new approaches for the selective production of enantiomers. Here we report the use of mesoporous metal structures with encoded geometric chiral information for inducing asymmetry in the electrochemical synthesis of mandelic acid as a model molecule. The chiral-encoded mesoporous metal, obtained by the electrochemical reduction of platinum salts in the presence of a liquid crystal phase and the chiral template molecule, perfectly retains the chiral information after removal of the template. Starting from a prochiral compound we demonstrate enantiomeric excess of the (R)-enantiomer when using (R)-imprinted electrodes and vice versa for the (S)-imprinted ones. Moreover, changing the amount of chiral cavities in the material allows tuning the enantioselectivity.

  19. Optical image encryption using chaos-based compressed sensing and phase-shifting interference in fractional wavelet domain

    Science.gov (United States)

    Liu, Qi; Wang, Ying; Wang, Jun; Wang, Qiong-Hua

    2018-02-01

    In this paper, a novel optical image encryption system combining compressed sensing with phase-shifting interference in fractional wavelet domain is proposed. To improve the encryption efficiency, the volume data of original image are decreased by compressed sensing. Then the compacted image is encoded through double random phase encoding in asymmetric fractional wavelet domain. In the encryption system, three pseudo-random sequences, generated by three-dimensional chaos map, are used as the measurement matrix of compressed sensing and two random-phase masks in the asymmetric fractional wavelet transform. It not only simplifies the keys to storage and transmission, but also enhances our cryptosystem nonlinearity to resist some common attacks. Further, holograms make our cryptosystem be immune to noises and occlusion attacks, which are obtained by two-step-only quadrature phase-shifting interference. And the compression and encryption can be achieved in the final result simultaneously. Numerical experiments have verified the security and validity of the proposed algorithm.

  20. A phase III randomized trial comparing glucocorticoid monotherapy versus glucocorticoid and rituximab in patients with autoimmune haemolytic anaemia

    DEFF Research Database (Denmark)

    Birgens, Henrik Sverre; Frederiksen, Henrik; Hasselbalch, Hans C

    2013-01-01

    The impact of first-line treatment with the anti-CD 20 chimeric monoclonal antibody rituximab in patients with warm-antibody reactive autoimmune haemolytic anaemia (WAIHA) is unknown. We report the first randomized study of 64 patients with newly diagnosed WAIHA who received prednisolone and ritu...

  1. Individualized versus conventional ovarian stimulation for in vitro fertilization: a multicenter, randomized, controlled, assessor-blinded, phase 3 noninferiority trial

    DEFF Research Database (Denmark)

    Nyboe Andersen, Anders; Nelson, Scott M; Fauser, Bart C J M

    2017-01-01

    OBJECTIVE: To compare the efficacy and safety of follitropin delta, a new human recombinant FSH with individualized dosing based on serum antimüllerian hormone (AMH) and body weight, with conventional follitropin alfa dosing for ovarian stimulation in women undergoing IVF. DESIGN: Randomized, mul...

  2. Wavelength-encoded OCDMA system using opto-VLSI processors.

    Science.gov (United States)

    Aljada, Muhsen; Alameh, Kamal

    2007-07-01

    We propose and experimentally demonstrate a 2.5 Gbits/sper user wavelength-encoded optical code-division multiple-access encoder-decoder structure based on opto-VLSI processing. Each encoder and decoder is constructed using a single 1D opto-very-large-scale-integrated (VLSI) processor in conjunction with a fiber Bragg grating (FBG) array of different Bragg wavelengths. The FBG array spectrally and temporally slices the broadband input pulse into several components and the opto-VLSI processor generates codewords using digital phase holograms. System performance is measured in terms of the autocorrelation and cross-correlation functions as well as the eye diagram.

  3. Wavelength-encoded OCDMA system using opto-VLSI processors

    Science.gov (United States)

    Aljada, Muhsen; Alameh, Kamal

    2007-07-01

    We propose and experimentally demonstrate a 2.5 Gbits/sper user wavelength-encoded optical code-division multiple-access encoder-decoder structure based on opto-VLSI processing. Each encoder and decoder is constructed using a single 1D opto-very-large-scale-integrated (VLSI) processor in conjunction with a fiber Bragg grating (FBG) array of different Bragg wavelengths. The FBG array spectrally and temporally slices the broadband input pulse into several components and the opto-VLSI processor generates codewords using digital phase holograms. System performance is measured in terms of the autocorrelation and cross-correlation functions as well as the eye diagram.

  4. A Randomized, Double-Blind, Placebo-Controlled, Phase 2b Study to Evaluate the Safety and Efficacy of Recombinant Human Soluble Thrombomodulin, ART-123, in Patients With Sepsis and Suspected Disseminated Intravascular Coagulation

    NARCIS (Netherlands)

    Vincent, Jean-Louis; Ramesh, Mayakonda K.; Ernest, David; Larosa, Steven P.; Pachl, Jan; Aikawa, Naoki; Hoste, Eric; Levy, Howard; Hirman, Joe; Levi, Marcel; Daga, Mradul; Kutsogiannis, Demetrios J.; Crowther, Mark; Bernard, Gordon R.; Devriendt, Jacques; Puigserver, Joan Vidal; Blanzaco, Daniel U.; Esmon, Charles T.; Parrillo, Joseph E.; Guzzi, Louis; Henderson, Seton J.; Pothirat, Chaicharn; Mehta, Parthiv; Fareed, Jawed; Talwar, Deepak; Tsuruta, Kazuhisa; Gorelick, Kenneth J.; Osawa, Yutaka; Kaul, Inder

    2013-01-01

    Objectives: To determine the safety and efficacy of recombinant thrombomodulin (ART-123) in patients with suspected sepsis-associated disseminated intravascular coagulation. Design: Phase 2b, international, multicenter, double-blind, randomized, placebo-controlled, parallel group, screening trial.

  5. Time-dependent Gross-Pitaevskii equation for composite bosons as the strong-coupling limit of the fermionic broken-symmetry random-phase approximation

    International Nuclear Information System (INIS)

    Strinati, G.C.; Pieri, P.

    2004-01-01

    The linear response to a space- and time-dependent external disturbance of a system of dilute condensed composite bosons at zero temperature, as obtained from the linearized version of the time-dependent Gross-Pitaevskii equation, is shown to result also from the strong-coupling limit of the time-dependent BCS (or broken-symmetry random-phase) approximation for the constituent fermions subject to the same external disturbance. In this way, it is possible to connect excited-state properties of the bosonic and fermionic systems by placing the Gross-Pitaevskii equation in perspective with the corresponding fermionic approximations

  6. Communication: An effective linear-scaling atomic-orbital reformulation of the random-phase approximation using a contracted double-Laplace transformation

    International Nuclear Information System (INIS)

    Schurkus, Henry F.; Ochsenfeld, Christian

    2016-01-01

    An atomic-orbital (AO) reformulation of the random-phase approximation (RPA) correlation energy is presented allowing to reduce the steep computational scaling to linear, so that large systems can be studied on simple desktop computers with fully numerically controlled accuracy. Our AO-RPA formulation introduces a contracted double-Laplace transform and employs the overlap-metric resolution-of-the-identity. First timings of our pilot code illustrate the reduced scaling with systems comprising up to 1262 atoms and 10 090 basis functions. 

  7. Low-lying dipole response in the stable {sup 40,48}Ca nuclei within the second random-phase approximation

    Energy Technology Data Exchange (ETDEWEB)

    Gambacurta, D.; Grasso, M.; Catara, F. [GANIL,CEA/DSM-CNRS/IN2P3, Caen (France); Institut de Physique Nucleaire, Universite Paris-Sud, IN2P3-CNRS, F-91406 Orsay Cedex (France); Dipartimento di Fisica e Astronomia dell' Universita di and INFN Catania (Italy)

    2012-10-20

    The low-lying dipole strength distributions of {sup 40}CaCa and {sup 48}Ca, in the energy region between 5 and 10 MeV, are studied within the second random phase approximation (RPA) with Skyrme interaction. Standard RPA models do not usually predict any presence of strength in this energy region, while experimentally a significant amount of strength is found. The inclusion of the 2 particle -2 hole configurations allows to obtain a description in a rather good agreement with the experimental data. The properties of the most collective state are analyzed in terms of its 1 particle -1 hole nature and its transition densities.

  8. Design of the randomized, Phase III, QUAZAR AML Maintenance trial of CC-486 (oral azacitidine) maintenance therapy in acute myeloid leukemia.

    Science.gov (United States)

    Roboz, Gail J; Montesinos, Pau; Selleslag, Dominik; Wei, Andrew; Jang, Jun-Ho; Falantes, Jose; Voso, Maria T; Sayar, Hamid; Porkka, Kimmo; Marlton, Paula; Almeida, Antonio; Mohan, Sanjay; Ravandi, Farhad; Garcia-Manero, Guillermo; Skikne, Barry; Kantarjian, Hagop

    2016-02-01

    Older patients with acute myeloid leukemia (AML) have worse rates of complete remission and shorter overall survival than younger patients. The epigenetic modifier CC-486 is an oral formulation of azacitidine with promising clinical activity in patients with AML in Phase I studies. The Phase III, randomized, double-blind, placebo-controlled QUAZAR AML Maintenance trial (CC-486-AML-001) examines CC-486 maintenance therapy (300 mg/day for 14 days of 28-day treatment cycles) for patients aged ≥55 years with AML in first complete remission. The primary end point is overall survival. Secondary end points include relapse-free survival, safety, health-related quality of life and healthcare resource utilization. This trial will investigate whether CC-486 maintenance can prolong remission and improve survival for older patients with AML.

  9. Effects of thermal and particle-number fluctuations on the giant isovector dipole modes for the 58Ni nucleus in the finite-temperature random-phase approximation

    International Nuclear Information System (INIS)

    Nguyen Dinhdang; Nguyen Zuythang

    1988-01-01

    Using the realistic single-particle energy spectrum obtained in the Woods-Saxon nucleon mean-field potential, we calculate the BCS pairing gap for 58 Ni as a function of temperature taking into account the thermal and particle-number fluctuations. The strength distributions of the electric dipole transitions and the centroids of the isovector giant dipole resonance (IV-GDR) are computed in the framework of the finite-temperature random-phase approximation (RPA) based on the Hamiltonian of the quasiparticle-phonon nuclear model with separate dipole forces. It is shown that the change of the pairing gap at finite temperature can noticeably influence the IV-GDR localisation in realistic nuclei. By taking both thermal and quasiparticle fluctuations in the pairing gap into account the effect of the phase transition from superfluid to normal in the temperature dependence of the IV-GDR centroid is completely smeared out. (author)

  10. A 0.18-μm 3.3 V 16 k Bits 1R1T Phase Change Random Access Memory (PCRAM) Chip

    International Nuclear Information System (INIS)

    Sheng, Ding; Zhi-Tang, Song; Bo, Liu; Min, Zhu; Xiao-Gang, Chen; Yi-Feng, Chen; Ju, Shen; Cong, Fu; Song-Lin, Feng

    2008-01-01

    Using standard 0.18-μm CMOS process and the special platform for 8-inch phase change random access memory (PCRAM), the first Chinese 16k bits PCRAM chip has been successfully achieved. A 1R1T structure has been designed for low voltage drop and low cost compared to the 1R1D structure and the BJT-switch structure. Full integration of the 16k bits PCRAM chip, including memory cell, array structure, critical circuit module, and physical layout, has been designed and verified. The critical integration technology of the phase change material (PCM) fabrication and the standard CMOS process has been solved. Test results about PCM in a large-scale array have been generated for the next research of PCRAM chip

  11. Rikkunshito for Preventing Chemotherapy-Induced Nausea and Vomiting in Lung Cancer Patients: Results from 2 Prospective, Randomized Phase 2 Trials

    Directory of Open Access Journals (Sweden)

    Toshiyuki Harada

    2018-01-01

    Full Text Available The herbal medicine rikkunshito has the potential to improve chemotherapy-induced nausea and vomiting (CINV by stimulating ghrelin secretion. We aimed to evaluate the efficacy and safety of rikkunshito in preventing CINV for patients with lung cancer. Two separate prospective, randomized, phase II parallel design studies were conducted in patients with lung cancer. Fifty-eight and sixty-two patients scheduled to receive highly emetogenic chemotherapy (HEC and moderately emetogenic chemotherapy (MEC, respectively, were randomized 1:1 to receive either standard antiemetic therapy in accordance with international guidelines (S group or standard antiemetic therapy plus oral rikkunshito (R group. The primary endpoint was overall complete response (CR—that is, no emesis and rescue medication in the first 120 h post-chemotherapy. Secondary endpoints included CR in the acute (0–24 h and delayed (>24–120 h phases and safety. Fifty-seven patients (S group, 28; R group, 29 receiving HEC and sixty-two patients (S group, 30; R group, 32 receiving MEC with comparable characteristics were evaluated. The CR rates were similar across the S and R groups for the HEC study in the overall (67.9% vs. 62.1%, acute (96.4% vs. 89.6%, and delayed (67.9% vs. 62.1% phases, respectively, and for the MEC study in the overall (83.3% vs. 84.4%, acute (100% vs. 100%, and delayed (83.3% vs. 84.4% phases, respectively. No severe adverse events were observed. Although rikkunshito was well tolerated, it did not demonstrate an additional preventative effect against CINV in lung cancer patients receiving HEC or MEC.Clinical Trial Registry Information: This study is registered with the University Hospital Medical Information Network (UMIN Clinical Trial Registry1, identification numbers UMIN 000014239 and UMIN 000014240.

  12. Impact of more intensive written information in patients having radical radiation therapy: Results of a prospective randomized phase III trial

    International Nuclear Information System (INIS)

    Zissiadis, Yvonne; Harper, Emily; Kearney, Elizabeth

    2010-01-01

    Background and purpose: A diagnosis of malignancy and its treatment is a very stressful time for patients and their families. This study was conducted to determine the impact of more intensive written information on patients' anxiety levels. The secondary aim was to determine the impact of this information on patients' satisfaction levels. Materials and methods: This prospective randomized trial consisted of patients with a pathological diagnosis of cancer having radical radiotherapy (RT). Patients were randomized to receive the more intensive information (including written information and a telephone call from the research nurse) or not to receive the more intensive information at the time of their initial consultation with the radiation oncologist. Study questionnaires measuring anxiety (STAI form) were completed prior to their first consultation (baseline) at the time of simulation (pre-RT) and at the completion of radiotherapy. A second questionnaire assessing satisfaction with the information given (ISQ) was completed at the time of simulation prior to commencing RT. Results: One hundred and ninety-four patients were enrolled in the study. The mean age of the patients was 58.5 years and 70% of patients were female. Breast cancer (67%) was the commonest cancer. One hundred and two patients were randomized to receive the intensive information package and 92 patients received the standard consultation. There was no significant difference in mean State or Trait anxiety scores between any of the time intervals and no difference between the two information groups. There was no significant difference between the groups with regard to mean satisfaction scores with the overall information given, nor with any individual question. The satisfaction scores with lifestyle information given were lower than those for any other type of information in both randomization arms. Conclusion: More intensive information did not significantly change patients' anxiety scores or

  13. Antitumor activity and safety of tivozanib (AV-951) in a phase II randomized discontinuation trial in patients with renal cell carcinoma.

    Science.gov (United States)

    Nosov, Dmitry A; Esteves, Brooke; Lipatov, Oleg N; Lyulko, Alexei A; Anischenko, A A; Chacko, Raju T; Doval, Dinesh C; Strahs, Andrew; Slichenmyer, William J; Bhargava, Pankaj

    2012-05-10

    The antitumor activity and safety of tivozanib, which is a potent and selective vascular endothelial growth factor receptor-1, -2, and -3 inhibitor, was assessed in patients with advanced/metastatic renal cell carcinoma (RCC). In this phase II, randomized discontinuation trial, 272 patients received open-label tivozanib 1.5 mg/d (one cycle equaled three treatment weeks followed by a 1-week break) orally for 16 weeks. Thereafter, 78 patients who demonstrated ≥ 25% tumor shrinkage continued to take tivozanib, and 118 patients with less than 25% tumor change were randomly assigned to receive tivozanib or a placebo in a double-blind manner; patients with ≥ 25% tumor growth were discontinued. Primary end points included safety, the objective response rate (ORR) at 16 weeks, and the percentage of randomly assigned patients who remained progression free after 12 weeks of double-blind treatment; secondary end points included progression-free survival (PFS). Of 272 patients enrolled onto the study, 83% of patients had clear-cell histology, 73% of patients had undergone nephrectomy, and 54% of patients were treatment naive. The ORR after 16 weeks of tivozanib treatment was 18% (95% CI, 14% to 23%). Of the 118 randomized patients, significantly more patients who were randomly assigned to receive double-blind tivozanib remained progression free after 12 weeks versus patients who received the placebo (49% v 21%; P = .001). Throughout the study, the ORR was 24% (95% CI, 19% to 30%), and the median PFS was 11.7 months (95% CI, 8.3 to 14.3 months) in the overall study population. The most common grade 3 and 4 treatment-related adverse event was hypertension (12%). Tivozanib was active and well tolerated in patients with advanced RCC. These data support additional development of tivozanib in advanced RCC.

  14. Random magnetism

    International Nuclear Information System (INIS)

    Tsallis, C.

    1980-03-01

    The 'ingredients' which control a phase transition in well defined system as well as in random ones (e.g. random magnetic systems) are listed and discussed within a somehow unifying perspective. Among these 'ingredients' we find the couplings and elements responsible for the cooperative phenomenon, the topological connectivity as well as possible topological incompatibilities, the influence of new degrees of freedom, the order parameter dimensionality, the ground state degeneracy and finally the 'quanticity' of the system. The general trends, though illustrated in magnetic systems, essentially hold for all phase transitions, and give a basis for connection of this area with Field theory, Theory of dynamical systems, etc. (Author) [pt

  15. Random magnetism

    International Nuclear Information System (INIS)

    Tsallis, C.

    1981-01-01

    The 'ingredients' which control a phase transition in well defined systems as well as in random ones (e.q. random magnetic systems) are listed and discussed within a somehow unifying perspective. Among these 'ingredients' the couplings and elements responsible for the cooperative phenomenon, the topological connectivity as well as possible topological incompatibilities, the influence of new degrees of freedom, the order parameter dimensionality, the ground state degeneracy and finally the 'quanticity' of the system are found. The general trends, though illustrated in magnetic systems, essentially hold for all phase transitions, and give a basis for connection of this area with Field theory, Theory of dynamical systems, etc. (Author) [pt

  16. Gefitinib plus cisplatin and radiotherapy in previously untreated head and neck squamous cell carcinoma: A phase II, randomized, double-blind, placebo-controlled study

    International Nuclear Information System (INIS)

    Gregoire, Vincent; Hamoir, Marc; Chen Changhu; Kane, Madeleine; Kawecki, Andrzej; Julka, Pramod K.; Wang, Hung-Ming; Prasad, Srihari; D'Cruz, Anil K.; Radosevic-Jelic, Ljiljana; Kumar, Rejnish R.; Korzeniowski, Stanislaw; Fijuth, Jacek; Machiels, Jean-Pascal; Sellers, Mark V.; Tchakov, Ilian; Raben, David

    2011-01-01

    Background and purpose: To assess the efficacy and safety of gefitinib given concomitantly and/or as maintenance therapy to standard cisplatin/radiotherapy for previously untreated, unresected, stage III/IV non-metastatic SCCHN. Materials and methods: In this phase II, double-blind, study, 226 patients were randomized to gefitinib 250 mg/day, 500 mg/day or placebo in two phases: a concomitant phase (gefitinib or placebo with chemoradiotherapy), followed by a maintenance phase (gefitinib or placebo alone). Primary endpoint was local disease control rate (LDCR) at 2 years; secondary endpoints were LDCR at 1 year, objective response rate, progression-free survival, overall survival, and safety and tolerability. Results: Gefitinib (250 and 500 mg/day) did not improve 2-year LDCR compared with placebo either when given concomitantly with chemoradiotherapy (32.7% vs. 33.6%, respectively; OR 0.921, 95% CI 0.508, 1.670 [1-sided p = 0.607]) or as maintenance therapy (28.8% vs. 37.4%, respectively; OR 0.684, 95% CI 0.377, 1.241 [1-sided p = 0.894]). Secondary efficacy outcomes were broadly consistent with the 2-year LDCR results. In both doses, gefitinib was well-tolerated and did not adversely affect the safety and tolerability of concomitant chemoradiotherapy. Conclusion: Gefitinib was well-tolerated, but did not improve efficacy compared with placebo when given concomitantly with chemoradiotherapy, or as maintenance therapy alone.

  17. Lapatinib versus hormone therapy in patients with advanced renal cell carcinoma: a randomized phase III clinical trial

    DEFF Research Database (Denmark)

    Ravaud, Alain; Hawkins, Robert; Gardner, Jason P

    2008-01-01

    PURPOSE: Lapatinib is an orally reversible inhibitor of epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor 2 (HER-2) tyrosine kinases with demonstrated activity in patients with HER-2-positive breast cancer. In the current phase III open-label trial, lapatinib was comp...

  18. Formation of random and regular relief-phase structures on silver halide photographic emulsions by holographic methods

    Science.gov (United States)

    Ganzherli, N. M.; Gulyaev, S. N.; Gurin, A. S.; Kramushchenko, D. D.; Maurer, I. A.; Chernykh, D. F.

    2009-07-01

    The formation of diffusers and microlens rasters on silver halide emulsions by holographic methods is considered. Two techniques for converting amplitude holographic recording to relief-phase recording, selective curing and irradiation of the emulsion gelatin by short-wavelength UV radiation, are compared.

  19. Contributions of Feature Binding During Encoding and Functional Connectivity of the Medial Temporal Lobe Structures to Episodic Memory Deficits Across the Prodromal and First-Episode Phases of Schizophrenia.

    Science.gov (United States)

    Haut, Kristen M; van Erp, Theo G M; Knowlton, Barbara; Bearden, Carrie E; Subotnik, Kenneth; Ventura, Joseph; Nuechterlein, Keith H; Cannon, Tyrone D

    2015-03-01

    Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia ( n = 27) and high psychosis risk ( n = 28) compared with control participants ( n = 22 and n = 20, respectively) underwent functional MRI during a remember-know memory task. Psychophysiological interaction analyses, using medial temporal lobe (MTL) structures as regions of interest, were conducted to measure functional connectivity patterns supporting successful episodic memory. During encoding, patients with first-episode schizophrenia demonstrated reduced functional coupling between MTL regions and regions involved in stimulus representations, stimulus selection, and cognitive control. Relative to control participants and patients with high psychosis risk who did not convert to psychosis, patients with high psychosis risk who later converted to psychosis also demonstrated reduced connectivity between MTL regions and auditory-verbal and visual-association regions. These results suggest that episodic memory deficits in schizophrenia are related to inefficient recruitment of cortical connections involved in associative memory formation; such deficits precede the onset of psychosis among those individuals at high clinical risk.

  20. Once daily controlled-release pregabalin in the treatment of patients with fibromyalgia: a phase III, double-blind, randomized withdrawal, placebo-controlled study.

    Science.gov (United States)

    Arnold, Lesley M; Arsenault, Pierre; Huffman, Cynthia; Patrick, Jeffrey L; Messig, Michael; Chew, Marci L; Sanin, Luis; Scavone, Joseph M; Pauer, Lynne; Clair, Andrew G

    2014-10-01

    Safety and efficacy of a once daily controlled-released (CR) formulation of pregabalin was evaluated in patients with fibromyalgia using a placebo-controlled, randomized withdrawal design. This multicenter study included 6 week single-blind pregabalin CR treatment followed by 13 week double-blind treatment with placebo or pregabalin CR. The starting dose of 165 mg/day was escalated during the first 3 weeks, up to 495 mg/day based on efficacy and tolerability. Patients with ≥50% reduction in average daily pain score at the end of the single-blind phase were randomized to continue pregabalin CR at the optimized dose (330-495 mg/day) or to placebo. The primary endpoint was time to loss of therapeutic response (LTR), defined as treatment' (Benefit, Satisfaction, and Willingness to Continue Scale) in the pregabalin CR group; no other secondary endpoints were statistically significant. Most AEs were mild to moderate in severity (most frequent: dizziness, somnolence). The percentage of pregabalin CR patients discontinuing because of AEs was 12.2% and 4.8% in the single-blind and double-blind phases, respectively (placebo, 0%). Time to LTR was significantly longer with pregabalin CR versus placebo in fibromyalgia patients who initially showed improvement with pregabalin CR, indicating maintenance of response. Pregabalin CR was well tolerated in most patients. Generalizability may be limited by study duration and selective population.

  1. Tensor hypercontracted ppRPA: Reducing the cost of the particle-particle random phase approximation from O(r {sup 6}) to O(r {sup 4})

    Energy Technology Data Exchange (ETDEWEB)

    Shenvi, Neil; Yang, Yang; Yang, Weitao [Department of Chemistry, Duke University, Durham, NC 27708 (United States); Aggelen, Helen van [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States)

    2014-07-14

    In recent years, interest in the random-phase approximation (RPA) has grown rapidly. At the same time, tensor hypercontraction has emerged as an intriguing method to reduce the computational cost of electronic structure algorithms. In this paper, we combine the particle-particle random phase approximation with tensor hypercontraction to produce the tensor-hypercontracted particle-particle RPA (THC-ppRPA) algorithm. Unlike previous implementations of ppRPA which scale as O(r{sup 6}), the THC-ppRPA algorithm scales asymptotically as only O(r{sup 4}), albeit with a much larger prefactor than the traditional algorithm. We apply THC-ppRPA to several model systems and show that it yields the same results as traditional ppRPA to within mH accuracy. Our method opens the door to the development of post-Kohn Sham functionals based on ppRPA without the excessive asymptotic cost of traditional ppRPA implementations.

  2. Lanthanum carbonate versus placebo for management of hyperphosphatemia in patients undergoing peritoneal dialysis: a subgroup analysis of a phase 2 randomized controlled study of dialysis patients

    Directory of Open Access Journals (Sweden)

    Hutchison Alastair J

    2013-02-01

    Full Text Available Abstract Background This short-term study assessed the efficacy and safety of lanthanum carbonate in the treatment of hyperphosphatemia in dialysis patients; here, we report a prespecified subgroup analysis of patients undergoing peritoneal dialysis. Methods Men and women (n = 39 who had received continuous ambulatory peritoneal dialysis for chronic kidney disease for 6 months or more were enrolled in eight renal medicine departments in the United Kingdom. A 2-week washout period was followed by a 4-week dose-titration phase during which patients received lanthanum carbonate titrated up to 2250 mg/day. This was followed by a 4-week, randomized, placebo-controlled, parallel-group phase during which patients continued to receive either lanthanum carbonate at the titrated dose, or a matched dose of placebo. The main outcome measure was control of serum phosphate levels (1.3-1.8 mmol/l at the end of the parallel-group phase. Results Serum phosphate was controlled in 3/39 (8% patients at the beginning of the dose-titration phase (after washout and in 18/31 (58% patients treated with lanthanum carbonate at its end. After the parallel-group phase, 60% of lanthanum carbonate-treated patients and 10% of those receiving placebo had controlled serum phosphate. There was no difference in mean (95% confidence interval serum phosphate levels between groups at randomization: lanthanum carbonate, 1.57 (1.34-1.81 mmol/l; placebo, 1.58 (1.40-1.76 mmol/l (p = 0.96. However, a difference was seen at the end of the parallel-group phase: lanthanum carbonate, 1.56 (1.33-1.79 mmol/l; placebo, 2.25 (1.81-2.68 mmol/l (p = 0.0015. There were no clinically important changes in nutritional parameters and no serious treatment-related adverse events were recorded. Conclusions At doses up to 2250 mg/day, lanthanum carbonate is well tolerated and controls hyperphosphatemia effectively. Treatment with higher doses of lanthanum carbonate may allow patients undergoing

  3. Coherent diffractive imaging using randomly coded masks

    Energy Technology Data Exchange (ETDEWEB)

    Seaberg, Matthew H., E-mail: seaberg@slac.stanford.edu [CNRS and D.I., UMR 8548, École Normale Supérieure, 45 Rue d' Ulm, 75005 Paris (France); Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); D' Aspremont, Alexandre [CNRS and D.I., UMR 8548, École Normale Supérieure, 45 Rue d' Ulm, 75005 Paris (France); Turner, Joshua J. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)

    2015-12-07

    We experimentally demonstrate an extension to coherent diffractive imaging that encodes additional information through the use of a series of randomly coded masks, removing the need for typical object-domain constraints while guaranteeing a unique solution to the phase retrieval problem. Phase retrieval is performed using a numerical convex relaxation routine known as “PhaseCut,” an iterative algorithm known for its stability and for its ability to find the global solution, which can be found efficiently and which is robust to noise. The experiment is performed using a laser diode at 532.2 nm, enabling rapid prototyping for future X-ray synchrotron and even free electron laser experiments.

  4. Safety, tolerability, and immunogenicity of the novel antituberculous vaccine RUTI: randomized, placebo-controlled phase II clinical trial in patients with latent tuberculosis infection.

    Science.gov (United States)

    Nell, Andre S; D'lom, Eva; Bouic, Patrick; Sabaté, Montserrat; Bosser, Ramon; Picas, Jordi; Amat, Mercè; Churchyard, Gavin; Cardona, Pere-Joan

    2014-01-01

    To evaluate the safety, tolerability and immunogenicity of three different doses (5, 25 and 50 µg) of the novel antituberculous vaccine RUTI compared to placebo in subjects with latent tuberculosis infection. Double-blind, randomized, placebo-controlled Phase II Clinical Trial (95 patients randomized). Three different RUTI doses and placebo were tested, randomized both in HIV-positive (n = 47) and HIV-negative subjects (n = 48), after completion of one month isoniazid (INH) pre-vaccination. Each subject received two vaccine administrations, 28 Days apart. Five patients withdrew and 90 patients completed the study. Assessment of safety showed no deaths during study. Two subjects had serious adverse events one had a retinal detachment while taking INH and was not randomized and the other had a severe local injection site abscess on each arm and was hospitalized; causality was assessed as very likely and by the end of the study the outcome had resolved. All the patients except 5 (21%) patients of the placebo group (3 HIV+ and 2 HIV-) reported at least one adverse event (AE) during the study. The most frequently occurring AEs among RUTI recipients were (% in HIV+/-): injection site reactions [erythema (91/92), induration (94/92), local nodules (46/25), local pain (66/75), sterile abscess (6/6), swelling (74/83), ulcer (20/11), headache (17/22) and nasopharyngitis (20/5)]. These events were mostly mild and well tolerated. Overall, a polyantigenic response was observed, which differed by HIV- status. The best polyantigenic response was obtained when administrating 25 µg RUTI, especially in HIV-positive subjects which was not increased after the second inoculation. This Phase II clinical trial demonstrates reasonable tolerability of RUTI. The immunogenicity profile of RUTI vaccine in LTBI subjects, even being variable among groups, allows us considering one single injection of one of the highest doses in future trials, preceded by an extended safety clinical

  5. Bioengineered Temporomandibular Joint Disk Implants: Study Protocol for a Two-Phase Exploratory Randomized Preclinical Pilot Trial in 18 Black Merino Sheep (TEMPOJIMS)

    Science.gov (United States)

    Monje, Florencio Gil; González-García, Raúl; Little, Christopher B; Mónico, Lisete; Pinho, Mário; Santos, Fábio Abade; Carrapiço, Belmira; Gonçalves, Sandra Cavaco; Morouço, Pedro; Alves, Nuno; Moura, Carla; Wang, Yadong; Jeffries, Eric; Gao, Jin; Sousa, Rita; Neto, Lia Lucas; Caldeira, Daniel; Salvado, Francisco

    2017-01-01

    Background Preclinical trials are essential to test efficacious options to substitute the temporomandibular joint (TMJ) disk. The contemporary absence of an ideal treatment for patients with severe TMJ disorders can be related to difficulties concerning the appropriate study design to conduct preclinical trials in the TMJ field. These difficulties can be associated with the use of heterogeneous animal models, the use of the contralateral TMJ as control, the absence of rigorous randomized controlled preclinical trials with blinded outcomes assessors, and difficulties involving multidisciplinary teams. Objective This study aims to develop a new, reproducible, and effective study design for preclinical research in the TMJ domain, obtaining rigorous data related to (1) identify the impact of bilateral discectomy in black Merino sheep, (2) identify the impact of bilateral discopexy in black Merino sheep, and (3) identify the impact of three different bioengineering TMJ discs in black Merino sheep. Methods A two-phase exploratory randomized controlled preclinical trial with blinded outcomes is proposed. In the first phase, nine sheep are randomized into three different surgical bilateral procedures: bilateral discectomy, bilateral discopexy, and sham surgery. In the second phase, nine sheep are randomized to bilaterally test three different TMJ bioengineering disk implants. The primary outcome is the histological gradation of TMJ. Secondary outcomes are imaging changes, absolute masticatory time, ruminant time per cycle, ruminant kinetics, ruminant area, and sheep weight. Results Previous preclinical studies in this field have used the contralateral unoperated side as a control, different animal models ranging from mice to a canine model, with nonrandomized, nonblinded and uncontrolled study designs and limited outcomes measures. The main goal of this exploratory preclinical protocol is to set a new standard for future preclinical trials in oromaxillofacial surgery

  6. Relationship between clustering and algorithmic phase transitions in the random k-XORSAT model and its NP-complete extensions

    International Nuclear Information System (INIS)

    Altarelli, F; Monasson, R; Zamponi, F

    2008-01-01

    We study the performances of stochastic heuristic search algorithms on Uniquely Extendible Constraint Satisfaction Problems with random inputs. We show that, for any heuristic preserving the Poissonian nature of the underlying instance, the (heuristic-dependent) largest ratio α a of constraints per variables for which a search algorithm is likely to find solutions is smaller than the critical ratio α d above which solutions are clustered and highly correlated. In addition we show that the clustering ratio can be reached when the number k of variables per constraints goes to infinity by the so-called Generalized Unit Clause heuristic

  7. A high-speed on-chip pseudo-random binary sequence generator for multi-tone phase calibration

    Science.gov (United States)

    Gommé, Liesbeth; Vandersteen, Gerd; Rolain, Yves

    2011-07-01

    An on-chip reference generator is conceived by adopting the technique of decimating a pseudo-random binary sequence (PRBS) signal in parallel sequences. This is of great benefit when high-speed generation of PRBS and PRBS-derived signals is the objective. The design implemented standard CMOS logic is available in commercial libraries to provide the logic functions for the generator. The design allows the user to select the periodicity of the PRBS and the PRBS-derived signals. The characterization of the on-chip generator marks its performance and reveals promising specifications.

  8. A high-speed on-chip pseudo-random binary sequence generator for multi-tone phase calibration

    International Nuclear Information System (INIS)

    Gommé, Liesbeth; Vandersteen, Gerd; Rolain, Yves

    2011-01-01

    An on-chip reference generator is conceived by adopting the technique of decimating a pseudo-random binary sequence (PRBS) signal in parallel sequences. This is of great benefit when high-speed generation of PRBS and PRBS-derived signals is the objective. The design implemented standard CMOS logic is available in commercial libraries to provide the logic functions for the generator. The design allows the user to select the periodicity of the PRBS and the PRBS-derived signals. The characterization of the on-chip generator marks its performance and reveals promising specifications

  9. The Ising model on a random planar lattice: The structure of the phase transition and the exact critical exponents

    International Nuclear Information System (INIS)

    Boulatov, D.V.; Kazakov, V.A.

    1987-01-01

    We investigate the critical properties of a recently proposed exactly soluble Ising model on a planar random dynamical lattice representing a regularization of the zero-dimensional string with internal fermions. The sum over all lattices gives rise to a new quantum degree of freedom - fluctuation of the metric. The whole system of critical exponents is found: α = -1, β = 1/2, γ = 2, δ = 5, v . D = 3. To test the universality we have used the planar graphs with the coordination number equal to 4 (Φ 4 theory graphs) as well as with the equal to 3 (Φ 3 theory graphs or triangulations). The critical exponents coincide for both cases. (orig.)

  10. Randomized Phase II Trial of High-Dose Melatonin and Radiation Therapy for RPA Class 2 Patients With Brain Metastases (RTOG 0119)

    International Nuclear Information System (INIS)

    Berk, Lawrence; Berkey, Brian; Rich, Tyvin; Hrushesky, William; Blask, David; Gallagher, Michael; Kudrimoti, Mahesh; McGarry, Ronald C.; Suh, John; Mehta, Minesh

    2007-01-01

    Purpose: To determine if high-dose melatonin for Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) Class 2 patients with brain metastases improved survival over historical controls, and to determine if the time of day melatonin was given affected its toxicity or efficacy. RTOG 0119 was a phase II randomized trial for this group of patients. Methods and Materials: RTOG RPA Class 2 patients with brain metastases were randomized to 20 mg of melatonin, given either in the morning (8-9 AM) or in the evening (8-9 PM). All patients received radiation therapy (30 Gy in 10 fractions) in the afternoon. Melatonin was continued until neurologic deterioration or death. The primary endpoint was overall survival time. Neurologic deterioration, as reflected by the Mini-Mental Status Examination, was also measured. Results: Neither of the randomized groups had survival distributions that differed significantly from the historic controls of patients treated with whole-brain radiotherapy. The median survivals of the morning and evening melatonin treatments were 3.4 and 2.8 months, while the RTOG historical control survival was 4.1 months. Conclusions: High-dose melatonin did not show any beneficial effect in this group of patients

  11. Phase Vocoder

    Directory of Open Access Journals (Sweden)

    J.L. Flanagan

    2013-08-01

    Full Text Available A vocoder technique is described in which speech signals are represented by their short-time phase and amplitude spectra. A complete transmission system utilizing this approach is simulated on a digital computer. The encoding method leads to an economy in transmission bandwidth and to a means for time compression and expansion of speech signals.

  12. 5-Fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus sunitinib or bevacizumab as first-line treatment for metastatic colorectal cancer: a randomized Phase IIb study

    Science.gov (United States)

    Hecht, J Randolph; Mitchell, Edith P; Yoshino, Takayuki; Welslau, Manfred; Lin, Xun; Chow Maneval, Edna; Paolini, Jolanda; Lechuga, Maria Jose; Kretzschmar, Albrecht

    2015-01-01

    Background Sunitinib is an oral inhibitor of tyrosine kinase receptors implicated in tumor proliferation, angiogenesis, and metastasis. In this randomized, multicenter, open-label Phase IIb study, sunitinib plus mFOLFOX6 (oxaliplatin plus leucovorin plus 5-fluorouracil) was compared with bevacizumab plus mFOLFOX6 as first-line therapy in patients with metastatic colorectal cancer. Methods Patients were stratified by performance status, baseline lactate dehydrogenase level, and prior adjuvant treatment, and randomized 1:1 to receive sunitinib 37.5 mg/day for 4 weeks on and 2 weeks off plus mFOLFOX6 every 2 weeks or bevacizumab 5 mg/kg every 2 weeks plus mFOLFOX6 every 2 weeks. The primary endpoint was progression-free survival. Secondary endpoints included objective response rate, overall survival, safety, and quality of life. Results Enrollment was closed early following accrual of 191 patients, based on an interim analysis showing an inferior trend in the primary progression-free survival efficacy endpoint for sunitinib. Ninety-six patients were randomized to sunitinib plus mFOLFOX6 and 95 to bevacizumab plus mFOLFOX6. Median progression-free survival was 9.3 months and 15.4 months, respectively, but the objective response rate was similar between the study arms. Median overall survival was 23.7 months and 34.1 months, respectively. Dose reductions and interruptions were more common with sunitinib. Hematologic toxicity was more common in the sunitinib arm. Conclusion While the results of the sunitinib arm are comparable with those of previously reported FOLFOX combinations, the sunitinib-based combination was associated with more toxicity than that observed with bevacizumab and mFOLFOX6. The bevacizumab arm had an unexpectedly good outcome, and was much better than that seen in the Phase III trials. Combination therapy with sunitinib plus mFOLFOX6 is not recommended for patients with metastatic colorectal cancer. PMID:26109878

  13. 5-Fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus sunitinib or bevacizumab as first-line treatment for metastatic colorectal cancer: a randomized Phase IIb study

    International Nuclear Information System (INIS)

    Hecht, J Randolph; Mitchell, Edith P; Yoshino, Takayuki; Welslau, Manfred; Lin, Xun; Chow Maneval, Edna; Paolini, Jolanda; Lechuga, Maria Jose; Kretzschmar, Albrecht

    2015-01-01

    Sunitinib is an oral inhibitor of tyrosine kinase receptors implicated in tumor proliferation, angiogenesis, and metastasis. In this randomized, multicenter, open-label Phase IIb study, sunitinib plus mFOLFOX6 (oxaliplatin plus leucovorin plus 5-fluorouracil) was compared with bevacizumab plus mFOLFOX6 as first-line therapy in patients with metastatic colorectal cancer. Patients were stratified by performance status, baseline lactate dehydrogenase level, and prior adjuvant treatment, and randomized 1:1 to receive sunitinib 37.5 mg/day for 4 weeks on and 2 weeks off plus mFOLFOX6 every 2 weeks or bevacizumab 5 mg/kg every 2 weeks plus mFOLFOX6 every 2 weeks. The primary endpoint was progression-free survival. Secondary endpoints included objective response rate, overall survival, safety, and quality of life. Enrollment was closed early following accrual of 191 patients, based on an interim analysis showing an inferior trend in the primary progression-free survival efficacy endpoint for sunitinib. Ninety-six patients were randomized to sunitinib plus mFOLFOX6 and 95 to bevacizumab plus mFOLFOX6. Median progression-free survival was 9.3 months and 15.4 months, respectively, but the objective response rate was similar between the study arms. Median overall survival was 23.7 months and 34.1 months, respectively. Dose reductions and interruptions were more common with sunitinib. Hematologic toxicity was more common in the sunitinib arm. While the results of the sunitinib arm are comparable with those of previously reported FOLFOX combinations, the sunitinib-based combination was associated with more toxicity than that observed with bevacizumab and mFOLFOX6. The bevacizumab arm had an unexpectedly good outcome, and was much better than that seen in the Phase III trials. Combination therapy with sunitinib plus mFOLFOX6 is not recommended for patients with metastatic colorectal cancer

  14. Encoded low swing for ultra low power interconnect

    NARCIS (Netherlands)

    Krishnan, R.; Pineda de Gyvez, J.

    2003-01-01

    We present a novel encoded-low swing technique for ultra low power interconnect. Using this technique and an efficient circuit implementation, we achieve an average of 45.7% improvement in the power-delay product over the schemes utilizing low swing techniques alone, for random bit streams. Also, we

  15. A double-blind, randomized, multicenter phase 2 study of prasugrel versus placebo in adult patients with sickle cell disease

    Directory of Open Access Journals (Sweden)

    Wun Ted

    2013-02-01

    Full Text Available Abstract Background Platelet activation has been implicated in the pathogenesis of sickle cell disease (SCD suggesting antiplatelet agents may be therapeutic. To evaluate the safety of prasugrel, a thienopyridine antiplatelet agent, in adult patients with SCD, we conducted a double-blind, randomized, placebo-controlled study. Methods The primary endpoint, safety, was measured by hemorrhagic events requiring medical intervention. Patients were randomized to prasugrel 5 mg daily (n = 41 or placebo (n = 21 for 30 days. Platelet function by VerifyNow® P2Y12 and vasodilator-stimulated phosphoprotein assays at days 10 and 30 were significantly inhibited in prasugrel- compared with placebo-treated SCD patients. Results There were no hemorrhagic events requiring medical intervention in either study arm. Mean pain rate (percentage of days with pain and intensity in the prasugrel arm were decreased compared with placebo. However, these decreases did not reach statistical significance. Platelet surface P-selectin and plasma soluble P-selectin, biomarkers of in vivo platelet activation, were significantly reduced in SCD patients receiving prasugrel compared with placebo. In sum, prasugrel was well tolerated and not associated with serious hemorrhagic events. Conclusions Despite the small size and short duration of this study, there was a decrease in platelet activation biomarkers and a trend toward decreased pain.

  16. Analysing and Comparing Encodability Criteria

    Directory of Open Access Journals (Sweden)

    Kirstin Peters

    2015-08-01

    Full Text Available Encodings or the proof of their absence are the main way to compare process calculi. To analyse the quality of encodings and to rule out trivial or meaningless encodings, they are augmented with quality criteria. There exists a bunch of different criteria and different variants of criteria in order to reason in different settings. This leads to incomparable results. Moreover it is not always clear whether the criteria used to obtain a result in a particular setting do indeed fit to this setting. We show how to formally reason about and compare encodability criteria by mapping them on requirements on a relation between source and target terms that is induced by the encoding function. In particular we analyse the common criteria full abstraction, operational correspondence, divergence reflection, success sensitiveness, and respect of barbs; e.g. we analyse the exact nature of the simulation relation (coupled simulation versus bisimulation that is induced by different variants of operational correspondence. This way we reduce the problem of analysing or comparing encodability criteria to the better understood problem of comparing relations on processes.

  17. Accelerated radial Fourier-velocity encoding using compressed sensing

    International Nuclear Information System (INIS)

    Hilbert, Fabian; Han, Dietbert

    2014-01-01

    Purpose:Phase Contrast Magnetic Resonance Imaging (MRI) is a tool for non-invasive determination of flow velocities inside blood vessels. Because Phase Contrast MRI only measures a single mean velocity per voxel, it is only applicable to vessels significantly larger than the voxel size. In contrast, Fourier Velocity Encoding measures the entire velocity distribution inside a voxel, but requires a much longer acquisition time. For accurate diagnosis of stenosis in vessels on the scale of spatial resolution, it is important to know the velocity distribution of a voxel. Our aim was to determine velocity distributions with accelerated Fourier Velocity Encoding in an acquisition time required for a conventional Phase Contrast image. Materials and Methods:We imaged the femoral artery of healthy volunteers with ECG - triggered, radial CINE acquisition. Data acquisition was accelerated by undersampling, while missing data were reconstructed by Compressed Sensing. Velocity spectra of the vessel were evaluated by high resolution Phase Contrast images and compared to spectra from fully sampled and undersampled Fourier Velocity Encoding. By means of undersampling, it was possible to reduce the scan time for Fourier Velocity Encoding to the duration required for a conventional Phase Contrast image. Results:Acquisition time for a fully sampled data set with 12 different Velocity Encodings was 40 min. By applying a 12.6 - fold retrospective undersampling, a data set was generated equal to 3:10 min acquisition time, which is similar to a conventional Phase Contrast measurement. Velocity spectra from fully sampled and undersampled Fourier Velocity Encoded images are in good agreement and show the same maximum velocities as compared to velocity maps from Phase Contrast measurements. Conclusion: Compressed Sensing proved to reliably reconstruct Fourier Velocity Encoded data. Our results indicate that Fourier Velocity Encoding allows an accurate determination of the velocity

  18. Accelerated radial Fourier-velocity encoding using compressed sensing

    Energy Technology Data Exchange (ETDEWEB)

    Hilbert, Fabian; Han, Dietbert [Wuerzburg Univ. (Germany). Inst. of Radiology; Wech, Tobias; Koestler, Herbert [Wuerzburg Univ. (Germany). Inst. of Radiology; Wuerzburg Univ. (Germany). Comprehensive Heart Failure Center (CHFC)

    2014-10-01

    Purpose:Phase Contrast Magnetic Resonance Imaging (MRI) is a tool for non-invasive determination of flow velocities inside blood vessels. Because Phase Contrast MRI only measures a single mean velocity per voxel, it is only applicable to vessels significantly larger than the voxel size. In contrast, Fourier Velocity Encoding measures the entire velocity distribution inside a voxel, but requires a much longer acquisition time. For accurate diagnosis of stenosis in vessels on the scale of spatial resolution, it is important to know the velocity distribution of a voxel. Our aim was to determine velocity distributions with accelerated Fourier Velocity Encoding in an acquisition time required for a conventional Phase Contrast image. Materials and Methods:We imaged the femoral artery of healthy volunteers with ECG - triggered, radial CINE acquisition. Data acquisition was accelerated by undersampling, while missing data were reconstructed by Compressed Sensing. Velocity spectra of the vessel were evaluated by high resolution Phase Contrast images and compared to spectra from fully sampled and undersampled Fourier Velocity Encoding. By means of undersampling, it was possible to reduce the scan time for Fourier Velocity Encoding to the duration required for a conventional Phase Contrast image. Results:Acquisition time for a fully sampled data set with 12 different Velocity Encodings was 40 min. By applying a 12.6 - fold retrospective undersampling, a data set was generated equal to 3:10 min acquisition time, which is similar to a conventional Phase Contrast measurement. Velocity spectra from fully sampled and undersampled Fourier Velocity Encoded images are in good agreement and show the same maximum velocities as compared to velocity maps from Phase Contrast measurements. Conclusion: Compressed Sensing proved to reliably reconstruct Fourier Velocity Encoded data. Our results indicate that Fourier Velocity Encoding allows an accurate determination of the velocity

  19. Accelerated radial Fourier-velocity encoding using compressed sensing.

    Science.gov (United States)

    Hilbert, Fabian; Wech, Tobias; Hahn, Dietbert; Köstler, Herbert

    2014-09-01

    Phase Contrast Magnetic Resonance Imaging (MRI) is a tool for non-invasive determination of flow velocities inside blood vessels. Because Phase Contrast MRI only measures a single mean velocity per voxel, it is only applicable to vessels significantly larger than the voxel size. In contrast, Fourier Velocity Encoding measures the entire velocity distribution inside a voxel, but requires a much longer acquisition time. For accurate diagnosis of stenosis in vessels on the scale of spatial resolution, it is important to know the velocity distribution of a voxel. Our aim was to determine velocity distributions with accelerated Fourier Velocity Encoding in an acquisition time required for a conventional Phase Contrast image. We imaged the femoral artery of healthy volunteers with ECG-triggered, radial CINE acquisition. Data acquisition was accelerated by undersampling, while missing data were reconstructed by Compressed Sensing. Velocity spectra of the vessel were evaluated by high resolution Phase Contrast images and compared to spectra from fully sampled and undersampled Fourier Velocity Encoding. By means of undersampling, it was possible to reduce the scan time for Fourier Velocity Encoding to the duration required for a conventional Phase Contrast image. Acquisition time for a fully sampled data set with 12 different Velocity Encodings was 40 min. By applying a 12.6-fold retrospective undersampling, a data set was generated equal to 3:10 min acquisition time, which is similar to a conventional Phase Contrast measurement. Velocity spectra from fully sampled and undersampled Fourier Velocity Encoded images are in good agreement and show the same maximum velocities as compared to velocity maps from Phase Contrast measurements. Compressed Sensing proved to reliably reconstruct Fourier Velocity Encoded data. Our results indicate that Fourier Velocity Encoding allows an accurate determination of the velocity distribution in vessels in the order of the voxel size. Thus

  20. Effect of Ixekizumab Treatment on Work Productivity for Patients With Moderate-to-Severe Plaque Psoriasis: Analysis of Results From 3 Randomized Phase 3 Clinical Trials.

    Science.gov (United States)

    Armstrong, April W; Lynde, Charles W; McBride, Sandy R; Ståhle, Mona; Edson-Heredia, Emily; Zhu, Baojin; Amato, David; Nikaï, Enkeleida; Yang, Fan Emily; Gordon, Kenneth B

    2016-06-01

    Therapies that reduce psoriasis symptoms may improve work productivity. To assess the effect of ixekizumab therapy on work productivity, measured by the Work Productivity and Activity Impairment-Psoriasis (WPAI-PSO). Three multicenter, randomized double-blind phase 3 trials conducted during the following periods: December 2011 through August 2014 (UNCOVER-1), May 2012 through April 2015 (UNCOVER-2), and August 2012 through July 2014 (UNCOVER-3). Adult outpatients with moderate-to-severe chronic plaque psoriasis were included. In UNCOVER-1, patients were randomized 1:1:1 to subcutaneous placebo or 80 mg ixekizumab every 2 weeks (Q2W) or every 4 weeks (Q4W) for 12 weeks; UNCOVER-2 and UNCOVER-3 also had an etanercept arm (50 mg twice weekly). Maintenance of initial ixekizumab response was evaluated in UNCOVER-1 and UNCOVER-2 during a randomized withdrawal period following week 12 through week 60. The WPAI-PSO questionnaire was administered at baseline and week 12 for all patients and at weeks 24, 36, 52, and 60 for patients in UNCOVER-1 and UNCOVER-2. Change in work productivity from baseline as measured by WPAI-PSO scores. Across trials, 5101 patients consented; 3866 were randomized (mean [SD] age, UNCOVER-1, 45.7 [12.9] y, 68.1% male; UNCOVER-2: 45.0 [13.0] y, 67.1% male; UNCOVER-3: 45.8 [13.1] y, 68.2% male). At week 12 in UNCOVER-1, the ixekizumab Q4W and ixekizumab Q2W groups showed significantly greater improvements in WPAI-PSO scores (least squares mean change from baseline [SE]) relative to placebo: absenteeism (-3.5 [0.87], P productivity loss (-20.6 [1.38], P productivity loss, activity impairment (P productivity, which could lead to reduced productivity-related cost burden in patients with psoriasis. clinicaltrials.gov Identifiers: NCT01474512, NCT01597245, NCT01646177.

  1. Neoadjuvant chemoradiation therapy with gemcitabine/cisplatin and surgery versus immediate surgery in resectable pancreatic cancer. Results of the first prospective randomized phase II trial

    International Nuclear Information System (INIS)

    Golcher, Henriette; Merkel, Susanne; Hohenberger, Werner; Brunner, Thomas B.; Witzigmann, Helmut; Marti, Lukas; Bechstein, Wolf-Otto; Bruns, Christiane; Jungnickel, Henry; Schreiber, Stefan; Grabenbauer, Gerhard G.; Meyer, Thomas; Fietkau, Rainer

    2015-01-01

    In nonrandomized trials, neoadjuvant treatment was reported to prolong survival in patients with pancreatic cancer. As neoadjuvant chemoradiation is established for the treatment of rectal cancer we examined the value of neoadjuvant chemoradiotherapy in pancreatic cancer in a randomized phase II trial. Radiological staging defining resectability was basic information prior to randomization in contrast to adjuvant therapy trials resting on pathological staging. Patients with resectable adenocarcinoma of the pancreatic head were randomized to primary surgery (Arm A) or neoadjuvant chemoradiotherapy followed by surgery (Arm B), which was followed by adjuvant chemotherapy in both arms. A total of 254 patients were required to detect a 4.33-month improvement in median overall survival (mOS). The trial was stopped after 73 patients; 66 patients were eligible for analysis. Twenty nine of 33 allocated patients received chemoradiotherapy. Radiotherapy was completed in all patients. Chemotherapy was changed in 3 patients due to toxicity. Tumor resection was performed in 23 vs. 19 patients (A vs. B). The R0 resection rate was 48 % (A) and 52 % (B, P = 0.81) and (y)pN0 was 30 % (A) vs. 39 % (B, P = 0.44), respectively. Postoperative complications were comparable in both groups. mOS was 14.4 vs. 17.4 months (A vs. B; intention-to-treat analysis; P = 0.96). After tumor resection, mOS was 18.9 vs. 25.0 months (A vs. B; P = 0.79). This worldwide first randomized trial for neoadjuvant chemoradiotherapy in pancreatic cancer showed that neoadjuvant chemoradiation is safe with respect to toxicity, perioperative morbidity, and mortality. Nevertheless, the trial was terminated early due to slow recruiting and the results were not significant. ISRCTN78805636; NCT00335543. (orig.) [de

  2. Adjunctive Taurine in First-Episode Psychosis: A Phase 2, Double-Blind, Randomized, Placebo-Controlled Study.

    Science.gov (United States)

    O'Donnell, Colin P; Allott, Kelly A; Murphy, Brendan P; Yuen, Hok Pan; Proffitt, Tina-Marie; Papas, Alicia; Moral, Jennifer; Pham, Tee; O'Regan, Michaela K; Phassouliotis, Christina; Simpson, Raelene; McGorry, Patrick D

    2016-12-01

    Taurine is an inhibitory neuromodulatory amino acid in the central nervous system that activates the GABA- and glycine-insensitive chloride channel and inhibits the N-methyl-D-aspartate receptor. It also functions as a neuroprotective agent and has a role in neural development and neurogenesis. The aim of this study was to determine the efficacy of adjunctive taurine in improving symptomatology and cognition among patients with a DSM-IV first-episode psychotic disorder. 121 patients with first-episode psychosis, aged 18-25 years, attending early intervention services consented to participate in this randomized, double-blind, placebo-controlled trial conducted from January 2007 to May 2009. Patients taking low-dose antipsychotic medication were randomly assigned to receive once-daily taurine 4 g or placebo for 12 weeks. The coprimary outcomes were change in symptomatology (measured by the Brief Psychiatric Rating Scale [BPRS] total score) and change in cognition (measured by the Measurement and Treatment Research to Improve Cognition in Schizophrenia [MATRICS] Consensus Cognitive Battery composite score) at 12 weeks. Secondary outcomes included tolerability and safety and additional clinical and functioning measures. 86 participants (n = 47 taurine; n = 39 placebo) were included in the final analysis. Taurine significantly improved symptomatology measured by the BPRS total score (95% CI, 1.8-8.5; P = .004) and psychotic subscale (95% CI, 0.1-1.5; P = .026) compared to placebo. Additionally, improvements were observed in the Calgary Depression Scale for Schizophrenia (95% CI, 0.1-3.0; P = .047) and Global Assessment of Functioning (95% CI, 0.3-8.8; P = .04) scores. There was no group difference in composite cognitive score (95% CI, -1.7 to 1.0; P = .582). A significant group difference was found on one safety and tolerability item (psychic item 2, asthenia/lassitude/increased fatigability) of the Udvalg for Kliniske Undersogelser, with the taurine group showing a

  3. Advanced ovarian cancer: phase III randomized study of sequential cisplatin-topotecan and carboplatin-paclitaxel vs carboplatin-paclitaxel.

    Science.gov (United States)

    Hoskins, P; Vergote, I; Cervantes, A; Tu, D; Stuart, G; Zola, P; Poveda, A; Provencher, D; Katsaros, D; Ojeda, B; Ghatage, P; Grimshaw, R; Casado, A; Elit, L; Mendiola, C; Sugimoto, A; D'Hondt, V; Oza, A; Germa, J R; Roy, M; Brotto, L; Chen, D; Eisenhauer, E A

    2010-10-20

    Topotecan has single-agent activity in recurrent ovarian cancer. It was evaluated in a novel combination compared with standard frontline therapy. Women aged 75 years or younger with newly diagnosed stage IIB or greater ovarian cancer, Eastern Cooperative Oncology Group Performance Status of 1 or less, were stratified by type of primary surgery and residual disease, treatment center, and age; then randomly assigned to one of the two 21-day intravenous regimens. Patients in arm 1 (n = 409) were administered four cycles of cisplatin 50 mg/m(2) on day 1 and topotecan 0.75 mg/m(2) on days 1-5, then four cycles of paclitaxel 175 mg/m(2) over 3 hours on day 1 followed by carboplatin (area under the curve = 5) on day 1. Patients in arm 2 (n = 410) were given paclitaxel plus carboplatin as in arm 1 for eight cycles. We compared progression-free survival (PFS), overall survival, and cancer antigen-125 normalization rates in the two treatment arms. A stratified log-rank test was used to assess the primary endpoint, PFS. All statistical tests were two-sided. A total of 819 patients were randomly assigned. At baseline, the median age of the patients was 57 years (range = 28-78); 81% had received debulking surgery, and of these, 55% had less than 1 cm residual disease; 66% of patients were stage III and 388 (47.4%) patients had measurable disease. After a median follow-up of 43 months, 650 patients had disease progression or died without documented progression and 406 had died. Patients in arm 1 had more hematological toxicity and hospitalizations than patients in arm 2; PFS was 14.6 months in arm 1 vs 16.2 months in arm 2 (hazard ratio = 1.10, 95% confidence interval = 0.94 to 1.28, P = .25). Among patients with elevated baseline cancer antigen-125, fewer in arm 1 than in arm 2 had levels return to normal by 3 months after random assignment (51.6% vs 63.3%, P = .007) Topotecan and cisplatin, followed by carboplatin and paclitaxel, were more toxic than carboplatin and

  4. Effect of homeopathy on analgesic intake following knee ligament reconstruction: a phase III monocentre randomized placebo controlled study

    Science.gov (United States)

    Paris, A; Gonnet, N; Chaussard, C; Belon, P; Rocourt, F; Saragaglia, D; Cracowski, J L

    2008-01-01

    Aims The efficacy of homeopathy is still under debate. The objective of this study was to assess the efficacy of homeopathic treatment (Arnica montana 5 CH, Bryonia alba 5 CH, Hypericum perforatum 5 CH and Ruta graveolens 3 DH) on cumulated morphine intake delivered by PCA over 24 h after knee ligament reconstruction. Methods This was an add-on randomized controlled study with three parallel groups: a double-blind homeopathic or placebo arm and an open-label noninterventional control arm. Eligible patients were 18–60 years old candidates for surgery of the anterior cruciate ligament. Treatment was administered the evening before surgery and continued for 3 days. The primary end-point was cumulated morphine intake delivered by PCA during the first 24 h inferior or superior/equal to 10 mg day−1. Results One hundred and fifty-eight patients were randomized (66 in the placebo arm, 67 in the homeopathic arm and 25 in the noninterventional group). There was no difference between the treated and the placebo group for primary end-point (mean (95% CI) 48% (35.8, 56.3), and 56% (43.7, 68.3), required less than 10 mg day−1 of morphine in each group, respectively). The homeopathy treatment had no effect on morphine intake between 24 and 72 h or on the visual analogue pain scale, or on quality of life assessed by the SF-36 questionnaire. In addition, these parameters were not different in patients enrolled in the open-label noninterventional control arm. Conclusions The complex of homeopathy tested in this study was not superior to placebo in reducing 24 h morphine consumption after knee ligament reconstruction. What is already known about this subject The efficacy of homeopathy is still under debate and a recent meta-analysis recommended further randomized double-blind clinical trials to identify any clinical situation in which homeopathy might be effective. What this study adds The complex of homeopathy tested in this study (Arnica montana 5 CH, Bryonia alba 5 CH

  5. Aerobic Exercise During Encoding Impairs Hippocampus-Dependent Memory.

    Science.gov (United States)

    Soga, Keishi; Kamijo, Keita; Masaki, Hiroaki

    2017-08-01

    We investigated how aerobic exercise during encoding affects hippocampus-dependent memory through a source memory task that assessed hippocampus-independent familiarity and hippocampus-dependent recollection processes. Using a within-participants design, young adult participants performed a memory-encoding task while performing a cycling exercise or being seated. The subsequent retrieval phase was conducted while sitting on a chair. We assessed behavioral and event-related brain potential measures of familiarity and recollection processes during the retrieval phase. Results indicated that source accuracy was lower for encoding with exercise than for encoding in the resting condition. Event-related brain potential measures indicated that the parietal old/new effect, which has been linked to recollection processing, was observed in the exercise condition, whereas it was absent in the rest condition, which is indicative of exercise-induced hippocampal activation. These findings suggest that aerobic exercise during encoding impairs hippocampus-dependent memory, which may be attributed to inefficient source encoding during aerobic exercise.

  6. A phase 2b randomized, controlled trial of the efficacy of the GMZ2 malaria vaccine in African children

    DEFF Research Database (Denmark)

    Sirima, Sodiomon B; Mordmüller, Benjamin; Milligan, Paul

    2016-01-01

    randomized to receive three injections of either 100μg GMZ2 adjuvanted with aluminum hydroxide or a control vaccine (rabies) four weeks apart and were followed up for six months to measure the incidence of malaria defined as fever or history of fever and a parasite density ⩾5000/μL. RESULTS: A cohort of 1849...... in the rabies vaccine group and 14 in the GMZ2 group), VE 27% (95% CI -44%, 63%). CONCLUSIONS: GMZ2 is the first blood-stage malaria vaccine to be evaluated in a large multicenter trial. GMZ2 was well tolerated and immunogenic, and reduced the incidence of malaria, but efficacy would need to be substantially...

  7. Carboplatin versus alternating carboplatin and doxorubicin for the adjuvant treatment of canine appendicular osteosarcoma: a randomized, phase III trial†

    Science.gov (United States)

    Skorupski, K. A.; Uhl, J. M.; Szivek, A; Allstadt Frazier, S. D.; Rebhun, R. B.; Rodriguez, C. O.

    2016-01-01

    Despite numerous published studies describing adjuvant chemotherapy for canine appendicular osteosarcoma, there is no consensus as to the optimal chemotherapy protocol. The purpose of this study was to determine whether either of two protocols would be associated with longer disease-free interval (DFI) in dogs with appendicular osteosarcoma following amputation. Dogs with histologically confirmed appendicular osteosarcoma that were free of gross metastases and underwent amputation were eligible for enrollment. Dogs were randomized to receive either six doses of carboplatin or three doses each of carboplatin and doxorubicin on an alternating schedule. Fifty dogs were included. Dogs receiving carboplatin alone had a significantly longer DFI (425 versus 135 days) than dogs receiving alternating carboplatin and doxorubicin (P = 0.04). Toxicity was similar between groups. These results suggest that six doses of carboplatin may be associated superior DFI when compared to six total doses of carboplatin and doxorubicin. PMID:24118677

  8. Carboplatin versus alternating carboplatin and doxorubicin for the adjuvant treatment of canine appendicular osteosarcoma: a randomized, phase III trial.

    Science.gov (United States)

    Skorupski, K A; Uhl, J M; Szivek, A; Allstadt Frazier, S D; Rebhun, R B; Rodriguez, C O

    2016-03-01

    Despite numerous published studies describing adjuvant chemotherapy for canine appendicular osteosarcoma, there is no consensus as to the optimal chemotherapy protocol. The purpose of this study was to determine whether either of two protocols would be associated with longer disease-free interval (DFI) in dogs with appendicular osteosarcoma following amputation. Dogs with histologically confirmed appendicular osteosarcoma that were free of gross metastases and underwent amputation were eligible for enrollment. Dogs were randomized to receive either six doses of carboplatin or three doses each of carboplatin and doxorubicin on an alternating schedule. Fifty dogs were included. Dogs receiving carboplatin alone had a significantly longer DFI (425 versus 135 days) than dogs receiving alternating carboplatin and doxorubicin (P = 0.04). Toxicity was similar between groups. These results suggest that six doses of carboplatin may be associated superior DFI when compared to six total doses of carboplatin and doxorubicin. © 2013 John Wiley & Sons Ltd.

  9. Hepatic and vascular enhancement at dual-phase helical CT: comparison of Iobitridol 300 and Iohexol 300 in a prospective randomized study

    International Nuclear Information System (INIS)

    Legmann, P.; Vignaux, O.; Bahurel, H.; Oudjit, A.; Coste, J.

    2001-01-01

    The purpose of this study was to determine hepatic and vascular enhancement, clinical tolerance, and iconographic quality of Iobitridol (300 mg/ml) at dual-phase helical CT and to compare it with Iohexol (300 mg/ml). One hundred forty-six patients were randomly divided into two groups. Each group received 120 ml of Iohexol (group A) or Iobitridol (group B). Mean enhancement of liver, aorta and portal vein was obtained at the arterial phase and at the portal-venous phase. Overall image quality was assessed by two independent blinded investigators. Adverse reactions were recorded. There were no significant differences in demographic characteristics and distribution of patient intrinsic parameters between the two groups, except for blood pressure but without statistical correlation between the difference in blood pressure and the impact on enhancement measurements. There was no significant difference in clinical tolerance and image quality. Mean liver as well as aortic and portal vein enhancement measurements did not show any significant difference. Iobitridol compares favorably with Iohexol. Both products have similar safety, tolerance, and efficacy. Both contrast media have equivalent blood pool concentration and interstitial compartment diffusion. (orig.)

  10. Hepatic and vascular enhancement at dual-phase helical CT: comparison of Iobitridol 300 and Iohexol 300 in a prospective randomized study

    Energy Technology Data Exchange (ETDEWEB)

    Legmann, P.; Vignaux, O.; Bahurel, H.; Oudjit, A. [Dept. of Radiology, Universite Rene Descartes, Paris (France); Coste, J. [Dept. of Biostatistics and Epidemiology, Universite Rene Descartes, Paris (France)

    2001-11-01

    The purpose of this study was to determine hepatic and vascular enhancement, clinical tolerance, and iconographic quality of Iobitridol (300 mg/ml) at dual-phase helical CT and to compare it with Iohexol (300 mg/ml). One hundred forty-six patients were randomly divided into two groups. Each group received 120 ml of Iohexol (group A) or Iobitridol (group B). Mean enhancement of liver, aorta and portal vein was obtained at the arterial phase and at the portal-venous phase. Overall image quality was assessed by two independent blinded investigators. Adverse reactions were recorded. There were no significant differences in demographic characteristics and distribution of patient intrinsic parameters between the two groups, except for blood pressure but without statistical correlation between the difference in blood pressure and the impact on enhancement measurements. There was no significant difference in clinical tolerance and image quality. Mean liver as well as aortic and portal vein enhancement measurements did not show any significant difference. Iobitridol compares favorably with Iohexol. Both products have similar safety, tolerance, and efficacy. Both contrast media have equivalent blood pool concentration and interstitial compartment diffusion. (orig.)

  11. Randomized phase III trial of postoperative radiochemotherapy ± amifostine in head and neck cancer. Is there evidence for radioprotection?

    International Nuclear Information System (INIS)

    Vacha, P.; Fehlauer, F.; Mahlmann, B.; Marx, M.; Richter, E.; Hinke, A.; Sommer, K.; Feyerabend, T.

    2003-01-01

    Purpose: Experimental and clincial data suggest a reduction of radiation-induced acute toxicity by amifostine (A). We investigated this issue in a randomized trial comparing radiochemotherapy (RT + CT) versus radiochemotherapy plus amifostine (RC + CT + A) in patients with head and neck cancer. Patients and Methods: 56 patients with oro-/hypopharynx or larynx cancer (T1-2 N1-2 G3, T3-4 N0-2 G1-3) were randomized to received RC + CT alone or RC + CT + A. Patients were irradiated up to 60 Gy (R0) or 70 Gy (R1/2) and received chemotherapy (70 mg/m 2 carboplatin, day 1-5 week 1 and 5 of radiotherapy). 250 mg amifostine were applied daily before each radiotherapy session. Acute toxicity was evaluated according to the common toxicity criteria (CTC). As for acute xerostomia, patients with laryngeal cancer were excluded from evaluation. Results: 50 patients were evaluable (25 patients in the RC + CT, 25 patients in the RC + CT + A group). Clinical characteristics were well balanced in both treatment groups. Amifostine provided reduction in acute xerostomia and mucositis but had no obvious influence on Karnofsky performance status, body weight, cutaneous side effects, and alopecia. The differences between both groups were statistically significant for acute xerostomia and nonsignificant, but with a trend for mucositis. Conclusions: According to our results, there is a radioprotective effect on salivary glands and a potential effect on oral mucosa by amifostine in postoperative radiotherapy combined with carboplatin. To improve the radio- and chemoprotective effects of amifostine in clinical practice, the application of a higher dose (> 250 mg) seems to be necessary. (orig.)

  12. Randomized phase III trial of postoperative radiochemotherapy {+-} amifostine in head and neck cancer. Is there evidence for radioprotection?

    Energy Technology Data Exchange (ETDEWEB)

    Vacha, P; Fehlauer, F; Mahlmann, B; Marx, M; Richter, E [Dept. of Radiation Oncology and Nuclear Medicine, Univ. of Luebeck (Germany); Hinke, A [WiSP Research Inst., Langenfeld (Germany); Sommer, K [Dept. of Head and Neck Surgery, Univ. of Luebeck (Germany); Feyerabend, T [Practice for Radiation Therapy Bonn-Rhein-Sieg, Bonn (Germany)

    2003-06-01

    Purpose: Experimental and clincial data suggest a reduction of radiation-induced acute toxicity by amifostine (A). We investigated this issue in a randomized trial comparing radiochemotherapy (RT + CT) versus radiochemotherapy plus amifostine (RC + CT + A) in patients with head and neck cancer. Patients and Methods: 56 patients with oro-/hypopharynx or larynx cancer (T1-2 N1-2 G3, T3-4 N0-2 G1-3) were randomized to received RC + CT alone or RC + CT + A. Patients were irradiated up to 60 Gy (R0) or 70 Gy (R1/2) and received chemotherapy (70 mg/m{sup 2} carboplatin, day 1-5 week 1 and 5 of radiotherapy). 250 mg amifostine were applied daily before each radiotherapy session. Acute toxicity was evaluated according to the common toxicity criteria (CTC). As for acute xerostomia, patients with laryngeal cancer were excluded from evaluation. Results: 50 patients were evaluable (25 patients in the RC + CT, 25 patients in the RC + CT + A group). Clinical characteristics were well balanced in both treatment groups. Amifostine provided reduction in acute xerostomia and mucositis but had no obvious influence on Karnofsky performance status, body weight, cutaneous side effects, and alopecia. The differences between both groups were statistically significant for acute xerostomia and nonsignificant, but with a trend for mucositis. Conclusions: According to our results, there is a radioprotective effect on salivary glands and a potential effect on oral mucosa by amifostine in postoperative radiotherapy combined with carboplatin. To improve the radio- and chemoprotective effects of amifostine in clinical practice, the application of a higher dose (> 250 mg) seems to be necessary. (orig.)

  13. Phase II multicenter randomized study of amifostine for prevention of acute radiation rectal toxicity: Topical intrarectal versus subcutaneous application

    International Nuclear Information System (INIS)

    Kouloulias, Vassilis E.; Kouvaris, John R.; Pissakas, George; Mallas, Elias; Antypas, Christos; Kokakis, John D.; Matsopoulos, George; Michopoulos, Spyros; Mystakidou, Kyriaki; Vlahos, Lambros J.

    2005-01-01

    Purpose: To investigate the cytoprotective effect of subcutaneous vs. intrarectal administration of amifostine against acute radiation toxicity. Methods and materials: Patients were randomized to receive amifostine either intrarectally (Group A, n = 27) or a 500-mg flat dose subcutaneously (Group B, n = 26) before irradiation. Therapy was delivered using a four-field technique with three-dimensional conformal planning. In Group A, 1,500 mg of amifostine was administered intrarectally as an aqueous solution in 40 mL of enema. Two different toxicity scales were used: the European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group (RTOG) rectal and urologic toxicity criteria and the Subjective-RectoSigmoid scale based on the endoscopic terminology of the World Organization for Digestive Endoscopy. Objective measurements with rectosigmoidoscopy were performed at baseline and 1-2 days after radiotherapy completion. The area under the curve for the time course of mucositis (RTOG criteria) during irradiation represented the mucositis index. Results: Intrarectal amifostine was feasible and well tolerated without any systemic or local side effects. According to the RTOG toxicity scale, Group A had superior results with a significantly lower incidence of Grades I-II rectal radiation morbidity (11% vs. 42%, p 0.04) but inferior results concerning urinary toxicity (48% vs. 15%, p 0.03). The mean rectal mucositis index and Subjective-RectoSigmoid score were significantly lower in Group A (0.44 vs. 2.45 [p = 0.015] and 3.9 vs. 6.0 [p = 0.01], respectively), and the mean urinary mucositis index was lower in Group B (2.39 vs. 0.34, p < 0.028). Conclusions: Intrarectal administration of amifostine (1,500 mg) seemed to have a cytoprotective efficacy in acute radiation rectal mucositis but was inferior to subcutaneous administration in terms of urinary toxicity. Additional randomized studies are needed for definitive decisions concerning the

  14. Topical Minocycline Foam for the Treatment of Impetigo in Children: Results of a Randomized, Double-Blind, Phase 2 Study.

    Science.gov (United States)

    Chamny, Shlomo; Miron, Dan; Lumelsky, Nadia; Shalev, Hana; Gazal, Elana; Keynan, Rita; Shemer, Avner; Tamarkin, Dov

    2016-10-01

    Currently available treatment options for impetigo are limited by either systemic side effects (for oral therapy) or lack of ease of use (for topical ointment). A novel foam formulation of minocycline for topical use may improve convenience and treatment utilization for pediatric patients with impetigo. To evaluate the safety and efficacy of topically applied minocycline foam (FMX-102 1% and 4%) in the treatment of impetigo and to determine the optimal therapeutic active ingredient concentration. In this randomized, parallel-group, double-blind, comparative clinical trial, 32 subjects aged ≥2 years with a clinical diagnosis of pure impetigo, impetigo contagiosa, or uncomplicated blistering impetigo were randomized to treatment with FMX-102 1% or 4%, twice daily for 7 days. Subjects were followed for up to 7 days post-treatment. Clinical cure, defined as ≥80% cured lesions (fully recovered lesions, visually determined by investigators), was achieved by 57.1% and 50.0% of FMX-102 1% and 4% subjects, respectively, at the end of treatment (visit 3). Clinical success, defined as the absence of lesions, or the drying or improvement of treated lesions (decrease in size of affected area, lesion number, or both), was demonstrated in 81.3% and 78.6% of FMX-102 1% and 4% subjects, respectively, following 3 days of treatment (visit 2), in 92.3% and 100% of the respective subjects at the end of treatment, and in 100% in both groups at follow-up (visit 4). Bacteriologic success rates at the end of treatment, defined as complete pathogen eradication, were 85% and 74% in the FMX-102 1% and 4% groups, respectively. The bacteriologic success rate for MRSA infections was 100% (11/11), with no recurrences. Both FMX-102 1% and 4% were considered well tolerated and safe. Topical minocycline foam may be a safe and effective new treatment option for impetigo in children, including those with MRSA. J Drugs Dermatol. 2016;15(10):1238-1243.

  15. A randomized phase II chemoprevention trial of 13-CIS retinoic acid with or without alpha tocopherol or observation in subjects at high risk for lung cancer.

    Science.gov (United States)

    Kelly, Karen; Kittelson, John; Franklin, Wilbur A; Kennedy, Timothy C; Klein, Catherine E; Keith, Robert L; Dempsey, Edward C; Lewis, Marina; Jackson, Mary K; Hirsch, Fred R; Bunn, Paul A; Miller, York E

    2009-05-01

    No chemoprevention strategies have been proven effective for lung cancer. We evaluated the effect of 13-cis retinoic acid (13-cis RA), with or without alpha tocopherol, as a lung cancer chemoprevention agent in a phase II randomized controlled clinical trial of adult subjects at high risk for lung cancer as defined by the presence of sputum atypia, history of smoking, and airflow obstruction, or a prior surgically cured nonsmall cell lung cancer (disease free, >3 years). Subjects were randomly assigned to receive either 13-cis RA, 13-cis RA plus alpha tocopherol (13-cis RA/alpha toco) or observation for 12 months. Outcome measures are derived from histologic evaluation of bronchial biopsy specimens obtained by bronchoscopy at baseline and follow-up. The primary outcome measure is treatment "failure" defined as histologic progression (any increase in the maximum histologic score) or failure to return for follow-up bronchoscopy. Seventy-five subjects were randomized (27/22/26 to observations/13-cis RA/13-cis RA/alpha toco); 59 completed the trial; 55 had both baseline and follow-up bronchoscopy. The risk of treatment failure was 55.6% (15 of 27) and 50% (24 of 48) in the observation and combined (13 cis RA plus 13 cis RA/alpha toco) treatment arms, respectively (odds ratio adjusted for baseline histology, 0.97; 95% confidence interval, 0.36-2.66; P = 0.95). Among subjects with complete histology data, maximum histology score in the observation arm increased by 0.37 units and by 0.03 units in the treated arms (difference adjusted for baseline, -0.18; 95% confidence interval, -1.16 to 0.81; P = 0.72). Similar (nonsignificant) results were observed for treatment effects on endobronchial proliferation as assessed by Ki-67 immunolabeling. Twelve-month treatment with 13-cis RA produced nonsignificant changes in bronchial histology, consistent with results in other trials. Agents advancing to phase III randomized trials should produce greater histologic changes. The

  16. A Randomized Phase II Chemoprevention Trial of 13-CIS Retinoic Acid with Or without α Tocopherol or Observation in Subjects at High Risk for Lung Cancer

    Science.gov (United States)

    Kelly, Karen; Kittelson, John; Franklin, Wilbur A.; Kennedy, Timothy C.; Klein, Catherine E.; Keith, Robert L.; Dempsey, Edward C.; Lewis, Marina; Jackson, Mary K.; Hirsch, Fred R.; Bunn, Paul A.; Miller, York E.

    2011-01-01

    No chemoprevention strategies have been proven effective for lung cancer. We evaluated the effect of 13-cis retinoic acid (13-cis RA), with or without α tocopherol, as a lung cancer chemoprevention agent in a phase II randomized controlled clinical trial of adult subjects at high risk for lung cancer as defined by the presence of sputum atypia, history of smoking, and airflow obstruction, or a prior surgically cured nonsmall cell lung cancer (disease free, >3 years). Subjects were randomly assigned to receive either 13-cis RA, 13-cis RA plus α tocopherol (13-cis RA/α toco) or observation for 12 months. Outcome measures are derived from histologic evaluation of bronchial biopsy specimens obtained by bronchoscopy at baseline and follow-up. The primary outcome measure is treatment “failure” defined as histologic progression (any increase in the maximum histologic score) or failure to return for follow-up bronchoscopy. Seventy-five subjects were randomized (27/22/26 to obervations/13-cis RA/13-cis RA/α toco); 59 completed the trial; 55 had both baseline and follow-up bronchoscopy. The risk of treatment failure was 55.6% (15 of 27) and 50% (24 of 48) in the observation and combined (13 cis RA plus 13 cis RA/α toco) treatment arms, respectively (odds ratio adjusted for baseline histology, 0.97; 95% confidence interval, 0.36–2.66; P = 0.95). Among subjects with complete histology data, maximum histology score in the observation arm increased by 0.37 units and by 0.03 units in the treated arms (difference adjusted for baseline, −0.18; 95% confidence interval, −1.16 to 0.81; P = 0.72). Similar (nonsignificant) results were observed for treatment effects on endobronchial proliferation as assessed by Ki-67 immunolabeling. Twelve-month treatment with 13-cis RA produced nonsignificant changes in bronchial histology, consistent with results in other trials. Agents advancing to phase III randomized trials should produce greater histologic changes. The addition of

  17. Early-stage squamous cell carcinoma of the oropharynx: Radiotherapy vs. Trans-Oral Robotic Surgery (ORATOR) – study protocol for a randomized phase II trial

    International Nuclear Information System (INIS)

    Nichols, Anthony C; Kuruvilla, Sara; Chen, Jeff; Corsten, Martin; Odell, Michael; Eapen, Libni; Theurer, Julie; Doyle, Philip C; Wehrli, Bret; Kwan, Keith; Palma, David A; Yoo, John; Hammond, J Alex; Fung, Kevin; Winquist, Eric; Read, Nancy; Venkatesan, Varagur; MacNeil, S Danielle; Ernst, D Scott

    2013-01-01

    The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has markedly increased over the last three decades due to newly found associations with human papillomavirus (HPV) infection. Primary radiotherapy (RT) is the treatment of choice for OPSCC at most centers, and over the last decade, the addition of concurrent chemotherapy has led to a significant improvement in survival, but at the cost of increased acute and late toxicity. Transoral robotic surgery (TORS) has emerged as a promising alternative treatment, with preliminary case series demonstrating encouraging oncologic, functional, and quality of life (QOL) outcomes. However, comparisons of TORS and RT in a non-randomized fashion are susceptible to bias. The goal of this randomized phase II study is to compare QOL, functional outcomes, toxicity profiles, and survival following primary RT (± chemotherapy) vs. TORS (± adjuvant [chemo] RT) in patients with OPSCC. The target patient population comprises OPSCC patients who would be unlikely to require chemotherapy post-resection: Tumor stage T1-T2 with likely negative margins at surgery; Nodal stage N0-2, ≤3 cm in size, with no evidence of extranodal extension on imaging. Participants will be randomized in a 1:1 ratio between Arm 1 (RT ± chemotherapy) and Arm 2 (TORS ± adjuvant [chemo] RT). In Arm 1, patients with N0 disease will receive RT alone, whereas N1-2 patients will receive concurrent chemoradiation. In Arm 2, patients will undergo TORS along with selective neck dissections, which may be staged. Pathologic high-risk features will be used to determine the requirement for adjuvant radiotherapy +/- chemotherapy. The primary endpoint is QOL score using the M.D. Anderson Dysphagia Inventory (MDADI), with secondary endpoints including survival, toxicity, other QOL outcomes, and swallowing function. A sample of 68 patients is required. This study, if successful, will provide a much-needed randomized comparison of the conventional strategy of primary RT

  18. Enhancing evidence-based diabetes and chronic disease control among local health departments: a multi-phase dissemination study with a stepped-wedge cluster randomized trial component.

    Science.gov (United States)

    Parks, Renee G; Tabak, Rachel G; Allen, Peg; Baker, Elizabeth A; Stamatakis, Katherine A; Poehler, Allison R; Yan, Yan; Chin, Marshall H; Harris, Jenine K; Dobbins, Maureen; Brownson, Ross C

    2017-10-18

    The rates of diabetes and prediabetes in the USA are growing, significantly impacting the quality and length of life of those diagnosed and financially burdening society. Premature death and disability can be prevented through implementation of evidence-based programs and policies (EBPPs). Local health departments (LHDs) are uniquely positioned to implement diabetes control EBPPs because of their knowledge of, and focus on, community-level needs, contexts, and resources. There is a significant gap, however, between known diabetes control EBPPs and actual diabetes control activities conducted by LHDs. The purpose of this study is to determine how best to support the use of evidence-based public health for diabetes (and related chronic diseases) control among local-level public health practitioners. This paper describes the methods for a two-phase study with a stepped-wedge cluster randomized trial that will evaluate dissemination strategies to increase the uptake of public health knowledge and EBPPs for diabetes control among LHDs. Phase 1 includes development of measures to assess practitioner views on and organizational supports for evidence-based public health, data collection using a national online survey of LHD chronic disease practitioners, and a needs assessment of factors influencing the uptake of diabetes control EBPPs among LHDs within one state in the USA. Phase 2 involves conducting a stepped-wedge cluster randomized trial to assess effectiveness of dissemination strategies with local-level practitioners at LHDs to enhance capacity and organizational support for evidence-based diabetes prevention and control. Twelve LHDs will be selected and randomly assigned to one of the three groups that cross over from usual practice to receive the intervention (dissemination) strategies at 8-month intervals; the intervention duration for groups ranges from 8 to 24 months. Intervention (dissemination) strategies may include multi-day in-person workshops, electronic

  19. Neuropsychiatric safety with liraglutide 3.0 mg for weight management: Results from randomized controlled phase 2 and 3a trials.

    Science.gov (United States)

    O'Neil, Patrick M; Aroda, Vanita R; Astrup, Arne; Kushner, Robert; Lau, David C W; Wadden, Thomas A; Brett, Jason; Cancino, Ana-Paula; Wilding, John P H

    2017-11-01

    Liraglutide, a GLP-1 receptor agonist, regulates appetite via receptors in the brain. Because of concerns regarding the potential of centrally-acting anti-obesity medications to affect mental health, pooled neuropsychiatric safety data from all phase 2 and 3a randomized, double-blind trials with liraglutide 3.0 mg were evaluated post hoc. Data from the liraglutide weight-management programme were pooled. Across trials, individuals with a body mass index ≥30 or ≥27 kg/m 2 with weight-related comorbidities were randomized to once-daily subcutaneous liraglutide 3.0 mg (n = 3384) or placebo (n = 1941), both with a 500 kcal/d deficit diet, plus exercise. Adverse events related to neuropsychiatric safety were collected in all trials. Additionally, in the phase 3a trials, validated mental-health questionnaires were prospectively and systematically administered. In the pooled analysis of 5325 randomized and exposed individuals, rates of depression (2.1 vs 2.1 events/100 person-years) and anxiety (1.9 vs 1.7 events/100 person-years) through adverse event reporting were similarly low in liraglutide and placebo groups. Nine (0.3%) individuals receiving liraglutide and 2 (0.1%) receiving placebo reported adverse events of suicidal ideation or behaviour. In phase 3a trials, mean baseline Patient Health Questionnaire-9 scores of 2.8 ± 3.0 vs 2.9 ± 3.1 for liraglutide vs placebo improved to 1.8 ± 2.7 vs 1.9 ± 2.7, respectively, at treatment end; 34/3291 individuals (1.0%) receiving liraglutide 3.0 mg vs 19/1843 (1.0%) receiving placebo reported suicidal ideation on the Columbia-Suicide Severity Rating Scale. Results of this exploratory pooled analysis provide no cause for concern regarding the neuropsychiatric safety of treatment with liraglutide 3.0 mg in patients similar to those included in the examined trials. Although there was a small numerical imbalance in suicidal ideation with liraglutide through adverse event reporting, no

  20. Quetiapine monotherapy in acute phase for major depressive disorder: a meta-analysis of randomized, placebo-controlled trials

    Directory of Open Access Journals (Sweden)

    Maneeton Narong

    2012-09-01

    Full Text Available Abstract Background Schizophrenia and bipolar depression trials suggest that quetiapine may have an antidepressant effect. Objectives This meta-analysis aimed to determine the efficacy, acceptability and tolerability of quetiapine treatment for major depressive disorder (MDD. Only the randomized controlled trials (RCTs comparison between quetiapine and placebo were included. The authors searched such clinical trials carried out between 1991 and February 2012. Data sources MEDLINE, EMBASE, CINHL, PsycINFO and Cochrane Controlled Trials Register were searched in February 2012. Study populations comprised adults with MDD or major depression. Study eligible criteria, participants and interventions Eligible studies were randomized, placebo-controlled trials of quetiapine monotherapy carried out in adults with MDD and presenting endpoint outcomes relevant to: i depression severity, ii response rate, iii overall discontinuation rate, or iv discontinuation rate due to adverse events. No language restriction was applied. Study appraisal and synthesis methods All abstracts identified by the electronic searches were examined. The full reports of relevant studies were assessed, and the data of interest were extracted. Based on the Cochrane methods of bias assessment, risks of bias were determined. The studies with two risks or less were included. The efficacy outcomes were the mean change scores of depression rating scales, the overall response rate, and the overall remission rates. The overall discontinuation rate was considered as a measure of acceptability. The discontinuation rate due to adverse events was a measure of tolerability. Relative risks (RRs and weighted mean differences (WMDs with 95% confidence intervals (CIs were computed by using a random effect model. Results A total of 1,497 participants in three RCTs were included. All trials examined the quetiapine extended-release (XR. The pooled mean change scores of the Montgomery-Asberg Depression

  1. Anodal tDCS Over the Left DLPFC Did Not Affect the Encoding and Retrieval of Verbal Declarative Information

    Directory of Open Access Journals (Sweden)

    Gabriel A. de Lara

    2017-08-01

    Full Text Available Several studies imply that anodal transcranial direct current stimulation (tDCS over the left dorsolateral prefrontal cortex (DLPFC can modulate the formation of verbal episodic memories. The aim of this study was to test if tDCS through a multi-electrode Laplacian montage over the left DLPFC could differentially modulate declarative memory performance depending on the application phase. Two groups of healthy participants (n = 2 × 15 received 1 mA anodal or sham stimulation for 20 min during the encoding or during the recall phase on a delayed cued-recall, using a randomized, double-blinded, repeated-measures experimental design. Memory performance was assessed at two time points: 10 min and 24 h after learning. We found no significant difference between anodal and sham stimulation with regard to the memory scores between conditions (stimulation during encoding or recall or between time points, suggesting that anodal tDCS over the left DLPFC with these stimulation parameters had no effect on the encoding and the consolidation of associative verbal content.

  2. Response to duloxetine in chronic low back pain: exploratory post hoc analysis of a Japanese Phase III randomized study

    Directory of Open Access Journals (Sweden)

    Tsuji T

    2017-09-01

    Full Text Available Toshinaga Tsuji,1 Naohiro Itoh,1 Mitsuhiro Ishida,2 Toshimitsu Ochiai,3 Shinichi Konno4 1Medical Affairs Department, 2Clinical Research Development, 3Biostatistics Department, Shionogi & Co. Ltd, Osaka, 4Department of Orthopedic Surgery, Fukushima Medical University, Fukushima, Japan Purpose: Duloxetine is efficacious for chronic low back pain (CLBP. This post hoc analysis of a Japanese randomized, placebo-controlled trial (ClinicalTrials.gov, NCT01855919 assessed whether patients with CLBP with early pain reduction or treatment-related adverse events of special interest (TR-AESIs; nausea, somnolence, constipation have enhanced responses to duloxetine. Patients and methods: Patients (N = 456 with CLBP for ≥6 months and Brief Pain Inventory (BPI average pain severity score of ≥4 were randomized (1:1 to duloxetine 60 mg/day or placebo for 14 weeks. Primary outcome was change from baseline in BPI average pain severity score (pain reduction. Subgroup analyses included early pain reduction (≥30%, 10%–30%, or <10% at Week 4 and early TR-AESIs (with or without TR-AESIs by Week 2. Measures included changes from baseline in BPI average pain severity score and BPI Interference scores (quality of life; QOL, and response rate (≥30% or ≥50% pain reduction at Week 14. Results: Patients with ≥30% early pain reduction (n = 108 or early TR-AESIs (n = 50 had significantly greater improvements in pain and QOL than placebo-treated patients (n = 226, whereas patients with 10%–30% (n = 63 or <10% (n = 48 pain reduction did not; patients without early TR-AESIs (n = 180 had significant improvements in pain at Week 14. Response rates (≥30%/≥50% pain reduction were 94.4%/82.4%, 66.7%/49.2%, and 25.0%/18.8% for patients with ≥30%, 10%–30%, and <10% early pain reduction, respectively, 74.0%/64.0% for patients with early TR-AESIs, 67.2%/54.4% for patients without early TR-AESIs, and 52.2%/39.4% for placebo.Conclusion: Early pain reduction or TR

  3. Sirolimus Use in Liver Transplant Recipients With Hepatocellular Carcinoma: A Randomized, Multicenter, Open-Label Phase 3 Trial

    Science.gov (United States)

    Geissler, Edward K.; Schnitzbauer, Andreas A.; Zülke, Carl; Lamby, Philipp E.; Proneth, Andrea; Duvoux, Christophe; Burra, Patrizia; Jauch, Karl-Walter; Rentsch, Markus; Ganten, Tom M.; Schmidt, Jan; Settmacher, Utz; Heise, Michael; Rossi, Giorgio; Cillo, Umberto; Kneteman, Norman; Adam, René; van Hoek, Bart; Bachellier, Philippe; Wolf, Philippe; Rostaing, Lionel; Bechstein, Wolf O.; Rizell, Magnus; Powell, James; Hidalgo, Ernest; Gugenheim, Jean; Wolters, Heiner; Brockmann, Jens; Roy, André; Mutzbauer, Ingrid; Schlitt, Angela; Beckebaum, Susanne; Graeb, Christian; Nadalin, Silvio; Valente, Umberto; Turrión, Victor Sánchez; Jamieson, Neville; Scholz, Tim; Colledan, Michele; Fändrich, Fred; Becker, Thomas; Söderdahl, Gunnar; Chazouillères, Olivier; Mäkisalo, Heikki; Pageaux, Georges-Philippe; Steininger, Rudolf; Soliman, Thomas; de Jong, Koert P.; Pirenne, Jacques; Margreiter, Raimund; Pratschke, Johann; Pinna, Antonio D.; Hauss, Johann; Schreiber, Stefan; Strasser, Simone; Klempnauer, Jürgen; Troisi, Roberto I.; Bhoori, Sherrie; Lerut, Jan; Bilbao, Itxarone; Klein, Christian G.; Königsrainer, Alfred; Mirza, Darius F.; Otto, Gerd; Mazzaferro, Vincenzo; Neuhaus, Peter; Schlitt, Hans J.

    2016-01-01

    Background We investigated whether sirolimus-based immunosuppression improves outcomes in liver transplantation (LTx) candidates with hepatocellular carcinoma (HCC). Methods In a prospective-randomized open-label international trial, 525 LTx recipients with HCC initially receiving mammalian target of rapamycin inhibitor–free immunosuppression were randomized 4 to 6 weeks after transplantation into a group on mammalian target of rapamycin inhibitor–free immunosuppression (group A: 264 patients) or a group incorporating sirolimus (group B: 261). The primary endpoint was recurrence-free survival (RFS); intention-to-treat (ITT) analysis was conducted after 8 years. Overall survival (OS) was a secondary endpoint. Results Recurrence-free survival was 64.5% in group A and 70.2% in group B at study end, this difference was not significant (P = 0.28; hazard ratio [HR], 0.84; 95% confidence interval [95% CI], 0.62; 1.15). In a planned analysis of RFS rates at yearly intervals, group B showed better outcomes 3 years after transplantation (HR, 0.7; 95% CI, 0.48-1.00). Similarly, OS (P = 0.21; HR, 0.81; 95% CI, 0.58-1.13) was not statistically better in group B at study end, but yearly analyses showed improvement out to 5 years (HR, 0.7; 95% CI, 0.49-1.00). Interestingly, subgroup (Milan Criteria-based) analyses revealed that low-risk, rather than high-risk, patients benefited most from sirolimus; furthermore, younger recipients (age ≤60) also benefited, as well sirolimus monotherapy patients. Serious adverse event numbers were alike in groups A (860) and B (874). Conclusions Sirolimus in LTx recipients with HCC does not improve long-term RFS beyond 5 years. However, a RFS and OS benefit is evident in the first 3 to 5 years, especially in low-risk patients. This trial provides the first high-level evidence base for selecting immunosuppression in LTx recipients with HCC. PMID:26555945

  4. Enclomiphene citrate stimulates testosterone production while preventing oligospermia: a randomized phase II clinical trial comparing topical testosterone.

    Science.gov (United States)

    Wiehle, Ronald D; Fontenot, Gregory K; Wike, Jenny; Hsu, Kuang; Nydell, Jennifer; Lipshultz, Larry

    2014-09-01

    To determine the effect of enclomiphene citrate in men with secondary hypogonadism. Phase II clinical trial. Community dwelling men making visits to physician offices. Men with secondary hypogonadism. Oral administration of enclomiphene citrate or 1% topical T gel. Luteinizing hormone, FSH, T, and semen analysis. Treatment with enclomiphene citrate resulted in increased morning serum T, E2, and LH levels similar to those obtained with a topical T gel in men with secondary hypogonadism. Follicle-stimulating hormone and LH were increased with enclomiphene, and sperm counts were conserved. Enclomiphene citrate reverses the two hallmarks of secondary hypogonadism, namely, low serum total T and low or inappropriately normal LH while preserving sperm production. NCT01270841 (ClinicalTrials.gov Identifier NCT01270841). Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  5. Multidimensionally encoded magnetic resonance imaging.

    Science.gov (United States)

    Lin, Fa-Hsuan

    2013-07-01

    Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. Copyright © 2012 Wiley Periodicals, Inc.

  6. A Phase 1 Randomized, Open Label, Rectal Safety, Acceptability, Pharmacokinetic, and Pharmacodynamic Study of Three Formulations of Tenofovir 1% Gel (the CHARM-01 Study.

    Directory of Open Access Journals (Sweden)

    Ian Mcgowan

    Full Text Available The CHARM-01 study characterized the safety, acceptability, pharmacokinetics (PK, and pharmacodynamics (PD of three tenofovir (TFV gels for rectal application. The vaginal formulation (VF gel was previously used in the CAPRISA 004 and VOICE vaginal microbicide Phase 2B trials and the RMP-02/MTN-006 Phase 1 rectal safety study. The reduced glycerin VF (RGVF gel was used in the MTN-007 Phase 1 rectal microbicide trial and is currently being evaluated in the MTN-017 Phase 2 rectal microbicide trial. A third rectal specific formulation (RF gel was also evaluated in the CHARM-01 study.Participants received 4 mL of the three TFV gels in a blinded, crossover design: seven daily doses of RGVF, seven daily doses of RF, and six daily doses of placebo followed by one dose of VF, in a randomized sequence. Safety, acceptability, compartmental PK, and explant PD were monitored throughout the trial.All three gels were found to be safe and acceptable. RF and RGVF PK were not significantly different. Median mucosal mononuclear cell (MMC TFV-DP trended toward higher values for RF compared to RGVF (1136 and 320 fmol/106 cells respectively. Use of each gel in vivo was associated with significant inhibition of ex vivo colorectal tissue HIV infection. There was also a significant negative correlation between the tissue levels of TFV, tissue TFV-DP, MMC TFV-DP, rectal fluid TFV, and explant HIV-1 infection.All three formulations were found to be safe and acceptable. However, the safety profile of the VF gel was only based on exposure to one dose whereas participants received seven doses of the RGVF and RF gels. There was a trend towards higher tissue MMC levels of TFV-DP associated with use of the RF gel. Use of all gels was associated with significant inhibition of ex vivo tissue HIV infection.ClinicalTrials.gov NCT01575405.

  7. A Phase III, Randomized, Controlled Trial of Apremilast in Patients with Psoriatic Arthritis: Results of the PALACE 2 Trial.

    Science.gov (United States)

    Cutolo, Maurizio; Myerson, Gary E; Fleischmann, Roy M; Lioté, Frédéric; Díaz-González, Federico; Van den Bosch, Filip; Marzo-Ortega, Helena; Feist, Eugen; Shah, Kamal; Hu, ChiaChi; Stevens, Randall M; Poder, Airi

    2016-09-01

    Apremilast, an oral phosphodiesterase 4 inhibitor, downregulates intracellular inflammatory mediator synthesis by elevating cyclic adenosine monophosphate levels. The PALACE 2 trial evaluated apremilast efficacy and safety in patients with active psoriatic arthritis (PsA) despite prior conventional disease-modifying antirheumatic drugs and/or biologic therapy. Eligible patients were randomized (1:1:1) to placebo, apremilast 20 mg BID, or apremilast 30 mg BID. At Week 16, patients with swollen and tender joint count improvement 20% improvement in American College of Rheumatology response criteria (ACR20) at Week 16. In the intent-to-treat population (N = 484), ACR20 at Week 16 was achieved by more patients receiving apremilast 20 mg BID [37.4% (p = 0.0002)] and 30 mg BID [32.1% (p = 0.0060)] versus placebo (18.9%). Clinically meaningful improvements in signs and symptoms of PsA, physical function, and psoriasis were observed with apremilast through Week 52. The most common adverse events were diarrhea, nausea, headache, and upper respiratory tract infection. Diarrhea and nausea generally occurred early and usually resolved spontaneously with continued treatment. Laboratory abnormalities were infrequent and transient. Apremilast demonstrated clinical improvements in PsA for up to 52 weeks, including signs and symptoms, physical function, and psoriasis. No new safety signals were observed. ClinicalTrials.gov identifier: NCT01212757.

  8. A random phased-array for MR-guided transcranial ultrasound neuromodulation in non-human primates.

    Science.gov (United States)

    Chaplin, Vandiver; Phipps, Marshal A; Caskey, Charles F

    2018-04-18

    Transcranial focused ultrasound (FUS) is a non-invasive technique for therapy and study of brain neural activation. Here we report on the design and characterization of a new MR-guided FUS transducer for neuromodulation in non-human primates at 650 kHz. The array is randomized with 128 elements 6.6 mm in diameter, radius of curvature 7.2 cm, opening diameter 10.3 cm (focal ratio 0.7), and 46% coverage. Simulations were used to optimize transducer geometry with respect to focus size, grating lobes, and directivity. Focus size and grating lobes during electronic steering were quantified using hydrophone measurements in water and a three-axis stage. A novel combination of optical tracking and acoustic mapping enabled measurement of the 3D pressure distribution in the cortical region of an ex vivo skull to within ~3.5 mm of the surface, and allowed accurate modelling of the experiment via non-homogeneous 3D acoustic simulations. The data demonstrates acoustic focusing beyond the skull bone, with the focus slightly broadened and shifted proximal to the skull. The fabricated design is capable of targeting regions within the S1 sensorimotor cortex of macaques. © 2018 Institute of Physics and Engineering in Medicine.

  9. Decision Making in the PICU: An Examination of Factors Influencing Participation Decisions in Phase III Randomized Clinical Trials

    Science.gov (United States)

    Slosky, Laura E.; Burke, Natasha L.; Siminoff, Laura A.

    2014-01-01

    Background. In stressful situations, decision making processes related to informed consent may be compromised. Given the profound levels of distress that surrogates of children in pediatric intensive care units (PICU) experience, it is important to understand what factors may be influencing the decision making process beyond the informed consent. The purpose of this study was to evaluate the role of clinician influence and other factors on decision making regarding participation in a randomized clinical trial (RCT). Method. Participants were 76 children under sedation in a PICU and their surrogate decision makers. Measures included the Post Decision Clinician Survey, observer checklist, and post-decision interview. Results. Age of the pediatric patient was related to participation decisions in the RCT such that older children were more likely to be enrolled. Mentioning the sponsoring institution was associated with declining to participate in the RCT. Type of health care provider and overt recommendations to participate were not related to enrollment. Conclusion. Decisions to participate in research by surrogates of children in the PICU appear to relate to child demographics and subtleties in communication; however, no modifiable characteristics were related to increased participation, indicating that the informed consent process may not be compromised in this population. PMID:25161672

  10. A random phased-array for MR-guided transcranial ultrasound neuromodulation in non-human primates

    Science.gov (United States)

    Chaplin, Vandiver; Phipps, Marshal A.; Caskey, Charles F.

    2018-05-01

    Transcranial focused ultrasound (FUS) is a non-invasive technique for therapy and study of brain neural activation. Here we report on the design and characterization of a new MR-guided FUS transducer for neuromodulation in non-human primates at 650 kHz. The array is randomized with 128 elements 6.6 mm in diameter, radius of curvature 7.2 cm, opening diameter 10.3 cm (focal ratio 0.7), and 46% coverage. Simulations were used to optimize transducer geometry with respect to focus size, grating lobes, and directivity. Focus size and grating lobes during electronic steering were quantified using hydrophone measurements in water and a three-axis stage. A novel combination of optical tracking and acoustic mapping enabled measurement of the 3D pressure distribution in the cortical region of an ex vivo skull to within ~3.5 mm of the surface, and allowed accurate modelling of the experiment via non-homogeneous 3D acoustic simulations. The data demonstrates acoustic focusing beyond the skull bone, with the focus slightly broadened and shifted proximal to the skull. The fabricated design is capable of targeting regions within the S1 sensorimotor cortex of macaques.

  11. Priming with r-metHuSCF and filgrastim or chemotherapy and filgrastim in patients with malignant lymphomas: a randomized phase II pilot study of mobilization and engraftment

    DEFF Research Database (Denmark)

    Johnsen, Hanne; Geisler, C; Juvonen, E

    2011-01-01

    methionyl human G-CSF (filgrastim, r-metHuG-CSF) (experimental arm A) or routine chemotherapy plus filgrastim (conventional arm B). The primary objective was to evaluate the side effects and toxicity during priming and mobilization. The secondary objectives were efficacy by the level of blood......-circulating PBPCs, the number of harvest days and the time to three-lineage engraftment after autografting. First, during priming 5 patients had 8 serious events, 4 in each arm. A summary of all adverse events revealed 30 (94%) patients suffering from 132 events of all grading. Second, neutropenia...... and thrombocytopenia was documented in arm B. Third, 9/14 (64%) patients in arm A reached the target of 5 million CD34(+) cells/kg body weight (bw) compared with 13/15 (87%) in arm B. The results represent the first randomized trial of growth factor plus chemotherapy priming and indicate that a formal phase III trial...

  12. Dataset for Phase I randomized clinical trial for safety and tolerability of GET 73 in single and repeated ascending doses including preliminary pharmacokinetic parameters

    Directory of Open Access Journals (Sweden)

    Carolina L. Haass-Koffler

    2017-12-01

    Full Text Available The data in this article outline the methods used for the administration of GET 73 in the first time-in-human manuscript entitled “Phase I randomized clinical trial for the safety, tolerability and preliminary pharmacokinetics of the mGluR5 negative allosteric modulator GET 73 following single and repeated doses in healthy male volunteers” (Haass-Koffler et al., 2017 [1]. Data sets are provided in two different manners. The first series of tables provided includes procedural information about the experiments conducted. The next series of tables provided includes Pharmacokinetic (PK parameters for GET 73 and its main metabolite MET 2. This set of data is comprised by two experiments: Experiment 1 references a single ascending dose administration of GET 73 and Experiment 2 references a repeated ascending dose administration of GET 73. Keywords: Glutamate receptor subtype 5 (mGlu5, Allosteric modulator, GET 73, Safety, Tolerability

  13. Efficacy and safety of long-acting pasireotide in Japanese patients with acromegaly or pituitary gigantism: results from a multicenter, open-label, randomized, phase 2 study.

    Science.gov (United States)

    Tahara, Shigeyuki; Murakami, Mami; Kaneko, Tomomi; Shimatsu, Akira

    2017-07-28

    A multicenter, open-label, phase 2 study was conducted to investigate the efficacy and safety of long-acting pasireotide formulation in Japanese patients with acromegaly or pituitary gigantism. Medically naïve or inadequately controlled patients (on somatostatin analogues or dopamine agonists) were included. Primary end point was the proportion of all patients who achieved biochemical control (mean growth hormone [GH] levelsacromegaly, n=32; pituitary gigantism, n=1) were enrolled and randomized 1:1:1 to receive open-label pasireotide 20mg, 40mg, or 60mg. The median age was 52 years (range, 31-79) and 20 patients were males. At month 3, 18.2% of patients (6/33; 90% confidence interval: 8.2%, 32.8%) had biochemical control (21.2% [7/33] when including a patient with mean GHacromegaly or pituitary gigantism.

  14. Dataset for Phase I randomized clinical trial for safety and tolerability of GET 73 in single and repeated ascending doses including preliminary pharmacokinetic parameters.

    Science.gov (United States)

    Haass-Koffler, Carolina L; Goodyear, Kimberly; Long, Victoria M; Tran, Harrison H; Loche, Antonella; Cacciaglia, Roberto; Swift, Robert M; Leggio, Lorenzo

    2017-12-01

    The data in this article outline the methods used for the administration of GET 73 in the first time-in-human manuscript entitled "Phase I randomized clinical trial for the safety, tolerability and preliminary pharmacokinetics of the mGluR5 negative allosteric modulator GET 73 following single and repeated doses in healthy male volunteers" (Haass-Koffler et al., 2017) [1]. Data sets are provided in two different manners. The first series of tables provided includes procedural information about the experiments conducted. The next series of tables provided includes Pharmacokinetic (PK) parameters for GET 73 and its main metabolite MET 2. This set of data is comprised by two experiments: Experiment 1 references a single ascending dose administration of GET 73 and Experiment 2 references a repeated ascending dose administration of GET 73.

  15. Radiofrequency ablation combined with systemic treatment versus systemic treatment alone in patients with non-resectable colorectal liver metastases: a randomized EORTC Intergroup phase II study (EORTC 40004).

    Science.gov (United States)

    Ruers, T; Punt, C; Van Coevorden, F; Pierie, J P E N; Borel-Rinkes, I; Ledermann, J A; Poston, G; Bechstein, W; Lentz, M A; Mauer, M; Van Cutsem, E; Lutz, M P; Nordlinger, B

    2012-10-01

    This study investigates the possible benefits of radiofrequency ablation (RFA) in patients with non-resectable colorectal liver metastases. This phase II study, originally started as a phase III design, randomly assigned 119 patients with non-resectable colorectal liver metastases between systemic treatment (n = 59) or systemic treatment plus RFA ( ± resection) (n = 60). Primary objective was a 30-month overall survival (OS) rate >38% for the combined treatment group. The primary end point was met, 30-month OS rate was 61.7% [95% confidence interval (CI) 48.2-73.9] for combined treatment. However, 30-month OS for systemic treatment was 57.6% (95% CI 44.1-70.4), higher than anticipated. Median OS was 45.3 for combined treatment and 40.5 months for systemic treatment (P = 0.22). PFS rate at 3 years for combined treatment was 27.6% compared with 10.6% for systemic treatment only (hazard ratio = 0.63, 95% CI 0.42-0.95, P = 0.025). Median progression-free survival (PFS) was 16.8 months (95% CI 11.7-22.1) and 9.9 months (95% CI 9.3-13.7), respectively. This is the first randomized study on the efficacy of RFA. The study met the primary end point on 30-month OS; however, the results in the control arm were in the same range. RFA plus systemic treatment resulted in significant longer PFS. At present, the ultimate effect of RFA on OS remains uncertain.

  16. Randomized phase 2 trial to evaluate the clinical efficacy of two high-dosage tigecycline regimens versus imipenem-cilastatin for treatment of hospital-acquired pneumonia.

    Science.gov (United States)

    Ramirez, Julio; Dartois, Nathalie; Gandjini, Hassan; Yan, Jean Li; Korth-Bradley, Joan; McGovern, Paul C

    2013-04-01

    In a previous phase 3 study, the cure rates that occurred in patients with hospital-acquired pneumonia treated with tigecycline at the approved dose were lower than those seen with patients treated with imipenem and cilastatin (imipenem/cilastatin). We hypothesized that a higher dose of tigecycline is necessary in patients with hospital-acquired pneumonia. This phase 2 study compared the safety and efficacy of two higher doses of tigecycline with imipenem/cilastatin in subjects with hospital-acquired pneumonia. Subjects with hospital-acquired pneumonia were randomized to receive one of two doses of tigecycline (150 mg followed by 75 mg every 12 h or 200 mg followed by 100 mg every 12 h) or 1 g of imipenem/cilastatin every 8 h. Empirical adjunctive therapy was administered for initial coverage of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa infection, depending on the randomization regimen. Clinical response, defined as cure, failure of treatment, or indeterminate outcome, was assessed 10 to 21 days after the last day of therapy. In the clinically evaluable population, clinical cure with tigecycline 100 mg (17/20, 85.0%) was numerically higher than with tigecycline 75 mg (16/23, 69.6%) and imipenem/cilastatin (18/24, 75.0%). No new safety signals with the high-dose tigecycline were identified. A numerically higher clinical response was observed with the 100-mg dose of tigecycline. This supports our hypothesis that a higher area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) may be necessary to achieve clinical cure in patients with hospital-acquired pneumonia. Further studies are necessary. (The ClinicalTrials.gov identifier for this clinical trial is NCT00707239.).

  17. The impact of written information and counseling (WOMAN-PRO II Program) on symptom outcomes in women with vulvar neoplasia: A multicenter randomized controlled phase II study.

    Science.gov (United States)

    Raphaelis, Silvia; Mayer, Hanna; Ott, Stefan; Mueller, Michael D; Steiner, Enikö; Joura, Elmar; Senn, Beate

    2017-07-01

    To determine whether written information and/or counseling based on the WOMAN-PRO II Program decreases symptom prevalence in women with vulvar neoplasia by a clinically relevant degree, and to explore the differences between the 2 interventions in symptom prevalence, symptom distress prevalence, and symptom experience. A multicenter randomized controlled parallel-group phase II trial with 2 interventions provided to patients after the initial diagnosis was performed in Austria and Switzerland. Women randomized to written information received a predefined set of leaflets concerning wound care and available healthcare services. Women allocated to counseling were additionally provided with 5 consultations by an Advanced Practice Nurse (APN) between the initial diagnosis and 6months post-surgery that focused on symptom management, utilization of healthcare services, and health-related decision-making. Symptom outcomes were simultaneously measured 5 times to the counseling time points. A total of 49 women with vulvar neoplasia participated in the study. Symptom prevalence decreased in women with counseling by a clinically relevant degree, but not in women with written information. Sporadically, significant differences between the 2 interventions could be observed in individual items, but not in the total scales or subscales of the symptom outcomes. The results indicate that counseling may reduce symptom prevalence in women with vulvar neoplasia by a clinically relevant extent. The observed group differences between the 2 interventions slightly favor counseling over written information. The results justify testing the benefit of counseling thoroughly in a comparative phase III trial. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. EFFECT OF SUPERVISED MODERATE INTENSITY EXERCISE PROGRAM IN PHASE ONE CARDIAC REHABILITATION OF POST OPERATIVE CABG PATIENTS - A RANDOMIZED CONTROLLED TRAIL

    Directory of Open Access Journals (Sweden)

    Rajan Modi

    2014-10-01

    Full Text Available Background: With the increasing number of cases for CABG, the cardiac rehabilitation has gained importance. The trends in rehabilitation of a coronary artery disease patient are changing by incorporating a variety of aerobic exercises and resisted training in to their rehabilitation program. The outcome of any exercise chiefly depends on the training parameters like intensity, frequency and duration. Hence the present study focused to know the effects of supervised moderate intensity exercises on patients during hospital discharge following CABG. The objective of is to study the effectiveness of supervised moderate intensity exercise on distance walked and Quality of Life at hospital discharge following CABG. Methods: Study recruited randomly 46 patients between age group 40-65 years who were posted for non-emergency CABG for the first time. Pre-operative assessment was done thoroughly and was divided in to two groups, Group A conventional treatment and Group B Moderate intensity exercise group. The patients were treated using different protocols in terms of intensity for 8-10 days immediate post CABG. Then the outcome parameters of 6MWT and sf-36 were compared for analysis. Results: Both groups individually showed extremely significant results for two outcome measures. 6 MWD difference between two treatment groups showed significant results with unpaired t test (t = 8.5720,p<0.001. Quality of life score difference within group showed very significant results but there is no difference found between both groups. Conclusion: Moderate intensity exercises can also be included in the immediate post-operative phase of CABG, as they reduce the length of hospital stay and quicken the cardiac rehabilitation process. But there need to be a lot of randomized control trails to confirm the benefits of moderate intensity exercises in phase one rehabilitation program after CABG.

  19. Randomized phase III trial of concurrent chemoradiotherapy vs accelerated hyperfractionation radiotherapy in locally advanced head and neck cancer

    International Nuclear Information System (INIS)

    Chitapanarux, Imjai; Kamnerdsupaphon, Pimkhuan; Pukanhapan, Nantaka; Tharavichitkul, Ekkasit; Vongtama, Roy

    2013-01-01

    The aim of this study was to compare the efficacy and safety of concurrent chemoradiotherapy (CCRT) vs accelerated hyperfractionation with concomitant boost (CCB) as a primary treatment for patients with Stage III-IV squamous cell carcinoma of head and neck (SCCHN). A total of 85 non-metastatic advanced SCCHN patients were accrued from January 2003 to December 2007. Of these, 48 and 37 patients received CCRT and CCB, respectively. The patients were randomized to receive either three cycles of carboplatin and 5-fluorouracil plus conventional radiotherapy (CCRT, 66 Gy in 6.5 weeks) or hybrid accelerated radiotherapy (CCB, 70 Gy in 6 weeks). The primary endpoint was determined by locoregional control rate. The secondary endpoints were overall survival and toxicity. With a median follow-up of 43 months (range, 3-102), the 5-year locoregional control rate was 69.6% in the CCRT arm vs 55.0% in the CCB arm (P = 0.184). The 5-year overall survival rate was marginally significantly different (P = 0.05): 76.1% in the CCRT arm vs 63.5% in the CCB arm. Radiotherapy treatment interruptions of more than three days were 60.4% and 40.5% in the CCRT arm and CCB arm, respectively. The median total treatment time was 55.5 days in the CCRT arm and 49 days in the CCB arm. The rate of Grade 3 - 4 acute mucositis was significantly higher in the CCB arm (67.6% vs 41.7%, P = 0.01), but no high grade hematologic toxicities were found in the CCB arm (27.2% vs 0%). CCRT has shown a trend of improving outcome over CCB irradiation in locoregionally advanced head and neck cancer. (author)

  20. Virtual immersive gaming to optimize recovery (VIGOR) in low back pain: A phase II randomized controlled trial.

    Science.gov (United States)

    France, Christopher R; Thomas, James S

    2018-06-01

    The virtual immersive gaming to optimize recovery (VIGOR) study is a randomized controlled trial of the effects of virtual reality games to encourage lumbar spine flexion among individuals with chronic low back pain and fear of movement. Whereas traditional graded activity or graded exposure therapies for chronic low back pain have high attrition and poor long-term efficacy, we believe that virtual reality games have distinct advantages that can enhance adherence and clinical outcomes. First, they are engaging and enjoyable activities that can distract from pain and fear of harm. In addition, because they gradually reinforce increases in lumbar spine flexion to achieve game objectives, continued engagement over time is expected to promote recovery through restoration of normal spinal motion. The study design includes two treatment groups which differ in the amount of lumbar flexion required to achieve the game objectives. All participants will play the games for nine weeks, and pre-treatment to 1-week post-treatment changes in pain and disability will serve as the co-primary clinical outcomes. In addition, changes in lumbar flexion and expectations of pain/harm will be examined as potential treatment outcome mediators. Maintenance of treatment outcomes will also be assessed for up to 48-weeks post-treatment. In brief, we hypothesize that the virtual reality games will reduce pain and disability by promoting spinal motion and allowing participants to develop an implicit understanding that they are capable of engaging in significant lumbar spine motion in their daily lives without a risk of injury to their back. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Phase 1 Safety, Pharmacokinetics, and Pharmacodynamics of Dapivirine and Maraviroc Vaginal Rings: A Double-Blind Randomized Trial.

    Science.gov (United States)

    Chen, Beatrice A; Panther, Lori; Marzinke, Mark A; Hendrix, Craig W; Hoesley, Craig J; van der Straten, Ariane; Husnik, Marla J; Soto-Torres, Lydia; Nel, Annalene; Johnson, Sherri; Richardson-Harman, Nicola; Rabe, Lorna K; Dezzutti, Charlene S

    2015-11-01

    Variable adherence limits effectiveness of daily oral and intravaginal tenofovir-containing pre-exposure prophylaxis. Monthly vaginal antiretroviral rings are one approach to improve adherence and drug delivery. MTN-013/IPM 026, a multisite, double-blind, randomized, placebo-controlled trial in 48 HIV-negative US women, evaluated vaginal rings containing dapivirine (DPV) (25 mg) and maraviroc (MVC) (100 mg), DPV only, MVC only, and placebo used continuously for 28 days. Safety was assessed by adverse events. Drug concentrations were quantified in plasma, cervicovaginal fluid (CVF), and cervical tissue. Cervical biopsy explants were challenged with HIV ex vivo to evaluate pharmacodynamics. There was no difference in related genitourinary adverse events between treatment arms compared with placebo. DPV and MVC concentrations rose higher initially before falling more rapidly with the combination ring compared with relatively stable concentrations with the single-drug rings. DPV concentrations in CVF were 1 and 5 log10 greater than cervical tissue and plasma for both rings. MVC was consistently detected only in CVF. DPV and MVC CVF and DPV tissue concentrations dropped rapidly after ring removal. Cervical tissue showed a significant inverse linear relationship between HIV replication and DPV levels. In this first study of a combination microbicide vaginal ring, all 4 rings were safe and well tolerated. Tissue DPV concentrations were 1000 times greater than plasma concentrations and single drug rings had more stable pharmacokinetics. DPV, but not MVC, demonstrated concentration-dependent inhibition of HIV-1 infection in cervical tissue. Because MVC concentrations were consistently detectable only in CVF and not in plasma, improved drug release of MVC rings is needed.

  2. Omeprazole-Domperidone Fixed Dose Combination vs Omeprazole Monotherapy: A Phase 4, Open-Label, Comparative, Parallel Randomized Controlled Study in Mild to Moderate Gastroesophageal Reflux Disease

    Directory of Open Access Journals (Sweden)

    KY Marakhouski

    2017-05-01

    Full Text Available Aim: To compare the efficacy and safety of omeprazole-domperidone combination vs omeprazole monotherapy in gastroesophageal reflux disease (GERD. Methods: In a comparative, randomized controlled, phase 4 study, outpatients with GERD were randomly allocated to either group 1 (omeprazole 20 mg + domperidone 30 mg or group 2 (omeprazole 20 mg in an equal ratio; 2 capsules daily in the morning were administered for 8 weeks. Results: Sixty patients were enrolled. Esophagitis reversal was observed in 92% patients in group 1 vs 65.2% in group 2. Approximately, 83.3% patients in group 1 vs 43.3% patients in group 2 demonstrated full cupping of reflux symptoms at 8 weeks. Combined therapy resulted in significantly longer period of heartburn-free days (23 vs 12 days on omeprazole. There were no safety concerns. Conclusions: Omeprazole-domperidone combination was more effective than omeprazole alone in providing complete cupping of reflux symptoms and healing of esophagitis in patients with GERD. Both the treatments were well tolerated with few reports of adverse events. Trial registration: This trial is registered with http://clinicaltrials.gov , number NCT02140073.

  3. Phase II randomized trial of neoadjuvant metformin plus letrozole versus placebo plus letrozole for estrogen receptor positive postmenopausal breast cancer (METEOR)

    International Nuclear Information System (INIS)

    Kim, Jisun; Kim, Lee Su; Han, Sehwan; Nam, Seok Jin; Kang, Han-Sung; Kim, Seung Il; Yoo, Young Bum; Jeong, Joon; Kim, Tae Hyun; Kang, Taewoo; Kim, Sung-Won; Lim, Woosung; Jung, Yongsik; Lee, Jeong Eon; Kim, Ku Sang; Yu, Jong-Han; Chae, Byung Joo; Jung, So-Youn; Kang, Eunyoung; Choi, Su Yun; Moon, Hyeong-Gon; Noh, Dong-Young; Kim, Eun-Kyu; Han, Wonshik; Kim, Min-Kyoon; Paik, Nam-Sun; Jeong, Sang-Seol; Yoon, Jung-han; Park, Chan Heun; Ahn, Sei Hyun

    2014-01-01

    Neoadjuvant endocrine therapy with an aromatase inhibitor has shown efficacy comparable to that of neoadjuvant chemotherapy in patients with postmenopausal breast cancer. Preclinical and clinical studies have shown that the antidiabetic drug metformin has anti-tumor activity. This prospective, multicenter, phase II randomized, placebo controlled trial was designed to evaluate the direct anti-tumor effect of metformin in non-diabetic postmenopausal women with estrogen-receptor (ER) positive breast cancer. Patients meeting the inclusion criteria and providing written informed consent will be randomized to 24 weeks of neoadjuvant treatment with letrozole (2.5 mg/day) and either metformin (2000 mg/day) or placebo. Target accrual number is 104 patients per arm. The primary endpoint will be clinical response rate, as measured by calipers. Secondary endpoints include pathologic complete response rate, breast conserving rate, change in Ki67 expression, breast density change, and toxicity profile. Molecular assays will be performed using samples obtained before treatment, at week 4, and postoperatively. This study will provide direct evidence of the anti-tumor effect of metformin in non-diabetic, postmenopausal patients with ER-positive breast cancer. ClinicalTrials.gov Identifier http://clinicaltrial.gov/ct2/show/NCT01589367?term

  4. Efficacy of tofacitinib for the treatment of nail psoriasis: Two 52-week, randomized, controlled phase 3 studies in patients with moderate-to-severe plaque psoriasis.

    Science.gov (United States)

    Merola, Joseph F; Elewski, Boni; Tatulych, Svitlana; Lan, Shuping; Tallman, Anna; Kaur, Mandeep

    2017-07-01

    Tofacitinib is an oral Janus kinase inhibitor. Efficacy and safety of tofacitinib in patients with moderate-to-severe plaque psoriasis have been demonstrated. We sought to assess the efficacy of tofacitinib for the treatment of nail psoriasis over a period of 52 weeks. In 2 identical phase 3 studies (OPT Pivotal 1 and 2), patients were randomized 2:2:1 to receive tofacitinib 5 mg, tofacitinib 10 mg, or placebo, twice daily. At week 16, placebo-treated patients were re-randomized to tofacitinib. This post hoc analysis of patients with existing nail psoriasis assessed the Nail Psoriasis Severity Index (NAPSI) score and proportions of patients achieving ≥50% reduction in NAPSI from baseline (NAPSI50), NAPSI75, or NAPSI100. Baseline mean NAPSI scores for patients treated with tofacitinib 5 mg (N = 487), tofacitinib 10 mg (N = 476), and placebo (N = 233) twice daily were 27.0, 27.3, and 26.9, respectively. At week 16, significantly (all P psoriasis versus placebo at week 16; improvements were maintained over 52 weeks [NCT01276639; NCT01309737]. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  5. Adalimumab for nail psoriasis: Efficacy and safety from the first 26 weeks of a phase 3, randomized, placebo-controlled trial.

    Science.gov (United States)

    Elewski, Boni E; Okun, Martin M; Papp, Kim; Baker, Christopher S; Crowley, Jeffrey J; Guillet, Gérard; Sundaram, Murali; Poulin, Yves; Gu, Yihua; Geng, Ziqian; Williams, David A; Rich, Phoebe A

    2018-01-01

    Previous clinical trials have not evaluated improvement in nail psoriasis as a primary end point. This phase 3 trial evaluated the safety and efficacy of adalimumab in patients with moderate-to-severe fingernail psoriasis and moderate-to-severe plaque psoriasis. Patients were randomized 1:1 to 40 mg adalimumab every other week or placebo. The primary efficacy end point was at least 75% improvement in total-fingernail modified Nail Psoriasis Severity Index (NAPSI75) response rate at week 26. Ranked secondary end point scores evaluated at week 26 were total-fingernail NAPSI and modified NAPSI, nail pain, Nail Psoriasis Physical Functioning Severity, Brigham Scalp Nail Inverse Palmo-Plantar Psoriasis Index, and Physician's Global Assessment (fingernail psoriasis). Of the 217 randomized patients (108 received placebo and 109 received adalimumab), 188 (86.6%) completed 26 weeks of treatment (period A) or escaped early to the open-label period. The study met the primary end point (response rate of 3.4% with placebo vs 46.6% with adalimumab [P psoriasis versus with placebo and no new safety risks were identified. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  6. 8 Gy single-dose radiotherapy is effective in metastatic spinal cord compression: Results of a phase III randomized multicentre Italian trial

    International Nuclear Information System (INIS)

    Maranzano, Ernesto; Trippa, Fabio; Casale, Michelina; Costantini, Sara; Lupattelli, Marco; Bellavita, Rita; Marafioti, Luigi; Pergolizzi, Stefano; Santacaterina, Anna; Mignogna, Marcello; Silvano, Giovanni; Fusco, Vincenzo

    2009-01-01

    Background and purpose: In a previous randomized trial we showed that the short-course radiotherapy (RT) regimen of 8 Gy x 2 was feasible in patients with metastatic spinal cord compression (MSCC) and short life expectancy. This phase III trial was planned to determine whether in the same category of patients 8 Gy single-dose is as effective as 8 Gy x 2. Materials and methods: Three hundred and twenty-seven patients with MSCC and short life expectancy were randomly assigned to a short-course of 8 Gy x 2 or to 8 Gy single-dose RT. Median follow-up was 31 months (range, 4-58). Results: A total of 303 (93%) patients are assessable, 150 treated with the short-course and 153 with the single-dose RT. No difference in response was found between the two RT schedules adopted. Median duration of response was 5 and 4.5 months for short-course and single-dose RT (p = 0.4), respectively. The median overall survival was 4 months for all cases. Light acute toxicity was registered in a minority of cases. Late toxicity was never recorded. Conclusions: Both RT schedules adopted were effective. As already shown in several trials evaluating RT regimens in uncomplicated painful bone metastases, also MSCC patients may achieve palliation with minimal toxicity and inconvenience with a single-dose of 8 Gy.

  7. Randomized phase II trial evaluating two paclitaxel and cisplatin-containing chemoradiation regimens as adjuvant therapy in resected gastric cancer (RTOG-0114).

    Science.gov (United States)

    Schwartz, Gary K; Winter, Kathryn; Minsky, Bruce D; Crane, Christopher; Thomson, P John; Anne, Pramila; Gross, Howard; Willett, Christopher; Kelsen, David

    2009-04-20

    The investigational arm of INT0116, a fluorouracil (FU) and leucovorin-containing chemoradiotherapy regimen, is a standard treatment for patients with resected gastric cancer with a 2-year disease-free survival rate (DFS) of 52%. Toxicity is also significant. More beneficial and safer regimens are needed. We performed a randomized phase II study among 39 cancer centers to evaluate two paclitaxel and cisplatin-containing regimens, one with FU (PCF) and the other without (PC) in patients with resected gastric cancer. Patients received two cycles of postoperative chemotherapy followed by 45 Gy of radiation with either concurrent FU and paclitaxel or paclitaxel and cisplatin. The primary objective was to show an improvement in 2-year DFS to 67% as compared with INT 0116. From May 2001 to February 2004 (study closure), 78 patients entered this study, and 73 were evaluable. At the planned interim analysis of 22 patients on PCF, grade 3 or higher GI toxicity was 59%. This was significantly worse than INT0116, and this arm was closed. Accrual continued on PC. The median DFS was 14.6 months for PCF and has not been reached for PC. For PC the 2-year DFS is 52% (95% CI, 36% to 68%). Though PC appears to be safe and the median DFS favorable, the DFS failed to exceed the lower bound of 52.9% for the targeted 67% DFS at 2 years and can not be recommended as the adjuvant arm for future randomized trials.

  8. Randomized phase II study of vandetanib alone or with paclitaxel and carboplatin as first-line treatment for advanced non-small-cell lung cancer.

    Science.gov (United States)

    Heymach, John V; Paz-Ares, Luis; De Braud, Filippo; Sebastian, Martin; Stewart, David J; Eberhardt, Wilfried E E; Ranade, Anantbhushan A; Cohen, Graham; Trigo, Jose Manuel; Sandler, Alan B; Bonomi, Philip D; Herbst, Roy S; Krebs, Annetta D; Vasselli, James; Johnson, Bruce E

    2008-11-20

    Vandetanib is a once-daily, oral inhibitor of vascular endothelial growth factor receptor and epidermal growth factor receptor signaling. The antitumor activity of vandetanib monotherapy or vandetanib with paclitaxel and carboplatin (VPC) was compared with paclitaxel and carboplatin (PC) in previously untreated patients with non-small-cell lung cancer (NSCLC). All NSCLC histologies and previously treated CNS metastases were permitted in this partially blinded, placebo-controlled, randomized phase II study. Patients were randomly assigned 2:1:1 to receive vandetanib, VPC, or PC. Progression-free survival (PFS) was the primary end point, and the study was powered to detect a reduced risk of progression with VPC versus PC (hazard ratio = 0.70; one-sided P 1.33 v PC). Overall survival was not significantly different between patients receiving VPC or PC. Rash, diarrhea, and hypertension were common adverse events; no pulmonary or CNS hemorrhage events required intervention. VPC could be safely administered to patients with NSCLC, including those with squamous cell histology and treated brain metastases. Compared with the PC control arm, patients receiving VPC had longer PFS, meeting the prespecified study end point, whereas those receiving vandetanib monotherapy had shorter PFS.

  9. Phase-only optical encryption based on the zeroth-order phase-contrast technique

    Science.gov (United States)

    Pizolato, José Carlos; Neto, Luiz Gonçalves

    2009-09-01

    A phase-only encryption/decryption scheme with the readout based on the zeroth-order phase-contrast technique (ZOPCT), without the use of a phase-changing plate on the Fourier plane of an optical system based on the 4f optical correlator, is proposed. The encryption of a gray-level image is achieved by multiplying the phase distribution obtained directly from the gray-level image by a random phase distribution. The robustness of the encoding is assured by the nonlinearity intrinsic to the proposed phase-contrast method and the random phase distribution used in the encryption process. The experimental system has been implemented with liquid-crystal spatial modulators to generate phase-encrypted masks and a decrypting key. The advantage of this method is the easy scheme to recover the gray-level information from the decrypted phase-only mask applying the ZOPCT. An analysis of this decryption method was performed against brute force attacks.

  10. The RESPIRE trials: Two phase III, randomized, multicentre, placebo-controlled trials of Ciprofloxacin Dry Powder for Inhalation (Ciprofloxacin DPI) in non-cystic fibrosis bronchiectasis.

    Science.gov (United States)

    Aksamit, Timothy; Bandel, Tiemo-Joerg; Criollo, Margarita; De Soyza, Anthony; Elborn, J Stuart; Operschall, Elisabeth; Polverino, Eva; Roth, Katrin; Winthrop, Kevin L; Wilson, Robert

    2017-07-01

    The primary goals of long-term disease management in non-cystic fibrosis bronchiectasis (NCFB) are to reduce the number of exacerbations, and improve quality of life. However, currently no therapies are licensed for this. Ciprofloxacin Dry Powder for Inhalation (Ciprofloxacin DPI) has potential to be the first long-term intermittent therapy approved to reduce exacerbations in NCFB patients. The RESPIRE programme consists of two international phase III prospective, parallel-group, randomized, double-blinded, multicentre, placebo-controlled trials of the same design. Adult patients with idiopathic or post-infectious NCFB, a history of ≥2 exacerbations in the previous 12months, and positive sputum culture for one of seven pre-specified pathogens, undergo stratified randomization 2:1 to receive twice-daily Ciprofloxacin DPI 32.5mg or placebo using a pocket-sized inhaler in one of two regimens: 28days on/off treatment or 14days on/off treatment. The treatment period is 48weeks plus an 8-week follow-up after the last dose. The primary efficacy endpoints are time to first exacerbation after treatment initiation and frequency of exacerbations using a stringent definition of exacerbation. Secondary endpoints, including frequency of events using different exacerbation definitions, microbiology, quality of life and lung function will also be evaluated. The RESPIRE trials will determine the efficacy and safety of Ciprofloxacin DPI. The strict entry criteria and stratified randomization, the inclusion of two treatment regimens and a stringent definition of exacerbation should clarify the patient population best positioned to benefit from long-term inhaled antibiotic therapy. Additionally RESPIRE will increase understanding of NCFB treatment and could lead to an important new therapy for sufferers. The RESPIRE trials are registered in ClinicalTrials.gov, ID number NCT01764841 (RESPIRE 1; date of registration January 8, 2013) and NCT02106832 (RESPIRE 2; date of registration

  11. Results of a Randomized Controlled Multicenter Phase III Trial of Percutaneous Hepatic Perfusion Compared with Best Available Care for Patients with Melanoma Liver Metastases.

    Science.gov (United States)

    Hughes, Marybeth S; Zager, Jonathan; Faries, Mark; Alexander, H Richard; Royal, Richard E; Wood, Bradford; Choi, Junsung; McCluskey, Kevin; Whitman, Eric; Agarwala, Sanjiv; Siskin, Gary; Nutting, Charles; Toomey, Mary Ann; Webb, Carole; Beresnev, Tatiana; Pingpank, James F

    2016-04-01

    There is no consensus for the treatment of melanoma metastatic to the liver. Percutaneous hepatic perfusion with melphalan (PHP-Mel) is a method of delivering regional chemotherapy selectively to the liver. In this study, we report the results of a multicenter, randomized controlled trial comparing PHP-Mel with best alternative care (BAC) for patients with ocular or cutaneous melanoma metastatic to the liver. A total of 93 patients were randomized to PHP-Mel (n = 44) or BAC (n = 49). On the PHP-Mel arm, melphalan was delivered via the hepatic artery, and the hepatic effluent captured and filtered extracorporeally prior to return to the systemic circulation via a venovenous bypass circuit. PHP-Mel was repeatable every 4-8 weeks. The primary endpoint was hepatic progression-free survival (hPFS), and secondary endpoints included overall PFS (oPFS), overall survival (OS), hepatic objective response (hOR), and safety. hPFS was 7.0 months for PHP-Mel and 1.6 months for BAC (p PHP-Mel and 1.6 months for BAC (p PHP-Mel 10.6 months vs. BAC 10.0 months), likely due to crossover to PHP-Mel treatment (57.1 %) from the BAC arm, and the hOR was 36.4 % for PHP-Mel and 2.0 % for BAC (p PHP-Mel, three in the primary PHP-Mel group, and one post-crossover to PHP-Mel from BAC. This randomized, phase III study demonstrated the efficacy of the PHP-Mel procedure. hPFS, oPFS, and hOR were significantly improved with PHP-Mel. PHP with melphalan should provide a new treatment option for unresectable metastatic melanoma in the liver.

  12. Once-weekly versus every-other-day stereotactic body radiotherapy in patients with prostate cancer (PATRIOT): A phase 2 randomized trial.

    Science.gov (United States)

    Quon, Harvey C; Ong, Aldrich; Cheung, Patrick; Chu, William; Chung, Hans T; Vesprini, Danny; Chowdhury, Amit; Panjwani, Dilip; Pang, Geordi; Korol, Renee; Davidson, Melanie; Ravi, Ananth; McCurdy, Boyd; Zhang, Liying; Mamedov, Alexandre; Deabreu, Andrea; Loblaw, Andrew

    2018-05-01

    Prostate stereotactic body radiotherapy (SBRT) regimens differ in time, dose, and fractionation. We completed a multicentre, randomized phase II study to investigate the impact of overall treatment time on quality of life (QOL). Men with low and intermediate-risk prostate cancer were randomly assigned to 40 Gy in 5 fractions delivered once per week (QW) vs. every other day (EOD). QOL was assessed using the Expanded Prostate Cancer Index Composite. The primary endpoint was the proportion with a minimum clinically important change (MCIC) in bowel QOL during the acute (≤12 week) period, and analysis was by intention-to-treat. ClinicalTrials.gov NCT01423474. 152 men from 3 centres were randomized with median follow-up of 47 months. Patients treated QW had superior acute bowel QOL with 47/69 (68%) reporting a MCIC compared to 63/70 (90%) treated EOD (p = 0.002). Fewer patients treated QW reported moderate-severe problems with bowel QOL during the acute period compared with EOD (14/70 [20%] vs. 40/70 [57%], p < 0.001). Acute urinary QOL was also better in the QW arm, with 52/67 (78%) vs 65/69 (94%) experiencing a MCIC (p = 0.006). There were no significant differences in late urinary or bowel QOL at 2 years or last follow-up. Prostate SBRT delivered QW improved acute bowel and urinary QOL compared to EOD. Patients should be counselled regarding the potential for reduced short-term toxicity and improved QOL with QW prostate SBRT. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Axitinib dose titration: analyses of exposure, blood pressure and clinical response from a randomized phase II study in metastatic renal cell carcinoma.

    Science.gov (United States)

    Rini, B I; Melichar, B; Fishman, M N; Oya, M; Pithavala, Y K; Chen, Y; Bair, A H; Grünwald, V

    2015-07-01

    In a randomized, double-blind phase II trial in patients with metastatic renal cell carcinoma (mRCC), axitinib versus placebo titration yielded a significantly higher objective response rate. We evaluated pharmacokinetic and blood pressure (BP) data from this study to elucidate relationships among axitinib exposure, BP change, and efficacy. Patients received axitinib 5 mg twice daily during a lead-in period. Patients who met dose-titration criteria were randomized 1:1 to stepwise dose increases with axitinib or placebo. Patients ineligible for randomization continued without dose increases. Serial 6-h and sparse pharmacokinetic sampling were carried out; BP was measured at clinic visits and at home in all patients, and by 24-h ambulatory BP monitoring (ABPM) in a subset of patients. Area under the plasma concentration-time curve from 0 to 24 h throughout the course of treatment (AUCstudy) was higher in patients with complete or partial responses than those with stable or progressive disease in the axitinib-titration arm, but comparable between these groups in the placebo-titration and nonrandomized arms. In the overall population, AUCstudy and efficacy outcomes were not strongly correlated. Mean BP across the population was similar when measured in clinic, at home, or by 24-h ABPM. Weak correlations were observed between axitinib steady-state exposure and diastolic BP. When grouped by change in diastolic BP from baseline, patients in the ≥10 and ≥15 mmHg groups had longer progression-free survival. Optimal axitinib exposure may differ among patients with mRCC. Pharmacokinetic or BP measurements cannot be used exclusively to guide axitinib dosing. Individualization of treatment with vascular endothelial growth factor receptor tyrosine kinase inhibitors, including axitinib, is thus more complex than anticipated and cannot be limited to a single clinical factor. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical

  14. Accelerated Partial Breast Irradiation With IMRT: New Technical Approach and Interim Analysis of Acute Toxicity in a Phase III Randomized Clinical Trial

    International Nuclear Information System (INIS)

    Livi, Lorenzo; Buonamici, Fabrizio Banci; Simontacchi, Gabriele; Scotti, Vieri; Fambrini, Massimiliano; Compagnucci, Antonella; Paiar, Fabiola; Scoccianti, Silvia; Pallotta, Stefania; Detti, Beatrice; Agresti, Benedetta; Talamonti, Cinzia; Mangoni, Monica; Bianchi, Simonetta; Cataliotti, Luigi; Marrazzo, Livia; Bucciolini, Marta; Biti, Giampaolo

    2010-01-01

    Purpose: To evaluate with a randomized clinical trial the possibility of treating the index quadrant with external intensity-modulated radiotherapy (IMRT) in a selected group of patients with early-stage breast cancer and to analyze the acute toxicity. Methods and Materials: From September 2005, a randomized Phase III clinical trial has been conducted to compare conventional (tangential field) fractionated whole breast treatment (Arm A) with accelerated partial breast irradiation plus intensity-modulated radiotherapy (Arm B). For intensity-modulated radiotherapy, the clinical target volume was drawn with a uniform 1-cm margin around the surgical clips in three dimensions. The ipsilateral and contralateral breast, ipsilateral and contralateral lung, heart, and spinal cord were contoured as organs at risk. All the regions of interest were contoured according to the International Commission on Radiation Units and Measurements reports 50 and 62 recommendations. Results: In September 2008, 259 patients were randomized and treated. The mean clinical target volume in Arm B was 44 cm 3 and the mean planning target volume was 123 cm 3 . The mean value of the ratio between the planning target volume and the ipsilateral breast volume was 21%. The rate of Grade 1 and Grade 2 acute skin toxicity was 22% and 19% in Arm A (Radiation Therapy Oncology Group scale), respectively. The tolerance in Arm B was excellent with only 5% Grade 1 and 0.8% Grade 2 acute skin toxicity. The planning constraints were fully satisfied in most patients. In a very few cases, this was not possible because of very unfavorable anatomy. Quality assurance procedures were performed according to our internal quality assurance protocol, with excellent results. Conclusion: In the present preliminary analysis, we have demonstrated that accelerated partial breast irradiation is feasible, with very low acute toxicity.

  15. Postoperative Concurrent Chemoradiotherapy Versus Postoperative Radiotherapy in High-Risk Cutaneous Squamous Cell Carcinoma of the Head and Neck: The Randomized Phase III TROG 05.01 Trial.

    Science.gov (United States)

    Porceddu, Sandro Virgilio; Bressel, Mathias; Poulsen, Michael Geoffrey; Stoneley, Adam; Veness, Michael John; Kenny, Lizbeth Moira; Wratten, Chris; Corry, June; Cooper, Stephen; Fogarty, Gerald Blaise; Collins, Marnie; Collins, Michael Kevin; Macann, Andrew Martin John; Milross, Christopher Gerard; Penniment, Michael Gordon; Liu, Howard Yu-Hao; King, Madeleine Trudy; Panizza, Benedict James; Rischin, Danny

    2018-05-01

    Purpose To report the results of the Trans Tasman Radiation Oncology Group randomized phase III trial designed to determine whether the addition of concurrent chemotherapy to postoperative radiotherapy (CRT) improved locoregional control in patients with high-risk cutaneous squamous cell carcinoma of the head and neck. Patients and Methods The primary objective was to determine whether there was a difference in freedom from locoregional relapse (FFLRR) between 60 or 66 Gy (6 to 6.5 weeks) with or without weekly carboplatin (area under the curve 2) af