Unconditionally stable microwave Si-IMPATT amplifiers

International Nuclear Information System (INIS)

Seddik, M.M.

1986-07-01

The purpose of this investigation has been the development of an improved understanding of the design and analysis of microwave reflection amplifiers employing the negative resistance property of the IMPATT devices. Unconditionally stable amplifier circuit using a Silicon IMPATT diode is designed. The problems associated with the design procedures and the stability criterion are discussed. A computer program is developed to perform the computations. The stable characteristics of a reflection-type Si-IMPATT amplifier, such as gain, frequency and bandwidth are examined. It was found that at large signal drive levels, 7 dB gain with bandwidth of 800 MHz at 22,5 mA was obtained. (author)

Development of a Safety Management Web Tool for Horse Stables.

Science.gov (United States)

Leppälä, Jarkko; Kolstrup, Christina Lunner; Pinzke, Stefan; Rautiainen, Risto; Saastamoinen, Markku; Särkijärvi, Susanna

2015-11-12

Managing a horse stable involves risks, which can have serious consequences for the stable, employees, clients, visitors and horses. Existing industrial or farm production risk management tools are not directly applicable to horse stables and they need to be adapted for use by managers of different types of stables. As a part of the InnoEquine project, an innovative web tool, InnoHorse, was developed to support horse stable managers in business, safety, pasture and manure management. A literature review, empirical horse stable case studies, expert panel workshops and stakeholder interviews were carried out to support the design. The InnoHorse web tool includes a safety section containing a horse stable safety map, stable safety checklists, and examples of good practices in stable safety, horse handling and rescue planning. This new horse stable safety management tool can also help in organizing work processes in horse stables in general.

Plasmodium chabaudi chabaudi malaria parasites can develop stable resistance to atovaquone with a mutation in the cytochrome b gene

Directory of Open Access Journals (Sweden)

Alves Ana C

2010-05-01

Full Text Available Abstract Background Plasmodium falciparum, has developed resistance to many of the drugs in use. The recommended treatment policy is now to use drug combinations. The atovaquone-proguanil (AP drug combination, is one of the treatment and prophylaxis options. Atovaquone (ATQ exerts its action by inhibiting plasmodial mitochondria electron transport at the level of the cytochrome bc1 complex. Plasmodium falciparum in vitro resistance to ATQ has been associated with specific point mutations in the region spanning codons 271-284 of the cytochrome b gene. ATQ -resistant Plasmodium yoelii and Plasmodium berghei lines have been obtained and resistant lines have amino acid mutations in their CYT b protein sequences. Plasmodium chabaudi model for studying drug-responses and drug-resistance selection is a very useful rodent malaria model but no ATQ resistant parasites have been reported so far. The aim of this study was to determine the ATQ sensitivity of the P. chabaudi clones, to select a resistant parasite line and to perform genotypic characterization of the cytb gene of these clones. Methods To select for ATQ resistance, Plasmodium. chabaudi chabaudi clones were exposed to gradually increasing concentrations of ATQ during several consecutive passages in mice. Plasmodium chabaudi cytb gene was amplified and sequenced. Results ATQ resistance was selected from the clone AS-3CQ. In order to confirm whether an heritable genetic mutation underlies the response of AS-ATQ to ATQ, the stability of the drug resistance phenotype in this clone was evaluated by measuring drug responses after (i multiple blood passages in the absence of the drug, (ii freeze/thawing of parasites in liquid nitrogen and (iii transmission through a mosquito host, Anopheles stephensi. ATQ resistance phenotype of the drug-selected parasite clone kept unaltered. Therefore, ATQ resistance in clone AS-ATQ is genetically encoded. The Minimum Curative Dose of AS-ATQ showed a six

Development plates for stable internal fixation: Study of mechanical resistance in simulated fractures of the mandibular condyle.

Science.gov (United States)

Celegatti Filho, Tóride Sebastião; Rodrigues, Danillo Costa; Lauria, Andrezza; Moreira, Roger William Fernandes; Consani, Simonides

2015-01-01

To develop Y-shaped plates with different thicknesses to be used in simulated fractures of the mandibular condyle. Ten plates were developed in Y shape, containing eight holes, and 30 synthetic polyurethane mandible replicas were developed for the study. The load test was performed on an Instron Model 4411 universal testing machine, applying load in the mediolateral and anterior-posterior positions on the head of the condyle. Two-way ANOVA with Tukey testing with a 5% significance level was used. It was observed that when the load was applied in the medial-lateral plate of greater thickness (1.5 mm), it gave the highest strength, while in the anteroposterior direction, the plate with the highest resistance was of the lesser thickness (0.6 mm). A plate with a thickness of 1.5 mm was the one with the highest average value for all displacements. In the anteroposterior direction, the highest values of resistance were seen in the displacement of 15 mm. After comparing the values of the biomechanical testing found in the scientific literature, it is suggested that the use of Y plates are suitable for use in subcondylar fractures within the limitations of the study. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Development of fire-resistant, low smoke generating, thermally stable end items for aircraft and spacecraft

Science.gov (United States)

Gagliani, J.; Sorathia, U. A. K.; Wilcoxson, A. L.

1977-01-01

Materials were developed to improve aircraft interior materials by modifying existing polymer structures, refining the process parameters, and by the use of mechanical configurations designed to overcome specific deficiencies. The optimization, selection, and fabrication of five fire resistant, low smoke emitting open cell foams are described for five different types of aircraft cabin structures. These include: resilient foams, laminate floor and wall paneling, thermal/acoustical insulation, molded shapes, and coated fabrics. All five have been produced from essentially the same polyimide precursor and have resulted in significant benefits from transfer of technology between the various tasks.

Stable gene transfer of CCR5 and CXCR4 siRNAs by sleeping beauty transposon system to confer HIV-1 resistance

Directory of Open Access Journals (Sweden)

Akkina Ramesh

2008-07-01

Full Text Available Abstract Background Thus far gene therapy strategies for HIV/AIDS have used either conventional retroviral vectors or lentiviral vectors for gene transfer. Although highly efficient, their use poses a certain degree of risk in terms of viral mediated oncogenesis. Sleeping Beauty (SB transposon system offers a non-viral method of gene transfer to avoid this possible risk. With respect to conferring HIV resistance, stable knock down of HIV-1 coreceptors CCR5 and CXCR4 by the use of lentiviral vector delivered siRNAs has proved to be a promising strategy to protect cells from HIV-1 infection. In the current studies our aim is to evaluate the utility of SB system for stable gene transfer of CCR5 and CXCR4 siRNA genes to derive HIV resistant cells as a first step towards using this system for gene therapy. Results Two well characterized siRNAs against the HIV-1 coreceptors CCR5 and CXCR4 were chosen based on their previous efficacy for the SB transposon gene delivery. The siRNA transgenes were incorporated individually into a modified SB transfer plasmid containing a FACS sortable red fluorescence protein (RFP reporter and a drug selectable neomycin resistance gene. Gene transfer was achieved by co-delivery with a construct expressing a hyperactive transposase (HSB5 into the GHOST-R3/X4/R5 cell line, which expresses the major HIV receptor CD4 and and the co-receptors CCR5 and CXCR4. SB constructs expressing CCR5 or CXCR4 siRNAs were also transfected into MAGI-CCR5 or MAGI-CXCR4 cell lines, respectively. Near complete downregulation of CCR5 and CXCR4 surface expression was observed in transfected cells. During viral challenge with X4-tropic (NL4.3 or R5-tropic (BaL HIV-1 strains, the respective transposed cells showed marked viral resistance. Conclusion SB transposon system can be used to deliver siRNA genes for stable gene transfer. The siRNA genes against HIV-1 coreceptors CCR5 and CXCR4 are able to downregulate the respective cell surface proteins

Functional Marker Assisted Improvement of Stable Cytoplasmic Male Sterile Lines of Rice for Bacterial Blight Resistance

Directory of Open Access Journals (Sweden)

Jegadeesan Ramalingam

2017-06-01

Full Text Available Bacterial blight (BB, caused by Xanthomonas oryzae pv.oryzae is one among the major diseases in rice, which in severe condition cause losses up to 60% in total yield. Marker assisted pyramiding of three broad spectrum BB resistance genes (xa5, xa13, and Xa21 in prominent rice varieties is the most economical and effective strategy for the management of the BB disease. We report here the pyramiding of three genes (xa5, xa13, and Xa21 in maintainer lines (CO 2B, CO 23B, and CO 24B of three promising wild abortive cytoplasmic male sterile lines (CO 2A, CO 23A, and CO 24A through functional markers assisted back cross breeding. IRBB60 with xa5, xa13, and Xa21 genes is used as a donor parent. BC2F1 and BC2F2 generations from a cross of CO 2B, CO 23B, and CO 24B with IRBB60 were evaluated for bacterial blight and non-fertility restoration. In BC2F1, plants with all three resistance genes (xa5, xa13, and Xa21 and high parent genome recovery was identified. In BC2F2, plants with all resistance genes and without fertility restorer (Rf3 and Rf4 were selected. Based on agronomic traits, BB resistance and maintenance of sterility, two plants each in CO 2B × IRBB60, CO 24B × IRBB60 and one plant in CO 23B × IRBB60 combinations were identified. The identified lines were crossed with respective male sterile lines for conversion of improved B line into CMS line through back-crossing, in addition to selfing. The plants with high recurrent genome and phenotypically similar to parental lines and sterile are being used for the hybrid rice development program. Currently, using these lines (improved CMS line, test crosses were made to develop new rice hybrids. Hybrids combinations viz., CO 23A × AD08009R and CO 24A × IET20898R were found to be stable at different locations with high yield. The R line used in this study has been introgressed with xa5, xa13, and Xa21 genes in a separate breeding program. These new hybrids with resistance against bacterial blight

Development of a platinum resistance thermometer on the silicon substrate for phase change studies

International Nuclear Information System (INIS)

Cai, Qingjun; Chen, Ya-Chi; Tsai, Chialun; DeNatale, Jeffrey F

2012-01-01

Resistance temperature detectors are commonly used measurement sensors in heat transfer studies. In many resistance temperature detectors, the platinum resistance thermometer (PRT) is chemically stable, has a wide temperature measurement range and possesses high measurement accuracy. In phase change studies of carbon nanotubes, bi-porous structures for microelectronic thermal management, 100 nm thick PRTs are developed on silicon substrates with 10 nm titanium adhesive to achieve precise and interface-free temperature measurements. After an annealing at 375 °C, the PRT samples are calibrated at a temperature range from 20 to 180 °C. Measurement hysteresis of temperature appears in thermal cycles. Electrical resistance tends to become low during all heating periods, which establishes the maximum measurement deviation of 10 °C. Experimental results from two different thin-film PRTs indicate that accurate and repeatable temperature measurements can be achieved by either reducing heating speed or using data in the cooling period. (paper)

Development of stable marker-free nuclear transformation strategy ...

African Journals Online (AJOL)

Development of stable marker-free nuclear transformation strategy in the green microalga Chlorella vulgaris. ... into Chlorella by electroporation has very low stability and it is hard to screen the transformants without antibiotic marker genes.

Latest developments at GANIL for stable and radioactive ion beam production

International Nuclear Information System (INIS)

Jardin, P.; Barue, C.; Bajeat, O.; Canet, C.; Clement, E.; Cornell, J. C.; Delahaye, P.; Dubois, M.; Dupuis, M.; Flambard, J. L.; Fraanberg, H.; Frigot, R.; Leboucher, C.; Lecesne, N.; Lecomte, P.; Leherissier, P.; Lemagnen, F.; Leroy, R.; Maunoury, L.; Mery, A.

2010-01-01

In the frame of the SPIRAL II (Systeme de Production d'Ions Radioactifs Acceleres en Ligne Partie II) project, several developments of stable and radioactive ion production systems have been started up. In parallel, GANIL has the ambition to preserve the existing stable and radioactive beams and also to increase its range by offering new ones. In order to identify the best directions for this development, a new group called GANISOL has been formed. Its preliminary conclusions and the latest developments at GANIL are presented.

Stable self-compliance resistive switching in AlOδ/Ta2O5−x/TaOy triple layer devices

International Nuclear Information System (INIS)

Wu, Huaqiang; Li, Xinyi; Huang, Feiyang; Yu, Zhiping; Qian, He; Chen, An

2015-01-01

Stable self-compliance property was observed in the AlO δ /Ta 2 O 5−x /TaO y triple-layer resistive random access memory structure. The impact of AlO δ barrier layer was studied with different thicknesses. Endurance of more than 10 10 cycles and data retention for more than 3 h at 125 °C were demonstrated. All the measurements were carried out without external current compliance and no hard breakdown was observed. Systematic analysis reveals the self-compliance property is due to the built-in series resistance of the thin AlO δ barrier layer. A model is proposed to explain this self-compliance property. (paper)

Development of O-18 stable isotope separation technology using membrane

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Woo; Kim, Taek Soo; Choi, Hwa Rim; Park, Sung Hee; Lee, Ki Tae; Chang, Dae Shik

2006-06-15

The ultimate goal of this investigation is to develop the separation technology for O-18 oxygen stable isotope used in a cyclotron as a target for production of radioisotope F-18. F-18 is a base material for synthesis of [F-18]FDG radio-pharmaceutical, which is one of the most important tumor diagnostic agent used in PET (Positron Emission Tomography). More specifically, this investigation is focused on three categories as follow, 1) development of the membrane distillation isotope separation process to re-enrich O-18 stable isotope whose isotopic concentration is reduced after used in a cyclotron, 2) development of organic impurity purification technology to remove acetone, methanol, ethanol, and acetonitrile contained in a used cyclotron O-18 enriched target water, and 3) development of a laser absorption spectroscopic system for analyzing oxygen isotopic concentration in water.

Fractionated irradiation of H69 small-cell lung cancer cells causes stable radiation and drug resistance with increased MRP1, MRP2, and topoisomerase IIα expression

International Nuclear Information System (INIS)

Henness, Sheridan; Davey, Mary W.; Harvie, Rozelle M.; Davey, Ross A.

2002-01-01

Purpose: After standard treatment with chemotherapy and radiotherapy, small-cell lung cancer (SCLC) often develops resistance to both treatments. Our aims were to establish if fractionated radiation treatment alone would induce radiation and drug resistance in the H69 SCLC cell line, and to determine the mechanisms of resistance. Methods and Materials: H69 SCLC cells were treated with fractionated X-rays to an accumulated dose of 37.5 Gy over 8 months to produce the H69/R38 subline. Drug and radiation resistance was determined using the MTT (3,-4,5 dimethylthiazol-2,5 diphenyltetrazolium bromide) cell viability assay. Protein expression was analyzed by Western blot. Results: The H69/R38 subline was resistant to radiation (2.0 ± 0.2-fold, p<0.0001), cisplatin (14 ± 7-fold, p < 0.001), daunorubicin (6 ± 3-fold, p<0.05), and navelbine (1.7 ± 0.15-fold, p<0.02). This was associated with increased expression of the multidrug resistance-associated proteins, MRP1 and MRP2, and topoisomerase IIα and decreased expression of glutathione-S-transferase π (GSTπ) and bcl-2 and decreased cisplatin accumulation. Treatment with 4 Gy of X-rays produced a 66% decrease in MRP2 in the H69 cells with no change in the H69/R38 cells. This treatment also caused a 5-fold increase in topoisomerase IIα in the H69/R38 cells compared with a 1.5-fold increase in the H69 cells. Conclusions: Fractionated radiation alone can lead to the development of stable radiation and drug resistance and an altered response to radiation in SCLC cells

Fabrication of Water Jet Resistant and Thermally Stable Superhydrophobic Surfaces by Spray Coating of Candle Soot Dispersion.

Science.gov (United States)

Qahtan, Talal F; Gondal, Mohammed A; Alade, Ibrahim O; Dastageer, Mohammed A

2017-08-08

A facile synthesis method for highly stable carbon nanoparticle (CNP) dispersion in acetone by incomplete combustion of paraffin candle flame is presented. The synthesized CNP dispersion is the mixture of graphitic and amorphous carbon nanoparticles of the size range of 20-50 nm and manifested the mesoporosity with an average pore size of 7 nm and a BET surface area of 366 m 2 g -1 . As an application of this material, the carbon nanoparticle dispersion was spray coated (spray-based coating) on a glass surface to fabricate superhydrophobic (water contact angle > 150° and sliding angle fabricated from direct candle flame soot deposition (candle-based coating). This study proved that water jet resistant and thermally stable superhydrophobic surfaces can be easily fabricated by simple spray coating of CNP dispersion gathered from incomplete combustion of paraffin candle flame and this technique can be used for different applications with the potential for the large scale fabrication.

Development of redox stable, multifunctional substrates for anode supported SOFCS

DEFF Research Database (Denmark)

Sudireddy, Bhaskar Reddy; Foghmoes, Søren Preben Vagn; Ramos, Tania

2017-01-01

Redox stable solid oxide fuel cells are beneficial in many aspects such as tolerance against system failures e.g fuel cut off and emergency shut down, but also allow for higher fuel utilization, which increases efficiency. State-ofthe-art Ni-cermet based anodes suffer from microstructural changes...... with a multifunctional anode support, the development of a two layer fuel electrode based on a redox stable strontium titanate layer for the electrochemically active layer and a redox stable Ni-YSZ support was pursued. Half-cells with well adhearing strontium titante anode layers on stateof-the-art Ni-YSZ cermet...... supports have been achieved. Redox tolerance of the half-cell depends could be increased by optimizing the redox stability of the cermet support....

Highly Stable, Dual-Gated MoS2 Transistors Encapsulated by Hexagonal Boron Nitride with Gate-Controllable Contact, Resistance, and Threshold Voltage.

Science.gov (United States)

Lee, Gwan-Hyoung; Cui, Xu; Kim, Young Duck; Arefe, Ghidewon; Zhang, Xian; Lee, Chul-Ho; Ye, Fan; Watanabe, Kenji; Taniguchi, Takashi; Kim, Philip; Hone, James

2015-07-28

Emerging two-dimensional (2D) semiconductors such as molybdenum disulfide (MoS2) have been intensively studied because of their novel properties for advanced electronics and optoelectronics. However, 2D materials are by nature sensitive to environmental influences, such as temperature, humidity, adsorbates, and trapped charges in neighboring dielectrics. Therefore, it is crucial to develop device architectures that provide both high performance and long-term stability. Here we report high performance of dual-gated van der Waals (vdW) heterostructure devices in which MoS2 layers are fully encapsulated by hexagonal boron nitride (hBN) and contacts are formed using graphene. The hBN-encapsulation provides excellent protection from environmental factors, resulting in highly stable device performance, even at elevated temperatures. Our measurements also reveal high-quality electrical contacts and reduced hysteresis, leading to high two-terminal carrier mobility (33-151 cm(2) V(-1) s(-1)) and low subthreshold swing (80 mV/dec) at room temperature. Furthermore, adjustment of graphene Fermi level and use of dual gates enable us to separately control contact resistance and threshold voltage. This novel vdW heterostructure device opens up a new way toward fabrication of stable, high-performance devices based on 2D materials.

METALLOPROTEINS DURING DEVELOPMENT OF WALKER-256 CARCINOSARCOMA RESISTANT PHENOTYPE.

Science.gov (United States)

Chekhun, V F; Lozovska, Yu V; Burlaka, A P; Ganusevich, I I; Shvets, Yu V; Lukianova, N Yu; Todor, I M; Demash, D V; Pavlova, A A; Naleskina, L A

2015-01-01

The study was focused on the detection of changes in serum and tumor metal-containing proteins in animals during development ofdoxorubicin-resistant phenotype in malignant cells after 12 courses of chemotherapy. We found that on every stage of resistance development there was a significant increase in content of ferritin and transferrin proteins (which take part in iron traffick and storage) in Walker-256 carc'inosarcoma tissue. We observed decreased serumferritin levels at the beginning stage of the resistance development and significant elevation of this protein levels in the cases withfully developed resistance phenotype. Transferrin content showed changes opposite to that offerritin. During the development of resistance phenotype the tumor tissue also exhibited increased 'free iron' concentration that putatively correlate with elevation of ROS generation and levels of MMP-2 and MMP-9 active forms. The tumor non-protein thiol content increases gradually as well. The serum of animals with early stages of resistance phenotype development showed high ceruloplasmin activity and its significant reduction after loss of tumor sensitivity to doxorubicin. Therefore, the development of resistance phenotype in Walker-256 carcinosarcoma is accompanied by both the deregulation of metal-containing proteins in serum and tumor tissue and by the changes in activity of antioxidant defense system. Thus, the results of this study allow us to determine the spectrum of metal-containing proteins that are involved in the development of resistant tumor phenotype and that may be targeted for methods for doxorubicin sensitivity correction therapy.

Development of Laser Application Technology for Stable Isotope Production

Energy Technology Data Exchange (ETDEWEB)

Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] (and others)

2007-04-15

Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed.

Development of Laser Application Technology for Stable Isotope Production

International Nuclear Information System (INIS)

Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee

2007-04-01

Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed

Metalloproteins during development of Walker-256 carcinosarcoma resistant phenotype

Directory of Open Access Journals (Sweden)

V. F. Chekhun

2015-04-01

Full Text Available The study was focused on the detection of changes in serum and tumor metal-containing proteins in animals during development of doxorubicin-resistant phenotype in malignant cells after 12 courses of chemotherapy. We found that on every stage of resistance development there was a significant increase in content of ferritin and transferrin proteins (which take part in iron traffick and storage in Walker-256 carcinosarcoma tissue. We observed decreased serum ferritin levels at the beginning stage of the resistance development and significant elevation of this protein levels in the cases with fully developed resistance phenotype. Transferrin content showed changes opposite to that of ferritin. During the development of resistance phenotype the tumor tissue also exhibited increased ‘free iron’ concentration that putatively correlate with elevation of ROS generation and levels of MMP-2 and MMP-9 active forms. The tumor non-protein thiol content increases gradually as well. The serum of animals with early stages of resistance phenotype development showed high ceruloplasmin activity and its significant reduction after loss of tumor sensitivity to doxorubicin. Therefore, the development of resistance phenotype in Walker-256 carcinosarcoma is accompanied by both the deregulation of metal-containing proteins in serum and tumor tissue and by the changes in activity of antioxidant defense system. Thus, the results of this study allow us to determine the spectrum of metal-containing proteins that are involved in the development of resistant tumor phenotype and that may be targeted for methods for doxorubicin sensitivity correction therapy.

Determination of Resistant Starch Assimilating Bacteria in Fecal Samples of Mice by In vitro RNA-Based Stable Isotope Probing

Science.gov (United States)

Herrmann, Elena; Young, Wayne; Rosendale, Douglas; Conrad, Ralf; Riedel, Christian U.; Egert, Markus

2017-01-01

The impact of the intestinal microbiota on human health is becoming increasingly appreciated in recent years. In consequence, and fueled by major technological advances, the composition of the intestinal microbiota in health and disease has been intensively studied by high throughput sequencing approaches. Observations linking dysbiosis of the intestinal microbiota with a number of serious medical conditions including chronic inflammatory disorders and allergic diseases suggest that restoration of the composition and activity of the intestinal microbiota may be a treatment option at least for some of these diseases. One possibility to shape the intestinal microbiota is the administration of prebiotic carbohydrates such as resistant starch (RS). In the present study, we aim at establishing RNA-based stable isotope probing (RNA-SIP) to identify bacterial populations that are involved in the assimilation of RS using anaerobic in vitro fermentation of murine fecal material with stable [U13C] isotope-labeled potato starch. Total RNA from these incubations was extracted, processed by gradient ultracentrifugation and fractionated by density. 16S rRNA gene sequences were amplified from reverse transcribed RNA of high and low density fractions suspected to contain labeled and unlabeled RNA, respectively. Phylogenetic analysis of the obtained sequences revealed a distinct subset of the intestinal microbiota involved in starch metabolism. The results suggest Bacteroidetes, in particular genera affiliated with Prevotellaceae, as well as members of the Ruminococcacea family to be primary assimilators of resistant starch due to a significantly higher relative abundance in higher density fractions in RNA samples isolated after 2 h of incubation. Using high performance liquid chromatography coupled to isotope ratio mass spectrometry (HPLC-IRMS) analysis, some stable isotope label was recovered from acetate, propionate and butyrate. Here, we demonstrate the suitability of RNA

Determination of Resistant Starch Assimilating Bacteria in Fecal Samples of Mice by In vitro RNA-Based Stable Isotope Probing

Directory of Open Access Journals (Sweden)

Elena Herrmann

2017-07-01

Full Text Available The impact of the intestinal microbiota on human health is becoming increasingly appreciated in recent years. In consequence, and fueled by major technological advances, the composition of the intestinal microbiota in health and disease has been intensively studied by high throughput sequencing approaches. Observations linking dysbiosis of the intestinal microbiota with a number of serious medical conditions including chronic inflammatory disorders and allergic diseases suggest that restoration of the composition and activity of the intestinal microbiota may be a treatment option at least for some of these diseases. One possibility to shape the intestinal microbiota is the administration of prebiotic carbohydrates such as resistant starch (RS. In the present study, we aim at establishing RNA-based stable isotope probing (RNA-SIP to identify bacterial populations that are involved in the assimilation of RS using anaerobic in vitro fermentation of murine fecal material with stable [U13C] isotope-labeled potato starch. Total RNA from these incubations was extracted, processed by gradient ultracentrifugation and fractionated by density. 16S rRNA gene sequences were amplified from reverse transcribed RNA of high and low density fractions suspected to contain labeled and unlabeled RNA, respectively. Phylogenetic analysis of the obtained sequences revealed a distinct subset of the intestinal microbiota involved in starch metabolism. The results suggest Bacteroidetes, in particular genera affiliated with Prevotellaceae, as well as members of the Ruminococcacea family to be primary assimilators of resistant starch due to a significantly higher relative abundance in higher density fractions in RNA samples isolated after 2 h of incubation. Using high performance liquid chromatography coupled to isotope ratio mass spectrometry (HPLC-IRMS analysis, some stable isotope label was recovered from acetate, propionate and butyrate. Here, we demonstrate the

Observations on resistive wall modes

International Nuclear Information System (INIS)

Gerwin, R.A.; Finn, J.M.

1996-01-01

Several results on resistive wall modes and their application to tokamaks are presented. First, it is observed that in the presence of collisional parallel dynamics there is an exact cancellation to lowest order of the dissipative and sound wave effects for an ideal Ohm's law. This is easily traced to the fact that the parallel dynamics occurs along the perturbed magnetic field lines for such electromagnetic modes. Such a cancellation does not occur in the resistive layer of a tearing-like mode. The relevance to models for resistive wall modes using an electrostatic Hammett-Perkins type operator to model Landau damping will be discussed. Second, we observe that with an ideal Ohm's law, resistive wall modes can be destabilized by rotation in that part of parameter space in which the ideal MHD modes are stable with the wall at infinity. This effect can easily be explained by interpreting the resistive wall instability in terms of mode coupling between the backward stable MHD mode and a stable mode locked into the wall. Such an effect can occur for very small rotation for tearing-resistive wall modes in which inertia dominates viscosity in the layer, but the mode is stabilized by further rotation. For modes for which viscosity dominates in the layer, rotation is purely stabilizing. For both tearing models, a somewhat higher rotation frequency gives stability essentially whenever the tearing mode is stable with a perfectly conducting wall. These tearing/resistive wall results axe also simply explained in terms of mode coupling. It has been shown that resonant external ideal modes can be stabilized in the presence of resistive wall and resistive plasma with rotation of order the nominal tearing mode growth rate. We show that these modes behave as resistive wall tearing modes in the sense above. This strengthens the suggestion that rotational stabilization of the external kink with a resistive wall is due to the presence of resistive layers, even for ideal modes

Percutaneous coronary intervention for poor coronary microcirculation reperfusion of patients with stable angina pectoris.

Science.gov (United States)

Li, J S; Zhao, X J; Ma, B X; Wang, Z

2016-01-01

Percutaneous coronary intervention (PCI) has been extensively applied to repair the forward flow of diseased coronary artery and can achieve significant curative results. However, some patients with acute myocardial infarction (AMI) develop non-perfusion or poor perfusion of cardiac muscle tissue after PCI, which increases the incidence of cardiovascular events and the death rate. PCI can dredge narrowed or infarct-related artery (IRA) and thus induce full reperfusion of ischemic myocardium. It is found in practice that some cases of AMI still have no perfusion or poor perfusion in myocardial tissue even though coronary angiography suggests opened coronary artery after PCI, which increases the incidence of vascular events and mortality. Therefore, to explore the detailed mechanism of PCI in treating coronary microcirculation of patients with stable angina pectoris, we selected 140 patients with stable angina pectoris for PCI, observing the index of microcirculatory resistance (IMR) of descending branch and changes of myocardial injury markers and left ventricular systolic function, and made a subgroup analysis based on the correlation between clinical indexes, IMR and other variables of diabetic and non-diabetic patients, PCI-related and non-PCI-related myocardial infarction patients. The results suggest that IMR of anterior descending branch after PCI was higher compared to that before PCI, and the difference was significant (P less than 0.05); creatine kinase-MB (CK-MB), myohemoglobin and high sensitive troponin T were all increased after PCI, and the difference was also significant (P less than 0.05); brain natriuretic peptide (BNP) level became higher after PCI, with significant difference (P less than 0.05); left ventricular ejection fraction (LVEF) declined after PCI, and the difference before and after PCI was statistically significant (P less than 0.05). Moreover, subgroup analysis results of the three groups all demonstrated statistically significant

Evolutionary Aspects of Acaricide-Resistance Development in Spider Mites

Directory of Open Access Journals (Sweden)

Masahiro (Mh. Osakabe

2009-01-01

Full Text Available Although the development of acaricide resistance in spider mites is a long-standing issue in agricultural fields, recent problems with acaricide resistance may be characterized by the development of complex- and/or multiresistance to acaricides in distinct classes. Such complexity of resistance is not likely to be a single mechanism. Pesticide resistance involves the microevolution of arthropod pests, and population genetics underlies the evolution. In this review, we address the genetic mechanisms of acaricide resistance evolution. We discuss genetic diversity and linkage of resistance genes, relationships between mite habitat and dispersal, and the effect of dispersal on population genetic structure and the dynamics of resistance genes. Finally, we attempt to present a comprehensive view of acaricide resistance evolution and suggest risks under globalization as well as possible approaches to managing acaricide resistance evolution or emergence.

Analysis of Rapidly Developing Low Cloud Ceilings in a Stable Environment

Science.gov (United States)

Bauman, William H., III; Barrett, Joe H., III; Case, Jonathan L.; Wheeler, Mark M.; Baggett, G. Wayne

2006-01-01

Forecasters at the Space Meteorology Group (SMG) issue 30 to 90 minute forecasts for low cloud ceilings at the Space Shuttle Landing Facility (TTS) to support Space Shuttle landings. Mission verification statistics have shown ceilings to be the number one forecast challenge for SMG. More specifically, forecasters at SMG are concerned with any rapidly developing clouds/ceilings below 8000 ft in a stable, capped thermodynamic environment. Therefore, the Applied Meteorology Unit (AMU) was tasked to examine archived events of rapid stable cloud formation resulting in ceilings below 8000 ft, and document the atmospheric regimes favoring this type of cloud development. The AMU examined the cool season months of November to March during the years of 1993-2003 for days that had low-level inversions and rapid, stable low cloud formation that resulted in ceilings violating the Space Shuttle Flight Rules. The AMU wrote and modified existing code to identify inversions from the morning (-10 UTC) Cape Canaveral, FL rawinsonde (XMR) during the cool season and output pertinent sounding information. They parsed all days with cloud ceilings below 8000 ft at TTS, forming a database of possible rapidly-developing low ceiling events. Days with precipitation or noticeable fog burn-off situations were excluded from the database. In the first phase of this work, only the daytime hours were examined for possible ceiling development events since low clouds are easier to diagnose with visible satellite imagery. Phase II of this work includes expanding the database to include nighttime cases which is underway as this abstract is being written. For the nighttime cases, the AMU will analyze both the 00 UTC soundings and the 10 UTC soundings to examine those data for the presence of a low-level inversion. The 00 UTC soundings will probably not have a surface-based inversion, but the presence of inversions or "neutral" layers aloft and below 8,000 ft will most likely help define the stable

Development of transgenic cotton lines expressing Allium sativum agglutinin (ASAL) for enhanced resistance against major sap-sucking pests.

Science.gov (United States)

Vajhala, Chakravarthy S K; Sadumpati, Vijaya Kumar; Nunna, Hariprasad Rao; Puligundla, Sateesh Kumar; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

2013-01-01

Mannose-specific Allium sativum leaf agglutinin encoding gene (ASAL) and herbicide tolerance gene (BAR) were introduced into an elite cotton inbred line (NC-601) employing Agrobacterium-mediated genetic transformation. Cotton transformants were produced from the phosphinothricin (PPT)-resistant shoots obtained after co-cultivation of mature embryos with the Agrobacterium strain EHA105 harbouring recombinant binary vector pCAMBIA3300-ASAL-BAR. PCR and Southern blot analysis confirmed the presence and stable integration of ASAL and BAR genes in various transformants of cotton. Basta leaf-dip assay, northern blot, western blot and ELISA analyses disclosed variable expression of BAR and ASAL transgenes in different transformants. Transgenes, ASAL and BAR, were stably inherited and showed co-segregation in T1 generation in a Mendelian fashion for both PPT tolerance and insect resistance. In planta insect bioassays on T2 and T3 homozygous ASAL-transgenic lines revealed potent entomotoxic effects of ASAL on jassid and whitefly insects, as evidenced by significant decreases in the survival, development and fecundity of the insects when compared to the untransformed controls. Furthermore, the transgenic cotton lines conferred higher levels of resistance (1-2 score) with minimal plant damage against these major sucking pests when bioassays were carried out employing standard screening techniques. The developed transgenics could serve as a potential genetic resource in recombination breeding aimed at improving the pest resistance of cotton. This study represents the first report of its kind dealing with the development of transgenic cotton resistant to two major sap-sucking insects.

Development of late blight resistance and heat tolerance through gamma irradiation of shoot cultures in potato

International Nuclear Information System (INIS)

Gosal, S.S.; Jitender Kaur, Adas; Minocha, J.L.

2001-01-01

In vitro shoot cultures of two potato varieties viz., Kufri jyoti and Kufri Chandramukhi were gamma irradiated at 20 Gy and 40 Gy. Micro tubers were induced in micro propagated M1V3 generation. For heat tolerance micro tubers were induced at elevated (28 C ) incubation temperature (optimum being 20 1C ) and were characterized by early sowing, chlorophyll persistence and harvest index. The number of micro tubers/plant was highly reduced at elevated temperature and the resulting tubers exhibited distorted shapes and growth of apical buds. Thus obtained micro tubers exhibited better germination (62.3%) even in early sowing at relatively higher temperature. The progenies from putative heat tolerant plants were grown in the field by sowing at higher temperature for four subsequent generations. Heat tolerant plants segregated in each generation but the frequency of heat tolerant plants increased in the advanced generation. For developing late blight resistance micro tubers produced from irradiated shoot cultures were sown in pots and resulting plants were screened using detached leaf method. The progenies of putative resistant plants grown in the field were artificially inoculated with sporangial inoculum of Phytophthora infection's. Field grown plants exhibited segregation with respect to disease reaction and about 56 per cent plants showed resistance. Segregation was reduced during following generation and the frequency of resistant plants was increased up to 72.3 per cent. Thus, repeated selections has helped in developing stable mutants in both the varieties

Development of Resistive Micromegas for Sampling Calorimetry

Science.gov (United States)

Geralis, T.; Fanourakis, G.; Kalamaris, A.; Nikas, D.; Psallidas, A.; Chefdeville, M.; Karyotakis, I.; Koletsou, I.; Titov, M.

2018-02-01

Resistive micromegas is proposed as an active element for sampling calorimetry. Future linear collider experiments or the HL-LHC experiments can profit from those developments for Particle Flow Calorimetry. Micromegas possesses remarkable properties concerning gain stability, reduced ion feedback, response linearity, adaptable sensitive element granularity, fast response and high rate capability. Recent developments on Micromegas with a protective resistive layer present excellent results, resolving the problem of discharges caused by local high charge deposition, thanks to its RC-slowed charge evacuation. Higher resistivity though, may cause loss of the response linearity at high rates. We have scanned a wide range of resistivities and performed laboratory tests with X-rays that demonstrate excellent response linearity up to rates of (a few) times 10MHz/cm2, with simultaneous mitigation of discharges. Beam test studies at SPS/CERN with hadrons have also shown a remarkable stability of the resistive Micromegas and low currents for rates up to 15MHz/cm2. We present results from the aforementioned studies confronted with MC simulation

Surface-Controlled Metal Oxide Resistive Memory

KAUST Repository

Ke, Jr-Jian

2015-10-28

To explore the surface effect on resistive random-access memory (ReRAM), the impact of surface roughness on the characteristics of ZnO ReRAM were studied. The thickness-independent resistance and the higher switching probability of ZnO ReRAM with rough surfaces indicate the importance of surface oxygen chemisorption on the switching process. Furthermore, the improvements in switching probability, switching voltage and resistance distribution observed for ReRAM with rough surfaces can be attributed to the stable oxygen adatoms under various ambience conditions. The findings validate the surface-controlled stability and uniformity of ReRAM and can serve as the guideline for developing practical device applications.

Recent developments in low cost stable structures for space

International Nuclear Information System (INIS)

Thompson, T.C.; Grastataro, C.; Smith, B.G.

1994-01-01

The Los Alamos National Laboratory (LANL) in partnership with Composite Optics Incorporated (COI) is advancing the development of low cost, lightweight, composite technology for use in spacecraft and stable structures. The use of advanced composites is well developed, but the application of an all-composite tracker structure has never been achieved. This paper investigates the application of composite technology to the design and fabrication of an all-composite spacecraft bus for small satellites, using technology directly applicable to central tracking in a high luminosity environment. The satellite program Fast On-Orbit Recording of Transient Events (FORTE) is the second in a series of satellites to be launched into orbit for the US Department of Energy (DOE). This paper will discuss recent developments in the area of low cost composites, used for either spacecraft or ultra stable applications in high energy physics (HEP) detectors. The use of advanced composites is a relatively new development in the area of HEP. The Superconducting Super Collider (SSC) spawned a new generation of Trackers which made extensive use of graphite fiber reinforced plastic (GFRP) composite systems. LANL has designed a structure employing new fabrication technology. This concept will lower the cost of composite structures to a point that they may now compete with conventional materials. This paper will discuss the design, analysis and proposed fabrication of a small satellite structure. Central tracking structures using advanced materials capable of operating in an adverse environment typical of that found in a high luminosity collider could use identical concepts

Development of Stable Solidification Method for Insoluble Ferrocyanides-13170

Energy Technology Data Exchange (ETDEWEB)

Ikarashi, Yuki; Masud, Rana Syed; Mimura, Hitoshi [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Aramaki-Aza-Aoba6-6-01-2, Sendai, 980-8579 (Japan); Ishizaki, Eiji; Matsukura, Minoru [UNION SHOWA K.K. 17-20, Mita 2-chome, Minato-ku, Tokyo 108-0073 (Japan)

2013-07-01

The development of stable solidification method of insoluble ferrocyanides sludge is an important subject for the safety decontamination in Fukushima NPP-1. By using the excellent immobilizing properties of zeolites such as gas trapping ability and self-sintering properties, the stable solidification of insoluble ferrocyanides was accomplished. The immobilization ratio of Cs for K{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O saturated with Cs{sup +} ions (Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O) was estimated to be less than 0.1% above 1,000 deg. C; the adsorbed Cs{sup +} ions are completely volatilized. In contrast, the novel stable solid form was produced by the press-sintering of the mixture of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O and zeolites at higher temperature of 1,000 deg. C and 1,100 deg. C; Cs volatilization and cyanide release were completely depressed. The immobilization ratio of Cs, under the mixing conditions of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O:CP= 1:1 and calcining temperature: 1,000 deg. C, was estimated to be nearly 100%. As for the kinds of zeolites, natural mordenite (NM), clinoptilolite (CP) and Chabazite tended to have higher immobilization ratio compared to zeolite A. This may be due to the difference in the phase transformation between natural zeolites and synthetic zeolite A. In the case of the composites (K{sub 2-X}Ni{sub X/2}[NiFe(CN){sub 6}].nH{sub 2}O loaded natural mordenite), relatively high immobilization ratio of Cs was also obtained. This method using zeolite matrices can be applied to the stable solidification of the solid wastes of insoluble ferrocyanides sludge. (authors)

Genetics of host-parasite relationships and the stability of resistance

International Nuclear Information System (INIS)

Eenink, A.H.

1977-01-01

Between host and parasite there is an intimate relationship controlled by matching gene systems. Stability of resistance is determined by the genetics of this relationship and not by the genetics of resistance. Both monogenic and polygenic resistances can be stable or unstable. Research on the backgrounds of stable resistances is of great importance. (author)

Development of transgenic finger millet (Eleusine coracana (L.) Gaertn.) resistant to leaf blast disease.

Science.gov (United States)

Ignacimuthu, S; Ceasar, S Antony

2012-03-01

Finger millet plants conferring resistance to leaf blast disease have been developed by inserting a rice chitinase (chi11) gene through Agrobacterium-mediated transformation. Plasmid pHyg-Chi.11 harbouring the rice chitinase gene under the control of maize ubiquitin promoter was introduced into finger millet using Agrobacterium strain LBA4404 (pSB1). Transformed plants were selected and regenerated on hygromycin-supplemented medium. Transient expression of transgene was confirmed by GUS histochemical staining. The incorporation of rice chitinase gene in R0 and R1 progenies was confirmed by PCR and Southern blot analyses. Expression of chitinase gene in finger millet was confirmed by Western blot analysis with a barley chitinase antibody. A leaf blast assay was also performed by challenging the transgenic plants with spores of Pyricularia grisea. The frequency of transient expression was 16.3% to 19.3%. Stable frequency was 3.5% to 3.9%. Southern blot analysis confirmed the integration of 3.1 kb chitinase gene. Western blot analysis detected the presence of 35 kDa chitinase enzyme. Chitinase activity ranged from 19.4 to 24.8. In segregation analysis, the transgenic R1 lines produced three resistant and one sensitive for hygromycin, confirming the normal Mendelian pattern of transgene segregation. Transgenic plants showed high level of resistance to leaf blast disease compared to control plants. This is the first study reporting the introduction of rice chitinase gene into finger millet for leaf blast resistance.

Resistance development of cystic fibrosis respiratory pathogens when exposed to fosfomycin and tobramycin alone and in combination under aerobic and anaerobic conditions.

Science.gov (United States)

McCaughey, Gerard; Diamond, Paul; Elborn, J Stuart; McKevitt, Matt; Tunney, Michael M

2013-01-01

Although antibiotics from different classes are frequently prescribed in combination to prevent the development of resistance amongst Cystic Fibrosis (CF) respiratory pathogens, there is a lack of data as to the efficacy of this approach. We have previously shown that a 4:1 (w/w) combination of fosfomycin and tobramycin (F:T) has excellent activity against CF pathogens with increased activity under physiologically relevant anaerobic conditions. Therefore, the aim of this study was to determine whether F:T could delay or prevent the onset of resistance compared to either fosfomycin or tobramycin alone under aerobic and anaerobic conditions. The frequency of spontaneous mutants arising following exposure to fosfomycin, tobramycin and F:T was determined for clinical Pseudomonas aeruginosa and MRSA isolates under aerobic and anaerobic conditions. The effect of sub-inhibitory concentrations of fosfomycin, tobramycin and F:T on the induction of resistance was also investigated, with the stability of resistance and fitness cost associated with resistance assessed if it developed. P. aeruginosa and MRSA isolates had a lower frequency of spontaneous mutants to F:T compared to fosfomycin and tobramycin under both aerobic and anaerobic conditions. There was a maximum two-fold increase in F:T MICs when P. aeruginosa and MRSA isolates were passaged in sub-inhibitory F:T for 12 days. In contrast, sequential resistance to fosfomycin and tobramycin developed quickly (n = 3 days for both) after passage in sub-inhibitory concentrations. Once developed, both fosfomycin and tobramycin resistance was stable and not associated with a biological fitness cost to either P. aeruginosa or MRSA isolates. The results of this study suggest that F:T may prevent the development of resistance compared to fosfomycin or tobramycin alone under aerobic and physiologically relevant anaerobic conditions. F:T may be a potential treatment option in CF patients chronically colonised by MRSA and/or P

Development of Creep-Resistant and Oxidation-Resistant Austenitic Stainless Steels for High Temperature Applications

Science.gov (United States)

Maziasz, Philip J.

2018-01-01

Austenitic stainless steels are cost-effective materials for high-temperature applications if they have the oxidation and creep resistance to withstand prolonged exposure at such conditions. Since 1990, Oak Ridge National Laboratory (ORNL) has developed advanced austenitic stainless steels with creep resistance comparable to Ni-based superalloy 617 at 800-900°C based on specially designed "engineered microstructures" utilizing a microstructure/composition database derived from about 20 years of radiation effect data on steels. The wrought high temperature-ultrafine precipitate strengthened (HT-UPS) steels with outstanding creep resistance at 700-800°C were developed for supercritical boiler and superheater tubing for fossil power plants in the early 1990s, the cast CF8C-Plus steels were developed in 1999-2001 for land-based gas turbine casing and diesel engine exhaust manifold and turbocharger applications at 700-900°C, and, in 2015-2017, new Al-modified cast stainless steels with oxidation and creep resistance capabilities up to 950-1000°C were developed for automotive exhaust manifold and turbocharger applications. This article reviews and summarizes their development and their properties and applications.

Development of botanicals to combat antibiotic resistance

Directory of Open Access Journals (Sweden)

Pooja D. Gupta

2017-10-01

Full Text Available The discovery of antibiotics in the previous century lead to reduction in mortality and morbidity due to infectious diseases but their inappropriate and irrational use has resulted in emergence of resistant microbial populations. Alteration of target sites, active efflux of drugs and enzymatic degradations are the strategies employed by the pathogenic bacteria to develop intrinsic resistance to antibiotics. This has led to an increased interest in medicinal plants since 25–50% of current pharmaceuticals are plant derived. Crude extracts of medicinal plants could serve as an alternate source of resistance modifying agents owing to the wide variety of secondary metabolites. These metabolites (alkaloids, tannins, polyphenols etc. could act as potentials for antimicrobials and resistance modifiers. Plant extracts have the ability to bind to protein domains leading to modification or inhibition protein–protein interactions. This enables the herbals to also present themselves as effective modulators of host related cellular processes viz immune response, mitosis, apoptosis and signal transduction. Thus they may exert their activity not only by killing the microorganism but by affecting key events in the pathogenic process, thereby, the bacteria, fungi and viruses may have a reduced ability to develop resistance to botanicals. The article is meant to stimulate research wherein the cidal activity of the extract is not the only parameter considered but other mechanism of action by which plants can combat drug resistant microbes are investigated. The present article emphasizes on mechanisms involved in countering multi drug resistance.

a stable simple sequence repeat marker for resistance to white ...

African Journals Online (AJOL)

ACSS

between resistant and susceptible materials in parental and advanced generations. ... efforts de sélection de variétés de tabac résistantes à la moisissure blanche. A cet effet, deux ... dominant monogenic type of resistance is being used in ...

Highly Stable Trypsin-Aggregate Coatings on Polymer Nanofibers for Repeated Protein Digestion

Energy Technology Data Exchange (ETDEWEB)

Kim, Byoung Chan; Lopez-Ferrer, Daniel; Lee, Sang-mok; Ahn, Hye-kyung; Nair, Sujith; Kim, Seong H.; Kim, Beom S.; Petritis, Konstantinos; Camp, David G.; Grate, Jay W.; Smith, Richard D.; Koo, Yoon-mo; Gu, Man Bock; Kim, Jungbae

2009-04-01

A stable and robust trypsin-based biocatalytic system was developed and demonstrated for proteomic applications. The system utilizes polymer nanofibers coated with trypsin aggregates for immobilized protease digestions. After covalently attaching an initial layer of trypsin to the polymer nanofibers, highly concentrated trypsin molecules are crosslinked to the layered trypsin by way of a glutaraldehyde treatment. This new process produced a 300-fold increase in trypsin activity compared with a conventional method for covalent trypsin immobilization and proved to be robust in that it still maintained a high level of activity after a year of repeated recycling. This highly stable form of immobilized trypsin was also resistant to autolysis, enabling repeated digestions of bovine serum albumin over 40 days and successful peptide identification by LC-MS/MS. Finally, the immobilized trypsin was resistant to proteolysis when exposed to other enzymes (i.e. chymotrypsin), which makes it suitable for use in “real-world” proteomic applications. Overall, the biocatalytic nanofibers with enzyme aggregate coatings proved to be an effective approach for repeated and automated protein digestion in proteomic analyses.

Effects of pyriproxyfen and buprofezin on immature development and reproduction in the stable fly.

Science.gov (United States)

Liu, S S; Li, A Y; Lohmeyer, K H; Pérez De León, A A

2012-12-01

The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most significant biting flies that affect cattle. The use of traditional insecticides for stable fly control has only a limited success owing to the insect's unique feeding behaviours and immature development sites. A laboratory study was conducted to evaluate the effects of two insect growth regulator (IGR) products, pyriproxyfen and buprofezin, on the development of the immature stages of the stable fly and the effects of pyriproxyfen on oviposition and egg hatch. Both pyriproxyfen and buprofezin had significant inhibitory effects on immature development. The LC(50) s of pyriproxyfen and buprofezin were 0.002 and 18.92 p.p.m., respectively. Topical treatment of adult females with different doses of pyriproxyfen had significant negative effects on both female oviposition and egg hatching when 1- and 3-day-old females were treated, and the effects were dose dependent. A significant reduction in the mean number of eggs laid was observed only at the highest pyriproxyfen dose (8 µg/fly) and egg hatch was unaffected by pyriproxyfen treatment when 5-day-old females were treated. Results from the present study indicate that pyriproxyfen has the potential to be used as part of an integrated stable fly management programme. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Aedes aegypti resistance development to commonly used insecticides in Jakarta, Indonesia.

Directory of Open Access Journals (Sweden)

Penny Humaidah Hamid

Full Text Available Aedes aegypti is the primary vector of various relevant arthropod-borne viral infectious diseases worldwide. The mosquito control is still mainly performed by using insecticides but their effectiveness is increasingly questioned nowadays. We here conducted a study on Ae. aegypti resistance development towards several commonly used insecticides in the capital city of Jakarta, Indonesia. In order to achieve this goal, Ae. aegypti eggs from Jakarta were collected with ovitraps and hatched in the insectary of the Gadjah Mada University, Indonesia. The F0 generations were used for WHO resistance tests and knockdown resistance (kdr assays. Presented results clearly showed that there was resistance development of Ae. aegypti populations to the here tested pyrethroid insecticides (i. e. permethrin. Observed mortalities were less than 90% with highest resistance against 0.75% permethrin concentrations. Furthermore, a significant association of V1016G gene mutations with resistance phenotypes to 0.75% permethrin was observed. Nevertheless, the F1534C mutation did not show a significant correlation to resistance development. In conclusion, our results show that populations of Ae. aegypti mosquitoes within the city of Jakarta have developed resistance against several routinely used pyrethroid insecticides in local performed control programs. Thus, the regular verification/assessment of resistance development status will hopefully help in the future to assist local public health authorities in their mosquito control programs by recommending and managing the rotation of different routinely used insecticides with diverse effector mechanisms in order to delay Ae. aegypti resistance development.

Application of stable crack growth in fracture assessment of defects in ductile materials

International Nuclear Information System (INIS)

Dillstroem, Peter

2009-06-01

This report goes through the use of methods/standards, which consider stable (J-controlled) crack growth. We have demonstrated the following: - ASME XI, App. C, App. H, which deals with analysis of stainless steel and ferritic piping, take account of stable growth. In App. C, this corresponds to the inclusion of stable growth up to Δa ∼ 10 mm. - R6-method, BS 7910:1999 and ASME XI, Code Case N-494, contains an established formalism to take account of stable growth. A prerequisite is that you have access to relevant and authentic material data in the form of fracture resistance K k /J k and J r curves. - All of the above methods/standards are applicable in the nuclear context. We reported also that required to produce relevant and valid data (fracture resistance K k /J k and J r curves) to be used for the analysis of stable growth. This report does not specify how much stable crack that can be counted at a Safety Assessment

Stable isotope-resolved metabolomics and applications for drug development

Science.gov (United States)

Fan, Teresa W-M.; Lorkiewicz, Pawel; Sellers, Katherine; Moseley, Hunter N.B.; Higashi, Richard M.; Lane, Andrew N.

2012-01-01

Advances in analytical methodologies, principally nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS), during the last decade have made large-scale analysis of the human metabolome a reality. This is leading to the reawakening of the importance of metabolism in human diseases, particularly cancer. The metabolome is the functional readout of the genome, functional genome, and proteome; it is also an integral partner in molecular regulations for homeostasis. The interrogation of the metabolome, or metabolomics, is now being applied to numerous diseases, largely by metabolite profiling for biomarker discovery, but also in pharmacology and therapeutics. Recent advances in stable isotope tracer-based metabolomic approaches enable unambiguous tracking of individual atoms through compartmentalized metabolic networks directly in human subjects, which promises to decipher the complexity of the human metabolome at an unprecedented pace. This knowledge will revolutionize our understanding of complex human diseases, clinical diagnostics, as well as individualized therapeutics and drug response. In this review, we focus on the use of stable isotope tracers with metabolomics technologies for understanding metabolic network dynamics in both model systems and in clinical applications. Atom-resolved isotope tracing via the two major analytical platforms, NMR and MS, has the power to determine novel metabolic reprogramming in diseases, discover new drug targets, and facilitates ADME studies. We also illustrate new metabolic tracer-based imaging technologies, which enable direct visualization of metabolic processes in vivo. We further outline current practices and future requirements for biochemoinformatics development, which is an integral part of translating stable isotope-resolved metabolomics into clinical reality. PMID:22212615

Use of stable isotopes in developing countries: safe markers for nutrition regime study

International Nuclear Information System (INIS)

Klein, P.D.; Klein, E.R.

1987-01-01

Possible use of stable radioisotopes in studies on nutrition and medicine problems that may be used in investigations of babies, children, pregnant women is shown. Attention is paid to behaviour of limited number of elements: hydrogen, carbon, nitrogen, oxygen. The IAEA plans implementation of a new coordinated research program on use of stable isotopes for studying nutrition problems and related diseases. The program emphasis will be placed on protein metabolism measurements and estimation of energy consumption in control population groups in developing countries

Engineering more stable, selectable marker-free autoluminescent mycobacteria by one step.

Science.gov (United States)

Yang, Feng; Njire, Moses M; Liu, Jia; Wu, Tian; Wang, Bangxing; Liu, Tianzhou; Cao, Yuanyuan; Liu, Zhiyong; Wan, Junting; Tu, Zhengchao; Tan, Yaoju; Tan, Shouyong; Zhang, Tianyu

2015-01-01

In our previous study, we demonstrated that the use of the autoluminescent Mycobacterium tuberculosis as a reporter strain had the potential to drastically reduce the time, effort, animals and costs consumed in evaluation of the activities of drugs and vaccines in live mice. However, the strains were relatively unstable and lost reporter with time without selection. The kanamycin selection marker used wasn't the best choice as it provides resistance to amino glycosides which are an important class of second line drugs used in tuberculosis treatment. In addition, the marker could limit utility of the strains for screening of new potential drugs or evaluating drug combinations for tuberculosis treatment. Limited selection marker genes for mycobacterial genetic manipulation is a major drawback for such a marker-containing strain in many research fields. Therefore, selectable marker-free, more stable autoluminescent mycobacteria are highly needed. After trying several strategies, we created such mycobacterial strains successfully by using an integrative vector and removing both the resistance maker and integrase genes by Xer site-specific recombination in one step. The corresponding plasmid vectors developed in this study could be very convenient in constructing other selectable marker-free, more stable reporter mycobacteria with diverse applications.

Methods for stable recording of short-circuit current in a Na+-transporting epithelium.

Science.gov (United States)

Gondzik, Veronika; Awayda, Mouhamed S

2011-07-01

Epithelial Na(+) transport as measured by a variety of techniques, including the short-circuit current technique, has been described to exhibit a "rundown" phenomenon. This phenomenon manifests as time-dependent decrease of current and resistance and precludes the ability to carry out prolonged experiments aimed at examining the regulation of this transport. We developed methods for prolonged stable recordings of epithelial Na(+) transport using modifications of the short-circuit current technique and commercial Ussing-type chambers. We utilize the polarized MDCK cell line expressing the epithelial Na(+) channel (ENaC) to describe these methods. Briefly, existing commercial chambers were modified to allow continuous flow of Ringer solution and precise control of such flow. Chamber manifolds and associated plumbing were modified to allow precise temperature clamp preventing temperature oscillations. Recording electrodes were modified to eliminate the use of KCl and prevent membrane depolarization from KCl leakage. Solutions utilized standard bicarbonate-based buffers, but all gasses were prehydrated to clamp buffer osmolarity. We demonstrate that these modifications result in measurements of current and resistance that are stable for at least 2 h. We further demonstrate that drifts in osmolarity similar to those obtained before prior to our modifications can lead to a decrease of current and resistance similar to those attributed to rundown.

Development of large area resistive electrodes for ATLAS NSW Micromegas

Science.gov (United States)

Ochi, Atsuhiko

2018-02-01

Micromegas with resistive anodes will be used for the NSW upgrades of the ATLAS experiment at LHC. Resistive electrodes are used in MPGD devices to prevent sparks in high-rate operation. Large-area resistive electrodes for Micromegas have been developed using two different technologies: screen printing and carbon sputtering. The maximum resistive foil size is 45 × 220 cm with a printed pattern of 425-μm pitch strips. These technologies are also suitable for mass production. Prototypes of a production model series have been successfully produced. In this paper, we report the development, the production status, and the test results of resistive Micromegas.

Development of radiation resistant organic composites for cryogenic use

International Nuclear Information System (INIS)

Nishijima, S.

1997-01-01

The mechanism of the radiation induced degradation of the mechanical properties in composite materials have been studied and based on the mechanism the radiation resistant organic composites for fusion magnet have been developing. It was found that the degradation was brought by the change of the fracture mode from tensile (or flexural) to shear failure. Consequently the intrinsic parameter which control the degradation was concluded to be the interlaminar shear strength. To develop the radiation resistant composites, therefore, means to develop the composites showing the radiation resistant interlaminar shear strength. The mechanism was confirmed using three dimensional fabric reinforced plastics which do not have the interlaminar area. The roles of matrix in the composites were also revealed. The effects of dose quality and irradiated temperature on the radiation induced degradation were also discussed and the selection standards of the components for radiation resistant composites were proposed

Transgenic approaches for development of disease resistance in banana

International Nuclear Information System (INIS)

Shekhawat, Upendra K.S.; Ghag, Siddhesh B.; Ganapathi, Thumballi R.

2014-01-01

Banana (Musa spp.) is an important food and cash crop worldwide. Diseases and pests pose the most serious constraint to banana cultivation. Among the diseases, Fusarium wilt and Banana Bunchy Top Virus (BBTV) are the most important economically. We have explored different transgenic approaches for development of efficient resistance in banana against these two diseases. For countering Fusarium wilt, we have over expressed Petunia floral defensins using a strong constitutive promoter in transgenic banana plants. We have also tested a host induced gene silencing strategy targeting two vital fungal genes to obtain Fusarium resistant banana plants. For development of BBTV resistant banana plants also, we have used a host-induced gene silencing approach utilizing the full and partial coding sequence of the viral replication initiation protein. Successful bioassays performed in controlled greenhouse conditions have shown the efficacy of using these strategies to develop disease resistant banana plants. (author)

Stable isotopic analysis of fossil chironomids as an approach to environmental reconstruction: state of development and future challenges

Directory of Open Access Journals (Sweden)

Oliver Heiri

2012-10-01

Full Text Available Remains of chironomid larvae, especially their strongly sclerotized head capsules, can be found abundantly and well preserved in most lake sediment records. These remains mainly consist of chitin and proteins and, since their chemical composition does not seem to be strongly affected by decompositional processes, they can be used to develop palaeoenvironmental reconstructions based on their stable isotopic composition. Here we review available stable isotope studies based on fossil chironomids and indicate future research necessary to further develop this still relatively new research approach. Efforts to produce stable isotope records based on fossil chironomids have mainly examined the elements H, N, C, and O. They have focussed on (1 developing the methodology for preparing samples for isotopic analysis, (2 laboratory studies cultivating chironomid larvae under controlled conditions to determine the factors affecting their stable isotopic composition, (3 ecosystem-scale studies relating stable isotopic measurements of fossil chironomid assemblages to environmental conditions, and (4 developing first down-core records describing past changes in the stable isotopic composition of chironomid assemblages. These studies have shown that chemical sample pretreatment may affect the isotopic composition for some elements. Laboratory runs suggest that the diet of the larvae influences their stable isotopic composition for H, N, C and O, whereas stable isotopes in the ambient water also strongly influence their oxygen and to a lesser extent hydrogen isotopic composition. These experiments also indicate only minor offsets between the nitrogen and carbon isotopic composition of chironomid soft tissue and the fossilizing head capsules, whereas for hydrogen and oxygen this offset remains to be explored. Though few datasets have been published, the available ecosystem studies and developed down-core sediment records indicate that stable isotopes in

Development of fire resistant, nontoxic aircraft interior materials

Science.gov (United States)

Haley, G.; Silverman, B.; Tajima, Y.

1976-01-01

All available newly developed nonmetallic polymers were examined for possible usage in developing fire resistant, nontoxic nonmetallic parts or assemblies for aircraft interiors. Specifically, feasibility for the development of clear films for new decorative laminates, compression moldings, injection molded parts, thermoformed plastic parts, and flexible foams were given primary considerations. Preliminary data on the flame resistant characteristics of the materials were obtained. Preliminary toxicity data were generated from samples of materials submitted from the contractor. Preliminary data on the physical characteristics of various thermoplastic materials to be considered for either compression molded, injection molded, or thermoformed parts were obtained.

Transcriptome Analysis of Chlorantraniliprole Resistance Development in the Diamondback Moth Plutella xylostella

Science.gov (United States)

Hu, Zhendi; Chen, Huanyu; Yin, Fei; Li, Zhenyu; Dong, Xiaolin; Zhang, Deyong; Ren, Shunxiang; Feng, Xia

2013-01-01

Background The diamondback moth Plutella xyllostella has developed a high level of resistance to the latest insecticide chlorantraniliprole. A better understanding of P. xylostella’s resistance mechanism to chlorantraniliprole is needed to develop effective approaches for insecticide resistance management. Principal Findings To provide a comprehensive insight into the resistance mechanisms of P. xylostella to chlorantraniliprole, transcriptome assembly and tag-based digital gene expression (DGE) system were performed using Illumina HiSeq™ 2000. The transcriptome analysis of the susceptible strain (SS) provided 45,231 unigenes (with the size ranging from 200 bp to 13,799 bp), which would be efficient for analyzing the differences in different chlorantraniliprole-resistant P. xylostella stains. DGE analysis indicated that a total of 1215 genes (189 up-regulated and 1026 down-regulated) were gradient differentially expressed among the susceptible strain (SS) and different chlorantraniliprole-resistant P. xylostella strains, including low-level resistance (GXA), moderate resistance (LZA) and high resistance strains (HZA). A detailed analysis of gradient differentially expressed genes elucidated the existence of a phase-dependent divergence of biological investment at the molecular level. The genes related to insecticide resistance, such as P450, GST, the ryanodine receptor, and connectin, had different expression profiles in the different chlorantraniliprole-resistant DGE libraries, suggesting that the genes related to insecticide resistance are involved in P. xylostella resistance development against chlorantraniliprole. To confirm the results from the DGE, the expressional profiles of 4 genes related to insecticide resistance were further validated by qRT-PCR analysis. Conclusions The obtained transcriptome information provides large gene resources available for further studying the resistance development of P. xylostella to pesticides. The DGE data provide

Transcriptome analysis of chlorantraniliprole resistance development in the diamondback moth Plutella xylostella.

Directory of Open Access Journals (Sweden)

Qingsheng Lin

Full Text Available BACKGROUND: The diamondback moth Plutella xyllostella has developed a high level of resistance to the latest insecticide chlorantraniliprole. A better understanding of P. xylostella's resistance mechanism to chlorantraniliprole is needed to develop effective approaches for insecticide resistance management. PRINCIPAL FINDINGS: To provide a comprehensive insight into the resistance mechanisms of P. xylostella to chlorantraniliprole, transcriptome assembly and tag-based digital gene expression (DGE system were performed using Illumina HiSeq™ 2000. The transcriptome analysis of the susceptible strain (SS provided 45,231 unigenes (with the size ranging from 200 bp to 13,799 bp, which would be efficient for analyzing the differences in different chlorantraniliprole-resistant P. xylostella stains. DGE analysis indicated that a total of 1215 genes (189 up-regulated and 1026 down-regulated were gradient differentially expressed among the susceptible strain (SS and different chlorantraniliprole-resistant P. xylostella strains, including low-level resistance (GXA, moderate resistance (LZA and high resistance strains (HZA. A detailed analysis of gradient differentially expressed genes elucidated the existence of a phase-dependent divergence of biological investment at the molecular level. The genes related to insecticide resistance, such as P450, GST, the ryanodine receptor, and connectin, had different expression profiles in the different chlorantraniliprole-resistant DGE libraries, suggesting that the genes related to insecticide resistance are involved in P. xylostella resistance development against chlorantraniliprole. To confirm the results from the DGE, the expressional profiles of 4 genes related to insecticide resistance were further validated by qRT-PCR analysis. CONCLUSIONS: The obtained transcriptome information provides large gene resources available for further studying the resistance development of P. xylostella to pesticides. The DGE data

Development of Magnetorheological Resistive Exercise Device for Rowing Machine

Directory of Open Access Journals (Sweden)

Vytautas Grigas

2016-01-01

Full Text Available Training equipment used by professional sportsmen has a great impact on their sport performance. Most universal exercisers may help only to improve the general physical condition due to the specific kinematics and peculiar resistance generated by their loading units. Training of effective techniques and learning of psychomotor skills are possible only when exercisers conform to the movements and resistance typical for particular sports kinematically and dynamically. Methodology of developing a magnetorheological resistive exercise device for generating the desired law of passive resistance force and its application in a lever-type rowing machine are described in the paper. The structural parameters of a controllable hydraulic cylinder type device were found by means of the computational fluid dynamics simulation performed by ANSYS CFX software. Parameters describing the magnetorheological fluid as non-Newtonian were determined by combining numerical and experimental research of the resistance force generated by the original magnetorheological damper. A structural scheme of the device control system was developed and the variation of the strength of magnetic field that affects the magnetorheological fluid circulating in the device was determined, ensuring a variation of the resistance force on the oar handle adequate for the resistance that occurs during a real boat rowing stroke.

A new intermediate for the production of flexible stable polymers

Science.gov (United States)

Webster, J. A.

1973-01-01

Method of incorporating ether linkages into perfluoroalkylene segment of a dianydride intermediate yields intermediate that may be used in synthesis of flexible, stable polyimides for use as high-temperature, solvent-resistant sealants.

[Role of oral cavity colonization resistance in dental caries development].

Science.gov (United States)

Petrushanko, T A; Chereda, V V; Loban', G A

2013-01-01

Colonization resistance is one of local immunity mechanisms determined by a combination of factors that inhibit the adhesion and growth of mucous membrane bacteria. We examined patients with different levels of caries intensity assessing oral mucosa colonization resistance by our own method. Caries development resulted in changes of colonization resistance with the increased rate of inhibition of the oral mucosa colonization resistance barrier.

Engineering more stable, selectable marker-free autoluminescent mycobacteria by one step.

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Feng Yang

Full Text Available In our previous study, we demonstrated that the use of the autoluminescent Mycobacterium tuberculosis as a reporter strain had the potential to drastically reduce the time, effort, animals and costs consumed in evaluation of the activities of drugs and vaccines in live mice. However, the strains were relatively unstable and lost reporter with time without selection. The kanamycin selection marker used wasn't the best choice as it provides resistance to amino glycosides which are an important class of second line drugs used in tuberculosis treatment. In addition, the marker could limit utility of the strains for screening of new potential drugs or evaluating drug combinations for tuberculosis treatment. Limited selection marker genes for mycobacterial genetic manipulation is a major drawback for such a marker-containing strain in many research fields. Therefore, selectable marker-free, more stable autoluminescent mycobacteria are highly needed. After trying several strategies, we created such mycobacterial strains successfully by using an integrative vector and removing both the resistance maker and integrase genes by Xer site-specific recombination in one step. The corresponding plasmid vectors developed in this study could be very convenient in constructing other selectable marker-free, more stable reporter mycobacteria with diverse applications.

Development of flame retardant, radiation resistant insulating materials

Energy Technology Data Exchange (ETDEWEB)

Hagiwara, M.

1984-01-01

On the cables used for nuclear power stations, in particular those ranked as IE class, flame retardation test, simulated LOCA environment test, radiation resistance test and so on are imposed. The results of the evaluation of performance by these tests largely depend on the insulating materials mainly made of polymers. Ethylene propylene copolymer rubber has been widely used as cable insulator because of its electrical characteristics, workability, economy and relatively good radiation resistance, but it is combustible, therefore, in the practical use, it is necessary to make it fire resistant. The author et al. have advanced the research on the molecular design of new fire retarding materials, and successfully developed acenaphthylene bromide condensate, which is not only fire resistant but also effective for improving radiation resistance. The condition of flame retardant, radiation resistant auxiliary agents is explained, and there are additive type and reaction type in fire retarding materials. The synthesis of acenaphthylene bromide condensate and its effect of giving flame retardant and radiation resistant properties are reported. The characteristics of the cables insulated with the flame retardant ethylene propylene rubber containing acenaphthylene bromide condensate were tested, and the results are shown. (Kako, I.).

Stable Amplification and High Current Drop Bistable Switching in Supercritical GaAs Tills

DEFF Research Database (Denmark)

Izadpanah, S.H; Jeppsson, B; Jeppesen, Palle

1974-01-01

Bistable switching with current drops of 40% and switching times of 100 ps are obtained in pulsed operation of 10¿m supercritically doped n+ nn+ GaAs Transferred Electron Devices (TEDs). When CW-operated the same devices exhibit a 5-17 GHz bandwidth for the stable negative resistance.......Bistable switching with current drops of 40% and switching times of 100 ps are obtained in pulsed operation of 10¿m supercritically doped n+ nn+ GaAs Transferred Electron Devices (TEDs). When CW-operated the same devices exhibit a 5-17 GHz bandwidth for the stable negative resistance....

Development of large area resistive electrodes for ATLAS NSW MicroMEGAS

CERN Document Server

Ochi, Atsuhiko; The ATLAS collaboration

2015-01-01

MicroMegas with resistive anode will be used for the NSW upgrade of the ATLAS experiment at LHC. The resistive electrode is one of key technology for MPGDs to prevent sparks. Large area resistive electrodes for the MM have been developed using two different technology; screen printing and carbon sputtering. Maximum size of each resistive foil is 45cm x 220cm with printed pattern of 425 micron pitch strips. Those technologies are also suitable to mass production. The prototypes of series production model have been produced successfully. We will report the development and production status and test results of the resistive MicroMegas.

New developments in the use of stable activable tracers in environmental science

International Nuclear Information System (INIS)

Loveland, W.; Keasler, K.; Ghannam, L.; Borovik, A.

1980-01-01

Recent developments in the use of stable activable tracers (SATs) in environmental science are reported. (A stable activable tracer is a stable material injected into a system under study and whose concentration is measured by post-sampling activation analysis.) The activable nuclear parts of the tracers studied have been rare earth nuclides with short-lived activation products or Cu. To trace the fate of fluid-bound pollutants (and/or water masses) in marine waters, we have used anionic DTPA complexes of the rare earths. These tracers were shown to be stable (80 to 90% nondissociated) in extensive laboratory tests involving solutions of the tracer in estuarine water including large amounts of marine sediments. Results of a field study in which the flushing time and other hydrological characteristics of an estuarine marina were measured by simultaneously using a fluorescent dye and a SAT are presented. To trace the path of potentially toxic organic molecules, three stable activable tracers, dysprosium(III)-trisacetylacetonate DY(acac) 3 3H 2 O), dysprosium(III)-trisdibenzoylmethane (DY(dbm) 3 H 2 O and copper oxinate Cu (C 9 H 6 ON) 2 were synthesized. Their octanol/water partition coefficients and their solubility in water were measured and used to correlate the tracer species and its biological activity with that of known toxic materials. In a project to demonstrate the simple use of SATs to trace the origin of common insecticides and herbicides, seven common insecticides and herbicides were marked with anionic rare earth DTPA complexes and shown to be detectable at dilutions of 1 part in 10 12 . Two arsenical herbicides were chosen for further study and the tracer/herbicide ratio was shown to remain constant in samples of herbicide material collected on plant surfaces and runoff waters in the environment for long periods

Hydrothermally stable molecular separation membranes from organically linked silica

Energy Technology Data Exchange (ETDEWEB)

Castricum, H.L.; Sah, A; Blank, D.H.A.; Ten Elshof, J.E. [Inorganic Materials Science, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Kreiter, R.; Vente, J.F. [ECN Energy Efficiency in the Industry, Petten (Netherlands)

2008-06-15

A highly hydrothermally stable microporous network material has been developed that can be applied in energy-efficient molecular sieving. The material was synthesized by employing organically bridged monomers in acid-catalysed sol-gel hydrolysis and condensation, and is composed of covalently bonded organic and inorganic moieties. Due to its hybrid nature, it withstands higher temperatures than organic polymers and exhibits high solvolytical and acid stability. A thin film membrane that was prepared with the hybrid material was found to be stable in the dehydration of n-butanol at 150C for almost two years. This membrane is the first that combines a high resistance against water at elevated temperatures with a high separation factor and permeance. It therefore has high potential for energy-efficient molecular separation under industrial conditions, including the dehydration of organic solvents. The organically bridged monomers induce increased toughness in the thin film layer. This suppresses hydrolysis of Si-O-Si network bonds and results in a high resistance towards stress-induced cracking. The large non-hydrolysable units thus remain well incorporated in the surrounding matrix such that the material combines high (pore) structural and mechanical stability. The sol mean particle size was found to be a viable parameter to tune the thickness of the membrane layer and thus optimize the separation performance. We anticipate that other hybrid organosilicas can be made in a similar fashion, to yield a whole new class of materials with superior molecular sieving properties and high hydrothermal stability.

WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT

Energy Technology Data Exchange (ETDEWEB)

Phillips, M.; Robinson, C.; Gupta, N.; Werth, D.

2012-10-10

This report describes the development of a software tool, entitled “WildFire Ignition Resistance Estimator Wizard” (WildFIRE Wizard, Version 2.10). This software was developed within the Wildfire Ignition Resistant Home Design (WIRHD) program, sponsored by the U. S. Department of Homeland Security, Science and Technology Directorate, Infrastructure Protection & Disaster Management Division. WildFIRE Wizard is a tool that enables homeowners to take preventive actions that will reduce their home’s vulnerability to wildfire ignition sources (i.e., embers, radiant heat, and direct flame impingement) well in advance of a wildfire event. This report describes the development of the software, its operation, its technical basis and calculations, and steps taken to verify its performance.

Control of the development and prevalence of antimicrobial resistance in bacteria of food animal origin in Japan: a new approach for risk management of antimicrobial veterinary medicinal products in Japan.

Science.gov (United States)

Asai, Tetsuo; Hiki, Mototaka; Ozawa, Manao; Koike, Ryoji; Eguchi, Kaoru; Kawanishi, Michiko; Kojima, Akemi; Endoh, Yuuko S; Hamamoto, Shuichi; Sakai, Masato; Sekiya, Tatsuro

2014-03-01

Antimicrobial agents are essential for controlling bacterial disease in food-producing animals and contribute to the stable production of safe animal products. The use of antimicrobial agents in these animals affects the emergence and prevalence of antimicrobial resistance in bacteria isolated from animals and animal products. As disease-causing bacteria are often transferred from food-producing animals to humans, the food chain is considered a route of transmission for the resistant bacteria and/or resistance genes. The Food Safety Commission of Japan (FSC) has been assessing the risk posed to human health by the transmission of antimicrobial-resistant bacteria from livestock products via the food chain. In addition to the FSC's risk assessments, the Japanese Ministry of Agriculture, Forestry and Fisheries has developed risk-management guidelines to determine feasible risk-management options for the use of antimicrobial veterinary medicinal products during farming practices. This report includes information on risk assessment and novel approaches for risk management of antimicrobial veterinary medicinal products for mitigating the risk of development and prevalence of antimicrobial resistance in bacteria originating from food-producing animals in Japan.

Development of fire-resistant, low smoke generating, thermally stable end items for commercial aircraft and spacecraft using a basic polyimide resin

Science.gov (United States)

Gagliani, J.; Lee, R.; Sorathia, U. A.; Wilcoxson, A. L.

1980-01-01

A terpolyimide precursor was developed which can be foamed by microwave methods and yields foams possessing the best seating properties. A continuous process, based on spray drying techniques, permits production of polyimide powder precursors in large quantities. The constrained rise foaming process permits fabrication of rigid foam panels with improved mechanical properties and almost unlimited density characteristics. Polyimide foam core rigid panels were produced by this technique with woven fiberglass fabric bonded to each side of the panel in a one step microwave process. The fire resistance of polyimide foams was significantly improved by the addition of ceramic fibers to the powder precursors. Foams produced from these compositions are flexible, possess good acoustical attenuation and meet the minimum burnthrough requirements when impinged by high flux flame sources.

Stable Boundary Layer Issues

OpenAIRE

Steeneveld, G.J.

2012-01-01

Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The development of robust stable boundary layer parameterizations for use in NWP and climate models is hampered by the multiplicity of processes and their unknown interactions. As a result, these models suffer ...

Hyperleptinemia is required for the development of leptin resistance.

Directory of Open Access Journals (Sweden)

Zachary A Knight

2010-06-01

Full Text Available Leptin regulates body weight by signaling to the brain the availability of energy stored as fat. This negative feedback loop becomes disrupted in most obese individuals, resulting in a state known as leptin resistance. The physiological causes of leptin resistance remain poorly understood. Here we test the hypothesis that hyperleptinemia is required for the development of leptin resistance in diet-induced obese mice. We show that mice whose plasma leptin has been clamped to lean levels develop obesity in response to a high-fat diet, and the magnitude of this obesity is indistinguishable from wild-type controls. Yet these obese animals with constant low levels of plasma leptin remain highly sensitive to exogenous leptin even after long-term exposure to a high fat diet. This shows that dietary fats alone are insufficient to block the response to leptin. The data also suggest that hyperleptinemia itself can contribute to leptin resistance by downregulating cellular response to leptin as has been shown for other hormones.

1-Dodecanethiol based highly stable self-assembled monolayers for germanium passivation

International Nuclear Information System (INIS)

Cai, Qi; Xu, Baojian; Ye, Lin; Di, Zengfeng; Huang, Shanluo; Du, Xiaowei; Zhang, Jishen; Jin, Qinghui; Zhao, Jianlong

2015-01-01

Highlights: • A simple and effective approach for higly stable germanium passivation. • 1-Dodecanethiol self-assembled monolayers for germanium oxidation resistance. • The influence factors of germanium passivation were systematically studied. • The stability of the passivated Ge was more than 10 days even in water conditions. - Abstract: As a typical semiconductor material, germanium has the potential to replace silicon for future-generation microelectronics, due to its better electrical properties. However, the lack of stable surface state has limited its extensive use for several decades. In this work, we demonstrated highly stable self-assembled monolayers (SAMs) on Ge surface to prevent oxidization for further applications. After the pretreatment in hydrochloric acid, the oxide-free and Cl-terminated Ge could be further coated with 1-dodecanethiol (NDM) SAMs. The influence factors including reaction time, solvent component and reaction temperature were optimized to obtain stable passivated monolayer for oxidation resistance. Contact angle analysis, atomic force microscopy, ellipsometer and X-ray photoelectron spectroscopy were performed to characterize the functionalized Ge surface respectively. Meanwhile, the reaction mechanism and stability of thiols SAMs on Ge (1 1 1) surface were investigated. Finally, highly stable passivated NDM SAMs on Ge surface could be formed through immersing oxide-free Ge in mixture solvent (water/ethanol, v/v = 1:1) at appropriately elevated temperature (∼80 °C) for 24 h. And the corresponding optimized passivated Ge surface was stable for more than 10 days even in water condition, which was much longer than the data reported and paved the way for the future practical applications of Ge.

1-Dodecanethiol based highly stable self-assembled monolayers for germanium passivation

Energy Technology Data Exchange (ETDEWEB)

Cai, Qi [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No. 865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No. 19A, Yuquan Road, Beijing 100049 (China); Xu, Baojian, E-mail: xbj@mail.sim.ac.cn [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No. 865, Changning Road, Shanghai 200050 (China); Shanghai Internet of Things Co., LTD, No. 1455, Pingcheng Road, Shanghai 201899 (China); Ye, Lin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No. 865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No. 19A, Yuquan Road, Beijing 100049 (China); Di, Zengfeng [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No. 865, Changning Road, Shanghai 200050 (China); Huang, Shanluo; Du, Xiaowei [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No. 865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No. 19A, Yuquan Road, Beijing 100049 (China); Zhang, Jishen; Jin, Qinghui [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No. 865, Changning Road, Shanghai 200050 (China); Zhao, Jianlong, E-mail: jlzhao@mail.sim.ac.cn [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No. 865, Changning Road, Shanghai 200050 (China)

2015-10-30

Highlights: • A simple and effective approach for higly stable germanium passivation. • 1-Dodecanethiol self-assembled monolayers for germanium oxidation resistance. • The influence factors of germanium passivation were systematically studied. • The stability of the passivated Ge was more than 10 days even in water conditions. - Abstract: As a typical semiconductor material, germanium has the potential to replace silicon for future-generation microelectronics, due to its better electrical properties. However, the lack of stable surface state has limited its extensive use for several decades. In this work, we demonstrated highly stable self-assembled monolayers (SAMs) on Ge surface to prevent oxidization for further applications. After the pretreatment in hydrochloric acid, the oxide-free and Cl-terminated Ge could be further coated with 1-dodecanethiol (NDM) SAMs. The influence factors including reaction time, solvent component and reaction temperature were optimized to obtain stable passivated monolayer for oxidation resistance. Contact angle analysis, atomic force microscopy, ellipsometer and X-ray photoelectron spectroscopy were performed to characterize the functionalized Ge surface respectively. Meanwhile, the reaction mechanism and stability of thiols SAMs on Ge (1 1 1) surface were investigated. Finally, highly stable passivated NDM SAMs on Ge surface could be formed through immersing oxide-free Ge in mixture solvent (water/ethanol, v/v = 1:1) at appropriately elevated temperature (∼80 °C) for 24 h. And the corresponding optimized passivated Ge surface was stable for more than 10 days even in water condition, which was much longer than the data reported and paved the way for the future practical applications of Ge.

Knowledge, access and utilization of bed-nets among stable and seasonal migrants in an artemisinin resistance containment area of Myanmar.

Science.gov (United States)

Phyo Than, Wint; Oo, Tin; Wai, Khin Thet; Thi, Aung; Owiti, Philip; Kumar, Binay; Deepak Shewade, Hemant; Zachariah, Rony

2017-09-14

Myanmar lies in the Greater Mekong sub-region of South-East Asia faced with the challenge of emerging resistance to artemisinin combination therapies (ACT). Migrant populations are more likely than others to spread ACT resistance. A vital intervention to reduce malaria transmission, resistance spread and eliminate malaria is the use of bed nets. Among seasonal and stable migrants in an artemisinin resistance containment region of Myanmar, we compared a) their household characteristics, b) contact with health workers and information material, and c) household knowledge, access and utilization of bed nets. Secondary data from community-based surveys on 2484 migrant workers (2013 and 2014, Bago Region) were analyzed of which 37% were seasonal migrants. Bed net access and utilization were assessed using a) availability of at least one bed net per household, and b) one bed net per two persons, and c) proportion of household members who slept under abed net during the previous night (Indicator targets = 100%). Over 70% of all migrants were from unstable work settings with short transitory stays. Average household size was five (range 1-25) and almost half of all households had children under-five years. Roughly 10 % of migrants were night-time workers. Less than 40% of households had contact with health workers and less than 30% had exposure to information education and communication (IEC) materials, the latter being significantly lower among seasonal migrants. About 70% of households were aware of the importance of insecticide-treated bed-nets/long-lasting insecticidal nets (ITNs/LLINs), but knowledge on insecticide impregnation and retreatment of ITNs was poor (Myanmar. Possible ways forward include frequent distribution campaigns to compensate for short transitory stays, matching household distributions to household size, enhanced information campaigns and introducing legislation to make mosquito repellents available for night-time workers at plantations and farms

Enhanced Production and Characterization of a Solvent Stable Amylase from Solvent Tolerant Bacillus tequilensis RG-01: Thermostable and Surfactant Resistant

Directory of Open Access Journals (Sweden)

Soni Tiwari

2014-01-01

Full Text Available Ten bacterial strains isolated from the soil samples in the presence of cyclohexane were screened for amylase production. Among them, culture RG-01 was adjudged as the best amylase producer and was identified as Bacillus tequilensis from MTCC, Chandigarh. The isolate showed maximum amylase production (8100 U/mL in the presence of starch, peptone, and Ca2+ ions at 55°C pH 7.0 within 24 h of incubation. The enzyme was stable in the presence of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the amylase stability, respectively. The enzyme was showed it 100% activity at 55°C and pH 7.0 with 119% and 127% stability at 55°C and pH 7.0, respectively. The enzyme was also stable in the presence of SDS, Tween-40, Tween-60, and Tween-80 (1% and was found stimulatory effect, respectively. Only Triton-X-100 showed a moderate inhibitory effect (5% on amylase activity. This isolate (Bacillus tequilensis RG-01 may be useful in several industrial applications owing to its thermotolerant and organic solvents and surfactants resistance characteristics.

Development of heat-resistant magnetic sensor

International Nuclear Information System (INIS)

Takaya, Shigeru; Arakawa, Hisashi; Keyakida, Satoshi

2013-01-01

A heat-resistant flux gate magnetic sensor has been developed. Permendur, which has high Curie point, is employed as the magnetic core material and the detection method of the external magnetic field is modified. The characteristics of the developed magnetic sensor up to 500degC were evaluated. The sensor output increased linearly with the external magnetic field in the range of ±5 G and the standard deviation at 500degC was about 0.85G. (author)

Development status und future possibilities for martensitic creep resistant steels

Energy Technology Data Exchange (ETDEWEB)

Hald, J. [Technical Univ. Denmark, Lyngby (Denmark). Dept. of Mechanical Engineering

2010-07-01

In the last four decades new stronger modified 9%Cr martensitic creep resistant steels have been introduced in power plants, which has enabled increases in maximum achievable steam conditions from the previous 250 bar and 540-560 C up to the values of 300 bar and 600-620 C currently being introduced all over the world. In order to further increase the steam parameters of steel based power plants up to a target value of 650 C/325 bar it is necessary to double the creep strength of the martensitic steels. At the same time the resistance against steam oxidation must be improved by an increase of the chromium content in the steels from 9% to 12%. However, so far all attempts to make stronger 12%Cr steels have led to breakdowns in long-term creep strength. Significant progress has been achieved in the understanding of microstructure stability of the martensitic 9-12%Cr steels: Observed microstructure instabilities in 11-12%Cr steels are explained by Z-phase precipitation, which dissolves fine MN nitrides. Improved understanding of effects of B and N on long-term creep properties has formed the basis of a series of new stronger 9%Cr test alloys with improved creep strength. In parallel 9%Cr test steels with low C content show very promising behavior in long-term tests. However, the 9%Cr steels must be surface coated to protect against steam oxidation at high temperature applications above 620%C. A possibility to use fine Z-phases for strengthening of the martensitic steels has been identified, and this opens a new pathway for development of stable strong 12%Cr steels. There are still good prospects for the realization of a 325 bar / 650 C steam power plant all based on steel. (orig.)

Understanding effects of microstructural inhomogeneity on creep response – New approaches to improve the creep resistance in magnesium alloys

Directory of Open Access Journals (Sweden)

Yuanding Huang

2014-06-01

Full Text Available Previous investigations indicate that the creep resistance of magnesium alloys is proportional to the stability of precipitated intermetallic phases at grain boundaries. These stable intermetallic phases were considered to be effective to suppress the deformation by grain boundary sliding, leading to the improvement of creep properties. Based on this point, adding the alloying elements to form the stable intermetallics with high melting point became a popular way to develop the new creep resistant magnesium alloys. The present investigation, however, shows that the creep properties of binary Mg–Sn alloy are still poor even though the addition of Sn possibly results in the precipitation of thermal stable Mg2Sn at grain boundaries. That means other possible mechanisms function to affect the creep response. It is finally found that the poor creep resistance is attributed to the segregation of Sn at dendritic and grain boundaries. Based on this observation, new approaches to improve the creep resistance are suggested for magnesium alloys because most currently magnesium alloys have the commonality with the Mg–Sn alloys.

Wall-crossing between stable and co-stable ADHM data

Science.gov (United States)

Ohkawa, Ryo

2018-06-01

We prove formula between Nekrasov partition functions defined from stable and co-stable ADHM data for the plane following method by Nakajima and Yoshioka (Kyoto J Math 51(2):263-335, 2011) based on the theory of wall-crossing formula developed by Mochizuki (Donaldson type invariants for algebraic surfaces: transition of moduli stacks, Lecture notes in mathematics, vol 1972, Springer, Berlin, 2009). This formula is similar to conjectures by Ito et al. [J High Energy Phys 2013(5):045, 2013, (4.1), (4.2)] for A1 singularity.

Developing Inset Resistant Maize Varieties for Food Security in Kenya

International Nuclear Information System (INIS)

Mugo, S.

2002-01-01

The Insect Resistant Maize for Africa (IRMA) project aims at increasing maize production and food security through development and deployment of stem borer resistant maize germplasm developed using conventional and through biotechnology methods such as Bt maize. Bt maize offers farmers an effective and practical option for controlling stem borers. It was recognized that the development and routine use of Bt maize will require addressing relevant bio-safety, environmental, and community concerns and research and information gathering activities are in place to address these concerns and research and information gathering activities are in place to address these concerns. Suitable Bt gene have been acquired or synthesized and back-crossed into elite maize germplasm at CIMMYT-Mexico, and the effective Cry-proteins against the major maize stem borers in Kenya were identified to better target pests. Stem borer resistant maize germplasm is being developed through conventional breeding, using locally adapted and exotic germplasm. for safe and effective deployment of Bt maize,studies on its impacts on target and non-target arthropods as well as studies on the effects of Bt maize on key non-target arthropods as well as studies on gene flow are underway. Insect resistance management strategies are being developed through quantifying the effectiveness, ???. Socioeconomic impact studies are revealing factors in the society that may influence the adoption of Bt maize in Kenya. Also, baseline data, essential for the monitoring and evaluation of the Bt maize technology in Kenya, has been established. Technology transfer and capacity building, creating awareness and communications have received attention in the project. This paper describes the major research activities as they relate to development of the stem bore resistant maize germplasm

Elisa development for detection of glyphosat resistant gm soybean

Directory of Open Access Journals (Sweden)

Владислав Геннадійович Спиридонов

2015-11-01

Full Text Available During research we have utilized recombinant enzyme 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS, conferring resistance to glyphosate for GM soybean, for the hen immunization and obtaining specific yolk antibodies IgY. Stages of ELISA development that can detect at least 0,1 % of GM-soybean resistant to glyphosate were present

Development and applications of the contact electric resistance technique

Energy Technology Data Exchange (ETDEWEB)

Saario, T.

1995-12-31

At the moment both the scientific understanding of corrosion processes and the engineering practices of corrosion control in power plants can benefit considerably from the development of in situ on-line instruments for characterisation of the surface films on construction materials. In this work a new in situ Contact Electric Resistance (CER) technique has been developed for measurement of electric resistance of surface films on metals. The CER technique was applied in this work in several different research areas. These include e.g. localized corrosion of stainless steel in paper mill wet end environment, investigation of the effect of inhibitors in steam generator crevice environments, passivation of GaAs single crystals by sulphate treatment and monitoring of the kinetics of oxide growth on zirconium metals in high temperature water. The CER technique has a measurement capacity ranging from 10-9 {omega} to 105 {omega}. The lowest range of resistance is typical for metallic layers deposited on the surface in electrodeposition processes. The highest range of resistance is found for insulator type of films e.g. on zirconium metals. (author)

Prevalence of transmitted drug resistance and impact of transmitted resistance on treatment success in the German HIV-1 Seroconverter Cohort.

Directory of Open Access Journals (Sweden)

Barbara Bartmeyer

Full Text Available BACKGROUND: The aim of this study is to analyse the prevalence of transmitted drug resistance, TDR, and the impact of TDR on treatment success in the German HIV-1 Seroconverter Cohort. METHODS: Genotypic resistance analysis was performed in treatment-naïve study patients whose sample was available 1,312/1,564 (83.9% October 2008. A genotypic resistance result was obtained for 1,276/1,312 (97.3%. The resistance associated mutations were identified according to the surveillance drug resistance mutations list recommended for drug-naïve patients. Treatment success was determined as viral suppression below 500 copies/ml. RESULTS: Prevalence of TDR was stable at a high level between 1996 and 2007 in the German HIV-1 Seroconverter Cohort (N = 158/1,276; 12.4%; CI(wilson 10.7-14.3; p(for trend = 0.25. NRTI resistance was predominant (7.5% but decreased significantly over time (CI(Wilson: 6.2-9.1, p(for trend = 0.02. NNRTI resistance tended to increase over time (NNRTI: 3.5%; CI(Wilson: 2.6-4.6; p(for trend= 0.07, whereas PI resistance remained stable (PI: 3.0%; CI(Wilson: 2.1-4.0; p(for trend = 0.24. Resistance to all drug classes was frequently caused by singleton resistance mutations (NRTI 55.6%, PI 68.4%, NNRTI 99.1%. The majority of NRTI-resistant strains (79.8% carried resistance-associated mutations selected by the thymidine analogues zidovudine and stavudine. Preferably 2NRTI/1PIr combinations were prescribed as first line regimen in patients with resistant HIV as well as in patients with susceptible strains (susceptible 45.3%; 173/382 vs. resistant 65.5%; 40/61. The majority of patients in both groups were treated successfully within the first year after ART-initiation (susceptible: 89.9%; 62/69; resistant: 7/9; 77.8%. CONCLUSION: Overall prevalence of TDR remained stable at a high level but trends of resistance against drug classes differed over time. The significant decrease of NRTI-resistance in patients newly infected

Geospatial modeling of plant stable isotope ratios - the development of isoscapes

Science.gov (United States)

West, J. B.; Ehleringer, J. R.; Hurley, J. M.; Cerling, T. E.

2007-12-01

Large-scale spatial variation in stable isotope ratios can yield critical insights into the spatio-temporal dynamics of biogeochemical cycles, animal movements, and shifts in climate, as well as anthropogenic activities such as commerce, resource utilization, and forensic investigation. Interpreting these signals requires that we understand and model the variation. We report progress in our development of plant stable isotope ratio landscapes (isoscapes). Our approach utilizes a GIS, gridded datasets, a range of modeling approaches, and spatially distributed observations. We synthesize findings from four studies to illustrate the general utility of the approach, its ability to represent observed spatio-temporal variability in plant stable isotope ratios, and also outline some specific areas of uncertainty. We also address two basic, but critical questions central to our ability to model plant stable isotope ratios using this approach: 1. Do the continuous precipitation isotope ratio grids represent reasonable proxies for plant source water?, and 2. Do continuous climate grids (as is or modified) represent a reasonable proxy for the climate experienced by plants? Plant components modeled include leaf water, grape water (extracted from wine), bulk leaf material ( Cannabis sativa; marijuana), and seed oil ( Ricinus communis; castor bean). Our approaches to modeling the isotope ratios of these components varied from highly sophisticated process models to simple one-step fractionation models to regression approaches. The leaf water isosocapes were produced using steady-state models of enrichment and continuous grids of annual average precipitation isotope ratios and climate. These were compared to other modeling efforts, as well as a relatively sparse, but geographically distributed dataset from the literature. The latitudinal distributions and global averages compared favorably to other modeling efforts and the observational data compared well to model predictions

Environmental factors influencing the development and spread of antibiotic resistance.

Science.gov (United States)

Bengtsson-Palme, Johan; Kristiansson, Erik; Larsson, D G Joakim

2018-01-01

Antibiotic resistance and its wider implications present us with a growing healthcare crisis. Recent research points to the environment as an important component for the transmission of resistant bacteria and in the emergence of resistant pathogens. However, a deeper understanding of the evolutionary and ecological processes that lead to clinical appearance of resistance genes is still lacking, as is knowledge of environmental dispersal barriers. This calls for better models of how resistance genes evolve, are mobilized, transferred and disseminated in the environment. Here, we attempt to define the ecological and evolutionary environmental factors that contribute to resistance development and transmission. Although mobilization of resistance genes likely occurs continuously, the great majority of such genetic events do not lead to the establishment of novel resistance factors in bacterial populations, unless there is a selection pressure for maintaining them or their fitness costs are negligible. To enable preventative measures it is therefore critical to investigate under what conditions and to what extent environmental selection for resistance takes place. In addition, understanding dispersal barriers is not only key to evaluate risks, but also to prevent resistant pathogens, as well as novel resistance genes, from reaching humans. © FEMS 2017.

Metabolic changes during development of Walker-256 carcinosarcoma resistance to doxorubicin.

Science.gov (United States)

Todor, I N; Lukyanova, N Yu; Shvets, Yu V; Lozovska, Yu V; Chekhun, V F

2015-03-01

To study indices of energy metabolism, content of K(+) and Mg(++) both in peripheral blood and in Walker-256 carcinosarcoma during development of resistance to doxorubicin. Resistance of Walker-256 carcinosarcoma to doxorubicin has been developed through 12 subsequent transplantations of tumor after the chemotherapy. Parental strain was inhibited by drug by 65%, while transitional resistant substrains - by 30% and 2%, respectively. Determination of biochemical indices in blood serum and homogenates of tumor tissue, level of potassium, magnesium, lactate, glucose, activities of lactate dehydrogenase and glucose-6-phosphate dehydrogenase was performed with the help of biochemical and immune-enzyme analyzer GBG ChemWell 2990 (USA) using standard kits. Polarography was used to determine indices of mitochondrial oxidative phosphorylation. Study of mitochondrial membrane potential was carried out on flow cytometer Beckman Coulter Epics XL using dye JC-1. It has been determined that development of drug resistance causes the decrease of K(+), Mg(++), glucose content in blood serum and increase of these indices in tumor tissue. At the same time, gradual tumor's loss of sensitivity is characterized by decrease of glycolysis activity in it and activation of mitochondrial oxidative phosphorylation and pentose phosphate pathway of glucose degradation, which causes more intensive formation of NADPH. Development of drug resistance of tumor causes certain metabolic changes in organism and tumor. Further study of such changes will make possible to determine tumor and extratumor markers of resistance.

A reassessment of the risk of rust fungi developing resistance to fungicides.

Science.gov (United States)

Oliver, Richard P

2014-11-01

Rust fungi are major pathogens of many annual and perennial crops. Crop protection is largely based on genetic and chemical control. Fungicide resistance is a significant issue that has affected many crop pathogens. Some pathogens have rapidly developed resistance and hence are regarded as high-risk species. Rust fungi have been classified as being low risk, in spite of sharing many relevant features with high-risk pathogens. An examination of the evidence suggests that rust fungi may be wrongly classified as low risk. Of the nine classes of fungicide to which resistance has developed, six are inactive against rusts. The three remaining classes are quinone outside inhibitors (QoIs), demethylation inhibitors (DMIs) and succinate dehydrogenase inhibitors (SDHIs). QoIs have been protected by a recently discovered intron that renders resistant mutants unviable. Low levels of resistance have developed to DMIs, but with limited field significance. Older SDHI fungicides were inactive against rusts. Some of the SDHIs introduced since 2003 are active against rusts, so it may be that insufficient time has elapsed for resistance to develop, especially as SDHIs are generally sold in mixtures with other actives. It would therefore seem prudent to increase the level of vigilance for possible cases of resistance to established and new fungicides in rusts. © 2014 Society of Chemical Industry.

Error free physically unclonable function with programmed resistive random access memory using reliable resistance states by specific identification-generation method

Science.gov (United States)

Tseng, Po-Hao; Hsu, Kai-Chieh; Lin, Yu-Yu; Lee, Feng-Min; Lee, Ming-Hsiu; Lung, Hsiang-Lan; Hsieh, Kuang-Yeu; Chung Wang, Keh; Lu, Chih-Yuan

2018-04-01

A high performance physically unclonable function (PUF) implemented with WO3 resistive random access memory (ReRAM) is presented in this paper. This robust ReRAM-PUF can eliminated bit flipping problem at very high temperature (up to 250 °C) due to plentiful read margin by using initial resistance state and set resistance state. It is also promised 10 years retention at the temperature range of 210 °C. These two stable resistance states enable stable operation at automotive environments from -40 to 125 °C without need of temperature compensation circuit. The high uniqueness of PUF can be achieved by implementing a proposed identification (ID)-generation method. Optimized forming condition can move 50% of the cells to low resistance state and the remaining 50% remain at initial high resistance state. The inter- and intra-PUF evaluations with unlimited separation of hamming distance (HD) are successfully demonstrated even under the corner condition. The number of reproduction was measured to exceed 107 times with 0% bit error rate (BER) at read voltage from 0.4 to 0.7 V.

Resistive effects in EXTRAP

International Nuclear Information System (INIS)

Tendler, M.

1987-01-01

Theoretical studies of the resistive equilibrium and stability of an EXTRAP Z-pinch are reported. Extending the previous analysis we reasses properties of the resistive equilibrium in EXTRAP with the emphasis on the time dependence of the latter. We also qualitatively consider the role of resistive instabilities in EXTRAP, showing that the typical timescale of the filamentation of the discharge (i.e., the non-linear development of the tearing instability) is comparable, at present, to the discharge duration. On the other hand, we emphasize that this phenomenon may still be consistent with the experimental observation of the Bennet's equilibrium. The processes of the current start-up and ramp-up are also analysed for EXTRAP and it is shown that the peculiarities of these processes may lead to the compression oscillations around an evolving rather stable equilibrium. Finally, some consequences of the average minimum-B concept for EXTRAP are discussed and it is shown that this issue virtually reduces to the appearance of the negative curvature of the magnetic field at the periphery. The maximum attainable value of β at the periphery of the pinch is obtained, as required by the ballooning stability criterion. The influence of the finite resistivity on the ballooning mode is also estimated. (orig.)

Can microbial cells develop resistance to oxidative stress in antimicrobial photodynamic inactivation?

Science.gov (United States)

Kashef, Nasim; Hamblin, Michael R

2017-03-01

Infections have been a major cause of disease throughout the history of humans on earth. With the introduction of antibiotics, it was thought that infections had been conquered. However, bacteria have been able to develop resistance to antibiotics at an exponentially increasing rate. The growing threat from multi-drug resistant organisms calls for intensive action to prevent the emergence of totally resistant and untreatable infections. Novel, non-invasive, non-antibiotic strategies are needed that act more efficiently and faster than current antibiotics. One promising alternative is antimicrobial photodynamic inactivation (APDI), an approach that produces reactive oxygen species when dyes and light are combined. So far, it has been questionable if bacteria can develop resistance against APDI. This review paper gives an overview of recent studies concerning the susceptibility of bacteria towards oxidative stress, and suggests possible mechanisms of the development of APDI-resistance that should at least be addressed. Some ways to potentiate APDI and also to overcome future resistance are suggested. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is hormesis an underestimated factor in the development of herbicide resistance?

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Belz, Regina G.

2014-02-01

Full Text Available The growing impact of herbicide resistant weeds increasingly affects weed management and the delay of resistance evolution has become a major task of chemical weed control. Hormesis and, thus, the phenomenon that low doses of herbicides can boost weed growth could be of importance in this regard since the recommended field rate may represent a low dose for weeds that have evolved resistance to the applied herbicide and, thus, a potential hormetic dose. Applying the field rate may thus not only directly select resistant biotypes, it may also indirectly promote the success and spread of resistant biotypes via hormesis. Nevertheless, hormetic effects in resistant weeds are hitherto merely randomly observed and, thus, a clear quantitative basis to judge the significance of hormesis for resistance evolution is lacking. Therefore, this study aimed at quantifying the degree and frequency of herbicide hormesis in sensitive and resistant weed species in order to provide a first indication of whether the phenomenon deserves consideration as a potential factor contributing to the development of herbicide resistance. In germination assays complete dose-response experiments were conducted with sensitive and resistant biotypes of Matricaria inodora (ALS-target-site resistant; treated with iodosulfuron-methyl-sodium/mesosulfuron-methyl, Eleusine indica (glyphosateresistant; treated with glyphosate, and Chenopodium album (triazine/triazinone-target-site resistant; treated with terbuthylazine. After 10 days of cultivation under controlled conditions plant growth was analyzed by measuring shoot/root length and mass. Results indicated that herbicide hormesis occurred on average with a total frequency of 29% in sensitive/resistant biotypes with an average growth increase of 53% occurring typically within a dose zone exceeding 350fold. Hormetic effects occurred, however, very variable and only for specific endpoints and not plant growth in general. If such a

Status of Methodology Development for the Evaluation of Proliferation Resistance

International Nuclear Information System (INIS)

Lee, Yong Deok; Ko, Won Il; Lee, Jung Won

2010-01-01

Concerning the increasing energy demand and green house effect, nuclear energy is now the most feasible option. Therefore, recently, oil countries even have a plan to build the nuclear power plant for energy production. If nuclear systems are to make a major and sustainable contribution to the worlds energy supply, future nuclear energy systems must meet specific requirements. One of the requirements is to satisfy the proliferation resistance condition in an entire nuclear system. Therefore, from the beginning of future nuclear energy system development, it is important to consider a proliferation resistance to prevent the diversion of nuclear materials. The misuse of a nuclear system must be considered as well. Moreover, in the import and export of nuclear system, the evaluation of the proliferation resistance on the nuclear system becomes a key factor The INPRO (International Project on Innovative Nuclear Reactors and Fuel Cycles) program initiated by the IAEA proposed proliferation resistance (PR) as a key component of a future innovative nuclear system (INS) with a sustainability, economics, safety of nuclear installation and waste management. The technical goal for Generation IV (Gen IV) nuclear energy systems (NESs) highlights a Proliferation Resistance and Physical Protection (PR and PP), sustainability, safety, reliability and economics as well. Based on INPRO and Gen IV study, the methodology development for the evaluation of proliferation resistance has been carried out in KAERI. Finally, the systematic procedure for methodology was setup and the indicators for the procedure were decided. The methodology involves the evaluation from total nuclear system to individual process. Therefore, in this study, the detailed procedure for the evaluation of proliferation resistance and the newly proposed additional indicators are described and several conditions are proposed to increase the proliferation resistance in the future nuclear system. The assessment of PR

Equilibrium contact angle or the most-stable contact angle?

Science.gov (United States)

Montes Ruiz-Cabello, F J; Rodríguez-Valverde, M A; Cabrerizo-Vílchez, M A

2014-04-01

It is well-established that the equilibrium contact angle in a thermodynamic framework is an "unattainable" contact angle. Instead, the most-stable contact angle obtained from mechanical stimuli of the system is indeed experimentally accessible. Monitoring the susceptibility of a sessile drop to a mechanical stimulus enables to identify the most stable drop configuration within the practical range of contact angle hysteresis. Two different stimuli may be used with sessile drops: mechanical vibration and tilting. The most stable drop against vibration should reveal the changeless contact angle but against the gravity force, it should reveal the highest resistance to slide down. After the corresponding mechanical stimulus, once the excited drop configuration is examined, the focus will be on the contact angle of the initial drop configuration. This methodology needs to map significantly the static drop configurations with different stable contact angles. The most-stable contact angle, together with the advancing and receding contact angles, completes the description of physically realizable configurations of a solid-liquid system. Since the most-stable contact angle is energetically significant, it may be used in the Wenzel, Cassie or Cassie-Baxter equations accordingly or for the surface energy evaluation. © 2013 Elsevier B.V. All rights reserved.

Conjugated polymer dots for ultra-stable full-color fluorescence patterning.

Science.gov (United States)

Chang, Kaiwen; Liu, Zhihe; Chen, Haobin; Sheng, Lan; Zhang, Sean Xiao-An; Chiu, Daniel T; Yin, Shengyan; Wu, Changfeng; Qin, Weiping

2014-11-12

Stable full-color fluorescence patterning are achieved by multicolor polymer-dot inks. The fluorescent patterns show extraordinary stability upon various treatments, offering a superior combination of bright fluorescence, excellent photostability, chemical resistance, and eco-friendship. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Methods for Genetic Assessment of Antibiotic Resistance In Animal Herds

DEFF Research Database (Denmark)

Schmidt, Gunilla Veslemøy

with a parallel selection for resistant bacteria. Since the hazards related to antibiotic resistance development have been recognized, the prudent use of antibiotics has been in focus, especially concerning their use in animal production. For many years antibiotics have been, and still are, recklessly used...... in the animal production especially in the form of growth promoters. Due to the associated risks of resistant zoonotic bacteria transmission from animals to humans, it is of interest to keep antibiotic use and antibiotic resistance under strict surveillance.This PhD study was based on the development of real......-time PCR (qPCR) assays that supply an easy and rapid method for quantifying antibiotic resistance levels in animal herds. The pig production is accountable for a large portion of the antibiotics used for food producing animals in Denmark. Therefore, the antibiotic resistance genes included in this study...

Study of multidrug resistance and radioresistance

International Nuclear Information System (INIS)

Kang, Yoon Koo; Yoo, Young Do

1999-04-01

We investigated the mechanism of 5-FU, adriamycin, radiation resistance in Korean gastric cancer cells. First we investigated the relation between Rb and multidrug resistance. Rb stable transfectants exhibited 5- to 10- fold more resistance to adriamycin than the control cells. These Rb transfectants showed increased MDR1 expression. We also investigated up-regulation in radiation-resistant tumor tissues. HSP27, MRP-8, GST, and NKEF-B were up-regulated in radiation resistant tumor. Expression of NKEF-B was also increased by radiation exposure in Head and Neck cells. These results demonstrated that NKEF-B is a stress response protein and it may have an important role in radiation resistance

Incorporation of disease resistance from Lycopersicon peruvianum L. to cultivated tomatoes, 1: Breeding of new varieties ''Ryugyoku'' etc., having resistance to Fusarium root rot and tobacco mosaic virus inherited from L. peruvianum

International Nuclear Information System (INIS)

Yamakawa, K.; Yasui, H.; Mochizuki, T.; Hida, K.; Komochi, S.

1987-01-01

Fusarium crown and root rot (FCR) resistance and Tobacco Mosaic Virus (TMV) resistance (Tm-2) of a wild tomato (Lycopersicon peruvianum) were incorporated into cultivated tomatoes (L. esculentum). With this material, F1 hybrid varieties 'Kagyoku, Ryugyoku' and their parental lines 'Tomato parental lines No. 4, -No. 5' were developed. In addition, 'Kagyoku, Ryugyoku' possess Fusarium wild (J1), Nematode (Meloidogyne incognita) and TMV (Tm-2a) resistance introduced from the other varieties. Among the resistances introduced from L. peruvianum, TMV resistance is simply inherited and stable enough. FCR resistance is basically monogenic, but the strong influence of the genetic background hinders the development of FCR resistant varieties with high quality and yield. Whereas 'Ryugyoku' which is highly resistant to FCR has less attractive fruit characters, 'Kagyoku' yields fruits of high quality with a comparatively low FCR resistance. In this report, the breeding process from interspecific hybridization to the development of F1 varieties and the methods of selection applied were described. Also the difficulties which arose in the process of incorporation of the resistance from the wild species were discussed

Applications of stable isotopes

International Nuclear Information System (INIS)

Letolle, R.; Mariotti, A.; Bariac, T.

1991-06-01

This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

Anabolic resistance assessed by oral stable isotope ingestion following bed rest in young and older adult volunteers: Relationships with changes in muscle mass.

Science.gov (United States)

Biolo, Gianni; Pišot, Rado; Mazzucco, Sara; Di Girolamo, Filippo Giorgio; Situlin, Roberta; Lazzer, Stefano; Grassi, Bruno; Reggiani, Carlo; Passaro, Angelina; Rittweger, Joern; Gasparini, Mladen; Šimunič, Boštjan; Narici, Marco

2017-10-01

Aging and experimental bed rest are associated with muscle atrophy and resistance to post-prandial stimulation of protein synthesis or anabolic resistance (AR). We have used in young and older adult volunteers, during short-term bed rest, a quick and non-invasive method, based on a single oral bolus of the stable isotope L[ring- 2 H 5 ]phenylalanine (D 5 Phe), to determine post-prandial AR, defined as ratio between irreversible hydroxylation and incorporation into body protein of ingested phenylalanine. We compared in older (O, 59 ± 1 y) and young (Y, 23 ± 1 y) healthy male volunteers the effects of two-week bed rest on post-prandial protein kinetics, assessed during absorption of a standard ready-to-use oral nutritional supplement, through stable-labeled isotope amino acid D 5 Phe, diluted in water, given as single oral load. The metabolic fate of D 5 Phe is either utilization for protein synthesis or irreversible hydroxylation to L[ring- 2 H 4 ]tyrosine (D 4 Tyr). AR was defined as ratio between the areas under the curves of D 4 Tyr-to-D 5 Phe plasma concentrations over 6 h meal absorption. To determine the relationships between AR and muscle changes following bed rest, quadriceps muscle volume (QMV) was determined by magnetic resonance imaging (MRI). At baseline, in pooled Y and O subjects, values of AR were inversely correlated with QMV (R = -0.75; p < 0.03). Following 2-weeks of inactivity, there were significant bed rest effects on AR (p < 0.01) and QMV (p < 0.03), as well as significant bed rest × group interaction for AR (p < 0.03; +9.2% in Y; +21.9% in O) and QMV (p < 0.05; -5.7% in Y; -%7.3 in O). In pooled subjects, the percentage delta changes in AR and QMV, induced by bed rest, were inversely correlated (R = -0.57; p < 0.05). Bed rest-induced AR is much greater in the older than in younger adults. We have developed a new, simple, non-invasive method for the assessment of AR. The results indicate that this metabolic

Fire Resistant, Moisture Barrier Membrane

Science.gov (United States)

St.Clair, Terry L. (Inventor)

2000-01-01

A waterproof and breathable, fire-resistant laminate is provided for use in tents, garments, shoes, and covers, especially in industrial, military and emergency situations. The laminate permits water vapor evaporation while simultaneously preventing liquid water penetration. Further, the laminate is fire-resistant and significantly reduces the danger of toxic compound production when exposed to flame or other high heat source. The laminate may be applied to a variety of substrates and is comprised of a silicone rubber and plurality of fire-resistant, inherently thermally-stable polyimide particles.

Development of application technology of radiation-resistant microorganism

International Nuclear Information System (INIS)

Kim, Dong Ho; Lim, Sang Yong; Joe, Min Ho; Jung, Jin Woo; Jung, Sun Wook; Song, Du Sup; Choi, Young Ji

2009-02-01

The scope of the project is divided into of three parts; (i) to define the survival strategy of radiation-resistant microbes, especially Deinococcus (ii) acquisition of gene resources encoding the novel protein and related with the production of functional materials (iii) development of control technology against radiation-resistant microbes. To this aim, first, the whole transcriptional response of the D. radiodurans strain haboring pprI mutation, which plays an important role in radiation resistance, was analyzed by cDNA microarray. The anti-oxidant activity of the major carotenoid of D. radiodurans, deinoxanthin, was analyzed and the strain was constructed, in which the gene necessary for bio- synthesis of deinoxanthin is deleted. The response to cadmium of D. radiodurans was also investigated through cDNA microarray analysis. Radiogenic therapy, one of the cancer treatments, is designed to use radiation-inducible gene for the treatment. To develop the gene-transfer vehicle for radiogenic therapy, we have investigated the virulence mechanism of Salmonella, which is tumor-targeting bacteria and studied the synergistic effect of some anti-cancer agents on radiation treatment for cancer. Finally, we confirmed that irradiation could decompose a fungus toxin, patulin, into various harmless by-products

Development of application technology of radiation-resistant microorganism

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Ho; Lim, Sang Yong; Joe, Min Ho; Jung, Jin Woo; Jung, Sun Wook; Song, Du Sup; Choi, Young Ji [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-02-15

The scope of the project is divided into of three parts; (i) to define the survival strategy of radiation-resistant microbes, especially Deinococcus (ii) acquisition of gene resources encoding the novel protein and related with the production of functional materials (iii) development of control technology against radiation-resistant microbes. To this aim, first, the whole transcriptional response of the D. radiodurans strain haboring pprI mutation, which plays an important role in radiation resistance, was analyzed by cDNA microarray. The anti-oxidant activity of the major carotenoid of D. radiodurans, deinoxanthin, was analyzed and the strain was constructed, in which the gene necessary for bio- synthesis of deinoxanthin is deleted. The response to cadmium of D. radiodurans was also investigated through cDNA microarray analysis. Radiogenic therapy, one of the cancer treatments, is designed to use radiation-inducible gene for the treatment. To develop the gene-transfer vehicle for radiogenic therapy, we have investigated the virulence mechanism of Salmonella, which is tumor-targeting bacteria and studied the synergistic effect of some anti-cancer agents on radiation treatment for cancer. Finally, we confirmed that irradiation could decompose a fungus toxin, patulin, into various harmless by-products.

Resistive switching properties and low resistance state relaxation in Al/Pr0.7Ca0.3MnO3/Pt junctions

International Nuclear Information System (INIS)

Li Songlin; Liao, Z L; Li, J; Gang, J L; Zheng, D N

2009-01-01

Metal/insulator/metal structures composed of active Al top electrodes (TEs) and oxygen-deficient Pr 0.7 Ca 0.3 MnO 3 (PCMO) insulator layers are prepared on platinized silicon substrates. The junction resistance exhibits an obvious negative differential resistance region in the first bias sweep and an irreversible increase from 2 to 100 MΩ in repeated ±4 V sweeps. The pulse duration needed to fully switch the junctions is found to be on the order of milliseconds. When 100-500 μs negative pulses are used, the junctions show an incomplete switch to the low resistance state (LRS) which exhibits fluctuating resistances. The fluctuation in the LRS is suppressed and the high-to-low resistance ratio increases gradually when the negative pulse duration is increased from 100 to 500 μs. For relaxed junctions, pulse switching experiments reveal that the LRS undergoes a dynamically stable process at the beginning and then reaches a lower and metastable resistance value. Resistance retention tests also indicate that the high resistance state is very stable, while the metastable LRS gradually relaxes to higher resistance values. The experimental results are discussed with the formation and dissociation of an interfacial AlO x layer at the interface between Al TEs and PCMO layers.

Design of ultra-stable insulin analogues for the developing world

Directory of Open Access Journals (Sweden)

Michael A Weiss

2013-01-01

Full Text Available The engineering of insulin analogues illustrates the application of structure-based protein design to clinical medicine. Such design has traditionally been based on structures of wild-type insulin hexamers in an effort to optimize the pharmacokinetic (PK and pharmacodynamic properties of the hormone. Rapid-acting insulin analogues (in chronological order of their clinical introduction, Humalog ® [Eli Lilly & Co.], Novolog ® [Novo-Nordisk], and Apidra ® [Sanofi-Aventis] exploit the targeted destabilization of subunit interfaces to facilitate capillary absorption. Conversely, long-acting insulin analogues exploit the stability of the insulin hexamer and its higher-order self-assembly within the subcutaneous depot to enhance basal glycemic control. Current products either operate through isoelectric precipitation (insulin glargine, the active component of Lantus ® ; Sanofi-Aventis or employ an albumin-binding acyl tether (insulin detemir, the active component of Levemir ® ; Novo-Nordisk. Such molecular engineering has often encountered a trade-off between PK goals and product stability. Given the global dimensions of the diabetes pandemic and complexity of an associated cold chain of insulin distribution, we envisage that concurrent engineering of ultra-stable protein analogue formulations would benefit the developing world, especially for patients exposed to high temperatures with inconsistent access to refrigeration. We review the principal mechanisms of insulin degradation above room temperature and novel molecular approaches toward the design of ultra-stable rapid-acting and basal formulations.

Antibiotic Resistance in the Food Chain: A Developing Country-Perspective.

Science.gov (United States)

Founou, Luria Leslie; Founou, Raspail Carrel; Essack, Sabiha Yusuf

2016-01-01

Antibiotics are now "endangered species" facing extinction due to the worldwide emergence of antibiotic resistance (ABR). Food animals are considered as key reservoirs of antibiotic-resistant bacteria with the use of antibiotics in the food production industry having contributed to the actual global challenge of ABR. There are no geographic boundaries to impede the worldwide spread of ABR. If preventive and containment measures are not applied locally, nationally and regionally, the limited interventions in one country, continent and for instance, in the developing world, could compromise the efficacy and endanger ABR containment policies implemented in other parts of the world, the best-managed high-resource countries included. Multifaceted, comprehensive, and integrated measures complying with the One Health approach are imperative to ensure food safety and security, effectively combat infectious diseases, curb the emergence and spread of ABR, and preserve the efficacy of antibiotics for future generations. Countries should follow the World Health Organization, World Organization for Animal Health, and the Food and Agriculture Organization of the United Nations recommendations to implement national action plans encompassing human, (food) animal, and environmental sectors to improve policies, interventions and activities that address the prevention and containment of ABR from farm-to-fork. This review covers (i) the origin of antibiotic resistance, (ii) pathways by which bacteria spread to humans from farm-to-fork, (iii) differences in levels of antibiotic resistance between developed and developing countries, and (iv) prevention and containment measures of antibiotic resistance in the food chain.

Development of debris resistant bottom end piece

International Nuclear Information System (INIS)

Lee, Jae Kyung; Sohn, Dong Seong; Yim, Jeong Sik; Hwang, Dae Hyun; Song, Kee Nam; Oh, Dong Seok; Rhu, Ho Sik; Lee, Chang Woo; Kim, Seong Soo; Oh, Jong Myung

1993-12-01

Debris-related fuel failures have been identified as one of the major causes of fuel failures. In order to reduce the possibility of debris-related fuel failures, it is necessary to develop Debris-Resistant Bottom End Piece. For this development, mechanical strength test and pressure drop test were performed, and the test results were analyzed. And the laser cutting, laser welding and electron beam welding technology, which were the core manufacturing technology of DRBEP, were developed. Final design were performed, and the final drawing and specifications were prepared. The prototype of DRBEP was manufactured according to the developed munufacturing procedure. (Author)

Detection of resistance, cross-resistance, and stability of resistance to new chemistry insecticides in Bemisia tabaci (Homoptera: Aleyrodidae).

Science.gov (United States)

Basit, Muhammad; Saeed, Shafqat; Saleem, Mushtaq Ahmad; Denholm, Ian; Shah, Maqbool

2013-06-01

Resistance levels in whitefly, Bemisia tabaci (Gennadius) collections from cotton and sunflower (up to four districts) for five neonicotinoids and two insect growth regulators (IGRs) were investigated for two consecutive years. Based on the LC50(s), all collections showed slight to moderate levels of resistance for the tested insecticides compared with the laboratory susceptible population. The data also indicated that cotton and sunflower collections had similar resistance levels. In comparison (four collections), Vehari collections showed higher resistance for acetamiprid, thiacloprid, and nitenpyram compared with those of others. Average resistance ratios for acetamiprid, thiacloprid, and nitenpyram ranged from 5- to 13-, 4- to 8-, and 9- to 13-fold, respectively. Multan and Vehari collections also exhibited moderate levels (9- to 16-fold) of resistance to buprofezin. Furthermore, toxicity of neonicotinoids against immature stages was equal to that of insect growth regulators. The data also suggested that resistance in the field populations was stable. After selection for four generations with bifenthrin (G1 to G4), resistance to bifenthrin increased to 14-fold compared with the laboratory susceptible population. Selection also increased resistance to fenpropathrin, lambdacyhalothrin, imidacloprid, acetamiprid, and diafenthuron. Cross-resistance and stability of resistance in the field populations is of some concern. Rotation of insecticides having no cross-resistance and targeting the control against immature stages may control the resistant insects, simultaneously reducing the selection pressure imposed.

In situ analysis of negative-tone resist pattern formation using organic-solvent-based developer process

Science.gov (United States)

Santillan, Julius Joseph; Yamada, Keisaku; Itani, Toshiro

2014-01-01

In situ resist “pattern formation” analysis during the development process using high-speed atomic force microscopy has been improved for application not only for conventional aqueous 0.26 N tetramethylammonium hydroxide (aq. TMAH), but also organic solvent n-butyl acetate (nBA) developers. Comparative investigations of resist dissolution in these developers, using the same resist material (hybrid of polyhydroxystyrene and methacrylate), showed a grainlike, uniform dissolution of the “unexposed resist film” in nBA development and uneven dissolution of the “exposed resist film” in aq. TMAH development. These results suggest the importance of dissolution uniformity in further improving the resulting pattern line width roughness.

Resistance of green lacewing, Chrysoperla carnea Stephens to nitenpyram: Cross-resistance patterns, mechanism, stability, and realized heritability.

Science.gov (United States)

Mansoor, Muhammad Mudassir; Raza, Abu Bakar Muhammad; Abbas, Naeem; Aqueel, Muhammad Anjum; Afzal, Muhammad

2017-01-01

The green lacewing, Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) is a major generalist predator employed in integrated pest management (IPM) plans for pest control on many crops. Nitenpyram, a neonicotinoid insecticide has widely been used against the sucking pests of cotton in Pakistan. Therefore, a field green lacewing strain was exposed to nitenpyram for five generations to investigate resistance evolution, cross-resistance pattern, stability, realized heritability, and mechanisms of resistance. Before starting the selection with nitenpyram, a field collected strain showed 22.08-, 23.09-, 484.69- and 602.90-fold resistance to nitenpyram, buprofezin, spinosad and acetamiprid, respectively compared with the Susceptible strain. After continuous selection for five generations (G1-G5) with nitenpyram in the laboratory, the Field strain (Niten-SEL) developed a resistance ratio of 423.95 at G6. The Niten-SEL strain at G6 showed no cross-resistance to buprofezin and acetamiprid and negative cross-resistance to spinosad compared with the Field strain (G1). For resistance stability, the Niten-SEL strain was left unexposed to any insecticide for four generations (G6-G9) and bioassay results at G10 showed that resistance to nitenpyram, buprofezin and spinosad was stable, while resistance to acetamiprid was unstable. The realized heritability values were 0.97, 0.16, 0.03, and -0.16 to nitenpyram, buprofezin, acetamiprid and spinosad, respectively, after five generations of selection. Moreover, the enzyme inhibitors (PBO or DEF) significantly decreased the nitenpyram resistance in the resistant strain, suggesting that resistance was due to microsomal oxidases and esterases. These results are very helpful for integration of green lacewings in IPM programs. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of high temperature stable Ohmic and Schottky contacts on n-gallium nitride

Science.gov (United States)

Khanna, Rohit

In this work the effort was made to towards develop and investigate high temperature stable Ohmic and Schottky contacts for n type GaN. Various borides and refractory materials were incorporated in metallization scheme to best attain the desired effect of minimal degradation of contacts when placed at high temperatures. This work focuses on achieving a contact scheme using different borides which include two Tungsten Borides (namely W2B, W2B 5), Titanium Boride (TiB2), Chromium Boride (CrB2) and Zirconium Boride (ZrB2). Further a high temperature metal namely Iridium (Ir) was evaluated as a potential contact to n-GaN, as part of continuing improved device technology development. The main goal of this project was to investigate the most promising boride-based contact metallurgies on GaN, and finally to fabricate a High Electron Mobility Transistor (HEMT) and compare its reliability to a HEMT using present technology contact. Ohmic contacts were fabricated on n GaN using borides in the metallization scheme of Ti/Al/boride/Ti/Au. The characterization of the contacts was done using current-voltage measurements, scanning electron microscopy (SEM) and Auger Electron Spectroscopy (AES) measurements. The contacts formed gave specific contact resistance of the order of 10-5 to 10-6 Ohm-cm2. A minimum contact resistance of 1.5x10-6 O.cm 2 was achieved for the TiB2 based scheme at an annealing temperature of 850-900°C, which was comparable to a regular ohmic contact of Ti/Al/Ni/Au on n GaN. When some of borides contacts were placed on a hot plate or in hot oven for temperature ranging from 200°C to 350°C, the regular metallization contacts degraded before than borides ones. Even with a certain amount of intermixing of the metallization scheme the boride contacts showed minimal roughening and smoother morphology, which, in terms of edge acuity, is crucial for very small gate devices. Schottky contacts were also fabricated and characterized using all the five boride

Development of ceftazidime resistance in an acute Burkholderia pseudomallei infection

Directory of Open Access Journals (Sweden)

Sarovich DS

2012-08-01

Full Text Available Derek S Sarovich,1,2,* Erin P Price,1,2,* Direk Limmathurotsakul,3 James M Cook,1 Alex T Von Schulze,1 Spenser R Wolken,1 Paul Keim,1 Sharon J Peacock,3,4 Talima Pearson1 1Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA; 2Tropical and Emerging Infectious Diseases Division, Menzies School of Health Research, Darwin, Australia; 3Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; 4Department of Medicine, University of Cambridge, Cambridge, United Kingdom*These authors contributed equally to this workAbstract: Burkholderia pseudomallei, a bacterium that causes the disease melioidosis, is intrinsically resistant to many antibiotics. First-line antibiotic therapy for treating melioidosis is usually the synthetic β-lactam, ceftazidime (CAZ, as almost all B. pseudomallei strains are susceptible to this drug. However, acquired CAZ resistance can develop in vivo during treatment with CAZ, which can lead to mortality if therapy is not switched to a different drug in a timely manner. Serial B. pseudomallei isolates obtained from an acute Thai melioidosis patient infected by a CAZ susceptible strain, who ultimately succumbed to infection despite being on CAZ therapy for the duration of their infection, were analyzed. Isolates that developed CAZ resistance due to a proline to serine change at position 167 in the β-lactamase PenA were identified. Importantly, these CAZ resistant isolates remained sensitive to the alternative melioidosis treatments; namely, amoxicillin-clavulanate, imipenem, and meropenem. Lastly, real-time polymerase chain reaction-based assays capable of rapidly identifying CAZ resistance in B. pseudomallei isolates at the position 167 mutation site were developed. The ability to rapidly identify the emergence of CAZ resistant B. pseudomallei populations in melioidosis patients will allow timely alterations in treatment strategies

Development of herbicide resistance in black-grass (Alopecurus myosuroides in Bavaria

Directory of Open Access Journals (Sweden)

Gehring, Klaus

2016-02-01

Full Text Available Black-grass (Alopecurus myosuroides is one of the most important grass weeds in Bavaria. Chemical weed control with high efficacy is very important in crops like winter cereals, oilseed rape and maize. Crop rotations with more winter cereals, reduced soil cultivation and e.g. contract harvesting enhanced distribution of blackgrass in arable farming regions. Effects of herbicide resistance were observed since the last 20 years. The blackgrass herbicide resistance is well observed by the official plant protection service of Bavaria. A wide experience of resistance tests shows the development of resistant black-grass and provides an opportunity for future prospects in resistance dynamics.

5 Development of a resistance management.cdr

African Journals Online (AJOL)

user

the rotaional use of the acaricidal products in ways that reduces the selection pressure of active ingredients of same chemistry on the target-site in tick populations and as a result retard resistance development. acaricidal products on the market was based on mode of action of the active ingredients. The strategy requires.

A Fundamental Approach to Developing Aluminium based Bulk Amorphous Alloys based on Stable Liquid Metal Structures and Electronic Equilibrium - 154041

Science.gov (United States)

2017-03-28

AFRL-AFOSR-JP-TR-2017-0027 A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal Structures and...to 16 Dec 2016 4.  TITLE AND SUBTITLE A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal...Air Force Research Laboratory for accurately predicting compositions of new amorphous alloys specifically based on aluminium with properties superior

Development of new technology for the use of stable isotopic tracers in the study of human health and disease

International Nuclear Information System (INIS)

Hacyey, D.L.; Klein, P.D.; Szczepanik, P.A.; Niu, W.; Stellaard, F.; Tserng, K.Y.

1977-01-01

This program has five major aspects: first, the development of analytical instrumentation of requisite sensitivity, stability, and simplicity to conduct stable isotope measurements in a routine manner; second, the development of appropriately labeled compounds for metabolic investigations, initially through custom syntheses but eventually through commercial sources; third, development of analytical methodology to isolate, purify, and determine the isotopic content of specific organic compounds reflecting metabolic processes or disease states; fourth, collaborative development of clinical applications and testing on a routine basis, through a network of clinical centers around the country; and finally, the collection and dissemination of stable isotope information on an international scale through survey publications and conferences

Antibiotic resistance in the food chain: A developing country-perspective

Directory of Open Access Journals (Sweden)

Luria Leslie Founou

2016-11-01

Full Text Available Antibiotics are now endangered species facing extinction due to the worldwide emergence of antibiotic resistance (ABR. Food animals are considered as key reservoirs of antibiotic-resistant bacteria with the use of antibiotics in the food production industry having contributed to the actual global challenge of ABR. There are no geographic boundaries to impede the worldwide spread of ABR. If preventive and containment measures are not applied locally, nationally and regionally, the limited interventions in one country, continent and for instance, in the developing world, could compromise the efficacy and endanger ABR containment policies implemented in other parts of the world, the best-managed high-resource countries included. Multifaceted, comprehensive and integrated measures complying with the One Health approach are imperative to ensure food safety and security, effectively combat infectious diseases, curb the emergence and spread of ABR, and preserve the efficacy of antibiotics for future generations. Countries should follow the World Health Organization, World Organization for Animal Health, and the Food and Agriculture Organization of the United Nations recommendations to implement national action plans encompassing human, (food animal, and environmental sectors to improve policies, interventions and activities that address the prevention and containment of ABR from farm-to-fork. This review covers (i the origin of antibiotic resistance, (ii pathways by which bacteria spread to humans from farm-to-fork, (iii differences in levels of antibiotic resistance between developed and developing countries, and (iv prevention and containment measures of antibiotic resistance in the food chain.

Development of shelf stable, processed, low acid food products using heat-irradiation combination treatments

International Nuclear Information System (INIS)

Minnaar, A.

1998-01-01

The amount of ionizing irradiation needed to sterilize low acid vegetable and starch products (with and without sauces) commercially impairs their sensorial and nutritive qualities, and use of thermal processes for the same purpose may also have an adverse effect on the product quality. A systematic approach to the establishment of optimized combination parameters was developed for heat-irradiation processing to produce high quality, shelf stable, low acid food products. The effects of selected heat, heat-irradiation combination and irradiation treatments on the quality of shelf stable mushrooms in brine and rice, stored at ambient temperature, were studied. From a quality viewpoint, use of heat-irradiation combination treatments favouring low irradiation dose levels offered a feasible alternative to thermally processed or radappertized mushrooms in brine. However, shelf stable rice produced by heat-irradiation combination treatments offered a feasible alternative only to radappertized rice from the standpoint of quality. The technical requirements for the heat and irradiation processing of a long grain rice cultivar from the United States of America oppose each other directly, thereby reducing the feasibility of using heat-irradiation combination processing to produce shelf stable rice. The stability of starch thickened white sauces was found to be affected severely during high dose irradiation and subsequent storage at ambient temperature. However, use of pea protein isolate as a thickener in white sauces was found to have the potential to maintain the viscosity of sauces for irradiated meat and sauce products throughout processing and storage. (author)

Rolling Resistance Measurement and Model Development

DEFF Research Database (Denmark)

Andersen, Lasse Grinderslev; Larsen, Jesper; Fraser, Elsje Sophia

2015-01-01

There is an increased focus worldwide on understanding and modeling rolling resistance because reducing the rolling resistance by just a few percent will lead to substantial energy savings. This paper reviews the state of the art of rolling resistance research, focusing on measuring techniques, s......, surface and texture modeling, contact models, tire models, and macro-modeling of rolling resistance...

Human health risk assessment (HHRA) for environmental development and transfer of antibiotic resistance

DEFF Research Database (Denmark)

Ashbolt, Nicholas J.; Amézquita, Alejandro; Backhaus, Thomas

2013-01-01

to enable human health risk assessments (HHRA) that focus on the role of the environment in the failure of antibiotic treatment caused by antibiotic-resistant pathogens. Methods: The authors participated in a workshop held 4-8 March 2012 in Québec, Canada, to define the scope and objectives...... of an environmental assessment of antibiotic-resistance risks to human health. We focused on key elements of environmental-resistance-development "hot spots," exposure assessment (unrelated to food), and dose response to characterize risks that may improve antibiotic-resistance management options. Discussion: Various...... novel aspects to traditional risk assessments were identified to enable an assessment of environmental antibiotic resistance. These include a) accounting for an added selective pressure on the environmental resistome that, over time, allows for development of antibiotic-resistant bacteria (ARB); b...

Cures for the shock instability: Development of a shock-stable Roe scheme

CERN Document Server

Kim, S S; Rho, O H; Kyu-Hong, S

2003-01-01

This paper deals with the development of an improved Roe scheme that is free from the shock instability and still preserves the accuracy and efficiency of the original Roe's Flux Difference Splitting (FDS). Roe's FDS is known to possess good accuracy but to suffer from the shock instability, such as the carbuncle phenomenon. As the first step towards a shock-stable scheme, Roe's FDS is compared with the HLLE scheme to identify the source of the shock instability. Through a linear perturbation analysis on the odd-even decoupling problem, damping characteristic is examined and Mach number-based functions f and g are introduced to balance damping and feeding rates, which leads to a shock-stable Roe scheme. In order to satisfy the conservation of total enthalpy, which is crucial in predicting surface heat transfer rate in high-speed steady flows, an analysis of dissipation mechanism in the energy equation is carried out to find out the error source and to make the proposed scheme preserve total enthalpy. By modif...

DEVELOPMENT OF RESISTANCE IN BACTERIA AGAINST ANTI - MICROBIAL AGENTS: REASONS, THREATS AND ONGOING ENCOUNTER

OpenAIRE

Shibabrata Pattanayak

2011-01-01

Development of Multi Druug Resistant bacteria is creating a very severe problem in anti-microbial chemotherapy. Many recently developed antibiotics are found incapable to control resistant organisms.The reasons of development of resistance gene in the bacterial plasmid and their quick spread among various related and unrelated bacteria are analysed in this article along with discussion of world wide ongoing research to combat the problem.

Resistive effects in EXTRAP

International Nuclear Information System (INIS)

Tendler, M.

1985-10-01

Theoretical studies of the resistive equilibrium and stability of an EXTRAP z-pinch are reported. Extending the previous analysis we reassess properties of the resistive equilibrium in EXTRAP with the emphasis on the time dependence of the latter. We also qualitatively consider the role of resistive instabilities in EXTRAP, showing that the typical timescale of the filamentation of the discharge (i.e. the non-linear development of the tearing instability) is comparable at present, to the discharge duration. On the other hand, we emphasize that this phenomenon may still be consistent with the experimental observation of the Bennet's equilibrium. The processes of the current start-up and ramp up are also analysed for EXTRAP and it is shown that the peculiarities if these processes in EXTRAP may lead to the compression oscillations around and evolving rather stable equilibrium. The frequency of these oscillations is given. Finally, some consequences of the average minimum-B concept for EXTRAP are discussed and it is shown that this issue virtually reduces to the appearance of the negative curvature of the magnetic field at the periphery. The maximum attainable value of β at the periphery of the pinch is obtained, as required by the ballooning stability criterion. The influence of the finite resistivity on the ballooning mode is also estimated. With 4 figures and 21 refs. (Author)

Is going into stable symptomatic remission associated with a more positive development of life satisfaction?

DEFF Research Database (Denmark)

Gardsjord, Erlend Strand; Romm, Kristin Lie; Røssberg, Jan Ivar

2017-01-01

BACKGROUND: Quality of life is an important outcome measure for patients with psychosis. We investigated whether going into stable symptomatic remission is associated with a more positive development of subjective quality of life (S-QoL) and if different patient characteristics are associated wit...

Compound deterioration properties of non-halogen flame-resisting cables

International Nuclear Information System (INIS)

Yamamoto, Yasuaki; Yagyu, Hideki; Onishi, Takao; Kamiharako, Shinji

1984-01-01

Conventional flame-resisting cables release harmful gas such as hydrogen chloride and smoke on burning. To improve this disadvantage, the cables for nuclear power plants using new non-halogen flame-resisting insulating material have been developed. In this experiment, the non-halogen flame-resisting cables were subjected to the environmental test with varying test conditions. The test conditions included the order of exposure (heat treatment, γ-ray irradiation and steam exposure) and dose rate. After the environmental test, the mechanical and electrical properties of the samples were measured. In all test conditions, the samples did not crack in bending, and withstood the bending and withstand-voltage in-water test. The tensile strength and a.c. breakdown voltage did not change, and were stable. The elongation decreased greatly, but maintained the value of about 100 %, and the volumetric resistivity decreased by only one figure. It was confirmed that these cables were able to withstand various environmental tests. (Yoshitake, I.)

Development of high-performance concrete having high resistance to chloride penetration

International Nuclear Information System (INIS)

Oh, Byung Hwan; Cha, Soo Won; Jang, Bong Seok; Jang, Seung Yup

2002-01-01

The resistance to chloride penetration is one of the simplest measures to determine the durability of concrete, e.g. resistance to freezing and thawing, corrosion of steel in concrete and other chemical attacks. Thus, high-performance concrete may be defined as the concrete having high resistance to chloride penetration as well as high strength. The purpose of this paper is to investigate the resistance to chloride penetration of different types of concrete and to develop high-performance concrete that has very high resistance to chloride penetration, and thus, can guarantee high durability. A large number of concrete specimens have been tested by the rapid chloride permeability test method as designated in AASHTO T 277 and ASTM C 1202. The major test variables include water-to-binder ratios, type of cement, type and amount of mineral admixtures (silica fume, fly ash and blast-furnace slag), maximum size of aggregates and air-entrainment. Test results show that concrete containing optimal amount of silica fume shows very high resistance to chloride penetration, and high-performance concrete developed in this study can be efficiently employed to enhance the durability of concrete structures in severe environments such as nuclear power plants, water-retaining structures and other offshore structures

SCREENING FOR DEVELOPMENT OF HOST PLANT RESISTANCE ...

African Journals Online (AJOL)

Tangaza

losses of cowpea yields and if not controlled, they limit the yields to less than 300kg/ha (Singh et al., 1990). A considerable progress has been made during the past decade in cowpea breeding and a range of varieties have been developed with resistance to several diseases, insect pests and parasitic weeds. Much time ...

Antimicrobial resistance 1979-2009 at Karolinska hospital, Sweden: normalized resistance interpretation during a 30-year follow-up on Staphylococcus aureus and Escherichia coli resistance development.

Science.gov (United States)

Kronvall, Göran

2010-09-01

To utilize a material of inhibition zone diameter measurements from disc diffusion susceptibility tests between 1979 and 2009, an objective setting of epidemiological breakpoints was necessary because of methodological changes. Normalized resistance interpretation (NRI) met this need and was applied to zone diameter histograms for Staphylococcus aureus and Escherichia coli isolates. The results confirmed a slow resistance development as seen in Northern countries. The S. aureus resistance levels for erythromycin, clindamycin and fusidic acid in 2009 were 3.2%, 1.8% and 1.4% with denominator correction. A rise in resistance to four antimicrobials in 1983 was probably because of a spread of resistant Methicillin Susceptible Staphylococcus Aureus (MSSA). For E. coli, the denominator-corrected resistance levels in 2009 were 27% for ampicillin, around 3% for third-generation cephalosporins, 0.1% for imipenem, 2.5% for gentamicin, 19% for trimethoprim, 4.5% for co-trimoxazole, 1.2% for nitrofurantoin and 9% for ciprofloxacin. The temporal trends showed a rise in fluoroquinolone resistance from 1993, a parallel increase in gentamicin resistance, a substantial increase in trimethoprim and sulphonamide resistance in spite of decreased consumption, and a steady rise in ampicillin resistance from a constant level before 1989. A short review of global resistance surveillance studies is included.

HDAC Inhibitors Disrupt Programmed Resistance to Apoptosis During Drosophila Development

Directory of Open Access Journals (Sweden)

Yunsik Kang

2017-06-01

Full Text Available We have previously shown that the ability to respond to apoptotic triggers is regulated during Drosophila development, effectively dividing the fly life cycle into stages that are either sensitive or resistant to apoptosis. Here, we show that the developmentally programmed resistance to apoptosis involves transcriptional repression of critical proapoptotic genes by histone deacetylases (HDACs. Administration of HDAC inhibitors (HDACi, like trichostatin A or suberoylanilide hydroxamic acid, increases expression of proapoptotic genes and is sufficient to sensitize otherwise resistant stages. Conversely, reducing levels of proapoptotic genes confers resistance to otherwise sensitive stages. Given that resistance to apoptosis is a hallmark of cancer cells, and that HDACi have been recently added to the repertoire of FDA-approved agents for cancer therapy, our results provide new insights for how HDACi help kill malignant cells and also raise concerns for their potential unintended effects on healthy cells.

DEVELOPMENT OF RESISTANCE IN BACTERIA AGAINST ANTI - MICROBIAL AGENTS: REASONS, THREATS AND ONGOING ENCOUNTER

Directory of Open Access Journals (Sweden)

Shibabrata Pattanayak

2011-07-01

Full Text Available Development of Multi Druug Resistant bacteria is creating a very severe problem in anti-microbial chemotherapy. Many recently developed antibiotics are found incapable to control resistant organisms.The reasons of development of resistance gene in the bacterial plasmid and their quick spread among various related and unrelated bacteria are analysed in this article along with discussion of world wide ongoing research to combat the problem.

Development of proliferation resistance assessment methodology based on international standard

International Nuclear Information System (INIS)

Ko, W. I.; Chang, H. L.; Lee, Y. D.; Lee, J. W.; Park, J. H.; Kim, Y. I.; Ryu, J. S.; Ko, H. S.; Lee, K. W.

2012-04-01

Nonproliferation is one of the main requirements to be satisfied by the advanced future nuclear energy systems that have been developed in the Generation IV and INPRO studies. The methodologies to evaluate proliferation resistance has been developed since 1980s, however, the systematic evaluation approach has begun from around 2000. Domestically a study to develop national method to evaluate proliferation resistance (PR) of advanced future nuclear energy systems has started in 2007 as one of the long-term nuclear R and D subjects in order to promote export and international credibility and transparency of national nuclear energy systems and nuclear fuel cycle technology development program. In the first phase (2007-2010) development and improvement of intrinsic evaluation parameters for the evaluation of proliferation resistance, quantification of evaluation parameters, development of evaluation models, and development of permissible ranges of evaluation parameters have been carried out. In the second phase (2010-2012) generic principle of to evaluate PR was established, and techincal guidelines, nuclear material diversion pathway analysis method, and a method to integrate evaluation parameters have been developed. which were applied to 5 alternative nuclear fuel cycles to estimate their appicability and objectivity. In addition, measures to enhance PR of advanced future nuclear energy systems and technical guidelines of PR assessment using intrinsic PR evaluation parameters were developed. Lastly, requlatory requirements to secure nonproliferation requirements of nuclear energy systems from the early design stage, operation and to decommissioning which will support the export of newly developed advanced future nuclear energy system

Proton beam micromachining on strippable aqueous base developable negative resist

International Nuclear Information System (INIS)

Rajta, I.; Uzonyi, I.; Baradacs, E.; Chatzichristidi, M.; Raptis, I.; Valamontes, E.S.

2004-01-01

Complete text of publication follows. Proton Beam Micromachining (PBM, also known as P-beam writing), a novel direct- write process for the production of 3D microstructures, can be used to make multilevel structures in a single layer of resist by varying the ion energy. The interaction between the bombarding ions and the target material is mainly ionization, and very few ions suffer high angle nuclear collisions, therefore structures made with PBM have smooth near vertical side walls. The most commony applied resists in PBM are the positive, conventional, polymethyl methacrylate (PMMA); and the negative, chemically amplified, SU-8 (Micro Chem Corp). SU-8 is an epoxy based resist suitable also for LIGA and UV-LIGA processes, it offers good sensitivity, good process latitude, very high aspect ratio and therefore it dominates in the high aspect ratio micromachining applications. SU-8 requires 30 nC/mm 2 fluence for PBM irradiations at 2 MeV protons. Its crosslinking chemistry is based on the eight epoxy rings in the polymer chain, which provide a very dense three dimensional network in the presence of suitably activated photo acid generators (PAGs) which is very difficult to be stripped away after development. Thus, stripping has to be assisted with plasma processes or with special liquid removers. Moreover, the SU-8 developer is organic, propylene glycol methyl ether acetate (PGMEA), and thus environmentally non-friendly. To overcome the SU-8 stripping limitations, design of a negative resist system where solubility change is not based solely on cross- linking but also on the differentiation of hydrophilicity between exposed and non-exposed areas is desirable. A new resist formulation, fulfilling the above specifications has been developed recently [1]. This formulation is based on a specific grade epoxy novolac (EP) polymer, a partially hydrogenated poly-4-hydroxy styrene (PHS) polymer, and an onium salt as photoacid generator (PAG), and has been successfully

Zinc and copper in animal feed - development of resistance and co-resistance to antimicrobial agents in bacteria of animal origin

OpenAIRE

Yazdankhah, Siamak; Rudi, Knut; Bernhoft, Aksel

2014-01-01

Farmed animals such as pig and poultry receive additional Zn and Cu in their diets due to supplementing elements in compound feed as well as medical remedies. Enteral bacteria in farmed animals are shown to develop resistance to trace elements such as Zn and Cu. Resistance to Zn is often linked with resistance to methicillin in staphylococci, and Zn supplementation to animal feed may increase the proportion of multiresistant E. coli in the gut. Resistance to Cu in bacteria, in particular ente...

Stable Alfven-wave dynamo action in the reversed-field pinch

International Nuclear Information System (INIS)

Werley, K.A.

1984-01-01

Previous theoretical work has suggested that Alfven waves may be related to the anomalous toroidal magnetic flux generation and extended (over classical expectations) discharge times observed in the reversed-field pinch. This thesis examines the dynamo action of stable Alfven waves as a means of generating toroidal flux. Recent advances in linear resistive MHD stability analysis are used to calculate the quasi-linear dynamo mean electromotive force of Alfven waves. This emf is incorporated into a one-dimensional transport and mean-field evolution code. The changing equilibrium is then fed back to the stability code to complete a computational framework that self-consistently evaluates a dynamic plasma dynamo. This technique is readily extendable to other plasmas in which dynamic stable model action is of interest. Such plasmas include Alfven wave current-drive and plasma heating for fusion devices, as well as astrophysical and geophysical dynamo systems. This study also contains extensive studies of resistive Alfven wave properties. This includes behavior versus spectral location, magnetic Reynolds number and wave number

Stable convergence and stable limit theorems

CERN Document Server

Häusler, Erich

2015-01-01

The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

Using and development of multi adversity resistance system in cotton

Directory of Open Access Journals (Sweden)

Metin Durmuş ÇETİN

2014-12-01

Full Text Available The basic approach in plant breeding, make it possible to show the full genetic potential of plant. This methods also protect the health of plant growth over the period, by increasing resistance to diseases and pests is expected to provide. For this purpose, by Bird in 1963, with the name of multi adversity resistance has been initiated in cotton breeding and for many years as a result of the work carried out important varieties and germplasm have been developed. Nowadays, those using for varieties resistant to stress factors such as heat and drought are evaluated. And successful results are obtained.

Enzyme-mediated formulation of stable elliptical silver nanoparticles tested against clinical pathogens and MDR bacteria and development of antimicrobial surgical thread.

Science.gov (United States)

Thapa, Rupak; Bhagat, Chintan; Shrestha, Pragya; Awal, Suvash; Dudhagara, Pravin

2017-05-16

Silver nanoparticles (AgNPs) are believed to be emerging tool against various infectious diseases including multi-drug resistant (MDR) bacteria. In the present study, in vitro synthesis of AgNPs was optimized using 1:50 ratio of macerozyme (25 μg/μl) and 1 mM AgNO 3 incubated at 80 °C for 8 h. AgNPs were characterized by UV-Visible spectroscopy, dynamic light scattering (DLS), scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Characterization studies suggest the synthesis of elliptical, stable and crystalline AgNPs with an average size of 38.26 ± 0.4 nm calculated using TEM. The XRD pattern revealed the face-centered-cubic (fcc) form of metallic silver. Good shape integrity and dispersion of AgNPs after 1 year of incubation confirmed their stability. AgNPs were exibited the antimicrobial property against ten pathogenic bacteria, three molds and one yeast. The AgNPs also revealed remarkable antimicrobial activity against three MDR strains i.e. Extended spectrum beta-lactamase positive Escherichia coli, Staphylococcus aureus (MRSA) and Teicoplanin resistant Streptococcus Pneumoniae. The AgNPs coated surgical threads (suture) were revealed the remarkble antibacterial activity against three MDR strains. This is the first report to synthesize antimicrobial elliptical AgNPs using enzymes. The results suggest the possibilities to develop the nanoparticles coated antimicrobial medical fabric to combat against MDR infection.

Cell-Specific Establishment of Poliovirus Resistance to an Inhibitor Targeting a Cellular Protein

Science.gov (United States)

Viktorova, Ekaterina G.; Nchoutmboube, Jules; Ford-Siltz, Lauren A.

2015-01-01

ABSTRACT It is hypothesized that targeting stable cellular factors involved in viral replication instead of virus-specific proteins may raise the barrier for development of resistant mutants, which is especially important for highly adaptable small (+)RNA viruses. However, contrary to this assumption, the accumulated evidence shows that these viruses easily generate mutants resistant to the inhibitors of cellular proteins at least in some systems. We investigated here the development of poliovirus resistance to brefeldin A (BFA), an inhibitor of the cellular protein GBF1, a guanine nucleotide exchange factor for the small cellular GTPase Arf1. We found that while resistant viruses can be easily selected in HeLa cells, they do not emerge in Vero cells, in spite that in the absence of the drug both cultures support robust virus replication. Our data show that the viral replication is much more resilient to BFA than functioning of the cellular secretory pathway, suggesting that the role of GBF1 in the viral replication is independent of its Arf activating function. We demonstrate that the level of recruitment of GBF1 to the replication complexes limits the establishment and expression of a BFA resistance phenotype in both HeLa and Vero cells. Moreover, the BFA resistance phenotype of poliovirus mutants is also cell type dependent in different cells of human origin and results in a fitness loss in the form of reduced efficiency of RNA replication in the absence of the drug. Thus, a rational approach to the development of host-targeting antivirals may overcome the superior adaptability of (+)RNA viruses. IMPORTANCE Compared to the number of viral diseases, the number of available vaccines is miniscule. For some viruses vaccine development has not been successful after multiple attempts, and for many others vaccination is not a viable option. Antiviral drugs are needed for clinical practice and public health emergencies. However, viruses are highly adaptable and can

Biological trait analysis and stability of lambda-cyhalothrin resistance in the house fly, Musca domestica L. (Diptera: Muscidae).

Science.gov (United States)

Abbas, Naeem; Shah, Rizwan Mustafa; Shad, Sarfraz Ali; Iqbal, Naeem; Razaq, Muhammad

2016-05-01

House flies, Musca domestica L., (Diptera: Muscidae), are pests of poultry and have the ability to develop resistance to insecticides. To design a strategy for resistance management, life history traits based on laboratory observations were established for lambda-cyhalothrin-resistant, susceptible and reciprocal crosses of M. domestica strains. Bioassay results showed that the lambda-cyhalothrin-selected strain developed a resistance ratio of 98.34 compared to its susceptible strain. The lambda-cyhalothrin-selected strain had a relative fitness of 0.26 and lower fecundity, hatchability, lower number of next generation larvae, and net reproductive rate compared with its susceptible strain. Mean population growth rates, such as intrinsic rate of population increase, and biotic potential were lower for the lambda-cyhalothrin-selected strain compared to its susceptible strain. Resistance to lambda-cyhalothrin, indoxacarb, and abamectin was unstable while resistance to bifenthrin and methomyl was stable in the lambda-cyhalothrin-selected strain of M. domestica. Development of resistance can cost considerable fitness for the lambda-cyhalothrin-selected strain. The present study provided useful information for making potential management strategies to delay resistance development in M. domestica.

Development of heat resistant ion exchange resin. First Report

International Nuclear Information System (INIS)

Onozuka, Teruo; Shindo, Manabu

1995-01-01

In nuclear power stations, as a means of maintaining the soundness of nuclear reactors, the cleaning of reactor cooling water has been carried out. But as for the ion exchange resin which is used as the cleaning agent in the filtrating and desalting facility in reactor water cleaning system, since the heat resistance is low, high temperature reactor water is cooled once and cleaned, therefore large heat loss occurs. If the cleaning can be done at higher temperature, the reduction of heat loss and compact cleaning facilities become possible. In this study, a new ion exchange resin having superior heat resistance has been developed, and the results of the test of evaluating the performance of the developed ion exchange resin are reported. The heat loss in reactor water cleaning system, the heat deterioration of conventional ion exchange resin, and the development of the anion exchange resin of alkyl spacer type are described. The outline of the performance evaluation test, the experimental method, and the results of the heat resistance, ion exchange characteristics and so on of C4 resin are reported. The with standable temperature of the developed anion exchange resin was estimated as 80 - 90degC. The ion exchange performance at 95degC of this resin did not change from that at low temperature in chloride ions and silica, and was equivalent to that of existing anion exchange resin. (K.I.)

Development of heat resistant ion exchange resin. First Report

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Teruo; Shindo, Manabu [Tohoku Electric Power Co., Inc., Sendai (Japan)

1995-01-01

In nuclear power stations, as a means of maintaining the soundness of nuclear reactors, the cleaning of reactor cooling water has been carried out. But as for the ion exchange resin which is used as the cleaning agent in the filtrating and desalting facility in reactor water cleaning system, since the heat resistance is low, high temperature reactor water is cooled once and cleaned, therefore large heat loss occurs. If the cleaning can be done at higher temperature, the reduction of heat loss and compact cleaning facilities become possible. In this study, a new ion exchange resin having superior heat resistance has been developed, and the results of the test of evaluating the performance of the developed ion exchange resin are reported. The heat loss in reactor water cleaning system, the heat deterioration of conventional ion exchange resin, and the development of the anion exchange resin of alkyl spacer type are described. The outline of the performance evaluation test, the experimental method, and the results of the heat resistance, ion exchange characteristics and so on of C4 resin are reported. The with standable temperature of the developed anion exchange resin was estimated as 80 - 90degC. The ion exchange performance at 95degC of this resin did not change from that at low temperature in chloride ions and silica, and was equivalent to that of existing anion exchange resin. (K.I.).

Development of debris-resistant bottom end piece

International Nuclear Information System (INIS)

Sohn, Dong Seong; Lee, Jae Kyung; Hwang, Dae Hyun; Yim, Jung Sik; Song, Kee Nam; Oh, Dong Seok; Im, Hyun Tae

1993-01-01

Debris-related fuel failures has been identified to be one of the major causes of fuel failures recently occured in nuclear power plants. In order to reduce the possibility of debris-related fuel failures, it is necessary to prevent the debris from reaching to fuel rods. In this regard, it is important to develop Debris-Resistant Bottom End Piece. (Author)

Surveillance for linezolid resistance via the Zyvox® Annual Appraisal of Potency and Spectrum (ZAAPS) programme (2014): evolving resistance mechanisms with stable susceptibility rates.

Science.gov (United States)

Mendes, Rodrigo E; Hogan, Patricia A; Jones, Ronald N; Sader, Helio S; Flamm, Robert K

2016-07-01

The objective of this study was to report the linezolid in vitro activity observed during the Zyvox(®) Annual Appraisal of Potency and Spectrum (ZAAPS) programme for 2014. In total, 7541 organisms causing documented infections were consecutively collected in 66 centres in 33 countries, excluding the USA. Susceptibility testing was performed by broth microdilution. Isolates displaying linezolid MIC results of ≥4 mg/L were molecularly characterized. Linezolid inhibited all Staphylococcus aureus at ≤2 mg/L, with MIC50 results of 1 mg/L, regardless of methicillin resistance. A similar linezolid MIC50 result (i.e. 0.5 mg/L) was observed against CoNS, with the vast majority of isolates (99.4%) also inhibited at ≤2 mg/L. Six CoNS that exhibited elevated linezolid MIC values were found to contain alterations in the 23S rRNA and/or L3 ribosomal protein. Linezolid exhibited consistent modal MIC and MIC50 results (1 mg/L) against enterococci, regardless of species or vancomycin resistance. Three Enterococcus faecalis from Galway and Dublin (Ireland) and Kelantan (Malaysia) showed MIC results of 4 to 8 mg/L and carried optrA. All Streptococcus pneumoniae, viridans-group streptococci and β-haemolytic streptococci were inhibited by linezolid at ≤2, ≤2 and ≤1 mg/L, respectively, with equivalent MIC90 results (1 mg/L for all groups). These results document the continued long-term and stable in vitro potency of linezolid and reveal a limited number of isolates with decreased susceptibility to linezolid (i.e. MIC ≥4 mg/L). The latter isolates primarily showed mutations in the 23S rRNA gene and/or L3 protein, but cfr was not detected. Moreover, this study shows that isolates carrying the newly described ABC transporter optrA are not restricted to China. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

AXL mediates resistance to cetuximab therapy.

Science.gov (United States)

Brand, Toni M; Iida, Mari; Stein, Andrew P; Corrigan, Kelsey L; Braverman, Cara M; Luthar, Neha; Toulany, Mahmoud; Gill, Parkash S; Salgia, Ravi; Kimple, Randall J; Wheeler, Deric L

2014-09-15

The EGFR antibody cetuximab is used to treat numerous cancers, but intrinsic and acquired resistance to this agent is a common clinical outcome. In this study, we show that overexpression of the oncogenic receptor tyrosine kinase AXL is sufficient to mediate acquired resistance to cetuximab in models of non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC), where AXL was overexpressed, activated, and tightly associated with EGFR expression in cells resistant to cetuximab (Ctx(R) cells). Using RNAi methods and novel AXL-targeting agents, we found that AXL activation stimulated cell proliferation, EGFR activation, and MAPK signaling in Ctx(R) cells. Notably, EGFR directly regulated the expression of AXL mRNA through MAPK signaling and the transcription factor c-Jun in Ctx(R) cells, creating a positive feedback loop that maintained EGFR activation by AXL. Cetuximab-sensitive parental cells were rendered resistant to cetuximab by stable overexpression of AXL or stimulation with EGFR ligands, the latter of which increased AXL activity and association with the EGFR. In tumor xenograft models, the development of resistance following prolonged treatment with cetuximab was associated with AXL hyperactivation and EGFR association. Furthermore, in an examination of patient-derived xenografts established from surgically resected HNSCCs, AXL was overexpressed and activated in tumors that displayed intrinsic resistance to cetuximab. Collectively, our results identify AXL as a key mediator of cetuximab resistance, providing a rationale for clinical evaluation of AXL-targeting drugs to treat cetuximab-resistant cancers. Cancer Res; 74(18); 5152-64. ©2014 AACR. ©2014 American Association for Cancer Research.

Stable propagation of an electron beam in gas

International Nuclear Information System (INIS)

Lee, E.P.; Chambers, F.W.; Lodestro, L.L.; Yu, S.S.

1977-01-01

Conditions for the stable propagation of a pinched electron beam in low pressure gas (p approximately 0.1 to 100 torr) are described. The observed window of good propagation around p approximately 2 torr air is interpreted as the quenching of the two-stream mode by sufficiently high plasma density and collision frequency, and the simultaneous suppression of the resistive hose mode by sufficiently rapid generation of electrical conductivity from breakdown ionization

Uses of stable isotopes

International Nuclear Information System (INIS)

Axente, Damian

1998-01-01

The most important fields of stable isotope use with examples are presented. These are: 1. Isotope dilution analysis: trace analysis, measurements of volumes and masses; 2. Stable isotopes as tracers: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic; 3. Isotope equilibrium effects: measurement of equilibrium effects, investigation of equilibrium conditions, mechanism of drug action, study of natural processes, water cycle, temperature measurements; 4. Stable isotope for advanced nuclear reactors: uranium nitride with 15 N as nuclear fuel, 157 Gd for reactor control. In spite of some difficulties of stable isotope use, particularly related to the analytical techniques, which are slow and expensive, the number of papers reporting on this subject is steadily growing as well as the number of scientific meetings organized by International Isotope Section and IAEA, Gordon Conferences, and regional meeting in Germany, France, etc. Stable isotope application development on large scale is determined by improving their production technologies as well as those of labeled compound and the analytical techniques. (author)

Population Games, Stable Games, and Passivity

Directory of Open Access Journals (Sweden)

Michael J. Fox

2013-10-01

Full Text Available The class of “stable games”, introduced by Hofbauer and Sandholm in 2009, has the attractive property of admitting global convergence to equilibria under many evolutionary dynamics. We show that stable games can be identified as a special case of the feedback-system-theoretic notion of a “passive” dynamical system. Motivated by this observation, we develop a notion of passivity for evolutionary dynamics that complements the definition of the class of stable games. Since interconnections of passive dynamical systems exhibit stable behavior, we can make conclusions about passive evolutionary dynamics coupled with stable games. We show how established evolutionary dynamics qualify as passive dynamical systems. Moreover, we exploit the flexibility of the definition of passive dynamical systems to analyze generalizations of stable games and evolutionary dynamics that include forecasting heuristics as well as certain games with memory.

Human Health Risk Assessment (HHRA) for Environmental Development and Transfer of Antibiotic Resistance

Science.gov (United States)

Amézquita, Alejandro; Backhaus, Thomas; Borriello, Peter; Brandt, Kristian K.; Collignon, Peter; Coors, Anja; Finley, Rita; Gaze, William H.; Heberer, Thomas; Lawrence, John R.; Larsson, D.G. Joakim; McEwen, Scott A.; Ryan, James J.; Schönfeld, Jens; Silley, Peter; Snape, Jason R.; Van den Eede, Christel; Topp, Edward

2013-01-01

Background: Only recently has the environment been clearly implicated in the risk of antibiotic resistance to clinical outcome, but to date there have been few documented approaches to formally assess these risks. Objective: We examined possible approaches and sought to identify research needs to enable human health risk assessments (HHRA) that focus on the role of the environment in the failure of antibiotic treatment caused by antibiotic-resistant pathogens. Methods: The authors participated in a workshop held 4–8 March 2012 in Québec, Canada, to define the scope and objectives of an environmental assessment of antibiotic-resistance risks to human health. We focused on key elements of environmental-resistance-development “hot spots,” exposure assessment (unrelated to food), and dose response to characterize risks that may improve antibiotic-resistance management options. Discussion: Various novel aspects to traditional risk assessments were identified to enable an assessment of environmental antibiotic resistance. These include a) accounting for an added selective pressure on the environmental resistome that, over time, allows for development of antibiotic-resistant bacteria (ARB); b) identifying and describing rates of horizontal gene transfer (HGT) in the relevant environmental “hot spot” compartments; and c) modifying traditional dose–response approaches to address doses of ARB for various health outcomes and pathways. Conclusions: We propose that environmental aspects of antibiotic-resistance development be included in the processes of any HHRA addressing ARB. Because of limited available data, a multicriteria decision analysis approach would be a useful way to undertake an HHRA of environmental antibiotic resistance that informs risk managers. Citation: Ashbolt NJ, Amézquita A, Backhaus T, Borriello P, Brandt KK, Collignon P, Coors A, Finley R, Gaze WH, Heberer T, Lawrence JR, Larsson DG, McEwen SA, Ryan JJ, Schönfeld J, Silley P, Snape JR

Tempered stable laws as random walk limits

OpenAIRE

Chakrabarty, Arijit; Meerschaert, Mark M.

2010-01-01

Stable laws can be tempered by modifying the L\\'evy measure to cool the probability of large jumps. Tempered stable laws retain their signature power law behavior at infinity, and infinite divisibility. This paper develops random walk models that converge to a tempered stable law under a triangular array scheme. Since tempered stable laws and processes are useful in statistical physics, these random walk models can provide a basic physical model for the underlying physical phenomena.

Induced mutations to develop sources of resistance to rice blast, Pyricularia grisea Sacc

International Nuclear Information System (INIS)

Correa-Victoria, F.J.

2001-01-01

Rice blast caused by Pyricularia grisea is the most important disease limiting yields worldwide. The pathogen has many virulent forms or pathotypes, hence durable blast resistance is lacking. Studies on strategy to develop durable blast resistance based on defining the genetic structure of the population, using DNA-fingerprinting, and virulence diversity are described. This strategy is leading to the identification of resistance genes/sources against all isolates within a genetic family of the pathogen. Combinations of genes showing complementary resistance to different genetic families of the fungus exclude any compatible interaction with a blast isolate. Identification of complementary resistance genes is based on detecting those virulence factors whose combinations in individual isolates within the pathogen population have a frequency near zero. Identifying and combining resistance genes to which combinations of corresponding virulence genes are absent in the pathogen population should confer more durable resistance than that previously obtained. The use of induced mutations in the development of resistance was limited, since in most cases single gene changes were responsible for the induced resistance against all the pathogen population. The main objective here is to develop many mutants, each with a gene resistant to just one or a few families of the blast pathogen; and crossing them can accumulate the different resistance genes. A total of 201 Latin American commercial cultivars, including Cuban, Brazilian and Venezuelan were analyzed with different genetic families of the blast pathogen to identify potential sources of resistance to blast and identify complementary resistance sources. Characterization of the resistance of 37 mutants of the Colombian rice cultivar Oryzica 1 was conducted in collaboration with the INEA in Colombia. Results suggested that mutations for resistance to genetic families to which Oryzica 1 is susceptible were induced, although one

Laboratory investigation into the development of resistance of Daphnia manga (straus) to environmental pollutants

Energy Technology Data Exchange (ETDEWEB)

LeBlanc, G.A.

1982-04-01

The purpose of this study was to determine the ability of Daphnia magna (Straus) to develop resistance to selected environmental pollutants through physiological adaptation or the selection of genetically fit organisms. The results of the study demonstrated that daphnids pre-exposed to copper, lead or zinc for 20 h had become significantly resistant to the toxic effects of these metals. Similar tests performed with sodium lauryl sulfate, however, resulted in no increased resistance. Exposure of successive generations of daphnids to copper resulted in the development of significant resistance to copper. However, this resistance was determined to be the result of physiological adaptation and was not due to the selection of genetically fit organisms. Multigeneration exposures to sodium lauryl sulfate failed to produce any increased resistance to the toxic effects of this compound.Exposure of successive generations to sodium lauryl sulfate increased each generation's sensitivity to the toxicity of this compound. To determine if resistance to one pollutant might confer resistance to others, the resistance, to zinc and lead, of daphnids pre-exposed to copper was assessed. Copper-resistant daphnids demonstrated no increased resistance to the toxic effects of zinc or lead.

Corrosion-resistant coating development

Energy Technology Data Exchange (ETDEWEB)

Stinton, D.P.; Kupp, D.M.; Martin, R.L. [Oak Ridge National Lab., TN (United States)

1997-12-01

SiC-based heat exchangers have been identified as the prime candidate material for use as heat exchangers in advanced combined cycle power plants. Unfortunately, hot corrosion of the SiC-based materials created by alkali metal salts present in the combustion gases dictates the need for corrosion-resistant coatings. The well-documented corrosion resistance of CS-50 combined with its low (and tailorable) coefficient of thermal expansion and low modulus makes CS-50 an ideal candidate for this application. Coatings produced by gelcasting and traditional particulate processing have been evaluated.

Current voltage characteristics of composite superconductors with high contact resistance

International Nuclear Information System (INIS)

Akhmetov, A.A.; Baev, V.P.

1984-01-01

An experimental study has been made of current-voltage characteristics of composite superconductors with contact resistance between superconducting filaments and normal metal with high electrical conductivity. It is shown that stable resistive states exist in such conductors over a wide range of currents. The presence of resistive states is interpreted in terms of the resistive domain concept. The minimum and maximum currents of resistive states are found to be dependent on the electrical resistance of normal metal and magnetic field. (author)

Mechanisms of Acquired Resistance to Trastuzumab Emtansine in Breast Cancer Cells.

Science.gov (United States)

Li, Guangmin; Guo, Jun; Shen, Ben-Quan; Bumbaca Yadav, Daniela; Sliwkowski, Mark X; Crocker, Lisa M; Lacap, Jennifer A; Lewis Phillips, Gail D

2018-04-25

The receptor tyrosine kinase HER2 is overexpressed in approximately 20% of breast cancer, and its amplification is associated with reduced survival. Trastuzumab emtansine (Kadcyla®, T-DM1), an antibody-drug conjugate that is comprised of trastuzumab covalently linked to the anti-mitotic agent DM1 through a stable linker, was designed to selectively deliver DM1 to HER2-overexpressing tumor cells. T-DM1 is approved for the treatment of patients with HER2-positive metastatic breast cancer following progression on trastuzumab and a taxane. Despite the improvement in clinical outcome, many patients who initially respond to T-DM1 treatment eventually develop progressive disease. The mechanisms that contribute to T-DM1 resistance are not fully understood. To this end, we developed T-DM1-resistant in vitro models to examine the mechanisms of acquired T-DM1 resistance. We demonstrate that decreased HER2 and up-regulation of MDR1 contribute to T-DM1 resistance in KPL-4 T-DM1 resistant cells. In contrast, both loss of SLC46A3 and PTEN deficiency play a role in conferring resistance in BT-474M1 T-DM1 resistant cells. Our data suggest that these two cell lines acquire resistance through distinct mechanisms. Furthermore, we show that the KPL-4 T-DM1 resistance can be overcome by treatment with an inhibitor of MDR1, whereas a PI3K inhibitor can rescue PTEN loss-induced resistance in T-DM1-resistant BT-474M1 cells. Our results provide a rationale for developing therapeutic strategies to enhance T-DM1 clinical efficacy by combining T-DM1 and other inhibitors that target signaling transduction or resistance pathways. Copyright ©2018, American Association for Cancer Research.

Development of linseed oil-free bakelite resistive plate chambers

International Nuclear Information System (INIS)

Biswas, S.; Bhattacharya, S.; Bose, S.; Chattopadhyay, S.; Saha, S.; Viyogi, Y.P.

2009-01-01

In this paper we would like to present a few characteristics of the Resistive Plate Chambers (RPCs) made of a particular grade of bakelite paper laminates (P-120, NEMA LI-1989 Grade XXX), produced and commercially available in India. This particular grade is used for high voltage insulation in humid conditions. The chambers are tested with cosmic rays in the streamer mode using argon, tetrafluroethane and isobutane in 34:59:7 mixing ratio. In the first set of detectors made with such grade, a thin coating of silicone fluid on the inner surfaces of the bakelite was found to be necessary for operation of the detector. Those silicone coated RPCs were found to give satisfactory performance with stable efficiency of >90% continuously for a long period as reported earlier. Results of the crosstalk measurement of these silicone coated RPC will be presented in this paper. Very recently RPCs made with the same grade of bakelite but having better surface finish are found to give equivalent performance even without any coating inside. Preliminary results of this type of RPCs are also being presented.

Resistive switching characteristics of solution-processed Al-Zn-Sn-O films annealed by microwave irradiation

Science.gov (United States)

Kim, Tae-Wan; Baek, Il-Jin; Cho, Won-Ju

2018-02-01

In this study, we employed microwave irradiation (MWI) at low temperature in the fabrication of solution-processed AlZnSnO (AZTO) resistive random access memory (ReRAM) devices with a structure of Ti/AZTO/Pt and compared the memory characteristics with the conventional thermal annealing (CTA) process. Typical bipolar resistance switching (BRS) behavior was observed in AZTO ReRAM devices treated with as-deposited (as-dep), CTA and MWI. In the low resistance state, the Ohmic conduction mechanism describes the dominant conduction of these devices. On the other hand, the trap-controlled space charge limited conduction (SCLC) mechanism predominates in the high resistance state. The AZTO ReRAM devices processed with MWI showed larger memory windows, uniform distribution of resistance state and operating voltage, stable DC durability (>103 cycles) and stable retention characteristics (>104 s). In addition, the AZTO ReRAM devices treated with MWI exhibited multistage storage characteristics by modulating the amplitude of the reset bias, and eight distinct resistance levels were obtained with stable retention capability.

Development of a CB Resistant Durable, Flexible Hydration System

National Research Council Canada - National Science Library

Hall, Peyton W; Zeller, Frank T; Bulluck, John W; Dingus, Michael L

2002-01-01

A durable, flexible hydration system resistant to contamination by contact with VX, GD, and HD chemical agents, as well as damage by the decontaminants sodium hypochlorite and DS-2 is being developed for aviator use...

Postnatal development of resistance to short-term high-dose toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in TCDD-resistant and -semiresistant rats

International Nuclear Information System (INIS)

Simanainen, Ulla; Tuomisto, Jouni T.; Pohjanvirta, Raimo; Syrjaelae, Paula; Tuomisto, Jouko; Viluksela, Matti

2004-01-01

Despite great interspecies differences in adult 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) sensitivity, the toxic potency of TCDD is similar across species in fetal mortality. Han/Wistar (Kuopio; H/W) rats are exceptionally resistant to acute toxicity of TCDD, but show sensitivity to embryotoxicity and teratogenicity. The resistance of adult H/W rats to acute TCDD toxicity is based on a point mutation in the transactivation domain of the aryl hydrocarbon receptor (AHR) and to an unknown gene ''B''. This study investigated the time course of postnatal development of resistance to TCDD and the significance of genotypic variation in resistance development. H/W, line A (a new line with the H/W-type mutated AHR), and line B rats (a line with normal AHR but moderately resistant because of gene ''B'') were exposed to a single dose of TCDD 2-56 days after birth. H/W and line A rats received 1000 μg/kg; male and female B rats received 200 and 100 μg/kg, respectively. Survival was monitored for 42 days. Interestingly, although TCDD ceased growth and weight gain in all TCDD groups, the younger dosed animals did not seem to reach the body weight of the older dosed animals even in 100 days. The survival results after 42 days showed that line A rats are fairly resistant to TCDD immediately after birth, and their full TCDD resistance develops during the first week of life. The moderate resistance of line B rats develops approximately at the time of weaning. This difference in the time course of resistance development suggests that there are basic differences in pathways mediating resistance in lines A and B rats

Development of radiation resistant PEEK insulation cable

International Nuclear Information System (INIS)

Mio, Keigo; Ogiwara, Norio; Hikichi, Yusuke; Furukori, Hisayoshi; Arai, Hideyuki; Nishizawa, Daiji; Nishidono, Toshiro

2009-04-01

Material characterization and development has been carried out for cable insulation suitable for use in the J-PARC 3-GeV RCS radiation environment. In spite of its high cost, PEEK (polyether-ether-ketone) has emerged as the leading candidate satisfying requirements of being non-halogen based, highly incombustible and with radiation resistant at least 10 MGy, along with the usual mechanical characteristics such as good elongation at break, which are needed in a cable insulation. Gamma-ray irradiation tests have been done in order to study radiation resistance of PEEK cable. Further, mechanical, electrical and fire retardant characteristics of a complete cable such as would be used at the J-PARC RCS were investigated. As a result, PEEK cables were shown to be not degraded by radiation up to at least 10 MGy, and thus could be expected to operate stably under the 3-GeV RCS radiation environment. (author)

Zinc and copper in animal feed – development of resistance and co-resistance to antimicrobial agents in bacteria of animal origin

Directory of Open Access Journals (Sweden)

Siamak Yazdankhah

2014-09-01

Full Text Available Farmed animals such as pig and poultry receive additional Zn and Cu in their diets due to supplementing elements in compound feed as well as medical remedies. Enteral bacteria in farmed animals are shown to develop resistance to trace elements such as Zn and Cu. Resistance to Zn is often linked with resistance to methicillin in staphylococci, and Zn supplementation to animal feed may increase the proportion of multiresistant E. coli in the gut. Resistance to Cu in bacteria, in particular enterococci, is often associated with resistance to antimicrobial drugs like macrolides and glycopeptides (e.g. vancomycin. Such resistant bacteria may be transferred from the food-producing animals to humans (farmers, veterinarians, and consumers. Data on dose-response relation for Zn/Cu exposure and resistance are lacking; however, it seems more likely that a resistance-driven effect occurs at high trace element exposure than at more basal exposure levels. There is also lack of data which could demonstrate whether Zn/Cu-resistant bacteria may acquire antibiotic resistance genes/become antibiotics resistant, or if antibiotics-resistant bacteria are more capable to become Zn/Cu resistant than antibiotics-susceptible bacteria. Further research is needed to elucidate the link between Zn/Cu and antibiotic resistance in bacteria.

Experimental induction of paromomycin resistance in antimony-resistant strains of L. donovani: outcome dependent on in vitro selection protocol.

Directory of Open Access Journals (Sweden)

Sarah Hendrickx

Full Text Available Paromomycin (PMM has recently been introduced for treatment of visceral leishmaniasis in India. Although no clinical resistance has yet been reported, proactive vigilance should be warranted. The present in vitro study compared the outcome and stability of experimental PMM-resistance induction on promastigotes and intracellular amastigotes. Cloned antimony-resistant L. donovani field isolates from India and Nepal were exposed to stepwise increasing concentrations of PMM (up to 500 µM, either as promastigotes or intracellular amastigotes. One resulting resistant strain was cloned and checked for stability of resistance by drug-free in vitro passage as promastigotes for 20 weeks or a single in vivo passage in the golden hamster. Resistance selection in promastigotes took about 25 weeks to reach the maximal 97 µM inclusion level that did not affect normal growth. Comparison of the IC(50 values between the parent and the selected strains revealed a 9 to 11-fold resistance for the Indian and 3 to 5-fold for the Nepalese strains whereby the resistant phenotype was also maintained at the level of the amastigote. Applying PMM pressure to intracellular amastigotes produced resistance after just two selection cycles (IC(50 = 199 µM compared to the parent strain (IC(50 = 45 µM. In the amastigote-induced strains/clones, lower PMM susceptibilities were seen only in amastigotes and not at all in promastigotes. This resistance phenotype remained stable after serial in vitro passage as promastigote for 20 weeks and after a single in vivo passage in the hamster. This study clearly demonstrates that a different PMM-resistance phenotype is obtained whether drug selection is applied to promastigotes or intracellular amastigotes. These findings may have important relevance to resistance mechanism investigations and the likelihood of resistance development and detection in the field.

Improved swelling resistance for PCA austenitic stainless steel under HFIR irradiation through microstructural control

International Nuclear Information System (INIS)

Maziasz, P.J.; Braski, D.N.

1983-01-01

Six microstructural variants of Prime Candidate Alloy (PCA) were evaluated for swelling resistance during HFIR irradiation, together with several heats of type 316 stainless steel (316). Swelling was negligible in all the steels at 300 0 C after approx. 44 dpa. At 500 to 600 0 C 25%-cold-worked PCA showed better void swelling resistance than type 316 at approx. 44 dpa. There was less swelling variability among alloys at 400 0 C, but again 25%-cold-worked PCA was the best. Microstructurally, swelling resistance correlated with development of fine, stable bubbles whereas high swelling was due to coarser distributions of bubbles becoming unstable and converting to voids (bias-driven cavities)

Development of Efficient Screening Methods for Resistant Cucumber Plants to Meloidogyne incognita

Directory of Open Access Journals (Sweden)

Sung Min Hwang

2014-06-01

Full Text Available Root-knot nematodes represent a significant problem in cucumber, causing reduction in yield and quality. To develop screening methods for resistance of cucumber to root-knot nematode Meloidogyne incognita, development of root-knot nematode of four cucumber cultivars (‘Dragonsamchuk’, ‘Asiastrike’, ‘Nebakja’ and ‘Hanelbakdadaki’ according to several conditions such as inoculum concentration, plant growth stage and transplanting period was investigated by the number of galls and egg masses produced in each seedling 45 days after inoculation. There was no difference in galls and egg masses according to the tested condition except for inoculum concentration. Reproduction of the nematode on all the tested cultivars according to inoculum concentration increased in a dose-dependent manner. On the basis of the result, the optimum conditions for root-knot development on the cultivars is to transplant period of 1 week, inoculum concentration of 5,000 eggs/plant and plant growth stage of 3-week-old in a greenhouse (25 ± 5°C. In addition, under optimum conditions, resistance of 45 commercial cucumber cultivars was evaluated. One rootstock cultivar, Union was moderately resistant to the root-knot nematode. However, no significant difference was in the resistance of the others cultivar. According to the result, we suggest an efficient screening method for new resistant cucumber to the root-knot nematode, M. incognita.

Micromechanisms of ductile stable crack growth in nuclear pressure vessel steels

Energy Technology Data Exchange (ETDEWEB)

Belcher, W.P.A.; Druce, S.G.

1981-10-01

The objective of this work was to investigate the relationship between the micromechanisms of ductile crack growth, the microstructural constituent phases present in nuclear pressure vessel steel, and the observed fracture behavior as determined by impact and fracture mechanics tests. Results from a microstructural and mechanical property comparison of an A508 Class 3 pressurized water reactor nozzle forging cutout and a 150-mm-thick A533B Class 1 plate are reported. The variation of upper-shelf toughness between the two steels and its orientation sensitivity are discussed on the basis of inclusion and precipitate distributions. Inclusion clusters in A533B, deformed to elongated disks in the rolling plane, have a profound effect on short transverse fracture properties. Data derived using the multi-specimen J-integral method to characterize the initiation of ductile crack extension and resistance to stable crack growth are compared with equivalent Charpy results. Results of the J /SUB R/ -curve analyses indicate (1) that the A533B short transverse crack growth resistance is approximately half that observed from transverse and longitudinal specimen orientations, and (2) that the A508 initiation toughness and resistance to stable crack growth are insensitive to position through the forging wall, and are higher than exhibited by A533B at any orientation in the midthickness position.

[Resistance risk, cross-resistance and biochemical resistance mechanism of Laodelphax striatellus to buprofezin].

Science.gov (United States)

Mao, Xu-lian; Liu, Jin; Li, Xu-ke; Chi, Jia-jia; Liu, Yong-jie

2016-01-01

In order to investigate the resistance development law and biochemical resistance mechanism of Laodelphax striatellus to buprofezin, spraying rice seedlings was used to continuously screen resistant strains of L. striatellus and dipping rice seedlings was applied to determine the toxicity and cross-resistance of L. striatellus to insecticides. After 32-generation screening with buprofezin, L. striatellus developed 168.49 folds resistance and its reality heritability (h2) was 0.11. If the killing rate was 80%-90%, L. striatellus was expected to develop 10-fold resistance to buprofezin only after 5 to 6 generations breeding. Because the actual reality heritability of field populations was usually lower than that of the resistant strains, the production of field populations increasing with 10-fold resistance would need much longer time. The results of cross-resistance showed that resistant strain had high level cross-resistance with thiamethoxam and imidacloprid, low level cross-resistance with acetamiprid, and no cross-resistance with pymetrozine and chlorpyrifos. The activity of detoxification enzymes of different strains and the syergism of synergist were measured. The results showed that cytochrome P450 monooxygenase played a major role in the resistance of L. striatellus to buprofezin, the esterase played a minor role and the GSH-S-transferase had no effect. Therefore, L. striatellus would have high risk to develop resistance to buprofezin when used in the field and might be delayed by using pymetrozine and chlorpyrifos.

Prediction of resistance development against drug combinations by collateral responses to component drugs

DEFF Research Database (Denmark)

Munck, Christian; Gumpert, Heidi; Nilsson Wallin, Annika

2014-01-01

the genomes of all evolved E. coli lineages, we identified the mutational events that drive the differences in drug resistance levels and found that the degree of resistance development against drug combinations can be understood in terms of collateral sensitivity and resistance that occurred during...... adaptation to the component drugs. Then, using engineered E. coli strains, we confirmed that drug resistance mutations that imposed collateral sensitivity were suppressed in a drug pair growth environment. These results provide a framework for rationally selecting drug combinations that limit resistance......Resistance arises quickly during chemotherapeutic selection and is particularly problematic during long-term treatment regimens such as those for tuberculosis, HIV infections, or cancer. Although drug combination therapy reduces the evolution of drug resistance, drug pairs vary in their ability...

Quantitative trait loci for broomrape (Orobanche cumana Wallr.) resistance in sunflower.

Science.gov (United States)

Pérez-Vich, B; Akhtouch, B; Knapp, S J; Leon, A J; Velasco, L; Fernández-Martínez, J M; Berry, S T

2004-06-01

Broomrape (Orobanche cumana Wallr.) is a root parasite of sunflower that is regarded as one of the most important constraints of sunflower production in the Mediterranean region. Breeding for resistance is the most effective method of control. P-96 is a sunflower line which shows dominant resistance to broomrape race E and recessive resistance to the very new race F. The objective of this study was to map and characterize quantitative trait loci (QTL) for resistance to race E and to race F of broomrape in P-96. A population from a cross between P-96 and the susceptible line P-21 was phenotyped for broomrape resistance in four experiments, two for race E and two for race F, by measuring different resistance parameters (resistance or susceptibility, number of broomrape per plant, and proportion of resistant plants per F(3) family). This population was also genotyped with microsatellite and RFLP markers. A linkage map comprising 103 marker loci distributed on 17 linkage groups was developed, and composite interval mapping analyses were performed. In total, five QTL ( or1.1, or3.1, or7.1 or13.1 and or13.2) for resistance to race E and six QTL ( or1.1, or4.1, or5.1, or13.1, or13.2 and or16.1) for resistance to race F of broomrape were detected on 7 of the 17 linkage groups. Phenotypic variance for race E resistance was mainly explained by the major QTL or3.1 associated to the resistance or susceptibility character ( R(2)=59%), while race F resistance was explained by QTL with a small to moderate effect ( R(2) from 15.0% to 38.7%), mainly associated with the number of broomrape per plant. Or3.1 was race E-specific, while or1.1, or13.1 and or13.2 of were non-race specific. Or13.1, and or13.2 were stable across the four experiments. Or3.1, and or7.1 were stable over the two race E experiments and or1.1 and or5.1 over the two race F experiments. The results from this study suggest that resistance to broomrape in sunflower is controlled by a combination of qualitative, race

Mice deficient in PAPP-A show resistance to the development of diabetic nephropathy.

Science.gov (United States)

Mader, Jessica R; Resch, Zachary T; McLean, Gary R; Mikkelsen, Jakob H; Oxvig, Claus; Marler, Ronald J; Conover, Cheryl A

2013-10-01

We investigated pregnancy-associated plasma protein-A (PAPP-A) in diabetic nephropathy. Normal human kidney showed specific staining for PAPP-A in glomeruli, and this staining was markedly increased in diabetic kidney. To assess the possible contribution of PAPP-A in the development of diabetic nephropathy, we induced diabetes with streptozotocin in 14-month-old WT and Papp-A knockout (KO) mice. Renal histopathology was evaluated after 4 months of stable hyperglycemia. Kidneys from diabetic WT mice showed multiple abnormalities including thickening of Bowman's capsule (100% of mice), increased glomerular size (80% of mice), tubule dilation (80% of mice), and mononuclear cell infiltration (90% of mice). Kidneys of age-matched non-diabetic WT mice had similar evidence of tubule dilation and mononuclear cell infiltration to those of diabetic WT mice, indicating that these changes were predominantly age-related. However, thickened Bowman's capsule and increased glomerular size appeared specific for the experimental diabetes. Kidneys from diabetic Papp-A KO mice had significantly reduced or no evidence of changes in Bowman's capsule thickening and glomerular size. There was also a shift to larger mesangial area and increased macrophage staining in diabetic WT mice compared with Papp-A KO mice. In summary, elevated PAPP-A expression in glomeruli is associated with diabetic nephropathy in humans and absence of PAPP-A is associated with resistance to the development of indicators of diabetic nephropathy in mice. These data suggest PAPP-A as a potential therapeutic target for diabetic nephropathy.

Multiple-height microstructure fabricated by deep reactive ion etching and soft resist masks combined with UV curing

International Nuclear Information System (INIS)

Sato, R; Sawada, T; Kumagai, S; Sasaki, M

2014-01-01

Multiple-height microstructures are realized by deep reactive ion etching and UV-cured photoresist used in the embedded mask process. Although the UV-cured photoresist is a soft mask, its material property becomes stable against resist thinner and UV exposure. A layered resist pattern can be realized by stacking normal photoresist on the UV-cured photoresist. The normal photoresist can be selectively removed by the flush exposure and developing after the first Si etching. This technique is applied to two MEMS devices

Ultrathin split-thickness skin grafting followed by narrowband UVB therapy for stable vitiligo: An effective and cosmetically satisfying treatment option

Directory of Open Access Journals (Sweden)

Imran Majid

2012-01-01

Full Text Available Background: Different surgical techniques in the form of tissue or cellular grafting procedures are used alone or in combination with narrowband UVB (NBUVB to treat stable vitiligo resistant to medical treatment. Aim: To evaluate the cosmetic results obtained with ultrathin split-thickness skin grafts followed by NBUVB therapy in resistant, stable vitiligo. Methods: Forty patients of stable vitiligo were treated with ultrathin split-thickness grafting and the patients were then put on NBUVB therapy. The results obtained were analyzed by the extent of repigmentation achieved as well as the final cosmetic outcome at the recipient as well as donor sites. Results: The first evidence of repigmentation was seen in the second week after starting NBUVB. On objective assessment, more than 90% repigmentation was seen in 83% of patients and the overall cosmetic results at the recipient site were graded as good to excellent in 90% patients at the end of NBUVB treatment. Perigraft halo of depigmentation was seen in six patients (15% on the recipient site. Hypertrophic scarring was observed in two patients at the donor site. Conclusions: Ultrathin split-thickness skin grafting, when combined with NBUVB therapy, leads to better cosmetic outcome with faster onset of repigmentation in resistant stable vitiligo.

Pharmaceuticals labelled with stable isotopes

International Nuclear Information System (INIS)

Krumbiegel, P.

1986-11-01

The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

Development of LP turbine rotor steels resistant to stress corrosion cracking

International Nuclear Information System (INIS)

Nakayama, Takenori; Sugie, Kiyoshi; Fujiwara, Kazuo; Takano, Masayoshi; Kinoshita, Shushi

1988-01-01

The effect of various alloying elements on caustic SCC of 3.5 NiCrMoV steel for turbine rotor forgings was studied. From the results, low P (≤ 0.005 %) steel and low P (≤ 0.005 %) - Nb (0.02/0.03 %) steel has been developed as a rotor material, resistant to SCC. It is confirmed that the developed steel has a higher resistance to SCC and to temper embrittlement, and has equivalent other mechanical properties to those of conventional rotor steel. In addition, the role of P and Nb in SCC was also discussed. (author)

Resistance leveling to changes on railway enterprises under implementation of reforms

Directory of Open Access Journals (Sweden)

E.N. Shyrokova

2013-06-01

Full Text Available Purpose. The observed tendencies in the development of the national economy require stable implementation of planned reforms in the sphere of industrial and economic activities of the railway transport in the strategic railway branch. At the same time the issue of resistance elimination to changes that innovative solutions may cause is topical. To study the subject matter of resistance manifestation to implementable changes and search for solutions on the problem in question as well. Methodology. Methodology in an article is based on the use of consistent methodological technique. Findings. It contains the author’s point of view on necessity of taking changes resistance into account during restructuring and further reformation. Emphasized is the need for careful planning of changes and current detection of obstacles that inevitably, for a variety of reasons, arise. Originality. The causes of resistance to changes from different points of view were identified in this paper. Their classification was made and some advice for manifestation leveling of resistance to changes was offered. Practical value. The rational application of measures for resistance leveling to the introduced measures will provide not only high-quality and fast implementation of the reform program, but also its implementation with minimum time and finance losses. That is an important factor in competitiveness increase of railways under unstable economic development.

Utilization of SRNL-developed radiation-resistant polymer in high radiation environments

Energy Technology Data Exchange (ETDEWEB)

Skibo, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-09-27

The radiation-resistant polymer developed by the Savannah River National Laboratory is adaptable for multiple applications to enhance polymer endurance and effectiveness in radiation environments. SRNL offers to collaborate with TEPCO in evaluation, testing, and utilization of SRNL’s radiation-resistant polymer in the D&D of the Fukushima Daiichi NPS. Refinement of the scope and associated costs will be conducted in consultation with TECPO.

Effect of surface texture and structure on the development of stable fluvial armors

Science.gov (United States)

Bertin, Stephane; Friedrich, Heide

2018-04-01

Stable fluvial armors are found in river systems under conditions of partial sediment transport and limited sediment supply, a common occurrence in nature. Stable armoring is also readily recreated in experimental flumes. Initially, this bed stabilizing phenomenon was examined for different flow discharges and solely related to surface coarsening and bedload transport reduction. The models developed suggest a specific armor composition (i.e., texture) dependent on the parent bed material and formative discharge. Following developments in topographic remote sensing, recent research suggests that armor structure is an important control on bed stability and roughness. In this paper, replicated flume runs during which digital elevation models (DEMs) were collected from both exposed and flooded gravel beds are used to interpret armoring manifestations and to assess their replicability. A range of methodologies was used for the analysis, providing information on (i) surface grain size and orientation, (ii) bed-elevation distributions, (iii) the spatial coherence of the elevations at the grain-scale, (iv) surface slope and aspect, (v) grain imbrication and (vi) the spatial variability in DEM properties. The bed-surface topography was found to be more responsive than bed-material size to changes in flow strength. Our experimental results also provide convincing evidence that gravel-beds' response to water-work during parallel degradation is unique (i.e., replicable) given the formative parameters. Based on this finding, relationships between the armors' properties and formative parameters are proposed, and are supported by adding extensive data from previous research.

Development of a high strength, hydrogen-resistant austenitic alloy

International Nuclear Information System (INIS)

Chang, K.M.; Klahn, D.H.; Morris, J.W. Jr.

1980-08-01

Research toward high-strength, high toughness nonmagnetic steels for use in the retaining rings of large electrical generators led to the development of a Ta-modified iron-based superalloy (Fe-36 Ni-3 Ti-3 Ta-0.5 Al-1.3 Mo-0.3 V-0.01 B) which combines high strength with good toughness after suitable aging. The alloy did, however, show some degradation in fatigue resistance in gaseous hydrogen. This sensitivity was associated with a deformation-induced martensitic transformation near the fracture surface. The addition of a small amount of chromium to the alloy suppressed the martensite transformation and led to a marked improvement in hydrogen resistance

Development of Elite BPH-Resistant Wide-Spectrum Restorer Lines for Three and Two Line Hybrid Rice.

Science.gov (United States)

Fan, Fengfeng; Li, Nengwu; Chen, Yunping; Liu, Xingdan; Sun, Heng; Wang, Jie; He, Guangcun; Zhu, Yingguo; Li, Shaoqing

2017-01-01

Hybrid rice has contributed significantly to the world food security. Breeding of elite high-yield, strong-resistant broad-spectrum restorer line is an important strategy for hybrid rice in commercial breeding programs. Here, we developed three elite brown planthopper (BPH)-resistant wide-spectrum restorer lines by pyramiding big-panicle gene Gn8.1 , BPH-resistant genes Bph6 and Bph9 , fertility restorer genes Rf3, Rf4, Rf5 , and Rf6 through molecular marker assisted selection. Resistance analysis revealed that the newly developed restorer lines showed stronger BPH-resistance than any of the single-gene donor parent Luoyang-6 and Luoyang-9. Moreover, the three new restorer lines had broad spectrum recovery capabilities for Honglian CMS, Wild abortive CMS and two-line GMS sterile lines, and higher grain yields than that of the recurrent parent 9,311 under nature field conditions. Importantly, the hybrid crosses also showed good performance for grain yield and BPH-resistance. Thus, the development of elite BPH-resistant wide-spectrum restorer lines has a promising future for breeding of broad spectrum BPH-resistant high-yield varieties.

Interplay between lipids and branched-chain amino acids in development of insulin resistance

Science.gov (United States)

Newgard, Christopher B.

2013-01-01

Summary Fatty acids (FA) and FA-derived metabolites have long been implicated in the development of insulin resistance and type 2 diabetes. Surprisingly, application of metabolomics technologies has revealed that branched-chain amino acids (BCAA) and related metabolites are more strongly associated with insulin resistance than many common lipid species. Moreover, the BCAA-related signature is predictive of incident diabetes and intervention outcomes, and uniquely responsive to therapeutic interventions. Nevertheless, in animal feeding studies, BCAA supplementation requires the background of a high-fat diet to promote insulin resistance. This article develops a model to explain how lipids and BCAA may synergize to promote metabolic diseases. PMID:22560213

Stable switching of resistive random access memory on the nanotip array electrodes

KAUST Repository

Tsai, Kun-Tong; Ho, Chih-Hsiang; Chang, Wen-Yuan; Ke, Jr-Jian; Mungan, Elif Selin; Wang, Yuh-Lin; He, Jr-Hau

2016-01-01

] and external environments [3,4]. Therefore, controlling repetitive formation/rupture of CF as well as the spatial uniformity of formed CF are fundamentally important for improving the resistive switching (RS) performance. In this context, we have shown

Development of Convenient Screening Method for Resistant Radish to Plasmodiophora brassicae

Directory of Open Access Journals (Sweden)

Su-Jung Jo

2011-08-01

Full Text Available To establish simple and reliable screening method for resistant radish to Plasmodiophora brassicae Woron. using soil-drenching inoculation, the development of clubroot on radish seedlings inoculated with P. brassicae GN-1 isolate according to several conditions such as inoculum concentration, plant growth stage and incubation period after inoculation was studied. To select resistant radish against clubroot, 10-day-old seedlings were inoculated with P. brassicae by drenching the roots with the spore suspension of the pathogen to give 1×10(9 spores/pot. The inoculated seedlings were incubated in a growth chamber at 20℃ for 3 days then cultivated in a greenhouse (20±5℃ for 6 weeks. Under the optimum conditions, 46 commercial cultivars of radish were tested for resistance to YC-1 (infecting 15 clubroot-resistant cultivars of Chinese cabbage and GN-1 (wild type isolates of P. brassicae. Among them, thirty-five cultivars showed resistance to both isolates and one cultivar represented susceptible response to the pathogens. On the other hand, the other cultivars showed different responses against the tested P. brassicae pathogens. The results suggest that this method is an efficient system for screening radish with resistance to clubroot.

Comparison of the effects of an eight-week push-up program using stable versus unstable surfaces.

Science.gov (United States)

Chulvi-Medrano, Iván; Martínez-Ballester, Esteban; Masiá-Tortosa, Laura

2012-12-01

Recently, the trend among physical training and rehabilitation professionals is the use of resistance exercise on unstable equipment in order to increase the effort of the agonist and stabilizing muscles. It is unknown if performing exercises on unstable surfaces provides a greater training stimulus as compared to training on a stable training surface. Therefore, the purpose of this research was to compare the effect that push-up training on stable and unstable surfaces had on strength performance in healthy young men. Thirty subjects with experience in resistance training participated in push-up training two days per week for eight weeks on one of three different surfaces: the floor (Tp), the T-Bow® (TBp) or the BOSU® (Bp). Strength, as measured by one repetition maximum (1-RM) and muscle endurance, as measured by number of pushups performed did not improve significantly (p>0.05) for any of the intervention groups. The addition of unstable surfaces in push-up training does not provide greater improvement in muscular strength and endurance than push up training performed on a stable surface in young men. 3b.

Development of fire-resistant, low smoke generating, thermally stable end items for aircraft and spacecraft

Science.gov (United States)

Gagliani, J.

1978-01-01

A new approach to the problem of flammability by the use of materials obtained from foamy polyimide resins is developed. The ability of these materials to provide fire protection is demonstrated. The development of processes for producing resilient cell foam for use in aircraft seating, thermal acoustical insulation, floor and wall panels, coated glass fabrics, and molded hardware.

Formulation of stable protein powders by supercritical fluid drying

NARCIS (Netherlands)

Jovanović, N.

2007-01-01

Protein pharmaceuticals are potent drugs for the treatment of several chronic and life-threatening diseases. However, the complex and sensitive nature of protein molecules requires special attention in the development of stable dosage forms. Developing stable aqueous protein formulations is often a

Analytic study of resistive instabilities

Energy Technology Data Exchange (ETDEWEB)

Svensson, Magnus

2003-05-01

In a fusion plasma there is always a small amount of resistivity that may cause instabilities. Although their rather slow growth rates they can be of major importance for fusion plasma confinement. In this work a MAPLE-code was rewritten and simplified to make it possible to analytically solve the linearized MHD-equations with resistivity in an RFP-configuration. By using the MHD-equations and expanding the unknown perturbed quantities u{sub 1r}(r) and B{sub 1r}(r) as Taylor series and solving each coefficient we could get eigenvalues, dispersion relations and a relation between the growth rate and the resistivity. The new code was first used to solve two cases with no resistivity and simple unstable equilibria which after running gave the correct expected results. The difference from running the original code with these two cases was the greater speed of the calculations and the less memory needed. Then by using an ideal MHD-stable equilibrium in a plasma with no resistivity the code gave us solutions which unfortunately were not of the expected kind but the time of the calculations was still very fast. The resistivity was finally added to the code with the ideal MHD-stable equilibrium. The program also this time gave incorrect results. We could, however, see from a relation between the growth rate and the resistivity that the solution may be approximately correct in this domain. Although we did not get all the correct results we have to consider the fact that we got results, that were not possible before. Before this work was carried out we could not get any results at all in the resistive cue because of the very long memory demanding expressions. In future work and studies it is not only possible to get the desired eigenvalues {gamma} as function of {eta} but also possible to get expressions for eigenfunctions, dispersion relations and other significant relations with a number of variable parameters. We could also use the method for any geometry and possibly for

Analytic study of resistive instabilities

International Nuclear Information System (INIS)

Svensson, Magnus

2003-05-01

In a fusion plasma there is always a small amount of resistivity that may cause instabilities. Although their rather slow growth rates they can be of major importance for fusion plasma confinement. In this work a MAPLE-code was rewritten and simplified to make it possible to analytically solve the linearized MHD-equations with resistivity in an RFP-configuration. By using the MHD-equations and expanding the unknown perturbed quantities u 1r (r) and B 1r (r) as Taylor series and solving each coefficient we could get eigenvalues, dispersion relations and a relation between the growth rate and the resistivity. The new code was first used to solve two cases with no resistivity and simple unstable equilibria which after running gave the correct expected results. The difference from running the original code with these two cases was the greater speed of the calculations and the less memory needed. Then by using an ideal MHD-stable equilibrium in a plasma with no resistivity the code gave us solutions which unfortunately were not of the expected kind but the time of the calculations was still very fast. The resistivity was finally added to the code with the ideal MHD-stable equilibrium. The program also this time gave incorrect results. We could, however, see from a relation between the growth rate and the resistivity that the solution may be approximately correct in this domain. Although we did not get all the correct results we have to consider the fact that we got results, that were not possible before. Before this work was carried out we could not get any results at all in the resistive cue because of the very long memory demanding expressions. In future work and studies it is not only possible to get the desired eigenvalues γ as function of η but also possible to get expressions for eigenfunctions, dispersion relations and other significant relations with a number of variable parameters. We could also use the method for any geometry and possibly for non

Fractional CO2 lasers contribute to the treatment of stable non-segmental vitiligo.

Science.gov (United States)

Yuan, Jinping; Chen, Hongqiang; Yan, Ru; Cui, Shaoshan; Li, Yuan-Hong; Wu, Yan; Gao, Xing-Hua; Chen, Hong-Duo

2016-12-01

Stable non-segmental vitiligo is often resistant to conventional therapies. The purpose of this study was to investigate the effect of three types of fractional lasers in the treatment of stable non-segmental vitiligo. Twenty patients were enrolled in the study. The vitiligo lesions of each patient were divided into four treatment parts, and all parts were treated with narrowband ultraviolet-B (NB-UVB). Three of the four parts were respectively treated with three types of fractional lasers (two ablative 10,600-nm CO 2 lasers and one non-ablative 1,565-nm laser), followed by topical betamethasone solution application. The treatment period lasted six months. Efficacy and satisfaction were respectively assessed by dermatologists and patients. The ablative CO 2 lasers, in combination with topical betamethasone solution and NB-UVB, achieved marked to excellent improvement on white patches assessed by dermatologists. Patients showed high satisfaction scores for the treatments. The non-ablative 1,565-nm fractional laser did not provide any further benefit in the treatment of vitiligo. No severe adverse events developed for any of the treatments. The treatment protocol with ablative CO 2 lasers, in combination with topical betamethasone solution and NB-UVB, was suitable for stable non-segmental vitiligo. For vitiligo, the ablative fractional CO 2 laser is more effective than the non-ablative fractional laser.

In vivo measurement of vocal fold surface resistance.

Science.gov (United States)

Mizuta, Masanobu; Kurita, Takashi; Dillon, Neal P; Kimball, Emily E; Garrett, C Gaelyn; Sivasankar, M Preeti; Webster, Robert J; Rousseau, Bernard

2017-10-01

A custom-designed probe was developed to measure vocal fold surface resistance in vivo. The purpose of this study was to demonstrate proof of concept of using vocal fold surface resistance as a proxy of functional tissue integrity after acute phonotrauma using an animal model. Prospective animal study. New Zealand White breeder rabbits received 120 minutes of airflow without vocal fold approximation (control) or 120 minutes of raised intensity phonation (experimental). The probe was inserted via laryngoscope and placed on the left vocal fold under endoscopic visualization. Vocal fold surface resistance of the middle one-third of the vocal fold was measured after 0 (baseline), 60, and 120 minutes of phonation. After the phonation procedure, the larynx was harvested and prepared for transmission electron microscopy. In the control group, vocal fold surface resistance values remained stable across time points. In the experimental group, surface resistance (X% ± Y% relative to baseline) was significantly decreased after 120 minutes of raised intensity phonation. This was associated with structural changes using transmission electron microscopy, which revealed damage to the vocal fold epithelium after phonotrauma, including disruption of the epithelium and basement membrane, dilated paracellular spaces, and alterations to epithelial microprojections. In contrast, control vocal fold specimens showed well-preserved stratified squamous epithelia. These data demonstrate the feasibility of measuring vocal fold surface resistance in vivo as a means of evaluating functional vocal fold epithelial barrier integrity. Device prototypes are in development for additional testing, validation, and for clinical applications in laryngology. NA Laryngoscope, 127:E364-E370, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Electroforming-free resistive switching memory effect in transparent p-type tin monoxide

KAUST Repository

Hota, M. K.; Caraveo-Frescas, J. A.; McLachlan, M. A.; Alshareef, Husam N.

2014-01-01

We report reproducible low bias bipolar resistive switching behavior in p-type SnO thin film devices without extra electroforming steps. The experimental results show a stable resistance ratio of more than 100 times, switching cycling performance up

Development of Magneto-Resistive Angular Position Sensors for Space Applications

Science.gov (United States)

Hahn, Robert; Langendorf, Sven; Seifart, Klaus; Slatter, Rolf; Olberts, Bastian; Romera, Fernando

2015-09-01

Magnetic microsystems in the form of magneto- resistive (MR) sensors are firmly established in automobiles and industrial applications. They measure path, angle, electrical current, or magnetic fields. MR technology opens up new sensor possibilities in space applications and can be an enabling technology for optimal performance, high robustness and long lifetime at reasonable costs. In a recent assessment study performed by HTS GmbH and Sensitec GmbH under ESA Contract a market survey has confirmed that space industry has a very high interest in novel, contactless position sensors based on MR technology. Now, a detailed development stage is pursued, to advance the sensor design up to Engineering Qualification Model (EQM) level and to perform qualification testing for a representative pilot space application.The paper briefly reviews the basics of magneto- resistive effects and possible sensor applications and describes the key benefits of MR angular sensors with reference to currently operational industrial and space applications. The results of the assessment study are presented and potential applications and uses of contactless magneto-resistive angular sensors for spacecraft are identified. The baseline mechanical and electrical sensor design will be discussed. An outlook on the EQM development and qualification tests is provided.

Potent antiviral agents fail to elicit genetically-stable resistance mutations in either enterovirus 71 or Coxsackievirus A16.

Science.gov (United States)

Kelly, James T; De Colibus, Luigi; Elliott, Lauren; Fry, Elizabeth E; Stuart, David I; Rowlands, David J; Stonehouse, Nicola J

2015-12-01

Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) are the two major causative agents of hand, foot and mouth disease (HFMD), for which there are currently no licenced treatments. Here, the acquisition of resistance towards two novel capsid-binding compounds, NLD and ALD, was studied and compared to the analogous compound GPP3. During serial passage, EV71 rapidly became resistant to each compound and mutations at residues I113 and V123 in VP1 were identified. A mutation at residue 113 was also identified in CVA16 after passage with GPP3. The mutations were associated with reduced thermostability and were rapidly lost in the absence of inhibitors. In silico modelling suggested that the mutations prevented the compounds from binding the VP1 pocket in the capsid. Although both viruses developed resistance to these potent pocket-binding compounds, the acquired mutations were associated with large fitness costs and reverted to WT phenotype and sequence rapidly in the absence of inhibitors. The most effective inhibitor, NLD, had a very large selectivity index, showing interesting pharmacological properties as a novel anti-EV71 agent. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Resolving the effects of toroidal and poloidal coupling on resistive modes in Heliotron E and LHD

International Nuclear Information System (INIS)

McMillan, B.F.; Dewar, R.L.; Storer, R.G.

2003-01-01

In general, stellarators are less subject than axisymmetric configurations to the most dangerous of instabilities, which lead to disruption of the plasma. For example, the LHD experiment has been shown to be remarkably stable to large scale instabilities, even where analysis suggests the presence of (unstable) ballooning modes. This may not be the case for configurations which contain large parallel currents, where possible kink and tearing modes might lead to unfavourable confinement or even disruptions. These effects can only be approximately modelled while averaging over poloidal and/or toroidal angles, so a complete study would include both a full 3D resistive linear stability analysis and a determination of the non-linear behaviour of the plasma. We have developed a linear, fully 3D resistive MHD code, Spector3D, to examine the stable and unstable wavemodes in a plasma. As verification of the applicability and correctness of the code, we have checked our results against resistive codes of lower dimensionality, and we present here a comparsion with published ideal MHD results for LHD and Heliotron E. As an application of the code, we then determine the stability of current-carrying Heliotron E plasmas against resistive tearing modes under the variation of plasma current and pressure. (orig.)

Loss and stabilization of resistance to aminopterin in mouse cell lines

International Nuclear Information System (INIS)

Safronov, V.V.; Kapitsa, O.S.; Sapegina, M.B.; Gorodetskii, S.I.

1986-01-01

Using step-wise selection, lines of mouse L-cells were obtained (clones B-82, TK-), resistance to aminopterin (AP) of which exceeds resistance of parental cells by 10 3 -5 x 10 4 times. Increased resistance is the result of amplification of the gene for dihydrofolate reductase (DHFR), which was established according to increase in enzyme activity by 15-120 times and by cytogenetic methods. Development and disappearance of resistance to AP was studied and karyological analysis of lines obtained was conducted. Two types of karylogical changes were revealed: the presence of double microchromosomes (DM) and of a marker chromosome having homogeneously staining regions (HSR). The localization of the DHFR and HSR genes was demonstrated using in situ hybridization. At early stages of the development of resistance and for a long time, an extrachromosomal localization of amplified genes in the structure of DM, which determine unstable resistance to toxin, is fundamental. The possibility was demonstrated of the long-term existence of cells in which DM and HSR are present simultaneously. Change in number of copies of the DHFR gene in lines of such cells occurs through change in the number of DM, while size and localization of HSR are constant in different conditions of cell culturing. The presence of HSR determines stable resistance to AP. Data were obtained in support of an intermediate relative stabilization of resistance, which is caused by temporary insertion of copies of the DHFR gene into other sections of chromosomes, in addition to HSR dispersed variously through the genome

Development of antibiotic marker-free creeping bentgrass resistance against herbicides.

Science.gov (United States)

Lee, Ki-Won; Kim, Ki-Yong; Kim, Kyung-Hee; Lee, Byung-Hyun; Kim, Jin-Seog; Lee, Sang-Hoon

2011-01-01

Herbicide-resistant creeping bentgrass plants (Agrostis stolonifera L.) without antibiotic-resistant markers were produced by Agrobacterium-mediated transformation. Embryogenic callus tissues were infected with Agrobacterium tumefaciens EHA105, harboring the bar and the CP4-EPSPS genes for bialaphos and glyphosate resistance. Phosphinothricin-resistant calli and plants were selected. Soil-grown plants were obtained at 14-16 weeks after transformation. Genetic transformation of the selected, regenerated plants was validated by PCR. Southern blot analysis revealed that at least one copy of the transgene was integrated into the genome of the transgenic plants. Transgene expression was confirmed by Northern blot. CP4-EPSPS protein was detected by ELISA. Transgenic plants remained green and healthy when sprayed with Basta, containing 0.5% glufosinate ammonium or glyphosate. The optimized Agrobacterium-mediated transformation method resulted in an average of 9.4% transgenic plants. The results of the present study suggest that the optimized marker-free technique could be used as an effective and reliable method for routine transformation, which may facilitate the development of varieties of new antibiotic-free grass species.

ST37 Klebsiella pneumoniae: development of carbapenem resistance in vivo during antimicrobial therapy in neonates.

Science.gov (United States)

Li, Pengling; Wang, Min; Li, Xianping; Hu, Feihu; Yang, Min; Xie, Yixin; Cao, Wei; Xia, Xiaomeng; Zheng, Rong; Tian, Jingjing; Zhang, Kan; Chen, Fang; Tang, Aiguo

2017-08-01

To investigate the mechanism leading to in vivo carbapenem resistance development in Klebsiella pneumoniae. Carbapenemase was detected using the modified carbapenem inactivation method. β-lactamases resistant genes were identified by PCR and sequencing. Clonal relatedness was evaluated by random amplified polymorphic DNA and multiple locus sequence typing. The relationship between sequence typing and resistant genes was analyzed by using the chi-squared test. All ST37 carbapenem-resistant isolates were bla OXA-1 positive and all ST37 carbapenem-sensitive isolates were bla OXA-1 negative at Stage I. A significant relationship between carbapenem resistance and bla OXA-1 was observed. The bla OXA-1 -positive rate was significantly higher in ST37 K. pneumoniae than others. This is the first study about the development of carbapenem resistance in vivo potentially mediated by bla OXA-1 in ST37 K. pneumoniae among neonates.

Esters of pyrazinoic acid are active against pyrazinamide-resistant strains of Mycobacterium tuberculosis and other naturally resistant mycobacteria in vitro and ex vivo within macrophages.

KAUST Repository

Pires, David; Valente, Emí lia; Simoes, Marta; Carmo, Nuno; Testa, Bernard; Constantino, Luí s; Anes, Elsa

2015-01-01

In previous work, we have shown that POA esters and amides synthesized in our laboratory were stable in plasma. Although the amides did not present significant activity, the esters were active against sensitive mycobacteria at concentrations 5-to-10 fold lower than those of PZA. Here, we report that these POA derivatives possess antibacterial efficacy in vitro and ex vivo against several species and strains of Mycobacterium with natural or acquired resistance to PZA, including M. bovis and M. avium. Our results indicate that the resistance was probably overcome by cleavage of the prodrugs into POA and a long-chain alcohol. Although it is not possible to rule out that the esters may have intrinsic activity per se, we bring evidence here that long-chain fatty alcohols possess a significant anti-mycobacterial effect against PZA-resistant species and strains and are not mere inactive promoieties. These findings may lead to candidate dual-drugs having enhanced activity against both PZA-susceptible and PZA-resistant isolates and being suitable for clinical development.

Macrolides and lincosamides in cattle and pigs: use and development of antimicrobial resistance.

Science.gov (United States)

Pyörälä, Satu; Baptiste, Keith Edward; Catry, Boudewijn; van Duijkeren, Engeline; Greko, Christina; Moreno, Miguel A; Pomba, M Constança Matias Ferreira; Rantala, Merja; Ružauskas, Modestas; Sanders, Pascal; Threlfall, E John; Torren-Edo, Jordi; Törneke, Karolina

2014-05-01

Macrolides and lincosamides are important antibacterials for the treatment of many common infections in cattle and pigs. Products for in-feed medication with these compounds in combination with other antimicrobials are commonly used in Europe. Most recently approved injectable macrolides have very long elimination half-lives in both pigs and cattle, which allows once-only dosing regimens. Both in-feed medication and use of long-acting injections result in low concentrations of the active substance for prolonged periods, which causes concerns related to development of antimicrobial resistance. Acquired resistance to macrolides and lincosamides among food animal pathogens, including some zoonotic bacteria, has now emerged. A comparison of studies on the prevalence of resistance is difficult, since for many micro-organisms no agreed standards for susceptibility testing are available. With animal pathogens, the most dramatic increase in resistance has been seen in the genus Brachyspira. Resistance towards macrolides and lincosamides has also been detected in staphylococci isolated from pigs and streptococci from cattle. This article reviews the use of macrolides and lincosamides in cattle and pigs, as well as the development of resistance in target and some zoonotic pathogens. The focus of the review is on European conditions. Copyright © 2014. Published by Elsevier Ltd.

Stable electroluminescence from passivated nano-crystalline porous silicon using undecylenic acid

Science.gov (United States)

Gelloz, B.; Sano, H.; Boukherroub, R.; Wayner, D. D. M.; Lockwood, D. J.; Koshida, N.

2005-06-01

Stabilization of electroluminescence from nanocrystalline porous silicon diodes has been achieved by replacing silicon-hydrogen bonds terminating the surface of nanocrystalline silicon with more stable silicon-carbon (Si-C) bonds. Hydrosilylation of the surface of partially and anodically oxidized porous silicon samples was thermally induced at about 90 °C using various different organic molecules. Devices whose surface have been modified with stable covalent bonds shows no degradation in the EL efficiency and EL output intensity under DC operation for several hours. The enhanced stability can be attributed to the high chemical resistance of Si-C bonds against current-induced surface oxidation associated with the generation of nonradiative defects. Although devices treated with 1-decene exhibit reduced EL efficiency and brightness compared to untreatred devices, other molecules, such as ethyl-undecylenate and particularly undecylenic acid provide stable and more efficient visible electroluminescence at room temperature. Undecylenic acid provides EL brightness as high as that of an untreated device.

Biology and trapping of stable flies (Diptera: Muscidae) developing in pineapple residues (Ananas comosus) in Costa Rica.

Science.gov (United States)

Solórzano, José-Arturo; Gilles, Jeremie; Bravo, Oscar; Vargas, Cristina; Gomez-Bonilla, Yannery; Bingham, Georgina V; Taylor, David B

2015-01-01

Pineapple production in Costa Rica increased nearly 300-fold during the last 30 yr, and >40,000 hectares of land are currently dedicated to this crop. At the end of the pineapple cropping cycle, plants are chopped and residues incorporated into the soil in preparation for replanting. Associated with increased pineapple production has been a large increase in stable fly, Stomoxys calcitrans (L.), populations. Stable flies are attracted to, and oviposit in, the decomposing, chopped pineapple residues. In conjunction with chemical control of developing larvae, adult trapping is an important control strategy. In this study, four blue-black fabric traps, Nzi, Vavoua, Model H, and Ngu, were compared with a white sticky trap currently used for stable fly control in Costa Rica. Overall, the white sticky trap caught the highest number of stable flies, followed by the Nzi, Vavoua, Model H, and Ngu. Collections on the white sticky trap increased 16 d after residues were chopped; coinciding with the expected emergence of flies developing in the pineapple residues. During this same time period, collections in the blue-black fabric traps decreased. Sex ratio decreased from >7:1 (females:males) 3-7 d after chopping to 1:1 at 24-28 d. White sticky, Nzi and Vavoua traps collected similar numbers of colonizing flies 3-7 d after residues were chopped. However, white sticky traps collected more flies once emergence from the pineapple residues began. Although white sticky traps collected more flies than fabric traps, they remain labor intensive and environmentally unsound because of their disposable and nonbiodegradable nature. Published by Oxford University Press on behalf of the Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

Candida Biofilms: Development, Architecture, and Resistance

Science.gov (United States)

CHANDRA, JYOTSNA; MUKHERJEE, PRANAB K.

2015-01-01

Intravascular device–related infections are often associated with biofilms (microbial communities encased within a polysaccharide-rich extracellular matrix) formed by pathogens on the surfaces of these devices. Candida species are the most common fungi isolated from catheter-, denture-, and voice prosthesis–associated infections and also are commonly isolated from contact lens–related infections (e.g., fungal keratitis). These biofilms exhibit decreased susceptibility to most antimicrobial agents, which contributes to the persistence of infection. Recent technological advances have facilitated the development of novel approaches to investigate the formation of biofilms and identify specific markers for biofilms. These studies have provided extensive knowledge of the effect of different variables, including growth time, nutrients, and physiological conditions, on biofilm formation, morphology, and architecture. In this article, we will focus on fungal biofilms (mainly Candida biofilms) and provide an update on the development, architecture, and resistance mechanisms of biofilms. PMID:26350306

Stable switching of resistive random access memory on the nanotip array electrodes

KAUST Repository

Tsai, Kun-Tong

2016-09-13

The formation/rupture of conducting filaments (CFs) in resistive random access memory (ReRAM) materials tune the electrical conductivities non-volatilely and are largely affected by its material composition [1], internal configurations [2] and external environments [3,4]. Therefore, controlling repetitive formation/rupture of CF as well as the spatial uniformity of formed CF are fundamentally important for improving the resistive switching (RS) performance. In this context, we have shown that by adding a field initiator, typically a textured electrode, both performance and switching uniformity of ReRAMs can be improved dramatically [5]. In addition, despite its promising characteristics, the scalable fabrication and structural homogeneity of such nanostructured electrodes are still lacking or unattainable, making miniaturization of ReRAM devices an exceeding challenge. Here, we employ nanostructured electrode (nanotip arrays, extremely uniform) formed spontaneously via a self-organized process to improve the ZnO ReRAM switching characteristics.

Development of DC active filter for high magnetic field stable power supply

International Nuclear Information System (INIS)

Wang Lei; Liu Xiaoning

2008-01-01

The DC active filter (DAF), with very low current ripple, of the stable power supply system of high magnetic field device is developed by using the PWM and parallel active power filter technique. Due to the PWM control technique, the required DAF current can be obtained and the current ripple can be compensated by means of monitoring the load voltage, and the current ripple becomes very low by adjusting the load voltage. The simulation and analysis show that this system can respond to the reference quickly and is effective in suppressing the harmonics, especially the low-order harmonics. The feasibility of the proposed scheme is proved on the equipment built in the laboratory. (authors)

Recent developments and future directions for stable isotope applications in nutrition research. Report of a consultants meeting

International Nuclear Information System (INIS)

2001-01-01

The International Atomic Energy Agency (IAEA) at its Headquarters in Vienna convened a consultants meeting to provide the Agency with an overview of the current status of isotopic techniques in nutritional science with respect to both methodology and applications. The main objectives were: To assess the practice of stable isotope methodologies in human nutrition research; To explore high quality stable isotope spikes for use in humans; To standardise the mathematical approaches to evaluate mass spectrometric data when using stable isotope labels within metabolic studies; To identify new strategies for improving sensitivity of nutrition monitoring techniques for use in projects in nutrition. This exercise was conducted to also identify strengths and weaknesses of methodologies currently used in IAEA funded research (CRPs and Technical Cooperation Projects) and to see how they can be improved for the general user, and to provide a basis for the assessment of outcomes delivered by collaborating laboratories in IAEA funded studies. The consultants reviewed the methods relating to the measurement of energy expenditure and noted that the analytical methodologies had changed substantially and that there was further refinement to data fitting and the calculation of uncertainties. They also felt that a repeat of a comparison of laboratory performances with a dilution series similar to the one carried out earlier should be performed for quality control. Other methods using labelled isotopes 13 C and 2 H were also discussed. The meeting noted that it was IAEA's intention to support the development of compound specific reference materials for 2 H, 13 C, 15 N and 18 O. Contrary to light isotope techniques where attempts have been made in the past towards standardization, in particular by IAEA and Stable Isotopes in Gastroenterology and Nutrition (SIGN) harmonization of techniques between laboratories is unsatisfactory for the minerals and trace elements. It was decided that

Recent developments and future directions for stable isotope applications in nutrition research. Report of a consultants meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The International Atomic Energy Agency (IAEA) at its Headquarters in Vienna convened a consultants meeting to provide the Agency with an overview of the current status of isotopic techniques in nutritional science with respect to both methodology and applications. The main objectives were: To assess the practice of stable isotope methodologies in human nutrition research; To explore high quality stable isotope spikes for use in humans; To standardise the mathematical approaches to evaluate mass spectrometric data when using stable isotope labels within metabolic studies; To identify new strategies for improving sensitivity of nutrition monitoring techniques for use in projects in nutrition. This exercise was conducted to also identify strengths and weaknesses of methodologies currently used in IAEA funded research (CRPs and Technical Cooperation Projects) and to see how they can be improved for the general user, and to provide a basis for the assessment of outcomes delivered by collaborating laboratories in IAEA funded studies. The consultants reviewed the methods relating to the measurement of energy expenditure and noted that the analytical methodologies had changed substantially and that there was further refinement to data fitting and the calculation of uncertainties. They also felt that a repeat of a comparison of laboratory performances with a dilution series similar to the one carried out earlier should be performed for quality control. Other methods using labelled isotopes {sup 13}C and {sup 2}H were also discussed. The meeting noted that it was IAEA's intention to support the development of compound specific reference materials for {sup 2}H, {sup 13}C, {sup 15}N and {sup 18}O. Contrary to light isotope techniques where attempts have been made in the past towards standardization, in particular by IAEA and Stable Isotopes in Gastroenterology and Nutrition (SIGN) harmonization of techniques between laboratories is unsatisfactory for the minerals and trace

Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants

Directory of Open Access Journals (Sweden)

Silvestre A.

2004-06-01

Full Text Available In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control ? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole. Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial : it is not possible to avoid it, but only to delay its development in farm animal industry.

Top-coatless 193nm positive-tone development immersion resist for logic application

Science.gov (United States)

Liu, Lian Cong; Yeh, Tsung Ju; Lin, Yeh-Sheng; Huang, Yu Chin; Kuo, Chien Wen; Huang, Wen Liang; Lin, Chia Hung; Yu, Chun Chi; Hsu, Ray; Wan, I.-Yuan; Lin, Jeff; Im, Kwang-Hwyi; Lim, Hae Jin; Jeon, Hyun K.; Suzuki, Yasuhiro; Xu, Cheng Bai

2015-03-01

In this paper, we summarize our development efforts for a top-coatless 193nm immersion positive tone development (PTD) contact hole (C/H) resist with improved litho and defect performances for logic application specifically with an advance node. The ultimate performance goal was to improve the depth of focus (DoF) margin, mask error enhancement factor (MEEF), critical dimension uniformity (CDU), contact edge roughness (CER), and defect performance. Also, the through pitch CD difference was supposed to be comparable to the previous control resist. Effects of polymer and PAG properties have been evaluated for this purpose. The material properties focused in the evaluation study were polymer activation energy (Ea), polymer solubility differentiated by polymerization process types, and diffusion length (DL) and acidity (pKa) of photoacid generator (PAG). Additionally, the impact of post exposure bake (PEB) temperature was investigated for process condition optimization. As a result of this study, a new resist formulation to satisfy all litho and defect performance was developed and production yield was further improved.

Development of weldable, corrosion-resistant iron-aluminide alloys

Energy Technology Data Exchange (ETDEWEB)

Maziasz, P.J.; Goodwin, G.M.; Wang, X.L. [Oak Ridge National Laboratory, TN (United States)

1995-05-01

Corrosion-resistant, weldable FeAl alloys have been developed with improved high-temperature strength industrial applications. Previous processing difficulties with these alloys led to their evaluation as weld-overlay claddings on conventional structural steels to take advantage of their good properties now. Simplified and better processing methods for monolithic FeAl components are also currently being developed so that components for industrial testing can be made. Other avenues for producing FeAl coatings are currently being explored. Neutron scattering experiments residual stress distributions in the FeAl weld-overlay cladding began in FY 1993 and continued this year.

Estimation of interface resistivity in bonded Si for the development of high performance radiation detectors

International Nuclear Information System (INIS)

Kanno, Ikuo; Yamashita, Makoto; Nomiya, Seiichiro; Onabe, Hideaki

2007-01-01

For the development of high performance radiation detectors, direct bonding of Si wafers would be an useful method. Previously, p-n bonded Si were fabricated and they showed diode characteristics. The interface resistivity was, however, not investigated in detail. For the study of interface resistivity, n-type Si wafers with different resistivities were bonded. The resistivity of bonded Si wafers were measured and the interface resistivity was estimated by comparing with the results of model calculations. (author)

Eco-friendly electron beam lithography using water-developable resist material derived from biomass

Science.gov (United States)

Takei, Satoshi; Oshima, Akihiro; Wakabayashi, Takanori; Kozawa, Takahiro; Tagawa, Seiichi

2012-07-01

We investigated the eco-friendly electron beam (EB) lithography using a high-sensitive negative type of water-developable resist material derived from biomass on hardmask layer for tri-layer processes. A water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB lithography was developed for environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of trimethylphenylammonium hydroxide. The images of 200 nm line and 800 nm space pattern with exposure dose of 7.0 μC/cm2 and CF4 etching selectivity of 2.2 with hardmask layer were provided by specific process conditions.

DEVELOPMENT OF ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS

International Nuclear Information System (INIS)

Adeyinka A. Adeyiga

2001-01-01

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H 2 ) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. The use of iron-based catalysts is attractive not only due to their low cost and ready availability, but also due to their high water-gas shift activity which makes it possible to use these catalysts with low H 2 /CO ratios. However, a serious problem with use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, makes the separation of catalyst from the oil/wax product very difficult if not impossible, and results in a steady loss of catalyst from the reactor. Recently, fundamental understanding of physical attrition is being addressed by incorporating suitable binders into the catalyst recipe. This has resulted in the preparation of a spray dried Fe-based catalyst having aps of 70 mm with high attrition resistance. This Fe-based attrition resistant, active and selective catalyst gave 95% CO conversion through 125 hours of testing in a fixed-bed at 270 C, 1.48 MPa, H 2 /CO=0.67 and 2.0 NL/g-cat/h with C 5 + selectivity of >78% and methane selectivity of <5%. However, further development of the catalyst is needed to address the chemical attrition due to phase changes that any Fe-catalyst goes through potentially causing internal stresses within the particle and resulting in weakening, spalling or cracking. The objective of this research is to develop robust iron-based Fischer-Tropsch catalysts that have suitable activity, selectivity and stability to be used in the slurry bubble column reactor. Specifically we aim to develop to: (i) improve the performance and preparation procedure of the high activity, high attrition resistant, high alpha iron

Development of a resistance management strategy for ixodid ticks ...

African Journals Online (AJOL)

The strategy developed for managing resistance in ticks with the acaricidal products on the market was based on mode of action of the active ingredients. The strategy requires the rotaional use of the acaricidal products in ways that reduces the selection pressure of active ingredients of same chemistry on the target-site in ...

Developing artemisinin based drug combinations for the treatment of drug resistant falciparum malaria: A review

Directory of Open Access Journals (Sweden)

Olliaro P

2004-01-01

Full Text Available The emergence and spread of drug resistant malaria represents a considerable challenge to controlling malaria. To date, malaria control has relied heavily on a comparatively small number of chemically related drugs, belonging to either the quinoline or the antifolate groups. Only recently have the artemisinin derivatives been used but mostly in south east Asia. Experience has shown that resistance eventually curtails the life-span of antimalarial drugs. Controlling resistance is key to ensuring that the investment put into developing new antimalarial drugs is not wasted. Current efforts focus on research into new compounds with novel mechanisms of action, and on measures to prevent or delay resistance when drugs are introduced. Drug discovery and development are long, risky and costly ventures. Antimalarial drug development has traditionally been slow but now various private and public institutions are at work to discover and develop new compounds. Today, the antimalarial development pipeline is looking reasonably healthy. Most development relies on the quinoline, antifolate and artemisinin compounds. There is a pressing need to have effective, easy to use, affordable drugs that will last a long time. Drug combinations that have independent modes of action are seen as a way of enhancing efficacy while ensuring mutual protection against resistance. Most research work has focused on the use of artesunate combined with currently used standard drugs, namely, mefloquine, amodiaquine, sulfadoxine/pyrimethamine, and chloroquine. There is clear evidence that combinations improve efficacy without increasing toxicity. However, the absolute cure rates that are achieved by combinations vary widely and depend on the level of resistance of the standard drug. From these studies, further work is underway to produce fixed dose combinations that will be packaged in blister packs. This review will summarise current antimalarial drug developments and outline recent

Development of superior radiation resistant materials and cables. 2

Energy Technology Data Exchange (ETDEWEB)

Ikehara, Junichiro; Kanemitsuya, Kazuhiko; Ohara, Hideo; Araki, Syogo; Hamachi, Katsuhiko [Mitsubishi Cable Industries Ltd., Tokyo (Japan)

1996-01-01

Many nuclear power plants have been constructed in Japan and electric power generation is now highly dependent on this technology. Therefore, the needs for facilities that will enrich and reprocess nuclear fuel from nuclear power stations will be high. As there are areas with high levels of radiation, the cables which can be used in these environments are needed. We have developed a superior radiation-resistant cable which uses halogen flame-retardant materials. This radiation-resistant cable consists of Ethylene-propylene rubber (EPDM) insulation and Chlorosulfonated polyethylene (CSM) sheath can be safely used in areas with high levels of radiation. We developed this product to aid in disaster prevention. Non-halogen, flame-retardant EPDM is used for the insulation, and low-halogen, flame-retardant CSM and new non-halogen, flame-retardant materials are used for the sheath. These cables have superior flame-retardant properties and generate little smoke on corrosive gas. This products can hence reduce the danger of a secondary disaster in a fire. We expect that these cables will find application in areas with high levels of radiation. (author).

Development of superior radiation resistant materials and cables. 2

International Nuclear Information System (INIS)

Ikehara, Junichiro; Kanemitsuya, Kazuhiko; Ohara, Hideo; Araki, Syogo; Hamachi, Katsuhiko

1996-01-01

Many nuclear power plants have been constructed in Japan and electric power generation is now highly dependent on this technology. Therefore, the needs for facilities that will enrich and reprocess nuclear fuel from nuclear power stations will be high. As there are areas with high levels of radiation, the cables which can be used in these environments are needed. We have developed a superior radiation-resistant cable which uses halogen flame-retardant materials. This radiation-resistant cable consists of Ethylene-propylene rubber (EPDM) insulation and Chlorosulfonated polyethylene (CSM) sheath can be safely used in areas with high levels of radiation. We developed this product to aid in disaster prevention. Non-halogen, flame-retardant EPDM is used for the insulation, and low-halogen, flame-retardant CSM and new non-halogen, flame-retardant materials are used for the sheath. These cables have superior flame-retardant properties and generate little smoke on corrosive gas. This products can hence reduce the danger of a secondary disaster in a fire. We expect that these cables will find application in areas with high levels of radiation. (author)

FAO/IAEA Consultants Group Meeting on The Potential for Tsetse Flies to Develop Resistance to Insecticides

International Nuclear Information System (INIS)

1993-01-01

Chemical insecticides are playing an increasingly important role in control of tsetse flies (Glossina spp), vectors of human and animal trypanosomiasis in large regions of Africa. Although insecticide resistance has not yet been reported in tsetse, there is no cause for complacency regarding its occurrence in the future. As new reports of insecticide resistance in other disease vectors and agronomic pests continue to accumulate at a rapid rate, it is increasingly clear that no comprehensive approach to tsetse control can afford to ignore the potential resistance problem, as the loss of insecticides from the limited set of options for control would be disastrous. it is likely that one or more of the pyrethroid resistance mechanisms already known from several other species of Diptera will manifest itself in tsetse, in response to the increased selection engendered by the wider adoption of deltamethrin-treated targets in tsetse control at the local level and in eradication efforts. Also, selection for behavioural avoidance of traps and targets could result in decreased control efficiency, although the mechanisms that might cause such behavioural resistance are poorly understood at present. There is thus an increasingly urgent need for information on the potential for resistance development in tsetse, on accurate and feasible methods for detection, monitoring, and characterization of resistance, on properties of resistant strains, and on appropriate tactics for resistance prevention and management. Because of the extraordinary difficulties in rearing posed by tsetse life history, it is essential that these research efforts get underway immediately. The Consultants Group on the Possibility of Development of Insecticide Resistance in Tsetse has accordingly prepared this report with a consideration of the present state of knowledge, a discussion of the essential elements of a resistance research program, and specific recommendations. A summary of the recommendations in

FAO/IAEA Consultants Group Meeting on The Potential for Tsetse Flies to Develop Resistance to Insecticides

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-07-01

Chemical insecticides are playing an increasingly important role in control of tsetse flies (Glossina spp), vectors of human and animal trypanosomiasis in large regions of Africa. Although insecticide resistance has not yet been reported in tsetse, there is no cause for complacency regarding its occurrence in the future. As new reports of insecticide resistance in other disease vectors and agronomic pests continue to accumulate at a rapid rate, it is increasingly clear that no comprehensive approach to tsetse control can afford to ignore the potential resistance problem, as the loss of insecticides from the limited set of options for control would be disastrous. it is likely that one or more of the pyrethroid resistance mechanisms already known from several other species of Diptera will manifest itself in tsetse, in response to the increased selection engendered by the wider adoption of deltamethrin-treated targets in tsetse control at the local level and in eradication efforts. Also, selection for behavioural avoidance of traps and targets could result in decreased control efficiency, although the mechanisms that might cause such behavioural resistance are poorly understood at present. There is thus an increasingly urgent need for information on the potential for resistance development in tsetse, on accurate and feasible methods for detection, monitoring, and characterization of resistance, on properties of resistant strains, and on appropriate tactics for resistance prevention and management. Because of the extraordinary difficulties in rearing posed by tsetse life history, it is essential that these research efforts get underway immediately. The Consultants Group on the Possibility of Development of Insecticide Resistance in Tsetse has accordingly prepared this report with a consideration of the present state of knowledge, a discussion of the essential elements of a resistance research program, and specific recommendations. A summary of the recommendations in

Development of the sex quality of the material for high; Kotaiyosei suritto puragu zaishitsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Egashira, R. [TYK Corp., Gifu (Japan)

1999-02-01

When it works for the stable durability of the gas business slit flag, a spooling is made a problem like heat, and the improvement of the quality of the material is being done. It is formed, and a thermostability spooling causes curving, and the existence of that gap is being improved by substituting some of the bone materials for the special alumina bone material during the bone material and the matrix by being connected with the resistance of the crack development the gap when a crack develops, it branches off .A stable durability is confirmed even in an actual opportunity, and heat shock crack resistance Rst is placed on the effective method as an evaluation of the thermostability spooling. (translated by NEDO)

Stable isotopes

International Nuclear Information System (INIS)

Evans, D.K.

1986-01-01

Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

Model development for quantitative evaluation of proliferation resistance of nuclear fuel cycles

Energy Technology Data Exchange (ETDEWEB)

Ko, Won Il; Kim, Ho Dong; Yang, Myung Seung

2000-07-01

This study addresses the quantitative evaluation of the proliferation resistance which is important factor of the alternative nuclear fuel cycle system. In this study, model was developed to quantitatively evaluate the proliferation resistance of the nuclear fuel cycles. The proposed models were then applied to Korean environment as a sample study to provide better references for the determination of future nuclear fuel cycle system in Korea. In order to quantify the proliferation resistance of the nuclear fuel cycle, the proliferation resistance index was defined in imitation of an electrical circuit with an electromotive force and various electrical resistance components. The analysis on the proliferation resistance of nuclear fuel cycles has shown that the resistance index as defined herein can be used as an international measure of the relative risk of the nuclear proliferation if the motivation index is appropriately defined. It has also shown that the proposed model can include political issues as well as technical ones relevant to the proliferation resistance, and consider all facilities and activities in a specific nuclear fuel cycle (from mining to disposal). In addition, sensitivity analyses on the sample study indicate that the direct disposal option in a country with high nuclear propensity may give rise to a high risk of the nuclear proliferation than the reprocessing option in a country with low nuclear propensity.

Model development for quantitative evaluation of proliferation resistance of nuclear fuel cycles

International Nuclear Information System (INIS)

Ko, Won Il; Kim, Ho Dong; Yang, Myung Seung

2000-07-01

This study addresses the quantitative evaluation of the proliferation resistance which is important factor of the alternative nuclear fuel cycle system. In this study, model was developed to quantitatively evaluate the proliferation resistance of the nuclear fuel cycles. The proposed models were then applied to Korean environment as a sample study to provide better references for the determination of future nuclear fuel cycle system in Korea. In order to quantify the proliferation resistance of the nuclear fuel cycle, the proliferation resistance index was defined in imitation of an electrical circuit with an electromotive force and various electrical resistance components. The analysis on the proliferation resistance of nuclear fuel cycles has shown that the resistance index as defined herein can be used as an international measure of the relative risk of the nuclear proliferation if the motivation index is appropriately defined. It has also shown that the proposed model can include political issues as well as technical ones relevant to the proliferation resistance, and consider all facilities and activities in a specific nuclear fuel cycle (from mining to disposal). In addition, sensitivity analyses on the sample study indicate that the direct disposal option in a country with high nuclear propensity may give rise to a high risk of the nuclear proliferation than the reprocessing option in a country with low nuclear propensity

Gas phase thermal diffusion of stable isotopes

International Nuclear Information System (INIS)

Eck, C.F.

1979-01-01

The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

Effect of structure state on the microplastic resistance of thermobimetals

International Nuclear Information System (INIS)

Bashnin, Yu.A.; Ulanovskij, F.B.; Shiryaeva, A.N.

1983-01-01

The effect of structural state on microplastic resistance of nickel alloy thermobimetals with butt oint of layers has been studied. It has been shown that a stable polygonal structure with minimum level of residual stresses is achieved in thermobimetals by a three-fold thermocyclic treatment with heating up to 400 deg C, holding during 1 hour and slow cooling up to room temperature after each cycle with a speed of 2-4 deg C per min. The stable polygonal structure of alloys-components of thermobimetals provides growth of microplastic resistance and drop of residual deflection. The maximum thermobimetal thermosensitivity is provided at 50% preliminary plastic deformation degree on thermocouples cut out along the direction of rolli

Effect of structure state on the microplastic resistance of thermobimetals

Energy Technology Data Exchange (ETDEWEB)

Bashnin, Yu.A.; Ulanovskij, F.B.; Shiryaeva, A.N. (Moskovskij Vechernij Metallurgicheskij Inst. (USSR))

1983-01-01

The effect of structural state on microplastic resistance of nickel alloy thermobimetals with butt joint of layers has been studied. It has been shown that a stable polygonal structure with minimum level of residual stresses is achieved in thermobimetals by a three-fold thermocyclic treatment with heating up to 400 deg C, holding during 1 hour and slow cooling up to room temperature after each cycle with a speed of 2-4 deg C per min. The stable polygonal structure of alloys-components of thermobimetals provides growth of microplastic resistance and drop of residual deflection. The maximum thermobimetal thermosensitivity is provided at 50% preliminary plastic deformation degree on thermocouples cut out along the direction of rolli.

Stability Analysis of an HIV/AIDS Dynamics Model with Drug Resistance

Directory of Open Access Journals (Sweden)

Qianqian Li

2012-01-01

Full Text Available A mathematical model of HIV/AIDS transmission incorporating treatment and drug resistance was built in this study. We firstly calculated the threshold value of the basic reproductive number (R0 by the next generation matrix and then analyzed stability of two equilibriums by constructing Lyapunov function. When R0<1, the system was globally asymptotically stable and converged to the disease-free equilibrium. Otherwise, the system had a unique endemic equilibrium which was also globally asymptotically stable. While an antiretroviral drug tried to reduce the infection rate and prolong the patients’ survival, drug resistance was neutralizing the effects of treatment in fact.

Development of hyper osmotic resistant CHO host cells for enhanced antibody production.

Science.gov (United States)

Kamachi, Yasuharu; Omasa, Takeshi

2018-04-01

Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased. In this study, osmotic resistant CHO host cells were developed to attain a high product concentration. To establish hyper osmotic resistant CHO host cells, CHO-S host cells were passaged long-term in a hyper osmotic basal medium. There were marked differences in cell growth of the original and established host cells under iso- (328 mOsm/kg) or hyper-osmolality (over 450 mOsm/kg) conditions. Cell growth of the original CHO host cells was markedly decreased by the induction of osmotic stress, whereas cell growth of the hyper osmotic resistant CHO host cells was not affected. The maximum viable cell concentration of hyper osmotic resistant CHO host cells was 132% of CHO-S host cells after the induction of osmotic stress. Moreover, the hyper osmotic resistant characteristic of established CHO host cells was maintained even after seven passages in iso-osmolality basal medium. The use of hyper osmotic resistance CHO host cells to create a monoclonal antibody production cell line might be a new approach to increase final antibody concentrations with a fed-batch process. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Inheritance of black sigatoka disease resistance in plantain-banana (Musa spp.) hybrids.

Science.gov (United States)

Ortiz, R; Vuylsteke, D

1994-10-01

Black sigatoka (Mycosphaerella fijiensis Morelet), an airborne fungal leaf-spot disease, is a major constraint to plantain and banana (Musa spp.) production world-wide. Gaining further knowledge of the genetics of host-plant resistance will enhance the development of resistant cultivars, which is considered to be the most appropriate means to achieve stable production. Genetic analysis was conducted on 101 euploid (2x, 3x and 4x) progenies, obtained from crossing two susceptible triploid plantain cultivars with the resistant wild diploid banana 'Calcutta 4'. Segregating progenies, and a susceptible reference plantain cultivar, were evaluated over 2 consecutive years. Three distinct levels of host response to black sigatoka were defined as follows: susceptible ( 10). Segregation ratios for resistance at the 2x level fitted a genetic model having one major recessive resistance allele (bs 1) and two independent alleles with additive effects (bsr 2 and bsr 3). A similar model explains the results at the 4x level assuming that the favourable resistance alleles have a dosage effect when four copies of them are present in their respective loci (bs i (4) ). The proposed model was further validated by segregation data of S 1 progenies. Mechanisms of black sigatoka resistance are discussed in relation to the genetic model.

An optimal method for generating stable vancomycin heteroresistance and intermediate susceptibility in methicillin-resistant Staphylococcus aureusblood isolates under in-vitro vancomycin pressure

Directory of Open Access Journals (Sweden)

Riad Khatib

2012-12-01

Full Text Available Objectives: The relevance of vancomycin intermediately-susceptible (VISA and hetero-resistant (hVISA methicillin-resistantStaphylococcus aureus (MRSA remains uncertain because of their low frequency. In vitro attempts to generate reducedsusceptibility have been inconsistent. We describe a simple method for generating VISA/hVISA.Materials and methods: Twenty-four SCCmec type II and IV MRSA blood isolates plus USA100 and USA300 controls werecultured (107 CFU/ml in BHI broth with 0, 2 and 3 mg/L vancomycin for 10 days followed by 10 days vancomycin-freepassage.We monitored vancomycin minimum inhibitory concentration (MIC; Etest and population analysis profile-areaunder the curve (PAP-AUC ratios of tested isolate-Mu3 during and after vancomycin pressure (VP. PAP-AUC ratios 1.3 were considered consistent with susceptible, hVISA and VISA, respectively.Results: VP at 2 mg/L (VP-2 increased MIC to 3 mg/L in 20 (83.3% isolates and raised PAP-AUC ratio to hVISA (n=18; 75.0%and VISA (six; 25.0% ranges. VP-3 increased MIC to 3 and 4 mg/L in 19 (79.2% and three (12.5% isolates, respectively andraised PAP-AUC ratio to hVISA (n=3; 12.5% and VISA (n=19; 79.2% ranges. SCCmec IV isolates had lower pre-exposurePAP-AUC ratios (0.48±0.14 vs. 0.69±0.10; p<0.001 and lower MIC (1.6±0.2 vs. 1.8±0.2 mg/L; p=0.1 but MIC rise and VISA/hVISA emergence was comparable. MIC and PAP-AUC ratio rises were stable in 20/22 isolates during drug-free passages.Conclusions: VISA/hVISA readily emerges among MRSA SCCmec type II and IV isolates under VP. VP at the MIC level generateshVISA while pressure at slightly higher level results in the VISA phenotype. J Microbiol Infect Dis 2012; 2(4: 129-134Key words: Staphylococcus aureus; heteroresistance; glycopeptides; resistance; bacteremia.

Comparative analysis of antimicrobial resistance in enterotoxigenic Escherichia coli isolates from two paediatric cohort studies in Lima, Peru.

Science.gov (United States)

Medina, Anicia M; Rivera, Fulton P; Pons, Maria J; Riveros, Maribel; Gomes, Cláudia; Bernal, María; Meza, Rina; Maves, Ryan C; Huicho, Luis; Chea-Woo, Elsa; Lanata, Claudio F; Gil, Ana I; Ochoa, Theresa J; Ruiz, Joaquim

2015-08-01

Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children Peru. ETEC were identified by an in-house multiplex real-time PCR. Susceptibility to 13 antimicrobial agents was tested by disk diffusion; mechanisms of resistance were evaluated by PCR. ETEC isolates were resistant to ampicillin (64%), cotrimoxazole (52%), tetracycline (37%); 39% of the isolates were multidrug-resistant. Heat-stable toxin producing (ETEC-st) (48%) and heat-labile toxin producing ETEC (ETEC-lt) (40%) had higher rates of multidrug resistance than isolates producing both toxins (ETEC-lt-st) (21%), pPeru. However, further development of resistance should be closely monitored. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Nonvolatile conductive filaments resistive switching behaviors in Ag/GaO{sub x} /Nb:SrTiO{sub 3}/Ag structure

Energy Technology Data Exchange (ETDEWEB)

Li, P.G. [Beijing University of Posts and Telecommunications, State Key Laboratory of Information Photonics and Optical Communication, Beijing (China); Zhejiang Sci-Tech University, Center for Optoelectronics Materials and Devices, Hangzhou (China); Zhi, Y.S.; An, Y.H.; Guo, D.Y.; Tang, W.H.; Xiao, J.H. [Beijing University of Posts and Telecommunications, State Key Laboratory of Information Photonics and Optical Communication, Beijing (China); Wang, P.C. [Zhejiang Sci-Tech University, Center for Optoelectronics Materials and Devices, Hangzhou (China); Sun, Z.B. [Chinese Academy of Sciences, Key Laboratory of Electronics and Information Technology for Space Systems, National Space Science Center, Beijing (China); Li, L.H. [State University of New York at Potsdam, Department of Physics, Potsdam, NY (United States)

2016-07-15

Ag/GaO{sub x} /NSTO/Ag structures were fabricated, and the electrical properties measurement results show that the device behaviors a unipolar resistance switching characteristic with bi-stable resistance ratio of three orders. In the positive voltage region, the dominant conducting mechanism of high resistance state obeys Poole-Frenkel emission rules, while in the negative region, that obeys space-charge-limited current mechanism. Both the I-V curves of ON and OFF states and temperature-dependent variation resistances indicate that the unipolar resistance switching behavior can be explained by the formation/rupture of conductive filaments, which composed of oxygen vacancies. The stable switching results demonstrated that the structure can be applied in resistance random access memory devices. (orig.)

Development of shelf-stable meat sausages using gamma irradiation

International Nuclear Information System (INIS)

Seri Chempaka Mohd Yusof; Muhammad Lebai Juri; Mariani Deraman

2006-01-01

Irradiation techniques have been applied in development of ready to eat or shelf stable sausages. These sausages can be eaten directly without the need for prior heating or cooking procedure and displayed in the room temperature on the shelves of the retailers without frozen facilities. This study was designed to investigate the acceptability and microbial status of packed ready to eat sausages that had been sterilized using gamma irradiation at MINTec-Sinagama. Packed pre-cooked sausage samples (sealed in plastic-polyethylene individually) were irradiated with different doses of 2.5 kGy, 3.5 kGy and 5.5 kGy. Acceptability of the sausages was determined through sensory evaluation by 30 members of untrained panelists comprising of staffs of MINT. A 5 points hedonic rating scale was used. The attributes evaluated were rancidity, texture, chewiness, juiciness, aroma, colour, shape and overall acceptance. Samples irradiated with doses 3.5 kGy were the most acceptable followed by samples irradiated with doses 2.5 kGy and 5.5 kGy respectively. Irradiation with doses up to 2.5 kGy will virtually eliminate disease-causing microorganisms and pathogens. The total microbial count, detection of Salmonella, Escherichia coli, Staphylococcus aureus and fungi in these samples were determined and discussed. (Author)

Stable Isotope Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

stableGP

Data.gov (United States)

National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

Effect of tetracycline residues in pig manure slurry on tetracycline-resistant bacteria and resistance gene tet(M) in soil microcosms

DEFF Research Database (Denmark)

Agersø, Yvonne; Wulff, Gitte; Vaclavik, Elvira

2006-01-01

and oxytetracycline were almost stable through out the experimental period, but the tetracycline concentrations had no effect on prevalence of tetracycline-resistant bacteria. The presented microcosm approach simulated natural farmland conditions well and supported results from previous field studies. (c) 2006...

Bacterial cheating limits antibiotic resistance

Science.gov (United States)

Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

2012-02-01

The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

Resistive ballooning modes in W7-AS and W7-X

International Nuclear Information System (INIS)

Kaiser, R.

1993-01-01

'Critical' pressure gradients due to resistive ballooning modes and their growth rates were computed for the W7-AS stellarator and for a HELIAS configuration with W7-X parameters, and the two configurations were compared. The results are based on the evaluation of a fourth order magnetic differential equation along closed magnetic field lines. The numerical procedure applying a variational approach uses the 'Garching resistive ballooning code', GARBO, which was originally developed for the stability analysis of axisymmetric plasmas. Concerning purely growing modes, this analysis shows that the favourable stability properties of W7-X, already optimized with respect to ideal ballooning modes, persist in the resistive regime: the destabilizing effect of resistivity is largely compensated by the stabilizing contribution of plasma compression. As a consequence, the ideal β limit continues only moderately shifted in the resistive case and likewise ideal ballooning stable equilibria (up to β 0 ≅ 5%) do not become resistively unstable. The situation is different for W7-AS. Greater resistive effects (in comparison with W7-X) are found in a configuration that is already ideally much more unstable. A basic feature in resistive calculations is the occurrence of overstable modes. These modes no longer show a stability threshold and, for realistic values of pressure and resistivity, linear instability is obtained for W7-AS as well as for W7-X, with growth rates and oscillation frequencies in the kilo-Hertz range. (author). 29 refs, 13 figs

Development of a novel zirconia dental post resistant to hydrothermal degradation

International Nuclear Information System (INIS)

Camposilvan, E; Marro, F G; Mestra, A; Anglada, M J

2012-01-01

Tetragonal Zirconia Polycrystals stabilized with 3% mol. content of yttria (3Y-TZP) has excellent properties in terms of strength and fracture toughness. These properties are mostly imputable to the transformation toughening mechanism, by which the doped metastable tetragonal phase of zirconia transforms to monoclinic under applied stress ahead of a crack. This phenomenon is accompanied by a volume expansion of 5%, and increases the resistance to crack growth, thus leading to higher toughness and strength. An important drawback of this material is represented by the Low Temperature Degradation (LTD or aging), which consists in the progressive tetragonal-to-monoclinic phase transformation by the influence of water. This work focuses on the improvement of 3Y-TZP aging behavior in order to develop a novel dental post, by means of the addition of ceria from the surface. This was achieved through the impregnation of the pre-sintered samples with a solution containing Cerium, followed by sintering. Various pre-sintering temperatures were studied in terms of microstructure, mechanical properties and aging resistance. The novel zirconia dental posts developed in this work are much more resistant to LTD as compared to the base material with no loss in mechanical properties.

ABC transporters as multidrug resistance mechanisms and the development of chemosensitizers for their reversal

Directory of Open Access Journals (Sweden)

Choi Cheol-Hee

2005-10-01

Full Text Available Abstract One of the major problems related with anticancer chemotherapy is resistance against anticancer drugs. The ATP-binding cassette (ABC transporters are a family of transporter proteins that are responsible for drug resistance and a low bioavailability of drugs by pumping a variety of drugs out cells at the expense of ATP hydrolysis. One strategy for reversal of the resistance of tumor cells expressing ABC transporters is combined use of anticancer drugs with chemosensitizers. In this review, the physiological functions and structures of ABC transporters, and the development of chemosensitizers are described focusing on well-known proteins including P-glycoprotein, multidrug resistance associated protein, and breast cancer resistance protein.

Identification of stable resistance to Phytophthora infestans in potato genotypes evaluated in field experiments in Peru

DEFF Research Database (Denmark)

Wulff, Ednar Gadelha; Pérez, W.; Nelson, R.J.

2007-01-01

Abstract: In this study, genotype by environment (G x E) interactions and phenotypic stability of resistance to Phytophthora infestans, the cause of late blight, were analysed in Peru lot 13 potato genotypes, using additive main effects and multiplicative interaction (AMMI) analysis and Huehn's non......-parametric test. The potato genotypes were tested in seven experiments over two years in the vicinity of Comas, Peru, an area used by the International potato Center to screen for resistance to late blight. Results of the two analyses generally correlated and indicated that quantitative resistance to P. infestans...

A maize resistance gene functions against bacterial streak disease in rice

OpenAIRE

Zhao, Bingyu; Lin, Xinghua; Poland, Jesse; Trick, Harold; Leach, Jan; Hulbert, Scot

2005-01-01

Although cereal crops all belong to the grass family (Poacea), most of their diseases are specific to a particular species. Thus, a given cereal species is typically resistant to diseases of other grasses, and this nonhost resistance is generally stable. To determine the feasibility of transferring nonhost resistance genes (R genes) between distantly related grasses to control specific diseases, we identified a maize R gene that recognizes a rice pathogen, Xanthomonas oryzae pv. oryzicola, wh...

Stable electroluminescence from passivated nano-crystalline porous silicon using undecylenic acid

Energy Technology Data Exchange (ETDEWEB)

Gelloz, B.; Sano, H.; Koshida, N. [Dept. Elec. and Elec. Eng., Tokyo Univ. of A and T, Koganei, Tokyo 184-8588 (Japan); Boukherroub, R. [Laboratoire de Physique de la Matiere Condensee, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau (France); Wayner, D.D.M.; Lockwood, D.J. [National Research Council, Ottawa (Canada)

2005-06-01

Stabilization of electroluminescence from nanocrystalline porous silicon diodes has been achieved by replacing silicon-hydrogen bonds terminating the surface of nanocrystalline silicon with more stable silicon-carbon (Si-C) bonds. Hydrosilylation of the surface of partially and anodically oxidized porous silicon samples was thermally induced at about 90 C using various different organic molecules. Devices whose surface have been modified with stable covalent bonds shows no degradation in the EL efficiency and EL output intensity under DC operation for several hours. The enhanced stability can be attributed to the high chemical resistance of Si-C bonds against current-induced surface oxidation associated with the generation of nonradiative defects. Although devices treated with 1-decene exhibit reduced EL efficiency and brightness compared to untreated devices, other molecules, such as ethyl-undecylenate and particularly undecylenic acid provide stable and more efficient visible electroluminescence at room temperature. Undecylenic acid provides EL brightness as high as that of an untreated device. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Metallization systems for stable ohmic contacts to GaAs

International Nuclear Information System (INIS)

Tandon, J.L.; Douglas, K.D.; Vendura, G.; Kolawa, E.; So, F.C.T.; Nicolet, M.A.

1986-01-01

A metallization scheme to form reproducible and stable ohmic contacts to GaAs is described. The approach is based on the configuration: GaAs/X/Y/Z; where X is a thin metal film (e.g. Pt, Ti, Pd, Ru), Y is an electrically conducting diffusion barrier layer (TiN, W or W/sub 0.7/N/sub 0.3/), and Z is a thick metal layer (e.g. Ag) typically required for bonding or soldering purposes. The value and reproducibility of the contact resistance in these metallization systems results from the uniform steady-state solid-phase reaction of the metal X with GaAs. The stability of the contacts is achieved by the diffusion barrier layer Y, which not only confines the reaction of X with GaAs, but also prevents the top metal layer Z from interfering with this reaction. Applications of such contacts in fabricating stable solar cells are also discussed

Development of a stable positive control to be used for quality assurance of rapid diagnostic tests for malaria

NARCIS (Netherlands)

Versteeg, Inge; Mens, Petra F.

2009-01-01

The objective of this study is to develop and evaluate a simple, cheap, and stable positive control for the quality control and quality assurance (QA) of rapid diagnostic tests (RDT) for the diagnosis of malaria. Plasmodium falciparum in vitro culture of known parasite concentrations was dried on a

Rugged Packaging for Damage Resistant Inertial Fusion Energy Optics

Energy Technology Data Exchange (ETDEWEB)

Stelmack, Larry

2003-11-17

The development of practical fusion energy plants based on inertial confinement with ultraviolet laser beams requires durable, stable final optics that will withstand the harsh fusion environment. Aluminum-coated reflective surfaces are fragile, and require hard overcoatings resistant to contamination, with low optical losses at 248.4 nanometers for use with high-power KrF excimer lasers. This program addresses the definition of requirements for IFE optics protective coatings, the conceptual design of the required deposition equipment according to accepted contamination control principles, and the deposition and evaluation of diamondlike carbon (DLC) test coatings. DLC coatings deposited by Plasma Immersion Ion Processing were adherent and abrasion-resistant, but their UV optical losses must be further reduced to allow their use as protective coatings for IFE final optics. Deposition equipment for coating high-performance IFE final optics must be designed, constructed, and operated with contamination control as a high priority.

Development and oviposition preference of house flies and stable flies (Diptera: Muscidae) in six substrates from Florida equine facilities

Science.gov (United States)

House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae), common pests on equine facilities, were studied in the laboratory to determine their oviposition preferences and larval development on six substrates commonly found on equine facilities. The substrates...

Development and first tests of GEM-like detectors with resistive electrodes

CERN Document Server

Peskov, Vladimir; Centro, Sandro; Di Mauro, A; Lund-Jensen, B; Martinengo, P; Nappi, E; Oliveira, R; Pietropaolo, F; Picchi, P; Periale, L; Rodionov, I; Ventura, Sandro

2007-01-01

We have developed and tested several prototypes of GEM-like detectors with electrodes coated with resistive layers or completely made of resistive materials. These detectors can operate stably at gains close to 105. The resistive layers limit the energy of discharges appearing at higher gains thus making the detectors very robust. We demonstrated that the cathodes of some of these detectors could be coated by CsI or SbCs layers to enhance the detection efficiency for the UV and visible photons. We also discovered that such detectors can operate stably in the cascade mode and high overall gains ($~10^{6}$) are reachable. Applications in several areas, for example in RICH or in noble liquid TPCs are therefore possible. The first results from the detection of UV photons at room and cryogenic temperatures will be given.

Low-resistivity C54-TiSi2 as a sidewall-confinement nanoscale electrode for three-dimensional vertical resistive memory

KAUST Repository

Duran Retamal, Jose Ramon; Kang, Chen-Fang; Yang, Po-Kang; Lee, Chuan-Pei; Lien, Der-Hsien; Ho, Chih-Hsiang; He, Jr-Hau

2014-01-01

A three-dimensional (3D) double-layer HfO2-based vertical-resistive random access memory (VRRAM) with low-resistivity C54-TiSi2 as horizontal electrodes is demonstrated using complementary metal-oxide semiconductor processing. The electrical measurements show bipolar resistive switching by using C54-TiSi2 as electrodes for resistive switching (RS) applications. The statistical analysis exhibits cycle-to-cycle and cell-to-cell stable non-volatile properties with robust endurance (100 cycles) and long term data retention (104s), suggesting that the ultrathin sidewall of C54-TiSi2 nanoscale electrodes serve to confine and stabilize the random nature of the conducting nanofilaments. The superior RS characteristics demonstrated here highlight the applicability of C54-TiSi2 sidewall-confinement nanoscale electrodes to VRRAM.

Low-resistivity C54-TiSi2 as a sidewall-confinement nanoscale electrode for three-dimensional vertical resistive memory

KAUST Repository

Duran Retamal, Jose Ramon

2014-11-03

A three-dimensional (3D) double-layer HfO2-based vertical-resistive random access memory (VRRAM) with low-resistivity C54-TiSi2 as horizontal electrodes is demonstrated using complementary metal-oxide semiconductor processing. The electrical measurements show bipolar resistive switching by using C54-TiSi2 as electrodes for resistive switching (RS) applications. The statistical analysis exhibits cycle-to-cycle and cell-to-cell stable non-volatile properties with robust endurance (100 cycles) and long term data retention (104s), suggesting that the ultrathin sidewall of C54-TiSi2 nanoscale electrodes serve to confine and stabilize the random nature of the conducting nanofilaments. The superior RS characteristics demonstrated here highlight the applicability of C54-TiSi2 sidewall-confinement nanoscale electrodes to VRRAM.

Influence of horse stable environment on human airways

Directory of Open Access Journals (Sweden)

Pringle John

2009-05-01

Full Text Available Abstract Background Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel. Methods The horse stable environment and stable-workers (n = 13 in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function. Results Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-β-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated. Conclusion Biomarkers involved in the development of airway diseases have been studied in relation to

Influence of horse stable environment on human airways.

Science.gov (United States)

Elfman, Lena; Riihimäki, Miia; Pringle, John; Wålinder, Robert

2009-05-25

Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel. The horse stable environment and stable-workers (n = 13) in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function. Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-beta-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated. Biomarkers involved in the development of airway diseases have been studied in relation to environmental exposure levels in equine stables. Respirable dust and 1

Enhanced Oxidation-Resistant Cu@Ni Core-Shell Nanoparticles for Printed Flexible Electrodes.

Science.gov (United States)

Kim, Tae Gon; Park, Hye Jin; Woo, Kyoohee; Jeong, Sunho; Choi, Youngmin; Lee, Su Yeon

2018-01-10

In this work, the fabrication and application of highly conductive, robust, flexible, and oxidation-resistant Cu-Ni core-shell nanoparticle (NP)-based electrodes have been reported. Cu@Ni core-shell NPs with a tunable Ni shell thickness were synthesized by varying the Cu/Ni molar ratios in the precursor solution. Through continuous spray coating and flash photonic sintering without an inert atmosphere, large-area Cu@Ni NP-based conductors were fabricated on various polymer substrates. These NP-based electrodes demonstrate a low sheet resistance of 1.3 Ω sq -1 under an optical energy dose of 1.5 J cm -2 . In addition, they exhibit highly stable sheet resistances (ΔR/R 0 flexible heater fabricated from the Cu@Ni film is demonstrated, which shows uniform heat distribution and stable temperature compared to those of a pure Cu film.

A study on heat resistance of high temperature resistant coating

Energy Technology Data Exchange (ETDEWEB)

Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu [Research Institute of Engineering Technology of CNPC, Tianjin (China)

2005-04-15

A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

A study on heat resistance of high temperature resistant coating

International Nuclear Information System (INIS)

Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu

2005-01-01

A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

Ampicillin resistance in Haemophilus influenzae from COPD patients in the UK

Directory of Open Access Journals (Sweden)

Maddi S

2017-05-01

Full Text Available Satyanarayana Maddi,1 Umme Kolsum,1 Sarah Jackson,1 Richard Barraclough,2 Barbara Maschera,3 Karen D Simpson,3 Thierry G Pascal,4 Serge Durviaux,4 Edith M Hessel,3 Dave Singh1 1Division of Infection, Immunity and Respiratory Medicine, Medicines Evaluation Unit, University Hospital of South Manchester Foundation Trust, University of Manchester, 2Department of Respiratory Medicine, University Hospital of South Manchester Foundation Trust, Manchester, 3Refractory Respiratory Inflammation DPU, GlaxoSmithKline Medicines Research Centre, Stevenage, Hertfordshire, UK; 4Clinical Laboratory Sciences, GlaxoSmithKline Vaccines, Wavre, Belgium Background: Haemophilus influenzae is commonly isolated from the airways of COPD patients. Antibiotic treatment may cause the emergence of resistant H. influenzae strains, particularly ampicillin-resistant strains, including β-lactamase-negative ampicillin resistance (BLNAR strains. Genetic identification using ftsI sequencing is the optimum method for identifying mutations within BLNAR strains. The prevalence of BLNAR in COPD patients during the stable state has not been reported. We investigated the antibiotic resistance patterns of H. influenzae present in the sputum of stable COPD patients, focusing on ampicillin resistance; the prevalence of enzyme and non-enzyme-mediated ampicillin resistance was determined. A subset of patients was followed up longitudinally to study H. influenzae strain switching and antibiotic sensitivity changes.Patients and methods: Sputum sampling was performed in 61 COPD patients, with 42 samples obtained at baseline; H. influenzae was detected by polymerase chain reaction in 28 samples. In all, 45 patients completed the follow-up for 2 years; 24 H. influenzae isolates were obtained.Results: Disk diffusion showed the highest antibiotic resistance in the penicillin antibiotic group (eg, 67% for ampicillin and macrolides (eg, 46% for erythromycin, whereas all isolates were susceptible to

The development of patterns of stable, transient, and school-age onset aggressive behavior in young children.

Science.gov (United States)

Kingston, L; Prior, M

1995-03-01

To examine the development of patterns of aggressive behavior in children from the age of 2 to 8 years. Children with early histories of aggressive behavior were selected from a community sample of 2,400 infants participating in a longitudinal study. The sample was divided into four groups: children with stable aggressive behavior, those with transient aggression, those with aggression only after age 5 years (late onset), and a comparison group of nonaggressive children. Children with stable aggressive behavior were characterized by a difficult temperament, hostile sibling interactions, maternal perception of the child as difficult, and harsher child-rearing practices. Children whose early aggression decreased over time and those who became aggressive only after entering school could not be reliably classified with the selected family variables. Teacher ratings of temperament factors of task orientation and reactivity and ability ratings correctly classified 74% of children whose aggression began at school-age. Children with persistent aggressive behavior differed from those who improved, predominantly in terms of symptom severity. Problems with aggression can be identified early in development, and a significant proportion of aggressive children are at risk for continuing social and scholastic difficulties. Knowledge of associated factors may play an important role in prevention.

Refusing Relevance: School Administrator Resistance to Offering Professional Development Addressing LGBTQ Issues in Schools

Science.gov (United States)

Payne, Elizabethe C.; Smith, Melissa J.

2018-01-01

Purpose: The purpose of this article is to provide insight to the multiple ways that school leaders resist, avoid, or block LGBTQ (lesbian, gay, bisexual, and transgender, queer, and questioning) professional development for their staff and, thus, resist the conversations around school responsibility to these students and families. Research…

The Effect of Surface Patterning on Corrosion Resistance of Biomedical Devices

Science.gov (United States)

Guo, Mengnan; Toloei, Alisina; Rotermund, Harm H.

2016-10-01

In this study, two styles of surface topographies have been created on stainless steel wires to test their corrosion resistance as simulated implanted biomedical devices. Grade 316 LVM stainless steel wire was initially polished to G1500 surface finish before treatment to produce the two different topographies: 1. Unidirectional roughness was created using SiC papers and 2. Various patterns were created with specific hole diameter and inter-hole spacing using focused ion beam (FIB). In order to simulate the environment of implanted biomedical devices, a three-electrode electrochemical cell with 0.9% (by mass) NaCl solution has been used to test the corrosion resistance of the samples by potentiodynamic polarization test method. SEM and EDS analyzed the appearance and chemical composition of different elements including oxygen on the surface. The potential of stable pitting, time related to the initiation of the stable pitting, and the highest corrosion current associated with stable pitting have been compared for samples with the two styles of topography. It was found that surfaces with patterns have a relatively higher pitting potential and it takes longer time to initiate stable pitting than the surface without any patterns.

Infection of inbred rat strains with Rift Valley fever virus: development of a congenic resistant strain and observations on age-dependence of resistance.

Science.gov (United States)

Anderson, G W; Rosebrock, J A; Johnson, A J; Jennings, G B; Peters, C J

1991-05-01

A congenic rat strain (WF.LEW) was derived from the susceptible Wistar-Furth (WF) (background strain) and the resistant LEW (donor strain) inbred strains and was used to evaluate the phenotypic expression of a dominant Mendelian gene that confers resistance to fatal hepatic disease caused by the ZH501 strain of Rift Valley fever virus (RVFV). Resistance to hepatic disease developed gradually with age, with full expression at approximately 10 weeks in the WF.LEW and LEW rat strains. The ZH501 strain caused fatal hepatitis in WF rats regardless of age. However, resistance to the SA75 RVFV strain (relatively non-pathogenic for adult rats), was age- and dose-dependent in both WF and LEW rats. The resistance gene transferred to the newly derived WF.LEW congenic rat strain appears to amplify age-dependent resistance of adult rats, resulting in protection against fatal hepatic disease caused by the virulent ZH501 strain. The congenic rat strain will be a valuable asset in elucidating the mechanism of resistance to Rift Valley fever virus governed by the dominant Mendelian gene.

In vitro development of resistance to enrofloxacin, erythromycin, tylosin, tiamulin and oxytetracycline in Mycoplasma gallisepticum, Mycoplasma iowae and Mycoplasma synoviae.

Science.gov (United States)

Gautier-Bouchardon, A V; Reinhardt, A K; Kobisch, M; Kempf, I

2002-08-02

The in vitro emergence of resistance to enrofloxacin, erythromycin, tylosin, tiamulin, and oxytetracycline in three avian Mycoplasma species, Mycoplasma gallisepticum, Mycoplasma synoviae and Mycoplasma iowae was studied. Mutants were selected stepwise and their MICs were determined after 10 passages in subinhibitory concentrations of antibiotic. High-level resistance to erythromycin and tylosin developed within 2-6 passages in the three Mycoplasma species. Resistance to enrofloxacin developed more gradually. No resistance to tiamulin or oxytetracycline could be evidenced in M. gallisepticum or M. synoviae after 10 passages whereas, resistant mutants were obtained with M. iowae. Cross-sensitivity tests performed on mutants demonstrated that mycoplasmas made resistant to tylosin were also resistant to erythromycin, whereas mutants made resistant to erythromycin were not always resistant to tylosin. Some M. iowae tiamulin-resistant mutants were also resistant to both macrolide antibiotics. Enrofloxacin and oxytetracycline did not induce any cross-resistance to the other antibiotics tested. These results show that Mycoplasma resistance to macrolides can be quickly selected in vitro, and thus, providing that similar results could be obtained under field conditions, that development of resistance to these antibiotics in vivo might also be a relatively frequent event.

Development of advanced metallic coatings resistant to corrosion in high temperature industrial atmospheres

Energy Technology Data Exchange (ETDEWEB)

Weber, T.; Bender, R.; Rosado, C.; Schuetze, M. [DECHEMA e.V., Frankfurt am Main (Germany)

2004-07-01

Following the experimental results that {gamma}-TiAl is highly resistant in reducing sulfidizing atmospheres the development of Ti-Al-co-diffusion coatings produced in a single step pack cementation process was started. The appropriate diffusion powder compositions were selected using thermodynamical calculations. Different Al-Ti-, Al-Si- and Al-Ti-Si-diffusion coatings were successfully applied on austenitic steels as well as Ni-base materials and showed excellent behaviour in reducing sulfidizing atmospheres with high carbon contents (CH{sub 4} - 1% CO - 1% CO{sub 2} - 10% H{sub 2} - 7% H{sub 2}S) up to 700 deg. C, under metal dusting conditions (H{sub 2} - 25 CO - 2% H{sub 2}O and CO - 2.4% CO{sub 2} - 1% CH{sub 4} - 9.4% N{sub 2} - 23.4% H{sub 2} - 0.2% H{sub 2}O - 1 ppm H{sub 2}S-0.3 ppm HCl) at temperatures of 620 deg. C and 700 deg. C. The application of diffusion coatings on ferritic materials has to be modified due to the specific requirements on the mechanical properties which are affected by the heat treatment during the diffusion process. TiAl was also applied by the HVOF thermal spray method on ferritic steels. Due to similarity of the thermal expansion coefficients this substrate-coating system proved to be mechanically very stable also under thermal cycling conditions. (authors)

Development of Acid Resistance Velocity Sensor for Analyzing Acidic Fluid Flow Characteristics

Energy Technology Data Exchange (ETDEWEB)

Choi, Gyujin; Yoon, Jinwon; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

2016-10-15

This study presents the development of an acid resistance velocity sensor that is used for measuring velocity inside a copper sulfate plating bath. First, researchers investigated the acid resistance coating to confirm the suitability of the anti-acid sensor in a very corrosive environment. Then, researchers applied signal processing methods to reduce noise and amplify the signal. Next, researchers applied a pressure-resistive sensor with an operation amplifier (Op Amp) and low-pass filter with high impedance to match the output voltage of a commercial flowmeter. Lastly, this study compared three low-pass filters (Bessel, Butterworth and Chebyshev) to select the appropriate signal process circuit. The results show 0.0128, 0.0023, and 5.06% of the mean square error, respectively. The Butterworth filter yielded more precise results when compared to a commercial flowmeter. The acid resistive sensor is capable of measuring velocities ranging from 2 to 6 m/s with a 2.7% margin of error.

Metabolic studies in man using stable isotopes

International Nuclear Information System (INIS)

Faust, H.; Jung, K.; Krumbiegel, P.

1993-01-01

In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15 N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15 N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15 N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

Susceptibility to neonicotinoids and risk of resistance development in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

Science.gov (United States)

Wang, Yanhua; Chen, Jin; Zhu, Yu Cheng; Ma, Chongyong; Huang, Yue; Shen, Jinliang

2008-12-01

In recent years, outbreaks of the brown planthopper, Nilaparvata lugens (Stål), have occurred more frequently in China. The objective of this study was to determine the susceptibility of N. lugens to neonicotinoids and other insecticides in major rice production areas in China. Results indicated that substantial variations in the susceptibility to different insecticides existed in N. lugens. Field populations had developed variable resistance levels to neonicotinoids, with a high resistance level to imidacloprid (RR: 135.3-301.3-fold), a medium resistance level to imidaclothiz (RR: 35-41.2-fold), a low resistance level to thiamethoxam (up to 9.9-fold) and no resistance to dinotefuran, nitenpyram and thiacloprid (RR buprofezin. In addition, N. lugens had been able to develop 1424-fold resistance to imidacloprid in the laboratory after the insect was selected with imidacloprid for 26 generations. Long-term use of imidacloprid in a wide range of rice-growing areas might be associated with high levels of resistance in N. lugens. Therefore, insecticide resistance management strategies must be developed to prevent further increase in resistance.

The role of oxidative stress in the development of cisplatin resistance in epithelial ovarian cancer.

Science.gov (United States)

Belotte, Jimmy; Fletcher, Nicole M; Awonuga, Awoniyi O; Alexis, Mitchell; Abu-Soud, Husam M; Saed, Mohammed G; Diamond, Michael P; Saed, Ghassan M

2014-04-01

To investigate the role of oxidative stress in the development of cisplatin resistance in epithelial ovarian cancer (EOC). Two parent EOC cell lines (MDAH-2774 and SKOV-3) and their chemoresistant counterparts (cisplatin, 50 µmol/L) were used. Total RNA was extracted and subjected to real-time reverse transcriptase polymerase chain reaction to evaluate the expression of glutathione reductase (GSR) and inducible nitric oxide synthase (iNOS), as well as nitrate/nitrite levels. Analysis of variance was used for main effects and Tukey for post hoc analysis at P nitrate/nitrite levels were significantly higher in SKOV-3 cisplatin resistant cells while iNOS mRNA levels were significantly higher in MDAH-2774 cisplatin resistant cells (P < .05). Our data suggest that the development of cisplatin resistance tilts the balance toward a pro-oxidant state in EOC.

In Vitro Development of Ciprofloxacin Resistance of Salmonella enterica Serovars Typhimurium, Enteritidis, and Indiana Isolates from Food Animals.

Science.gov (United States)

Zhang, Wen-Hui; Zhang, Chuan-Zhen; Liu, Zhi-Jie; Gu, Xi-Xi; Li, Wan; Yang, Ling; Liu, Ya-Hong; Zeng, Zhen-Ling; Jiang, Hong-Xia

2017-09-01

Difference in the development of resistance may be associated with the epidemiological spread and drug resistance of different Salmonella enterica serovar strains. In the present study, three susceptible S. enterica serovars, Typhimurium (ST), Enteritidis (SE), and Indiana (SI) strains, were subjected to stepwise selection with increasing ciprofloxacin concentrations. The results indicated that the mutation frequencies of the SI group were 10 1 -10 4 higher and developed resistance to ciprofloxacin more rapidly compared with the ST and SE groups. Ciprofloxacin accumulation in the SI strain was also higher than the other two strains in the presence of an efflux pump inhibitor. The development of ciprofloxacin resistance was quite different among the three serovar strains. In SI, increasing AcrAB-TolC efflux pump expression and single or double mutations in gyrA with or without a single parC mutation (T57S) were found in the development of ciprofloxacin resistance. In SE, an increase in the AcrAB-TolC efflux pump regulatory gene ramA gradually decreased as resistant bacteria developed; then resistance resulted from gyrA D87G and gyrB E466D mutations and/or in other active efflux pumps besides AcrAB-TolC. For ST, ramA expression increased rapidly along with gyrA D87 N and/or gyrB S464F mutations. In conclusion, persistent use of ciprofloxacin may aggravate the resistance of different S. enterica serovars and prudent use of the fluoroquinolones is needed. The quicker resistance and higher mutation frequency of the SI isolates present a potential public health threat.

Oxidation resistant high creep strength austenitic stainless steel

Science.gov (United States)

Brady, Michael P.; Pint, Bruce A.; Liu, Chain-Tsuan; Maziasz, Philip J.; Yamamoto, Yukinori; Lu, Zhao P.

2010-06-29

An austenitic stainless steel displaying high temperature oxidation and creep resistance has a composition that includes in weight percent 15 to 21 Ni, 10 to 15 Cr, 2 to 3.5 Al, 0.1 to 1 Nb, and 0.05 to 0.15 C, and that is free of or has very low levels of N, Ti and V. The alloy forms an external continuous alumina protective scale to provide a high oxidation resistance at temperatures of 700 to 800.degree. C. and forms NbC nanocarbides and a stable essentially single phase fcc austenitic matrix microstructure to give high strength and high creep resistance at these temperatures.

Development of Antibiotic Resistance Against Ureaplasma urealyticum Strains Isolated from Urogenital Samples

Directory of Open Access Journals (Sweden)

Musa Saraçoğlu

2018-04-01

Full Text Available Objective: To assess any change in the antibiotic sensitivity of Ureaplasma urealyticum strains isolated from urogenital samples in the course of time. Materials and Methods: Hospital records were retrospectively examined and cases with growth of U. urealyticum in urogenital samples in the years 2008 and 2013 were identified. Furthermore, the change in the course of time was examined by taking into consideration the cases we reported in 2001. Results: Higher rates of sensitivity against tetracycline and doxycycline were observed in 60 patients with isolated U. urealyticum. Higher rates of resistance against ofloxacin and ciprofloxacin were observed. A significant difference was found in resistance against antibiotics when the records of 2008 and 2013 were compared. A statistically significant increase was found in resistance against ofloxacin and ciprofloxacin when the records of 2001 were compared with the records of 2008 and 2013 (p<0.0005. Conclusion: U. urealyticum strains demonstrated high levels of resistance to quinolones. Resistance development is increasing in the course of time. Sensitivity against tetracycline and doxycycline has continued at high rates. It would be beneficial to consider these results during empirical treatment to be applied in cases ineligible for culturing.

Corrosion resistance of high-performance materials titanium, tantalum, zirconium

CERN Document Server

2012-01-01

Corrosion resistance is the property of a material to resist corrosion attack in a particular aggressive environment. Although titanium, tantalum and zirconium are not noble metals, they are the best choice whenever high corrosion resistance is required. The exceptionally good corrosion resistance of these high–performance metals and their alloys results from the formation of a very stable, dense, highly adherent, and self–healing protective oxide film on the metal surface. This naturally occurring oxide layer prevents chemical attack of the underlying metal surface. This behavior also means, however, that high corrosion resistance can be expected only under neutral or oxidizing conditions. Under reducing conditions, a lower resistance must be reckoned with. Only very few inorganic and organic substances are able to attack titanium, tantalum or zirconium at ambient temperature. As the extraordinary corrosion resistance is coupled with an excellent formability and weldability these materials are very valua...

Development of 25 near-isogenic lines (NILs) with ten BPH resistance genes in rice (Oryza sativa L.): production, resistance spectrum, and molecular analysis.

Science.gov (United States)

Jena, Kshirod K; Hechanova, Sherry Lou; Verdeprado, Holden; Prahalada, G D; Kim, Sung-Ryul

2017-11-01

A first set of 25 NILs carrying ten BPH resistance genes and their pyramids was developed in the background of indica variety IR24 for insect resistance breeding in rice. Brown planthopper (Nilaparvata lugens Stal.) is one of the most destructive insect pests in rice. Development of near-isogenic lines (NILs) is an important strategy for genetic analysis of brown planthopper (BPH) resistance (R) genes and their deployment against diverse BPH populations. A set of 25 NILs with 9 single R genes and 16 multiple R gene combinations consisting of 11 two-gene pyramids and 5 three-gene pyramids in the genetic background of the susceptible indica rice cultivar IR24 was developed through marker-assisted selection. The linked DNA markers for each of the R genes were used for foreground selection and confirming the introgressed regions of the BPH R genes. Modified seed box screening and feeding rate of BPH were used to evaluate the spectrum of resistance. BPH reaction of each of the NILs carrying different single genes was variable at the antibiosis level with the four BPH populations of the Philippines. The NILs with two- to three-pyramided genes showed a stronger level of antibiosis (49.3-99.0%) against BPH populations compared with NILs with a single R gene NILs (42.0-83.5%) and IR24 (10.0%). Background genotyping by high-density SNPs markers revealed that most of the chromosome regions of the NILs (BC 3 F 5 ) had IR24 genome recovery of 82.0-94.2%. Six major agronomic data of the NILs showed a phenotypically comparable agronomic performance with IR24. These newly developed NILs will be useful as new genetic resources for BPH resistance breeding and are valuable sources of genes in monitoring against the emerging BPH biotypes in different rice-growing countries.

Resistance training intensity and volume affect changes in rate of force development in resistance-trained men.

Science.gov (United States)

Mangine, Gerald T; Hoffman, Jay R; Wang, Ran; Gonzalez, Adam M; Townsend, Jeremy R; Wells, Adam J; Jajtner, Adam R; Beyer, Kyle S; Boone, Carleigh H; Miramonti, Amelia A; LaMonica, Michael B; Fukuda, David H; Ratamess, Nicholas A; Stout, Jeffrey R

2016-12-01

To compare the effects of two different resistance training programs, high intensity (INT) and high volume (VOL), on changes in isometric force (FRC), rate of force development (RFD), and barbell velocity during dynamic strength testing. Twenty-nine resistance-trained men were randomly assigned to either the INT (n = 15, 3-5 RM, 3-min rest interval) or VOL (n = 14, 10-12 RM, 1-min rest interval) training group for 8 weeks. All participants completed a 2-week preparatory phase prior to randomization. Measures of barbell velocity, FRC, and RFD were performed before (PRE) and following (POST) the 8-week training program. Barbell velocity was determined during one-repetition maximum (1RM) testing of the squat (SQ) and bench press (BP) exercises. The isometric mid-thigh pull was used to assess FRC and RFD at specific time bands ranging from 0 to 30, 50, 90, 100, 150, 200, and 250 ms. Analysis of covariance revealed significant (p velocity. Results indicate that INT is more advantageous than VOL for improving FRC and RFD, while changes in barbell velocity during dynamic strength testing are similarly improved by both protocols in resistance-trained men.

Dietary components in the development of leptin resistance.

Science.gov (United States)

Vasselli, Joseph R; Scarpace, Philip J; Harris, Ruth B S; Banks, William A

2013-03-01

Classically, leptin resistance has been associated with increased body fat and circulating leptin levels, and the condition is believed to contribute to the onset and/or maintenance of obesity. Although a great deal is known about the central nervous system mechanisms mediating leptin resistance, considerably less is known about the role of diet in establishing and maintaining this altered hormonal state. An exciting new finding has recently been published demonstrating the existence of leptin resistance in normal-weight rats with lean leptin levels by feeding them a high-concentration-fructose diet. This finding has opened the possibility that specific macronutrients may be capable of inducing leptin resistance, independently of the amount of body fat or circulating leptin present in the treated animals. This review describes several lines of research that have recently emerged indicating that specific types of dietary sugars and fats are capable of inducing leptin resistance in experimental rodent models. The results further show that diet-induced leptin resistance is capable of increasing energy intake and elevating body weight gain under appropriate dietary challenges. It appears that biological mechanisms on multiple levels may underlie the dietary induction of leptin resistance, including alterations in the leptin blood-to-brain transport system, in peripheral glucose metabolism, and in central leptin receptor signaling pathways. What is clear from the findings reviewed here is that diet-induced leptin resistance can occur in the absence of elevated circulating leptin levels and body weight, rendering it a potential cause and/or predisposing factor to excess body weight gain and obesity.

NethMap 2017: Consumption of antimicrobial agents and antimicrobial resistance among medically important bacteria in the Netherlands / MARAN 2017: Monitoring of antimicrobial resistance and antibiotic usage in animals in the Netherlands in 2016

NARCIS (Netherlands)

de Greeff SC; Mouton JW; ZIA; I&V

2017-01-01

The number of bacteria that are resistant to antimicrobials is increasing worldwide. In the Netherlands, the number of resistant bacteria that can cause infections in humans has remained broadly stable. Nevertheless there is cause for concern and caution. Compared to 2015, in 2016 more 'outbreaks'

Aquaculture as yet another environmental gateway to the development and globalisation of antimicrobial resistance.

Science.gov (United States)

Cabello, Felipe C; Godfrey, Henry P; Buschmann, Alejandro H; Dölz, Humberto J

2016-07-01

Aquaculture uses hundreds of tonnes of antimicrobials annually to prevent and treat bacterial infection. The passage of these antimicrobials into the aquatic environment selects for resistant bacteria and resistance genes and stimulates bacterial mutation, recombination, and horizontal gene transfer. The potential bridging of aquatic and human pathogen resistomes leads to emergence of new antimicrobial-resistant bacteria and global dissemination of them and their antimicrobial resistance genes into animal and human populations. Efforts to prevent antimicrobial overuse in aquaculture must include education of all stakeholders about its detrimental effects on the health of fish, human beings, and the aquatic ecosystem (the notion of One Health), and encouragement of environmentally friendly measures of disease prevention, including vaccines, probiotics, and bacteriophages. Adoption of these measures is a crucial supplement to efforts dealing with antimicrobial resistance by developing new therapeutic agents, if headway is to be made against the increasing problem of antimicrobial resistance in human and veterinary medicine. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stable MoS2 Field-Effect Transistors Using TiO2 Interfacial Layer at Metal/MoS2 Contact

KAUST Repository

Park, Woojin; Min, Jung-Wook; Shaikh, Sohail F.; Hussain, Muhammad Mustafa

2017-01-01

dioxide (TiO2) interfacial layer between contact metal and MoS2 channel is suggested to achieve more stable performances. The reduced threshold voltage (VTH) shift and reduced series resistance (RSD) were simultaneously achieved.

Development of safe and shelf-stable Intermediate Moisture (IM) convenience meat products through radiation processing

International Nuclear Information System (INIS)

Ramesh Chander; Kanatt, S.R.; Chawla, S.P.; Bongirwar, D.R.

2001-01-01

Ready-to-use shelf stable mutton and chicken sheek kababs, and chicken chilly were developed by reducing the water activity either by grilling or by hot air drying, vacuum packing and irradiation. Microbiological analysis revealed a dose dependent reduction in total viable count and in Staphylococcus species on irradiation treatment ( 2.5, 5.0 and 10.0 kGy). The products subjected to irradiation at 10 kGy showed absence of viable micro-organisms and also had high sensory acceptability up to 9 months at ambient temperature. (author)

Myocardial perfusion SPECT in stable angina;Place de la scintigraphie myocardique dans l'angor stable

Energy Technology Data Exchange (ETDEWEB)

Jau, P.; Jacob, T. [HP Clairval, Service de medecine nucleaire, 13 - Marseille (France); Lecorff, G.; Bouvier, J.L.; Novella, P.; Bechet, V.; Pelet, V. [HP Clairval, Service de cardiologie, 13 - Marseille (France)

2010-03-15

We study the precise contribution of myocardial scintigraphy in the therapeutic management of stable coronary artery disease. Until recently, treatment was focused on revascularization, often by coronary angioplasty.Recent studies have challenged this practice by showing the absence of superiority of angioplasty compared to optimal medical therapy.The problem now is to define for each stable coronary artery disease, and individually, the best of both treatment options. In this spirit, the functional approach to coronary artery disease by myocardial perfusion scintigraphy is most interesting.The diagnostic performance, including sensitivity and negative predictive value, and the prognostic value of the technique are clearly established. Recent studies show that a therapeutic decision based on a functional approach to the patient is valid.We need to know this development in cardiology for best position in the multidisciplinary discussions, myocardial scintigraphy as a functional approach to stable coronary artery disease. (N.C.)

Development of a microprocessor-controlled coulometric system for stable ph control

NARCIS (Netherlands)

Bergveld, Piet; van der Schoot, B.H.

1983-01-01

The coulometric pH control system utilizes a programmable coulostat for controlling the pH of a certain volume of unbuffered solution. Based on theoretical considerations, conditions are established which guarantee stable operation with maximum suppression of disturbances from the dissolution of

Interplay between Lipids and Branched-Chain Amino Acids in Development of Insulin Resistance

OpenAIRE

Newgard, Christopher B.

2012-01-01

Fatty acids (FA) and FA-derived metabolites have long been implicated in the development of insulin resistance and type 2 diabetes. Surprisingly, application of metabolomics technologies has revealed that branched-chain amino acids (BCAA) and related metabolites are more strongly associated with insulin resistance than many common lipid species. Moreover, the BCAA-related signature is predictive of incident diabetes and intervention outcomes, and uniquely responsive to therapeutic interventio...

Development of a leak detection system using high temperature-resistant microphones

International Nuclear Information System (INIS)

Morishita, Yoshitsugu; Mochizuki, Hiroyasu; Watanabe, Kenshiu; Nakamura, Takahisa; Nakajima, Yoshiaki; Yamauchi, Tatsuya

1991-01-01

This report describes the development of a detection system of coolant leak from an inlet feeder pipe of an Advanced Thermal Reactor (ATR) with high temperature-resistant microphones. A microphone having resistance to both high temperature and high radiation dose has been developed at first. The characteristics with regard to leakage sound, attenuation of sound level in a heat insulating box for the inlet feeder pipes and background noise were clarified by laboratory experiments and measurements in the prototype ATR 'Fugen'. On the basis of these experimental findings, appropriate frequency ranges were surveyed to detect the leakage sound with a high S/N ratio under the background noise. Reliability of the system to a malfunction caused by burst-type noises observed in the plant was also investigated by statistical analyses. Finally, it was confirmed that the present method could detect a leak within a couple of seconds. (author)

Early and late rate of force development: differential adaptive responses to resistance training?

DEFF Research Database (Denmark)

Andersen, L L; Andersen, Jesper Løvind; Zebis, M K

2010-01-01

The objective of this study is to investigate the potentially opposing influence of qualitative and quantitative muscular adaptations in response to high-intensity resistance training on contractile rate of force development (RFD) in the early (200 ms) of rising muscle force. Fifteen healthy young......-intensity resistance training due to differential influences of qualitative and quantitative muscular adaptations on early and later phases of rising muscle force....... males participated in a 14-week resistance training intervention for the lower body and 10 matched subjects participated as controls. Maximal muscle strength (MVC) and RFD were measured during maximal voluntary isometric contraction of the quadriceps femoris muscle. Muscle biopsies were obtained from...

[Progress in stable isotope labeled quantitative proteomics methods].

Science.gov (United States)

Zhou, Yuan; Shan, Yichu; Zhang, Lihua; Zhang, Yukui

2013-06-01

Quantitative proteomics is an important research field in post-genomics era. There are two strategies for proteome quantification: label-free methods and stable isotope labeling methods which have become the most important strategy for quantitative proteomics at present. In the past few years, a number of quantitative methods have been developed, which support the fast development in biology research. In this work, we discuss the progress in the stable isotope labeling methods for quantitative proteomics including relative and absolute quantitative proteomics, and then give our opinions on the outlook of proteome quantification methods.

Mutants of Aspergillus nidulans with increased resistance to the alkylating agent, N-methyl-N'-nitro-N-nitrosoguanidine.

Science.gov (United States)

Hooley, P; Shawcross, S G; Strike, P

1988-05-01

The isolation and characterisation of mutants of Aspergillus nidulans showing resistance to MNNG is described. Such isolates were stable through prolonged subculture in the absence of the selective agent, and resistance segregated as an allele of a single gene in meiotic and mitotic analysis. MNNG-resistant strains showed an increase in resistance to EMS and UV irradiation but no cross-resistance to MMS was detected. Possible mechanisms of resistance to alkylating agents are discussed.

Rigidity in routines and the development of resistance to change in individuals with Prader-Willi syndrome.

Science.gov (United States)

Haig, E L; Woodcock, K A

2017-05-01

Individuals with Prader-Willi syndrome (PWS) commonly show debilitating resistance to change, which has been linked to cognitive deficits in task switching. Anecdotal reports suggest that exposure to flexibility in routines during development may be beneficial for limiting subsequent resistance to change in people with PWS, which is consistent with a beneficial role of such exposure on the development of task switching, highlighted in typical children. Here, we aim to investigate the development of resistance to change in individuals with PWS and hypothesise that exposure to increased rigidity in routines will be associated with increased subsequent resistance to change. An author-compiled informant report interview and two previously validated questionnaires were administered to the caregivers of 10 individuals with PWS (5-23 years). The interview examined rigidity in routines and resistance to change across life stages defined by easily distinguishable events (before school, during primary school, during secondary school, after school, currently), using open-ended and structured yes/no and 5-point Likert questions. Open-ended data were coded using an author-compiled system. Responses from two additional informants and data from the questionnaires were used to assess inter-informant reliability and concurrent validity of the structured questions. The validity of the interview was supported by acceptable inter-rater reliability of the open-ended coding system and inter-informant reliability, internal consistency and concurrent validity of structured questions. Descriptive analyses of ratings of behaviour change showed a pattern of increasing resistance to change over the life course for the four oldest individuals, who had all been exposed to substantial rigidity in routines before and during primary school. Furthermore, only one individual - currently in primary school - was exposed to very little rigidity in routines before and during primary school, and he had

Stable and low contact resistance electrical contacts for high temperature SiGe thermoelectric generators

KAUST Repository

Zhang, Bo

2018-04-14

The thermal stability and contact resistance of TaAlN thin films as electrical contacts to SiGe thermoelectric elements are reported. We demonstrate that a sharp interface is maintained after the device annealed at 800°C for over 100h, indicating that no interdiffusion takes place between TaAlN and SiGe. A specific contact resistivity of (2.1±1.3)×10−6Ω-cm2 for p-type SiGe and (2.8±1.6)×10−5 Ω-cm2 for n-type SiGe is demonstrated after the high temperature annealing. These results show that TaAlN is a promising contact material for high temperature thermoelectrics such as SiGe.

Rapid on-site evaluation of the development of resistance to quinone outside inhibitors in Botrytis cinerea.

Science.gov (United States)

Hu, X R; Dai, D J; Wang, H D; Zhang, C Q

2017-10-24

Botrytis cinerea, a typical "high-risk" pathogenic fungus that rapidly develops resistance to fungicides, affects more than 1,000 species of 586 plant genera native to most continents and causes great economic losses. Therefore, a rapid and sensitive assay of fungicide resistance development in B. cinerea populations is crucial for scientific management. In this study, we established a Loop-mediated isothermal amplification (LAMP) system for the monitoring and evaluation of the risk of development of B. cinerea resistance to QoI fungicides; the method uses two LAMP assays. The first assay detects G143A mutants of B. cinerea, which are highly resistance to QoI fungicides. BCbi143/144 introns in B. cinerea are then detected by the second assay. HNB acts as a visual LAMP reaction indicator. The optimum reaction conditions of the LAMP assays were 61 °C for 50 min, and the detection limit of the LAMP assays was 100 × 10 -4  ng/μl. We directly pre-treated the field samples by using All-DNA-Fast-Out to extract DNA within ten minutes, then performed the LAMP assay to achieve one-step rapid detection. In conclusion, we established a rapid and sensitive LAMP assay system for resistance risk assessment and for monitoring QoI-resistance of B. cinerea in the field.

Re-Inventing Infectious Disease: Antibiotic Resistance and Drug Development at the Bayer Company 1945-80.

Science.gov (United States)

Gradmann, Christoph

2016-04-01

This paper analyses how research on antibiotic resistance has been a driving force in the development of new antibiotics. Drug resistance, while being a problem for physicians and patients, offers attractive perspectives for those who research and develop new medicines. It imposes limits on the usability of older medicines and simultaneously modifies pathologies in a way that opens markets for new treatments. Studying resistance can thus be an important part of developing and marketing antibiotics. The chosen example is that of the German pharmaceutical company Bayer. Before World War Two, Bayer had pioneered the development of anti-infective chemotherapy, sulpha drugs in particular, but had missed the boat when it came to fungal antibiotics. Exacerbated by the effects of war, Bayer's world market presence, which had been considerable prior to the war, had plummeted. In this critical situation, the company opted for a development strategy that tried to capitalise on the problems created by the use of first-generation antibiotics. Part and parcel of this strategy was monitoring what can be called the structural change of infectious disease. In practice, this meant to focus on pathologies resulting from resistance and hospital infections. In addition, Bayer also focused on lifestyle pathologies such as athlete's foot. This paper will follow drug development and marketing at Bayer from 1945 to about 1980. In this period, Bayer managed to regain some of its previous standing in markets but could not escape from the overall crisis of anti-infective drug development from the 1970s on.

Recapitulation of physiological spatiotemporal signals promotes in vitro formation of phenotypically stable human articular cartilage

Science.gov (United States)

Wei, Yiyong; Zhou, Bin; Bernhard, Jonathan; Robinson, Samuel; Burapachaisri, Aonnicha; Guo, X. Edward

2017-01-01

Standard isotropic culture fails to recapitulate the spatiotemporal gradients present during native development. Cartilage grown from human mesenchymal stem cells (hMSCs) is poorly organized and unstable in vivo. We report that human cartilage with physiologic organization and in vivo stability can be grown in vitro from self-assembling hMSCs by implementing spatiotemporal regulation during induction. Self-assembling hMSCs formed cartilage discs in Transwell inserts following isotropic chondrogenic induction with transforming growth factor β to set up a dual-compartment culture. Following a switch in the basal compartment to a hypertrophic regimen with thyroxine, the cartilage discs underwent progressive deep-zone hypertrophy and mineralization. Concurrent chondrogenic induction in the apical compartment enabled the maintenance of functional and hyaline cartilage. Cartilage homeostasis, chondrocyte maturation, and terminal differentiation markers were all up-regulated versus isotropic control groups. We assessed the in vivo stability of the cartilage formed under different induction regimens. Cartilage formed under spatiotemporal regulation in vitro resisted endochondral ossification, retained the expression of cartilage markers, and remained organized following s.c. implantation in immunocompromised mice. In contrast, the isotropic control groups underwent endochondral ossification. Cartilage formed from hMSCs remained stable and organized in vivo. Spatiotemporal regulation during induction in vitro recapitulated some aspects of native cartilage development, and potentiated the maturation of self-assembling hMSCs into stable and organized cartilage resembling the native articular cartilage. PMID:28228529

Development and partial metabolic characterization of a dietary cholesterol-resistant colony of rabbits

International Nuclear Information System (INIS)

Overturf, M.L.; Smith, S.A.; Hewett-Emmett, D.; Loose-Mitchell, D.S.; Soma, M.R.; Gotto, A.M. Jr.; Morrisett, J.D.

1989-01-01

A colony of New Zealand white rabbits has been developed which, when fed a cholesterol-supplemented diet, exhibit unusual resistance to hypercholesterolemia and atherosclerosis, disorders usually observed in normal cholesterol-fed rabbits. When resistant rabbits (RT) were fed a normal low cholesterol diet (ND), their plasma lipoprotein patterns were significantly different from those of normal rabbits (NR) fed the same diet. The low density lipoprotein cholesterol (LDL-c)/high density lipoprotein cholesterol (HDL-c) ratio and LDL-c/very low density lipoprotein cholesterol (VLDL-c) ratio were lower in the resistant rabbits. The hydrated density of HDL of the normal-responsive rabbits was greater than that of the resistant rabbits. LDL from resistant rabbits contained a lower proportion of esterified cholesterol and protein than LDL from normal rabbits. Peripheral mononuclear cells from resistant rabbits bound about 30% more 125 I-labeled rabbit LDL than mononuclear cells from normal rabbits. These results demonstrate that the plasma cholesterol levels of these animals is at least partly under genetic control and that compositional differences exist between the major plasma lipoprotein classes of normal and resistant rabbits even during the ingestion of low-cholesterol diet. The results indicate that at least a part of the difference in the cholesterolemic responses between the two rabbit groups is due to an enhanced LDL uptake by the mononuclear cells, and presumably by other somatic cells of the resistant group

Theory of resistive magnetohydrodynamic instabilities excited by energetic trapped particles in large-size tokamaks

International Nuclear Information System (INIS)

Biglari, H.

1987-01-01

A theory describing excitation of resistive magnetohydrodynamic instabilities due to a population of energetic particles, trapped in region of adverse curvature on energetic particles, trapped in region of adverse curvature in tokamaks, is presented. Theory's principal motivation is observation that high magnetic-field strengths and large geometric dimensions characteristic of present-generation thermonuclear fusion devices, places them in a frequency regime whereby processional drift frequency of auxiliary hot-ion species, in order of magnitude, falls below a typical inverse resistive interchange time scale, so that inclusion of resistive dissipation effects becomes important. Destabilization of the resistive internal kink mode by these suprathermal particles is first investigated. Using variational techniques, a generalized dispersion relation governing such modes, which recovers ideal theory in its appropriate limit, is derived and analyzed using Nyquist-diagrammatic techniques. An important implication of theory for present-generation fusion devices is that they will be stable to fishbone activity. Interaction of energetic particles with resistive interchange-ballooning modes is taken up. A population of hot particles, deeply trapped on adverse curvature side in tokamaks, can resonantly destabilize resistive interchange mode, which is stable in their absence because of favorable average curvature. Both modes are different from their usual resistive magnetohydrodynamic counterparts in their destabilization mechanism

Optimization of treatment protocols to prevent de novo development of antibiotic resistance in Pseudomonas aeruginosa

NARCIS (Netherlands)

Feng, Yanfang

2016-01-01

The ever-increasing rate of drug resistant bacteria has been one of the most challenging problem worldwide. This thesis studied the following subjects with mostly the clinically leading pathogen, P. aeruginosa, as the model strain: de novo development of antibiotic resistance in patient during the

Computational Simulation Techniques to Understand Rifampicin Resistance Mutation (S425L) of rpoB in M. leprae.

Science.gov (United States)

Nisha, J; Shanthi, V

2015-07-01

Mycobacterium leprae, the etiologic agent of leprosy, is non-cultivable in vitro. Consequently, the assessment of antibiotic activity against M. leprae hinge mainly upon the time consuming mouse footpad system. As M. leprae develops resistance against most of the drugs, the evolution of new long acting antimycobacterial compounds stand in need for leprosy control. The rpoB of M. leprae is the target of antimycobacterial drug, rifampicin. Recently, cases were reported that rpoB mutation (S425L) became resistant to rifampicin and the mechanism of resistance is still not well understood. The present study is aimed at studying the molecular and structural mechanism of the rifampicin binding to both native and mutant rpoB through computational approaches. From molecular docking, we demonstrated the stable binding of rifampicin through two hydrogen bonding with His420 residue of native than with mutant rpoB where one hydrogen bonding was found with Ser406. The difference in binding energies observed in the docking study evidently signifies that rifampicin is less effective in the treatment of patients with S425L variant. Moreover, the molecular dynamics studies also highlight the stable binding of rifampicin with native than mutant (S425L) rpoB. © 2015 Wiley Periodicals, Inc.

Recent developments in application of stable isotope analysis on agro-product authenticity and traceability.

Science.gov (United States)

Zhao, Yan; Zhang, Bin; Chen, Gang; Chen, Ailiang; Yang, Shuming; Ye, Zhihua

2014-02-15

With the globalisation of agro-product markets and convenient transportation of food across countries and continents, the potential for distribution of mis-labelled products increases accordingly, highlighting the need for measures to identify the origin of food. High quality food with identified geographic origin is a concern not only for consumers, but also for agriculture farmers, retailers and administrative authorities. Currently, stable isotope ratio analysis in combination with other chemical methods gradually becomes a promising approach for agro-product authenticity and traceability. In the last five years, a growing number of research papers have been published on tracing agro-products by stable isotope ratio analysis and techniques combining with other instruments. In these reports, the global variety of stable isotope compositions has been investigated, including light elements such as C, N, H, O and S, and heavy isotopes variation such as Sr and B. Several factors also have been considered, including the latitude, altitude, evaporation and climate conditions. In the present paper, an overview is provided on the authenticity and traceability of the agro-products from both animal and plant sources by stable isotope ratio analysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characteristics and use of wheat mutants tolerant or resistant to Septoria nodorum Berk

International Nuclear Information System (INIS)

Fossati, A.; Kleijer, G.; Fried, P.M.

1983-01-01

Mutation induction was used to obtain mutants tolerant or resistant to Septoria nodorum. This technique is valuable but many genotypes had to be treated because mutants could not be selected from all the genotypes. Short tolerant mutants could be obtained from 3 of the 15 treated tall tolerant lines. Induction of tolerance in susceptible lines of good agronomic value succeeded for 2 of 5 treated varieties. All these mutants showed a reduction in yield potential. One mutant showed partial resistance to S. nodorum. The disease development on the leaves and the spikes of this mutant was much slower than on the original variety. The characteristics of this mutant are discussed in detail. The genetics of tolerance proved to be polygenic and additive, which has consequences on the breeding method. A good way of obtaining a stable system would be the combination of high tolerance and partial resistance in the same cultivar. (author)

How does brain insulin resistance develop in Alzheimer's disease?

Science.gov (United States)

De Felice, Fernanda G; Lourenco, Mychael V; Ferreira, Sergio T

2014-02-01

Compelling preclinical and clinical evidence supports a pathophysiological connection between Alzheimer's disease (AD) and diabetes. Altered metabolism, inflammation, and insulin resistance are key pathological features of both diseases. For many years, it was generally considered that the brain was insensitive to insulin, but it is now accepted that this hormone has central neuromodulatory functions, including roles in learning and memory, that are impaired in AD. However, until recently, the molecular mechanisms accounting for brain insulin resistance in AD have remained elusive. Here, we review recent evidence that sheds light on how brain insulin dysfunction is initiated at a molecular level and why abnormal insulin signaling culminates in synaptic failure and memory decline. We also discuss the cellular basis underlying the beneficial effects of stimulation of brain insulin signaling on cognition. Discoveries summarized here provide pathophysiological background for identification of novel molecular targets and for development of alternative therapeutic approaches in AD. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Heat control in HVDC resistive divider by PID and NN controllers

International Nuclear Information System (INIS)

Yilmaz, S.; Dincer, H.; Eksin, I.; Kalenderli, O.

2007-01-01

In this study, a control system is presented that is devised to increase measurement precisions within a prototype high voltage DC resistive divider (HVDC-RD). Since one of the major sources of measurement errors in such devices is the self heating effect, a system controlling the temperature within the high voltage DC resistive divider is devised so that suitable and stable temperature conditions are maintained that, in return, will decrease the measurement errors. The resistive divider system is cooled by oil, and PID and neural network (NN) controllers try to keep the temperature within the prescribed limits. The system to be controlled exhibits a nonlinear character, and therefore, a control approach based on NN controllers is proposed. Thus, a system that can fulfill the various requirements dictated by the designer is constructed. The performance of the NN controller is compared with that of the PID controller developed for the same purpose, and the values of the performance indices indicate the superiority of the NN controller over that of the classical PID controller

Cooperative Antibiotic Resistance in a Multi-Drug Environment

Science.gov (United States)

Yurtsev, Eugene; Dai, Lei; Gore, Jeff

2013-03-01

The emergence of antibiotic resistance in bacteria is a significant health concern. A frequent mechanism of antibiotic resistance involves the production of an enzyme which inactivates the antibiotic. By inactivating the antibiotic, resistant cells can ``share'' their resistance with other cells in the bacterial population, suggesting that it may be possible to observe cooperation between strains that inactivate different antibiotics. Here, we experimentally track the population dynamics of two E. coli strains in the presence of two different antibiotics. We find that together the strains are able to grow in antibiotic concentrations that inhibit growth of either of the strains individually. We observe that even when there is stable coexistence between the two strains, the population size of each strain can undergo large oscillations. We expect that our results will provide insight into the evolution of antibiotic resistance and the evolutionary origin of phenotypic diversity and cooperative behaviors.

Survey of rice blast race identity for blast resistance gene identification in the USA and Puerto Rico

Science.gov (United States)

Rice blast disease is a significant threat to stable rice production in the USA and worldwide. The major resistance gene (Pi-ta) located within a cluster of resistance genes on rice chromosome 12 has been demonstrated to confer resistance to the rice blast disease. Katy, a rice cultivar released in ...

Development of leak detection system using high temperature-resistant microphones

International Nuclear Information System (INIS)

Morishita, Yoshitsugu; Mochizuki, Hiroyasu; Watanabe, Kenshiu; Nakamura, Takahisa; Nakazima, Yoshiaki; Yamauchi, Tatsuya

1995-01-01

This report describes the development and testing of a coolant leak detection system for an inlet feeder pipe of an advanced thermal reactor (ATR) using high temperature-resistant microphones. Such microphones must be resistant to both high temperatures and high radiation doses. Leakage sound characteristics, attenuation of the sound level in a heat insulating box for the inlet feeder pipes, and background noise were investigated using the experimental facility and the prototype ATR 'FUGEN'. The optimum frequency ranges for the microphone were then determined based on the observed leakage sound and background noise. The ability of the microphone to discriminate between leaks and other burst-type noises was also investigated by statistical analyses. Finally, it was confirmed that the present method could detect a leak within a couple of seconds. (author)

Development of innovative micro-pattern gaseous detectors with resistive electrodes and first results of their applications

CERN Document Server

Di Mauro, A; Martinengo, P; Nappi, E; Oliveira, R; Peskov, Vladimir; Periale, L; Picchi, P; Pietropaolo, F; Rodionov, I; Santiard, Jean-Claude

2007-01-01

The paper summarizes our latest progress in the development of newly introduced micro pattern gaseous detectors with resistive electrodes. These resistive electrodes protect the detector and the front-end electronics in case of occasional discharges and thus make the detectors very robust and reliable in operation. As an example, we describe in greater detail a new recently developed GEM-like detector, fully spark-protected with electrodes made of resistive kapton. We discovered that all resistive layers used in these studies (including kapton), that are coated with photosensitive layers, such as CsI, can be used as efficient photo cathodes for detectors operating in a pulse counting mode. We describe the first applications of such detectors combined with CsI or SbCs photo cathodes for the detection of UV photons at room and cryogenic temperatures.

Development of a highly weldable and corrosion resistant nickel-chromium filler metal

International Nuclear Information System (INIS)

Young, G.A.; Capobianco, T.E.; Etien, R.A.; Mullen, J.V.; Leveillee, S.; Sander, P.C.

2007-01-01

This paper reports on a long term research effort to develop an improved filler metal for gas-tungsten- arc welding of Alloy 690. The goal of this work was to maintain the corrosion resistance of wrought Alloy 690 while eliminating ductility dip cracking (DDC) or other as welded defects in prototypical welds. Results from weld mockups, weldability testing, microstructural and microchemical characterization, and computational modeling show that ductility dip cracking is a form of precipitation-induced-cracking and can be mitigated via alloying to control the type and extent of carbide formation. Additionally, these tests illustrate that in commercially available filler metals, alloying additions intended to provide DDC resistance (Nb, B, and Zr) are not effective and, in many cases, cause solidification cracking in addition to DDC. Based on these welding results, three candidate alloys of 24 wt.%, 27 wt.%, and 30 wt.% chromium were further evaluated for their mechanical properties, phase stability, and resistance to environmentally assisted cracking (EAC). Results to date show weldability mechanical properties, and phase stability comparable to EN82, but significantly improved resistance to EAC. These findings are used to define an alloy designated EN52i, that offers a desirable combination of weldability and corrosion resistance. (author)

Development of a highly weldable and corrosion resistant nickel-chromium filler metal

Energy Technology Data Exchange (ETDEWEB)

Young, G.A.; Capobianco, T.E.; Etien, R.A.; Mullen, J.V.; Leveillee, S.; Sander, P.C. [Lockheed Martin Corp., Schenectady, New York (United States)

2007-07-01

This paper reports on a long term research effort to develop an improved filler metal for gas-tungsten- arc welding of Alloy 690. The goal of this work was to maintain the corrosion resistance of wrought Alloy 690 while eliminating ductility dip cracking (DDC) or other as welded defects in prototypical welds. Results from weld mockups, weldability testing, microstructural and microchemical characterization, and computational modeling show that ductility dip cracking is a form of precipitation-induced-cracking and can be mitigated via alloying to control the type and extent of carbide formation. Additionally, these tests illustrate that in commercially available filler metals, alloying additions intended to provide DDC resistance (Nb, B, and Zr) are not effective and, in many cases, cause solidification cracking in addition to DDC. Based on these welding results, three candidate alloys of 24 wt.%, 27 wt.%, and 30 wt.% chromium were further evaluated for their mechanical properties, phase stability, and resistance to environmentally assisted cracking (EAC). Results to date show weldability mechanical properties, and phase stability comparable to EN82, but significantly improved resistance to EAC. These findings are used to define an alloy designated EN52i, that offers a desirable combination of weldability and corrosion resistance. (author)

Identification of protein expression alterations in gefitinib-resistant human lung adenocarcinoma: PCNT and mPR play key roles in the development of gefitinib-associated resistance

Energy Technology Data Exchange (ETDEWEB)

Lin, Chi-Chen [Institute of Biomedical Science, National Chung-Hsing University, Taichung, Taiwan (China); Institute of Biomedical Science, and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taiwan (China); Department of Medical Research and Education, Taichung Veterans General Hospital, Taichung, Taiwan (China); Division of Chest Medicine, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan (China); Chen, Jing-Ting [Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan (China); Lin, Meng-Wei [Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan (China); Department of Applied Science, National Hsinchu University of Education, Hsinchu, Taiwan (China); Chan, Chia-Hao [Department of Obstetrics and Gynecology, Hsinchu Mackay Memorial Hospital, Hsinchu 30071, Taiwan (China); Wen, Yueh-Feng [Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan (China); Wu, Shin-Bei [Department of Applied Science, National Hsinchu University of Education, Hsinchu, Taiwan (China); Chung, Ting-Wen [Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan (China); Lyu, Kevin W. [Lutheran Medical Center, Brooklyn, NY (United States); Global Scholars Program, St. George' s University/Northumbria University, Newcastle upon Tyne (United Kingdom); Chou, Hsiu-Chuan, E-mail: chouhc@mail.nhcue.edu.tw [Department of Applied Science, National Hsinchu University of Education, Hsinchu, Taiwan (China); and others

2015-11-01

Gefitinib is the first-line chemotherapeutic drug for treating non-small cell lung cancer (NSCLC), which comprises nearly 85% of all lung cancer cases worldwide. However, most patients eventually develop drug resistance after 12–18 months of treatment. Hence, investigating the drug resistance mechanism and resistance-associated biomarkers is necessary. Two lung adenocarcinoma cell lines, PC9 and gefitinib-resistant PC9/Gef, were established for examining resistance mechanisms and identifying potential therapeutic targets. Two-dimensional differential gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were used for examining global protein expression changes between PC9 and PC9/Gef. The results revealed that 164 identified proteins were associated with the formation of gefitinib resistance in PC9 cells. Additional studies using RNA interference showed that progesterone receptor membrane component 1 and pericentrin proteins have major roles in gefitinib resistance. In conclusion, the proteomic approach enabled identifying of numerous proteins involved in gefitinib resistance. The results provide useful diagnostic markers and therapeutic candidates for treating gefitinib-resistant NSCLC. - Highlights: • 164 proteins associated with gefitinib resistance were identified through proteomic analysis. • In this study, a lung adenocarcinoma and its gefitinib resistant partner were established. • mPR and PCNT proteins have evidenced to play important roles in gefitinib resistance.

Identification of protein expression alterations in gefitinib-resistant human lung adenocarcinoma: PCNT and mPR play key roles in the development of gefitinib-associated resistance

International Nuclear Information System (INIS)

Lin, Chi-Chen; Chen, Jing-Ting; Lin, Meng-Wei; Chan, Chia-Hao; Wen, Yueh-Feng; Wu, Shin-Bei; Chung, Ting-Wen; Lyu, Kevin W.; Chou, Hsiu-Chuan

2015-01-01

Gefitinib is the first-line chemotherapeutic drug for treating non-small cell lung cancer (NSCLC), which comprises nearly 85% of all lung cancer cases worldwide. However, most patients eventually develop drug resistance after 12–18 months of treatment. Hence, investigating the drug resistance mechanism and resistance-associated biomarkers is necessary. Two lung adenocarcinoma cell lines, PC9 and gefitinib-resistant PC9/Gef, were established for examining resistance mechanisms and identifying potential therapeutic targets. Two-dimensional differential gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were used for examining global protein expression changes between PC9 and PC9/Gef. The results revealed that 164 identified proteins were associated with the formation of gefitinib resistance in PC9 cells. Additional studies using RNA interference showed that progesterone receptor membrane component 1 and pericentrin proteins have major roles in gefitinib resistance. In conclusion, the proteomic approach enabled identifying of numerous proteins involved in gefitinib resistance. The results provide useful diagnostic markers and therapeutic candidates for treating gefitinib-resistant NSCLC. - Highlights: • 164 proteins associated with gefitinib resistance were identified through proteomic analysis. • In this study, a lung adenocarcinoma and its gefitinib resistant partner were established. • mPR and PCNT proteins have evidenced to play important roles in gefitinib resistance.

Effects of pyriproxyfen and buprofezin on immature development, female oviposition, and egg-hatching in the stable fly

Science.gov (United States)

The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most economically significant biting flies affecting cattle. Use of traditional insecticides have only limited success in control of stable flies largely due to the stable fly’s unique feeding behaviors and immature developm...

Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis.

Science.gov (United States)

Tacconelli, Evelina; Carrara, Elena; Savoldi, Alessia; Harbarth, Stephan; Mendelson, Marc; Monnet, Dominique L; Pulcini, Céline; Kahlmeter, Gunnar; Kluytmans, Jan; Carmeli, Yehuda; Ouellette, Marc; Outterson, Kevin; Patel, Jean; Cavaleri, Marco; Cox, Edward M; Houchens, Chris R; Grayson, M Lindsay; Hansen, Paul; Singh, Nalini; Theuretzbacher, Ursula; Magrini, Nicola

2018-03-01

The spread of antibiotic-resistant bacteria poses a substantial threat to morbidity and mortality worldwide. Due to its large public health and societal implications, multidrug-resistant tuberculosis has been long regarded by WHO as a global priority for investment in new drugs. In 2016, WHO was requested by member states to create a priority list of other antibiotic-resistant bacteria to support research and development of effective drugs. We used a multicriteria decision analysis method to prioritise antibiotic-resistant bacteria; this method involved the identification of relevant criteria to assess priority against which each antibiotic-resistant bacterium was rated. The final priority ranking of the antibiotic-resistant bacteria was established after a preference-based survey was used to obtain expert weighting of criteria. We selected 20 bacterial species with 25 patterns of acquired resistance and ten criteria to assess priority: mortality, health-care burden, community burden, prevalence of resistance, 10-year trend of resistance, transmissibility, preventability in the community setting, preventability in the health-care setting, treatability, and pipeline. We stratified the priority list into three tiers (critical, high, and medium priority), using the 33rd percentile of the bacterium's total scores as the cutoff. Critical-priority bacteria included carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, and carbapenem-resistant and third-generation cephalosporin-resistant Enterobacteriaceae. The highest ranked Gram-positive bacteria (high priority) were vancomycin-resistant Enterococcus faecium and meticillin-resistant Staphylococcus aureus. Of the bacteria typically responsible for community-acquired infections, clarithromycin-resistant Helicobacter pylori, and fluoroquinolone-resistant Campylobacter spp, Neisseria gonorrhoeae, and Salmonella typhi were included in the high-priority tier. Future development strategies should focus on

Development of assembly techniques for fire resistant aircraft interior panels

Science.gov (United States)

Lee, S. C. S.

1978-01-01

Ten NASA Type A fire resistant aircraft interior panels were fabricated and tested to develop assembly techniques. These techiques were used in the construction of a full scale lavatory test structure for flame propagation testing. The Type A panel is of sandwich construction consisting of Nomex honeycomb filled with quinone dioxime foam, and bismaleimide/glass face sheets bonded to the core with polyimide film adhesive. The materials selected and the assembly techniques developed for the lavatory test structure were designed for obtaining maximum fire containment with minimum smoke and toxic emission.

Tokamak m = 1 magnetohydrodynamic calculations in toroidal geometry using a full set of nonlinear resistive magnetohydrodynamic equations

International Nuclear Information System (INIS)

Charlton, L.A.; Carreras, B.A.; Holmes, J.A.; Lynch, V.E.

1988-01-01

The linear stability and nonlinear evolution of the resistive m = 1 mode in tokamaks is studied using a full set of resistive magnetohydrodynamic (MHD) equations in toroidal geometry. The modification of the linear and nonlinear properties of the mode by a combination of strong toroidal effects and low resistivity is the focus of this work. Linearly there is a transition from resistive kink to resistive tearing behavior as the aspect ratio and resistivity are reduced, and there is a corresponding modification of the nonlinear behavior, including a slowing of the island growth and development of a Rutherford regime, as the tearing regime is approached. In order to study the sensitivity of the stability and evolution to assumptions concerning the equation of state, two sets of full nonlinear resistive MHD equations (a pressure convection set and an incompressible set) are used. Both sets give more stable nonlinear behavior as the aspect ratio is reduced. The pressure convection set shows a transition from a Kadomtsev reconnection at large aspect ratio to a saturation at small aspect ratio. The incompressible set yields Kadomtsev reconnection for all aspect ratios, but with a significant lengthening of the reconnection time and development of a Rutherford regime at an aspect ratio approaching the transition from a resistive kink mode to a tearing mode. The pressure convection set gives an incomplete reconnection similar to that sometimes seen experimentally. The pressure convection set is, however, strictly justified only at high beta

Development of elvitegravir resistance and linkage of integrase inhibitor mutations with protease and reverse transcriptase resistance mutations.

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Mark A Winters

Full Text Available Failure of antiretroviral regimens containing elvitegravir (EVG and raltegravir (RAL can result in the appearance of integrase inhibitor (INI drug-resistance mutations (DRMs. While several INI DRMs have been identified, the evolution of EVG DRMs and the linkage of these DRMs with protease inhibitor (PI and reverse transcriptase inhibitor (RTI DRMs have not been studied at the clonal level. We examined the development of INI DRMs in 10 patients failing EVG-containing regimens over time, and the linkage of INI DRMs with PI and RTI DRMs in these patients plus 6 RAL-treated patients. A one-step RT-nested PCR protocol was used to generate a 2.7 kB amplicon that included the PR, RT, and IN coding region, and standard cloning and sequencing techniques were used to determine DRMs in 1,277 clones (mean 21 clones per time point. Results showed all patients had multiple PI, NRTI, and/or NNRTI DRMs at baseline, but no primary INI DRM. EVG-treated patients developed from 2 to 6 strains with different primary INI DRMs as early as 2 weeks after initiation of treatment, predominantly as single mutations. The prevalence of these strains fluctuated and new strains, and/or strains with new combinations of INI DRMs, developed over time. Final failure samples (weeks 14 to 48 typically showed a dominant strain with multiple mutations or N155H alone. Single N155H or multiple mutations were also observed in RAL-treated patients at virologic failure. All patient strains showed evidence of INI DRM co-located with single or multiple PI and/or RTI DRMs on the same viral strand. Our study shows that EVG treatment can select for a number of distinct INI-resistant strains whose prevalence fluctuates over time. Continued appearance of new INI DRMs after initial INI failure suggests a potent, highly dynamic selection of INI resistant strains that is unaffected by co-location with PI and RTI DRMs.

Construction of RNA-Quantum Dot Chimera for Nanoscale Resistive Biomemory Application.

Science.gov (United States)

Lee, Taek; Yagati, Ajay Kumar; Pi, Fengmei; Sharma, Ashwani; Choi, Jeong-Woo; Guo, Peixuan

2015-07-28

RNA nanotechnology offers advantages to construct thermally and chemically stable nanoparticles with well-defined shape and structure. Here we report the development of an RNA-QD (quantum dot) chimera for resistive biomolecular memory application. Each QD holds two copies of the pRNA three-way junction (pRNA-3WJ) of the bacteriophage phi29 DNA packaging motor. The fixed quantity of two RNAs per QD was achieved by immobilizing the pRNA-3WJ with a Sephadex aptamer for resin binding. Two thiolated pRNA-3WJ serve as two feet of the chimera that stand on the gold plate. The RNA nanostructure served as both an insulator and a mediator to provide defined distance between the QD and gold. Immobilization of the chimera nanoparticle was confirmed with scanning tunneling microscopy. As revealed by scanning tunneling spectroscopy, the conjugated pRNA-3WJ-QD chimera exhibited an excellent electrical bistability signal for biomolecular memory function, demonstrating great potential for the development of resistive biomolecular memory and a nano-bio-inspired electronic device for information processing and computing.

Prostate Cancer Stem-like Cells Contribute to the Development of Castration-Resistant Prostate Cancer

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Diane Ojo

2015-11-01

Full Text Available Androgen deprivation therapy (ADT has been the standard care for patients with advanced prostate cancer (PC since the 1940s. Although ADT shows clear benefits for many patients, castration-resistant prostate cancer (CRPC inevitably occurs. In fact, with the two recent FDA-approved second-generation anti-androgens abiraterone and enzalutamide, resistance develops rapidly in patients with CRPC, despite their initial effectiveness. The lack of effective therapeutic solutions towards CRPC largely reflects our limited understanding of the underlying mechanisms responsible for CRPC development. While persistent androgen receptor (AR signaling under castration levels of serum testosterone (<50 ng/mL contributes to resistance to ADT, it is also clear that CRPC evolves via complex mechanisms. Nevertheless, the physiological impact of individual mechanisms and whether these mechanisms function in a cohesive manner in promoting CRPC are elusive. In spite of these uncertainties, emerging evidence supports a critical role of prostate cancer stem-like cells (PCSLCs in stimulating CRPC evolution and resistance to abiraterone and enzalutamide. In this review, we will discuss the recent evidence supporting the involvement of PCSLC in CRPC acquisition as well as the pathways and factors contributing to PCSLC expansion in response to ADT.

Induction of a stable sigma factor SigR by translation-inhibiting antibiotics confers resistance to antibiotics

OpenAIRE

Yoo, Ji-Sun; Oh, Gyeong-Seok; Ryoo, Sungweon; Roe, Jung-Hye

2016-01-01

Antibiotic-producing streptomycetes are rich sources of resistance mechanisms against endogenous and exogenous antibiotics. An ECF sigma factor ?R (SigR) is known to govern the thiol-oxidative stress response in Streptomyces coelicolor. Amplification of this response is achieved by producing an unstable isoform of ?R called ?R?. In this work, we present evidence that antibiotics induce the SigR regulon via a redox-independent pathway, leading to antibiotic resistance. The translation-inhibiti...

Development of functional milk desserts enriched with resistant starch based on consumers' perception.

Science.gov (United States)

Ares, Florencia; Arrarte, Eloísa; De León, Tania; Ares, Gastón; Gámbaro, Adriana

2012-10-01

Sensory characteristics play a key role in determining consumers' acceptance of functional foods. In this context, the aim of the present work was to apply a combination of sensory and consumer methodologies to the development of chocolate milk desserts enriched with resistant starch. Chocolate milk desserts containing modified waxy maize starch were formulated with six different concentrations of two types of resistant starch (which are part of insoluble dietary fiber). The desserts were evaluated by trained assessors using Quantitative Descriptive Analysis. Moreover, consumers scored their overall liking and willingness to purchase and answered an open-ended question. Resistant starch caused significant changes in the sensory characteristics of the desserts and a significant decrease in consumers' overall liking and willingness to purchase. Consumer data was analyzed applying survival analysis on overall liking scores, considering the risk on consumers liking and willing to purchase the functional products less than their regular counterparts. The proposed methodologies proved to be useful to develop functional foods taking into account consumers' perception, which could increase their success in the market.

Mutagenesis and haploid culture for disease resistance in Brassica napus

Energy Technology Data Exchange (ETDEWEB)

MacDonald, M V; Ahmad, I; Ingram, D S [Botany School, University of Cambridge, Cambridge (United Kingdom)

1990-01-01

Full text: Most winter oilseed rape cultivars share parentage and therefore show little genetic diversity. There is no known resistance to Alternaria spp. in oilseed rape or in any related Brassica species. Experiments with tissue culture yielded only transient, non-genetic resistance. Therefore, mutagenesis may be used to generate heritable resistance to Alternaria spp. Gamma irradiation was applied to seeds of 'Bienvenue', secondary embryoids of cvs 'Primor' and 'Rapora', and buds of cvs 'Primor' and 'Ariana'. Isolated microspores from cv 'Ariana' and rapid cycling B. napus were also treated. The doses used ranged from 0-100 Gy for isolated microspores and buds, up to 600 Gy for seeds and 960 Gy for secondary embryoids. EMS was used to treat seeds of line WRG-42 (supplied by Nickersons RPB) and microspores of cv 'Bienvenue' and rapid cycling B. napus. Seeds were treated with up to 2.0% EMS for 0.2 h. before plating them on the culture medium. Seed irradiation up to 600 Gy did not reduce germination. M{sub 1} and M{sub 2} progenies were tested both in the laboratory and in field trials, and none of these were found to be resistant to Alternaria. However, considerable variation for other characters was observed. Haploid cultures from these plants were extremely difficult to regenerate, and for this reason no regenerant plants have been tested for resistance. For irradiated secondary embryoids the regeneration capacity decreased with increasing dose. Regenerated plants have been tested for resistance to Alternaria, but stable resistance was not observed. Haploid cultures were obtained from irradiated buds, using both anther and microspore culture. Low irradiation treatment was beneficial to developing embryoids. Some regenerants have been obtained from EMS treated microspores and seeds. Four plants have repeatedly given increased levels of resistance to A. brassicicola, and progenies are being tested to determine the genetic nature of the resistance. (author)

Mutagenesis and haploid culture for disease resistance in Brassica napus

International Nuclear Information System (INIS)

MacDonald, M.V.; Ahmad, I.; Ingram, D.S.

1990-01-01

Full text: Most winter oilseed rape cultivars share parentage and therefore show little genetic diversity. There is no known resistance to Alternaria spp. in oilseed rape or in any related Brassica species. Experiments with tissue culture yielded only transient, non-genetic resistance. Therefore, mutagenesis may be used to generate heritable resistance to Alternaria spp. Gamma irradiation was applied to seeds of 'Bienvenue', secondary embryoids of cvs 'Primor' and 'Rapora', and buds of cvs 'Primor' and 'Ariana'. Isolated microspores from cv 'Ariana' and rapid cycling B. napus were also treated. The doses used ranged from 0-100 Gy for isolated microspores and buds, up to 600 Gy for seeds and 960 Gy for secondary embryoids. EMS was used to treat seeds of line WRG-42 (supplied by Nickersons RPB) and microspores of cv 'Bienvenue' and rapid cycling B. napus. Seeds were treated with up to 2.0% EMS for 0.2 h. before plating them on the culture medium. Seed irradiation up to 600 Gy did not reduce germination. M 1 and M 2 progenies were tested both in the laboratory and in field trials, and none of these were found to be resistant to Alternaria. However, considerable variation for other characters was observed. Haploid cultures from these plants were extremely difficult to regenerate, and for this reason no regenerant plants have been tested for resistance. For irradiated secondary embryoids the regeneration capacity decreased with increasing dose. Regenerated plants have been tested for resistance to Alternaria, but stable resistance was not observed. Haploid cultures were obtained from irradiated buds, using both anther and microspore culture. Low irradiation treatment was beneficial to developing embryoids. Some regenerants have been obtained from EMS treated microspores and seeds. Four plants have repeatedly given increased levels of resistance to A. brassicicola, and progenies are being tested to determine the genetic nature of the resistance. (author)

A novel approach for the detection of potentially hazardous pepsin stable hazelnut proteins as contaminants in chocolate-based food.

Science.gov (United States)

Akkerdaas, Jaap H; Wensing, Marjolein; Knulst, André C; Stephan, Oliver; Hefle, Susan L; Aalberse, Rob C; van Ree, Ronald

2004-12-15

Contamination of food products with pepsin resistant allergens is generally believed to be a serious threat to patients with severe food allergy. A sandwich type enzyme-linked immunosorbent assay (ELISA) was developed to measure pepsin resistant hazelnut protein in food products. Capturing and detecting rabbit antibodies were raised against pepsin-digested hazelnut and untreated hazelnut protein, respectively. The assay showed a detection limit of 0.7 ng/mL hazelnut protein or food matrix and a maximum of 0.034% cross-reactivity (peanut). Chocolate samples spiked with 0.5-100 microg hazelnut/g chocolate showed a mean recovery of 97.3%. In 9/12 food products labeled "may contain nuts", hazelnut was detected between 1.2 and 417 microg hazelnut/g food. It can be concluded that the application of antibodies directed to pepsin-digested food extracts in ELISA can facilitate specific detection of stable proteins that have the highest potential of inducing severe food anaphylaxis.

Stabilization of ideal plasma resistive wall modes in cylindrical geometry: The effect of resistive layers

International Nuclear Information System (INIS)

Finn, J.M.

1995-01-01

A cylindrical model with finite beta having an external resonant ideal magnetohydrodynamic instability has been constructed. This resonant mode has a mode rational surface, where the safety factor q equals m/n, within the plasma. In this model, the perturbed radial magnetic field for the ideal mode is nonzero between the mode rational surface and the wall, even though it must vanish at the mode rational surface. This property of the mode is in common with the toroidal external kink. Results are presented showing that in the parameter range for which this ideal mode is stable with a conducting wall but unstable with the wall at infinity, a resistive wall mode persists. However, in the presence of plasma resistivity in a resistive layer about the mode rational surface, this resistive wall mode can be stabilized by a plasma rotation frequency of order a nominal resistive instability growth rate. Furthermore, the stabilization occurs in a large gap in wall position or beta. It is also shown that for the ideal resonant mode, as well as resistive plasma modes and nonresonant ideal plasma modes, there is a maximum value of plasma rotation above which there is no stability gap. Discussions are presented suggesting that these properties may hold for the toroidal external kink. copyright 1995 American Institute of Physics

Electrical resistivity monitoring of the single heater test in Yucca Mountain

International Nuclear Information System (INIS)

Ramirez, A.

1997-10-01

Of the several thermal, mechanical and hydrological measurements being used to monitor the rockmass response in the Single Heater Test, electrical resistance tomography (ERT) is being used to monitor the movement of liquid water with a special interest in the movement of condensate out of the system. Images of resistivity change were calculated using data collected before, during and after the heating episode. This report will concentrate on the results obtained after heating ceased; previous reports discuss the results obtained during the heating phase. The changes recovered show a region of increasing resistivity approximately centered around the heater as the rock mass cooled. The size of this region grows with time and the resistivity increases become stronger. The increases in resistivity are caused by both temperature and saturation changes. The Waxman Smits model has been used to calculate rock saturation after accounting for temperature effects. The saturation estimates suggest that during the heating phase, a region of drying forms around the heater. During the cooling phase, the dry region has remained relatively stable. Wetter rock regions which developed below the heater during the heating phase, are slowly becoming smaller in size during the cooling phase. The last set of images indicate that some rewetting of the dry zone may be occurring. The accuracy of the saturation estimates depends on several factors that are only partly understood

Cast thermally stable high temperature nickel-base alloys and casting made therefrom

International Nuclear Information System (INIS)

Acuncius, D.A.; Herchenroeder, R.B.; Kirchner, R.W.; Silence, W.L.

1977-01-01

A cast thermally stable high temperature nickel-base alloy characterized by superior oxidation resistance, sustainable hot strength and retention of ductility on aging is provided by maintaining the alloy chemistry within the composition molybdenum 13.7% to 15.5%; chromium 14.7% to 16.5%; carbon up to 0.1%, lanthanum in an effective amount to provide oxidation resistance up to 0.08%; boron up to 0.015%; manganese 0.3% to 1.0%; silicon 0.2% to 0.8%; cobalt up to 2.0%; iron up to 3.0%; tungsten up to 1.0%; copper up to 0.4%; phosphorous up to 0.02%; sulfur up to 0.015%; aluminum 0.1% to 0.5% and the balance nickel while maintaining the Nv number less than 2.31

Dissemination of antibiotic resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant S aureus strains isolated from hospital effluents.

Science.gov (United States)

Mandal, Santi M; Ghosh, Ananta K; Pati, Bikas R

2015-12-01

Vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant S aureus (MRSA) strains were examined in hospital effluents. Most S aureus strains are resistant to methicillin (MRSA), followed by tetracycline. Approximately 15% of MRSA strains are also resistant to vancomycin (VRSA). All VRSA strains developed a VanR/VanS-regulated 2-component system of VanA-type resistance in their genome. Results indicate that there is a possibility of developing resistance to aminoglycosides by VRSA strains in the near future. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Taxane-Platin-Resistant Lung Cancers Co-develop Hypersensitivity to JumonjiC Demethylase Inhibitors

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Maithili P. Dalvi

2017-05-01

Full Text Available Although non-small cell lung cancer (NSCLC patients benefit from standard taxane-platin chemotherapy, many relapse, developing drug resistance. We established preclinical taxane-platin-chemoresistance models and identified a 35-gene resistance signature, which was associated with poor recurrence-free survival in neoadjuvant-treated NSCLC patients and included upregulation of the JumonjiC lysine demethylase KDM3B. In fact, multi-drug-resistant cells progressively increased the expression of many JumonjiC demethylases, had altered histone methylation, and, importantly, showed hypersensitivity to JumonjiC inhibitors in vitro and in vivo. Increasing taxane-platin resistance in progressive cell line series was accompanied by progressive sensitization to JIB-04 and GSK-J4. These JumonjiC inhibitors partly reversed deregulated transcriptional programs, prevented the emergence of drug-tolerant colonies from chemo-naive cells, and synergized with standard chemotherapy in vitro and in vivo. Our findings reveal JumonjiC inhibitors as promising therapies for targeting taxane-platin-chemoresistant NSCLCs.

The effect of vorinostat on the development of resistance to doxorubicin in neuroblastoma.

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Timothy B Lautz

Full Text Available Histone deacetylase (HDAC inhibitors, especially vorinostat, are currently under investigation as potential adjuncts in the treatment of neuroblastoma. The effect of vorinostat co-treatment on the development of resistance to other chemotherapeutic agents is unknown. In the present study, we treated two human neuroblastoma cell lines [SK-N-SH and SK-N-Be(2C] with progressively increasing doses of doxorubicin under two conditions: with and without vorinsotat co-therapy. The resultant doxorubicin-resistant (DoxR and vorinostat-treated doxorubicin resistant (DoxR-v cells were equally resistant to doxorubicin despite significantly lower P-glycoprotein expression in the DoxR-v cells. Whole genome analysis was performed using the Ilumina Human HT-12 v4 Expression Beadchip to identify genes with differential expression unique to the DoxR-v cells. We uncovered a number of genes whose differential expression in the DoxR-v cells might contribute to their resistant phenotype, including hypoxia inducible factor-2. Finally, we used Gene Ontology to categorize the biological functions of the differentially expressed genes unique to the DoxR-v cells and found that genes involved in cellular metabolism were especially affected.

Resistance switching memory in perovskite oxides

International Nuclear Information System (INIS)

Yan, Z.B.; Liu, J.-M.

2015-01-01

The resistance switching behavior has recently attracted great attentions for its application as resistive random access memories (RRAMs) due to a variety of advantages such as simple structure, high-density, high-speed and low-power. As a leading storage media, the transition metal perovskite oxide owns the strong correlation of electrons and the stable crystal structure, which brings out multifunctionality such as ferroelectric, multiferroic, superconductor, and colossal magnetoresistance/electroresistance effect, etc. The existence of rich electronic phases, metal–insulator transition and the nonstoichiometric oxygen in perovskite oxide provides good platforms to insight into the resistive switching mechanisms. In this review, we first introduce the general characteristics of the resistance switching effects, the operation methods and the storage media. Then, the experimental evidences of conductive filaments, the transport and switching mechanisms, and the memory performances and enhancing methods of perovskite oxide based filamentary RRAM cells have been summarized and discussed. Subsequently, the switching mechanisms and the performances of the uniform RRAM cells associating with the carrier trapping/detrapping and the ferroelectric polarization switching have been discussed. Finally, the advices and outlook for further investigating the resistance switching and enhancing the memory performances are given

Stable nuclear transformation of Eudorina elegans

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Lerche Kai

2013-02-01

Full Text Available Abstract Background A fundamental step in evolution was the transition from unicellular to differentiated, multicellular organisms. Volvocine algae have been used for several decades as a model lineage to investigate the evolutionary aspects of multicellularity and cellular differentiation. There are two well-studied volvocine species, a unicellular alga (Chlamydomonas reinhardtii and a multicellular alga with differentiated cell types (Volvox carteri. Species with intermediate characteristics also exist, which blur the boundaries between unicellularity and differentiated multicellularity. These species include the globular alga Eudorina elegans, which is composed of 16–32 cells. However, detailed molecular analyses of E. elegans require genetic manipulation. Unfortunately, genetic engineering has not yet been established for Eudorina, and only limited DNA and/or protein sequence information is available. Results Here, we describe the stable nuclear transformation of E. elegans by particle bombardment using both a chimeric selectable marker and reporter genes from different heterologous sources. Transgenic algae resistant to paromomycin were achieved using the aminoglycoside 3′-phosphotransferase VIII (aphVIII gene of Streptomyces rimosus, an actinobacterium, under the control of an artificial promoter consisting of two V. carteri promoters in tandem. Transformants exhibited an increase in resistance to paromomycin by up to 333-fold. Co-transformation with non-selectable plasmids was achieved with a rate of 50 - 100%. The luciferase (gluc gene from the marine copepod Gaussia princeps, which previously was engineered to match the codon usage of C. reinhardtii, was used as a reporter gene. The expression of gluc was mediated by promoters from C. reinhardtii and V. carteri. Heterologous heat shock promoters induced an increase in luciferase activity (up to 600-fold at elevated temperatures. Long-term stability and both constitutive and

Development of MATLAB Scripts for the Calculation of Thermal Manikin Regional Resistance Values

Science.gov (United States)

2016-01-01

TECHNICAL NOTE NO. TN16-1 DATE January 2016 ADA DEVELOPMENT OF MATLAB ® SCRIPTS FOR THE...USARIEM TECHNICAL NOTE TN16-1 DEVELOPMENT OF MATLAB ® SCRIPTS FOR THE CALCULATION OF THERMAL MANIKIN REGIONAL RESISTANCE VALUES...EXECUTIVE SUMMARY A software tool has been developed via MATLAB ® scripts to reduce the amount of repetitive and time-consuming calculations that are

Poor efficacy of the most commonly used anthelmintics in sport horse nematodes in Morocco in relation to resistance

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Zouiten H.

2005-12-01

Full Text Available Sport and leisure horses in Morocco are treated with several anthelmintics, organophosphates (dichlorvos, benzimidazoles (mostly thiabendazole or tetrahydropyrimidines (mostly pyrantel pamoate against nematodes. We studied three horse stables in Rabat, one in Meknes and one in Bouznika. Two of the Rabat and Bouznika stables had introduced a large number of horses from countries (Argentina or Europe where resistance to benzimidazoles is frequent, whereas the Meknes stud farm remained without foreign introduction. The number of treatments was not very frequent (twice a year in adult horses but the same anthelmintics were used repeatedly. No resistance to dichlorvos was detected whereas benzimidazole and pyrantel pamoate resistances were detected for the first time in African horses, outside South Africa.

Physiological quality and gene expression related to heat-resistant proteins at different stages of development of maize seeds.

Science.gov (United States)

Andrade, T; Von Pinho, E V R; Von Pinho, R G; Oliveira, G E; Andrade, V; Fernandes, J S

2013-09-13

We quantified and characterized the expression of heat-resistant proteins during seed development of maize lines with distinct levels of tolerance to high drying temperature. A corn field was planted for multiplication of seeds of different lines, two tolerant and two non-tolerant to high drying temperatures. Harvest of the seeds was carried out at various stages of development and they were then subjected to tests of moisture content, germination, first count of germination, accelerated aging, and cold test. The seeds were stored in a freezer for later analysis of expression of heat-resistant proteins by means of real-time PCR, electrophoresis, and spectrophotometry. We observed that heat-resistant proteins are expressed in a differential manner in seeds from different lines and at different stages of development. The expression of heat-resistant proteins was earlier in lines tolerant to high drying temperatures. Greater germination and vigor values was found for seeds collected at the last stage of development.

A collaboration on development of requirements and guidelines for proliferation resistance of future nuclear system in the IAEA INPRO

International Nuclear Information System (INIS)

Oh, Keun Bae; Lee, Kwang Seok; Kim, Hyun Jun; Jeong, Ik; Yang, Myung Seung; Ko, Won Il

2003-10-01

This study surveyed and analyzed the existing activities and international status concerning proliferation resistance of nuclear energy systems, reviewed the features of proliferation resistance, and derived the requirements of future innovative nuclear energy systems. In IAEA INPRO, guidance for the evaluation of innovative nuclear reactors and fuel cycles on proliferation resistance was finalized through collaboration of member countries including Korea in reviewing technological status and developing the methodology for evaluation of proliferation resistance. This report, first, describes the progress of INPRO and the participation status of Korea in the project, and briefly summarizes the report of phase IA of INPRO. Next, features of proliferation resistance of nuclear systems, collaboration in the GIF and the INPRO for development of requirements and guidelines for proliferation resistance, and the final result of guidance for the evaluation of proliferation resistance were described. Finally, this study proposed measures for participation of further progress of the INPRO

Resolution of Mild Ganciclovir-Resistant Cytomegalovirus Disease with Reduced-Dose Cidofovir and CMV-Hyperimmune Globulin.

Science.gov (United States)

Patel, Samir J; Kuten, Samantha A; Knight, Richard J; Hong, Dana M; Gaber, A Osama

2014-01-01

Ganciclovir-resistant cytomegalovirus (CMV) is associated with significant morbidity in solid organ transplant recipients. Management of ganciclovir-resistant CMV may be complicated by nephrotoxicity which is commonly observed with recommended therapies and/or rejection induced by "indirect" viral effects or reduction of immunosuppression. Herein, we report a series of four high serologic risk (donor CMV positive/recipient CMV negative) kidney transplant patients diagnosed with ganciclovir-resistant CMV disease. All patients initially developed "breakthrough" viremia while still receiving valganciclovir prophylaxis after transplant and were later confirmed to exhibit UL97 mutations after failing to eradicate virus on adequate dosages of valganciclovir. The patients were subsequently and successfully treated with reduced-dose (1-2 mg/kg) cidofovir and CMV-hyperimmune globulin, given in 2-week intervals. In addition, all patients exhibited stable renal function after completion of therapy, and none experienced acute rejection. The combination of reduced-dose cidofovir and CMV-hyperimmune globulin appeared to be a safe and effective regimen in patients with mild disease due to ganciclovir-resistant CMV.

Resistive effect on ion fishbone mode in tokamak plasma

International Nuclear Information System (INIS)

Shi Bingren; Vandam, J.W.; Carrera, R.; Zhang, Y.Z.

1992-07-01

A consistent theoretical description of the resistive internal mode is presented to discuss the effect of resistivity on fishbone mode for different parameter regime of bulk and hot components. It is found that the ideal fishbone mode theory ceases to be correct for the low frequency fishbone branch, the so-called ion fishbone mode, which has a real frequency very close to ω *i (the diamagnetic frequency) in marginal state. The stability domain analysis in β h , γ mhd ) space based on the resistive dispersion relation shows that the transition between the stable and unstable region is more complicated than predicted by the ideal limit theory. Another salient feature of the resistive fishbone mode is the existence of a weakly unstable regime. For high frequency fishbone with ω ∼ ω dm (the toroidal precession frequency of the hot ions) resistivity has negligible effect and the ideal theory is correct

Appraisal of wheat germplasm for adult plant resistance against stripe rust

Directory of Open Access Journals (Sweden)

Saleem Kamran

2015-12-01

Full Text Available The resurgence of wheat stripe rust is of great concern for world food security. Owing to resistance breakdown and the appearance of new virulent high-temperature adapted races of Puccinia striiformis f. sp. tritici (Pst, many high yielding commercial varieties in the country lost their yield potential. Searching for new sources of resistance is the best approach to mitigate the problem. Quantitative resistance (partial or adult plant or durable resistance is reported to be more stable than race specific resistance. In the current perusal, a repertoire of 57 promising wheat lines along with the KLcheck line Morocco, developed through hybridisation and selection of local and international lines with International Maize and Wheat Improvement Center (CIMMYT origin, were evaluated under natural field conditions at Nuclear Institute for Agriculture and Biology (NIAB during the 2012−2013 and 2013−2014 time periods. Final rust severity (FRS, the area under the rust progress curve (AURPC, the relative area under the rust progress curve (rAURPC, and the coefficient of infection (CI were unraveled to infer the level of quantitative resistance. Final rust severity was recorded when the susceptible check exhibited 100% severity. There were 21 lines which were immune (no disease, 16 which were resistant, five moderately resistant, two resistant-to-moderately resistant, one moderately resistant-to-moderately susceptible, 5 moderately susceptible-to-susceptible, one moderately susceptible, and six exhibited a susceptible response. Nevertheless, 51 lines exhibited a high level of partial resistance while the three lines, NW-5-1212-1, NW-7-30-1, and NW-7-5 all showed a moderate level of partial resistance based on FRS, while 54 lines, on the basis of AURPC and rAURPC, were identified as conferring a high level of partial resistance. Moreover, adult plant resistance was conferred by 47 wheat lines, based on CI value. It was striking that, 13 immune lines

One-dimensional stable distributions

CERN Document Server

Zolotarev, V M

1986-01-01

This is the first book specifically devoted to a systematic exposition of the essential facts known about the properties of stable distributions. In addition to its main focus on the analytic properties of stable laws, the book also includes examples of the occurrence of stable distributions in applied problems and a chapter on the problem of statistical estimation of the parameters determining stable laws. A valuable feature of the book is the author's use of several formally different ways of expressing characteristic functions corresponding to these laws.

Development on traceability based on changes of stable isotopes in animal tissues and organs

International Nuclear Information System (INIS)

Cai Xianfeng; Guo Boli; Wei Yimin; Sun Shumin; Wei Shuai

2011-01-01

Stable isotope analysis is a new method in food traceability, which can be used to trace animals' geographical origin and life history. This paper reviews the recent progress of researches on characteristics of stable isotopes and turnover time in different animal tissues and organs, as well as their influence caused by feed, drinking water, geographical origin, storing and processing. The aim of this paper is to provide theoretical reference for studies on the traceability of animal derived food and animals' life history. (authors)

Disease resistance breeding in rose: current status and potential of biotechnological tools.

Science.gov (United States)

Debener, Thomas; Byrne, David H

2014-11-01

The cultivated rose is a multispecies complex for which a high level of disease protection is needed due to the low tolerance of blemishes in ornamental plants. The most important fungal diseases are black spot, powdery mildew, botrytis and downy mildew. Rose rosette, a lethal viral pathogen, is emerging as a devastating disease in North America. Currently rose breeders use a recurrent phenotypic selection approach and perform selection for disease resistance for most pathogen issues in a 2-3 year field trial. Marker assisted selection could accelerate this breeding process. Thus far markers have been identified for resistance to black spot (Rdrs) and powdery mildew and with the ability of genotyping by sequencing to generate 1000s of markers our ability to identify markers useful in plant improvement should increase exponentially. Transgenic rose lines with various fungal resistance genes inserted have shown limited success and RNAi technology has potential to provide virus resistance. Roses, as do other plants, have sequences homologous to characterized R-genes in their genomes, some which have been related to specific disease resistance. With improving next generation sequencing technology, our ability to do genomic and transcriptomic studies of the resistance related genes in both the rose and the pathogens to reveal novel gene targets to develop resistant roses will accelerate. Finally, the development of designer nucleases opens up a potentially non-GMO approach to directly modify a rose's DNA to create a disease resistant rose. Although there is much potential, at present rose breeders are not using marker assisted breeding primarily because a good suite of marker/trait associations (MTA) that would ensure a path to stable disease resistance is not available. As our genomic analytical tools improve, so will our ability to identify useful genes and linked markers. Once these MTAs are available, it will be the cost savings, both in time and money, that will

Bordism, stable homotopy and adams spectral sequences

CERN Document Server

Kochman, Stanley O

1996-01-01

This book is a compilation of lecture notes that were prepared for the graduate course "Adams Spectral Sequences and Stable Homotopy Theory" given at The Fields Institute during the fall of 1995. The aim of this volume is to prepare students with a knowledge of elementary algebraic topology to study recent developments in stable homotopy theory, such as the nilpotence and periodicity theorems. Suitable as a text for an intermediate course in algebraic topology, this book provides a direct exposition of the basic concepts of bordism, characteristic classes, Adams spectral sequences, Brown-Peter

THE ROLES OF DETOXIFYING ENZYMES AND AChE INSENSITIVITY IN METHAMIDOPHOS RESISTANCE DEVELOPMENT AND DECLINE IN NILAPARVATA LUGENS

Institute of Scientific and Technical Information of China (English)

Ze-wenLiu; Zhao-junHan; Ling-chunZhang

2003-01-01

Methamidophos resistance of brown planthopper (Nilaparvata lugens Stal, BPH) was selected in laboratory. After successive selection for 9 generations, the selection was ceased by rearing BPH without contact with any insecticide for 9 generations. In the full course, the successive changes of esterase activity, MFO activity, GSTs activity and AChE insensitivity were analyzed. The results showed that the change of esterase activity was high correlated with that of methamidophos in the full course, which indicated that esterase played very important role both in the resistance development and in the resistance decline. However, the change of AChE insensitivity only significantly correlated with that of resistance in the development stage, and the change of MFO activity or GSTs activity only significantly correlated with that of the resistance in the decline stage, which indicated the changes of AChE insensitivity, MFO activity or GSTs activity only played some roles in different stages of the resistance change.

Effects of ceftiofur treatment on the susceptibility of commensal porcine E.coli--comparison between treated and untreated animals housed in the same stable.

Science.gov (United States)

Beyer, Anne; Baumann, Sven; Scherz, Gesine; Stahl, Jessica; von Bergen, Martin; Friese, Anika; Roesler, Uwe; Kietzmann, Manfred; Honscha, Walther

2015-10-15

Healthy farm animals have been found to act as a reservoir of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli). Therefore, the objective of the study was to determine the input of antimicrobial active ceftiofur metabolites in the stable via faeces and urine after intramuscular administration of the drug to pigs and the elucidation of the Escherichia coli ESBL resistance pattern of treated and untreated pigs housed in the same barn during therapy. For determination of the minimal inhibitory concentration (MIC) the method of microdilutionaccording to the recommended procedure of the Clinical and Laboratory Standards Institute was used. Inaddition to that, a qualitative determination was performed by agar dilution. Unsusceptible E. coli speciesselected via agar dilution with cefotaxime were confirmed by MALDI-TOF and ESBL encoding genes wereidentified by PCR. The amounts of ceftiofur measured as desfuroylceftiofur (DFC) in the different probes (plasma, urine, faeces and dust) were analysed by UPLC-MS/MS. In a first experiment two groups of pigs (6 animals per group) were housed in the same barn in two separated boxes. One group (group B) were treated with ceftiofur according to the licence (3 mg/kg administered intramuscularly (i.m.) on three consecutive days, day 1-3). During a second treatment period (day 29-31) an increased rate of ESBL resistant E. coli was detectable in these treated pigs and in the air of the stable. Moreover, the second group of animals (group A) formerly untreated but housed for the whole period in the same stable as the treated animals revealed increased resistance rates during their first treatment (day 45-47) with ceftiofur. In order to investigate the environmental input of ceftiofur during therapy and to simulate oral uptake of ceftiofur residues from the air of the stable a second set of experiments were performed. Pigs (6 animals) were treated with an interval of 2 weeks for 3 days with different doses of

Development of a plastic fracture methodology for nuclear systems

International Nuclear Information System (INIS)

Marston, T.U.; Jones, R.L.; Kanninen, M.F.; Mowbray, D.F.

1981-01-01

This paper describes research conducted to develop a fundamental basis for flaw tolerance assessment procedures suitable for components exhibiting ductile behavior. The research was composed of an integrated combination of stable crack growth experiments and elastic-plastic analyses. A number of candidate fracture criteria were assembled and investigated to determine the proper basis for plastic fracture mechanics assessments. The results demonstrate that many different fracture criteria can be used as the basis of a resistance curve approach to predicting stable crack growth and fracture instability. While all have some disadvantages, none is completely unacceptable. On balance, the best criteria were found to be the J-integral for initiation and limited amounts of stable crack growth and the local crack-tip opening angle for extended amounts of stable growth. A combination of the two, which may preserve the advantages of each while reducing their disadvantages, also was suggested by these results. The influence of biaxial and mixed flat/shear fracture behavior was investigated and found to not alter the basic results. Further work in the development of simplified ductile fracture analyses for routine engineering assessments of nuclear pressure vessels and piping evolving from this research is also described

Development of marker-free transgenic lettuce resistant to Mirafiori lettuce big-vein virus.

Science.gov (United States)

Kawazu, Yoichi; Fujiyama, Ryoi; Imanishi, Shunsuke; Fukuoka, Hiroyuki; Yamaguchi, Hirotaka; Matsumoto, Satoru

2016-10-01

Lettuce big-vein disease caused by Mirafiori lettuce big-vein virus (MLBVV) is found in major lettuce production areas worldwide, but highly resistant cultivars have not yet been developed. To produce MLBVV-resistant marker-free transgenic lettuce that would have a transgene with a promoter and terminator of lettuce origin, we constructed a two T-DNA binary vector, in which the first T-DNA contained the selectable marker gene neomycin phosphotransferase II, and the second T-DNA contained the lettuce ubiquitin gene promoter and terminator and inverted repeats of the coat protein (CP) gene of MLBVV. This vector was introduced into lettuce cultivars 'Watson' and 'Fuyuhikari' by Agrobacterium tumefaciens-mediated transformation. Regenerated plants (T0 generation) that were CP gene-positive by PCR analysis were self-pollinated, and 312 T1 lines were analyzed for resistance to MLBVV. Virus-negative plants were checked for the CP gene and the marker gene, and nine lines were obtained which were marker-free and resistant to MLBVV. Southern blot analysis showed that three of the nine lines had two copies of the CP gene, whereas six lines had a single copy and were used for further analysis. Small interfering RNAs, which are indicative of RNA silencing, were detected in all six lines. MLBVV infection was inhibited in all six lines in resistance tests performed in a growth chamber and a greenhouse, resulting in a high degree of resistance to lettuce big-vein disease. Transgenic lettuce lines produced in this study could be used as resistant cultivars or parental lines for breeding.

Bi-stable optical actuator

Science.gov (United States)

Holdener, Fred R.; Boyd, Robert D.

2000-01-01

The present invention is a bi-stable optical actuator device that is depowered in both stable positions. A bearing is used to transfer motion and smoothly transition from one state to another. The optical actuator device may be maintained in a stable position either by gravity or a restraining device.

CRISPR/Cas9-Mediated Gene Editing in Rice (Oryza sativa L. japonica cv. Katy) for Stable Resistance against Blast Fungus (Magnaporthe oryzae)

Science.gov (United States)

Rice blast is a recurring and devastating disease in the USA and worldwide. In the USA, the blast-resistance (R) genes found in a tropical japonica cultivar, Katy, reduce blast damages from 1990 to present. The cultivar is still used as a principal donor of blast R genes in developing numerous elit...

The Stromal Contribution to the Development of Resistance to New-Generation Drugs by Castration-Resistant Prostate Cancer

Science.gov (United States)

2015-10-01

abiraterone treatment by further increasing their expressions of steroidogenic genes and by further increasing their outputs of T and DHT . Finally, we...support (stromal) cells within a bone metastasis have a supportive role in the development of CRPC through their ability to synthesize T and DHT upon Hh...dihydrotestosterone ( DHT ) (3, 9-11). 4 After ADT, recurrence as castration-resistant disease is common (8). For PCa, the most common site for metastasis is bone

A graphene integrated highly transparent resistive switching memory device

Science.gov (United States)

Dugu, Sita; Pavunny, Shojan P.; Limbu, Tej B.; Weiner, Brad R.; Morell, Gerardo; Katiyar, Ram S.

2018-05-01

We demonstrate the hybrid fabrication process of a graphene integrated highly transparent resistive random-access memory (TRRAM) device. The indium tin oxide (ITO)/Al2O3/graphene nonvolatile memory device possesses a high transmittance of >82% in the visible region (370-700 nm) and exhibits stable and non-symmetrical bipolar switching characteristics with considerably low set and reset voltages (ITO/Al2O3/Pt device and studied its switching characteristics for comparison and a better understanding of the ITO/Al2O3/graphene device characteristics. The conduction mechanisms in high and low resistance states were analyzed, and the observed polarity dependent resistive switching is explained based on electro-migration of oxygen ions.

Development of an efficient Procedure for Resist Wall Space Experiment

Science.gov (United States)

Matsumoto, Shouhei; Kumasaki, Saori; Higuchi, Sayoko; Kirihata, Kuniaki; Inoue, Yasue; Fujie, Miho; Soga, Kouichi; Wakabayashi, Kazuyuki; Hoson, Takayuki

The Resist Wall space experiment aims to examine the role of the cortical microtubule-plasma membrane-cell wall continuum in plant resistance to the gravitational force, thereby clarifying the mechanism of gravity resistance. For this purpose, we will cultivate Arabidopsis mutants defective in organization of cortical microtubules (tua6 ) or synthesis of membrane sterols (hmg1 ) as well as the wild type under microgravity and 1 g conditions in the European Modular Cultivation System on the International Space Station up to reproductive stage, and compare phenotypes on growth and development. We will also analyze cell wall properties and gene expression levels using collected materials. However, the amounts of materials collected will be severely limited, and we should develop an efficient procedure for this space experiment. In the present study, we examined the possibility of analyzing various parameters successively using the identical material. On orbit, plant materials will be fixed with RNAlater solution, kept at 4° C for several days and then frozen in a freezer at -20° C. We first examined whether the cell wall extensibility of inflorescence stems can be measured after RNAlater fixation. The gradient of the cell wall extensibility along inflorescence stems was detected in RNAlater-fixed materials as in methanol-killed ones. The sufficient amounts of RNA to analyze the gene expression were also obtained from the materials after measurement of the cell wall extensibility. Furthermore, the levels and composition of cell wall polysaccharides could be measured using the materials after extraction of RNA. These results show that we can analyze the physical and chemical properties of the cell wall as well as gene expression using the identical material obtained in the space experiments.

High-Order Entropy Stable Formulations for Computational Fluid Dynamics

Science.gov (United States)

Carpenter, Mark H.; Fisher, Travis C.

2013-01-01

A systematic approach is presented for developing entropy stable (SS) formulations of any order for the Navier-Stokes equations. These SS formulations discretely conserve mass, momentum, energy and satisfy a mathematical entropy inequality. They are valid for smooth as well as discontinuous flows provided sufficient dissipation is added at shocks and discontinuities. Entropy stable formulations exist for all diagonal norm, summation-by-parts (SBP) operators, including all centered finite-difference operators, Legendre collocation finite-element operators, and certain finite-volume operators. Examples are presented using various entropy stable formulations that demonstrate the current state-of-the-art of these schemes.

Oseltamivir (Tamiflu® in the environment, resistance development in influenza A viruses of dabbling ducks and the risk of transmission of an oseltamivir-resistant virus to humans – a review

Directory of Open Access Journals (Sweden)

Josef D. Järhult

2012-06-01

Full Text Available The antiviral drug oseltamivir (Tamiflu® is a cornerstone in influenza pandemic preparedness plans worldwide. However, resistance to the drug is a growing concern. The active metabolite oseltamivir carboxylate (OC is not degraded in surface water or sewage treatment plants and has been detected in river water during seasonal influenza outbreaks. The natural influenza reservoir, dabbling ducks, can thus be exposed to OC in aquatic environments. Environmental-like levels of OC induce resistance development in influenza A/H1N1 virus in mallards. There is a risk of resistance accumulation in influenza viruses circulating among wild birds when oseltamivir is used extensively. By reassortment or direct transmission, oseltamivir resistance can be transmitted to humans potentially causing a resistant pandemic or human-adapted highly-pathogenic avian influenza virus. There is a need for more research on resistance development in the natural influenza reservoir and for a prudent use of antivirals.

Molecular Mechanisms of Insulin Resistance Development

Directory of Open Access Journals (Sweden)

Vsevolod Arsen'evich Tkachuk

2014-05-01

Full Text Available Insulin resistance (IR is a phenomenon associated with an impaired ability of insulin to stimulate glucose uptake by target cells and to reduce the blood glucose level. A response increase in insulin secretion by the pancreas and hyperinsulinemia are compensatory reactions of the body. The development of IR leads to the inability of target cells to respond to insulin that results in developing type 2 diabetes mellitus (T2DM and metabolic syndrome. For this reason, the metabolic syndrome is defined in practice as a combination of IR with one or more pathologies such as T2DM, arterial hypertension, dyslipidemia, abdominal obesity, non-alcoholic fatty liver disease, and some others. However, a combination of high blood glucose and insulin levels always serves as its physiological criterion.IR should be considered as a systemic failure of the endocrine regulation in the body. Physiological causes of IR are diverse. The main ones are nutritional overload and accumulation of certain lipids and their metabolites in cells, low physical activity, chronic inflammation and stress of various nature, including oxidative and endoplasmic reticulum stress (impairment of damaged protein degradation in the cell. Recent studies have demonstrated that these physiological mechanisms likely act through a single intracellular scenario. This is the impairment of signal transduction from the insulin receptor to its targets via the negative feedback mechanism in intracellular insulin-dependent signaling cascades.This review describes the physiological and intracellular mechanisms of insulin action and focuses on their abnormalities upon IR development. Finally, feasible trends in early molecular diagnosis and therapy of IR are discussed.

Remarks on stable and quasi-stable k-strings at large N

International Nuclear Information System (INIS)

Armoni, A.; Shifman, M.

2003-01-01

We discuss k-strings in the large-N Yang-Mills theory and its supersymmetric extension. Whereas the tension of the bona fide (stable) QCD string is expected to depend only on the N-ality of the representation, tensions that depend on specific representation R are often reported in the lattice literature. In particular, adjoint strings are discussed and found in certain simulations. We clarify this issue by systematically exploiting the notion of the quasi-stable strings which becomes well-defined at large N. The quasi-stable strings with representation-dependent tensions decay, but the decay rate (per unit length per unit time) is suppressed as Λ 2 F(N) where F(N) falls off as a function of N. It can be determined on the case-by-case basis. The quasi-stable strings eventually decay into stable strings whose tension indeed depends only on the N-ality. We also briefly review large-N arguments showing why the Casimir formula for the string tension cannot be correct, and present additional arguments in favor of the sine formula. Finally, we comment on the relevance of our estimates to Euclidean lattice measurements

Evolutionary Stable Strategy

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General Article Volume 21 Issue 9 September 2016 pp 803- ... Keywords. Evolutionary game theory, evolutionary stable state, conflict, cooperation, biological games.

Application of enriched stable isotopes as tracers in biological systems

DEFF Research Database (Denmark)

Stürup, Stefan; Hansen, Helle Rüsz; Gammelgaard, Bente

2008-01-01

The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry...... (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments......, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched...

Heat-stable proteins and abscisic acid action in barley aleurone cells

International Nuclear Information System (INIS)

Jacobsen, J.V.; Shaw, D.C.

1989-01-01

[ 35 S]Methionine labeling experiments showed that abscisic acid (ABA) induced the synthesis of at least 25 polypeptides in mature barley (Hordeum vulgare) aleurone cells. The polypeptides were not secreted. Whereas most of the proteins extracted from aleurone cells were coagulated by heating to 100 degree C for 10 minutes, most of the ABA-induced polypeptides remained in solution (heat-stable). ABA had little effect on the spectrum of polypeptides that were synthesized and secreted by aleurone cells, and most of these secreted polypeptides were also heat-stable. Coomassie blue staining of sodium dodecyl sulfate polyacrylamide gels indicated that ABA-induced polypeptides already occurred in high amounts in mature aleurone layers having accumulated during grain development. About 60% of the total protein extracted from mature aleurone was heat stable. Amino acid analyses of total preparations of heat-stable and heat-labile proteins showed that, compared to heat-labile proteins, heat-stable intracellular proteins were characterized by higher glutamic acid/glutamine (Glx) and glycine levels and lower levels of neutral amino acids. Secreted heat-stable proteins were rich in Glx and proline. The possibilities that the accumulation of the heat-stable polypeptides during grain development is controlled by ABA and that the function of these polypeptides is related to their abundance and extraordinary heat stability are considered

Dietary Components in the Development of Leptin Resistance123

Science.gov (United States)

Vasselli, Joseph R.; Scarpace, Philip J.; Harris, Ruth B. S.; Banks, William A.

2013-01-01

Classically, leptin resistance has been associated with increased body fat and circulating leptin levels, and the condition is believed to contribute to the onset and/or maintenance of obesity. Although a great deal is known about the central nervous system mechanisms mediating leptin resistance, considerably less is known about the role of diet in establishing and maintaining this altered hormonal state. An exciting new finding has recently been published demonstrating the existence of leptin resistance in normal-weight rats with lean leptin levels by feeding them a high-concentration-fructose diet. This finding has opened the possibility that specific macronutrients may be capable of inducing leptin resistance, independently of the amount of body fat or circulating leptin present in the treated animals. This review describes several lines of research that have recently emerged indicating that specific types of dietary sugars and fats are capable of inducing leptin resistance in experimental rodent models. The results further show that diet-induced leptin resistance is capable of increasing energy intake and elevating body weight gain under appropriate dietary challenges. It appears that biological mechanisms on multiple levels may underlie the dietary induction of leptin resistance, including alterations in the leptin blood-to-brain transport system, in peripheral glucose metabolism, and in central leptin receptor signaling pathways. What is clear from the findings reviewed here is that diet-induced leptin resistance can occur in the absence of elevated circulating leptin levels and body weight, rendering it a potential cause and/or predisposing factor to excess body weight gain and obesity. PMID:23493533

Development of wear resistant ceramic coatings for diesel engine components

Energy Technology Data Exchange (ETDEWEB)

Haselkorn, M.H. (Caterpillar, Inc., Peoria, IL (United States))

1992-04-01

Improved fuel economy and a reduction of emissions can be achieved by insulation of the combustion chamber components to reduce heat rejection. However, insulating the combustion chamber components will also increase the operating temperature of the piston ring/cylinder liner interface from approximately 150{degree}C to over 300{degree}C. Existing ring/liner materials can not withstand these higher operating temperatures and for this reason, new materials need to be developed for this critical tribological interface. The overall goal of this program is the development of piston ring/cylinder liner material pairs which would be able to provide the required friction and wear properties at these more severe operating conditions. More specifically, this program first selected, and then evaluated, potential d/wear resistant coatings which could be applied to either piston rings an or cylinder liners and provide, at 350{degree}C under lubricated conditions, coefficients of friction below 0.1 and wear rates of less than 25 {times} lO{sup {minus}6} mm/hour. The processes selected for applying the candidate wear resistant coatings to piston rings and/or cylinder liners were plasma spraying, chemical vapor, physical vapor and low temperature arc vapor deposition techniques as well as enameling techniques.

Antimicrobial resistance and its association with tolerance to heavy metals in agriculture production.

Science.gov (United States)

Yu, Zhongyi; Gunn, Lynda; Wall, Patrick; Fanning, Séamus

2017-06-01

Antimicrobial resistance is a recognized public health challenge that since its emergence limits the therapeutic options available to veterinarians and clinicians alike, when treatment is warranted. This development is further compounded by the paucity of new antibiotics. The agri-food industry benefits from the availability of antimicrobial compounds for food-animal production and crop protection. Nonetheless, their improper use can result in the selection for bacteria that are phenotypically resistant to these compounds. Another class of agents used in agriculture includes various cationic metals that can be included in animal diets as nutritional supplements or spread on pastures to support crop growth and protection. Heavy metals, in particular, are giving rise to concerns among public health professionals, as they can persist in the environment remaining stable for prolonged periods. Moreover, bacteria can also exhibit resistance to these chemical elements and the genes encoding this phenotype can be physically localized to plasmids that may also contain one or more antimicrobial resistance-encoding gene(s). This paper reviews our current understanding of the role that bacteria play in expressing resistance to heavy metals. It will describe how heavy metals are used in agri-food production, and explore evidence available to link resistance to heavy metals and antimicrobial compounds. In addition, possible solutions to reduce the impact of heavy metal resistance are also discussed, including using organic minerals and reducing the level of trace minerals in animal feed rations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identifying Quantitative Trait Loci (QTLs) and Developing Diagnostic Markers Linked to Orange Rust Resistance in Sugarcane (Saccharum spp.).

Science.gov (United States)

Yang, Xiping; Islam, Md S; Sood, Sushma; Maya, Stephanie; Hanson, Erik A; Comstock, Jack; Wang, Jianping

2018-01-01

Sugarcane ( Saccharum spp.) is an important economic crop, contributing up to 80% of table sugar used in the world and has become a promising feedstock for biofuel production. Sugarcane production has been threatened by many diseases, and fungicide applications for disease control have been opted out for sustainable agriculture. Orange rust is one of the major diseases impacting sugarcane production worldwide. Identifying quantitative trait loci (QTLs) and developing diagnostic markers are valuable for breeding programs to expedite release of superior sugarcane cultivars for disease control. In this study, an F 1 segregating population derived from a cross between two hybrid sugarcane clones, CP95-1039 and CP88-1762, was evaluated for orange rust resistance in replicated trails. Three QTLs controlling orange rust resistance in sugarcane (qORR109, qORR4 and qORR102) were identified for the first time ever, which can explain 58, 12 and 8% of the phenotypic variation, separately. We also characterized 1,574 sugarcane putative resistance ( R ) genes. These sugarcane putative R genes and simple sequence repeats in the QTL intervals were further used to develop diagnostic markers for marker-assisted selection of orange rust resistance. A PCR-based Resistance gene-derived maker, G1 was developed, which showed significant association with orange rust resistance. The putative QTLs and marker developed in this study can be effectively utilized in sugarcane breeding programs to facilitate the selection process, thus contributing to the sustainable agriculture for orange rust disease control.

Ethical conflicts in public health research and practice: antimicrobial resistance and the ethics of drug development.

Science.gov (United States)

Aiello, Allison E; King, Nicholas B; Foxman, B

2006-11-01

Since the 1960s, scientists and pharmaceutical representatives have called for the advancement and development of new antimicrobial drugs to combat infectious diseases. In January 2005, Senate Majority Leader Bill Frist (R-TN), MD, introduced a biopreparedness bill that included provisions for patent extensions and tax incentives to stimulate industry research on new antimicrobials. Although government stimulus for private development of new antimicrobials is important, it does not resolve long-standing conflicts of interest between private entities and society. Rising rates of antimicrobial resistance have only exacerbated these conflicts. We used methicillin-resistant Staphylococcus aureus as a case study for reviewing these problems, and we have suggested alternative approaches that may halt the vicious cycle of resistance and obsolescence generated by the current model of antimicrobial production.

Permanent Data Storage in ZnO Thin Films by Filamentary Resistive Switching.

Directory of Open Access Journals (Sweden)

Adolfo Henrique Nunes Melo

Full Text Available Resistive memories are considered the most promising candidates for the next generation of non-volatile memory; however, attention has so far been limited to rewritable memory features for applications in resistive random access memories (RRAM. In this article, we provide a new insight into the applicability of resistive memories. The characteristics of non-rewritable resistive memories (NRRM were investigated. Devices with Pt/ZnO/ITO architecture were prepared using magnetron sputtering, upon which various bipolar and unipolar resistive switching tests were performed. The results showed excellent distinction between the high resistance state (HRS and low resistance state (LRS, with RHRS/RLRS = 5.2 × 1011 for the Pt/ZnO/ITO device with deposition time of 1 h. All samples were stable for more than 104 s, indicating that the devices have excellent applicability in NRRMs.

Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

KAUST Repository

Semple, James; Wyatt-Moon, Gwenhivir; Georgiadou, Dimitra G.; McLachlan, Martyn A.; Anthopoulos, Thomas D.

2017-01-01

Electronic memory cells are of critical importance in modern-day computing devices, including emerging technology sectors such as large-area printed electronics. One technology that has being receiving significant interest in recent years is resistive switching primarily due to its low dimensionality and nonvolatility. Here, we describe the development of resistive switching memory device arrays based on empty aluminum nanogap electrodes. By employing adhesion lithography, a low-temperature and large-area compatible nanogap fabrication technique, dense arrays of memory devices are demonstrated on both rigid and flexible plastic substrates. As-prepared devices exhibit nonvolatile memory operation with stable endurance, resistance ratios >10⁴ and retention times of several months. An intermittent analysis of the electrode microstructure reveals that controlled resistive switching is due to migration of metal from the electrodes into the nanogap under the application of an external electric field. This alternative form of resistive random access memory is promising for use in emerging sectors such as large-area electronics as well as in electronics for harsh environments, e.g., space, high/low temperature, magnetic influences, radiation, vibration, and pressure.

Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

KAUST Repository

Semple, James

2017-01-02

Electronic memory cells are of critical importance in modern-day computing devices, including emerging technology sectors such as large-area printed electronics. One technology that has being receiving significant interest in recent years is resistive switching primarily due to its low dimensionality and nonvolatility. Here, we describe the development of resistive switching memory device arrays based on empty aluminum nanogap electrodes. By employing adhesion lithography, a low-temperature and large-area compatible nanogap fabrication technique, dense arrays of memory devices are demonstrated on both rigid and flexible plastic substrates. As-prepared devices exhibit nonvolatile memory operation with stable endurance, resistance ratios >10⁴ and retention times of several months. An intermittent analysis of the electrode microstructure reveals that controlled resistive switching is due to migration of metal from the electrodes into the nanogap under the application of an external electric field. This alternative form of resistive random access memory is promising for use in emerging sectors such as large-area electronics as well as in electronics for harsh environments, e.g., space, high/low temperature, magnetic influences, radiation, vibration, and pressure.

Development and characterization of mutant winter wheat (Triticum aestivum L.) accessions resistant to the herbicide quizalofop.

Science.gov (United States)

Ostlie, Michael; Haley, Scott D; Anderson, Victoria; Shaner, Dale; Manmathan, Harish; Beil, Craig; Westra, Phillip

2015-02-01

New herbicide resistance traits in wheat were produced through the use of induced mutagenesis. While herbicide-resistant crops have become common in many agricultural systems, wheat has seen few introductions of herbicide resistance traits. A population of Hatcher winter wheat treated with ethyl methanesulfonate was screened with quizalofop to identify herbicide-resistant plants. Initial testing identified plants that survived multiple quizalofop applications. A series of experiments were designed to characterize this trait. In greenhouse studies the mutants exhibited high levels of quizalofop resistance compared to non-mutant wheat. Sequencing ACC1 revealed a novel missense mutation causing an alanine to valine change at position 2004 (Alopecurus myosuroides reference sequence). Plants carrying single mutations in wheat's three genomes (A, B, D) were identified. Acetyl co-enzyme A carboxylase in resistant plants was 4- to 10-fold more tolerant to quizalofop. Populations of segregating backcross progenies were developed by crossing each of the three individual mutants with wild-type wheat. Experiments conducted with these populations confirmed largely normal segregation, with each mutant allele conferring an additive level of resistance. Further tests showed that the A genome mutation conferred the greatest resistance and the B genome mutation conferred the least resistance to quizalofop. The non-transgenic herbicide resistance trait identified will enhance weed control strategies in wheat.

Development of a Midscale Test for Flame Resistant Protection

Science.gov (United States)

2016-08-01

Evaluation of Flame Resistant Clothing for Protection against Fire Simulations Using an Instrumented Manikin, which provides both radiant and convective heat...TEST METHODS FIRE RESISTANT MATERIALS TORCHES SIMULATION TEST EQUIPMENT FLAME RESISTANT CLOTHING PERFORMANCE(ENGINEERING... fabric during a fire , and even after the fire has been extinguished. The best known full scale transmitted heat flux test is the "ASTM F1930

Development of bushing material with higher corrosion and wear resistance; Taishoku taimamosei dogokin bush zairyo no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kira, T; Yokota, H; Kamiya, S [Taiho Kogyo Co. Ltd., Osaka (Japan)

1997-10-01

Recent diesel engines require a higher performance and a longer life. Due to higher cylinder pressure, the operating load and temperature of piston pin bushings become higher. Therefore, higher load capacity, higher wear resistance and higher corrosion resistance are required for piston pin bushings. For this reason, we have studied the effect of components added to copper alloy upon the corrosion resistance and the effect of hard particles dispersed in copper matrix upon the wear resistance and the influence of hard particles on the machinablity of materials. Based on the experimental results, we have developed a new bushing material improving wear and corrosion resistance. 17 figs., 3 tabs.

Fractional flow reserve-guided management in stable coronary disease and acute myocardial infarction: recent developments

Science.gov (United States)

Berry, Colin; Corcoran, David; Hennigan, Barry; Watkins, Stuart; Layland, Jamie; Oldroyd, Keith G.

2015-01-01

Coronary artery disease (CAD) is a leading global cause of morbidity and mortality, and improvements in the diagnosis and treatment of CAD can reduce the health and economic burden of this condition. Fractional flow reserve (FFR) is an evidence-based diagnostic test of the physiological significance of a coronary artery stenosis. Fractional flow reserve is a pressure-derived index of the maximal achievable myocardial blood flow in the presence of an epicardial coronary stenosis as a ratio to maximum achievable flow if that artery were normal. When compared with standard angiography-guided management, FFR disclosure is impactful on the decision for revascularization and clinical outcomes. In this article, we review recent developments with FFR in patients with stable CAD and recent myocardial infarction. Specifically, we review novel developments in our understanding of CAD pathophysiology, diagnostic applications, prognostic studies, clinical trials, and clinical guidelines. PMID:26038588

Phenotypic and genomic comparisons of highly vancomycin-resistant Staphylococcus aureus strains developed from multiple clinical MRSA strains by in vitro mutagenesis.

Science.gov (United States)

Ishii, Kenichi; Tabuchi, Fumiaki; Matsuo, Miki; Tatsuno, Keita; Sato, Tomoaki; Okazaki, Mitsuhiro; Hamamoto, Hiroshi; Matsumoto, Yasuhiko; Kaito, Chikara; Aoyagi, Tetsuji; Hiramatsu, Keiichi; Kaku, Mitsuo; Moriya, Kyoji; Sekimizu, Kazuhisa

2015-11-25

The development of vancomycin (VCM) resistance in Staphylococcus aureus threatens global health. Studies of the VCM-resistance mechanism and alternative therapeutic strategies are urgently needed. We mutagenized S. aureus laboratory strains and methicillin-resistant S. aureus (MRSA) with ethyl methanesulfonate, and isolated mutants that exhibited high resistance to VCM (minimum inhibitory concentration = 32 μg/ml). These VCM-resistant strains were sensitive to linezolid and rifampicin, and partly to arbekacin and daptomycin. Beta-lactams had synergistic effects with VCM against these mutants. VCM-resistant strains exhibited a 2-fold increase in the cell wall thickness. Several genes were commonly mutated among the highly VCM-resistant mutants. These findings suggest that MRSA has a potential to develop high VCM resistance with cell wall thickening by the accumulation of mutations.

Monitoring the agricultural landscape for insect resistance

Science.gov (United States)

Casas, Joseph; Glaser, J. A.; Copenhaver, Ken

Farmers in 25 countries on six continents are using plant biotechnology to solve difficult crop production challenges and conserve the environment. In fact, 13.3 million farmers, which include 90 percent of the farming in developing countries, choose to plant biotech crops. Over the past decade, farmers increased area planted in genetically modified (GM) crops by more than 10 percent each year, thus increasing their farm income by more than 44 billion US dollars (1996-2007), and achieved economic, environmental and social benefits in crops such as soybeans, canola, corn and cotton. To date, total acres of biotech crops harvested exceed more than 2 billion with a proven 13-year history of safe use. Over the next decade, expanded adoption combined with current research on 57 crops in 63 countries will broaden the advantages of genetically modified foods for growers, consumers and the environment. Genetically modified (GM) crops with the ability to produce toxins lethal to specific insect pests are covering a larger percentage of the agricultural landscape every year. The United States department of Agriculture (USDA) estimated that 63 percent of corn and 65 percent of cotton contained these specific genetic traits in 2009. The toxins could protect billions of dollars of loss from insect damage for crops valued at greater than 165 billion US dollars in 2008. The stable and efficient production of these crops has taken on even more importance in recent years with their use, not only as a food source, but now also a source of fuel. It is in the best interest of the United States Environmental Protection Agency (USEPA) to ensure the continued efficacy of toxin producing GM crops as their use reduces pesticides harmful to humans and animals. However, population genetics models have indicated the risk of insect pests developing resistance to these toxins if a high percentage of acreage is grown in these crops. The USEPA is developing methods to monitor the agricultural

Corrosion resistance of chromium-nickel steel containing rare earths

International Nuclear Information System (INIS)

Asatiani, G.N.; Mandzhgaladze, S.N.; Tavadze, L.F.; Chuvatina, S.N.; Saginadze, D.I.

1983-01-01

Effect of additional out-of-furnace treatment with complex alloy (foundry alloy) calcite-silicon-magnesium-rare earth metal on corrosion resistance of the 03Kh18N20M3D3C3B steel has been studied. It is shown that introduction of low additions of rare earths improves its corrosion resistance improves its corrosion resistance in agressive media (in 70% - sulfuric acid) in the range of transition from active to passive state. Effect of additional introduction of rare earth metals is not considerable, if potential of steel corrosion is in the range of stable passive state (32% - sulfuric acid). Additional out-of-furnace treatment with complex foundry alloy, containing rare earth metals, provides a possibility to use a steel with a lower content of Cr, Ni, Mo, than in conventional acid-resistant steels in highly agressive media

Development of stable monolithic wide-field Michelson interferometers.

Science.gov (United States)

Wan, Xiaoke; Ge, Jian; Chen, Zhiping

2011-07-20

Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations. © 2011 Optical Society of America

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj; Khan, Yasser; Cha, Dong Kyu; Almadhoun, Mahmoud N.; Li, Ruipeng; Chen, Long; Amassian, Aram; Odeh, Ihab N.; Alshareef, Husam N.

2013-01-01

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj

2013-12-23

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

Solvent-resistant nanofiltration for product purification and catalyst recovery in click chemistry reactions.

Science.gov (United States)

Cano-Odena, Angels; Vandezande, Pieter; Fournier, David; Van Camp, Wim; Du Prez, Filip E; Vankelecom, Ivo F J

2010-01-18

The quickly developing field of "click" chemistry would undoubtedly benefit from the availability of an easy and efficient technology for product purification to reduce the potential health risks associated with the presence of copper in the final product. Therefore, solvent-resistant nanofiltration (SRNF) membranes have been developed to selectively separate "clicked" polymers from the copper catalyst and solvent. By using these solvent-stable cross-linked polyimide membranes in diafiltration, up to 98 % of the initially present copper could be removed through the membrane together with the DMF solvent, the polymer product being almost completely retained. This paper also presents the first SRNF application in which the catalyst permeates through the membrane and the reaction product is retained.

Stable isotopes and the environment

International Nuclear Information System (INIS)

Krouse, H.R.

1990-01-01

Whereas traditionally, stable isotope research has been directed towards resource exploration and development, it is finding more frequent applications in helping to assess the impacts of resource utilization upon ecosystems. Among the many pursuits, two themes are evident: tracing the transport and conversions of pollutants in the environment and better understanding of the interplay among environmental receptors, e.g. food web studies. Stable isotope data are used primarily to identify the presence of pollutants in the environment and with a few exceptions, the consequence of their presence must be assessed by other techniques. Increasing attention has been given to the isotopic composition of humans with many potential applications in areas such as paleodiets, medicine, and criminology. In this brief overview examples are used from the Pacific Rim to illustrate the above concepts. 26 refs., 1 tab., 3 figs

Development of a novel ozone- and photo-stable HyPer5 red fluorescent dye for array CGH and microarray gene expression analysis with consistent performance irrespective of environmental conditions

Directory of Open Access Journals (Sweden)

Kille Peter

2008-11-01

Full Text Available Abstract Background Array-based comparative genomic hybridization (CGH and gene expression profiling have become vital techniques for identifying molecular defects underlying genetic diseases. Regardless of the microarray platform, cyanine dyes (Cy3 and Cy5 are one of the most widely used fluorescent dye pairs for microarray analysis owing to their brightness and ease of incorporation, enabling high level of assay sensitivity. However, combining both dyes on arrays can become problematic during summer months when ozone levels rise to near 25 parts per billion (ppb. Under such conditions, Cy5 is known to rapidly degrade leading to loss of signal from either "homebrew" or commercial arrays. Cy5 can also suffer disproportionately from dye photobleaching resulting in distortion of (Cy5/Cy3 ratios used in copy number analysis. Our laboratory has been active in fluorescent dye research to find a suitable alternative to Cy5 that is stable to ozone and resistant to photo-bleaching. Here, we report on the development of such a dye, called HyPer5, and describe its' exceptional ozone and photostable properties on microarrays. Results Our results show HyPer5 signal to be stable to high ozone levels. Repeated exposure of mouse arrays hybridized with HyPer5-labeled cDNA to 300 ppb ozone at 5, 10 and 15 minute intervals resulted in no signal loss from the dye. In comparison, Cy5 arrays showed a dramatic 80% decrease in total signal during the same interval. Photobleaching experiments show HyPer5 to be resistant to light induced damage with 3- fold improvement in dye stability over Cy5. In high resolution array CGH experiments, HyPer5 is demonstrated to detect chromosomal aberrations at loci 2p21-16.3 and 15q26.3-26.2 from three patient sample using bacterial artificial chromosome (BAC arrays. The photostability of HyPer5 is further documented by repeat array scanning without loss of detection. Additionally, HyPer5 arrays are shown to preserve sensitivity and

Genetic stability in potato germplasm for resistance to root galling caused by the powdery scab pathogen spongospora subterranea

Science.gov (United States)

Spongospora subteranea, the causal agent of potato powdery scab is becoming increasingly important worldwide. Little is known about the genetic basis of resistance to this disease. The present study tested the hypothesis that potato genotypes with stable genetic resistance to "Spongospora root galli...

Development of live attenuated sparfloxacin-resistant Streptococcus agalactiae polyvalent vaccines to protect Nile tilapia

Science.gov (United States)

To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resi...

Insecticide resistance and resistance mechanisms in bed bugs, Cimex spp. (Hemiptera: Cimicidae).

Science.gov (United States)

Dang, Kai; Doggett, Stephen L; Veera Singham, G; Lee, Chow-Yang

2017-06-29

The worldwide resurgence of bed bugs [both Cimex lectularius L. and Cimex hemipterus (F.)] over the past two decades is believed in large part to be due to the development of insecticide resistance. The transcriptomic and genomic studies since 2010, as well as morphological, biochemical and behavioral studies, have helped insecticide resistance research on bed bugs. Multiple resistance mechanisms, including penetration resistance through thickening or remodelling of the cuticle, metabolic resistance by increased activities of detoxification enzymes (e.g. cytochrome P450 monooxygenases and esterases), and knockdown resistance by kdr mutations, have been experimentally identified as conferring insecticide resistance in bed bugs. Other candidate resistance mechanisms, including behavioral resistance, some types of physiological resistance (e.g. increasing activities of esterases by point mutations, glutathione S-transferase, target site insensitivity including altered AChEs, GABA receptor insensitivity and altered nAChRs), symbiont-mediated resistance and other potential, yet undiscovered mechanisms may exist. This article reviews recent studies of resistance mechanisms and the genes governing insecticide resistance, potential candidate resistance mechanisms, and methods of monitoring insecticide resistance in bed bugs. This article provides an insight into the knowledge essential for the development of both insecticide resistance management (IRM) and integrated pest management (IPM) strategies for successful bed bug management.

Leaf water stable isotopes and water transport outside the xylem.

Science.gov (United States)

Barbour, M M; Farquhar, G D; Buckley, T N

2017-06-01

How water moves through leaves, and where the phase change from liquid to vapour occurs within leaves, remain largely mysterious. Some time ago, we suggested that the stable isotope composition of leaf water may contain information on transport pathways beyond the xylem, through differences in the development of gradients in enrichment within the various pathways. Subsequent testing of this suggestion provided ambiguous results and even questioned the existence of gradients in enrichment within the mesophyll. In this review, we bring together recent theoretical developments in understanding leaf water transport pathways and stable isotope theory to map a path for future work into understanding pathways of water transport and leaf water stable isotope composition. We emphasize the need for a spatially, anatomically and isotopically explicit model of leaf water transport. © 2016 John Wiley & Sons Ltd.

Development of wear-resistant coatings for cobalt-base alloys

International Nuclear Information System (INIS)

Cockeram, B.V.

1999-01-01

The costs and hazards resulting from nuclear plant radiation exposure with activated cobalt wear debris could potentially be reduced by covering the cobalt-base materials with a wear resistant coating. However, the hardnesses of many cobalt-base wear alloys are significantly lower than conventional PVD hard coatings, and mechanical support of the hard coating is a concern. Four approaches have been taken to minimize the hardness differences between the substrate and PVD hard coating: (1) use a thin Cr-nitride hard coating with layers that are graded with respect to hardness, (2) use a thicker, multilayered coating (Cr-nitride or Zr-nitride) with graded layers, (3) use nitriding to harden the alloy subsurface followed by application of a multilayered coating of Cr-nitride, and (4) use of nitriding alone. Since little work has been done on application of PVD hard coatings to cobalt-base alloys, some details on process development and characterization of the coatings is presented. Scratch testing was used to evaluate the adhesion of the different coatings. A bench-top rolling contact test was used to evaluate the wear resistance of the coatings. The test results are discussed, and the more desirable coating approaches are identified

Heat-resistant fungi of importance to the food and beverage industry.

Science.gov (United States)

Tournas, V

1994-01-01

Spoilage of pasteurized and canned fruit and fruit products caused by heat-resistant molds have been reported repeatedly in recent years. Species most commonly implicated in fruit and fruit product disintegration are Byssochlamys fulva, Byssochlamys nivea, Neosartorya fischeri, Talaromyces flavus, and Eupenicillium brefeldianum. These organisms are saprophytic rather than parasitic and usually contaminate fruits on or near the ground. They can survive heat treatments used for fruit processing and can grow and spoil the products during storage at room temperature, which results in great economic losses. Mold heat resistance is attributed to the formation of sexual spores, ascospores. Ascospores have a wide range of heat resistance, depending on species, strain, age of organism, heating medium, pH, presence of sugars, fats, and acids in heating medium, growth conditions, etc. The mechanism(s) of thermoresistance are not clear; probably some very stable compound(s) critical to germination and outgrowth are present in the heat-resistant ascospores. Besides spoilage, the heat-resistant molds produce a number of toxic secondary metabolites, such as byssotoxin A; byssochlamic acid; the carcinogen, patulin, the tremorgenic substances, fumitremorgin A and C, and verruculogen; fischerin, which caused fatal peritonitis in mice; and eupenifeldin, a compound possessing cytotoxicity as well as in vivo antitumor activity. Growth of heat-resistant fungi can be controlled by lowering the water activity, adding sulfur dioxide, sorbate, or benzoate; washing of fruits in hypochlorite solution before heat treatment reduces the number of ascospores and makes the heat destruction more successful. More research is needed to elucidate the mechanism(s) of thermoresistance and develop new methods for the complete inactivation of resistant ascospores.

Desiccation resistance: effect of cuticular hydrocarbons and water content in Drosophila melanogaster adults

Directory of Open Access Journals (Sweden)

Jean-Francois Ferveur

2018-02-01

Full Text Available Background The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydrocarbons that prevent rapid dehydration. The waterproofing properties of cuticular hydrocarbons (CHs depend on their chain length and desaturation number. Drosophila CH biosynthesis involves an enzymatic pathway including several elongase and desaturase enzymes. Methods The link between desiccation resistance and CH profile remains unclear, so we tested (1 experimentally selected desiccation-resistant lines, (2 transgenic flies with altered desaturase expression and (3 natural and laboratory-induced CH variants. We also explored the possible relationship between desiccation resistance, relative water content and fecundity in females. Results We found that increased desiccation resistance is linked with the increased proportion of desaturated CHs, but not with their total amount. Experimentally-induced desiccation resistance and CH variation both remained stable after many generations without selection. Conversely, flies with a higher water content and a lower proportion of desaturated CHs showed reduced desiccation resistance. This was also the case in flies with defective desaturase expression in the fat body. Discussion We conclude that rapidly acquired desiccation resistance, depending on both CH profile and water content, can remain stable without selection in a humid environment. These three phenotypes, which might be expected to show a simple relationship, turn out to have complex physiological and genetic links.

Development of Steel Fiber-Reinforced Expanded-Shale Lightweight Concrete with High Freeze-Thaw Resistance

Directory of Open Access Journals (Sweden)

Mingshuang Zhao

2018-01-01

Full Text Available For the popularized structural application, steel fiber-reinforced expanded-shale lightweight concrete (SFRELC with high freeze-thaw resistance was developed. The experimental study of this paper figured out the effects of air-entraining content, volume fraction of steel fibers, and fine aggregate type. Results showed that while the less change of mass loss rate was taken place for SFRELC after 300 freeze-thaw cycles, the relative dynamic modulus of elasticity and the relative flexural strength presented clear trends of freeze-thaw resistance of SFRELC. The compound effect of the air-entraining agent and the steel fibers was found to support the SFRELC with high freeze-thaw resistance, and the mechanisms were explored with the aid of the test results of water penetration of SFRELC. The beneficial effect was appeared from the replacement of lightweight sand with manufactured sand. Based on the test results, suggestions are given out for the optimal mix proportion of SFRELC to satisfy the durability requirement of freeze-thaw resistance.

Development of a bio-chip dedicated to planetary exploration. First step: resistance studies to space conditions

International Nuclear Information System (INIS)

Le Postollec, A.; Dobrijevic, M.; Incerti, S.; Moretto, Ph.; Seznec, H.; Desorgher, L.; Santin, G.; Nieminen, P.; Dartnell, L.; Vandenabeele-Trambouze, O.; Coussot, G.

2008-02-01

For upcoming exploration missions, space agencies advocate the development of a new promising technique to search for traces of extent or extinct life: the bio-chip use. A bio-chip is a miniaturized device composed of biological sensitive systems fixed on a solid substrate. As space is a hazardous environment, a main concern relies on the resistance of a bio-chip to a panel of harsh constraints among which the resistance to radiations. Within the framework of the BiOMAS (Bio-chip for Organic Matter Analysis in Space) project, our team is currently developing a bio-chip especially designed for planetary exploration. We present here the methodology adopted and the beginning experiments to select the best constituents, to determine resistance levels and to define well-adapted protection for the bio-chip

Development of drug resistance mutations in patients on highly active antiretroviral therapy: does competitive advantage drive evolution.

Science.gov (United States)

Kolber, Michael A

2007-01-01

Most physicians that treat individuals with HIV-1 disease are able to successfully suppress viral replication with the pharmacologic armamentarium available today. For the majority of patients this results in immune reconstitution and improved quality of life. However, a large fraction of these patients have transient elevations in their viral burden and even persistence of low-level viremia. In fact, many individuals whose viral load is suppressed to < 50 c/ml have evidence of low-level viral replication. The impact of low-level viremia and persistent viral replication is an area of significant study and interest owing to the potential for the development of drug resistance mutations. Here the fundamental question is whether and perhaps what factors provide a venue for the development of resistant virus. The concern is clearly the eventual progression of disease with the exhaustion of treatment options. The purpose of this review is to evaluate the current literature regarding the effect of low-level viremia on the development of drug resistance mutations. Herein, we discuss the impact of different levels of viral suppression on the development of mutations. In addition, we look at the role that resistance and fitness play in determining the survival of a breakthrough mutation within the background of drug.

Development of a novel Sinapis arvensis disomic addition line in Brassica napus containing the restorer gene for Nsa CMS and improved resistance to Sclerotinia sclerotiorum and pod shattering.

Science.gov (United States)

Wei, Wenhui; Li, Yunchang; Wang, Lijun; Liu, Shengyi; Yan, Xiaohong; Mei, Desheng; Li, Yinde; Xu, Yusong; Peng, Pengfei; Hu, Qiong

2010-04-01

An allo-cytoplasmic male sterile line, which was developed through somatic hybridization between Brassica napus and Sinapis arvensis (thus designated as Nsa CMS line), possesses high potential for hybrid production of rapeseed. In order to select for restorer lines, fertile plants derived from the same somatic hybridization combination were self-pollinated and testcrossed with the parental Nsa CMS line for six generations. A novel disomic alien addition line, B. napus-S. arvensis, has been successfully developed. GISH analysis showed that it contains one pair of chromosomes from S. arvensis and 19 pairs from B. napus, and retains stable and regular mitotic and meiotic processes. The addition line displays very strong restoration ability to Nsa CMS line, high resistance to Sclerotinia sclerotiorum and a low incidence of pod shattering. Because the addition line shares these very important agricultural characters, it is a valuable restorer to Nsa CMS line, and is named NR1 here (Nsa restorer no. 1).

Understanding the Formation of Kinetically Stable Compounds and the Development of Thin Film Pair Distribution Function Analysis

Science.gov (United States)

Wood, Suzannah Rebecca

Navigating the synthesis landscape poses many challenges when developing novel solid state materials. Advancements in both synthesis and characterization are necessary to facilitate the targeting of specific materials. This dissertation discusses the formation of chalcogenide heterostructures and their properties in the first part and the development of thin film pair distribution function analysis (tfPDF) in the second part. The heterostructures were formed by the self-assembly of designed precursors deposited by physical vapor deposition in a modulated elemental reactants approach, which provides the control and predictability to synthesis. Specifically, a series of (BiSe)1+delta(TiSe2) n, where n = 2,3,&4, were synthesized to explore the extent of charge transfer from the BiSe to TiSe2 layers. To further explore the role Bi plays in charge donation, a family of structurally similar compounds, (Bix Sn1-xSe)1+deltaTiSe2, where 0≥x≥1, were synthesized and characterized. Electrical measurements show doping efficiency decreases as x increases, correlated with the structural distortion and the formation of periodic antiphase boundaries containing Bi-Bi pairs. The first heterostructures composed of three unique structural types were synthesized and Bi2Se3 layer thickness was used to tune electrical properties and further explore charge transfer. To better understand the potential energy landscape on which these kinetically stable compounds exist, two investigations were undertaken. The first was a study of the formation and subsequent decomposition of [(BiSe)1+delta]n(TiSe2)n compounds, where n= 2&3, the second an investigation of precursor structure for thermodynamically stable FeSb2 and kinetically stable FeSb3. The second section describes the development of thin film pair distribution function analysis, a technique in which total scattering data for pair distribution function (PDF) analysis is obtained from thin films, suitable for local structure analysis

The instability criterion for ideal and resistive MHD modes

International Nuclear Information System (INIS)

Li Ding

2002-01-01

The instability criterions for ideal helical perturbation and resistive kink/tearing modes are derived for arbitrary q profile. It is found that the q=1 mode can be unstable only within the q=1 surface in positive shear plasma. The instability region is enlarged as q 0 decreases and/or the current density is flatted. The instability can be completely suppressed in the reverse shear plasma for peaked, and flatted current profile. The q>1 modes are stable in the plasma core and marginal stable within the rational surface in the positive shear plasma. They become more stable in the plasma core and still marginal stable around the rational surface in the reversed shear plasma. It is shown that in the positive shear plasma, the q=1, 5/4, 4/3, 3/2 and 2/1 modes are in turn destabilized and becomes dominant unstable mode as q 0 increases for fixed q a . In the reversed shear plasma, all the q=1 and q>1 modes can be stable when q0 1 modes in turn becomes unstable as q 0 (>1) increases. At first, the inner branch is stable while the outer branch weakly unstable. Then, the both branches can become strongly unstable as q0 increases. (author)

Development of live attenuated Streptococcus agalactiae as potential vaccines by selecting for resistance to sparfloxacin.

Science.gov (United States)

Pridgeon, Julia W; Klesius, Phillip H

2013-05-31

To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resistant S. agalactiae isolates were tested in 10-12g Nile tilapia by intraperitoneal injection at dose of 2×10(7)CFU/fish, 31 were found to be avirulent to fish. Of the 31 avirulent sparfloxacin-resistant S. agalactiae isolates, 30 provided 75-100% protection to 10-12g Nile tilapia against challenges with a virulent S. agalactiae isolate Sag 50. When the virulence of the 30 sparfloxacin-resistant S. agalactiae isolates was tested in 3-5g Nile tilapia by intraperitoneal injection at dose of 2×10(7)CFU/fish, six were found to be avirulent to 3-5g Nile tilapia. Of the six avirulent sparfloxacin-resistant S. agalactiae isolates, four provided 3-5g Nile tilapia 100% protection against challenges with homologous isolates, including Sag 97-spar isolate that was non-hemolytic. However, Sag 97-spar failed to provide broad cross-protection against challenges with heterologous isolates. When Nile tilapia was vaccinated with a polyvalent vaccine consisting of 30 sparfloxacin-resistant S. agalactiae isolates at dose of 2×10(6)CFU/fish, the polyvalent vaccine provided significant (PS. agalactiae. Taken together, our results suggest that a polyvalent vaccine consisting of various strains of S. agalactiae might be essential to provide broader protection to Nile tilapia against infections caused by S. agalactiae. Published by Elsevier Ltd.

DIRProt: a computational approach for discriminating insecticide resistant proteins from non-resistant proteins.

Science.gov (United States)

Meher, Prabina Kumar; Sahu, Tanmaya Kumar; Banchariya, Anjali; Rao, Atmakuri Ramakrishna

2017-03-24

Insecticide resistance is a major challenge for the control program of insect pests in the fields of crop protection, human and animal health etc. Resistance to different insecticides is conferred by the proteins encoded from certain class of genes of the insects. To distinguish the insecticide resistant proteins from non-resistant proteins, no computational tool is available till date. Thus, development of such a computational tool will be helpful in predicting the insecticide resistant proteins, which can be targeted for developing appropriate insecticides. Five different sets of feature viz., amino acid composition (AAC), di-peptide composition (DPC), pseudo amino acid composition (PAAC), composition-transition-distribution (CTD) and auto-correlation function (ACF) were used to map the protein sequences into numeric feature vectors. The encoded numeric vectors were then used as input in support vector machine (SVM) for classification of insecticide resistant and non-resistant proteins. Higher accuracies were obtained under RBF kernel than that of other kernels. Further, accuracies were observed to be higher for DPC feature set as compared to others. The proposed approach achieved an overall accuracy of >90% in discriminating resistant from non-resistant proteins. Further, the two classes of resistant proteins i.e., detoxification-based and target-based were discriminated from non-resistant proteins with >95% accuracy. Besides, >95% accuracy was also observed for discrimination of proteins involved in detoxification- and target-based resistance mechanisms. The proposed approach not only outperformed Blastp, PSI-Blast and Delta-Blast algorithms, but also achieved >92% accuracy while assessed using an independent dataset of 75 insecticide resistant proteins. This paper presents the first computational approach for discriminating the insecticide resistant proteins from non-resistant proteins. Based on the proposed approach, an online prediction server DIRProt has

Development and Testing of Abrasion Resistant Hard Coats For Polymer Film Reflectors: Preprint

Energy Technology Data Exchange (ETDEWEB)

Jorgensen, G.; Gee, R.; DiGrazia, M.

2010-10-01

Reflective polymer film technology can significantly reduce the cost of solar reflectors and installed Concentrated Solar Power (CSP) plants by both reduced material cost and lower weight. One challenge of polymer reflectors in the CSP environment pertains to contact cleaning methods typically used with glass mirrors. Such contact cleaning methods can scratch the surface of polymer reflectors and thereby reduce specular reflectance. ReflecTech, Inc. (a subsidiary of SkyFuel, Inc.) and the National Renewable Energy Laboratory (NREL) initiated a cooperative research and development agreement (CRADA) to devise and develop an abrasion resistant coating (ARC) suitable for deposition onto polymer based mirror film. A number of candidate ARC products were identified as candidate formulations. Industrial collaborators prepared samples having their ARCs deposited onto ReflecTech Mirror Film pre-laminated to aluminum sheet substrates. Samples were provided for evaluation and subjected to baseline (unweathered) and accelerated exposure conditions and subsequently characterized for abrasion resistance and adhesion. An advanced ARC product has been identified that exhibits outstanding initial abrasion resistance and adhesion to ReflecTech Mirror Film. These properties were also retained after exposure to the various accelerated stress conditions. This material has been successfully manufactured as a 1.5 m wide roll-to-roll construction in a production environment.

Positional stability of field-reversed-configurations in the presence of resistive walls

Energy Technology Data Exchange (ETDEWEB)

Rath, N., E-mail: nrath@trialphanenergy.com; Onofri, M.; Barnes, D. C. [Tri Alpha Energy, P.O. Box 7010, Rancho Santa Margarita, California 92688-7010 (United States)

2016-06-15

We show that in a field-reversed-configuration, the plasma is unstable to either transverse or axial rigid displacement, but never to both. Driving forces are found to be parallel to the direction of displacement with no orthogonal components. Furthermore, we demonstrate that the properties of a resistive wall (geometry and resistivity) in the vicinity of the plasma do not affect whether the plasma is stable or unstable, but in the case of an unstable system determine the instability growth rate. Depending on the properties of the wall, the instability growth is dominated by plasma inertia (and not affected by wall resistivity) or dominated by ohmic dissipation of wall eddy currents (and thus proportional to the wall resistivity).

An Update on Genetic Resistance of Chickpea to Ascochyta Blight

Directory of Open Access Journals (Sweden)

Mamta Sharma

2016-03-01

Full Text Available Ascochyta blight (AB caused by Ascochyta rabiei (Pass. Labr. is an important and widespread disease of chickpea (Cicer arietinum L. worldwide. The disease is particularly severe under cool and humid weather conditions. Breeding for host resistance is an efficient means to combat this disease. In this paper, attempts have been made to summarize the progress made in identifying resistance sources, genetics and breeding for resistance, and genetic variation among the pathogen population. The search for resistance to AB in chickpea germplasm, breeding lines and land races using various screening methods has been updated. Importance of the genotype × environment (GE interaction in elucidating the aggressiveness among isolates from different locations and the identification of pathotypes and stable sources of resistance have also been discussed. Current and modern breeding programs for AB resistance based on crossing resistant/multiple resistant and high-yielding cultivars, stability of the breeding lines through multi-location testing and molecular marker-assisted selection method have been discussed. Gene pyramiding and the use of resistant genes present in wild relatives can be useful methods in the future. Identification of additional sources of resistance genes, good characterization of the host–pathogen system, and identification of molecular markers linked to resistance genes are suggested as the key areas for future study.

Development and evaluation of a HEPA filter for increased strength and resistance to elevated temperature

International Nuclear Information System (INIS)

Gilbert, H.; Bergman, W.; Fretthold, J.K.

1992-01-01

We have developed an improved HEPA filter for increased strength and resistance to elevated temperature to improve the reliability of HEPA filters under accident conditions. The improvements to the HEPA filter consist of a silicone rubber sealant and a new HEPA medium reinforced with a glass cloth. Several prototype filters were built and evaluated for temperature and pressure resistance and resistance to rough handling. The temperature resistance test consisted of exposing the HEPA filter to 1,000 scan at 700 degrees F for five minutes. The pressure resistance test consisted of exposing the HEPA filter to a differential pressure of 10 in. w.g. using a water saturated air flow at 95 degrees F. For the rough handling test, we used a vibrating machine designated the Q110. DOP filter efficiency tests were performed before and after each of the environmental tests. In addition to following the standard practice of using a separate new filter for each environmental test, we also subjected the same filter to the elevated temperature test followed by the pressure resistance test. The efficiency test results show that the improved HEPA filter is significantly better than the standard HEPA filter

Study to develop improved fire resistant aircraft passenger seat materials

Science.gov (United States)

Duskin, F. E.; Schutter, K. J.; Sieth, H. H.; Trabold, E. L.

1980-01-01

The Phase 3 study of the NASA 'Improved Fire Resistant Aircraft Seat Materials' involved fire tests of improved materials in multilayered combinations representative of cushion configurations. Tests were conducted to determine their thermal, smoke, and fire resistance characteristics. Additionally, a 'Design Guideline' for Fire Resistant Passenger Seats was written outlining general seat design considerations. Finally, a three-abreast 'Tourist Class' passenger seat assembly fabricated from the most advanced fire-resistant materials was delivered.

Development of high-performance monitoring system under severe accident condition

International Nuclear Information System (INIS)

Takeuchi, Tomoaki; Tsuchiya, Kunihiro; Ishihara, Masahiro; Komanome, H.; Miura, K.

2017-01-01

A research and development of a monitoring system for NPPs situations even during severe accidents have been performed. The R and D consists of the three objectives. The major findings are briefly summarized in the followings: 1) Radiation-resistant monitoring camera. The image sensor with the photogate and three transistors was found to be advantageous in terms of dark current and sensitivity. In addition, radiation-resistant optical parts and signal circuits were successfully fabricated. The results suggested that the monitoring camera system with 10 6 Gy in radiation resistance was possible. 2) Radiation-resistant in-water wireless transmission system. A two-dimensional LED matrix with 10 6 Gy in radiation resistance and a camera were used as the transmission devices. The results of the in-water transmission tests suggested that stable wireless transmission between 5 m distance was possible even with bubble, turbidity, or obstacles. 3) Heat-resistant signal cable. In order to develop a cable that can transmit the data inside reactor pressure vessels, heat-proof tests were performed for candidate metallic sheath materials of mineral insulation (MI) cables. The results indicated MI cables which can be used at 1000degC in air were possible. These results indicate the feasibility of the monitoring system even during severe accidents. (author)

On the Restriction of the Location of Stable Points for Generalized Lotka-Volterra

OpenAIRE

Livesay, Michael Richard

2017-01-01

We develop tools to determine which fixed points in a generalized Lotka-Volterra system are stable, under certain non-degeneracy conditions. We characterize which faces of the boundary of the domain of the Lotka-Volterra system could contain a stable fixed point. Under various relaxed conditions, we show that whenever a face of the boundary contains a stable point there are no other stable points in any strictly larger face of the boundary.

Esters of pyrazinoic acid are active against pyrazinamide-resistant strains of Mycobacterium tuberculosis and other naturally resistant mycobacteria in vitro and ex vivo within macrophages.

KAUST Repository

Pires, David

2015-10-05

Pyrazinamide (PZA) is active against major Mycobacterium tuberculosis species (M. tuberculosis, M. africanum, and M. microti), but not against M. bovis and M. avium. The latter two are mycobacteria species involved in human and cattle tuberculosis and in HIV co-infections, respectively. PZA is a first-line agent for the treatment of human tuberculosis and requires activation by a mycobacterial pyrazinamidase to form the active metabolite pyrazinoic acid (POA). As a result of this mechanism, resistance to PZA as often found in tuberculosis patients is caused by point mutations in pyrazinamidase. In previous work, we have shown that POA esters and amides synthesized in our laboratory were stable in plasma. Although the amides did not present significant activity, the esters were active against sensitive mycobacteria at concentrations 5-to-10 fold lower than those of PZA. Here, we report that these POA derivatives possess antibacterial efficacy in vitro and ex vivo against several species and strains of Mycobacterium with natural or acquired resistance to PZA, including M. bovis and M. avium. Our results indicate that the resistance was probably overcome by cleavage of the prodrugs into POA and a long-chain alcohol. Although it is not possible to rule out that the esters may have intrinsic activity per se, we bring evidence here that long-chain fatty alcohols possess a significant anti-mycobacterial effect against PZA-resistant species and strains and are not mere inactive promoieties. These findings may lead to candidate dual-drugs having enhanced activity against both PZA-susceptible and PZA-resistant isolates and being suitable for clinical development.

Bipolar resistive switching behaviors of ITO nanowire networks

Directory of Open Access Journals (Sweden)

Qiang Li

2016-02-01

Full Text Available We have fabricated indium tin oxide (ITO nanowire (NW networks on aluminum electrodes using electron beam evaporation. The Ag/ITO-NW networks/Al capacitor exhibits bipolar resistive switching behavior. The resistive switching characteristics of ITO-NW networks are related to the morphology of NWs. The x-ray photoelectron spectroscopy was used to obtain the chemical nature from the NWs surface, investigating the oxygen vacancy state. A stable switching voltages and a clear memory window were observed in needle-shaped NWs. The ITO-NW networks can be used as a new two-dimensional metal oxide material for the fabrication of high-density memory devices.

Oridonin Targets Multiple Drug-Resistant Tumor Cells as Determined by in Silico and in Vitro Analyses

Directory of Open Access Journals (Sweden)

Onat Kadioglu

2018-04-01

Full Text Available Drug resistance is one of the main reasons of chemotherapy failure. Therefore, overcoming drug resistance is an invaluable approach to identify novel anticancer drugs that have the potential to bypass or overcome resistance to established drugs and to substantially increase life span of cancer patients for effective chemotherapy. Oridonin is a cytotoxic diterpenoid isolated from Rabdosia rubescens with in vivo anticancer activity. In the present study, we evaluated the cytotoxicity of oridonin toward a panel of drug-resistant cancer cells overexpressing ABCB1, ABCG2, or ΔEGFR or with a knockout deletion of TP53. Interestingly, oridonin revealed lower degree of resistance than the control drug, doxorubicin. Molecular docking analyses pointed out that oridonin can interact with Akt/EGFR pathway proteins with comparable binding energies and similar docking poses as the known inhibitors. Molecular dynamics results validated the stable conformation of oridonin docking pose on Akt kinase domain. Western blot experiments clearly revealed dose-dependent downregulation of Akt and STAT3. Pharmacogenomics analyses pointed to a mRNA signature that predicted sensitivity and resistance to oridonin. In conclusion, oridonin bypasses major drug resistance mechanisms and targets Akt pathway and might be effective toward drug refractory tumors. The identification of oridonin-specific gene expressions may be useful for the development of personalized treatment approaches.

Development of manufacturing method of thermal-resisting concrete with highly synthesizing xonotolite

International Nuclear Information System (INIS)

Yamamoto, Takeshi; Hironaga, Michihiko

2006-01-01

Xonotolite is one of the most stable Ca-Si hydration compounds in the cementitious material. The authors have been developing anti-drying shrinkage concrete with focusing on the stable compounds, i.e. Tobermorite and Xonotolite. In this study, we proposed the manufacturing method of anti-drying shrinkage concrete with using low calcium/silica ratio cementitious material and applying autoclave curing. The compressive strength of proposed concrete was about 40N/mm 2 , and drying shrinkage under 110degC for 1 year was ranged from 0.04 to 0.06%. There was no amount released of combined water from the proposed concrete during exposure, so the stability of main synthesized compound in the proposed concrete was clarified. On the other hand, the conventional cementitious mortar showed from 0.1 to 0.13% of drying shrinkage and high amount release of combined water from the surface area of C-S-H colloid with resulting to widen the volume of pore among the colloid particle of C-S-H. (author)

Resistance and cross-resistance profile of the diaryltriazine NNRTI and candidate microbicide UAMC01398.

Science.gov (United States)

Ariën, Kevin K; Venkatraj, Muthusamy; Michiels, Johan; Joossens, Jurgen; Vereecken, Katleen; Van der Veken, Pieter; Heeres, Jan; De Winter, Hans; Heyndrickx, Leo; Augustyns, Koen; Vanham, Guido

2016-05-01

The resistance development, cross-resistance to other NNRTIs and the impact of resistance on viral replicative fitness were studied for the new and potent NNRTI UAMC01398. Resistance was selected by dose escalation and by single high-dose selection against a comprehensive panel of NNRTIs used as therapeutics and NNRTIs under investigation for pre-exposure prophylaxis of sexual HIV transmission. A panel of 27 site-directed mutants with single mutations or combinations of mutations involved in reverse transcriptase (RT) inhibitor-mediated resistance was developed and used to confirm resistance to UAMC01398. Cross-resistance to other NNRTIs was assessed, as well as susceptibility of UAMC01398-resistant HIV to diarylpyrimidine-resistant viruses. Finally, the impact of UAMC01398 resistance on HIV replicative fitness was studied. We showed that UAMC01398 has potent activity against dapivirine-resistant HIV, that at least four mutations in the RT are required in concert for resistance and that the resistance profile is similar to rilpivirine, both genotypically and phenotypically. Resistance development to UAMC01398 is associated with a severe fitness cost. These data, together with the enhanced safety profile and good solubility in aqueous gels, make UAMC01398 an excellent candidate for HIV topical prevention. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Lack of resistance development in Bemisia tabaci to Isaria fumosorosea after multiple generations of selection

Science.gov (United States)

Gao, Tianni; Wang, Zhaolei; Huang, Yü; Keyhani, Nemat O.; Huang, Zhen

2017-02-01

The emergence of insecticide resistant insect pests is of significant concern worldwide. The whitefly, Bemisia tabaci, is an important agricultural pest and has shown incredible resilience developing resistance to a number of chemical pesticides. Entomopathogenic fungi such as Isaria fumosorosea offer an attractive alternative to chemical pesticides for insect control, and this fungus has been shown to be an effective pathogen of B. tabaci. Little is known concerning the potential for the development of resistance to I. fumosorosea by B. tabaci. Five generations of successive survivors of B. tabaci infected by I. fumosorosea were assayed with I. fumosorosea. No significant differences in susceptibility to I. fumosorosea, number of ovarioles, or ovipostioning were seen between any of the generations tested. Effects of I. fumosorosea and cell-free ethyl acetate fractions derived from the fungus on the B. tabaci fat body, ovary, and vitellogenin were also investigated. These data revealed significant deformation and degradation of ovary tissues and associated vitellogenin by the fungal mycelium as well as by cell-free ethyl acetate fungal extracts. These data indicate the lack of the emergence of resistance to I. fumosorosea under the conditions tested and demonstrate invasion of the insect reproductive tissues during fungal infection.

Robust stator resistance identification of an IM drive using model reference adaptive system

International Nuclear Information System (INIS)

Madadi Kojabadi, Hossein; Abarzadeh, Mostafa; Aghaei Farouji, Said

2013-01-01

Highlights: ► We estimate the stator resistance and rotor speed of the IM. ► We proposed a new quantity to estimate the speed and stator resistance of IM. ► The proposed algorithm is robust to rotor resistance variations. ► We estimate the IM speed and stator resistance simultaneously to avoid speed error. - Abstract: Model reference adaptive system (MRAS) based robust stator resistance estimator for sensorless induction motor (IM) drive is proposed. The MRAS is formed with a semi-active power quantity. The proposed identification method can be achieved with on-line tuning of the stator resistance with robustness against rotor resistance variations. Stable and efficient estimation of IM speed at low region will be guaranteed by simultaneous identification of IM speed and stator resistance. The stability of proposed stator resistance estimator is checked through Popov’s hyperstability theorem. Simulation and experimental results are given to highlight the feasibility, the simplicity, and the robustness of the proposed method.

Development of a stable cell line with an intact PGC-1α/ERRα axis for screening environmental chemicals

International Nuclear Information System (INIS)

Teng, Christina T.; Beames, Burton; Alex Merrick, B.; Martin, Negin; Romeo, Charles; Jetten, Anton M.

2014-01-01

Highlights: • We developed a stable cell line with intact PGC-1α/ERRα axis. • The ERRα repressor, XCT790, down regulates this pathway. • Phytoestrogen, genisten stimulates this pathway. - Abstract: The estrogen-related receptor α (ERRα) and the peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α (PGC-1α) play critical roles in the control of several physiological functions, including the regulation of genes involved in energy homeostasis. However, little is known about the ability of environmental chemicals to disrupt or modulate this important bioenergetics pathway in humans. The goal of this study was to develop a cell-based assay system with an intact PGC-1α/ERRα axis that could be used as a screening assay for detecting such chemicals. To this end, we successfully generated several stable cell lines expressing PGC-1α and showed that the reporter driven by the native ERRα hormone response unit (AAB-Luc) is active in these cell lines and that the activation is PGC-1α-dependent. Furthermore, we show that this activation can be blocked by the ERRα selective inverse agonist, XCT790. In addition, we find that genistein and bisphenol A further stimulate the reporter activity, while kaempferol has minimal effect. These cell lines will be useful for identifying environmental chemicals that modulate this important pathway

Development of a stable cell line with an intact PGC-1α/ERRα axis for screening environmental chemicals

Energy Technology Data Exchange (ETDEWEB)

Teng, Christina T., E-mail: teng1@niehs.nih.gov [DNTP, BioMolecular Screening Branch, Division, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 (United States); Beames, Burton; Alex Merrick, B. [DNTP, BioMolecular Screening Branch, Division, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 (United States); Martin, Negin; Romeo, Charles [DIR, Viral Core Lab, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 (United States); Jetten, Anton M. [DIR Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 (United States)

2014-02-07

Highlights: • We developed a stable cell line with intact PGC-1α/ERRα axis. • The ERRα repressor, XCT790, down regulates this pathway. • Phytoestrogen, genisten stimulates this pathway. - Abstract: The estrogen-related receptor α (ERRα) and the peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α (PGC-1α) play critical roles in the control of several physiological functions, including the regulation of genes involved in energy homeostasis. However, little is known about the ability of environmental chemicals to disrupt or modulate this important bioenergetics pathway in humans. The goal of this study was to develop a cell-based assay system with an intact PGC-1α/ERRα axis that could be used as a screening assay for detecting such chemicals. To this end, we successfully generated several stable cell lines expressing PGC-1α and showed that the reporter driven by the native ERRα hormone response unit (AAB-Luc) is active in these cell lines and that the activation is PGC-1α-dependent. Furthermore, we show that this activation can be blocked by the ERRα selective inverse agonist, XCT790. In addition, we find that genistein and bisphenol A further stimulate the reporter activity, while kaempferol has minimal effect. These cell lines will be useful for identifying environmental chemicals that modulate this important pathway.

Stable isotope methodology and its application to nutrition and gastroenterology

International Nuclear Information System (INIS)

Klein, P.D.; Hachey, D.L.; Wong, W.W.; Abrams, S.A.

1993-01-01

This report describes the activities of the Stable Isotope Laboratory in its function as a core resource facility for stable isotope applications in human nutrition research. Three aspects are covered: Training of visitors, assessment of new instrumentation, and development of new methodology. The research achievements of the laboratory are indicated in the publications that appeared during this period. (author). 23 refs

Development of Proliferation Resistance Assessment Methodology Based on International Standards

International Nuclear Information System (INIS)