WorldWideScience

Sample records for attached molecular design

  1. Imaging the molecular dynamics of dissociative electron attachment to water

    Energy Technology Data Exchange (ETDEWEB)

    Adaniya, Hidihito; Rudek, B.; Osipov, Timur; Haxton, Dan; Weber, Thorsten; Rescigno, Thomas N.; McCurdy, C.W.; Belkacem, Ali

    2009-10-19

    Momentum imaging experiments on dissociative electron attachment to the water molecule are combined with ab initio theoretical calculations of the angular dependence of the quantum mechanical amplitude for electron attachment to provide a detailed picture of the molecular dynamics of dissociation attachment via the two lowest energy Feshbach resonances. The combination of momentum imaging experiments and theory can reveal dissociation dynamics for which the axial recoil approximation breaks down and thus provides a powerful reaction microscope for DEA to polyatomics.

  2. Jet-diffuser Ejector - Attached Nozzle Design

    Science.gov (United States)

    Alperin, M.; Wu, J. J.

    1980-01-01

    Attached primary nozzles were developed to replace the detached nozzles of jet-diffuser ejectors. Slotted primary nozzles located at the inlet lip and injecting fluid normal to the thrust axis, and rotating the fluid into the thrust direction using the Coanda Effect were investigated. Experiments indicated excessive skin friction or momentum cancellation due to impingement of opposing jets resulted in performance degradation. This indicated a desirability for location and orientation of the injection point at positions removed from the immediate vicinity of the inlet surface, and at an acute angle with respect to the thrust axis. Various nozzle designs were tested over a range of positions and orientations. The problems of aircraft integration of the ejector, and internal and external nozzle losses were also considered and a geometry for the attached nozzles was selected. The effect of leaks, protrusions, and asymmetries in the ejector surfaces was examined. The results indicated a relative insensitivity to all surface irregularities, except for large protrusions at the throat of the ejector.

  3. Design of a Power Tool Attachment for Sawing Operation

    Directory of Open Access Journals (Sweden)

    Mayur Appaiah

    2015-07-01

    Full Text Available The Design of a Power Tool Attachment for Sawing Operation is discussed. First, the Target Specifications are established. The Design work is carried out, especially that of the Main Shaft and Support Tube. Calculations and Finite Element Analysis (FEA are also done. The Prototype is fabricated and assembled. The Testing of the prototype is done, by Sawing commercial plywood of maximum thickness 25mm. Weight of the Attachment is 1.3 kg, and the Machine is easy to use, benefitting unskilled users.

  4. Design and Development of Attachment for Hydraulic Stacker

    Directory of Open Access Journals (Sweden)

    S.H. Gawande

    2010-05-01

    Full Text Available The main purpose of this paper is to develop an Attachment which will enable the lateral movement of the manufacturing Dies by mounting it on the forks of any Hydraulic Stacker or Fork Lift. The Attachmentmanufactured is unique because it can be attached or mounted on any hydraulic stalker in the One Tonne range. The attachment is a combination of two separate bed of rollers, a lead screw, a gear mechanism and a moving frame which enables the hydraulic stacker to easily load or unload Dies upto the range of one tonne, in and out of Machine Presses and Storage Racks which reduces material handling time and cost, manual effort and increases safety. The developed attachment in this work can also be easily detached and kept aside when not in use, so that the stacker can be used for regular purposes in the logistics department. The detail design, fabrication and testing work is carried out at A.V.M Seating Systems Ltd, Pune-26.

  5. Molecular modelling and radiopharmaceutical design

    International Nuclear Information System (INIS)

    Aim: Among several headings for radiopharmaceuticals (RPs) design, molecular modelling (MM) could be used for the prediction of ligands and metal-complexes structures. Using MM it is also possible to simulate molecular interactions between predicted structures and specific biomolecules. Bisphosphonates (BPs) are ligands that are able to coordinate radioactive metals, such as 153Sm, 166Ho, 186Re, etc., but they are all polymeric complexes difficult to characterize. It is reported that the bone uptake does not depend on the nature of metal center, but is primarily driven by the nature of the ligand, as in the case of HEDP-M (M=99mTc, 186Re, 113Sn). So, it would be interesting to estimate the relevant molecular properties of BPs by MM, simulate their interaction with hydroxyapatite (HAP) the main bone component, and then correlate the predicted molecular parameters with experimental data obtained from HAP binding and biodistribution studies of BPs carrying radioactive metals. Materials and Methods: The molecular structures and preferred conformations of BPs differing in the length of the aliphatic chain attached to their substituted amine groups (pami-dronate, olpadronate and ibandronate) were obtained using the second-generation CVFF 950 (version 1.01) force field of Hwang et al. Simulation of the interactions between the studied BPs and HAP were performed using a Cerius-2 system of programs running on a Silicon Graphics O2 workstation. BPs-153Sm complexes were synthesized and characterized by ITLC. Their binding to HAP and in vivo biodistribution studies were carried out as usual described in literature. Results: A direct correlation could be established between in vitro BPs affinity towards HAP and their corresponding energies from the Coulomb interactions involving the N and P atoms of the studied BPs bound to the HAP (0,0,1) surface and the nearest Ca atoms of HAP. The BPs-153Sm showing the highest binding to HAP and skeletal uptake are those which possess the

  6. Attachments

    International Nuclear Information System (INIS)

    In this attachment to the Annual report 1999 of the Nuclear Regulatory Authority of the Slovak Republic (UJD) the economic and personnel data of the UJD, used abbreviations, as well as the International nuclear event scales - INES are presented. Professional level of staff of the UJD is influenced by the education structure of its staff, when nearly 75% of the total number of staff has a university degree. A of 31.12.1999 there were 79 employees as average calculated number. Financing of the regulator in 1999 was mainly provided from the state budget, which represented 96% of all expenditures. The total volume of expenditures for UJD activity funded from the state budget achieved as of 31.12.1999 Slovak crowns (SK) 67 067 thousands. In the main category of expenditures an amount of SK 63 499 thous. was used for current activities, and the difference of SK 3 587 thous. was used for raising capital assets. Significant increase expenditures in the evaluated year compared to the 1998 was caused by a special purpose payment made by the Slovakia into the Fund for reconstruction of the Chernobyl cover (SK 19 996 thous.) funded through the budget chapter of the regulator. In the structure of current expenditures the highest share is taken by current transfers to abroad in total of SK 22 543 thous., i.e. contribution to reconstruction of Chernobyl cover made to the EBRD and contributions to the Fund of Technical Co-operation of the IAEA. For procurement of goods and services an amount of SK 19 814 thous. was spent, of which SK 7 054 thous. was used for funding science and technology tasks which were contracted out. The decision-making process in performing state supervision forced UJD to contact out various expert opinions and studies, for which UJD paid SK 2 058 thous. in total. Other expenditures in a volume of SK 10 702 thous. represent travel expenses, goods and services for UJD, rent for offices and other inevitable expenses. Salaries of staff represented SK 15 953

  7. DESIGN OF A PORTABLE AND ATTACHABLE BABY COT

    Directory of Open Access Journals (Sweden)

    SOWAH BORIS NII-AKO

    2013-05-01

    Full Text Available To solve congestion problems facing many hospitals in developing countries, baby cots are being eliminated and mothers are made to sleep on the same bed with their new-born babies; a practice known as co-sleeping. The work presented here seeks to reduce risks of Sudden Infant Death Syndrome (SIDS and suffocation associated with co-sleeping by employing the formal engineering design process to develop a portable, safe and cost effective baby cot. The cot is attachable to the mother’s bed, has four movement restrictors to regulate the movement of the baby within a given range and a hard surface mattress to ensure the safety of the baby. There are ventilation ports provided to keep the temperature within the cot comfortable. The design can be modified to be used by older babies and may be mounted on a collapsible stand where space limitations are not critical.

  8. Design and Development of Attachment for Hydraulic Stacker

    OpenAIRE

    S.H. Gawande; A.A. Arole; K.H. Barhate,; R.P. Gujar; M. Viroff

    2010-01-01

    The main purpose of this paper is to develop an Attachment which will enable the lateral movement of the manufacturing Dies by mounting it on the forks of any Hydraulic Stacker or Fork Lift. The Attachmentmanufactured is unique because it can be attached or mounted on any hydraulic stalker in the One Tonne range. The attachment is a combination of two separate bed of rollers, a lead screw, a gear mechanism and a moving frame which enables the hydraulic stacker to easily load or unload Dies up...

  9. Highly Transient Molecular Interactions Underlie the Stability of Kinetochore–Microtubule Attachment During Cell Division

    Science.gov (United States)

    Zaytsev, Anatoly V.; Ataullakhanov, Fazly I.; Grishchuk, Ekaterina L.

    2013-01-01

    Chromosome segregation during mitosis is mediated by spindle microtubules that attach to chromosomal kinetochores with strong yet labile links. The exact molecular composition of the kinetochore–microtubule interface is not known but microtubules are thought to bind to kinetochores via the specialized microtubule-binding sites, which contain multiple microtubule-binding proteins. During prometaphase the lifetime of microtubule attachments is short but in metaphase it increases 3-fold, presumably owing to dephosphorylation of the microtubule-binding proteins that increases their affinity. Here, we use mathematical modeling to examine in quantitative and systematic manner the general relationships between the molecular properties of microtubule-binding proteins and the resulting stability of microtubule attachment to the protein-containing kinetochore site. We show that when the protein connections are stochastic, the physiological rate of microtubule turnover is achieved only if these molecular interactions are very transient, each lasting fraction of a second. This “microscopic” time is almost four orders of magnitude shorter than the characteristic time of kinetochore–microtubule attachment. Cooperativity of the microtubule-binding events further increases the disparity of these time scales. Furthermore, for all values of kinetic parameters the microtubule stability is very sensitive to the minor changes in the molecular constants. Such sensitivity of the lifetime of microtubule attachment to the kinetics and cooperativity of molecular interactions at the microtubule-binding site may hinder the accurate regulation of kinetochore–microtubule stability during mitotic progression, and it necessitates detailed experimental examination of the microtubule-binding properties of kinetochore-localized proteins. PMID:24376473

  10. Highly Transient Molecular Interactions Underlie the Stability of Kinetochore-Microtubule Attachment During Cell Division.

    Science.gov (United States)

    Zaytsev, Anatoly V; Ataullakhanov, Fazly I; Grishchuk, Ekaterina L

    2013-12-13

    Chromosome segregation during mitosis is mediated by spindle microtubules that attach to chromosomal kinetochores with strong yet labile links. The exact molecular composition of the kinetochore-microtubule interface is not known but microtubules are thought to bind to kinetochores via the specialized microtubule-binding sites, which contain multiple microtubule-binding proteins. During prometaphase the lifetime of microtubule attachments is short but in metaphase it increases 3-fold, presumably owing to dephosphorylation of the microtubule-binding proteins that increases their affinity. Here, we use mathematical modeling to examine in quantitative and systematic manner the general relationships between the molecular properties of microtubule-binding proteins and the resulting stability of microtubule attachment to the protein-containing kinetochore site. We show that when the protein connections are stochastic, the physiological rate of microtubule turnover is achieved only if these molecular interactions are very transient, each lasting fraction of a second. This "microscopic" time is almost four orders of magnitude shorter than the characteristic time of kinetochore-microtubule attachment. Cooperativity of the microtubule-binding events further increases the disparity of these time scales. Furthermore, for all values of kinetic parameters the microtubule stability is very sensitive to the minor changes in the molecular constants. Such sensitivity of the lifetime of microtubule attachment to the kinetics and cooperativity of molecular interactions at the microtubule-binding site may hinder the accurate regulation of kinetochore-microtubule stability during mitotic progression, and it necessitates detailed experimental examination of the microtubule-binding properties of kinetochore-localized proteins. PMID:24376473

  11. Inverse strategies for molecular design

    International Nuclear Information System (INIS)

    An 'inverse' molecular design strategy is described to assist in the development of new molecules with optimized properties. This approach is based on a molecular orbital view and can be used to tailor ground state or excited state properties subject to particular constrains. In this scheme, wave functions are sought that optimize a chemical or electronic property, and then a Hamiltonian is constructed that generates these optimized wave functions. Analysis of the chemical properties in the optimized systems may suggest new synthetic targets. Examples are presented that optimize the transition dipole moment in some simple structures. 15 refs., 6 figs

  12. Comparison of the FRM-II HEU design with an alternative LEU design. Attachment

    International Nuclear Information System (INIS)

    After presentation of the foregoing paper by Dr. Nelson Hanan of Argonne National Laboratory (ANL) proposing an alternative LEU core with one fuel ring and a power level of 33 MW, a presentation was made by Dr. Klaus Boning of the Technical University of Munich comparing the FRM-II HEU design with an LEU design by Tlm that had two fuel rings and a power level of 40 MW. Dr. Boning raised the following issues concerning the use of LEU fuel in FRM-H reactor designs: (1) qualification of HEU and LEU silicide fuels, (2) gamma heating in the heavy water reflector, (3) the radiological consequences of hypothetical accidents, and (4) cost and schedule. These issues are addressed in this Attachment. In his presentation, Dr. Hanan mentioned that ANL was also investigating other LEU designs. This work led to a second alternative LEU design that has the same neutron flux performance (8 x 1014 n/cm2/s peak neutron flux in the reflector) and the same fuel lifetime (50 full power days) as the HEU design, but uses LEU silicide fuel with a uranium density of only 4.5 g/cm3. This design was achieved by using a fuel plate that has a fuel meat thickness of 0.76 mm, a cladding thickness of 0.38 mm, and a water channel gap of 2.2 mm. A comparison is shown of the main characteristics of this second alternative LEU design with those of the FRM-II HEU design. The ANL core again has one fuel ring with the same dimensions. With this LEU design, a two stage process is no longer necessary because LEU silicide fuel with a uranium density of 4.5 g/cm3 is fully qualified, licensable, and available now for use in a high flux reactor such as the FRM-II

  13. Molecular design of Mycoplasma hominis Vaa adhesin

    DEFF Research Database (Denmark)

    Boesen, Thomas; Fedosova, Natalya U.; Kjeldgaard, Morten;

    2001-01-01

    The variable adherence-associated (Vaa) adhesin of the opportunistic human pathogen Mycoplasma hominis is a surface-exposed, membrane-associated protein involved in the attachment of the bacterium to host cells. The molecular masses of recombinant 1 and 2 cassette forms of the protein determined by...

  14. Application of a modified harness design for attachment of radio transmitters to shorebirds

    Science.gov (United States)

    Sanzenbacher, Peter; Haig, Susan M.; Oring, L.W.

    2000-01-01

    Radio transmitter attachment methodology is important to the design of radio telemetry studies. In 1998, we attached 5 transmitters to a captive population of Western Sandpipers(Calidris mauri) and 7 transmitters to wild Killdeer (Charadriusv ociferus) using a modified version of the Rappolea nd Tipton (1991) figure-8 leg-loop harness. Captive birds fitted with harnesses did not exhibit quantifiable differences in behavior relative to control birds. Based on initial success in using the leg-loop harnesses, we used harnesses to attach transmitters in the wild to 30 Killdeer and 49 Dunlin (Calidris alpina) during the winters of 1998-1999 and 1999-2000. This was part of a study on movements of wintering shorebirds in the Willamette Valley of Oregon,USA. Wild birds showed no adverse effects of the harnesses.Thus, the described harness is a practical method for attachment of transmitters to shorebirds. Advantages of this harness method include a reduction in handling time at capture, elimination of the need to clip feathers for attachment, and increased transmitter retention time.

  15. Formation of carbon chain molecular anions by radiative electron attachment and their destruction by photodetachment

    Science.gov (United States)

    Khamesian, Marjan; Douguet, Nicolas; Raoult, Maurice; Dulieu, Olivier; Kokoouline, Viatcheslav

    2016-05-01

    Several negative ions Cn H- (n = 4 , 6 , 8), Cn N- (n = 1 , 3 , 5) have been recently observed in the interstellar medium (ISM). A possible mechanism of formation is radiative electron attachment (REA). In this study we develop a first principle theoretical approach to study the REA and apply the approach to the formation of the negative molecular ions CN-, C2 H-, C3 N-, C4 H-, C5 N-, C6 H-, and C8 H-. The theoretical approach is based on the UK R-matrix calculations. Cross sections and rate coefficients for formation of these ions by REA to the corresponding neutral radicals are calculated. There is no experimental data on REA of these ions. However, using a similar approach we have also calculated cross sections for photodetachment of the negative ions and compared the obtained results with available experimental data. The good agreement with photodetachment experimental data provides a confirmation that the REA cross sections obtained in this study is also reliable. NSF Grant PHYS-1506391.

  16. On the dissociative electron attachment as a potential source of molecular hydrogen in irradiated liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Cobut, V.; Jay-Gerin, J.-P.; Frongillo, Y. [Sherbrooke Univ., PQ (Canada). Faculte de Medecine; Patau, J.P. [Toulouse-3 Univ., 31 (France)

    1996-02-01

    In the radiolysis of liquid water, different mechanisms for the formation of molecular hydrogen (H{sub 2}) are involved at different times after the initial energy disposition. It has been suggested that the contributions of the e{sub aq}{sup -} + e{sub aq}{sup -}, H + e{sub aq}{sup -} and H + H reactions between hydrated electrons (e{sub aq}{sup -}) and hydrogen atoms in the spurs are not sufficient to account for all of the observed H{sub 2} yield (0.45 molecules/100 eV) on the microsecond time scale. Addressing the question of the origin of an unscavengeable H{sub 2} yield of 0.15 molecules/100 eV produced before spur expansion, we suggest that the dissociative capture of the so-called vibrationally-relaxing electrons by H{sub 2}O molecules is a possible pathway for the formation of part of the initial H{sub 2} yield. Comparison of recent dissociative-electron-attachment H{sup -}-anion yield-distribution measurements from amorphous H{sub 2}O films with the energy spectrum of vibrationally-relaxing electrons in irradiated liquid water, calculated by Monte Carlo simulations, plays in favor of this hypothesis. (author).

  17. Designed self-assembly of molecular necklaces.

    Science.gov (United States)

    Park, Ki-Min; Kim, Soo-Young; Heo, Jungseok; Whang, Dongmok; Sakamoto, Shigeru; Yamaguchi, Kentaro; Kim, Kimoon

    2002-03-13

    This paper reports an efficient strategy to synthesize molecular necklaces, in which a number of small rings are threaded onto a large ring, utilizing the principles of self-assembly and coordination chemistry. Our strategy involves (1) threading a molecular "bead" with a short "string" to make a pseudorotaxane and then (2) linking the pseudorotaxanes with a metal complex with two cis labile ligands acting as an "angle connector" to form a cyclic product (molecular necklace). A 4- or 3-pyridylmethyl group is attached to each end of 1,4-diaminobutane or 1,5-diaminopentane to produce the short "strings" (C4N4(2+), C4N3(2+), C5N4(2+), and C5N3(2+)), which then react with a cucurbituril (CB) "bead" to form stable pseudorotaxanes (PR44(2+), PR43(2+), PR54(2+), and PR53(2+), respectively). The reaction of the pseudorotaxanes with Pt(en)(NO(3))(2) (en = ethylenediamine) produces a molecular necklace [4]MN, in which three molecular "beads" are threaded on a triangular framework, and/or a molecular necklace [5]MN, in which four molecular "beads" are threaded on a square framework. Under refluxing conditions, the reaction with PR44(2+) or PR54(2+) yields exclusively [4]MN (MN44T or MN54T, respectively), whereas that with PR43(2+) or PR53(2+) produces exclusively [5]MN (MN43S or MN53S, respectively). The products have been characterized by various methods including X-ray crystallography. At lower temperatures, on the other hand, the reaction with PR44(2+) or PR54(2+) affords both [4]MN and [5]MN. The supermolecules reported here are the first series of molecular necklaces obtained as thermodynamic products. The overall structures of the molecular necklaces are strongly influenced by the structures of pseudorotaxane building blocks, which is discussed in detail on the basis of the X-ray crystal structures. The temperature dependence of the product distribution observed in this self-assembly process is also discussed. PMID:11878967

  18. Bacterial Attachment to Polymeric Materials Correlates with Molecular Flexibility and Hydrophilicity

    OpenAIRE

    Sanni, Olutoba; Chang, Chien-Yi; Anderson, Daniel G.; Langer, Robert; Davies, Martyn C.; Williams, Philip M; Williams, Paul; Alexander, Morgan R.; Hook, Andrew L.

    2014-01-01

    A new class of material resistant to bacterial attachment has been discovered that is formed from polyacrylates with hydrocarbon pendant groups. In this study, the relationship between the nature of the hydrocarbon moiety and resistance to bacteria is explored, comparing cyclic, aromatic, and linear chemical groups. A correlation is shown between bacterial attachment and a parameter derived from the partition coefficient and the number of rotatable bonds of the materials' pendant groups. This...

  19. Design of underwater video attached to buoy for observing shallow water substrate

    Science.gov (United States)

    Dingtian, Y.; Wenxi, C.; Delu, P.

    2007-01-01

    Knowledge of shallow water substrate is very important for protection and management of coastal ecosystem. Traditional methods for observing shallow water substrate was by sending diver to photography and recorded with eye, which was laborious and money taking. In order to obtain the easier way to study the shallow water substrate, an underwater video system was designed. Underwater video sensor, optical sensor, sonar sensor, tiltometer, GPS system, and ascending and descending system were all attached to the buoy system, and data was gathered and processed by the computer on the ship. The obtained data could be used for analyzing substrate type, activity of benthos and ground truth data for satellite remote sensing.

  20. Bacterial attachment to polymeric materials correlates with molecular flexibility and hydrophilicity.

    Science.gov (United States)

    Sanni, Olutoba; Chang, Chien-Yi; Anderson, Daniel G; Langer, Robert; Davies, Martyn C; Williams, Philip M; Williams, Paul; Alexander, Morgan R; Hook, Andrew L

    2015-04-01

    A new class of material resistant to bacterial attachment has been discovered that is formed from polyacrylates with hydrocarbon pendant groups. In this study, the relationship between the nature of the hydrocarbon moiety and resistance to bacteria is explored, comparing cyclic, aromatic, and linear chemical groups. A correlation is shown between bacterial attachment and a parameter derived from the partition coefficient and the number of rotatable bonds of the materials' pendant groups. This correlation is applicable to 86% of the hydrocarbon pendant moieties surveyed, quantitatively supporting the previous qualitative observation that bacteria are repelled from poly(meth)acrylates containing a hydrophilic ester group when the pendant group is both rigid and hydrophobic. This insight will help inform and predict the further development of polymers resistant to bacterial attachment. PMID:25491266

  1. Prevalence and first molecular characterization of Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis, in Rhipicephalus sanguineus ticks attached to dogs from Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed W. Ghafar

    2012-04-01

    Full Text Available PCR targeting 16S rRNA gene integrated with sequence analysis were performed to investigate the prevalence and the molecular identity of Anaplasma phagocytophilum in Egyptian Rhipicephalus sanguineus ticks attached to dogs. A total of 413 adult and nymphal R. sanguineus ticks were collected while attached to 72 free-roaming dogs from four locations (Imbaba, Boulaq, Haram, Monib in Giza Governorate, Egypt. DNA was successfully extracted from 401 specimens (133 nymphs and 268 adults. The overall prevalence rate was 13.7% and adult ticks showed a significantly higher infection rate (16.4% compared to nymphs (8.3%. Sequence comparisons of 218-bp showed that detected organism belongs to A. phagocytophilum. The sequence showed 99.1% similarity (2 nucleotide differences with some strains described as human pathogens and with that detected in the established tick vectors. Phylogenetic analysis placed the bacteria on a separate branch with that found in R. annulatus from Egypt (DQ379972 (99.5% similarity. Our variant strain was designated as A. phagocytophilum-Ghafar-EGY (AB608266. This report is the first molecular characterization of A. phagocytophilum in R. sanguineus in Egypt, suggesting that this tick species may act as a competent vector for a variant strain of human granulocytic anaplasmosis agent.

  2. Optimally designed fields for controlling molecular dynamics

    Science.gov (United States)

    Rabitz, Herschel

    1991-10-01

    This research concerns the development of molecular control theory techniques for designing optical fields capable of manipulating molecular dynamic phenomena. Although is has been long recognized that lasers should be capable of manipulating dynamic events, many frustrating years of intuitively driven laboratory studies only serve to illustrate the point that the task is complex and defies intuition. The principal new component in the present research is the recognition that this problem falls into the category of control theory and its inherent complexities require the use of modern control theory tools largely developed in the engineering disciplines. Thus, the research has initiated a transfer of the control theory concepts to the molecular scale. Although much contained effort will be needed to fully develop these concepts, the research in this grant set forth the basic components of the theory and carried out illustrative studies involving the design of optical fields capable of controlling rotational, vibrational and electronic degrees of freedom. Optimal control within the quantum mechanical molecular realm represents a frontier area with many possible ultimate applications. At this stage, the theoretical tools need to be joined with merging laboratory optical pulse shaping capabilities to illustrate the power of the concepts.

  3. Molecular Rift: Virtual Reality for Drug Designers.

    Science.gov (United States)

    Norrby, Magnus; Grebner, Christoph; Eriksson, Joakim; Boström, Jonas

    2015-11-23

    Recent advances in interaction design have created new ways to use computers. One example is the ability to create enhanced 3D environments that simulate physical presence in the real world--a virtual reality. This is relevant to drug discovery since molecular models are frequently used to obtain deeper understandings of, say, ligand-protein complexes. We have developed a tool (Molecular Rift), which creates a virtual reality environment steered with hand movements. Oculus Rift, a head-mounted display, is used to create the virtual settings. The program is controlled by gesture-recognition, using the gaming sensor MS Kinect v2, eliminating the need for standard input devices. The Open Babel toolkit was integrated to provide access to powerful cheminformatics functions. Molecular Rift was developed with a focus on usability, including iterative test-group evaluations. We conclude with reflections on virtual reality's future capabilities in chemistry and education. Molecular Rift is open source and can be downloaded from GitHub. PMID:26558887

  4. Design and development of a secure DICOM-Network Attached Server.

    Science.gov (United States)

    Tachibana, Hidenobu; Omatsu, Masahiko; Higuchi, Ko; Umeda, Tokuo

    2006-03-01

    It is not easy to connect a web-based server with an existing DICOM server, and using a web-based server on the INTERNET has risks. In this study, we designed and developed the secure DICOM-Network Attached Server (DICOM-NAS) through which the DICOM server in a hospital-Local Area Network (LAN) was connected to the INTERNET. After receiving a Client's image export request, the DICOM-NAS sent it to the DICOM server with DICOM protocol. The server then provided DICOM images to the DICOM-NAS, which transferred them to the Client using HTTP. The DICOM-NAS plays an important role between DICOM protocol and HTTP, and only temporarily stores the requested images. The DICOM server keeps all of the original DICOM images. When unwanted outsiders attempt to get into the DICOM-NAS, they cannot access any medical images because these images are not stored in the DICOM-NAS. Therefore, the DICOM-NAS does not require large storage, but can greatly improve information security. PMID:16503366

  5. [Design and development of a secure DICOM-Network Attached Server].

    Science.gov (United States)

    Tachibana, Hidenobu; Omatsu, Masahiko; Higuchi, Ko; Umeda, Tokuo

    2006-04-20

    It is not easy to connect a Web-based server with an existing DICOM server, and using a Web-based server on the Internet has risks. In this study, we designed and developed a secure DICOM-Network Attached Server (DICOM-NAS) through which the DICOM server in a hospital LAN was connected to the Internet. After receiving a client's image export request, the DICOM-NAS sent it to the DICOM server using the DICOM protocol. The server then provided DICOM images to the DICOM-NAS, which transferred them to the client, using HTTP. The DICOM-NAS plays an important role between the DICOM protocol and HTTP, and stores the requested images only temporarily. The DICOM server keeps all of the original DICOM images. If an unauthorized user attempts to access the DICOM-NAS, medical images cannot be accessed because images are not stored in the DICOM-NAS. Furthermore, the DICOM-NAS has features related to reporting and MPR. Therefore, the DICOM-NAS does not require a large storage capacity, but can greatly improve information security. PMID:16639395

  6. Mercury-Mediated Attachment of Metal-Sandwich-Based Altitudinal Molecular Rotors to Gold Surfaces

    Czech Academy of Sciences Publication Activity Database

    Mulcahy, M. E.; Bastl, Zdeněk; Stensrud, Kenneth F.; Magnera, T. F.; Michl, Josef

    2010-01-01

    Roč. 114, č. 33 (2010), s. 14050-14060. ISSN 1932-7447 R&D Projects: GA AV ČR KAN100400702; GA ČR GA203/07/1619 Grant ostatní: ERC Advanced Grant(XE) 227756 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40550506 Keywords : XPS * STM * molecular rotors Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.520, year: 2010

  7. Surface-attached molecular beacons light the way for DNA sequencing

    Czech Academy of Sciences Publication Activity Database

    Paleček, Emil

    2004-01-01

    Roč. 22, č. 2 (2004), s. 55-58. ISSN 0167-7799 R&D Projects: GA AV ČR IBS5004355; GA ČR GA204/03/0566 Institutional research plan: CEZ:AV0Z5004920 Keywords : molecular beacon * DNA stem-loop structure * DNA sensors Subject RIV: BO - Biophysics Impact factor: 8.606, year: 2004

  8. Electron-attachment processes

    International Nuclear Information System (INIS)

    Topics covered include: (1) modes of production of negative ions, (2) techniques for the study of electron attachment processes, (3) dissociative electron attachment to ground-state molecules, (4) dissociative electron attachment to hot molecules (effects of temperature on dissociative electron attachment), (5) molecular parent negative ions, and (6) negative ions formed by ion-pair processes and by collisions of molecules with ground state and Rydberg atoms

  9. Molecular characterization of a human matrix attachment region that improves transgene expression in CHO cells.

    Science.gov (United States)

    Sun, Qiu-Li; Zhao, Chun-Peng; Chen, Shao-Nan; Wang, Li; Wang, Tian-Yun

    2016-05-15

    Chinese hamster ovary (CHO) cells offer many advantages for recombinant gene expression, including proper folding and post-translational modification of the recombinant protein. However, due to positional effects resulting from the neighboring chromatin, transgenes are often expressed at low levels in these cells. While previous studies demonstrated that matrix attachment regions (MARs) can be utilized to increase transgene expression by buffering transgene silencing, the mechanism by which this occurs is poorly understood. We therefore performed a deletion analysis of the human β-globin MAR sequence to characterize the regions that are necessary to enhance transgene expression in CHO cells. Our results indicate that of the six β-globin MAR fragments tested (MAR-1-6; nucleotides 1-540, 420-1020, 900-1500, 1380-1980, 1860-2460, and 2340-2999, respectively), MAR-2, followed by MAR-3, was the most effective region for promoting stable and elevated transgene expression. Meanwhile, bioinformatic analyses demonstrated that these fragments encode a MAR-like motif and several transcription factor binding sites, including special AT-rich binding protein 1 (SATB1), CCAAT-enhancer-binding proteins (C/EBP), CCCTC-binding factor (CTCF), and Glutathione (GSH) binding motifs, indicating that these elements may contribute to the MAR-mediated enhancement of transgene expression. In addition, we found that truncated MAR derivatives yield more stable transgene expression levels than transgenes lacking the MAR. We concluded that the MAR-mediated transcriptional activation of transgenes requires a specific AT-rich sequence, as well as specific transcription factor-binding motifs. PMID:26869318

  10. Attached molecular motor in a trapped single molecule assay as a bidimensional Brownian multistable system.

    Science.gov (United States)

    Marcucci, L; Yanagida, T

    2013-06-01

    To elucidate the physical properties of the force generation mechanism in molecular motors, we have obtained an analytical solution of the bidimensional Fokker-Plank equation which describes a common setup used in single molecule experiments. As a first application of this general result, we have shown that the size of the trapping system affects the dwell time of a multistable particle linearly. A quantitative application to skeletal actomyosin complex, using direct observation of force generation dynamics in the literature, shows that the size of the trapping system used was important for increasing the dwell time of the myosin head stable states to an observable time scale. PMID:23848719

  11. Design of 8-ft-Diameter Barrel Test Article Attachment Rings for Shell Buckling Knockdown Factor Project

    Science.gov (United States)

    Lovejoy, Andrew E.; Hilburger, Mark W.

    2010-01-01

    The Shell Buckling Knockdown Factor (SBKF) project includes the testing of sub-scale cylinders to validate new shell buckling knockdown factors for use in the design of the Ares-I and Ares-V launch vehicles. Test article cylinders represent various barrel segments of the Ares-I and Ares-V vehicles, and also include checkout test articles. Testing will be conducted at Marshall Space Flight Center (MSFC) for test articles having an eight-foot diameter outer mold line (OML) and having lengths that range from three to ten feet long. Both ends of the test articles will be connected to the test apparatus using attachment rings. Three multiple-piece and one single-piece design for the attachment rings were developed and analyzed. The single-piece design was chosen and will be fabricated from either steel or aluminum (Al) depending on the required safety factors (SF) for test hardware. This report summarizes the design and analysis of these attachment ring concepts.

  12. Metalloporphyrin catalysts for oxygen reduction developed using computer-aided molecular design

    Energy Technology Data Exchange (ETDEWEB)

    Ryba, G.N.; Hobbs, J.D.; Shelnutt, J.A. [and others

    1996-04-01

    The objective of this project is the development of a new class of metalloporphyrin materials used as catalsyts for use in fuel cell applications. The metalloporphyrins are excellent candidates for use as catalysts at both the anode and cathode. The catalysts reduce oxygen in 1 M potassium hydroxide, as well as in 2 M sulfuric acid. Covalent attachment to carbon supports is being investigated. The computer-aided molecular design is an iterative process, in which experimental results feed back into the design of future catalysts.

  13. Molecular Recognition Units: Design and diagnostic applications

    International Nuclear Information System (INIS)

    Molecular Recognition Units (MRUs), small peptides derived from complementarity-determining region (CDR) of IgM antibodies, can mimic the recognition site found in the antibody. One example of an MRU fusion peptide designed to image thrombi was derived from PAC 1.1, an IgM monoclonal antibody specific for the GPIIb/IIa receptor on platelets. The peptide sequence from the third CDR of the heavy chain was engineered for optimal binding activity and synthesized with a metal-binding peptide sequence. After labeling with 99m-Tc, the peptides were injected into either animal models of experimentally induced thrombi in order to determine their effectiveness in imaging model thrombi. Data are presented which demonstrate enhanced binding with open-quotes tandem repeatsclose quotes of the MRU domain and no loss of activity after incorporation of the metal-binding domain. These studies have led to a clinical candidate consisting of 17 amino acids. Extension of this concept to other MRUs and fusion peptides is also discussed

  14. Diverse redox-active molecules bearing O-, S-, or Se-terminated tethers for attachment to silicon in studies of molecular information storage.

    Science.gov (United States)

    Balakumar, Arumugham; Lysenko, Andrey B; Carcel, Carole; Malinovskii, Vladimir L; Gryko, Daniel T; Schweikart, Karl-Heinz; Loewe, Robert S; Yasseri, Amir A; Liu, Zhiming; Bocian, David F; Lindsey, Jonathan S

    2004-03-01

    A molecular approach to information storage employs redox-active molecules tethered to an electroactive surface. Attachment of the molecules to electroactive surfaces requires control over the nature of the tether (linker and surface attachment group). We have synthesized a collection of redox-active molecules bearing different linkers and surface anchor groups in free or protected form (hydroxy, mercapto, S-acetylthio, and Se-acetylseleno) for attachment to surfaces such as silicon, germanium, and gold. The molecules exhibit a number of cationic oxidation states, including one (ferrocene), two [zinc(II)porphyrin], three [cobalt(II)porphyrin], or four (lanthanide triple-decker sandwich compound). Electrochemical studies of monolayers of a variety of the redox-active molecules attached to Si(100) electrodes indicate that molecules exhibit a regular mode of attachment (via a Si-X bond, X = O, S, or Se), relatively homogeneous surface organization, and robust reversible electrochemical behavior. The acetyl protecting group undergoes cleavage during the surface deposition process, enabling attachment to silicon via thio or seleno groups without handling free thiols or selenols. PMID:14986994

  15. Brownian molecular rotors: Theoretical design principles and predicted realizations

    OpenAIRE

    Schönborn, Jan Boyke; Herges, Rainer; Hartke, Bernd

    2009-01-01

    We propose simple design concepts for molecular rotors driven by Brownian motion and external photochemical switching. Unidirectionality and efficiency of the motion is measured by explicit simulations. Two different molecular scaffolds are shown to yield viable molecular rotors when decorated with suitable substituents.

  16. A CONCEPTUAL DESIGN OF WIND FRICTION REDUCTION ATTACHMENTS TO THE REAR PORTION OF A CAR FOR BETTER FUEL ECONOMY AT HIGH SPEEDS

    Directory of Open Access Journals (Sweden)

    Dr. G.Jayachandra Reddy

    2012-05-01

    Full Text Available Normally all the car bodies are streamlined for very less wind drag coefficient, but still due to the length of car as constraint the rear portion of the car was not fully streamlined. The present paper objective is to design the wind friction reduction attachments to the rear portion of a car which can be opened and closed depending onthe requirement, thereby mileage of the vehicle at high speeds will be improved and the car can travel at higher speeds without increasing the engine capacity. The rear attachments of car can be closed in traffic and parking periods and when the vehicle is travelling on highways at high speed, the attachments are opened. To open and close the wind friction reduction attachments a hydraulic system is designed. The wind friction reduction attachments are designed to be inside the rear door in the closed condition so that there won’t be any problem in aesthetic point of view.

  17. Nanoscale molecular systems : designed phenyl-acetylene architectures

    OpenAIRE

    Eaton, Thomas R.

    2015-01-01

    Molecular design should be about fulfilling function. However designing molecular structures that will fulfill a particular function is incredibly difficult. The delicate interplay of structure-property relationships and further emergent phenomena that arise when molecules come together are very unpredictable. This thesis sets out tools to guide the budding molecular architect in successfully making the transition in mindset from structure-property relationships to structure-function relatio...

  18. A quantum chemical study from a molecular perspective: ionization and electron attachment energies for species often used to fabricate single-molecule junctions

    CERN Document Server

    Baldea, Ioan

    2015-01-01

    The accurate determination of the lowest electron attachment ($EA$) and ionization ($IP$) energies for molecules embedded in molecular junctions is important for correctly estimating, \\emph{e.g.}, the magnitude of the currents ($I$) or the biases ($V$) where an $I-V$-curve exhibits a significant non-Ohmic behavior. Benchmark calculations for the lowest electron attachment and ionization energies of several typical molecules utilized to fabricate single-molecule junctions characterized by n-type conduction (4,4'-bipyridine, 1,4-dicyanobenzene, and 4,4'-dicyano-1,1'-biphenyl) and p-type conduction (benzenedithiol, biphenyldithiol, hexanemonothiol, and hexanedithiol] based on the EOM-CCSD (equation-of-motion coupled-cluster singles and doubles) state-of-the-art method of quantum chemistry are presented. They indicate significant differences from the results obtained within current approaches to molecular transport. The present study emphasizes that, in addition to a reliable quantum chemical method, basis sets m...

  19. Beyond Cell Penetrating Peptides: Designed Molecular Transporters

    OpenAIRE

    Wender, Paul A.; Cooley, Christina B.; Geihe, Erika I.

    2012-01-01

    Inspired originally by peptides that traverse biological barriers, research on molecular transporters has since identified the key structural requirements that govern cellular entry, leading to new, significantly more effective and more readily available agents. These new drug delivery systems enable or enhance cellular and tissue uptake, can be targeted, and provide numerous additional advantages of significance in imaging, diagnostics and therapy.

  20. Design and Application of Surface Modification at Molecular Scale

    Institute of Scientific and Technical Information of China (English)

    CHEN Miao; XUE Qun-Ji; ZHOU Feng; GUAN Fei; LIU Wei-Min

    2004-01-01

    The structuring of surfaces on a nanoscale level-both chemically and topographically has become an increasingly relevant field of research in nanotechnology with widespread application potential in various fields of science ( e. g.surface engineering, electronics, biotechnology, optics). Two examples on surface modification at molecular scale with self-assembly monolayers are shown: ( 1 ) Chemically attaching ultra-thin polymer films through the self-assembly of silane fictionalized copolymer have been approved in this article. (2) The patterned films with microstructures on different substrates have been prepared through micro-contact printing technique and electro polymerization.

  1. Biorefinery: a design tool for molecular gelators.

    Science.gov (United States)

    John, George; Shankar, Balachandran Vijai; Jadhav, Swapnil R; Vemula, Praveen Kumar

    2010-12-01

    Molecular gels, the macroscopic products of a nanoscale bottom-up strategy, have emerged as a promising functional soft material. The prospects of tailoring the architecture of gelator molecules have led to the formation of unique, highly tunable gels for a wide spectrum of applications from medicine to electronics. Biorefinery is a concept that integrates the processes of converting biomass/renewable feedstock and the associated infrastructure used to produce chemicals and materials, which is analogous to petroleum-based refinery. The current review assimilates the successful efforts to demonstrate the prospects of the biorefinery concept for developing new amphiphiles as molecular gelators. Amphiphiles based on naturally available raw materials such as amygdalin, vitamin C, cardanol, arjunolic acid, and trehalose that possess specific functionality were synthesized using biocatalysis and/or chemical synthesis. The hydrogels and organogels obtained from such amphiphiles were conceptually demonstrated for diverse applications including drug-delivery systems and the templated synthesis of hybrid materials. PMID:20465204

  2. DESIGN AND CHARACTERIZATION OF MOLECULAR SCAFFOLDS

    OpenAIRE

    Ziaco, Barbara

    2009-01-01

    In the post-genomic era the study of the interactions between biomolecules and in particular protein-protein interactions is of growing interest, since they are the basis of all the physiological processes mediated by the formation of complexes between biomolecules. Therefore, detailed knowledge of the molecular mechanisms responsible for these interactions is essential to develop molecules capable of modulating the biological activity of the protein target and then its cellular processes. ...

  3. A revised design approach of the attachment system for the ITER EU-HCPB-TBM based on a central cylindrical connection element

    Energy Technology Data Exchange (ETDEWEB)

    Zeile, Christian, E-mail: christian.zeile@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology (INR), 76344 Eggenstein-Leopoldshafen (Germany); Neuberger, Heiko [Karlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology (INR), 76344 Eggenstein-Leopoldshafen (Germany)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Design of an attachment system based on a cylinder to connect TBM and shield. Black-Right-Pointing-Pointer Attachment system has to cope with high EM loads and different thermal expansions. Black-Right-Pointing-Pointer Stiff design and central position fulfill these requirements. Black-Right-Pointing-Pointer Transient thermal-structural analyses confirm compliance of design with design codes. - Abstract: The EU-Helium Cooled Pebble Bed Test Blanket Module (HCPB-TBM), which is located inside an equatorial port plug, is attached to the shield by an attachment system. The design of the attachment system has to fulfill two conflicting requirements. On the one hand, it has to transfer the high electromagnetic forces acting on the TBM to the shield and on the other hand, it has to compensate the different thermal expansions between the shield and the back plate of the TBM. The recent design approach of the attachment system consists of a hollow cylinder located at the center of the back plate. This design combines two advantages: a simple geometry and correspondingly low fabrication effort and the central location where the differential strain between back plate and shield is minimal. Static and transient thermal-structural analyses of the most demanding load cases, a fast vertical displacement event type II and the operation state tritium outgassing, have been performed to evaluate the design and confirm the compliance with the relevant design codes. A welded connection of the attachment system to the TBM back plate and a bolted connection in combination with a splined shaft is proposed for the shield side because of the dissimilar materials.

  4. A revised design approach of the attachment system for the ITER EU-HCPB-TBM based on a central cylindrical connection element

    International Nuclear Information System (INIS)

    Highlights: ► Design of an attachment system based on a cylinder to connect TBM and shield. ► Attachment system has to cope with high EM loads and different thermal expansions. ► Stiff design and central position fulfill these requirements. ► Transient thermal-structural analyses confirm compliance of design with design codes. - Abstract: The EU-Helium Cooled Pebble Bed Test Blanket Module (HCPB-TBM), which is located inside an equatorial port plug, is attached to the shield by an attachment system. The design of the attachment system has to fulfill two conflicting requirements. On the one hand, it has to transfer the high electromagnetic forces acting on the TBM to the shield and on the other hand, it has to compensate the different thermal expansions between the shield and the back plate of the TBM. The recent design approach of the attachment system consists of a hollow cylinder located at the center of the back plate. This design combines two advantages: a simple geometry and correspondingly low fabrication effort and the central location where the differential strain between back plate and shield is minimal. Static and transient thermal-structural analyses of the most demanding load cases, a fast vertical displacement event type II and the operation state tritium outgassing, have been performed to evaluate the design and confirm the compliance with the relevant design codes. A welded connection of the attachment system to the TBM back plate and a bolted connection in combination with a splined shaft is proposed for the shield side because of the dissimilar materials.

  5. Molecular Thermodynamics for Chemical Process Design

    Science.gov (United States)

    Prausnitz, J. M.

    1976-01-01

    Discusses that aspect of thermodynamics which is particularly important in chemical process design: the calculation of the equilibrium properties of fluid mixtures, especially as required in phase-separation operations. (MLH)

  6. Research on the improvement design for the attachment of supports to AP1000 module wall

    International Nuclear Information System (INIS)

    Background: Modularization is one of the main characteristics for AP1000 nuclear power plant building. The steel-concrete-steel module wall is used instead of reinforced concrete structure wall. Usually, lots of Overlay Plate Embedments will be installed on the module wall to connect and fasten other structures, such as pipes, equipment and operation platforms. As for many supports taking less design loads, the safety margin is too big when using OLP embedment. Purpose: An improvement design will make sense that the supports with less design loads can be welded directly to the module wall instead of embedments. Methods: A finite element analysis based on nuclear-related concrete code is carried out. Results: Through analysis, the equations for the allowable design loads of supports to be welded directly to module wall are provided in this paper. Conclusions: The improvement design is proved feasible. In this way, the strength for steel face plate and studs will be utilized fully and this method will facilitate and simplify the design and construction with considerable engineering application value. (authors)

  7. Distribution of lifetimes of kinetochore–microtubule attachments: interplay of energy landscape, molecular motors and microtubule (de-)polymerization

    International Nuclear Information System (INIS)

    Before a cell divides into two daughter cells, chromosomes are replicated resulting in two sister chromosomes embracing each other. Each sister chromosome is bound to a separate proteinous structure, called kinetochore (kt), that captures the tip of a filamentous protein, called microtubule (MT). Two oppositely oriented MTs pull the two kts attached to two sister chromosomes, thereby pulling the two sisters away from each other. Here we theoretically study an even simpler system, namely an isolated kt coupled to a single MT; this system mimics an in vitro experiment where a single kt–MT attachment is reconstituted using purified extracts from budding yeast. Our models not only account for the experimentally observed ‘catch-bond-like’ behavior of the kt–MT coupling, but also make new predictions on the probability distribution of the lifetimes of the attachments. In principle, our new predictions can be tested by analyzing the data collected in the in vitro experiments, provided that the experiment is repeated a sufficiently large number of times. Our theory provides a deep insight into the effects of (a) size, (b) energetics, and (c) stochastic kinetics of the kt–MT coupling on the distribution of the lifetimes of these attachments. (paper)

  8. MOLECULAR THERMODYNAMICS IN THE DESIGN OF SUBSTITUTE SOLVENTS

    Science.gov (United States)

    The use of physical properties and fluid behavior from molecular thermodynamics can lead to better decision making in the design of substitute solvents and can greatly reduce the expense and time required to find substitutes compared to designing solvents by experiment. this pape...

  9. Participatory Design to Enhance ICT Learning and Community Attachment: A Case Study in Rural Taiwan

    Directory of Open Access Journals (Sweden)

    Yi-Ting Huang

    2015-03-01

    Full Text Available This study used observation and interviews with participants in “PunCar Action” to understand how participatory design methods can be applied to the education of rural individuals in information and communication technology (ICT. PunCar Action is a volunteer program in which ICT educators tour the rural communities of Taiwan, offering courses on the use of digital technology. This paper makes three contributions: First, we found that participatory design is an excellent way to teach ICT and Web 2.0 skills, co-create community blogs, and sustain intrinsic motivation to use Web applications. Second, PunCar Action provides an innovative bottom-up intergenerational ICT education model with high penetrability capable of enhancing the confidence of rural residents in the use of ICT. Third, the content of basic courses was based on applications capable of making the lives of elderly individuals more convenient, and the advanced course was based on the co-creation of community blogs aimed at reviving the core functions of communities and expanding local industry. Our research was conducted with the use of a non-quantitative index to measure ICT learning performance of participants from a rural community. The results show that PunCar Action emphasizes interpersonal communication and informational applications and creates a collaborative process that encourages rural residents to take action to close the digital divide.

  10. MOLECULAR DESIGN OF COLLOIDS IN SUPERCRITICAL FLUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Keith P. Johnston

    2009-04-06

    The environmentally benign, non-toxic, non-flammable fluids water and carbon dioxide (CO2) are the two most abundant and inexpensive solvents on earth. Emulsions of these fluids are of interest in many industrial processes, as well as CO2 sequestration and enhanced oil recovery. Until recently, formation of these emulsions required stabilization with fluorinated surfactants, which are expensive and often not environmentally friendly. In this work we overcame this severe limitation by developing a fundamental understanding of the properties of surfactants the CO2-water interface and using this knowledge to design and characterize emulsions stabilized with either hydrocarbon-based surfactants or nanoparticle stabilizers. We also discovered a new concept of electrostatic stabilization for CO2-based emulsions and colloids. Finally, we were able to translate our earlier work on the synthesis of silicon and germanium nanocrystals and nanowires from high temperatures and pressures to lower temperatures and ambient pressure to make the chemistry much more accessible.

  11. Distribution of lifetimes of kinetochore-microtubule attachments:interplay of energy landscape, molecular motors and microtubule (de-)polymerization

    CERN Document Server

    Sharma, Ajeet K; Chowdhury, Debashish

    2013-01-01

    Before a cell divides into two daughter cells, the chromosomes are replicated resulting in two sister chromosomes embracing each other. Each sister chromosome is bound to a separate proteinous structure, called kinetochore (kt), that captures the tip of a filamentous protein, called microtubule (MT). Two oppositely oriented MTs pull the two kts attached to two sister chromosomes thereby pulling the two sisters away from each other. Here we theoretically study an even simpler system, namely an isolated kt coupled to a single MT; this system mimics an {\\it in-vitro} experiment where a single kt-MT attachment is reconstituted using purified extracts from budding yeast. Our models not only account for the experimentally observed "catch-bond-like" behavior of the kt-MT coupling, but also make new predictions on the probability distribution of the lifetimes of the attachments. In principle, our new predictions can be tested by analyzing the data collected in the {\\it in-vitro} experiments provided the experiment is...

  12. Product Attachment

    OpenAIRE

    Mugge, R.

    2007-01-01

    The topic of this doctoral research is the concept of product attachment for ordinary consumer durables. Product attachment is defined as the strength of the emotional bond a consumer experiences with a specific product. Specifically, the research investigated how this bond develops over time and the relationship between product attachment and product lifetime. In addition, we studied which determinants may affect the strength of the emotional bond with products and uncovered the role of the ...

  13. Effects of temperature and isotopic substitution on electron attachment dynamics of guanine-cytosine base pair: Ring-polymer and classical molecular dynamics simulations

    Science.gov (United States)

    Minoshima, Yusuke; Seki, Yusuke; Takayanagi, Toshiyuki; Shiga, Motoyuki

    2016-06-01

    The dynamical process of electron attachment to a guanine-cytosine pair in the normal (h-GC) and deuterated (d-GC) forms has been studied theoretically by semiclassical ring-polymer molecular dynamics (RPMD) simulations using the empirical valence bond model. The initially formed dipole-bound anion is converted rapidly to the valence-bound anion within about 0.1 ps in both h-GC and d-GC. However, the subsequent proton transfer in h-GC occurs with a rate five times greater than the deuteron transfer in d-GC. The change of rates with isotopic substitution and temperature variation in the RPMD simulations are quantitatively and qualitatively different from those in the classical molecular dynamics (MD) simulations, demonstrating the importance of nuclear quantum effects on the dynamics of this system.

  14. Product Attachment

    NARCIS (Netherlands)

    Mugge, R.

    2007-01-01

    The topic of this doctoral research is the concept of product attachment for ordinary consumer durables. Product attachment is defined as the strength of the emotional bond a consumer experiences with a specific product. Specifically, the research investigated how this bond develops over time and th

  15. Designing π-stacked molecular structures to control heat transport through molecular junctions

    Energy Technology Data Exchange (ETDEWEB)

    Kiršanskas, Gediminas [Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø (Denmark); Mathematical Physics and Nanometer Structure Consortium (nmC-LU), Lund University, Box 118, 221 00 Lund (Sweden); Li, Qian; Solomon, Gemma C. [Nano-Science Center and Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen Ø (Denmark); Flensberg, Karsten [Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø (Denmark); Leijnse, Martin [Solid State Physics and Nanometer Structure Consortium (nmC-LU), Lund University, 221 00 Lund (Sweden)

    2014-12-08

    We propose and analyze a way of using π stacking to design molecular junctions that either enhance or suppress a phononic heat current, but at the same time remain conductors for an electric current. Such functionality is highly desirable in thermoelectric energy converters, as well as in other electronic components where heat dissipation should be minimized or maximized. We suggest a molecular design consisting of two masses coupled to each other with one mass coupled to each lead. By having a small coupling (spring constant) between the masses, it is possible to either reduce or perhaps more surprisingly enhance the phonon conductance. We investigate a simple model system to identify optimal parameter regimes and then use first principle calculations to extract model parameters for a number of specific molecular realizations, confirming that our proposal can indeed be realized using standard molecular building blocks.

  16. Computer aided molecular design with combined molecular modeling and group contribution

    DEFF Research Database (Denmark)

    Harper, Peter Mathias; Gani, Rafiqul; Kolar, Petr;

    1999-01-01

    and on the availability of suitable models for property prediction. A new CAMD methodology that addresses this issue by combining molecular modeling techniques with a traditional CAMD approach is presented. The new method includes a new molecular/atomic structure generation algorithm, a large collection of property...... estimation methods, and, a link to molecular modelling tools. Application of the new CAMD method is highlighted through two industrial examples. (C) 1999 Elsevier Science B.V. All rights reserved.......Computer-aided molecular design (CAMD) provides a means for determining molecules or mixtures of molecules (CAMMD) having a desirable set of physicochemical properties. The application range of CAMD is restricted due to limitations on the complexity of the generated molecular structures...

  17. A systematic molecular circuit design method for gene networks under biochemical time delays and molecular noises

    Directory of Open Access Journals (Sweden)

    Chang Yu-Te

    2008-11-01

    Full Text Available Abstract Background Gene networks in nanoscale are of nonlinear stochastic process. Time delays are common and substantial in these biochemical processes due to gene transcription, translation, posttranslation protein modification and diffusion. Molecular noises in gene networks come from intrinsic fluctuations, transmitted noise from upstream genes, and the global noise affecting all genes. Knowledge of molecular noise filtering and biochemical process delay compensation in gene networks is crucial to understand the signal processing in gene networks and the design of noise-tolerant and delay-robust gene circuits for synthetic biology. Results A nonlinear stochastic dynamic model with multiple time delays is proposed for describing a gene network under process delays, intrinsic molecular fluctuations, and extrinsic molecular noises. Then, the stochastic biochemical processing scheme of gene regulatory networks for attenuating these molecular noises and compensating process delays is investigated from the nonlinear signal processing perspective. In order to improve the robust stability for delay toleration and noise filtering, a robust gene circuit for nonlinear stochastic time-delay gene networks is engineered based on the nonlinear robust H∞ stochastic filtering scheme. Further, in order to avoid solving these complicated noise-tolerant and delay-robust design problems, based on Takagi-Sugeno (T-S fuzzy time-delay model and linear matrix inequalities (LMIs technique, a systematic gene circuit design method is proposed to simplify the design procedure. Conclusion The proposed gene circuit design method has much potential for application to systems biology, synthetic biology and drug design when a gene regulatory network has to be designed for improving its robust stability and filtering ability of disease-perturbed gene network or when a synthetic gene network needs to perform robustly under process delays and molecular noises.

  18. Segmented molecular design of self-healing proteinaceous materials

    OpenAIRE

    Veikko Sariola; Abdon Pena-Francesch; Huihun Jung; Murat Çetinkaya; Carlos Pacheco; Metin Sitti; Demirel, Melik C.

    2015-01-01

    Hierarchical assembly of self-healing adhesive proteins creates strong and robust structural and interfacial materials, but understanding of the molecular design and structure–property relationships of structural proteins remains unclear. Elucidating this relationship would allow rational design of next generation genetically engineered self-healing structural proteins. Here we report a general self-healing and -assembly strategy based on a multiphase recombinant protein based material. Segme...

  19. A computational molecular design framework for crosslinked polymer networks

    OpenAIRE

    Eslick, J.C.; Q. Ye; J. Park; Topp, E.M.; Spencer, P.; Camarda, K.V.

    2008-01-01

    Crosslinked polymers are important in a very wide range of applications including dental restorative materials. However, currently used polymeric materials experience limited durability in the clinical oral environment. Researchers in the dental polymer field have generally used a time-consuming experimental trial-and-error approach to the design of new materials. The application of computational molecular design (CMD) to crosslinked polymer networks has the potential to facilitate developmen...

  20. New Synthetic Thrombin Inhibitors: Molecular Design and Experimental Verification

    OpenAIRE

    Sinauridze, Elena I.; Alexey N Romanov; Gribkova, Irina V.; Kondakova, Olga A.; Stepan S Surov; Aleksander S Gorbatenko; Butylin, Andrey A.; Monakov, Mikhail Yu.; Bogolyubov, Alexey A.; Kuznetsov, Yuryi V.; Sulimov, Vladimir B.; Ataullakhanov, Fazoyl I.

    2011-01-01

    Background The development of new anticoagulants is an important goal for the improvement of thromboses treatments. Objectives The design, synthesis and experimental testing of new safe and effective small molecule direct thrombin inhibitors for intravenous administration. Methods Computer-aided molecular design of new thrombin inhibitors was performed using our original docking program SOL, which is based on the genetic algorithm of global energy minimization in the framework of a Merck Mole...

  1. Lattice enumeration for inverse molecular design using the signature descriptor.

    Science.gov (United States)

    Martin, Shawn

    2012-07-23

    We describe an inverse quantitative structure-activity relationship (QSAR) framework developed for the design of molecular structures with desired properties. This framework uses chemical fragments encoded with a molecular descriptor known as a signature. It solves a system of linear constrained Diophantine equations to reorganize the fragments into novel molecular structures. The method has been previously applied to problems in drug and materials design but has inherent computational limitations due to the necessity of solving the Diophantine constraints. We propose a new approach to overcome these limitations using the Fincke-Pohst algorithm for lattice enumeration. We benchmark the new approach against previous results on LFA-1/ICAM-1 inhibitory peptides, linear homopolymers, and hydrofluoroether foam blowing agents. Software implementing the new approach is available at www.cs.otago.ac.nz/homepages/smartin. PMID:22657105

  2. Structure and conformational behavior of the DNA oligonucleotide attached to the charged surface: a molecular dynamics study

    Czech Academy of Sciences Publication Activity Database

    Kroutil, O.; Lankaš, Filip; Šíp, M.; Předota, M.; Kabeláč, Martin

    2011-01-01

    Roč. 18, č. 1 (2011), s. 32-32. ISSN 1211-5894. [Discussions in Structural Molecular Biology /9./. 24.03.2011-26.03.2011, Nové Hrady] Grant ostatní: GA ČR(CZ) GC204/09/J010 Institutional research plan: CEZ:AV0Z40550506 Keywords : DNA * oligonucleotide Subject RIV: EB - Genetics ; Molecular Biology

  3. Molecular docking sites designed for the generation of highly crystalline covalent organic frameworks

    Science.gov (United States)

    Ascherl, Laura; Sick, Torben; Margraf, Johannes T.; Lapidus, Saul H.; Calik, Mona; Hettstedt, Christina; Karaghiosoff, Konstantin; Döblinger, Markus; Clark, Timothy; Chapman, Karena W.; Auras, Florian; Bein, Thomas

    2016-04-01

    Covalent organic frameworks (COFs) formed by connecting multidentate organic building blocks through covalent bonds provide a platform for designing multifunctional porous materials with atomic precision. As they are promising materials for applications in optoelectronics, they would benefit from a maximum degree of long-range order within the framework, which has remained a major challenge. We have developed a synthetic concept to allow consecutive COF sheets to lock in position during crystal growth, and thus minimize the occurrence of stacking faults and dislocations. Hereby, the three-dimensional conformation of propeller-shaped molecular building units was used to generate well-defined periodic docking sites, which guided the attachment of successive building blocks that, in turn, promoted long-range order during COF formation. This approach enables us to achieve a very high crystallinity for a series of COFs that comprise tri- and tetradentate central building blocks. We expect this strategy to be transferable to a broad range of customized COFs.

  4. Design of Carborane Molecular Architectures via Electronic Structure Computations

    Directory of Open Access Journals (Sweden)

    Josep M. Oliva

    2009-01-01

    Full Text Available Quantum-mechanical electronic structure computations were employed to explore initial steps towards a comprehensive design of polycarborane architectures through assembly of molecular units. Aspects considered were (i the striking modification of geometrical parameters through substitution, (ii endohedral carboranes and proposed ejection mechanisms for energy/ion/atom/energy storage/transport, (iii the excited state character in single and dimeric molecular units, and (iv higher architectural constructs. A goal of this work is to find optimal architectures where atom/ion/energy/spin transport within carborane superclusters is feasible in order to modernize and improve future photoenergy processes.

  5. Designing an university-level module on molecular imaging chemistry

    International Nuclear Information System (INIS)

    training in radiopharmacy both in theory and hands-on practice. Final-year radiology students in Polytechnic have to go through a series of lectures on radiopharmacy and also practicals in hospital radiopharmacy laboratory. But due to the Government's initiatives on biomedical industries and also due to a global trend, interest in bio/medical imaging is rising among scientists and students. There is a need to fulfil this demand by introducing new course or modules at the University level. Designing an university-level module on molecular imaging chemistry: In National University of Singapore, a graduate student (MSc and PhD) level 5 module on ''Medical Imaging'' has already been introduced and a new module on ''Molecular Imaging Chemistry'' will be introduced soon. A module of this kind should serve as a link between chemistry, molecular imaging and clinical application with emphasis on chemical probe design. And should introduce contemporary topics and emerging concepts in chemistry related to molecular imaging. A brief introduction on different modalities of molecular imaging and principles of biomedical imaging should be introduced including principles of medical imaging equipment. How this knowledge will direct the chemical synthesis should be highlighted (lead directed synthesis). There should be a coverage on pharmacology and drug discovery process as imaging probes could be considered as drugs. Here is an example of an outline for such module: - Introduction: - What is molecular imaging? - Why molecular imaging? - What is biomedical imaging? - Different modalities of molecular imaging; - Different types of molecular imaging; - In vitro, ex vivo, in vivo imaging; Drug discovery process; - Pharmacological basis. Molecular Imaging Chemistry: - general construct of imaging probe (molecular reporter system); - Bioimaging factors influencing chemical probe synthesis; Optical imaging probes; - Radioimaging probes; - MR contrast agents; - Probes for other modalities, X ray

  6. Designing Molecular Printboards: A Photolithographic Platform for Recodable Surfaces.

    Science.gov (United States)

    Abt, Doris; Schmidt, Bernhard V K J; Pop-Georgievski, Ognen; Quick, Alexander S; Danilov, Denis; Kostina, Nina Yu; Bruns, Michael; Wenzel, Wolfgang; Wegener, Martin; Rodriguez-Emmenegger, Cesar; Barner-Kowollik, Christopher

    2015-09-14

    A light induced strategy for the design of β-cyclodextrin (CD) based supramolecular devices is introduced, presenting a novel tool to fabricate multifunctional biointerfaces. Precision photolithography of a modified β-CD was established on a light sensitive tetrazole surface immobilized on a bioinspired polydopamine (PDA) anchor layer via various shadow masks, as well as via direct laser writing (DLW), in order to craft any desired printboard design. Interfacial molecular recognition provided by light generated cavitate domains was demonstrated via spatially resolved encoding, erasing, and recoding of distinct supramolecular guest patterns. Thus, the light directed shaping of receptor monolayers introduces a powerful path to control supramolecular assemblies on various surfaces. PMID:26235994

  7. Influence of a charged graphene surface on the orientation and conformation of covalently attached oligonucleotides: a molecular dynamics study

    Czech Academy of Sciences Publication Activity Database

    Kabeláč, Martin; Kroutil, O.; Předota, M.; Lankaš, Filip; Šíp, M.

    2012-01-01

    Roč. 14, č. 12 (2012), s. 4217-4229. ISSN 1463-9076 R&D Projects: GA ČR GC204/09/J010; GA MŠk LC512; GA AV ČR IAA400550808 Grant ostatní: GA ČR(CZ) GA203/08/0094; GA MŠk(CZ) LM2010005 Institutional research plan: CEZ:AV0Z40550506 Keywords : DNA * graphene * charge density * molecular dynamics * Amber Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.829, year: 2012

  8. MOLECULAR DESIGN OF NEW KINDS OF AUXETIC POLYMERS AND NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Hong-mei Wu; Gao-yuan Wei

    2004-01-01

    Three new kinds of molecular networks are designed and predicted to exhibit negative Poisson ratios. Molecular mechanics calculations on these networks show that the magnitude of Poisson ratios depends on the relative flexibility of beam and arm structures. Several new kinds of auxetic polymers, whose successful synthesis should be easier than that of the corresponding auxetic networks, are then proposed. It is found that the kabob-like polymers with auxegens lying vertically on the main chain can acquire auxeticity while those with auxegens lying horizontally on the main chain cannot. Besides, a half kabob-like or pseudo-ladder polymer with auxegens linked at the intersection of the beam and the arm does show auxeticity when adopting constrictive conformers. It is, however, worthwhile noting that the origins of auxeticity still await and strongly deserve further experimental and theoretical investigations.

  9. Molecular Understanding and Structural-Based Design of Polyacrylamides and Polyacrylates as Antifouling Materials.

    Science.gov (United States)

    Chen, Hong; Zhao, Chao; Zhang, Mingzhen; Chen, Qiang; Ma, Jie; Zheng, Jie

    2016-04-12

    Design and synthesis of highly bioinert and biocompatible antifouling materials are crucial for a broad range of biomedical and engineering applications. Among antifouling materials, polyacrylamides and polyacrylates have proved so promising because of cheap raw materials, ease of synthesis and applicability, and abundant functional groups. The strong surface hydration and the high surface packing density of polyacrylamides and polyacrylates are considered to be the key contributors to their antifouling property. In this article, we review our studies on the design and synthesis of a series of polyacrylamides and polyacrylates with different molecular structures. These polymers can be fabricated into different architectural forms (brushes, nanoparticles, nanogels, and hydrogels), all of which are highly resistant to the attachment of proteins, cells, and bacteria. We find that small structural changes in the polymers can lead to large enhancement in surface hydration and antifouling performance, both showing a positive correlation. This reveals a general design rule for effective antifouling materials. Furthermore, polyacrylamides and polyacrylates are readily functionalized with other bioactive compounds to achieve different new multifunctionalities. PMID:26986442

  10. On the optimal design of molecular sensing interfaces with lipid bilayer assemblies - A knowledge based approach

    Science.gov (United States)

    Siontorou, Christina G.

    2012-12-01

    Biosensors are analytic devices that incorporate a biochemical recognition system (biological, biologicalderived or biomimic: enzyme, antibody, DNA, receptor, etc.) in close contact with a physicochemical transducer (electrochemical, optical, piezoelectric, conductimetric, etc.) that converts the biochemical information, produced by the specific biological recognition reaction (analyte-biomolecule binding), into a chemical or physical output signal, related to the concentration of the analyte in the measuring sample. The biosensing concept is based on natural chemoreception mechanisms, which are feasible over/within/by means of a biological membrane, i.e., a structured lipid bilayer, incorporating or attached to proteinaceous moieties that regulate molecular recognition events which trigger ion flux changes (facilitated or passive) through the bilayer. The creation of functional structures that are similar to natural signal transduction systems, correlating and interrelating compatibly and successfully the physicochemical transducer with the lipid film that is self-assembled on its surface while embedding the reconstituted biological recognition system, and at the same time manage to satisfy the basic conditions for measuring device development (simplicity, easy handling, ease of fabrication) is far from trivial. The aim of the present work is to present a methodological framework for designing such molecular sensing interfaces, functioning within a knowledge-based system built on an ontological platform for supplying sub-systems options, compatibilities, and optimization parameters.

  11. Three decades of structure- and property-based molecular design

    DEFF Research Database (Denmark)

    Müller, Klaus

    2014-01-01

    Roche has pioneered structure- and property-based molecular design to drug discovery. While this is an ongoing development, the past three decades feature key events that have revolutionized the way drug discovery is conducted in Big Pharma industry. It has been a great privilege to have been...... of bioinformatics. It describes the strategic shift to large compound libraries and high-throughput screening with the development of novel compound storage and ultra-high-throughput screening facilities, as well as the strategic return to focused screening of small motif-based compound libraries...

  12. GABA uptake inhibitors. Design, molecular pharmacology and therapeutic aspects

    DEFF Research Database (Denmark)

    Krogsgaard-Larsen, P; Frølund, B; Frydenvang, Karla Andrea

    2000-01-01

    In the mid seventies a drug design programme using the Amanita muscaria constituent muscimol (7) as a lead structure, led to the design of guvacine (23) and (R)-nipecotic acid (24) as specific GABA uptake inhibitors and the isomeric compounds isoguvacine (10) and isonipecotic acid (11) as specific...... GABAA receptor agonists. The availability of these compounds made it possible to study the pharmacology of the GABA uptake systems and the GABAA receptors separately. Based on extensive cellular and molecular pharmacological studies using 23, 24, and a number of mono- and bicyclic analogues, it has been...... demonstrated that neuronal and glial GABA transport mechanisms have dissimilar substrate specificities. With GABA transport mechanisms as pharmacological targets, strategies for pharmacological interventions with the purpose of stimulating GABA neurotransmission seem to be (1) effective blockade of neuronal as...

  13. Segmented molecular design of self-healing proteinaceous materials

    Science.gov (United States)

    Sariola, Veikko; Pena-Francesch, Abdon; Jung, Huihun; Çetinkaya, Murat; Pacheco, Carlos; Sitti, Metin; Demirel, Melik C.

    2015-09-01

    Hierarchical assembly of self-healing adhesive proteins creates strong and robust structural and interfacial materials, but understanding of the molecular design and structure-property relationships of structural proteins remains unclear. Elucidating this relationship would allow rational design of next generation genetically engineered self-healing structural proteins. Here we report a general self-healing and -assembly strategy based on a multiphase recombinant protein based material. Segmented structure of the protein shows soft glycine- and tyrosine-rich segments with self-healing capability and hard beta-sheet segments. The soft segments are strongly plasticized by water, lowering the self-healing temperature close to body temperature. The hard segments self-assemble into nanoconfined domains to reinforce the material. The healing strength scales sublinearly with contact time, which associates with diffusion and wetting of autohesion. The finding suggests that recombinant structural proteins from heterologous expression have potential as strong and repairable engineering materials.

  14. Comparing Simulated Emission from Molecular Clouds Using Experimental Design

    CERN Document Server

    Yeremi, Miayan; Offner, Stella; Loeppky, Jason; Rosolowsky, Erik

    2014-01-01

    We propose a new approach to comparing simulated observations that enables us to determine the significance of the underlying physical effects. We utilize the methodology of experimental design, a subfield of statistical analysis, to establish a framework for comparing simulated position-position-velocity data cubes to each other. We propose three similarity metrics based on methods described in the literature: principal component analysis, the spectral correlation function, and the Cramer multi-variate two sample similarity statistic. Using these metrics, we intercompare a suite of mock observational data of molecular clouds generated from magnetohydrodynamic simulations with varying physical conditions. Using this framework, we show that all three metrics are sensitive to changing Mach number and temperature in the simulation sets, but cannot detect changes in magnetic field strength and initial velocity spectrum. We highlight the shortcomings of one-factor-at-a-time designs commonly used in astrophysics an...

  15. Molecular design of new chromophores for high performance poled polymers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the principles of molecular engineering, a series of new chromophores with high second-or der nonlinear optical(NLO)activities have been designed for achieving a trade-off of the nonlinearity-transparency-ther mal stability. The NLO properties of these chromophores have been investigated theoretically by employing the AMI/Fi nite Field approach. It is found that the calculated μβ0 values of some designed chromophores can reach the magnitude of 10-45 esu, and the highest decomposition temperature Td can be as high as 377℃, the highest glass transition tem perature Ts of their donor-embedded addition-type polyimides can be as high as 324℃.

  16. Design and function of molecular and bioelectronics devices.

    Science.gov (United States)

    Krstic, Predrag; Forzani, Erica; Tao, Nongjian; Korkin, Anatoli

    2007-10-24

    Further rapid progress of electronics, in particular the increase of computer power and breakthroughs in sensor technology for industrial, medical diagnostics and environmental applications, strongly depends on the scaling of electronic devices, ultimately to the size of molecules. Design of controllable molecular-scale devices may resolve the problem of energy dissipation at the nanoscale and take advantage of molecular self-assembly in the so-called bottom-up approach. This special issue of Nanotechnology is devoted to a better understanding of the function and design of molecular-scale devices that are relevant to future electronics and sensor technology. Papers contained in this special issue are selected from the symposium Nano and Giga Challenges in Electronics and Photonics: From Atoms to Materials to Devices to System Architecture (12-16 March, 2007, Phoenix, Arizona, USA), as well as from original and novel scientific contributions of invited world-renown researchers. It addresses both theoretical and experimental achievements in the fields of molecular and bioelectronics, chemical and biosensors at the molecular level, including carbon nanotubes, novel nanostructures, as well as related research areas and industrial applications. The conference series Nano and Giga Challenges in Electronics and Photonics was launched as a truly interdisciplinary forum to bridge scientists and engineers to work across boundaries in the design of future information technologies, from atoms to materials to devices to system architecture. Following the first two successful meetings in Moscow, Russia (NGCM2002) and Krakow, Poland (NGCM2004), the third Nano and Giga Forum (NGC2007) was held in 2007 hosted by Arizona State University. Besides this special issue of Nanotechnology, two other collections (in the journal Solid State Electronics and the tutorial book in the series Nanostructure Science and Technology Springer) have published additional selected and invited papers

  17. EDITORIAL: Design and function of molecular and bioelectronics devices

    Science.gov (United States)

    Krstic, Predrag; Forzani, Erica; Tao, Nongjian; Korkin, Anatoli

    2007-10-01

    Further rapid progress of electronics, in particular the increase of computer power and breakthroughs in sensor technology for industrial, medical diagnostics and environmental applications, strongly depends on the scaling of electronic devices, ultimately to the size of molecules. Design of controllable molecular-scale devices may resolve the problem of energy dissipation at the nanoscale and take advantage of molecular self-assembly in the so-called bottom-up approach. This special issue of Nanotechnology is devoted to a better understanding of the function and design of molecular-scale devices that are relevant to future electronics and sensor technology. Papers contained in this special issue are selected from the symposium Nano and Giga Challenges in Electronics and Photonics: From Atoms to Materials to Devices to System Architecture (12-16 March, 2007, Phoenix, Arizona, USA), as well as from original and novel scientific contributions of invited world-renown researchers. It addresses both theoretical and experimental achievements in the fields of molecular and bioelectronics, chemical and biosensors at the molecular level, including carbon nanotubes, novel nanostructures, as well as related research areas and industrial applications. The conference series Nano and Giga Challenges in Electronics and Photonics was launched as a truly interdisciplinary forum to bridge scientists and engineers to work across boundaries in the design of future information technologies, from atoms to materials to devices to system architecture. Following the first two successful meetings in Moscow, Russia (NGCM2002) and Krakow, Poland (NGCM2004), the third Nano and Giga Forum (NGC2007) was held in 2007 hosted by Arizona State University. Besides this special issue of Nanotechnology, two other collections (in the journal Solid State Electronics and the tutorial book in the series Nanostructure Science and Technology Springer) have published additional selected and invited papers

  18. Molecular Design of Branched and Binary Molecules at Ordered Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kirsten Larson Genson

    2005-12-27

    This study examined five different branched molecular architectures to discern the effect of design on the ability of molecules to form ordered structures at interfaces. Photochromic monodendrons formed kinked packing structures at the air-water interface due to the cross-sectional area mismatch created by varying number of alkyl tails and the hydrophilic polar head group. The lower generations formed orthorhombic unit cell with long range ordering despite the alkyl tails tilted to a large degree. Favorable interactions between liquid crystalline terminal groups and the underlying substrate were observed to compel a flexible carbosilane dendrimer core to form a compressed elliptical conformation which packed stagger within lamellae domains with limited short range ordering. A twelve arm binary star polymer was observed to form two dimensional micelles at the air-water interface attributed to the higher polystyrene block composition. Linear rod-coil molecules formed a multitude of packing structures at the air-water interface due to the varying composition. Tree-like rod-coil molecules demonstrated the ability to form one-dimensional structures at the air-water interface and at the air-solvent interface caused by the preferential ordering of the rigid rod cores. The role of molecular architecture and composition was examined and the influence chemically competing fragments was shown to exert on the packing structure. The amphiphilic balance of the different molecular series exhibited control on the ordering behavior at the air-water interface and within bulk structures. The shell nature and tail type was determined to dictate the preferential ordering structure and molecular reorganization at interfaces with the core nature effect secondary.

  19. Molecular Design Basis for Hydrogen Storage in Clathrate Hydrates

    Energy Technology Data Exchange (ETDEWEB)

    John, Vijay T [Tulane University; McPherson, Gary L [Tulane University; Ashbaugh, Hank [Tulane University; Johnes, Camille Y [Columbia University

    2013-06-28

    We attach a final technical report for the project. The report contains the list of all peer reviewed publications that have resulted from the contract. I will be happy to send the pdf files of the papers.

  20. A computational molecular design framework for crosslinked polymer networks.

    Science.gov (United States)

    Eslick, J C; Ye, Q; Park, J; Topp, E M; Spencer, P; Camarda, K V

    2009-05-21

    Crosslinked polymers are important in a very wide range of applications including dental restorative materials. However, currently used polymeric materials experience limited durability in the clinical oral environment. Researchers in the dental polymer field have generally used a time-consuming experimental trial-and-error approach to the design of new materials. The application of computational molecular design (CMD) to crosslinked polymer networks has the potential to facilitate development of improved polymethacrylate dental materials. CMD uses quantitative structure property relations (QSPRs) and optimization techniques to design molecules possessing desired properties. This paper describes a mathematical framework which provides tools necessary for the application of CMD to crosslinked polymer systems. The novel parts of the system include the data structures used, which allow for simple calculation of structural descriptors, and the formulation of the optimization problem. A heuristic optimization method, Tabu Search, is used to determine candidate monomers. Use of a heuristic optimization algorithm makes the system more independent of the types of QSPRs used, and more efficient when applied to combinatorial problems. A software package has been created which provides polymer researchers access to the design framework. A complete example of the methodology is provided for polymethacrylate dental materials. PMID:23904665

  1. From molecular design and materials construction to organic nanophotonic devices.

    Science.gov (United States)

    Zhang, Chuang; Yan, Yongli; Zhao, Yong Sheng; Yao, Jiannian

    2014-12-16

    CONSPECTUS: Nanophotonics has recently received broad research interest, since it may provide an alternative opportunity to overcome the fundamental limitations in electronic circuits. Diverse optical materials down to the wavelength scale are required to develop nanophotonic devices, including functional components for light emission, transmission, and detection. During the past decade, the chemists have made their own contributions to this interdisciplinary field, especially from the controlled fabrication of nanophotonic molecules and materials. In this context, organic micro- or nanocrystals have been developed as a very promising kind of building block in the construction of novel units for integrated nanophotonics, mainly due to the great versatility in organic molecular structures and their flexibility for the subsequent processing. Following the pioneering works on organic nanolasers and optical waveguides, the organic nanophotonic materials and devices have attracted increasing interest and developed rapidly during the past few years. In this Account, we review our research on the photonic performance of molecular micro- or nanostructures and the latest breakthroughs toward organic nanophotonic devices. Overall, the versatile features of organic materials are highlighted, because they brings tunable optical properties based on molecular design, size-dependent light confinement in low-dimensional structures, and various device geometries for nanophotonic integration. The molecular diversity enables abundant optical transitions in conjugated π-electron systems, and thus brings specific photonic functions into molecular aggregates. The morphology of these micro- or nanostructures can be further controlled based on the weak intermolecular interactions during molecular assembly process, making the aggregates show photon confinement or light guiding properties as nanophotonic materials. By adoption of some active processes in the composite of two or more

  2. Modeling the role of electron attachment rates on column density ratios for CnH-/CnH (n=4,6,8) in dense molecular clouds

    CERN Document Server

    Gianturco, F A; Wester, R

    2016-01-01

    (abridged) The fairly recent detection of a variety of anions in the Interstellar Molecular Clouds have underlined the importance of realistically modeling the processes governing their abundance. To this aim, our earlier calculations for the radiative electron attachment (REA) rates for C4H-, C6H-, and C8H- are employed to generate the corresponding column density ratios of anion/neutral (A/N) relative abundances. The latter are then compared with those obtained from observational measurements. The calculations involved the time-dependent solutions of a large network of chemical processes over an extended time interval and included a series of runs in which the values of REA rates were repeatedly scaled. Macroscopic parameters for the clouds' modeling were also varied to cover a broad range of physical environments. It was found that, within the range and quality of the processes included in the present network,and selected from state-of-the-art astrophysical databases, the REA values required to match the o...

  3. New synthetic thrombin inhibitors: molecular design and experimental verification.

    Directory of Open Access Journals (Sweden)

    Elena I Sinauridze

    Full Text Available BACKGROUND: The development of new anticoagulants is an important goal for the improvement of thromboses treatments. OBJECTIVES: The design, synthesis and experimental testing of new safe and effective small molecule direct thrombin inhibitors for intravenous administration. METHODS: Computer-aided molecular design of new thrombin inhibitors was performed using our original docking program SOL, which is based on the genetic algorithm of global energy minimization in the framework of a Merck Molecular Force Field. This program takes into account the effects of solvent. The designed molecules with the best scoring functions (calculated binding energies were synthesized and their thrombin inhibitory activity evaluated experimentally in vitro using a chromogenic substrate in a buffer system and using a thrombin generation test in isolated plasma and in vivo using the newly developed model of hemodilution-induced hypercoagulation in rats. The acute toxicities of the most promising new thrombin inhibitors were evaluated in mice, and their stabilities in aqueous solutions were measured. RESULTS: New compounds that are both effective direct thrombin inhibitors (the best K(I was 1111.1 mg/kg. A plasma-substituting solution supplemented with one of the new inhibitors prevented hypercoagulation in the rat model of hemodilution-induced hypercoagulation. Activities of the best new inhibitors in physiological saline (1 µM solutions were stable after sterilization by autoclaving, and the inhibitors remained stable at long-term storage over more than 1.5 years at room temperature and at 4°C. CONCLUSIONS: The high efficacy, stability and low acute toxicity reveal that the inhibitors that were developed may be promising for potential medical applications.

  4. Design of gecko-inspired fibrillar surfaces with strong attachment and easy-removal properties: a numerical analysis of peel-zone.

    Science.gov (United States)

    Zhou, Ming; Pesika, Noshir; Zeng, Hongbo; Wan, Jin; Zhang, Xiangjun; Meng, Yonggang; Wen, Shizhu; Tian, Yu

    2012-10-01

    Despite successful fabrication of gecko-inspired fibrillar surfaces with strong adhesion forces, how to achieve an easy-removal property becomes a major concern that may restrict the wide applications of these bio-inspired surfaces. Research on how geckos detach rapidly has inspired the design of novel adhesive surfaces with strong and reversible adhesion capabilities, which relies on further fundamental understanding of the peeling mechanisms. Recent studies showed that the peel-zone plays an important role in the peeling off of adhesive tapes or fibrillar surfaces. In this study, a numerical method was developed to evaluate peel-zone deformation and the resulting mechanical behaviour due to the deformations of fibrillar surfaces detaching from a smooth rigid substrate. The effect of the geometrical parameters of pillars and the stiffness of backing layer on the peel-zone and peel strength, and the strong attachment and easy-removal properties have been analysed to establish a design map for bio-inspired fibrillar surfaces, which shows that the optimized strong attachment and easy-removal properties can vary by over three orders of magnitude. The adhesion and peeling design map established provides new insights into the design and development of novel gecko-inspired fibrillar surfaces. PMID:22572030

  5. Design and performance simulation of a molecular Doppler wind lidar

    Institute of Scientific and Technical Information of China (English)

    Fahua Shen; Hyunki Cha; Jihui Dong; Dukhyeon Kim; Dongsong Sun; Sung Ok Kwon

    2009-01-01

    A mobile molecular Doppler wind lidar at an eye-safe wavelength of 355 nm based on double-edge technique is being built in Hefei (China) for wind measurement from 10-to 40-km altitude. The structure of this lidar system is described. A triple Fabry-Perot etalon is employed as a frequency discriminator whose parameters are optimized. The receiver system is designed to achieve compactness and stability by putting in a standard 19-inch socket bench. Simulation results show that within the wind speed dynamic range of ±100 m/s, the horizontal wind errors due to noise are less than 1 m/s below 20-km altitude for 100-m vertical resolution, and less than 5.5 m/s from 20 km up to 40 km for 500-m vertical resolution with 400-mJ laser energy, 30-min temporal resolution, and a 45-cm aperture telescope.

  6. Design strategies for the molecular level synthesis of supported catalysts.

    Science.gov (United States)

    Wegener, Staci L; Marks, Tobin J; Stair, Peter C

    2012-02-21

    Supported catalysts, metal or oxide catalytic centers constructed on an underlying solid phase, are making an increasingly important contribution to heterogeneous catalysis. For example, in industry, supported catalysts are employed in selective oxidation, selective reduction, and polymerization reactions. Supported structures increase the thermal stability, dispersion, and surface area of the catalyst relative to the neat catalytic material. However, structural and mechanistic characterization of these catalysts presents a formidable challenge because traditional preparations typically afford complex mixtures of structures whose individual components cannot be isolated. As a result, the characterization of supported catalysts requires a combination of advanced spectroscopies for their characterization, unlike homogeneous catalysts, which have relatively uniform structures and can often be characterized using standard methods. Moreover, these advanced spectroscopic techniques only provide ensemble averages and therefore do not isolate the catalytic function of individual components within the mixture. New synthetic approaches are required to more controllably tailor supported catalyst structures. In this Account, we review advances in supported catalyst synthesis and characterization developed in our laboratories at Northwestern University. We first present an overview of traditional synthetic methods with a focus on supported vanadium oxide catalysts. We next describe approaches for the design and synthesis of supported polymerization and hydrogenation catalysts, using anchoring techniques which provide molecular catalyst structures with exceptional activity and high percentages of catalytically significant sites. We then highlight similar approaches for preparing supported metal oxide catalysts using atomic layer deposition and organometallic grafting. Throughout this Account, we describe the use of incisive spectroscopic techniques, including high

  7. Intelligent Design of Nano-Scale Molecular Imaging Agents

    Directory of Open Access Journals (Sweden)

    Takeaki Ozawa

    2012-12-01

    Full Text Available Visual representation and quantification of biological processes at the cellular and subcellular levels within living subjects are gaining great interest in life science to address frontier issues in pathology and physiology. As intact living subjects do not emit any optical signature, visual representation usually exploits nano-scale imaging agents as the source of image contrast. Many imaging agents have been developed for this purpose, some of which exert nonspecific, passive, and physical interaction with a target. Current research interest in molecular imaging has mainly shifted to fabrication of smartly integrated, specific, and versatile agents that emit fluorescence or luminescence as an optical readout. These agents include luminescent quantum dots (QDs, biofunctional antibodies, and multifunctional nanoparticles. Furthermore, genetically encoded nano-imaging agents embedding fluorescent proteins or luciferases are now gaining popularity. These agents are generated by integrative design of the components, such as luciferase, flexible linker, and receptor to exert a specific on–off switching in the complex context of living subjects. In the present review, we provide an overview of the basic concepts, smart design, and practical contribution of recent nano-scale imaging agents, especially with respect to genetically encoded imaging agents.

  8. A computer-aided molecular design framework for crystallization solvent design

    DEFF Research Database (Denmark)

    Karunanithi, Arunprakash T.; Achenie, Luke E.K.; Gani, Rafiqul

    2006-01-01

    , property requirements such as solubility, crystal morphology, flashpoint, toxicity, viscosity, normal boiling and melting point are posed as constraints. All the properties are estimated using group contribution methods. The MINLP model is then solved using a decomposition approach to obtain optimal......One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem...... is formulated as a mixed integer nonlinear programming (MINLP) model. Although, the model allows any combination of performance objectives and property constraints, in the case studies, potential recovery was considered as the performance objective. The latter, needs to be maximized, while other solvent...

  9. Molecular and cellular designs of insect taste receptor system

    Directory of Open Access Journals (Sweden)

    Kunio Isono

    2010-06-01

    Full Text Available The insect gustatory receptors (GRs are members of a large G-protein coupled receptor family distantly related to the insect olfactory receptors. They are phylogenetically different from taste receptors of most other animals. GRs are often coexpressed with other GRs in single receptor neurons. Taste receptors other than GRs are also expressed in some neurons. Recent molecular studies in the fruitfly Drosophila revealed that the insect taste receptor system not only covers a wide ligand spectrum of sugars, bitter substances or salts that are common to mammals but also includes reception of pheromone and somatosensory stimulants. However, the central mechanism to perceive and discriminate taste information is not yet elucidated. Analysis of the primary projection of taste neurons to the brain shows that the projection profiles depend basically on the peripheral locations of the neurons as well as the GRs that they express. These results suggest that both peripheral and central design principles of insect taste perception are different from those of olfactory perception.

  10. Strategy for Molecular Design of Photochromic Diarylethenes Having Thermal Functionality.

    Science.gov (United States)

    Kitagawa, Daichi; Kobatake, Seiya

    2016-08-01

    Thermal reactivities of photochromic diarylethene closed-ring isomers can be controlled by the introduction of substituents at the reactive positions. Diarylethenes having bulky alkyl groups undergo thermal cycloreversion reactions. When bulky alkoxy groups are introduced, the diarylethenes have both thermal cycloreversion reactivities and low photocycloreversion quantum yields. Such photochromic compounds can be applied to thermally reusable photoresponsive-image recordings. The thermal cycloreversion reactivity of the closed-ring isomers can be evaluated using specific steric substituent constants and be correlated with the parameters. By introduction of trimethylsilyl or methoxymethyl groups at the reactive positions, the diarylethene closed-ring isomers undergo thermal irreversible reactions to produce by-products at high temperatures. These diarylethenes may be useful for secret-image recordings. Furthermore, thiophene-S,S-dioxidized diarylethenes having secondary alkyl groups at the reactive positions undergo thermal by-product formation reactions, in addition to the photostability of the colored closed-ring isomers. Such materials may be used for light-starting thermosensors. The thermal by-product formation reactivity can be evaluated by the specific substituent constants and theoretical calculations of quantum chemistry. These results supply the strategy for the molecular design of the photochromic diarylethenes having thermal functionality. PMID:27321920

  11. Design and Synthesis of Chiral Molecular Tweezers Based on Deoxycholic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms.Instead of using toxic phosgene,the triphosgene was employed in synthesis of the molecular tweezers receptors.These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.

  12. Paternal Attachment, Parenting Beliefs and Children's Attachment

    Science.gov (United States)

    Howard, Kimberly S.

    2010-01-01

    Relationships between fathers' romantic attachment style, parenting beliefs and father-child attachment security and dependence were examined in a diverse sample of 72 fathers of young children. Paternal romantic attachment style was coded based on fathers' endorsement of a particular style represented in the Hazan and Shaver Three-Category…

  13. Molecular-level Design of Heterogeneous Chiral Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gellman, Andrew John [Carnegie Mellon University; Sholl, David S. [Georgia Institute of Technology; Tysoe, Wilfred T. [University of Wisconsin - Milwaukee; Zaera, Francisco [University of California at Riverside

    2013-04-28

    Understanding and controlling selectivity is one of the key challenges in heterogeneous catalysis. Among problems in catalytic selectivity enantioselectivity is perhaps the most the most challenging. The primary goal of the project on “Molecular-level Design of Heterogeneous Chiral Catalysts” is to understand the origins of enantioselectivity on chiral heterogeneous surfaces and catalysts. The efforts of the project team include preparation of chiral surfaces, characterization of chiral surfaces, experimental detection of enantioselectivity on such surfaces and computational modeling of the interactions of chiral probe molecules with chiral surfaces. Over the course of the project period the team of PI’s has made some of the most detailed and insightful studies of enantioselective chemistry on chiral surfaces. This includes the measurement of fundamental interactions and reaction mechanisms of chiral molecules on chiral surfaces and leads all the way to rationale design and synthesis of chiral surfaces and materials for enantioselective surface chemistry. The PI’s have designed and prepared new materials for enantioselective adsorption and catalysis. Naturally Chiral Surfaces • Completion of a systematic study of the enantiospecific desorption kinetics of R-3-methylcyclohexanone (R-3-MCHO) on 9 achiral and 7 enantiomeric pairs of chiral Cu surfaces with orientations that span the stereographic triangle. • Discovery of super-enantioselective tartaric acid (TA) and aspartic acid (Asp) decomposition as a result of a surface explosion mechanism on Cu(643)R&S. Systematic study of super-enantiospecific TA and Asp decomposition on five enantiomeric pairs of chiral Cu surfaces. • Initial observation of the enantiospecific desorption of R- and S-propylene oxide (PO) from Cu(100) imprinted with {3,1,17} facets by L-lysine adsorption. Templated Chiral Surfaces • Initial observation of the enantiospecific desorption of R- and S-PO from Pt(111) and Pd(111

  14. The Design of Molecular Hosts, Guests, and Their Complexes.

    Science.gov (United States)

    Cram, Donald J.

    1988-01-01

    Describes the origins, definitions, tools, and principles of host-guest chemistry. Gives examples of chiral recognition in complexation, of partial transacylase mimics, of caviplexes, and of a synthetic molecular cell. (Author/RT)

  15. Design and construction of a VHGT-attached WDM-type triplex transceiver module using polymer PLC hybrid integration technology

    Science.gov (United States)

    Jerábek, Vitezslav; Hüttel, Ivan; Prajzler, Václav; Busek, K.; Seliger, P.

    2008-11-01

    We report about design and construction of the bidirectional transceiver TRx module for subscriber part of the passive optical network PON for a fiber to the home FTTH topology. The TRx module consists of a epoxy novolak resin polymer planar lightwave circuit (PLC) hybrid integration technology with volume holographic grating triplex filter VHGT, surface-illuminated photodetectors and spot-size converted Fabry-Pérot laser diode in SMD package. The hybrid PLC has composed from a two parts-polymer optical waveguide including VHGT filter section and a optoelectronic microwave section. The both parts are placed on the composite substrate.

  16. A Modified Design for the Eastern Radiation Canyon for Cobalt60 Irradiator Maintain Attachment For Research and Production

    International Nuclear Information System (INIS)

    About 160 industrial radiation facilities using Co60 are currently in operation in about 45 countries, many of them in developing countries. Most of these facilities are used for sterilization of medical products and pharmaceuticals, with a small number being used for processing of food items. The total installed capacity for processing of medical products at 20-25 k.Gy is about one million ton annually. There is a need to make some modifications on the design of these radiation canyons to allow radiation research, during mass production. By designing a new track for experimental research which can pass inside and outside radiation canyon through a special maze (labyrinth). The research samples will be put in two boxes out side the research door and they will go inside the canyon through research maze and stopped behind the products cars on two position, facing the source rack which will be in radiation position. The boxes will return back after finishing the exposure period

  17. Synthesis and Evaluation of CO2 Thickeners Designed with Molecular Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Robert Enick; Erick Beckman; J. Karl Johnson

    2009-08-31

    The objective of this research was to use molecular modeling techniques, coupled with our prior experimental results, to design, synthesize and evaluate inexpensive, non-fluorous carbon dioxide thickening agents. The first type of thickener that was considered was associating polymers. Typically, these thickeners are copolymers that contain a highly CO{sub 2}-philic monomer, and a small concentration of a CO{sub 2}-phobic associating monomer. Yale University was solely responsible for the synthesis of a second type of thickener; small, hydrogen bonding compounds. These molecules have a core that contains one or more hydrogen-bonding groups, such as urea or amide groups. Non-fluorous, CO{sub 2}-philic functional groups were attached to the hydrogen bonding core of the compound to impart CO{sub 2} stability and macromolecular stability to the linear 'stack' of these compounds. The third type of compound initially considered for this investigation was CO{sub 2}-soluble surfactants. These surfactants contain conventional ionic head groups and composed of CO{sub 2}-philic oligomers (short polymers) or small compounds (sugar acetates) previously identified by our research team. Mobility reduction could occur as these surfactant solutions contacted reservoir brine and formed mobility control foams in-situ. The vast majority of the work conducted in this study was devoted to the copolymeric thickeners and the small hydrogen-bonding thickeners; these thickeners were intended to dissolve completely in CO{sub 2} and increase the fluid viscosity. A small but important amount of work was done establishing the groundwork for CO{sub 2}-soluble surfactants that reduced mobility by generating foams in-situ as the CO{sub 2}+surfactant solution mixed with in-situ brine.

  18. Molecular-Level Design of Heterogeneous Chiral Catalysis

    International Nuclear Information System (INIS)

    The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration

  19. Molecular-Level Design of Heterogeneous Chiral Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Zaera

    2012-03-21

    The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration

  20. Using circumacenes to improve organic electronics and molecular electronics: design clues

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Jimenez, Angel J; Sancho-Garcia, Juan C, E-mail: aj.perez@ua.e, E-mail: jc.sancho@ua.e [Departamento de Quimica-Fisica, Universidad de Alicante, E-03080, Alicante (Spain)

    2009-11-25

    Theoretical modeling is used here to ascertain the potential use of circumacenes to improve the transport parameters of {pi}-conjugated materials acting as: (i) the layered molecular constituent for organic electronic devices; and (ii) the molecular component of gold-molecule-gold nanobridges for molecular electronic device use. It is concluded that, to a first approximation, the molecular length or, alternatively, the HOMO-LUMO gap (HOMO: highest occupied molecular orbital; LUMO: lowest unoccupied molecular orbital) can be used to relate the two transport regimes usually found in these two fields, thus serving as a key design parameter for guaranteeing good performance of circumanthracene for both regimes. It is also clearly established that going beyond this simple relationship requires knowledge of the detailed molecule-contact geometry of the molecular nanobridge, and how its tremendous impact on the binding strength and the conductance prevents blind extrapolation of results obtained for molecular nanobridges built by means of different experimental set-ups.

  1. Using circumacenes to improve organic electronics and molecular electronics: design clues

    International Nuclear Information System (INIS)

    Theoretical modeling is used here to ascertain the potential use of circumacenes to improve the transport parameters of π-conjugated materials acting as: (i) the layered molecular constituent for organic electronic devices; and (ii) the molecular component of gold-molecule-gold nanobridges for molecular electronic device use. It is concluded that, to a first approximation, the molecular length or, alternatively, the HOMO-LUMO gap (HOMO: highest occupied molecular orbital; LUMO: lowest unoccupied molecular orbital) can be used to relate the two transport regimes usually found in these two fields, thus serving as a key design parameter for guaranteeing good performance of circumanthracene for both regimes. It is also clearly established that going beyond this simple relationship requires knowledge of the detailed molecule-contact geometry of the molecular nanobridge, and how its tremendous impact on the binding strength and the conductance prevents blind extrapolation of results obtained for molecular nanobridges built by means of different experimental set-ups.

  2. Designing molecular printboards: a photolithographic platform for recodable surfaces

    Czech Academy of Sciences Publication Activity Database

    Abt, D.; Schmidt, B. V. K. J.; Pop-Georgievski, Ognen; Quick, A. S.; Danilov, D.; Kostina, Nina Yu.; Bruns, M.; Wenzel, W.; Wegener, M.; Rodriguez-Emmenegger, Cesar; Barner-Kowollik, C.

    2015-01-01

    Roč. 21, č. 38 (2015), s. 13186-13190. ISSN 0947-6539 R&D Projects: GA ČR(CZ) GJ15-09368Y Institutional support: RVO:61389013 Keywords : cyclodextrin * molecular printboard * photoconjugation Subject RIV: BO - Biophysics Impact factor: 5.731, year: 2014

  3. Adult Attachment and Psychotherapy

    OpenAIRE

    Rietzschel, Julia

    2012-01-01

    This thesis explores the association between adult attachment and psychological therapy by examining attachment as an outcome variable of therapy, as well as a predictor of therapy outcome. The literature review systematically explores research that has examined changes in attachment representations during psychological therapy. The purpose of the review is to enhance understanding of change processes in adult attachment and to provide empirical support to the premises of attachment theory. I...

  4. Attachment behavior in rats

    OpenAIRE

    Sigling, H.O.

    2009-01-01

    This thesis describes studies into the rat as an animal model for attachment, along the lines of Bowlby's attachment theory. First, the relation between attachment and human psychopathology is reviewed. The conclusion is that psychopathology is more frequent in insecure attached persons and that there is a relationship between specific types of insecure attachment and specific types of psychiatric disorders. Next, a reinterpretation of the literature on social preference experiments in rodent...

  5. Recent advances in the molecular design of synthetic vaccines

    Science.gov (United States)

    Jones, Lyn H.

    2015-12-01

    Vaccines have typically been prepared using whole organisms. These are normally either attenuated bacteria or viruses that are live but have been altered to reduce their virulence, or pathogens that have been inactivated and effectively killed through exposure to heat or formaldehyde. However, using whole organisms to elicit an immune response introduces the potential for infections arising from a reversion to a virulent form in live pathogens, unproductive reactions to vaccine components or batch-to-batch variability. Synthetic vaccines, in which a molecular antigen is conjugated to a carrier protein, offer the opportunity to circumvent these problems. This Perspective will highlight the progress that has been achieved in developing synthetic vaccines using a variety of molecular antigens. In particular, the different approaches used to develop conjugate vaccines using peptide/proteins, carbohydrates and other small molecule haptens as antigens are compared.

  6. A Real-World Perspective on Molecular Design.

    Science.gov (United States)

    Kuhn, Bernd; Guba, Wolfgang; Hert, Jérôme; Banner, David; Bissantz, Caterina; Ceccarelli, Simona; Haap, Wolfgang; Körner, Matthias; Kuglstatter, Andreas; Lerner, Christian; Mattei, Patrizio; Neidhart, Werner; Pinard, Emmanuel; Rudolph, Markus G; Schulz-Gasch, Tanja; Woltering, Thomas; Stahl, Martin

    2016-05-12

    We present a series of small molecule drug discovery case studies where computational methods were prospectively employed to impact Roche research projects, with the aim of highlighting those methods that provide real added value. Our brief accounts encompass a broad range of methods and techniques applied to a variety of enzymes and receptors. Most of these are based on judicious application of knowledge about molecular conformations and interactions: filling of lipophilic pockets to gain affinity or selectivity, addition of polar substituents, scaffold hopping, transfer of SAR, conformation analysis, and molecular overlays. A case study of sequence-driven focused screening is presented to illustrate how appropriate preprocessing of information enables effective exploitation of prior knowledge. We conclude that qualitative statements enabling chemists to focus on promising regions of chemical space are often more impactful than quantitative prediction. PMID:26878596

  7. Adult attachment styles

    Directory of Open Access Journals (Sweden)

    Maša Žvelc

    2007-01-01

    Full Text Available Theory of attachment primarily described early relationships between a child and his caretakers. In the last twenty years there is a growing interest in adult attachment research. Theories and research findings of adult attachment stem from two different methodological approaches. The first approach measures adult attachment through Adult Attachment Interview (AAI; Main, 1991 where the attachment is assessed through the narratives of adult people of their early child experiences with their primary caretakers. The second approach measures adult attachment with the help of self-evaluative questionnaires, developed by (a Hazan and Shaver (1987 who started this approach in the field of personality and social psychology, and (b Bartholomew and Horowitz (1991. Research shows that there is significant correlation between early and adult attachment style. Attachment styles are passed from generation to generation. Basic adult attachment styles are: securely attached, preoccupied, fearful-avoidant, dismissing-avoidant and disorganized. Previous research using Barholomew and Horowitz (1991 Relationship Questionnaire on 176 Slovenian students showed that 48% students are securely attached, 29% are fearful-avoidant, 10% are dismissing-avoidant, and 13% have preoccupied attachment style. Theory of attachment is very useful for understanding the behavior and subjective experiences of children and adults. It is applicable to different contexts (psychotherapy, counseling, education .... The paper proposes further research focused on integration of adult attachment styles and types of object relations measured by Test of object relations (Žvelc, 1998 and Pictorial test of Separation and Individuation (Žvelc, 2003.

  8. Application of molecular simulation techniques to the design of nanosystems

    OpenAIRE

    Rodríguez Ropero, Francisco

    2009-01-01

    Nanotechnology is a multidisciplinary branch of science and technology that involves a widerange of different fields such as chemistry, materials science, physics or chemical engineeringwhose goal is the production of new functional materials and devicesthrough the control of their organization at the atomic and molecular scale.Nanotechnology has jumped from research laboratories to our daily life and today all theprogresses made in this field have been translated into direct applications in ...

  9. Refrigeration Cycle Design for Refrigerant Mixtures by Molecular Simulation

    Czech Academy of Sciences Publication Activity Database

    Smith, W.R.; Francová, Magda; Kowalski, M.; Nezbeda, Ivo

    2010-01-01

    Roč. 75, č. 4 (2010), s. 383-391. ISSN 0010-0765 R&D Projects: GA AV ČR IAA400720710 Grant ostatní: NSERC(CA) OGP1041 Institutional research plan: CEZ:AV0Z40720504 Keywords : refrigerants * molecular simulations * vapor–liquid equilibrium Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.853, year: 2010

  10. Designing bistable [2]rotaxanes for molecular electronic devices.

    Science.gov (United States)

    Dichtel, William R; Heath, James R; Stoddart, J Fraser

    2007-06-15

    The development of molecular electronic components has been accelerated by the promise of increased circuit densities and reduced power consumption. Bistable rotaxanes have been assembled into nanowire crossbar devices, where they may be switched between low- and high-conductivity states, forming the basis for a molecular memory. These memory devices have been scaled to densities of 10(11) bits cm(-2), the 2020 node for memory of the International Technology Roadmap for Semiconductors. Investigations of the kinetics and thermodynamics associated with the electromechanical switching processes of several bistable [2]rotaxane derivatives in solution, self-assembled monolayers on gold, polymer electrolyte gels and in molecular switch tunnel junction devices are consistent with a single, universal switching mechanism whose speed is dependent largely on the environment, as well as on the structure of the switching molecule. X-ray reflectometry studies of the bistable rotaxanes assembled into Langmuir monolayers also lend support to an oxidatively driven mechanical switching process. Structural information obtained from Fourier transform reflection absorption infrared spectroscopy of rotaxane monolayers taken before and after evaporation of a Ti top electrode confirmed that the functionality responsible for switching is not affected by the metal deposition process. All the considerable experimental data, taken together with detailed computational work, support the hypothesis that the tunnelling current hysteresis, which forms the basis of memory operation, is a direct result of the electromechanical switching of the bistable rotaxanes. PMID:17430812

  11. Characterization-Based Molecular Design of Bio-Fuel Additives Using Chemometric and Property Clustering Techniques

    OpenAIRE

    Subin eHada; Charles Conrad Solvason; Mario Richard Eden

    2014-01-01

    In this work, multivariate characterization data such as infrared spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis allowed capturing important features of the molecular architecture from enormous amount of complex data to build appropriate latent variable models. Combining the property clusterin...

  12. Digital learning material for experimental design and model building in molecular biology

    NARCIS (Netherlands)

    Aegerter-Wilmsen, T.

    2005-01-01

    Designing experimental approaches is a major cognitive skill in molecular biology research, and building models, including quantitative ones, is a cognitive skill which is rapidly gaining importance. Since molecular biology education at university level is aimed at educating future researchers, we c

  13. Development of Lathe Attachment for a CNC Machine

    Science.gov (United States)

    Roy, V.; Kumar, S.

    2013-04-01

    A lathe attachment has been developed for an existing CNC machine (installed with rapid prototyping attachment) using conceptual design. The CNC machine operates on mechatronic controls and a computer interface called CAMSOFT, and is used as a CNC Lathe after installing the respective attachment to it. The conceptual design phase, starts from an idea and different components of the lathe are designed as attachment using CAD modelling and is followed by fabrication phase. The lathe attachment is successfully developed and is installed to the CNC machine. The working of the CNC Lathe attachment is checked by making some machining operation like turning and thread cutting. The machining operations are successfully done. The CNC machine becomes multifunctional with the presently developed lathe attachment and the existing RP (rapid prototyping) attachment, and can be used accordingly by installing the respective attachment to it. The CNC machine is useful for carrying research work in both the fields, when installed with the appropriate attachment.

  14. Design and setup of a testing device to investigate a reduced sized attachment system mock up for the ITER EU HCPB-TBM under different mechanical loading conditions

    International Nuclear Information System (INIS)

    Highlights: • A measurement system is developed to measure the electro-magnetic forces acting on the ITER EU HCPB TBM during operation. • A system based on the measurement of strain signals in combination with two force reconstruction methods is proposed. • Two mock ups have been designed to test and calibrate the measurement system. • A suitable testing device has been built to test the measuring system. • First results with simulated strain data are presented. - Abstract: In order to determine the forces acting on the EU-Helium Cooled Pebble Bed Test Blanket Module (HCPB-TBM) during operation, a measurement system is developed. Therefore, two force reconstruction (FR) methods using measured strain signals are selected that are suitable for the application to the TBM. The first one, the augmented Kalman filter is a combined deterministic-stochastic approach. A second FR method based on the concept of a model predictive controller is proposed in this paper, which uses an optimization algorithm. In order to test the selected methods a testing device has been built which can be used to apply different force excitations on a reduced sized TBM mock up and measure the resulting strain signals of 16 strain gages. A simple tube mock up has been designed and manufactured to test and calibrate the FR algorithms. In addition, a second TBM mock up with attachment system is described. Finally, first results of the FR of a worst-case test case from simulated strain data of the simple tube mock up are presented

  15. Molecular Designs for Enhancement of Polarity in Ferroelectric Soft Materials

    Science.gov (United States)

    Ohtani, Ryo; Nakaya, Manabu; Ohmagari, Hitomi; Nakamura, Masaaki; Ohta, Kazuchika; Lindoy, Leonard F.; Hayami, Shinya

    2015-11-01

    The racemic oxovanadium(IV) salmmen complexes, [VO((rac)-(4-X-salmmen))] (X = C12C10C5 (1), C16 (2), and C18 (3); salmmen = N,N‧-monomethylenebis-salicylideneimine) with “banana shaped” molecular structures were synthesized, and their ferroelectric properties were investigated. These complexes exhibit well-defined hysteresis loops in their viscous phases, moreover, 1 also displays liquid crystal behaviour. We observed a synergetic effect influenced by three structural aspects; the methyl substituents on the ethylene backbone, the banana shaped structure and the square pyramidal metal cores all play an important role in generating the observed ferroelectricity, pointing the way to a useful strategy for the creation of advanced ferroelectric soft materials.

  16. Molecular Design for Tuning Work Functions of Transparent Conducting Electrodes.

    Science.gov (United States)

    Koldemir, Unsal; Braid, Jennifer L; Morgenstern, Amanda; Eberhart, Mark; Collins, Reuben T; Olson, Dana C; Sellinger, Alan

    2015-06-18

    In this Perspective, we provide a brief background on the use of aromatic phosphonic acid modifiers for tuning work functions of transparent conducting oxides, for example, zinc oxide (ZnO) and indium tin oxide (ITO). We then introduce our preliminary results in this area using conjugated phosphonic acid molecules, having a substantially larger range of dipole moments than their unconjugated analogues, leading to the tuning of ZnO and ITO electrodes over a 2 eV range as derived from Kelvin probe measurements. We have found that these work function changes are directly correlated to the magnitude and the direction of the computationally derived molecular dipole of the conjugated phosphonic acids, leading to the predictive power of computation to drive the synthesis of new and improved phosphonic acid ligands. PMID:26266603

  17. A New Optimization Model for Computer-Aided Molecular Design Problems

    DEFF Research Database (Denmark)

    Zhang, Lei; Cignitti, Stefano; Gani, Rafiqul

    Computer-Aided Molecular Design (CAMD) is a method to design molecules with desired properties. That is, through CAMD, it is possible to generate molecules that match a specified set of target properties. CAMD has attracted much attention in recent years due to its ability to design novel as well...... as known molecules with desired properties. The attention is in particular targeted at the design of chemical based products, such as solvents, refrigerants, active pharmaceutical ingredients, polymers, surfactants, lubricants, and more [1]. Property prediction methods are needed in molecular design...... higher level analysis of the molecular structure and the final selection of the product. Samudra and Sahinidis [4] proposed a new optimization model using relaxed property targets and refined property targets with structural corrections. It is usually difficult to model and solve the MILP/MINLP problem...

  18. Remedial action plan and site design for stabilization of the Inactive Uranium Mill Tailings Site, Maybell, Colorado. Final report, Appendixes to attachment 3

    International Nuclear Information System (INIS)

    This document contains supporting appendices to attachment 3 for the remedial action and site stabilization plan for Maybell, Colorado UMTRA site. Appendix A includes the Hydrological Services Calculations and Appendix B contains Ground Water Quality by Location data

  19. Belt attachment and system

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Abraham D.; Davidson, Erick M.

    2016-02-02

    Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

  20. Attachment Without Fear

    OpenAIRE

    Bell, David C.

    2009-01-01

    John Bowlby hypothesized an attachment system that interacts with caregiving, exploration, and fear systems in the brain, with a particular emphasis on fear. Neurobiological research confirms many of his hypotheses and also raises some new questions. A psychological model based on this neurobiological research is presented here. The model extends conventional attachment theory by describing additional attachment processes independent of fear. In this model, the attachment elements of trust, o...

  1. Precision Attachment: Retained Overdenture

    OpenAIRE

    Jayasree, K; Mrs.M.Bharathi; Nag, V. Dileep; B. Vinod

    2011-01-01

    Precision attachments are small interlocking devices to connect prosthesis and abutments that offer a variety of solutions to the challenge of balance between functional stability and cosmetic appeal. Precision attachments have wide applications, used in fixed removable bridge, removable partial dentures, overdentures, implant retained overdentures, and maxillofacial prosthesis. Attachment retained overdentures helps in distribution of masticatory forces, minimizes trauma to abutments and sof...

  2. Special Attachments. Module 19.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on special attachments, one in a series dealing with industrial sewing machines, their attachments, and operation, covers four topics: gauges; cording attachment; zipper foot; and hemming, shirring, and binding. For each topic these components are provided: an introduction, directions, an objective, learning activities, student…

  3. A Multi-Step and Multi-Level Approach for Computer Aided Molecular Design

    DEFF Research Database (Denmark)

    Harper, Peter Mathias; Gani, Rafiqul

    . The problem formulation step incorporates a knowledge base for the identification and setup of the design criteria. Candidate compounds are identified using a multi-level generate and test CAMD solution algorithm capable of designing molecules having a high level of molecular detail. A post solution......A general multi-step approach for setting up, solving and solution analysis of computer aided molecular design (CAMD) problems is presented. The approach differs from previous work within the field of CAMD since it also addresses the need for a computer aided problem formulation and result analysis...

  4. A Multi-Step and Multi-Level Approach for Computer Aided Molecular Design

    DEFF Research Database (Denmark)

    Harper, Peter Mathias; Gani, Rafiqul

    A general multi-step approach for setting up, solving and solution analysis of computer aided molecular design (CAMD) problems is presented. The approach differs from previous work within the field of CAMD since it also addresses the need for a computer aided problem formulation and result analysis....... The problem formulation step incorporates a knowledge base for the identification and setup of the design criteria. Candidate compounds are identified using a multi-level generate and test CAMD solution algorithm capable of designing molecules having a high level of molecular detail. A post solution...... step for result analysis and verification is included in the methodology. (C) 2000 Elsevier Science Ltd. All rights reserved....

  5. A Multi-step and Multi-level approach for Computer Aided Molecular Design

    DEFF Research Database (Denmark)

    A general multi-step approach for setting up, solving and solution analysis of computer aided molecular design (CAMD) problems is presented. The approach differs from previous work within the field of CAMD since it also addresses the need for a computer aided problem formulation and result analysis....... The problem formulation step incorporates a knowledge base for the identification and setup of the design criteria. Candidate compounds are identified using a multi-level generate and test CAMD solution algorithm capable of designing molecules having a high level of molecular detail. A post solution...... step using an Integrated Computer Aided System (ICAS) for result analysis and verification is included in the methodology. Keywords: CAMD, separation processes, knowledge base, molecular design, solvent selection, substitution, group contribution, property prediction, ICAS Introduction The use of...

  6. Final Report, "Molecular Design of Hydrocarbon Oxidation Catalytic Processes"

    Energy Technology Data Exchange (ETDEWEB)

    Professor Francisco Zaera

    2007-08-09

    The main goal of this project had been to use model systems to correlate selectivities in partial oxidation catalysis with the presence of specific sites on the surface of the catalyst. Extensive work was performed this year on characterizing oxygen-treated nickel surfaces by chemical means. Specifically, the surface chemistry of ammonia coadsorbed with atomic oxygen on Ni(110) single-crystal surfaces was studied by temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). It was determined that at intermediate oxygen coverages direct ammonia adsorption on nickel sites is suppressed, but a new high-temperature reaction regime is generated at 400 K where NHx surface fragments are rehydrogenated concurrently with the production of water and molecular hydrogen. The extensive isotope scrambling and hydrogen transfer seen from nitrogen- to oxygen-containing surface intermediates, and the optimum yields seen for this 400 K state at intermediate oxygen coverages, strongly suggest the direct interaction of the adsorbed ammonia with oxygen atoms at the end of the –Ni–O- rows that form upon reconstruction of the surface. Hydrogen transfer between ammonia and oxygen appears to take place directly via hydrogen bonding, and to be reversible but biased towards water formation. An equilibrium is reached between the produced water and the reacting surface oxygen and hydrogen. The strong influence of the OH surface groups on the thermal chemistry of the adsorbed ammonia was interpreted in terms of the adsorbing geometry of the OH groups on the surface, and of hydrogen bonding between adsorbed OH and NH3 species. In terms of alcohol reactivity, the adsorption of 2-iodoethanol, a precursor for the preparation of 2-hydroxyethyl and oxametallacycle surface species, was found to lead to two configurations involving either just the iodine atom or both iodine and hydroxyl ends of the molecule. A complex chemical behavior starts around 140 K with the

  7. Remedial action plan and site design for stabilization of the inactive Uranium Mill Tailing site Maybell, Colorado. Attachment 3, ground water hydrology report, Attachment 4, water resources protection strategy. Final report

    International Nuclear Information System (INIS)

    The U.S. Environmental Protection Agency (EPA) has established health and environmental regulations to correct and prevent ground water contamination resulting from former uranium processing activities at inactive uranium processing sites (40 CFR Part 192 (1993)) (52 FR 36000 (1978)). According to the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 (42 USC section 7901 et seq.), the U.S. Department of Energy (DOE) is responsible for assessing the inactive uranium processing sites. The DOE has decided that each assessment will include information on hydrogeologic site characterization. The water resources protection strategy that describes the proposed action compliance with the EPA ground water protection standards is presented in Attachment 4, Water Resources Protection Strategy. Site characterization activities discussed in this section include the following: (1) Definition of the hydrogeologic characteristics of the environment, including hydrostratigraphy, aquifer parameters, areas of aquifer recharge and discharge, potentiometric surfaces, and ground water velocities. (2) Definition of background ground water quality and comparison with proposed EPA ground water protection standards. (3) Evaluation of the physical and chemical characteristics of the contaminant source and/or residual radioactive materials. (4) Definition of existing ground water contamination by comparison with the EPA ground water protection standards. (5) Description of the geochemical processes that affect the migration of the source contaminants at the processing site. (6) Description of water resource use, including availability, current and future use and value, and alternate water supplies

  8. Design of molecularly imprinted polymers for sensors and solid phase extraction

    OpenAIRE

    Subrahmanyam, Sreenath

    2002-01-01

    This thesis presents broadly the applications of molecularly imprinted polymers in sensors and solid phase extraction. Sensors for creatine and creatinine have been reported using a novel method of rational design of molecularly imprinted polymers (MIPs), and solid phase extraction of aflatoxin-B 1 has also been described in the thesis. A method for the selective detection of creataine and creatinine is reported in this thesis, which is based on the reaction between polymeri...

  9. Attachment fixation of the overdenture: part II.

    Science.gov (United States)

    Mensor, M C

    1978-01-01

    Many attachment systems of the bar or stud type increase the stability of an overdenture. When selecting an attachment it is essential to consider the skill of the dentist-laboratory team as well as the dexterity of the patient and to use the easiest system that will still improve stabilization. Generally simplicity in design, ease of maintenance, and minimum leverage should be paramount considerations in selection. Use of a guide such as the EM Gauge and of the EM Attachment Selector significantly reduces the confusion in selecting attachments and increases the working armamentarium for stabilizing an overdenture. PMID:340660

  10. Positron-attachment to small molecules: Vibrational enhancement of positron affinities with configuration interaction level of multi-component molecular orbital approach

    Energy Technology Data Exchange (ETDEWEB)

    Tachikawa, Masanori [Quantum Chemistry Division, Graduate School of NanoBioScience, Yokohama City University, 22-2 Seto, Kanazawa, Yokohama 236-0027 (Japan)

    2015-12-31

    To theoretically demonstrate the binding of a positron to small polarized molecules, we have calculated the vibrational averaged positron affinity (PA) values along the local vibrational contribution with the configuration interaction level of multi-component molecular orbital method. This method can take the electron-positron correlation contribution into account through single electronic - single positronic excitation configurations. The PA values are enhanced by including the local vibrational contribution from vertical PA values due to the anharmonicity of the potential.

  11. Generic Mathematical Programming Formulation and Solution for Computer-Aided Molecular Design

    DEFF Research Database (Denmark)

    Zhang, Lei; Cignitti, Stefano; Gani, Rafiqul

    2015-01-01

    This short communication presents a generic mathematical programming formulation for Computer-Aided Molecular Design (CAMD). A given CAMD problem, based on target properties, is formulated as a Mixed Integer Linear/Non-Linear Program (MILP/MINLP). The mathematical programming model presented here......, which is formulated as an MILP/MINLP problem, considers first-order and second-order molecular groups for molecular structure representation and property estimation. It is shown that various CAMD problems can be formulated and solved through this model....

  12. Attachment theory: A review of research

    Directory of Open Access Journals (Sweden)

    Polovina Nada

    2005-01-01

    Full Text Available Research of attachment is numerous and versatile. They differ according to problems addressed, methodology applied (longitudinal studies, studies with horizontal designs, different instruments used, different methods of data analysis, and characteristics of samples involved (concerning age socio/economic status, family ecology. The research is commonly relied on the core assumptions of the theory itself, and the shared characteristic is orientation to explore complex phenomena of human experience and functioning. From the vast variety of research only those who most directly test the basic assumptions of the attachment theory are focused and addressed in the paper: representation of patterns of attachment in the childhood and adulthood, stability and change of attachment security from infancy to early adulthood, transgenerational transmission of attachment characteristics, the place and the role of attachment behavioral system in the personality development. The aim of the paper is to highlight the basic research and theory issues and directions, and illustrate them with concrete research date.

  13. Maximizing the dielectric response of molecular thin films via quantum chemical design.

    Science.gov (United States)

    Heitzer, Henry M; Marks, Tobin J; Ratner, Mark A

    2014-12-23

    Developing high-capacitance organic gate dielectrics is critical for advances in electronic circuitry based on unconventional semiconductors. While high-dielectric constant molecular substances are known, the mechanism of dielectric response and the fundamental chemical design principles are not well understood. Using a plane-wave density functional theory formalism, we show that it is possible to map the atomic-scale dielectric profiles of molecule-based materials while capturing important bulk characteristics. For molecular films, this approach reveals how basic materials properties such as surface coverage density, molecular tilt angle, and π-system planarity can dramatically influence dielectric response. Additionally, relatively modest molecular backbone and substituent variations can be employed to substantially enhance film dielectric response. For dense surface coverages and proper molecular alignment, conjugated hydrocarbon chains can achieve dielectric constants of >8.0, more than 3 times that of analogous saturated chains, ∼2.5. However, this conjugation-related dielectric enhancement depends on proper molecular orientation and planarization, with enhancements up to 60% for proper molecular alignment with the applied field and an additional 30% for conformations such as coplanarity in extended π-systems. Conjugation length is not the only determinant of dielectric response, and appended polarizable high-Z substituents can increase molecular film response more than 2-fold, affording estimated capacitances of >9.0 μF/cm2. However, in large π-systems, polar substituent effects are substantially attenuated. PMID:25415650

  14. Molecular modeling for the design of novel performance chemicals and materials

    CERN Document Server

    Rai, Beena

    2012-01-01

    Molecular modeling (MM) tools offer significant benefits in the design of industrial chemical plants and material processing operations. While the role of MM in biological fields is well established, in most cases MM works as an accessory in novel products/materials development rather than a tool for direct innovation. As a result, MM engineers and practitioners are often seized with the question: ""How do I leverage these tools to develop novel materials or chemicals in my industry?"" Molecular Modeling for the Design of Novel Performance Chemicals and Materials answers this important questio

  15. Blade attachment assembly

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  16. Molecular docking as a popular tool in drug design, an in silico travel

    Science.gov (United States)

    de Ruyck, Jerome; Brysbaert, Guillaume; Blossey, Ralf; Lensink, Marc F

    2016-01-01

    New molecular modeling approaches, driven by rapidly improving computational platforms, have allowed many success stories for the use of computer-assisted drug design in the discovery of new mechanism-or structure-based drugs. In this overview, we highlight three aspects of the use of molecular docking. First, we discuss the combination of molecular and quantum mechanics to investigate an unusual enzymatic mechanism of a flavoprotein. Second, we present recent advances in anti-infectious agents’ synthesis driven by structural insights. At the end, we focus on larger biological complexes made by protein–protein interactions and discuss their relevance in drug design. This review provides information on how these large systems, even in the presence of the solvent, can be investigated with the outlook of drug discovery. PMID:27390530

  17. Oxytocin enhances the experience of attachment security

    Science.gov (United States)

    Buchheim, Anna; Heinrichs, Markus; George, Carol; Pokorny, Dan; Koops, Eva; Henningsen, Peter; O’Connor, Mary-Frances; Gundel, Harald

    2011-01-01

    Summary Repeated interactions between infant and caregiver result in either secure or insecure relationship attachment patterns, and insecure attachment may affect individual emotion-regulation and health. Given that oxytocin enhances social approach behavior in animals and humans, we hypothesized that oxytocin might also promote the experience of attachment security in humans. Within a 3-week interval 26 healthy male students classified with an insecure attachment pattern were invited twice to an experimental session. Within each session, a single dose of oxytocin or placebo was administered, using a double-blind, placebo-controlled within-subject design. In both conditions, subjects completed an attachment task based on the Adult Attachment Projective Picture System (AAP). Thirty-two AAP picture system presentations depicted attachment-related events (e.g. illness, solitude, separation, loss), and were each accompanied by four prototypical phrases representing one secure and three insecure attachment categories. In the oxytocin condition, a significant proportion of these insecure subjects (N = 18; 69%) changed their rankings of “secure attachment” phrases towards the more appropriate for the AAP picture presentation, and the same subjects decreased in overall rating of the “insecure attachment” phrases. In particular, there was a significant decrease in the number of subjects ranking the pictures with “insecure-preoccupied” phrases from the placebo to the oxytocin condition. We find that a single dose of intranasally administered oxytocin is sufficient to induce a significant increase in the experience of attachment security in adults classified previously as insecure. PMID:19457618

  18. The Journal of Computer-Aided Molecular Design: a bibliometric note

    OpenAIRE

    Willett, P.

    2012-01-01

    Summarizes the articles in, and the citations to, volumes 2-24 of the Journal of Computer-Aided Molecular Design. The citations to the journal come from almost 2000 different sources that span a very wide range of academic subjects, with the most heavily cited articles being descriptions of software systems and of computational methods.

  19. Web based learning support for experimental design in molecular biology: a top-down approach

    NARCIS (Netherlands)

    Aegerter-Wilmsen, T.; Hartog, R.; Bisseling, T.

    2003-01-01

    An important learning goal of a molecular biology curriculum is the attainment of a certain competence level in experimental design. Currently, undergraduate students are confronted with experimental approaches in textbooks, lectures and laboratory courses. However, most students do not reach a sati

  20. Design and Application of Self-Assembled Low Molecular Weight Hydrogels

    NARCIS (Netherlands)

    Loos, Maaike de; Esch, Jan H. van; Feringa, Bernard

    2005-01-01

    Over the past years, the gelation of aqueous solutions by low molecular weight (LMW) compounds has become an area of increasing interest, owing to developments in the field of LMW organogelators. Until recently, LMW hydrogelators were found only by serendipity, nowadays rational design as well as ap

  1. Design and application of self-assembled low molecular weight hydrogels

    NARCIS (Netherlands)

    de Loos, M.; Feringa, B.L.; van Esch, J.

    2005-01-01

    Over the past years, the gelation of aqueous solutions by low molecular weight (LMW) compounds has become an area of increasing interest, owing to developments in the field of LMW organogelators. Until recently, LMW hydrogelators were found only by serendipity, nowadays rational design as well as ap

  2. Design of two-photon molecular tandem architectures for solar cells by ab initio theory

    DEFF Research Database (Denmark)

    Ørnsø, Kristian Baruël; García Lastra, Juan Maria; De La Torre, Gema;

    2015-01-01

    structural and energetic properties of several thousand porphyrin dyes. The third design is a molecular analogy of the intermediate band solar cell, and involves a single dye molecule with strong intersystem crossing to ensure a long lifetime of the intermediate state. Based on the calculated energy levels...

  3. Attachment Security and Pain

    DEFF Research Database (Denmark)

    Andersen, Tonny Elmose; Lahav, Yael; Defrin, Ruth;

    2015-01-01

    The present study assesses for the first time, the possible disruption effect of posttraumatic stress symptoms (PTSS) with regard to the protective role of attachment on pain, among ex-POWs. While secure attachment seems to serve as a buffer, decreasing the perception of pain, this function may be...

  4. Attachment and Early Maltreatment.

    Science.gov (United States)

    Egeland, Byron; Sroufe, L. Alan

    1981-01-01

    Attachment outcomes of 31 maltreatment cases (involving extreme neglect or abuse), selected from a total poverty sample of 267 high-risk mothers and their children, were compared to those of a subsample of 33 cases with a history of excellent care. Attachment was assessed when infants were 12 and 18 months old. (Author/MP)

  5. Computer-Aided Molecular Design of Bis-phosphine Oxide Lanthanide Extractants.

    Science.gov (United States)

    McCann, Billy W; Silva, Nuwan De; Windus, Theresa L; Gordon, Mark S; Moyer, Bruce A; Bryantsev, Vyacheslav S; Hay, Benjamin P

    2016-06-20

    Computer-aided molecular design and high-throughput screening of viable host architectures can significantly reduce the efforts in the design of novel ligands for efficient extraction of rare earth elements. This paper presents a computational approach to the deliberate design of bis-phosphine oxide host architectures that are structurally organized for complexation of trivalent lanthanides. Molecule building software, HostDesigner, was interfaced with molecular mechanics software, PCModel, providing a tool for generating and screening millions of potential R2(O)P-link-P(O)R2 ligand geometries. The molecular mechanics ranking of ligand structures is consistent with both the solution-phase free energies of complexation obtained with density functional theory and the performance of known bis-phosphine oxide extractants. For the case where the link is -CH2-, evaluation of the ligand geometry provides the first characterization of a steric origin for the "anomalous aryl strengthening" effect. The design approach has identified a number of novel bis-phosphine oxide ligands that are better organized for lanthanide complexation than previously studied examples. PMID:26883005

  6. Characterization-Based Molecular Design of Biofuel Additives Using Chemometric and Property Clustering Techniques

    Directory of Open Access Journals (Sweden)

    Subin eHada

    2014-06-01

    Full Text Available In this work, multivariate characterization data such as infrared (IR spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis (PCA allowed capturing important features of the molecular architecture from complex data to build appropriate latent variable models. Combining the property clustering techniques and group contribution methods (GCM based on characterization data in a reverse problem formulation enabled identifying candidate components by combining or mixing molecular fragments until the resulting properties match the targets. The developed methodology is demonstrated using molecular design of biodiesel additive which when mixed with off-spec biodiesel produces biodiesel that meets the desired fuel specifications. The contribution of this work is that the complex structures and orientations of the molecule can be included in the design, thereby allowing enumeration of all feasible candidate molecules that matched the identified target but were not part of original training set of molecules.

  7. Molecular Model Design and Quantum Chemistry Calculation of Cluster B4N4

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The B4N4 configurations were designed by using the molecular figure software. The full geometry optimization and harmonic vibration frequency analysis were performed at the 6-31G(d) level using density functional theory B3LYP method, which indicates that the five isomers are stationary points on the potential energy surface of B4N4 molecules. The geometry structure, frontier molecular orbital (FMO) and mulliken population have been analyzed. The bonding properties and hybrid type were also discussed in detail, showing the addition of hydro- gen atoms to boron or nitrogen atom would increase the stabilities of the BN clusters.

  8. Design of a molecular beam surface scattering apparatus for velocity and angular distribution measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ceyer, S.T.; Siekhaus, W.J.; Somorjai, G.A.

    1981-09-01

    A molecular beam surface scattering apparatus designed for the study of corrosion and catalytic surface reactions is described. The apparatus incorporates two molecular or atomic beams aimed at a surface characterized by low energy electron diffraction (LEED) and Auger electron spectroscopy (AES), a rotatable, differentially pumped quadrupole mass spectrometer, and a versatile manipulator. Angular distributions and energy distributions as a function of angle and independent of the surface residence time can be measured. Typical data for the oxidation of deuterium to D/sub 2/O on a Pt(111) crystal surface are presented.

  9. DESIGN OF A MOLECULAR BEAM SURFACE SCATTERING APPARATUS FOR VELOCITY AND ANGULAR DISTRIBUTION MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Ceyer, S. T.; Siekhaus, W. J.; Somorjai, G. A.

    1980-11-01

    A molecular beam surface scattering apparatus designed for the study of corrosion and catalyticsurfacereactions is described. The apparatus incorporates two molecular or atomic beams aimed at a surface characterized by low energy electron diffraction (LEED) and Auger electron spectroscopy (AES), a rotatable, differentially pumped quadrupole mass spectrometer, and a versatile manipulator. Angular distributions and energy distributions as a funcion of angle and independent of the surface residence time can be measured. Typical data for the oxidation of deuterium to D{sub 2}O on a Pt(lll) crystal surface are presented.

  10. Preliminary Design of Molecular Sieve for Removing Organic Iodide in Containment Filtered Venting System

    International Nuclear Information System (INIS)

    In this paper, to increase the DF for gaseous iodine species, especially organic iodide, molecular sieve filled by silver exchanged zeolites is proposed and designed preliminarily. Its aerodynamic analysis is also performed and presented. In order to increase the DF for gaseous organic iodide, deep-bed type molecular sieve was proposed and designed preliminarily. Total 1,620kg of silver exchanged zeolites were filled evenly in 10 beds of the molecular sieve. The safety factor in the case of 20m3/s will be smaller than the counterpart of the standard case (6m3/s). However, if the adsorption capacity of the zeolites is larger than 3.09mg/g when the residence time is 0.09 second, the designed molecular sieve can be used at 20m3/s of volumetric flow rate. The removal efficiency for organic iodide should be considered as well as economical aspects in the design of molecular sieve. In the event of nuclear power plant (NPP) severe accident, the nuclear reactor containment might suffer damage resulting from overpressure caused by decay heat. In order to prevent this containment damage, containment venting has been considered as one of effective methods. However, since vented gases contain radioactive fission products, they should be filtered to be released to environment. Generally, containment filtered venting system (CFVS) is installed on NPP to achieve this aim. Even though great amount of efforts have been devoted to developing the CFVS using various filtering methods, the decontaminant factor (DF) for radioactive gaseous iodide is still unsatisfactory while DFs for radioactive aerosols and elemental iodine are very high

  11. Crystal Growth Inhibitors for the Prevention of L-Cystine Kidney Stones Through Molecular Design

    Energy Technology Data Exchange (ETDEWEB)

    Rimer, Jeffrey D.; An, Zhihua; Zhu, Zina; Lee, Michael H.; Goldfarb, David S.; Wesson, Jeffrey A.; Ward, Michael D. (NY Univ.); (MCW)

    2010-11-12

    Crystallization of L-cystine is a critical step in the pathogenesis of cystine kidney stones. Treatments for this disease are somewhat effective but often lead to adverse side effects. Real-time in situ atomic force microscopy (AFM) reveals that L-cystine dimethylester (L-CDME) and L-cystine methylester (L-CME) dramatically reduce the growth velocity of the six symmetry-equivalent {l_brace}100{r_brace} steps because of specific binding at the crystal surface, which frustrates the attachment of L-cystine molecules. L-CDME and L-CME produce L-cystine crystals with different habits that reveal distinct binding modes at the crystal surfaces. The AFM observations are mirrored by reduced crystal yield and crystal size in the presence of L-CDME and L-CME, collectively suggesting a new pathway to the prevention of L-cystine stones by rational design of crystal growth inhibitors.

  12. Amphiphilic, hydrophilic, or hydrophobic synthetic bacteriochlorins in biohybrid light-harvesting architectures: consideration of molecular designs.

    Science.gov (United States)

    Jiang, Jianbing; Reddy, Kanumuri Ramesh; Pavan, M Phani; Lubian, Elisa; Harris, Michelle A; Jiao, Jieying; Niedzwiedzki, Dariusz M; Kirmaier, Christine; Parkes-Loach, Pamela S; Loach, Paul A; Bocian, David F; Holten, Dewey; Lindsey, Jonathan S

    2014-11-01

    Biohybrid light-harvesting architectures can be constructed that employ native-like bacterial photosynthetic antenna peptides as a scaffold to which synthetic chromophores are attached to augment overall spectral coverage. Synthetic bacteriochlorins are attractive to enhance capture of solar radiation in the photon-rich near-infrared spectral region. The effect of the polarity of the bacteriochlorin substituents on the antenna self-assembly process was explored by the preparation of a bacteriochlorin-peptide conjugate using a synthetic amphiphilic bacteriochlorin (B1) to complement prior studies using hydrophilic (B2, four carboxylic acids) or hydrophobic (B3) bacteriochlorins. The amphiphilic bioconjugatable bacteriochlorin B1 with a polar ammonium-terminated tail was synthesized by sequential Pd-mediated reactions of a 3,13-dibromo-5-methoxybacteriochlorin. Each bacteriochlorin bears a maleimido-terminated tether for attachment to a cysteine-containing analog of the Rhodobacter sphaeroides antenna β-peptide to give conjugates β-B1, β-B2, and β-B3. Given the hydrophobic nature of the β-peptide, the polarity of B1 and B2 facilitated purification of the respective conjugate compared to the hydrophobic B3. Bacteriochlorophyll a (BChl a) associates with each conjugate in aqueous micellar media to form a dyad containing two β-peptides, two covalently attached synthetic bacteriochlorins, and a datively bonded BChl-a pair, albeit to a limited extent for β-B2. The reversible assembly/disassembly of dyad (β-B2/BChl)2 was examined in aqueous detergent (octyl glucoside) solution by temperature variation (15-35 °C). The energy-transfer efficiency from the synthetic bacteriochlorin to the BChl-a dimer was found to be 0.85 for (β-B1/BChl)2, 0.40 for (β-B2/BChl)2, and 0.85 for (β-B3/BChl)2. Thus, in terms of handling, assembly and energy-transfer efficiency taken together, the amphiphilic design examined herein is more attractive than the prior hydrophilic or

  13. Attachment and Psychotherapy

    OpenAIRE

    McKay, J.M.

    2010-01-01

    The aim of this study was to explore the relationship between therapy outcome, the therapeutic alliance and both patient and therapist attachment styles. 14 therapists and 27 patients participated. 78.57% (n = 11) therapists and 29.63% (n = 8) patients were classified as securely attached by self-report measures. It was predicted that more patients of secure therapists would show clinically significant improvement as determined by CORE-OM scores. However, 21.05% of patients with a secure atta...

  14. Examinations on retention of overdentures with elastic frictional attachments

    OpenAIRE

    W. Chladek; G. Chladek; M. Wrzuś-Wieliński; J. Żmudzki

    2010-01-01

    frictional attachments.Design/methodology/approach: The examinations of retention characteristics of traditional attachments, elastic frictional attachments and models of overdentures have been carried out using Zwick testing machine. Retention forces and work essential for separating the attachments have been determined as well. Next the force – displacement characteristics for overdenture model have been registered for two places where the force was applied and for three inclination angles ...

  15. Attachment to land

    Directory of Open Access Journals (Sweden)

    Paul Rozin

    2008-04-01

    Full Text Available This is a first study on attachment to national and sacred land and land as a protected value. A measure of attachment to the land of Israel is developed and administered to two groups, Jewish college students in Israel and the United States. Levels of land attachment are high and not significantly different in the two groups, with a great deal of variation. Land may become more important through being inhabited by a group over centuries. This is a positive contagion effect, and is opposed in some cases by negative contagion produced when the ``enemies'' live on the land for some period of time. We demonstrate a significant correlation of positive contagion sensitivity with attachment to the land of Israel. Unlike many other cases of the interaction of positive and negative contagion, negative contagion does not overwhelm positive contagion in the domain of land attachment. We also present evidence for linkages between political positions, religiosity, importance of Israel, Arab aversion, and vulnerability of Israel with attachment to land, but these do not fully account for the contagion effects. A number of significant differences between Israelis and Americans are described.

  16. From Computational Photobiology to the Design of Vibrationally Coherent Molecular Devices and Motors

    Science.gov (United States)

    Olivucci, Massimo

    2014-03-01

    In the past multi-configurational quantum chemical computations coupled with molecular mechanics force fields have been employed to investigate spectroscopic, thermal and photochemical properties of visual pigments. Here we show how the same computational technology can nowadays be used to design, characterize and ultimately, prepare light-driven molecular switches which mimics the photophysics of the visual pigment bovine rhodopsin (Rh). When embedded in the protein cavity the chromophore of Rh undergoes an ultrafast and coherent photoisomerization. In order to design a synthetic chromophore displaying similar properties in common solvents, we recently focused on indanylidene-pyrroline (NAIP) systems. We found that these systems display light-induced ground state coherent vibrational motion similar to the one detected in Rh. Semi-classical trajectories provide a mechanistic description of the structural changes associated to the observed coherent motion which is shown to be ultimately due to periodic changes in the π-conjugation.

  17. Multi-objective molecular de novo design by adaptive fragment prioritization.

    Science.gov (United States)

    Reutlinger, Michael; Rodrigues, Tiago; Schneider, Petra; Schneider, Gisbert

    2014-04-14

    We present the development and application of a computational molecular de novo design method for obtaining bioactive compounds with desired on- and off-target binding. The approach translates the nature-inspired concept of ant colony optimization to combinatorial building block selection. By relying on publicly available structure-activity data, we developed a predictive quantitative polypharmacology model for 640 human drug targets. By taking reductive amination as an example of a privileged reaction, we obtained novel subtype-selective and multitarget-modulating dopamine D4 antagonists, as well as ligands selective for the sigma-1 receptor with accurately predicted affinities. The nanomolar potencies of the hits obtained, their high ligand efficiencies, and an overall success rate of 90 % demonstrate that this ligand-based computer-aided molecular design method may guide target-focused combinatorial chemistry. PMID:24623390

  18. Strategic approaches to drug design. I. An integrated software framework for molecular modelling.

    Science.gov (United States)

    Vinter, J G; Davis, A; Saunders, M R

    1987-04-01

    An integrated molecular graphics and computational chemistry framework is described which has been designed primarily to handle small molecules of up to 300 atoms. The system provides a means of integrating software from any source into a single framework. It is split into two functional subsystems. The first subsystem, called COSMIC, runs on low-cost, serial-linked colour graphics terminals and allows the user to prepare and examine structural data and to submit them for extensive computational chemistry. Links also allow access to databases, other modelling systems and user-written modules. Much of the output from COSMIC cannot be examined with low level graphics. A second subsystem, called ASTRAL, has been developed for the high-resolution Evans & Sutherland PS300 colour graphics terminal and is designed to manipulate complex display structures. The COSMIC minimisers, geometry investigators, molecular orbital displays, electrostatic isopotential generators and various interfaces and utilities are described. PMID:3505586

  19. Molecular design of specific metal-binding peptide sequences from protein fragments: Theory and Experiment

    Czech Academy of Sciences Publication Activity Database

    Kožíšek, Milan; Svatoš, A.; Buděšínský, Miloš; Muck, A.; Bauer, M. C.; Kotrba, P.; Ruml, T.; Havlas, Zdeněk; Linse, S.; Rulíšek, Lubomír

    2008-01-01

    Roč. 14, č. 26 (2008), s. 7836-7846. ISSN 0947-6539 R&D Projects: GA MŠk LC512; GA MŠk 1M0508 Grant ostatní: GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z40550506 Keywords : ab initio calculations * massspectrometry * metal-ion chelation * molecular design * peptides Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.454, year: 2008

  20. Design principle for increasing charge mobility of π-conjugated polymers using regularly localized molecular orbitals

    OpenAIRE

    Terao, Jun; Wadahama, Akihisa; Matono, Akitoshi; Tada, Tomofumi; Watanabe, Satoshi; Seki, Shu; Fujihara, Tetsuaki; Tsuji, Yasushi

    2013-01-01

    The feasibility of using π-conjugated polymers as next-generation electronic materials is extensively studied; however, their charge mobilities are lower than those of inorganic materials. Here we demonstrate a new design principle for increasing the intramolecular charge mobility of π-conjugated polymers by covering the π-conjugated chain with macrocycles and regularly localizing π-molecular orbitals to realize an ideal orbital alignment for charge hopping. Based on theoretical predictions, ...

  1. Interactive Multimodal Molecular Set – Designing Ludic Engaging Science Learning Content

    DEFF Research Database (Denmark)

    Thorsen, Tine Pinholt; Christiansen, Kasper Holm Bonde; Jakobsen Sillesen, Kristian;

    2014-01-01

    This paper reports on an exploratory study investigating 10 primary school students’ interaction with an interactive multimodal molecular set fostering ludic engaging science learning content in primary schools (8th and 9th grade). The concept of the prototype design was to bridge the physical and...... tags facilitate the application and provide the students to articulate knowledge through different modes; images, gestures, and 3D objects...

  2. Drug design based on x-ray diffraction and steered molecular dynamics

    Czech Academy of Sciences Publication Activity Database

    Hašek, Jindřich; Skálová, Tereza; Dohnálek, Jan; Dušková, Jarmila; Petroková, Hana; Vondráčková, Eva; Zimmermann, K.

    2005-01-01

    Roč. 12, č. 3 (2005), s. 208-210. ISSN 1211-5894. [VUFB Conference on Modern Methods in Synthesis and Analysis of Active Pharmaceutical Substances /5./. Praha, 23.11.2005-24.11.2005] R&D Projects: GA AV ČR KJB4050312 Institutional research plan: CEZ:AV0Z40500505 Keywords : drug design * X-ray diffraction * steered molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry

  3. Molecular Dynamics Simulations Reveal the Mechanisms of Allosteric Activation of Hsp90 by Designed Ligands

    Science.gov (United States)

    Vettoretti, Gerolamo; Moroni, Elisabetta; Sattin, Sara; Tao, Jiahui; Agard, David A.; Bernardi, Anna; Colombo, Giorgio

    2016-04-01

    Controlling biochemical pathways through chemically designed modulators may provide novel opportunities to develop therapeutic drugs and chemical tools. The underlying challenge is to design new molecular entities able to act as allosteric chemical switches that selectively turn on/off functions by modulating the conformational dynamics of their target protein. We examine the origins of the stimulation of ATPase and closure kinetics in the molecular chaperone Hsp90 by allosteric modulators through atomistic molecular dynamics (MD) simulations and analysis of protein-ligand interactions. In particular, we focus on the cross-talk between allosteric ligands and protein conformations and its effect on the dynamic properties of the chaperone’s active state. We examine the impact of different allosteric modulators on the stability, structural and internal dynamics properties of Hsp90 closed state. A critical aspect of this study is the development of a quantitative model that correlates Hsp90 activation to the presence of a certain compound, making use of information on the dynamic adaptation of protein conformations to the presence of the ligand, which allows to capture conformational states relevant in the activation process. We discuss the implications of considering the conformational dialogue between allosteric ligands and protein conformations for the design of new functional modulators.

  4. Molecular docking as a popular tool in drug design, an in silico travel

    Directory of Open Access Journals (Sweden)

    de Ruyck J

    2016-06-01

    Full Text Available Jerome de Ruyck, Guillaume Brysbaert, Ralf Blossey, Marc F Lensink University Lille, CNRS UMR8576 UGSF, Lille, FranceAbstract: New molecular modeling approaches, driven by rapidly improving computational platforms, have allowed many success stories for the use of computer-assisted drug design in the discovery of new mechanism- or structure-based drugs. In this overview, we highlight three aspects of the use of molecular docking. First, we discuss the combination of molecular and quantum mechanics to investigate an unusual enzymatic mechanism of a flavoprotein. Second, we present recent advances in anti-infectious agents' synthesis driven by structural insights. At the end, we focus on larger biological complexes made by protein–protein interactions and discuss their relevance in drug design. This review provides information on how these large systems, even in the presence of the solvent, can be investigated with the outlook of drug discovery.Keywords: structure-based drug design, protein–protein docking, quaternary structure prediction, residue interaction networks, RINs, water position

  5. Structural informatics, modeling, and design with an open-source Molecular Software Library (MSL).

    Science.gov (United States)

    Kulp, Daniel W; Subramaniam, Sabareesh; Donald, Jason E; Hannigan, Brett T; Mueller, Benjamin K; Grigoryan, Gevorg; Senes, Alessandro

    2012-07-30

    We present the Molecular Software Library (MSL), a C++ library for molecular modeling. MSL is a set of tools that supports a large variety of algorithms for the design, modeling, and analysis of macromolecules. Among the main features supported by the library are methods for applying geometric transformations and alignments, the implementation of a rich set of energy functions, side chain optimization, backbone manipulation, calculation of solvent accessible surface area, and other tools. MSL has a number of unique features, such as the ability of storing alternative atomic coordinates (for modeling) and multiple amino acid identities at the same backbone position (for design). It has a straightforward mechanism for extending its energy functions and can work with any type of molecules. Although the code base is large, MSL was created with ease of developing in mind. It allows the rapid implementation of simple tasks while fully supporting the creation of complex applications. Some of the potentialities of the software are demonstrated here with examples that show how to program complex and essential modeling tasks with few lines of code. MSL is an ongoing and evolving project, with new features and improvements being introduced regularly, but it is mature and suitable for production and has been used in numerous protein modeling and design projects. MSL is open-source software, freely downloadable at http://msl-libraries.org. We propose it as a common platform for the development of new molecular algorithms and to promote the distribution, sharing, and reutilization of computational methods. PMID:22565567

  6. Interactive Multimodal Molecular Set – Designing Ludic Engaging Science Learning Content

    DEFF Research Database (Denmark)

    Thorsen, Tine Pinholt; Christiansen, Kasper Holm Bonde; Jakobsen Sillesen, Kristian;

    2014-01-01

    collaboratorium sessions, interviews and observations. The results indicated that bridging the physical and digital worlds can support learning where the affordances of the technologies can be described in terms of meaningful activity: exploration, reasoning, reflection, and ludic engagement. Here, the electronic......This paper reports on an exploratory study investigating 10 primary school students’ interaction with an interactive multimodal molecular set fostering ludic engaging science learning content in primary schools (8th and 9th grade). The concept of the prototype design was to bridge the physical and...... virtual worlds with electronic tags and, through this, blend the familiarity of the computer and toys, to create a tool that provided a ludic approach to learning about atoms and molecules. The study was inspired by the participatory design and informant design methodologies and included design...

  7. Impact of Binding Site Comparisons on Medicinal Chemistry and Rational Molecular Design.

    Science.gov (United States)

    Ehrt, Christiane; Brinkjost, Tobias; Koch, Oliver

    2016-05-12

    Modern rational drug design not only deals with the search for ligands binding to interesting and promising validated targets but also aims to identify the function and ligands of yet uncharacterized proteins having impact on different diseases. Additionally, it contributes to the design of inhibitors with distinct selectivity patterns and the prediction of possible off-target effects. The identification of similarities between binding sites of various proteins is a useful approach to cope with those challenges. The main scope of this perspective is to describe applications of different protein binding site comparison approaches to outline their applicability and impact on molecular design. The article deals with various substantial application domains and provides some outstanding examples to show how various binding site comparison methods can be applied to promote in silico drug design workflows. In addition, we will also briefly introduce the fundamental principles of different protein binding site comparison methods. PMID:27046190

  8. A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

    DEFF Research Database (Denmark)

    Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

    2005-01-01

    This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective is to be...... optimized subject to structural, property, and process constraints. The general molecular/mixture design problem is divided into two parts. For optimal single-compound design, the first part is solved. For mixture design, the single-compound design is first carried out to identify candidates and then the...... second part is solved to determine the optimal mixture. The decomposition of the CAMD MINLP model into relatively easy to solve subproblems is essentially a partitioning of the constraints from the original set. This approach is illustrated through two case studies. The first case study involves the...

  9. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Attachment 3, Groundwater hydrology report. Revised final report

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    The US Environmental Protection Agency (EPA) has established health and environmental protection regulations to correct and prevent groundwater contamination resulting from processing activities at inactive uranium milling sites. According to the Uranium Mill Tailings Radiation Control Act of 1978, (UMTRCA) the US Department of Energy (DOE) is responsible for assessing the inactive uranium processing sites. The DOE has determined this assessment shall include information on hydrogeologic site characterization. The water resources protection strategy that describes how the proposed action will comply with the EPA groundwater protection standards is presented in Attachment 4. Site characterization activities discussed in this section include: Characterization of the hydrogeologic environment; characterization of existing groundwater quality; definition of physical and chemical characteristics of the potential contaminant source; and description of local water resources.

  10. Molecular Design Properties of OxyVita Hemoglobin, a New Generation Therapeutic Oxygen Carrier: A Review

    Directory of Open Access Journals (Sweden)

    Hanna Wollocko

    2011-12-01

    Full Text Available OxyVita Hb is a new generation hemoglobin based oxygen carrier (HBOC produced through modification of a zero-linked polymerization mechanism using activators which incorporate cross-linked bovine tetramer hemoglobin into “super-polymeric” macromolecules (Average molecular weight = 17 MDa for the purpose of oxygen delivery when whole blood or packed red cells are not available. This molecular design approach was generated in order to address several fundamental biochemical and physiological weaknesses of previous generations of HBOCs. Observation during pre-clinical and clinical studies provided evidence that these early generation acellular HBOCs were directly associated with loss of retention within the circulatory system, extravasation across endothelial tissue membranes due to their small molecular size leading to arterial and venous vasoconstriction with coupled increases in mean arterial pressure (MAP. The inherent increase in molecular size and structural stability of the OxyVita Hb is a direct response to addressing these serious weaknesses that have occurred during the evolution of HBOC development within the past two decades. The nature of the zero-linked synthetic route eliminates any chemical linkers remaining in the product, eliminating side reaction concerns, such as reversibility and decomposition due to weak chemical bonds, dependency on temperature and pressure, and residual toxicity.

  11. In-silico design of computational nucleic acids for molecular information processing.

    Science.gov (United States)

    Ramlan, Effirul Ikhwan; Zauner, Klaus-Peter

    2013-01-01

    Within recent years nucleic acids have become a focus of interest for prototype implementations of molecular computing concepts. During the same period the importance of ribonucleic acids as components of the regulatory networks within living cells has increasingly been revealed. Molecular computers are attractive due to their ability to function within a biological system; an application area extraneous to the present information technology paradigm. The existence of natural information processing architectures (predominately exemplified by protein) demonstrates that computing based on physical substrates that are radically different from silicon is feasible. Two key principles underlie molecular level information processing in organisms: conformational dynamics of macromolecules and self-assembly of macromolecules. Nucleic acids support both principles, and moreover computational design of these molecules is practicable. This study demonstrates the simplicity with which one can construct a set of nucleic acid computing units using a new computational protocol. With the new protocol, diverse classes of nucleic acids imitating the complete set of boolean logical operators were constructed. These nucleic acid classes display favourable thermodynamic properties and are significantly similar to the approximation of successful candidates implemented in the laboratory. This new protocol would enable the construction of a network of interconnecting nucleic acids (as a circuit) for molecular information processing. PMID:23647621

  12. Direction-specific interactions control crystal growth by oriented attachment

    DEFF Research Database (Denmark)

    Li, Dongsheng; Nielsen, Michael H; Lee, Jonathan R.I.;

    2012-01-01

    The oriented attachment of molecular clusters and nanoparticles in solution is now recognized as an important mechanism of crystal growth in many materials, yet the alignment process and attachment mechanism have not been established. We performed high-resolution transmission electron microscopy ...

  13. Fuel rod attachment system

    International Nuclear Information System (INIS)

    A reusable system for removably attaching a nuclear reactor fuel rod to a support member. A locking cap is secured to the fuel rod and a locking strip is fastened to the support member or vice versa. The locking cap has two opposing fingers and shaped to form a socket having a body portion. The locking strip has an extension shaped to rigidly attach to the socket's body portion. The locking cap's fingers are resiliently deflectable. For attachment, the locking cap is longitudinally pushed onto the locking strip causing the extension to temporarily deflect open the fingers to engage the socket's body portion. For removal, the process is reversed. In an alternative embodiment, the cap is rigid and the strip is transversely resiliently compressible. (author)

  14. Pain, Affect, and Attachment

    Directory of Open Access Journals (Sweden)

    Carl Eduard Scheidt

    2015-03-01

    Full Text Available Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure dismissing representation of attachment. Psychodynamic psychotherapy in psychogenic pain disorder should focus on the reintegration of split-off affects which may provoke intensive counter-transference and which in order to be used therapeutically must be linked to attachment experiences within and outside of the therapeutic relationship.

  15. Mechanistic and quantitative insight into cell surface targeted molecular imaging agent design.

    Science.gov (United States)

    Zhang, Liang; Bhatnagar, Sumit; Deschenes, Emily; Thurber, Greg M

    2016-01-01

    Molecular imaging agent design involves simultaneously optimizing multiple probe properties. While several desired characteristics are straightforward, including high affinity and low non-specific background signal, in practice there are quantitative trade-offs between these properties. These include plasma clearance, where fast clearance lowers background signal but can reduce target uptake, and binding, where high affinity compounds sometimes suffer from lower stability or increased non-specific interactions. Further complicating probe development, many of the optimal parameters vary depending on both target tissue and imaging agent properties, making empirical approaches or previous experience difficult to translate. Here, we focus on low molecular weight compounds targeting extracellular receptors, which have some of the highest contrast values for imaging agents. We use a mechanistic approach to provide a quantitative framework for weighing trade-offs between molecules. Our results show that specific target uptake is well-described by quantitative simulations for a variety of targeting agents, whereas non-specific background signal is more difficult to predict. Two in vitro experimental methods for estimating background signal in vivo are compared - non-specific cellular uptake and plasma protein binding. Together, these data provide a quantitative method to guide probe design and focus animal work for more cost-effective and time-efficient development of molecular imaging agents. PMID:27147293

  16. Mechanistic and quantitative insight into cell surface targeted molecular imaging agent design

    Science.gov (United States)

    Zhang, Liang; Bhatnagar, Sumit; Deschenes, Emily; Thurber, Greg M.

    2016-05-01

    Molecular imaging agent design involves simultaneously optimizing multiple probe properties. While several desired characteristics are straightforward, including high affinity and low non-specific background signal, in practice there are quantitative trade-offs between these properties. These include plasma clearance, where fast clearance lowers background signal but can reduce target uptake, and binding, where high affinity compounds sometimes suffer from lower stability or increased non-specific interactions. Further complicating probe development, many of the optimal parameters vary depending on both target tissue and imaging agent properties, making empirical approaches or previous experience difficult to translate. Here, we focus on low molecular weight compounds targeting extracellular receptors, which have some of the highest contrast values for imaging agents. We use a mechanistic approach to provide a quantitative framework for weighing trade-offs between molecules. Our results show that specific target uptake is well-described by quantitative simulations for a variety of targeting agents, whereas non-specific background signal is more difficult to predict. Two in vitro experimental methods for estimating background signal in vivo are compared – non-specific cellular uptake and plasma protein binding. Together, these data provide a quantitative method to guide probe design and focus animal work for more cost-effective and time-efficient development of molecular imaging agents.

  17. Designing molecular complexes using free-energy derivatives from liquid-state integral equation theory

    Science.gov (United States)

    Mrugalla, Florian; Kast, Stefan M.

    2016-09-01

    Complex formation between molecules in solution is the key process by which molecular interactions are translated into functional systems. These processes are governed by the binding or free energy of association which depends on both direct molecular interactions and the solvation contribution. A design goal frequently addressed in pharmaceutical sciences is the optimization of chemical properties of the complex partners in the sense of minimizing their binding free energy with respect to a change in chemical structure. Here, we demonstrate that liquid-state theory in the form of the solute–solute equation of the reference interaction site model provides all necessary information for such a task with high efficiency. In particular, computing derivatives of the potential of mean force (PMF), which defines the free-energy surface of complex formation, with respect to potential parameters can be viewed as a means to define a direction in chemical space toward better binders. We illustrate the methodology in the benchmark case of alkali ion binding to the crown ether 18-crown-6 in aqueous solution. In order to examine the validity of the underlying solute–solute theory, we first compare PMFs computed by different approaches, including explicit free-energy molecular dynamics simulations as a reference. Predictions of an optimally binding ion radius based on free-energy derivatives are then shown to yield consistent results for different ion parameter sets and to compare well with earlier, orders-of-magnitude more costly explicit simulation results. This proof-of-principle study, therefore, demonstrates the potential of liquid-state theory for molecular design problems.

  18. Designing molecular complexes using free-energy derivatives from liquid-state integral equation theory.

    Science.gov (United States)

    Mrugalla, Florian; Kast, Stefan M

    2016-09-01

    Complex formation between molecules in solution is the key process by which molecular interactions are translated into functional systems. These processes are governed by the binding or free energy of association which depends on both direct molecular interactions and the solvation contribution. A design goal frequently addressed in pharmaceutical sciences is the optimization of chemical properties of the complex partners in the sense of minimizing their binding free energy with respect to a change in chemical structure. Here, we demonstrate that liquid-state theory in the form of the solute-solute equation of the reference interaction site model provides all necessary information for such a task with high efficiency. In particular, computing derivatives of the potential of mean force (PMF), which defines the free-energy surface of complex formation, with respect to potential parameters can be viewed as a means to define a direction in chemical space toward better binders. We illustrate the methodology in the benchmark case of alkali ion binding to the crown ether 18-crown-6 in aqueous solution. In order to examine the validity of the underlying solute-solute theory, we first compare PMFs computed by different approaches, including explicit free-energy molecular dynamics simulations as a reference. Predictions of an optimally binding ion radius based on free-energy derivatives are then shown to yield consistent results for different ion parameter sets and to compare well with earlier, orders-of-magnitude more costly explicit simulation results. This proof-of-principle study, therefore, demonstrates the potential of liquid-state theory for molecular design problems. PMID:27366935

  19. Design Through Simulation of a Molecular Sieve Column for Treatment of MON-3

    Science.gov (United States)

    Swartz, A. Ben; Wilson, D. B.

    1999-01-01

    The presence of water in propellant-grade MON-3 is a concern in the Aerospace Industry. NASA Johnson Space Center (JSC), White Sands Test Facility (WSTF) Propulsion Department has evaluated many types of molecular sieves for control of iron, the corrosion product of water in Mixed Oxides of Nitrogen (MON-3). In 1995, WSTF initiated laboratory and pilot-scale testing of molecular sieve type 3A for removal of water and iron. These tests showed sufficient promise that a series of continuous recycle tests were conducted at WSTF. Periodic samples of the circulating MON-3 solution were analyzed for water (wt %) and iron (ppm, wt). This test column was modeled as a series of transfer units; i. e., each unit represented the height equivalent of a theoretical plate. Such a model assumes there is equilibrium between the adsorbent material and the effluent stream from the unit. Operational and design parameters were derived based on the simulation results. These parameters were used to predict the design characteristics of a proposed molecular sieve column for removal of water and iron from MON-3 at the NASA Kennedy Space Center (KSC). In addition, these parameters were used to simulate a small, single-pass operation column at KSC currently used for treating MON-3. The results of this work indicated that molecular sieve type 3A in 1/16 in. diameter pellets, in a column 2.5 ft. in diameter, 18 ft. in height, and operated at 25 gpm is adequate for the required removal of water and iron from MON-3.

  20. Electrochemical Attachment of Diazonium-Generated Films on Nanoporous Gold.

    Science.gov (United States)

    Chevalier, Christine L; Landis, Elizabeth C

    2015-08-11

    Nanoporous gold provides a high surface area platform for further chemistry, but the stability of the molecular linkages to the surface will limit applications. We attached aryl molecular layers to nanoporous gold electrodes through electrochemical reduction of the corresponding aryl-diazonium salt and studied the properties and stability of the resulting films in varied attachment conditions. Infrared reflection absorption spectroscopy and X-ray photoelectron spectroscopy were used to confirm the presence of the molecular layers. X-ray photoelectron spectroscopy indicates that the molecular layer is thick and that attachment conditions can form multilayers. However, cyclic voltammetry shows that the multilayers do not block electrochemical activity at the nanoporous gold surface. The molecular layers are resistant to replacement by alkane-thiol chains and exhibit some stability with respect to applied potential. These results indicate that a thick but highly defective molecular film forms with a mixture of strongly and weakly bound molecules. PMID:26186600

  1. Studies towards the understanding of the effects of ionizing radiations at the molecular scale (20-150 keV H+/H + He Collisions; dissociative electron attachment to water)

    International Nuclear Information System (INIS)

    This work comes within the scope of recent studies towards a better understanding of the effect of ionizing radiation at the molecular scale on biological systems. It is composed of two parts. The first one presents a new set of coincidence measurements of cross sections for the impact of protons or hydrogen atoms on helium in the energy range 20-150 keV of interest for the radiation biology. It is an archetypical system of interest for the theoreticians and there exists only a few studies on the impact of hydrogen atoms on helium. This study with helium was also motivated for the sake of performing a general test of functioning of the apparatus before investigating more complicated systems. Similar studies were then performed by replacing helium with water and biological molecules of relevance (Uracil, Thymine...) as target. This constitutes a study of direct effects of fast ionizing radiations on molecules of biological interest. The second part of the thesis deals with another type of ionizing radiations which can be seen as indirect effects of the first fast ionizing radiations studied in the first part. Low energy electrons emission in the energy range 1 to 16 eV follows the bombardment of the matter by swift protons/hydrogen atoms; these electrons have in turn an ionizing influence on the environment. A review of the dissociative electron attachment to water was undertaken motivated by the existing discrepancies between old studies on the same subject. A special attention was given to the problem of high energy kinetic ion discrimination in the trochoidal monochromator used for this work. (author)

  2. Studies towards the understanding of the effects of ionizing radiations at the molecular scale (20-150 keV H{sup +}/H + He Collisions; dissociative electron attachment to water)

    Energy Technology Data Exchange (ETDEWEB)

    Coupier, B

    2005-11-15

    This work comes within the scope of recent studies towards a better understanding of the effect of ionizing radiation at the molecular scale on biological systems. It is composed of two parts. The first one presents a new set of coincidence measurements of cross sections for the impact of protons or hydrogen atoms on helium in the energy range 20-150 keV of interest for the radiation biology. It is an archetypical system of interest for the theoreticians and there exists only a few studies on the impact of hydrogen atoms on helium. This study with helium was also motivated for the sake of performing a general test of functioning of the apparatus before investigating more complicated systems. Similar studies were then performed by replacing helium with water and biological molecules of relevance (Uracil, Thymine...) as target. This constitutes a study of direct effects of fast ionizing radiations on molecules of biological interest. The second part of the thesis deals with another type of ionizing radiations which can be seen as indirect effects of the first fast ionizing radiations studied in the first part. Low energy electrons emission in the energy range 1 to 16 eV follows the bombardment of the matter by swift protons/hydrogen atoms; these electrons have in turn an ionizing influence on the environment. A review of the dissociative electron attachment to water was undertaken motivated by the existing discrepancies between old studies on the same subject. A special attention was given to the problem of high energy kinetic ion discrimination in the trochoidal monochromator used for this work. (author)

  3. The Folding of de Novo Designed Protein DS119 via Molecular Dynamics Simulations.

    Science.gov (United States)

    Wang, Moye; Hu, Jie; Zhang, Zhuqing

    2016-01-01

    As they are not subjected to natural selection process, de novo designed proteins usually fold in a manner different from natural proteins. Recently, a de novo designed mini-protein DS119, with a βαβ motif and 36 amino acids, has folded unusually slowly in experiments, and transient dimers have been detected in the folding process. Here, by means of all-atom replica exchange molecular dynamics (REMD) simulations, several comparably stable intermediate states were observed on the folding free-energy landscape of DS119. Conventional molecular dynamics (CMD) simulations showed that when two unfolded DS119 proteins bound together, most binding sites of dimeric aggregates were located at the N-terminal segment, especially residues 5-10, which were supposed to form β-sheet with its own C-terminal segment. Furthermore, a large percentage of individual proteins in the dimeric aggregates adopted conformations similar to those in the intermediate states observed in REMD simulations. These results indicate that, during the folding process, DS119 can easily become trapped in intermediate states. Then, with diffusion, a transient dimer would be formed and stabilized with the binding interface located at N-terminals. This means that it could not quickly fold to the native structure. The complicated folding manner of DS119 implies the important influence of natural selection on protein-folding kinetics, and more improvement should be achieved in rational protein design. PMID:27128902

  4. The Folding of de Novo Designed Protein DS119 via Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Moye Wang

    2016-04-01

    Full Text Available As they are not subjected to natural selection process, de novo designed proteins usually fold in a manner different from natural proteins. Recently, a de novo designed mini-protein DS119, with a βαβ motif and 36 amino acids, has folded unusually slowly in experiments, and transient dimers have been detected in the folding process. Here, by means of all-atom replica exchange molecular dynamics (REMD simulations, several comparably stable intermediate states were observed on the folding free-energy landscape of DS119. Conventional molecular dynamics (CMD simulations showed that when two unfolded DS119 proteins bound together, most binding sites of dimeric aggregates were located at the N-terminal segment, especially residues 5–10, which were supposed to form β-sheet with its own C-terminal segment. Furthermore, a large percentage of individual proteins in the dimeric aggregates adopted conformations similar to those in the intermediate states observed in REMD simulations. These results indicate that, during the folding process, DS119 can easily become trapped in intermediate states. Then, with diffusion, a transient dimer would be formed and stabilized with the binding interface located at N-terminals. This means that it could not quickly fold to the native structure. The complicated folding manner of DS119 implies the important influence of natural selection on protein-folding kinetics, and more improvement should be achieved in rational protein design.

  5. Attachment and Personality Disorders

    Science.gov (United States)

    Sinha, Preeti; Sharan, Pratap

    2007-01-01

    Personality disorders (PDs) arise from core psychopathology of interpersonal relationships and understanding of self and others. The distorted representations of self and others, as well as unhealthy relationships that characterize persons with various PDs, indicate the possibility that persons with PDs have insecure attachment. Insecure…

  6. MOWER ATTACHMENT NOISE

    OpenAIRE

    Mosdzianowski, G.

    1990-01-01

    The noise produced by grass mowing attachments fitted to small tractors and combining a number of rotary blades with a total cutting width of up to 120 cm was investigated. The paper develops a noise reduction concept based on an analysis of sound sources.

  7. Molecular Design and Functional Control of Novel Self-Oscillating Polymers

    Directory of Open Access Journals (Sweden)

    Ryo Yoshida

    2010-02-01

    Full Text Available If we could realize an autonomous polymer system driven under biological conditions by a tailor-made molecular design, human beings could create unprecedented biomimetic functions and materials such as heartbeats, autonomous peristaltic pumps, etc. In order to achieve this objective, we have investigated the molecular design of such a polymer system. As a result, we were the first to demonstrate a self-oscillating polymer system driven in a solution where only malonic acid existed, which could convert the chemical energy of the Belousov-Zhabotinsky (BZ reaction into a change in the conformation of the polymer chain. To cause the self-oscillation in solution, we have attempted to construct a built-in system where the required BZ system substrates other than the organic acid are incorporated into the polymer itself. That is, the novel polymer chain incorporated the metal catalyst of the BZ reaction, a pH-control site and an oxidant supply site at the same time. As a result of introducing the pH control and oxidant supply sites into the conventional-type self-oscillating polymer chain, the novel polymer chain caused aggregation-disaggregation self-oscillations in the solution. We clarified that the period of the self-oscillation of the novel self-oscillating polymer chain was proportional to the concentration of the malonic acid. Therefore, the concentration of the malonic acid can be determined by measuring the period of the novel self-oscillating polymer solution. In this review, we introduce the detailed molecular design of the novel self-oscillating polymer chain and its self-oscillating behavior. Moreover, we report an autonomous self-oscillating polymer gel actuator that causes a bending-stretching motion under the constant conditions.

  8. Design of a Comprehensive Biochemistry and Molecular Biology Experiment: Phase Variation Caused by Recombinational Regulation of Bacterial Gene Expression

    Science.gov (United States)

    Sheng, Xiumei; Xu, Shungao; Lu, Renyun; Isaac, Dadzie; Zhang, Xueyi; Zhang, Haifang; Wang, Huifang; Qiao, Zheng; Huang, Xinxiang

    2014-01-01

    Scientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about "Salmonella enterica" serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation,…

  9. The Control System Design of Ultra-high Molecular Weight Polyethylene Composite Pipe Production Line

    Directory of Open Access Journals (Sweden)

    Yongrui Zhao

    2013-04-01

    Full Text Available This paper develops a set of centralized-control system for Ultra-high molecular weight polyethylene composite pipe production line and the hardware circuit diagram of control cabinet both inside and outside. The designed system in the paper improves the accuracy of control in the production line and stabilizes the runs, which is realized by the applications of B&R power panel as the controller and the transducer based on two different types (SJ200, SJ300, as well the establishment of the RS485 two-circuit communication network. We’ll elaborate the control system both on hardware and software in this paper.

  10. Molecular design of luminescent Eu(III) complexes as lanthanide lasing material and their optical properties

    International Nuclear Information System (INIS)

    Luminescent polymer (PMMA) containing a Eu(III) complex with a fast radiation rate and a high luminescence quantum efficiency (75 ± 5%) (bis-triphenylphosphineoxide)(tris-hexafluoroacetylacetonato)europium(III) (Eu(hfa)3(TPPO)2), was fabricated. The quantum yield and the radiation rate of the luminescent polymer were found to be 75 ± 5% and 1.1 x 103 s-1, respectively. An Eu(III) complex-doped polymer thin-film was also prepared by use of polyphenylsilsesquioxane (PPSQ) to construct a waveguide lanthanide laser. We propose a strategy for the molecular design of luminescent Eu(III) complexes aiming at lanthanide lasing

  11. Molecular design chemical structure generation from the properties of pure organic compounds

    CERN Document Server

    Horvath, AL

    1992-01-01

    This book is a systematic presentation of the methods that have been developed for the interpretation of molecular modeling to the design of new chemicals. The main feature of the compilation is the co-ordination of the various scientific disciplines required for the generation of new compounds. The five chapters deal with such areas as structure and properties of organic compounds, relationships between structure and properties, and models for structure generation. The subject is covered in sufficient depth to provide readers with the necessary background to understand the modeling

  12. System analysis study of space platform and station accommodations for life sciences research facilities. Volume 2: Study results, attachment 2. Phase A: Conceptual design and programmatics

    Science.gov (United States)

    Wiley, Lowell F.

    1985-01-01

    The study results from the conceptual design and programmatics segment of the Space Platform and Station Accommodation for Life Sciences Research Facilities. The results and significant findings of the conceptual design and programmatics were generated by these tasks: (1) the review and update engineering and science requirements; (2) analysis of life sciences mission transition scenario; (3) the review and update of key trade issues; (4) the development of conceptual definition and designs; and (5) the development of the work breakdown schedule and its dictionary, program schedule, and estimated costs.

  13. Structural Correspondence of the Oriented Attachment Growth Mechanism of Crystals of the Pharmaceutical Dirithromycin.

    Science.gov (United States)

    Liang, Zuozhong; Wang, Yuan; Wang, Wei; Han, Xianglong; Chen, Jian-Feng; Xue, Chunyu; Zhao, Hong

    2015-12-29

    The oriented attachment (OA) mechanism is promising for designing novel nanomaterials, yet an intensive understanding of the relationship between the crystal structure and attachment orientation is still lacking. In this work, we report layered hexagonal crystals of the pharmaceutical dirithromycin (DIR) containing multiple layers fabricated via a solvothermal method for a certain period of time at 40 °C. These elongated hexagonal crystals experience an OA that is preferentially on the face (001) of the initial crystals to assemble the final crystals into layered stacks. Through agreement with molecular modeling calculations, we predicted the final crystal growth morphology and confirmed the favored attachment surface based on the energy change ΔE following an OA event. These simulation results at the molecular level yielded good agreement with the crystal growth experiments. This study demonstrates the critical importance of combining experiments with a computational approach to understand the intrinsic molecular details of the OA growth mechanism of other compounds and to design nanomaterials with a desirable morphology and physical and chemical properties. PMID:26632998

  14. Molecular design and control of fullerene-based bi-thermoelectric materials

    Science.gov (United States)

    Rincón-García, Laura; Ismael, Ali K.; Evangeli, Charalambos; Grace, Iain; Rubio-Bollinger, Gabino; Porfyrakis, Kyriakos; Agraït, Nicolás; Lambert, Colin J.

    2016-03-01

    Molecular junctions are a versatile test bed for investigating nanoscale thermoelectricity and contribute to the design of new cost-effective environmentally friendly organic thermoelectric materials. It was suggested that transport resonances associated with discrete molecular levels could play a key role in thermoelectric performance, but no direct experimental evidence has been reported. Here we study single-molecule junctions of the endohedral fullerene Sc3N@C80 connected to gold electrodes using a scanning tunnelling microscope. We find that the magnitude and sign of the thermopower depend strongly on the orientation of the molecule and on applied pressure. Our calculations show that Sc3N inside the fullerene cage creates a sharp resonance near the Fermi level, whose energetic location, and hence the thermopower, can be tuned by applying pressure. These results reveal that Sc3N@C80 is a bi-thermoelectric material, exhibiting both positive and negative thermopower, and provide an unambiguous demonstration of the importance of transport resonances in molecular junctions.

  15. Molecular Design of Semiconducting Polymers for High-Performance Organic Electrochemical Transistors.

    Science.gov (United States)

    Nielsen, Christian B; Giovannitti, Alexander; Sbircea, Dan-Tiberiu; Bandiello, Enrico; Niazi, Muhammad R; Hanifi, David A; Sessolo, Michele; Amassian, Aram; Malliaras, George G; Rivnay, Jonathan; McCulloch, Iain

    2016-08-17

    The organic electrochemical transistor (OECT), capable of transducing small ionic fluxes into electronic signals in an aqueous environment, is an ideal device to utilize in bioelectronic applications. Currently, most OECTs are fabricated with commercially available conducting poly(3,4-ethylenedioxythiophene) (PEDOT)-based suspensions and are therefore operated in depletion mode. Here, we present a series of semiconducting polymers designed to elucidate important structure-property guidelines required for accumulation mode OECT operation. We discuss key aspects relating to OECT performance such as ion and hole transport, electrochromic properties, operational voltage, and stability. The demonstration of our molecular design strategy is the fabrication of accumulation mode OECTs that clearly outperform state-of-the-art PEDOT-based devices, and show stability under aqueous operation without the need for formulation additives and cross-linkers. PMID:27444189

  16. Molecular Design of Semiconducting Polymers for High-Performance Organic Electrochemical Transistors

    KAUST Repository

    Nielsen, Christian B.

    2016-07-22

    The organic electrochemical transistor (OECT), capable of transducing small ionic fluxes into electronic signals in an aqueous envi-ronment, is an ideal device to utilize in bioelectronic applications. Currently, most OECTs are fabricated with commercially availa-ble conducting poly(3,4-ethylenedioxythiophene) (PEDOT)-based suspensions and are therefore operated in depletion mode. Here, we present a series of semiconducting polymers designed to elucidate important structure-property guidelines required for accumulation mode OECT operation. We discuss key aspects relating to OECT performance such as ion and hole transport, elec-trochromic properties, operational voltage and stability. The demonstration of our molecular design strategy is the fabrication of accumulation mode OECTs that clearly outperform state-of-the-art PEDOT based devices, and show stability under aqueous oper-ation without the need for formulation additives and cross-linkers.

  17. Remedial action plan and site design for stabilization of the inactive uranium processing site at Naturita, Colorado. Remedial Action Selection Report, Appendix B of Attachment 2: Geology report, Final

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), 42 USC {section} 7901 et seq. Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which describes the proposed remedial action for the Naturita site. An extensive amount of data and supporting information has been generated and evaluated for this remedial action. These data and supporting information are not incorporated into this single document but are included or referenced in the supporting documents. The RAP consists of this RAS and four supporting documents or attachments. This Attachment 2, Geology Report describes the details of geologic, geomorphic, and seismic conditions at the Dry Flats disposal site.

  18. A multiscale simulation technique for molecular electronics: design of a directed self-assembled molecular n-bit shift register memory device

    Science.gov (United States)

    Lambropoulos, Nicholas A.; Reimers, Jeffrey R.; Crossley, Maxwell J.; Hush, Noel S.; Silverbrook, Kia

    2013-12-01

    A general method useful in molecular electronics design is developed that integrates modelling on the nano-scale (using quantum-chemical software) and on the micro-scale (using finite-element methods). It is applied to the design of an n-bit shift register memory that could conceivably be built using accessible technologies. To achieve this, the entire complex structure of the device would be built to atomic precision using feedback-controlled lithography to provide atomic-level control of silicon devices, controlled wet-chemical synthesis of molecular insulating pillars above the silicon, and controlled wet-chemical self-assembly of modular molecular devices to these pillars that connect to external metal electrodes (leads). The shift register consists of n connected cells that read data from an input electrode, pass it sequentially between the cells under the control of two external clock electrodes, and deliver it finally to an output device. The proposed cells are trimeric oligoporphyrin units whose internal states are manipulated to provide functionality, covalently connected to other cells via dipeptide linkages. Signals from the clock electrodes are conveyed by oligoporphyrin molecular wires, and μ-oxo porphyrin insulating columns are used as the supporting pillars. The developed multiscale modelling technique is applied to determine the characteristics of this molecular device, with in particular utilization of the inverted region for molecular electron-transfer processes shown to facilitate latching and control using exceptionally low energy costs per logic operation compared to standard CMOS shift register technology.

  19. Proton-Coupled Electron Transfer in Molecular Electrocatalysis: Theoretical Methods and Design Principles

    Energy Technology Data Exchange (ETDEWEB)

    Solis, Brian H.; Hammes-Schiffer, Sharon

    2014-07-07

    Molecular electrocatalysts play an essential role in a wide range of energy conversion processes. The objective of electrocatalyst design is to maximize the turnover frequency and minimize the overpotential for the overall catalytic cycle. Typically the catalytic cycle is dominated by key proton-coupled electron transfer (PCET) processes comprised of sequential or concerted electron transfer and proton transfer steps. A variety of theoretical methods have been developed to investigate the mechanisms, thermodynamics, and kinetics of PCET processes in electrocatalytic cycles. Electronic structure methods can be used to calculate the reduction potentials and pKa’s and to generate thermodynamic schemes, free energy reaction pathways, and Pourbaix diagrams, which indicate the most stable species at each pH and potential. These types of calculations have assisted in identifying the thermodynamically favorable mechanisms under specified experimental conditions, such as acid strength and overpotential. Such calculations have also revealed linear correlations among the thermodynamic properties, which can be used to predict the impact of modifying the ligand, substituents, or metal center. The role of non-innocent ligands, namely ligand protonation or reduction, has also been examined theoretically. In addition, the rate constants for electron and proton transfer reactions, as well as concerted PCET reactions, have been calculated to investigate the kinetics of molecular electrocatalysts. The concerted PCET mechanism is thought to lower the overpotential required for catalysis by avoiding high-energy intermediates. Rate constant calculations have revealed that the concerted mechanism involving intramolecular proton transfer will be favored by designing more flexible ligands that facilitate the proton donor-acceptor motion while also maintaining a sufficiently short equilibrium proton donor-acceptor distance. Overall, theoretical methods have assisted in the interpretation

  20. Molecular Design of Doped Polymers for Thermoelectric Systems-Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Chabinyc, Michael L. [University of California, Santa Barbara; Hawker, Craig J. [University of California, Santa Barbara

    2013-10-09

    The self-assembly of organic semiconducting molecules and polymers is critical for their electrical properties. This project addressed the design of organic semiconductors with novel synthetic building blocks for proton-dopable conducting materials and the molecular order and microstructure of high performance semiconducting polymers blended with charge transfer dopants. Novel azulene donor-acceptor materials were designed and synthesized with unique electronic effects upon protonation to generate charged species in solution. The microstructure and optical properties of these derivatives were examined to develop structure-property relationships. Studies of the microstructure of blends of charge transfer doped semiconducting polymers revealed highly ordered conductive phases in blends. The molecular packing of one blend was studied in detail using a combination of solid-state NMR and x-ray scattering revealing that dopant incorporation is unlikely to be random as assumed in transport models. Studies of the electrical properties of these highly ordered blends revealed a universal trend between the thermopower and electrical conductivity of semiconducting polymers that is independent of the doping mechanism.

  1. Molecular Dynamics Driven Design of pH-Stabilized Mutants of MNEI, a Sweet Protein.

    Directory of Open Access Journals (Sweden)

    Serena Leone

    Full Text Available MNEI is a single chain derivative of monellin, a plant protein that can interact with the human sweet taste receptor, being therefore perceived as sweet. This unusual physiological activity makes MNEI a potential template for the design of new sugar replacers for the food and beverage industry. Unfortunately, applications of MNEI have been so far limited by its intrinsic sensitivity to some pH and temperature conditions, which could occur in industrial processes. Changes in physical parameters can, in fact, lead to irreversible protein denaturation, as well as aggregation and precipitation. It has been previously shown that the correlation between pH and stability in MNEI derives from the presence of a single glutamic residue in a hydrophobic pocket of the protein. We have used molecular dynamics to study the consequences, at the atomic level, of the protonation state of such residue and have identified the network of intramolecular interactions responsible for MNEI stability at acidic pH. Based on this information, we have designed a pH-independent, stabilized mutant of MNEI and confirmed its increased stability by both molecular modeling and experimental techniques.

  2. Epitope engineering and molecular metrics of immunogenicity: a computational approach to VLP-based vaccine design.

    Science.gov (United States)

    Joshi, Harshad; Lewis, Kristen; Singharoy, Abhishek; Ortoleva, Peter J

    2013-10-01

    Developing antiviral vaccines is increasingly challenging due to associated time and cost of production as well as emerging drug-resistant strains. A computer-aided vaccine design strategy is presented that could greatly accelerate the discovery process and yield vaccines with high immunogenicity and thermal stability. Our strategy is based on foreign viral epitopes engineered onto well-established virus-like particles (VLPs) and demonstrates that such constructs present similar affinity for antibodies as does a native virus. This binding affinity serves as one molecular metric of immunogenicity. As a demonstration, we engineered a preS1 epitope of hepatitis B virus (HBV) onto the EF loop of human papillomavirus VLP (HPV-VLP). HBV-associated HzKR127 antibody displayed binding affinity for this structure at distances and strengths similar to those for the complex of the antibody with the full HBV (PDBID: 2EH8). This antibody binding affinity assessment, along with other molecular immunogenicity metrics, could be a key component of a computer-aided vaccine design strategy. PMID:23933338

  3. Computer-aided Molecular Design of Compounds Targeting Histone Modifying Enzymes

    Directory of Open Access Journals (Sweden)

    Federico Andreoli

    2015-01-01

    Full Text Available Growing evidences show that epigenetic mechanisms play crucial roles in the genesis and progression of many physiopathological processes. As a result, research in epigenetic grew at a fast pace in the last decade. In particular, the study of histone post-translational modifications encountered an extraordinary progression and many modifications have been characterized and associated to fundamental biological processes and pathological conditions. Histone modifications are the catalytic result of a large set of enzyme families that operate covalent modifications on specific residues at the histone tails. Taken together, these modifications elicit a complex and concerted processing that greatly contribute to the chromatin remodeling and may drive different pathological conditions, especially cancer. For this reason, several epigenetic targets are currently under validation for drug discovery purposes and different academic and industrial programs have been already launched to produce the first pre-clinical and clinical outcomes. In this scenario, computer-aided molecular design techniques are offering important tools, mainly as a consequence of the increasing structural information available for these targets. In this mini-review we will briefly discuss the most common types of known histone modifications and the corresponding operating enzymes by emphasizing the computer-aided molecular design approaches that can be of use to speed-up the efforts to generate new pharmaceutically relevant compounds.

  4. Molecular interactions in biomineralized hydroxyapatite amino acid modified nanoclay: In silico design of bone biomaterials

    International Nuclear Information System (INIS)

    A simulations driven approach to design of a novel biomaterial nanocomposite system is described in this study. Nanoclays modified with amino acids (OMMT) were used to mineralize hydroxyapatite (HAP), mimicking biomineralization. Representative models of organically modified montmorillonite clay (OMMT) and OMMT-hydroxyapatite (OMMT-HAP) were constructed using molecular dynamics and validated using X-ray Diffraction (XRD), Fourier Transforms Infrared (FTIR) spectroscopy and Transmission Electron Microscopy (TEM). Attractive interactions exist between Ca atoms of HAP and C=O group of aminovaleric acid, indicating chelate formation in OMMT-HAP. Interaction energy maps describe molecular interactions among different constituents and their quantitative contributions in the OMMT and OMMT-HAP systems at both parallel and perpendicular orientations. High attractive and high repulsive interactions were found between PO43− and MMT clay as well as aminovaleric molecules in OMMT-HAP perpendicular and parallel models. Large non-bonded interactions in OMMT-HAP indicate influence of neighboring environment on PO43− in in situ HAPclay. Extensive hydrogen bonds were observed between functional hydrogen atoms of modifier and MMT clay in OMMT-HAP as compared to OMMT. Thus, HAP interacts with clay through the aminovaleric acid. This computational study provides a framework for materials design and selection for biomaterials used in tissue engineering and other areas of regenerative medicine. - Highlights: • Representative models of a hybrid nanoclay-hydroxyapatite biomaterial are built. • Interaction energy maps are constructed using a molecular dynamics. • Quantitative interactions between the three components of the biomaterial are found. • The modeling and experimental approach provides insight into the complex nanomaterial

  5. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    International Nuclear Information System (INIS)

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard SPECT. Methods: Computer-aided design (CAD) studies were performed to assess the feasibility of maneuvering a robotic SPECT system about a patient in position for radiation therapy. In order to obtain fast, high-quality SPECT images, a 49-pinhole SPECT camera was designed which provides high sensitivity to photons emitted from an imaging region of interest. This multipinhole system was investigated by computer-simulation studies. Seventeen hot spots 10 and 7 mm in diameter were placed in the breast region of a supine female phantom. Hot spot activity concentration was six times that of background. For the 49-pinhole camera and a reference, more conventional, broad field-of-view (FOV) SPECT system, projection data were computer simulated for 4-min scans and SPECT images were reconstructed. Hot-spot localization was evaluated using a nonprewhitening forced-choice numerical observer. Results: The CAD simulation studies found that robots could maneuver SPECT cameras about patients in position for radiation therapy. In the imaging studies, most hot spots were apparent in the 49-pinhole images. Average localization errors for 10-mm- and 7-mm-diameter hot spots were 0.4 and 1.7 mm, respectively, for the 49-pinhole system, and 3.1 and 5.7 mm, respectively, for the reference broad-FOV system. Conclusions: A robot could maneuver a multipinhole SPECT system about a patient in position for radiation therapy. The system could provide onboard functional and molecular imaging with 4-min

  6. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Bowsher, James, E-mail: james.bowsher@duke.edu; Giles, William; Yin, Fang-Fang [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Yan, Susu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Roper, Justin [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2014-01-15

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard SPECT. Methods: Computer-aided design (CAD) studies were performed to assess the feasibility of maneuvering a robotic SPECT system about a patient in position for radiation therapy. In order to obtain fast, high-quality SPECT images, a 49-pinhole SPECT camera was designed which provides high sensitivity to photons emitted from an imaging region of interest. This multipinhole system was investigated by computer-simulation studies. Seventeen hot spots 10 and 7 mm in diameter were placed in the breast region of a supine female phantom. Hot spot activity concentration was six times that of background. For the 49-pinhole camera and a reference, more conventional, broad field-of-view (FOV) SPECT system, projection data were computer simulated for 4-min scans and SPECT images were reconstructed. Hot-spot localization was evaluated using a nonprewhitening forced-choice numerical observer. Results: The CAD simulation studies found that robots could maneuver SPECT cameras about patients in position for radiation therapy. In the imaging studies, most hot spots were apparent in the 49-pinhole images. Average localization errors for 10-mm- and 7-mm-diameter hot spots were 0.4 and 1.7 mm, respectively, for the 49-pinhole system, and 3.1 and 5.7 mm, respectively, for the reference broad-FOV system. Conclusions: A robot could maneuver a multipinhole SPECT system about a patient in position for radiation therapy. The system could provide onboard functional and molecular imaging with 4-min

  7. Molecular interactions in biomineralized hydroxyapatite amino acid modified nanoclay: In silico design of bone biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Katti, Dinesh R., E-mail: Dinesh.Katti@ndsu.edu; Sharma, Anurag; Ambre, Avinash H.; Katti, Kalpana S.

    2015-01-01

    A simulations driven approach to design of a novel biomaterial nanocomposite system is described in this study. Nanoclays modified with amino acids (OMMT) were used to mineralize hydroxyapatite (HAP), mimicking biomineralization. Representative models of organically modified montmorillonite clay (OMMT) and OMMT-hydroxyapatite (OMMT-HAP) were constructed using molecular dynamics and validated using X-ray Diffraction (XRD), Fourier Transforms Infrared (FTIR) spectroscopy and Transmission Electron Microscopy (TEM). Attractive interactions exist between Ca atoms of HAP and C=O group of aminovaleric acid, indicating chelate formation in OMMT-HAP. Interaction energy maps describe molecular interactions among different constituents and their quantitative contributions in the OMMT and OMMT-HAP systems at both parallel and perpendicular orientations. High attractive and high repulsive interactions were found between PO{sub 4}{sup 3−} and MMT clay as well as aminovaleric molecules in OMMT-HAP perpendicular and parallel models. Large non-bonded interactions in OMMT-HAP indicate influence of neighboring environment on PO{sub 4}{sup 3−} in in situ HAPclay. Extensive hydrogen bonds were observed between functional hydrogen atoms of modifier and MMT clay in OMMT-HAP as compared to OMMT. Thus, HAP interacts with clay through the aminovaleric acid. This computational study provides a framework for materials design and selection for biomaterials used in tissue engineering and other areas of regenerative medicine. - Highlights: • Representative models of a hybrid nanoclay-hydroxyapatite biomaterial are built. • Interaction energy maps are constructed using a molecular dynamics. • Quantitative interactions between the three components of the biomaterial are found. • The modeling and experimental approach provides insight into the complex nanomaterial.

  8. Turbine nozzle attachment system

    Science.gov (United States)

    Norton, Paul F.; Shaffer, James E.

    1995-01-01

    A nozzle guide vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The nozzle guide vane assembly includes a pair of legs extending radially outwardly from an outer shroud and a pair of mounting legs extending radially inwardly from an inner shroud. Each of the pair of legs and mounting legs have a pair of holes therein. A plurality of members attached to the gas turbine engine have a plurality of bores therein which axially align with corresponding ones of the pair of holes in the legs. A plurality of pins are positioned within the corresponding holes and bores radially positioning the nozzle guide vane assembly about a central axis of the gas turbine engine.

  9. Pain, Affect, and Attachment

    OpenAIRE

    Carl Eduard Scheidt; Elisabeth Waller

    2015-01-01

    Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure di...

  10. Design of Molecular Solar Cells via Feedback from Soft X-ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Himpsel, Franz J. [Univ. of Wisconsin, Madison, WI (United States)

    2015-06-12

    Spectroscopy with soft X-rays was used to develop new materials and novel designs for solar cells and artificial photosynthesis. In order to go beyond the widely-used trial-and-error approach of gradually improving a particular design, we started from the most general layout of a solar cell (or a photo-electrochemical device) and asked which classes of materials are promising for best performance. For example, the most general design of a solar cell consists of a light absorber, an electron donor, and an electron acceptor. These are characterized by four energy levels, which were measured by a combination of spectroscopic X-ray techniques. Tuning synchrotron radiation to the absorption edges of specific elements provided element- and bond-selectivity. The spectroscopic results were complemented by state-of-the-art calculations of the electronic states. These helped explaining the observed energy levels and the orbitals associated with them. The calculations were extended to a large class of materials (for example thousands of porphyrin dye complexes) in order to survey trends in the energy level structure. A few highlights serve as examples: 1) Organic molecules combining absorber, donor, and acceptor with atomic precision. 2) Exploration of highly p-doped diamond films as inert, transparent electron donors. 3) Surface-sensitive characterization of nanorod arrays used as photoanodes in water splitting. 4) Computational design of molecular complexes for efficient solar cells using two photons.

  11. Pharmacogenomics of the human ABC transporter ABCG2: from functional evaluation to drug molecular design

    Science.gov (United States)

    Ishikawa, Toshihisa; Tamura, Ai; Saito, Hikaru; Wakabayashi, Kanako; Nakagawa, Hiroshi

    2005-10-01

    In the post-genome-sequencing era, emerging genomic technologies are shifting the paradigm for drug discovery and development. Nevertheless, drug discovery and development still remain high-risk and high-stakes ventures with long and costly timelines. Indeed, the attrition of drug candidates in preclinical and development stages is a major problem in drug design. For at least 30% of the candidates, this attrition is due to poor pharmacokinetics and toxicity. Thus, pharmaceutical companies have begun to seriously re-evaluate their current strategies of drug discovery and development. In that light, we propose that a transport mechanism-based design might help to create new, pharmacokinetically advantageous drugs, and as such should be considered an important component of drug design strategy. Performing enzyme- and/or cell-based drug transporter, interaction tests may greatly facilitate drug development and allow the prediction of drug-drug interactions. We recently developed methods for high-speed functional screening and quantitative structure-activity relationship analysis to study the substrate specificity of ABC transporters and to evaluate the effect of genetic polymorphisms on their function. These methods would provide a practical tool to screen synthetic and natural compounds, and these data can be applied to the molecular design of new drugs. In this review article, we present an overview on the genetic polymorphisms of human ABC transporter ABCG2 and new camptothecin analogues that can circumvent AGCG2-associated multidrug resistance of cancer.

  12. Universally Rigid Framework Attachments

    CERN Document Server

    Ratmanski, Kiril

    2010-01-01

    A framework is a graph and a map from its vertices to R^d. A framework is called universally rigid if there is no other framework with the same graph and edge lengths in R^d' for any d'. A framework attachment is a framework constructed by joining two frameworks on a subset of vertices. We consider an attachment of two universally rigid frameworks that are in general position in R^d. We show that the number of vertices in the overlap between the two frameworks must be sufficiently large in order for the attachment to remain universally rigid. Furthermore, it is shown that universal rigidity of such frameworks is preserved even after removing certain edges. Given positive semidefinite stress matrices for each of the two initial frameworks, we analytically derive the PSD stress matrices for the combined and edge-reduced frameworks. One of the benefits of the results is that they provide a general method for generating new universally rigid frameworks.

  13. Attachment disorganization in different clinical groups: What underpins unresolved attachment?

    OpenAIRE

    Juen Florian; Arnold Lisa; Meissner Dominik; Nolte Tobias; Buchheim Anna

    2013-01-01

    This paper summarizes findings and clinical implications of research on attachment disorganization in diverse clinical groups. Disorganized/unresolved attachment is overrepresented in these groups compared to healthy control participants, but disorder specific characteristics of this attachment pattern are still poorly understood. The focus of this study was to explore defensive processes in participants whose narratives were classified as disorganized/unresolved using the Adult Attach...

  14. Remedial action and site design for stabilization of the inactive uranium mill tailings sites at Slick Rock, Colorado. Attachment 2, Geology report: Appendix B, Preliminary final

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    Detailed investigations of geologic, geomorphic, and seismic conditions at the Burro Canyon site were conducted by the US Department of Energy (DOE) as a disposal site for the tailings at two processing sites near the Slick Rock, Colorado, post office. The purposes of these studies are basic site characterization and identification of potential geologic hazards that could affect long-term site stability. Subsequent engineering studies (e.g., analyses of hydrologic and liquefaction hazards) used the data developed in these studies. The geomorphic analysis was employed in the design of effective erosion protection. Studies of the regional and local seismotectonic setting, which included a detailed search for possible capable faults within a 65-km radius of the site, provided the basis for seismic design parameters.

  15. A comparison of stress distribution and flexion among various designs of bar attachments for implant overdentures: A three dimensional finite element analysis

    OpenAIRE

    Prakash Vijay; D′Souza Mariette; Adhikari Raviraj

    2009-01-01

    Context: Bar overdentures are popular choices among clinicians worldwide but configurations that provide an optimal biomechanical distribution of stress are still debatable. Aims: To compare the stresses and elastic flexion between implant supported bar overdentures in various configurations using finite element analysis. Settings and Design: A CAT scan of a human mandible was used to generate an anatomically accurate mechanical model. Materials and Methods: Three models with bars an...

  16. Design of gecko-inspired fibrillar surfaces with strong attachment and easy-removal properties: a numerical analysis of peel-zone

    OpenAIRE

    Zhou, Ming; Pesika, Noshir; Zeng, Hongbo; Wan, Jin; Zhang, Xiangjun; Meng, Yonggang; Wen, Shizhu; Tian, Yu(School of Physics, University of Chinese Academy of Sciences, Beijing, 100049, China)

    2012-01-01

    Despite successful fabrication of gecko-inspired fibrillar surfaces with strong adhesion forces, how to achieve an easy-removal property becomes a major concern that may restrict the wide applications of these bio-inspired surfaces. Research on how geckos detach rapidly has inspired the design of novel adhesive surfaces with strong and reversible adhesion capabilities, which relies on further fundamental understanding of the peeling mechanisms. Recent studies showed that the peel-zone plays a...

  17. Attachment as an Organizational Construct

    Science.gov (United States)

    Sroufe, L. Alan; Waters, Everett

    1977-01-01

    Discusses the conflict between situational influences and stable individual differences in attachment behavior and attempts to resolve this conflict by examining the functions, outcomes, and context sensitivity of attachment behavior and the underlying behavioral control systems that organize it. (JMB)

  18. Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Site, Maybell, Colorado. Remedial action selection report: Attachment 2, Geology report, Final

    International Nuclear Information System (INIS)

    The Maybell uranium mill tailings site is 25 miles (mi) (40 kilometers [km]) west of the town of Craig, Colorado, in Moffat County, in the northwestern part of the state. The unincorporated town of Maybell is 5 road mi (8 km) southwest of the site. The designated site covers approximately 110 acres (ac) (45 hectares [ha]) and consists of a concave-shaped tailings pile and rubble from the demolition of the mill buildings buried in the former mill area. Contaminated materials at the Maybell processing site include the tailings pile, which has an average depth of 20 feet (ft) (6 meters [m]) and contains 2.8 million cubic yards (yd3) (2.1 million cubic meters [m3]) of tailings. The former mill processing area is on the north side of the site and contains 20,000 yd3 (15,000 m3) of contaminated demolition debris. Off-pile contamination is present and includes areas adjacent to the tailings pile, as well as contamination dispersed by wind and surface water flow. The volume of off-pile contamination to be placed in the disposal cell is 550,000 yd3 (420,000 m3). The total volume of contaminated materials to be disposed of as part of the remedial action is estimated to be 3.37 million yd3 (2.58 million m3). Information presented in this Final Remedial Action Plan (RAP) and referenced in supporting documents represents the current disposal cell design features and ground water compliance strategy proposed by the US Department of Energy (DOE) for the Maybell, Colorado, tailings site. Both the disposal cell design and the ground water compliance strategy have changed from those proposed prior to the preliminary final RAP document as a result of prudent site-specific technical evaluations

  19. Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Site, Maybell, Colorado. Remedial action selection report: Attachment 2, Geology report, Final

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Maybell uranium mill tailings site is 25 miles (mi) (40 kilometers [km]) west of the town of Craig, Colorado, in Moffat County, in the northwestern part of the state. The unincorporated town of Maybell is 5 road mi (8 km) southwest of the site. The designated site covers approximately 110 acres (ac) (45 hectares [ha]) and consists of a concave-shaped tailings pile and rubble from the demolition of the mill buildings buried in the former mill area. Contaminated materials at the Maybell processing site include the tailings pile, which has an average depth of 20 feet (ft) (6 meters [m]) and contains 2.8 million cubic yards (yd{sup 3}) (2.1 million cubic meters [m{sup 3}]) of tailings. The former mill processing area is on the north side of the site and contains 20,000 yd{sup 3} (15,000 m{sup 3}) of contaminated demolition debris. Off-pile contamination is present and includes areas adjacent to the tailings pile, as well as contamination dispersed by wind and surface water flow. The volume of off-pile contamination to be placed in the disposal cell is 550,000 yd{sup 3} (420,000 m{sup 3}). The total volume of contaminated materials to be disposed of as part of the remedial action is estimated to be 3.37 million yd{sup 3} (2.58 million m{sup 3}). Information presented in this Final Remedial Action Plan (RAP) and referenced in supporting documents represents the current disposal cell design features and ground water compliance strategy proposed by the US Department of Energy (DOE) for the Maybell, Colorado, tailings site. Both the disposal cell design and the ground water compliance strategy have changed from those proposed prior to the preliminary final RAP document as a result of prudent site-specific technical evaluations.

  20. Attachment Behaviors in Autistic Children.

    Science.gov (United States)

    Sigman, Marian; Ungerer, Judy A.

    1984-01-01

    Observation of 14 autistic and 14 nonautistic children of equivalent mental age revealed that autistic Ss showed evidence of attachment to their mothers. Among autistic Ss, those showing increased attachment behaviors in response to separation and reunion demonstrated more advanced symbolic play skills than those showing no attachment change.…

  1. Optimization of a Spring for Dental Attachments

    OpenAIRE

    Hack, P.; Fritzen, C.-P.

    1989-01-01

    Special technological applications like the construction of a dental attachment require structural parts which have very small operall dimensions. Very often these parts are subjected to high loadings. The failure of a small spring was the starting point for an investigation with the aim to design a suitable new spring shape.

  2. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Falls City, Texas. Remedial action selection report, attachment 2, geology report; attachment 3, groundwater hydrology report; and attachment 4, water resources protection strategy. Final report

    International Nuclear Information System (INIS)

    The uranium processing site near Falls City, Texas, was one of 24 inactive uranium mill sites designated to be remediated by the U.S. Department of Energy (DOE) under Title I of the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the U.S. Nuclear Regulatory Commission (NRC) concur with the DOE's remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the U.S. Environmental Protection Agency (EPA). The RAP, which includes this summary remedial action selection report (RAS), serves a two-fold purpose. First, it describes the activities proposed by the DOE to accomplish long-term stabilization and control of the residual radioactive materials at the inactive uranium processing site near Falls City, Texas. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Texas, and the NRC, becomes Appendix B of the Cooperative Agreement between the DOE and the State of Texas

  3. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Falls City, Texas. Remedial action selection report, attachment 2, geology report; attachment 3, groundwater hydrology report; and attachment 4, water resources protection strategy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-09-01

    The uranium processing site near Falls City, Texas, was one of 24 inactive uranium mill sites designated to be remediated by the U.S. Department of Energy (DOE) under Title I of the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the U.S. Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the U.S. Environmental Protection Agency (EPA). The RAP, which includes this summary remedial action selection report (RAS), serves a two-fold purpose. First, it describes the activities proposed by the DOE to accomplish long-term stabilization and control of the residual radioactive materials at the inactive uranium processing site near Falls City, Texas. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Texas, and the NRC, becomes Appendix B of the Cooperative Agreement between the DOE and the State of Texas.

  4. Design of potentially active ligands for SH2 domains by molecular modeling methods

    Directory of Open Access Journals (Sweden)

    Hurmach V. V.

    2014-07-01

    Full Text Available Search for new chemical structures possessing specific biological activity is a complex problem that needs the use of the latest achievements of molecular modeling technologies. It is well known that SH2 domains play a major role in ontogenesis as intermediaries of specific protein-protein interactions. Aim. Developing an algorithm to investigate the properties of SH2 domain binding, search for new potential active compounds for the whole SH2 domains class. Methods. In this paper, we utilize a complex of computer modeling methods to create a generic set of potentially active compounds targeting universally at the whole class of SH2 domains. A cluster analysis of all available three-dimensional structures of SH2 domains was performed and general pharmacophore models were formulated. The models were used for virtual screening of collection of drug-like compounds provided by Enamine Ltd. Results. The design technique for library of potentially active compounds for SH2 domains class was proposed. Conclusions. The original algorithm of SH2 domains research with molecular docking method was developed. Using our algorithm, the active compounds for SH2 domains were found.

  5. Design and growth of a P N diode by molecular beam epitaxy

    International Nuclear Information System (INIS)

    In this work, design, growth and characterization of a GaAs p-n contact is presented. The contact growth has been performed by Molecular Beam Epitaxy. The n layer with thickness of 1μm and electron concentration of 6 * 1017 cm-3 has been grown on a p-type GaAs substrate with hole concentration of 1 * 1017cm-3. During growth, in situ monitoring of the layer stoichiometry has been made possible by using Reflection High Energy Electron Diffraction technique. After growth characterization was performed by the use of Hall-effect measurement, the results for the carrier concentration was further confirmed by Electrochemical Capacitance-Voltage profiling technique

  6. Design, preparation, surface recognition properties, and characteristics of icariin molecularly imprinted polymers

    Directory of Open Access Journals (Sweden)

    Xiaohe Jia

    2015-12-01

    Full Text Available Icariin molecularly imprinted polymers (MIPs were prepared by precipitation polymerization. Prior to the polymerization, computer simulation was performed to sketchily choose the suitable functional monomer and the corresponding polymerization solvent. The optimized synthesis parameters, including the functional monomer acrylamide, the mixture of methanol and acetonitrile (V:V = 3:1 as the polymerization solvent, and the reaction molar ratio (1:6:80 of template molecule, functional monomer and cross-linker, were respectively obtained by single factor analysis and orthogonal design methods. The results of the adsorption experiments showed that the resultant MIPs exhibited good adsorption and recognition abilities to icariin. Scatchard analysis illustrated that the homogeneous binding sites only for icariin molecules were formed in the prepared MIPs.

  7. Development of a Confocal Optical System Design for Molecular Imaging Applications of Biochip

    Directory of Open Access Journals (Sweden)

    Guoliang Huang

    2007-08-01

    Full Text Available A novel confocal optical system design and a dual laser confocal scanner have been developed to meet the requirements of highly sensitive detection of biomolecules on microarray chips, which is characterized by a long working distance (wd>3.0 mm, high numerical aperture (NA=0.72, and only 3 materials and 7 lenses used. This confocal optical system has a high scanning resolution, an excellent contrast and signal-to-noise ratio, and an efficiency of collected fluorescence of more than 2-fold better than that of other commercial confocal biochip scanners. The scanner is as equally good for the molecular imaging detection of enclosed biochips as for the detection of biological samples on a slide surface covered with a cover-slip glass. Some applications of gene and protein imagings using the dual laser confocal scanner are described.

  8. Molecular design and ordering effects in π-functional materials for transistor and solar cell applications

    KAUST Repository

    Beaujuge, Pierre

    2011-12-21

    Organic electronics are broadly anticipated to impact the development of flexible thin-film device technologies. Among these, solution-processable π-conjugated polymers and small molecules are proving particularly promising in field-effect transistors and bulk heterojunction solar cells. This Perspective analyzes some of the most exciting strategies recently suggested in the design and structural organization of π-functional materials for transistor and solar cell applications. Emphasis is placed on the interplay between molecular structure, self-assembling properties, nanoscale and mesoscale ordering, and device efficiency parameters. A critical look at the various approaches used to optimize both materials and device performance is provided to assist in the identification of new directions and further advances. © 2011 American Chemical Society.

  9. Remedial Action Plan and Site design for stabilization of the inactive Uranium Mill Tailings sites at Slick Rock, Colorado: Revision 1. Remedial action selection report, Attachment 2, geology report, Attachment 3, ground water hydrology report, Attachment 4, water resources protection strategy. Final

    International Nuclear Information System (INIS)

    The Slick Rock uranium mill tailings sites are located near the small community of Slick Rock, in San Miguel County, Colorado. There are two designated Uranium Mill Tailings Remedial Action (UMTRA) Project sites at Slick Rock: the Union Carbide site and the North Continent site. Both sites are adjacent to the Dolores River. The sites contain former mill building concrete foundations, tailings piles, demolition debris, and areas contaminated by windblown and waterborne radioactive materials. The total estimated volume of contaminated materials is approximately 621,000 cubic yards (475,000 cubic meters). In addition to the contamination at the two processing site areas, 13 vicinity properties were contaminated. Contamination associated with the UC and NC sites has leached into ground water. Pursuant to the requirements of the Uranium Mill Tailings Radiation Control Act (UMTRCA) (42 USC section 7901 et seq.), the proposed remedial action plan (RAP) will satisfy the final US Environmental Protection Agency (EPA) standards in 40 CFR Part 192 (60 FR 2854) for cleanup, stabilization, and control of the residual radioactive material (RRM) (tailings and other contaminated materials) at the disposal site at Burro Canyon. The requirements for control of the RRM (Subpart A) will be satisfied by the construction of an engineered disposal cell. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/weaterborne materials to a permanent repository at the Burro Canyon disposal site. The site is approximately 5 road mi (8 km) northeast of the mill sites on land recently transferred to the DOE by the Bureau of Land Management

  10. Remedial Action Plan and Site design for stabilization of the inactive Uranium Mill Tailings sites at Slick Rock, Colorado: Revision 1. Remedial action selection report, Attachment 2, geology report, Attachment 3, ground water hydrology report, Attachment 4, water resources protection strategy. Final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Slick Rock uranium mill tailings sites are located near the small community of Slick Rock, in San Miguel County, Colorado. There are two designated Uranium Mill Tailings Remedial Action (UMTRA) Project sites at Slick Rock: the Union Carbide site and the North Continent site. Both sites are adjacent to the Dolores River. The sites contain former mill building concrete foundations, tailings piles, demolition debris, and areas contaminated by windblown and waterborne radioactive materials. The total estimated volume of contaminated materials is approximately 621,000 cubic yards (475,000 cubic meters). In addition to the contamination at the two processing site areas, 13 vicinity properties were contaminated. Contamination associated with the UC and NC sites has leached into ground water. Pursuant to the requirements of the Uranium Mill Tailings Radiation Control Act (UMTRCA) (42 USC {section}7901 et seq.), the proposed remedial action plan (RAP) will satisfy the final US Environmental Protection Agency (EPA) standards in 40 CFR Part 192 (60 FR 2854) for cleanup, stabilization, and control of the residual radioactive material (RRM) (tailings and other contaminated materials) at the disposal site at Burro Canyon. The requirements for control of the RRM (Subpart A) will be satisfied by the construction of an engineered disposal cell. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/weaterborne materials to a permanent repository at the Burro Canyon disposal site. The site is approximately 5 road mi (8 km) northeast of the mill sites on land recently transferred to the DOE by the Bureau of Land Management.

  11. Molecular modeling study for inhibition mechanism of human chymase and its application in inhibitor design.

    Directory of Open Access Journals (Sweden)

    Mahreen Arooj

    Full Text Available Human chymase catalyzes the hydrolysis of peptide bonds. Three chymase inhibitors with very similar chemical structures but highly different inhibitory profiles towards the hydrolase function of chymase were selected with the aim of elucidating the origin of disparities in their biological activities. As a substrate (angiotensin-I bound crystal structure is not available, molecular docking was performed to dock the substrate into the active site. Molecular dynamics simulations of chymase complexes with inhibitors and substrate were performed to calculate the binding orientation of inhibitors and substrate as well as to characterize conformational changes in the active site. The results elucidate details of the 3D chymase structure as well as the importance of K40 in hydrolase function. Binding mode analysis showed that substitution of a heavier Cl atom at the phenyl ring of most active inhibitor produced a great deal of variation in its orientation causing the phosphinate group to interact strongly with residue K40. Dynamics simulations revealed the conformational variation in region of V36-F41 upon substrate and inhibitor binding induced a shift in the location of K40 thus changing its interactions with them. Chymase complexes with the most active compound and substrate were used for development of a hybrid pharmacophore model which was applied in databases screening. Finally, hits which bound well at the active site, exhibited key interactions and favorable electronic properties were identified as possible inhibitors for chymase. This study not only elucidates inhibitory mechanism of chymase inhibitors but also provides key structural insights which will aid in the rational design of novel potent inhibitors of the enzyme. In general, the strategy applied in the current study could be a promising computational approach and may be generally applicable to drug design for other enzymes.

  12. Designing and preparation of cytisine alkaloid surface-imprinted material and its molecular recognition characteristics

    International Nuclear Information System (INIS)

    Highlights: • An elaborate molecular design was well done for molecule surface-imprinting. • The new method of “pre-graft polymerizing and post-imprinting” was used. • Cytisine molecule surface-imprinted material was prepared. • Cytisine surface-imprinting depends on electrostatic interaction between host–guest. • The imprinted material has special recognition selectivity for template cytisine. - Abstract: Based on molecular design, a cytisine surface-imprinted material was prepared using the new surface-imprinting technique of “pre-graft polymerizing and post-imprinting”. The graft-polymerization of glycidyl methacrylate (GMA) on the surfaces of micron-sized silica gel particles was first performed with a surface-initiating system, preparing the grafted particles PGMA/SiO2. Subsequently, a polymer reaction, the ring-opening reaction of the epoxy groups of the grafted PGMA, was conducted with sodium 2,4-diaminobenzene sulfonate (SAS) as reagent, resulting in the functional grafted particles SAS-PGMA/SiO2. The adsorption of cytisine on SAS-PGMA/SiO2 particles reached saturation via strong electrostatic interaction between the sulfonate groups of SAS-PGMA/SiO2 particles and the protonated N atoms in cytisine molecule. Finally, cytisine surface-imprinting was successfully carried out with glutaraldehyde as crosslinker, obtaining cytisine surface-imprinted material MIP-SASP/SiO2. The binding and recognition characteristics of MIP-SASP/SiO2 towards cytisine were investigated in depth. The experimental results show that there is strong electrostatic interaction between particles and cytisine molecules, and on this basis, cytisine surface-imprinting can be smoothly performed. The surface-imprinted MIP-SASP/SiO2 has special recognition selectivity and excellent binding affinity for cytisine, and the selectivity coefficients of MIP-SASP/SiO2 particles for cytisine relative to matrine and oxymatrine, which were used as two contrast alkaloids, are 9.5 and

  13. An integrated molecular modeling approach for in silico design of new tetracyclic derivatives as ALK inhibitors.

    Science.gov (United States)

    Peddi, Saikiran Reddy; Sivan, Sree Kanth; Manga, Vijjulatha

    2016-10-01

    Anaplastic lymphoma kinase (ALK), a promising therapeutic target for treatment of human cancers, is a receptor tyrosine kinase that instigates the activation of several signal transduction pathways. In the present study, in silico methods have been employed in order to explore the structural features and functionalities of a series of tetracyclic derivatives displaying potent inhibitory activity toward ALK. Initially docking was performed using GLIDE 5.6 to probe the bioactive conformation of all the compounds and to understand the binding modes of inhibitors. The docking results revealed that ligand interaction with Met 1199 plays a crucial role in binding of inhibitors to ALK. Further to establish a robust 3D-QSAR model using CoMFA and CoMSIA methods, the whole dataset was divided into three splits. Model obtained from Split 3 showed high accuracy ([Formula: see text] of 0.700 and 0.682, [Formula: see text] of 0.971 and 0.974, [Formula: see text] of 0.673 and 0.811, respectively for CoMFA and CoMSIA). The key structural requirements for enhancing the inhibitory activity were derived from CoMFA and CoMSIA contours in combination with site map analysis. Substituting small electronegative groups at Position 8 by replacing either morpholine or piperidine rings and maintaining hydrophobic character at Position 9 in tetracyclic derivatives can enhance the inhibitory potential. Finally, we performed molecular dynamics simulations in order to investigate the stability of protein ligand interactions and MM/GBSA calculations to compare binding free energies of co-crystal ligand and newly designed molecule N1. Based on the coherence of outcome of various molecular modeling studies, a set of 11 new molecules having potential predicted inhibitory activity were designed. PMID:26758803

  14. Attachment Theory in Tourism

    Directory of Open Access Journals (Sweden)

    Maximiliano Korstanje

    2007-01-01

    Full Text Available The following work is intended to a revision on attachment theory. The postulates of the theory of the sure base point that the system of exploration meets in narrow relation the system of conducts of attachment and the figure of the keepers. The conducts that characterize and symbolize the relation of the adult with the environment are carried back to the early age, in the moment in which the child develops the affective capacity. What difference does exist between someone who decides to journey to England and that one that one decides to travel to Mar del Plata? How it is possible to study this topic of on a manner trustworthy? These three questions were key to begin the investigation. Nevertheless, the matter began to find certain limitations linked to the methodology that had to be in use. It is possible to use careless they on the leisure scope, a theory which still demonstrates certain inconsistencies in its own clinical application?

  15. Attachment is a dynamic system

    Directory of Open Access Journals (Sweden)

    Zlatka Cugmas

    2003-04-01

    Full Text Available On the basis of the study of recent scientific literature about the development of attachment, the author answers the following questions: which are the postulates the theory of attachment has about the stability of the patterns of attachment, which level of stability in the patterns of attachment from infancy to adulthood these studies illuminate and which factors significantly influence the (instability of the patterns of attachment in time. The theory of attachment assumes that normal circumstances elicit stability. Changes, however, can be the result of important events influencing the sensitivity of the object of attachment. Agreement has not yet been reached regarding the percentage of stability in the patterns of attachment. There is more agreement regarding attachment in adulthood than that in childhood. The results depend on the size and characteristics of the subjects of the research, the measuring instruments, type of data analysis etc. The author concludes that attachment is a dynamic system influenced by significant changes in life (the cognitive development of the child, external care, parents' divorce, different stressful situations. As the influence of stressful events on the individual person' s quality of attachment is examined, it is necessary to consider also his/her temperamental characteristics, role of other people in their lives, etc.

  16. Mapping and measuring place attachment

    DEFF Research Database (Denmark)

    Brown, Greg; Raymond, Christopher Mark; Corcoran, Jonathan

    2015-01-01

    home range, (3) identify how participant socio-demographic and home location attributes influence place attachment, (4) provide some guidance for mapping place attachment in future research. We found large spatial variability in individual place attachment and mapped landscape values using both area...... and distance-based measures. The area of place attachment is influenced by occupational roles such as farming or conservation, as well as home location, especially in coastal versus non-coastal contexts. The spatial distribution of mapped landscape values or values home range is related to, but not...... area. Aggregated place attachment across participants in the region showed similar spatial intensity to aggregated values home range, but area-based assessment of place attachment and values home range are distorted by edge effects such as a coastline. To further develop the mapping of place attachment...

  17. A comparison of stress distribution and flexion among various designs of bar attachments for implant overdentures: A three dimensional finite element analysis

    Directory of Open Access Journals (Sweden)

    Prakash Vijay

    2009-01-01

    Full Text Available Context: Bar overdentures are popular choices among clinicians worldwide but configurations that provide an optimal biomechanical distribution of stress are still debatable. Aims: To compare the stresses and elastic flexion between implant supported bar overdentures in various configurations using finite element analysis. Settings and Design: A CAT scan of a human mandible was used to generate an anatomically accurate mechanical model. Materials and Methods: Three models with bars and clips in three different configurations were constructed. Model 1 had a single bar connecting two implants, Model 2 had three bars connecting all the four implants, and Model 3 had two bars connecting the medial and distal implants on the sides only. The models were loaded under static conditions with 100N load distributed at the approximate position of the clip. The mandibular boundary conditions were modeled considering the real geometry of its muscle supporting system. Maximum von Mises stress at the level of the bar and at the bone implant interface were compared in all three models. The flexion of mandible and the bar was also compared qualitatively. Statistical Analysis Used: The analyses were accomplished using the ANSYS software program and were processed by a personal computer. Stress on these models was analyzed after loading conditions. Results: Qualitative comparisons showed that stress at the level of the bar and at the bone implant interface were in the following order: Model 1> Model 3> Model 2. The flexion of the mandible and the bar were in the following order: Model 2 > Model 1 > Model 3. Conclusions: Four implant bar systems connected by bars on the sides only is a better choice than two implant bar systems and four implant bar systems with bars connecting all four implants.

  18. Design, synthesis, antimicrobial activity and molecular modeling studies of novel benzofuroxan derivatives against Staphylococcus aureus.

    Science.gov (United States)

    Jorge, Salomão Dória; Masunari, Andrea; Rangel-Yagui, Carlota Oliveira; Pasqualoto, Kerly Fernanda Mesquita; Tavares, Leoberto Costa

    2009-04-15

    Molecular modification is a quite promising strategy in the design and development of drug analogs with better bioavailability, higher intrinsic activity and less toxicity. In the search of new leads with potential antimicrobial activity, a new series of 14 4-substituted [N'-(benzofuroxan-5-yl)methylene]benzohydrazides, nifuroxazide derivatives, were synthesized and tested against standard and multidrug-resistant Staphylococcus aureus strains. The selection of the substituent groups was based on physicochemical properties, such as hydrophobicity and electronic effect. These properties were also evaluated through the lipophilic and electrostatic potential maps, respectively, considering the compounds with better biological profile. Twelve compounds exhibited similar bacteriostatic activity against standard and multidrug-resistant strains. The most active compound was the 4-CF(3) substituted derivative, which presented a minimum inhibitory concentration (MIC) value of 14.6-13.1 microg/mL, and a ClogP value of 1.87. The results highlight the benzofuroxan derivatives as potential leads for designing new future antimicrobial drug candidates. PMID:19324556

  19. Adult Attachment and Developmental Personality Styles: An Empirical Study

    Science.gov (United States)

    Sherry, Alissa; Lyddon, William J.; Henson, Robin K.

    2007-01-01

    The current study was designed to test specific hypotheses associated with W. J. Lyddon and A. Sherry's (2001) attachment theory model of developmental personality styles. More specifically, 4 adult attachment dimensions were correlated with 10 personality scales on the Millon Clinical Multiaxial Inventory-III (T. Millon, R. Davis, & C. Millon,…

  20. Design and Synthesis of Near-Infrared Peptide for in Vivo Molecular Imaging of HER2.

    Science.gov (United States)

    Joshi, Bishnu P; Zhou, Juan; Pant, Asha; Duan, Xiyu; Zhou, Quan; Kuick, Rork; Owens, Scott R; Appelman, Henry; Wang, Thomas D

    2016-02-17

    We report the development, characterization, and validation of a peptide specific for the extracellular domain of HER2. This probe chemistry was developed for molecular imaging by using a structural model to select an optimal combination of amino acids that maximize the likelihood for unique hydrophobic and hydrophilic interactions with HER2 domain 3. The sequence KSPNPRF was identified and conjugated with either FITC or Cy5.5 via a GGGSK linker using Fmoc-mediated solid-phase synthesis to demonstrate flexibility for this chemical structure to be labeled with different fluorophores. A scrambled sequence was developed for control by altering the conformationally rigid spacer and moving both hydrophobic and hydrophilic amino acids on the C-terminus. We validated peptide specificity for HER2 in knockdown and competition experiments using human colorectal cancer cells in vitro, and measured a binding affinity of kd = 21 nM and time constant of k = 0.14 min(-1) (7.14 min). We used this peptide with either topical or intravenous administration in a preclinical model of colorectal cancer to demonstrate specific uptake in spontaneous adenomas and to show feasibility for real time in vivo imaging with near-infrared fluorescence. We used this peptide in immunofluorescence studies of human proximal colon specimens to evaluate specificity for sessile serrated and sporadic adenomas. Improved visualization can be used endoscopically to guide tissue biopsy and detect premalignant lesions that would otherwise be missed. Our peptide design for specificity to HER2 is promising for clinical translation in molecular imaging methods for early cancer detection. PMID:26709709

  1. Molecular simulation of ligand binding with DNA: implications for new radiopharmaceutical design

    International Nuclear Information System (INIS)

    We have been using computer-assisted molecular modeling software to assess the effects of structural modification on the interaction of DNA-binding iodine-125 (125I)-labeled Hoechst ligands with DNA and to predict DNA double-strand break (DSB) formation post 125I decay. To ascertain the robustness of the approach, the Lamarckian genetic algorithm (AutoDock 3.0) was first used to model the interaction/binding between DNA and m-iodo-p-methoxyHoechst (IMH), a ligand whose binding to the minor groove of DNA had been demonstrated (crystal structure) and which is available in the Protein Data Bank. m-Iodo-p- ethoxyHoechst (IEH), a radioligand that we had previously synthesized and characterized, was then docked onto DNA, the IEH-DNA complex minimized, and the free binding energy and inhibition constant (K i ) were estimated and compared with those obtained for IMH-DNA. Finally, Insight II was used to measure the distances between any atom (e.g. 125I) and the central axis of the targeted DNA and these were correlated with the DSB yield when these agents are bound to DNA. The data demonstrate that the docking of IMH onto DNA leads to a ligand-DNA complex that is only about 1Angstroms RMSD (root mean square deviation) from the crystal-structure position reported. The docking of IEH (a close analog of IMH) onto DNA also results in a very small RMSD (1.27Angstroms). These software programs allow the estimation of radionuclide-to-DNA molecular distances and thus can guide us in the selection of radiolabeled molecules to be synthesized and used to deposit DNA-breaking radiation doses in mammalian cell DNA. Compared with traditional/current radiopharmaceutical development approaches, the method greatly saves time and money, especially since the reactivity of newly designed radiolabeled compounds with their targeted DNA molecules can be predicted by means of molecular modeling prior to chemical synthesis

  2. Collimator design for a dedicated molecular breast imaging-guided biopsy system: Proof-of-concept

    International Nuclear Information System (INIS)

    Purpose: Molecular breast imaging (MBI) is a dedicated nuclear medicine breast imaging modality that employs dual-head cadmium zinc telluride (CZT) gamma cameras to functionally detect breast cancer. MBI has been shown to detect breast cancers otherwise occult on mammography and ultrasound. Currently, a MBI-guided biopsy system does not exist to biopsy such lesions. Our objective was to consider the utility of a novel conical slant-hole (CSH) collimator for rapid (<1 min) and accurate monitoring of lesion position to serve as part of a MBI-guided biopsy system. Methods: An initial CSH collimator design was derived from the dimensions of a parallel-hole collimator optimized for MBI performed with dual-head CZT gamma cameras. The parameters of the CSH collimator included the collimator height, cone slant angle, thickness of septa and cones of the collimator, and the annular areas exposed at the base of the cones. These parameters were varied within the geometric constraints of the MBI system to create several potential CSH collimator designs. The CSH collimator designs were evaluated using Monte Carlo simulations. The model included a breast compressed to a thickness of 6 cm with a 1-cm diameter lesion located 3 cm from the collimator face. The number of particles simulated was chosen to represent the count density of a low-dose, screening MBI study acquired with the parallel-hole collimator for 10 min after a ∼150 MBq (4 mCi) injection of Tc-99m sestamibi. The same number of particles was used for the CSH collimator simulations. In the resulting simulated images, the count sensitivity, spatial resolution, and accuracy of the lesion depth determined from the lesion profile width were evaluated. Results: The CSH collimator design with default parameters derived from the optimal parallel-hole collimator provided 1-min images with error in the lesion depth estimation of 1.1 ± 0.7 mm and over 21 times the lesion count sensitivity relative to 1-min images acquired with

  3. Collimator design for a dedicated molecular breast imaging-guided biopsy system: Proof-of-concept

    Energy Technology Data Exchange (ETDEWEB)

    Weinmann, Amanda L.; Hruska, Carrie B.; Conners, Amy L.; O' Connor, Michael K. [Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905 (United States)

    2013-01-15

    Purpose: Molecular breast imaging (MBI) is a dedicated nuclear medicine breast imaging modality that employs dual-head cadmium zinc telluride (CZT) gamma cameras to functionally detect breast cancer. MBI has been shown to detect breast cancers otherwise occult on mammography and ultrasound. Currently, a MBI-guided biopsy system does not exist to biopsy such lesions. Our objective was to consider the utility of a novel conical slant-hole (CSH) collimator for rapid (<1 min) and accurate monitoring of lesion position to serve as part of a MBI-guided biopsy system. Methods: An initial CSH collimator design was derived from the dimensions of a parallel-hole collimator optimized for MBI performed with dual-head CZT gamma cameras. The parameters of the CSH collimator included the collimator height, cone slant angle, thickness of septa and cones of the collimator, and the annular areas exposed at the base of the cones. These parameters were varied within the geometric constraints of the MBI system to create several potential CSH collimator designs. The CSH collimator designs were evaluated using Monte Carlo simulations. The model included a breast compressed to a thickness of 6 cm with a 1-cm diameter lesion located 3 cm from the collimator face. The number of particles simulated was chosen to represent the count density of a low-dose, screening MBI study acquired with the parallel-hole collimator for 10 min after a {approx}150 MBq (4 mCi) injection of Tc-99m sestamibi. The same number of particles was used for the CSH collimator simulations. In the resulting simulated images, the count sensitivity, spatial resolution, and accuracy of the lesion depth determined from the lesion profile width were evaluated. Results: The CSH collimator design with default parameters derived from the optimal parallel-hole collimator provided 1-min images with error in the lesion depth estimation of 1.1 {+-} 0.7 mm and over 21 times the lesion count sensitivity relative to 1-min images

  4. Sentence-Level Attachment Prediction

    Science.gov (United States)

    Albakour, M.-Dyaa; Kruschwitz, Udo; Lucas, Simon

    Attachment prediction is the task of automatically identifying email messages that should contain an attachment. This can be useful to tackle the problem of sending out emails but forgetting to include the relevant attachment (something that happens all too often). A common Information Retrieval (IR) approach in analyzing documents such as emails is to treat the entire document as a bag of words. Here we propose a finer-grained analysis to address the problem. We aim at identifying individual sentences within an email that refer to an attachment. If we detect any such sentence, we predict that the email should have an attachment. Using part of the Enron corpus for evaluation we find that our finer-grained approach outperforms previously reported document-level attachment prediction in similar evaluation settings.

  5. Attachment theory: Old and new approach

    OpenAIRE

    Polovina Nada

    2005-01-01

    The article is an attempt to present holistically the key concepts of attachment theory rediscovered for its potentials. The presented concepts include: narrow definition of attachment, behavioral control system of attachment, attachment working model and patterns of attachment. The concepts are presented in the context of child attachment theory and adult attachment theory, in addition to description of the development of attachment. Concepts, as well as developmental processes are presented...

  6. Design and fabrication of a new class of nano hybrid materials based on reactive polymeric molecular cages.

    Science.gov (United States)

    Zhang, De Suo; Liu, Xiang Yang; Li, Jing Liang; Xu, Hong Yao; Lin, Hong; Chen, Yu Yue

    2013-09-10

    This paper describes a strategy of fabricating a new class of nano hybrid particles in terms of the "nanocages" of reactive molecular matrices/networks. The concept is to design molecular matrices functionalized with particular reactive groups, which can on-site synthesize and fix nanoparticles at the designated positions of the molecular networks. The cages of the molecular networks impose the confinement and protection to the nanoparticles so that the size and the stability of nano hybrid particles can be better controlled. To this end, polyamide network polymers (PNP) were synthesized and adopted as the reactive molecular cages for the control of silver nanoparticles formation. It follows that the silver nano hybrid particles fabricated by this method have an average diameter of 4.34 nm much smaller than any other or similar methods ie by a hyperbranched polyamide polymer (HB-PA). As per our design, the size of the silver nano hybrid particles can also be tuned by controlling the molar ratio between silver ions and the functional groups in the polymeric matrices. The silver nano hybrid particles reveal the substantially enhanced stability in aqueous solutions, which gives rise to the long stable performance of localized surface plasmon resonance. As the nano hybrid particles display long eminent nanoeffects, they exert broad implications for a wide range of applications such as biomedicine, catalysis, and optoelectronics. PMID:23980927

  7. Attachment theory and therapeutic relationships

    OpenAIRE

    Boysan, Zehra

    2015-01-01

    The aims of this study were to examine the associations between current self-reported attachment styles, retrospective reports of childhood experiences, and the development of the therapeutic alliance. It was hypothesised that anxious and avoidant attachment would be correlated with negative childhood experiences and that both attachment anxiety and avoidance would be inversely correlated with the therapeutic alliance. The third hypothesis stated that negative childhood recollections would co...

  8. Molecular design driving tetraporphyrin self-assembly on graphite: a joint STM, electrochemical and computational study

    Science.gov (United States)

    El Garah, M.; Santana Bonilla, A.; Ciesielski, A.; Gualandi, A.; Mengozzi, L.; Fiorani, A.; Iurlo, M.; Marcaccio, M.; Gutierrez, R.; Rapino, S.; Calvaresi, M.; Zerbetto, F.; Cuniberti, G.; Cozzi, P. G.; Paolucci, F.; Samorì, P.

    2016-07-01

    Tuning the intermolecular interactions among suitably designed molecules forming highly ordered self-assembled monolayers is a viable approach to control their organization at the supramolecular level. Such a tuning is particularly important when applied to sophisticated molecules combining functional units which possess specific electronic properties, such as electron/energy transfer, in order to develop multifunctional systems. Here we have synthesized two tetraferrocene-porphyrin derivatives that by design can selectively self-assemble at the graphite/liquid interface into either face-on or edge-on monolayer-thick architectures. The former supramolecular arrangement consists of two-dimensional planar networks based on hydrogen bonding among adjacent molecules whereas the latter relies on columnar assembly generated through intermolecular van der Waals interactions. Scanning Tunneling Microscopy (STM) at the solid-liquid interface has been corroborated by cyclic voltammetry measurements and assessed by theoretical calculations to gain multiscale insight into the arrangement of the molecule with respect to the basal plane of the surface. The STM analysis allowed the visualization of these assemblies with a sub-nanometer resolution, and cyclic voltammetry measurements provided direct evidence of the interactions of porphyrin and ferrocene with the graphite surface and offered also insight into the dynamics within the face-on and edge-on assemblies. The experimental findings were supported by theoretical calculations to shed light on the electronic and other physical properties of both assemblies. The capability to engineer the functional nanopatterns through self-assembly of porphyrins containing ferrocene units is a key step toward the bottom-up construction of multifunctional molecular nanostructures and nanodevices.Tuning the intermolecular interactions among suitably designed molecules forming highly ordered self-assembled monolayers is a viable approach to

  9. Applying universal scaling laws to identify the best molecular design paradigms for second-order nonlinear optics

    CERN Document Server

    Perez-Moreno, Javier; Kuzyk, Mark G

    2016-01-01

    We apply scaling and the theory of the fundamental limits of the second-order molecular susceptibility to identify material classes with ultralarge nonlinear-optical response. Size effects are removed by normalizing all nonlinearities to get intrinsic values so that the scaling behavior of a series of molecular homologues can be determined. Several new figures of merit are proposed that quantify the desirable properties for molecules that can be designed by adding a sequence of repeat units, and used in the assessment of the data. Three molecular classes are found. They are characterized by sub-scaling, nominal scaling, or super-scaling. Super-scaling homologues most efficiently take advantage of increased size. We apply our approach to data currently available in the literature to identify the best super-scaling molecular paradigms with the aim of identifying desirable traits of new materials.

  10. Towards the design of new and improved drilling fluid additives using molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Richard L. Anderson

    2010-03-01

    Full Text Available During exploration for oil and gas, a technical drilling fluid is used to lubricate the drill bit, maintain hydrostatic pressure, transmit sensor readings, remove rock cuttings and inhibit swelling of unstable clay based reactive shale formations. Increasing environmental awareness and resulting legislation has led to the search for new, improved biodegradable drilling fluid components. In the case of additives for clay swelling inhibition, an understanding of how existing effective additives interact with clays must be gained to allow the design of improved molecules. Owing to the disordered nature and nanoscopic dimension of the interlayer pores of clay minerals, computer simulations have become an increasingly useful tool for studying clay-swelling inhibitor interactions. In this work we briefly review the history of the development of technical drilling fluids, the environmental impact of drilling fluids and the use of computer simulations to study the interactions between clay minerals and swelling inhibitors. We report on results from some recent large-scale molecular dynamics simulation studies on low molecular weight water-soluble macromolecular inhibitor molecules. The structure and interactions of poly(propylene oxide-diamine, poly(ethylene glycol and poly(ethylene oxide-diacrylate inhibitor molecules with montmorillonite clay are studied.Durante a exploração de óleo e gás um fluido de perfuração é usado para lubrificar 'bit' da perfuradora, manter a pressão hidrostática, transmitir sensores de leitura, remover resíduos da rocha e inibir o inchamento da argila instável baseada nas formações dos folhelhos. O aumento das preocupações ambientais bem como a legislação resultante levou à procura de novos fluidos de perfuração com componentes biodegradáveis. No caso dos aditivos para inibir o inchamento das argilas o entendimento das interações entre os aditivos e as argilas tem que ser adquirido para permitir o

  11. Molecular Electrical Doping of Organic Semiconductors: Fundamental Mechanisms and Emerging Dopant Design Rules.

    Science.gov (United States)

    Salzmann, Ingo; Heimel, Georg; Oehzelt, Martin; Winkler, Stefanie; Koch, Norbert

    2016-03-15

    Today's information society depends on our ability to controllably dope inorganic semiconductors, such as silicon, thereby tuning their electrical properties to application-specific demands. For optoelectronic devices, organic semiconductors, that is, conjugated polymers and molecules, have emerged as superior alternative owing to the ease of tuning their optical gap through chemical variability and their potential for low-cost, large-area processing on flexible substrates. There, the potential of molecular electrical doping for improving the performance of, for example, organic light-emitting devices or organic solar cells has only recently been established. The doping efficiency, however, remains conspicuously low, highlighting the fact that the underlying mechanisms of molecular doping in organic semiconductors are only little understood compared with their inorganic counterparts. Here, we review the broad range of phenomena observed upon molecularly doping organic semiconductors and identify two distinctly different scenarios: the pairwise formation of both organic semiconductor and dopant ions on one hand and the emergence of ground state charge transfer complexes between organic semiconductor and dopant through supramolecular hybridization of their respective frontier molecular orbitals on the other hand. Evidence for the occurrence of these two scenarios is subsequently discussed on the basis of the characteristic and strikingly different signatures of the individual species involved in the respective doping processes in a variety of spectroscopic techniques. The critical importance of a statistical view of doping, rather than a bimolecular picture, is then highlighted by employing numerical simulations, which reveal one of the main differences between inorganic and organic semiconductors to be their respective density of electronic states and the doping induced changes thereof. Engineering the density of states of doped organic semiconductors, the Fermi

  12. Molecular design driving tetraporphyrin self-assembly on graphite: a joint STM, electrochemical and computational study.

    Science.gov (United States)

    El Garah, M; Santana Bonilla, A; Ciesielski, A; Gualandi, A; Mengozzi, L; Fiorani, A; Iurlo, M; Marcaccio, M; Gutierrez, R; Rapino, S; Calvaresi, M; Zerbetto, F; Cuniberti, G; Cozzi, P G; Paolucci, F; Samorì, P

    2016-07-14

    Tuning the intermolecular interactions among suitably designed molecules forming highly ordered self-assembled monolayers is a viable approach to control their organization at the supramolecular level. Such a tuning is particularly important when applied to sophisticated molecules combining functional units which possess specific electronic properties, such as electron/energy transfer, in order to develop multifunctional systems. Here we have synthesized two tetraferrocene-porphyrin derivatives that by design can selectively self-assemble at the graphite/liquid interface into either face-on or edge-on monolayer-thick architectures. The former supramolecular arrangement consists of two-dimensional planar networks based on hydrogen bonding among adjacent molecules whereas the latter relies on columnar assembly generated through intermolecular van der Waals interactions. Scanning Tunneling Microscopy (STM) at the solid-liquid interface has been corroborated by cyclic voltammetry measurements and assessed by theoretical calculations to gain multiscale insight into the arrangement of the molecule with respect to the basal plane of the surface. The STM analysis allowed the visualization of these assemblies with a sub-nanometer resolution, and cyclic voltammetry measurements provided direct evidence of the interactions of porphyrin and ferrocene with the graphite surface and offered also insight into the dynamics within the face-on and edge-on assemblies. The experimental findings were supported by theoretical calculations to shed light on the electronic and other physical properties of both assemblies. The capability to engineer the functional nanopatterns through self-assembly of porphyrins containing ferrocene units is a key step toward the bottom-up construction of multifunctional molecular nanostructures and nanodevices. PMID:27376633

  13. Mechanistic Characterization and Designing Possible Molecular Ligand Interactions with RdRp from CHIKV

    Directory of Open Access Journals (Sweden)

    D. P. Jobidhas

    2013-04-01

    Full Text Available To date, no suitable vaccine or specific antiviral drug is available to treat Chikungunya viral (CHIKV fever. Hence, it is essential to identify drug candidates that could potentially impede CHIKV infection. The present study focused with the development of Designing Possible Docking and Molecular Ligand Interactions with RdRp from CHIK-V protein based on the crystal structure. When, Rifapentine was interact with RdRp viral protein which were clearly showed the significantly excellent glide score of -5.690530 (Kcal/mol as well as poor glide score of 2.874727 (Kcal/mol. The docking results showed that among the four ligand molecules Efavirenz have the lowest binding values among the other ligands because it has residue contact with total of 13 residues. Two of them were Glut-31, Glut-46, which are catalytic site residues. It is expected that this ligand could prevented the catalytic process. Rimantadine peptide has hydrogen bond interaction with five other residues and them binded with GLU-28, ASP-38 and ILE-45. Based on docking result visualization, it is known that Rifapentine and Rifampin peptide ligand was bound with RdRp enzyme inside the cavity also viral RNA entry when it covets to begin initiation and elongation process. From this study clearly revealed, the ligands such as Rifapentine, Rifampin and Rimantadine may inhibit the RNA dependent RNA polymerase protein activity in chikungunya virus. Furthermore, the backbone structural scaffolds of these four lead compounds could serve as building blocks when designing drug-like molecules for the treatment of Chikungunya viral fever.

  14. A two-stage algorithm for designing phase I cancer clinical trials for two new molecular entities.

    Science.gov (United States)

    Su, Zheng

    2010-01-01

    The continual reassessment method (CRM) and subsequent developments of the Bayesian approach provide important tools for the design of Phase I cancer clinical trials for a new molecular entity. In recent years the idea of developing a treatment composed of two molecular entities has been proposed. For example, for some tumor types there may be two signaling pathways, both of which need to be blocked simultaneously using two molecules to achieve therapeutic benefit. A two-stage Bayesian and likelihood based algorithm is introduced herein for designing Phase I cancer clinical trials for two new molecular entities. It starts with a modified CRM approach in the first stage and makes use of the accumulated data from the first stage to provide likelihood estimates of model parameters for use in the second stage. PMID:19879974

  15. Molecular Design for Tailoring a Single-Source Precursor for Bismuth Ferrite.

    Science.gov (United States)

    Bendt, Georg; Schiwon, Rafael; Salamon, Soma; Landers, Joachim; Hagemann, Ulrich; Limberg, Christian; Wende, Heiko; Schulz, Stephan

    2016-08-01

    Nearly phase-pure bismuth ferrite particles were formed by thermolysis of the single-source precursor [Cp(CO)2FeBi(OAc)2] (1) in octadecene at 245 °C, followed by subsequent calcination at 600 °C for 3 h. In contrast, the slightly modified compound [Cp(CO)2FeBi(O2C(t)Bu)2] (2) yielded only mixtures of different bismuth oxide phases, revealing the distinctive influence of molecular design in material synthesis. The chemical composition, morphology, and crystallinity of the resulting materials were investigated by X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. In addition, the optical properties were investigated by Fourier transform infrared and UV-vis spectroscopies, showing a strong band gap absorption in the visible range at 590 nm (2.2 eV). The magnetic behavior was probed by vibrating-sample and superconducting quantum interference device magnetometry, as well as (57)Fe Mössbauer spectroscopy. PMID:27391769

  16. Chalcone based azacarboline analogues as novel antitubulin agents: design, synthesis, biological evaluation and molecular modelling studies.

    Science.gov (United States)

    Sharma, Sahil; Kaur, Charanjit; Budhiraja, Abhishek; Nepali, Kunal; Gupta, Manish K; Saxena, A K; Bedi, P M S

    2014-10-01

    The present study involves the design of a series of 3-aryl-9-acetyl-pyridazino[3,4-b]indoles as constrained chalcone analogues. A retrosynthetic route was proposed for the synthesis of target compounds. All the synthesized compounds were evaluated for in-vitro cytotoxicity against THP-1, COLO-205, HCT-116 and A-549 human cancer cell lines. The results indicated that 2a, 3a, 5a and 6a possessed significant cytotoxic potential with an IC50 value ranging from 1.13 to 5.76 μM. Structure activity relationship revealed that the nature of both Ring A and Ring B influences the activity. Substitution of methoxy groups on the phenyl ring (Ring A) and unsubstituted phenyl ring (Ring B) were found to be the preferred structural features. The most potent compound 2a was further tested for tubulin inhibition. Compound 2a was found to significantly inhibit the tubulin polymerization (IC50 value - 2.41 μM against THP-1). Compound 2a also caused disruption of microtubule assembly as evidenced by Immunoflourescence technique. The significant cytotoxicity and tubulin inhibition by 2a was rationalized by molecular modelling studies. The most potent structure was docked at colchicine binding site (PDB ID-1SA0) and was found to be stabilized in the cavity via various hydrophobic and hydrogen bonding interactions. PMID:25128667

  17. Attachment disorganization in different clinical groups: What underpins unresolved attachment?

    Directory of Open Access Journals (Sweden)

    Juen Florian

    2013-01-01

    Full Text Available This paper summarizes findings and clinical implications of research on attachment disorganization in diverse clinical groups. Disorganized/unresolved attachment is overrepresented in these groups compared to healthy control participants, but disorder specific characteristics of this attachment pattern are still poorly understood. The focus of this study was to explore defensive processes in participants whose narratives were classified as disorganized/unresolved using the Adult Attachment Projective Picture System (AAP. Besides the predominance of disorganized attachment, clinical participants demonstrated more “segregated system material” especially in stories representing aloneness and more “Personal Experience material” compared to healthy individuals. Within the disorganized/ unresolved clinical individuals, BPD and PTSD patients showed the highest proportion of attachment disorganization and were less able to use other attachment-related defenses to maintain organized. Furthermore, PTSD patients were emotionally overwhelmed by the projective attachment scenes compared to the other clinical groups as indexed by an incapacity to complete sections of the AAP. BPD and addicted patients were characterized by a high degree of self-other boundary confusion. Depressive and schizophrenic patients showed a high overall defensive intensity to remain organized.

  18. Fiber Attachment Module Experiment

    Science.gov (United States)

    Agostini, Reinaldo J.

    2014-01-01

    Hollow Fiber Membrane Bioreactors (HFMB) are ideal systems for biological pretreatment of wastewater, however, optimization is still underway. The Fiber Attachment Module Experiment (FAME) allows the simultaneous testing of potential materials, treatments on these and varying inoculums. Polydimethylsiloxane (PDMS), the material chosen for its ideal oxygen permeation properties, was treated with 1 sodium hydroxide 0.1 M ether for 18 seconds and ultraviolet (UV) irradiation oxygen plasma (OP) exposure for 1 hour. Preliminary chemistry and visual data indicate promising treatments when using OP and sodium hydroxide as treatments for PDMS fibers; however, due to the biological nature of the experiment, time is a constraint. Sodium hydroxide treatment chemistry data shows nitrification is occurring as urea and ammonia are decreasing and nitrite is increasing. A higher amount of biofilm can also be observed for this particular case. During the final two weeks of the internship x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and acridine orange (AO) cell counts will be employed for treatment effectiveness on the first batch of treatments (ether and sodium hydroxide). These same strategies will be used for the second batch of experiments due in four weeks (2nd week of August).

  19. Protein Attachment on Nanodiamonds.

    Science.gov (United States)

    Lin, Chung-Lun; Lin, Cheng-Huang; Chang, Huan-Cheng; Su, Meng-Chih

    2015-07-16

    A recent advance in nanotechnology is the scale-up production of small and nonaggregated diamond nanoparticles suitable for biological applications. Using detonation nanodiamonds (NDs) with an average diameter of ∼4 nm as the adsorbents, we have studied the static attachment of three proteins (myoglobin, bovine serum albumin, and insulin) onto the nanoparticles by optical spectroscopy, mass spectrometry, and dynamic light scattering, and electrophoretic zeta potential measurements. Results show that the protein surface coverage is predominantly determined by the competition between protein-protein and protein-ND interactions, giving each protein a unique and characteristic structural configuration in its own complex. Specifically, both myoglobin and bovine serum albumin show a Langmuir-type adsorption behavior, forming 1:1 complexes at saturation, whereas insulin folds into a tightly bound multimer before adsorption. The markedly different adsorption patterns appear to be independent of the protein concentration and are closely related to the affinity of the individual proteins for the NDs. The present study provides a fundamental understanding for the use of NDs as a platform for nanomedical drug delivery. PMID:25815400

  20. Molecular modeling methods in the study and design of bioactive compounds: An introduction [Métodos de Modelagem Molecular para estudo e planejamento de compostos bioativos: Uma introdução

    OpenAIRE

    Carlos Mauricio R. Sant´Anna

    2009-01-01

    This paper presents an introduction to the main methods used in molecular modeling calculations applied in the design of bioactive compounds. An introductory description of the two approaches methods predominantly used in molecular modeling studies is presented: the classical approach, which includes molecular mechanics and molecular dynamics; and the quantum mechanical approach, which includes ab initio and semi-empirical methods. We discuss how these methods can be applied to determine the ...

  1. Substratum interfacial energetic effects on the attachment of marine bacteria

    Science.gov (United States)

    Ista, Linnea Kathryn

    Biofilms represent an ancient, ubiquitous and influential form of life on earth. Biofilm formation is initiated by attachment of bacterial cells from an aqueous suspension onto a suitable attachment substratum. While in certain, well studied cases initial attachment and subsequent biofilm formation is mediated by specific ligand-receptor pairs on the bacteria and attachment substratum, in the open environment, including the ocean, it is assumed to be non-specific and mediated by processes similar to those that drive adsorption of colloids at the water-solid interface. Colloidal principles are studied to determine the molecular and physicochemical interactions involved in the attachment of the model marine bacterium, Cobetia marina to model self-assembled monolayer surfaces. In the simplest application of colloidal principles the wettability of attachment substrata, as measured by the advancing contact angle of water (theta AW) on the surface, is frequently used as an approximation for the surface tension. We demonstrate the applicability of this approach for attachment of C. marina and algal zoospores and extend it to the development of a means to control attachment and release of microorganisms by altering and tuning surface thetaAW. In many cases, however, thetaAW does not capture all the information necessary to model attachment of bacteria to attachment substrata; SAMs with similar thetaAW attach different number of bacteria. More advanced colloidal models of initial bacterial attachment have evolved over the last several decades, with the emergence of the model proposed by van Oss, Chaudhury and Good (VCG) as preeminent. The VCG model enables calculation of interfacial tensions by dividing these into two major interactions thought to be important at biointerfaces: apolar, Lifshitz-van der Waals and polar, Lewis acid-base (including hydrogen bonding) interactions. These interfacial tensions are combined to yield DeltaGadh, the free energy associated with

  2. Examinations on retention of overdentures with elastic frictional attachments

    Directory of Open Access Journals (Sweden)

    W. Chladek

    2010-11-01

    Full Text Available frictional attachments.Design/methodology/approach: The examinations of retention characteristics of traditional attachments, elastic frictional attachments and models of overdentures have been carried out using Zwick testing machine. Retention forces and work essential for separating the attachments have been determined as well. Next the force – displacement characteristics for overdenture model have been registered for two places where the force was applied and for three inclination angles of the line of application of force.Findings: The obtained results of laboratory examinations gave evidence of high effectiveness of elastic frictional attachments.Research limitations/implications: It has not been possible to register mechanical characteristics due to limitations of clinical conditions. Wide analysis of retention characteristics requires examinations carried out in laboratory conditions.Practical implications: Thorough analysis of force - displacement characteristics enables to understand better the mechanisms which are essential for the effectiveness of particular attachments. Applying such knowledge in practice helps to use more effectively the properties of silicone rubbers for making the elastic frictional attachments.Originality/value: The presented method of evaluating the effectiveness of attachments is based on determining retention work of the attachments and it allows to compare quite objectively even relatively different solutions. The so far used criterion of measuring vertical retention force makes it possible to compare only the solutions which are based on similar mechanical principles.

  3. Diameters in preferential attachment models

    NARCIS (Netherlands)

    Dommers, S.; Van der Hofstad, R.; Hooghiemstra, G.

    2010-01-01

    In this paper, we investigate the diameter in preferential attachment (PA-) models, thus quantifying the statement that these models are small worlds. The models studied here are such that edges are attached to older vertices proportional to the degree plus a constant, i.e., we consider affine PA-mo

  4. Association between attachment and schizotypy

    OpenAIRE

    Dunne, Colm

    2011-01-01

    Background: The human genome project has affirmed the importance of non-genetic factors in human development. Attachment style is considered to be a diathesis for psychopathology and an important determinant regarding interpersonal functioning. Epidemiological research has indicated that there is significant aetiological continuity between symptoms of schizotypy and clinical symptoms of schizophrenia. Limited research has investigated the association between attachment and schi...

  5. Computer-Assisted Drug Design: Genetic Algorithms and Structures of Molecular Clusters of Aromatic Hydrocarbons and Actinomycin D-Deoxyguanosine

    Science.gov (United States)

    Xiao, Yong Liang

    Molecular packing, clustering, and docking computations have been performed by empirical intermolecular energy minimization methods. The main focus of this study is finding a robust global search algorithm to solve intermolecular interaction problems, especially to apply an efficient algorithm to large-scale complex molecular systems such as drug-DNA binding or site selectivity which has increasing importance in drug design and drug discovery. Molecular packing in benzene, naphthalene, and anthracene crystals is analyzed in terms of molecular dimer interaction. Intermolecular energies of the gas dimer molecules are calculated for various intermolecular distances and orientations using empirical potential energy functions. The gas dimers are compared to pairs of molecules extracted from the observed crystal structures. Net atomic charges are obtained by the potential-derived method from 6-31G and 6-31G^{**} level ab initio wavefunctions. A new approach using a genetic algorithm is applied to predict structures of benzene, naphthalene, and anthracene molecular clusters. The computer program GAME (genetic algorithm for minimization of energy) has been developed to obtain the global energy minimum of clusters of dimer, trimer, and tetramer molecules. This test model has been further developed to applications of molecular docking. Docking calculations of deoxyguanosine molecules to actinomycin D were performed successfully to identify the binding sites of the drug molecule, which was revealed by actinomycin D-deoxyguanosine complex from the solved x-ray crystal structure. The comparison between the evolutionary computing method and conventional local optimization methods concluded that genetic algorithms are very competitive when it comes to complex, large-scale optimization. Full power of genetic algorithms can be unveiled in computer-assisted drug design only when the difficulties of including optimized molecular conformation in the algorithm are overcome. These

  6. [Set of radiocirculographic attachments for radioisotope laboratories].

    Science.gov (United States)

    Devishev, M I; Panfilova, N P; Ostrogradskaia, M G

    1980-01-01

    A set of radiocirculographic attachments is offered which serves for calibration and verification of readings taken from the apparatus during radiographic procedures. The set is designed for operation with all colimators of radiocirculographs produced in the USSR and Hungarian People's Republic. The set is able to imitate the investigation geometry, accumulation of radioactivity in the organ under study, absorption and scattering of radioactivty in the organism tissues. Series production of this device has already been initiated. PMID:7392870

  7. Evolutionary Design of Low Molecular Weight Organic Anolyte Materials for Applications in Nonaqueous Redox Flow Batteries.

    Science.gov (United States)

    Sevov, Christo S; Brooner, Rachel E M; Chénard, Etienne; Assary, Rajeev S; Moore, Jeffrey S; Rodríguez-López, Joaquín; Sanford, Melanie S

    2015-11-18

    The integration of renewable energy sources into the electric grid requires low-cost energy storage systems that mediate the variable and intermittent flux of energy associated with most renewables. Nonaqueous redox-flow batteries have emerged as a promising technology for grid-scale energy storage applications. Because the cost of the system scales with mass, the electroactive materials must have a low equivalent weight (ideally 150 g/(mol·e(-)) or less), and must function with low molecular weight supporting electrolytes such as LiBF4. However, soluble anolyte materials that undergo reversible redox processes in the presence of Li-ion supports are rare. We report the evolutionary design of a series of pyridine-based anolyte materials that exhibit up to two reversible redox couples at low potentials in the presence of Li-ion supporting electrolytes. A combination of cyclic voltammetry of anolyte candidates and independent synthesis of their corresponding charged-states was performed to rapidly screen for the most promising candidates. Results of this workflow provided evidence for possible decomposition pathways of first-generation materials and guided synthetic modifications to improve the stability of anolyte materials under the targeted conditions. This iterative process led to the identification of a promising anolyte material, N-methyl 4-acetylpyridinium tetrafluoroborate. This compound is soluble in nonaqueous solvents, is prepared in a single synthetic step, has a low equivalent weight of 111 g/(mol·e(-)), and undergoes two reversible 1e(-) reductions in the presence of LiBF4 to form reduced products that are stable over days in solution. PMID:26514666

  8. Hydration Free Energy as a Molecular Descriptor in Drug Design: A Feasibility Study.

    Science.gov (United States)

    Zafar, Ayesha; Reynisson, Jóhannes

    2016-05-01

    In this work the idea was investigated whether calculated hydration energy (ΔGhyd ) can be used as a molecular descriptor in defining promising regions of chemical space for drug design. Calculating ΔGhyd using the Density Solvation Model (SMD) in conjunction with the density functional theory (DFT) gave an excellent correlation with experimental values. Furthermore, calculated ΔGhyd correlates reasonably well with experimental water solubility (r(2) =0.545) and also log P (r(2) =0.530). Three compound collections were used: Known drugs (n=150), drug-like compounds (n=100) and simple organic compounds (n=140). As an approximation only molecules, which do not de/protonate at physiological pH were considered. A relatively broad distribution was seen for the known drugs with an average at -15.3 kcal/mol and a standard deviation of 7.5 kcal/mol. Interestingly, much lower averages were found for the drug-like compounds (-7.5 kcal/mol) and the simple organic compounds (-3.1 kcal/mol) with tighter distributions; 4.3 and 3.2 kcal/mol, respectively. This trend was not observed for these collections when calculated log P and log S values were used. The considerable greater exothermic ΔGhyd average for the known drugs clearly indicates in order to develop a successful drug candidate value of ΔGhyd <-5 kcal/mol or less is preferable. PMID:27492087

  9. Molecular mechanics approach for design and conformational studies of macrocyclic ligands

    International Nuclear Information System (INIS)

    Computational Chemistry has revolutionized way of viewing molecules at the quantum mechanical scale by allowing simulating various chemical scenarios that are not possible to study in a laboratory. The remarkable applications of computational chemistry have promoted to design and test of the effectiveness of various methods for searching the conformational space of highly flexible molecules. In this context, we conducted a series of optimization and conformational searches on macrocyclic based ligands, 9N3Me5Ox, (1,4,7-tris(5-methyl-8-hydroxyquinoline)-1,4,7-triazacyclononane) and 12N3Me5Ox, (1,5,9-tris(5-methyl-8-hydroxyquinoline)-1,5,9-triazacyclododecane) and studied their selectivity and coordination behavior with some lanthanide metal ions in molecular mechanics and semiempirical methods. The methods include both systematic and random conformational searches for dihedral angles, torsion angles and Cartesian coordinates. Structural studies were carried out by using geometry optimization, coordination scans and electronic properties were evaluated. The results clearly show that chair-boat conformational isomer of 9N3Me5Ox ligand is more stable due to lower eclipsing ethane interaction and form stronger adduct complexes with lanthanide metal ion. This is because of the fact that, in a central unit of 9N3 of the ligand form six endo type bonds out of nine. The rest of bonds have trans conformation. In contrast, for the adduct of 12N3Me5Ox, two C-C bonds have on eclipsed conformation, and others have synclinal and antiperiplanar confirmations. The distortion of the two eclipsed conformations may affect the yields and the stability of the complexes

  10. Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Sites at Slick Rock, Colorado: Appendix B to Attachment 3, Lithologic logs and monitor well construction information. Final report

    International Nuclear Information System (INIS)

    This volume contains lithology logs and monitor well construction information for: NC processing site; UC processing site; and Burro Canyon disposal site. This information pertains to the ground water hydrology investigations which is attachment 3 of this series of reports

  11. Designed self-assembly of molecular necklaces using host-stabilized charge-transfer interactions.

    Science.gov (United States)

    Ko, Young Ho; Kim, Kyungpil; Kang, Jin-Koo; Chun, Hyungphil; Lee, Jae Wook; Sakamoto, Shigeru; Yamaguchi, Kentaro; Fettinger, James C; Kim, Kimoon

    2004-02-25

    A novel approach to the noncovalent synthesis of molecular necklaces successfully led to the first quantitative self-assembly of a molecular necklace [6]MN, in which five small rings are threaded on a large ring, from 10 components. Our strategy involves the host-guest complex formation between the molecular host cucurbit[8]uril (CB[8]) and a guest molecule in which an electron donor and an electron acceptor unit are connected by a rigid linker with a proper angle, to form a cyclic oligomer through the host-stabilized intermolecular charge-transfer (CT) complex formation. In the structure of the molecular necklace [6]MN, five molecules of the guest form a cyclic framework by the intermolecular CT interactions, on which five CB[8] molecules are threaded with an arrangement reminiscent of a five-fold propeller. The molecular necklace measures approximately 3.7 nm in diameter and approximately 1.8 nm in thickness. PMID:14971915

  12. Direction-Specific Interactions Control Crystal Growth by Oriented Attachment

    Science.gov (United States)

    Li, Dongsheng; Nielsen, Michael H.; Lee, Jonathan R. I.; Frandsen, Cathrine; Banfield, Jillian F.; De Yoreo, James J.

    2012-05-01

    The oriented attachment of molecular clusters and nanoparticles in solution is now recognized as an important mechanism of crystal growth in many materials, yet the alignment process and attachment mechanism have not been established. We performed high-resolution transmission electron microscopy using a fluid cell to directly observe oriented attachment of iron oxyhydroxide nanoparticles. The particles undergo continuous rotation and interaction until they find a perfect lattice match. A sudden jump to contact then occurs over less than 1 nanometer, followed by lateral atom-by-atom addition initiated at the contact point. Interface elimination proceeds at a rate consistent with the curvature dependence of the Gibbs free energy. Measured translational and rotational accelerations show that strong, highly direction-specific interactions drive crystal growth via oriented attachment.

  13. Molecular modeling methods in the study and design of bioactive compounds: An introduction [Métodos de Modelagem Molecular para estudo e planejamento de compostos bioativos: Uma introdução

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio R. Sant´Anna

    2009-01-01

    Full Text Available This paper presents an introduction to the main methods used in molecular modeling calculations applied in the design of bioactive compounds. An introductory description of the two approaches methods predominantly used in molecular modeling studies is presented: the classical approach, which includes molecular mechanics and molecular dynamics; and the quantum mechanical approach, which includes ab initio and semi-empirical methods. We discuss how these methods can be applied to determine the molecular structure and properties from these compounds and how to make the best choice according to the problem being addressed.

  14. Simulation of Molecular Signaling in Blood Vessels: Software Design and Application to Atherogenesis

    OpenAIRE

    Felicetti, Luca; Femminella, Mauro; Reali, Gianluca

    2013-01-01

    This paper presents a software platform, named BiNS2, able to simulate diffusion-based molecular communications with drift inside blood vessels. The contribution of the paper is twofold. First a detailed description of the simulator is given, under the software engineering point of view, by highlighting the innovations and optimizations introduced. Their introduction into the previous version of the BiNS simulator was needed to provide to functions for simulating molecular signaling and commu...

  15. Design principles of molecular networks revealed by global comparisons and composite motifs

    OpenAIRE

    Yu, Haiyuan; Xia, Yu; Trifonov, Valery; Gerstein, Mark

    2006-01-01

    Background Molecular networks are of current interest, particularly with the publication of many large-scale datasets. Previous analyses have focused on topologic structures of individual networks. Results Here, we present a global comparison of four basic molecular networks: regulatory, co-expression, interaction, and metabolic. In terms of overall topologic correlation - whether nearby proteins in one network are close in another - we find that the four are quite similar. However, focusing ...

  16. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    OpenAIRE

    Bowsher, James; Yan, Susu; Roper, Justin; Giles, William; Yin, Fang-Fang

    2013-01-01

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard S...

  17. Molecular modeling assisted hapten design to produce broad selectivity antibodies for fluoroquinolone antibiotics.

    Science.gov (United States)

    Pinacho, Daniel G; Sánchez-Baeza, Francisco; Marco, M-Pilar

    2012-05-15

    Antibodies with a wide recognition profile of fluoroquinolone antibiotics have been produced based on chemical criteria, theoretical studies, and molecular modeling assisted hapten design. The immunizing hapten preserves the most important and characteristic epitopes of this antibiotic family. The studies have taken into consideration the zwitterionic character of most of the fluoroquinolones and the relative concentration of the different species in equilibrium at physiologic pH. The hapten is prepared in the form of a stable prehapten through a 5 step synthetic pathway. Immediately before conjugation, the immunizing hapten is obtained by removing the diphenylmethane protecting group. The specificity of the antibodies obtained is directed toward the common area defined by the fluorine atom at position 6 and the β-ketoacid moiety. The ELISA developed is able to recognize with very good detectability important fluoroquinolones used in the veterinary field such as ciprofloxacin (CPFX, IC(50), 0.35 μg L(-1)), enrofloxacin (ERFX, IC(50), 0.65 μg L(-1)), danofloxacin (DNFX, IC(50), 7.31 μg L(-1)), difloxacin (DFX, IC(50), 0.91 μg L(-1)), sarafloxacin (SRFX, IC(50), 0.96 μg L(-1)), norfloxacin (NRFX, IC(50), 0.78 μg L(-1)), ofloxacin (OFX, IC(50), 1.84 μg L(-1)), flumequine (Flume, IC(50), 3.91 μ gL(-1)), marbofloxacin (MBFX, IC(50), 4.30 μ gL(-1)), and oxolinic acid (OXO, IC(50), 23.53 μg L(-1)). The results presented here demonstrate that the antibody affinity is strongly affected by the presence of divalent cations, owing to their complexation with the fluoroquinolone molecules. Moreover, the outcome from the effect of the pH on the immunochemical assays suggests that the selectivity could be modulated with the pH due to the zwitterionic character of the fluoroquinolones and as a function of their different pK(a) values. PMID:22545705

  18. Attachment at work and performance.

    Science.gov (United States)

    Neustadt, Elizabeth A; Chamorro-Premuzic, Tomas; Furnham, Adrian

    2011-09-01

    This paper examines the relations between self-reported attachment orientation at work and personality, self-esteem, trait emotional intelligence (aka emotional self-efficacy), and independently assessed career potential and job performance. Self-report data were collected from 211 managers in an international business in the hospitality industry; independent assessments of these managers' job performance and career potential were separately obtained from the organization. A self-report measure of romantic attachment was adapted for application in the work context; a two-factor solution was found for this measure. Secure/autonomous attachment orientation at work was positively related to self-esteem, trait emotional intelligence, extraversion, agreeableness, and conscientiousness, and also to job performance. Not only was secure/autonomous attachment orientation at work statistically predictive of job performance, but the new measure also made a distinct contribution, beyond conscientiousness, to this prediction. PMID:21838647

  19. Electron attachment to fluorocarbon radicals

    Science.gov (United States)

    Shuman, Nicholas

    2014-10-01

    Most plasma environments contain populations of short-lived species such as radicals, the chemistry of which can have significant effects on the overall chemistry of the system. However, few experimental measurements of the kinetics of electron attachment to radicals exist due to the inherent difficulties of working with transient species. Calculations from first principles have been attempted, but are arduous and, because electron attachment is so sensitive to the specifics of the potential surface, their accuracy has not been established. Electron attachment to small fluorocarbon radicals is particularly important, as the data are needed for predictive modeling of plasma etching of semiconductor materials, a key process in the industrial fabrication of microelectronics. We have recently developed a novel flowing afterglow technique to measure several types of otherwise difficult to study plasma processes, including thermal electron attachment to radicals. Variable Electron and Neutral Density Attachment Mass Spectrometry (VENDAMS) exploits dissociative electron attachment in a weakly ionized plasma as a radical source. Here, we apply VENDAMS to a series of halofluorocarbon precursors in order to measure the kinetics of thermal electron attachment to fluorocarbon radicals. Results are presented for CF2, CF3, C2F5,C2F3,1-C3F7, 2-C3F7, and C3F5 from 300 K to 900 K. Both the magnitude and the temperature dependences of rate coefficients as well as product branching between associative and dissociative attachment are highly system specific; however, thermal attachment to all species is inefficient, never exceeding 5% of the collision rate. The data are analyzed using a recently developed kinetic modeling approach, which uses extended Vogt-Wannier theory as a starting point, accounts for dynamic effects such as coupling between the electron and nuclear motions through empirically validated functional forms, and finally uses statistical theory to determine the fate of

  20. A radio transmitter attachment technique for soras

    Science.gov (United States)

    Haramis, G.M.; Kearns, G.D.

    2000-01-01

    We modified a figure-8 leg-loop harness designed for small passerines to attach successfully 1.8-g radio transmitters over the synsacrum of migrant Soras (Porzana carolina). Because of the short caudal region of Soras, addition of a waist loop was critical to securing the transmitter while leg loops were maintained to center the package. Thin gauge (0.6-mm diameter) elastic thread proved ideal for transmitter attachment and allowed for freedom of movement and girth expansion associated with fattening during a 6-10 week stopover. Of 110 Soras radio tagged during three field seasons, only a single mortality was observed and only a single bird lost its transmitter. Migration from the study area was confirmed for 76 (69%) and suspected for another 25 birds (total 92%).

  1. Attachment Narratives in Refugee Children

    DEFF Research Database (Denmark)

    De Haene, L.; Dalgård, Nina Thorup; Montgomery, E.;

    2013-01-01

    J Trauma Stress. 2013 Jun;26(3):413-7. doi: 10.1002/jts.21820. Attachment narratives in refugee children: interrater reliability and qualitative analysis in pilot findings from a two-site study.......J Trauma Stress. 2013 Jun;26(3):413-7. doi: 10.1002/jts.21820. Attachment narratives in refugee children: interrater reliability and qualitative analysis in pilot findings from a two-site study....

  2. Estimation and Uncertainty Analysis of Flammability Properties for Computer-aided molecular design of working fluids for thermodynamic cycles

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    Computer Aided Molecular Design (CAMD) is an important tool to generate, test and evaluate promising chemical products. CAMD can be used in thermodynamic cycle for the design of pure component or mixture working fluids in order to improve the heat transfer capacity of the system. The safety...... analysis. In this case property prediction models like group contribution (GC) models can estimate flammability data. The estimation needs to be accurate, reliable and as less time consuming as possible [1]. However, GC property prediction methods frequently lack rigorous uncertainty analysis. Hence, there...

  3. Design, Synthesis, and Biological Evaluation of Novel Nonsteroidal Farnesoid X Receptor (FXR) Antagonists: Molecular Basis of FXR Antagonism.

    Science.gov (United States)

    Huang, Huang; Si, Pei; Wang, Lei; Xu, Yong; Xu, Xin; Zhu, Jin; Jiang, Hualiang; Li, Weihua; Chen, Lili; Li, Jian

    2015-07-01

    Farnesoid X receptor (FXR) plays an important role in the regulation of cholesterol, lipid, and glucose metabolism. Recently, several studies on the molecular basis of FXR antagonism have been reported. However, none of these studies employs an FXR antagonist with nonsteroidal scaffold. On the basis of our previously reported FXR antagonist with a trisubstituted isoxazole scaffold, a novel nonsteroidal FXR ligand was designed and used as a lead for structural modification. In total, 39 new trisubstituted isoxazole derivatives were designed and synthesized, which led to pharmacological profiles ranging from agonist to antagonist toward FXR. Notably, compound 5s (4'-[(3-{[3-(2-chlorophenyl)-5-(2-thienyl)isoxazol-4-yl]methoxy}-1H-pyrazol-1-yl)methyl]biphenyl-2-carboxylic acid), containing a thienyl-substituted isoxazole ring, displayed the best antagonistic activity against FXR with good cellular potency (IC50 =12.2 ± 0.2 μM). Eventually, this compound was used as a probe in a molecular dynamics simulation assay. Our results allowed us to propose an essential molecular basis for FXR antagonism, which is consistent with a previously reported antagonistic mechanism; furthermore, E467 on H12 was found to be a hot-spot residue and may be important for the future design of nonsteroidal antagonists of FXR. PMID:25982493

  4. Nano-design of quantum dot-based photocatalysts for hydrogen generation using advanced surface molecular chemistry

    KAUST Repository

    Yu, Weili

    2015-01-01

    Efficient photocatalytic hydrogen generation in a suspension system requires a sophisticated nano-device that combines a photon absorber with effective redox catalysts. This study demonstrates an innovative molecular linking strategy for fabricating photocatalytic materials that allow effective charge separation of excited carriers, followed by efficient hydrogen evolution. The method for the sequential replacement of ligands with appropriate molecules developed in this study tethers both quantum dots (QDs), as photosensitizers, and metal nanoparticles, as hydrogen evolution catalysts, to TiO2 surfaces in a controlled manner at the nano-level. Combining hydrophobic and hydrophilic interactions on the surface, CdSe-ZnS core-shell QDs and an Au-Pt alloy were attached to TiO2 without overlapping during the synthesis. The resultant nano-photocatalysts achieved substantially high-performance visible-light-driven photocatalysis for hydrogen evolution. All syntheses were conducted at room temperature and in ambient air, providing a promising route for fabricating visible-light-responsive photocatalysts.

  5. Porphyrin architectures tailored for studies of molecular information storage.

    Science.gov (United States)

    Carcel, Carole M; Laha, Joydev K; Loewe, Robert S; Thamyongkit, Patchanita; Schweikart, Karl-Heinz; Misra, Veena; Bocian, David F; Lindsey, Jonathan S

    2004-10-01

    A molecular approach to information storage employs redox-active molecules tethered to an electroactive surface. Zinc porphyrins tethered to Au(111) or Si(100) provide a benchmark for studies of information storage. Three sets of porphyrins have been synthesized for studies of the interplay of molecular design and charge-storage properties: (1) A set of porphyrins is described for probing the effect of surface attachment atom on electron-transfer kinetics. Each porphyrin bears a meso-CH2X group for surface attachment where X = OH, SAc, or SeAc. (2) A set of porphyrins is described for studying the effect of surface-charge density in monolayers. Each porphyrin bears a benzyl alcohol for surface attachment and three nonlinking meso substituents of a controlled degree of bulkiness. (3) A set of porphyrins is described that enables investigation of on-chip patterning of the electrolyte. Each porphyrin bears a formyl group distal to the surface attachment group for subsequent derivatization with a molecular entity that comprises the electrolyte. Taken together, this collection of molecules enables a variety of studies to elucidate design issues in molecular-based information storage. PMID:15387598

  6. Molecular Cloning of cpcU and Heterodimeric Bilin Lyase Activity Analysis of CpcU and CpcS for Attachment of Phycocyanobilin to Cys-82 on the β-Subunit of Phycocyanin in Arthrospira platensis FACHB314.

    Science.gov (United States)

    Wu, Fei; Zang, Xiaonan; Zhang, Xuecheng; Zhang, Ran; Huang, Xiaoyun; Hou, Lulu; Jiang, Minjie; Liu, Chang; Pang, Chunhong

    2016-01-01

    A new bilin lyase gene cpcU was cloned from Arthrospira platensis FACHB314 to study the assembly of the phycocyanin β-Subunit. Two recombinant plasmids, one contained the phycocyanobilin (PCB) producing genes (hoxI and pcyA), while the other contained the gene of the β-Subunit of phycobiliprotein (cpcB) and the lyase gene (cpcU, cpcS, or cpcU/S) were constructed and separately transferred into Escherichia coli in order to test the activities of relevant lyases for catalyzing PCB addition to CpcB during synthesizing fluorescent β-PC of A. platensis FACHB314. The fluorescence intensity examination showed that Cys-82 maybe the active site for the β-Subunit binding to PCBs and the attachment could be carried out by CpcU, CpcS, or co-expressed cpcU/S in A. platensis FACHB314. PMID:26999083

  7. Molecular Cloning of cpcU and Heterodimeric Bilin Lyase Activity Analysis of CpcU and CpcS for Attachment of Phycocyanobilin to Cys-82 on the β-Subunit of Phycocyanin in Arthrospira platensis FACHB314

    Directory of Open Access Journals (Sweden)

    Fei Wu

    2016-03-01

    Full Text Available A new bilin lyase gene cpcU was cloned from Arthrospira platensis FACHB314 to study the assembly of the phycocyanin β-Subunit. Two recombinant plasmids, one contained the phycocyanobilin (PCB producing genes (hoxI and pcyA, while the other contained the gene of the β-Subunit of phycobiliprotein (cpcB and the lyase gene (cpcU, cpcS, or cpcU/S were constructed and separately transferred into Escherichia coli in order to test the activities of relevant lyases for catalyzing PCB addition to CpcB during synthesizing fluorescent β-PC of A. platensis FACHB314. The fluorescence intensity examination showed that Cys-82 maybe the active site for the β-Subunit binding to PCBs and the attachment could be carried out by CpcU, CpcS, or co-expressed cpcU/S in A. platensis FACHB314.

  8. The evaluation of selected attachment systems for implant-retained overdenture based on retention characteristics analysis.

    Science.gov (United States)

    Chladek, Grzegorz; Wrzuś-Wieliński, Marcin

    2010-01-01

    The results of mechanical characteristics of attachments used for retaining and stabilizing overdenture have been analysed. Two commercially used attachments (a ball attachment and a bar attachment) and elastic frictional attachments designed by the research team with Professor Chladek as the leader have been investigated. The diagrams of force-displacement characteristics have been registered. Retention forces (F(R)) have been determined and total work (W(T)) disconnecting the attachments has been calculated on the basis of these diagrams. The analysis of total work corresponding to different types of attachments made it possible to distinguish some characteristic areas which illustrate specific features of particular designs. It has been revealed that determining the retention force allows us to compare only the attachments which work on similar bases. In order to conduct a purely objective comparison of the efficiency of different designs, it is necessary to analyze complete force-displacement characteristics as well as to determine on this basis the subsequent phases of separating the parts of attachments and to find the value of the work which in fact determines their quality. The comparison of selected commercially used designs and the presented elastic frictional attachments (taking into account the criterion of work) gives clear evidence that the introduced design of attachment enables us to create very good conditions of retaining overdenture. PMID:21247057

  9. Computer-aided de novo ligand design and docking/molecular dynamics study of vitamin D receptor agonists.

    Science.gov (United States)

    Shen, Xiu-Long; Takimoto-Kamimura, Midori; Wei, Jing; Gao, Qing-Zhi

    2012-01-01

    1α,25(OH)(2)D(3), which is directly mediated by the vitamin D receptor (VDR), exerts a wide variety of biological actions. However, the treatment with 1α,25(OH)(2)D(3) is limited because of its side effects. Many analogs and several nonsteroidal mimics with potent biological activity have been reported so far, and our rationale for designing the VDR agonists was on the basis of computer-aided drug design method by de novo design of A-ring and C/D-ring position of 1α,25(OH)(2)D(3). Pyrimidine-2,4-diamine was selected as A-ring, and naphthalene and benzene were chosen as C/D-ring. By linking different components, a virtue compound library was obtained. To evaluate the contribution to activity of each component, we performed a series of automated molecular docking operations. Results revealed that the 19-dimethyl derivatives (the C-19 position correspond to C-20 in 1α,25(OH)(2)D(3)) show the favorable docking affinity to VDR. Moreover, the docking results are quite robust when further validated by molecular dynamics simulations. In addition, by free energy analysis using molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) method, the driving force of the binding between VDR and the ligands is proved to be hydrophobic interactions. Thus, a possible strategy to design new series of VDR agonists is proposed. The strategy can be successfully applied to explain the high potential activities of the 19-dimethyl derivatives. It is anticipated that the findings reported here may provide useful information for designing effective VDR agonists as well as the therapeutic treatment of VDR-related diseases. PMID:21523537

  10. A mixed molecular building block strategy for the design of nested polyhedron metal-organic frameworks.

    Science.gov (United States)

    Tian, Dan; Chen, Qiang; Li, Yue; Zhang, Ying-Hui; Chang, Ze; Bu, Xian-He

    2014-01-13

    A mixed molecular building block (MBB) strategy for the synthesis of double-walled cage-based porous metal-organic frameworks (MOFs) is presented. By means of this method, two isostructural porous MOFs built from unprecedented double-walled metal-organic octahedron were obtained by introducing two size-matching C3 -symmetric molecular building blocks with different rigidities. With their unique framework structures, these MOFs provide, to the best of our knowledge, the first examples of double-walled octahedron-based MOFs. PMID:24282117

  11. Attachment and the Body in Suicidal Adolescents: A Pilot Study

    OpenAIRE

    Wright, John; Briggs, Stephen; Behringer, Johanna

    2013-01-01

    There is a relative dearth of studies in the field of adolescent attachment despite the potential impact of such developmental changes on the organization of attachment systems. This omission is even more acute among clinical populations, although adolescence is notable for dramatic increases in specific psychopathologies, e.g. eating disorders, delinquency, and suicide and self-harm. This article attempts to address the shortfall using a mixed quantitative/qualitative research design. First,...

  12. Pyrotechnic shock at the orbiter/external tank forward attachment

    Science.gov (United States)

    Rogers, W. F.; Grissom, D. S.; Rhodes, L. R.

    1980-01-01

    During the initial certification test of the forward structural attachment of the space shuttle orbiter to the external tank, pyrotechnic shock from actuation of the separation device resulted in structural failure of the thermal protection tiles surrounding the attachment. Because of the high shock associated with the separation bolt, the development of alternative low shock separation designs was initiated. Two concepts that incorporate a 5.08 centimeter frangible nut as the release device were developed and tested.

  13. Attachment to inanimate objects and early childcare: A twin study

    OpenAIRE

    ArielKnafo; LioraBaor; SalomonIsrael

    2014-01-01

    Extensive non-maternal childcare plays an important role in children’s development. This study examined a potential coping mechanism for dealing with daily separation from caregivers involved in childcare experience – children’s development of attachments toward inanimate objects. We employed the twin design to estimate relative environmental and genetic contributions to the presence of object attachment, and assess whether childcare explains some of the environmental variation in this develo...

  14. Self-assembly, redox activity, and charge transport of functional surface nano-architectures by molecular design

    Science.gov (United States)

    Skomski, Daniel

    Surface-assisted molecular self-assembly is a promising strategy to program the structure and chemical state of atoms and molecules in nano-architectures to achieve a specific function. The experiments described in this thesis demonstrate that the design and programming of basic organic components leads to desired characteristics by self-assembly. The fabrication of uniform single-site metal centers at surfaces, important for high selectivity in next-generation catalysts, was accomplished by coordination to redox non-innocent phenanthroline and tetrazine-based ligands. These examples were the first demonstrating tuning of the metal oxidation state in surface coordination architectures through rational ligand design. The molecular-scale coordination architectures were the first formed from chromium and vanadium, and the first from platinum in a non-porphyrin system. The first mixed valence metal-ligand surface structure was fabricated that attained the same ligand coordination number for all metal sites. A new surface reaction method was demonstrated between an inexpensive sodium chloride reagent and carboxylate ligands. High-temperature, molecular-resolution microscopy and spectroscopy of the ordered metal-organic structures demonstrated thermal stability up to 300 °C, the highest molecular-level thermal stability in organic surface nanostructures yet achieved, making such systems potential candidates for moderate-temperature catalytic reactions. Molecular self-assembly was expanded into organic semiconductor thin films. In a two-component, bi-layered system, hydrogen bonding between carboxylates and carboxylic acid-substituted thiophenes was utilized, yielding the first real-space images of phenyl-thiophene stacking. In a one-component system, multiple donor-acceptor pi-pi contacts between phenyltriazole building blocks accomplished assembly of flat-lying molecules from a surface with molecular-scale precision through more than twenty molecular layers. Sufficient

  15. Designing and Implementing a Hands-On, Inquiry-Based Molecular Biology Course

    Science.gov (United States)

    Regassa, Laura B.; Morrison-Shetlar, Alison I.

    2007-01-01

    Inquiry-based learning was used to enhance an undergraduate molecular biology course at Georgia Southern University, a primarily undergraduate institution in rural southeast Georgia. The goal was to use a long-term, in-class project to accelerate higher-order thinking, thereby enabling students to problem solve and apply their knowledge to novel…

  16. Design of a novel molecular beacon: modification of the stem with artificially genetic alphabet†

    OpenAIRE

    Sheng, Pinpin; Yang, Zunyi; Kim, Youngmi; Wu, Yanrong; Tan, Weihong; Benner, Steven A

    2008-01-01

    A molecular beacon that incorporates components of an artificially expanded genetic information system (Aegis) in its stem is shown not to be opened by unwanted stem invasion by adventitious standard DNA; this should improve the “darkness” of the beacon in real-world applications.

  17. Molecular Thermodynamic Modeling and Design of Microencapsulation Systems for Drug Delivery

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    2011-01-01

    is based on fundamental thermodynamic relations and group contributions to properties of pure species (solvent, active ingredient and polymer) and their mixtures. The method is intended for pharmaceuticals with complex molecular structures, for which limited experimental information is known. Case studies...

  18. Designing voltage-sensitive probes for neural imaging - Insight from molecular dynamics simulations

    Czech Academy of Sciences Publication Activity Database

    Bonhenry, Daniel; Melcr, Josef; Timr, Štěpán; Lazar, Josef; Jungwirth, Pavel

    2015-01-01

    Roč. 44, Suppl 1 (2015), S162. ISSN 0175-7571. [EBSA European Biophysics Congress /10./. 18.07.2015-22.07.2015, Dresden] Institutional support: RVO:61388963 Keywords : molecular dynamics simulations * voltage-sensitive probes Subject RIV: CF - Physical ; Theoretical Chemistry

  19. Palmitate Luciferin: A molecular design for the second harmonic generation study of ion complexation at the air-water interface

    International Nuclear Information System (INIS)

    A molecular organic chromophore, Palmitate-Luciferin, has been synthesized for studying ion complexation at the air-water interface using second harmonic generation (SHG). This molecule was designed through the addition of a long hydrophobic palmitoyl alkyl chain to the aromatic π-electron system of Luciferin. We first demonstrate that this organic chromophore is a potential candidate for SHG studies of ion complexation with the measurement of its first hyper-polarizability in aqueous solutions by hyper Rayleigh scattering (HRS) with and without calcium ions. Then, we characterize the Palmitate-Luciferin surfactant properties at the air-water interface combining surface tension measurements with a surface SHG study and Brewster angle imaging. These results allow us to build a molecular description of the chromophore at the interface and observe its molecular reorganization during the monolayer compression leading to the formation of aggregates. Finally, we show that the initial goal of the designing work is achieved since Palmitate-Luciferin indeed exhibits a higher SHG response in the presence of calcium ions in the aqueous sub-phase as expected. (authors)

  20. Design rules for rational control of polymer glass formation behavior and mechanical properties with small molecular additives

    Science.gov (United States)

    Mangalara, Jayachandra Hari; Simmons, David

    Small molecule additives have long been employed to tune polymers' glass formation, mechanical and transport properties. For example, plasticizers are commonly employed to suppress polymer Tg and soften the glassy state, while antiplasticizers, which stiffen the glassy state of a polymer while suppressing its Tg, are employed to enhance protein and tissue preservation in sugar glasses. Recent literature indicates that additives can have a wide range of possible effects, but all of these have not been clearly understood and well appreciated. Here we employ molecular dynamics simulations to establish design rules for the selection of small molecule additives with size, molecular stiffness, and interaction energy chosen to achieve targeted effects on polymer properties. We furthermore find that a given additive's effect on a polymer's Tg can be predicted from its Debye-Waller factor via a function previously found to describe nanoconfinement effects on the glass transition. These results emphasize the potential for a new generation of targeted molecular additives to contribute to more targeted rational design of polymers. We acknowledge the Keck Foundation and the Ohio Supercomputing Center for financial and computational support of this effort, respectively.

  1. Design, synthesis, crystal structure, insecticidal activity, molecular docking, and QSAR studies of novel N3-substituted imidacloprid derivatives.

    Science.gov (United States)

    Wang, Mei-Juan; Zhao, Xiao-Bo; Wu, Dan; Liu, Ying-Qian; Zhang, Yan; Nan, Xiang; Liu, Huanxiang; Yu, Hai-Tao; Hu, Guan-Fang; Yan, Li-Ting

    2014-06-18

    Three novel series of N3-substituted imidacloprid derivatives were designed and synthesized, and their structures were identified on the basis of satisfactory analytical and spectral ((1)H NMR, (13)C NMR, MS, elemental analysis, and X-ray) data. Preliminary bioassays indicated that all of the derivatives exhibited significant insecticidal activities against Aphis craccivora, with LC50 values ranging from 0.00895 to 0.49947 mmol/L, and the insecticidal activities of some of them were comparable to those of the control imidacloprid. Some key structural features related to their insecticidal activities were identified, and the binding modes between target compounds and nAChR model were also further explored by molecular docking. By comparing the interaction features of imidacloprid and compound 26 with highest insecticidal activity, the origin of the high insecticidal activity of compound 26 was identified. On the basis of the conformations generated by molecular docking, a satisfactory 2D-QSAR model with six selected descriptors was built using genetic algorithm-multiple linear regression (GA-MLR) method. The analysis of the built model showed the molecular size, shape, and the ability to form hydrogen bond were important for insecticidal potency. The information obtained in the study will be very helpful for the design of new derivatives with high insecticidal activities. PMID:24834971

  2. Bio-rational design of photosystem Ⅱ inhibitors (Ⅷ)——Molecular design, synthesis and inhibitory activity of acrylates (acrylamides)

    Institute of Scientific and Technical Information of China (English)

    刘华银; 沙印林; 谭惠芬; 杨华铮; 来鲁华

    1999-01-01

    Molecular modeling of acrylates (acrylamides) with D1 protein of Pisum sativum is presented. Studies show that the binding force mainly includes H-bond interaction, Van der Waals and π-ring stacking interaction. It was found that SER 268 in D1 protein might be an important binding site. It is important for high inhibitory activity of compounds whether an electronegative atom in alkyl of ester linkage could make H-bond interaction with SER 268 in D1 protein. Thus some new acrylates (acrylamides) were designed and synthesized, Bioassay indicated that these new compounds showed expected Hill reaction inhibitory activity.

  3. Attachment bonding of delinquent adolescents

    Directory of Open Access Journals (Sweden)

    Čačić Sandra

    2013-01-01

    Full Text Available Main objective of this research is to define adolescence bonding as well as to identify their typical bonding type. The bonding was observed in two ways. The analysis was based on seven attachment dimensions that were defined by N. Hanak, as well as on the basis of Bartholomew’s four-style attachment model. The research was conducted at multiple sites: two secondary schools in Sombor, the Juvenile Correctional Institution in Kruševac and the Juvenile Correctional Facility in Niš. It included 524 persons, 421 adolescents and 103 delinquents. Adolescents are the second and the third grade students of the Secondary Technical School and the Second­ary School of Economics, while delinquents were testable juveniles. All of them are under correctional measures in the above mentioned institutions. All results are in accordance with the theoretical expectations. Delinquents attach in insecure way more frequently: 68, 9% delinquents from our sample showed insecure attachment. The fearful type of attachment appears to be typical of delinquents. Delinquents are facing difficulties in obtaining support of close persons, as well as in using significant persons they are related to as safe harbours in stressful situations. In addition, they would see themselves as not worthy of attention and love. There is a high level of painful feelings related to childhood and family, as well as ambivalent and nega­tive current family relations.

  4. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  5. Synthetic Molecular Machines for Active Self-Assembly: Prototype Algorithms, Designs, and Experimental Study

    Science.gov (United States)

    Dabby, Nadine L.

    Computer science and electrical engineering have been the great success story of the twentieth century. The neat modularity and mapping of a language onto circuits has led to robots on Mars, desktop computers and smartphones. But these devices are not yet able to do some of the things that life takes for granted: repair a scratch, reproduce, regenerate, or grow exponentially fast--all while remaining functional. This thesis explores and develops algorithms, molecular implementations, and theoretical proofs in the context of "active self-assembly" of molecular systems. The long-term vision of active self-assembly is the theoretical and physical implementation of materials that are composed of reconfigurable units with the programmability and adaptability of biology's numerous molecular machines. En route to this goal, we must first find a way to overcome the memory limitations of molecular systems, and to discover the limits of complexity that can be achieved with individual molecules. One of the main thrusts in molecular programming is to use computer science as a tool for figuring out what can be achieved. While molecular systems that are Turing-complete have been demonstrated [Winfree, 1996], these systems still cannot achieve some of the feats biology has achieved. One might think that because a system is Turing-complete, capable of computing "anything," that it can do any arbitrary task. But while it can simulate any digital computational problem, there are many behaviors that are not "computations" in a classical sense, and cannot be directly implemented. Examples include exponential growth and molecular motion relative to a surface. Passive self-assembly systems cannot implement these behaviors because (a) molecular motion relative to a surface requires a source of fuel that is external to the system, and (b) passive systems are too slow to assemble exponentially-fast-growing structures. We call these behaviors "energetically incomplete" programmable

  6. Design of optimal laser pulses to control molecular rovibrational excitation in a heteronuclear diatomic molecule

    Indian Academy of Sciences (India)

    Sitansh Sharma; Gabriel G Balint-Kurti; Harjinder Singh

    2012-01-01

    Optimal control theory in combination with time-dependent quantum dynamics is employed to design laser pulses which can perform selective vibrational and rotational excitations in a heteronuclear diatomic system. We have applied the conjugate gradient method for the constrained optimization of a suitably designed functional incorporating the desired objectives and constraints. Laser pulses designed for several excitation processes of the molecule were able to achieve predefined dynamical goals with almost 100% yield.

  7. Structure-based design and synthesis of small molecular inhibitors disturbing the interaction of MLL1-WDR5.

    Science.gov (United States)

    Li, Dong-Dong; Chen, Wei-Lin; Xu, Xiao-Li; Jiang, Fen; Wang, Lei; Xie, Yi-Yue; Zhang, Xiao-Jin; Guo, Xiao-Ke; You, Qi-Dong; Sun, Hao-Peng

    2016-08-01

    MLL1 complex catalyzes the methylation of H3K4, and plays important roles in the development of acute leukemia harboring MLL fusion proteins. Targeting MLL1-WDR5 protein-protein interaction (PPI) to inhibit the activity of histone methyltransferase of MLL1 complex is a novel strategy for treating of acute leukemia. WDR5-47 (IC50 = 0.3 μM) was defined as a potent small molecule to disturb the interaction of MLL1-WDR5. Here, we described structure-based design and synthesis of small molecular inhibitors to block MLL1-WDR5 PPI. Especially, compound 23 (IC50 = 104 nM) was the most potent small molecular, and about 3-times more potent than WDR5-47. We also discussed the SAR of these series of compounds with docking study, which may stimulate more potent compounds. PMID:27116709

  8. Pyrroloaryls and pyrroloheteroaryls: Inhibitors of the HIV fusion/attachment, reverse transcriptase and integrase.

    Science.gov (United States)

    Patel, Rahul V; Park, Se Won

    2015-09-01

    Heterocyclic compounds execute a very important role in drug design and discovery. This article provides the basic milestones of the research for pyrroloaryl and pyrroloheteroaryl based components targeting HIV viral replication cycle. Anti-HIV activity is elaborated for several classes of pyrrolo-compounds as pyrrolopyridines, pyrrolopyrimidines, pyrrolopyridazines, pyrrolobenzodiazepinones, pyrrolobenzothiazepines, pyrrolobenzoxazepinones, pyrrolophenanthridines, pyrroloquinoxalines, pyrrolotriazines, pyrroloquinolines, pyrrolopyrazinones, pyrrolothiatriazines, arylthiopyrroles and pyrrolopyrazolones targeting two essential HIV enzymes, reverse transcriptase and integrase as well as attachment/fusion of HIV virons to the host CD-4 cell. Such attempts were resulted in a discovery of highly potent anti-HIV agents suitable for clinical trials, for example, BMS-378806, BMS-585248, BMS-626529, BMS-663068, BMS-488043 and BMS-663749, etc. as anti-HIV attachment agents, triciribine, QX432, BI-1 and BI-2 as HIV RT inhibitors which are in preclinical or clinical development. Mechanism of action of compounds presented in this article towards the suppression of HIV attachment/fusion as well as against the activities of HIV enzymes reverse transcriptase and integrase has been discussed. Relationships of new compounds' molecular framework and HIV viral target has been overviewed in order to facilitate further construction of promising anti-HIV agents in future drug discovery process. PMID:26116177

  9. Hamiltonian Dynamics of Preferential Attachment

    CERN Document Server

    Zuev, Konstantin; Krioukov, Dmitri

    2015-01-01

    Prediction and control of network dynamics are grand-challenge problems in network science. The lack of understanding of fundamental laws driving the dynamics of networks is among the reasons why many practical problems of great significance remain unsolved for decades. Here we study the dynamics of networks evolving according to preferential attachment, known to approximate well the large-scale growth dynamics of a variety of real networks. We show that this dynamics is Hamiltonian, thus casting the study of complex networks dynamics to the powerful canonical formalism, in which the time evolution of a dynamical system is described by Hamilton's equations. We derive the explicit form of the Hamiltonian that governs network growth in preferential attachment. This Hamiltonian turns out to be nearly identical to graph energy in the configuration model, which shows that the ensemble of random graphs generated by preferential attachment is nearly identical to the ensemble of random graphs with scale-free degree d...

  10. Partner attachment and interpersonal characteristics.

    Science.gov (United States)

    Kilmann, Peter R; Finch, Holmes; Parnell, Michele M; Downer, Jason T

    2013-01-01

    This study investigated partner attachment and interpersonal characteristics in 134 nonclinical couples in long-term marriages. Irrespective of gender, spouses with greater anxiety over abandonment or discomfort with closeness endorsed dysfunctional relationship beliefs to a greater extent. On the anxiety over abandonment dimension, husbands with higher scores were rated less aggressive, less controlling, and more rebellious, whereas wives with higher scores were rated more dependent, more self-critical, and less competitive. Husbands higher on discomfort with closeness were rated less cooperative and responsible and were rated more aggressive and rebellious. Matched secure couples reported lower marital dissatisfaction than matched insecure or mismatched couples. Future research should contrast samples of nonclinical and clinical couples by marital duration to identify specific partner behaviors that are likely to foster marital dissatisfaction within particular attachment pairings. The authors' findings suggest the importance of marital therapists being attuned to the attachment-related beliefs and interpersonal styles uniquely operating within each couple. PMID:23252639

  11. Design, synthesis and evaluation of molecularly targeted hypoxia-activated prodrugs.

    Science.gov (United States)

    O'Connor, Liam J; Cazares-Körner, Cindy; Saha, Jaideep; Evans, Charles N G; Stratford, Michael R L; Hammond, Ester M; Conway, Stuart J

    2016-04-01

    Regions of insufficient oxygen supply-hypoxia-occur in diverse contexts across biology in both healthy and diseased organisms. The difference in the chemical environment between a hypoxic biological system and one with normal oxygen levels provides an opportunity for targeting compound delivery to hypoxic regions by using bioreductive prodrugs. Here we detail a protocol for the efficient synthesis of (1-methyl-2-nitro-1H-imidazol-5-yl)methanol, which is a key intermediate that can be converted into a range of 1-methyl-2-nitro-1H-imidazole-based precursors of bioreductive prodrugs. We outline methods for attaching the bioreductive group to a range of functionalities, and we discuss the strategy for positioning of the group on the biologically active parent compound. We have used two parent checkpoint kinase 1 (Chk1) inhibitors to exemplify the protocol. The PROCEDURE also describes a suite of reduction assays, of increasing biological relevance, to validate the bioreductive prodrug. These assays are applied to an exemplar compound, CH-01, which is a bioreductive Chk1 inhibitor. This protocol has broad applications to the development of hypoxia-targeted compounds. PMID:27010756

  12. MOLECULAR DESIGN OF FUNCTIONAL POLYMERS BASED ON UNIQUE PROPERTIES OF POLYMER CHAINS

    Institute of Scientific and Technical Information of China (English)

    Mikiharu Kamachi

    2000-01-01

    The inclusion complex formation of α-CD, β-CD, and γ-CD with various water-soluble polymers has been investigated, and the relationship between the chain cross-sectional areas of the polymers and the diameters of the cavities of cyclodextrins (molecular recognition) was found. Polyrotaxanes and tubular polymers were prepared on the basis of molecular recognition. Several kinds of polymers having tetraphenylporphyrin (TPP) and paramagnetic metallotetraphenylporphyrin (AgTPP, CuTPP, VOTPP or ZnTPP) have been prepared by radical polymerization of the corresponding monomers. Visible spectra of these polymers show hypochromism in the Soret bands of TPP moieties as compared with those of monomers. Polymer effects were observed in the magnetic behavior and oxygen adsorption of paramagnetic metallotetraphenylporphyrin moieties. Moreover, polymer effects on photophysical and photochemical behavior were found in the amphiphilic polymers covalently tethered with small amounts of zinc(Ⅱ)-tetraphenylporphyrin (ZnTPP).

  13. Molecular dynamics explorations of active site structure in designed and evolved enzymes

    OpenAIRE

    Osuna Oliveras, Sílvia; Jiménez-Osés, Gonzalo; Noey, Elizabeth L.; Houk, Kendall N.

    2015-01-01

    This Account describes the use of molecular dynamics (MD) simulations to reveal how mutations alter the structure and organization of enzyme active sites. As proposed by Pauling about 70 years ago and elaborated by many others since then, biocatalysis is efficient when functional groups in the active site of an enzyme are in optimal positions for transition state stabilization. Changes in mechanism and covalent interactions are often critical parts of enzyme catalysis. We describe our explora...

  14. Selective self-assembly of molecular clusters with designed sizes on metal surfaces

    Science.gov (United States)

    Wang, Jun; Li, Qing; Fuentes-Cabrera, Miguel; Sumpter, Bobby G.; Baddorf, Arthur P.; Pan, Minghu

    2014-03-01

    The self-assembly of ``magic'' molecular clusters on various substrates provides a new arena for studies of surface nanocatalysis and molecular electronics. Here we present the self-assembly of phenylacetylene molecules on Cu(100) by a combined low-temperature STM and in-depth density functional theory investigation. We observe the molecules form distinct tetramer clusters on Cu(100) at 40 K. Each cluster has a four-fold symmetry and consists of four molecules. A delicate balance of intramolecular and dipole-dipole interactions between clusters maintains this magic tetramer configuration on Cu(100). The strong interaction between the molecules and the copper surface creates an anchor at each adsorption site. Through comparison with our previous observed hexamer (six-molecule) clusters on Au(111), we conclude that the epitaxial relationship between the molecules and metal surfaces is crucial in defining magic numbers of surface-supported molecular clusters under weak intermolecular interaction. This research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.

  15. Synthetic Molecular Machines for Active Self-Assembly: Prototype Algorithms, Designs, and Experimental Study

    Science.gov (United States)

    Dabby, Nadine L.

    Computer science and electrical engineering have been the great success story of the twentieth century. The neat modularity and mapping of a language onto circuits has led to robots on Mars, desktop computers and smartphones. But these devices are not yet able to do some of the things that life takes for granted: repair a scratch, reproduce, regenerate, or grow exponentially fast--all while remaining functional. This thesis explores and develops algorithms, molecular implementations, and theoretical proofs in the context of "active self-assembly" of molecular systems. The long-term vision of active self-assembly is the theoretical and physical implementation of materials that are composed of reconfigurable units with the programmability and adaptability of biology's numerous molecular machines. En route to this goal, we must first find a way to overcome the memory limitations of molecular systems, and to discover the limits of complexity that can be achieved with individual molecules. One of the main thrusts in molecular programming is to use computer science as a tool for figuring out what can be achieved. While molecular systems that are Turing-complete have been demonstrated [Winfree, 1996], these systems still cannot achieve some of the feats biology has achieved. One might think that because a system is Turing-complete, capable of computing "anything," that it can do any arbitrary task. But while it can simulate any digital computational problem, there are many behaviors that are not "computations" in a classical sense, and cannot be directly implemented. Examples include exponential growth and molecular motion relative to a surface. Passive self-assembly systems cannot implement these behaviors because (a) molecular motion relative to a surface requires a source of fuel that is external to the system, and (b) passive systems are too slow to assemble exponentially-fast-growing structures. We call these behaviors "energetically incomplete" programmable

  16. MaMiCo: Software design for parallel molecular-continuum flow simulations

    Science.gov (United States)

    Neumann, Philipp; Flohr, Hanno; Arora, Rahul; Jarmatz, Piet; Tchipev, Nikola; Bungartz, Hans-Joachim

    2016-03-01

    The macro-micro-coupling tool (MaMiCo) was developed to ease the development of and modularize molecular-continuum simulations, retaining sequential and parallel performance. We demonstrate the functionality and performance of MaMiCo by coupling the spatially adaptive Lattice Boltzmann framework waLBerla with four molecular dynamics (MD) codes: the light-weight Lennard-Jones-based implementation SimpleMD, the node-level optimized software ls1 mardyn, and the community codes ESPResSo and LAMMPS. We detail interface implementations to connect each solver with MaMiCo. The coupling for each waLBerla-MD setup is validated in three-dimensional channel flow simulations which are solved by means of a state-based coupling method. We provide sequential and strong scaling measurements for the four molecular-continuum simulations. The overhead of MaMiCo is found to come at 10%-20% of the total (MD) runtime. The measurements further show that scalability of the hybrid simulations is reached on up to 500 Intel SandyBridge, and more than 1000 AMD Bulldozer compute cores.

  17. Solid state photochemistry. Subpanel A-2(a): Design of molecular precursors for electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    Wells, R.L. [Duke Univ., Durham, NC (United States)

    1996-09-01

    Recent achievements of synthetic chemistry in the field of electronic materials are presented in three categories; viz, precursor design for improved processing, new chemistry for selective growth, and new growth techniques. This is followed by a discussion of challenges and opportunities in two general areas designated as composition and structure, and growth and processing.

  18. Diameters in preferential attachment models

    OpenAIRE

    Dommers, S.; van der Hofstad, R.; Hooghiemstra, G.

    2010-01-01

    In this paper, we investigate the diameter in preferential attachment (PA-) models, thus quantifying the statement that these models are small worlds. The models studied here are such that edges are attached to older vertices proportional to the degree plus a constant, i.e., we consider affine PA-models. There is a substantial amount of literature proving that, quite generally, PA-graphs possess power-law degree sequences with a power-law exponent \\tau>2. We prove that the diameter of the PA-...

  19. Electron attachment to HCl clusters

    International Nuclear Information System (INIS)

    Negatively charged cluster ions of hydrogen chloride are formed by electron attachment to HCl clusters, which are produced in a seeded supersonic beam traversing a sustained gas discharge. Cluster ions of (HCl)n-, with n = 2, and tentatively with n = 3 and 4 are observed. Cluster ions like Cln-, Cln- (HCl)m, and with Ar attached to them are also seen. The relevance to radiation chemistry of HCl is briefly discussed. Atoms evaporating from the hot, thoriated tungsten filament of the glow discharge lead to clusters such as Thn- and its oxides. (orig.)

  20. Computational design and multivariate optimization of an electrochemical metoprolol sensor based on molecular imprinting in combination with carbon nanotubes.

    Science.gov (United States)

    Nezhadali, Azizollah; Mojarrab, Maliheh

    2016-06-14

    This work describes the development of an electrochemical sensor based on a new molecularly imprinted polymer for detection of metoprolol (MTP) at ultra-trace level. The polypyrrole (PPy) was electrochemically synthesized on the tip of a pencil graphite electrode (PGE) which modified whit functionalized multi-walled carbon nanotubes (MWCNTs). The fabrication process of the sensor was characterized by cyclic voltammetry (CV) and the measurement process was carried out by differential pulse voltammetry (DPV). A computational approach was used to screening functional monomers and polymerization solvent for rational design of molecularly imprinted polymer (MIP). Based on computational results, pyrrole and water were selected as functional monomer and polymerization solvent, respectively. Several significant parameters controlling the performance of the MIP sensor were examined and optimized using multivariate optimization methods such as Plackett-Burman design (PBD) and central composite design (CCD). Under the selected optimal conditions, MIP sensor was showed a linear range from 0.06 to 490 μmol L(-1) MTP, a limit of detection of 2.88 nmol L(-1), a highly reproducible response (RSD 3.9%) and a good selectivity in the presence of structurally related molecules. Furthermore, the applicability of the method was successfully tested with determination of MTP in real samples (tablet, and serum). PMID:27181648

  1. Attachments to the common-place

    DEFF Research Database (Denmark)

    Blok, Anders

    2015-01-01

    This article builds on ethnographic work concerning on-going collective efforts in the Japanese city of Kyoto aiming to reposition a vernacular style of wooden housing, known as kyō-machiya, into a hybrid eco-design widely considered an appropriate local response to the global challenges of climate...... change. To understand the dynamic interplay of architecture and community-building in this case, the article stages a theoretical debate on the politics of shared attachments between three proponents of French pragmatic sociology: Bruno Latour, Antoine Hennion, and Laurent Thévenot. Drawing in particular...

  2. Design and synthesis of a fluorescent molecular imprinted polymer for use in an optical fibre-based cocaine sensor

    Science.gov (United States)

    Wren, Stephen P.; Piletsky, Sergey A.; Karim, Kal; Gascoine, Paul; Lacey, Richard; Sun, Tong; Grattan, Kenneth T. V.

    2014-05-01

    Previously, we have developed chemical sensors using fibre optic-based techniques for the detection of Cocaine, utilising molecularly imprinted polymers (MIPs) containing fluorescein moieties as the signalling groups. Here, we report the computational design of a fluorophore which was incorporated into a MIP for the generation of a novel sensor that offers improved sensitivity for Cocaine with a detection range of 1-100μM. High selectivity for Cocaine over a suite of known Cocaine interferants (25μM) was also demonstrated by measuring changes in the intensity of fluorescence signals received from the sensor.

  3. Design of supramolecular ordered systems for mesoscopic colloids and molecular composites. Progress report, November 10, 1993--June 10, 1994

    International Nuclear Information System (INIS)

    During this reporting period, the authors group has been active in five areas of research: (1) improvements on their x-ray instrumentation at the SUNY Beamline, National Synchrotron Light Source (NSLS) so that they can perform new experiments which are not accessible otherwise; (2) characterization of functionalized hairy rod polymers designed for studying the macromolecular structures in molecular composites; (3) investigation of supramolecular ordered systems composed mainly of block copolymers from dilute to concentrated solutions, including the gel state; (4) evolution of crystalline structures in polymer blends and melts; and (5) multiphase structure of segment polyurethanes

  4. Guest-responsive structural adaptation of a rationally-designed molecular tweezer based on Tröger’s base

    Indian Academy of Sciences (India)

    Ishita Neogi; Alankriti Bajpai; Jarugu Narasimha Moorthy

    2014-09-01

    We have designed and synthesized a modified Tröger’s base TB in which the sterically-rigidified aryl rings that protrude into its groove were envisaged to preclude self-inclusion. From a limited preliminary experimentation, TB has been found to exhibit guest inclusion. The X-ray determined structures of the crystals of guest-free TB and its inclusion compounds with acetonitrile and -dichlorobenzene reveal remarkable adaptability of the TB core to undergo subtle structural changes in response to the guest that is included. The structural analyses demonstrate the fact that TB behaves like a molecular tweezer.

  5. Structural Interfaces and Attachments in Biology

    CERN Document Server

    Birman, Victor; Genin, Guy

    2013-01-01

    Attachment of dissimilar materials in engineering and surgical practice is a perennial challenge. Bimaterial attachment sites are common locations for injury, repeated injury, and mechanical failure. Nature presents several highly effective solutions to the challenge of bimaterial attachment that differ from those found in engineering practice. Structural Interfaces and Attachments in Biology describes the attachment of dissimilar materials from multiple perspectives. The text will simultaneously elucidate natural bimaterial attachments and outline engineering principles underlying successful attachments to the communities of tissue engineers and surgeons. Included an in-depth analysis of the biology of attachments in the body and mechanisms by which robust attachments are formed, a review of current concepts of attaching dissimilar materials in surgical practice and a discussion of bioengineering approaches that are currently being developed. This book also: Provides the first comprehensive treatment of phys...

  6. Attachment to inanimate objects and early childcare: A twin study

    Science.gov (United States)

    Fortuna, Keren; Baor, Liora; Israel, Salomon; Abadi, Adi; Knafo, Ariel

    2014-01-01

    Extensive non-maternal childcare plays an important role in children’s development. This study examined a potential coping mechanism for dealing with daily separation from caregivers involved in childcare experience – children’s development of attachments toward inanimate objects. We employed the twin design to estimate relative environmental and genetic contributions to the presence of object attachment, and assess whether childcare explains some of the environmental variation in this developmental phenomenon. Mothers reported about 1122 3-year-old twin pairs. Variation in object attachment was accounted for by heritability (48%) and shared environment (48%), with childcare quantity accounting for 2.2% of the shared environment effect. Children who spent half-days in childcare were significantly less likely to attach to objects relative to children who attended full-day childcare. PMID:24904499

  7. Attachment to Inanimate Objects and Early Childcare: A Twin Study

    Directory of Open Access Journals (Sweden)

    Keren Fortuna

    2014-05-01

    Full Text Available Extensive nonmaternal childcare plays an important role in children's development. This study examined a potential coping mechanism for dealing with daily separation from caregivers involved in childcare experience—children's development of attachments toward inanimate objects. We employed the twin design to estimate relative environmental and genetic contributions to the presence of object attachment, and assess whether childcare explains some of the environmental variation in this developmental phenomenon. Mothers reported about 1122 3-year-old twin pairs. Variation in object attachment was accounted for by heritability (48% and shared environment (48%, with childcare quantity accounting for 2.2% of the shared environment effect. Children who spent half-days in childcare were significantly less likely to attach to objects relative to children who attended full-day childcare.

  8. CD Attached with Books Management System Management System Based on Struts2 File upload Module Design%基于Struts2的随书光盘管理系统文件上传模块设计

    Institute of Scientific and Technical Information of China (English)

    夏宇红; 夏文忠

    2013-01-01

    为有效解决随书光盘文件的上传,以Struts2框架的Common-FileUpload组件为基础,讨论了使用Struts2框架上传文件的开发配置,在满足随书光盘系统功能的情况下,优化系统功能,保证系统性能稳定,方便管理员和读者的使用.%To effectively solve the file upload of CD attached with books, on the basis of the Struts2 framework, Common-FileUpload components, discussed the development configuration using the Struts2 framework, upload files, in the case of system functions meet the CD attached with books, the optimization of system function, system performance is stable, convenient the use of the librarians and readers.

  9. Abnormality Detection in Correlated Gaussian Molecular Nano-Networks: Design and Analysis

    OpenAIRE

    Ghavami, Siavash; Lahouti, Farshad

    2016-01-01

    A nano abnormality detection scheme (NADS) in molecular nano-networks is studied. This is motivated by the fact that early detection of diseases such as cancer play a crucial role in their successful treatment. The proposed NADS is in fact a two-tier network of sensor nano-machines (SNMs) in the first tier and a data-gathering node (DGN) at the sink. The SNMs detect the presence of competitor cells (abnormality) by variations in input and/or parameters of a nano-communications channel (NCC). ...

  10. Personality and attachment to romantic partners

    OpenAIRE

    Marušić, Iris; Kamenov, Željka; Jelić, Margareta

    2007-01-01

    Since Hazan and Shaver formulated their theory of adult romantic attachment in the late 1980's (Hazan & Shaver, 1987), attachment theory has become one of the principal theoretical frameworks for the study of intimate relationships in adulthood. It conceptualizes romantic love, or couple bonding, as an attachment process that reflects the same kinds of individual differences as infant-parent attachment. However, this idea is not a new one. Although attachment theory (Bowlby, 1969) was origina...

  11. Attachment patterns and separation anxiety symptom

    OpenAIRE

    Sakineh - Mofrad; Rohani - Abdullah; Ikechkwu - Uba

    2010-01-01

    Literature suggests that child attachment and anxiety symptoms are related. One purpose of the present study was to assess whether attachment patterns related differently to separation anxiety symptoms (fear of being alone, and fear of abandonment). Three attachment patterns assessed were secure, avoidant and ambivalent attachment. Findings indicated that ambivalent attachment was most consistently related with higher separation anxiety symptom. And also, different associations were found bet...

  12. PRECISION ATTACHMENTS; APPLICATIONS AND LIMITATIONS

    Directory of Open Access Journals (Sweden)

    Prabhakar

    2012-12-01

    Full Text Available ABSTRACT: A unique concern of a removable denture when compare d to others is retention. Retention is the ability of the prosthesis to resist the movement of denture away from the supporting tissues/teeth. The component of removable d enture which provides retention is called as direct retainer. 1,3,4 A direct retainer can be either an extracoronal or intracoronal retainer. Extracoronal direct retainer uses mechanical resistance to displa cement through components placed on external surface of abutment teeth. Intracoronal retainer is either cast or attached to tally within the restored natural contours of an abutment tooth. 1 One of the main drawbacks of extracoronal retainers used in partial dentures is visibility. Many patients find themselves in an aest hetically compromised state when these retainers are placed on teeth in visible area. Preci sion attachments provide solution for this problem. Also, precision attachments provide better ve rtical support and better stimulation to the underlying tissue through intermittent vertical massage. 1,9 Although the history of intracoronal retainers goes back to 5 th and 4 th centuries BC, technically more sound developments began in early 2 0 th century AD, with Dr. Herman E. S. Chayes formulating the principle of internal attachme nt in 1906. Since then precision attachments are playing an important role in removabl e and fixed partial denture, conventional and implant supported overdenture. 9

  13. Molecular recognition in the human immunodeficiency virus capsid and antiviral design.

    Science.gov (United States)

    Bocanegra, Rebeca; Rodríguez-Huete, Alicia; Fuertes, Miguel Ángel; Del Álamo, Marta; Mateu, Mauricio G

    2012-11-01

    Many compounds able to interfere with HIV-1 infection have been identified; some 25 of them have been approved for clinical use. Current anti-HIV-1 therapy involves the use of drug cocktails, which reduces the probability of virus escape. However, many issues remain, including drug toxicity and the emergence of drug-resistant mutant viruses, even in treated patients. Therefore, there is a constant need for the development of new anti-HIV-1 agents targeting other molecules in the viral cycle. The capsid protein CA plays a key role in many molecular recognition events during HIV-1 morphogenesis and uncoating, and is eliciting increased interest as a promising target for antiviral intervention. This article provides a structure-based, integrated review on the CA-binding small molecules and peptides identified to date, and their effects on virus capsid assembly and stability, with emphasis on recent results not previously reviewed. As a complement, we present novel experimental results on the development and proof-of-concept application of a combinatorial approach to study molecular recognition in CA and its inhibition by peptide compounds. PMID:22728445

  14. Design, synthesis, α-glucosidase inhibitory activity, molecular docking and QSAR studies of benzimidazole derivatives

    Science.gov (United States)

    Dinparast, Leila; Valizadeh, Hassan; Bahadori, Mir Babak; Soltani, Somaieh; Asghari, Behvar; Rashidi, Mohammad-Reza

    2016-06-01

    In this study the green, one-pot, solvent-free and selective synthesis of benzimidazole derivatives is reported. The reactions were catalyzed by ZnO/MgO containing ZnO nanoparticles as a highly effective, non-toxic and environmentally friendly catalyst. The structure of synthesized benzimidazoles was characterized using spectroscopic technics (FT-IR, 1HNMR, 13CNMR). Synthesized compounds were evaluated for their α-glucosidase inhibitory potential. Compounds 3c, 3e, 3l and 4n were potent inhibitors with IC50 values ranging from 60.7 to 168.4 μM. In silico studies were performed to explore the binding modes and interactions between enzyme and synthesized benzimidazoles. Developed linear QSAR model based on density and molecular weight could predict bioactivity of newly synthesized compounds well. Molecular docking studies revealed the availability of some hydrophobic interactions. In addition, the bioactivity of most potent compounds had good correlation with estimated free energy of binding (ΔGbinding) which was calculated according to docked best conformations.

  15. Computer aided-molecular design of high performance nano-carbon materials: Na+ on graphenes

    International Nuclear Information System (INIS)

    The electronic states of sodium ion (Na+) trapped on the model surfaces of amorphous carbon have been investigated by means of hybrid density functional theory (DFT) calculations to elucidate the nature of interaction between Na+/Na and the amorphous carbon surfaces. Also, direct molecular orbital-molecular dynamics (MO-MD) calculation [Tachikawa and Shimizu, J. Phys. Chem. B, 110 (2006) 20445] was applied to diffusion processes of the Na+ ion on the model surface of amorphous carbon. Seven models of graphene sheets (n = 7, 14, 19, 29, 37, 44 and 52, where n means numbers of rings in each carbon cluster) were considered in the present study. The B3LYP/LANL2MB calculations showed that the sodium ion is located at 2.24-2.26 A from the graphene surfaces. The direct MO-MD calculations showed that the Na+ ion diffuses freely on the surface above 300 K. At higher temperature (1100 K), the Na+ ion moved from the center to edge region of the model surface. The nature of the interaction between Na+ and the amorphous carbon surfaces was discussed on the basis of theoretical results

  16. Design, modeling and control of a piezoelectric ultrasonic microdissection technique for the molecular analysis of tissue

    International Nuclear Information System (INIS)

    Molecular techniques are transforming our understanding of cellular function and disease. However, accurate molecular analysis methods will be limited if the input DNA, RNA or protein is not derived from a pure population of cells or is contaminated by the wrong cells. The modeling and control of the piezoelectric actuator, with an objective application towards ultrasonic vibration cutting (UVC), is addressed in this paper. The piezoelectric actuator is used in realizing the fast and precise movements of the developed UVC so as to procure a pure population of targeted cells from tissue sections for subsequent pathology analysis with precision and without causing a large deformation. To address the nonlinearities and uncertainties of the piezoelectric actuator, an adaptive controller based on a hysteresis model is proposed to yield robust control performance. A multilayer piezoelectric actuator is used to actuate a sharp needle vibrating at high frequency and low amplitude to cut the tissue. Experimental results showed that the embedded tissue can be quickly and precisely cut with this ultrasonic vibration microdissection method

  17. Sensitivity analysis of Computer-aided molecular design problem for the development of novel working fluids for power cycles

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    is vital. Multi-criteria database search and Computer Aided Molecular Design(CAMD) can be applied to generate, test and evaluate promising pure component/mixture candidate as process fluids to help optimize cycle design and performance. The problem formulation for the development of novel working...... technical tool to convert this waste heat into usable energy. So far the low-temperature heat cannot be utilized efficiently for electricity generation.In order to optimize the heat transfer process and the power generation, the influence of the working fluid, the cycledesigns and the operating conditions......, in this study, we propose the use of sensitivity analysis. The sensitivity analysis, among others,provides using information concerning the influence of a certain property of a candidate working fluid on the performanceof the power cycle, i.e. the net power output in this particular application. This...

  18. Design of Far-Red Sensitizing Squaraine Dyes Aiming Towards the Fine Tuning of Dye Molecular Structure.

    Science.gov (United States)

    Morimoto, Takuya; Fujikawa, Naotaka; Ogomi, Yuhei; Pandey, Shyam S; Ma, Tingli; Hayase, Shuzi

    2016-04-01

    Model squaraine dyes having sharp and narrow absorptions mainly in the far-red wavelength region has been logically designed, synthesized and used for their application as sensitizer in the dyesensitized solar cells (DSSC). In order to have fine control on energetics, dyes having same mother core and alkyl chain length varying only in molecular symmetry and position of substituent were designed. It has been found that even keeping all other structural factor constant, only positional variation of substituent leads to not only in the variation of energetics by 0.1 eV but affects the photovoltaic characteristics also. Optimum concentration of dye de-aggregating agent was found to be 100 times with respect to the sensitizing dye concentration. Amongst dyes utilized in this work best performance was obtained for unsymmetrical dye SQ-40 giving a photoconversion efficiency of 4.01% under simulated solar irradiation at global AM 1.5. PMID:27451618

  19. MaMiCo: Software design for parallel molecular-continuum flow simulations

    KAUST Repository

    Neumann, Philipp

    2015-11-19

    The macro-micro-coupling tool (MaMiCo) was developed to ease the development of and modularize molecular-continuum simulations, retaining sequential and parallel performance. We demonstrate the functionality and performance of MaMiCo by coupling the spatially adaptive Lattice Boltzmann framework waLBerla with four molecular dynamics (MD) codes: the light-weight Lennard-Jones-based implementation SimpleMD, the node-level optimized software ls1 mardyn, and the community codes ESPResSo and LAMMPS. We detail interface implementations to connect each solver with MaMiCo. The coupling for each waLBerla-MD setup is validated in three-dimensional channel flow simulations which are solved by means of a state-based coupling method. We provide sequential and strong scaling measurements for the four molecular-continuum simulations. The overhead of MaMiCo is found to come at 10%-20% of the total (MD) runtime. The measurements further show that scalability of the hybrid simulations is reached on up to 500 Intel SandyBridge, and more than 1000 AMD Bulldozer compute cores. Program summary: Program title: MaMiCo. Catalogue identifier: AEYW_v1_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEYW_v1_0.html Program obtainable from: CPC Program Library, Queen\\'s University, Belfast, N. Ireland. Licensing provisions: BSD License. No. of lines in distributed program, including test data, etc.: 67905. No. of bytes in distributed program, including test data, etc.: 1757334. Distribution format: tar.gz. Programming language: C, C++II. Computer: Standard PCs, compute clusters. Operating system: Unix/Linux. RAM: Test cases consume ca. 30-50 MB. Classification: 7.7. External routines: Scons (http:www.scons.org), ESPResSo, LAMMPS, ls1 mardyn, waLBerla. Nature of problem: Coupled molecular-continuum simulation for multi-resolution fluid dynamics: parts of the domain are resolved by molecular dynamics whereas large parts are covered by a CFD solver, e.g. a lattice Boltzmann automaton

  20. Energy Decomposition Analysis Based on Absolutely Localized Molecular Orbitals for Large-Scale Density Functional Theory Calculations in Drug Design.

    Science.gov (United States)

    Phipps, M J S; Fox, T; Tautermann, C S; Skylaris, C-K

    2016-07-12

    We report the development and implementation of an energy decomposition analysis (EDA) scheme in the ONETEP linear-scaling electronic structure package. Our approach is hybrid as it combines the localized molecular orbital EDA (Su, P.; Li, H. J. Chem. Phys., 2009, 131, 014102) and the absolutely localized molecular orbital EDA (Khaliullin, R. Z.; et al. J. Phys. Chem. A, 2007, 111, 8753-8765) to partition the intermolecular interaction energy into chemically distinct components (electrostatic, exchange, correlation, Pauli repulsion, polarization, and charge transfer). Limitations shared in EDA approaches such as the issue of basis set dependence in polarization and charge transfer are discussed, and a remedy to this problem is proposed that exploits the strictly localized property of the ONETEP orbitals. Our method is validated on a range of complexes with interactions relevant to drug design. We demonstrate the capabilities for large-scale calculations with our approach on complexes of thrombin with an inhibitor comprised of up to 4975 atoms. Given the capability of ONETEP for large-scale calculations, such as on entire proteins, we expect that our EDA scheme can be applied in a large range of biomolecular problems, especially in the context of drug design. PMID:27248370

  1. Photomobile polymer materials with crosslinked liquid-crystalline structures: molecular design, fabrication, and functions.

    Science.gov (United States)

    Ube, Toru; Ikeda, Tomiki

    2014-09-22

    Crosslinked liquid-crystalline polymer materials that macroscopically deform when irradiated with light have been extensively studied in the past decade because of their potential in various applications, such as microactuators and microfluidic devices. The basic motions of these materials are contraction-expansion and bending-unbending, which are observed mainly in polysiloxanes and polyacrylates that contain photochromic moieties. Other sophisticated motions such as twisting, oscillation, rotation, and translational motion have also been achieved. In recent years, efforts have been made to improve the photoresponsive and mechanical properties of this novel class of materials through the modification of molecular structures, development of new fabrication methods, and construction of composite structures. Herein, we review structures, functions, and working mechanisms of photomobile materials and recent advances in this field. PMID:25196371

  2. A modular design of molecular qubits to implement universal quantum gates

    Science.gov (United States)

    Ferrando-Soria, Jesús; Moreno Pineda, Eufemio; Chiesa, Alessandro; Fernandez, Antonio; Magee, Samantha A.; Carretta, Stefano; Santini, Paolo; Vitorica-Yrezabal, Iñigo J.; Tuna, Floriana; Timco, Grigore A.; McInnes, Eric J. L.; Winpenny, Richard E. P.

    2016-04-01

    The physical implementation of quantum information processing relies on individual modules--qubits--and operations that modify such modules either individually or in groups--quantum gates. Two examples of gates that entangle pairs of qubits are the controlled NOT-gate (CNOT) gate, which flips the state of one qubit depending on the state of another, and the gate that brings a two-qubit product state into a superposition involving partially swapping the qubit states. Here we show that through supramolecular chemistry a single simple module, molecular {Cr7Ni} rings, which act as the qubits, can be assembled into structures suitable for either the CNOT or gate by choice of linker, and we characterize these structures by electron spin resonance spectroscopy. We introduce two schemes for implementing such gates with these supramolecular assemblies and perform detailed simulations, based on the measured parameters including decoherence, to demonstrate how the gates would operate.

  3. A modular design of molecular qubits to implement universal quantum gates

    Science.gov (United States)

    Ferrando-Soria, Jesús; Moreno Pineda, Eufemio; Chiesa, Alessandro; Fernandez, Antonio; Magee, Samantha A.; Carretta, Stefano; Santini, Paolo; Vitorica-Yrezabal, Iñigo J.; Tuna, Floriana; Timco, Grigore A.; McInnes, Eric J.L.; Winpenny, Richard E.P.

    2016-01-01

    The physical implementation of quantum information processing relies on individual modules—qubits—and operations that modify such modules either individually or in groups—quantum gates. Two examples of gates that entangle pairs of qubits are the controlled NOT-gate (CNOT) gate, which flips the state of one qubit depending on the state of another, and the gate that brings a two-qubit product state into a superposition involving partially swapping the qubit states. Here we show that through supramolecular chemistry a single simple module, molecular {Cr7Ni} rings, which act as the qubits, can be assembled into structures suitable for either the CNOT or gate by choice of linker, and we characterize these structures by electron spin resonance spectroscopy. We introduce two schemes for implementing such gates with these supramolecular assemblies and perform detailed simulations, based on the measured parameters including decoherence, to demonstrate how the gates would operate. PMID:27109358

  4. A modular design of molecular qubits to implement universal quantum gates.

    Science.gov (United States)

    Ferrando-Soria, Jesús; Moreno Pineda, Eufemio; Chiesa, Alessandro; Fernandez, Antonio; Magee, Samantha A; Carretta, Stefano; Santini, Paolo; Vitorica-Yrezabal, Iñigo J; Tuna, Floriana; Timco, Grigore A; McInnes, Eric J L; Winpenny, Richard E P

    2016-01-01

    The physical implementation of quantum information processing relies on individual modules-qubits-and operations that modify such modules either individually or in groups-quantum gates. Two examples of gates that entangle pairs of qubits are the controlled NOT-gate (CNOT) gate, which flips the state of one qubit depending on the state of another, and the gate that brings a two-qubit product state into a superposition involving partially swapping the qubit states. Here we show that through supramolecular chemistry a single simple module, molecular {Cr7Ni} rings, which act as the qubits, can be assembled into structures suitable for either the CNOT or gate by choice of linker, and we characterize these structures by electron spin resonance spectroscopy. We introduce two schemes for implementing such gates with these supramolecular assemblies and perform detailed simulations, based on the measured parameters including decoherence, to demonstrate how the gates would operate. PMID:27109358

  5. Design, synthesis and molecular docking studies of novel triazole antifungal compounds

    Institute of Scientific and Technical Information of China (English)

    Qiu Qin He; Ke Li; Yong Bing Cao; Huan Wen Dong; Li Hua Zhao; Chao Mei Liu; Chun Quan Sheng

    2007-01-01

    Based on the active site of Candida albicans lanosterol 14α-demethylase (CACYP51), novel triazole compounds structurally different from the current triazole drugs were designed and synthesized.In vitro antifungal activities showed that compounds 10,11,16 and 20 exhibited strong activities.In addition, compounds 10,11 and 16 also displayed certain activities against fluconazole-resistant fungi.

  6. From Molecular to Macroscopic via the Rational Design of a Self-Assembled 3D DNA Crystal

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, J.; Birktoft, J; Yi, C; Tong, W; Ruojie, S; Constantinou, P; Ginell, S; Chenge, M; Seeman, N

    2009-01-01

    We live in a macroscopic three-dimensional (3D) world, but our best description of the structure of matter is at the atomic and molecular scale. Understanding the relationship between the two scales requires a bridge from the molecular world to the macroscopic world. Connecting these two domains with atomic precision is a central goal of the natural sciences, but it requires high spatial control of the 3D structure of matter1. The simplest practical route to producing precisely designed 3D macroscopic objects is to form a crystalline arrangement by self-assembly, because such a periodic array has only conceptually simple requirements: a motif that has a robust 3D structure, dominant affinity interactions between parts of the motif when it self-associates, and predictable structures for these affinity interactions. Fulfilling these three criteria to produce a 3D periodic system is not easy, but should readily be achieved with well-structured branched DNA motifs tailed by sticky ends2. Complementary sticky ends associate with each other preferentially and assume the well-known B-DNA structure when they do so3; the helically repeating nature of DNA facilitates the construction of a periodic array. It is essential that the directions of propagation associated with the sticky ends do not share the same plane, but extend to form a 3D arrangement of matter. Here we report the crystal structure at 4?Angstroms resolution of a designed, self-assembled, 3D crystal based on the DNA tensegrity triangle4. The data demonstrate clearly that it is possible to design and self-assemble a well-ordered macromolecular 3D crystalline lattice with precise control.

  7. Creation of stable molecular junctions with a custom-designed scanning tunneling microscope

    International Nuclear Information System (INIS)

    The scanning tunneling microscope break junction (STMBJ) technique is a powerful approach for creating single-molecule junctions and studying electrical transport in them. However, junctions created using the STMBJ technique are usually mechanically stable for relatively short times (<1 s), impeding detailed studies of their charge transport characteristics. Here, we report a custom-designed scanning tunneling microscope that enables the creation of metal–single molecule–metal junctions that are mechanically stable for more than 1 minute at room temperature. This stability is achieved by a design that minimizes thermal drift as well as the effect of environmental perturbations. The utility of this instrument is demonstrated by performing transition voltage spectroscopy—at the single-molecule level—on Au–hexanedithiol–Au, Au–octanedithiol–Au and Au–decanedithiol–Au junctions.

  8. Design of novel porous melamine-formaldehyde materials for molecular recognition

    OpenAIRE

    Meghani, Lina

    2011-01-01

    Porous materials have played a pivotal role in the hosting of guest species. They provide a good diffusion medium, display high surface area and often the pores are size specific and bear the correct functionality to enhance retention of analytes. This work shows how such materials, based on melamine-formaldehyde (MF) chemistry are designed. The melamine motif has been known to form supramolecular aggregates in solution with other triazine-containing molecules. It was, thus, anticipated t...

  9. Molecular design of Calix[4]arene derivatives for uranyl ion extraction from aqueous media

    International Nuclear Information System (INIS)

    Uranyl ion extraction is an important part of nuclear waste reprocessing. Use of organic ligands having chelating property with uranyl ions is a promising tool in this area, because of the possibility to improve the selectivity and the affinity of the ligands towards uranyl ions. In this study, Calix[4]arene derivatives containing B, Al, C, Si, N, P, O and S elements in bridging positions were designed and their chelating energetics with uranyl cation are calculated by means of DFT methods.

  10. Nonlinear relaxation dynamics in elastic networks and design principles of molecular machines

    OpenAIRE

    Togashi, Y.; A. Mikhailov

    2007-01-01

    Analyzing nonlinear conformational relaxation dynamics in elastic networks corresponding to two classical motor proteins, we find that they respond by well defined internal mechanical motions to various initial deformations and that these motions are robust against external perturbations. We show that this behavior is not characteristic for random elastic networks. However, special network architectures with such properties can be designed by evolutionary optimization methods. Using them, an ...

  11. ATTACHMENTS IN PROSTHODONTICS: DIFFERENT SYSTEMS OF CLASSIFICATION: A REVIEW

    Directory of Open Access Journals (Sweden)

    Khuthija Khanam

    2014-07-01

    Full Text Available Attachments are mechanical devices for the fixation and stabilisation of a dental prosthesis and include frictional, internal, intracoronal, extracoronal, key-key way, parallel, precision and slotted types. (Boucher 1976. Attachments are used as alternative to clasps in removable partial denture therapy for both aesthetic and functional purpose. Their application is not only limited to removable partial dentures, but has a broader usage in fixed bridges, overdentures, implant supported dentures as well. Hundreds of attachments are available commercially and significant differences exist between them. In this article, different systems of classification of attachments have been reviewed. They are categorised as precision and semi-precision depending on the method of manufacture, intracoronal and extra coronal depending on their location relative to the abutment tooth, rigid and resilient determined by the amount of movement allowed between the component parts, also as stud and bar attachments depending on the design. A classification system to more accurately evaluate differences among resilient attachments has also been described here.

  12. [First clinical experiences with ceramic ball attachments for overdentures].

    Science.gov (United States)

    Büttel, Adrian E; Schmidli, Fredy; Marinello, Carlo P; Lüthy, Heinz

    2008-01-01

    In this prospective clinical study on 40 patients with similar clinical conditions (edentulous jaw with 2 interforaminal implants) commercially available ceramic ball attachments (ruby) were compared to commercial titanium ball attachments. The primary aim of the study was to measure the wear of the ball attachments after being 1 year in function. However, in the course of the study already after 7 to 12 months multiple failures with ceramic ball attachments occurred. Twelve (28%) of 43 ceramic ball attachments had to be replaced, mostly because of fractures (8) of the ceramic ball. It seems that ceramic ball attachments of the investigated design are not able to withstand normal intraoral stresses. The short-term susceptibility to fractures didn't allow to examine the ceramic-inherent features such as compressive strength and wear resistance. Furthermore, a secure connection between a titan base and a ceramic ball seems to be challenging. Based on these results, in implant-retained removable prosthesis the use of metal-based retainers is still recommended, although during maintenance a higher wear has to be expected. This wear can be compensated by either activating or changing the matrix or the patrix. PMID:18293602

  13. Iodine atoms: a new molecular feature for the design of potent transthyretin fibrillogenesis inhibitors.

    Directory of Open Access Journals (Sweden)

    Teresa Mairal

    Full Text Available The thyroid hormone and retinol transporter protein known as transthyretin (TTR is in the origin of one of the 20 or so known amyloid diseases. TTR self assembles as a homotetramer leaving a central hydrophobic channel with two symmetrical binding sites. The aggregation pathway of TTR into amiloid fibrils is not yet well characterized but in vitro binding of thyroid hormones and other small organic molecules to TTR binding channel results in tetramer stabilization which prevents amyloid formation in an extent which is proportional to the binding constant. Up to now, TTR aggregation inhibitors have been designed looking at various structural features of this binding channel others than its ability to host iodine atoms. In the present work, greatly improved inhibitors have been designed and tested by taking into account that thyroid hormones are unique in human biochemistry owing to the presence of multiple iodine atoms in their molecules which are probed to interact with specific halogen binding domains sitting at the TTR binding channel. The new TTR fibrillogenesis inhibitors are based on the diflunisal core structure because diflunisal is a registered salicylate drug with NSAID activity now undergoing clinical trials for TTR amyloid diseases. Biochemical and biophysical evidence confirms that iodine atoms can be an important design feature in the search for candidate drugs for TTR related amyloidosis.

  14. Iodine atoms: a new molecular feature for the design of potent transthyretin fibrillogenesis inhibitors.

    Science.gov (United States)

    Mairal, Teresa; Nieto, Joan; Pinto, Marta; Almeida, Maria Rosário; Gales, Luis; Ballesteros, Alfredo; Barluenga, José; Pérez, Juan J; Vázquez, Jesús T; Centeno, Nuria B; Saraiva, Maria Joao; Damas, Ana M; Planas, Antoni; Arsequell, Gemma; Valencia, Gregorio

    2009-01-01

    The thyroid hormone and retinol transporter protein known as transthyretin (TTR) is in the origin of one of the 20 or so known amyloid diseases. TTR self assembles as a homotetramer leaving a central hydrophobic channel with two symmetrical binding sites. The aggregation pathway of TTR into amiloid fibrils is not yet well characterized but in vitro binding of thyroid hormones and other small organic molecules to TTR binding channel results in tetramer stabilization which prevents amyloid formation in an extent which is proportional to the binding constant. Up to now, TTR aggregation inhibitors have been designed looking at various structural features of this binding channel others than its ability to host iodine atoms. In the present work, greatly improved inhibitors have been designed and tested by taking into account that thyroid hormones are unique in human biochemistry owing to the presence of multiple iodine atoms in their molecules which are probed to interact with specific halogen binding domains sitting at the TTR binding channel. The new TTR fibrillogenesis inhibitors are based on the diflunisal core structure because diflunisal is a registered salicylate drug with NSAID activity now undergoing clinical trials for TTR amyloid diseases. Biochemical and biophysical evidence confirms that iodine atoms can be an important design feature in the search for candidate drugs for TTR related amyloidosis. PMID:19125186

  15. Plant cell walls throughout evolution: towards a molecular understanding of their design principles

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Purbasha; Bosneaga, Elena; Auer, Manfred

    2009-02-16

    Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche,which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway.

  16. Application of an R-group search technique into molecular design of HIV-1 integrase inhibitors

    Directory of Open Access Journals (Sweden)

    Tong Jian-Bo

    2016-01-01

    Full Text Available In this paper, a three-dimensional quantitative structure-activity relationship (3D-QSAR study for 62 HIV-1 integrase(IN inhibitors was established using Topomer CoMFA. The multiple correlation coefficient of fitting, cross validation and external validation were 0.942, 0.670 and 0.748, respectively. The results indicated that the Topomer CoMFA model obtained has both favorable estimation stability and good prediction capability. Topomer Search was used to search R group from ZINC database. As the result, a series of R groups with relatively high activity contribution was obtained. By filtering with the most potent molecule in the set, 1 Ra group and 21 Rb groups were selected. We employed the 1 Ra groups and 21 Rb groups to alternately substitute the Ra and Rb of sample 42. Finally, we designed 21 new compounds and further predicted their activities using the Topomer CoMFA model and there were 10 new compounds with higher activity than that of the template molecule. The results suggested the Topomer Search technology could be effectively used to screen and design new HIV-1 IN inhibitors and has good predictive capability to guide the design of new HIV/AIDS drugs.

  17. Stud attachments for the mandibular implant-retained overdentures: Prosthetic complications. A literature review.

    Science.gov (United States)

    Daou, Elie E

    2013-04-01

    A plethora of attachment systems for mandibular two-implant overdentures is currently available often without evidence-based support. Technical aspects are now parameters considered when choosing the appropriate attachment. Despite the increasing use of the Locator attachments, studies regarding their properties remain scarce. Peer reviewed articles published in English up to 2011, were identified through a MEDLINE search (Pubmed and Elsevier) and a hand search of relevant textbooks and annual publications. Emphasis was made on the technical complications as well as the loss of retention related to the attachments in implant-retained overdentures, primarily the Locator attachment. The evaluation of the long-term outcome of implant overdentures and complications associated with different attachment systems may provide useful guidelines for the clinician in selecting the type of attachment system and overdenture design. PMID:23960557

  18. Design of Multiplex Polymerase Chain Reaction (PCR Method for Molecular Detection of Yersinia pestis Bacterium

    Directory of Open Access Journals (Sweden)

    Mohammad Soleimani

    2010-01-01

    Full Text Available Objective: Yersinia pestis, the causative agent of the zoonotic plague infection, is a majorpublic health concern both as a threat and potential bioweapon. The objective of thepresent study was to establish a uniplex and multiplex - polymerase chain reaction (PCRtest for the specific detection of Y. pestis.Materials and Methods: PCR reactions performed by three pair primers which targetedthe caf1 and pla genes located on the pFra and pPst plasmids and the irp2 chromosomalgene located on the ‘pathogenicity island’. After TA cloning of the PCR products, the test’slimit of detection (LOD was determined. For evaluating the specificity, PCR reactionswere performed with negative control bacteria.Results: Assays were performed with the genome of Y. pestis which produced three DNAfragments of the expected sizes 300, 400 and 520 bp which corresponded to the irp2,caf1 and pla genes, respectively. The lower LoD was 370 copy numbers for the caf1 geneand 21 for the pla gene. In PCR reactions that used negative control bacteria, detectablefragments were not observed.Conclusion: Our method clearly discriminated Y. pestis DNA. The rapidity, specificityand sensitivity of this procedure suggest that it can serve as a useful alternative methodfor the inoculation of laboratory animals or the use of specific culture media for routineplaque surveillance and outbreak investigations. Another vital result of this study was theestablishment of Y. pestis molecular detection technique in Iran.

  19. In Silico Design of Human IMPDH Inhibitors Using Pharmacophore Mapping and Molecular Docking Approaches

    Directory of Open Access Journals (Sweden)

    Rui-Juan Li

    2015-01-01

    Full Text Available Inosine 5′-monophosphate dehydrogenase (IMPDH is one of the crucial enzymes in the de novo biosynthesis of guanosine nucleotides. It has served as an attractive target in immunosuppressive, anticancer, antiviral, and antiparasitic therapeutic strategies. In this study, pharmacophore mapping and molecular docking approaches were employed to discover novel Homo sapiens IMPDH (hIMPDH inhibitors. The Güner-Henry (GH scoring method was used to evaluate the quality of generated pharmacophore hypotheses. One of the generated pharmacophore hypotheses was found to possess a GH score of 0.67. Ten potential compounds were selected from the ZINC database using a pharmacophore mapping approach and docked into the IMPDH active site. We find two hits (i.e., ZINC02090792 and ZINC00048033 that match well the optimal pharmacophore features used in this investigation, and it is found that they form interactions with key residues of IMPDH. We propose that these two hits are lead compounds for the development of novel hIMPDH inhibitors.

  20. Cobaltoporphyrin-Catalyzed CO 2 /Epoxide Copolymerization: Selectivity Control by Molecular Design

    KAUST Repository

    Anderson, Carly E.

    2012-09-11

    A series of cobalt(III) chloride porphyrin complexes of the general formula 5,10,15,20-tetra(p-alkoxy)phenylporphyrin cobalt chloride (4b-e) and the related 5,10,15,20-tetra(p-nitro)phenylporphyrin cobalt chloride (4f) are presented and their reactivity toward propylene oxide (PO)/CO 2 coupling/copolymerization is explored. While the nitro-substituted complex (4f), in conjunction with an onium salt, shows moderate activity toward cyclization, the 4b-e/onium systems show superior copolymerization activity in comparison to tetraphenylporphyrin Co(III) chloride (4a) with high selectivity and conversion to poly(propylene carbonate) (PPC). A comprehensive copolymerization behavior study of the alkoxy-substituted porphyrin complexes 4b-e in terms of reaction temperature and CO 2 pressure is presented. Complexes bearing longer alkoxy-substituents demonstrate the highest polymerization activity and molecular weights, however all substituted catalyst systems display a reduced tolerance to increased temperature with respect to PPC formation. Studies of the resulting polymer microstructures show excellent head-to-tail epoxide incorporation and near perfectly alternating poly(carbonate) character at lower polymerization temperatures. © 2012 American Chemical Society.

  1. Molecular docking studies with rabies virus glycoprotein to design viral therapeutics

    Directory of Open Access Journals (Sweden)

    Tomar N

    2010-01-01

    Full Text Available The genome of rabies virus encodes five proteins; the nucleoprotein, the phosphoprotein, the matrix protein, the glycoprotein, and the RNA-dependent RNA polymerase. Among these, the glycoprotein is the most important as it is the major contributor to pathogenicity and virus neutralizing antibody response. Keeping in mind that glycoprotein is the only protein exposed on the surface of virus and is thought to be responsible for the interaction with the cell membrane, it was attempted to target glycoprotein by a ligand polyethylene glycol 4000, which blocks its active site, as seen by molecular operating environment software, so that it may be possible to prevent the spread of virus into the host. The ligand polyethylene glycol 4000 was retrieved from Research Collaboratory for Structural Bioinformatics protein data bank by providing the glycoprotein sequence to the databank. In this study it was observed that the ligand was successfully docked on a major portion of antigenic site II of glycoprotein by mimicking the virus neutralizing antibodies. This knowledge may be important for the development of novel therapies for the treatment of rabies and other viral diseases in the future.

  2. Molecular design, synthesis and biological activities of amidines as new ketol-acid reductoisomerase inhibitors

    Institute of Scientific and Technical Information of China (English)

    Bao Lei Wang; Yong Hong Li; Jian Guo Wang; Yi Ma; Zheng Ming Li

    2008-01-01

    Diamidine (A) was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase (KARI) from the ACD database search based on the known three-dimensional crystal structure of KARI. An investigation on interaction of A on KARI active sites, led to the design and synthesis of 15 novel monoamidines. Some of those showed better biological activity than A on rice KARI (in vitro) and in greenhouse herbicidal tests (in vivo). The structure-biological activity relationship was investigated, which provides valuable information to further study of potential KARI inhibitors.

  3. De novo design of protein-protein interactions through modification of inter-molecular helix-helix interface residues.

    Science.gov (United States)

    Yagi, Sota; Akanuma, Satoshi; Yamagishi, Manami; Uchida, Tatsuya; Yamagishi, Akihiko

    2016-05-01

    For de novo design of protein-protein interactions (PPIs), information on the shape and chemical complementarity of their interfaces is generally required. Recent advances in computational PPI design have allowed for de novo design of protein complexes, and several successful examples have been reported. In addition, a simple and easy-to-use approach has also been reported that arranges leucines on a solvent-accessible region of an α-helix and places charged residues around the leucine patch to induce interactions between the two helical peptides. For this study, we adopted this approach to de novo design a new PPI between the helical bundle proteins sulerythrin and LARFH. A non-polar patch was created on an α-helix of LARFH around which arginine residues were introduced to retain its solubility. The strongest interaction found was for the LARFH variant cysLARFH-IV-3L3R and the sulerythrin mutant 6L6D (KD=0.16 μM). This artificial protein complex is maintained by hydrophobic and ionic interactions formed by the inter-molecular helical bundle structure. Therefore, by the simple and easy-to-use approach to create de novo interfaces on the α-helices, we successfully generated an artificial PPI. We also created a second LARFH variant with the non-polar patch surrounded by positively charged residues at each end. Upon mixing this LARFH variant with 6L6D, mesh-like fibrous nanostructures were observed by atomic force microscopy. Our method may, therefore, also be applicable to the de novo design of protein nanostructures. PMID:26867971

  4. GIANT MOLECULAR CLOUDS AND STAR FORMATION IN THE NON-GRAND DESIGN SPIRAL GALAXY NGC 6946

    International Nuclear Information System (INIS)

    We present high spatial resolution observations of giant molecular clouds (GMCs) in the eastern part of the nearby spiral galaxy NGC 6946 obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We have observed CO(1 → 0), CO(2 → 1) and 13CO(1 → 0), achieving spatial resolutions of 5.''4 × 5.''0, 2.''5 × 2.''0, and 5.''6 × 5.''4, respectively, over a region of 6 × 6 kpc. This region extends from 1.5 kpc to 8 kpc galactocentric radius, thus avoiding the intense star formation in the central kpc. We have recovered short-spacing u-v components by using single dish observations from the Nobeyama 45 m and IRAM 30 m telescopes. Using the automated CPROPS algorithm, we identified 45 CO cloud complexes in the CO(1 → 0) map and 64 GMCs in the CO(2 → 1) maps. The sizes, line widths, and luminosities of the GMCs are similar to values found in other extragalactic studies. We have classified the clouds into on-arm and inter-arm clouds based on the stellar mass density traced by the 3.6 μm map. Clouds located on-arm present in general higher star formation rates than clouds located in inter-arm regions. Although the star formation efficiency shows no systematic trend with galactocentric radius, some on-arm clouds—which are more luminous and more massive compared to inter-arm GMCs—are also forming stars more efficiently than the rest of the identified GMCs. We find that these structures appear to be located in two specific regions in the spiral arms. One of them shows a strong velocity gradient, suggesting that this region of high star formation efficiency may be the result of gas flow convergence.

  5. Molecular Design and Immunogenicity of a Multiple-epitope FMDV Antigen and DNA Vaccination

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article reports the design and construction of a multiple-epitope foot and mouth disease virus (FMDV)antigen, designated as OAAT. This recombinant antigen consists of the structural protein VP1 genes from serotypes A and O FMDV, five major VP1 immunodominant epitopes from two genotypes of Asia1 serotype, and three Th2 epitopes originating from the nonstructural protein, three ABC gene and structural protein VP4 gene. Expressions of target gene from these plasmids in HeLa cells were verified by Western-blot. BALB/c mice were immunized intramuscularly with the DNA vaccines thrice every two weeks. We found that pA could induce simultaneously specific antibodies against serotypes A, Asia1, and O FMDV. Compared to those of the controls, the spots of FMDV-specific IFN-γ and cytotoxic activity from mice immunized with pA were significantly increased. pA provided full protection in 2/4 guinea pigs from challenge with FMDV O/NY00 and Asia1/YNBS/58, respectively. The results show that although pA did not give full protection in 100% immunized guinea pigs from challenge with type O and Asia1 FMDV, respectively, OAAT may be potential immunogen against FMDV and pA may be potential DNA vaccines against FMDV.

  6. 3D-QSAR and molecular docking studies on designing inhibitors of the hepatitis C virus NS5B polymerase

    Science.gov (United States)

    Li, Wenlian; Si, Hongzong; Li, Yang; Ge, Cuizhu; Song, Fucheng; Ma, Xiuting; Duan, Yunbo; Zhai, Honglin

    2016-08-01

    Viral hepatitis C infection is one of the main causes of the hepatitis after blood transfusion and hepatitis C virus (HCV) infection is a global health threat. The HCV NS5B polymerase, an RNA dependent RNA polymerase (RdRp) and an essential role in the replication of the virus, has no functional equivalent in mammalian cells. So the research and development of efficient NS5B polymerase inhibitors provides a great strategy for antiviral therapy against HCV. A combined three-dimensional quantitative structure-activity relationship (QSAR) modeling was accomplished to profoundly understand the structure-activity correlation of a train of indole-based inhibitors of the HCV NS5B polymerase to against HCV. A comparative molecular similarity indices analysis (COMSIA) model as the foundation of the maximum common substructure alignment was developed. The optimum model exhibited statistically significant results: the cross-validated correlation coefficient q2 was 0.627 and non-cross-validated r2 value was 0.943. In addition, the results of internal validations of bootstrapping and Y-randomization confirmed the rationality and good predictive ability of the model, as well as external validation (the external predictive correlation coefficient rext2 = 0.629). The information obtained from the COMSIA contour maps enables the interpretation of their structure-activity relationship. Furthermore, the molecular docking study of the compounds for 3TYV as the protein target revealed important interactions between active compounds and amino acids, and several new potential inhibitors with higher activity predicted were designed basis on our analyses and supported by the simulation of molecular docking. Meanwhile, the OSIRIS Property Explorer was introduced to help select more satisfactory compounds. The satisfactory results from this study may lay a reliable theoretical base for drug development of hepatitis C virus NS5B polymerase inhibitors.

  7. A conserved haem redox and trafficking pathway for cofactor attachment

    OpenAIRE

    Richard-Fogal, Cynthia L; Frawley, Elaine R.; Bonner, Eric R.; Zhu, Huifen; San Francisco, Brian; Kranz, Robert G.

    2009-01-01

    A pathway for cytochrome c maturation (Ccm) in bacteria, archaea and eukaryotes (mitochondria) requires the genes encoding eight membrane proteins (CcmABCDEFGH). The CcmABCDE proteins are proposed to traffic haem to the cytochrome c synthetase (CcmF/H) for covalent attachment to cytochrome c by unknown mechanisms. For the first time, we purify pathway complexes with trapped haem to elucidate the molecular mechanisms of haem binding, trafficking and redox control. We discovered an early step i...

  8. Quantum transport and geometric integration for molecular systems

    OpenAIRE

    Odell, Anders

    2010-01-01

    Molecular electronics is envisioned as a possible next step in device miniaturization. It is usually taken to mean the design and manufacturing of electronic devices and applications where organic molecules work as the fundamental functioning unit. It involves the measurement and manipulation of electronic response and transport in molecules attached to conducting leads. Organic molecules have the advantages over conventional solid state electronics of inherent small sizes, endless chemical d...

  9. Simulational nanoengineering: Molecular dynamics implementation of an atomistic Stirling engine.

    Science.gov (United States)

    Rapaport, D C

    2009-04-01

    A nanoscale-sized Stirling engine with an atomistic working fluid has been modeled using molecular dynamics simulation. The design includes heat exchangers based on thermostats, pistons attached to a flywheel under load, and a regenerator. Key aspects of the behavior, including the time-dependent flows, are described. The model is shown to be capable of stable operation while producing net work at a moderate level of efficiency. PMID:19518394

  10. Simulational nanoengineering: Molecular dynamics implementation of an atomistic Stirling engine

    CERN Document Server

    Rapaport, D C

    2009-01-01

    A nanoscale-sized Stirling engine with an atomistic working fluid has been modeled using molecular dynamics simulation. The design includes heat exchangers based on thermostats, pistons attached to a flywheel under load, and a regenerator. Key aspects of the behavior, including the time-dependent flows, are described. The model is shown to be capable of stable operation while producing net work at a moderate level of efficiency.

  11. Simulational nanoengineering: Molecular dynamics implementation of an atomistic Stirling engine

    Science.gov (United States)

    Rapaport, D. C.

    2009-04-01

    A nanoscale-sized Stirling engine with an atomistic working fluid has been modeled using molecular dynamics simulation. The design includes heat exchangers based on thermostats, pistons attached to a flywheel under load, and a regenerator. Key aspects of the behavior, including the time-dependent flows, are described. The model is shown to be capable of stable operation while producing net work at a moderate level of efficiency.

  12. Attaching Chuck Keys to Machine Tools

    Science.gov (United States)

    Richardson, V.

    1984-01-01

    Chuck keys attached to portable machine tools by retracting lanyards. Lanyard held taut by recoil caddy attached to tool base. Chuck key available for use when needed and safely secured during operation of tool.

  13. Hapten design and indirect competitive immunoassay for parathion determination: Correlation with molecular modeling and principal component analysis

    International Nuclear Information System (INIS)

    A novel procedure for parathion hapten design is described. The optimal antigen for parathion was selected after molecular modeling studies of six types of potentially immunizing haptens with the aim to identify the best mimicking target analyte. Heterologous competitive indirect enzyme-linked immunosorbent assay (ELISA) was developed after screening a battery of competitors as coating antigens. The relationship between the heterology degree of the competitor and the resulting immunoassay detectability was investigated according to the electronic similarities of the competitor haptens and the target analyte. Molecular modeling and principal component analysis were performed to understand the electronic distribution and steric parameters of the haptens at their minimum energetic levels. The results suggested that the competitors should have a high heterology to produce assays with good detectability values. An indirect competitive ELISA was finally selected for further investigation. The immunoassay had an IC50 value of 4.79 ng mL-1 and a limit of detection of 0.31 ng mL-1. There was little or no cross-reactivity to similar compounds tested except for the insecticide parathion-methyl, which showed a cross-reactivity of 7.8%

  14. Benefits of statistical molecular design, covariance analysis, and reference models in QSAR: a case study on acetylcholinesterase.

    Science.gov (United States)

    Andersson, C David; Hillgren, J Mikael; Lindgren, Cecilia; Qian, Weixing; Akfur, Christine; Berg, Lotta; Ekström, Fredrik; Linusson, Anna

    2015-03-01

    Scientific disciplines such as medicinal- and environmental chemistry, pharmacology, and toxicology deal with the questions related to the effects small organic compounds exhort on biological targets and the compounds' physicochemical properties responsible for these effects. A common strategy in this endeavor is to establish structure-activity relationships (SARs). The aim of this work was to illustrate benefits of performing a statistical molecular design (SMD) and proper statistical analysis of the molecules' properties before SAR and quantitative structure-activity relationship (QSAR) analysis. Our SMD followed by synthesis yielded a set of inhibitors of the enzyme acetylcholinesterase (AChE) that had very few inherent dependencies between the substructures in the molecules. If such dependencies exist, they cause severe errors in SAR interpretation and predictions by QSAR-models, and leave a set of molecules less suitable for future decision-making. In our study, SAR- and QSAR models could show which molecular sub-structures and physicochemical features that were advantageous for the AChE inhibition. Finally, the QSAR model was used for the prediction of the inhibition of AChE by an external prediction set of molecules. The accuracy of these predictions was asserted by statistical significance tests and by comparisons to simple but relevant reference models. PMID:25351962

  15. Molecular design and downstream processing of turoctocog alfa (NovoEight), a B-domain truncated factor VIII molecule

    Science.gov (United States)

    Ahmadian, Haleh; Hansen, Ernst B.; Faber, Johan H.; Sejergaard, Lars; Karlsson, Johan; Bolt, Gert; Hansen, Jens J.; Thim, Lars

    2016-01-01

    Turoctocog alfa (NovoEight) is a third-generation recombinant factor VIII (rFVIII) with a truncated B-domain that is manufactured in Chinese hamster ovary cells. No human or animal-derived materials are used in the process. The aim of this study is to describe the molecular design and purification process for turoctocog alfa. A five-step purification process is applied to turoctocog alfa: protein capture on mixed-mode resin; immunoaffinity chromatography using a unique, recombinantly produced anti-FVIII mAb; anion exchange chromatography; nanofiltration and size exclusion chromatography. This process enabled reduction of impurities such as host cell proteins (HCPs) and high molecular weight proteins (HMWPs) to a very low level. The immunoaffinity step is very important for the removal of FVIII-related degradation products. Manufacturing scale data shown in this article confirmed the robustness of the purification process and a reliable and consistent reduction of the impurities. The contribution of each step to the final product purity is described and shown for three manufacturing batches. Turoctocog alfa, a third-generation B-domain truncated rFVIII product is manufactured in Chinese hamster ovary cells without the use of animal or human-derived proteins. The five-step purification process results in a homogenous, highly purified rFVIII product. PMID:26761578

  16. Influence of the molecular design on the antifouling performance of poly(ethylene glycol) monolayers grafted on (111) Si.

    Science.gov (United States)

    Perez, Emmanuel; Lahlil, Khalid; Rougeau, Cyrille; Moraillon, Anne; Chazalviel, Jean-Noël; Ozanam, François; Gouget-Laemmel, Anne Chantal

    2012-10-16

    Various poly(ethylene glycol) monomethyl ether moieties were grafted onto hydrogenated silicon surfaces in order to investigate the influence of the molecular design on the antifouling performance of such coatings. The grafted chains were either oligo(ethylene oxide) chains (EG)(n)OMe bound to silicon via Si-O-C covalent bonds, or hybrid alkyl/oligo(ethylene oxide) chains C(p)(EG)(n)OMe bound via Si-C covalent bonds (from home-synthesized precursors). Quantitative IR spectroscopy gave the molecular coverage of the grafted layers, and AFM imaging demonstrated that a proper surfactinated rinse yields C(p)(EG)(n)OMe layers free of unwanted residues. The protein-repellent character of these grafted layers (here, toward BSA) was studied by IR and AFM imaging. C(p)(EG)(n)OMe layers exhibit a lower surface concentration than (EG)(n)OMe layers, because of the presence of a solvent in the grafting solution; they however demonstrate high resistance against BSA adsorption for high values of the n/p ratio and a higher stability than (EG)(n)OMe. This behavior is consistently explained by the poor ordering capability of the alkyl part of the layer, contrary to what is observed for similar layers on Au, and the key role of an entangled arrangement of the ethylene oxide chains which forms when these chains are long enough. PMID:22988984

  17. Engineered microtopographies and surface chemistries direct cell attachment and function

    Science.gov (United States)

    Magin, Chelsea Marie

    topographically modified surface (R2=0.82). Functionalized PEGDMA hydrogels significantly reduced attachment and attachment strength of Navicula and C. marina. These hydrogels also reduced attachment of zoospores of Ulva compared to PDMSe. Attachment of Ulva to microtopographies in PDMSe and PEGDMA-co-HEMA negatively correlated with ERIII*Re (R2 = 0.94 and R2 = 0.99, respectively). Incorporating a surface energy term into this equation created a correlation between the attachment densities of cells from two evolutionarily diverse groups on substrates of two surface chemistries with an equation that describes the various microtopographies and surface chemistries in terms of surface energy (R2 = 0.80). The current Attachment Model can now be used to design engineered antifouling surface microtopographies and chemistries that inhibit the attachment of organisms from three evoluntionarily diverse groups. Hydrogels based on PEGDMA were also chosen as a substratum material for mammalian cell culture. Capturing endothelial progenitor cells (EPCs) and inducing differentiation into the endothelial cell (EC) phenotype is the ideal way to re-endothelialize a small-diameter vascular graft. Substratum elasticity has been reported to direct stem cell differentiation into specific lineages. Functionalized PEGDMA hydrogels provided good compliance, high fidelity of topographic features and sites for surface modification with biomolecules. Fibronectin grafting and topography both increased EC attachment. This combination of adjustable elasticity, surface chemistry and topography has the potential to promote the capture and differentiation of EPCs into a confluent EC monolayer. Engineered microtopographies replicated in PDMSe directed elongation and alignment of human coronary artery endothelial cells (HCAECs) and human coronary artery smooth muscle cells (HCASMCs) compared to smooth surfaces. Engineered cellular micro-environments were created with specific surface energies defined by chemistry

  18. Probing the Nanosecond Dynamics of a Designed Three-Stranded Beta-Sheet with a Massively Parallel Molecular Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    Vincent A. Voelz

    2009-03-01

    Full Text Available Recently a temperature-jump FTIR study of a designed three-stranded sheet showing a fast relaxation time of ~140 ± 20 ns was published. We performed massively parallel molecular dynamics simulations in explicit solvent to probe the structural events involved in this relaxation. While our simulations produce similar relaxation rates, the structural ensemble is broad. We observe the formation of turn structure, but only very weak interaction in the strand regions, which is consistent with the lack of strong backbone-backbone NOEs in previous structural NMR studies. These results suggest that either DPDP-II folds at time scales longer than 240 ns, or that DPDP-II is not a well-defined three-stranded β-sheet. This work also provides an opportunity to compare the performance of several popular forcefield models against one another.

  19. Molecular design of organic dyes based on vinylene hexylthiophene bridge for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Three donor-(π-spacer)-acceptor(D-π-A) organic dyes,containing different groups(triphenylamine,di(p-tolyl)phenylamine,and 9-octylcarbazole moieties) as electron donors,were designed and synthesized.Nanocrystalline TiO2 dye-sensitized solar cells were fabricated by using these dyes.It was found that the variation of electron donors in the D-π-A dyes played an important role in modifying and tuning photophysical properties of organic dyes.Under standard global AM 1.5 solar condition,the DSSC based on the dye D2 showed the best photovoltaic performance:a short-circuit photocurrent density(Jsc) of 13.93 mA/cm2,an open-circuit photovoltage(Voc) of 0.71 V,and a fill factor(FF) of 0.679,corresponding to solar-to-electric power conversion efficiency(η) of 6.72%.

  20. Attachment Theory, Foster Parents and Diversity Tolerance

    OpenAIRE

    Kenny, Michael; Fleming, Ted

    2009-01-01

    relevance to attachment within the biological and foster family. Yet every foster parent has a childhood attachment history that influences their interpersonal relationships in adulthood. The primary concern of the foster parent and their supports is with the foster child. But as a result the foster parent may distract or block reflection on their own attachment history. This presentation will focus on attachment theory and the adult, with particular reference to the foster parent. The pre...

  1. Development of foster mother-child attachment

    OpenAIRE

    Korhonen, J

    2014-01-01

    The impact of early attachment relationships and child-adult attachment relationships to children’s social and emotional development has been recognised for a long time. Since the pioneering attachment theories of John Bowlby and Mary Ainsworth highlighting the importance of secure child-adult attachments, many other theories from various perspectives have risen to fill in the gaps. These theories are examined with the framework of foster care in mind. In Finland, the primary solution fo...

  2. Oxytocin enhances the experience of attachment security

    OpenAIRE

    Buchheim, Anna; Heinrichs, Markus; George, Carol; Pokorny, Dan; Koops, Eva; Henningsen, Peter; O’Connor, Mary-Frances; Gundel, Harald

    2009-01-01

    Repeated interactions between infant and caregiver result in either secure or insecure relationship attachment patterns, and insecure attachment may affect individual emotion-regulation and health. Given that oxytocin enhances social approach behavior in animals and humans, we hypothesized that oxytocin might also promote the experience of attachment security in humans. Within a 3-week interval 26 healthy male students classified with an insecure attachment pattern were invited twice to an ex...

  3. Molecular designing of novel ternary copolymers of donor-acceptor polymers using genetic algorithm

    International Nuclear Information System (INIS)

    Graphical abstract: Alternate arrangement of donor acceptor moieties in the carbon backbone chain of an organic conjugated polymer is capable of inducing charge transfer and affects the electronic properties of the copolymer. Genetic algorithm along with simple NFC (negative factor counting) and IIM (inverse iteration method) has been used to optimize the properties of novel ternary copolymers based on polypyrrole PPy, polythiophene PTh and polyfuran PFu (as donor moieties) and containing >C=O and >C=CF2 bridging units as acceptor moieties. - Abstract: An efficient designing route to novel ternary copolymers consisting of polypyrrole (PPy), polythiophene (PTh) and polyfuran (PFu) is developed with the help of genetic algorithm. Using the band structure results obtained from ab initio crystal orbital (CO) calculations, the electronic structures and conduction properties of real ternary copolymers based on donor acceptor type polymers are investigated. The electron rich heterocyclic rings in the backbone chain of the copolymer are joined together by electron withdrawing groups Y, carbonyl group (>C=O) and difluoromethylene group (>C=CF2) in an attempt to design the conducting polymer with lowest band gap. A comparative study of various electronic properties is presented. The effects of substitution on the behaviour and properties of the copolymers as well as on the density of states (DOS) are discussed. Band gap decreases as a result of substitution on the polymer backbone chain due to decrease in ionization potential and increase in electron affinity values. This is expected to enhance the intrinsic conductivity of the resulting copolymer. Use of alternate donor acceptor moieties within the repeat units should maximize the extended π conjugation.

  4. Molecular and process design for rotavirus-like particle production in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Palomares Laura A

    2011-05-01

    Full Text Available Abstract Background Virus-like particles (VLP have an increasing range of applications including vaccination, drug delivery, diagnostics, gene therapy and nanotechnology. These developments require large quantities of particles that need to be obtained in efficient and economic processes. Production of VLP in yeast is attractive, as it is a low-cost protein producer able to assemble viral structural proteins into VLP. However, to date only single-layered VLP with simple architecture have been produced in this system. In this work, the first steps required for the production of rotavirus-like particles (RLP in S. cerevisiae were implemented and improved, in order to obtain the recombinant protein concentrations required for VLP assembly. Results The genes of the rotavirus structural proteins VP2, VP6 and VP7 were cloned in four Saccharomyces cerevisiae strains using different plasmid and promoter combinations to express one or three proteins in the same cell. Performance of the best constructs was evaluated in batch and fed-batch cultures using a complete synthetic media supplemented with leucine, glutamate and succinate. The strain used had an important effect on recombinant protein concentration, while the type of plasmid, centromeric (YCp or episomal (YEp, did not affect protein yields. Fed-batch culture of the PD.U-267 strain resulted in the highest concentration of rotavirus proteins. Volumetric and specific productivities increased 28.5- and 11-fold, respectively, in comparison with batch cultures. Expression of the three rotavirus proteins was confirmed by immunoblotting and RLP were detected using transmission electron microscopy. Conclusions We present for the first time the use of yeast as a platform to express multilayered rotavirus-like particles. The present study shows that the combined use of molecular and bioprocess tools allowed the production of triple-layered rotavirus RLP. Production of VLP with complex architecture in yeasts

  5. Control over Structure and Function of Peptide Amphiphile Supramolecular Assemblies through Molecular Design and Energy Landscapes

    Science.gov (United States)

    Tantakitti, Faifan

    Supramolecular chemistry is a powerful tool to create a material of a defined structure with tunable properties. This strategy has led to catalytically active, bioactive, and environment-responsive materials, among others, that are valuable in applications ranging from sensor technology to energy and medicine. Supramolecular polymers formed by peptide amphiphiles (PAs) have been especially relevant in tissue regeneration due to their ability to form biocompatible structures and mimic many important signaling molecules in biology. These supramolecular polymers can form nanofibers that create networks which mimic natural extracellular matrices. PA materials have been shown to induce growth of blood vessels, bone, cartilage, and nervous tissue, among others. The work described in this thesis not only studied the relationship between molecular structure and functions of PA assemblies, but also uncovered a powerful link between the energy landscape of their supramolecular self-assembly and the ability of PA materials to interact with cells. In chapter 2, it is argued that fabricating fibrous nanostructures with defined mechanical properties and decoration with bioactive molecules is not sufficient to create a material that can effectively communicate with cells. By systemically placing the fibronectin-derived RGDS epitope at increasing distances from the surface of PA nanofibers through a linker of one to five glycine residues, integrin-mediated RGDS signaling was enhanced. The results suggested that the spatial presentation of an epitope on PA nanofibers strongly influences the bioactivity of the PA substrates. In further improving functionality of a PA-based scaffold to effectively direct cell growth and differentiation, chapter 3 explored the use of a cell microcarrier to compartmentalize and simultaneously tune insoluble and soluble signals in a single matrix. PA nanofibers were incorporated at the surface of the microcarrier in order to promote cell adhesion, while

  6. After Love: Attachment Styles and Grief Themes.

    Science.gov (United States)

    Pistole, M. Carole

    1996-01-01

    Examines the association of attachment organization and recalled grief responses following the dissolution of a romantic relationship. Data based on college students' (N=118) responses resulted in four interpretable grief themes. Preoccupied attachment predicted self-reproach, fearful attachment predicted partner blame, whereas both fearful and…

  7. Adolescents' Attachment and Coping with Stress

    Science.gov (United States)

    Howard, Michelle S.; Medway, Frederic J.

    2004-01-01

    This study examined how high school students cope with stress as a function of their attachment style. Data were gathered from 75 adolescent-parent pairs in Texas and included measures of attachment, coping style, life stress, and whom the respondent would turn to in times of stress. Adolescents' attachment security was positively related to…

  8. Design of polymer-biopolymer-hydroxyapatite biomaterials for bone tissue engineering: Through molecular control of interfaces

    Science.gov (United States)

    Verma, Devendra

    In this dissertation, novel biomaterials are designed for bone biomaterials and bone tissue engineering applications. Novel biomaterials of hydroxyapatite with synthetic and natural polymers have been fabricated using a combination of processing routes. Initially, we investigated hydroxyapatite-polycaprolactone-polyacrylic acid composites and observed that minimal interfacial interactions between polymer and mineral led to inadequate improvement in the mechanical properties. Bioactivity experiments on these composites showed that the presence of functional groups, such as carboxylate groups, influence bioactivity of the composites. We have developed and investigated composites of hydroxyapatite with chitosan and polygalacturonic acid (PgA). Chitosan and PgA are biocompatible, biodegradable, and also electrostatically complementary to each other. This strategy led to significant improvement in mechanical properties of new composites. The nanostructure analysis using atomic force microscopy revealed a multilevel organization in these composites. Enhancement in mechanical response was attributed to stronger interfaces due to strong electrostatic interaction between oppositely charged chitosan and PgA. Further analysis using the Rietveld method showed that biopolymers have marked impact on hydroxyapatite crystal growth and also on its crystal structure. Significant changes were observed in the lattice parameters of hydroxyapatite synthesized by following biomineralization method (organics mediated mineralization). For scaffold preparation, chitosan and PgA were mixed first, and then, nano-hydroxyapatite was added. Oppositely charged polyelectrolytes, such as chitosan and PgA, spontaneously form complex upon mixing. The poly-electrolyte complex exists as nano-sized particles. Chitosan/PgA scaffolds with and without hydroxyapatite were prepared by the freeze drying method. By controlling the rate of cooling and concentration, we have produced both fibrous and sheet

  9. Molecular Structure of RADA16-I Designer Self-Assembling Peptide Nanofibers

    Science.gov (United States)

    Cormier, Ashley R.; Pang, Xiaodong; Zimmerman, Maxwell I.; Zhou, Huan-Xiang; Paravastu, Anant K.

    2013-01-01

    The designer self-assembling peptide RADA16-I forms nanofiber matrices which have shown great promise for regenerative medicine and 3-dimensional cell culture. RADA16-I has a β-strand-promoting alternating hydrophobic/charged motif, but arrangement of β-strands into the nanofiber structure has not been previously determined. Here we present a structural model of RADA16-I nanofibers, based on solid-state NMR measurements on samples with different schemes for 13C isotopic labeling. NMR peak positions and line widths indicate an ordered structure composed of β-strands. The NMR data show that the nanofibers are composed of two stacked β-sheets stabilized by a hydrophobic core formed by alanine sidechains, consistent with previous proposals. However, the previously proposed antiparallel β-sheet structure is ruled out by 13C-13C dipolar couplings. Instead, neighboring β-strands within β-sheets are parallel, with a registry shift that allows for cross-strand staggering of oppositely charged arginine and aspartate sidechains. The resulting structural model is compared to nanofiber dimensions observed via images taken by transmission electron microscopy and atomic force microscopy. Multiple NMR peaks for each alanine sidechain were observed and could be attributed to multiple configurations of sidechain packing within a single scheme for intermolecular packing. PMID:23977885

  10. Design of perylene diimides for organic solar cell: Effect of molecular steric hindrance and extended conjugation

    Energy Technology Data Exchange (ETDEWEB)

    Kozma, Erika, E-mail: erika.kozma@ismac.cnr.it [Istituto per lo Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, 20133 Milano (Italy); Kotowski, Dariusz; Catellani, Marinella; Luzzati, Silvia [Istituto per lo Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, 20133 Milano (Italy); Cavazzini, Marco; Bossi, Alberto; Orlandi, Simonetta [Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche, 20133 Milano (Italy); Bertini, Fabio [Istituto per lo Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, 20133 Milano (Italy)

    2015-08-01

    Core-substituted perylene diimides (PDI) are promising candidates as n-type semiconductor materials for organic photovoltaics. The chemical functionalization of perylene diimides in the bay positions is a versatile tool to obtain a series of electron acceptor materials with tunable electron affinity. These materials usually feature a donor-acceptor D-A structure in which the electron withdrawing PDI core is covalently linked with different electron donating chemical groups. The structural and electronic properties of the substituents define and modulate the optical/electrical properties of the semiconductor and the performance as photovoltaic material. In this work we designed two PDI molecules with D-A-D structure using spirobifluorene group as substituent directly linked to the perylene core (PDI-SF) and with insertion of a bithiophene moiety (PDI-BSF). In both molecules we found a reduced tendency to form aggregates in the solid state thanks to the cross-shaped rigid structure and strong steric hindrance of the spirobifluorene group. Additionally, in the case of PDI-BSF the presence of the bithiophene linker contributes significantly to extend the conjugation, resulting in a panchromatic absorption in the whole visible to NIR region. We present the synthesis of these materials and their characterisation in terms of absorption spectroscopy, cyclic voltammetry and computational calculations. Finally we show preliminary results of their use as active components in P3HT/PDIs bulk heterojunction solar cells. - Highlights: • New D-A-D n-type materials have been synthesized. • PDI-SF and PDI-BSF were used as acceptors in organic solar cells. • Performances of 1.32% were achieved in blend with P3HT in a BHJ conventional architecture.

  11. New renewable resource amphiphilic molecular design for size-controlled and highly ordered polyaniline nanofibers.

    Science.gov (United States)

    Anilkumar, P; Jayakannan, M

    2006-06-20

    We demonstrate here, for the first time, a unique strategy for conducting polyaniline nanofibers based on renewable resources. Naturally available cardanol, which is an industrial waste and main pollutant from the cashew nut industry, is utilized for producing well-defined polyaniline nanofibers. A new amphiphilic molecule is designed and developed from cardanol, which forms a stable emulsion with aniline for a wide composition range in water (1:1 to 1:100 dopant/aniline mole ratio) to produce polyaniline nanofibers. The scanning electron microscopy and transmission electron microscopy analysis of the nanofibers reveals that the dopant/aniline ratio plays a major role in determining the shape and size of polyaniline nanofibers. The nanofiber length increases with the increase in the dopant/aniline ratio, and perfectly linear, well-defined nanofibers of lengths as long as 7-8 muM were produced. The amphiphilic dopant has a built-in head-to-tail geometry and effectively penetrates into the polyaniline chains to form highly organized nanofibers. Wide-angle X-ray diffraction (WXRD) spectra of the nanofibers showed a new peak at 2theta = 6.3 (d spacing = 13.9 A) corresponding to the three-dimensional solid-state ordering of polyaniline-dopant chains, and this peak intensity increases with increase in the nanofiber length. The comparison of morphology and WXRD reveals that high ordering in polyaniline chains results in the formation of long, well-defined nanofibers, and this direct correlation for the polyaniline nanofibers with solid-state ordering has been established. The conductivity of the polyaniline nanofibers also increases with increase in the solid-state ordering rather than increasing with the extent of doping. The polyaniline nanofibers are freely soluble in water and possess high environmental and thermal stability up to 300 degrees C for various applications. PMID:16768535

  12. Design of perylene diimides for organic solar cell: Effect of molecular steric hindrance and extended conjugation

    International Nuclear Information System (INIS)

    Core-substituted perylene diimides (PDI) are promising candidates as n-type semiconductor materials for organic photovoltaics. The chemical functionalization of perylene diimides in the bay positions is a versatile tool to obtain a series of electron acceptor materials with tunable electron affinity. These materials usually feature a donor-acceptor D-A structure in which the electron withdrawing PDI core is covalently linked with different electron donating chemical groups. The structural and electronic properties of the substituents define and modulate the optical/electrical properties of the semiconductor and the performance as photovoltaic material. In this work we designed two PDI molecules with D-A-D structure using spirobifluorene group as substituent directly linked to the perylene core (PDI-SF) and with insertion of a bithiophene moiety (PDI-BSF). In both molecules we found a reduced tendency to form aggregates in the solid state thanks to the cross-shaped rigid structure and strong steric hindrance of the spirobifluorene group. Additionally, in the case of PDI-BSF the presence of the bithiophene linker contributes significantly to extend the conjugation, resulting in a panchromatic absorption in the whole visible to NIR region. We present the synthesis of these materials and their characterisation in terms of absorption spectroscopy, cyclic voltammetry and computational calculations. Finally we show preliminary results of their use as active components in P3HT/PDIs bulk heterojunction solar cells. - Highlights: • New D-A-D n-type materials have been synthesized. • PDI-SF and PDI-BSF were used as acceptors in organic solar cells. • Performances of 1.32% were achieved in blend with P3HT in a BHJ conventional architecture

  13. Reliability Testing the Die-Attach of CPV Cell Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Bosco, N.; Sweet, C.; Kurtz, S.

    2011-02-01

    Results and progress are reported for a course of work to establish an efficient reliability test for the die-attach of CPV cell assemblies. Test vehicle design consists of a ~1 cm2 multijunction cell attached to a substrate via several processes. A thermal cycling sequence is developed in a test-to-failure protocol. Methods of detecting a failed or failing joint are prerequisite for this work; therefore both in-situ and non-destructive methods, including infrared imaging techniques, are being explored as a method to quickly detect non-ideal or failing bonds.

  14. Handcrafting Attachment: A User-Centered Approach

    Directory of Open Access Journals (Sweden)

    George S. Lowry

    2011-04-01

    Full Text Available Management, above all, is the controlling element responsible for coordinating the three basic business functions; production, marketing, and finance.  Mechanisms exist to facilitate the finance function with influence coming from outside regulatory bodies such as the AICPA, IIA, SEC, and other regulators.  Integrating the finance function into organizations, then, becomes somewhat generic (although some would argue this point.  Coordinating the functions of marketing and production is a much more difficult endeavor because it lacks the standardization seen in finance.  This paper suggests employing a more user-focused approach as a means to improving the overall quality of products, and eventually, the success of the organization.  Specifically, this paper explores the role of the human brain in the calculus of choice, discusses the role of consumer involvement as it leads to product attachment, and offers suggestions for employing contextual research to improve product design and quality.

  15. The Turkish version of Maternal Attachment Inventory

    Directory of Open Access Journals (Sweden)

    Oya Kavlak

    2009-01-01

    Full Text Available Objective: The research has been designed as methodological with purpose of the validity and the reliability of the Turkish language version of Maternal Attachment Inventory on mothers within one and four months postpartum. Method: This study was carried out with mothers registered at 19 Health Clinics and three Maternal-Child Health and Family Planning Clinics in which connected to Bornova Health Presidency in Izmir. The sample of research has been composed three clinics in which determined with the purposive sampling technique. First stage, the research was studied on 165 mothers when their babies were approximately 30-40 days old in these registered clinics.At the second stage of research has been interviewed again with 78 mothers when their babies were approximately 90-105 days old.Results: It is determined that experts consensuses about content of items as a result of analysis (Kendall’s W=0.274, p=0.001

  16. Ultrasound molecular imaging: Moving toward clinical translation

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Elkacem, Lotfi; Bachawal, Sunitha V.; Willmann, Jürgen K., E-mail: willmann@stanford.edu

    2015-09-15

    Highlights: • Ultrasound molecular imaging is a highly sensitive modality. • A clinical grade ultrasound contrast agent has entered first in human clinical trials. • Several new potential future clinical applications of ultrasound molecular imaging are being explored. - Abstract: Ultrasound is a widely available, cost-effective, real-time, non-invasive and safe imaging modality widely used in the clinic for anatomical and functional imaging. With the introduction of novel molecularly-targeted ultrasound contrast agents, another dimension of ultrasound has become a reality: diagnosing and monitoring pathological processes at the molecular level. Most commonly used ultrasound molecular imaging contrast agents are micron sized, gas-containing microbubbles functionalized to recognize and attach to molecules expressed on inflamed or angiogenic vascular endothelial cells. There are several potential clinical applications currently being explored including earlier detection, molecular profiling, and monitoring of cancer, as well as visualization of ischemic memory in transient myocardial ischemia, monitoring of disease activity in inflammatory bowel disease, and assessment of arteriosclerosis. Recently, a first clinical grade ultrasound contrast agent (BR55), targeted at a molecule expressed in neoangiogenesis (vascular endothelial growth factor receptor type 2; VEGFR2) has been introduced and safety and feasibility of VEGFR2-targeted ultrasound imaging is being explored in first inhuman clinical trials in various cancer types. This review describes the design of ultrasound molecular imaging contrast agents, imaging techniques, and potential future clinical applications of ultrasound molecular imaging.

  17. Ultrasound molecular imaging: Moving toward clinical translation

    International Nuclear Information System (INIS)

    Highlights: • Ultrasound molecular imaging is a highly sensitive modality. • A clinical grade ultrasound contrast agent has entered first in human clinical trials. • Several new potential future clinical applications of ultrasound molecular imaging are being explored. - Abstract: Ultrasound is a widely available, cost-effective, real-time, non-invasive and safe imaging modality widely used in the clinic for anatomical and functional imaging. With the introduction of novel molecularly-targeted ultrasound contrast agents, another dimension of ultrasound has become a reality: diagnosing and monitoring pathological processes at the molecular level. Most commonly used ultrasound molecular imaging contrast agents are micron sized, gas-containing microbubbles functionalized to recognize and attach to molecules expressed on inflamed or angiogenic vascular endothelial cells. There are several potential clinical applications currently being explored including earlier detection, molecular profiling, and monitoring of cancer, as well as visualization of ischemic memory in transient myocardial ischemia, monitoring of disease activity in inflammatory bowel disease, and assessment of arteriosclerosis. Recently, a first clinical grade ultrasound contrast agent (BR55), targeted at a molecule expressed in neoangiogenesis (vascular endothelial growth factor receptor type 2; VEGFR2) has been introduced and safety and feasibility of VEGFR2-targeted ultrasound imaging is being explored in first inhuman clinical trials in various cancer types. This review describes the design of ultrasound molecular imaging contrast agents, imaging techniques, and potential future clinical applications of ultrasound molecular imaging

  18. A combination of evolutionary trace method, molecular surface accessibility and hydrophobicity analysis to design a high hydrophobicity laccase.

    Science.gov (United States)

    Mohamad, Saharuddin Bin; Ong, Ai Ling; Khairuddin, Raja Farhana; Ripen, Adiratna Mat

    2010-01-01

    Laccases are industrially attractive enzymes and their applications have expanded to the field of bioremediation. The challenge of today's biotechnology in enzymatic studies is to design enzymes that not only have a higher activity but are also more stable and could fit well with the condition requirements. Laccases are known to oxidize non-natural substrates like polycyclic aromatic hydrocarbons (PAHs). We suppose by increasing the hydrophobicity of laccase, it would increase the chance of the enzyme to meet the hydrophobic substrates in a contamination site, therefore increasing the bioremediation efficacy of PAHs from environment. In this attempt, the applications of evolutionary trace (ET), molecular surface accessibility and hydrophobicity analysis on laccase sequences and laccase's crystal structure (1KYA) are described for optimal design of an enzyme with higher hydrophobicity. Our analysis revealed that Q23A, Q45I, N141A, Q237V, N262L, N301V, N331A, Q360L and Q482A could be promising exchanges to be tested in mutagenesis experiments. PMID:22430288

  19. A rational design for improving the trypsin resistance of aflatoxin-detoxifizyme (ADTZ) based on molecular structure evaluation.

    Science.gov (United States)

    Qiu, Yuxin; Wu, Xiyang; Xie, Chunfang; Hu, Yadong; Liu, Daling; Ma, Yi; Yao, Dongsheng

    2016-05-01

    The resistance of feed enzymes against proteases is crucial in livestock farming. In this study, the trypsin resistance of aflatoxin-detoxifizyme (ADTZ) is improved. ADTZ possesses 72 lys/arg residue sites, 45 of which are scattered on the outermost layers of the molecule (RSA≧25%). These 45 lys/arg sites could be target sites for trypsin hydrolysis. By considering shape-matching (including physical and secondary bond interactions) and the "induced fit-effect", we hypothesized that some of these lys/arg sites are vulnerable to trypsin. A protein-protein docking simulation method was used to avoid the massive computational requirements and to address the intricacy of selecting candidate sites, as candidate site selection is affected by space displacement. Optimal mutants (K244Q/K213C/K270T and R356E/K357T/R623C) were predicted by computational design with protein folding energy analysis and molecular dynamics simulations. A trypsin digestion assay was performed, and the mutants displayed much higher stability against trypsin hydrolysis compared to the native enzyme. Moreover, temperature- and pH-activity profiles revealed that the designed mutations did not affect the catalytic activity of the enzyme. PMID:26992797

  20. Development of the designed ankyrin repeat protein (DARPin) G3 for HER2 molecular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Robert; Livanos, Maria; Bhavsar, Gaurav; Rashid, Mohammed; Miranda, Enrique; Tolner, Berend; Meyer, Tim; Chester, Kerry [UCL Cancer Institute, London (United Kingdom); Sosabowski, Jane; Leyton, Julius; Mather, Stephen [Queen Mary University of London, Centre for Molecular Oncology, Barts Cancer Institute, London (United Kingdom); Vigor, Kim [Clare Hall Laboratories, Biotherapeutics Development Unit, Cancer Research UK, South Mimms (United Kingdom); Nagy-Davidescu, Gabriela; Plueckthun, Andreas [Universitaet Zuerich, Biochemisches Institut, Zuerich (Switzerland); Yeung, Jenny [UCL Cancer Institute, London (United Kingdom); UCL Institute of Child Health, London (United Kingdom)

    2014-11-13

    Human epidermal growth factor receptor-2 (HER2) overexpression is a predictor of response to anti-HER2 therapy in breast and gastric cancer. Currently, HER2 status is assessed by tumour biopsy, but this may not be representative of the larger tumour mass or other metastatic sites, risking misclassification and selection of suboptimal therapy. The designed ankyrin repeat protein (DARPin) G3 binds HER2 with high affinity at an epitope that does not overlap with trastuzumab and is biologically inert. We hypothesized that radiolabelled DARPin G3 would be capable of selectively imaging HER2-positive tumours, and aimed to identify a suitable format for clinical application. G3 DARPins tagged with hexahistidine (His{sub 6}) or with histidine glutamate (HE){sub 3} and untagged G3 DARPins were manufactured using a GMP-compatible Pichia pastoris protocol and radiolabelled with {sup 125}I, or with {sup 111}In via DOTA linked to a C-terminal cysteine. BALB/c mice were injected with radiolabelled G3 and tissue biodistribution was evaluated by gamma counting. The lead construct ((HE){sub 3}-G3) was assessed in mice bearing HER2-positive human breast tumour (BT474) xenografts. For both isotopes, (HE){sub 3}-G3 had significantly lower liver uptake than His{sub 6}-G3 and untagged G3 counterparts in non-tumour-bearing mice, and there was no significantly different liver uptake between His{sub 6}-G3 and untagged G3. (HE){sub 3}-G3 was taken forward for evaluation in mice bearing HER2-positive tumour xenografts. The results demonstrated that radioactivity from {sup 111}In-(HE){sub 3}-G3 was better maintained in tumours and cleared faster from serum than radioactivity from {sup 125}I-(HE){sub 3}-G3, achieving superior tumour-to-blood ratios (343.7 ± 161.3 vs. 22.0 ± 11.3 at 24 h, respectively). On microSPECT/CT, {sup 111}In-labelled and {sup 125}I-labelled (HE){sub 3}-G3 could image HER2-positive tumours at 4 h after administration, but there was less normal tissue uptake of

  1. Development of the designed ankyrin repeat protein (DARPin) G3 for HER2 molecular imaging

    International Nuclear Information System (INIS)

    Human epidermal growth factor receptor-2 (HER2) overexpression is a predictor of response to anti-HER2 therapy in breast and gastric cancer. Currently, HER2 status is assessed by tumour biopsy, but this may not be representative of the larger tumour mass or other metastatic sites, risking misclassification and selection of suboptimal therapy. The designed ankyrin repeat protein (DARPin) G3 binds HER2 with high affinity at an epitope that does not overlap with trastuzumab and is biologically inert. We hypothesized that radiolabelled DARPin G3 would be capable of selectively imaging HER2-positive tumours, and aimed to identify a suitable format for clinical application. G3 DARPins tagged with hexahistidine (His6) or with histidine glutamate (HE)3 and untagged G3 DARPins were manufactured using a GMP-compatible Pichia pastoris protocol and radiolabelled with 125I, or with 111In via DOTA linked to a C-terminal cysteine. BALB/c mice were injected with radiolabelled G3 and tissue biodistribution was evaluated by gamma counting. The lead construct ((HE)3-G3) was assessed in mice bearing HER2-positive human breast tumour (BT474) xenografts. For both isotopes, (HE)3-G3 had significantly lower liver uptake than His6-G3 and untagged G3 counterparts in non-tumour-bearing mice, and there was no significantly different liver uptake between His6-G3 and untagged G3. (HE)3-G3 was taken forward for evaluation in mice bearing HER2-positive tumour xenografts. The results demonstrated that radioactivity from 111In-(HE)3-G3 was better maintained in tumours and cleared faster from serum than radioactivity from 125I-(HE)3-G3, achieving superior tumour-to-blood ratios (343.7 ± 161.3 vs. 22.0 ± 11.3 at 24 h, respectively). On microSPECT/CT, 111In-labelled and 125I-labelled (HE)3-G3 could image HER2-positive tumours at 4 h after administration, but there was less normal tissue uptake of radioactivity with 111In-(HE)3-G3. Preadministration of trastuzumab did not affect the uptake of (HE)3-G

  2. Design and synthesis of tag-free photoprobes for the identification of the molecular target for CCG-1423, a novel inhibitor of the Rho/MKL1/SRF signaling pathway

    Directory of Open Access Journals (Sweden)

    Jessica L. Bell

    2013-05-01

    Full Text Available CCG-1423 and related analogues represent a new class of inhibitors of Rho/MKL1/SRF-mediated gene transcription, a pathway that has been implicated in both cancer and fibrosis. The molecular target for these compounds is unknown. To facilitate its identification, a series of tag-free photoaffinity probes was designed and synthesized, each one containing a photoactivatable group and an acetylenic end group for subsequent attachment to a fluorescent tag using click chemistry. All were confirmed to maintain biological activity in a cell-based assay for inhibition of SRE-Luc expression. The functional activity of the most potent probe 24 was further confirmed in an assay for PC-3 cell migration. Photolysis of 24 in intact PC-3 cells followed by cell lysis, click ligation of a fluorescent dye, and gel electrophoresis revealed specific labeling of a single 24 kDa band that could be blocked with an active competitor. Future work will focus on identifying the labeled protein(s.

  3. Design and synthesis of tag-free photoprobes for the identification of the molecular target for CCG-1423, a novel inhibitor of the Rho/MKL1/SRF signaling pathway

    Science.gov (United States)

    Bell, Jessica L; Haak, Andrew J; Wade, Susan M; Sun, Yihan; Neubig, Richard R

    2013-01-01

    Summary CCG-1423 and related analogues represent a new class of inhibitors of Rho/MKL1/SRF-mediated gene transcription, a pathway that has been implicated in both cancer and fibrosis. The molecular target for these compounds is unknown. To facilitate its identification, a series of tag-free photoaffinity probes was designed and synthesized, each one containing a photoactivatable group and an acetylenic end group for subsequent attachment to a fluorescent tag using click chemistry. All were confirmed to maintain biological activity in a cell-based assay for inhibition of SRE-Luc expression. The functional activity of the most potent probe 24 was further confirmed in an assay for PC-3 cell migration. Photolysis of 24 in intact PC-3 cells followed by cell lysis, click ligation of a fluorescent dye, and gel electrophoresis revealed specific labeling of a single 24 kDa band that could be blocked with an active competitor. Future work will focus on identifying the labeled protein(s). PMID:23766813

  4. Non-linear optical response by functionalized gold nanospheres: identifying design principles to maximize the molecular photo-release

    Science.gov (United States)

    Bergamini, Luca; Voliani, Valerio; Cappello, Valentina; Nifosì, Riccardo; Corni, Stefano

    2015-08-01

    In a recent study by Voliani et al. [Small, 2011, 7, 3271], the electromagnetic field enhancement in the vicinity of the gold nanoparticle surface has been exploited to achieve photocontrolled release of a molecular cargo conjugated to the nanoparticles via 1,2,3-triazole, a photocleavable moiety. The aim of the present study is to investigate the mechanism of the photorelease by characterizing the nanoparticle aggregation status within the cells and simulating the electric field enhancement in a range of experimentally realistic geometries, such as single Au nanoparticles, dimers, trimers and random aggregates. Two plasmon-enhanced processes are examined for triazole photocleavage, i.e. three-photon excitation and third-harmonic-generation (one-photon) excitation. Taking into account the absorption cross sections of the triazole, we conclude that the latter mechanism is more efficient, and provides a photocleavage rate that explains the experimental findings. Moreover, we determine which aggregate geometries are required to maximize the field enhancement, and the dependence of such enhancement on the excitation wavelength. Our results provide design principles for maximizing the multiphoton molecular photorelease by such functionalized gold nanoparticles.In a recent study by Voliani et al. [Small, 2011, 7, 3271], the electromagnetic field enhancement in the vicinity of the gold nanoparticle surface has been exploited to achieve photocontrolled release of a molecular cargo conjugated to the nanoparticles via 1,2,3-triazole, a photocleavable moiety. The aim of the present study is to investigate the mechanism of the photorelease by characterizing the nanoparticle aggregation status within the cells and simulating the electric field enhancement in a range of experimentally realistic geometries, such as single Au nanoparticles, dimers, trimers and random aggregates. Two plasmon-enhanced processes are examined for triazole photocleavage, i.e. three-photon excitation

  5. Molecular modeling of directed self-assembly of block copolymers: Fundamental studies of processing conditions and evolutionary pattern design

    Science.gov (United States)

    Khaira, Gurdaman Singh

    Rapid progress in the semi-conductor industry has pushed for smaller feature sizes on integrated electronic circuits. Current photo-lithographic techniques for nanofabrication have reached their technical limit and are problematic when printing features small enough to meet future industrial requirements. "Bottom-up'' techniques, such as the directed self-assembly (DSA) of block copolymers (BCP), are the primary contenders to compliment current "top-down'' photo-lithography ones. For industrial requirements, the defect density from DSA needs to be less than 1 defect per 10 cm by 10 cm. Knowledge of both material synthesis and the thermodynamics of the self-assembly process are required before optimal operating conditions can be found to produce results adequate for industry. The work present in this thesis is divided into three chapters, each discussing various aspects of DSA as studied via a molecular model that contains the essential physics of BCP self-assembly. Though there are various types of guiding fields that can be used to direct BCPs over large wafer areas with minimum defects, this study focuses only on chemically patterned substrates. The first chapter addresses optimal pattern design by describing a framework where molecular simulations of various complexities are coupled with an advanced optimization technique to find a pattern that directs a target morphology. It demonstrates the first ever study where BCP self-assembly on a patterned substrate is optimized using a three-dimensional description of the block-copolymers. For problems pertaining to DSA, the methodology is shown to converge much faster than the traditional random search approach. The second chapter discusses the metrology of BCP thin films using TEM tomography and X-ray scattering techniques, such as CDSAXS and GISAXS. X-ray scattering has the advantage of being able to quickly probe the average structure of BCP morphologies over large wafer areas; however, deducing the BCP morphology

  6. LC/MS quantitative study of glucose by iodine attachment

    International Nuclear Information System (INIS)

    We explored the potential of iodine attachment to improve the sensitivity of glucose measurement by LC/MS. After sample preparation, glucose was separated by normal phase chromatography, followed by anionization by I--attachment prior to MS by post-column addition of a methanolic solution of iodoform. Iodine is capable of forming an anionic adduct with neutral monosaccharides in negative ion mode electrospray mass spectrometry. Quasi-molecular ions [M + I]- of glucose, and [6,6-2H2]glucose (abbreviated d2-glucose) internal standard were quantitated in selected ion monitoring (SIM) mode. Iodine attachment LC/MS analysis provided high sensitivity, superior to GC/MS. It greatly simplified sample preparation and increased throughput. The advantages of iodine attachment can be realized even on old mass spectrometers. A LOD of 50 pg glucose on column was achieved. Due to iodine's predisposition to sublimate, the iodoform concentration must be minimized, which adds complexity to method development. To optimize reagent concentration we developed an efficient and flexible gradient-based delivery platform. Strategy for method development with iodoform is given

  7. Molecular beams

    International Nuclear Information System (INIS)

    This book is a timeless and rather complete theoretical and experimental treatment of electric and magnetic resonance molecular-beam experiments for studying the radio frequency spectra of atoms and molecules. The theory of interactions of the nucleus with atomic and molecular fields is extensively presented. Measurements of atomic and nuclear magnetic moments, electric multipole moments, and atomic fine and hyperfine structure are detailed. Useful but somewhat outdated chapters on gas kinetics, molecular beam design, and experimental techniques are also included

  8. Multipurpose hooks for elastic attachment

    Directory of Open Access Journals (Sweden)

    Siddharth Shashidhar Revankar

    2014-01-01

    Full Text Available As certain bracket systems do not include hooks on premolar brackets for elastic attachment, Kobayashi or custom made ligature hooks have proven as an alternative. However, these hooks tend to bend labially when used with heavy elastics and these elastics can even pop loose from the hooks on mouth opening. The following article describes an innovative multipurpose hook which is simple, stiff and inexpensive and can be used for engagement of class II elastics on premolars in case of missing molars as well as engagement of intermaxillary elastics for settling of occlusion in finishing stages. As the hooks can be prefabricated, this saves a lot of chair side time and is more practical for use in day-to-day orthodontic practice.

  9. Antecedents of maternal parenting stress: the role of attachment style, prenatal attachment, and dyadic adjustment in first-time mothers.

    Science.gov (United States)

    Mazzeschi, Claudia; Pazzagli, Chiara; Radi, Giulia; Raspa, Veronica; Buratta, Livia

    2015-01-01

    The transition to parenthood is widely considered a period of increased vulnerability often accompanied by stress. Abidin conceived parenting stress as referring to specific difficulties in adjusting to the parenting role. Most studies of psychological distress arising from the demands of parenting have investigated the impact of stress on the development of dysfunctional parent-child relationships and on adult and child psychopathology. Studies have largely focused on mothers' postnatal experience; less attention has been devoted to maternal prenatal characteristics associated with subsequent parental stress and studies of maternal prenatal predictors are few. Furthermore, no studies have examined that association exclusively with samples of first-time mothers. With an observational prospective study design with two time periods, the aim of this study was to investigate the role of mothers' attachment style, maternal prenatal attachment to the fetus and dyadic adjustment during pregnancy (7th months of gestation) and their potential unique contribution to parenting stress 3 months after childbirth in a sample of nulliparous women. Results showed significant correlations between antenatal measures. Maternal attachment style (especially relationship anxiety) was negatively correlated with prenatal attachment and with dyadic adjustment; positive correlations resulted between prenatal attachment and dyadic adjustment. Each of the investigated variables was also good predictor of parenting stress 3 months after childbirth. Findings suggested how these dimensions could be considered as risk factors in the transition to motherhood and in the very beginning of the emergence of the caregiving system, especially with first-time mothers. PMID:26441808

  10. Antecedents of maternal parenting stress: the role of attachment style, prenatal attachment and dyadic adjustment in first-time mothers

    Directory of Open Access Journals (Sweden)

    Claudia eMazzeschi

    2015-09-01

    Full Text Available The transition to parenthood is widely considered a period of increased vulnerability often accompanied by stress. Abidin conceived parenting stress as referring to specific difficulties in adjusting to the parenting role. Most studies of psychological distress arising from the demands of parenting have investigated the impact of stress on the development of dysfunctional parent-child relationships and on adult and child psychopathology. Studies have largely focused on mothers’ postnatal experience; less attention has been devoted to maternal prenatal characteristics associated with the subsequent parental stress and studies of maternal prenatal predictors are few. Furthermore, no studies have examined that association exclusively with samples of first-time mothers. With an observational prospective study design with two time periods, the aim of this study was to investigate the role of mothers’ attachment style, maternal prenatal attachment to the fetus and dyadic adjustment during pregnancy (7th month of gestation and their potential unique contribution to parenting stress three months after childbirth in a sample of nulliparous women. Results showed significant correlations between antenatal measures. Maternal attachment style (especially relationship anxiety was negatively correlated with prenatal attachment and with dyadic adjustment; positive correlations resulted between prenatal attachment and dyadic adjustment. Each of the investigated variables was also good predictor of parenting stress three months after childbirth. Findings suggested how these dimensions could be considered as risk factors in the transition to motherhood and in the very beginning of the emergence of the caregiving system, especially with first-time mothers

  11. Electron attachment to biological relevant molecules

    International Nuclear Information System (INIS)

    Full text: The interaction of low energy electrons with compounds of DNA/RNA leading to negative ions gives insight into radiation damage processes in human cells. We demonstrate that electrons at sub excitation energies (- with X = T, C, U or G. This observation has significant consequences for the molecular picture of radiation damage, i.e. genotoxic effects or damage of living cells due to the secondary component of high energy radiation. The present experiment is performed in a crossed electron/neutral molecule beam arrangement. A highly monochromatized electron beam, generated by an electrostatic hemispherical electron monochromator, interacts with an effusive molecular beam of biomolecules. Negative ions are extracted from the collision region and focused into a quadrupole mass spectrometer, where they are mass analyzed and detected by single pulse counting electronics. In the present measurements the dominant negative ions formed via electron attachment (EA) reaction to T, C, U and G, are (T-H)-, (C-H)-, (U-H)- and (G-H)-. Using a simple calibration procedure, values for the respective partial EA cross section for (T-H)-, (C-H)-, (U-H)-, and (G-H)- could be determined yielding a peak value of σ (1.05 eV) = 1.2 x 10-19 m2, σ (1.54 eV) = 2.3 x 10-20 m2, σ (1.0 eV) = 3 x 10-20 m2, σ (1.3 eV) = 5 x 10-20 m2 , respectively. At higher electron energies, we observe further product anions, but at significantly lower cross sections. (author)

  12. A bio-inspired design strategy: Organization of tryptophan-appended naphthalenediimide into well-defined architectures induced by molecular interactions

    Science.gov (United States)

    Avinash, M. B.; Govindaraju, T.

    2011-06-01

    The chemistry of molecular assemblies involves weak yet complex non-covalent interactions, and the molecular organization of the π-conjugated material is crucial in determining the performance of an organic electronic device. Herein we demonstrate a bioinspired design strategy to tune the self-assembly of naphthalenediimides (NDIs) by minute structural variations, π-π stacking, hydrophobic interactions and metal interactions. We address some of the limitations associated with current design strategies, such as restriction to a specific molecular interaction or the difficulty in controlling the assembly due to several complicated intermolecular interactions. Hydrophobic-effect-induced J-type aggregation and sodium-interaction-induced H-type aggregation of tryptophan-appended NDIs have been illustrated. 1H NMR spectra further reveal sodium cation-π interactions in tryptophan-appended NDIs, while NMR and IR spectroscopic studies confirm the structural variations associated with the molecular assembly. In summary, the molecular organization has been successfully transformed from nanospheres to particles, nanobelts, fibers and fractals. Such drastic changes in the morphology are clear and striking evidence of the importance of non-trivial weak non-covalent forces.The chemistry of molecular assemblies involves weak yet complex non-covalent interactions, and the molecular organization of the π-conjugated material is crucial in determining the performance of an organic electronic device. Herein we demonstrate a bioinspired design strategy to tune the self-assembly of naphthalenediimides (NDIs) by minute structural variations, π-π stacking, hydrophobic interactions and metal interactions. We address some of the limitations associated with current design strategies, such as restriction to a specific molecular interaction or the difficulty in controlling the assembly due to several complicated intermolecular interactions. Hydrophobic-effect-induced J-type aggregation

  13. Estratégia de simplificação molecular no planejamento racional de fármacos: a descoberta de novo agente cardioativo Strategy of molecular simplification in rational drug design: the discovery of a new cardioactive agent

    Directory of Open Access Journals (Sweden)

    Eliezer J. Barreiro

    2002-12-01

    Full Text Available In this article are described examples of the successful use of molecular simplification strategy in the discovery of new drugs from bioactive natural products and synthetic compounds. The discovery of a new cardiotonic derivative (37, 2-thienylidene-3,4-methylenedioxybenzoylhydrazine; LASSBio-294, efficiently synthesized from Brazilian natural product and structurally designed by molecular simplification of active pyridazinone compounds reported in the literature, is described. A brief description of the pharmacological profile of this new cardiotonic lead-compound, belonging to the N-acylhydrazone (NAH class, is also reported herein.

  14. SSZ-13 Crystallization by Particle Attachment and Deterministic Pathways to Crystal Size Control.

    Science.gov (United States)

    Kumar, Manjesh; Luo, Helen; Román-Leshkov, Yuriy; Rimer, Jeffrey D

    2015-10-14

    Many synthetic and natural crystalline materials are either known or postulated to grow via nonclassical pathways involving the initial self-assembly of precursors that serve as putative growth units for crystallization. Elucidating the pathway(s) by which precursors attach to crystal surfaces and structurally rearrange (postattachment) to incorporate into the underlying crystalline lattice is an active and expanding area of research comprising many unanswered fundamental questions. Here, we examine the crystallization of SSZ-13, which is an aluminosilicate zeolite that possesses exceptional physicochemical properties for applications in separations and catalysis (e.g., methanol upgrading to chemicals and the environmental remediation of NO(x)). We show that SSZ-13 grows by two concerted mechanisms: nonclassical growth involving the attachment of amorphous aluminosilicate particles to crystal surfaces and classical layer-by-layer growth via the incorporation of molecules to advancing steps on the crystal surface. A facile, commercially viable method of tailoring SSZ-13 crystal size and morphology is introduced wherein growth modifiers are used to mediate precursor aggregation and attachment to crystal surfaces. We demonstrate that small quantities of polymers can be used to tune crystal size over 3 orders of magnitude (0.1-20 μm), alter crystal shape, and introduce mesoporosity. Given the ubiquitous presence of amorphous precursors in a wide variety of microporous crystals, insight of the SSZ-13 growth mechanism may prove to be broadly applicable to other materials. Moreover, the ability to selectively tailor the physical properties of SSZ-13 crystals through molecular design offers new routes to optimize their performance in a wide range of commercial applications. PMID:26376337

  15. Association Between Insecure Attachment and ADHD

    DEFF Research Database (Denmark)

    Storebo, Ole Jakob; Darling Rasmussen, Pernille; Simonsen, Erik

    2016-01-01

    Objective: Psychological theories have postulated an association between insecure attachment and ADHD. The objective of this study is to investigate possible association between insecure attachment and ADHD in children and adults. Method: Review of literature was performed using the Psyc......INFO, Medline, and EMBASE databases. Results: Twenty-nine studies were included in the review. Overall, the studies showed that parental attachment problems and environmental mediating factors were significantly associated with childhood ADHD. Adults with ADHD had a much higher incidence of insecure attachment...... styles than reported in the general population. Conclusion: There seems to be a clear association between ADHD and insecure attachment. It is likely that early intervention in the form of parent training and pharmacological treatment may prevent development of attachment problems. But such studies have...

  16. Design of Acceptors with Suitable Frontier Molecular Orbitals to Match Donors via Substitutions on Perylene Diimide for Organic Solar Cells

    Science.gov (United States)

    Lv, Xiaoli; Li, Zhuoxin; Li, Songyang; Luan, Guoyou; Liang, Dadong; Tang, Shanshan; Jin, Ruifa

    2016-01-01

    A series of perylene diimide (PDI) derivatives have been investigated at the CAM-B3LYP/6-31G(d) and the TD-B3LYP/6-31+G(d,p) levels to design solar cell acceptors with high performance in areas such as suitable frontier molecular orbital (FMO) energies to match oligo(thienylenevinylene) derivatives and improved charge transfer properties. The calculated results reveal that the substituents slightly affect the distribution patterns of FMOs for PDI-BI. The electron withdrawing group substituents decrease the FMO energies of PDI-BI, and the electron donating group substituents slightly affect the FMO energies of PDI-BI. The di-electron withdrawing group substituents can tune the FMOs of PDI-BI to be more suitable for the oligo(thienylenevinylene) derivatives. The electron withdrawing group substituents result in red shifts of absorption spectra and electron donating group substituents result in blue shifts for PDI-BI. The –CN substituent can improve the electron transport properties of PDI-BI. The –CH3 group in different positions slightly affects the electron transport properties of PDI-BI. PMID:27187370

  17. A regenerable fluorescent quantum dot based nanoprobe for zinc(II), and the design of a molecular logic gate

    International Nuclear Information System (INIS)

    We report on a simple, sensitive and regenerable fluorescent nanoprobe for Zn(II) ion. It is based on the use of glutathione capped CdTe quantum dots (GSH-CdTe Q-dots). The bright fluorescence of these Q-dots is quenched on addition of diethylenetriaminepentaacetic acid (DTPA) due to the binding of DTPA to GSH. If, however, Zn(II) is added, it will bind DTPA and detach it from the surface of the Q-dots, this resulting in the fluorescence recovery. Under optimum conditions, the intensity of the restored fluorescence is proportional to the concentration of Zn(II) in the 0.48 to 90 μmol · L−1 range, with a limit of detection of 0.14 μmol · L−1. The nanoprobe was applied to the determination of Zn(II) in spiked tap water and river water and gave satisfactory results. The findings were also applied to design a molecular logic gate where DTPA acts as the first input to the system by quenching the fluorescence of the GSH-CdTe Q-dots. Zn(II) acts as the second input and causes the detachment of DTPA from the Q-dots and a restoration of fluorescence. This system therefore represents a new IMP (IMPLICATION) logic gate. (author)

  18. Fabrication of an electrochemical sensor based on computationally designed molecularly imprinted polymer for the determination of mesalamine in real samples

    International Nuclear Information System (INIS)

    A novel electrochemical sensor based on mesalamine molecularly imprinted polymer (MIP) film on a glassy carbon electrode was fabricated. Density functional theory (DFT) in gas and solution phases was developed to study the intermolecular interactions in the pre-polymerization mixture and to find the suitable functional monomers in MIP preparation. On the basis of computational results, o-phenylenediamine (OP), gallic acid (GA) and p-aminobenzoic acid (ABA) were selected as functional monomers. The MIP film was cast on glassy carbon electrode by electropolymerization of solution containing ternary monomers and then followed by Ag dendrites (AgDs) with nanobranch deposition. The surface feature of the modified electrode (AgDs/MIP/GCE) was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Under the optimal experimental conditions, the peak current was proportional to the concentration of mesalamine ranging from 0.05 to 100 μM, with the detection limit of 0.015 μM. The proposed sensor was applied successfully for mesalamine determination in real samples. - Highlights: • The determination of MES using AgDs/MIP/GCE is reported for the first time. • The computer assisted design of terpolymer MIPs was used to screen monomers. • Theoretical results of DFT approach were in agreement with experimental results. • The sensor displayed a high selectivity for template in the presence of interferes. • The developed sensor has been applied to determine mesalamine in real samples

  19. Adsorption of Electrolytes within Narrow Slit-Shaped Silica Pores: Molecular Dynamics Simulation Results to Design Separation Strategies

    Science.gov (United States)

    Striolo, Alberto; Argyris, Dimitrios

    2010-03-01

    We report equilibrium molecular dynamics simulation results for structural and dynamic properties of aqueous electrolyte solutions confined within narrow pores. The slit-shaped pores are carved from cristobalite silica and show various degrees of hydroxylation. The pore width is in the range 08 -- 2.0 nm. The aqueous solutions contain NaCl, CsCl, CaCl2, and SrCl2 electrolytes at 1M concentration or larger. Simulations are performed at ambient conditions within the NVT ensemble. The results are analyzed in terms of density profiles away from the solid substrates, self diffusion coefficients in the direction parallel to the solid substrate, and residence time at contact with the solid substrate. The data suggest the formation of layered structures, consistent with results obtained for thin films of solution supported on free-standing surfaces. Because the self-diffusion coefficient is faster as the distance from the solid increases, the ions that are at the pore center diffuse more quickly through the pore than those adsorbed closer to the wall. Further, our results are important for exploring and understanding Hofmeister effects under confinement, and also for deploying a number of practical applications including water desalination, remediating nuclear waste sites, and designing nanofluidic devices.

  20. Fabrication of an electrochemical sensor based on computationally designed molecularly imprinted polymer for the determination of mesalamine in real samples

    Energy Technology Data Exchange (ETDEWEB)

    Torkashvand, M. [Department of Analytical Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Gholivand, M.B., E-mail: mbgholivand@yahoo.com [Department of Analytical Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Taherkhani, F. [Department of Physical Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of)

    2015-10-01

    A novel electrochemical sensor based on mesalamine molecularly imprinted polymer (MIP) film on a glassy carbon electrode was fabricated. Density functional theory (DFT) in gas and solution phases was developed to study the intermolecular interactions in the pre-polymerization mixture and to find the suitable functional monomers in MIP preparation. On the basis of computational results, o-phenylenediamine (OP), gallic acid (GA) and p-aminobenzoic acid (ABA) were selected as functional monomers. The MIP film was cast on glassy carbon electrode by electropolymerization of solution containing ternary monomers and then followed by Ag dendrites (AgDs) with nanobranch deposition. The surface feature of the modified electrode (AgDs/MIP/GCE) was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Under the optimal experimental conditions, the peak current was proportional to the concentration of mesalamine ranging from 0.05 to 100 μM, with the detection limit of 0.015 μM. The proposed sensor was applied successfully for mesalamine determination in real samples. - Highlights: • The determination of MES using AgDs/MIP/GCE is reported for the first time. • The computer assisted design of terpolymer MIPs was used to screen monomers. • Theoretical results of DFT approach were in agreement with experimental results. • The sensor displayed a high selectivity for template in the presence of interferes. • The developed sensor has been applied to determine mesalamine in real samples.

  1. Novel nanodispersed coal liquefaction catalysts: Molecular design via microemulsion-based synthesis. Technical progress report, July--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Boakye, E.; Vittal, M.; Osseo-Asare, K. [and others

    1993-10-01

    The objective of this project is to pursue the development of highly dispersed and inexpensive catalysts for improved coal solubilization and upgrading of coal liquids. A novel study of the synthesis of liquefaction catalysts of manometer size is being carried out. It is based on the molecular design of inverse micelles (microemulsions). These surfactant-stabilized, metal-bearing microdrops offer unique opportunities for synthesizing very small particles by providing a cage-like effect that limits particle nucleation, growth and agglomeration. The emphasis is on molybdenum- and iron-based catalysts, but the techniques being developed should also be generally applicable. The size of these very small and monodispersed particles will be accurately determined both separately and after in situ and ex situ coal impregnation. The as-prepared nanoparticles as well as the catalyst-impregnated coal matrix are characterized using a battery of techniques, including dynamic light scattering, x-ray diffraction and transmission electron microscopy. Catalytic activity tests are conducted under standardized coal liquefaction conditions. The effects of particle size of these unsupported catalysts on the product yield and distribution during conversion of a bituminous and a subbituminous coal are being determined.

  2. Bad blood revisited: Attachment and psychoanalysis, 2015

    OpenAIRE

    Fonagy, P; Campbell, C

    2015-01-01

    "There is bad blood between psychoanalysis and attachment theory. As with many family feuds, it is hard to identify where the problem began. (Fonagy, 2001, p.1)" Thus began an attempt, Attachment Theory and Psychoanalysis, written 15 years ago, to trace the relationship between attachment and psychoanalysis, disentangle conceptual similarities and differences, and point to areas of convergence that were then emerging in the field. Here, we will attempt a conceptual progress report on how thin...

  3. Emergence of tempered preferential attachment from optimization

    OpenAIRE

    D'Souza, Raissa M.; Borgs, Christian; Chayes, Jennifer T.; Berger, Noam; Kleinberg, Robert D.

    2007-01-01

    We show how preferential attachment can emerge in an optimization framework, resolving a long-standing theoretical controversy. We also show that the preferential attachment model so obtained has two novel features, saturation and viability, which have natural interpretations in the underlying network and lead to a power-law degree distribution with exponential cutoff. Moreover, we consider a generalized version of this preferential attachment model with independent saturation and viability, ...

  4. Explaining gender differences in preschoolers’ attachment style

    OpenAIRE

    Tønnessen, Ellen

    2014-01-01

    Gender has throughout most attachment literature not been considered an important factor in the development of individual differences in attachment. However, some studies on preschoolers, especially using story completion/narrative measures of attachment representations, have found prominent gender differences. The present study aims to replicate such gender differences, and to examine possible explanatory variables. This will be done by using a large community sample of preschoolers from Nor...

  5. Positron-molecule interactions: resonant attachment, annihilation, and bound states

    CERN Document Server

    Gribakin, G F; Surko, C M; 10.1103/RevModPhys.82.2557

    2010-01-01

    This article presents an overview of current understanding of the interaction of low-energy positrons with molecules with emphasis on resonances, positron attachment and annihilation. Annihilation rates measured as a function of positron energy reveal the presence of vibrational Feshbach resonances (VFR) for many polyatomic molecules. These resonances lead to strong enhancement of the annihilation rates. They also provide evidence that positrons bind to many molecular species. A quantitative theory of VFR-mediated attachment to small molecules is presented. It is tested successfully for selected molecules (e.g., methyl halides and methanol) where all modes couple to the positron continuum. Combination and overtone resonances are observed and their role is elucidated. In larger molecules, annihilation rates from VFR far exceed those explicable on the basis of single-mode resonances. These enhancements increase rapidly with the number of vibrational degrees of freedom. While the details are as yet unclear, intr...

  6. A conserved haem redox and trafficking pathway for cofactor attachment

    Science.gov (United States)

    Richard-Fogal, Cynthia L; Frawley, Elaine R; Bonner, Eric R; Zhu, Huifen; San Francisco, Brian; Kranz, Robert G

    2009-01-01

    A pathway for cytochrome c maturation (Ccm) in bacteria, archaea and eukaryotes (mitochondria) requires the genes encoding eight membrane proteins (CcmABCDEFGH). The CcmABCDE proteins are proposed to traffic haem to the cytochrome c synthetase (CcmF/H) for covalent attachment to cytochrome c by unknown mechanisms. For the first time, we purify pathway complexes with trapped haem to elucidate the molecular mechanisms of haem binding, trafficking and redox control. We discovered an early step in trafficking that involves oxidation of haem (to Fe3+), yet the final attachment requires reduced haem (Fe2+). Surprisingly, CcmF is a cytochrome b with a haem never before realized, and in vitro, CcmF functions as a quinol:haem oxidoreductase. Thus, this ancient pathway has conserved and orchestrated mechanisms for trafficking, storing and reducing haem, which assure its use for cytochrome c synthesis even in limiting haem (iron) environments and reducing haem in oxidizing environments. PMID:19629033

  7. Rate coefficients for dissociative attachment and resonant electron-impact dissociation involving vibrationally excited O{sub 2} molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laporta, V. [Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari, Italy and Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Celiberto, R. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica, Politecnico di Bari, Italy and Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari (Italy); Tennyson, J. [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2014-12-09

    Rate coefficients for dissociative electron attachment and electron-impact dissociation processes, involving vibrationally excited molecular oxygen, are presented. Analytical fits of the calculated numerical data, useful in the applications, are also provided.

  8. Fundamentals in Microalgae Harvesting: From Flocculation to Self-attachment

    Science.gov (United States)

    Cui, Yan

    envisioned algal attachment, the third objective was to investigate the cell to substrata attachment by a thermodynamic model. Based on the theoretical analysis, when the polar surface energy of the cell is greater than that of water, cellular attachment would be more favorable on materials with higher dispersive surface energy but lower polar surface energy. If the polar surface energy of the cell is smaller than that of water, more cell attachment would be expected on materials that are higher in both dispersive and polar surface energies. The model was also validated its capability in designing, selecting, and matching algal strains and solid carrier materials to enhance cell attachment. The forth objective was to investigate the effect of surface texturing on algal attachment. It was found that surface texturing had a greater effect than surface free energy, by changing the liquid wetting behavior and real contact area. The attachment is preferred when the feature size is close to the diameter of the cell attempting to settle. Larger or smaller feature dimensions have the potential to reduce cellular attachment. The fifth objective was to study the role of carrier materials and their surface roughness in attachment. If the surface chemical composition was similar, the attachment and orientation of algal cells was found to depend on the surface average roughness, wherein rougher surfaces resulted in increased attachment. Whereas, the attachment was strongly related to surface free energy as described by the thermodynamic model if materials were chemically different.

  9. Temperament and attachment: one construct or two?

    Science.gov (United States)

    Mangelsdorf, S C; Frosch, C A

    1999-01-01

    In this chapter we described the constructs of temperament and attachment and have discussed similarities and differences between the two. We addressed the issue of whether temperament contributes to overall attachment security or to the specific type of attachment that children display. We conclude that although temperament may influence the type of secure and insecure attachment relationship children form with their parent, temperament alone will not determine if a child is classified as securely or insecurely attached. We presented evidence suggesting that certain dimensions of temperament, specifically negative emotionality, may be associated with infants' behavior during the Strange Situation, such as proneness-to-distress during separations. However, we noted that these temperament dimensions do not predict overall security of attachment. It is likely that although no single temperament characteristic, such as proneness-to-distress, in and of itself determines overall attachment security, it is possible that a constellation of temperament characteristics may be more strongly related to attachment security. The examination of constellations of temperament characteristics may be particularly useful for furthering our understanding of individual differences within attachment classifications. Such an approach may elucidate the reasons why infants are classified into one subgroup of secure, insecure-avoidant, or insecure-resistant attachment versus another subgroup. Furthermore, we suggest that the collection of findings regarding temperament and attachment not only underscores the importance of a transactional approach to early social-emotional development, but emphasizes that temperament and attachment can make unique and interactive contributions to children's social-emotional functioning. That is, the goodness-of-fit between infant and parent characteristics may best predict security of attachment. Although child characteristics clearly contribute to the

  10. Attachment theory: Old and new approach

    Directory of Open Access Journals (Sweden)

    Polovina Nada

    2005-01-01

    Full Text Available The article is an attempt to present holistically the key concepts of attachment theory rediscovered for its potentials. The presented concepts include: narrow definition of attachment, behavioral control system of attachment, attachment working model and patterns of attachment. The concepts are presented in the context of child attachment theory and adult attachment theory, in addition to description of the development of attachment. Concepts, as well as developmental processes are presented from the stand point of pioneers in this field (John Bowlby and Mary Ainsworth as well as from the standpoint of their successors (Everett Waters and Malcolm West. Compacted ness of the theory, possibilities for operationalization of its key concepts and its application to empirical studies of complex psychological issues that have never been scientifically explored, makes it a very prospective theory in view of possible integration of existing research findings and initiating new research and new practices in psychotherapy, social work and work in schools. The goal of this integral presentation of attachment theory is to highlight its benefits and possibilities for understanding and research complex field of human's psychosocial functioning.

  11. Sine-Bar Attachment For Machine Tools

    Science.gov (United States)

    Mann, Franklin D.

    1988-01-01

    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  12. Hamiltonian dynamics of preferential attachment

    Science.gov (United States)

    Zuev, Konstantin; Papadopoulos, Fragkiskos; Krioukov, Dmitri

    2016-03-01

    Prediction and control of network dynamics are grand-challenge problems in network science. The lack of understanding of fundamental laws driving the dynamics of networks is among the reasons why many practical problems of great significance remain unsolved for decades. Here we study the dynamics of networks evolving according to preferential attachment (PA), known to approximate well the large-scale growth dynamics of a variety of real networks. We show that this dynamics is Hamiltonian, thus casting the study of complex networks dynamics to the powerful canonical formalism, in which the time evolution of a dynamical system is described by Hamilton’s equations. We derive the explicit form of the Hamiltonian that governs network growth in PA. This Hamiltonian turns out to be nearly identical to graph energy in the configuration model, which shows that the ensemble of random graphs generated by PA is nearly identical to the ensemble of random graphs with scale-free degree distributions. In other words, PA generates nothing but random graphs with power-law degree distribution. The extension of the developed canonical formalism for network analysis to richer geometric network models with non-degenerate groups of symmetries may eventually lead to a system of equations describing network dynamics at small scales.

  13. Hamiltonian dynamics of preferential attachment

    International Nuclear Information System (INIS)

    Prediction and control of network dynamics are grand-challenge problems in network science. The lack of understanding of fundamental laws driving the dynamics of networks is among the reasons why many practical problems of great significance remain unsolved for decades. Here we study the dynamics of networks evolving according to preferential attachment (PA), known to approximate well the large-scale growth dynamics of a variety of real networks. We show that this dynamics is Hamiltonian, thus casting the study of complex networks dynamics to the powerful canonical formalism, in which the time evolution of a dynamical system is described by Hamilton’s equations. We derive the explicit form of the Hamiltonian that governs network growth in PA. This Hamiltonian turns out to be nearly identical to graph energy in the configuration model, which shows that the ensemble of random graphs generated by PA is nearly identical to the ensemble of random graphs with scale-free degree distributions. In other words, PA generates nothing but random graphs with power-law degree distribution. The extension of the developed canonical formalism for network analysis to richer geometric network models with non-degenerate groups of symmetries may eventually lead to a system of equations describing network dynamics at small scales. (paper)

  14. Coexistence in preferential attachment networks

    CERN Document Server

    Antunović, Tonći; Racz, Miklos Z

    2013-01-01

    Competition in markets is ubiquitous: cell-phone providers, computer manufacturers, and sport gear brands all vie for customers. Though several coexisting competitors are often observed in empirical data, many current theoretical models of competition on small-world networks predict a single winner taking over the majority of the network. We introduce a new model of product adoption that focuses on word-of-mouth recommendations to provide an explanation for this coexistence of competitors. The key property of our model is that customer choices evolve simultaneously with the network of customers. When a new node joins the network, it chooses neighbors according to preferential attachment, and then chooses its type based on the number of initial neighbors of each type. This can model a new cell-phone user choosing a cell-phone provider, a new student choosing a laptop, or a new athletic team member choosing a gear provider. We provide a detailed analysis of the new model; in particular, we determine the possibl...

  15. Dissociative Electron Attachment to NO, CO and N2O in a 0.5 T Magnetic Field

    International Nuclear Information System (INIS)

    Dissociative electron attachment to CO, NO and N2O is studied in a 0.5 T magnetic field. The magnetic field dependence of the attachment process is analyzed to understand the possible role of magnetically-coupled excited molecular states. The present technique converts the O−(2P) ions produced by the attachment to fast O(3P) by steps of ion acceleration and laser photodetachment. The resulting fast O(2P) atoms are then detected with a microchannel plate. This method facilitates analysis of any B-field enhancements in the resonant attachment phenomena, with minimal contribution from backgrounds of positive and negative charges.

  16. Unconventional, Chemically Stable, and Soluble Two-Dimensional Angular Polycyclic Aromatic Hydrocarbons: From Molecular Design to Device Applications

    KAUST Repository

    Zhang, Lei

    2015-03-17

    Polycyclic aromatic hydrocarbons (PAHs), consisting of laterally fused benzene rings, are among the most widely studied small-molecule organic semiconductors, with potential applications in organic field-effect transistors (OFETs) and organic photovoltaics (OPVs). Linear acenes, including tetracene, pentacene, and their derivatives, have received particular attention due to the synthetic flexibility in tuning their chemical structure and properties and to their high device performance. Unfortunately, longer acenes, which could exhibit even better performance, are susceptible to oxidation, photodegradation, and, in solar cells which contain fullerenes, Diels-Alder reactions. This Account highlights recent advances in the molecular design of two-dimensional (2-D) PAHs that combine device performance with environmental stability. New synthetic techniques have been developed to create stable PAHs that extend conjugation in two dimensions. The stability of these novel compounds is consistent with Clar\\'s sextet rule as the 2-D PAHs have greater numbers of sextets in their ground-state configuration than their linear analogues. The ionization potentials (IPs) of nonlinear acenes decrease more slowly with annellation in comparison to their linear counterparts. As a result, 2-D bistetracene derivatives that are composed of eight fused benzene rings are measured to be about 200 times more stable in chlorinated organic solvents than pentacene derivatives with only five fused rings.Single crystals of the bistetracene derivatives have hole mobilities, measured in OFET configuration, up to 6.1 cm2 V-1 s-1, with remarkable Ion/Ioff ratios of 107. The density functional theory (DFT) calculations can provide insight into the electronic structures at both molecular and material levels and to evaluate the main charge-transport parameters. The 2-D acenes with large aspect ratios and appropriate substituents have the potential to provide favorable interstack electronic interactions

  17. Measuring Patients’ Attachment Avoidance in Psychotherapy: Development of the Attachment Avoidance in Therapy Scale (AATS

    Directory of Open Access Journals (Sweden)

    András Láng

    2012-11-01

    Full Text Available A new scale measuring patient-therapist attachment avoidance was developed. Attachment Avoidance in Therapy Scale is a new measure based on the Bartholomew model of adult attachment (Bartholomew & Horowitz, 1991 and the Experience in Close Relationships Scale (Brennan, Clark, & Shaver, 1998 to measure patients’ attachment avoidance towards therapists. With 112 patient-therapist dyads participating in the study, validation of a preliminary scale – measuring both attachment anxiety and attachment avoidance in therapy – took place using therapists’ evaluations of patients’ relational behavior and patients’ self-reports about their attitude toward psychotherapy. Analysis of the data revealed six underlying scales. Results showed all six scales to be reliable. Validation of scales measuring attachment anxiety failed. The importance of Attachment Avoidance in Therapy Scale and its subscales is discussed.

  18. Experimental and Computational Mechanistic Studies Guiding the Rational Design of Molecular Electrocatalysts for Production and Oxidation of Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Raugei, Simone; Helm, Monte L.; Hammes-Schiffer, Sharon; Appel, Aaron M.; O' Hagan, Molly J.; Wiedner, Eric S.; Bullock, R. Morris

    2016-01-19

    Understanding how to control the movement of protons and electrons is crucial to the design of fast, efficient electrocatalysts for hydrogen production and oxidation based on earth-abundant metals. Our work seeks to elucidate fundamental questions about proton movement. We have demonstrated that incorporating a pendant amine functioning as a proton relay in the second coordination sphere of a metal complex helps proton mobility, resulting in faster and more energy efficient catalysts. Proton transfer reactions are often rate limiting, and are influenced by several factors, such as pKa values, steric effects, hydrogen bonding, and solvation/desolvation of the exogenous base and acid employed. The presence of multiple protonation sites introduces branching points along the catalytic cycle, making less productive pathways accessible, or leading to the formation of stable off-cycle species. Using ligands with only one pendant amine mitigates this problem and results in catalysts with high rates for production of H2. For H2 oxidation catalysts, iron complexes with a high H2 binding affinity were developed. However, the improvement of H2 binding enthalpy resulted in a pKa mismatch between the protonated metal center and the protonated pendant amine, and consequently to rate-limiting intramolecular proton movement. Taken altogether, our results demonstrate the necessity of optimizing the entire catalytic cycle, as the optimization of a specific catalytic step can negatively influence another step, and not necessarily lead to better catalytic performance. We discuss a general procedure, based on thermodynamic arguments, which allows the simultaneous minimization of the free energy change of each catalytic step, yielding a nearly flat free energy surface, with no large barriers due to energy mismatches from either high- or low-energy intermediates. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by

  19. Improvement of a new rotation function for molecular replacement by designing new scoring functions and dynamic correlation coefficient

    International Nuclear Information System (INIS)

    A previously published new rotation function has been improved by using a dynamic correlation coefficient as well as two new scoring functions of relative entropy and mean-square-residues to make the rotation function more robust and independent of a specific set of weights for scoring and ranking. The previously described new rotation function calculates the rotation function of molecular replacement by matching the search model directly with the Patterson vector map. The signal-to-noise ratio for the correct match was increased by averaging all the matching peaks. Several matching scores were employed to evaluate the goodness of matching. These matching scores were then combined into a single total score by optimizing a set of weights using the linear regression method. It was found that there exists an optimal set of weights that can be applied to the global rotation search and the correct solution can be ranked in the top 100 or less. However, this set of optimal weights in general is dependent on the search models and the crystal structures with different space groups and cell parameters. In this work, we try to solve this problem by designing a dynamic correlation coefficient. It is shown that the dynamic correlation coefficient works for a variety of space groups and cell parameters in the global search of rotation function. We also introduce two new matching scores: relative entropy and mean-square-residues. Last but not least, we discussed a valid method for the optimization of the adjustable parameters for matching vectors. (condensed matter: structure, thermal and mechanical properties)

  20. Computational molecular modeling and structural rationalization for the design of a drug-loaded PLLA/PVA biopolymeric membrane

    Energy Technology Data Exchange (ETDEWEB)

    Sibeko, B; Pillay, V; Choonara, Y E; Khan, R A; Danckwerts, M P [Department of Pharmacy and Pharmacology, University of the Witwatersrand, 7 York Road, Parktown, 2193 Johannesburg (South Africa); Modi, G [Division of Neurosciences, Department of Neurology, University of the Witwatersrand, Johannesburg (South Africa); Iyuke, S E [School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg (South Africa); Naidoo, D, E-mail: viness.pillay@wits.ac.z [Division of Neurosciences, Department of Neurosurgery, University of the Witwatersrand, Johannesburg (South Africa)

    2009-02-15

    The purpose of this study was to design, characterize and assess the influence of triethanolamine (TEA) on the physicomechanical properties and release of methotrexate (MTX) from a composite biopolymeric membrane. Conjugated poly(L-lactic acid) (PLLA) and poly(vinyl alcohol) (PVA) membranes were prepared by immersion precipitation with and without the addition of TEA. Drug entrapment efficiency (DEE) and release studies were performed in phosphate buffered saline (pH 7.4, 37 deg. C). Scanning electron microscopy elucidated the membrane surface morphology. Computational and structural molecular modeling rationalized the potential mechanisms of membrane formation and MTX release. Bi-axial force-distance (F-D) extensibility profiles were generated to determine the membrane toughness, elasticity and fracturability. Membranes were significantly toughened by the addition of TEA as a discrete rubbery phase within the co-polymer matrix. MTX-TEA-PLLA-PVA membranes were tougher (F = 89 N) and more extensible (D = 8.79 mm) compared to MTX-PLLA-PVA (F = 35 N, D = 3.7 mm) membranes as a greater force of extension and fracture distance were required (N = 10). DEE values were relatively high (>80%, N = 5) for both formulations. Photomicrographs revealed distinct crystalline layered morphologies with macro-pores. MTX was released by tri-phasic kinetics with a lower fractional release of MTX from MTX-TEA-PLLA-PVA membranes compared to MTX-PLLA-PVA. TEA provided a synergistic approach to improving the membrane physicomechanical properties and modulation of MTX release. The composite biopolymeric membrane may therefore be suitable for the novel delivery of MTX in the treatment of chronic primary central nervous system lymphoma.

  1. Molecular Design, Graft Polymerization and Performance Evaluation of Radiation Curable Flame Retardant Monomers Derived from Phosphorus-Nitrogen Systems

    Science.gov (United States)

    Edwards, Brian Tyndall

    The textile industry is constantly seeking new technologies to make its production more efficient, economical and environmentally friendly. An exciting new strategy to impart value-added functional finishes to textiles is the use of radiation, such as ultraviolet (UV) light, to drive the polymerization of monomers onto the surface of the substrates. These grafted polymeric layers provide the fiber or fabric with interesting new properties, such as antimicrobial behavior, water and oil repellency or flame retardancy. With the aid of a photoinitiator, UV curing can take place very rapidly and the process is waterless and uses less energy than traditional textile wet processing. With these thoughts in mind, this research explores the molecular design, synthesis, UV induced graft polymerization and performance evaluation of nine phosphorus-based flame retardant monomers for cellulosic cotton substrates. All monomers in this work were easily prepared using one-pot reactions procedures. With the assistance of Irgacure 819 photoinitiator, seven of the nine monomers were shown to simultaneously graft and polymerize onto the surface of cotton fabrics under UV radiation. JMPRTM Pro 10 software was used to explore the effect of variables, such as monomer concentration, photoinitiator concentration and UV exposure time, on the yield of the grafted polymeric layer. Burn testing of the treated fabrics in the vertical, 45° and horizontal orientations showed that all nine monomers were effective flame retardants that function via the condensed phase mechanism by encouraging the formation of nonflammable char. These burn test results were validated by thermogravimetric analysis, which demonstrated quantitatively that all nine monomers strongly promote the generation of a protective char. Finally, scanning electron microscopy was used to examine the surface morphology of the treated fabrics and visualize the grafted polymeric layer.

  2. Designing and preparation of novel alkaloid-imprinted membrane with grafting type and its molecular recognition characteristic and permselectivity.

    Science.gov (United States)

    Gao, Baojiao; Zhang, Liqin; Li, Yanbin

    2016-09-01

    A novel polysulfone-based molecularly imprinted membrane (MIM) with graft type (designated as GMIM) was successfully prepared by a combination of film-forming method of immersion-precipitation phase transformation with molecule surface-imprinting technique. The porous asymmetry membrane of chloromethylated polysulfone (CMPSF) was first prepared by a phase inversion method, and then the CMPSF membrane was amination-modified with ethanediamine as reagent, resulting aminated polysulfone membrane AMPSF, on whose surface primary amino groups were contained. Then the graft-polymerization of methacrylic acid (MAA) was realized by initiating of the surface-initiating system of -NH2/S2O8(-), obtaining the grafted membrane PSF-g-PMAA. After PSF-g-PMAA membrane adsorbed matrine, the crosslinking reaction of the grafted PMAA was allowed to be carried out with ethylene glycol diglycidyl ether (EGDE) as crosslinker, resulting in the matrine imprinted membrane with graft type, GMIM. The binding characteristics of the imprinted membrane GMIM, the permeability and separation property for matrine were investigated in depth. The experimental results show that the imprinted membrane consists of a thin imprinted layer, a thin skin layer containing channels at nanoscale and a support layer with macroporous structure. The imprinted membrane GMIM has specific recognition selectivity and excellent binding affinity for matrine, and its selectivity coefficient for matrine relative to cytisine is 4.85. More importantly, the imprinted membrane can produce good "gate effect" because of its own structure characteristic, so that it has fine permselectivity for the template, matrine molecule. The separation coefficient of the imprinted membrane GMIM for matrine relative to cytisine as a contrast reaches up to 5.9, displaying the excellent performance of a selectively permeable membrane. PMID:27207062

  3. Attachment of Salmonella spp. to pork meat

    DEFF Research Database (Denmark)

    Hansen, Trine; Riber, Leise; Löfström, Charlotta;

    2011-01-01

    Five strains of Salmonella, one wildtype and four knock-out mutants (the prg, flhDC, yhjH and fliC genes) were investigated based on their probability to attach and subsequently detach from a surface of pork fillet. The attachment followed by detachment was measured and modelled for two different...

  4. Attachment of Salmonella spp. to pork meat

    DEFF Research Database (Denmark)

    Hansen, Trine; Riber, Leise; Löfström, Charlotta; Hoorfar, Jeffrey

    Five strains of Salmonella, one wildtype and four knock-out mutants (the prg, flhDC, yhjH and fliC genes) were investigated based on their probability to attach and subsequently detach from a surface of pork fillet. The attachment followed by detachment was measured and modelled for two different...

  5. Attachment Theory Applied to Juvenile Sex Offending.

    Science.gov (United States)

    Goodrow, Kenneth K.; Lim, Mee-Gaik

    1998-01-01

    Attachment theory is applied to identify systemic patterns encouraging juveniles to commit sexual offenses. The role of the helping system in perpetuating offenses is reviewed. The priority of family integrity and the role of professionals in breaking cycles of abuse and repairing earlier destructive emotional attachments are discussed. (EMK)

  6. Attachment patterns and Mentalization in Traumatized Refugees

    DEFF Research Database (Denmark)

    Riber, Karin

    nærværende projekt bestod af de patienter i moderforsøget, som var arabisktalende (N=68). Måleredskaber består i The Adult Attachment Interview, The Reflective Functioning Scale, Revised Adult Attachment Scale, Working Alliance Inventory og Feeling Word Checklist-58. PTSD, depressions- og angstsymptomer...

  7. Study on thermocouple attachment in reflood experiments

    International Nuclear Information System (INIS)

    The method of thermocouple attachment to a heater rods has been studied for surface temperature measurement in reflood experiments. The method used as far in JAERI's reflood experiments had some possibilities of not estimating exactly the quench times. Various attachment method have been tested and some proved to be effective in the respect. (auth.)

  8. Adolescent Self-Esteem, Attachment and Loneliness

    Science.gov (United States)

    Dhal, Anubha; Bhatia, Sangeeta; Sharma, Vidhi; Gupta, Priyanka

    2007-01-01

    Objectives: To assess self-esteem, loneliness and attachment styles among adolescents and examine their association with each other and with age and gender. Method: Adolescents (55 males and 55 females) from a public school in Delhi, aged 10-13 years were administered Coopersmith Self-Esteem Inventory (School Form), Attachment Scale and UCLA…

  9. Romantic adult attachment and basic personality structure

    Directory of Open Access Journals (Sweden)

    Jelena Zeleskov Djoric

    2012-03-01

    Full Text Available The main goal of this study was localization of attachment dimensions in the space described by basic personality traits. Study purported to examine relations between attachment and basic personality structure, in a sample of 203 respondents. Romantic adult attachment was measured by the Experience in Close Relationship Scale, basic personality structure was assessed by the NEO-PI-R personality inventory, and Disintegration, which represents operationalization of Schizotypy as a basic personality trait, was estimated by the Delta 10 test. The results of Principal component analysis showed that attachment dimensions are not separate constructs in relation to basic personality traits. Furthermore, results indicate that attachment dimensions represent emotional dysregulation in close interpersonal relationships, because positive correlations are found between dimensions of Attachment and Mania (.35, Anxiety (.51 and Depression (.55. Negative correlations have been obtained between Attachment and Positive emotions (-.34 and Feelings (-.31. These results suggest that Attachment dimensions should be considered as an expression of basic personality traits in romantic adult's relationships.

  10. Attachment and Dependency in Developmental Perspective.

    Science.gov (United States)

    Sroufe, L. Alan; And Others

    1983-01-01

    Distinguishes between attachment (the relationship between infant and caregiver) and dependency (the reliance of the child on adults for nurturance, attention, or assistance). Assesses preschool children with varying attachment histories and suggests that the roots of overdependency lie in the quality of the early infant-caregiver relationship.…

  11. Bolting sequence for attaching the container to the strong-back for 241SY101

    International Nuclear Information System (INIS)

    This bolting sequence is for attaching the container to the strong-back for Tank 241-SY-101. This supporting document includes information for the proper bolting sequence for attaching the container to the strong-back is found in supporting document WHC-SD-WM-DA-165 (WHC 1994a) and is in accordance with Standard Arch-Civil Design Criteria, Design Loads for Facilities (SDC 4.1) Safety Class 3

  12. Attachment to spextrophotometers for measuring scattering patterns

    Energy Technology Data Exchange (ETDEWEB)

    Fsel' son, M.P.; Krikum, A.Z.; Sivyakov, Y.A.; Spivak, R.Y.

    1986-02-01

    The authors have developed a simple attachment to the Shimadsu MPS 50L spectrophotometer for measuring scattering patterns. The attachment is mounted directly at the cuvette section of the spectrophotometer. The radiation detector of the attachment is formed by an FR1-4 photoresistor disposed on the vertical section of a gamma-shaped bar adapted to be inclined by plus or minus 90 degrees with respect to the direction of the radiation beam. When the attachment is used, its radiation detector is connected into the measuring circuit of the spectrophotometer in place of the spectrophotometer's detector. When the spectrophotometer alone is used the detector of the attachment is moved out of the beam and the detector of the spectrophotometer proper is inserted into the measuring circuit.

  13. The Antimicrobial Activity of Porphyrin Attached Polymers

    Science.gov (United States)

    Thompson, Lesley

    2008-03-01

    We are interested in testing the antimicrobial activity of a porphyrin that is attached to a polymer. The porphyrin (5-(4-carboxyphenyl)-10,15,20-tris-(4-pryridyl)) was synthesized from methyl 4-formyl benzoate, 4-pyridinecarboxaldehyde, and pyrrole and attached to a copolymer of polystyrene/poly(vinyl benzyl chloride), which was synthesized by free radical polymerization. The antimicrobial activity of the polymer-attached porphyrin was then determined for gram-negative E. Coli grown to 0.80 OD. In this procedure, glass slides were coated with polymer-attached porphyrin via dip-coating, and the E. Coli bacteria were plated in Luria Broth media. The plates were subsequently exposed to light overnight before they were incubated as porphyrins act as photo-sensitizers when irradiated with light. The polymer-attached porphyrin did exhibit antimicrobial activity and parameters that affect its efficiency will be discussed.

  14. Attachment to groups: theory and measurement.

    Science.gov (United States)

    Smith, E R; Murphy, J; Coats, S

    1999-07-01

    Aspects of people's identification with groups may be understood by borrowing theoretical ideas and measurement strategies from research on attachment in close relationships. People have mental models of the self as a group member and of groups as sources of identity and esteem. These models affect thoughts, emotions, and behaviors related to group membership. Three studies show that two dimensions of attachment to groups, attachment anxiety and avoidance, can be assessed with good reliability, validity, and over-time stability. These factors are distinct from relationship attachment and from other measures of group identification. Group attachment predicts several important outcomes, including emotions concerning the group, time and activities shared with a group, social support, collective self-esteem, and ways of resolving conflict. This conceptualization provides new insights into the nature of people's psychological ties to groups. PMID:10434410

  15. Continuous monitoring of bacterial attachment

    Science.gov (United States)

    Koeing, D. W.; Mishra, S. K.; Pierson, D. L.

    1994-01-01

    A major concern with the Space Station Freedom (SSF) water supply system is the control of longterm microbial contamination and biofilm development in the water storage and distribution systems. These biofilms have the potential for harboring pathogens as well as microbial strains containing resistance factors that could negatively influence crew health. The proposed means for disinfecting the water system on SSF (iodine) may encourage the selection of resistant strains. In fact, biofilm bacteria were observed in water lines from the Space Shuttle Columbia (OV-102); therefore, an alternative remediation method is required to disinfect spacecraft water lines. A thorough understanding of colonization events and the physiological parameters that will influence bacteria adhesion is required. The limiting factor for development of this technology is the ability to continuously monitor adhesion events and the effects of biocides on sessile bacteria. Methods were developed to allow bacterial adhesion and subsequent biocidal treatment to be monitored continuously. This technique couples automated image analysis with a continuous flow of a bacterial suspension through an optical flow cell. A strain of Pseudomonas cepacia isolated from the water supply of the Space Shuttle Discovery (OV-103) during STS-39 was grown in a nitrogen-limited continuous culture. This culture was challenged continuously with iodine during growth, and the adhesion characteristics of this strain was measure with regard to flow rate. Various biocides (ozone, hypochlorite, and iodine) were added to the flow stream to evaluate how well each chemical removed the bacteria. After biocide treatment, a fresh bacterial suspension was introduced into the flow cell, and the attachment rate was evaluated on the previously treated surface. This secondary fouling was again treated with biocide to determine the efficacy of multiple batch chemical treatments in removing biofilm.

  16. Active screen plasma nitriding enhances cell attachment to polymer surfaces

    OpenAIRE

    Kaklamani, Georgia; Bowen, James; Mehrban, Nazia; Dong, Hanshan; Grover, Liam M.; Stamboulis, Artemis

    2013-01-01

    Active screen plasma nitriding (ASPN) is a well-established technique used for the surface modification of materials, the result of which is often a product with enhanced functional performance. Here we report the modification of the chemical and mechanical properties of ultra-high molecular weight poly(ethylene) (UHMWPE) using 80:20 (v/v) N2/H2 ASPN, followed by growth of 3T3 fibroblasts on the treated and untreated polymer surfaces. ASPN-treated UHMWPE showed extensive fibroblast attachment...

  17. Traffic of cytoskeletal motors with disordered attachment rates

    Science.gov (United States)

    Grzeschik, H.; Harris, R. J.; Santen, L.

    2010-03-01

    Motivated by experimental results on the interplay between molecular motors and tau proteins, we extend lattice-based models of intracellular transport to include a second species of particle which locally influences the motor-filament attachment rate. We consider various exactly solvable limits of a stochastic multiparticle model before focusing on the low-motor-density regime. Here, an approximate treatment based on the random-walk behavior of single motors gives good quantitative agreement with simulation results for the tau dependence of the motor current. Finally, we discuss the possible physiological implications of our results.

  18. New molecular scaffolds for the design of Mycobacterium tuberculosis type II dehydroquinase inhibitors identified using ligand and receptor based virtual screening.

    Science.gov (United States)

    Kumar, Ashutosh; Siddiqi, Mohammad Imran; Miertus, Stanislav

    2010-04-01

    Using ligand and receptor based virtual screening approaches we have identified potential virtual screening hits targeting type II dehydroquinase from Mycobacterium tuberculosis, an effective and validated anti-mycobacterial target. Initially, we applied a virtual screening workflow based on a combination of 2D structural fingerprints, 3D pharmacophore and molecular docking to identify compounds that rigidly match specific aspects of ligand bioactive conformation. Subsequently, the resulting compounds were ranked and prioritized using receptor interaction fingerprint based scoring and quantitative structure activity relationship model developed using already known actives. The virtual screening hits prioritized belong to several classes of molecular scaffolds with several available substitution positions that could allow chemical modification to enhance binding affinity. Finally, identified hits may be useful to a medicinal chemist or combinatorial chemist to pick up the new molecular starting points for medicinal chemistry optimization for the design of novel type II dehydroquinase inhibitors. PMID:19816720

  19. Radiative electronic attachment to molecules of astrophysical interest

    Science.gov (United States)

    Douguet, Nicolas; Kokoouline, Viatcheslav; Fonseca Dos Santos, Samantha; Dulieu, Olivier; Raoult, Maurice; Orel, Ann

    2013-05-01

    We have developed a first-principles approach to study the process of radiative electron attachment (REA) to linear molecules of astrophysical interest Mol +e- --> Mol- + ℏω (Mo l- = CnH-, CnN-). The approach is based on accurate ab initio calculations of electronic bound and continuum states of the negative ion, obtained through the complex Kohn variational method. We present our benchmark calculation for the formation of the simplest observed ion CN- by REA, as well as our preliminary results for the formation of C3N- and C4H- by REA. We calculated a low rate of 10-15cm3 / s at 30 K for CN- and rates about 20 time larger for C3N- and C4H- due to larger transition dipole moments. These two latter ions possess dipole states and we have also considered their potential role in the process of radiative electronic attachment. Finally, our results suggest that the negative molecular ions, recently observed in the interstellar medium, can hardly be formed by the process of radiative electron attachment. This work is supported by the DOE Office of Basic Energy Science and the National Science Foundation, Grant No's PHY-10-68785 and PHY-11-60611.

  20. Slides with no attached paper

    International Nuclear Information System (INIS)

    This document brings together the different presentations (slides) given at the workshop but with no attached paper. These slides refer to the following presentations: - Presentation of ITN (Instituto Tecnologico e Nuclear); - Minor Actinide Partitioning (Dominique Warin); - Transmutation (Janne Wallenius); - Radioactive Waste Management, IGD-TP (Gerald Ouzounian); - Present status of the Swedish nuclear waste management programme (Peter Wikberg); - The U.S. Fuel Cycle Research and Development Program - Separations Research and Development (Terry Todd); - Strategies and national programs of closed fuel cycles - Russian Expert Vision (Mikhael Kormilitsyn) - Extraction Studies Of Potential Solvent Formulations For The GANEX Process (Fiona MacLachlan); - Investigations of The Fundamental Chemistry of the TALSPEAK Process (Ken Nash); - Extraction Separation of Trivalent Minor Actinides and Lanthanides by Hexa-dentate Nitrogen-donor Extractant, TPEN, and its Analogs (Kenji Takeshita); - Fluorinated Diluents for HLW Processing - technological point of view (Vasiliy Babain); - Extraction properties of some new pyridine molecules and search for better diluents (Irena Spendlikova); - Kinetics of extraction of Eu3+ ion by TODGA and CyMe4-BTBP studied using the RMC technique (Trong Hung Vu); - Redox Chemistry of Neptunium in Solutions of Nitric Acid (Alena Paulenova); - NMR applied to actinide ions and their complexes. In search of covalency effects (Geoffrey Vidick); - Towards 'Stability Rules' for Radiolysis of bis-DGA compounds (Ana Nunez); - Pyroprocess Research Activities at IGCAR, Kalpakkam, India (K. Nagarajan); - Critical issues of nuclear energy systems employing molten salt fluorides: from ISTC No. 1606 to No. 3749 (1. year of project activity) and MARS/EVOL cooperation (Victor Ignatiev); - Conversion processes: Internal Gelation and the Sphere-pac concept (Manuel Pouchon); - A Combined Nuclear Technology and Nuclear Chemistry Master. A Unique Initiative

  1. Applying universal scaling laws to identify the best molecular design paradigms for third-order nonlinear optics

    CERN Document Server

    Perez-Moreno, Javier; Kuzyk, Mark G

    2016-01-01

    The scaling of the fundamental limits of the second hyperpolarizability is used to define the intrinsic second hyperpolarizability, which aids in identifying material classes with ultralarge nonlinear-optical response per unit of molecular size. The intrinsic nonlinear response is a size-independent metric that we apply to comparing classes of molecular homologues, which are made by adding repeat units to extend their lengths. Several new figures of merit are proposed that quantify not only the intrinsic nonlinear response, but also how the second hyperpolarizability increases with size within a molecular class. Scaling types can be classified into sub-scaling, nominal scaling that follows the theory of limits, and super-scaling behavior. Super-scaling homologues that have large intrinsic nonlinearity are the most promising because they efficiently take advantage of increased size. We apply our approach to data in the literature to identify the best super-scaling molecular paradigms and articulate the importa...

  2. Nuclear reactor fuel rod attachment system

    International Nuclear Information System (INIS)

    The invention involves a technique to quickly, inexpensively and rigidly attach a nuclear reactor fuel rod to a support member. The invention also allows for the repeated non-destructive removal and replacement of the fuel rod. The proposed fuel rod and support member attachment and removal system consists of a locking cap fastened to the fuel rod and a locking strip fastened to the support member or vice versa. The locking cap has two or more opposing fingers shaped to form a socket. The fingers spring back when moved apart and released. The locking strip has an extension shaped to rigidly attach to the socket's body portion

  3. The fourth pattern of attachment: Disorganized / disoriented

    Directory of Open Access Journals (Sweden)

    Zlatka Cugmas

    2003-09-01

    Full Text Available On the basis of the study of recent scientific literature about the development of attachment behavior, the author answers the following questions about: the behavior children categorized as Disorganized/disorientated or Controlling in the procedure of the Strange situation; the life circumstances, in which these children live; the reasons for lack of balanced strategies of attachment and characteristics of their general manner of adaptation. The author finds the characteristics of the mothers' (insensitivity to be significantly influential for the emergence of the fourth pattern of attachment. These children are heterogeneous regarding adaptation in general. Professional help preceding negative consequences for their socioemotional development is neccesary.

  4. Design, Synthesis and Biological Evaluation of a Simplified Fluorescently Labeled Discodermolide as a Molecular Probe to Study the Binding of Discodermolide to Tubulin

    OpenAIRE

    Qi, Jun; Blanden, Adam R.; Bane, Susan; Kingston, David G I

    2011-01-01

    The design, synthesis, and biological evaluation of a simplified fluorescently labeled discodermolide analogue possessing a dimethylaminobenzoyl fluorophore has been achieved. Stereoselective Suzuki coupling, Horner–Wadsworth–Emmons reaction or the Wittig reaction comprised the key tactics for its construction. The analogue exhibited qualitatively similar activity to paclitaxel in a tubulin assembly assay, and it can thus be used as a fluorescent molecular probe to explore the local environme...

  5. Understanding the Role of Solvation Forces on the Preferential Attachment of Nanoparticles in Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Welch, David A.; Woehl, Taylor J.; Park, Chiwoo; Faller, Roland; Evans, James E.; Browning, Nigel D.

    2016-01-20

    Optimization of colloidal nanoparticle synthesis techniques requires an understanding of underlying particle growth mechanisms. Non-classical growth mechanisms are particularly important as they affect nanoparticle size and shape distributions which in turn influence functional properties. For example, preferential attachment of nanoparticles is known to lead to the formation of mesocrystals, although the formation mechanism is currently not well understood. Here we employ in situ liquid cell scanning transmission electron microscopy (STEM) and steered molecular dynamics (SMD) simulations to demonstrate that the experimentally observed preference for end-to-end attachment of silver nanorods is a result of weaker solvation forces occurring at rod ends. SMD reveals that when the side of a nanorod approaches another rod, perturbation in the surface bound water at the nanorod surface creates significant energy barriers to attachment. Additionally, rod morphology (i.e. facet shape) effects can explain the majority of the side attachment effects that are observed experimentally.

  6. Neural Response during the Activation of the Attachment System in Patients with Borderline Personality Disorder: An fMRI Study

    Science.gov (United States)

    Buchheim, Anna; Erk, Susanne; George, Carol; Kächele, Horst; Martius, Philipp; Pokorny, Dan; Spitzer, Manfred; Walter, Henrik

    2016-01-01

    Individuals with borderline personality disorder (BPD) are characterized by emotional instability, impaired emotion regulation and unresolved attachment patterns associated with abusive childhood experiences. We investigated the neural response during the activation of the attachment system in BPD patients compared to healthy controls using functional magnetic resonance imaging (fMRI). Eleven female patients with BPD without posttraumatic stress disorder (PTSD) and 17 healthy female controls matched for age and education were telling stories in the scanner in response to the Adult Attachment Projective Picture System (AAP), an eight-picture set assessment of adult attachment. The picture set includes theoretically-derived attachment scenes, such as separation, death, threat and potential abuse. The picture presentation order is designed to gradually increase the activation of the attachment system. Each picture stimulus was presented for 2 min. Analyses examine group differences in attachment classifications and neural activation patterns over the course of the task. Unresolved attachment was associated with increasing amygdala activation over the course of the attachment task in patients as well as controls. Unresolved controls, but not patients, showed activation in the right dorsolateral prefrontal cortex (DLPFC) and the rostral cingulate zone (RCZ). We interpret this as a neural signature of BPD patients’ inability to exert top-down control under conditions of attachment distress. These findings point to possible neural mechanisms for underlying affective dysregulation in BPD in the context of attachment trauma and fear. PMID:27531977

  7. Cryogenic devices attached to electron accelerators

    International Nuclear Information System (INIS)

    The cryoeenic equipement attached to electron accelerators used at the CEN.G for fundamental research on point defects in solids is presented and some of their essential technical characteristics are briefly described

  8. Attachment and the Roots of Competence.

    Science.gov (United States)

    Sroufe, L. Alan

    1981-01-01

    Describes research with 12- to 18-month-old infants (N=108) determining whether the quality of an infant's attachment to his/her primary caregiver could predict the nature of his/her emerging personality. (CS)

  9. Attachment of Gold Nanoparticles to Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Xi Cheng MA; Ning LUN; Shu Lin WEN

    2005-01-01

    Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment,and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.

  10. Attachment and Personality Disorders: A Short Review

    OpenAIRE

    Lorenzini, N.; Fonagy, P

    2013-01-01

    Attachment theory is a biopsychosocial model referring to a person’s characteristic ways of relating in close relationships, such as with parents, children, and romantic partners. These ways of relating are learned during early infancy and mold subsequent intimate relationships. An adult who is securely attached has internalized a reliable relationship to his/her caregivers in infancy, and thus is capable of adapting to different social contexts and, more importantly, of maintaining an adequa...

  11. Attachment an interpersonal processes in hearing voices

    OpenAIRE

    Robson, G. E.

    2012-01-01

    Aims: This study investigated the link between attachment anxiety/avoidance, interpersonal aspects of the voice relationship, and distress whilst considering the impact of beliefs about voices and paranoia. Method: A cross sectional correlational method was employed and participants were recruited mainly via online forums for people who hear voices. 44 participants who heard voices completed a number of self-report measures tapping attachment, interpersonal processes in the voice relationship...

  12. MLP Tools: a PyMOL plugin for using the molecular lipophilicity potential in computer-aided drug design.

    Science.gov (United States)

    Oberhauser, Nils; Nurisso, Alessandra; Carrupt, Pierre-Alain

    2014-05-01

    The molecular lipophilicity potential (MLP) is a well-established method to calculate and visualize lipophilicity on molecules. We are here introducing a new computational tool named MLP Tools, written in the programming language Python, and conceived as a free plugin for the popular open source molecular viewer PyMOL. The plugin is divided into several sub-programs which allow the visualization of the MLP on molecular surfaces, as well as in three-dimensional space in order to analyze lipophilic properties of binding pockets. The sub-program Log MLP also implements the virtual log P which allows the prediction of the octanol/water partition coefficients on multiple three-dimensional conformations of the same molecule. An implementation on the recently introduced MLP GOLD procedure, improving the GOLD docking performance in hydrophobic pockets, is also part of the plugin. In this article, all functions of the MLP Tools will be described through a few chosen examples. PMID:24777339

  13. God as an Attachment Figure : A Case Study of the God Attachment Language and God Concepts of Anxiously Attached Christian Youths in South Africa

    NARCIS (Netherlands)

    Counted, Agina Victor

    2016-01-01

    This study examines the role of the Christian God as an attachment figure, using the attachment language criteria of a strong and enduring affectionate bond. Respondents were 15 anxiously attached Christian youths, purposefully selected for in-depth interviews to explore their God attachment languag

  14. Attachment of Adolescents to Parents: Turkey Profile

    Directory of Open Access Journals (Sweden)

    Turkan Dogan

    2016-12-01

    Full Text Available The present study aims to determine the attachment of adolescents to their parents according to geographical regions in Turkey and gender. The research group consisted of 6061 adolescents. With an age average of 15.53 years. The Inventory of Attachment to Parents and Friends- Brief Form (EABE was used as data acquisition tool. The results of the study indicated significant difference between the scores of students regarding the inventory of attachment to parents according to regions. Evaluating the findings regarding attachment to father and mother together, the findings were similar, and the attachment levels of adolescents in Middle Anatolia, Eastern Anatolia and Black Sea Region were found to be higher than the ones in other regions. This result may be related with socioeconomic, geographical and cultural structures of the regions. Examining the finding according to gender variable, the scores of male students are significantly lower than the scores of female students. As a result according to the data gained from a wide sample group; the main factors for the attachment of adolescents to their parents in Turkey are the geographical regions in Turkey and the gender. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(4.000: 406-419

  15. Removable partial overdentures with mechanical (precision) attachments.

    Science.gov (United States)

    Mensor, M C

    1990-10-01

    Mechanical attachments for overdentures have been available in various forms for over a century. The explosive interest in osseointegration and the effort on the part of the profession to avoid the complete denture as a treatment modality has stirred the interest in positive retentive elements for overdentures represented by the mechanical stud and bar attachments. The cited references provide a resource as a trouble-free guide in the selection and use of the various stud and bar attachment systems. The clinical examples show a pattern of application not generally discussed by the manufacturers, illustrating the simplicity of use with the options for all attachments including magnets. The discussion on magnets comes from 9 years of clinical experience. Rare earth magnets provide excellent adjunct retention, and their assembly follows the same protocol and complexity as stud attachment systems. All magnets, at the present state of the art, have a corrosion potential with the exception of the Laser Sealed Units (Golden Dental, Golden, CO). Finally, the mechanics of the attachment overdenture serves as an excellent training field for the osseointegrated prosthesis, be it the classic Brånemark (Nobelpharma USA, Chicago, IL) restorative or the implant overdenture concept. PMID:2227040

  16. Attachment and cancer: a conceptual integration.

    Science.gov (United States)

    Tacón, Anna M

    2002-12-01

    Cancer traditionally has been explained by the biomedical model; however, it is limited in comprehensively accounting for all factors in this disease. Recently, it has been suggested that a broader theoretical framework that includes psychosocial components in cancer is needed to complement the traditional approach. The purpose of this article, therefore, is to explore the utility of attachment theory as a biopsychosocial model of both development and health. Attachment, a developmental theory, explains how repeated interactions between caregiver and child in the early years establish lifelong psychosocial, physiological, affective, and cognitive patterns as well as enduring patterns of stress response to threat or illness. Despite attachment theory's biopsychosocial foundation, the application of attachment security as a factor in physical health and psychosomatic medicine is relatively recent. The current work reviews attachment theory and psychosocial literature with regard to cancer and follows with a novel attempt to conceptually integrate both bodies of literature. A concluding integrative model of attachment theory and the type C behavior pattern is provided to illustrate potential links and integrative processes that may lead to disease resilience or vulnerability. PMID:14664730

  17. Attachment styles and violence within couples.

    Science.gov (United States)

    Bond, Sharon B; Bond, Michael

    2004-12-01

    This study examined whether an individual's attachment style and/or a couple's combination of attachment styles predicted violence within the marriage and explored whether other variables moderated the risk of violence. Measures of attachment style were administered to 41 discordant couples who presented to four different clinics. The couples' presenting complaints were not violence, and those who did report violence on questioning did not manifest severe violence, i.e., requiring shelters or legal intervention. Self-report measures of violence and marital satisfaction, including problem-solving communication, were also given. Using analysis of covariance and logistic regression, the relative contributions to strength of predicting being a victim of conjugal violence were calculated. An anxious attachment style was a significant predictor of females being victims of violence and of men not being victims. A dismissive style in men was predictive of men being victims when entered into the model with problem solving communication. The combination of anxiously attached females and dismissive males was a potent predictor of violence, and longer duration of marriage and poor problem-solving communication added power to the prediction. Marital interaction, which is influenced by couples' attachment styles and problem-solving communication, is a significant factor in marital partners experiencing physical violence. For couples with milder levels of violence, a more nuanced approach (compared with the legally based approach used for severe violence) seems indicated. PMID:15583508

  18. Effects of a Paternal Participation Program during Cesarean Section on Paternal Infant Attachment

    Directory of Open Access Journals (Sweden)

    Hyun Kyoung Kim

    2013-06-01

    Full Text Available PurposeIn this study effects of a paternal participation program during cesarean section on paternal infant attachment were investigate. The experimental treatment was an integrative nursing intervention to promote father to infant attachment.MethodsStudy design was a non-equivalent control group posttest design. The program consisted of emotional support to spouse and father towards infant attachment immediately following cesarean birth. Participants were 66 men, partners of women with normal full term pregnancy having a cesarean section with spinal or epidural anesthesia, (experimental group, 34; control group, 32. The experiment was carried out from August 1 to October 30, 2010. Control group data were obtained from May 1 to June 30, 2012. Posttest was performed 72 hours after cesarean birth. A self-report questionnaire including a paternal attachment instrument was used. Data were analyzed using t-test, propensity score matching, and analysis of covariance with the SPSS/WIN 18.0 program.ResultsTotal score for paternal infant attachment in the experimental group was significantly higher than the control group (p<.001. After matching, significant differences were found between the two groups through all subcategories. Adjusted mean score for paternal infant attachment verified experimental effects.ConclusionResults indicate that this paternal participation program during cesarean section is effective in improving paternal infant attachment.

  19. Application of attachment modes in the control of large space structures

    Science.gov (United States)

    Craig, Roy R., Jr.

    1989-01-01

    Various ways are examined to obtain reduced order mathematical models of structures for use in dynamic response analyses and in controller design studies. Attachment modes are deflection shapes of a structure subjected to specified unit load distributions. Attachment modes are frequently employed to supplement free-interface normal modes to improve the modeling of components (structures) employed in component mode synthesis analyses. Deflection shapes of structures subjected to generalized loads of some specified distribution and of unit magnitude can also be considered to be attachment modes. Several papers which were written under this contract are summarized herein.

  20. A quencher-free molecular beacon design based on pyrene excimer fluorescence using pyrene-labeled UNA (unlocked nucleic acid)

    DEFF Research Database (Denmark)

    Karlsen, Kasper Kannegård; Okholm, Anders Hauge; Kjems, Jørgen;

    2013-01-01

    A quencher-free molecular beacon capable of generating pyrene excimer fluorescence has been constructed using strategically positioned pyrene-UNA monomers. Hybridization of a fully complementary RNA target was accompanied by a pyrene excimer emission increase of more than 900%, and detection of RNA...

  1. Design and construction of a first-generation high-throughput integrated robotic molecular biology platform for bioenergy applications

    Science.gov (United States)

    The molecular biological techniques for plasmid-based assembly and cloning of gene open reading frames are essential for elucidating the function of the proteins encoded by the genes. These techniques involve the production of full-length cDNA libraries as a source of plasmid-based clones to expres...

  2. The relevance of molecular weight in the design of amorphous biodegradable polymers with optimized shape memory effect.

    Science.gov (United States)

    Petisco-Ferrero, S; Fernández, J; Fernández San Martín, M M; Santamaría Ibarburu, P A; Sarasua Oiz, J R

    2016-08-01

    The shape memory effect (SME) has long been the focus of interest of many research groups that have studied many facets of it, yet to the authors' knowledge some molecular parameters, such as the molecular weight, have been skipped. Thus, the aim of this work is to offer further insight into the shape memory effect, by disclosing the importance of the molecular weight as the relevant parameter dictating the extension of the rubbery plateau, which is the scenario where the entropic network of entanglements manifests. For this, a set of biodegradable amorphous poly(rac-d,l)lactides have been synthesised by ring opening copolymerization of a racemic mixture of L-and D-lactide. The analysis performed on the synthesised enantiomeric copolylactides includes the determination of molecular weights by means of Gel Permeation Chromatography (GPC), thermal properties by Differential Scanning Calorimetry (DSC), dynamic mechanical analysis (DMA) and rheological tests using small amplitude oscillatory flow analysis. Shape memory properties have been determined by means of specific cyclic thermo-mechanic test protocol. It has been shown that the recovery capacity of amorphous PDLLA is linked to the disentanglement time through an exponential law. PMID:27136090

  3. Molecular design of new hydrazone dyes for dye-sensitized solar cells: Synthesis, characterization and DFT study

    KAUST Repository

    Al-Sehemi, Abdullah G.

    2012-07-01

    Three new sensitizers 2-{4-[2-(4-Nitrobenzylidene)hydrazino)]phenyl} ethylene-1,1,2-tricarbonitrile (NBHPET), 2-{4-[2-p-Chlorobenzylidenehydrazino] phenyl}- ethylene-1,1,2-tri carbonitrile (CBHPET) and 2-{4-[2-p- Bromobenzylidenehydrazino] phenyl}ethylene-1,1,2-tricarbonitrile (BBHPET) have been synthesized. The dyes showed pronounced solvatochromic effects as the polarity of the solvents increased. The structures have been optimized at B3LYP/6-31G(d) level of theory. The torsion in E-isomer is smaller than Z-isomer and azo isomers. The highest occupied molecular orbitals are delocalized on whole molecule while lowest unoccupied molecular orbitals are distributed on the tricarbonitrile. The lowest unoccupied molecular orbital energies are above the conduction band of titanium dioxide, highest occupied molecular orbitals of the dyes are below the redox couple of new synthesized dyes and small energy gap revealed these dyes would be better sensitizers for dye-sensitized solar cells. © 2012 Elsevier B.V. All rights reserved.

  4. Structure, attachment properties, and ecological importance of the attachment system of English ivy (Hedera helix)

    OpenAIRE

    Melzer, Björn; Seidel, Robin; Steinbrecher, Tina; Speck, Thomas

    2011-01-01

    Root climbers such as English ivy (Hedera helix) rely on specialized adventitious roots for attachment, enabling the plants to climb on a wide range of natural and artificial substrates. Despite their importance for the climbing habit, the biomechanical properties of these specialized adventitious roots compared with standard roots and their performance in the attachment to different host species or inert substrates have not been studied. Here organs and tissues involved in the attachment are...

  5. Neurobiology of secure infant attachment and attachment despite adversity: a mouse model

    OpenAIRE

    Roth, T.L.; Raineki, C.; Salstein, L.; Perry, R; Wilson, T. A. Sullivan; Sloan, A.; Lalji, B.; Hammock, E.; Wilson, D. A.; Levitt, P; Okutani, F.; Kaba, H. (Harry); R.M. Sullivan

    2013-01-01

    Attachment to an abusive caregiver has wide phylogenetic representation, suggesting that animal models are useful in understanding the neural basis underlying this phenomenon and subsequent behavioral outcomes. We previously developed a rat model, in which we use classical conditioning to parallel learning processes evoked during secure attachment (odor-stroke, with stroke mimicking tactile stimulation from the caregiver) or attachment despite adversity (odor-shock, with shock mimicking maltr...

  6. Turbine airfoil to shround attachment

    Science.gov (United States)

    Campbell, Christian X; Morrison, Jay A; James, Allister W; Snider, Raymond G; Eshak, Daniel M; Marra, John J; Wessell, Brian J

    2014-05-06

    A turbine airfoil (31) with an end portion (42) that tapers (44) toward the end (43) of the airfoil. A ridge (46) extends around the end portion. It has proximal (66) and distal (67) sides. A shroud platform (50) is bi-cast onto the end portion around the ridge without bonding. Cooling shrinks the platform into compression (62) on the end portion (42) of the airfoil. Gaps between the airfoil and platform are formed using a fugitive material (56) in the bi-casting stage. These gaps are designed in combination with the taper angle (44) to accommodate differential thermal expansion while maintaining a gas seal along the contact surfaces. The taper angle (44) may vary from lesser on the pressure side (36) to greater on the suction side (38) of the airfoil. A collar portion (52) of the platform provides sufficient contact area for connection stability.

  7. A simple and reliable method for attaching radio-transmitters to lizards

    OpenAIRE

    Daniel Warner; Jai Thomas; Richard Shine

    2006-01-01

    Abstract.—The development of simple and effective techniques for attaching transmitters to animals is essential for radiotelemetricstudies. For a recent study, we developed a method for attaching radio-transmitters to Jacky Dragons(Amphibolurus muricatus), a semi-arboreal agamid lizard from southeastern Australia. Our method utilized a harness designand proved to be very effective. During the study, transmitters were never dislodged from the animals and our design did notappear to affect the ...

  8. THE EFFECTS OF DIFFERENT ATTACHMENT SYSTEMS ON STRESS IN 2-IMPLANT-RETAINED OVERDENTURES

    OpenAIRE

    Polat, Serdar; ULUDAG, Bulent

    2014-01-01

    Osseointegrated implants have been used to improve denture support, stability and retention. Currently, the placement of 2 implants and the fabrication of an implantretained overdenture is considered by some to be the standard of care. The influence of various types of attachments on stress distribution of 2-implant-retained mandibular overdenture designs has not been sufficiently assessed. The purpose of this study was to compare the load transfer characteristics of 5 attachment systems for ...

  9. Effectiveness of the pharmaceutical supply chain to clinics attached to Mafikeng Provincial Hospital / Moitsoadi Sarah Mokgatlha

    OpenAIRE

    Mokgatlha, Moitsoadi Sarah

    2013-01-01

    The study set out to investigate the factors that led to pharmaceutical outages in clinics attached to Mafikeng Provincial Hospital (MPH). An exploratory research design was adopted for this purpose and a survey that included respondents from Mmabatho Medical Stores (MMS), MPH, clinics attached to MPH and transporters was conducted to address a number of research questions. The findings are displayed in charts and tables. The findings show that there were constraints expe...

  10. The reflection of patterns of attachment in infancy in narratives of preschool children

    OpenAIRE

    Yabsley, S. A.

    1999-01-01

    This series of studies reports on the prospective and concurrent relation of attachment to a narrative based assessment of the five year old child's internal world. It relies on the exploration of a relatively new research measure designed to explore the internal world of the young child. No published studies have yet investigated the validity of this measure in relation to thoroughly tested measures of attachment patterns in infants and parents. Additionally, this study will i...

  11. Design of a tablet computer app for facilitation of a molecular blood culture test in clinical microbiology and preliminary usability evaluation

    DEFF Research Database (Denmark)

    Samson, Lasse L.; Pape-Haugaard, Louise; Meltzer, Michelle C.;

    2016-01-01

    through specialized applications (apps) while supporting the mobility of the users. The use of apps for mobile phones and tablet computers may support workflow of complex tasks, for example, molecular-based diagnostic tests in clinical microbiology. Multiplex Blood Culture Test (MuxBCT) is a molecular...... to assist users in reaching an exact bacterial or fungal diagnosis based on blood specimen observations and controls. Additionally, the app allows for entry of test results, and communication thereof to the laboratory information system (LIS). OBJECTIVE: The objective of the study was to describe the...... design considerations of the MuxBCT app and the results of a preliminary usability evaluation. METHODS: The MuxBCT tablet app was developed and set up for use in a clinical microbiology laboratory. A near-live simulation study was conducted in the clinical microbiology laboratory to evaluate the...

  12. Strain uniformity in biaxial specimens is highly sensitive to attachment details.

    Science.gov (United States)

    Eilaghi, Armin; Flanagan, John G; Brodland, G Wayne; Ethier, C Ross

    2009-09-01

    Biaxial testing has been used widely to characterize the mechanical properties of soft tissues and other flexible materials, but fundamental issues related to specimen design and attachment have remained. Finite element models and experiments were used to investigate how specimen geometry and attachment details affect uniformity of the strain field inside the attachment points. The computational studies confirm that increasing the number of attachment points increases the size of the area that experiences sensibly uniform strain (defined here as the central sample region where the ratio of principal strains E(11)/E(22)talc-sprinkled rubber specimens loaded using wire "rakes." Points on a grid having 12 x 12 bays were tracked, and a detailed strain map was constructed. A finite element model based on the actual geometry of an experiment having an off-pattern rake tine gave strain patterns that matched to within 4.4%. Finally, simulations using nonequibiaxial strains indicated that the strain field uniformity was more sensitive to sample attachment details for the nonequibiaxial case as compared to the equibiaxial case. Specimen design and attachment were found to significantly affect the uniformity of the strain field produced in biaxial tests. Practical guidelines were offered for design and mounting of biaxial test specimens. The issues addressed here are particularly relevant as specimens become smaller in size. PMID:19725692

  13. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  14. Design of structure of zeolitic catalysts on a molecular level as a key to highly effective industrial processes

    Czech Academy of Sciences Publication Activity Database

    Sazama, Petr; Wichterlová, Blanka; Dědeček, Jiří; Tvarůžková, Zdenka; Sathu, Naveen Kumar; Kreibich, Viktor; Sobalík, Zdeněk

    Prague: J. Heyrovský Institute of Physical Chemistry of the ASCR, v.v.i, 2011 - (Horáček, M.). P5 ISBN 978-80-87351-14-7. [Czech-Italian-Spanish Symposium on Molecular Sieves and Catalysis /4./. 15.06.2011-18.06.2011, Liblice] Institutional research plan: CEZ:AV0Z40400503 Keywords : zeolites * ZSM-5 Subject RIV: CF - Physical ; Theoretical Chemistry

  15. Design and physicochemical characterisation of novel dissolving polymeric microneedle arrays for transdermal delivery of high dose, low molecular weight drugs

    OpenAIRE

    McCrudden, Maelíosa T. C.; Alkilani, Ahlam Zaid; MCCRUDDEN, CIAN M.; McAlister, Emma; McCarthy, Helen O.; Woolfson, A. David; Donnelly, Ryan F.

    2014-01-01

    We describe formulation and evaluation of novel dissolving polymeric microneedle (MN) arrays for the facilitated delivery of low molecular weight, high dose drugs. Ibuprofen sodium was used as the model here and was successfully formulated at approximately 50% w/w in the dry state using the copolymer poly(methylvinylether/maleic acid). These MNs were robust and effectively penetrated skin in vitro, dissolving rapidly to deliver the incorporated drug. The delivery of 1.5mg ibuprofen sodium, th...

  16. Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study (SN--DREAMS III): Study design and research methodology

    OpenAIRE

    Sahu Chinmaya; Ganesan Suganeswari; Raman Rajiv; Saumya Pal Swakshyar; Sharma Tarun

    2011-01-01

    Abstract Background To describe the methodology of the Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III, an ongoing epidemiological study to estimate the prevalence of Diabetes and Diabetic Retinopathy in rural population of Kanchipuram and Thiravallur districts of Tamil Nadu, India and to elucidate the clinical, anthropometric, biochemical and genetic risk factors associated with diabetic retinopathy in this rural population. Methods Sankara Nethralaya Dia...

  17. Overview for Attached Payload Accommodations and Environments

    Science.gov (United States)

    Schaffer, Craig; Cook, Gene; Nabizadeh, Rodney; Phillion, James

    2007-01-01

    External payload accommodations are provided at attach sites on the U.S provided ELC, U.S. Truss, the Japanese Experiment Module Exposed Facility (JEM EF) and the Columbus EPF (External Payload Facilities). The Integrated Truss Segment (ITS) provides the backbone structure for the ISS. It attaches the solar and thermal control arrays to the rest of the complex, and houses cable distribution trays Extravehicular Activity (EVA) support equipment such as handholds and lighting; and providing for Extravehicular Robotic (EVR) accommodations using the Mobile Servicing System (MSS). It also provides logistics and maintenance, and payload attachment sites. The attachment sites accommodate logistics and maintenance and payloads carriers, zenith and nadir. The JEM-EF, a back porch-like attachment to the JEM Pressurized Module, accommodates up to eight payloads, which can be serviced by the crew via the JEM PM's airlock and dedicated robotic arm. The Columbus-EPF is another porch-like platform that can accommodate two zenith and two nadir looking payloads.

  18. Surface-attachment sequence in Vibrio Cholerae

    Science.gov (United States)

    Utada, Andrew; Gibiansky, Maxsim; Wong, Gerard

    2013-03-01

    Vibrio cholerae is a gram-negative bacterium that causes the human disease cholera. It is found natively in brackish costal waters in temperate climates, where it attaches to the surfaces of a variety of different aquatic life. V. cholerae has a single polar flagellum making it highly motile, as well as a number of different pili types, enabling it to attach to both biotic and abiotic surfaces. Using in-house built tracking software we track all surface-attaching bacteria from high-speed movies to examine the early-time attachment profile of v. cholerae onto a smooth glass surface. Similar to previous work, we observe right-handed circular swimming trajectories near surfaces; however, in addition we see a host of distinct motility mechanisms that enable rapid exploration of the surface before forming a more permanent attachment. Using isogenic mutants we show that the motility mechanisms observed are due to a complex combination of hydrodynamics and pili-surface interactions. Lauga, E., DiLuzio, W. R., Whitesides, G. M., Stone, H. A. Biophys. J. 90, 400 (2006).

  19. Preferential attachment in randomly grown networks

    Science.gov (United States)

    Weaver, Iain S.

    2015-12-01

    We reintroduce the model of Callaway et al. (2001) as a special case of a more general model for random network growth. Vertices are added to the graph at a rate of 1, while edges are introduced at rate δ. Rather than edges being introduced at random, we allow for a degree of preferential attachment with a linear attachment kernel, parametrised by m. The original model is recovered in the limit of no preferential attachment, m → ∞. As expected, even weak preferential attachment introduces a power-law tail to the degree distribution. Additionally, this generalisation retains a great deal of the tractability of the original along with a surprising range of behaviour, although key mathematical features are modified for finite m. In particular, the critical edge density, δc which marks the onset of a giant network component is reduced with increasing tendency for preferential attachment. The positive degree-degree correlation introduced by the unbiased growth process is offset by the skewed degree distribution, reducing the network assortativity.

  20. Mechanical testing of a FW panel attachment system for ITER

    International Nuclear Information System (INIS)

    An objective of experiments and finite element simulations was to check the stiffness, the strength and the fatigue resistance of the attachment of the First Wall panels onto a shield block of blanket modules according to the ITER 2001 design. The panel has a poloidal key at the rear side (in so-called option A with the rear access bolting) and it is attached by means of special studs located on a key-way in the shield block. Special device for a test of stud tensile pre-load relaxation during a thermal cycling was developed. True-to-scale panels, the shield block mock-up and simplified studs were fabricated and the assembly was loaded alternatively by radial moment, poloidal force or poloidal moment simulating the loading during off-normal plasma operations. Thermal cycling led to an acceptable stud pre-load relaxation. Mechanical cycling caused neither the pre-load relaxation nor the loss of the contact in the key-way nor a damage of the attachment system. The combination of poloidal moment and radial force during vertical displacement events (VDEs) seems to be a most dangerous case because it could lead to the loss of the key-key-way contact.