Effect of electrode shape on grounding resistances - Part 2

DEFF Research Database (Denmark)

Tomaskovicova, Sonia; Ingeman-Nielsen, Thomas; Christiansen, Anders V.

2016-01-01

Although electric resistivity tomography (ERT) is now regarded as a standard tool in permafrost monitoring, high grounding resistances continue to limit the acquisition of time series over complete freeze-thaw cycles. In an attempt to alleviate the grounding resistance problem, we have tested three...... electrode designs featuring increasing sizes and surface area, in the laboratory and at three different field sites in Greenland. Grounding resistance measurements showed that changing the electrode shape (using plates instead of rods) reduced the grounding resistances at all sites by 28%-69% during...... unfrozen and frozen ground conditions. Using meshes instead of plates (the same rectangular shape and a larger effective surface area) further improved the grounding resistances by 29%-37% in winter. Replacement of rod electrodes of one entire permanent permafrost monitoring array by meshes resulted...

Rate effects in resistive plate chambers

International Nuclear Information System (INIS)

Lippmann, C.; Riegler, W.; Kalweit, A.

2006-01-01

The resistive plates in RPCs cause a drop of the electric field in the gas gap at high particle rates or large gas gain, which affects efficiency and time resolution. This effect is typically estimated by assuming the particle flux to be a DC current that causes a voltage drop when it passes through the resistive plate. In an improved model by Abbrescia (Nucl. Instr. Meth. A 533 (2004) 7), the fluctuation of the field in the gas gap is modelled by assuming that the avalanche partially discharges a small capacitor which gets recharged with a time constant characteristic for the given RPC. In our approach, the effect is calculated by using the exact analytic solution for the time dependent electric field of a point charge sitting on the surface of a resistive plate in an RPC. This is, by definition, the best possible approximation to reality. The solution is obtained using the quasi-static approximation of Maxwell's equations. The formulas are presented as integral representations with 'cured' integrands, which allow easy numerical evaluation for Monte Carlo simulations. The solutions show that the charges in RPCs are 'destroyed' with a continuous distribution of time constants which are related in a very intuitive way to some limiting cases. Using these formulas we present a Monte Carlo simulation of rate effects, proving the applicability of this approach. Finally, we compare the Monte Carlo results to analytical calculations, similar to the ones proposed by Gonzalez-Diaz et al. (see proceedings of this conference)

The effect of resistance exercise on the thermic effect of food.

Science.gov (United States)

Denzer, Charlene M; Young, John C

2003-09-01

The thermic effect of food (TEF) is the increment in energy expenditure above resting metabolic rate associated with the cost of absorption and processing of food for storage. Previous studies have shown that TEF is enhanced by aerobic endurance exercise of sufficient duration and intensity. The purpose of this study was to determine if a similar effect occurs with a single bout of resistance exercise (weightlifting). VO2 was measured in 9 healthy volunteers (3 males and 6 females) for 2 hours after ingestion of a 2760 kJ (660 kcal) carbohydrate meal with and without prior completion of a resistance training regimen (2 sets of 10 repetitions of 10 different exercises). The meal caused an immediate and persistent thermic effect in both the control and the exercise trial. Mean oxygen consumption over baseline increased 20% in the control trial and 34% in the exercise trial. TEF calculated from VO2 and RER (total area under the response curve above baseline) was 73% greater in the exercise trial compared with the control trial (159 +/- 18 vs. 92 +/- 14 KJ/2 hrs, p carbohydrate meal is enhanced following a single bout of resistance exercise.

The effect of resistance exercise on sleep: A systematic review of randomized controlled trials.

Science.gov (United States)

Kovacevic, Ana; Mavros, Yorgi; Heisz, Jennifer J; Fiatarone Singh, Maria A

2018-06-01

Impaired sleep quality and quantity are associated with future morbidity and mortality. Exercise may be an effective non-pharmacological intervention to improve sleep, however, little is known on the effect of resistance exercise. Thus, we performed a systematic review of the literature to determine the acute and chronic effects of resistance exercise on sleep quantity and quality. Thirteen studies were included. Chronic resistance exercise improves all aspects of sleep, with the greatest benefit for sleep quality. These benefits of isolated resistance exercise are attenuated when resistance exercise is combined with aerobic exercise and compared to aerobic exercise alone. However, the acute effects of resistance exercise on sleep remain poorly studied and inconsistent. In addition to the sleep benefits, resistance exercise training improves anxiety and depression. These results suggest that resistance exercise may be an effective intervention to improve sleep quality. Further research is needed to better understand the effects of acute resistance exercise on sleep, the physiological mechanisms underlying changes in sleep, the changes in sleep architecture with chronic resistance exercise, as well its efficacy in clinical cohorts who commonly experience sleep disturbance. Future studies should also examine time-of-day and dose-response effects to determine the optimal exercise prescription for sleep benefits. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of chitosan on resist printing of cotton fabrics with reactive dyes

African Journals Online (AJOL)

user

2011-02-21

Feb 21, 2011 ... levels may cause the dyes to form a partial covalent bond with chitosan, thereby diminishing the resist-printing effect. In such a case, the resist printing would not be linear as a function of chitosan concentration. Red 184 exhibited the highest resist-printing effect, followed by. Blue 204 and Yellow 143.

Effect of resistance feedback on spin torque-induced switching of nanomagnets

International Nuclear Information System (INIS)

Garzon, Samir; Webb, Richard A.; Covington, Mark; Kaka, Shehzaad; Crawford, Thomas M.

2009-01-01

In large magnetoresistance devices spin torque-induced changes in resistance can produce GHz current and voltage oscillations which can affect magnetization reversal. In addition, capacitive shunting in large resistance devices can further reduce the current, adversely affecting spin torque switching. Here, we simultaneously solve the Landau-Lifshitz-Gilbert equation with spin torque and the transmission line telegrapher's equations to study the effects of resistance feedback and capacitance on magnetization reversal of both spin valves and magnetic tunnel junctions. While for spin valves parallel (P) to anti-parallel (AP) switching is adversely affected by the resistance feedback due to saturation of the spin torque, in low resistance magnetic tunnel junctions P-AP switching is enhanced. We study the effect of resistance feedback on the switching time of magnetic tunnel junctions, and show that magnetization switching is only affected by capacitive shunting in the pF range.

Effect of chitosan on resist printing of cotton fabrics with reactive dyes

African Journals Online (AJOL)

The concentration of chitosan, types of resist agent, curing temperature and curing time were varied to determine their effects on resist-printed cotton fabrics. An optimal chitosan concentration of 1.6% resulted in the greatest resist effect on printed cotton fabrics. For mixtures, a 6:4 ratio of citric acid : chitosan and an 8:2 ...

Applying of dilatometric effect for resistance welding automation

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Bondarenko O. F.

2017-06-01

Full Text Available The important issue of resistance spot welding control to obtain high quality welded joints, especially in living tissue welding, is considered. The actual state of the issue is described and analyzed. In order to improve the quality of welded joints, the applying of dilatometric effect to control the resistance spot welding process, namely of shifting the welding electrodes, is suggested. To register the shifting, the use of modern inertial microelectromechanical sensors (MEMS is proposed. The experimental measuring system, which processes the MEMS-sensor signal and makes it suitable for use as a feedback signal, is developed. The structure and operational algorithm of the system are described. The abilities of measuring with MEMS-sensors the values of electrode shifting caused by dilatometric effect under resistance welding are assessed. These method and equipment are recommended for welding the metals, as well as for welding the living tissues. The results of preliminary studies prove the advisability and relevance of the suggested solutions.

Effect of methylglyoxal on multidrug-resistant Pseudomonas aeruginosa

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Katsuhiko eHayashi

2014-04-01

Full Text Available Honey has a complex chemistry, and its broad-spectrum antimicrobial activity varies with floral source, climate, and harvesting conditions. Methylglyoxal was identified as the dominant antibacterial component of manuka honey. Although it has been known that methylglyoxal has antibacterial activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, there is not much information describing its activity against gram-negative bacteria. In this study, we report the effect of methylglyoxal against multidrug-resistant Pseudomonas aeruginosa (MDRP using 53 clinically isolated strains. We also assessed the effect of deleting the five multidrug efflux systems in P. aeruginosa, as well as the efflux systems in Escherichia coli and Salmonella enterica serovar Typhimurium, on MICs of methylglyoxal. Our results indicate that methylglyoxal inhibits the growth of MDRP at concentrations of 128–512 µg/ml (1.7–7.1 mM and is not recognized by drug efflux systems.

Effect of grain boundary microcracks on crack resistance of annealed tungsten

International Nuclear Information System (INIS)

Babak, A.V.; Uskov, E.I.

1984-01-01

Effect of grain boundary microcracks in tungsten, produced by the method of powder sintering, on its crack resistance after annealing at T=2200 deg C, has been considered. On the basis of complex physncomechanical study of tungsten crack resistance it is shown, that the value of ultimate tensile stress does not depend on temperature. The presence of grain boundary cracks in such material (in the limits from 2 to 8%) does not produce effect on its crack resistance

Effectiveness analysis of resistance and tolerance to infection

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Detilleux Johann C

2011-03-01

Full Text Available Abstract Background Tolerance and resistance provide animals with two distinct strategies to fight infectious pathogens and may exhibit different evolutionary dynamics. However, few studies have investigated these mechanisms in the case of animal diseases under commercial constraints. Methods The paper proposes a method to simultaneously describe (1 the dynamics of transmission of a contagious pathogen between animals, (2 the growth and death of the pathogen within infected hosts and (3 the effects on their performances. The effectiveness of increasing individual levels of tolerance and resistance is evaluated by the number of infected animals and the performance at the population level. Results The model is applied to a particular set of parameters and different combinations of values. Given these imputed values, it is shown that higher levels of individual tolerance should be more effective than increased levels of resistance in commercial populations. As a practical example, a method is proposed to measure levels of animal tolerance to bovine mastitis. Conclusions The model provides a general framework and some tools to maximize health and performances of a population under infection. Limits and assumptions of the model are clearly identified so it can be improved for different epidemiological settings.

Effects of pomegranate seed oil followed by resistance exercise on insulin resistance and lipid profile in non-athletic men

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Fereshteh Shahidi

2017-08-01

Full Text Available Background: Although some studies have reported the health-related benefits for the pomegranate seed oil (PSO, there is not enough information on its combined effect with exercise. Therefore, in this study the effect of supplementation with pomegranate seed oil followed by resistance exercise on insulin resistance and lipid profile was considered in non-athletes men. Materials and Methods: In this semi-experimental double-blind randomized study non-athletic male (n=14 were divided into two groups: Exercise+Supplementation (n=7 and Exercise +Placebo (n=7. Both groups performed resistance training for 4 weeks (3 sessions per week. The experimental group consumed 2 capsules of pomegranate seed oil (400 mg and the control group received 2 placebo capsules daily. Glucose, fasting insulin, total cholesterol, triglycerides, LDL-C, HDL-C, were measured at the beginning and end of the study. Insulin resistance was estimated using homeostasis formula (HOMA-IR. Results: While the average concentration of HDL-C in Supplement+Exercise group was significantly increased compared to pre-test, no significant increase was seen compared to Placebo + Exercise group (P<0.05. Between and within group comparison for the changes in total cholesterol, triglycerides, LDL-C, glucose, fasting insulin and insulin resistance was not significant. Conclusion: According to the results, it can be concluded that 4 weeks of resistance training followed by PSO supplementation, except for HDL-C, has no significant effect on the other lipid profiles and insulin resistance in healthy non-athlete men.

Alternative Evolutionary Paths to Bacterial Antibiotic Resistance Cause Distinct Collateral Effects.

Science.gov (United States)

Barbosa, Camilo; Trebosc, Vincent; Kemmer, Christian; Rosenstiel, Philip; Beardmore, Robert; Schulenburg, Hinrich; Jansen, Gunther

2017-09-01

When bacteria evolve resistance against a particular antibiotic, they may simultaneously gain increased sensitivity against a second one. Such collateral sensitivity may be exploited to develop novel, sustainable antibiotic treatment strategies aimed at containing the current, dramatic spread of drug resistance. To date, the presence and molecular basis of collateral sensitivity has only been studied in few bacterial species and is unknown for opportunistic human pathogens such as Pseudomonas aeruginosa. In the present study, we assessed patterns of collateral effects by experimentally evolving 160 independent populations of P. aeruginosa to high levels of resistance against eight commonly used antibiotics. The bacteria evolved resistance rapidly and expressed both collateral sensitivity and cross-resistance. The pattern of such collateral effects differed to those previously reported for other bacterial species, suggesting interspecific differences in the underlying evolutionary trade-offs. Intriguingly, we also identified contrasting patterns of collateral sensitivity and cross-resistance among the replicate populations adapted to the same drug. Whole-genome sequencing of 81 independently evolved populations revealed distinct evolutionary paths of resistance to the selective drug, which determined whether bacteria became cross-resistant or collaterally sensitive towards others. Based on genomic and functional genetic analysis, we demonstrate that collateral sensitivity can result from resistance mutations in regulatory genes such as nalC or mexZ, which mediate aminoglycoside sensitivity in β-lactam-adapted populations, or the two-component regulatory system gene pmrB, which enhances penicillin sensitivity in gentamicin-resistant populations. Our findings highlight substantial variation in the evolved collateral effects among replicates, which in turn determine their potential in antibiotic therapy. © The Author 2017. Published by Oxford University Press on

Effect of Air Gap Entrapped in Firefighter Protective Clothing on Thermal Resistance and Evaporative Resistance

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He Hualing

2018-03-01

Full Text Available Heat and water vapor transfer behavior of thermal protective clothing is greatly influenced by the air gap entrapped in multilayer fabric system. In this study, a sweating hot plate method was used to investigate the effect of air gap position and size on thermal resistance and evaporative resistance of firefighter clothing under a range of ambient temperature and humidity. Results indicated that the presence of air gap in multilayer fabric system decreased heat and water vapor transfer abilities under normal wear. Moreover, the air gap position slightly influenced the thermal and evaporative performances of the firefighter clothing. In this study, the multilayer fabric system obtained the highest thermal resistance, when the air space was located at position B. Furthermore, the effect of ambient temperature on heat and water vapor transfer properties of the multilayer fabric system was also investigated in the presence of a specific air gap. It was indicated that ambient temperature did not influence the evaporative resistance of thermal protective clothing. A thermographic image was used to test the surface temperature of multilayer fabric system when an air gap was incorporated. These results suggested that a certain air gap entrapped in thermal protective clothing system could affect wear comfort.

Antimicrobial Effects of β-Lactams on Imipenem-Resistant Ceftazidime-Susceptible Pseudomonas aeruginosa.

Science.gov (United States)

Wi, Yu Mi; Choi, Ji-Young; Lee, Ji-Young; Kang, Cheol-In; Chung, Doo Ryeon; Peck, Kyong Ran; Song, Jae-Hoon; Ko, Kwan Soo

2017-06-01

We studied the resistance mechanism and antimicrobial effects of β-lactams on imipenem-resistant Pseudomonas aeruginosa isolates that were susceptible to ceftazidime as detected by time-kill curve methods. Among 215 P. aeruginosa isolates from hospitalized patients in eight hospitals in the Republic of Korea, 18 isolates (23.4% of 77 imipenem-resistant isolates) were imipenem resistant and ceftazidime susceptible. Multilocus sequence typing revealed diverse genotypes, which indicated independent emergence. These 18 isolates were negative for carbapenemase genes. All 18 imipenem-resistant ceftazidime-susceptible isolates showed decreased mRNA expression of oprD , and overexpression of mexB was observed in 13 isolates. In contrast, overexpression of ampC , mexD , mexF , or mexY was rarely found. Time-kill curve methods were applied to three selected imipenem-resistant ceftazidime-susceptible isolates at a standard inoculum (5 × 10 5 CFU/ml) or at a high inoculum (5 × 10 7 CFU/ml) to evaluate the antimicrobial effects of β-lactams. Inoculum effects were detected for all three β-lactam antibiotics, ceftazidime, cefepime, and piperacillin-tazobactam, against all three isolates. The antibiotics had significant killing effects in the standard inoculum, but no effects in the high inoculum were observed. Our results suggest that β-lactam antibiotics should be used with caution in patients with imipenem-resistant ceftazidime-susceptible P. aeruginosa infection, especially in high-inoculum infections such as endocarditis and osteomyelitis. Copyright © 2017 American Society for Microbiology.

Anomalous behavior of chemically synthesized magneto plumbite strontium ferrite nano particles

International Nuclear Information System (INIS)

Asghar, G.; Nasir, S.; Awan, M.S.; Tariq, G.H.; Anis-ur-Rehman, M.

2011-01-01

Strontium hexa-ferrite nanoparticles were prepared successfully by simple co-precipitation method. The XRD analysis confirmed the formation of single phase MFe/sub 12/O/sub 19/ (M=Sr). Parameters such as crystallite size, lattice constant, X-ray density and porosity were calculated from the X-ray diffraction data. The crystallite sizes were in the range 12-26 nm. The temperature dependent dc electrical resistivity measurements showed that the material was highly. Dielectric constant and dielectric loss factor (tand) were measured in the frequency range 20Hz-3MHz. The anomalous behavior of dielectric loss revealed a very important behavior of the prepared sample of SrFe/sub 12/O/sub 19/ in different frequency regions and that could be used for new applications of this material. The magnetic properties were determined from the hystersis loop obtained from vibrating sample magnetometer (VSM). The Curie temperature was determined by susceptometer. This material is potentially suitable for use as a recording medium in identification cards and credit cards and for the fabrication of permanent magnets. (author)

Effective dominance of resistance of Spodoptera frugiperda to Bt maize and cotton varieties: implications for resistance management

Science.gov (United States)

Horikoshi, Renato J.; Bernardi, Daniel; Bernardi, Oderlei; Malaquias, José B.; Okuma, Daniela M.; Miraldo, Leonardo L.; Amaral, Fernando S. De A. E.; Omoto, Celso

2016-10-01

The resistance of fall armyworm (FAW), Spodoptera frugiperda, has been characterized to some Cry and Vip3A proteins of Bacillus thuringiensis (Bt) expressed in transgenic maize in Brazil. Here we evaluated the effective dominance of resistance based on the survival of neonates from selected Bt-resistant, heterozygous, and susceptible (Sus) strains of FAW on different Bt maize and cotton varieties. High survival of strains resistant to the Cry1F (HX-R), Cry1A.105/Cry2Ab (VT-R) and Cry1A.105/Cry2Ab/Cry1F (PW-R) proteins was detected on Herculex, YieldGard VT PRO and PowerCore maize. Our Vip3A-resistant strain (Vip-R) exhibited high survival on Herculex, Agrisure Viptera and Agrisure Viptera 3 maize. However, the heterozygous from HX-R × Sus, VT-R × Sus, PW-R × Sus and Vip-R × Sus had complete mortality on YieldGard VT PRO, PowerCore, Agrisure Viptera, and Agrisure Viptera 3, whereas the HX-R × Sus and Vip-R × Sus strains survived on Herculex maize. On Bt cotton, the HX-R, VT-R and PW-R strains exhibited high survival on Bollgard II. All resistant strains survived on WideStrike, but only PW-R and Vip-R × Sus survived on TwinLink. Our study provides useful data to aid in the understanding of the effectiveness of the refuge strategy for Insect Resistance Management of Bt plants.

Effects of prestressing on impact resistance of concrete beams

International Nuclear Information System (INIS)

Mikami, H.; Kishi, N.; Matsuoka, K.G.; Mikami, T.; Nomachi, S.G.

1995-01-01

In this paper, the effects of prestressing on impact resistance of concrete beams using two types of prestressed concrete (PC) tendons are discussed based on experimental results. Aramids Fiber Reinforced Plastic rods and PC steel strand were used as PC tendons. To clarify the effects of prestressing on concrete beam impact resistance, dynamic behavior of prestressed and/or non-prestressed concrete beams with different PC tendon arrangements were considered. Impact test were performed using a 200 kg f free falling steel weight on to the center of beam. (author). 10 refs., 5 figs., 2 tabs

Effect of resistance and aerobic exercises on bone mineral density ...

African Journals Online (AJOL)

Conclusion: Based on obtained data, it can be concluded that, resistance and aerobic exercise training program is effective in increasing BMD, muscle strength and functional ability in children with hemophilia. Keywords: Hemophilia; Resistance; Aerobic exercise; Bone mineral density; Strength; Functional ability ...

Resistance to Change among Veteran Teachers: Providing Voice for More Effective Engagement

Science.gov (United States)

Snyder, Richard R.

2017-01-01

Effective implementation of change remains a crucial concern for educational leaders in the 21st Century. One of the factors affecting effective implementation of reform is resistance to change. Veteran teachers in particular present unique challenges, and stereotypically the greatest resistance, for effective implementation of change. This study…

Effects of toroidicity on resistive tearing modes

International Nuclear Information System (INIS)

Izzo, R.; Monticello, D.A.; Manickam, J.; Strauss, H.R.; Grimm, R.; McGuire, K.

1983-03-01

A reduced set of resistive MHD equations is solved numerically in three dimensions to study the stability of tokamak plasmas. Toroidal effects are included self-consistently to leading and next order in inverse aspect ratio, epsilon. The equations satisfy an energy integral. In addition, the momentum equation yields the Grad-Shafranov equation correct to all orders in epsilon. Low beta plasma are studied using several different q-profiles. In all cases, the linear growth rates are reduced by finite toroidicity. Excellent agreement with resistive PEST is obtianed. In some cases, toroidal effects lead to complete stabilization of the mode. Nonlinear results show smaller saturated island widths for finite aspect ratio compared to the cylindrical limit. If the current channel is wide enough so as to produce steep gradients towards the outside of the plasma, both the finite aspect ratio cases and cylindrical cases disrupt

Chitosan as an effective inhibitor of multidrug resistant Acinetobacter baumannii.

Science.gov (United States)

Costa, E M; Silva, S; Vicente, S; Veiga, M; Tavaria, F; Pintado, M M

2017-12-15

Over the last two decades worldwide levels of antibiotic resistance have risen leading to the appearance of multidrug resistant microorganisms. Acinetobacter baumannii is a known skin pathogen which has emerged as a major cause of nosocomial outbreaks due to its capacity to colonize indwelling medical devices and natural antibiotic resistance. With chitosan being an effective antimicrobial agent against antibiotic resistant microorganisms, the aim of this work was to access its potential as an alternative to traditional antimicrobials in the management of A. baumannii growth. What the results showed was that both chitosan MW's tested were active upon A. baumannii's planktonic and sessile growth. For planktonic growth MICs and MBCs were obtained at relatively low concentrations (0.5-2mg/mL) while for sessile growth chitosan proved to be an effective inhibitor of A. baumannii's adhesion and biofilm formation. Considering these results chitosan shows a high potential for control of A. baumannii infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is electroconvulsive therapy effective as augmentation in clozapine-resistant schizophrenia?

Science.gov (United States)

Kittsteiner Manubens, Lucas; Lobos Urbina, Diego; Aceituno, David

2016-10-14

Clozapine is considered to be the most effective antipsychotic drug for patients with treatment resistant schizophrenia, but up to a third of the patients do not respond to this treatment. Various strategies have been tried to augment the effect of clozapine in non-responders, one of these strategies being electroconvulsive therapy. However, its efficacy and safety are not yet clear. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified six systematic reviews including 55 studies, among them six randomized controlled trials addressing clozapine-resistant schizophrenia. We combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded electroconvulsive therapy probably augments response to clozapine in patients with treatment resistant schizophrenia, but it is not possible to determine if it leads to cognitive adverse effects because the certainty of the evidence is very low.

In Vitro Antibacterial and Antibiotic Resistance Modifying Effect of Bioactive Plant Extracts on Methicillin-Resistant Staphylococcus epidermidis

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Romana Chovanová

2013-01-01

Full Text Available The crude extracts of plants from Asteraceae and Lamiaceae family and essential oils from Salvia officinalis and Salvia sclarea were studied for their antibacterial as well as antibiotic resistance modifying activity. Using disc diffusion and broth microdilution assays we determined higher antibacterial effect of three Salvia spp. and by evaluating the leakage of 260 nm absorbing material we detected effect of extracts and, namely, of essential oils on the disruption of cytoplasmic membrane. The evaluation of in vitro interactions between plant extracts and oxacillin described in terms of fractional inhibitory concentration (FIC indices revealed synergistic or additive effects of plant extracts and clearly synergistic effects of essential oil from Salvia officinalis with oxacillin in methicillin-resistant Staphylococcus epidermidis.

Synergistic effects of antimicrobial peptide DP7 combined with antibiotics against multidrug-resistant bacteria

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Wu X

2017-03-01

Full Text Available Xiaozhe Wu,1 Zhan Li,1 Xiaolu Li,2,3 Yaomei Tian,1 Yingzi Fan,1 Chaoheng Yu,1 Bailing Zhou,1 Yi Liu,4 Rong Xiang,5 Li Yang1 1State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, 2International Center for Translational Chinese Medicine, Sichuan Academy of Chinese Medicine Sciences, Chengdu, 3Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, Luzhou, 4Department of Microbial Examination, Sichuan Center for Disease Control and Prevention, Chengdu, 5Nankai University School of Medicine, Tianjin, People’s Republic of China Abstract: Antibiotic-resistant bacteria present a great threat to public health. In this study, the synergistic effects of antimicrobial peptides (AMPs and antibiotics on several multidrug-resistant bacterial strains were studied, and their synergistic effects on azithromycin (AZT-resistance genes were analyzed to determine the relationships between antimicrobial resistance and these synergistic effects. A checkerboard method was used to evaluate the synergistic effects of AMPs (DP7 and CLS001 and several antibiotics (gentamicin, vancomycin [VAN], AZT, and amoxicillin on clinical bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. The AZT-resistance genes (ermA, ermB, ermC, mefA, and msrA were identified in the resistant strains using quantitative polymerase chain reaction. For all the clinical isolates tested that were resistant to different antibiotics, DP7 had high antimicrobial activity (≤32 mg/L. When DP7 was combined with VAN or AZT, the effect was most frequently synergistic. When we studied the resistance genes of the AZT-resistant isolates, the synergistic effect of DP7–AZT occurred most frequently in highly resistant strains or strains carrying more than two AZT-resistance genes. A transmission electron microscopic analysis of the S. aureus

Anomaly effects of arrays for 3d geoelectrical resistivity imaging ...

African Journals Online (AJOL)

user

The effectiveness of using a net of orthogonal or parallel sets of two-dimensional (2D) profiles for three- dimensional (3D) geoelectrical resistivity imaging has been evaluated. A series of 2D apparent resistivity data were generated over two synthetic models which represent geological or environmental conditions for a ...

Effect of cigarette smoking on insulin resistance risk.

Science.gov (United States)

Haj Mouhamed, D; Ezzaher, A; Neffati, F; Douki, W; Gaha, L; Najjar, M F

2016-02-01

Smoking is one of the main risk factors for cardiovascular disease (CVD). The mechanism(s) of the effects of smoking on CVD are not clearly understood; however, a number of atherogenic characteristics, such as insulin resistance have been reported. We aim to investigate the effects of cigarette smoking on insulin resistance and to determine the correlation between this parameter with smoking status characteristics. This study was conducted on 138 non-smokers and 162 smokers aged respectively 35.6±16.0 and 38.5±21.9 years. All subjects are not diabetic. Fasting glucose was determined by enzymatic methods and insulin by chemiluminescence method. Insulin resistance (IR) was estimated using the Homeostasis Model of Assessment equation: HOMA-IR=[fasting insulin (mU/L)×fasting glucose (mmol/L)]/22.5. IR was defined as the upper quartile of HOMA-IR. Values above 2.5 were taken as abnormal and reflect insulin resistance. Compared to non-smokers, smokers had significantly higher levels of fasting glucose, fasting insulin and HOMA-IR index. These associations remained significant after adjustment for confounding factors (age, gender, BMI and alcohol consumption). A statistically significant association was noted between the smoking status parameters, including both the number of cigarettes smoked/day and the duration of smoking, and fasting insulin levels as well for HOMA-IR index. Among smokers, we noted a positive correlation between HOMA-IR index and both plasma thiocyanates and urinary cotinine. Our results show that smokers have a high risk to developing an insulin resistance and hyperinsulinemia, compared with a matched group of non-smokers, and may help to explain the high risk of cardiovascular diseases in smokers. Copyright © 2015. Published by Elsevier SAS.

Effect of MTA and Portland Cement on Fracture Resistance of Dentin

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Maryam Forghani

2013-06-01

Full Text Available Background and aims. It is important to evaluate the effects of endodontic materials on tooth structures to avoid endodontic treatment failure. The aim of the present study was to investigate the effect of mineral trioxide aggregates (MTA and Portland cement (PC on fracture resistance of dentin. Materials and methods. Thirty-six freshly extracted human single-rooted premolar teeth were selected. The crowns were removed and the roots were randomly divided into two experimental groups and one control group. The root samples were longitudinally divided into two halves and a dentin bar (2×2×10 mm was cut from each root section for short-term (2 weeks and long-term (12 weeks evaluations. The root sections in the experimental groups were exposed to MTA or PC, while keeping the control group specimens in physiologic saline. The fracture resistance of each specimen was measured using an Instron testing machine. The results were statistically analyzed using ANOVA, a post hoc Tukey test and paired ttest at 5% significance level. Results. The fracture resistance of MTA-treated specimens significantly increased between 2 and 12 weeks (P0.05. Conclusion. The results showed that MTA increased the fracture resistance of root dentin, while PC had no significant effect on dentin fracture resistance.

Effect of whole body resistance training on arterial compliance in young men.

NARCIS (Netherlands)

Rakobowchuk, M.; McGowan, C.L.; Groot, P.C.E. de; Bruinsma, D.; Hartman, J.W.; Phillips, S.M.; MacDonald, M.J.

2005-01-01

The effect of resistance training on arterial stiffening is controversial. We tested the hypothesis that resistance training would not alter central arterial compliance. Young healthy men (age, 23 +/- 3.9 (mean +/- s.e.m.) years; n = 28,) were whole-body resistance trained five times a week for 12

The Effect of Aging on the Cracking Resistance of Recycled Asphalt

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Mojtaba Mohammadafzali

2017-01-01

Full Text Available Fatigue cracking is an important concern when a high percentage of Reclaimed Asphalt Pavement (RAP is used in an asphalt mixture. The aging of the asphalt binder reduces its ductility and makes the pavement more susceptible to cracking. Rejuvenators are often added to high-RAP mixtures to enhance their performance. The aging of a rejuvenated binder is different from virgin asphalt. Therefore, the effect of aging on a recycled asphalt mixture can be different from its effect on a new one. This study evaluated the cracking resistance of 100% recycled asphalt binders and mixtures and investigated the effect of aging on this performance parameter. The cracking resistance of the binder samples was tested by a Bending Beam Rheometer. An accelerated pavement weathering system was used to age the asphalt mixtures and their cracking resistance was evaluated by the Texas Overlay Test. The results from binder and mixture tests mutually indicated that rejuvenated asphalt has a significantly better cracking resistance than virgin asphalt. Rejuvenated mixtures generally aged more rapidly, and the rate of aging was different for different rejuvenators.

Effect of fluid-filled boreholes on resistivity tomography; Hiteiko tomography ni okeru konaisui no eikyo

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, Y [DIA Consultants Co. Ltd., Tokyo (Japan)

1997-10-22

Theoretical discussions were given on the effect of fluid-filled boreholes on resistivity tomography. The discussions performed incorporation of earth resistance as a method to consider borehole diameters in an FEM calculation using wire elements. The numerical experiment conducted a simulation on the following two objects: resistivity tomography in a horizontal multi-layer structure consisted of layers with resistivity ranging from 10 to 10000 ohm-m, and a model with a slanted low resistivity band existing in a background of 5000 ohm-m. As a result of the discussions, it was made clear that the effect of the boreholes can be corrected by giving earth resistance between the wire elements and natural ground. An improved potential calculating program indicated that the effect of the fluid-filled boreholes in the resistivity tomography generates false images with high resistivity along the bores if the resistivity has high contrast. Incorporating the wire elements into an inverse analysis model reduces the false images and improves the accuracy. 1 ref., 12 figs.

The annealing effects on irradiated SiC piezo resistive pressure sensor

International Nuclear Information System (INIS)

Almaz, E.; Blue, T. E.; Zhang, P.

2009-01-01

The effects of temperature on annealing of Silicon Carbide (SiC) piezo resistive pressure sensor which was broken after high fluence neutron irradiation, were investigated. Previously, SiC piezo resistive sensor irradiated with gamma ray and fast neutron in the Co-60 gamma-ray irradiator and Beam Port 1 (BP1) and Auxiliary Irradiation Facility (AIF) at the Ohio State University Nuclear Reactor Laboratory (OSUNRL) respectively. The Annealing temperatures were tested up to 400 C. The Pressure-Output voltage results showed recovery after annealing process on SiC piezo resistive pressure sensor. The bridge resistances of the SiC pressure sensor stayed at the same level up to 300 C. After 400 C annealing, the resistance values changed dramatically.

Effects of Copper Addition on Copper Resistance, Antibiotic Resistance Genes, and intl1 during Swine Manure Composting

Science.gov (United States)

Yin, Yanan; Gu, Jie; Wang, Xiaojuan; Song, Wen; Zhang, Kaiyu; Sun, Wei; Zhang, Xin; Zhang, Yajun; Li, Haichao

2017-01-01

Copper is one of the most abundant heavy metals present in swine manure. In this study, a laboratory-scale aerobic composting system was amended with Cu at three levels (0, 200, and 2000 mg kg-1, i.e., control, Cu200, and Cu2000 treatments, respectively) to determine its effect on the fate of copper resistance genes [copper resistance genes (CRGs): pcoA, cusA, copA, and tcrB], antibiotic resistance genes [antibiotic resistance genes (ARGs): erm(A) and erm(B)], and intl1. The results showed that the absolute abundances of pcoA, tcrB, erm(A), erm(B), and intl1 were reduced, whereas those of copA and cusA increased after swine manure composting. Redundancy analysis showed that temperature significantly affected the variations in CRGs, ARGs, and intl1. The decreases in CRGs, ARGs, and intI1 were positively correlated with the exchangeable Cu levels. The bacterial community could be grouped according to the composting time under different treatments, where the high concentration of copper had a more persistent effect on the bacterial community. Network analysis determined that the co-occurrence of CRGs, ARGs, and intI1, and the bacterial community were the main contributors to the changes in CRGs, ARG, and intl1. Thus, temperature, copper, and changes in the bacterial community composition had important effects on the variations in CRGs, ARGs, and intl1 during manure composting in the presence of added copper. PMID:28316595

Inter-filament resistance, effective transverse resistivity and coupling loss in superconducting multifilamentary NbTi and Nb3Sn strands

NARCIS (Netherlands)

Zhou, Chao; Dhalle, Marc M.J.; Nijhuis, Arend

2012-01-01

The effective transverse resistivity of a range of multi-filamentary Nb3Sn and NbTi strands is measured with a direct four-probe method and the data are compared to the transverse resistivity values obtained from AC coupling loss experiments. Correspondence between both is satisfactory provided that

The biochar effect: plant resistance to biotic stresses

Directory of Open Access Journals (Sweden)

YIGAL ELAD

2012-01-01

Full Text Available Biochar (charcoal is the solid co-product of pyrolysis, the thermal degradation of biomass in the absence of oxygen. Pyrolysis also yields gaseous and liquid biofuel products. There is a growing interest worldwide in the pyrolysis platform, for at least four reasons: (i pyrolysis can be a source of renewable biofuels; (ii many biomass waste materials can be treated by pyrolysis and thus converted into a fuel resource; (iii long-term sequestration of carbon dioxide which originated in the atmosphere may result from adding biochar to soil; and (iv biochar soil amendment contributes to improved soil fertility and crop productivity. Currently, however, very little biochar is utilized in agriculture, in part because its agronomic value in terms of crop response and soil health benefits have yet to be quantified, and because the mechanisms by which it improves soil fertility are poorly understood. The positive effects of biochar on crop productivity under conditions of extensive agriculture are frequently attributed to direct effects of biochar-supplied nutrients and to several other indirect effects, including increased water and nutrient retention, improvements in soil pH, increased soil cation exchange capacity, effects on P and S transformations and turnover, neutralization of phytotoxic compounds in the soil, improved soil physical properties, promotion of mycorrhizal fungi, and alteration of soil microbial populations and functions. Yet, the biochar effect is also evident under conditions of intensive production where many of these parameters are not limited. Biochar addition to soil alters microbial populations in the rhizosphere, albeit via mechanisms not yet understood, and may cause a shift towards beneficial microorganism populations that promote plant growth and resistance to biotic stresses. In addition to some scant evidence for biochar-induced plant protection against soilborne diseases, the induction of systemic resistance towards

Resistive effects on line-tied magnetohydrodynamic modes in cylindrical geometry

International Nuclear Information System (INIS)

Delzanno, Gian Luca; Evstatiev, E. G.; Finn, John M.

2007-01-01

An investigation of the effect of resistivity on the linear stability of line-tied magnetohydrodynamic (MHD) modes is presented in cylindrical geometry, based on the method recently developed in the paper by Evstatiev et al. [Phys. Plasmas 13, 072902 (2006)]. The method uses an expansion of the full solution of the problem in one-dimensional radial eigenfunctions. This method is applied to study sausage modes (m=0, m being the poloidal wavenumber), kink modes (m=1), and m=2 modes. All these modes can be resistively unstable. It is found that m≠0 modes can be unstable below the ideal MHD threshold due to resistive diffusion of the field lines, with growth rates proportional to resistivity. For these resistive modes, there is no indication of tearing, i.e., current sheets or boundary layers due to ideal MHD singularities. That is, resistivity acts globally on the whole plasma column and not in layers. Modes with m=0, on the other hand, can exist as tearing modes if the equilibrium axial magnetic field reverses sign within the plasma

Effects of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents

International Nuclear Information System (INIS)

Meckes, M.C.

1982-01-01

Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistant to patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli

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.)

Effects of alloying elements on nodular and uniform corrosion resistance of zirconium-based alloys

International Nuclear Information System (INIS)

Abe, Katsuhiro

1992-01-01

The effects of alloying and impurity elements (tin, iron, chromium, nickel, niobium, tantalum, oxygen, aluminum, carbon, nitrogen, silicon, and phosphorus) on the nodular and uniform corrosion resistance of zirconium-based alloys were studied. The improving effect of iron, nickel and niobium in nodular corrosion resistance were observed. The uniform corrosion resistance was also improved by nickel, niobium and tantalum. The effects of impurity elements, nitrogen, aluminum and phosphorus were negligibly small but increasing the silicon content seemed to improve slightly the uniform corrosion resistance. Hydrogen pick-up fraction were not changed by alloying and impurity elements except nickel. Nickel addition increased remarkably hydrogen pick-up fraction. Although the composition of secondary precipitates changed with contents of alloying elements, the correlation of composition of secondary precipitates to corrosion resistance was not observed. (author)

Effect of Coffee and Caffeine Ingestion on Resistance Exercise Performance.

Science.gov (United States)

Richardson, Darren L; Clarke, Neil D

2016-10-01

Richardson, DL and Clarke, ND. Effect of coffee and caffeine ingestion on resistance exercise performance. J Strength Cond Res 30(10): 2892-2900, 2016-The aim of the present study was to determine the effect of ingesting caffeine dose-matched anhydrous caffeine, coffee, or decaffeinated coffee plus anhydrous caffeine during resistance exercise on performance. Nine resistance-trained men (mean ± SD: age, 24 ± 2 years; weight, 84 ± 8 kg; height, 180 ± 8 cm) completed a squat and bench press exercise protocol at 60% 1 repetition maximum until failure on 5 occasions consuming 0.15 g·kg caffeinated coffee (COF), 0.15 g·kg decaffeinated coffee (DEC), 0.15 g·kg decaffeinated coffee plus 5 mg·kg anhydrous caffeine (D + C), 5 mg·kg anhydrous caffeine (CAF), or a placebo (PLA). Felt arousal and rating of perceived exertion (RPE) were used to assess perceptual variables and heart rate (HR) to assess physiological responses between trials. There were significant differences in total weight lifted for the squat between conditions (p caffeine have the ability to improve performance during a resistance exercise protocol, although possibly not over multiple bouts.

Effect of modes interaction on the resistive wall mode stability

International Nuclear Information System (INIS)

Chen Longxi; Wu Bin

2013-01-01

Effects of modes interaction on the resistive wall mode (RWM) stability are studied. When considering the modes interaction effects, the linear growth rate of the most unstable (3, 1) mode decreases. After linear evolution, the RWM saturates at the nonlinear phase. The saturation can be attributed to flux piling up on the resistive wall. When some modes exist, the (3, 1) mode saturates at lower level compared with single mode evolution. Meanwhile, the magnetic energy of the (5, 2) mode increases correspondingly, but the magnetic energy saturation level of the (2, 1) mode changes weakly. (authors)

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)

Characterization of resistance to tetracyclines and aminoglycosides of sheep mastitis pathogens: study of the effect of gene content on resistance.

Science.gov (United States)

Lollai, S A; Ziccheddu, M; Duprè, I; Piras, D

2016-10-01

Mastitis causes economic losses and antimicrobials are frequently used for mastitis treatment. Antimicrobial resistance surveys are still rare in the ovine field and characterization of strains is important in order to acquire information about resistance and for optimization of therapy. Bacterial pathogens recovered in milk samples from mastitis-affected ewes were characterized for resistance to tetracyclines and aminoglycosides, members of which are frequently used antimicrobials in small ruminants. A total of 185 strains of staphylococci, streptococci, and enterococci, common mastitis pathogens, were tested for minimal inhibitory concentration (MIC) to tetracycline, doxycycline, minocycline, gentamicin, kanamycin, streptomycin, and for resistance genes by PCR. Effects of different tet genes arrangements on MICs were also investigated. Staphylococci expressed the lowest MIC for tetracycline and tet(K) was the most common gene recovered; tet(M) and tet(O) were also found. Gene content was shown to influence the tetracycline MIC values. Enterococci and streptococci showed higher MICs to tetracyclines and nonsusceptible strains always harboured at least one ribosomal protection gene (MIC above 8 μg ml(-1) ). Streptococci often harboured two or more tet determinants. As regards the resistance to aminoglycosides, staphylococci showed the lowest gentamicin and kanamycin median MIC along with streptomycin high level resistant (HLR) strains (MIC >1024 μg ml(-1) ) all harbouring str gene. The resistance determinant aac(6')-Ie-aph(2″)-Ia was present in few strains. Streptococci were basically nonsusceptible to aminoglycosides but neither HLR isolates nor resistance genes were detected. Enterococci revealed the highest MICs for gentamicin; two str harbouring isolates were shown to be HLR to streptomycin. Evidence was obtained for the circulation of antimicrobial-resistant strains and genes in sheep dairy farming. Tetracycline MIC of 64 μg ml(-1) and high

Effects of an Intensive Resistant Training Sessions and Green Tea

Directory of Open Access Journals (Sweden)

Mohammad Esmaeil Afzalpour

2014-03-01

Full Text Available Background: Intensive and acute exercise trainings may induce oxidative stress, but antioxidant supplements may attenuate its degenerative consequences. The aim of this research was to examine the effect of green tea supplementation on the oxidative stress indices after an intensive resistance training session. Materials and Methods: 40 non-athletes (without regular physical activity women were randomly divided into 4 equal (n=10 groups including green tea supplementation, green tea supplementation plus resistance training, resistance training, and control groups. After supplementation period (600 mg/day, 14 days, resistance training and green tea supplementation plus resistance training groups performed an intensive resistance training session at 75-85 % of one repetition maximum. The malondialdehyde and total thiol were measured as oxidative stress indices. Data were analyzed by using of repeated measure ANOVA and LSD tests at p<0.056T. Results: Results showed that after 14 days of green tea consumption, malondialdehyde significantly decreased in green tea supplementation (p=0.03 and green tea supplementation plus resistance training (p=0.01 groups, while total thiol increased significantly (p=0.01 in two green tea supplementation groups. However, an intensive resistance training session increased malondialdehyde (p=0.01 without any significantly changes in total thiol (p=0.426T. Conclusion: It seems that green tea supplementation can inhibit exercise-induced protein and lipid oxidation in non-athletes women via enhancement of antioxidant defense system of the body6T.6T

The effects of endurance and resistance training on blood pressure.

Science.gov (United States)

Schwartz, R S; Hirth, V A

1995-10-01

There now exists substantial clinical data supporting a blood pressure lowering effect of endurance training. Though the effect is modest (5-10 mmHg), epidemiologic studies indicate the possibility of protection against the development of hypertension and also indicate significantly reduced cardiovascular mortality and increased longevity associated with chronic endurance exercise. The data for blood pressure lowering effects of resistive training are much less compelling, and this area requires additional investigation. However, it appears that resistance training is not associated with chronic elevations in blood pressure. Future studies need to focus on: 1) the relative efficacy of low-, moderate- and high-intensity training on lowering blood pressure; 2) the effect of training on ambulatory blood pressure; 3) targeting of at risk and high responding populations; and 4) the importance of insulinemia, SNS tone and central adiposity in the mechanism of any blood pressure lowering effect of training.

Thermal resistance matrix representation of thermal effects and thermal design in multi-finger power heterojunction bipolar transistors

Institute of Scientific and Technical Information of China (English)

Jin Dong-Yue; Zhang Wan-Rong; Chen Liang; Fu Qiang; Xiao Ying; Wang Ren-Qing; Zhao Xin

2011-01-01

The thermal resistance matrix including self-heating thermal resistance and thermal coupling resistance is presented to describe the thermal effects of multi-finger power heterojunction bipolar transistors. The dependence of thermal resistance matrix on finger spacing is also investigated. It is shown that both self-heating thermal resistance and thermal coupling resistance are lowered by increasing the finger spacing, in which the downward dissipated heat path is widened and the heat flow from adjacent fingers is effectively suppressed. The decrease of self-heating thermal resistance and thermal coupling resistance is helpful for improving the thermal stability of power devices. Furthermore, with the aid of the thermal resistance matrix, a 10-finger power heterojunction bipolar transistor (HBT) with non-uniform finger spacing is designed for high thermal stability. The optimized structure can effectively lower the peak temperature while maintaining a uniformity of the temperature profile at various biases and thus the device effectively may operate at a higher power level.

Chaos-based wireless communication resisting multipath effects

Science.gov (United States)

Yao, Jun-Liang; Li, Chen; Ren, Hai-Peng; Grebogi, Celso

2017-09-01

In additive white Gaussian noise channel, chaos has been shown to be the optimal coherent communication waveform in the sense of using a very simple matched filter to maximize the signal-to-noise ratio. Recently, Lyapunov exponent spectrum of the chaotic signals after being transmitted through a wireless channel has been shown to be unaltered, paving the way for wireless communication using chaos. In wireless communication systems, inter-symbol interference caused by multipath propagation is one of the main obstacles to achieve high bit transmission rate and low bit-error rate (BER). How to resist the multipath effect is a fundamental problem in a chaos-based wireless communication system (CWCS). In this paper, a CWCS is built to transmit chaotic signals generated by a hybrid dynamical system and then to filter the received signals by using the corresponding matched filter to decrease the noise effect and to detect the binary information. We find that the multipath effect can be effectively resisted by regrouping the return map of the received signal and by setting the corresponding threshold based on the available information. We show that the optimal threshold is a function of the channel parameters and of the information symbols. Practically, the channel parameters are time-variant, and the future information symbols are unavailable. In this case, a suboptimal threshold is proposed, and the BER using the suboptimal threshold is derived analytically. Simulation results show that the CWCS achieves a remarkable competitive performance even under inaccurate channel parameters.

Efflux-mediated resistance to a benzothiadiazol derivative effective against Burkholderia cenocepacia

Directory of Open Access Journals (Sweden)

Viola Camilla eScoffone

2015-08-01

Full Text Available Burkholderia cenocepacia is a major concern for people suffering from Cystic Fibrosis as it contributes to serious respiratory tract infections. The lack of drugs effective against this opportunistic pathogen, along with the high level of resistance to multiple antibiotics, render the treatment of these infections particularly difficult.Here a new compound, belonging to the 2,1,3-benzothiadiazol-5-yl family (10126109, with a bactericidal effect and a MIC of 8 µg/ml against B. cenocepacia, is described. The compound is not cytotoxic and effective against B. cenocepacia clinical isolates and members of all the known Burkholderia cepacia complex species.Spontaneous mutants resistant to 10126109 were isolated and mutations in the MerR transcriptional regulator BCAM1948 were identified. In this way, a mechanism of resistance to this new molecule was described, which relies on the overexpression of the RND-9 efflux pump. Indeed, rnd-9 overexpression was confirmed by qRT-PCR, and RND-9 was identified in the membrane fractions of the mutant strains. Moreover, the increase in the MIC values of different drugs in the mutant strains, together with complementation experiments, suggested the involvement of RND-9 in the efflux of 10126109, thus indicating again the central role of efflux transporters in B. cenocepacia drug resistance.

Resistivity and Hall effect in Y9Co7

International Nuclear Information System (INIS)

Ali, N.; Datars, W.R.; Kozlowski, G.; Woods, S.B.

1987-01-01

The temperature dependence of the resistivity and Hall effect of Y 9 Co 7 has been measured from room temperature to 1.6 K. The saturation of the resistivity at high temperature is similar to that of A15 compounds and can be interpreted in terms of a localised phonon mode formation as shown by Yu and Anderson for A15 compounds. A T 2 -dependence of the resistivity is observed for temperatures below approx.= 25 K. A similar T 2 -dependence at low temperatures is always observed in A15 compounds as well and is not fully understood. However, a T 2 -dependence below 10 K does not seem to be due to itinerant ferromagnetism in Y 9 Co 7 as concluded recently by Kolodziejczyk and Spalek. The observation of a peak at approx.= 25 K in the Hall coefficient suggests a spin glass type of freezing at low temperatures which possibly can account for the T 2 -dependence of the resistivity below approx.= 10 K. (author)

Environmental Maternal Effects Mediate the Resistance of Maritime Pine to Biotic Stress

Science.gov (United States)

Vivas, María; Zas, Rafael; Sampedro, Luis; Solla, Alejandro

2013-01-01

The resistance to abiotic stress is increasingly recognised as being impacted by maternal effects, given that environmental conditions experienced by parent (mother) trees affect stress tolerance in offspring. We hypothesised that abiotic environmental maternal effects may also mediate the resistance of trees to biotic stress. The influence of maternal environment and maternal genotype and the interaction of these two factors on early resistance of Pinus pinaster half-sibs to the Fusarium circinatum pathogen was studied using 10 mother genotypes clonally replicated in two contrasting environments. Necrosis length of infected seedlings was 16% shorter in seedlings grown from favourable maternal environment seeds than in seedlings grown from unfavourable maternal environment seeds. Damage caused by F. circinatum was mediated by maternal environment and maternal genotype, but not by seed mass. Mechanisms unrelated to seed provisioning, perhaps of epigenetic nature, were probably involved in the transgenerational plasticity of P. pinaster, mediating its resistance to biotic stress. Our findings suggest that the transgenerational resistance of pines due to an abiotic stress may interact with the defensive response of pines to a biotic stress. PMID:23922944

Environmental maternal effects mediate the resistance of maritime pine to biotic stress.

Directory of Open Access Journals (Sweden)

María Vivas

Full Text Available The resistance to abiotic stress is increasingly recognised as being impacted by maternal effects, given that environmental conditions experienced by parent (mother trees affect stress tolerance in offspring. We hypothesised that abiotic environmental maternal effects may also mediate the resistance of trees to biotic stress. The influence of maternal environment and maternal genotype and the interaction of these two factors on early resistance of Pinus pinaster half-sibs to the Fusarium circinatum pathogen was studied using 10 mother genotypes clonally replicated in two contrasting environments. Necrosis length of infected seedlings was 16% shorter in seedlings grown from favourable maternal environment seeds than in seedlings grown from unfavourable maternal environment seeds. Damage caused by F. circinatum was mediated by maternal environment and maternal genotype, but not by seed mass. Mechanisms unrelated to seed provisioning, perhaps of epigenetic nature, were probably involved in the transgenerational plasticity of P. pinaster, mediating its resistance to biotic stress. Our findings suggest that the transgenerational resistance of pines due to an abiotic stress may interact with the defensive response of pines to a biotic stress.

The effect of energetic trapped particles on the resistive internal Kink

International Nuclear Information System (INIS)

Romanelli, F.; White, R.B.

1988-01-01

The effect of energetic trapped particles on the ideal and resistive internal Kink mode is analyzed including diamagnetic effects. The relation between different approaches to the problem is discussed

Elastic Resistance Effectiveness on Increasing Strength of Shoulders and Hips.

Science.gov (United States)

Picha, Kelsey J; Almaddah, Muataz R; Barker, Jordan; Ciochetty, Tavis; Black, W Scott; Uhl, Tim L

2017-09-12

Elastic resistance is a common training method used to gain strength. Currently, progression with elastic resistance is based on the perceived exertion of the exercise or completion of targeted repetitions; exact resistance is typically unknown. This study's objective is to determine if knowledge of load during elastic resistance exercise will increase strength gains during exercises. Participants were randomized into two strength training groups, elastic resistance only and elastic resistance using a load cell (LC) that displays force during exercise. The LC group used a Smart Handle (Patterson Medical Supply, Chicago, IL) to complete all exercises. Each participant completed the same exercises three times weekly for 8 weeks. The LC group was provided with a set load for exercises whereas the elastic resistance only group was not. Participant's strength was tested at baseline and program completion, measuring isometric strength for shoulder abduction (SAb), shoulder external rotation (SER), hip abduction (HAb), and hip extension (HEx). Independent t-tests were used to compare the normalized torques between groups. No significant differences were found between groups. Shoulder strength gains did not differ between groups (SAb p>0.05; SER p>0.05). Hip strength gains did not differ between groups (HAb p>0.05; HEx p>0.05). Both groups increased strength due to individual supervision, constantly evaluating degree of difficulty associated with exercise and providing feedback while using elastic resistance. Using a LC is as effective as supervised training and could provide value in a clinic setting when patients are working unsupervised.

Effects of electron irradiation on the resistive behaviour of YBCO-type ceramics

International Nuclear Information System (INIS)

Galatanu, A.; Novac, A.; Mosteanu, T.; Magureanu, M.

1998-01-01

YBCO-123 ceramic samples were irradiated with electron beams (E=0.5 MeV), the particle fluxes ranging between 10 15 and 10 19 e - /cm 2 . The induced structure modifications are analyzed through X-ray diffraction and their effects on the resistive behaviour are estimated. It is shown that a direct correlation can be established between the irradiation effects, oxygen disorder and hence the modification of the sample resistivity. A particular attention is given to the effects on the fluctuation mechanism arising near the transition temperature. (authors)

Effects of plant morphology on vegetation resistance, resilience and ...

African Journals Online (AJOL)

Effects of plant morphology on vegetation resistance, resilience and tolerance in. Mabira forest ... impacts of visitors activities of the camping sites and to understand the .... (Howard, 199 1 ): Milicia excels a, Cordia millenii, Irving/a gabonensis ...

Halogen effect for improving high temperature oxidation resistance of Ti-50Al by anodization

Science.gov (United States)

Mo, Min-Hua; Wu, Lian-Kui; Cao, Hua-Zhen; Lin, Jun-Pin; Zheng, Guo-Qu

2017-06-01

The high temperature oxidation resistance of Ti-50Al was significantly improved via halogen effect which was achieved by anodizing in an ethylene glycol solution containing with fluorine ion. The anodized Ti-50Al with holes and micro-cracks could be self-repaired during oxidation at 1000 °C. The thickness of the oxide scale increases with the prolonging of oxidation time. On the basis of halogen effect for improving the high temperature oxidation resistance of Ti-50Al by anodization, only fluorine addition into the electrolyte can effectively improve the high temperature oxidation resistance of Ti-50Al.

Investigating the effects of ABC transporter-based acquired drug resistance mechanisms at the cellular and tissue scale.

Science.gov (United States)

Liu, Cong; Krishnan, J; Xu, Xiao Yun

2013-03-01

In this paper we systematically investigate the effects of acquired drug resistance at the cellular and tissue scale, with a specific focus on ATP-binding cassette (ABC) transporter-based mechanisms and contrast this with other representative intracellular resistance mechanisms. This is done by developing in silico models wherein the drug resistance mechanism is overlaid on a coarse-grained description of apoptosis; these cellular models are coupled with interstitial drug transport, allowing for a transparent examination of the effect of acquired drug resistances at the tissue level. While ABC transporter-mediated resistance mechanisms counteract drug effect at the cellular level, its tissue-level effect is more complicated, revealing unexpected trends in tissue response as drug stimuli are systematically varied. Qualitatively different behaviour is observed in other drug resistance mechanisms. Overall the paper (i) provides insight into the tissue level functioning of a particular resistance mechanism, (ii) shows that this is very different from other resistance mechanisms of an apparently similar type, and (iii) demonstrates a concrete instance of how the functioning of a negative feedback based cellular adaptive mechanism can have unexpected higher scale effects.

Effect and Safety of Shihogyejitang for Drug Resistant Childhood Epilepsy

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Jinsoo Lee

2016-01-01

Full Text Available Objective. Herbal medicine has been widely used to treat drug resistant epilepsy. Shihogyejitang (SGT has been commonly used to treat epilepsy. We investigated the effect and safety of SGT in children with drug resistant epilepsy. Design. We reviewed medical records of 54 patients with epilepsy, who failed to respond to at least two antiepileptic drugs and have been treated with SGT between April 2006 and June 2014 at the Department of Pediatric Neurology, I-Tomato Hospital, Korea. Effect was measured by the response rate, seizure-free rate, and retention rate at six months. We also checked adverse events, change in antiepileptic drugs use, and the variables related to the outcome. Results. Intent-to-treat analysis showed that, after six months, 44.4% showed a >50% seizure reduction, 24.1% including seizure-free, respectively, and 53.7% remained on SGT. Two adverse events were reported, mild skin rash and fever. Focal seizure type presented significantly more positive responses when compared with other seizure types at six months (p=0.0284, Fisher’s exact test. Conclusion. SGT is an effective treatment with excellent tolerability for drug resistant epilepsy patients. Our data provide evidence that SGT may be used as alternative treatment option when antiepileptic drug does not work in epilepsy children.

Resistance training among young athletes: safety, efficacy and injury prevention effects.

Science.gov (United States)

Faigenbaum, A D; Myer, G D

2010-01-01

A literature review was employed to evaluate the current epidemiology of injury related to the safety and efficacy of youth resistance training. Several case study reports and retrospective questionnaires regarding resistance exercise and the competitive sports of weightlifting and powerlifting reveal that injuries have occurred in young lifters, although a majority can be classified as accidental. Lack of qualified instruction that underlies poor exercise technique and inappropriate training loads could explain, at least partly, some of the reported injuries. Current research indicates that resistance training can be a safe, effective and worthwhile activity for children and adolescents provided that qualified professionals supervise all training sessions and provide age-appropriate instruction on proper lifting procedures and safe training guidelines. Regular participation in a multifaceted resistance training programme that begins during the preseason and includes instruction on movement biomechanics may reduce the risk of sports-related injuries in young athletes. Strategies for enhancing the safety of youth resistance training are discussed.

Effects of compressibility on the resistive ballooning mode

International Nuclear Information System (INIS)

Hender, T.C.; Carreras, B.A.; Cooper, W.A.; Holmes, J.A.; Diamond, P.H.; Similon, P.L.

1983-09-01

The linear stability of the resistive ballooning mode, as described by the resistive MHD model, is investigated both analytically and numerically. When the pressure evolution is approximated by fluid convection (reduced MHD model), an instability driven by geodesic curvature, with a growth rate γ approx. eta/sup 1/3/β/sub rho//sup 2/3/, is found. For conditions relevant to the Impurity Study Experiment (ISX-B), it is shown that for modest poloidal beta (β/sub rho/ approx. = 1), high current, and relatively high temperatures, compressibility has a significant stabilizing influence, relative to the pressure convection model, for low toroidal mode number modes. However, at high β/sub rho/ (greater than or equal to 2), low current, and lower temperatures, compressibility has much less effect

The effect of acute aerobic and resistance exercise on working memory.

Science.gov (United States)

Pontifex, Matthew B; Hillman, Charles H; Fernhall, Bo; Thompson, Kelli M; Valentini, Teresa A

2009-04-01

The goal of this investigation was to assess the influence of acute bouts of aerobic versus resistance exercise on the executive control of working memory. Twenty-one young adult participants completed a cardiorespiratory fitness test and maximal strength tests. On subsequent days, task performance measures of reaction time (RT) and accuracy were collected while participants completed a modified Sternberg working memory task before the start of, immediately after, and 30 min after an intervention consisting of 30 min of either resistance or aerobic exercise and a seated rest control. Findings indicated shorter RT immediately and 30 min after acute aerobic exercise relative to the preexercise baseline with no such effects observed after resistance exercise or seated rest. Further, in the aerobic condition, a larger reduction in RT from the baseline occurred during task conditions requiring increased working memory capacity. Again, no effect was observed in the resistance exercise or the seated rest conditions. These data extend the current knowledge base by indicating that acute exercise-induced changes in cognition are disproportionately related to executive control and may be specific to the aerobic exercise domain.

Effect of Circuit Breaker Shunt Resistance on Chaotic Ferroresonance in Voltage Transformer

Directory of Open Access Journals (Sweden)

RADMANESH, H.

2010-08-01

Full Text Available Ferroresonance or nonlinear resonance is a complex electrical phenomenon, which may cause over voltages and over currents in the electrical power system which endangers the system reliability and continuous safe operating. This paper studies the effect of circuit breaker shunt resistance on the control of chaotic ferroresonance in a voltage transformer. It is expected that this resistance generally can cause ferroresonance dropout. For confirmation this aspect Simulation has been done on a one phase voltage transformer rated 100VA, 275kV. The magnetization characteristic of the transformer is modeled by a single-value two-term polynomial with q=7. The simulation results reveal that considering the shunt resistance on the circuit breaker, exhibits a great mitigating effect on ferroresonance over voltages. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos along with ferroresonance voltages has been obtained and presented.

Effect of psychological capital and resistance to change on organisational citizenship behaviour

Directory of Open Access Journals (Sweden)

Loyd Beal III

2013-09-01

Research purpose: This study examined the possible role of resistance to change as a moderator of the predictive relationship between PsyCap and organisational citizenship behaviour (OCB, in which OCB served as an index for measuring positive organisational change. Motivation for the study: Little empirical research has investigated the application of positive organisational behaviour to government organisations undergoing organisational change. Organisations can use the study results to increase positive outcomes and reduce resistance in government organisations experiencing a holistic change intervention. Research design, approach and method: The data comprised a cross-sectional survey of 97 employees from a government organisation that provides life-cycle career management support. Employees completed the 24-item psychological capital questionnaire, the 16-item organisational citizenship behaviour scale and the 17-item resistance to change scale. Data analyses used a mixed methods approach to merge quantitative inferential statistics with qualitative thematic analysis. Main findings: The quantitative analysis yielded high levels of resistance to change that moderated the positive effect of PsyCap on organisational citizenship behaviour. The thematic analysis revealed that affective, behavioural and cognitive forms of resistance to change were prevalent. Practical/managerial implications: Organisational leaders should seek to reduce resistance and increase the resources that organisations need to effect positive organisational change. Contribution/value-add: This study adds to the growing body of knowledge about positive organisational behaviour in government organisations.

The role of contact resistance in graphene field-effect devices

Science.gov (United States)

Giubileo, Filippo; Di Bartolomeo, Antonio

2017-08-01

The extremely high carrier mobility and the unique band structure, make graphene very useful for field-effect transistor applications. According to several works, the primary limitation to graphene based transistor performance is not related to the material quality, but to extrinsic factors that affect the electronic transport properties. One of the most important parasitic element is the contact resistance appearing between graphene and the metal electrodes functioning as the source and the drain. Ohmic contacts to graphene, with low contact resistances, are necessary for injection and extraction of majority charge carriers to prevent transistor parameter fluctuations caused by variations of the contact resistance. The International Technology Roadmap for Semiconductors, toward integration and down-scaling of graphene electronic devices, identifies as a challenge the development of a CMOS compatible process that enables reproducible formation of low contact resistance. However, the contact resistance is still not well understood despite it is a crucial barrier towards further improvements. In this paper, we review the experimental and theoretical activity that in the last decade has been focusing on the reduction of the contact resistance in graphene transistors. We will summarize the specific properties of graphene-metal contacts with particular attention to the nature of metals, impact of fabrication process, Fermi level pinning, interface modifications induced through surface processes, charge transport mechanism, and edge contact formation.

Magnetic property effect on transport processes in resistance spot welding

Energy Technology Data Exchange (ETDEWEB)

Wei, P S [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan 80424 (China); Wu, T H, E-mail: pswei@mail.nsysu.edu.tw, E-mail: wux0064@gmail.com [Department of Mechanical Engineering, Yung Ta Institute of Technology and Commerce, Pintong, Taiwan 909 (China)

2011-08-17

This study investigates the effects of the Curie temperature and magnetic permeability on transport variables, solute distribution and nugget shapes during resistance spot welding. The Curie temperature is the temperature below which a metal or alloy is ferromagnetic with a high magnetic permeability, and above which it is paramagnetic with a small magnetic permeability. The model proposed here accounts for electromagnetic force, heat generation and contact resistance at the faying surface and electrode-workpiece interfaces and bulk resistance in workpieces. Contact resistance includes constriction and film resistances, which are functions of hardness, temperature, electrode force and surface condition. The computed results show that transport variables and nugget shapes can be consistently interpreted from the delay of response time and jump of electric current density as a result of finite magnetic diffusion, rather than through the examination of the variations of dynamic electrical resistance with time. The molten nugget on the faying surface is initiated earlier with increasing magnetic permeability and Curie temperature. A high Curie temperature enhances convection and solute mixing, and readily melts through the workpiece surface near the electrode edge. Any means to reduce the Curie temperature or magnetic permeability, such as adjusting the solute content, can be a good way to control weld quality. This study can also be applied to interpret the contact problems encountered in various electronics and packaging technologies, and so on.

Temperature and mixing effects on electrical resistivity of carbon fiber enhanced concrete

International Nuclear Information System (INIS)

Chang, Christiana; Song, Gangbing; Gao, Di; Mo, Y L

2013-01-01

In this paper, the effect of temperature and mixing procedure on the electrical resistivity of carbon fiber enhanced concrete is investigated. Different compositions of concrete containing varying concentrations of carbon fiber into normal and self-consolidating concrete (SCC) were tested under DC electrical loading over the temperature range −10 to 20 °C. The electrical resistivity of the bulk samples was calculated and compared against temperature. It was observed that there is an inverse exponential relationship between resistivity and temperature which follows the Arrhenius relationship. The bulk resistivity decreased with increasing fiber concentration, though data from SCC indicates a saturation limit beyond which electrical resistivity begins to drop. The activation energy of the bulk electrically conductive concrete was calculated and compared. While SCC exhibited the lowest observed electrical resistance, the activation energy was similar amongst SCC and surfactant enhanced concrete, both of which were lower than fiber dispersed in normal concrete. (paper)

Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

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Takashi Furukawa

2017-07-01

Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

Effect of thiazolidinedione treatment on resistin levels in insulin resistant sprague dawley rats

International Nuclear Information System (INIS)

Yousaf, I.; Hameed, W.; Rajput, T.A.

2015-01-01

Insulin resistance is manifested by decreased effect of fixed quantity of insulin on glucose metabolism leading to type 2 diabetes mellitus. Visceral obesity has been positively correlated with insulin resistance but its mechanism is not fully defined. Insulin resistance may be the consequence of adipocytokines including visfatin and resistin. This study was designed to see the effect of thiazolidinediones on levels of resistin in insulin resistant rats. Methods: Ninety Sprague Dawley rats were randomly divided into three groups. Group I served as control. Rats in Group II and III were made insulin resistant diabetics. Group III was treated with rosiglitazone after development of diabetes. Plasma glucose, serum triglycerides, HDL, TG:HDL ratio and serum resistin levels were analysed. Results: Body weight and plasma glucose were significantly increased (p<0.05) along with TG:HDL ratio (p<0.05) in group II and group III at the end of 4th week. Serum resistin levels also increased significantly (p<0.05) in group II and III at the end of 4th week. Treatment of group III with rosiglitazone led to improvement in insulin resistance with decrease in serum resistin levels (p<0.05). Conclusion: Increased serum resistin level indicates insulin resistance and impending hyperglycaemia. Thiazolidinediones augment sensitivity of insulin to restore normoglycaemia by decreasing serum resistin level. (author)

Combined effects of fretting and pollutant particles on the contact resistance of the electrical connectors

Directory of Open Access Journals (Sweden)

Zhigang Kong

2017-06-01

Full Text Available Usually, when electrical connectors operate in vibration environments, fretting will be produced at the contact interfaces. In addition, serious environmental pollution particles will affect contact resistance of the connectors. The fretting will worsen the reliability of connectors with the pollutant particles. The combined effects of fretting and quartz particles on the contact resistance of the gold plating connectors are studied with a fretting test system. The results show that the frequencies have obvious effect on the contact resistance. The higher the frequency, the higher the contact resistance is. The quartz particles cause serious wear of gold plating, which make the nickel and copper layer exposed quickly to increase the contact resistance. Especially in high humidity environments, water supply certain adhesion function and make quartz particles easy to insert or cover the contact surfaces, and even cause opening resistance.

Effect of Environmental Variables on the Flammability of Fire Resistant Materials

OpenAIRE

Osorio, Andres Felipe

2014-01-01

This work investigates the effects of external radiation, ambient pressure and microgravity on the flammability limits of fire-resistant (FR) materials. Future space missions may require spacecraft cabin environments different than those used in the International Space Station, 21%O2, 101.3kPa. Environmental variables include flow velocity, oxygen concentration, ambient pressure, micro or partial-gravity, orientation, presence of an external radiant flux, etc. Fire-resistant materials are use...

Resistive switching phenomenon and hole wind effect in YBCO thin films

Energy Technology Data Exchange (ETDEWEB)

Truchly, Martin; Plecenik, Tomas [Department of Experimental Physics, Comenius University, Bratislava (Slovakia); Zhitlukhina, Elena [Donetsk Institute for Physics and Engineering, Kyiv (Ukraine)

2016-07-01

We present an overview of our experimental and theoretical activities aimed to clarify the mechanism of resistive memory effects in YBCO thin layers. The phenomenon was studied by scanning spreading resistance microscopy (SSRM) and scanning tunneling microscopy (STM) techniques. The most striking feature uncovered (in contrast to previous experiments on planar bilayers with YBCO films) was the opposite voltage-bias polarity of the switching effect in all SSRM and a number of STM measurements. Observed hysteresis in current-voltage characteristics is interpreted as a movement of oxygen vacancies in the vicinity of the tip-YBCO contact. Since the charge distribution in YBCO samples is expected to be strongly inhomogeneous, the balance between the direct electrostatic force on activated oxygen ions and that caused by momentum exchange with the current carriers (holes) hitting them determines direction in which the oxygen vacancies are moving. We propose a minimalist model with the only fitting parameter that accounts for the resistance hysteresis phenomenon in the YBCO films studied.

The effects of argon ion bombardment on the corrosion resistance of tantalum

Science.gov (United States)

Ramezani, A. H.; Sari, A. H.; Shokouhy, A.

2017-02-01

Application of ion beam has been widely used as a surface modification method to improve surface properties. This paper investigates the effect of argon ion implantation on surface structure as well as resistance against tantalum corrosion. In this experiment, argon ions with energy of 30 keV and in doses of 1 × 1017-10 × 1017 ions/cm2 were used. The surface bombardment with inert gases mainly produces modified topography and morphology of the surface. Atomic Force Microscopy was also used to patterned the roughness variations prior to and after the implantation phase. Additionally, the corrosion investigation apparatus wear was applied to compare resistance against tantalum corrosion both before and after ion implantation. The results show that argon ion implantation has a substantial impact on increasing resistance against tantalum corrosion. After the corrosion test, scanning electron microscopy (SEM) analyzed the samples' surface morphologies. In addition, the elemental composition is characterized by energy-dispersive X-ray (EDX) analysis. The purpose of this paper was to obtain the perfect condition for the formation of tantalum corrosion resistance. In order to evaluate the effect of the ion implantation on the corrosion behavior, potentiodynamic tests were performed. The results show that the corrosion resistance of the samples strongly depends on the implantation doses.

The multi-year effects of repeatedly growing cotton with moderate resistance to Meloidogyne incognita

Science.gov (United States)

Kemerait, Robert C.

2009-01-01

Meloidogyne incognita causes more damage to cotton in the US than any other pathogen. The objective of this study was to document the cumulative effect of moderate resistance on M. incognita population density, root galling, and yield suppression in the southern United States on a moderately resistant cotton genotype grown continuously for three years. Cotton genotypes were Phytogen PH98-3196 (77% suppression of M. incognita), Acala NemX (85% suppression of M. incognita), and Delta and Pine Land DP458 B/R (susceptible standard, 0% suppression). Cotton was grown in fumigated and non-fumigated plots to measure yield loss. Each genotype and nematicide combination was planted in the same place for three years at two sites to document cumulative effects. In 2006, following three years of the different genotypes, all plots at one site were planted with susceptible cotton to document residual effects of planting resistant genotypes. Root galling and nematode population densities in the soil were significantly lower, and percentage yield suppression was numerically lower, when moderately resistant cotton was grown compared to the susceptible standard in both fields in all three years. Differences between susceptible and moderately resistant genotypes are established quickly (after only one season) and then either maintained at similar levels or slightly increased in subsequent years depending on initial nematode levels. However, when susceptible cotton was grown following three years of the moderately resistant genotypes, the nematode suppression provided by moderate resistance was undetectable by the end of the first season. Moderately resistant cotton genotypes are more beneficial than previously reported and should be pursued for nematode management. Rotation of moderately resistant and susceptible cotton could be used along with nematicides to manage root-knot nematodes in a continuous cotton cropping system and reduce selection pressure on the nematodes. PMID:22661787

Postantibiotic effects and postantibiotic sub-MIC effects of tilmicosin, erythromycin and tiamulin on erythromycin-resistant Streptococcus suis.

Science.gov (United States)

Wang, Liping; Zhang, Yuanshu

2009-10-01

The postantibiotic effects (PAEs) and postantibiotic sub-MIC effects (PA SMEs) of tilmicosin, erythromycin and tiamulin on erythromycin-susceptible and erythromycin-resistant strains of Streptococcus suis (M phenotype) were investigated in vitro. Tilmicosin and tiamulin induced significantly longer PAE and PA SME against both erythromycin-susceptible and erythromycin-resistant strains than did erythromycin. The durations of PAE and PA SMEs were proportional to the concentrations of drugs used for exposure. The PA SMEs were substantially longer than PAEs on S. suis (P<0.05) regardless of the antimicrobial used for exposure. The results indicated that the PAE and PA SME could help in the design of efficient control strategies for infection especially caused by erythromycin-resistant S. suis and that they may provide additional valuable information for the rational drug use in clinical practice.

Effect of pentoxifylline on P-glycoprotein mediated vincristine resistance of L1210 mouse leukemic cell line

International Nuclear Information System (INIS)

Breier, A.; Uhrik, B.; Barancik, M.; Stefankova, Z.; Tribulova, N.

1994-01-01

Effect of pentoxifylline (PTX) on vincristine (VCR) resistance of multidrug resistant L1210/VCR mouse leukemic cell line was studied. Reversal effect of PTX (in concentration 50-150 mg dm -3 ) on vincristine resistance, i.e. potentiation of vincristine cytotoxicity on L1210/VCR cells by PTX was found. PTX alone in the above concentration did not exert any significant effect on sensitive or resistant cell lines in the absence of vincristine. Resistance of L1210/VCR cell line was found previously to be accompanied with overexpression of drug transporting P-glycoprotein. Indeed, lower level of 3 H-vincristine accumulation by resistant L1210/VCR cell line in comparison with sensitive L1210 cell line was observed. Accumulation of 3 H-vincristine by L1210/VCR cell line was significantly increased in the presence of PTX. PTX in the same condition did not exert any considerable effect on accumulation of 3 H-vincristine by nonresistant L1210 cells. Observable morphological damage was observed in 1210/VCR cells cultivated in medium containing vincristine (0.2 mg dm -3 ) and pentoxifylline (100 mg dm -3 ) in comparison with the non-damaged cells in the presence of vincristine or pentoxifylline alone. The results obtained indicate that pentoxifylline may be considered as a reversal agent in multidrug resistance. (author)

Effects of gamma-rays irradiation on tracking resistance of organic insulating materials

Energy Technology Data Exchange (ETDEWEB)

Du, Boxue; Suzuki, Akio; Kobayashi, Shigeo [Tokyo Univ. of Agriculture and Technology, Koganei (Japan). Faculty of Technology

1996-04-01

This paper describes the influence of gamma-rays irradiation on tracking failure of organic insulating materials by use of the IEC Publ.112 method. Tracking resistance of organic insulating materials under wet polluted condition has been studied by many investigators with a test method of the IEC Publ.112. The investigations on irradiation effects on tracking resistance should be enhanced due to the increasing usage of organic insulating materials in the radiation environments. The tracking resistance seems to be affected by gamma-irradiation, but the knowledge on the influence of gamma-irradiation is quite a few and systematic studies are needed. In this paper, modified polyphenylene oxide, polybutylene naphthalate, modified polycarbonate and polybutylene terephthalate which were irradiated in air until 1x10{sup 7}R and 1x10{sup 8}R with dose rate of 10{sup 6}R/hr using {sup 60}Co gamma-source have been employed. The total dose effects on the number of drops to tracking failure, contact angle and charges of scintillation have been studied. As the total doses are increased, the number of drops to tracking failure decreases with polybutylene terephthalate. On the other hand, the number of drops to tracking failure increases with polybutylene naphthalate and modified polycarbonate when the total doses are increased. The effects of gamma-rays irradiation on tracking failure are due to radiation-induced degradation or cross-linking of organic insulating materials. When the organic insulating materials are degraded by gamma-irradiation, the tracking resistance decreases, but for cross-linking type materials, the tracking resistance increases. (author)

Effect of implanted doses of N+-ions on the contact resistance of copper contacts

International Nuclear Information System (INIS)

Dubravec, B.; Kovac, P.; Lipka, F.; Padysak, M.

1997-01-01

The paper deals with the effect of implanted doses of N + ions on the contact resistance. Dependencies of the contact resistance versus contact force R c =f(F c ) and microhardness of implanted surfaces were measured for three implanted profiles. The influence of the aggressive environs on the contact resistance of implanted contact is given too

Pyridostigmine Improves the Effects of Resistance Exercise Training after Myocardial Infarction in Rats

Science.gov (United States)

Feriani, Daniele J.; Coelho-Júnior, Hélio J.; de Oliveira, Juliana C. M. F.; Delbin, Maria A.; Mostarda, Cristiano T.; Dourado, Paulo M. M.; Caperuto, Érico C.; Irigoyen, Maria C. C.; Rodrigues, Bruno

2018-01-01

Myocardial infarction (MI) remains the leading cause of morbidity and mortality worldwide. Exercise training and pharmacological treatments are important strategies to minimize the deleterious effects of MI. However, little is known about the effects of resistance training combined with pyridostigmine bromide (PYR) treatment on cardiac and autonomic function, as well as on the inflammatory profile after MI. Thus, in the present study, male Wistar rats were randomly assigned into: control (Cont); sedentary infarcted (Inf); PYR – treated sedentary infarcted rats (Inf+P); infarcted rats undergoing resistance exercise training (Inf+RT); and infarcted rats undergoing PYR treatment plus resistance training (Inf+RT+P). After 12 weeks of resistance training (15–20 climbs per session, with a 1-min rest between each climb, at a low to moderate intensity, 5 days a week) and/or PYR treatment (0.14 mg/mL of drink water), hemodynamic function, autonomic modulation, and cytokine expressions were evaluated. We observed that 3 months of PYR treatment, either alone or in combination with exercise, can improve the deleterious effects of MI on left ventricle dimensions and function, baroreflex sensitivity, and autonomic parameters, as well as systemic and tissue inflammatory profile. Furthermore, additional benefits in a maximal load test and anti-inflammatory state of skeletal muscle were found when resistance training was combined with PYR treatment. Thus, our findings suggest that the combination of resistance training and PYR may be a good therapeutic strategy since they promote additional benefits on skeletal muscle anti-inflammatory profile after MI. PMID:29483876

Effect of temperature on structure and corrosion resistance for ...

Indian Academy of Sciences (India)

The effect of plating temperatures between 60 and 90◦C on structure and corrosion resistance for elec- troless NiWP coatings ..... which helps to form fine grain. At 80 .... [23] Zhang W X, Jiang Z H, Li G Y and Jiang Q 2008 Surf. Coat. Technol.

Effect of methylxanthines derived from pentoxifylline on P-glycoprotein mediated multidrug resistance

International Nuclear Information System (INIS)

Kupsakova, I.; Drobna, Z.; Breier, A.

2001-01-01

In this paper study of multidrug resistance (MDR) antitumor agents - P-glycoprotein (PGP) is presented. The ability of pentoxifylline (PTX) to depress resistance mediated by overexpression of PGP in mouse leukemic cell line L 121 ONCR resistant to vincristine (VCR) was described earlier. PTX depressed the resistance of these cells in a dose and time dependent manner. This effect was accompanied by increased level of [ 3 H]-vincristine accumulation by these cells. The methylxanthines with different length of this aliphatic side chain were synthesized and their capability to depress MDR was tested. The results indicated that the position of carbonyl group plays a crucial role for the ability of the derivative to depress MDR of L 121 ONCR cells. (authors)

Investigation into the effect of common factors on rolling resistance of belt conveyor

Directory of Open Access Journals (Sweden)

Lu Yan

2015-08-01

Full Text Available Since indentation rolling resistance accounts for the major part of total resistance of belt conveyor, it is important to compute it using a proper method during the design and application study of the belt conveyor. First, an approximate formula for computing the indentation rolling resistance is offered. In this formula, a one-dimensional Winkler foundation and a three-parameter viscoelastic Maxwell solid model of the belt backing material are used to determine the resistance to motion of a conveyor belt over idlers. With the help of this formula, the authors analyze the effect of common factors on the rolling resistance. Finally, experiments are carried out under certain condition compared with theoretical analysis. A reasonable correlation exists between the experimental results and the theoretical formulae.

[Physiological and biochemical effects of intermittent fasting combined with hunger-resistant food on mice].

Science.gov (United States)

Shen, Xiao-Dong; Hua, Wei-Guo; Chu, Wei-Zhong; Xu, Feng; Wang, Yu-Ying; Chen, Hui-Ju

2006-11-01

To observe the physiological and biochemical effects of intermittent fasting combined with hunger-resistant food on mice, and to evaluate the safety and beneficial effects of this regimen. One hundred and forty-four adult ICR mice were divided into 4 groups: standard feed AL group (ad libitum intake of standard feed), hunger-resistant food AL group (ad libitum intake of hunger-resistant food), standard feed IF group (feeding standard feed and fasting on alternate days), and hunger-resistant food IF group (feeding hunger-resistant food and fasting on alternate days). The experiment lasted for 4-8 weeks and all mice drank water freely. The quality of life, body weight, fasting blood glucose, serum lipid, blood routine test, liver and kidney functions as well as the viscera indexes were examined. Compared to the standard feed AL group, the caloric taking and the increment of body-weight were reduced (Pfasting blood glucose were reduced in standard feed IF group and hunger-resistant food IF group (Pintermittent fasting combined with hunger-resistant food is safe and beneficial to metabolic regulation, such as controlling body-weight and adjusting blood glucose and serum lipid. It is expected that development of this regimen will be helpful to the control of obesity and diabetes, etc.

Pleotropic effects of leptin to reverse insulin resistance and diabetic ketoacidosis

DEFF Research Database (Denmark)

Perry, Rachel J; Petersen, Kitt Falk; Shulman, Gerald I.

2016-01-01

In this review we discuss the mechanisms for the pleotropic effects of leptin replacement therapy to reverse liver and muscle insulin resistance in lipodystrophic individuals, as well as insulin-independent effects of leptin replacement therapy to suppress white adipose tissue lipolysis, hepatic...

The Effect of a Pulsed Magnetic Field on Domain Wall Resistance in Magnetic Nanowires

Energy Technology Data Exchange (ETDEWEB)

Majidi, R; Tehranchi, M M; Tabrizi, K Ghafoori [Department of Physics, G.C., Shahid Beheshti University, Evin, 19838-63113, Tehran (Iran, Islamic Republic of); Phirouznia, A, E-mail: Teranchi@cc.sbu.ac.ir [Department of Physics, Azarbaijan University of Tarbiat Moallem, 53714-161 Tabriz (Iran, Islamic Republic of)

2011-04-01

The effect of a pulsed magnetic field on domain wall magnetoresistance for an ideal one-dimensional magnetic nanowire with a domain wall has been investigated. The analysis has been based on the Boltzmann transport equation, within the relaxation time approximation. The results indicate that the domain wall resistance increase when enhancing the magnetic field. The evaluation of local magnetization has been considered in the presence of a pulsed magnetic field. The time evaluation of the magnetization also has an effect on the domain wall resistance. The resistance depends on the contribution of the Zeeman and exchange interactions.

The Effect of a Pulsed Magnetic Field on Domain Wall Resistance in Magnetic Nanowires

International Nuclear Information System (INIS)

Majidi, R; Tehranchi, M M; Tabrizi, K Ghafoori; Phirouznia, A

2011-01-01

The effect of a pulsed magnetic field on domain wall magnetoresistance for an ideal one-dimensional magnetic nanowire with a domain wall has been investigated. The analysis has been based on the Boltzmann transport equation, within the relaxation time approximation. The results indicate that the domain wall resistance increase when enhancing the magnetic field. The evaluation of local magnetization has been considered in the presence of a pulsed magnetic field. The time evaluation of the magnetization also has an effect on the domain wall resistance. The resistance depends on the contribution of the Zeeman and exchange interactions.

Postantibiotic effects and postantibiotic sub-MIC effects of tilmicosin, erythromycin and tiamulin on erythromycin-resistant Streptococcus suis

Directory of Open Access Journals (Sweden)

Liping Wang

2009-12-01

Full Text Available The postantibiotic effects (PAEs and postantibiotic sub-MIC effects (PA SMEs of tilmicosin, erythromycin and tiamulin on erythromycin-susceptible and erythromycin-resistant strains of Streptococcus suis (M phenotype were investigated in vitro. Tilmicosin and tiamulin induced significantly longer PAE and PA SME against both erythromycin-susceptible and erythromycin-resistant strains than did erythromycin. The durations of PAE and PA SMEs were proportional to the concentrations of drugs used for exposure. The PA SMEs were substantially longer than PAEs on S. suis (P<0.05 regardless of the antimicrobial used for exposure. The results indicated that the PAE and PA SME could help in the design of efficient control strategies for infection especially caused by erythromycin-resistant S. suis and that they may provide additional valuable information for the rational drug use in clinical practice.

Effect of radiation decontamination on drug-resistant bacteria

International Nuclear Information System (INIS)

Ito, Hitoshi

2006-01-01

More than 80% of food poisoning bacteria such as Salmonella are reported as antibiotic-resistant to at least one type antibiotic, and more than 50% as resistant to two or more. For the decontamination of food poisoning bacteria in foods, radiation resistibility on drug-resistant bacteria were investigated compared with drug-sensitive bacteria. Possibility on induction of drug-resistant mutation by radiation treatment was also investigated. For these studies, type strains of Escherichia coli S2, Salmonella enteritidis YK-2 and Staphylococcus aureus H12 were used to induce drug-resistant strains with penicillin G. From the study of radiation sensitivity on the drug-resistant strain induced from E. coli S2, D 10 value was obtained to be 0.20 kGy compared with 0.25 kGy at parent strain. On S. enteritidis YK-2, D 10 value was obtained to be 0.14 kGy at drug-resistant strain compared with 0.16 kGy at parent strain. D 10 value was also obtained to be 0.15 kGy at drug-resistant strain compared with 0.21 kGy at parent strain of St. aureus H12. Many isolates of E. coli 157:H7 or other type of E. coli from meats such as beef were resistant to penicillin G, and looked to be no relationship on radiation resistivities between drug-resistant strains and sensitive strains. On the study of radiation sensitivity on E. coli S2 at plate agars containing antibiotics, higher survival fractions were obtained at higher doses compared with normal plate agar. The reason of higher survival fractions at higher doses on plate agar containing antibiotics should be recovery of high rate of injured cells by the relay of cell division, and drug-resistant strains by mutation are hardly induced by irradiation. (author)

Bias voltage induced resistance switching effect in single-molecule magnets’ tunneling junction

Science.gov (United States)

Zhang, Zhengzhong; Jiang, Liang

2014-09-01

An electric-pulse-induced reversible resistance change effect in a molecular magnetic tunneling junction, consisting of a single-molecule magnet (SMM) sandwiched in one nonmagnetic and one ferromagnetic electrode, is theoretically investigated. By applying a time-varying bias voltage, the SMM's spin orientation can be manipulated with large bias voltage pulses. Moreover, the different magnetic configuration at high-resistance/low-resistance states can be ‘read out’ by utilizing relative low bias voltage. This device scheme can be implemented with current technologies (Khajetoorians et al 2013 Science 339 55) and has potential application in molecular spintronics and high-density nonvolatile memory devices.

Bias voltage induced resistance switching effect in single-molecule magnets' tunneling junction.

Science.gov (United States)

Zhang, Zhengzhong; Jiang, Liang

2014-09-12

An electric-pulse-induced reversible resistance change effect in a molecular magnetic tunneling junction, consisting of a single-molecule magnet (SMM) sandwiched in one nonmagnetic and one ferromagnetic electrode, is theoretically investigated. By applying a time-varying bias voltage, the SMM's spin orientation can be manipulated with large bias voltage pulses. Moreover, the different magnetic configuration at high-resistance/low-resistance states can be 'read out' by utilizing relative low bias voltage. This device scheme can be implemented with current technologies (Khajetoorians et al 2013 Science 339 55) and has potential application in molecular spintronics and high-density nonvolatile memory devices.

Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance.

Science.gov (United States)

Ning, Dongfeng; Song, Alin; Fan, Fenliang; Li, Zhaojun; Liang, Yongchao

2014-01-01

It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si) in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae), including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.

Reversible Resistance Switching Effect in Amorphous Ge1Sb4Te7 Thin Films without Phase Transformation

International Nuclear Information System (INIS)

Hua-Jun, Sun; Li-Song, Hou; Yi-Qun, Wu; Xiao-Dong, Tang

2009-01-01

We demonstrate a reversible resistance switching effect that does not rely on amorphous-crystalline phase transformation in a nanoscale capacitor-like cell using Ge 1 Sb 4 Te 7 films as the working material. The polarity and amplitude of the applied electric voltage switches the cell resistance between low- and high-resistance states, as revealed in the current-voltage characteristics of the film by conductive atomic force microscopy (CAFM). This reversible SET/RESET switching effect is induced by voltage pulses and their polarity. The change of electrical resistance due to the switching effect is approximately two orders of magnitude

Effects of atmospheric moisture on rock resistivity.

Science.gov (United States)

Alvarez, R.

1973-01-01

This study examines the changes in resistivity of rock samples as induced by atmospheric moisture. Experiments were performed on samples of hematitic sandstone, pyrite, and galena. The sandstone underwent a change in resistivity of four orders of magnitude when it was measured in a vacuum of 500 ntorr and in air of 37% relative humidity. Pyrite and galena showed no variations in resistivity when they were measured under the same conditions. These results, plus others obtained elsewhere, indicate that rocks of the resistive type are affected in their electrical properties by atmospheric moisture, whereas rocks of the conductive type are not. The experimental evidence obtained is difficult to reconcile with a model of aqueous electrolytic conduction on the sample surface. It is instead suggested that adsorbed water molecules alter the surface resistivity in a manner similar to that observed in semiconductors and insulators.

The effect of inlet conditions on the air side hydraulic resistance and flow maldistribution in industrial air heaters

Energy Technology Data Exchange (ETDEWEB)

Hoffmann-Vocke, Jonas, E-mail: jh63@waikato.ac.nz [University of Waikato, Energy Research Group, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand); Neale, James, E-mail: jamesn@waikato.ac.nz [University of Waikato, Energy Research Group, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand); Walmsley, Michael, E-mail: walmsley@waikato.ac.nz [University of Waikato, Department of Engineering, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand)

2011-08-15

Highlights: > Measured the effects of air heater inlet header geometry on hydraulic performance. > Measured the effects of inlet header flow maldistribution on hydraulic performance. > Inlet header flow maldistribution increases air heater system hydraulic resistance. - Abstract: Experimental system hydraulic resistance measurements on a scale air heater unit have highlighted the excessive hydraulic resistance of typical industry configurations. Both poor header inlet conditions and large header expansion angles are shown to contribute to system hydraulic resistance magnitudes 20-100% higher than suitable benchmark cases. Typical centrifugal fan system efficiencies well under 80% multiply the system resistance effects resulting in larger fan power penalties. Velocity profile measurements taken upstream and downstream of the test heat exchanger under flow maldistribution conditions provide insight into the flow maldistribution spreading caused by the heat exchanger resistance. The anisotropic resistance of the plate fin-and-tube heat exchanger is shown to result in resistance induced flow dispersion being concentrated in the axis parallel to the plate fins.

The effect of inlet conditions on the air side hydraulic resistance and flow maldistribution in industrial air heaters

International Nuclear Information System (INIS)

Hoffmann-Vocke, Jonas; Neale, James; Walmsley, Michael

2011-01-01

Highlights: → Measured the effects of air heater inlet header geometry on hydraulic performance. → Measured the effects of inlet header flow maldistribution on hydraulic performance. → Inlet header flow maldistribution increases air heater system hydraulic resistance. - Abstract: Experimental system hydraulic resistance measurements on a scale air heater unit have highlighted the excessive hydraulic resistance of typical industry configurations. Both poor header inlet conditions and large header expansion angles are shown to contribute to system hydraulic resistance magnitudes 20-100% higher than suitable benchmark cases. Typical centrifugal fan system efficiencies well under 80% multiply the system resistance effects resulting in larger fan power penalties. Velocity profile measurements taken upstream and downstream of the test heat exchanger under flow maldistribution conditions provide insight into the flow maldistribution spreading caused by the heat exchanger resistance. The anisotropic resistance of the plate fin-and-tube heat exchanger is shown to result in resistance induced flow dispersion being concentrated in the axis parallel to the plate fins.

Effect of pretreatment HIV-1 drug resistance on immunological, virological, and drug-resistance outcomes of first-line antiretroviral treatment in sub-Saharan Africa: a multicentre cohort study

NARCIS (Netherlands)

Hamers, Raph L.; Schuurman, Rob; Sigaloff, Kim C. E.; Wallis, Carole L.; Kityo, Cissy; Siwale, Margaret; Mandaliya, Kishor; Ive, Prudence; Botes, Mariette E.; Wellington, Maureen; Osibogun, Akin; Wit, Ferdinand W.; van Vugt, Michèle; Stevens, Wendy S.; de Wit, Tobias F. Rinke

2012-01-01

Background The effect of pretreatment HIV-1 drug resistance on the response to first-line combination antiretroviral therapy (ART) in sub-Saharan Africa has not been assessed. We studied pretreatment drug resistance and virological, immunological, and drug-resistance treatment outcomes in a large

Identification of parental line specific effects of MLF2 on resistance to coccidiosis in chickens

Science.gov (United States)

2011-01-01

Background MLF2 was the candidate gene associated with coccidiosis resistance in chickens. Although single marker analysis supported the association between MLF2 and coccidiosis resistance, causative mutation relevant to coccidiosis was not identified yet. Thus, this study suggested segregation analysis of MLF2 haplotype and the association test of the other candidate genes using improved data transformation. Results A haplotype probably originated from one parental line was found out of 4 major haplotypes of MLF2. Frequency of this haplotype was 0.2 in parental chickens and its offspring in 12 families. Allele substitution effect of the MLF2 haplotype originated from a specific line was associated with increased body weight and fecal egg count explaining coccidiosis resistance. Nevertheless Box-Cox transformation was able to improve normality; association test did not produce obvious different results compared with analysis with log transformed phenotype. Conclusion Allele substitution effect analysis and classification of MLF2 haplotype identified the segregation of haplotype associated with coccidiosis resistance. The haplotype originated from a specific parental line was associated with improving disease resistance. Estimating effect of MLF2 haplotype on coccidiosis resistance will provide useful information for selecting animals or lines for future study. PMID:21645301

Effect of the interface resistance in non-local Hanle measurements

International Nuclear Information System (INIS)

Villamor, Estitxu; Hueso, Luis E.; Casanova, Fèlix

2015-01-01

We use lateral spin valves with varying interface resistance to measure non-local Hanle effect in order to extract the spin-diffusion length of the non-magnetic channel. A general expression that describes spin injection and transport, taking into account the influence of the interface resistance, is used to fit our results. Whereas the fitted spin-diffusion length value is in agreement with the one obtained from standard non-local measurements in the case of a finite interface resistance, in the case of transparent contacts a clear disagreement is observed. The use of a corrected expression, recently proposed to account for the anisotropy of the spin absorption at the ferromagnetic electrodes, still yields a deviation of the fitted spin-diffusion length which increases for shorter channel distances. This deviation shows how sensitive the non-local Hanle fittings are, evidencing the complexity of obtaining spin transport information from such type of measurements

Assessing resistance of stabilized corrosion resistant steels to intergranular corrosion

International Nuclear Information System (INIS)

Karas, A.; Cihal, V. Jr.; Vanek, V.; Herzan, J.; Protiva, K.; Cihal, V.

1987-01-01

Resistance to intergranular corrosion was determined for four types of titanium-stabilized steels from the coefficients of stabilization efficiency according to the degree the chemical composition was known. The ATA SUPER steel showed the highest resistance parameter value. The resistance of this type of steel of a specific composition, showing a relatively low value of mean nitrogen content was compared with steel of an optimized chemical composition and with low-carbon niobium stabilized, molybdenum modified steels. The comparison showed guarantees of a sufficient resistance of the steel to intergranular corrosion. The method of assessing the resistance to intergranular corrosion using the calculation of the minimum content of Cr', i.e., the effective chromium content, and the maximum effective carbon content C' giving the resistance parameter k seems to be prospective for practical use in the production of corrosion resistant steels. (author). 1 tab., 5 figs., 15 refs

Effects of Floor Covering Resistance of a Radiant Floor on System Energy and Exergy Performances

DEFF Research Database (Denmark)

Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

2016-01-01

Floor covering resistance (material and thickness) can be influenced by subjective choices (architectural design, interior design, texture, etc.) with significant effects on the performance of a radiant heating and cooling system. To study the effects of floor covering resistance on system...... performance, a water-based radiant floor heating and cooling system (dry, wooden construction) was considered to be coupled to an air-to-water heat pump, and the effects of varying floor covering resistances (0.05 m2K/W, 0.09 m2K/W and 0.15 m2K/W) on system performance were analyzed in terms of energy...... and exergy. In order to achieve the same heating and cooling outputs, higher average water temperatures are required in the heating mode (and lower temperatures in the cooling mode) with increasing floor covering resistance. These temperature requirements decrease the heat pump’s performance (lower...

Effect of forming-gas annealing on the resistance switching effect of heteroepitaxial Nb:SrTiO{sub 3} film on Si substrate

Energy Technology Data Exchange (ETDEWEB)

Xiang, Wenfeng; Hu, Minghao; Liu, Yi [China University of Petroleum, Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, Beijing (China)

2017-12-15

The influence of forming-gas annealing (FGA) on the resistance switching effect of epitaxial Nb:SrTiO{sub 3} [Nb-doped strontium titanates (NbSTO)] films on Si substrate has been investigated. The resistance values at low and high resistance states for NbSTO films after FGA are about two orders of magnitude lower than those of the as-deposited sample, which may effectively decrease the power dissipation of devices. Hysteretic I-V characteristic curves show that the stability of FGA sample was improved. The resistance ratio of NbSTO films measured via pulse voltage increased from 1.0-1.2 to 3.2-3.6 after FGA. Moreover, the resistance ratio of the FGA sample gradually increased with increasing number of cycles. These results indicate that FGA improves the resistance switching characteristics of NbSTO films. In addition, the underlying mechanism was discussed. (orig.)

Effect of electrode shape on grounding resistances - Part 1

DEFF Research Database (Denmark)

Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Dahlin, Torleif

2016-01-01

Electrode grounding resistance is a major factor affecting measurement quality in electric resistivity tomography (ERT) measurements for cryospheric applications. Still, little information is available on grounding resistances in the geophysical literature, mainly because it is difficult to measure....... The focus-one protocol is a new method for estimating single electrode grounding resistances by measuring the resistance between a single electrode in an ERT array and all the remaining electrodes connected in parallel. For large arrays, the measured resistance is dominated by the grounding resistance...... of the electrode under test, the focus electrode. We have developed an equivalent circuit model formulation for the resistance measured when applying the focus-one protocol. Our model depends on the individual grounding resistances of the electrodes of the array, the mutual resistances between electrodes...

[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.

Effect of Bi on the corrosion resistance of zirconium alloys

International Nuclear Information System (INIS)

Yao Meiyi; Zhou Bangxin; Li Qiang; Zhang Weipeng; Zhu Li; Zou Linghong; Zhang Jinlong; Peng Jianchao

2014-01-01

In order to investigate systematically the effect of Bi addition on the corrosion resistance of zirconium alloys, different zirconium-based alloys, including Zr-4 (Zr-l.5Sn-0.2Fe-0.1Cr), S5 (Zr-0.8Sn-0.35Nb-0.4Fe-0.1Cr), T5 (Zr-0.7Sn-l.0Nb-0.3Fe-0.1Cr) and Zr-1Nb, were adopted to prepare the zirconium alloys containing Bi of 0∼0.5% in mass fraction. These alloys were denoted as Zr-4 + xBi, S5 + xBi, T5 + xBi and Zr-1Nb + xBi, respectively. The corrosion behavior of these specimens was investigated by autoclave testing in lithiated water with 0.01 M LiOH or deionized water at 360 ℃/18.6 MPa and in superheated steam at 400 ℃/10.3 MPa. The microstructure of the alloys was examined by TEM and the second phase particles (SPPs) were analyzed by EDS. Microstructure observation shows that the addition of Bi promotes the precipitation of Sn as second phase particles (SPPs) because Sn is in solid solution in α-Zr matrix in Zr-4, S5 and T5 alloys. The concentration of Bi dissolved in α-Zr matrix increase with the increase of Nb in the alloys, and the excess Bi precipitates as Bi-containing SPPs. The corrosion results show that the effect of Bi addition on the corrosion behavior of different zirconium-based alloys is very complicated, depending on their compositions and corrosion conditions. In the case of higher Bi concentration in α-Zr, the zirconium alloys exhibit better corrosion resistance. However, in the case of precipitation of Bi-containing SPPs, the corrosion resistance gets worse. This indicates that the solid solution of Bi in α-Zr matrix can improve the corrosion resistance, while the precipitation of the Bi-containing SPPs is harmful to the corrosion resistance. (authors)

Predicting date rape perceptions: the effects of gender, gender role attitudes, and victim resistance.

Science.gov (United States)

Black, Katherine A; McCloskey, Kathy A

2013-08-01

The effects of participant gender and victim resistance on date rape perceptions have been inconsistent. Participant gender role attitudes may contribute to these inconsistencies. We found women with traditional gender role attitudes were least likely to agree that the perpetrator was guilty of rape. Participants were less convinced of the perpetrator's guilt when the victim resisted verbally than when she resisted verbally and physically, and participants with traditional gender role attitudes were less convinced of the negative impact on the victim when she resisted verbally than when she resisted verbally and physically. Perhaps previous inconsistencies resulted from varying proportions of men and women with traditional versus liberal gender role attitudes in the samples.

Effects of Hall current and electrical resistivity on the stability of gravitating anisotropic quantum plasma

Science.gov (United States)

Bhakta, S.; Prajapati, R. P.

2018-02-01

The effects of Hall current and finite electrical resistivity are studied on the stability of uniformly rotating and self-gravitating anisotropic quantum plasma. The generalized Ohm's law modified by Hall current and electrical resistivity is used along with the quantum magnetohydrodynamic fluid equations. The general dispersion relation is derived using normal mode analysis and discussed in the parallel and perpendicular propagations. In the parallel propagation, the Jeans instability criterion, expression of critical Jeans wavenumber, and Jeans length are found to be independent of non-ideal effects and uniform rotation but in perpendicular propagation only rotation affects the Jeans instability criterion. The unstable gravitating mode modified by Bohm potential and the stable Alfven mode modified by non-ideal effects are obtained separately. The criterion of firehose instability remains unaffected due to the presence of non-ideal effects. In the perpendicular propagation, finite electrical resistivity and quantum pressure anisotropy modify the dispersion relation, whereas no effect of Hall current was observed in the dispersion characteristics. The Hall current, finite electrical resistivity, rotation, and quantum corrections stabilize the growth rate. The stability of the dynamical system is analyzed using the Routh-Hurwitz criterion.

Effect of Microstructure and Environment on Static Crack Growth Resistance in Alloy 706

Science.gov (United States)

Yang, Ling; Hawk, Jeffrey A.; Duquette, David J.; Schwant, Robin C.

2009-06-01

The relationship between thermo-mechanical processing, resultant microstructure, and mechanical properties has been of interest in the field of metallurgy for centuries. In this work, the effect of heat treatment on microstructure and key mechanical properties important for turbine rotor design has been investigated. Specifically, the tensile yield strength and crack growth resistance for a nickel-iron based superalloy 706 has been examined. Through a systematic study, a correlation was found between the processing parameters and the microstructure. Specifically, differences in grain boundary and grain interior precipitates were identified and correlated with processing conditions. Further, a strong relationship between microstructure and mechanical properties was identified. The type and orientation of grain boundary precipitates affect time-dependent crack propagation resistance, and the size and volume fraction of grain interior precipitates were correlated with tensile yield strength. It was also found that there is a strong environmental effect on time-dependent crack propagation resistance, and the sensitivity to environmental damage is microstructure dependent. Microstructures with η decorated grain boundaries were more resistant to environmental damage through oxygen embrittlement than microstructures with no η phase on the grain boundaries. An effort was made to explore the mechanisms of improving the time-dependent crack propagation resistance through thermo-mechanical processing, and several mechanisms were identified in both the environment-dependent and the environment-independent category. These mechanisms were ranked based on their contributions to crack propagation resistance.

Effect of the ferrule on fracture resistance of teeth restored with ...

African Journals Online (AJOL)

However few studies have considered the effect of different ferrule designs on prefabricated post and composite core systems. Aim: This study investigated the effect of different ferrule designs on the fracture resistance of teeth incorporating prefabricated posts and composite cores. It also assessed the necessity of a post in ...

Effect of thermal annealing on resistance switching characteristics of Pt/ZrO2/TiN stacks

International Nuclear Information System (INIS)

Kim, Jonggi; Lee, Kyumin; Kim, Yonjae; Na, Heedo; Ko, Dae-Hong; Sohn, Hyunchul; Lee, Sunghoon

2013-01-01

In this study, the effect of thermal annealing on both the physical properties and the resistive switching properties of ZrO 2 films deposited by atomic layer deposition (ALD) method were investigated for its potential application to non-volatile memory devices. The ZrO 2 films in the Pt/ZrO 2 /TiN structure exhibited unipolar and bipolar resistance switching behaviors depending on the nature of the bias applied to Pt top electrodes for the electro-forming process. For unipolar switching, the resistance of the high resistance state (HRS) was reduced with increasing annealing temperature, accompanied with the increase of metallic Zr in the annealed ZrO 2 films. In contrast, the HRS resistance in the bipolar switching was increased while the low resistance state (LRS) resistance was decreased with increasing annealing temperature, producing a greater change in resistance. SIMS and EDX showed that the thickness of interfacial TiO x N y layer between the ZrO 2 and the TiN bottom electrode was enlarged with annealing. The enlarged TiO x N y layer was expected to produce the reduction of LRS resistance with the increase of HRS resistance in the bipolar resistance switching. - Highlights: • Effect of thermal annealing on resistive switching of ZrO 2 was investigated. • Both unipolar and bipolar switching were shown in the Pt/ZrO 2 /TiN stack. • TiO x N y interface layer was enlarged with increasing annealing temperature. • TiO x N y interface plays an important role in resistive switching properties

Recommendations for Methicillin-Resistant Staphylococcus aureus Prevention in Adult ICUs: A Cost-Effectiveness Analysis.

Science.gov (United States)

Whittington, Melanie D; Atherly, Adam J; Curtis, Donna J; Lindrooth, Richard C; Bradley, Cathy J; Campbell, Jonathan D

2017-08-01

Patients in the ICU are at the greatest risk of contracting healthcare-associated infections like methicillin-resistant Staphylococcus aureus. This study calculates the cost-effectiveness of methicillin-resistant S aureus prevention strategies and recommends specific strategies based on screening test implementation. A cost-effectiveness analysis using a Markov model from the hospital perspective was conducted to determine if the implementation costs of methicillin-resistant S aureus prevention strategies are justified by associated reductions in methicillin-resistant S aureus infections and improvements in quality-adjusted life years. Univariate and probabilistic sensitivity analyses determined the influence of input variation on the cost-effectiveness. ICU. Hypothetical cohort of adults admitted to the ICU. Three prevention strategies were evaluated, including universal decolonization, targeted decolonization, and screening and isolation. Because prevention strategies have a screening component, the screening test in the model was varied to reflect commonly used screening test categories, including conventional culture, chromogenic agar, and polymerase chain reaction. Universal and targeted decolonization are less costly and more effective than screening and isolation. This is consistent for all screening tests. When compared with targeted decolonization, universal decolonization is cost-saving to cost-effective, with maximum cost savings occurring when a hospital uses more expensive screening tests like polymerase chain reaction. Results were robust to sensitivity analyses. As compared with screening and isolation, the current standard practice in ICUs, targeted decolonization, and universal decolonization are less costly and more effective. This supports updating the standard practice to a decolonization approach.

Corrosion resistance of Ni-Cr-Mo alloys. Chemical composition and metallurgical condition's effects

International Nuclear Information System (INIS)

Zadorozne, N.S.; Rebak, Raul B.

2009-01-01

Ni-Cr-Mo alloys offer an outstanding corrosion resistance in a wide variety of highly-corrosive environments. This versatility is due to the excellent performance of nickel in hot alkaline solutions and the beneficial effect of chromium and molybdenum in oxidizing and reducing conditions, respectively. Alloy C-22 (22 % Cr-13 % Mo-3% W) is a well known versatile member of this family. Due to its excellent corrosion resistance in a wide variety of environments, Alloy C-22 has been selected for the fabrication of the corrosion-resistant outer shell of the high-level nuclear waste container. The increasing demand of the industry for corrosion resistant alloys with particular properties of corrosion and mechanical resistance has led to the development of new alloys. Alloy C-22HS (Ni-21 % Cr-17 % Mo) is a new high-strength corrosion resistant material recently developed and introduced into the market. This alloy provides a corrosion resistance comparable with that of other C-type alloys, and it can also be age hardened to effectively double its yield strength. HASTELLOY HYBRID-BC1 (Ni-22 % Mo-15 % Cr) is a new development intended for filling the gap between Ni-Mo and Ni-Cr-Mo alloys. This novel alloy is able to withstand HCl and H 2 SO 4 , even in the presence of dissolved oxygen and other oxidizing species. Its resistance to chloride-induced pitting corrosion, crevice corrosion and stress corrosion cracking is also remarkable. Thermal aging of Ni-Cr-Mo alloys leads to microstructure changes depending on the temperature range and exposure time at temperature. A Long Range Ordering (LRO) reaction can occur in the range of 350 C degrees to 600 C degrees, producing an ordered Ni 2 (Cr,Mo) phase. This ordering reaction does not seem to affect the corrosion resistance and produces only a slight loss in ductility. LRO transformation is homogeneous and has proven to be useful to fabricate the age-hard enable Alloy C22-HS. Tetrahedral Close Packed (TCP) phases, like μ, σ and

Effects of 16 weeks of aerobic, resistance and combination exercise ...

African Journals Online (AJOL)

Effects of 16 weeks of aerobic, resistance and combination exercise programmes on smoking. ... African Journal for Physical Activity and Health Sciences ... Abstract. Previous research on the cessation of smoking and the prevention of smoking recidivism using exercise training has mainly focused on aerobic training (AER).

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats

Directory of Open Access Journals (Sweden)

Moisés Felipe Pereira Gomes

Full Text Available Abstract Background: Baroreceptors act as regulators of blood pressure (BP; however, its sensitivity is impaired in hypertensive patients. Among the recommendations for BP reduction, exercise training has become an important adjuvant therapy in this population. However, there are many doubts about the effects of resistance exercise training in this population. Objective: To evaluate the effect of resistance exercise training on BP and baroreceptor sensitivity in spontaneously hypertensive rats (SHR. Method: Rats SHR (n = 16 and Wistar (n = 16 at 8 weeks of age, at the beginning of the experiment, were randomly divided into 4 groups: sedentary control (CS, n = 8; trained control (CT, n = 8; sedentary SHR (HS, n = 8 and trained SHR (HT, n = 8. Resistance exercise training was performed in a stairmaster-type equipment (1.1 × 0.18 m, 2 cm between the steps, 80° incline with weights attached to their tails, (5 days/week, 8 weeks. Baroreceptor reflex control of heart rate (HR was tested by loading/unloading of baroreceptors with phenylephrine and sodium nitroprusside. Results: Resistance exercise training increased the soleus muscle mass in SHR when compared to HS (HS 0.027 ± 0.002 g/mm and HT 0.056 ± 0.003 g/mm. Resistance exercise training did not alter BP. On the other hand, in relation to baroreflex sensitivity, bradycardic response was improved in the TH group when compared to HS (HS -1.3 ± 0.1 bpm/mmHg and HT -2.6 ± 0.2 bpm/mmHg although tachycardia response was not altered by resistance exercise (CS -3.3 ± 0.2 bpm/mmHg, CT -3.3 ± 0.1 bpm/mmHg, HS -1.47 ± 0.06 bpm/mmHg and HT -1.6 ± 0.1 bpm/mmHg. Conclusion: Resistance exercise training was able to promote improvements on baroreflex sensitivity of SHR rats, through the improvement of bradycardic response, despite not having reduced BP.

Effects of N+ implantation on polysaccharide and osmosis stress resistance of liquorice

International Nuclear Information System (INIS)

Wei Shenglin; Wu Lijun; Yu Zengliang

2007-01-01

In order to study the effects of N + implantation on osmosis stress resistance of plant, the experiment was taken with liquorice as plant model and 15% PEG as the osmosis stress agent. The results showed that the stem height growth of liquorice increased by 40.2% compared with controls (p + implantation parameters may be useful to increase osmosis stress resistance cultivation of liquorice and to make it mutated with ions beam implantation. (authors)

Effects of Disclosing Sponsored Content in Blogs: How the Use of Resistance Strategies Mediates Effects on Persuasion

NARCIS (Netherlands)

E.A. van Reijmersdal (Eva); M.L. Fransen (Marieke); G. van Noort (Guda); S.J. Opree (Suzanna); L. Vandeberg (Lisa); Reusch, S. (Sanne); van Lieshout, F. (Floor); Boerman, S.C. (Sophie C.)

2016-01-01

textabstractThis article presents two studies examining the effects of disclosing online native advertising (i.e., sponsored content in blogs) on people’s brand attitude and purchase intentions. To investigate the mechanisms underlying these effects, we integrated resistance theories with the

Effects of disclosing sponsored content in blogs : how the use of resistance strategies mediates effects on persuasion

NARCIS (Netherlands)

van Reijmersdal, E.A.; Fransen, M.L.; van Noort, G.; Opree, S.J.; Vandeberg, L.; Reusch, S.; van Lieshout, F.; Boerman, S.C.

2016-01-01

This article presents two studies examining the effects of disclosing online native advertising (i.e., sponsored content in blogs) on people’s brand attitude and purchase intentions. To investigate the mechanisms underlying these effects, we integrated resistance theories with the persuasion

Mechanism and degree of chemical elements effect on atmosphere corrosion resistance of steels

International Nuclear Information System (INIS)

Vu Din' Vuj

1991-01-01

It follows from the proposed regression equations that falourable effect of chemical elements on steel resistance to atmospheric corrosion is determined by their ability to increase interatom bond stability in iron crystal lattice and form corrosion products with high protection properties. Element positive influence on steel corrosion resistance decreases in the following order: S, P, Si, Mn, Cu, Cr, Ni, C in semiurban tropical atmosphere and S, Mn, Sr, Cu, Ni, Cr in coastal atmosphere. In the latter case C increases corrosion in a greater degree as compared to P. Small ammounts of Mo decrease steel resistance in semiurban atmosphere and almost do not influence it in the coastal one. Possible mechanisms of individual element influence on steel corrosion resistance are considered

Inheritance of Cry1F resistance, cross-resistance and frequency of resistant alleles in Spodoptera frugiperda (Lepidoptera: Noctuidae).

Science.gov (United States)

Vélez, A M; Spencer, T A; Alves, A P; Moellenbeck, D; Meagher, R L; Chirakkal, H; Siegfried, B D

2013-12-01

Transgenic maize, Zea maize L., expressing the Cry1F protein from Bacillus thuringiensis has been registered for Spodoptera frugiperda (J. E. Smith) control since 2003. Unexpected damage to Cry1F maize was reported in 2006 in Puerto Rico and Cry1F resistance in S. frugiperda was documented. The inheritance of Cry1F resistance was characterized in a S. frugiperda resistant strain originating from Puerto Rico, which displayed >289-fold resistance to purified Cry1F. Concentration-response bioassays of reciprocal crosses of resistant and susceptible parental populations indicated that resistance is recessive and autosomal. Bioassays of the backcross of the F1 generation crossed with the resistant parental strain suggest that a single locus is responsible for resistance. In addition, cross-resistance to Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba, Cry2Aa and Vip3Aa was assessed in the Cry1F-resistant strain. There was no significant cross-resistance to Cry1Aa, Cry1Ba and Cry2Aa, although only limited effects were observed in the susceptible strain. Vip3Aa was highly effective against susceptible and resistant insects indicating no cross-resistance with Cry1F. In contrast, low levels of cross-resistance were observed for both Cry1Ab and Cry1Ac. Because the resistance is recessive and conferred by a single locus, an F1 screening assay was used to measure the frequency of Cry1F-resistant alleles from populations of Florida and Texas in 2010 and 2011. A total frequency of resistant alleles of 0.13 and 0.02 was found for Florida and Texas populations, respectively, indicating resistant alleles could be found in US populations, although there have been no reports of reduced efficacy of Cry1F-expressing plants.

Effects and prevalence of nonresponders after 12 weeks of high-intensity interval or resistance training in women with insulin resistance: a randomized trial.

Science.gov (United States)

Álvarez, Cristian; Ramírez-Campillo, Rodrigo; Ramírez-Vélez, Robinson; Izquierdo, Mikel

2017-04-01

Our aim was to investigate the effects and prevalence of nonresponders (NR) to high-intensity interval training (HIIT) and resistance training (RT) in women with insulin resistance on cardiometabolic health parameters. Sedentary overweight/obese insulin-resistant women (age = 33.5 ± 6.5 yr; body mass index = 29.9 ± 3.7 kg/m 2 ) were randomly assigned to a triweekly HIIT program (HIIT; n = 18) or resistance training (RT; n = 17). Anthropometry (body mass, fat mass, muscle mass, waist circumference, and skinfold thickness), cardiovascular (blood pressure), metabolic [fasting glucose, fasting insulin, and homeostatic model of insulin resistance (HOMA-IR)], as well as muscle strength, and endurance performance covariables were measured before and after 12 wk in both intervention groups. The interindividual variability to exercise training of the subjects was categorized as responders and NR using as cut points two times the typical error of measurement in mean outcomes. After intervention, significant reduction in waist circumference, skinfold thicknesses, fat mass, blood pressure, fasting glucose, insulin, and HOMA-IR ( P HIIT and RT group, respectively. Both HIIT and RT groups exhibited a significant decrease in the endurance performance, whereas only RT exhibited increased muscle strength. Significant differences in the NR prevalence between the HIIT and RT groups were identified for a decrease in fat mass (HIIT 33.3% vs. RT 70.5%; P = 0.028), muscle mass (HIIT 100% vs. RT 52.9%; P = 0.001), and tricipital skinfold (HIIT 5.5% vs. RT 29.4%; P HIIT and RT groups (55.5% vs. 94.1; P = 0.009). However, there were no differences in the NR prevalence between HIIT and RT for decreasing fasting glucose. Twelve weeks of HIIT and RT have similar effects and NR prevalence to improve glucose control variables; however, there is different NR prevalence in other anthropometric, cardiovascular, strength, and endurance performance measurements in insulin-resistant women. These

Effect of non-uniform surface resistance on the quality factor of superconducting niobium cavity

Science.gov (United States)

Tan, Weiwei; Lu, Xiangyang; Yang, Ziqin; Zhao, Jifei; Yang, Deyu; Yang, Yujia

2016-08-01

The formula Rs = G /Q0 is commonly used in the calculation of the surface resistance of radio frequency niobium superconducting cavities. The applying of such equation is under the assumption that surface resistance is consistent over the cavity. However, the distribution of the magnetic field varies over the cavity. The magnetic field in the equator is much higher than that in the iris. According to Thermal Feedback Theory, it leads non-uniform distribution of the density of heat flux, which results in a different temperature distribution along the cavity inter surface. The BCS surface resistance, which depends largely on the temperature, is different in each local inner surface. In this paper, the effect of surface non-uniform resistance on the quality factor has been studied, through the calculation of Q0 in the original definition of it. The results show that it is necessary to consider the non-uniform distribution of magnetic field when the accelerating field is above 20 MV/m for TESLA cavities. Also, the effect of inhomogeneity of residual resistance on the quality factor is discussed. Its distribution barely affects the quality factor.

Insulin Sensitivity Determines Effects of Insulin and Meal Ingestion on Systemic Vascular Resistance in Healthy Subjects.

Science.gov (United States)

Woerdeman, Jorn; Meijer, Rick I; Eringa, Etto C; Hoekstra, Trynke; Smulders, Yvo M; Serné, Erik H

2016-01-01

In addition to insulin's metabolic actions, insulin can dilate arterioles which increase blood flow to metabolically active tissues. This effect is blunted in insulin-resistant subjects. Insulin's effect on SVR, determined by resistance arterioles, has, however, rarely been examined directly. We determined the effects of both hyperinsulinemia and a mixed meal on SVR and its relationship with insulin sensitivity. Thirty-seven lean and obese women underwent a hyperinsulinemic-euglycemic clamp, and 24 obese volunteers underwent a mixed-meal test. SVR was assessed using CPP before and during hyperinsulinemia as well as before and 60 and 120 minutes after a meal. SVR decreased significantly during hyperinsulinemia (-13%; p Insulin decreased SVR more strongly in insulin-sensitive individuals (standardized β: -0.44; p = 0.01). In addition, SVR at 60 minutes after meal ingestion was inversely related to the Matsuda index (β: -0.39; p = 0.04) and the change in postprandial SVR was directly related to postprandial glycemia (β: 0.53; p insulin resistance. This suggests that resistance to insulin-induced vasodilatation contributes to regulation of vascular resistance. © 2015 John Wiley & Sons Ltd.

3-bromopyruvate and buthionine sulfoximine effectively kill anoikis-resistant hepatocellular carcinoma cells.

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Minjong Lee

Full Text Available Acquisition of anoikis resistance is a prerequisite for metastasis in hepatocellular carcinoma (HCC. However, little is known about how energy metabolism and antioxidant systems are altered in anoikis-resistant (AR HCC cells. We evaluated anti-tumor effects of a combination treatment of 3-bromopyruvate (3-BP and buthionine sulfoximine (BSO in AR HCC cells.We compared glycolysis, reactive oxygen species (ROS production, and chemoresistance among Huh-BAT, HepG2 HCC cells, and the corresponding AR cells. Expression of hexokinase II, gamma-glutamylcysteine synthetase (rGCS, and epithelial-mesenchymal transition (EMT markers in AR cells was assessed. Anti-tumor effects of a combination treatment of 3-BP and BSO were evaluated in AR cells and an HCC xenograft mouse model.AR HCC cells showed significantly higher chemoresistance, glycolysis and lower ROS production than attached cells. Expression of hexokinase II, rGCS, and EMT markers was higher in AR HCC cells than attached cells. A combination treatment of 3-BP/BSO effectively suppressed proliferation of AR HCC cells through apoptosis by blocking glycolysis and enhancing ROS levels. In xenograft mouse models, tumor growth derived from AR HCC cells was significantly suppressed in the group treated with 3-BP/BSO compared to the group treated with 3-BP or sorafenib.These results demonstrated that a combination treatment of 3-BP/BSO had a synergistic anti-tumor effect in an AR HCC model. This strategy may be an effective adjuvant therapy for patients with sorafenib-resistant HCC.

3-bromopyruvate and buthionine sulfoximine effectively kill anoikis-resistant hepatocellular carcinoma cells.

Science.gov (United States)

Lee, Minjong; Jo, Ara; Lee, Seulki; Kim, Jong Bin; Chang, Young; Nam, Joon Yeul; Cho, Hyeki; Cho, Young Youn; Cho, Eun Ju; Lee, Jeong-Hoon; Yu, Su Jong; Yoon, Jung-Hwan; Kim, Yoon Jun

2017-01-01

Acquisition of anoikis resistance is a prerequisite for metastasis in hepatocellular carcinoma (HCC). However, little is known about how energy metabolism and antioxidant systems are altered in anoikis-resistant (AR) HCC cells. We evaluated anti-tumor effects of a combination treatment of 3-bromopyruvate (3-BP) and buthionine sulfoximine (BSO) in AR HCC cells. We compared glycolysis, reactive oxygen species (ROS) production, and chemoresistance among Huh-BAT, HepG2 HCC cells, and the corresponding AR cells. Expression of hexokinase II, gamma-glutamylcysteine synthetase (rGCS), and epithelial-mesenchymal transition (EMT) markers in AR cells was assessed. Anti-tumor effects of a combination treatment of 3-BP and BSO were evaluated in AR cells and an HCC xenograft mouse model. AR HCC cells showed significantly higher chemoresistance, glycolysis and lower ROS production than attached cells. Expression of hexokinase II, rGCS, and EMT markers was higher in AR HCC cells than attached cells. A combination treatment of 3-BP/BSO effectively suppressed proliferation of AR HCC cells through apoptosis by blocking glycolysis and enhancing ROS levels. In xenograft mouse models, tumor growth derived from AR HCC cells was significantly suppressed in the group treated with 3-BP/BSO compared to the group treated with 3-BP or sorafenib. These results demonstrated that a combination treatment of 3-BP/BSO had a synergistic anti-tumor effect in an AR HCC model. This strategy may be an effective adjuvant therapy for patients with sorafenib-resistant HCC.

Complex long-distance effects of mutations that confer linezolid resistance in the large ribosomal subunit

Science.gov (United States)

Fulle, Simone; Saini, Jagmohan S.; Homeyer, Nadine; Gohlke, Holger

2015-01-01

The emergence of multidrug-resistant pathogens will make current antibiotics ineffective. For linezolid, a member of the novel oxazolidinone class of antibiotics, 10 nucleotide mutations in the ribosome have been described conferring resistance. Hypotheses for how these mutations affect antibiotics binding have been derived based on comparative crystallographic studies. However, a detailed description at the atomistic level of how remote mutations exert long-distance effects has remained elusive. Here, we show that the G2032A-C2499A double mutation, located > 10 Å away from the antibiotic, confers linezolid resistance by a complex set of effects that percolate to the binding site. By molecular dynamics simulations and free energy calculations, we identify U2504 and C2452 as spearheads among binding site nucleotides that exert the most immediate effect on linezolid binding. Structural reorganizations within the ribosomal subunit due to the mutations are likely associated with mutually compensating changes in the effective energy. Furthermore, we suggest two main routes of information transfer from the mutation sites to U2504 and C2452. Between these, we observe cross-talk, which suggests that synergistic effects observed for the two mutations arise in an indirect manner. These results should be relevant for the development of oxazolidinone derivatives that are active against linezolid-resistant strains. PMID:26202966

Effect of creatine supplementation and drop-set resistance training in untrained aging adults.

Science.gov (United States)

Johannsmeyer, Sarah; Candow, Darren G; Brahms, C Markus; Michel, Deborah; Zello, Gordon A

2016-10-01

To investigate the effects of creatine supplementation and drop-set resistance training in untrained aging adults. Participants were randomized to one of two groups: Creatine (CR: n=14, 7 females, 7 males; 58.0±3.0yrs, 0.1g/kg/day of creatine+0.1g/kg/day of maltodextrin) or Placebo (PLA: n=17, 7 females, 10 males; age: 57.6±5.0yrs, 0.2g/kg/day of maltodextrin) during 12weeks of drop-set resistance training (3days/week; 2 sets of leg press, chest press, hack squat and lat pull-down exercises performed to muscle fatigue at 80% baseline 1-repetition maximum [1-RM] immediately followed by repetitions to muscle fatigue at 30% baseline 1-RM). Prior to and following training and supplementation, assessments were made for body composition, muscle strength, muscle endurance, tasks of functionality, muscle protein catabolism and diet. Drop-set resistance training improved muscle mass, muscle strength, muscle endurance and tasks of functionality (pcreatine to drop-set resistance training significantly increased body mass (p=0.002) and muscle mass (p=0.007) compared to placebo. Males on creatine increased muscle strength (lat pull-down only) to a greater extent than females on creatine (p=0.005). Creatine enabled males to resistance train at a greater capacity over time compared to males on placebo (p=0.049) and females on creatine (p=0.012). Males on creatine (p=0.019) and females on placebo (p=0.014) decreased 3-MH compared to females on creatine. The addition of creatine to drop-set resistance training augments the gains in muscle mass from resistance training alone. Creatine is more effective in untrained aging males compared to untrained aging females. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of Resistance Exercise Intensity on Cytokine and Chemokine Gene Expression in Atopic Dermatitis Mouse Model

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Eun-Ju Choi

2018-04-01

Full Text Available Background and Objective: Although the evidence is unclear, literature indicates that resistance exercise reduces inflammation in colorectal disease. The purpose of this study was to identify the effects of colon tissue on cytokine and chemokine gene expression with changes in resistance exercise intensity. Material and Methods: We divided male BABL/c mice into 6 groups (each group n=10, total=60 (control group: CON, low resistance exercise group: EX_L, high resistance exercise group: EX_H, atopic dermatitis group: AD, atopic dermatitis+low resistance exercise group: AD+EX_L, atopic dermatitis+high resistance exercise group: AD+EX_H and subjected them to ladder climbing resistance exercise for 4 weeks. After 24 h of each exercise schedule, a real-time polymerase chain reaction was performed to determine mRNA expression of interleukin-6 (IL-6 and chemokine ligand 20 (CCL20. Results: The AD group showed significantly higher mRNA expression of IL-6 and CCL20 compared with the CON, EX_L, EX_H, AD+EX_L, and AD+EX_H groups (p<0.05. Conclusion: In conclusion, both high and low resistance exercise effectively decreases the concentration of IL-6 and CCL20 in mice with and without AD.

Effect of aspirin or resistant starch on colorectal neoplasia in the Lynch syndrome

DEFF Research Database (Denmark)

Burn, John; Bishop, D Timothy; Mecklin, Jukka-Pekka

2008-01-01

BACKGROUND: Observational and epidemiologic data indicate that the use of aspirin reduces the risk of colorectal neoplasia; however, the effects of aspirin in the Lynch syndrome (hereditary nonpolyposis colon cancer) are not known. Resistant starch has been associated with an antineoplastic effect...... on the colon. METHODS: In a randomized, placebo-controlled trial, we used a two-by-two design to investigate the effects of aspirin, at a dose of 600 mg per day, and resistant starch (Novelose), at a dose of 30 g per day, in reducing the risk of adenoma and carcinoma among persons with the Lynch syndrome...... on the incidence of colorectal adenoma or carcinoma among carriers of the Lynch syndrome. (Current Controlled Trials number, ISRCTN59521990.)...

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.

Flow Resistance Interactions on Hillslopes With Heterogeneous Attributes: Effects on Runoff Hydrograph Characteristics

Science.gov (United States)

Papanicolaou, Athanasios N.; Abban, Benjamin K. B.; Dermisis, Dimitrios C.; Giannopoulos, Christos P.; Flanagan, Dennis C.; Frankenberger, James R.; Wacha, Kenneth M.

2018-01-01

An improved modeling framework for capturing the effects of space and time-variant resistance to overland flow is developed for intensively managed landscapes. The framework builds on the WEPP model but it removes the limitations of the "equivalent" plane and time-invariant roughness assumption. The enhanced model therefore accounts for spatiotemporal changes in flow resistance along a hillslope due to changes in roughness, in profile curvature, and downslope variability. The model is used to quantify the degree of influence—from individual soil grains to aggregates, "isolated roughness elements," and vegetation—on overland flow characteristics under different storm magnitudes, downslope gradients, and profile curvatures. It was found that the net effects of land use change from vegetation to a bare surface resulted in hydrograph peaks that were up to 133% larger. Changes in hillslope profile curvature instead resulted in peak runoff rate changes that were only up to 16%. The stream power concept is utilized to develop a taxonomy that relates the influence of grains, isolated roughness elements, and vegetation, on overland flow under different storm magnitudes and hillslope gradients. Critical storm magnitudes and hillslope gradients were found beyond which the effects of these landscape attributes on the peak stream power were negligible. The results also highlight weaknesses of the space/time-invariant flow resistance assumption and demonstrate that assumptions on landscape terrain characteristics exert a strong control both on the shape and magnitude of hydrographs, with deviations reaching 65% in the peak runoff when space/time-variant resistance effects are ignored in some cases.

Effect of yttrium chromite doping on its resistance to high-temperature salt and gas corrosions

International Nuclear Information System (INIS)

Oryshich, I.V.; Poryadchenko, N.E.; Rakitskij, A.N.; Bega, N.D.

1996-01-01

Effect of yttrium chromite doping with 2-4 group metal oxides on the corrosion resistance in the air at 1300 C during 5 hours and in sodium chloride and sulfate melts at 900 C during 20 hours is investigated. A notable increase of corrosion resistance is achieved under complex doping with zirconium and magnesium oxides in a quantity, close to solubility in yttrium oxide and solubility by aluminium oxide. Doping with calcium and strontium oxides in the quantities, dose to solubility in yttrium oxide does not produce any notable effect, and at higher concentrations it reduces the corrosion resistance in media indicated. Refs. 8, refs. 2, tabs. 1

Effect of whole body resistance training on arterial compliance in young men.

Science.gov (United States)

Rakobowchuk, M; McGowan, C L; de Groot, P C; Bruinsma, D; Hartman, J W; Phillips, S M; MacDonald, M J

2005-07-01

The effect of resistance training on arterial stiffening is controversial. We tested the hypothesis that resistance training would not alter central arterial compliance. Young healthy men (age, 23 +/- 3.9 (mean +/- s.e.m.) years; n = 28,) were whole-body resistance trained five times a week for 12 weeks, using a rotating 3-day split-body routine. Resting brachial blood pressure (BP), carotid pulse pressure, carotid cross-sectional compliance (CSC), carotid initima-media thickness (IMT) and left ventricular dimensions were evaluated before beginning exercise (PRE), after 6 weeks of exercise (MID) and at the end of 12 weeks of exercise (POST). CSC was measured using the pressure-sonography method. Results indicate reductions in brachial (61.1 +/- 1.4 versus 57.6 +/- 1.2 mmHg; P training and the mechanisms responsible for cardiac hypertrophy and reduced arterial compliance are either not inherent to all resistance-training programmes or may require a prolonged stimulus.

Effect of Spacecraft Environmental Variables on the Flammability of Fire Resistant Fabrics

Science.gov (United States)

Osorio, A. F.; Fernandez-Pello, C.; Takahashi, S.; Rodriguez, J.; Urban, D. L.; Ruff, G.

2012-01-01

Fire resistant fabrics are used for firefighter, racecar drivers as well as astronaut suits. However, their fire resistant characteristics depend on the environment conditions and require study. Particularly important is the response of these fabrics to elevated oxygen concentration environments and radiant heat from a source such as an adjacent fire. In this work, experiments using two fire resistant fabrics were conducted to study the effect of oxygen concentration, external radiant flux and oxidizer flow velocity in concurrent flame spread. Results show that for a given fabric the minimum oxygen concentration for flame spread depends strongly on the magnitude of the external radiant flux. At increased oxygen concentrations the external radiant flux required for flame spread decreases. Oxidizer flow velocity influences the external radiant flux only when the convective heat flux from the flame has similar values to the external radiant flux. The results of this work provide further understanding of the flammability characteristics of fire resistant fabrics in environments similar to those of future spacecrafts.

Effect of Myricetin, Pyrogallol, and Phloroglucinol on Yeast Resistance to Oxidative Stress

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Vanda Mendes

2015-01-01

Full Text Available The health beneficial effects of dietary polyphenols have been attributed to their intrinsic antioxidant activity, which depends on the structure of the compound and number of hydroxyl groups. In this study, the protective effects of pyrogallol, phloroglucinol, and myricetin on the yeast Saccharomyces cerevisiae were investigated. Pyrogallol and myricetin, which have a pyrogallol structure in the B ring, increased H2O2 resistance associated with a reduction in intracellular oxidation and protein carbonylation, whereas phloroglucinol did not exert protective effects. The acquisition of oxidative stress resistance in cells pretreated with pyrogallol and myricetin was not associated with an induction of endogenous antioxidant defences as assessed by the analysis of superoxide dismutase and catalase activities. However, myricetin, which provided greater stress resistance, prevented H2O2-induced glutathione oxidation. Moreover, myricetin increased the chronological lifespan of yeast lacking the mitochondrial superoxide dismutase (Sod2p, which exhibited a premature aging phenotype and oxidative stress sensitivity. These findings show that the presence of hydroxyl groups in the ortho position of the B ring in pyrogallol and myricetin contributes to the antioxidant protection afforded by these compounds. In addition, myricetin may alleviate aging-induced oxidative stress, particularly when redox homeostasis is compromised due to downregulation of endogenous defences present in mitochondria.

Effect of photoactivated riboflavin on the biodegradation-resistance of root-dentin collagen.

Science.gov (United States)

Priyadarshini, Balasankar Meera; Lu, Thong Beng; Fawzy, Amr S

2017-12-01

This study was conducted to evaluate the effect of UVA-activated 1% riboflavin solution on structural integrity; mechanical properties and stability; and collagenase-mediated collagen solubilisation resistance of demineralized root dentin collagen matrix. Root dentin specimens demineralized with 17% EDTA for 7days were treated with 1% RF for 1min followed by UVA photo-activation at intensity 7mW/cm 2 for 1min. Control specimens were completely devoid of riboflavin and/or UVA treatments. Specimens were challenged with bacterial collagenase type-I solution for different time-periods at 37°C. Collagen solubilisation resistance was evaluated in terms of hydroxyproline (HYP) liberation. Mechanical characterization of dentin specimens before and after 24h of exposure to collagenase solution was done in terms of apparent-elastic modulus (E appr ) and ultimate tensile strength (UTS). Variations in dentin collagen-network structure with exposure time in collagenase were visualized by TEM. Crosslinking dentin with UVA-activated riboflavin significantly decreased HYP release and increased E appr and UTS compared to control specimens with storage time in collagenase. Moreover, crosslinked specimens showed higher structural resistance to collagenase effect reflected from dense, well-formed collagen fibrils-network with characteristic collagen cross-banding. UVA-activated riboflavin treatment increased collagenase-mediated collagen degradation resistance and enhanced mechanical stability against collagenase challenges of root dentin after EDTA demineralization. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance

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Anne Muola

2017-05-01

Full Text Available The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar ‘Rügen’, leading to lower pollination success and yield. In addition we screened the most common commercial cultivar ‘Rügen’ and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar ‘Rügen’ were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.

Effects of intranasal insulin on endogenous glucose production in insulin-resistant men.

Science.gov (United States)

Xiao, Changting; Dash, Satya; Stahel, Priska; Lewis, Gary F

2018-03-14

The effects of intranasal insulin on the regulation of endogenous glucose production (EGP) in individuals with insulin resistance were assessed in a single-blind, crossover study. Overweight or obese insulin-resistant men (n = 7; body mass index 35.4 ± 4.4 kg/m 2 , homeostatic model assessment of insulin resistance 5.6 ± 1.6) received intranasal spray of either 40 IU insulin lispro or placebo in 2 randomized visits. Acute systemic spillover of intranasal insulin into the circulation was matched with a 30-minute intravenous infusion of insulin lispro in the nasal placebo arm. EGP was assessed under conditions of a pancreatic clamp with a primed, constant infusion of glucose tracer. Under these experimental conditions, compared with placebo, intranasal administration of insulin did not significantly affect plasma glucose concentrations, EGP or glucose disposal in overweight/obese, insulin-resistant men, in contrast to our previous study, in which an equivalent dose of intranasal insulin significantly suppressed EGP in lean, insulin-sensitive men. Insulin resistance is probably associated with impairment in centrally mediated insulin suppression of EGP. © 2018 John Wiley & Sons Ltd.

Adriamycin resistance, heat resistance and radiation response in Chinese hamster fibroblasts

International Nuclear Information System (INIS)

Wallner, K.; Li, G.

1985-01-01

Previous investigators have demonstrated synergistic interaction between hyperthermia and radiation or Adriamycin (ADR), using cell lines that are sensitive to heat or ADR alone. The authors investigated the effect of heat, radiation or ADR on Chinese hamster fibroblasts (HA-1), their heat resistant variants and their ADR resistant variants. Heat for ADR resistance did not confer cross resistance to radiation. Cells resistant to heat did show cross resistance to ADR. While cells selected for ADR resistance were not cross resistant to heat, they did not exhibit drug potentiation by hyperthermia, characteristic of ADR sensitive cells. Cytofluorometric measurement showed decreased ADR uptake in both heat and ADR resistant cells. The possibility of cross resistance between heat and ADR should be considered when designing combined modality trials

Antibiotic resistance

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Marianne Frieri

2017-07-01

Full Text Available Summary: Antimicrobial resistance in bacterial pathogens is a challenge that is associated with high morbidity and mortality. Multidrug resistance patterns in Gram-positive and -negative bacteria are difficult to treat and may even be untreatable with conventional antibiotics. There is currently a shortage of effective therapies, lack of successful prevention measures, and only a few new antibiotics, which require development of novel treatment options and alternative antimicrobial therapies. Biofilms are involved in multidrug resistance and can present challenges for infection control. Virulence, Staphylococcus aureus, Clostridium difficile infection, vancomycin-resistant enterococci, and control in the Emergency Department are also discussed. Keywords: Antibiotic resistance, Biofilms, Infections, Public health, Emergency Department

Statistical Study of the Effects of the Composition on the Oxidation Resistance of Ni-Based Superalloys

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Si-Jun Park

2015-01-01

Full Text Available The effects of alloying elements (Co, Cr, Mo, W, Al, Ti, and Ta on the oxidation resistance of Ni-based superalloys are studied using the Response Surface Methodology (RSM. The statistical analysis showed that Al and Ta generally improve the oxidation resistance of the alloy, whereas Ti and Mo degrade the oxidation resistance. Co, Cr, and W did not alter oxidation rate significantly when examined by the mass gain averaged for all model alloys. However, it is remarkable that the degree of the effects of alloying elements varied with the concentration of other elements. Further, the effect of each element was sometimes found to be reversed for alloy groups specified by the concentration of another element.

Multi-bunch effect of resistive wall in the Beam Delivery System of the Compact Linear Collider

CERN Document Server

Mutzner, R; Rumolo, G; Tomas, R; Pieloni, T

2010-01-01

Wake fields in the CLIC Beam Delivery System (BDS) can cause severe single or multi-bunch effects leading to luminosity loss. The main contributors in the BDS are geometric and resistive wall wake fields of the collimators and resistive wall wakes of the beam pipe. The present work focuses only on the multi-bunch effects from resistive wall. Using particle tracking with wake fields through the BDS, we have established the aperture radius, above which the effect of the wake fields becomes negligible. Our simulations were later extended to include a realistic aperture model along the BDS as well as the collimators. The two cases of 3 TeV and 500 GeV have been examined.

Resistant Hypertension.

Science.gov (United States)

Doroszko, Adrian; Janus, Agnieszka; Szahidewicz-Krupska, Ewa; Mazur, Grzegorz; Derkacz, Arkadiusz

2016-01-01

Resistant hypertension is a severe medical condition which is estimated to appear in 9-18% of hypertensive patients. Due to higher cardiovascular risk, this disorder requires special diagnosis and treatment. The heterogeneous etiology, risk factors and comorbidities of resistant hypertension stand in need of sophisticated evaluation to confirm the diagnosis and select the best therapeutic options, which should consider lifestyle modifications as well as pharmacological and interventional treatment. After having excluded pseudohypertension, inappropriate blood pressure measurement and control as well as the white coat effect, suspicion of resistant hypertension requires an analysis of drugs which the hypertensive patient is treated with. According to one definition - ineffective treatment with 3 or more antihypertensive drugs including diuretics makes it possible to diagnose resistant hypertension. A multidrug therapy including angiotensin - converting enzyme inhibitors, angiotensin II receptor blockers, beta blockers, diuretics, long-acting calcium channel blockers and mineralocorticoid receptor antagonists has been demonstrated to be effective in resistant hypertension treatment. Nevertheless, optional, innovative therapies, e.g. a renal denervation or baroreflex activation, may create a novel pathway of blood pressure lowering procedures. The right diagnosis of this disease needs to eliminate the secondary causes of resistant hypertension e.g. obstructive sleep apnea, atherosclerosis and renal or hormonal disorders. This paper briefly summarizes the identification of the causes of resistant hypertension and therapeutic strategies, which may contribute to the proper diagnosis and an improvement of the long term management of resistant hypertension.

Residual stress effects on the impact resistance and strength of fiber composites

Science.gov (United States)

Chamis, C. C.

1973-01-01

Equations have been derived to predict degradation effects of microresidual stresses on impact resistance of unidirectional fiber composites. Equations also predict lamination residual stresses in multilayered angle ply composites.

The effect of metallization contact resistance on the measurement of the field effect mobility of long-channel unannealed amorphous In–Zn–O thin film transistors

International Nuclear Information System (INIS)

Lee, Sunghwan; Park, Hongsik; Paine, David C.

2012-01-01

The effect of contact resistance on the measurement of the field effect mobility of compositionally homogeneous channel indium zinc oxide (IZO)/IZO metallization thin film transistors (TFTs) is reported. The TFTs studied in this work operate in depletion mode as n-channel field effect devices with a field effect mobility calculated in the linear regime (μ FE ) of 20 ± 1.9 cm 2 /Vs and similar of 18 ± 1.3 cm 2 /Vs when calculated in the saturation regime (μ FE sat ). These values, however, significantly underestimate the channel mobility since a large part of the applied drain voltage is dropped across the source/drain contact interface. The transmission line method was employed to characterize the contact resistance and it was found that the conducting-IZO/semiconducting-IZO channel contact is highly resistive (specific contact resistance, ρ C > 100 Ωcm 2 ) and, further, this contact resistance is modulated with applied gate voltage. Accounting for the contact resistance (which is large and modulated by gate voltage), the corrected μ FE is shown to be 39 ± 2.6 cm 2 /Vs which is consistent with Hall mobility measurements of high carrier density IZO.

Effect of specific resistance training on forearm pain and work disability in industrial technicians: cluster randomised controlled trial

DEFF Research Database (Denmark)

Andersen, Lars Louis; Jakobsen, Markus D; Pedersen, Mogens Theisen

2012-01-01

To determine the effect of specific resistance training on forearm pain and work disability in industrial technicians.......To determine the effect of specific resistance training on forearm pain and work disability in industrial technicians....

Evaluation of Fine Aggregate Morphology by Image Method and Its Effect on Skid-Resistance of Micro-Surfacing.

Science.gov (United States)

Xiao, Yue; Wang, Feng; Cui, Peide; Lei, Lei; Lin, Juntao; Yi, Mingwei

2018-05-29

Micro-surfacing is a widely used pavement preventive maintenance technology used all over the world, due to its advantages of fast construction, low maintenance cost, good waterproofness, and skid-resistance performance. This study evaluated the fine aggregate morphology and surface texture of micro-surfacing by AIMS (aggregate image measurement system), and explored the effect of aggregate morphology on skid-resistance of single-grade micro-surfacing. Sand patch test and British pendulum test were also used to detect skid-resistance for comparison with the image-based method. Wet abrasion test was used to measure skid-resistance durability for feasibility verification of single-grade micro-surfacing. The results show that the effect of Form2D on the skid-resistance of micro-surfacing is much stronger than that of angularity. Combining the feasibility analysis of durability and skid-resistance, 1.18⁻2.36 grade micro-surfacing meets the requirements of durability and skid-resistance at the same time. This study also determined that, compared with British pendulum test, the texture result obtained by sand patch test fits better with results of image method.

Effects of creatine supplementation along with resistance training on urinary formaldehyde and serum enzymes in wrestlers.

Science.gov (United States)

Nasseri, Azadeh; Jafari, Afshar

2016-04-01

Formaldehyde is a cytotoxic agent produced from creatine through a metabolic pathway, and in this regard, it has been claimed that creatine supplementation could be cytotoxic. Even though the cytotoxic effects of creatine supplementation have been widely studied, yet little is known about how resistance training can alter these toxic effects. This study aimed to determine the effects of short-term creatine supplementation plus resistance training on the level of urinary formaldehyde and concentrations of serum enzymes in young male wrestlers. In a double-blind design twenty-one subjects were randomized into creatine supplementation (Cr), creatine supplementation plus resistance training (Cr + T) and placebo plus resistance training (Pl + T) groups. Participants ingested creatine (0.3 g/kg/day) or placebo for 7 days. The training protocol consisted of 3 sessions in one week, each session including three sets of 6-9 repetitions at 80-85% of one-repetition maximum for whole-body exercise. Urine and blood samples were collected at baseline and at the end of the supplementation. Creatine supplementation significantly increased the excretion rate of urinary formaldehyde in the Cr and Cr + T groups by 63.4% and 30.4%, respectively (P0.05). These findings indicate that resistance training may lower the increase of urinary formaldehyde excretion induced by creatine supplementation, suggesting that creatine consumption could be relatively less toxic when combined with resistance training.

Effect of internal short fibers, steel reinforcement, and surface layer on impact and penetration resistance of concrete

Directory of Open Access Journals (Sweden)

Ali Abd_Elhakam Aliabdo

2013-09-01

Full Text Available This paper presents an experimental program to investigate the impact and penetration resistance of concrete. The research work is divided into two approaches. These approaches are effect of concrete constituents and effect of surface layer. Effect of concrete aggregate type, w/c ratio, fiber type, fiber shape, fiber volume fraction, and steel reinforcement is considered in the first approach. The second approach includes using fiber reinforced concrete and glass fiber reinforced polymer as surface layers. The evaluating tests include standard impact test according to ASTM D 1557 and suggested simulated penetration test to measure the impact and penetration resistance of concrete. The test results of plain and fibrous concrete from ASTM D 1557 method indicated that steel fiber with different configurations and using basalt have a great positive effect on impact resistance of concrete. Moreover, the simulated penetration test indicates that steel fibers are more effective than propylene fibers, type of coarse aggregate has negligible effect, and steel fiber volume fraction has a more significant influence than fiber shape for reinforced concrete test panels. Finally, as expectable, surface properties of tested concrete panels have a significant effect on impact and penetration resistance.

The effects of whey protein with or without carbohydrates on resistance training adaptations

OpenAIRE

Hulmi, Juha; Laakso, Mia; Mero, Antti; Häkkinen, Keijo; Ahtiainen, Juha; Peltonen, Heikki

2015-01-01

Background: Nutrition intake in the context of a resistance training (RT) bout may affect body composition and muscle strength. However, the individual and combined effects of whey protein and carbohydrates on long-term resistance training adaptations are poorly understood. Methods: A four-week preparatory RT period was conducted in previously untrained males to standardize the training background of the subjects. Thereafter, the subjects were randomized into three groups: 30 g of...

Effect of Isothermal Bainitic Quenching on Rail Steel Impact Strength and Wear Resistance

Science.gov (United States)

Çakir, Fatih Hayati; Çelik, Osman Nuri

2017-09-01

The effect of heat treatment regimes on hardness, impact strength, and wear resistance of rail steel for high-speed tracks (rail quality category R350HT) is studied. Analysis of steel properties with a different structure is compared: pearlitic, and upper and lower bainite. It is shown that the steel with bainitic structure has the best impact strength, but wear resistance is better for steel with a lower bainite structure.

Contrasting effects of specialist and generalist herbivores on resistance evolution in invasive plants.

Science.gov (United States)

Zhang, Zhijie; Pan, Xiaoyun; Blumenthal, Dana; van Kleunen, Mark; Liu, Mu; Li, Bo

2018-04-01

Invasive alien plants are likely to be released from specialist herbivores and at the same time encounter biotic resistance from resident generalist herbivores in their new ranges. The Shifting Defense hypothesis predicts that this will result in evolution of decreased defense against specialist herbivores and increased defense against generalist herbivores. To test this, we performed a comprehensive meta-analysis of 61 common garden studies that provide data on resistance and/or tolerance for both introduced and native populations of 32 invasive plant species. We demonstrate that introduced populations, relative to native populations, decreased their resistance against specialists, and increased their resistance against generalists. These differences were significant when resistance was measured in terms of damage caused by the herbivore, but not in terms of performance of the herbivore. Furthermore, we found the first evidence that the magnitude of resistance differences between introduced and native populations depended significantly on herbivore origin (i.e., whether the test herbivore was collected from the native or non-native range of the invasive plant). Finally, tolerance to generalists was found to be higher in introduced populations, while neither tolerance to specialists nor that to simulated herbivory differed between introduced and native plant populations. We conclude that enemy release from specialist herbivores and biotic resistance from generalist herbivores have contrasting effects on resistance evolution in invasive plants. Our results thus provide strong support for the Shifting Defense hypothesis. © 2018 by the Ecological Society of America.

Transgenerational Effects Alter Plant Defense and Resistance in Nature

Science.gov (United States)

Colicchio, Jack

2017-01-01

Trichomes, or leaf hairs, are epidermal extensions that take a variety of forms and perform many functions in plants, including herbivore defense. In this study, I document genetically determined variation, within-generation plasticity, and a direct role of trichomes in herbivore defense for Mimulus guttatus. After establishing the relationship between trichomes and herbivory, I test for transgenerational effects of wounding on trichome density and herbivore resistance. Patterns of inter-annual variation in herbivore density and the high cost of plant defense makes plant-herbivore interactions a system in which transgenerational phenotypic plasticity (TPP) is apt to evolve. Here, I demonstrate that parental damage alters offspring trichome density and herbivore resistance in nature. Moreover, this response varies between populations. This is among the first studies to demonstrate that TPP contributes to variation in nature, and also suggests that selection can modify TPP in response to local conditions. PMID:28102915

Resisting Mind Control.

Science.gov (United States)

Anderson, Susan M.; Zimbardo, Philip G.

1980-01-01

Provides conceptual analyses of mind control techniques along with practical advice on how to resist these techniques. The authors stress that effective mind control stems more from everyday social relations than from exotic technological gimmicks. Suggestions are given for resisting persuasion, resisting systems, and challenging the system.…

The Effect of Temperature and Host Plant Resistance on Population Growth of the Soybean Aphid Biotype 1 (Hemiptera: Aphididae).

Science.gov (United States)

Hough, Ashley R; Nechols, James R; McCornack, Brian P; Margolies, David C; Sandercock, Brett K; Yan, Donglin; Murray, Leigh

2017-02-01

A laboratory experiment was conducted to evaluate direct and indirect effects of temperature on demographic traits and population growth of biotype 1 of the soybean aphid, Aphis glycines Matsumura. Our objectives were to better understand how temperature influences the expression of host plant resistance, quantify the individual and interactive effects of plant resistance and temperature on soybean aphid population growth, and generate thermal constants for predicting temperature-dependent development on both susceptible and resistant soybeans. To assess indirect (plant-mediated) effects, soybean aphids were reared under a range of temperatures (15-30 °C) on soybean seedlings from a line expressing a Rag1 gene for resistance, and life history traits were quantified and compared to those obtained for soybean aphids on a susceptible soybean line. Direct effects of temperature were obtained by comparing relative differences in the magnitude of life-history traits among temperatures on susceptible soybeans. We predicted that temperature and host plant resistance would have a combined, but asymmetrical, effect on soybean aphid fitness and population growth. Results showed that temperature and plant resistance influenced preimaginal development and survival, progeny produced, and adult longevity. There also appeared to be a complex interaction between temperature and plant resistance for survival and developmental rate. Evidence suggested that the level of plant resistance increased at higher, but not lower, temperature. Soybean aphids required about the same number of degree-days to develop on resistant and susceptible plants. Our results will be useful for making predictions of soybean aphid population growth on resistant plants under different seasonal temperatures. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Correlation between resistance-change effect in transition-metal oxides and secondary-electron contrast of scanning electron microscope images

International Nuclear Information System (INIS)

Kinoshita, K.; Kishida, S.; Yoda, T.

2011-01-01

Conductive atomic-force microscopy (C-AFM) writing is attracting attention as a technique for clarifying the switching mechanism of resistive random-access memory by providing a wide area filled with filaments, which can be regarded as one filament with large radius. The writing area on a nickel-oxide (NiO) film formed by conductive atomic-force microscopy was observed by scanning electron microscope, and a correlation between the contrast in a secondary-electron image (SEI) and the resistance written by C-AFM was revealed. In addition, the dependence of the SEI contrast on the beam accelerating voltage (V accel ) suggests that the resistance-change effect occurs near the surface of the NiO film. As for the effects of electron irradiation and vacuum annealing on the C-AFM writing area, it was shown that the resistance-change effect is caused by exchange of oxygen with the atmosphere at the surface of the NiO film. This result suggests that the low-resistance and high-resistance areas are, respectively, p-type Ni 1+δ O (δ 1+δ O (δ≥ 0).

Effects of order and sequence of resistance and endurance training on body fat in elementary school-aged girls

Directory of Open Access Journals (Sweden)

Ana R. Alves

2017-12-01

Full Text Available The purpose of this study was to analyse the effects of order and sequence of concurrent resistance and endurance training on body fat percentage (BFP in a large sample of elementary school-aged girls. One hundred and twenty-six healthy girls, aged 10-11 years (10.95 ± 0.48 years, were randomly assigned to six groups to perform different training protocols per week for 8 weeks: Resistance-only (R, Endurance-only (E, Concurrent Distinct Endurance-Resistance (CDER, Concurrent Parallel Endurance-Resistance (CPER, Concurrent Parallel Resistance-Endurance (CPRE, and a Control group (C. In R and E, the subjects performed single sessions of resistance or endurance exercises, respectively (two days per week. In CDER, resistance-endurance training was performed on different days each week (four days per week. CPER and CPRE performed single-session combined endurance-resistance training or combined resistance-endurance training, respectively, each week (two days per week. After an 8-week training period, BFP decreased in all experimental groups (CPER: 13.3%, p0.05; and CDER: 5.6%, p>0.05. However, a significant difference was found in CPER and CPRE when compared to CDER, E, and R, indicating that training sequence may influence BFP. All programmes were effective, but CPER and CPRE obtained better results for BFP than CDER, E, or R. The effects of concurrent resistance and endurance training on body fat percentage can be mediated by order and sequence of exercise. These results provide insight into optimization of school-based fat loss exercise programmes in childhood.

Multi-Bunch effect of resistive wall in the beam delivery system of the Compact Linear Collider

CERN Document Server

Mutzner, Raphael; Pieloni, Tatiana; Rivkin, Leonid

2010-01-01

Wake fields in the CLIC Beam Delivery System (BDS) can cause severe single or multi-bunch effects leading to luminosity loss. The main contributors in the BDS are geometric and resistive wall wake fields of the collimators and resistive wall wakes of the beam pipe. The present master thesis focuses only on the multi-bunch effects from resistive wall. Using particle tracking with wake fields through the BDS, we have established the aperture radius, above which the effect of the wake fields becomes negligible. Simulations were later extended to include a realistic aperture model along the BDS as well as the collimators. We examine the two cases of 3 TeV and 500 GeV in this work, for stainless steel and copper pipes.

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...

Effect of filling surface-treated pyrolytic char on resistivity of rubber films

Directory of Open Access Journals (Sweden)

Pattraporn Yamkaya

2015-03-01

Full Text Available In this research, natural rubber (NR films filled with pyrolytic tire char, carbon black N234 and N330 were compared for their electrical resistivity. The filler loading was varied to be 5, 10, 15, 20 and 25% of dry rubber content. The effect of surfactant which is 2 %w/v sodium dodecyl sulfate (SDS was also investigated. In the experiments, it was necessary to disperse the pyrolytic char in ethyl alcohol while disperse carbon black (CB in ammonium hydroxide solution prior to mixing with the rubber latex and the filled NR film was prepared by casting the mixture on a plate. It was found that increasing the amount of pyrolytic char in the NR film could lower its resistivity. The surfactant, SDS, could help better dispersion of both CB and pyrolytic char, thereby decreasing the resistivity. In a separate experiment where hexane vapor was absorbed in NR film without surfactant, in the first 30 seconds, the rate of increasing resistivity of the CB-filled film was not seen as clearly as that of pyrolytic-char-filled film. For the films with surfactant, the slow increase in resistivity of the NR films filled with N330 and pyrolytic char during adsorbing hexane vapor was observed.

Effect that radiation exerts to insulation breakdown of heat resistant polymer materials

International Nuclear Information System (INIS)

Fujita, Shigetaka; Baba, Makoto; Noto, Fumitoshi; Ruike, Mitsuo.

1990-01-01

Artificial satellites are always exposed to cosmic rays which contain the radiations which do not reach the ground, therefore, the radiation resistance of the polymer insulators for cables and others used in such environment becomes a problem. Also the polymer insulator materials used for nuclear facilities require excellent radiation resistance. It is important to examine the effect that radiation exerts to electric insulation characteristics from the viewpoint of material development. In this paper, the insulation breakdown characteristics of heat resistant polymer films and the mini-cables made for trial of heat resistant polymer materials in the case without irradiation and in the case of gamma ray irradiation, and the results of the structural analysis are reported. The specimens tested, the experimental method and the results are described. The insulation breakdown strength of PFA and FEP films lowered from 0.15-0.2 MGy, but that of PEEK film did not change up to 5 MGy. It was found that fluorine group resins were apt to deteriorate by oxidation as dose increased. (K.I.)

Improved quantum backtracking algorithms using effective resistance estimates

Science.gov (United States)

Jarret, Michael; Wan, Kianna

2018-02-01

We investigate quantum backtracking algorithms of the type introduced by Montanaro (Montanaro, arXiv:1509.02374). These algorithms explore trees of unknown structure and in certain settings exponentially outperform their classical counterparts. Some of the previous work focused on obtaining a quantum advantage for trees in which a unique marked vertex is promised to exist. We remove this restriction by recharacterizing the problem in terms of the effective resistance of the search space. In this paper, we present a generalization of one of Montanaro's algorithms to trees containing k marked vertices, where k is not necessarily known a priori. Our approach involves using amplitude estimation to determine a near-optimal weighting of a diffusion operator, which can then be applied to prepare a superposition state with support only on marked vertices and ancestors thereof. By repeatedly sampling this state and updating the input vertex, a marked vertex is reached in a logarithmic number of steps. The algorithm thereby achieves the conjectured bound of O ˜(√{T Rmax }) for finding a single marked vertex and O ˜(k √{T Rmax }) for finding all k marked vertices, where T is an upper bound on the tree size and Rmax is the maximum effective resistance encountered by the algorithm. This constitutes a speedup over Montanaro's original procedure in both the case of finding one and the case of finding multiple marked vertices in an arbitrary tree.

Synthesis, antitubercular activity and mechanism of resistance of highly effective thiacetazone analogues.

Directory of Open Access Journals (Sweden)

Geoffrey D Coxon

Full Text Available Defining the pharmacological target(s of currently used drugs and developing new analogues with greater potency are both important aspects of the search for agents that are effective against drug-sensitive and drug-resistant Mycobacterium tuberculosis. Thiacetazone (TAC is an anti-tubercular drug that was formerly used in conjunction with isoniazid, but removed from the antitubercular chemotherapeutic arsenal due to toxic side effects. However, several recent studies have linked the mechanisms of action of TAC to mycolic acid metabolism and TAC-derived analogues have shown increased potency against M. tuberculosis. To obtain new insights into the molecular mechanisms of TAC resistance, we isolated and analyzed 10 mutants of M. tuberculosis that were highly resistant to TAC. One strain was found to be mutated in the methyltransferase MmaA4 at Gly101, consistent with its lack of oxygenated mycolic acids. All remaining strains harbored missense mutations in either HadA (at Cys61 or HadC (at Val85, Lys157 or Thr123, which are components of the β-hydroxyacyl-ACP dehydratase complex that participates in the mycolic acid elongation step. Separately, a library of 31 new TAC analogues was synthesized and evaluated against M. tuberculosis. Two of these compounds, 15 and 16, exhibited minimal inhibitory concentrations 10-fold lower than the parental molecule, and inhibited mycolic acid biosynthesis in a dose-dependent manner. Moreover, overexpression of HadAB HadBC or HadABC in M. tuberculosis led to high level resistance to these compounds, demonstrating that their mode of action is similar to that of TAC. In summary, this study uncovered new mutations associated with TAC resistance and also demonstrated that simple structural optimization of the TAC scaffold was possible and may lead to a new generation of TAC-derived drug candidates for the potential treatment of tuberculosis as mycolic acid inhibitors.

The post-activation potentiation effect on sprint performance after combined resistance/sprint training in junior basketball players.

Science.gov (United States)

Tsimachidis, Constantinos; Patikas, Dimitrios; Galazoulas, Christos; Bassa, Eleni; Kotzamanidis, Christos

2013-01-01

The aim of this study was to examine the effect of a 10-week combined resistance/sprint training programme in the post-activation potentiation of sprint performance before, between and after resistance training sets. Twenty-six junior basketball players were randomly divided into a control and a combined training group. The combined training group performed a combined training programme consisting of 5 sets at 5-8 RM (Repetition Maximum) half-squats with sprints performed between each set. Post-activation potentiation was considered as the increase in sprint velocity in trials executed between and after the resistance sets compared with the sprint trial performed before the resistance sets of the respective first and last training session. For sprint evaluation the running distances 0-10 and 0-30 m were selected. The intervention increased both strength and sprint performance. No post-activation potentiation effect was observed during the first training session in either group. Post-activation potentiation appeared in the combined training group during the last training session of the intervention in both 0-10 and 0-30 m sprint. This study illustrates that post-activation potentiation effect on sprint performance in junior basketball players, who did not previously follow systematic resistance training, emerges after a 10-week resistance/sprint combined training programme.

Cost-effectiveness of renal denervation therapy for the treatment of resistant hypertension in The Netherlands.

Science.gov (United States)

Henry, Thea L; De Brouwer, Bonnie F E; Van Keep, Marjolijn M L; Blankestijn, Peter J; Bots, Michiel L; Koffijberg, Hendrik

2015-01-01

Safety and efficacy data for catheter-based renal denervation (RDN) in the treatment of resistant hypertension have been used to estimate the cost-effectiveness of this approach. However, there are no Dutch-specific analyses. This study examined the cost-effectiveness of RDN from the perspective of the healthcare payer in The Netherlands. A previously constructed Markov state-transition model was adapted and updated with costs and utilities relevant to the Dutch setting. The cost-effectiveness of RDN was compared with standard of care (SoC) for patients with resistant hypertension. The efficacy of RDN treatment was modeled as a reduction in the risk of cardiovascular events associated with a lower systolic blood pressure (SBP). Treatment with RDN compared to SoC gave an incremental quality-adjusted life year (QALY) gain of 0.89 at an additional cost of €1315 over a patient's lifetime, resulting in a base case incremental cost-effectiveness ratio (ICER) of €1474. Deterministic and probabilistic sensitivity analyses (PSA) showed that treatment with RDN therapy was cost-effective at conventional willingness-to-pay thresholds (€10,000-80,000/QALY). RDN is a cost-effective intervention for patients with resistant hypertension in The Netherlands.

Effect of ultraviolet illumination on metal oxide resistive memory

KAUST Repository

Duran Retamal, Jose Ramon

2014-12-22

We investigate the photoelectrical and resistive switching properties of Pt/ZnO/Pt capacitor operated in unipolar mode under ultraviolet (UV) illumination. The oxygen photodesorption under UV illumination explains the photoconduction observed in initial and high resistance states. Meanwhile, oxygen readsorption at surface-related defects justifies the different photoresponses dynamics in both states. Finally, UV illumination significantly reduces the variations of resistance in high resistance state, set voltage and reset voltage by 58%, 33%, and 25%, respectively, stabilizing Pt/ZnO/Pt capacitor. Our findings in improved switching uniformity via UV light give physical insight into designing resistive memory devices.

Effect of ultraviolet illumination on metal oxide resistive memory

KAUST Repository

Duran Retamal, Jose Ramon; Kang, Chen-Fang; Ho, Chih-Hsiang; Ke, Jr-Jian; Chang, Wen-Yuan; He, Jr-Hau

2014-01-01

We investigate the photoelectrical and resistive switching properties of Pt/ZnO/Pt capacitor operated in unipolar mode under ultraviolet (UV) illumination. The oxygen photodesorption under UV illumination explains the photoconduction observed in initial and high resistance states. Meanwhile, oxygen readsorption at surface-related defects justifies the different photoresponses dynamics in both states. Finally, UV illumination significantly reduces the variations of resistance in high resistance state, set voltage and reset voltage by 58%, 33%, and 25%, respectively, stabilizing Pt/ZnO/Pt capacitor. Our findings in improved switching uniformity via UV light give physical insight into designing resistive memory devices.

Effect of vitamins C and E on insulin resistance in diabetes: a meta-analysis study.

Science.gov (United States)

Khodaeian, Mehrnoosh; Tabatabaei-Malazy, Ozra; Qorbani, Mostafa; Farzadfar, Farshad; Amini, Peyvand; Larijani, Bagher

2015-11-01

Data regarding the effect of vitamin C (VC) and vitamin E (VE) supplementation on insulin resistance in type 2 diabetes mellitus (T2DM) are controversial. We aimed to systematically review the current data on this topic. All randomized controlled trials (RCTs) conducted to assess the effect of VC and/or VE on insulin resistance in diabetes published in Google Scholar and PubMed web databases until January 2014 were included. Exclusion criteria were studies conducted in animal, type 1 DM, children or pregnant women. Main outcome measure was insulin resistance by homoeostasis model assessment (HOMA) index. According to degree of heterogeneity, fixed- or random-effect model was employed by stata software (11.0). We selected 14 RCTs involving 735 patients with T2DM. VE or mixture-mode supplementation did not have any significant effect on HOMA with a standardized mean difference (SMD): 0·017, 95% CI: -0·376 to 0·411 (P = 0·932); and SMD: -0·035, 95% CI: -0·634 to 0·025 (P = 0·070), respectively, by random-effect model. VC supplement alone did not improve insulin resistance with a SMD: -0·150, 95% CI: -0·494 to 0·194 (P = 0·391), by fixed-effect model. Meta-regression test demonstrated that HOMA index may have not been influenced by the year of publication, dosage or duration of treatment. The sole intake of VC, VE or their combination with other antioxidants could not improve insulin resistance in diabetes. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

Effect of composition on corrosion resistance of high-alloy austenitic stainless steel weld metals

International Nuclear Information System (INIS)

Marshall, P.I.; Gooch, T.G.

1993-01-01

The corrosion resistance of stainless steel weld metal in the ranges of 17 to 28% chromium (Cr), 6 to 60% nickel (Ni), 0 to 9% molybdenum (Mo), and 0.0 to 0.37% nitrogen (N) was examined. Critical pitting temperatures were determined in ferric chloride (FeCl 3 ). Passive film breakdown potentials were assessed from potentiodynamic scans in 3% sodium chloride (NaCl) at 50 C. Potentiodynamic and potentiostatic tests were carried out in 30% sulfuric acid (H 2 SO 4 ) ar 25 C, which was representative of chloride-free acid media of low redox potential. Metallographic examination and microanalysis were conducted on the test welds. Because of segregation of alloying elements, weld metal pitting resistance always was lower than that of matching composition base steel. The difference increased with higher Cr, Mo, and N contents. Segregation also reduced resistance to general corrosion in H 2 SO 4 , but the effect relative to the base steel was less marked than with chloride pitting. Segregation of Cr, Mo, and N in fully austenitic deposits decreased as the Ni' eq- Cr' eq ratio increased. Over the compositional range studied, weld metal pitting resistance was dependent mainly on Mo content and segregation. N had less effect than in wrought alloys. Both Mo and N enhanced weld metal corrosion resistance in H 2 SO 4

Evaluation of Fine Aggregate Morphology by Image Method and Its Effect on Skid-Resistance of Micro-Surfacing

Directory of Open Access Journals (Sweden)

Yue Xiao

2018-05-01

Full Text Available Micro-surfacing is a widely used pavement preventive maintenance technology used all over the world, due to its advantages of fast construction, low maintenance cost, good waterproofness, and skid-resistance performance. This study evaluated the fine aggregate morphology and surface texture of micro-surfacing by AIMS (aggregate image measurement system, and explored the effect of aggregate morphology on skid-resistance of single-grade micro-surfacing. Sand patch test and British pendulum test were also used to detect skid-resistance for comparison with the image-based method. Wet abrasion test was used to measure skid-resistance durability for feasibility verification of single-grade micro-surfacing. The results show that the effect of Form2D on the skid-resistance of micro-surfacing is much stronger than that of angularity. Combining the feasibility analysis of durability and skid-resistance, 1.18–2.36 grade micro-surfacing meets the requirements of durability and skid-resistance at the same time. This study also determined that, compared with British pendulum test, the texture result obtained by sand patch test fits better with results of image method.

Effects of Bariatric Surgery on Adipokine-Induced Inflammation and Insulin Resistance

Directory of Open Access Journals (Sweden)

Zeynep eGoktas

2013-06-01

Full Text Available Over a third of the US population is obese and at high risk for developing type 2 diabetes, insulin resistance and other metabolic disorders. Obesity is considered a chronic low grade inflammatory condition that is primarily attributed to expansion and inflammation of adipose tissues. Indeed, adipocytes produce and secrete numerous proinflammatory and anti-inflammatory cytokines known as adipokines. When the balance of these adipokines is shifted towards higher production of proinflammatory factors, local inflammation within adipose tissues and subsequently systemic inflammation occur. These adipokines including leptin, visfatin, resistin, apelin, vaspin, and retinol binding protein-4 can regulate inflammatory responses and contribute to the pathogenesis of diabetes. These effects are mediated by key inflammatory signaling molecules including activated serine kinases such as c-Jun N-terminal kinase (JNK and serine kinases inhibitor κB kinase (IKK and insulin signaling molecules including insulin receptor substrates, protein kinase B (PKB, also known as Akt, and nuclear factor kappa B (NF-kB. Bariatric surgery can decrease body weight and improve insulin resistance in morbidly obese subjects. However, despite reports suggesting reduced inflammation and weight-independent effects of bariatric surgery on glucose metabolism, mechanisms behind such improvements are not yet well understood. This review article focuses on some of these novel adipokines and discusses their changes after bariatric surgery and their relationship to insulin resistance, fat mass, inflammation, and glucose homeostasis.

Radiation Resistant Hybrid Lotus Effect Photoelectrocatalytic Self-Cleaning Anti-Contamination Coatings, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This project will develop radiation resistant hybrid Lotus Effect photoelectrocatalytic self-cleaning anti-contamination coatings for application to Lunar...

Transgenerational effects alter plant defence and resistance in nature.

Science.gov (United States)

Colicchio, J

2017-04-01

Trichomes, or leaf hairs, are epidermal extensions that take a variety of forms and perform many functions in plants, including herbivore defence. In this study, I document genetically determined variation, within-generation plasticity, and a direct role of trichomes in herbivore defence for Mimulus guttatus. After establishing the relationship between trichomes and herbivory, I test for transgenerational effects of wounding on trichome density and herbivore resistance. Patterns of interannual variation in herbivore density and the high cost of plant defence makes plant-herbivore interactions a system in which transgenerational phenotypic plasticity (TPP) is apt to evolve. Here, I demonstrate that parental damage alters offspring trichome density and herbivore resistance in nature. Moreover, this response varies between populations. This is among the first studies to demonstrate that TPP contributes to variation in nature, and also suggests that selection can modify TPP in response to local conditions. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Withanolide D Exhibits Similar Cytostatic Effect in Drug-Resistant and Drug-Sensitive Multiple Myeloma Cells

Directory of Open Access Journals (Sweden)

Mark E. Issa

2017-09-01

Full Text Available In spite of recent therapeutic advances, multiple myeloma (MM remains a malignancy with very low curability. This has been partly attributed to the existence of a drug-resistant subpopulation known as cancer stem cells (CSCs. MM-CSCs are equipped with the necessary tools that render them highly resistant to virtually all conventional therapies. In this study, the growth inhibitory effects of withanolide D (WND, a steroidal lactone isolated from Withania somnifera, on drug-sensitive tumoral plasma cells and drug-resistant MM cells have been investigated. In MTT/XTT assays, WND exhibited similar cytostatic effects between drug-resistant and drug-sensitive cell lines in the nM range. WND also induced cell death and apoptosis in MM-CSCs and RPMI 8226 cells, as examined by the calcein/ethidium homodimer and annexin V/propidium iodide stainings, respectively. To determine whether P-glycoprotein (P-gp efflux affected the cytostatic activity of WND, P-gp was inhibited with verapamil and results indicated that the WND cytostatic effect in MM-CSCs was independent of P-gp efflux. Furthermore, WND did not increase the accumulation of the fluorescent P-gp substrate rhodamine 123 in MM-CSCs, suggesting that WND may not inhibit P-gp at the tested relevant doses. Therefore, the WND-induced cytostatic effect may be independent of P-gp efflux. These findings warrant further investigation of WND in MM-CSC animal models.

Trophic compensation reinforces resistance: herbivory absorbs the increasing effects of multiple disturbances.

Science.gov (United States)

Ghedini, Giulia; Russell, Bayden D; Connell, Sean D

2015-02-01

Disturbance often results in small changes in community structure, but the probability of transitioning to contrasting states increases when multiple disturbances combine. Nevertheless, we have limited insights into the mechanisms that stabilise communities, particularly how perturbations can be absorbed without restructuring (i.e. resistance). Here, we expand the concept of compensatory dynamics to include countervailing mechanisms that absorb disturbances through trophic interactions. By definition, 'compensation' occurs if a specific disturbance stimulates a proportional countervailing response that eliminates its otherwise unchecked effect. We show that the compounding effects of disturbances from local to global scales (i.e. local canopy-loss, eutrophication, ocean acidification) increasingly promote the expansion of weedy species, but that this response is countered by a proportional increase in grazing. Finally, we explore the relatively unrecognised role of compensatory effects, which are likely to maintain the resistance of communities to disturbance more deeply than current thinking allows. © 2015 John Wiley & Sons Ltd/CNRS.

Synergistic effect of eugenol with Colistin against clinical isolated Colistin-resistant Escherichia coli strains

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Yi-ming Wang

2018-01-01

Full Text Available Abstract Background Bacterial infections have become more challenging to treat due to the emergence of multidrug-resistant pathogenic bacteria. Combined antibiotics prove to be a relatively effective method to control such resistant strains. This study aim to investigate synergistic activity of eugenol combined with colistin against a collection of clinical isolated Escherichia coli (E.coli strains, and to evaluate potential interaction. Methods Antimicrobial susceptibility, minimum inhibitory concentration (MIC and fractional inhibitory concentration index (FICI of the bacteria were determined by disk diffusion assay, broth microdilution method and checkerboard assay, respectively. The mcr-1 mRNA expression was measured by Real-time PCR. To predict possible interactions between eugenol and MCR-1, molecular docking assay was taken. Results For total fourteen strains including eight colistin-resistant strains, eugenol was determined with MIC values of 4 to 8 μg/mL. Checkerboard dilution test suggested that eugenol exhibited synergistic activity when combined with colistin (FICI ranging from 0.375 to 0.625. Comparison analysis of Real-time PCR showed that synergy could significantly down-regulate expression of mcr-1 gene. A metal ion coordination bond with catalytic zinc atom and a hydrogen bond with crucial amino acid residue Ser284 of MCR-1 were observed after molecular docking, indicating antibacterial activity and direct molecular interactions of eugenol with MCR-1 protein. Conclusions Our results demonstrated that eugenol exhibited synergistic effect with colistin and enhanced its antimicrobial activity. This might further contribute to the antibacterial actions against colistin-resistant E.coli strains. Graphical abstract Synergistic effect of eugenol with colistin against colistin-resistant Escherichia coli isolates.

Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells.

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Matthew A Ingersoll

Full Text Available Prostate cancer (PCa is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents.

Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells.

Science.gov (United States)

Ingersoll, Matthew A; Lyons, Anastesia S; Muniyan, Sakthivel; D'Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G; Bu, Xiu R; Batra, Surinder K; Lin, Ming-Fong

2015-01-01

Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents.

Submerged Arc Stainless Steel Strip Cladding—Effect of Post-Weld Heat Treatment on Thermal Fatigue Resistance

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Kuo, I. C.; Chou, C. P.; Tseng, C. F.; Lee, I. K.

2009-03-01

Two types of martensitic stainless steel strips, PFB-132 and PFB-131S, were deposited on SS41 carbon steel substrate by a three-pass submerged arc cladding process. The effects of post-weld heat treatment (PWHT) on thermal fatigue resistance and hardness were evaluated by thermal fatigue and hardness testing, respectively. The weld metal microstructure was investigated by utilizing optical microscopy, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Results showed that, by increasing the PWHT temperature, hardness decreased but there was a simultaneous improvement in weldment thermal fatigue resistance. During tempering, carbide, such as (Fe, Cr)23C6, precipitated in the weld metals and molybdenum appeared to promote (Fe, Cr, Mo)23C6 formation. The precipitates of (Fe, Cr, Mo)23C6 revealed a face-centered cubic (FCC) structure with fine grains distributed in the microstructure, thereby effectively increasing thermal fatigue resistance. However, by adding nickel, the AC1 temperature decreased, causing a negative effect on thermal fatigue resistance.

Improved anticoagulant effect of fucosylated chondroitin sulfate orally administered as gastro-resistant tablets.

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Fonseca, Roberto J C; Sucupira, Isabela D; Oliveira, Stephan Nicollas M C G; Santos, Gustavo R C; Mourão, Paulo A S

2017-04-03

Fucosylated chondroitin sulfate (FucCS) is a potent anticoagulant polysaccharide extracted from sea cucumber. Its anticoagulant activity is attributed to the presence of unique branches of sulfated fucose. Although this glycosaminoglycan exerts an antithrombotic effect following oral administration, high doses are necessary to achieve the maximum effect. The diminished activity of FucCS following oral administration is likely due to its degradation in the gastrointestinal tract and its limited ability to cross the intestinal cell membranes. The latter aspect is particularly difficult to overcome. However, gastro-resistant tablet formulation may help limit the degradation of FucCS in the gastrointestinal tract. In the present work, we found that the oral administration of FucCS as gastro-resistant tablets produces a more potent and prolonged anticoagulant effect compared with its administration as an aqueous solution, with no significant changes in the bleeding tendency or arterial blood pressure. Experiments using animal models of arterial thrombosis initiated by endothelial injury demonstrated that FucCS delivered as gastro-protective tablets produced a potent antithrombotic effect, whereas its aqueous solution was ineffective. However, there was no significant difference between the effects of FucCS delivered as gastro-resistant tablets or as aqueous solution in a venous thrombosis model, likely due to the high dose of thromboplastin used. New oral anticoagulants tested in these experimental models for comparison showed significantly increased bleeding tendencies. Our study provides a framework for developing effective oral anticoagulants based on sulfated polysaccharides from marine organisms. The present results suggest that FucCS is a promising oral anticoagulant.

Antimicrobial resistance determinant microarray for analysis of multi-drug resistant isolates

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Taitt, Chris Rowe; Leski, Tomasz; Stenger, David; Vora, Gary J.; House, Brent; Nicklasson, Matilda; Pimentel, Guillermo; Zurawski, Daniel V.; Kirkup, Benjamin C.; Craft, David; Waterman, Paige E.; Lesho, Emil P.; Bangurae, Umaru; Ansumana, Rashid

2012-06-01

The prevalence of multidrug-resistant infections in personnel wounded in Iraq and Afghanistan has made it challenging for physicians to choose effective therapeutics in a timely fashion. To address the challenge of identifying the potential for drug resistance, we have developed the Antimicrobial Resistance Determinant Microarray (ARDM) to provide DNAbased analysis for over 250 resistance genes covering 12 classes of antibiotics. Over 70 drug-resistant bacteria from different geographic regions have been analyzed on ARDM, with significant differences in patterns of resistance identified: genes for resistance to sulfonamides, trimethoprim, chloramphenicol, rifampin, and macrolide-lincosamidesulfonamide drugs were more frequently identified in isolates from sources in Iraq/Afghanistan. Of particular concern was the presence of genes responsible for resistance to many of the last-resort antibiotics used to treat war traumaassociated infections.

Effect of selective decontamination on antimicrobial resistance in intensive care units: a systematic review and meta-analysis.

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Daneman, Nick; Sarwar, Syed; Fowler, Robert A; Cuthbertson, Brian H

2013-04-01

Many meta-analyses have shown reductions in infection rates and mortality associated with the use of selective digestive decontamination (SDD) or selective oropharyngeal decontamination (SOD) in intensive care units (ICUs). These interventions have not been widely implemented because of concerns that their use could lead to the development of antimicrobial resistance in pathogens. We aimed to assess the effect of SDD and SOD on antimicrobial resistance rates in patients in ICUs. We did a systematic review of the effect of SDD and SOD on the rates of colonisation or infection with antimicrobial-resistant pathogens in patients who were critically ill. We searched for studies using Medline, Embase, and Cochrane databases, with no limits by language, date of publication, study design, or study quality. We included all studies of selective decontamination that involved prophylactic application of topical non-absorbable antimicrobials to the stomach or oropharynx of patients in ICUs, with or without additional systemic antimicrobials. We excluded studies of interventions that used only antiseptic or biocide agents such as chlorhexidine, unless antimicrobials were also included in the regimen. We used the Mantel-Haenszel model with random effects to calculate pooled odds ratios. We analysed 64 unique studies of SDD and SOD in ICUs, of which 47 were randomised controlled trials and 35 included data for the detection of antimicrobial resistance. When comparing data for patients in intervention groups (those who received SDD or SOD) versus data for those in control groups (who received no intervention), we identified no difference in the prevalence of colonisation or infection with Gram-positive antimicrobial-resistant pathogens of interest, including meticillin-resistant Staphylococcus aureus (odds ratio 1·46, 95% CI 0·90-2·37) and vancomycin-resistant enterococci (0·63, 0·39-1·02). Among Gram-negative bacilli, we detected no difference in aminoglycoside-resistance (0

Effects of resistive bodies on DC electrical soundings

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L. Alfano

1996-06-01

Full Text Available Some deep DC electrical soundings, performed in alpine and apenninic areas with the continuous polar dipole-dipole spread, show apparent resistivity curves with positive slopes. Measured values of apparent resistivity reach 30000 Wm. Applying the "surface charges" method we developed three dimensional mathematical models, by means of which we can state simple rules for determining the minimum extensions of the deep resistive bodies, fundamental information for a more precise interpretation of the field results.

Investigation of Resistance to Mechanical Effect of Braille Formed on Different Materials

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Ingrida VENYTĖ

2014-06-01

Full Text Available Qualitative analysis of stresses emerged in paperboard during Braille embossing, using specialized polarimetric equipment, was carried out. Resistance to mechanical effect of Braille dot surfaces, formed with different printing types on different materials (paper, paperboard, polymer, textile, Al foil was investigated. It was determined that Braille dot height change after period mechanical effect is different.

Risk Factors for Acquisition of Drug Resistance during Multidrug-Resistant Tuberculosis Treatment, Arkhangelsk Oblast, Russia, 2005–2010

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Ershova, Julia; Vlasova, Natalia; Nikishova, Elena; Tarasova, Irina; Eliseev, Platon; Maryandyshev, Andrey O.; Shemyakin, Igor G.; Kurbatova, Ekaterina; Cegielski, J. Peter

2015-01-01

Acquired resistance to antituberculosis drugs decreases effective treatment options and the likelihood of treatment success. We identified risk factors for acquisition of drug resistance during treatment for multidrug-resistant tuberculosis (MDR TB) and evaluated the effect on treatment outcomes. Data were collected prospectively from adults from Arkhangelsk Oblast, Russia, who had pulmonary MDR TB during 2005–2008. Acquisition of resistance to capreomycin and of extensively drug-resistant TB were more likely among patients who received 3 effective drugs (9.4% vs. 0% and 8.6% vs. 0.8%, respectively). Poor outcomes were more likely among patients with acquired capreomycin resistance (100% vs. 25.9%), acquired ofloxacin resistance (83.6% vs. 22.7%), or acquired extensive drug resistance (100% vs. 24.4%). To prevent acquired drug resistance and poor outcomes, baseline susceptibility to first- and second-line drugs should be determined quickly, and treatment should be adjusted to contain >3 effective drugs. PMID:25988954

Long-term effect of resistant starch on cancer risk in carriers of hereditary colorectal cancer

DEFF Research Database (Denmark)

Mathers, John C; Movahedi, Mohammad; Macrae, Finlay

2012-01-01

have been done. We assessed the effect of resistant starch on the incidence of colorectal cancer. METHODS: In the CAPP2 study, individuals with Lynch syndrome were randomly assigned in a two-by-two factorial design to receive 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo...

Host-plant-mediated effects of Nadefensin on herbivore and pathogen resistance in Nicotiana attenuata

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Baldwin Ian T

2008-10-01

Full Text Available Abstract Background The adage from Shakespeare, "troubles, not as single spies, but in battalions come," holds true for Nicotiana attenuata, which is commonly attacked by both pathogens (Pseudomonas spp. and herbivores (Manduca sexta in its native habitats. Defense responses targeted against the pathogens can directly or indirectly influence the responses against the herbivores. Nadefensin is an effective induced defense gene against the bacterial pathogen Pseudomonas syringae pv tomato (PST DC3000, which is also elicited by attack from M. sexta larvae, but whether this defense protein influences M. sexta's growth and whether M. sexta-induced Nadefensin directly or indirectly influences PST DC3000 resistance are unknown. Results M. sexta larvae consumed less on WT and on Nadefensin-silenced N. attenuata plants that had previously been infected with PST DC3000 than on uninfected plants. WT plants infected with PST DC3000 showed enhanced resistance to PST DC3000 and decreased leaf consumption by M. sexta larvae, but larval mass gain was unaffected. PST DC3000-infected Nadefensin-silenced plants were less resistant to subsequent PST DC3000 challenge, and on these plants, M. sexta larvae consumed less and gained less mass. WT and Nadefensin-silenced plants previously damaged by M. sexta larvae were better able to resist subsequent PST DC3000 challenges than were undamaged plants. Conclusion These results demonstrate that Na-defensin directly mediates defense against PST DC3000 and indirectly against M. sexta in N. attenuata. In plants that were previously infected with PST DC3000, the altered leaf chemistry in PST DC3000-resistant WT plants and PST DC3000-susceptible Nadefensin-silenced plants differentially reduced M. sexta's leaf consumption and mass gain. In plants that were previously damaged by M. sexta, the combined effect of the altered host plant chemistry and a broad spectrum of anti-herbivore induced metabolomic responses was more

Effect of reinforcing steel debonding on RC frame performance in resisting progressive collapse

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Waleed Mohamed Elsayed

2016-12-01

Full Text Available This paper presents the experimental program performed to study the effect of reinforcing steel debonding on progressive collapse resistance of moment resisting frame designed and detailed in accordance with the Egyptian code provisions for seismic design. Half-scale specimens of the first story were extracted from the frame structure prototype. Each specimen represented a two-bay beam resulting from the removal of middle supporting column of the lower floor. In all specimens, the exterior two short columns were restrained against horizontal and vertical displacements and a monotonic vertical load was applied on the middle column stub to simulate the vertical load of the upper stories. Gradually increasing vertical load at the location of the removed column is continuously applied and increased up to failure. The cracking patterns, strains and the deformations at selected locations of reinforcing steel and concrete are recorded for further analysis. Different debonded reinforcement ratios, places and length are examined in this study to evaluate its effect on the collapse resistance performance of the frame. The effect of debonding on the distribution of reinforcing steel strain is evaluated. The nonlinear response of the frame to the removal of the column is evaluated and the amount of energy absorbed during the course of deformation is calculated.

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.

Effect of heat treatment on the grooving corrosion resistance of ERW pipes

International Nuclear Information System (INIS)

Lee, Jong Kwon; Lee, Jae Young; Lim, Soo Hyun; Park, Ji Hwan; Seo, Bo Min; Kim, Seon Hwa

2002-01-01

The v-sharp grooving corrosion of ERW(electrical resistance welding) steel pipes limited their wide application in the industry in spite of their high productivity and efficiency. The grooving corrosion is caused mainly by the different microstructures between the matrix and weld that is formed during the rapid heating and cooling cycle in welding. By this localized corrosion reaction of pipes, it evolves economic problems such as the early damage of industrial facilities and pipe lines of apartment, and water pollution. Even though the diminishing of sulfur content is most effective to decrease the susceptibility of grooving corrosion, it requires costly process. In this study, improvement of grooving corrosion resistance was pursuited by post weld heat treatment in the temperature range between 650 .deg. C and 950 .deg. C. Also, the effect of heat input in the welding was investigated. By employing chromnoamperometry and potentiodynamic experiment, the corrosion rate and grooving corrosion index(α) were obtained. It was found that heat treatment could improve the grooving corrosion resistance. Among them, the heat treated at 900 .deg. C and 950 .deg. C had excellent grooving corrosion resistance. The index of heat treated specimen at 900 .deg. C and 950 .deg. C were 1.0, 1.2, respectively, which are almost immune to the grooving corrosion. Potential difference after the heat treatment, between base and weld metal was decreased considerably. While the as-received one measured 61∼71 mV, that of the 900 .deg. C heat treated steel pipe measured only 10mV. The results were explained and discussed

Postulation of rust resistance genes in Nordic spring wheat genotypes and identification of widely effective sources of resistance against the Australian rust flora.

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Randhawa, Mandeep; Bansal, Urmil; Lillemo, Morten; Miah, Hanif; Bariana, Harbans

2016-11-01

Wild relatives, landraces and cultivars from different geographical regions have been demonstrated as the sources of genetic variation for resistance to rust diseases. This study involved assessment of diversity for resistance to three rust diseases among a set of Nordic spring wheat cultivars. These cultivars were tested at the seedling stage against several pathotypes of three rust pathogens in the greenhouse. All stage stem rust resistance genes Sr7b, Sr8a, Sr12, Sr15, Sr17, Sr23 and Sr30, and leaf rust resistance genes Lr1, Lr3a, Lr13, Lr14a, Lr16 and Lr20 were postulated either singly or in different combinations among these cultivars. A high proportion of cultivars were identified to carry linked rust resistance genes Sr15 and Lr20. Although 51 cultivars showed variation against Puccinia striiformis f. sp. tritici (Pst) pathotypes used in this study, results were not clearly contrasting to enable postulation of stripe rust resistance genes in these genotypes. Stripe rust resistance gene Yr27 was postulated in four cultivars and Yr1 was present in cultivar Zebra. Cultivar Tjalve produced low stripe rust response against all Pst pathotypes indicating the presence either of a widely effective resistance gene or combination of genes with compensating pathogenic specificities. Several cultivars carried moderate to high level of APR to leaf rust and stripe rust. Seedling stem rust susceptible cultivar Aston exhibited moderately resistant to moderately susceptible response, whereas other cultivars belonging to this class were rated moderately susceptible or higher. Molecular markers linked with APR genes Yr48, Lr34/Yr18/Sr57, Lr68 and Sr2 detected the presence of these genes in some genotypes.

Investigation of surface resistance of copper in classical and anomalous skin-effect region

International Nuclear Information System (INIS)

Kutovoj, V.A.; Egorov, A.M.

2008-01-01

The surface resistance of copper in classical and anomalous skin-effect region has been investigated, and the surface resistance improvement factor equal to the ratio of the surface resistance of copper at room temperature to that of helium temperature, depending on the electromagnetic field frequency, has been determined. The improvement factor has been shown to have inverse power law dependence on frequency. The frequencies at which the improvement factor of copper equals 10 have been determined. It has been found that the quality factor of a resonance high-frequency system made of copper, operating at temperature T ≥ 4.2 K can be increased 10 times or more as against a quality factor of a resonance high-frequency system operating at room temperature

Predictable Phenotypes of Antibiotic Resistance Mutations.

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Knopp, M; Andersson, D I

2018-05-15

Antibiotic-resistant bacteria represent a major threat to our ability to treat bacterial infections. Two factors that determine the evolutionary success of antibiotic resistance mutations are their impact on resistance level and the fitness cost. Recent studies suggest that resistance mutations commonly show epistatic interactions, which would complicate predictions of their stability in bacterial populations. We analyzed 13 different chromosomal resistance mutations and 10 host strains of Salmonella enterica and Escherichia coli to address two main questions. (i) Are there epistatic interactions between different chromosomal resistance mutations? (ii) How does the strain background and genetic distance influence the effect of chromosomal resistance mutations on resistance and fitness? Our results show that the effects of combined resistance mutations on resistance and fitness are largely predictable and that epistasis remains rare even when up to four mutations were combined. Furthermore, a majority of the mutations, especially target alteration mutations, demonstrate strain-independent phenotypes across different species. This study extends our understanding of epistasis among resistance mutations and shows that interactions between different resistance mutations are often predictable from the characteristics of the individual mutations. IMPORTANCE The spread of antibiotic-resistant bacteria imposes an urgent threat to public health. The ability to forecast the evolutionary success of resistant mutants would help to combat dissemination of antibiotic resistance. Previous studies have shown that the phenotypic effects (fitness and resistance level) of resistance mutations can vary substantially depending on the genetic context in which they occur. We conducted a broad screen using many different resistance mutations and host strains to identify potential epistatic interactions between various types of resistance mutations and to determine the effect of strain

Effects of niacin supplementation on the insulin resistance in Holstein cows during early lactation

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Talija Hristovska

2017-01-01

Full Text Available Insulin resistance in early lactation includes low glucose concentration, low insulin release and responsiveness and high lipolysis. Niacin is important antilipolytic agent and leads to increase glucose and insulin concentration. The objectives of this study were to determine the influence of niacin on the insulin resistance in cows during early lactation using the difference of value and regression analysis between blood non-esterified fatty acid (NEFA, glucose and insulin concentrations, revised quantitative insulin sensitivity check index and glucose-to-insulin ratio. Niacin supplementation led to a decrease of NEFA concentration and an increase of glucose and insulin concentrations during the first three weeks after calving. Cows in the niacin group which were more resistant to insulin showed higher concentrations of non-esterified fatty acid in comparison with more sensitive cows from the same group, but still lower than the control. The regression analyses suggest the following characteristics of cows supplemented with niacin in comparison with the control group: the insulin response to glucose was more intense; the antilipolytic effect of insulin was lower; insulin efficiency expressed as glucose-to-insulin ratio increase with a decrease in NEFA. The metabolic changes due to niacin supplementation showed a dual influence on the insulin resistance in dairy cows during early lactation: decreased NEFA concentrations led to a decrease in the insulin resistance (due to an increase in insulin efficiency and insulin sensitivity index, but increased concentrations of insulin and glucose possibly caused an increase in the insulin resistance in dairy cows (due to lower insulin sensitivity index and possibly lower antilipolytic effects of insulin.

Effects of Ramadan fasting on aspirin resistance in type 2 diabetic patients.

Science.gov (United States)

Bouida, Wahid; Beltaief, Kaouthar; Baccouche, Houda; Sassi, Mouna; Dridi, Zohra; Trabelsi, Imen; Laaouiti, Kamel; Chakroun, Taher; Hellara, Ilhem; Boukef, Riadh; Sakly, Nabil; Hassine, Mohsen; Added, Faouzi; Razgallah, Rabie; Najjar, Fadhel; Nouira, Semir

2018-01-01

Ramadan fasting (RF) may affect aspirin resistance. We conducted this study in patients with cardiovascular risk (CVR) factors to assess the effect of RF on aspirin resistance and explore whether type 2 diabetes mellitus (DM) would influence this effect. A total of 177 stable patients with ≥2 CVR factors were recruited. All patients observed RF and were taking aspirin. Physical exam and standard biological tests including glycaemia and serum lipids data were performed before Ramadan (Pre-R), at the last week of Ramadan (R) and four weeks after the end of Ramadan (Post-R). In the same visits caloric intake was calculated and platelet reactivity to aspirin was assessed using Verify Now point-of-care assay. In the overall population, there was no significant change in absolute aspirin reaction unit (ARU) values and in metabolic parameters. In DM patients (n = 127), ARU change from Pre-R values was+19.7 (p = 0.01) and +14.4 (p = 0.02) respectively at R and Post-R. During Ramadan, glycaemia, triglycerides, and cholesterol levels increased significantly and returned to Pre-R values thereafter. These changes were not observed in non-DM patients. During RF aspirin resistance increased only in DM patients. This effect persisted one month after Ramadan. Simultaneous alteration of glycemic control and increase of serum lipids levels could potentially be a favorable factor. The protocol was registered at clinicaltrials.gov under: NCT02720133.

Effects of Ramadan fasting on aspirin resistance in type 2 diabetic patients

Science.gov (United States)

Bouida, Wahid; Beltaief, Kaouthar; Baccouche, Houda; Sassi, Mouna; Dridi, Zohra; Trabelsi, Imen; Laaouiti, Kamel; Chakroun, Taher; Hellara, Ilhem; Boukef, Riadh; Sakly, Nabil; Hassine, Mohsen; Added, Faouzi; Razgallah, Rabie; Najjar, Fadhel; Nouira, Semir

2018-01-01

Aims Ramadan fasting (RF) may affect aspirin resistance. We conducted this study in patients with cardiovascular risk (CVR) factors to assess the effect of RF on aspirin resistance and explore whether type 2 diabetes mellitus (DM) would influence this effect. Methods A total of 177 stable patients with ≥2 CVR factors were recruited. All patients observed RF and were taking aspirin. Physical exam and standard biological tests including glycaemia and serum lipids data were performed before Ramadan (Pre-R), at the last week of Ramadan (R) and four weeks after the end of Ramadan (Post-R). In the same visits caloric intake was calculated and platelet reactivity to aspirin was assessed using Verify Now point-of-care assay. Results In the overall population, there was no significant change in absolute aspirin reaction unit (ARU) values and in metabolic parameters. In DM patients (n = 127), ARU change from Pre-R values was+19.7 (p = 0.01) and +14.4 (p = 0.02) respectively at R and Post-R. During Ramadan, glycaemia, triglycerides, and cholesterol levels increased significantly and returned to Pre-R values thereafter. These changes were not observed in non-DM patients. Conclusions During RF aspirin resistance increased only in DM patients. This effect persisted one month after Ramadan. Simultaneous alteration of glycemic control and increase of serum lipids levels could potentially be a favorable factor. Study registration The protocol was registered at clinicaltrials.gov under: NCT02720133. PMID:29529091

High chlorpyrifos resistance in Culex pipiens mosquitoes: strong synergy between resistance genes

Science.gov (United States)

Alout, H; Labbé, P; Berthomieu, A; Makoundou, P; Fort, P; Pasteur, N; Weill, M

2016-01-01

We investigated the genetic determinism of high chlorpyrifos resistance (HCR), a phenotype first described in 1999 in Culex pipiens mosquitoes surviving chlorpyrifos doses ⩾1 mg l−1 and more recently found in field samples from Tunisia, Israel or Indian Ocean islands. Through chlorpyrifos selection, we selected several HCR strains that displayed over 10 000-fold resistance. All strains were homozygous for resistant alleles at two main loci: the ace-1 gene, with the resistant ace-1R allele expressing the insensitive G119S acetylcholinesterase, and a resistant allele of an unknown gene (named T) linked to the sex and ace-2 genes. We constructed a strain carrying only the T-resistant allele and studied its resistance characteristics. By crossing this strain with strains harboring different alleles at the ace-1 locus, we showed that the resistant ace-1R and the T alleles act in strong synergy, as they elicited a resistance 100 times higher than expected from a simple multiplicative effect. This effect was specific to chlorpyrifos and parathion and was not affected by synergists. We also examined how HCR was expressed in strains carrying other ace-1-resistant alleles, such as ace-1V or the duplicated ace-1D allele, currently spreading worldwide. We identified two major parameters that influenced the level of resistance: the number and the nature of the ace-1-resistant alleles and the number of T alleles. Our data fit a model that predicts that the T allele acts by decreasing chlorpyrifos concentration in the compartment targeted in insects. PMID:26463842

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

Linezolid Dose That Maximizes Sterilizing Effect While Minimizing Toxicity and Resistance Emergence for Tuberculosis.

Science.gov (United States)

Srivastava, Shashikant; Magombedze, Gesham; Koeuth, Thearith; Sherman, Carleton; Pasipanodya, Jotam G; Raj, Prithvi; Wakeland, Edward; Deshpande, Devyani; Gumbo, Tawanda

2017-08-01

Linezolid has an excellent sterilizing effect in tuberculosis patients but high adverse event rates. The dose that would maximize efficacy and minimize toxicity is unknown. We performed linezolid dose-effect and dose-scheduling studies in the hollow fiber system model of tuberculosis (HFS-TB) for sterilizing effect. HFS-TB units were treated with several doses to mimic human-like linezolid intrapulmonary pharmacokinetics and repetitively sampled for drug concentration, total bacterial burden, linezolid-resistant subpopulations, and RNA sequencing over 2 months. Linezolid-resistant isolates underwent whole-genome sequencing. The expression of genes encoding efflux pumps in the first 1 to 2 weeks revealed the same exposure-response patterns as the linezolid-resistant subpopulation. Linezolid-resistant isolates from the 2nd month of therapy revealed mutations in several efflux pump/transporter genes and a LuxR-family transcriptional regulator. Linezolid sterilizing effect was linked to the ratio of unbound 0- to 24-h area under the concentration-time curve (AUC 0-24 ) to MIC. Optimal microbial kill was achieved at an AUC 0-24 /MIC ratio of 119. The optimal sterilizing effect dose for clinical use was identified using Monte Carlo simulations. Clinical doses of 300 and 600 mg/day (or double the dose every other day) achieved this target in 87% and >99% of 10,000 patients, respectively. The susceptibility breakpoint identified was 2 mg/liter. The simulations identified that a 300-mg/day dose did not achieve AUC 0-24 s associated with linezolid toxicity, while 600 mg/day achieved those AUC 0-24 s in linezolid dose of 300 mg/day performed well and should be compared to 600 mg/day or 1,200 mg every other day in clinical trials. Copyright © 2017 Srivastava et al.

Effects of exercise intensity and creatine loading on post-resistance exercise hypotension

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Moreno Rodrigues Moreno

2009-09-01

Full Text Available Postexercise hypotension plays an important role in the non-pharmacological treat-ment of hypertension and is characterized by a decrease in blood pressure after a single exercise bout in relation to pre-exercise levels. This study investigated the effects of exercise intensity and creatine monohydrate supplementation on postexercise hypotension, as well as the possible role of blood lactate in this response. Ten normotensive subjects underwent resistance exercise sessions before (BC and after (AC creatine supplementation: 1 muscle endurance (ME consisting of 30 repetitions at 30% of one-repetition maximum; 2 hypertrophy (HP consisting of 8 repetitions at 75% of one-repetition maximum. Blood pressure was measured before and after the exercise bout. Blood lactate was measured after the exercise bout. The HP and ME sessions promoted a decrease in systolic blood pressure (∆ -19 ± 1.0 mmHg; ∆ -15 ± 0.9 mmHg, respectively, P 0.05. In conclusion, resistance exercise intensity did not influence postexercise hypotension. Creatine supplementation attenuated the decrease in blood pressure after resistance exercise. The results suggest the involvement of blood lactate in post-resistance exercise hypotension.

Effects of exercise intensity and creatine loading on post-resistance exercise hypotension

Directory of Open Access Journals (Sweden)

Moreno Rodrigues Moreno

2009-01-01

Postexercise hypotension plays an important role in the non-pharmacological treat-ment of hypertension and is characterized by a decrease in blood pressure after a single exercise bout in relation to pre-exercise levels. This study investigated the effects of exercise intensity and creatine monohydrate supplementation on postexercise hypotension, as well as the possible role of blood lactate in this response. Ten normotensive subjects underwent resistance exercise sessions before (BC and after (AC creatine supplementation: 1 muscle endurance (ME consisting of 30 repetitions at 30% of one-repetition maximum; 2 hypertrophy (HP consisting of 8 repetitions at 75% of one-repetition maximum. Blood pressure was measured before and after the exercise bout. Blood lactate was measured after the exercise bout. The HP and ME sessions promoted a decrease in systolic blood pressure (∆ -19 ± 1.0 mmHg; ∆ -15 ± 0.9 mmHg, respectively, P 0.05. In conclusion, resistance exercise intensity did not influence postexercise hypotension. Creatine supplementation attenuated the decrease in blood pressure after resistance exercise. The results suggest the involvement of blood lactate in post-resistance exercise hypotension.

Effects of electron acceptors on removal of antibiotic resistant Escherichia coli, resistance genes and class 1 integrons under anaerobic conditions.

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Yuan, Heyang; Miller, Jennifer H; Abu-Reesh, Ibrahim M; Pruden, Amy; He, Zhen

2016-11-01

Anaerobic biotechnologies can effectively remove antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), but there is a need to better understand the mechanisms. Here we employ bioelectrochemical systems (BES) as a platform to investigate the fate of a native tetracycline and sulfonamide-resistant Escherichia coli strain and its ARGs. The E. coli strain carrying intI1, sulI and tet(E) was isolated from domestic wastewater and dosed into a tubular BES. The BES was first operated as a microbial fuel cell (MFC), with aeration in the cathode, which resulted in enhanced removal of E. coli and ARGs by ~2 log (i.e., order of magnitude) when switched from high current to open circuit operation mode. The BES was then operated as a microbial electrolysis cell (MEC) to exclude the effects of oxygen diffusion, and the removal of E. coli and ARGs during the open circuit configuration was again 1-2 log higher than that at high current mode. Significant correlations of E. coli vs. current (R(2)=0.73) and ARGs vs. E. coli (R(2) ranged from 0.54 to 0.87), and the fact that the BES substrate contained no electron acceptors, implied that the persistence of the E. coli and its ARGs was determined by the availability of indigenous electron acceptors in the BES, i.e., the anode electrode or the electron shuttles generated by the exoelectrogens. Subsequent experiments with pure-culture tetracycline and sulfonamide-resistant E. coli being incubated in a two-chamber MEC and serum bottles demonstrated that the E. coli could survive by respiring anode electrode and/or electron shuttles released by exoelectrogens, and ARGs persisted with their host E. coli. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners.

Science.gov (United States)

Mikkola, Jussi; Vesterinen, Ville; Taipale, Ritva; Capostagno, Benoit; Häkkinen, Keijo; Nummela, Ari

2011-10-01

The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(₂max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(₂max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as

Antibiotic resistance in hospitals: a ward-specific random effect model in a low antibiotic consumption environment.

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Aldrin, Magne; Raastad, Ragnhild; Tvete, Ingunn Fride; Berild, Dag; Frigessi, Arnoldo; Leegaard, Truls; Monnet, Dominique L; Walberg, Mette; Müller, Fredrik

2013-04-15

Association between previous antibiotic use and emergence of antibiotic resistance has been reported for several microorganisms. The relationship has been extensively studied, and although the causes of antibiotic resistance are multi-factorial, clear evidence of antibiotic use as a major risk factor exists. Most studies are carried out in countries with high consumption of antibiotics and corresponding high levels of antibiotic resistance, and currently, little is known whether and at what level the associations are detectable in a low antibiotic consumption environment. We conduct an ecological, retrospective study aimed at determining the impact of antibiotic consumption on antibiotic-resistant Pseudomonas aeruginosa in three hospitals in Norway, a country with low levels of antibiotic use. We construct a sophisticated statistical model to capture such low signals. To reduce noise, we conduct our study at hospital ward level. We propose a random effect Poisson or binomial regression model, with a reparametrisation that allows us to reduce the number of parameters. Inference is likelihood based. Through scenario simulation, we study the potential effects of reduced or increased antibiotic use. Results clearly indicate that the effects of consumption on resistance are present under conditions with relatively low use of antibiotic agents. This strengthens the recommendation on prudent use of antibiotics, even when consumption is relatively low. Copyright © 2012 John Wiley & Sons, Ltd.

The repeated bout effect of traditional resistance exercises on running performance across 3 bouts.

Science.gov (United States)

Doma, Kenji; Schumann, Moritz; Leicht, Anthony Scott; Heilbronn, Brian Edward; Damas, Felipe; Burt, Dean

2017-09-01

This study investigated the repeated bout effect of 3 typical lower body resistance-training sessions on maximal and submaximal effort running performance. Twelve resistance-untrained men (age, 24 ± 4 years; height, 1.81 ± 0.10 m; body mass, 79.3 ± 10.9 kg; peak oxygen uptake, 48.2 ± 6.5 mL·kg -1 ·min -1 ; 6-repetition maximum squat, 71.7 ± 12.2 kg) undertook 3 bouts of resistance-training sessions at 6-repetitions maximum. Countermovement jump (CMJ), lower-body range of motion (ROM), muscle soreness, and creatine kinase (CK) were examined prior to and immediately, 24 h (T24), and 48 h (T48) after each resistance-training bout. Submaximal (i.e., below anaerobic threshold (AT)) and maximal (i.e., above AT) running performances were also conducted at T24 and T48. Most indirect muscle damage markers (i.e., CMJ, ROM, and muscle soreness) and submaximal running performance were significantly improved (P running performance was also improved following the third bout (P 0.05). In conclusion, the initial bout induced the greatest change in CK; however, at least 2 bouts were required to produce protective effects on other indirect muscle damage markers and submaximal running performance measures. This suggests that submaximal running sessions should be avoided for at least 48 h after resistance training until the third bout, although a greater recovery period may be required for maximal running sessions.

The effects of low-level ionizing radiation and copper exposure on the incidence of antibiotic resistance in lentic biofilm bacteria.

Science.gov (United States)

McArthur, J Vaun; Dicks, Christian A; Bryan, A Lawrence; Tuckfield, R Cary

2017-09-01

Environmental reservoirs of antibiotic resistant bacteria are poorly understood. Understanding how the environment selects for resistance traits in the absence of antibiotics is critical in developing strategies to mitigate this growing menace. Indirect or co-selection of resistance by environmental pollution has been shown to increase antibiotic resistance. However no attention has been given to the effects of low-level ionizing radiation or the interactions between radiation and heavy metals on the maintenance or selection for antibiotic resistance (AR) traits. Here we explore the effect of radiation and copper on antibiotic resistance. Bacteria were collected from biofilms in two ponds - one impacted by low-level radiocesium and the other an abandoned farm pond. Through laboratory controlled experiments we examined the effects of increasing concentrations of copper on the incidence of antibiotic resistance. Differences were detected in the resistance profiles of the controls from each pond. Low levels (0.01 mM) of copper sulfate increased resistance but 0.5 mM concentrations of copper sulfate depressed the AR response in both ponds. A similar pattern was observed for levels of multiple antibiotic resistance per isolate. The first principal component response of isolate exposure to multiple antibiotics showed significant differences among the six isolate treatment combinations. These differences were clearly visualized through a discriminant function analysis, which showed distinct antibiotic resistance response patterns based on the six treatment groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of iron on pancreatic beta cell function and insulin resistance ...

African Journals Online (AJOL)

Background: Increase in total body iron store has been reported in the aetiology and development of diabetes mellitus. The effect of iron supplementation in female with respect to the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal female rats. Methods: ...

Synergistic Effect of Fluconazole and Calcium Channel Blockers against Resistant Candida albicans.

Science.gov (United States)

Liu, Shuyuan; Yue, Longtao; Gu, Wenrui; Li, Xiuyun; Zhang, Liuping; Sun, Shujuan

2016-01-01

Candidiasis has increased significantly recently that threatens patients with low immunity. However, the number of antifungal drugs on the market is limited in comparison to the number of available antibacterial drugs. This fact, coupled with the increased frequency of fungal resistance, makes it necessary to develop new therapeutic strategies. Combination drug therapy is one of the most widely used and effective strategy to alleviate this problem. In this paper, we were aimed to evaluate the combined antifungal effects of four CCBs (calcium channel blockers), amlodipine (AML), nifedipine (NIF), benidipine (BEN) and flunarizine (FNZ) with fluconazole against C. albicans by checkerboard and time-killing method. In addition, we determined gene (CCH1, MID1, CNA1, CNB1, YVC1, CDR1, CDR2 and MDR1) expression by quantitative PCR and investigated the efflux pump activity of resistant candida albicans by rhodamine 6G assay to reveal the potential mechanisms. Finally, we concluded that there was a synergy when fluconazole combined with the four tested CCBs against resistant strains, with fractional inhibitory concentration index (FICI) <0.5, but no interaction against sensitive strains (FICI = 0.56 ~ 2). The mechanism studies revealed that fluconazole plus amlodipine caused down-regulating of CNA1, CNB1 (encoding calcineurin) and YVC1 (encoding calcium channel protein in vacuole membrane).

Effect of fractionated radiation on multidrug resistance in human ovarian cancer

International Nuclear Information System (INIS)

Kong Dejuan; Liu Xiaodong; Liang Bing; Jia Lili; Ma Shumei

2012-01-01

Objective: To investigate the effect of different subtypes of fractionated doses on multidrug resistance in ovarian cancer cells. Methods: The human ovarian cancer cell lines SKOV3 and its drug-resistant subtype SKVCR were divided into four groups i.e., sham-irradiated, single dose (10 Gy), fractionated dose (2 Gy × 5) and multi-fractionated dose (1 Gy × 2 × 5). Cell sensitivity to vincristine (VCR), etoposide (VP-16), pirarubicin (THP) and cisplatin (DDP) was measured by MTT assay. Western blot was applied to detect the expression of P-gp after irradiation. Results: The doubling time of SKVCR was about 1.8-fold of that of SKOV3 cells. P-gp was expressed in SKVCR but not in SKOV3. IC 50 values of SKVCR were higher than those of SKOV3. To SKOV3 cells, single dose irradiation decreased cell sensitivity to THP and DDP and fractionated irradiation decreased cell sensitivity to VCR, THP and VP-16. Multi-fractionated irradiation decreased cell sensitivity to VP-16. In SKVCR cells, all these irradiation treatments increased cell sensitivity to VCR and VP-16 but not to DDP. In addition, single and fractionated irradiation decreased P-gp expression in SKVCR cells. Conclusions: Single, fractionated and multi-fractionated radiation induced chemotherapy resistance in SKOV3 cells, while reversed drug resistance to VCR and VP-16 in SKVCR cells. (authors)

Effects of Resistance Training on Serum Level of Reproductive Hormones and Sperm Parameters in Type 2 Diabetes Rats

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Mohammad Parastesh

2016-11-01

Full Text Available Abstract Background: Diabetes mellitus is associated with reductions in fertility indices. Resistance training, on the other hand, through reducing the adverse effects of diabetes, exerts a positive impact on diabetic individuals. The aim of the present study was to examine the effects of ten weeks of resistance training on serum levels of reproductive hormones and sperm parameters in Wistar rats with diabetes mellitus type 2. Materials and Methods:In this experimental study, 36 Wistar rats with mean weight of 200±50 were ran-domly assigned to healthy control, diabetic control and diabetic training groups. The diabetic resistance training group received ten weeks of resistance training (climbing up the ladder following the induction of diabetes. Twenty-four hours after the last training session, left epididymis of the rats was examined for studying sperm parameters and blood serum samples were examined for evaluating reproductive hormones. Data were analyzed using one-way ANOVA and Turkey’s Post Hoc test at 0.05%. Results: Ten weeks of resistance training induced significant increases in serum testosterone and FSH levels in the resistance training group in comparison to the diabetic group (p<0.007.Resistance training did not have any significant effects on serum LH levels in the resistance training group compared to the diabetic control group. In ad-dition, sperm parameters (sperm count, survival rate and motility presented significant improvements compared to the diabetic group(p<0.05. Conclusion: Resistance training can improve sperm parameters, including sperm count, survival rate and motility, through increasing serum testosterone, LH and FSH levels (reproductive hormones in rats with diabetes mellitus type 2.

Parasitic resistive switching uncovered from complementary resistive switching in single active-layer oxide memory device

Science.gov (United States)

Zhu, Lisha; Hu, Wei; Gao, Chao; Guo, Yongcai

2017-12-01

This paper reports the reversible transition processes between the bipolar and complementary resistive switching (CRS) characteristics on the binary metal-oxide resistive memory devices of Pt/HfO x /TiN and Pt/TaO x /TiN by applying the appropriate bias voltages. More interestingly, by controlling the amplitude of the negative bias, the parasitic resistive switching effect exhibiting repeatable switching behavior is uncovered from the CRS behavior. The electrical observation of the parasitic resistive switching effect can be explained by the controlled size of the conductive filament. This work confirms the transformation and interrelationship among the bipolar, parasitic, and CRS effects, and thus provides new insight into the understanding of the physical mechanism of the binary metal-oxide resistive switching memory devices.

Experimental Studies on the Changes in Resistivity and Its Anisotropy Using Electrical Resistivity Tomography

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Tao Zhu

2012-01-01

Full Text Available Three measuring lines were arranged on one of free planes of magnetite cuboid samples. Apparent resistivity data were acquired by MIR-2007 resistivity meter when samples were under uniaxial compression of servocontrol YAW-5000F loadingmachine in laboratory. Then we constructed the residual resistivity images using electrical resistivity tomography (ERT and plotted the diagrams of apparent resistivity anisotropy coefficient (ARAC λ∗ and the included angle α between the major axis of apparent resistivity anisotropy ellipse and the axis of load with pressure and effective depth. Our results show that with increasing pressure, resistivity and the decreased (D region and increased (I region resistivity regions have complex behaviors, but when pressure is higher than a certain value, the average resistivity decrease and the area of D region expand gradually in all time with the increase of pressure, which may be significant to the monitoring and prediction of earthquake, volcanic activities, and large-scale geologic motions. The effects of pressure on λ∗ and α are not very outstanding for dry magnetite samples.

Acute effect of resistance, aerobic and combined exercise circuits on blood pressure of hypertensive women

Directory of Open Access Journals (Sweden)

Elizabeth Carpio Rivera

2012-11-01

Full Text Available Carpio-Rivera, E. y Solera-Herrera, A. (2012. Acute effect of resistance, aerobic and combined exercise circuits on blood pressure of hypertensive women. Pensar en Movimiento: Revista de Ciencias del Ejercicio y la Salud, 10 (2, 1-12. The purpose of this study was to observe the acute effect of different exercises executed in circuit on the resting blood pressure of hypertensive women. Nine trained persons (aged 53.22 ± 4.67 years, hypertensive but medicated with enalapril, participated in four training treatments, each carried out on different days under a randomized repeated measures design: (1 A: aerobic training condition (steps training; (2 R: resistance training condition (machine training (3 AR: aerobic and resistance training condition (alternating aerobic and resistance training every 30 seconds (4 C: control condition (30 minutes resting. Exercise conditions were performed during 30 minutes at 70% of maximum heart rate and resting blood pressure was measured 5 minutes before and immediately after each condition. A two-way analysis of variance detected a significant interaction between conditions and measurements (p<0.05 on systolic blood pressure (sBP. Tukey Post-hoc analyses showed a significant increase of sBP following the three exercise conditions (A: +19 mmHg; R: +28 mmHg; AR: +22 mmHg, while the sBP remained unchanged during the control condition. In contrast, there was no significant effect of any type of exercise on diastolic blood pressure (dBP. In conclusion, the acute elevation in sBP following this type of resistance exercise was similar to the increase produced by aerobic exercise.

Combined Effect of the Cfr Methyltransferase and Ribosomal Protein L3 Mutations on Resistance to Ribosome-Targeting Antibiotics.

Science.gov (United States)

Pakula, Kevin K; Hansen, Lykke H; Vester, Birte

2017-09-01

Several groups of antibiotics inhibit bacterial growth by binding to bacterial ribosomes. Mutations in ribosomal protein L3 have been associated with resistance to linezolid and tiamulin, which both bind at the peptidyl transferase center in the ribosome. Resistance to these and other antibiotics also occurs through methylation of 23S rRNA at position A2503 by the methyltransferase Cfr. The mutations in L3 and the cfr gene have been found together in clinical isolates, raising the question of whether they have a combined effect on antibiotic resistance or growth. We transformed a plasmid-borne cfr gene into a uL3-depleted Escherichia coli strain containing either wild-type L3 or L3 with one of seven mutations, G147R, Q148F, N149S, N149D, N149R, Q150L, or T151P, expressed from plasmid-carried rplC genes. The L3 mutations are well tolerated, with small to moderate growth rate decreases. The presence of Cfr has a very minor influence on the growth rate. The resistance of the transformants to linezolid, tiamulin, florfenicol, and Synercid (a combination of quinupristin and dalfopristin [Q-D]) was measured by MIC assays. The resistance from Cfr was, in all cases, stronger than the effects of the L3 mutations, but various effects were obtained with the combinations of Cfr and L3 mutations ranging from a synergistic to an antagonistic effect. Linezolid and tiamulin susceptibility varied greatly among the L3 mutations, while no significant effects on florfenicol and Q-D susceptibility were seen. This study underscores the complex interplay between various resistance mechanisms and cross-resistance, even from antibiotics with overlapping binding sites. Copyright © 2017 American Society for Microbiology.

Effect of deep stripping massage alone or with eccentric resistance on hamstring length and strength.

Science.gov (United States)

Forman, Jeffrey; Geertsen, Lisbeth; Rogers, Michael E

2014-01-01

Many studies have evaluated the effects of different interventions on hamstring length. However, little research has been conducted on the effects of deep stripping massage strokes (DSMS) alone, or combined with eccentric resistance, on hamstring length and strength. To determine: 1) if DSMS have an effect on hamstring length and strength and 2) if the effects on hamstring length and strength are any different when DSMS are combined with eccentric exercise. 89 Community College students and community members between the ages of 18 and 62 volunteered for the study. Of these, 64 demonstrated tight hamstrings on either one or both sides as defined by supine, passive terminal knee extension of ≤75° and participated in the study. Strength was assessed by pressing the posterior calcaneus into a strain gauge for approximately 5 s while seated with the knee flexed to 90°. On their tighter side, participants were administered longitudinal DSMS during 15, 10-s bouts of eccentric resistance with an elastic resistance band. On their other hamstring, participants were administered 15, 10-s longitudinal DSMS while lying passive. All massage strokes were performed at a depth of 7 out of 10 on a verbal pressure scale index. Afterwards, the hamstring flexibility and strength tests were repeated. Both DSMS with eccentric resistance (10.7%) and DSMS alone (6.3%) resulted in improved (p alone. Strength was not significantly affected by either treatment. These results suggest that DSMS increases hamstring length in less than 3 min but has no affect on strength. Furthermore, combining DSMS with eccentric resistance produces more hamstring flexibility gains than DSMS alone and does not affect strength. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Effect of Tensile Hysteresis and Contact Resistance on the Performance of Strain-Resistant Elastic-Conductive Webbing

Directory of Open Access Journals (Sweden)

Tien-Wei Shyr

2011-01-01

Full Text Available To use e-textiles as a strain-resistance sensor they need to be both elastic and conductive. Three kinds of elastic-conductive webbings, including flat, tubular, and belt webbings, made of Lycra fiber and carbon coated polyamide fiber, were used in this study. The strain-resistance properties of the webbings were evaluated in stretch-recovery tests and measured within 30% strain. It was found that tensile hysteresis and contact resistance significantly influence the tensile elasticity and the resistance sensitivity of the webbings. The results showed that the webbing structure definitely contributes to the tensile hysteresis and contact resistance. The smaller the friction is among the yarns in the belt webbing, the smaller the tensile hysteresis loss. However the close proximity of the conductive yarns in flat and tubular webbings results in a lower contact resistance.

The effect of low-dose spironolactone on resistant hypertension

DEFF Research Database (Denmark)

Engbaek, Mette; Hjerrild, Mette; Hallas, Jesper

2010-01-01

with three classes of antihypertensive drugs. The effect on blood pressure was estimated by office measurements together with serum potassium and adverse effects. The data were analyzed retrospectively. A total of 544 patients were identified; 200 were excluded because of secondary hypertension, other......Our objective was to estimate the effect of addition of low-dose spironolactone to previous antihypertensive therapy in patients with resistant hypertension. Patients had 25 to 50 mg of spironolactone once daily added to the treatment of hypertension that was uncontrolled despite previous treatment...... indications for spironolactone than hypertension, previous antihypertensive therapy with less than three drugs unless demonstrated intolerance to a third drug, insufficient compliance, and lack of follow-up data. Thus, 344 cases were included in the analysis. The population was 62.1 ± 12.8 years old, 45...

Maternal effects of the English grain aphids feeding on the wheat varieties with different resistance traits.

Science.gov (United States)

Hu, Xiang-Shun; Zhang, Zhan-Feng; Zhu, Tong-Yi; Song, Yue; Wu, Li-Juan; Liu, Xiao-Feng; Zhao, Hui-Yan; Liu, Tong-Xian

2018-05-09

The maternal effects of the English grain aphid, Sitobion avenae on offspring phenotypes and performance on wheat varieties with different resistance traits were examined. We found that both conditioning wheat varieties(the host plant for over 3 months) and transition wheat varieties affected the biological parameters of aphid offspring after they were transferred between wheat varieties with different resistance traits. The conditioning varieties affected weight gain, development time (DT), and the intrinsic rate of natural increase (r m ), whereas transition varieties affected the fecundity, r m , net reproductive rate, and fitness index. The conditioning and transition wheat varieties had significant interaction effects on the aphid offspring's DT, mean relative growth rate, and fecundity. Our results showed that there was obvious maternal effects on offspring when S. avenae transferred bwteen wheat varieties with different resistance level, and the resistance traits of wheat varieties could induce an interaction between the conditioning and transition wheat varieties to influence the growth, development, reproduction, and even population dynamics of S. avenae. The conditioning varieties affected life-history traits related to individual growth and development to a greater extent, whereas transition varieties affected fecundity and population parameters more.

[Effects and mechanisms of plant roots on slope reinforcement and soil erosion resistance: a research review].

Science.gov (United States)

Xiong, Yan-Mei; Xia, Han-Ping; Li, Zhi-An; Cai, Xi-An

2007-04-01

Plant roots play an important role in resisting the shallow landslip and topsoil erosion of slopes by raising soil shear strength. Among the models in interpreting the mechanisms of slope reinforcement by plant roots, Wu-Waldron model is a widely accepted one. In this model, the reinforced soil strength by plant roots is positively proportional to average root tensile strength and root area ratio, the two most important factors in evaluating slope reinforcement effect of plant roots. It was found that soil erosion resistance increased with the number of plant roots, though no consistent quantitative functional relationship was observed between them. The increase of soil erosion resistance by plant roots was mainly through the actions of fiber roots less than 1 mm in diameter, while fiber roots enhanced the soil stability to resist water dispersion via increasing the number and diameter of soil water-stable aggregates. Fine roots could also improve soil permeability effectively to decrease runoff and weaken soil erosion.

Effect of Resistance Training on Hematological Blood Markers in Older Men and Women: A Pilot Study

Directory of Open Access Journals (Sweden)

Florian Bobeuf

2009-01-01

Full Text Available The aim of this study was to examine the effects of resistance training on hematological blood markers in older individuals. Twenty-nine men and women participated to this study. Subjects were randomized in 2 groups: (1 control (n=13 and (2 resistance training (n=16. At baseline and after the intervention, subjects were submitted to a blood sample to determine their hematological profile (red blood cells, hemoglobin, hematocrit, platelets, leukocytes, neutrophils, lymphocytes, monocytes, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width. At baseline, no difference was observed between groups. Moreover, we found no significant difference after the intervention on any of these markers. A 6-month resistance program in healthy older individuals seems to have no beneficial nor deleterious effects on hematological blood parameters. However, resistance training was well tolerated and should be recommended for other health purposes. Further studies are needed to confirm these results in a large population.

A New Concept for Non-Volatile Memory: The Electric-Pulse Induced Resistive Change Effect in Colossal Magnetoresistive Thin Films

Science.gov (United States)

Liu, S. Q.; Wu, N. J.; Ignatiev, A.

2001-01-01

A novel electric pulse-induced resistive change (EPIR) effect has been found in thin film colossal magnetoresistive (CMR) materials, and has shown promise for the development of resistive, nonvolatile memory. The EPIR effect is induced by the application of low voltage (resistance of the thin film sample depending on pulse polarity. The sample resistance change has been shown to be over two orders of magnitude, and is nonvolatile after pulsing. The sample resistance can also be changed through multiple levels - as many as 50 have been shown. Such a device can provide a way for the development of a new kind of nonvolatile multiple-valued memory with high density, fast write/read speed, low power-consumption, and potential high radiation-hardness.

[Thin layer agar represents a cost-effective alternative for the rapid diagnosis of multi-drug resistant tuberculosis].

Science.gov (United States)

Hernández-Sarmiento, José M; Martínez-Negrete, Milton A; Castrillón-Velilla, Diana M; Mejía-Espinosa, Sergio A; Mejía-Mesa, Gloria I; Zapata-Fernández, Elsa M; Rojas-Jiménez, Sara; Marín-Castro, Andrés E; Robledo-Restrepo, Jaime A

2014-01-01

Using cost-benefit analysis for comparing the thin-layer agar culture method to the standard multiple proportion method used in diagnosing multidrug-resistant tuberculosis (MDR TB). A cost-benefit evaluation of two diagnostic tests was made at the Corporación para Investigaciones Biológicas (CIB) in Medellín, Colombia. 100 patients were evaluated; 10.8% rifampicin resistance and 14.3% isoniazid resistance were found. A computer-based decision tree model was used for cost-effectiveness analysis (Treeage Pro); the thin-layer agar culture method was most cost-effective, having 100% sensitivity, specificity and predictive values for detecting rifampicin and isoniazid resistance. The multiple proportion method value was calculated as being US$ 71 having an average 49 day report time compared to US$ 18 and 14 days for the thin-layer agar culture method. New technologies have been developed for diagnosing tuberculosis which are apparently faster and more effective; their operating characteristics must be evaluated as must their effectiveness in terms of cost-benefit. The present study established that using thin-layer agar culture was cheaper, equally effective and could provide results more quickly than the traditional method. This implies that a patient could receive MDR TB treatment more quickly.

The effects of nonlinear resistance and aerobic interval training on serum levels of apelin and insulin resistance in middle-aged obese men

Directory of Open Access Journals (Sweden)

Mahmoud Nikseresht

2015-08-01

Conclusion: The practical applications indicate that obese men can use both AIT and NRT exercise programs to reduce insulin resistance. However, the AIT may have better beneficial effects (as indicated by apelin-13 compared to NRT.

Effects of electron acceptors on removal of antibiotic resistant Escherichia coli, resistance genes and class 1 integrons under anaerobic conditions

Energy Technology Data Exchange (ETDEWEB)

Yuan, Heyang; Miller, Jennifer H. [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Abu-Reesh, Ibrahim M. [Department of Chemical Engineering, Qatar University, P.O. Box 2713, Doha (Qatar); Pruden, Amy [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); He, Zhen, E-mail: zhenhe@vt.edu [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States)

2016-11-01

Anaerobic biotechnologies can effectively remove antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), but there is a need to better understand the mechanisms. Here we employ bioelectrochemical systems (BES) as a platform to investigate the fate of a native tetracycline and sulfonamide-resistant Escherichia coli strain and its ARGs. The E. coli strain carrying intI1, sulI and tet(E) was isolated from domestic wastewater and dosed into a tubular BES. The BES was first operated as a microbial fuel cell (MFC), with aeration in the cathode, which resulted in enhanced removal of E. coli and ARGs by ~ 2 log (i.e., order of magnitude) when switched from high current to open circuit operation mode. The BES was then operated as a microbial electrolysis cell (MEC) to exclude the effects of oxygen diffusion, and the removal of E. coli and ARGs during the open circuit configuration was again 1–2 log higher than that at high current mode. Significant correlations of E. coli vs. current (R{sup 2} = 0.73) and ARGs vs. E. coli (R{sup 2} ranged from 0.54 to 0.87), and the fact that the BES substrate contained no electron acceptors, implied that the persistence of the E. coli and its ARGs was determined by the availability of indigenous electron acceptors in the BES, i.e., the anode electrode or the electron shuttles generated by the exoelectrogens. Subsequent experiments with pure-culture tetracycline and sulfonamide-resistant E. coli being incubated in a two-chamber MEC and serum bottles demonstrated that the E. coli could survive by respiring anode electrode and/or electron shuttles released by exoelectrogens, and ARGs persisted with their host E. coli. - Highlights: • The fate of an antibiotic resistant E. coli stain and its ARGs in BES is studied. • The removal of the E. coli and its ARGs is enhanced with decreased current. • The ARGs are removed when the host E. coli dies and persist when the host survives. • The survival of the E. coli depends

Effects of electron acceptors on removal of antibiotic resistant Escherichia coli, resistance genes and class 1 integrons under anaerobic conditions

International Nuclear Information System (INIS)

Yuan, Heyang; Miller, Jennifer H.; Abu-Reesh, Ibrahim M.; Pruden, Amy; He, Zhen

2016-01-01

Anaerobic biotechnologies can effectively remove antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), but there is a need to better understand the mechanisms. Here we employ bioelectrochemical systems (BES) as a platform to investigate the fate of a native tetracycline and sulfonamide-resistant Escherichia coli strain and its ARGs. The E. coli strain carrying intI1, sulI and tet(E) was isolated from domestic wastewater and dosed into a tubular BES. The BES was first operated as a microbial fuel cell (MFC), with aeration in the cathode, which resulted in enhanced removal of E. coli and ARGs by ~ 2 log (i.e., order of magnitude) when switched from high current to open circuit operation mode. The BES was then operated as a microbial electrolysis cell (MEC) to exclude the effects of oxygen diffusion, and the removal of E. coli and ARGs during the open circuit configuration was again 1–2 log higher than that at high current mode. Significant correlations of E. coli vs. current (R"2 = 0.73) and ARGs vs. E. coli (R"2 ranged from 0.54 to 0.87), and the fact that the BES substrate contained no electron acceptors, implied that the persistence of the E. coli and its ARGs was determined by the availability of indigenous electron acceptors in the BES, i.e., the anode electrode or the electron shuttles generated by the exoelectrogens. Subsequent experiments with pure-culture tetracycline and sulfonamide-resistant E. coli being incubated in a two-chamber MEC and serum bottles demonstrated that the E. coli could survive by respiring anode electrode and/or electron shuttles released by exoelectrogens, and ARGs persisted with their host E. coli. - Highlights: • The fate of an antibiotic resistant E. coli stain and its ARGs in BES is studied. • The removal of the E. coli and its ARGs is enhanced with decreased current. • The ARGs are removed when the host E. coli dies and persist when the host survives. • The survival of the E. coli depends on the

Effect of cold working on the stress corrosion cracking resistance of nickel-chromium-iron alloys

International Nuclear Information System (INIS)

Yonezawa, T.; Onimura, K.

1987-01-01

In order to grasp the stress corrosion cracking resistance of cold worked nickel base alloys in PWR primary water, the effect of cold working on the stress corrosion cracking resistance of alloys 600, X-750 and 690, in high temperature water, have been studied. Stress corrosion cracking tests were conducted at 360 0 C (633K) in a simulated PWR primary water for about 12,000 hours (43.2Ms). From the test results, it is concluded that the stress corrosion cracking resistance in the cold worked Alloy 600 at the same applied stress level increases with an increase in cold working ratio, and the cold worked alloys of thermally treated 690 and X-750 have excellent stress corrosion cracking resistance. (Author)

Fate of antibiotic resistant bacteria and genes during wastewater chlorination: implication for antibiotic resistance control.

Directory of Open Access Journals (Sweden)

Qing-Bin Yuan

Full Text Available This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L. The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L. By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L. However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination.

Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein

Directory of Open Access Journals (Sweden)

Stout Jeffrey R

2010-06-01

Full Text Available Abstract Regardless of age or gender, resistance training or provision of adequate amounts of dietary protein (PRO or essential amino acids (EAA can increase muscle protein synthesis (MPS in healthy adults. Combined PRO or EAA ingestion proximal to resistance training, however, can augment the post-exercise MPS response and has been shown to elicit a greater anabolic effect than exercise plus carbohydrate. Unfortunately, chronic/adaptive response data comparing the effects of different protein sources is limited. A growing body of evidence does, however, suggest that dairy PRO, and whey in particular may: 1 stimulate the greatest rise in MPS, 2 result in greater muscle cross-sectional area when combined with chronic resistance training, and 3 at least in younger individuals, enhance exercise recovery. Therefore, this review will focus on whey protein supplementation and its effects on skeletal muscle mass when combined with heavy resistance training.

Anti-cancer effect of oncolytic adenovirus-armed shRNA targeting MYCN gene on doxorubicin-resistant neuroblastoma cells.

Science.gov (United States)

Li, Yuan; Zhuo, Baobiao; Yin, Yiyu; Han, Tao; Li, Shixian; Li, Zhengwei; Wang, Jian

2017-09-09

Chemotherapy is one of the few effective choices for patients with neuroblastoma. However, the development of muti-drug resistance (MDR) to chemotherapy is a major obstacle to the effective treatment of advanced or recurrent neuroblastoma. The muti-drug resistance-associated protein (MRP), which encodes a transmembrane glycoprotein, is a key regulator of MDR. The expression of MRP is a close correlation with MYCN oncogene in neuroblastoma. We have recently shown ZD55-shMYCN (oncolytic virus armed with shRNA against MYCN) can down-regulate MYCN to inhibit tumor cells proliferation and induce apoptosis in neuroblastoma. Here we further report ZD55-shMYCN re-sensitized doxorubicin-resistant cells to doxorubicin (as shown by reduced proliferation, increased apoptosis, and inhibited cell migration), and reduced the in vivo growth rate of neuroblastoma xenografts by down-regulation of MRP expression. Sequential therapy with doxorubicin did not affect the replication of ZD55-shMYCN in doxorubicin-resistant neuroblastoma cells, but decreased the expression of Bcl-2, Bcl-X L , MMP-1. Thus, this synergistic effect of ZD55-shMYCN in combination with doxorubicin provides a novel therapy strategy for doxorubicin-resistant neuroblastoma, and is a promising approach for further clinical development. Copyright © 2017 Elsevier Inc. All rights reserved.

Global Phenotypic Characterization of Effects of Fluoroquinolone Resistance Selection on the Metabolic Activities and Drug Susceptibilities of Clostridium perfringens Strains

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Miseon Park

2014-01-01

Full Text Available Fluoroquinolone resistance affects toxin production of Clostridium perfringens strains differently. To investigate the effect of fluoroquinolone resistance selection on global changes in metabolic activities and drug susceptibilities, four C. perfringens strains and their norfloxacin-, ciprofloxacin-, and gatifloxacin-resistant mutants were compared in nearly 2000 assays, using phenotype microarray plates. Variations among mutant strains resulting from resistance selection were observed in all aspects of metabolism. Carbon utilization, pH range, osmotic tolerance, and chemical sensitivity of resistant strains were affected differently in the resistant mutants depending on both the bacterial genotype and the fluoroquinolone to which the bacterium was resistant. The susceptibilities to gentamicin and erythromycin of all resistant mutants except one increased, but some resistant strains were less susceptible to amoxicillin, cefoxitin, ceftriaxone, chloramphenicol, and metronidazole than their wild types. Sensitivity to ethidium bromide decreased in some resistant mutants and increased in others. Microarray analysis of two gatifloxacin-resistant mutants showed changes in metabolic activities that were correlated with altered expression of various genes. Both the chemical structures of fluoroquinolones and the genomic makeup of the wild types influenced the changes found in resistant mutants, which may explain some inconsistent reports of the effects of therapeutic use of fluoroquinolones on clinical isolates of bacteria.

Effects of centrifugal modification of magnetohydrodynamic equilibrium on resistive wall mode stability

International Nuclear Information System (INIS)

Shiraishi, J.; Aiba, N.; Miyato, N.; Yagi, M.

2014-01-01

Toroidal rotation effects are self-consistently taken into account not only in the linear magnetohydrodynamic (MHD) stability analysis but also in the equilibrium calculation. The MHD equilibrium computation is affected by centrifugal force due to the toroidal rotation. To study the toroidal rotation effects on resistive wall modes (RWMs), a new code has been developed. The RWMaC modules, which solve the electromagnetic dynamics in vacuum and the resistive wall, have been implemented in the MINERVA code, which solves the Frieman–Rotenberg equation that describes the linear ideal MHD dynamics in a rotating plasma. It is shown that modification of MHD equilibrium by the centrifugal force significantly reduces growth rates of RWMs with fast rotation in the order of M 2  = 0.1 where M is the Mach number. Moreover, it can open a stable window which does not exist under the assumption that the rotation affects only the linear dynamics. The rotation modifies the equilibrium pressure gradient and current density profiles, which results in the change of potential energy including rotational effects. (paper)

Genetic study of resistance to inhibitory effects of UV radiation in rice (Oryza sativa)

International Nuclear Information System (INIS)

Sato, T.; Kang, H.S.; Kumagai, T.

1994-01-01

Genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice (Oryza sativa L.) cultivars was carried out. Some experimental plants were grown in visible radiation supplemented with UV radiation containing a large amount of UV-B and a small amount of UV-C in a phytotron, while others were grown without UV radiation. The degree of resistance to UV radiation was estimated in terms of the degree of reduction caused by supplemental UV radiation in the fresh weight of the aboveground plant parts and the chlorophyll content per unit fresh weight. Fresh weight and chlorophyll content in F 2 plants generated by reciprocally crossing cv. Sasanishiki, a cultivar more resistant to UV radiation, and Norin 1, a cultivar less resistant to such radiation exhibited a normal frequency distribution. The heritabilities of these two properties in F 2 plants were low under conditions of non-supplemental UV radiation. Under elevated UV radiation, the F 2 population shifted to the lower range of fresh weight and chlorophyll content, and the means were close to those of Norin 1. The heritabilities of these two properties were the same in the reciprocal crosses, indicating that maternal inheritance was not involved. Inheritance of chlorophyll content per unit fresh weight was further determined in F 3 lines generated by self-fertilizing F 2 plants of Sasanishiki and Norin 1. The results showed that the F 3 population was segregated into three genotypes, namely, resistant homozygotes, segregated heterozygotes and sensitive homozygotes, with a ratio of 1:65:16. It was thus evident that the resistance to the inhibitory effect of elevated UV radiation in these rice plants was controlled by recessive polygenes. (author)

Effect of length and diameter of fiber reinforced composite post (FRC on fracture resistance of remaining tooth structure

Directory of Open Access Journals (Sweden)

Mahdiyeh seifi

2013-03-01

Full Text Available Introduction: Post and core has been considered for endodontically treated tooth, especially in cases with severe damage crowns. Recently fiber reinforced composite posts (FRC post have been used in the treatment of endodontically treated teeth. Because the length and diameter of posts are effective in stress distribution, the purpose of this study is to evaluate the effect of length and diameter of FRC post on fracture resistance. Methods: In this experimental study, 36 glass fiber posts with combination of 7mm, 9mm, and 12mm length and 1.1mm, 1.3mm and 1.5mm diameter were divided into 9 groups of 4. These posts were cemented in root canals by Panavia. Samples were tested with 45° compressive forces for the evaluation of fracture resistance. Datas were analyzed using SPSS soft ware and One- way and Two-way ANOVA analyses. Results: Fracture resistance did not increase significantly with the effect of length and diameter simultaneously (P=0.85. Samples with 12mm length and 1.5mm diameter had the greatest fracture resistance (1023/33N±239/22. The minimum fracture resistance had occurred in post with 7mm length and 1.5mm diameter (503/13N ±69/18. Fracture resistance increased significantly by increasing the length and the same diameter. Conclusion: It can be concluded that fracture resistance is affected by the length and not the diameter of FRC post.

The Effects of Fetal Gender on Maternal and Fetal Insulin Resistance.

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Jennifer M Walsh

Full Text Available Gender plays a role in the development of a number of cardiovascular and metabolic diseases and it has been suggested that females may be more insulin resistant in utero. We sought to assess the relationship between infant gender and insulin resistance in a large pregnancy cohort.This is a secondary analysis of a cohort from the ROLO randomized control trial of low GI diet in pregnancy. Serum insulin, glucose and leptin were measured in early pregnancy and at 28 weeks. At delivery cord blood C-peptide and leptin were measured. A comparison of maternal factors, fetal biometry, insulin resistance and leptin was made between male and female offspring. A multivariate regression model was built to account for the possible effects of maternal BMI, birthweight and original study group assignment on findings.A total of 582 women were included in this secondary analysis, of whom 304 (52.2% gave birth to male and 278 (47.8% gave birth to female infants. Compared to male infants at birth, female infants were significantly lighter, (3945 ± 436 vs. 4081± 549g, p<0.001, shorter in length (52.36 ± 2.3 vs. 53.05 ± 2.4cm, p<0.001 and with smaller head circumferences (35.36 ± 1.5 vs. 36.10 ± 1.1cm, p<0.001 than males. On multiple regression analysis, women pregnant with female fetuses were less insulin resistant in early pregnancy, i.e. had lower HOMA indices (B = -0.19, p = 0.01. Additionally female fetuses had higher concentrations of both cord blood leptin and C-peptide at birth when compared to male offspring (B = 0.38, p<0.001 and B = 0.31, p = 0.03 respectively.These findings suggest gender is a risk factor for insulin resistance in-utero. Additionally, carrying a female fetus decreases the risk of insulin resistance in the mother, from as early as the first trimester.

The Effects of Fetal Gender on Maternal and Fetal Insulin Resistance.

Science.gov (United States)

Walsh, Jennifer M; Segurado, Ricardo; Mahony, Rhona M; Foley, Michael E; McAuliffe, Fionnuala M

2015-01-01

Gender plays a role in the development of a number of cardiovascular and metabolic diseases and it has been suggested that females may be more insulin resistant in utero. We sought to assess the relationship between infant gender and insulin resistance in a large pregnancy cohort. This is a secondary analysis of a cohort from the ROLO randomized control trial of low GI diet in pregnancy. Serum insulin, glucose and leptin were measured in early pregnancy and at 28 weeks. At delivery cord blood C-peptide and leptin were measured. A comparison of maternal factors, fetal biometry, insulin resistance and leptin was made between male and female offspring. A multivariate regression model was built to account for the possible effects of maternal BMI, birthweight and original study group assignment on findings. A total of 582 women were included in this secondary analysis, of whom 304 (52.2%) gave birth to male and 278 (47.8%) gave birth to female infants. Compared to male infants at birth, female infants were significantly lighter, (3945 ± 436 vs. 4081± 549g, p<0.001), shorter in length (52.36 ± 2.3 vs. 53.05 ± 2.4cm, p<0.001) and with smaller head circumferences (35.36 ± 1.5 vs. 36.10 ± 1.1cm, p<0.001) than males. On multiple regression analysis, women pregnant with female fetuses were less insulin resistant in early pregnancy, i.e. had lower HOMA indices (B = -0.19, p = 0.01). Additionally female fetuses had higher concentrations of both cord blood leptin and C-peptide at birth when compared to male offspring (B = 0.38, p<0.001 and B = 0.31, p = 0.03 respectively). These findings suggest gender is a risk factor for insulin resistance in-utero. Additionally, carrying a female fetus decreases the risk of insulin resistance in the mother, from as early as the first trimester.

Effects of chlortetracycline and copper supplementation on antimicrobial resistance of fecal Escherichia coli from weaned pigs.

Science.gov (United States)

Agga, G E; Scott, H M; Amachawadi, R G; Nagaraja, T G; Vinasco, J; Bai, J; Norby, B; Renter, D G; Dritz, S S; Nelssen, J L; Tokach, M D

2014-06-01

Feed-grade chlortetracycline (CTC) and copper are both widely utilized in U.S. pig production. Cluster randomized experiment was conducted to evaluate the effects of CTC and copper supplementation in weaned pigs on antimicrobial resistance (AMR) among fecal Escherichia coli. Four treatment groups: control, copper, CTC, or copper plus CTC were randomly allocated to 32 pens with five pigs per pen. Fecal samples were collected weekly from three pigs per pen for six weeks. Two E. coli isolates per fecal sample were tested for phenotypic and genotypic resistance against antibiotics and copper. Data were analyzed with multilevel mixed effects logistic regression, multivariate probit analysis and discrete time survival analysis. CTC-supplementation was significantly (99% [95% CI=98-100%]) associated with increased tetracycline resistance compared to the control group (95% [95% CI=94-97%]). Copper supplementation was associated with decreased resistance to most of the antibiotics tested, including cephalosporins, over the treatment period. Overall, 91% of the E. coli isolates were multidrug resistant (MDR) (resistant to ≥3 antimicrobial classes). tetA and blaCMY-2 genes were positively associated (PpcoD were negatively associated with MDR. tetA and blaCMY-2 were positively associated with each other and in turn, these were negatively associated with both tetB and pcoD genes; which were also positively associated with one another. Copper minimum inhibitory concentration was not affected by copper supplementation or by pcoD gene carriage. CTC supplementation was significantly associated with increased susceptibilities of E. coli to copper (HR=7 [95% CI=2.5-19.5]) during treatment period. In conclusion, E. coli isolates from the nursery pigs exhibited high levels of antibiotic resistance, with diverse multi-resistant phenotypic profiles. The roles of copper supplementation in pig production, and pco-mediated copper resistance among E. coli in particular, need to be further

Effect of interstitial impurities on the field dependent microwave surface resistance of niobium

Science.gov (United States)

Martinello, M.; Grassellino, A.; Checchin, M.; Romanenko, A.; Melnychuk, O.; Sergatskov, D. A.; Posen, S.; Zasadzinski, J. F.

2016-08-01

Previous work has demonstrated that the radio frequency surface resistance of niobium resonators is dramatically reduced when nitrogen impurities are dissolved as interstitial in the material. This effect is attributed to the lowering of the Mattis-Bardeen surface resistance with increasing accelerating field; however, the microscopic origin of this phenomenon is poorly understood. Meanwhile, an enhancement of the sensitivity to trapped magnetic field is typically observed for such cavities. In this paper, we conduct a systematic study on these different components contributing to the total surface resistance as a function of different levels of dissolved nitrogen, in comparison with standard surface treatments for niobium resonators. Adding these results together, we are able to show which is the optimum surface treatment that maximizes the Q-factor of superconducting niobium resonators as a function of expected trapped magnetic field in the cavity walls. These results also provide insights on the physics behind the change in the field dependence of the Mattis-Bardeen surface resistance, and of the trapped magnetic vortex induced losses in superconducting niobium resonators.

Surface effects of electrode-dependent switching behavior of resistive random-access memory

KAUST Repository

Ke, Jr Jian

2016-09-26

The surface effects of ZnO-based resistive random-access memory (ReRAM) were investigated using various electrodes. Pt electrodes were found to have better performance in terms of the device\\'s switching functionality. A thermodynamic model of the oxygen chemisorption process was proposed to explain this electrode-dependent switching behavior. The temperature-dependent switching voltage demonstrates that the ReRAM devices fabricated with Pt electrodes have a lower activation energy for the chemisorption process, resulting in a better resistive switching performance. These findings provide an in-depth understanding of electrode-dependent switching behaviors and can serve as design guidelines for future ReRAM devices.

Resistance to Powdery Mildews

DEFF Research Database (Denmark)

Siwoszek, Agnieszka Izabela

in majority of them. Resistance to barley powdery mildew in the field is controlled by use of resistant varieties in a combination with fungicides. Early disease management is crucial for effective control. Yet, the pathogen commonly develops fungicide resistance due to simple point mutations. Several studies...... protection. In the present study, I provide an overview of the current knowledge about plant pathogens and plant disease resistance. I use Arabidopsis as a model to investigate the mechanism of non-host resistance, presumed to be the most durable and broad-spectrum form of resistance. I attempt to determine...

Postactivation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats on Short Sprint Performance.

Science.gov (United States)

Wyland, Timothy P; Van Dorin, Joshua D; Reyes, G Francis Cisco

2015-11-01

Applying accommodating resistance combined with isoinertial resistance has been demonstrated to be effective in improving neuromuscular attributes important for sport performance. The main purpose of this study was to determine whether short sprints can be acutely enhanced after several sets of back squats with or without accommodating resistance. Twenty recreationally resistance-trained males (age: 23.3 ± 4.4 years; height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) performed pre-post testing on 9.1-m sprint time. Three different interventions were implemented in randomized order between pre-post 9.1-m sprints. On 3 separate days, subjects either sat for 5 minutes (CTRL), performed 5 sets of 3 repetitions at 85% of their 1 repetition maximum (1RM) with isoinertial load (STND), or performed 5 sets of 3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from elastic band tension (BAND) between pre-post 9.1-m sprint testing. Posttesting for 9.1-m sprint time occurred immediately after the last set of squats (Post-Immediate) and on every minute for 4 minutes after the last set of squats (Post-1min, Post-2min, Post-3min, and Post-4min). Repeated-measures analysis of variance statistical analyses revealed no significant changes in sprint time across posttesting times during the CTRL and STND condition. During the BAND condition, sprint time significantly decreased from Post-Immediate to Post-4min (p = 0.002). The uniqueness of accommodating resistance could create an optimal postactivation potentiation effect to increase neuromuscular performance. Coaches and athletes can implement heavy accommodating resistance exercises to their warm-up when improving acute sprint time is desired.

The perspectives of polygenic resistance in breeding for durable disease resistance

NARCIS (Netherlands)

Lindhout, P.

2002-01-01

Polygenic resistance is generally quantitative without clear race specific effects. With the onset of molecular markers technologies, the identification of chromosome regions that are involved in quantitative resistance has become feasible. These regions are designated quantitative trait loci

Effect of tetracycline dose and treatment-mode on selection of resistant coliform bacteria in nursery pigs

DEFF Research Database (Denmark)

Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders

2017-01-01

This study describes results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on selection of antibiotic resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4-7 weeks of age) were treated...... with oxytetracycline against Lawsonia intracellularis induced diarrhea in five pig herds. Each group was randomly allocated to one of five treatment groups: oral flock treatment with (i) high (20 mg/kg), (ii) medium (10 mg/kg) and (iii) low (5 mg/kg) dosage, (iv) oral-pen-wise (small group) treatment (10 mg...... significant changes in number or proportion of tetracycline resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant, but not to cefotaxime-resistant strains. In conclusion, difference in dose of oxytetracycline...

Effect of simulated resistance, fleeing, and use of force on standardized field sobriety testing.

Science.gov (United States)

Ho, Jeffrey; Dawes, Donald; Nystrom, Paul; Moore, Johanna; Steinberg, Lila; Tilton, Annemarie; Miner, James

2015-07-01

When a law enforcement officer (LEO) stops a suspect believed to be operating (a vehicle) while impaired (OWI), the suspect may resist or flee, and the LEO may respond with force. The suspect may then undergo a Standardized Field Sobriety Test (SFST) to gauge impairment. It is not known whether resistance, fleeing, or actions of force can create an inaccurate SFST result. We examined the effect of resistance, fleeing, and force on the SFST. Human volunteers were prospectively randomized to have a SFST before and after one of five scenarios: (1) five-second conducted electrical weapon exposure; (2) 100-yard (91.4 m) sprint; (3) 45-second physical fight; (4) police dog bite with protective gear; and (5) Oleoresin Capsicum spray to the face with eyes shielded. The SFST was administered and graded by a qualified LEO. After the SFST, the volunteer entered their scenario and was then administered another SFST. Data were analyzed using descriptive statistics. SFST performance was compared before and after using chi-square tests. Fifty-seven subjects enrolled. Three received a single-point penalty during one component of the three-component SFST pre-scenario. No subject received a penalty point in any components of the SFST post-scenario (p = 0.08). This is the first human study to examine the effects of physical resistance, flight, and use of force on the SFST result. We did not detect a difference in the performance of subjects taking the SFST before and after exposure to resistance, flight, or a simulated use of force. © Australian Council for Educational Research 2014.

MRP- and BCL-2-mediated drug resistance in human SCLC: effects of apoptotic sphingolipids in vitro.

Science.gov (United States)

Khodadadian, M; Leroux, M E; Auzenne, E; Ghosh, S C; Farquhar, D; Evans, R; Spohn, W; Zou, Y; Klostergaard, J

2009-10-01

Multidrug-resistance-associated protein (MRP) and BCL-2 contribute to drug resistance expressed in SCLC. To establish whether MRP-mediated drug resistance affects sphingolipid (SL)-induced apoptosis in SCLC, we first examined the human SCLC cell line, UMCC-1, and its MRP over-expressing, drug-resistant subline, UMCC-1/VP. Despite significantly decreased sensitivity to doxorubicin (Dox) and to the etoposide, VP-16, the drug-selected line was essentially equally as sensitive to treatment with exogenous ceramide (Cer), sphingosine (Sp) or dimethyl-sphingosine (DMSP) as the parental line. Next, we observed that high BCL-2-expressing human H69 SCLC cells, that were approximately 160-fold more sensitive to Dox than their combined BCL-2 and MRP-over-expressing (H69AR) counterparts, were only approximately 5-fold more resistant to DMSP. Time-lapse fluorescence microscopy of either UMCC cell line treated with DMSP-Coumarin revealed comparable extents and kinetics of SL uptake, further ruling out MRP-mediated effects on drug uptake. DMSP potentiated the cytotoxic activity of VP-16 and Taxol, but not Dox, in drug-resistant UMCC-1/VP cells. However, this sensitization did not appear to involve DMSP-mediated effects on the function of MRP in drug export; nor did DMSP strongly shift the balance of pro-apoptotic Sps and anti-apoptotic Sp-1-Ps in these cells. We conclude that SL-induced apoptosis markedly overcomes or bypasses MRP-mediated drug resistance relevant to SCLC and may suggest a novel therapeutic approach to chemotherapy for these tumors.

Antibiotic and synergistic effect of Leu-Lys rich peptide against antibiotic resistant microorganisms isolated from patients with cholelithiasis.

Science.gov (United States)

Jeong, Nari; Kim, Jin-Young; Park, Seong-Cheol; Lee, Jong-Kook; Gopal, Ramamourthy; Yoo, Suyeon; Son, Byoung Kwan; Hahm, Joon Soo; Park, Yoonkyung; Hahm, Kyung-Soo

2010-09-03

Pseudomonas aeruginosa has eventually developed resistance against flomoxef sodium, isepamicin and cefpiramide. Therefore, in this study, the antibacterial activity and synergistic effects of the amphipathic-derived P5-18mer antimicrobial peptide were tested against pathogens associated with cholelithiasis that have developed resistance against commonly used antibiotics. The results were then compared with the activities of the amphipathic-derived peptide, P5-18mer, melittin and common antibiotics. Growth inhibition of planktonic bacteria was tested using the National Committee for Clinical Laboratory Standards (NCCLS). The bactericidal activity of the antimicrobial peptides was measured using time-kill curves. Synergistic effects were evaluated by testing the effects of P5-18mer alone and in combination with flomoxef sodium, isepamicin or cefpiramide at 0.5xMIC. P5-18mer peptide displayed strong activity against pathogens and flomoxef sodium, isepamicin and cefpiramide-resistant bacteria cell lines obtained from a patient with gallstones; however, it did not exert cytotoxicity against the human keratinocyte HaCat cell line. In addition, the results of time-kill curves indicated that P5-18mer peptide exerted bactericidal activity against four strains of P. aeruginosa. Finally, the use of P5-18mer and antibiotics exerted synergistic effects against cell lines that were resistant to commonly used antibiotics. These results indicate that this class of peptides has a rapid microbicidal effect on flomoxef sodium, isepamicin and cefpiramide-resistant strains of P. aeruginosa. Therefore, these peptides may be used as a lead drug for the treatment of acquired pathogens from patients with cholelithiasis who are affected with antibiotic-resistant bacteria. Copyright 2010 Elsevier Inc. All rights reserved.

Effect of aspirin or resistant starch on colorectal neoplasia in the Lynch syndrome.

Science.gov (United States)

Burn, John; Bishop, D Timothy; Mecklin, Jukka-Pekka; Macrae, Finlay; Möslein, Gabriela; Olschwang, Sylviane; Bisgaard, Marie-Luise; Ramesar, Raj; Eccles, Diana; Maher, Eamonn R; Bertario, Lucio; Jarvinen, Heikki J; Lindblom, Annika; Evans, D Gareth; Lubinski, Jan; Morrison, Patrick J; Ho, Judy W C; Vasen, Hans F A; Side, Lucy; Thomas, Huw J W; Scott, Rodney J; Dunlop, Malcolm; Barker, Gail; Elliott, Faye; Jass, Jeremy R; Fodde, Ricardo; Lynch, Henry T; Mathers, John C

2008-12-11

Observational and epidemiologic data indicate that the use of aspirin reduces the risk of colorectal neoplasia; however, the effects of aspirin in the Lynch syndrome (hereditary nonpolyposis colon cancer) are not known. Resistant starch has been associated with an antineoplastic effect on the colon. In a randomized, placebo-controlled trial, we used a two-by-two design to investigate the effects of aspirin, at a dose of 600 mg per day, and resistant starch (Novelose), at a dose of 30 g per day, in reducing the risk of adenoma and carcinoma among persons with the Lynch syndrome. Among 1071 persons in 43 centers, 62 were ineligible to participate in the study, 72 did not enter the study, and 191 withdrew from the study. These three categories were equally distributed across the study groups. Over a mean period of 29 months (range, 7 to 74), colonic adenoma or carcinoma developed in 141 participants. Of 693 participants randomly assigned to receive aspirin or placebo, neoplasia developed in 66 participants receiving aspirin (18.9%), as compared with 65 receiving placebo (19.0%) (relative risk, 1.0; 95% confidence interval [CI], 0.7 to 1.4). There were no significant differences between the two groups with respect to the development of advanced neoplasia (7.4% and 9.9%, respectively; P=0.33). Among the 727 participants receiving resistant starch or placebo, neoplasia developed in 67 participants receiving starch (18.7%), as compared with 68 receiving placebo (18.4%) (relative risk, 1.0; 95% CI, 0.7 to 1.4). Advanced adenomas and colorectal cancers were evenly distributed in the two groups. The prevalence of serious adverse events was low, and the events were evenly distributed. The use of aspirin, resistant starch, or both for up to 4 years has no effect on the incidence of colorectal adenoma or carcinoma among carriers of the Lynch syndrome. (Current Controlled Trials number, ISRCTN59521990.) 2008 Massachusetts Medical Society

The effects of elastic tubing-based resistance training compared with conventional resistance training in patients with moderate chronic obstructive pulmonary disease: a randomized clinical trial.

Science.gov (United States)

Ramos, Ercy Mara Cipulo; de Toledo-Arruda, Alessandra Choqueta; Fosco, Luciana Cristina; Bonfim, Rafaela; Bertolini, Giovana Navarro; Guarnier, Flavia Alessandra; Cecchini, Rubens; Pastre, Carlos Marcelo; Langer, Daniel; Gosselink, Rik; Ramos, Dionei

2014-11-01

To investigate the effects of elastic tubing training compared with conventional resistance training on the improvement of functional exercise capacity, muscle strength, fat-free mass, and systemic inflammation in patients with chronic obstructive pulmonary disease. A prospective, randomized, eight-week clinical trial. The study was conducted in a university-based, outpatient, physical therapy clinic. A total of 49 patients with moderate chronic obstructive pulmonary disease. Participants were randomly assigned to perform elastic tubing training or conventional resistance training three times per week for eight weeks. The primary outcome measure was functional exercise capacity. The secondary outcome measures were peripheral muscle strength, health-related quality of life assessed by the Chronic Respiratory Disease Questionnaire (CRDQ), fat-free mass, and cytokine profile. After eight weeks, the mean distance covered during six minutes increased by 73 meters (±69) in the elastic tubing group and by 42 meters (±59) in the conventional group (p tubing training had a greater effect on functional exercise capacity than conventional resistance training. Both interventions were equally effective in improving muscle strength and quality of life. © The Author(s) 2014.

Effect of surface treatment on the interfacial contact resistance and corrosion resistance of Fe–Ni–Cr alloy as a bipolar plate for polymer electrolyte membrane fuel cells

International Nuclear Information System (INIS)

Yang, Meijun; Zhang, Dongming

2014-01-01

The bipolar plate is an important component of the PEMFC (polymer electrolyte membrane fuel cell) because it supplies the pathway of electron flow between each unit cell. Fe–Ni–Cr alloy is considered as a good candidate material for bipolar plate, but it is limited to use as a bipolar plate due to its high ICR (interfacial contact resistance) and corrosion problem. In order to explore a cost-effective method on surface modification, various chemical and electrochemical treatments are performed on Fe–Ni–Cr alloy to acquire the effect of the surface modification on the ICR and corrosion behavior. The ICR and corrosion resistance of Fe–Ni–Cr alloy can be effectively controlled by the chemical treatment of immersion in the mixed acid solution with 10 vol% HNO 3 , 2 vol% HCl and 1 vol% HF for 10 min at 65 °C and then was placed in 30 vol% HNO 3 solution for 5 min. The chemical treatment is more effective on reducing ICR and improving corrosion resistance than that of electrochemical methods (be carried out in the 2 mol/L H 2 SO 4 solution with the electrical potential from −0.4 V to 0.6 V) for Fe–Ni–Cr alloy as a bipolar plate for polymer electrolyte membrane fuel cells. - Highlights: • The procedure of the surface treatments on Fe–Ni–Cr alloy as bipolar plate was described in detail. • Effects of various surface treatments on the interfacial contact resistivity and corrosion behavior were discussed. • The mechanism of the surface modification was particularly analyzed

Non-destructive reversible resistive switching in Cr doped Mott insulator Ca2RuO4: Interface vs bulk effects

Science.gov (United States)

Shen, Shida; Williamson, Morgan; Cao, Gang; Zhou, Jianshi; Goodenough, John; Tsoi, Maxim

2017-12-01

A non-destructive reversible resistive switching is demonstrated in single crystals of Cr-doped Mott insulator Ca2RuO4. An applied electrical bias was shown to reduce the DC resistance of the crystal by as much as 75%. The original resistance of the sample could be restored by applying an electrical bias of opposite polarity. We have studied this resistive switching as a function of the bias strength, applied magnetic field, and temperature. A combination of 2-, 3-, and 4-probe measurements provide a means to distinguish between bulk and interfacial contributions to the switching and suggests that the switching is mostly an interfacial effect. The switching was tentatively attributed to electric-field driven lattice distortions which accompany the impurity-induced Mott transition. This field effect was confirmed by temperature-dependent resistivity measurements which show that the activation energy of this material can be tuned by an applied DC electrical bias. The observed resistance switching can potentially be used for building non-volatile memory devices like resistive random access memory.

Non-destructive reversible resistive switching in Cr doped Mott insulator Ca2RuO4: Interface vs bulk effects

KAUST Repository

Shen, Shida

2017-12-29

A non-destructive reversible resistive switching is demonstrated in single crystals of Cr-doped Mott insulator Ca2RuO4. An applied electrical bias was shown to reduce the DC resistance of the crystal by as much as 75%. The original resistance of the sample could be restored by applying an electrical bias of opposite polarity. We have studied this resistive switching as a function of the bias strength, applied magnetic field, and temperature. A combination of 2-, 3-, and 4-probe measurements provide a means to distinguish between bulk and interfacial contributions to the switching and suggests that the switching is mostly an interfacial effect. The switching was tentatively attributed to electric-field driven lattice distortions which accompany the impurity-induced Mott transition. This field effect was confirmed by temperature-dependent resistivity measurements which show that the activation energy of this material can be tuned by an applied DC electrical bias. The observed resistance switching can potentially be used for building non-volatile memory devices like resistive random access memory.

Metagenomic insights into chlorination effects on microbial antibiotic resistance in drinking water.

Science.gov (United States)

Shi, Peng; Jia, Shuyu; Zhang, Xu-Xiang; Zhang, Tong; Cheng, Shupei; Li, Aimin

2013-01-01

This study aimed to investigate the chlorination effects on microbial antibiotic resistance in a drinking water treatment plant. Biochemical identification, 16S rRNA gene cloning and metagenomic analysis consistently indicated that Proteobacteria were the main antibiotic resistant bacteria (ARB) dominating in the drinking water and chlorine disinfection greatly affected microbial community structure. After chlorination, higher proportion of the surviving bacteria was resistant to chloramphenicol, trimethoprim and cephalothin. Quantitative real-time PCRs revealed that sulI had the highest abundance among the antibiotic resistance genes (ARGs) detected in the drinking water, followed by tetA and tetG. Chlorination caused enrichment of ampC, aphA2, bla(TEM-1), tetA, tetG, ermA and ermB, but sulI was considerably removed (p water chlorination could concentrate various ARGs, as well as of plasmids, insertion sequences and integrons involved in horizontal transfer of the ARGs. Water pipeline transportation tended to reduce the abundance of most ARGs, but various ARB and ARGs were still present in the tap water, which deserves more public health concerns. The results highlighted prevalence of ARB and ARGs in chlorinated drinking water and this study might be technologically useful for detecting the ARGs in water environments. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of nano-oxide particle size on radiation resistance of iron–chromium alloys

Energy Technology Data Exchange (ETDEWEB)

Xu, Weizong; Li, Lulu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Valdez, James A. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Saber, Mostafa [Department of Mechanical and Materials Engineering, Portland State University, Portland, OR 97201 (United States); Zhu, Yuntian, E-mail: ytzhu@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Koch, Carl C.; Scattergood, Ronald O. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

2016-02-15

Radiation resistance of Fe–14Cr alloys under 200 keV He irradiation at 500 °C was systematically investigated with varying sizes of nano oxide Zr, Hf and Cr particles. It is found that these nano oxide particles acted as effective sites for He bubble formation. By statistically analyzing 700–1500 He bubbles at the depth of about 150–700 nm from a series of HRTEM images for each sample, we established the variation of average He bubble size, He bubble density, and swelling percentage along the depth, and found them to be consistent with the He concentration profile calculated from the SIRM program. Oxide particles with sizes less than 3.5–4 nm are found most effective for enhancing radiation resistance in the studied alloy systems.

Effect of annealing treatments on normal state resistivity of YBa 2 ...

African Journals Online (AJOL)

Samples of YBa2(Cu1-xTix)3Oy superconductor with x=0.00 , 0.01, 0.03 have been prepared by solide state reaction method. The effect of annealing treatments on normal electrical resistivity has been done using the bipolaron model. The results of this study show the increase of localized charge when the dopant content ...

Effects of bed-load movement on flow resistance over bed forms

Indian Academy of Sciences (India)

Abstract. The effect of bed-load transport on flow resistance of alluvial channels with undulated bed was experimentally investigated. The experiments were carried out in a tilting flume 250mm wide and 12·5m long with glass-sides of rectan- gular cross-section and artificial dune shaped floor that was made from Plexi-glass.

Study of prevalence and effects of insulin resistance in patients with chronic hepatitis C genotype 4.

Science.gov (United States)

Amer, A F; Baddour, M M; Elshazly, M A; Fadally, G; Hanafi, N F; Assar, S L

2016-02-01

There is strong epidemiological evidence linking hepatitis C virus (HCV) infection and diabetes. Our aim was to evaluate the prevalence of insulin resistance in Egyptian patients with chronic HCV genotype 4 infection, to assess factors associated with insulin resistance and to test the impact of insulin resistance on outcomes of treatment with pegylated interferon/ribavirin. Insulin resistance [homeostasis model assessmentinsulin resistance (HOMA-IR) score > 3.0] was detected in 31 of 100 nondiabetic patients. The relationship between elevated HOMA-IR and baseline viral load and degree of fibrosis was statistically significant (r = 0.218 and r = 0.223). Follow-up of patients with complete early virological response until the end of treatment showed a statistically significant decrease in HOMA-IR score. Out of 29 liver tissue sections examined, 14 had a low level of expression of insulin receptor type 1 by immunohistochemical studies. This study confirms that insulin resistance affects treatment outcome, and thus HOMA-IR testing before initiation of therapy may be a cost-effective tool.

Recessive Resistance to Plant Viruses: Potential Resistance Genes Beyond Translation Initiation Factors

Directory of Open Access Journals (Sweden)

Masayoshi Hashimoto

2016-10-01

Full Text Available The ability of plant viruses to propagate their genomes in host cells depends on many host factors. In the absence of an agrochemical that specifically targets plant viral infection cycles, one of the most effective methods for controlling viral diseases in plants is taking advantage of the host plant’s resistance machinery. Recessive resistance is conferred by a recessive gene mutation that encodes a host factor critical for viral infection. It is a branch of the resistance machinery and, as an inherited characteristic, is very durable. Moreover, recessive resistance may be acquired by a deficiency in a negative regulator of plant defense responses, possibly due to the autoactivation of defense signaling. Eukaryotic translation initiation factor (eIF 4E and eIF4G and their isoforms are the most widely exploited recessive resistance genes in several crop species, and they are effective against a subset of viral species. However, the establishment of efficient, recessive resistance-type antiviral control strategies against a wider range of plant viral diseases requires genetic resources other than eIF4Es. In this review, we focus on recent advances related to antiviral recessive resistance genes evaluated in model plants and several crop species. We also address the roles of next-generation sequencing and genome editing technologies in improving plant genetic resources for recessive resistance-based antiviral breeding in various crop species.

Synergistic Effect of Fluconazole and Calcium Channel Blockers against Resistant Candida albicans.

Directory of Open Access Journals (Sweden)

Shuyuan Liu

Full Text Available Candidiasis has increased significantly recently that threatens patients with low immunity. However, the number of antifungal drugs on the market is limited in comparison to the number of available antibacterial drugs. This fact, coupled with the increased frequency of fungal resistance, makes it necessary to develop new therapeutic strategies. Combination drug therapy is one of the most widely used and effective strategy to alleviate this problem. In this paper, we were aimed to evaluate the combined antifungal effects of four CCBs (calcium channel blockers, amlodipine (AML, nifedipine (NIF, benidipine (BEN and flunarizine (FNZ with fluconazole against C. albicans by checkerboard and time-killing method. In addition, we determined gene (CCH1, MID1, CNA1, CNB1, YVC1, CDR1, CDR2 and MDR1 expression by quantitative PCR and investigated the efflux pump activity of resistant candida albicans by rhodamine 6G assay to reveal the potential mechanisms. Finally, we concluded that there was a synergy when fluconazole combined with the four tested CCBs against resistant strains, with fractional inhibitory concentration index (FICI <0.5, but no interaction against sensitive strains (FICI = 0.56 ~ 2. The mechanism studies revealed that fluconazole plus amlodipine caused down-regulating of CNA1, CNB1 (encoding calcineurin and YVC1 (encoding calcium channel protein in vacuole membrane.

Effective treatment with a tetrandrine/chloroquine combination for chloroquine-resistant falciparum malaria in Aotus monkeys

Science.gov (United States)

2013-01-01

Background In vitro evidence indicates that tetrandrine (TT) can potentiate the action of chloroquine 40-fold against choloquine-resistant Plasmodium falciparum. The key question emanating from that study is “would tetrandine and chloroquine be highly effective in a live Aotus monkey model with chloroquine-resistant parasites”. This study was designed to closely mimic the pharmacological/anti-malarial activity in man. Methods The Vietnam Smith/RE strain of P. falciparum, which is chloroquine-resistant was used in this study. Previous experimental procedures were followed. Panamanian owl monkeys (Aotus) were inoculated with 5×106 erythrocytes parasitized with the CQ-resistant strain of P. falciparum. Oral drug treatment was with CQ (20 mg/kg) and/or tetrandrine at 15 mg/Kg, 30 mg/Kg or 60 mg/Kg or 25 mg/Kg depending on experimental conditions. Results and Discussion Parasitaemia was cleared rapidly with CQ and TT while CQ treatment alone was ineffective. Recrudescence of malaria occurred after seven days post-infection. However, four animals were treated orally with TT and CQ parasites were cleared. It is likely that monkeys were cured via a combination of both drug and host immune responses. A single Aotus monkey infected with P. falciparum and untreated with drugs, died. No side effects were observed with these drug treatments. Conclusions This combination of chloroquine and tetrandrine forms the basis of a new attack on chloroquine-resistant malaria - one based upon inhibition of the basis of chloroquine resistance, the multiple drug resistance pump. Previous studies demonstrated that the parasite MDR pump was found on parasite membranes using 3H azidopine photoaffinity labelling. Since MDR-based choloroquine resistance is induced by chloroquine, the basis of the action of tetrandrine is the following: 1) tetrandrine inhibits the MDR pump by stimulating MDR ATPase which limits the energy of the pump by depletion of parasite ATP, 2) tetrandrine blocks the

Resistance Elasticity of Antibiotic Demand in Intensive Care.

Science.gov (United States)

Heister, Thomas; Hagist, Christian; Kaier, Klaus

2017-07-01

The emergence and spread of antimicrobial resistance (AMR) is still an unresolved problem worldwide. In intensive care units (ICUs), first-line antibiotic therapy is highly standardized and widely empiric while treatment failure because of AMR often has severe consequences. Simultaneously, there is a limited number of reserve antibiotics, whose prices and/or side effects are substantially higher than first-line therapy. This paper explores the implications of resistance-induced substitution effects in ICUs. The extent of such substitution effects is shown in a dynamic fixed effect regression analysis using a panel of 66 German ICUs with monthly antibiotic use and resistance data between 2001 and 2012. Our findings support the hypothesis that demand for reserve antibiotics substantially increases when resistance towards first-line agents rises. For some analyses the lagged effect of resistance is also significant, supporting the conjecture that part of the substitution effect is caused by physicians changing antibiotic choices in empiric treatment by adapting their resistance expectation to new information on resistance prevalence. The available information about resistance rates allows physicians to efficiently balance the trade-off between exacerbating resistance and ensuring treatment success. However, resistance-induced substitution effects are not free of charge. These effects should be considered an indirect burden of AMR. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

ACUTE EFFECTS OF A RESISTED DYNAMIC WARM-UP PROTOCOL ON JUMPING PERFORMANCE

Science.gov (United States)

Cilli, M; Yildiz, S; Saglam, T; Camur, MH

2014-01-01

This study aimed to investigate the kinematic and kinetic changes when resistance is applied in horizontal and vertical directions, produced by using different percentages of body weight, caused by jumping movements during a dynamic warm-up. The group of subjects consisted of 35 voluntary male athletes (19 basketball and 16 volleyball players; age: 23.4 ± 1.4 years, training experience: 9.6 ± 2.7 years; height: 177.2 ± 5.7 cm, body weight: 69.9 ± 6.9 kg) studying Physical Education, who had a jump training background and who were training for 2 hours, on 4 days in a week. A dynamic warm-up protocol containing seven specific resistance movements with specific resistance corresponding to different percentages of body weight (2%, 4%, 6%, 8%, 10%) was applied randomly on non consecutive days. Effects of different warm-up protocols were assessed by pre-/post- exercise changes in jump height in the countermovement jump (CMJ) and the squat jump (SJ) measured using a force platform and changes in hip and knee joint angles at the end of the eccentric phase measured using a video camera. A significant increase in jump height was observed in the dynamic resistance warm-up conducted with different percentages of body weight (p 0.05). In jump movements before and after the warm-up, while no significant difference between the vertical ground reaction forces applied by athletes was observed (p > 0.05), in some cases of resistance, a significant reduction was observed in hip and knee joint angles (p jumping movements, as well as an increase in jump height values. As a result, dynamic warm-up exercises could be applicable in cases of resistance corresponding to 6-10% of body weight applied in horizontal and vertical directions in order to increase the jump performance acutely. PMID:25435670

Targeting the Warburg effect with a novel glucose transporter inhibitor to overcome gemcitabine resistance in pancreatic cancer cells

Science.gov (United States)

Lai, I-Lu; Chou, Chih-Chien; Lai, Po-Ting; Fang, Chun-Sheng; Shirley, Lawrence A.; Yan, Ribai; Mo, Xiaokui; Bloomston, Mark; Kulp, Samuel K.; Bekaii-Saab, Tanios; Chen, Ching-Shih

2014-01-01

Gemcitabine resistance remains a significant clinical challenge. Here, we used a novel glucose transporter (Glut) inhibitor, CG-5, as a proof-of-concept compound to investigate the therapeutic utility of targeting the Warburg effect to overcome gemcitabine resistance in pancreatic cancer. The effects of gemcitabine and/or CG-5 on viability, survival, glucose uptake and DNA damage were evaluated in gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cell lines. Mechanistic studies were conducted to determine the molecular basis of gemcitabine resistance and the mechanism of CG-5-induced sensitization to gemcitabine. The effects of CG-5 on gemcitabine sensitivity were investigated in a xenograft tumor model of gemcitabine-resistant pancreatic cancer. In contrast to gemcitabine-sensitive pancreatic cancer cells, the resistant Panc-1 and Panc-1GemR cells responded to gemcitabine by increasing the expression of ribonucleotide reductase M2 catalytic subunit (RRM2) through E2F1-mediated transcriptional activation. Acting as a pan-Glut inhibitor, CG-5 abrogated this gemcitabine-induced upregulation of RRM2 through decreased E2F1 expression, thereby enhancing gemcitabine-induced DNA damage and inhibition of cell survival. This CG-5-induced inhibition of E2F1 expression was mediated by the induction of a previously unreported E2F1-targeted microRNA, miR-520f. The addition of oral CG-5 to gemcitabine therapy caused greater suppression of Panc-1GemR xenograft tumor growth in vivo than either drug alone. Glut inhibition may be an effective strategy to enhance gemcitabine activity for the treatment of pancreatic cancer. PMID:24879635

The effect of a commercial competitive exclusion product on the selection of enrofloxacin resistance in commensal E. coli in broilers.

Science.gov (United States)

Chantziaras, Ilias; Smet, Annemieke; Filippitzi, Maria Eleni; Damiaans, Bert; Haesebrouck, Freddy; Boyen, Filip; Dewulf, Jeroen

2018-06-07

The effect of a competitive exclusion product (Aviguard ® ) on the selection of fluoroquinolone resistance in poultry was assessed in vivo in the absence or presence of fluoroquinolone treatment. Two experiments using a controlled seeder-sentinel animal model (2seeders:4sentinels per group) with one-day-old chicks were used. For both experiments,as soon as the chicks were hatched, the animals of two groups were administered Aviguard ® and two groups were left untreated. Three days later, all groups were inoculated with an enrofloxacin-susceptible commensal E. coli strain. Five days after hatching, two animals per group were inoculated either with a bacteriologically-fit or a bacteriologically non-fit enrofloxacin-resistant commensal E. coli strain. In experiment 2, all groups were orally treated for three consecutive days (Day 8-10) with enrofloxacin. Throughout the experiments, faecal excretion of all inoculated E. coli strains was determined on days 2-5-8-11-18-23 by selective plating (via spiral plater). Linear mixed models were used to assess the effect of Aviguard ® on the selection of fluoroquinolone resistance. The use of Aviguard® (penrofloxacin-resistant E. coli when no enrofloxacin treatment was administered. However, this beneficial effect disappeared (p=0.37) when the animals were treated with enrofloxacin. Similarly, bacterial fitness of the enrofloxacin-resistant E. coli strain used for inoculation had an effect (penrofloxacin resistance when no treatment was administered, whereas this effect was no longer present when enrofloxacin was administered (p =0.70). Thus, enrofloxacin treatment cancelled the beneficial effects from administrating Aviguard ® in one-day-old broiler chicks and resulted in a enrofloxacin-resistant flora.

Heavy Resistance Training and Supplementation With the Alleged Testosterone Booster Nmda has No Effect on Body Composition, Muscle Performance, and Serum Hormones Associated With the Hypothalamo-Pituitary-Gonadal Axis in Resistance-Trained Males

Directory of Open Access Journals (Sweden)

Darryn S. Willoughby

2014-03-01

Full Text Available The effects of 28 days of heavy resistance training while ingesting the alleged testosterone-boosting supplement, NMDA, were determined on body composition, muscle strength, serum cortisol, prolactin, and hormones associated with the hypothalamo-pituitary- gonadal (HPG axis. Twenty resistance-trained males engaged in 28 days of resistance training 4 times/wk while orally ingesting daily either 1.78 g of placebo (PLAC or NMDA. Data were analyzed with separate 2 x 2 ANOVA (p 0.05 or supplementation (p > 0.05. In regard to total body mass and fat-free mass, however, each was significantly increased in both groups in response to resistance training (p 0.05. In both groups, lower-body muscle strength was significantly increased in response to resistance training (p 0.05. All serum hormones (total and free testosterone, LH, GnRH, estradiol, cortisol, prolactin were unaffected by resistance training (p > 0.05 or supplementation (p > 0.05. The gonadal hormones and cortisol and prolactin were unaffected by 28 days of NMDA supplementation and not associated with the observed increases in muscle strength and mass. At the dose provided, NMDA had no effect on HPG axis activity or ergogenic effects in skeletal muscle.

A note on the effective medium theory of random resistive-reactive medium

International Nuclear Information System (INIS)

Kumar, N.; Jayannavar, A.M.

1981-06-01

The effective medium theory for a system with randomly distributed point conductivity and polarizability is re-formulated, with attention to cross-terms involving the two disorder parameters. The treatment reveals a certain inconsistency of the conventional theory owing to the neglect of the Maxwell-Wagner effect. The results are significant for the critical resistivity and dielectric anomalies of a binary liquid mixture at the phase-separation point. (author)

Effects of rational surface density on resistive g turbulence

International Nuclear Information System (INIS)

Beklemishev, A.D.; Sugama, H.; Horton, W.

1993-01-01

The Beklemishev-Horton theory states that the anomalous transport coefficient is proportional to the density of rational surfaces provided that the interaction between the modes localized around different rational surfaces is weak compared with modes of the same helicity. The authors examine the effects of the density of states ρ using resistive g turbulence in 2D (single-helicity) and 3D (multi-helicity) simulations. They find that the modes with different helicities do not equipartition the available energy, but rather the coalescence or inverse cascade effect is strong so that a few low order mode rational surfaces receive most of the energy. The quasilinear flattening at the surfaces is a strong effect and they use bifurcation theory to derive that the effective diffusivity increases as χ eff = χ 0 ρ/(1 - Cρ) where C is a constant determined by interaction integrals. For a sufficiently high density of states Cρ ≤ 1, the higher order nonlinear interaction must be taken into account

Effect of combined aerobic and resistance training in body composition of obese postmenopausal women

Directory of Open Access Journals (Sweden)

Fabrício E. Rossi

2015-03-01

Full Text Available The aim of this study was to investigate the effects of a 16-week program of combined aerobic and resistance training on the body composition of postmenopausal women who are obese. The participants were divided into two groups: training group (TG, n = 37 and non-trained control group (CG, n = 18. The trunk fat, fat mass, percentage of fat mass and fat-free mass were estimated using DXA. Three nonconsecutive 24-hour dietary recalls were conducted. The training protocol consisted of 50 minutes of resistance training followed by 30 minutes of aerobic training. After the 16-week training program, differences were observed in trunk fat (CG= 0.064 x TG= -0.571 Kg; p-value = .020, fat mass (CG= -0.088 x TG= -1.037 Kg; p-value = .020 and fat-free mass (CG= -0.388 x TG= 1.049 Kg; p = .001. Therefore, a 16-week program of systematic combined aerobic and resistance training in obese postmenopausal women was effective in improving fat-free mass and decreasing both whole and abdominal adiposity.

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.

Significant effect of Ca2+ on improving the heat resistance of lactic acid bacteria.

Science.gov (United States)

Huang, Song; Chen, Xiao Dong

2013-07-01

The heat resistance of lactic acid bacteria (LAB) has been extensively investigated due to its highly practical significance. Reconstituted skim milk (RSM) has been found to be one of the most effective protectant wall materials for microencapsulating microorganisms during convective drying, such as spray drying. In addition to proteins and carbohydrate, RSM is rich in calcium. It is not clear which component is critical in the RSM protection mechanism. This study investigated the independent effect of calcium. Ca(2+) was added to lactose solution to examine its influence on the heat resistance of Lactobacillus rhamnosus ZY, Lactobacillus casei Zhang, Lactobacillus plantarum P8 and Streptococcus thermophilus ND03. The results showed that certain Ca(2+) concentrations enhanced the heat resistance of the LAB strains to different extents, that is produced higher survival and shorter regrowth lag times of the bacterial cells. In some cases, the improvements were dramatic. More scientifically insightful and more intensive instrumental study of the Ca(2+) behavior around and in the cells should be carried out in the near future. In the meantime, this work may lead to the development of more cost-effective wall materials with Ca(2+) added as a prime factor. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Hemibody irradiation. An effective second-line therapy in drug-resistance multiple myeloma

International Nuclear Information System (INIS)

Singer, C.R.; Tobias, J.S.; Giles, F.; Rudd, G.N.; Blackman, G.M.; Richards, J.D.

1989-01-01

The authors report the results of treatment of 41 patients with melphalan-resistant multiple myeloma using single half-body irradiation (HBI) or double half-body irradiation (DHBI). Patients were grouped using prognostic classification reported by the Medical Research Council. Patients in group I and II showed the best response to therapy with reduction in serum of urinary paraprotein and improvement in symptoms, most notably a marked reduction in bone pain. In these groups five patients have survived over 2 years after therapy. The therapeutic response appeared better in those patients who received DHBI as opposed to those whom treated with single HBI. Patients in group III did not achieve prolonged survival but effective relief of bone pain was a consistent finding in these patients also. Thus HBI represents an alternative to combination chemotherapy as second-line treatment of patients with melphalan-resistant multiple myeloma. A comparative study of HBI versus combination chemotherapy is now indicated to establish which therapeutic approach is most effective

In Vitro Evaluation of the Effect of Tooth Structure Loss on Fracture Resistance of Endodontically Treated Teeth

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Shirinzad M

2017-06-01

Full Text Available Introduction: Since preserving the structure of treated teeth is a critical success factor, studying the effects of tooth structure loss on fracture resistance of the tooth tissue appears necessary. The aim of this study was to evaluate the consequences of the loss of different tissues regarding fracture resistance of teeth undergoing root canal treatment without the use of indirect restorations. Methods :In this experimental study, 70 healthy maxillary first premolar teeth were randomly divided into 7 groups of 10 members, including control group, endodontic access preparation only, MOD cavity preparation, cutting buccal cusp, cutting palatal cusp, cutting buccal cusp and marginal ridge, and cutting the palatal cusp and marginal ridge. The coronal section of teeth was restored incrementally with light cure composite. Finally, samples underwent compressive load with 45˚ angle from each cusp slope in the middle of cusp with an instant speed of 1 mm per min in the Instron machine. Fracture resistance was measured and samples were examined under stereo-microscope to evaluate the mode of failure. Results: The resistance to fracture in root canal treated teeth in different groups in order from first to seventh was 797.13 ± 52.92, 722.50 ± 131.40, 432.15 ± 203.20, 592.66 ± 195.86 124.53 ± 33.09, 85.17 ± 18.45, and 26.03 ± 5.21 Newton. ANOVA test showed statistically significant differences between the groups in terms of their fracture resistance (P = 0.000. Conclusions: The results showed that fracture resistance levels of teeth were significantly affected by amount of their tissue loss. In this study, removal of teeth palatal cusp and marginal ridge had a significant effect on decreasing the fracture resistance, while removing the buccal cusps alone cannot have a significant effect.

Effect of paint on vapour resistivity in plaster

Directory of Open Access Journals (Sweden)

de Villanueva, L.

2008-12-01

Full Text Available The vapour resistivity of plaster coatings such as paint and their effectiveness as water repellents were studied in several types of plaster. To this end, painted, unpainted and pigmented specimens were tested. Experimental values were collected on diffusion and vapour permeability, or its inverse, water vapour resistivity.The data obtained were very useful for evaluating moisture exchange between plaster and the surrounding air, both during initial drying and throughout the life of the material. They likewise served as a basis for ensuring the proper evacuation of water vapour in walls, and use of the capacity of the porous network in plaster products to regulate moisture content or serve as a water vapour barrier to avoid condensation.Briefly, the research showed that pigments, water-based paints and silicon-based water repellents scantly raised vapour resistance. Plastic paints, enamels and lacquers, however, respectively induced five-, ten- and twenty-fold increases in vapour resistivity, on average.Se estudia el fenómeno de la resistividad al vapor de los de yeso y el efecto impermeabilizante que producen los recubrimientos de pintura sobre diversos tipos de yeso y escayola. Para ello, se ensayan probetas desnudas y recubiertas con distintos tipos de pintura, así como coloreados en masa. Se obtienen valores experimentales de la difusividad o permeabilidad al vapor o su inverso la resistividad al vapor de agua.Los datos obtenidos son muy útiles para valorar el fenómeno del intercambio de humedad entre el yeso y el ambiente, tanto durante el proceso de su secado inicial, como en el transcurso de su vida. Así como para disponer soluciones adecuadas para la evacuación del vapor de agua a través de los cerramientos, para utilizar la capacidad de regulación de la humedad, que proporciona el entramado poroso de los productos de yeso, o para impedir el paso del vapor de agua y evitar condensaciones.Como resumen de la investigación, se

Cost-effectiveness of HIV drug resistance testing to inform switching to second line antiretroviral therapy in low income settings

DEFF Research Database (Denmark)

Phillips, Andrew; Cambiano, Valentina; Nakagawa, Fumiyo

2014-01-01

BACKGROUND: To guide future need for cheap resistance tests for use in low income settings, we assessed cost-effectiveness of drug resistance testing as part of monitoring of people on first line ART - with switching from first to second line ART being conditional on NNRTI drug resistance mutations...... being identified. METHODS: An individual level simulation model of HIV transmission, progression and the effect of ART which accounts for adherence and resistance development was used to compare outcomes of various potential monitoring strategies in a typical low income setting in sub-Saharan Africa....... Underlying monitoring strategies considered were based on clinical disease, CD4 count or viral load. Within each we considered a strategy in which no further measures are performed, one with a viral load measure to confirm failure, and one with both a viral load measure and a resistance test. Predicted...

Mid-gestational serum uric acid concentration effect on neonate birth weight and insulin resistance in pregnant women.

Science.gov (United States)

Nasri, Khadijeh; Razavi, Maryamsadat; Rezvanfar, Mohammad Reza; Mashhadi, Esmat; Chehrei, Ali; Mohammadbeigi, Abolfazl

2015-01-01

To investigate the relationship between mid-gestational serum uric acid and birth weight in diabetic pregnant women with or without insulin resistance. In a prospective cohort study, fasting uric acid, blood glucose, and serum insulin were measured in 247 pregnant women between 20-22 weeks of gestational period. Insulin resistance was estimated using the homeostasis model assessment-insulin resistance (HOMA-IR). Stratification analysis and independent t-test was used to assess the association between uric acid and birth weights regarding to insulin resistance. The means of the mid-gestational serum uric acid concentrations were not significantly different in women with and without insulin resistance. But stratification analysis showed that there was a significant difference between uric acid concentration and macrosomic birth in diabetic women without insulin resistance. Higher mid - gestation serum uric acid concentration, even if it does not exceed the normal range, is accompanied by lower birth weight only in non-insulin resistance women. Insulin resistance could have a negative confounding effect on hyperuriemia and birth weight.

Effects of Elastic Resistance Exercise on Muscle Strength and Functional Performance in Healthy Adults: A Systematic Review and Meta-Analysis

NARCIS (Netherlands)

de Oliveira, Poliana Alves; Blasczyk, Juscelino Castro; Junior, Gerson Souza; Lagoa, Karina Ferreira; Soares, Milene; de Oliveira, Ricardo Jacó; Filho, Paulo José Barbosa Gutierres; Carregaro, Rodrigo Luiz; Martins, Wagner Rodrigues

2017-01-01

Background: Elastic Resistance Exercise (ERE) has already demonstrated its effectiveness in older adults and, when combined with the resistance generated by fixed loads, in adults. This review summarizes the effectiveness of ERE performed as isolated method on muscle strength and functional

Communication equipment radiation resistance ensurance

International Nuclear Information System (INIS)

Myrova, L.O.; Chelizhenko, A.Z.

1983-01-01

A review of works on radiation resistance of electronic equipment (epsilon epsilon) for 15 years is presented. The effect of ionizing radiation appearing as a result of nuclear explosions in nuclear facilities and in outerspace on epsilon epsilon has been considered. Types of radiation effects in epsilon epsilon, radiation effect on semiconductor devices and integrated circUits, types of epsilon epsilon failures, as well as the procass of radiation-resistant epsilon epsilon designing and selection of its main parameters have been described. The methods of epsilon epsilon flowsheet optimization, application of mathematical simulation and peculiarities of ensurance of epsilon epsilon radiation resistance of communication systems are considered. Peculiarities of designing of radiation-resistant quartz generators, secondary power supply sources and amplifiers are discussed

Effects of crystallographic texture on stress-migration resistance in copper thin films

International Nuclear Information System (INIS)

Koike, J.; Wada, M.; Sanada, M.; Maruyama, K.

2002-01-01

The crystallographic texture of heat-treated Cu thin films and its effects on stress-migration resistance were studied as a function of film thickness within a range of 50-900 nm. All as-deposited films had (111) texture. After heat treatment at 723 K, texture transition from (111) to (100) was observed in films of thickness greater than 300 nm. The (111) texture films after heat treatment showed severe stress migration; in contrast, the (100) texture films showed no noticeable stress migration. The observed stress-migration resistance in the (100) texture films can be attributed to the absence of twins and to lower thermal stress as compared with the (111) texture films

EFFECTS OF EXTRACTIVES AND DENSITY ON NATURAL RESISTANCE OF WOODS TO TERMITE Nasutitermes corniger

Directory of Open Access Journals (Sweden)

Juarez Benigno Paes

2015-12-01

Full Text Available The evaluation of the natural resistance of wood to wood-destroying organisms is of fundamental importance in the choice of species to be used in buildings and furniture industry. Thus, the effects of extractives and wood density on biological resistance of Acacia mangium, Casuarina equisetifolia, Corymbia torelliana, Eucalyptus cloeziana, Tectona grandis and Caesalpinia echinata woods to the xylophagous termite Nasutitermes corniger was evaluated under laboratory conditions. Test samples, with dimensions of 2.00 x 2.54 x 0.64 cm (radial x tangential x longitudinal in four positions in pith-bark direction (internal heart, intermediate heart, outer heart and sapwood were taken. The woods were exposed to termite action for 28 days in no-choice feeding test. The samples not selected for the termite test were turned into sawdust and the extractive contents were obtained using the shavings that passed through the sieve of 40 and were retained in the sieve of 60 mesh. The wood natural resistance, within the pith-bark positions, for the studied species, is not correlated with the density and extractive content. However, among the woods, those with higher density and extractive content are more resistant. The woods with greater biological resistance to the termite Nasutitermes corniger (smaller mass loss, waste and survival time of insects are Corymbia torelliana and Caesalpinia echinata and of less resistance is Casuarina equisetifolia.

Effects of particle's off-axis position, shape, orientation and entry position on resistance changes of micro Coulter counting devices

International Nuclear Information System (INIS)

Qin, Zhenpeng; Zhe, Jiang; Wang, Guo-Xiang

2011-01-01

With the recent advance in micro/nano-fabrication technology, micro Coulter counters have been widely used in detecting and characterizing micro- and nanoscale objects. In this paper, the electrical resistance change during translocation of a non-conducting particle through a channel is studied numerically. The numerical results are validated by proven analytical results available in the literature. The effects of particle's off-axis position, shape and orientation, and entry position are studied for particles with a large dynamic range. From the numerical results, a new fitted correlation is proposed that can accurately predict the resistance change caused by off-axis spherical particles regardless of their size. The shape and orientation effects of the electrical resistance change are studied by changing the axis ratio of spheroid particles and their orientation angles. Results show that a particle's shape and orientation have a significant influence on the resistance change. Simulation of an entry effect indicates that a particle starts to induce a resistance change before it enters the channel and still causes a resistance change even after the particle exits the channel completely. This study will offer some guidelines in designing and implementing Coulter counting devices and experiments, and provide insights into explaining experimental results

Effect of Rolling Resistance in Dem Models With Spherical Bodies

Directory of Open Access Journals (Sweden)

Dubina Radek

2016-12-01

Full Text Available The rolling resistance is an artificial moment arising on the contact of two discrete elements which mimics resistance of two grains of complex shape in contact rolling relatively to each other. The paper investigates the influence of rolling resistance on behaviour of an assembly of spherical discrete elements. Besides the resistance to rolling, the contacts between spherical particles obey the Hertzian law in normal straining and Coulomb model of friction in shear.

Effects of fish oil on oxidation resistance of VLDL in hypertriglyceridemic patients

NARCIS (Netherlands)

Hau, M.-F.; Smelt, A.H.M.; Bindels, A.J.G.H.; Sijbrands, E.J.G.; Laarse, A. van der; Onkenhout, W.; Duyvenvoorde, W. van; Princen, H.M.G.

1996-01-01

In hypertriglyceridemic (HTG) patients the addition of fish oil to the diet causes a marked reduction in the concentration of triglyceride-rich lipoproteins in the serum. To investigate the effects of fish oil on the oxidation resistance of VLDL and LDL in HTG patients, nine male patients received 1

Effects of heat input on the pitting resistance of Inconel 625 welds by overlay welding

Science.gov (United States)

Kim, Jun Seok; Park, Young IL; Lee, Hae Woo

2015-03-01

The objective of this study was to establish the relationship between the dilution ratio of the weld zone and pitting resistance depending on the heat input to welding of the Inconel alloy. Each specimen was produced by electroslag welding using Inconel 625 as the filler metal. In the weld zone of each specimen, dendrite grains were observed near the fusion line and equiaxed grains were observed on the surface. It was also observed that a melted zone with a high Fe content was formed around the fusion line, which became wider as the welding heat input increased. In order to evaluate the pitting resistance, potentiodynamic polarization tests and CPT tests were conducted. The results of these tests confirmed that there is no difference between the pitting resistances of each specimen, as the structures of the surfaces were identical despite the effect of the differences in the welding heat input for each specimen and the minor dilution effect on the surface.

Low-level quinolone-resistance in multi-drug resistant typhoid

Energy Technology Data Exchange (ETDEWEB)

Mirza, S H; Khan, M A [Armed Forces Inst. of Pathology, Rawalpindi (Pakistan). Dept. of Microbiolgy

2008-01-15

To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)

Low-level quinolone-resistance in multi-drug resistant typhoid

International Nuclear Information System (INIS)

Mirza, S.H.; Khan, M.A.

2008-01-01

To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)

Outwitting the series resistance in scanning spreading resistance microscopy

International Nuclear Information System (INIS)

Schulze, A.; Cao, R.; Eyben, P.; Hantschel, T.; Vandervorst, W.

2016-01-01

The performance of nanoelectronics devices critically depends on the distribution of active dopants inside these structures. For this reason, dopant profiling has been defined as one of the major metrology challenges by the international technology roadmap of semiconductors. Scanning spreading resistance microscopy (SSRM) has evolved as one of the most viable approaches over the last decade due to its excellent spatial resolution, sensitivity and quantification accuracy. However, in case of advanced device architectures like fins and nanowires a proper measurement of the spreading resistance is often hampered by the increasing impact of parasitic series resistances (e.g. bulk series resistance) arising from the confined nature of the aforementioned structures. In order to overcome this limitation we report in this paper the development and implementation of a novel SSRM mode (fast Fourier transform-SSRM: FFT-SSRM) which essentially decouples the spreading resistance from parasitic series resistance components. We show that this can be achieved by a force modulation (leading to a modulated spreading resistance signal) in combination with a lock-in deconvolution concept. In this paper we first introduce the principle of operation of the technique. We discuss in detail the underlying physical mechanisms as well as the technical implementation on a state-of-the-art atomic force microscope (AFM). We demonstrate the performance of FFT-SSRM and its ability to remove substantial series resistance components in practice. Eventually, the possibility of decoupling the spreading resistance from the intrinsic probe resistance will be demonstrated and discussed. - Highlights: • A novel electrical AFM mode for carrier profiling in confined volumes is presented. • Thereby the force and hence the contact area between AFM probe and sample is modulated. • Information on the spreading resistance is derived using a lock-in approach. • Bulk series resistance components are

Hepatic progenitor cell resistance to TGF-β1's proliferative and apoptotic effects

International Nuclear Information System (INIS)

Clark, J. Brian; Rice, Lisa; Sadiq, Tim; Brittain, Evan; Song, Lujun; Wang Jian; Gerber, David A.

2005-01-01

The success of hepatocellular therapies using stem or progenitor cell populations is dependent upon multiple factors including the donor cell, microenvironment, and etiology of the liver injury. The following experiments investigated the impact of TGF-β1 on a previously described population of hepatic progenitor cells (HPC). The majority of the hepatic progenitor cells were resistant to endogenously produced TGF-β1's proapoptotic and anti-proliferative effects unlike more well-differentiated cellular populations (e.g., mature hepatocytes). Surprisingly, in vitro TGF-β1 supplementation significantly inhibited de novo hepatic progenitor cell colony formation possibly via an indirect mechanism(s). Therefore despite the HPC's direct resistance to supplemental TGF-β1, this cytokine's inhibitory effect on colony formation could have a potential negative impact on the use of these cells as a therapy for patients with liver disease

Effect of La2O3 content on wear resistance of alumina ceramics

Institute of Scientific and Technical Information of China (English)

WU Tingting; ZHOU Jian; WU Bolin; LI Wenjie

2016-01-01

In order to improve the wear resistance, a kind of alumina ceramic with good wear resistance was created in an Al2O3-CaCO3-SiO2-MgO-La2O3 (ACSML) system. The effects of La2O3 content on sintering temperature, bulk density, and wear rate were investigated. The wear rate of sample was as low as 0.0393‰. The wear resistance of the sample containing La2O3 has im-proved 43% than that of the sample without La2O3. Appropriate La2O3 doping could inhibit grain growth, enhance density, and purify grain boundary. La2O3 could diffuse into Al2O3 to form a solid solution and react with Al2O3 to form high-aluminum low-lanthanum complex oxides. The combination among Al2O3, the solid solution layer, and the layer of high-aluminum low-lanthanum complex oxides combined closely, which could improve grain boundary cohesion. Besides, the homogeneous distributions of elements made uniform structure. Finally, the wear resistance of alumina ceramic was improved.

Biological improvement of radiation resistance

Energy Technology Data Exchange (ETDEWEB)

Chun, K J; Lee, Y K; Kim, J S; Kim, J K; Lee, S J

2000-08-01

To investigate the mechanisms of gene action related to the radiation resistance in microorganisms could be essentially helpful for the development of radiation protectants and hormeric effects of low dose radiation. This book described isolation of radiation-resistant microorganisms, induction of radiation-resistant and functionally improved mutants by gamma-ray radiation, cloning and analysis of the radiation resistance related genes and analysis of the expressed proteins of the radiation resistant related genes.

Biological improvement of radiation resistance

International Nuclear Information System (INIS)

Chun, K. J.; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.

2000-08-01

To investigate the mechanisms of gene action related to the radiation resistance in microorganisms could be essentially helpful for the development of radiation protectants and hormeric effects of low dose radiation. This book described isolation of radiation-resistant microorganisms, induction of radiation-resistant and functionally improved mutants by gamma-ray radiation, cloning and analysis of the radiation resistance related genes and analysis of the expressed proteins of the radiation resistant related genes

Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

Directory of Open Access Journals (Sweden)

Simone von Burg

Full Text Available In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew became more favourable for another pest (aphids.

Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

Science.gov (United States)

von Burg, Simone; Álvarez-Alfageme, Fernando; Romeis, Jörg

2012-01-01

In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici) and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM) mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew) became more favourable for another pest (aphids).

Studying the effect of administration route and treatment dose on the selection of enrofloxacin resistance in commensal Escherichia coli in broilers.

Science.gov (United States)

Chantziaras, Ilias; Smet, Annemieke; Haesebrouck, Freddy; Boyen, Filip; Dewulf, Jeroen

2017-07-01

Factors potentially contributing to fluoroquinolone resistance selection in commensal Escherichia coli strains in poultry were studied through a series of in vivo experiments. The effect of the initial prevalence of enrofloxacin resistance in the E. coli gut microbiota, effect of the bacterial fitness of the enrofloxacin-resistant strain and effect of treatment with enrofloxacin (effect of dose and effect of route of administration) were assessed. Four in vivo studies with broiler chickens were performed. Right after hatching, the chicks were inoculated with either a bacteriologically fit or a bacteriologically non-fit fluoroquinolone-resistant strain as either a minority or the majority of the total E. coli population. Six days later, the chicks were treated for three consecutive days either orally or parenterally and using three different doses (under-, correct- and over-dose) of enrofloxacin. The faecal shedding of E. coli strains was quantified by plating on agar plates either supplemented or not supplemented with enrofloxacin. Linear mixed models were used to assess the effect of the aforementioned variables on the selection of enrofloxacin resistance. The factors that significantly contributed were treatment ( P  <   0.001), bacterial fitness of the resistant donor strain ( P  <   0.001), administration route ( P  =   0.052) and interactions between bacterial fitness and administration route ( P  <   0.001). In the currently used models, fluoroquinolone resistance selection was influenced by treatment, bacterial fitness of the inoculation strain and administration route. The use of oral treatment seems to select more for fluoroquinolone resistance, particularly in the model where a non-fit strain was used for inoculation. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Strain-Modulated Bandgap and Piezo-Resistive Effect in Black Phosphorus Field-Effect Transistors.

Science.gov (United States)

Zhang, Zuocheng; Li, Likai; Horng, Jason; Wang, Nai Zhou; Yang, Fangyuan; Yu, Yijun; Zhang, Yu; Chen, Guorui; Watanabe, Kenji; Taniguchi, Takashi; Chen, Xian Hui; Wang, Feng; Zhang, Yuanbo

2017-10-11

Energy bandgap largely determines the optical and electronic properties of a semiconductor. Variable bandgap therefore makes versatile functionality possible in a single material. In layered material black phosphorus, the bandgap can be modulated by the number of layers; as a result, few-layer black phosphorus has discrete bandgap values that are relevant for optoelectronic applications in the spectral range from red, in monolayer, to mid-infrared in the bulk limit. Here, we further demonstrate continuous bandgap modulation by mechanical strain applied through flexible substrates. The strain-modulated bandgap significantly alters the density of thermally activated carriers; we for the first time observe a large piezo-resistive effect in black phosphorus field-effect transistors (FETs) at room temperature. The effect opens up opportunities for future development of electromechanical transducers based on black phosphorus, and we demonstrate an ultrasensitive strain gauge constructed from black phosphorus thin crystals.

Investigations into the corrosion resistance of copper aluminium alloys. Effect of phosphorus as corrosion resistant third alloying element in the ternary system CuAl20P1

International Nuclear Information System (INIS)

Allwardt, A.

1997-01-01

The effect of phosphorus on the corrosion resistance of Al-bronzes is studied in detail in this work. A literature review showed that there are a lot of things known about the microstructure and the mechanical properties of Al-bronzes. In spite of their corrosion resistance the corrosion properties and the structure of the protective oxide films of Al-bronzes were seldom a matter of interest. Systematic studies of the influence of different alloying elements on the oxide film and the corrosion properties are rare. Therefore, it is not possible to predict the corrosion resistance of Al-bronzes, made by alloying particular elements. The high corrosion resistance of the new alloy CuAl 20 P 1 was the reason to investigate the influence of phosphorus on the corrosion properties of Al-bronzes in more detail. A systematic study of the microstructure and the corrosion properties of Cu, CuP x , CuAl 20 and CuAl 20 P x offers an insight into the effect of aluminium and phosphorus on the formation of the oxide film on Al-bronzes. It was found that there exists a critical amount of 1 at.-% of phosphorus. Above and below this amount the corrosion resistance becomes worse. This behaviour could be explained by XPS-and electrochemical measurements. Although there are still some questions about the influence of phosphorus on the corrosion resistance of Al-bronzes, this work has produced some important results, which in the future may be helpful to develop new high corrosion resistant Al-bronzes more efficiently: - on clean surface Al-bronze, the oxidation of Al and Cu takes place simultaneously, - Al promotes the formation of Cu 2 O but impedes the formation of Cu(II)-oxide/-hydride in neutral solutions, - P impedes the formation of Cu 2 O and as a consequence promotes the formation of aluminium oxide. This results in a higher amount of Al in the oxide film on the surface of the alloy, which leads to a better corrosion resistance. (author) figs., tabs., 106 refs

Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic-Resistant Acne-Related Bacteria.

Science.gov (United States)

Kim, Ji-Hoon; Yu, Daeung; Eom, Sung-Hwan; Kim, Song-Hee; Oh, Junghwan; Jung, Won-Kyo; Kim, Young-Mog

2017-06-08

The object of this study was to discover an alternative therapeutic agent with fewer side effects against acne vulgaris, one of the most common skin diseases. Acne vulgaris is often associated with acne-related bacteria such as Propionibacterium acnes , Staphylococcus epidermidis , Staphylococcus aureus , and Pseudomonas aeruginosa . Some of these bacteria exhibit a resistance against commercial antibiotics that have been used in the treatment of acne vulgaris (tetracycline, erythromycin, and lincomycin). In the current study, we tested in vitro antibacterial effect of chitosan-phytochemical conjugates on acne-related bacteria. Three chitosan-phytochemical conjugates used in this study exhibited stronger antibacterial activity than that of chitosan (unmodified control). Chitosan-caffeic acid conjugate (CCA) showed the highest antibacterial effect on acne-related bacteria along with minimum inhibitory concentration (MIC; 8 to 256 μg/mL). Additionally, the MIC values of antibiotics against antibiotic-resistant P. acnes and P. aeruginosa strains were dramatically reduced in combination with CCA, suggesting that CCA would restore the antibacterial activity of the antibiotics. The analysis of fractional inhibitory concentration (FIC) indices clearly revealed a synergistic antibacterial effect of CCA with antibiotics. Thus, the median sum of FIC (∑FIC) values against the antibiotic-resistant bacterial strains ranged from 0.375 to 0.533 in the combination mode of CCA and antibiotics. The results of the present study suggested a potential possibility of chitosan-phytochemical conjugates in the control of infections related to acne vulgaris.

Effects of Eight-Weeks of Aerobic Training on Resistin Levels and Insulin Resistance in Sedentary Middle-Aged Women

Directory of Open Access Journals (Sweden)

Bahram Abedi

2017-11-01

Full Text Available Introduction: Resistin is an adipocyte-specific hormone secreted from adipose tissue which plays a significant role in the energy homeostasis and regulation of energy metabolism. The purpose of this study was to examine the effects of eight weeks of aerobic training on the resistin levels and insulin resistance in sedentary middle-aged women. Methods: In this quasi-experimental research, 20 sedentary women were randomly selected and assigned to two groups: experimental group, n=10, aged 47.70±5.35; and control, n=10, age 41.30±3.02, respectively. The participants in the training group performed an exercise protocol three times per week with the goal of 55 to 65 per cent of maximum heart rate. Before and after the completion, the resistin, insulin, glucose and insulin resistance levels were measured after 12 h of overnight fasting. Data were analyzed before and after the intervention by t-test. The significant level was defined as P≤0.05. Results: Aerobic training in compared with the control group showed significant effect in decreasing resistin levels (P=0.012, BMI (P=0.01, insulin resistance (P=0.01, and increasing VO2 max (P=0.004. Conclusion: It appears that eight weeks of aerobic training significantly changes the level of resistin and the insulin resistance index in sedentary middle-aged women. Plasma resistin may be associated with insulin resistance in sedentary women. In general, according to the results, we may say that an eight-week aerobic training with a significant reduction in plasma resistin has a preventive effect as a new and effective training method on insulin resistance in middle-aged sedentary women.

Etoxazole resistance in predatory mite Phytoseiulus persimilis A.-H. (Acari: Phytoseiidae): Cross-resistance, inheritance and biochemical resistance mechanisms.

Science.gov (United States)

Yorulmaz Salman, Sibel; Aydınlı, Fatma; Ay, Recep

2015-07-01

Phytoseiulus persimilis of the family Phytoseiidae is an effective predatory mite species that is used to control pest mites. The LC50 and LC60 values of etoxazole were determined on P. persimilis using a leaf-disc method and spraying tower. A laboratory selection population designated ETO6 was found to have a 111.63-fold resistance to etoxazole following 6 selection cycles. This population developed low cross-resistance to spinosad, spiromesifen, acetamiprid, indoxacarb, chlorantraniliprole, milbemectin and moderate cross-resistance to deltamethrin. PBO, IBP and DEM synergised resistance 3.17-, 2.85- and 3.60-fold respectively. Crossing experiments revealed that etoxazole resistance in the ETO6 population was an intermediately dominant and polygenic. In addition, detoxifying enzyme activities were increased 2.71-fold for esterase, 3.09-fold for glutathione S-transferase (GST) and 2.76-fold for cytochrome P450 monooxygenase (P450) in the ETO6 population. Selection for etoxazole under laboratory conditions resulted in the development of etoxazole resistance in the predatory mite P. persimilis that are resistant to pesticides are considered valuable for use in resistance management programmes within integrated pest control strategies. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of grain size on the corrosion resistance of pure magnesium by cooling rate-controlled solidification

Science.gov (United States)

Liu, Yichi; Liu, Debao; You, Chen; Chen, Minfang

2015-09-01

The aim of this study was to investigate the effect of grain size on the corrosion resistance of pure magnesium developed for biomedical applications. High-purity magnesium samples with different grain size were prepared by the cooling rate-controlled solidification. Electrochemical and immersion tests were employed to measure the corrosion resistance of pure magnesium with different grain size. The electrochemical polarization curves indicated that the corrosion susceptibility increased as the grain size decrease. However, the electrochemical impedance spectroscopy (EIS) and immersion tests indicated that the corrosion resistance of pure magnesium is improved as the grain size decreases. The improvement in the corrosion resistance is attributed to refine grain can produce more uniform and density film on the surface of sample.

Effect of Anthelmintic Treatment on Insulin Resistance: A Cluster-Randomized, Placebo-Controlled Trial in Indonesia

NARCIS (Netherlands)

Tahapary, D.L.; Ruiter, K. de; Martin, I.; Brienen, E.A.T.; Lieshout, L. van; Cobbaert, C.M.; Soewondo, P.; Djuardi, Y.; Wiria, A.E.; Houwing-Duistermaat, J.J.; Sartono, E.; Smit, J.W.A.; Yazdanbakhsh, M.; Supali, T.

2017-01-01

Background: Emerging evidence suggests that helminth infections are associated with lower insulin resistance (IR). Current deworming programs might remove this helminth-associated protective effect. Therefore, we evaluated the anthelmintic treatment effect on changes in IR. Methods: We conducted a

New target for rice lodging resistance and its effect in a typhoon.

Science.gov (United States)

Ishimaru, Ken; Togawa, Eiji; Ookawa, Taiichro; Kashiwagi, Takayuki; Madoka, Yuka; Hirotsu, Naoki

2008-02-01

We demonstrated the new target for lodging resistance in rice (Oryza sativa L.) by the analysis of physiological function of a locus for lodging resistance in a typhoon (lrt5) with the near isogenic line under rice "Koshihikari" genetic background (tentatively named S1). The higher lodging resistance of S1 was observed during a typhoon in September 2004 (28 days after heading), when most other plants in "Koshihikari" became lodged. Visual observations showed that bending of the upper stems triggered lodging during the typhoon; the upper stem of "Koshihikari" buckled completely, whereas that of S1 remained straight. In addition to the strong rain and winds during the typhoon, the weight of the buckled upper plant parts increased the pressure on adjacent plants and caused a domino effect in "Koshihikari". Young's modulus, an indicator of the rigidity of the culm, was significantly higher in S1 than in "Koshihikari". In the upper culm, the starch content in S1 was 4.8 times the value in "Koshihikari", and senescence was delayed in the upper leaves of S1. These results suggest that the rigidity of the upper culm by the higher starch content (as a result of delayed senescence in the upper leaves) may be responsible for the higher lodging resistance during a typhoon in rice.

Heat-resistant materials

CERN Document Server

1997-01-01

This handbook covers the complete spectrum of technology dealing with heat-resistant materials, including high-temperature characteristics, effects of processing and microstructure on high-temperature properties, materials selection guidelines for industrial applications, and life-assessment methods. Also included is information on comparative properties that allows the ranking of alloy performance, effects of processing and microstructure on high-temperature properties, high-temperature oxidation and corrosion-resistant coatings for superalloys, and design guidelines for applications involving creep and/or oxidation. Contents: General introduction (high-temperature materials characteristics, and mechanical and corrosion properties, and industrial applications); Properties of Ferrous Heat-Resistant Alloys (carbon, alloy, and stainless steels; alloy cast irons; and high alloy cast steels); Properties of superalloys (metallurgy and processing, mechanical and corrosion properties, degradation, and protective coa...

Protective effects of metformin on neointima formation in insulin resistance

Directory of Open Access Journals (Sweden)

Yu V Pankratova

2013-06-01

Full Text Available Реферат по материалам статьи Lu J, Ji J, Meng H, Wang D, Jiang B, Liu L, Randell E, Adeli K, Meng QH. The protective effect and underlying mechanism of metformin on neointima formation in fructose-induced insulin resistant rats. Cardiovasc Diabetol. 2013 Apr 5;12:58. doi: 10.1186/1475-2840-12-58.

Debris filtering effectiveness and pressure drop tests of debris resistance-bottom end piece

International Nuclear Information System (INIS)

Chung, Moon Ki; Song, Chul Hwa; Chung, Heung June; Won, Soon Yeun; Cho, Young Ro; Kim, Bok Deuk

1992-03-01

In this final report, described are the test conditions and test procedures for the debris filtering effectiveness and pressure drop tests for developing the Debris Resistance-Bottom End Piece (DR-BEP). And the test results are tabulated for later evaluation. (Author)

Cost-effectiveness of public-health policy options in the presence of pretreatment NNRTI drug resistance in sub-Saharan Africa

DEFF Research Database (Denmark)

Phillips, Andrew N; Cambiano, Valentina; Nakagawa, Fumiyo

2018-01-01

BACKGROUND: There is concern over increasing prevalence of non-nucleoside reverse-transcriptase inhibitor (NNRTI) resistance in people initiating antiretroviral therapy (ART) in low-income and middle-income countries. We assessed the effectiveness and cost-effectiveness of alternative public health...... sources and considers specific drugs and resistance mutations. We used this model to generate multiple setting scenarios mimicking those in sub-Saharan Africa and considered the prevalence of pretreatment NNRTI drug resistance in 2017. We then compared effectiveness and cost-effectiveness of alternative...... policy options. We took a 20 year time horizon, used a cost effectiveness threshold of US$500 per DALY averted, and discounted DALYs and costs at 3% per year. FINDINGS: A transition to use of a dolutegravir as a first-line regimen in all new ART initiators is the option predicted to produce the most...

Treatment Options for Carbapenem-Resistant and Extensively Drug-Resistant Acinetobacter baumannii Infections

Science.gov (United States)

Viehman, J. Alexander; Nguyen, Minh-Hong; Doi, Yohei

2014-01-01

Acinetobacter baumannii is a leading cause of healthcare-associated infections worldwide. Due to various intrinsic and acquired mechanisms of resistance, most β-lactam agents are not effective against many strains, and carbapenems have played an important role in therapy. Recent trends show many infections are caused by carbapenem-resistant, or even extensively drug-resistant (XDR) strains, for which effective therapy is not well established. Evidence to date suggests that colistin constitutes the backbone of therapy, but the unique pharmacokinetic properties of colistin have led many to suggest the use of combination antimicrobial therapy. However, the combination of agents and dosing regimens that delivers the best clinical efficacy while minimizing toxicity is yet to be defined. Carbapenems, sulbactam, rifampin and tigecycline have been the most studied in the context of combination therapy. Most data regarding therapy for invasive, resistant A. baumannii infections come from uncontrolled case series and retrospective analyses, though some clinical trials have been completed and others are underway. Early institution of appropriate antimicrobial therapy is shown to consistently improve survival of patients with carbapenem-resistant and XDR A. baumannii infection, but the choice of empiric therapy in these infections remains an open question. This review summarizes the most current knowledge regarding the epidemiology, mechanisms of resistance, and treatment considerations of carbapenem-resistant and XDR A. baumannii. PMID:25091170

Resource competition may lead to effective treatment of antibiotic resistant infections.

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Antonio L C Gomes

Full Text Available Drug resistance is a common problem in the fight against infectious diseases. Recent studies have shown conditions (which we call antiR that select against resistant strains. However, no specific drug administration strategies based on this property exist yet. Here, we mathematically compare growth of resistant versus sensitive strains under different treatments (no drugs, antibiotic, and antiR, and show how a precisely timed combination of treatments may help defeat resistant strains. Our analysis is based on a previously developed model of infection and immunity in which a costly plasmid confers antibiotic resistance. As expected, antibiotic treatment increases the frequency of the resistant strain, while the plasmid cost causes a reduction of resistance in the absence of antibiotic selection. Our analysis suggests that this reduction occurs under competition for limited resources. Based on this model, we estimate treatment schedules that would lead to a complete elimination of both sensitive and resistant strains. In particular, we derive an analytical expression for the rate of resistance loss, and hence for the time necessary to turn a resistant infection into sensitive (tclear. This time depends on the experimentally measurable rates of pathogen division, growth and plasmid loss. Finally, we estimated tclear for a specific case, using available empirical data, and found that resistance may be lost up to 15 times faster under antiR treatment when compared to a no treatment regime. This strategy may be particularly suitable to treat chronic infection. Finally, our analysis suggests that accounting explicitly for a resistance-decaying rate may drastically change predicted outcomes in host-population models.

Resource competition may lead to effective treatment of antibiotic resistant infections.

Science.gov (United States)

Gomes, Antonio L C; Galagan, James E; Segrè, Daniel

2013-01-01

Drug resistance is a common problem in the fight against infectious diseases. Recent studies have shown conditions (which we call antiR) that select against resistant strains. However, no specific drug administration strategies based on this property exist yet. Here, we mathematically compare growth of resistant versus sensitive strains under different treatments (no drugs, antibiotic, and antiR), and show how a precisely timed combination of treatments may help defeat resistant strains. Our analysis is based on a previously developed model of infection and immunity in which a costly plasmid confers antibiotic resistance. As expected, antibiotic treatment increases the frequency of the resistant strain, while the plasmid cost causes a reduction of resistance in the absence of antibiotic selection. Our analysis suggests that this reduction occurs under competition for limited resources. Based on this model, we estimate treatment schedules that would lead to a complete elimination of both sensitive and resistant strains. In particular, we derive an analytical expression for the rate of resistance loss, and hence for the time necessary to turn a resistant infection into sensitive (tclear). This time depends on the experimentally measurable rates of pathogen division, growth and plasmid loss. Finally, we estimated tclear for a specific case, using available empirical data, and found that resistance may be lost up to 15 times faster under antiR treatment when compared to a no treatment regime. This strategy may be particularly suitable to treat chronic infection. Finally, our analysis suggests that accounting explicitly for a resistance-decaying rate may drastically change predicted outcomes in host-population models.

Rapid and Longer-Term Antidepressant Effects of Repeated Ketamine Infusions in Treatment-Resistant Major Depression

NARCIS (Netherlands)

Murrough, James W.; Perez, Andrew M.; Pillemer, Sarah; Stern, Jessica; Parides, Michael K.; aan het Rot, Marije; Collins, Katherine A.; Mathew, Sanjay J.; Charney, Dennis S.; Iosifescu, Dan V.

2013-01-01

Background: Ketamine is reported to have rapid antidepressant effects; however, there is limited understanding of the time-course of ketamine effects beyond a single infusion. A previous report including 10 participants with treatment-resistant major depression (TRD) found that six ketamine

Effect of Tetracycline Dose and Treatment Mode on Selection of Resistant Coliform Bacteria in Nursery Pigs

Science.gov (United States)

Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders; Herrero-Fresno, Ana; Larsen, Inge; Holm, Anders; Nielsen, Jens Peter; Christiansen, Lasse Engbo; Angen, Øystein; Ahmed, Shahana

2017-01-01

ABSTRACT This study describes the results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on the selection of antibiotic-resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4 to 7 weeks of age) in five pig herds were treated with oxytetracycline for Lawsonia intracellularis-induced diarrhea. Each group was randomly allocated to one of five treatment groups: oral flock treatment with a (i) high (20 mg/kg of body weight), (ii) medium (10 mg/kg), or (iii) low (5 mg/kg) dose, (iv) oral pen-wise (small-group) treatment (10 mg/kg), and (v) individual intramuscular injection treatment (10 mg/kg). All groups were treated once a day for 5 days. In all groups, treatment caused a rise in the numbers and proportions of tetracycline-resistant coliform bacteria right after treatment, followed by a significant drop by the time that the pigs left the nursery unit. The counts and proportions of tetracycline-resistant coliforms did not vary significantly between treatment groups, except immediately after treatment, when the highest treatment dose resulted in the highest number of resistant coliforms. A control group treated with tiamulin did not show significant changes in the numbers or proportions of tetracycline-resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant strains but not to selection for cefotaxime-resistant strains. In conclusion, the difference in the dose of oxytetracycline and the way in which the drug was applied did not cause significantly different levels of selection of tetracycline-resistant coliform bacteria under the conditions tested. IMPORTANCE Antimicrobial resistance is a global threat to human health. Treatment of livestock with antimicrobials has a direct impact on this problem, and there is a need to improve the ways that we use antimicrobials in

Effect of Tetracycline Dose and Treatment Mode on Selection of Resistant Coliform Bacteria in Nursery Pigs.

Science.gov (United States)

Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders; Herrero-Fresno, Ana; Larsen, Inge; Holm, Anders; Nielsen, Jens Peter; Christiansen, Lasse Engbo; Angen, Øystein; Ahmed, Shahana; Folkesson, Anders; Olsen, John Elmerdahl

2017-06-15

This study describes the results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on the selection of antibiotic-resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4 to 7 weeks of age) in five pig herds were treated with oxytetracycline for Lawsonia intracellularis -induced diarrhea. Each group was randomly allocated to one of five treatment groups: oral flock treatment with a (i) high (20 mg/kg of body weight), (ii) medium (10 mg/kg), or (iii) low (5 mg/kg) dose, (iv) oral pen-wise (small-group) treatment (10 mg/kg), and (v) individual intramuscular injection treatment (10 mg/kg). All groups were treated once a day for 5 days. In all groups, treatment caused a rise in the numbers and proportions of tetracycline-resistant coliform bacteria right after treatment, followed by a significant drop by the time that the pigs left the nursery unit. The counts and proportions of tetracycline-resistant coliforms did not vary significantly between treatment groups, except immediately after treatment, when the highest treatment dose resulted in the highest number of resistant coliforms. A control group treated with tiamulin did not show significant changes in the numbers or proportions of tetracycline-resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant strains but not to selection for cefotaxime-resistant strains. In conclusion, the difference in the dose of oxytetracycline and the way in which the drug was applied did not cause significantly different levels of selection of tetracycline-resistant coliform bacteria under the conditions tested. IMPORTANCE Antimicrobial resistance is a global threat to human health. Treatment of livestock with antimicrobials has a direct impact on this problem, and there is a need to improve the ways that we use antimicrobials in livestock

Study of the effect of nano surface morphology on the stain-resistant property of ceramic tiles

International Nuclear Information System (INIS)

Pan, S P; Hung, J K; Liu, Y T

2014-01-01

In this study, six types of commercially available ceramic tiles, including nano-structured ceramic tiles and regular ceramic tiles, were selected to investigate the effect of surface morphology on their stain-resistant property. The stain-resistant efficiencies of various ceramic tiles with nano-size surface were measured in order to determine the appropriate method for testing ceramic tiles with nano-structure surface

Exploiting mitochondrial dysfunction for effective elimination of imatinib-resistant leukemic cells.

Directory of Open Access Journals (Sweden)

Jérome Kluza

Full Text Available Challenges today concern chronic myeloid leukemia (CML patients resistant to imatinib. There is growing evidence that imatinib-resistant leukemic cells present abnormal glucose metabolism but the impact on mitochondria has been neglected. Our work aimed to better understand and exploit the metabolic alterations of imatinib-resistant leukemic cells. Imatinib-resistant cells presented high glycolysis as compared to sensitive cells. Consistently, expression of key glycolytic enzymes, at least partly mediated by HIF-1α, was modified in imatinib-resistant cells suggesting that imatinib-resistant cells uncouple glycolytic flux from pyruvate oxidation. Interestingly, mitochondria of imatinib-resistant cells exhibited accumulation of TCA cycle intermediates, increased NADH and low oxygen consumption. These mitochondrial alterations due to the partial failure of ETC were further confirmed in leukemic cells isolated from some imatinib-resistant CML patients. As a consequence, mitochondria generated more ROS than those of imatinib-sensitive cells. This, in turn, resulted in increased death of imatinib-resistant leukemic cells following in vitro or in vivo treatment with the pro-oxidants, PEITC and Trisenox, in a syngeneic mouse tumor model. Conversely, inhibition of glycolysis caused derepression of respiration leading to lower cellular ROS. In conclusion, these findings indicate that imatinib-resistant leukemic cells have an unexpected mitochondrial dysfunction that could be exploited for selective therapeutic intervention.

Assessing the effects of Aedes aegypti kdr mutations on pyrethroid resistance and its fitness cost.

Directory of Open Access Journals (Sweden)

Luiz Paulo Brito

Full Text Available Pyrethroids are the most used insecticide class worldwide. They target the voltage gated sodium channel (NaV, inducing the knockdown effect. In Aedes aegypti, the main dengue vector, the AaNaV substitutions Val1016Ile and Phe1534Cys are the most important knockdown resistance (kdr mutations. We evaluated the fitness cost of these kdr mutations related to distinct aspects of development and reproduction, in the absence of any other major resistance mechanism. To accomplish this, we initially set up 68 crosses with mosquitoes from a natural population. Allele-specific PCR revealed that one couple, the one originating the CIT-32 strain, had both parents homozygous for both kdr mutations. However, this pyrethroid resistant strain also presented high levels of detoxifying enzymes, which synergistically account for resistance, as revealed by biological and biochemical assays. Therefore, we carried out backcrosses between CIT-32 and Rockefeller (an insecticide susceptible strain for eight generations in order to bring the kdr mutation into a susceptible genetic background. This new strain, named Rock-kdr, was highly resistant to pyrethroid and presented reduced alteration of detoxifying activity. Fitness of the Rock-kdr was then evaluated in comparison with Rockefeller. In this strain, larval development took longer, adults had an increased locomotor activity, fewer females laid eggs, and produced a lower number of eggs. Under an inter-strain competition scenario, the Rock-kdr larvae developed even slower. Moreover, when Rockefeller and Rock-kdr were reared together in population cage experiments during 15 generations in absence of insecticide, the mutant allele decreased in frequency. These results strongly suggest that the Ae. aegypti kdr mutations have a high fitness cost. Therefore, enhanced surveillance for resistance should be priority in localities where the kdr mutation is found before new adaptive alleles can be selected for diminishing the

Effect of an avocado oil-enhanced diet (Persea americana) on sucrose-induced insulin resistance in Wistar rats.

Science.gov (United States)

Del Toro-Equihua, Mario; Velasco-Rodríguez, Raymundo; López-Ascencio, Raúl; Vásquez, Clemente

2016-04-01

A number of studies have been conducted to evaluate the effects of vegetable oils with varying percentages of monounsaturated and polyunsaturated fatty acids on insulin resistance. However, there is no report on the effect of avocado oil on this pathologic condition. The aim of this work was to evaluate the effect of avocado oil on sucrose-induced insulin resistance in Wistar rats. An experimental study was carried out on Wistar rats that were randomly assigned into six groups. Each group received a different diet over an 8-week period (n = 11 in each group): the control group was given a standard diet, and the other five groups were given the standard feed plus sucrose with the addition of avocado oil at 0%, 5%, 10%, 20%, and 30%, respectively. Variables were compared using Student t test and analysis of variance. Statistically significant difference was considered when p avocado oil showed lower insulin resistance (p = 0.022 and p = 0.024, respectively). Similar insulin resistance responses were observed in the control and 30% avocado oil addition groups (p = 0.85). Addition of 5-30% avocado oil lowered high sucrose diet-induced body weight gain in Wistar rats. It was thus concluded that glucose tolerance and insulin resistance induced by high sucrose diet in Wistar rats can be reduced by the dietary addition of 5-20% avocado oil. Copyright © 2016. Published by Elsevier B.V.

Effects of Variable Resistance Using Chains on Bench Throw Performance in Trained Rugby Players.

Science.gov (United States)

Godwin, Mark S; Fernandes, John F T; Twist, Craig

2018-04-01

Godwin, MS, Fernandes, JFT, and Twist, C. Effects of variable resistance using chains on bench throw performance in trained rugby players. J Strength Cond Res 32(4): 950-954, 2018-This study sought to determine the effects of variable resistance using chain resistance on bench throw performance. Eight male rugby union players (19.4 ± 2.3 years, 88.8 ± 6.0 kg, 1RM 105.6 ± 17.0 kg) were recruited from a national league team. In a randomized crossover design, participant's performed 3 bench throws at 45% one repetition maximum (1RM) at a constant load (no chains) or a variable load (30% 1RM constant load and 15% 1RM variable load; chains) with 7 days between conditions. For each repetition, the peak and mean velocity, peak power, peak acceleration, and time to peak velocity were recorded. Differences in peak and mean power were very likely trivial and unclear between the chain and no chain conditions, respectively. Possibly greater peak and likely greater mean bar velocity were accompanied by likely to most likely greater bar velocity between 50 and 400 ms from initiation of bench press in the chain condition compared with the no chain condition. Accordingly, bar acceleration was very likely greater in the chain condition compared with the no chain condition. In conclusion, these results show that the inclusion of chain resistance can acutely enhance several variables in the bench press throw and gives support to this type of training.

In vitro effects of beta-lactams combined with beta-lactamase inhibitors against methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Kobayashi, S; Arai, S; Hayashi, S; Sakaguchi, T

1989-01-01

The effects of combinations of beta-lactams with two beta-lactamase inhibitors, sulbactam and clavulanic acid, were determined in vitro against 22 clinical isolates of methicillin-resistant Staphylococcus aureus. Combinations of cefpirome, cefotaxime, and cefazolin with sulbactam (10 micrograms/ml) showed synergistic effects against more than 70% of the strains. Combinations of methicillin and penicillin G with sulbactam also showed synergistic effects against 50 and 68% of the strains, respectively, while cefotiam, moxalactam, flomoxef, and cefmetazole in combination with sulbactam showed such effects against only 40% or fewer. Clavulanic acid was synergistic only when combined with penicillin G, the effect probably being due to the beta-lactamase inhibition by the inhibitor. Sulbactam did not improve the antimicrobial activities of the beta-lactams against methicillin-susceptible S. aureus strains. At 42 degrees C the MICs of cefotaxime, methicillin, and flomoxef alone were markedly decreased from the values at 35 degrees C, and no synergy between these beta-lactams and sulbactam appeared. The resistance to penicillin G was not inhibited by incubation at 42 degrees C, and combinations of penicillin G with sulbactam and clavulanic acid showed synergy. The amounts of beta-lactamase produced were not related to the decreases in the MICs of the beta-lactams, except for penicillin G combined with sulbactam. Clavulanic acid showed slightly stronger beta-lactamase-inhibiting activity than sulbactam did. These results suggest that the synergy between sulbactam and the beta-lactams, except for penicillin G, may not be due to beta-lactamase inhibition but to suppression of the methicillin-resistant S. aureus-specific resistance based on other factors. PMID:2786369

The effect of multiple blood-feeding on the longevity and insecticide resistant phenotype in the major malaria vector Anopheles arabiensis (Diptera: Culicidae).

Science.gov (United States)

Oliver, Shüné V; Brooke, Basil D

2014-08-23

Anopheles arabiensis is a major malaria vector in Africa. Adult females are likely to imbibe multiple blood meals during their lifetime. This results in regular exposure to potential toxins and blood-meal induced oxidative stress. Defence responses to these stressors may affect other factors of epidemiological significance, such as insecticide resistance and longevity. The aims of this study were to examine the effect of multiple blood-feeding on insecticide tolerance/resistance with increasing age, to assess the underlying biochemical mechanisms for the responses recorded, and to assess the effect of multiple blood-feeding on the life histories of adult females drawn from insecticide resistant and susceptible laboratory reared An. arabiensis. Laboratory reared An. arabiensis females from an insecticide resistant and an insecticide susceptible colony were offered either a single blood meal or multiple blood meals at 3-day intervals. Their tolerance or resistance to insecticide was then monitored by WHO bioassay four hours post blood-feeding. The biochemical basis of the phenotypic response was assessed by examining the effect of blood on detoxification enzyme activity and the effect of blood-meals on detoxification enzyme activity in ageing mosquitoes. Control cohorts that were not offered any blood meals showed steadily decreasing levels of insecticide tolerance/resistance with age, whereas a single blood meal significantly increased tolerance/resistance primarily at the age of three days. The expression of resistance/tolerance in those cohorts fed multiple blood meals generally showed the least variation with age. These results were consistent following exposure to DDT and pyrethroids but not to malathion. Multiple blood-meals also maintained the DDT and permethrin resistant phenotype, even after treatment females had stopped taking blood-meals. Biochemical analysis suggests that this phenotypic effect in resistant females may be mediated by the maintenance of

Alloying effect on the structure and properties of austenitic heat-resistant steels

International Nuclear Information System (INIS)

Levitin, V.V.; Grabovskij, V.Ya.; Korostelev, V.F.; Ryvkin, Yu.A.

1978-01-01

Investigated have been mechanical properties at test temperatures of 20-95O deg C, wear resistance, softening at thermomechanical cycling and microstructure of cast austenitic chromium-nickel steels (13%Cr + 35%Ni), produced by electroslag remelting with variations in Ti, Mo, Nb and W contents. Regression equations for relationship of the investigated characteristics to alloying element content have been obtained. Titanium, molybdenum and niobium increasing hardness and strength limit at room and high temperatures promote a decrease in ductility. Tungsten increases strength properties, wear resistance and thermal stability of the steels without negative effect on the impact strength. The impact strength decrease with an increase in alloying is due to brittle precipitations along the boundaries of as-cast grains, containing Ti, Mo, Nb and Si

Effects of striated laser tracks on thermal fatigue resistance of cast iron samples with biomimetic non-smooth surface

International Nuclear Information System (INIS)

Tong, Xin; Zhou, Hong; Liu, Min; Dai, Ming-jiang

2011-01-01

In order to enhance the thermal fatigue resistance of cast iron materials, the samples with biomimetic non-smooth surface were processed by Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser. With self-controlled thermal fatigue test method, the thermal fatigue resistance of smooth and non-smooth samples was investigated. The effects of striated laser tracks on thermal fatigue resistance were also studied. The results indicated that biomimetic non-smooth surface was benefit for improving thermal fatigue resistance of cast iron sample. The striated non-smooth units formed by laser tracks which were vertical with thermal cracks had the best propagation resistance. The mechanisms behind these influences were discussed, and some schematic drawings were introduced to describe them.

Effect of nosocomial vancomycin-resistant enterococcal bacteremia on mortality, length of stay, and costs.

Science.gov (United States)

Song, Xiaoyan; Srinivasan, Arjun; Plaut, David; Perl, Trish M

2003-04-01

To determine the impact of vancomycin-resistant enterococcal bacteremia on patient outcomes and costs by assessing mortality, excess length of stay, and charges attributable to it. A population-based, matched, historical cohort study. A 1,025-bed, university-based teaching facility and referral hospital. Two hundred seventy-seven vancomycin-resistant enterococcal bacteremia case-patients and 277 matched control-patients identified between 1993 and 2000. The crude mortality rate was 50.2% and 19.9% for case-patients and control-patients, respectively, yielding a mortality rate of 30.3% attributable to vancomycin-resistant enterococcal bacteremia. The excess length of hospital stay attributable to vancomycin-resistant enterococcal bacteremia was 17 days, of which 12 days were spent in intensive care units. On average, dollars 77,558 in extra charges was attributable to each vancomycin-resistant enterococcal bacteremia. To adjust for severity of illness, 159 pairs of case-patients and control-patients, who had the same severity of illness (All Patient Refined-Diagnosis Related Group complexity level), were further analyzed. When patients were stratified by severity of illness, the crude mortality rate was 50.3% among case-patients compared with 27.7% among control-patients, accounting for an attributable mortality rate of 22.6%. Attributable excess length of stay and charges were 17 days and dollars 81,208, respectively. Vancomycin-resistant enterococcal bacteremia contributes significantly to excess mortality and economic loss, once severity of illness is considered. Efforts to prevent these infections will likely be cost-effective.

Potential lifetime cost-effectiveness of catheter-based renal sympathetic denervation in patients with resistant hypertension.

Science.gov (United States)

Dorenkamp, Marc; Bonaventura, Klaus; Leber, Alexander W; Boldt, Julia; Sohns, Christian; Boldt, Leif-Hendrik; Haverkamp, Wilhelm; Frei, Ulrich; Roser, Mattias

2013-02-01

Recent studies have demonstrated the safety and efficacy of catheter-based renal sympathetic denervation (RDN) for the treatment of resistant hypertension. We aimed to determine the cost-effectiveness of this approach separately for men and women of different ages. A Markov state-transition model accounting for costs, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness was developed to compare RDN with best medical therapy (BMT) in patients with resistant hypertension. The model ran from age 30 to 100 years or death, with a cycle length of 1 year. The efficacy of RDN was modelled as a reduction in the risk of hypertension-related disease events and death. Analyses were conducted from a payer's perspective. Costs and QALYs were discounted at 3% annually. Both deterministic and probabilistic sensitivity analyses were performed. When compared with BMT, RDN gained 0.98 QALYs in men and 0.88 QALYs in women 60 years of age at an additional cost of €2589 and €2044, respectively. As the incremental cost-effectiveness ratios increased with patient age, RDN consistently yielded more QALYs at lower costs in lower age groups. Considering a willingness-to-pay threshold of €35 000/QALY, there was a 95% probability that RDN would remain cost-effective up to an age of 78 and 76 years in men and women, respectively. Cost-effectiveness was influenced mostly by the magnitude of effect of RDN on systolic blood pressure, the rate of RDN non-responders, and the procedure costs of RDN. Renal sympathetic denervation is a cost-effective intervention for patients with resistant hypertension. Earlier treatment produces better cost-effectiveness ratios.

Reversal of fluconazole resistance induced by a synergistic effect with Acca sellowiana in Candida glabrata strains.

Science.gov (United States)

R M Machado, Gabriella da; Pippi, Bruna; Dalla Lana, Daiane Flores; Amaral, Ana Paula S; Teixeira, Mário Lettieri; Souza, Kellen C B de; Fuentefria, Alexandre M

2016-11-01

The increased incidence of non-albicans Candida (NAC) resistant to fluconazole (FLZ) makes it necessary to use new therapeutic alternatives. Acca sellowiana (O.berg) Burret (Myrtaceae) is a guava with several proven biological activities. The interaction with fluconazole can be a feasible alternative to overcome this resistance. This study evaluates the in vitro antifungal activity of fractions obtained from the lyophilized aqueous extract of the leaves of A. sellowiana against resistant strains of NAC. The antifungal activity of the fractions was evaluated at 500 μg/mL by microdilution method. Checkerboard assay was performed to determine the effect of the combination of the F2 fraction and antifungal at concentrations: MIC/4, MIC/2, MIC, MIC × 2 and MIC × 4. Candida glabrata showed the lowest MIC values (500-3.90 μg/mL) and the F2 active fraction was the most effective. The association of F2 with FLZ showed a strong synergistic effect (FICI ≤ 0.5) against 100% of C. glabrata resistant isolates. Moreover, the F2 active fraction has demonstrated that probably acts in the cell wall of these yeasts. There was no observed acute dermal toxicity of lyophilized aqueous extract of leaves of A. sellowiana on pig ear skin cells. The interaction between substances present in the F2 active fraction is possibly responsible for the antifungal activity presented by this fraction. This study is unprecedented and suggests that the combination of F2 active fraction and FLZ might be used as an alternative treatment for mucocutaneus infections caused by C. glabrata resistant.

Effects of interset whole-body vibration on bench press resistance training in trained and untrained individuals.

Science.gov (United States)

Timon, Rafael; Collado-Mateo, Daniel; Olcina, Guillermo; Gusi, Narcis

2016-03-01

Previous studies have demonstrated positive effects of acute vibration exercise on concentric strength and power, but few have observed the effects of vibration exposure on resistance training. The aim of this study was to verify the effects of whole body vibration applied to the chest via hands on bench press resistance training in trained and untrained individuals. Nineteen participants (10 recreationally trained bodybuilders and 9 untrained students) performed two randomized sessions of resistance training on separate days. Each strength session consisted of 3 bench press sets with a load of 75% 1RM to failure in each set, with 2 minutes' rest between sets. All subjects performed the same strength training with either, vibration exposure (12 Hz, 4 mm) of 30 seconds immediately before each bench press set or without vibration. Number of total repetitions, kinematic parameters, blood lactate and perceived exertion were analyzed. In the untrained group, vibration exposure caused a significant increase in the mean velocity (from 0.36±0.02 to 0.39±0.03 m/s) and acceleration (from 0.75±0.10 to 0.86±0.09 m/s2), as well as a decrease in perceived effort (from 8±0.57 to 7.35±0.47) in the first bench press set, but no change was observed in the third bench press set. In the recreationally trained bodybuilders, vibration exposure did not cause any improvement on the performance of bench press resistance training. These results suggest that vibration exposure applied just before the bench press exercise could be a good practice to be implemented by untrained individuals in resistance training.

Boron effect on fabrication properties and service behaviour of complex corrosion-resistant steels

International Nuclear Information System (INIS)

Gol'dshtejn, Ya.E.; Piskunova, A.I.; Shmatko, M.N.

1978-01-01

In order to determine the optimum boron admixtures for the improvement of the technological plasticity without the considerable reduction in the corrosion resistance of the complex alloy Cr-Ni-Mo steels, industrial heats of the 03KH16N15M3, 03KH17N14M3 and other steels, containing 0.0005-0.003% boron, have been researched. The plasticity, corrosion resistance and microstructure of certain steels have been determined. It is shown that small additions of boron enhance the technological plasticity during the ingot rolling. In order to prevent a sharp reduction in the corrosion resistance, the boron content should be confined to 0.0015% and the quenching temperature raised to 1,120-1,150 deg C. The positive effect of the quenching temperature increase is accounted for by the solution of the excess phases and by the reduction of the dislocation density in the near-the-boundary zones

Effect of potassium supply on drought resistance in sorghum: plant growth and macronutrient content

International Nuclear Information System (INIS)

Asgharipour, M.R.; Heidari, M.

2011-01-01

Nowadays, the main limiting natural resource is widely considered to be water. Therefore, research into crop management practices that enhance drought resistance and plant growth when water supply is limited has become increasingly essential. This study was conducted to evaluate the effect of potassium (K) nutritional status on the drought resistance of grain sorghum during 2009. Drought stress by reducing the yield components, especially the number of panicle per plant and one-hundred grain weight reduced grain yield and greatest yield (3499 kg ha/sup -1/) obtained at full irrigation. Potassium sulfate increased grain and biological yield by 28% and 22%, respectively compared to control through improving growth conditions. Drought stress increased the N content, while reduced water availability decreased the K and Na in plant. No K fertilized plants had the lowest leaf K and N and highest Na concentrations. Chlorophyll content increased significantly with increase in K supply and increased frequency of irrigation. Interaction effect of drought stress and potassium sulfate on all studied traits except chlorophyll content was significant and optimum soil K levels protects plants from drought. These observations indicate that adequate K nutrition can improve drought resistance of sorghum. (author)

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

Study of antagonistic effects of Lactobacillus strains as probiotics on multi drug resistant (MDR) bacteria isolated from urinary tract infections (UTIs).

Science.gov (United States)

Naderi, Atiyeh; Kasra-Kermanshahi, Roha; Gharavi, Sara; Imani Fooladi, Abbas Ali; Abdollahpour Alitappeh, Meghdad; Saffarian, Parvaneh

2014-03-01

Urinary tract infection (UTI) caused by bacteria is one of the most frequent infections in human population. Inappropriate use of antibiotics, often leads to appearance of drug resistance in bacteria. However, use of probiotic bacteria has been suggested as a partial replacement. This study was aimed to assess the antagonistic effects of Lactobacillus standard strains against bacteria isolated from UTI infections. Among 600 samples; those with ≥10,000 cfu/ml were selected as UTI positive samples. Enterococcus sp., Klebsiella pneumoniae, Enterobacter sp., and Escherichia coli were found the most prevalent UTI causative agents. All isolates were screened for multi drug resistance and subjected to the antimicrobial effects of three Lactobacillus strains by using microplate technique and the MICs amounts were determined. In order to verify the origin of antibiotic resistance of isolates, plasmid curing using ethidium bromide and acridine orange was carried out. No antagonistic activity in Lactobacilli suspension was detected against test on Enterococcus and Enterobacter strains and K. pneumoniae, which were resistant to most antibiotics. However, an inhibitory effect was observed for E. coli which were resistant to 8-9 antibiotics. In addition, L. casei was determined to be the most effective probiotic. RESULTS from replica plating suggested one of the plasmids could be related to the gene responsible for ampicillin resistance. Treatment of E. coli with probiotic suspension was not effective on inhibition of the plasmid carrying hypothetical ampicillin resistant gene. Moreover, the plasmid profiles obtained from probiotic-treated isolates were identical to untreated isolates.

Methylation effect on the ohmic resistance of a poly-GC DNA-like chain

Energy Technology Data Exchange (ETDEWEB)

Moura, F.A.B.F. de, E-mail: fidelis@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, Maceió AL 57072-970 (Brazil); Lyra, M.L. [Instituto de Física, Universidade Federal de Alagoas, Maceió AL 57072-970 (Brazil); Almeida, M.L. de; Ourique, G.S.; Fulco, U.L.; Albuquerque, E.L. [Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970, Natal-RN (Brazil)

2016-10-14

We determine, by using a tight-binding model Hamiltonian, the characteristic current–voltage (IxV) curves of a 5-methylated cytosine single strand poly-GC DNA-like finite segment, considering the methyl groups attached laterally to a random fraction of the cytosine basis. Striking, we found that the methylation significantly impacts the ohmic resistance (R) of the DNA-like segments, indicating that measurements of R can be used as a biosensor tool to probe the presence of anomalous methylation. - Highlights: • Ohmic resistance of finite segments of poly-CG DNA-like segments. • Possibility for the development of biosensor devices. • Methylation effect and electronic transport in DNA-like segments.

Effect of vitamin D on stress-induced hyperglycaemia and insulin resistance in critically ill patients.

Science.gov (United States)

Alizadeh, N; Khalili, H; Mohammadi, M; Abdollahi, A; Ala, S

2016-05-01

Effects of vitamin D supplementation on the glycaemic indices and insulin resistance in diabetic and non-diabetic patients were studied. In this study, effects of vitamin D supplementation on stress-induced hyperglycaemia and insulin resistance were evaluated in non-diabetic surgical critically ill patients. Adult surgical patients with stress-induced hyperglycaemia within the first 24 h of admission to the ICU were recruited. The patients randomly assigned to receive either vitamin D or placebo. Patients in the vitamin D group received a single dose of 600,000 IU vitamin D3 as intramuscular injection at time of recruitment. Besides demographic and clinical characteristics of the patients, plasma glucose, insulin, 25(OH) D and adiponectin levels were measured at the time of ICU admission and day 7. Homoeostasis model assessment for insulin resistance (HOMA-IR) and homestasis model assessment adiponectin (HOMA-AD) ratio were considered at the times of assessment. Comparing with the baseline, plasma 25(OH) D level significantly increased in the subjects who received vitamin D (p = 0.04). Improvement in fasting plasma glucose levels was detected in day 7 of the study compared with the baseline status in both groups. HOMA-IR showed a decrement pattern in vitamin D group (p = 0.09). Fasting plasma adiponectin levels increased significantly in the vitamin D group (p = 0.007), but not in the placebo group (p = 0.38). Finally, changes in HOMA-AD ratio were not significant in the both groups. Vitamin D supplementation showed positive effect on plasma adiponectin level, as a biomarker of insulin sensitivity in surgical critically ill patients with stress-induced hyperglycaemia. However, effects of vitamin D supplementation on HOMA-IR and HOMA-AD as indicators of insulin resistance were not significant. © 2016 John Wiley & Sons Ltd.

The effect of progressive resistance training on lean body mass in post-treatment cancer patients – A systematic review

International Nuclear Information System (INIS)

Lønbro, Simon

2014-01-01

Loss of lean body mass is a common problem in many post-treatment cancer patients and may negatively affect physical capacity in terms of maximal muscle strength and functional performance. The purpose of this study was to systematically review the scientific evidence on the effect of progressive resistance training on lean body mass in post-treatment cancer patients. A comprehensive literature search was conducted and ultimately 12 studies were included. Methodological quality of the included studies was evaluated using the PEDro scale and the effect of progressive resistance training was reported as the range of mean changes among RCTs and non-RCTs. Six RCTs and six non-RCTs were included in the study. In the RCTs the change in lean body mass in the progressive resistance training groups relative to control groups ranged from −0.4% to 3.9%, and in four of six trials the training effect was significantly larger than the change in the control groups. In the six non-RCTs, the mean change in lean body mass over time ranged from −0.01 to 11.8% which was significant in two of the trials. The included studies reported no or very limited adverse events following progressive resistance training. Based on 12 heterogenic studies there is moderate evidence supporting a positive effect of progressive resistance training on lean body mass in post-treatment cancer patients

Combined Effect of the Cfr Methyltransferase and Ribosomal Protein L3 Mutations on Resistance to Ribosome-Targeting Antibiotics

DEFF Research Database (Denmark)

Pakula, Kevin K; Hansen, Lykke H; Vester, Birte

2017-01-01

. The presence of Cfr has a very minor influence on the growth rate. The resistance of the transformants to linezolid, tiamulin, florfenicol, and Synercid (a combination of quinupristin and dalfopristin [Q-D]) was measured by MIC assays. The resistance from Cfr was, in all cases, stronger than the effects...... of the L3 mutations, but various effects were obtained with the combinations of Cfr and L3 mutations ranging from a synergistic to an antagonistic effect. Linezolid and tiamulin susceptibility varied greatly among the L3 mutations, while no significant effects on florfenicol and Q-D susceptibility were...

Effect of Ultrasonic Waves on the Heat Resistance of Bacillus cereus and Bacillus licheniformis Spores

Science.gov (United States)

Burgos, J.; Ordóñez, J. A.; Sala, F.

1972-01-01

Heat resistance of Bacillus cereus and Bacillus licheniformis spores in quarter-strength Ringer solution decreases markedly after ultrasonic treatments which are unable to kill a significant proportion of the spore population. This effect does not seem to be caused by a loss of Ca2+ or dipicolinic acid. The use of ultrasonics to eliminate vegetative cells or to break aggregates in Bacillus spore suspensions to be used subsequently in heat resistance experiments appears to be unadvisable. PMID:4627969

Flow resistance interactions on hillslopes with heterogeneous attributes: Effects on runoff hydrograph characteristics

Science.gov (United States)

An improved modeling framework for capturing the effects of dynamic resistance to overland flow is developed for intensively managed landscapes. The framework builds on the WEPP model but it removes the limitations of the “equivalent” plane and static roughness assumption. The enhanced model therefo...

Cost-effectiveness of renal denervation therapy for the treatment of resistant hypertension in the Netherlands

NARCIS (Netherlands)

Henry, Thea L.; De Brouwer, Bonnie F E; Van Keep, Marjolijn M L; Blankestijn, Peter J.; Bots, Michiel L.; Koffijberg, Hendrik

2015-01-01

Objectives: Safety and efficacy data for catheter-based renal denervation (RDN) in the treatment of resistant hypertension have been used to estimate the cost-effectiveness of this approach. However, there are no Dutch-specific analyses. This study examined the cost-effectiveness of RDN from the

Effect of Heat treatment on Hardness and Corrosion Resistance of Super Cast Iron

Energy Technology Data Exchange (ETDEWEB)

Lee, Roun; Kim, Young Sik [Andong National University, Andong (Korea, Republic of)

2014-07-15

In fossil-fuel-fired power plants, a variety of pollutants are produced from the combustion of conventional fuels such as coal, oil and gas. Major component of such pollution are ash and corrosive chemicals, which also destroy pumps and piping; by causing erosion/corrosion, pitting, and wear. In order to over come such damage, materials with high hardness and high corrosion resistance are needed. In this work, we melted super-cast-iron with excellent corrosion resistance and high hardness. To elucidate the effect of heat treatment, microstructural analysis, hardness measurement, and corrosion tests were performed. Test results revealed that the super-cast-iron had several tens better corrosion resistance than 316 L stainless steel, and it also had a high surface hardness (> HRC45). High hardness, in spite of its low carbon content (0.74%C), could resulted from a hardening heat treatment to precipitate sufficient Cr{sub 7}C{sub 3} and Cr{sub 2}3C{sub 6}. Also, it was concluded that the excellent corrosion resistance of the super-cast-iron was due to the increase of the relative chromium content by minimizing the carbon content, and by the enhancement of passive film by the addition of Cr, Mo, Cu, and W.

Resistivity and thickness effects in dendritic web silicon solar cells

Science.gov (United States)

Meier, D. L.; Hwang, J. M.; Greggi, J.; Campbell, R. B.

1987-01-01

The decrease of minority carrier lifetime as resistivity decreases in dendritic-web silicon solar cells is addressed. This variation is shown to be consistent with the presence of defect levels in the bandgap which arise from extended defects in the web material. The extended defects are oxide precipitates (SiOx) and the dislocation cores they decorate. Sensitivity to this background distribution of defect levels increases with doping because the Fermi level moves closer to the majority carrier band edge. For high-resistivity dendritic-web silicon, which has a low concentration of these extended defects, cell efficiencies as high as 16.6 percent (4 sq cm, 40 ohm-cm boron-doped base, AM1.5 global, 100 mW/sq cm, 25 C JPL LAPSS1 measurement) and a corresponding electron lifetime of 38 microsec have been obtained. Thickness effects occur in bifacial cell designs and in designs which use light trapping. In some cases, the dislocation/precipitate defect can be passivated through the full thickness of web cells by hydrogen ion implantation.

Cost-Effectiveness of Antibiotic Prophylaxis Strategies for Transrectal Prostate Biopsy in an Era of Increasing Antimicrobial Resistance.

Science.gov (United States)

Lee, Kyueun; Drekonja, Dimitri M; Enns, Eva A

2018-03-01

To determine the optimal antibiotic prophylaxis strategy for transrectal prostate biopsy (TRPB) as a function of the local antibiotic resistance profile. We developed a decision-analytic model to assess the cost-effectiveness of four antibiotic prophylaxis strategies: ciprofloxacin alone, ceftriaxone alone, ciprofloxacin and ceftriaxone in combination, and directed prophylaxis selection based on susceptibility testing. We used a payer's perspective and estimated the health care costs and quality-adjusted life-years (QALYs) associated with each strategy for a cohort of 66-year-old men undergoing TRPB. Costs and benefits were discounted at 3% annually. Base-case resistance prevalence was 29% to ciprofloxacin and 7% to ceftriaxone, reflecting susceptibility patterns observed at the Minneapolis Veterans Affairs Health Care System. Resistance levels were varied in sensitivity analysis. In the base case, single-agent prophylaxis strategies were dominated. Directed prophylaxis strategy was the optimal strategy at a willingness-to-pay threshold of $50,000/QALY gained. Relative to the directed prophylaxis strategy, the incremental cost-effectiveness ratio of the combination strategy was $123,333/QALY gained over the lifetime time horizon. In sensitivity analysis, single-agent prophylaxis strategies were preferred only at extreme levels of resistance. Directed or combination prophylaxis strategies were optimal for a wide range of resistance levels. Facilities using single-agent antibiotic prophylaxis strategies before TRPB should re-evaluate their strategies unless extremely low levels of antimicrobial resistance are documented. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Metabolic effects of resistance or high-intensity interval training among glycemic control-nonresponsive children with insulin resistance.

Science.gov (United States)

Álvarez, C; Ramírez-Campillo, R; Ramírez-Vélez, R; Martínez, C; Castro-Sepúlveda, M; Alonso-Martínez, A; Izquierdo, M

2018-01-01

Little evidence exists on which variables of body composition or muscular strength mediates more glucose control improvements taking into account inter-individual metabolic variability to different modes of exercise training. We examined 'mediators' to the effects of 6-weeks of resistance training (RT) or high-intensity interval training (HIT) on glucose control parameters in physically inactive schoolchildren with insulin resistance (IR). Second, we also determined both training-induce changes and the prevalence of responders (R) and non-responders (NR) to decrease the IR level. Fifty-six physically inactive children diagnosed with IR followed a RT or supervised HIT program for 6 weeks. Participants were classified based on ΔHOMA-IR into glycemic control R (decrease in homeostasis model assessment-IR (HOMA-IR) training-induced changes to glucose control parameters; and third the report of R and NR to improve body composition, cardiovascular, metabolic and performance variables. Mediation analysis revealed that improvements (decreases) in abdominal fat by the waist circumference can explain more the effects (decreases) of HOMA-IR in physically inactive schoolchildren under RT or HIT regimes. The same analysis showed that increased one-maximum repetition leg-extension was correlated with the change in HOMA-IR (β=-0.058; P=0.049). Furthermore, a change in the waist circumference fully mediated the dose-response relationship between changes in the leg-extension strength and HOMA-IR (β'=-0.004; P=0.178). RT or HIT were associated with significant improvements in body composition, muscular strength, blood pressure and cardiometabolic parameters irrespective of improvement in glycemic control response. Both glucose control RT-R and HIT-R (respectively), had significant improvements in mean HOMA-IR, mean muscular strength leg-extension and mean measures of adiposity. The improvements in the lower body strength and the decreases in waist circumference can explain more

Shear flow generation and turbulence suppression by resistive ballooning and resistive interchange modes

International Nuclear Information System (INIS)

Guzdar, P.N.; Drake, J.F.

1993-01-01

The generation of shear flow by resistive ballooning modes and resistive interchange modes is compared and contrasted using a 3-D fluid code. The resistive ballooning modes give rise to poloidally asymmetric transport and hence drive poloidal rotation due to the Reynold's Stress as well as the anomalous Stringer/Winsor mechanism. On the other hand the resistive interchange mode can drive shear flow only through the Reynold's Stress. The studies show that if the self-consistent sheared flow is suppressed, the resistive ballooning modes give rise to a larger anomalous transport than produced by the resistive interchange modes. Furthermore the shear flow generated by the resistive ballooning modes is larger than that driven by the resistive interchange modes due to the combined effect of the dual mechanisms stated earlier. As a consequence strong suppression of the fluctuations as well as reduction of the transport occurs for resistive ballooning modes. On the other hand, for the resistive interchange modes the level of fluctuation as well as the anomalous transport is not reduced by the self consistent shear flow generated by the Reynold's Stress. This latter result is in agreement with some earlier 3-D simulation of resistive interchange modes

Effect of Clozapine on DNA Methylation in Peripheral Leukocytes from Patients with Treatment-Resistant Schizophrenia

Directory of Open Access Journals (Sweden)

Makoto Kinoshita

2017-03-01

Full Text Available Clozapine is an atypical antipsychotic, that is established as the treatment of choice for treatment-resistant schizophrenia (SCZ. To date, no study investigating comprehensive DNA methylation changes in SCZ patients treated with chronic clozapine has been reported. The purpose of the present study is to reveal the effects of clozapine on DNA methylation in treatment-resistant SCZ. We conducted a genome-wide DNA methylation profiling in peripheral leukocytes (485,764 CpG dinucleotides from treatment-resistant SCZ patients treated with clozapine (n = 21 in a longitudinal study. Significant changes in DNA methylation were observed at 29,134 sites after one year of treatment with clozapine, and these genes were enriched for “cell substrate adhesion” and “cell matrix adhesion” gene ontology (GO terms. Furthermore, DNA methylation changes in the CREBBP (CREB binding protein gene were significantly correlated with the clinical improvements. Our findings provide insights into the action of clozapine in treatment-resistant SCZ.

Mediating effects of resistance training skill competency on health-related fitness and physical activity: the ATLAS cluster randomised controlled trial.

Science.gov (United States)

Smith, Jordan J; Morgan, Philip J; Plotnikoff, Ronald C; Stodden, David F; Lubans, David R

2016-01-01

The purpose of this study was to examine the mediating effect of resistance training skill competency on percentage of body fat, muscular fitness and physical activity among a sample of adolescent boys participating in a school-based obesity prevention intervention. Participants were 361 adolescent boys taking part in the Active Teen Leaders Avoiding Screen-time (ATLAS) cluster randomised controlled trial: a school-based program targeting the health behaviours of economically disadvantaged adolescent males considered "at-risk" of obesity. Body fat percentage (bioelectrical impedance), muscular fitness (hand grip dynamometry and push-ups), physical activity (accelerometry) and resistance training skill competency were assessed at baseline and post-intervention (i.e., 8 months). Three separate multi-level mediation models were analysed to investigate the potential mediating effects of resistance training skill competency on each of the study outcomes using a product-of-coefficients test. Analyses followed the intention-to-treat principle. The intervention had a significant impact on the resistance training skill competency of the boys, and improvements in skill competency significantly mediated the effect of the intervention on percentage of body fat and the combined muscular fitness score. No significant mediated effects were found for physical activity. Improving resistance training skill competency may be an effective strategy for achieving improvements in body composition and muscular fitness in adolescent boys.

Effect of Bacteriophages on the Growth of Flavobacterium psychrophilum and Development of Phage-Resistant Strains

DEFF Research Database (Denmark)

Christiansen, Rói Hammershaimb; Madsen, Lone; Dalsgaard, Inger

2016-01-01

The controlling effect of single and multiple phages on the density of Flavobacterium psychrophilum at different initial multiplicity of infection (MOI) was assessed in batch cultures to explore the potential for phage-based treatment of this important fish pathogen. A high initial phage concentr......The controlling effect of single and multiple phages on the density of Flavobacterium psychrophilum at different initial multiplicity of infection (MOI) was assessed in batch cultures to explore the potential for phage-based treatment of this important fish pathogen. A high initial phage...... concentration (MOI = 0.3–4) was crucial for efficient viral lysis, resulting in a 104–105-fold reduction of phage-sensitive cells (both single phages and phage cocktails), which was maintained throughout the incubation (>10 days). Following cell lysis, regrowth of phage-resistant strains was examined...... and resistant strains were isolated for further characterization. The application of a mathematical model allowed simulation of phage-host interactions and resistance development, confirming indications from strain isolations that phage-sensitive strains dominated the regrowing population (>99.8 %) at low MOI...

Drought and flooding have distinct effects on herbivore-induced responses and resistance in Solanum dulcamara.

Science.gov (United States)

Nguyen, Duy; D'Agostino, Nunzio; Tytgat, Tom O G; Sun, Pulu; Lortzing, Tobias; Visser, Eric J W; Cristescu, Simona M; Steppuhn, Anke; Mariani, Celestina; van Dam, Nicole M; Rieu, Ivo

2016-07-01

In the field, biotic and abiotic stresses frequently co-occur. As a consequence, common molecular signalling pathways governing adaptive responses to individual stresses can interact, resulting in compromised phenotypes. How plant signalling pathways interact under combined stresses is poorly understood. To assess this, we studied the consequence of drought and soil flooding on resistance of Solanum dulcamara to Spodoptera exigua and their effects on hormonal and transcriptomic profiles. The results showed that S. exigua larvae performed less well on drought-stressed plants than on well-watered and flooded plants. Both drought and insect feeding increased abscisic acid and jasmonic acid (JA) levels, whereas flooding did not induce JA accumulation. RNA sequencing analyses corroborated this pattern: drought and herbivory induced many biological processes that were repressed by flooding. When applied in combination, drought and herbivory had an additive effect on specific processes involved in secondary metabolism and defence responses, including protease inhibitor activity. In conclusion, drought and flooding have distinct effects on herbivore-induced responses and resistance. Especially, the interaction between abscisic acid and JA signalling may be important to optimize plant responses to combined drought and insect herbivory, making drought-stressed plants more resistant to insects than well-watered and flooded plants. © 2016 John Wiley & Sons Ltd.

Improving outcomes for patients with medication-resistant anxiety: effects of collaborative care with cognitive behavioral therapy.

Science.gov (United States)

Campbell-Sills, Laura; Roy-Byrne, Peter P; Craske, Michelle G; Bystritsky, Alexander; Sullivan, Greer; Stein, Murray B

2016-12-01

Many patients with anxiety disorders remain symptomatic after receiving evidence-based treatment, yet research on treatment-resistant anxiety is limited. We evaluated effects of cognitive behavioral therapy (CBT) on outcomes of patients with medication-resistant anxiety disorders using data from the Coordinated Anxiety Learning and Management (CALM) trial. Primary care patients who met study entry criteria (including DSM-IV diagnosis of generalized anxiety disorder, panic disorder, posttraumatic stress disorder, or social anxiety disorder) despite ongoing pharmacotherapy of appropriate type, dose, and duration were classified as medication resistant (n = 227). Logistic regression was used to estimate effects of CALM's CBT program (CALM-CBT; chosen by 104 of 117 medication-resistant patients randomized to CALM) versus usual care (UC; n = 110) on response [≥ 50% reduction of 12-item Brief Symptom Inventory (BSI-12) anxiety and somatic symptom score] and remission (BSI-12 < 6) at 6, 12, and 18 months. Within-group analyses examined outcomes by treatment choice (CBT vs. CBT plus medication management) and CBT dose. Approximately 58% of medication-resistant CALM-CBT patients responded and 46% remitted during the study. Relative to UC, CALM-CBT was associated with greater response at 6 months (AOR = 3.78, 95% CI 2.02-7.07) and 12 months (AOR = 2.49, 95% CI 1.36-4.58) and remission at 6, 12, and 18 months (AORs = 2.44 to 3.18). Patients in CBT plus medication management fared no better than those in CBT only. Some evidence suggested higher CBT dose produced better outcomes. CBT can improve outcomes for patients whose anxiety symptoms are resistant to standard pharmacotherapy. © 2016 Wiley Periodicals, Inc.

The Effect of Inspiratory Resistance on Exercise Performance and Perception in Moderate Normobaric Hypoxia.

Science.gov (United States)

Seo, Yongsuk; Vaughan, Jeremiah; Quinn, Tyler D; Followay, Brittany; Roberge, Raymond; Glickman, Ellen L; Kim, Jung-Hyun

2017-12-01

Seo, Yongsuk, Jeremiah Vaughan, Tyler D. Quinn, Brittany Followay, Raymond Roberge, Ellen L. Glickman, and Jung-Hyun Kim. The effect of inspiratory resistance on exercise performance and perception in moderate normobaric hypoxia. High Alt Med Biol. 18:417-424, 2017. Respirators are simple and efficient in protecting workers against toxic airborne substances; however, their use may limit the physical performance of workers. The purpose of this study was to determine the effect of inspiratory resistance on physical performance and breathing perception in normobaric hypoxia. Nine healthy men wore a tight-fitting respiratory mask outfitted with one of four different inspiratory resistors (R) (0, 1.5, 4.5, 7.5 cm H 2 O/L/Sec) while exercising at normobaric hypoxia (17% O 2 ) at submaximal exercise workloads of 50, 100, and 150 W on a cycle ergometer for 10 minutes each, followed by a maximal oxygen uptake (VO 2 max) test to exhaustion. Maximal power output at R7.5 was significantly lower than R0 (p = 0.016) and R1.5 (p = 0.035). Respiration rate was significantly reduced at R4.5 (p = 0.011) and R7.5 (p ≤ 0.001) compared with R0. Minute ventilation was significantly decreased in R7.5 compared with R0 (p = 0.003), R1.5 (p = 0.010), and R4.5 (p = 0.016), whereas VO 2 was not significantly changed. Breathing comfort (BC) and breathing effort (BE) were significantly impaired in R7.5 (BC: p = 0.025, BE: p = 0.001) and R4.5 (BC: p = 0.007, BE: p = 0.001) compared with R0, but rating of perceived exertion (RPE) remained unchanged. Added inspiratory resistance limited maximal power output and increased perceptions of BC and BE in normobaric hypoxia. However, low-to-moderate inspiratory resistance did not have a deleterious effect on VO 2 or RPE at submaximal or maximal exercise. Perceptual and physiological characteristics of respirators of varying inspiratory resistances should be considered by manufacturers and end users during

Effect of Contact Pressure on the Resistance Contact Value and Temperature Changes in Copper Busbar Connection

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Agus Risdiyanto

2012-12-01

Full Text Available This paper discussed the influence of tightness or contacts pressure on copper busbar joints to determine changes in the value of the initial contact resistance and the maximum temperature at the joint due to high current load. The test sample was copper busbar 3 x 30 mm with configuration of bolted overlapping joint. Increasing contact pressure at the joint was measured to find out its effect on the value of contact resistance. The applied pressure was 6 to 36 MPa. Procedure of contact resistance measurement refer to the ASTM B539 standard using four-wire method. The sample subsequently loaded with the current of 350 A for 60 minutes and the maximum temperature at the joint was measured. The result showed that increasing contact pressure at the busbar joint will reduce the contact resistance and maximum temperature. The increase of contact pressure from 6 to 30 MPa causes decreasing contact resistance from 16 μΩ to 11 μΩ. Further increasing of contact pressure more than 30 MPa did not affect the contact resistance significantly. The lowest temperatur of busbar joint of 54°C was reached at a contact pressure of 36 Mpa.

Phenotypic- and Genotypic-Resistance Detection for Adaptive Resistance Management in Tetranychus urticae Koch.

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Deok Ho Kwon

Full Text Available Rapid resistance detection is necessary for the adaptive management of acaricide-resistant populations of Tetranychus urticae. Detection of phenotypic and genotypic resistance was conducted by employing residual contact vial bioassay (RCV and quantitative sequencing (QS methods, respectively. RCV was useful for detecting the acaricide resistance levels of T. urticae, particularly for on-site resistance detection; however, it was only applicable for rapid-acting acaricides (12 out of 19 tested acaricides. QS was effective for determining the frequencies of resistance alleles on a population basis, which corresponded to 12 nonsynonymous point mutations associated with target-site resistance to five types of acaricides [organophosphates (monocrotophos, pirimiphos-methyl, dimethoate and chlorpyrifos, pyrethroids (fenpropathrin and bifenthrin, abamectin, bifenazate and etoxazole]. Most field-collected mites exhibited high levels of multiple resistance, as determined by RCV and QS data, suggesting the seriousness of their current acaricide resistance status in rose cultivation areas in Korea. The correlation analyses revealed moderate to high levels of positive relationships between the resistance allele frequencies and the actual resistance levels in only five of the acaricides evaluated, which limits the general application of allele frequency as a direct indicator for estimating actual resistance levels. Nevertheless, the resistance allele frequency data alone allowed for the evaluation of the genetic resistance potential and background of test mite populations. The combined use of RCV and QS provides basic information on resistance levels, which is essential for choosing appropriate acaricides for the management of resistant T. urticae.

A Case Study: Effect of Progressive Resistance and Balance Training on Upper Trunk Muscle Strength of Children with Cerebral Palsy

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Mehrnoush Ismailiyan

2016-04-01

Conclusion The results of this study showed that 8 weeks of progressive resistance and balance training (in combination has increased muscle strength in children with cerebral palsy. The present research showed that resistance and balanced trainings have significant effects on muscle strength of children with CP. It seems that these practices have been effective, especially for the wrist flexor and elbow flexor muscles. It can be said that the increase in the muscles of children with CP was due to practice principle along with increase in neuronal compatibility. One of the important points in the effectiveness of resistance training is the intensity of training. The results showed that resistance and balanced trainings increase the muscle strength of children with CP. This power could be partly due to increase in muscle volume and partly due to anabolic hormones.

Evaluation of a cost effective in-house method for HIV-1 drug resistance genotyping using plasma samples.

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Devidas N Chaturbhuj

Full Text Available OBJECTIVES: Validation of a cost effective in-house method for HIV-1 drug resistance genotyping using plasma samples. DESIGN: The validation includes the establishment of analytical performance characteristics such as accuracy, reproducibility, precision and sensitivity. METHODS: The accuracy was assessed by comparing 26 paired Virological Quality Assessment (VQA proficiency testing panel sequences generated by in-house and ViroSeq Genotyping System 2.0 (Celera Diagnostics, US as a gold standard. The reproducibility and precision were carried out on five samples with five replicates representing multiple HIV-1 subtypes (A, B, C and resistance patterns. The amplification sensitivity was evaluated on HIV-1 positive plasma samples (n = 88 with known viral loads ranges from 1000-1.8 million RNA copies/ml. RESULTS: Comparison of the nucleotide sequences generated by ViroSeq and in-house method showed 99.41±0.46 and 99.68±0.35% mean nucleotide and amino acid identity respectively. Out of 135 Stanford HIVdb listed HIV-1 drug resistance mutations, partial discordance was observed at 15 positions and complete discordance was absent. The reproducibility and precision study showed high nucleotide sequence identities i.e. 99.88±0.10 and 99.82±0.20 respectively. The in-house method showed 100% analytical sensitivity on the samples with HIV-1 viral load >1000 RNA copies/ml. The cost of running the in-house method is only 50% of that for ViroSeq method (112$ vs 300$, thus making it cost effective. CONCLUSIONS: The validated cost effective in-house method may be used to collect surveillance data on the emergence and transmission of HIV-1 drug resistance in resource limited countries. Moreover, the wide applications of a cost effective and validated in-house method for HIV-1 drug resistance testing will facilitate the decision making for the appropriate management of HIV infected patients.

Effects of electrode material and configuration on the characteristics of planar resistive switching devices

KAUST Repository

Peng, H.Y.; Pu, L.; Wu, J.C.; Cha, Dong Kyu; Hong, J.H.; Lin, W.N.; Li, Yangyang; Ding, Junfeng; David, A.; Li, K.; Wu, Tao

2013-01-01

We report that electrode engineering, particularly tailoring the metal work function, measurement configuration and geometric shape, has significant effects on the bipolar resistive switching (RS) in lateral memory devices based on self-doped SrTiO3

Contrasting effects of ethylene biosynthesis on induced plant resistance against a chewing and a piercing-sucking herbivore in rice.

Science.gov (United States)

Lu, Jing; Li, Jiancai; Ju, Hongping; Liu, Xiaoli; Erb, Matthias; Wang, Xia; Lou, Yonggen

2014-11-01

Ethylene is a stress hormone with contrasting effects on herbivore resistance. However, it remains unknown whether these differences are plant- or herbivore-specific. We cloned a rice 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene, OsACS2, whose transcripts were rapidly up-regulated in response to mechanical wounding and infestation by two important pests: the striped stem borer (SSB) Chilo suppressalis and the brown planthopper (BPH) Nilaparvata lugens. Antisense expression of OsACS2 (as-acs) reduced elicited ethylene emission, SSB-elicited trypsin protease inhibitor (TrypPI) activity, SSB-induced volatile release, and SSB resistance. Exogenous application of ACC restored TrypPI activity and SSB resistance. In contrast to SSB, BPH infestation increased volatile emission in as-acs lines. Accordingly, BPH preferred to feed and oviposit on wild-type (WT) plants--an effect that could be attributed to two repellent volatiles, 2-heptanone and 2-heptanol, that were emitted in higher amounts by as-acs plants. BPH honeydew excretion was reduced and natural enemy attraction was enhanced in as-acs lines, resulting in higher overall resistance to BPH. These results demonstrate that ethylene signaling has contrasting, herbivore-specific effects on rice defense responses and resistance against a chewing and a piercing-sucking insect, and may mediate resistance trade-offs between herbivores of different feeding guilds in rice. © The Author 2014. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

Combination therapeutics of Nilotinib and radiation in acute lymphoblastic leukemia as an effective method against drug-resistance.

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Kamran Kaveh

2017-07-01

Full Text Available Philadelphia chromosome-positive (Ph+ acute lymphoblastic leukemia (ALL is characterized by a very poor prognosis and a high likelihood of acquired chemo-resistance. Although tyrosine kinase inhibitor (TKI therapy has improved clinical outcome, most ALL patients relapse following treatment with TKI due to the development of resistance. We developed an in vitro model of Nilotinib-resistant Ph+ leukemia cells to investigate whether low dose radiation (LDR in combination with TKI therapy overcome chemo-resistance. Additionally, we developed a mathematical model, parameterized by cell viability experiments under Nilotinib treatment and LDR, to explain the cellular response to combination therapy. The addition of LDR significantly reduced drug resistance both in vitro and in computational model. Decreased expression level of phosphorylated AKT suggests that the combination treatment plays an important role in overcoming resistance through the AKT pathway. Model-predicted cellular responses to the combined therapy provide good agreement with experimental results. Augmentation of LDR and Nilotinib therapy seems to be beneficial to control Ph+ leukemia resistance and the quantitative model can determine optimal dosing schedule to enhance the effectiveness of the combination therapy.

Effect of anomalous resistivity on the dynamics of plasma switching

Energy Technology Data Exchange (ETDEWEB)

Kingsep, A [Kurchatov Institute, Moscow (Russian Federation); Munier, A [Centre d` Etudes Limeil-Vaneton, Villeneuve St. Georges (France)

1997-12-31

Some of the conditions for electron MHD are recollected, and it is shown how this leads to anomalous resistivity which may play an important role in the dynamics of POS. It has been shown that not only the order of value of the resistance of the plasma-filled diode but rather basic scalings have to be changed in the regime of essential anomalous resistivity. (author). 11 refs.

The effect of progressive resistance training on lean body mass in post-treatment cancer patients - A systematic review

DEFF Research Database (Denmark)

Lønbro, Simon

2014-01-01

Loss of lean body mass is a common problem in many post-treatment cancer patients and may negatively affect physical capacity in terms of maximal muscle strength and functional performance. The purpose of this study was to systematically review the scientific evidence on the effect of progressive...... resistance training on lean body mass in post-treatment cancer patients. A comprehensive literature search was conducted and ultimately 12 studies were included. Methodological quality of the included studies was evaluated using the PEDro scale and the effect of progressive resistance training was reported...... as the range of mean changes among RCTs and non-RCTs. Six RCTs and six non-RCTs were included in the study. In the RCTs the change in lean body mass in the progressive resistance training groups relative to control groups ranged from -0.4% to 3.9%, and in four of six trials the training effect...

Strategies for improving rust resistance in oats

International Nuclear Information System (INIS)

Harder, D.E.; McKenzie, R.I.H.; Martens, J.W.; Brown, P.D.

1977-01-01

During the history of breeding oats for rust resistance in Canada the known sources of resistance proved inadequate to counter the virulence potential of both stem rust (Puccinia graminis avenae) and crown rust (P. coronata avenae). A major programme to overcome the rust problem was undertaken at Winnipeg, involving four alternate approaches: (1) A search for new resistance in wild oat species, particularly Avena sterilis, has provided a wealth of good resistance to crown rust, but less to stem rust. Much of the A. sterilis-derived crown rust resistance is now being used world-wide; (2) Efforts at synthesizing new resistance by mutation breeding methods have not been successful. Of about seven million plants examined, only one showed significant new resistance, but this was associated with poor plant type; (3) Resistance with low levels of expression but which appears broadly effective has been observed against both stem and crown rusts. It appears that numbers of these low-level genes exist, and that they can be accumulated to provide increasingly effective resistance. Problems in using this type of resistance in a practical way are discussed; (4) Excellent rust resistance has been found in lower ploidy species such as A. barbata, but it was not previously possible to stabilize this resistance in hexaploid species. By using mutagenic treatments attempts have been made to translocate smaller portions of the A. barbata chromosome carrying the resistance to the hexaploid cultivar Rodney. In conclusion, mutation breeding methods at present appear to have limited application in synthesizing new rust-resistant genotypes in oats. The search for already existing genetic resistance and its synthesis into multi-genic resistant lines appears to be the most effective way at present of resolving the rust problem in oats. (author)

Synergistic effects of tacrolimus and azole antifungal compounds in fluconazole-susceptible and fluconazole-resistant Candida glabrata isolates

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Laura Bedin Denardi

2015-03-01

Full Text Available In vitro interaction between tacrolimus (FK506 and four azoles (fluconazole, ketoconazole, itraconazole and voriconazole against thirty clinical isolates of both fluconazole susceptible and -resistant Candida glabrata were evaluated by the checkerboard microdilution method. Synergistic, indifferent or antagonism interactions were found for combinations of the antifungal agents and FK506. A larger synergistic effect was observed for the combinations of FK506 with itraconazole and voriconazole (43%, followed by that of the combination with ketoconazole (37%, against fluconazole-susceptible isolates. For fluconazole-resistant C. glabrata, a higher synergistic effect was obtained from FK506 combined with ketoconazole (77%, itraconazole (73%, voriconazole (63% and fluconazole (60%. The synergisms that we observed in vitro, notably against fluconazole-resistant C. glabrata isolates, are promising and warrant further analysis of their applications in experimental in vivo studies.

Selinexor is effective in acquired resistance to ibrutinib and synergizes with ibrutinib in chronic lymphocytic leukemia.

Science.gov (United States)

Hing, Zachary A; Mantel, Rose; Beckwith, Kyle A; Guinn, Daphne; Williams, Erich; Smith, Lisa L; Williams, Katie; Johnson, Amy J; Lehman, Amy M; Byrd, John C; Woyach, Jennifer A; Lapalombella, Rosa

2015-05-14

Despite the therapeutic efficacy of ibrutinib in chronic lymphocytic leukemia (CLL), complete responses are infrequent, and acquired resistance to Bruton agammaglobulinemia tyrosine kinase (BTK) inhibition is being observed in an increasing number of patients. Combination regimens that increase frequency of complete remissions, accelerate time to remission, and overcome single agent resistance are of considerable interest. We previously showed that the XPO1 inhibitor selinexor is proapoptotic in CLL cells and disrupts B-cell receptor signaling via BTK depletion. Herein we show the combination of selinexor and ibrutinib elicits a synergistic cytotoxic effect in primary CLL cells and increases overall survival compared with ibrutinib alone in a mouse model of CLL. Selinexor is effective in cells isolated from patients with prolonged lymphocytosis following ibrutinib therapy. Finally, selinexor is effective in ibrutinib-refractory mice and in a cell line harboring the BTK C481S mutation. This is the first report describing the combined activity of ibrutinib and selinexor in CLL, which represents a new treatment paradigm and warrants further evaluation in clinical trials of CLL patients including those with acquired ibrutinib resistance. © 2015 by The American Society of Hematology.

Effects of temephos resistance on life history traits of Aedes albopictus (Skuse (Diptera: Culicidae, a vector of arboviruses

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Junaid Rahim

2017-10-01

Full Text Available The effects of temephos resistance on the fitness cost of the wild populations of Aedes albopictus was evaluated. The larvae of two wild populations were exposed to the diagnostic dose of 0.02 mg and 0.012 mg/L. The larvae which survived after the 24 h exposure to diagnostic dose were considered as resistant and F1 generations were chosen for the comparisons of fitness parameters with the control strain, which includes larval developmental time, adult longevity, fecundity, wing length and hatchability. We found that temephos resistance had negative effects on larval developmental time which was longer for Gelugor strain among the populations with the median range of 10 days and a shorter longevity was observed with the median range of 13 days for males and 16 days for females. Whereas, an effective reduction of 29.8 and 38.6% was observed in fertility and fecundity of Gelugor strain as compared to control strain. In contrast, no clear differences were found in biological parameters of Balik Palau and USM strain, except fecundity and fertility with a reduction of 13.4 and 15.5%, respectively. Whereas, no significant differences were seen in the wing size between the populations with the mean length (mm of 2.40 for Gelugor, 2.44 for Balik Palau and 2.46 for USM control (p > 0.05. Present results indicated that the temephos resistance is associated with the developmental and reproduction potential of resistant population of A. albopictus and the fitness has been compromised. Keywords: Temephos, Insecticides resistance, Fitness cost, Aedes albopictus, Dengue

Human Skeletal Muscle Stem Cells in Adaptations to Exercise; Effects of Resistance Exercise Contraction Mode and Protein Supplementation

DEFF Research Database (Denmark)

Farup, Jean

2014-01-01

the effect of contraction mode specific resistance training and protein supplementation on whole muscle and tendon hypertrophy. Quadriceps muscle and patellar tendon cross-sectional area (CSA) was quantified using magnetic resonance imaging pre and post 12 weeks of eccentric (Ecc) or concentric (Conc...... concentric resistance training and ingestion of protein influence myocellular adaptations, with special emphasis on muscle stem cell adaptations, during both acute and prolonged resistance exercise in human skeletal muscle. Paper I. Whey protein supplementation accelerates satellite cell proliferation during...... recovery from eccentric exercise In paper I, we evaluated the effect of a single bout of unaccustomed eccentric exercise on fiber type specific SC content by immunohistochemistry. Subjects received either hydrolysed whey protein (Whey) or iso-caloric carbohydrate (Placebo) in the days post eccentric...

Analysis of creep effective stress in austenitic heat resistant steel

International Nuclear Information System (INIS)

Park, In Duck; Nam, Ki Woo

2002-01-01

This paper describes the comparison of calculated effective stress with experimental one in austenitic heat resistant steels, STS310J1TB and STS310S with and without a small amount of Nb and N. Based on a solute atoms diffusion model, contribution from soluble nitrogen to the high-temperature strength was numerically examined for austenitic heat-resisting Fe-Cr-Ni-N(STS310J1TB) and Fe-Cr-Ni(STS310S) alloys. The solute atmosphere dragging stress of dislocation was calculated in optional dislocation velocity of STS310J1TB and STS310S at 650 degree C, 675 degree C and 700 degree C. As a result of the numerical calculation, the solute atmosphere dragging stress of STS310J1TB was about 50 times larger than that of STS310S. When the temperature became high, the maximum value of solute atmosphere dragging stress was small and the velocity of moving dislocation was fast. From the relationship between the dislocation rate and the solute atmosphere dragging stress, the relation of both was proportional and the inclination is about 1 in the level with low velocity of moving dislocation. From above results, the mechanism of dislocation movement in STS310J1TB was the solute atmosphere dragging stress. The solute atmosphere dragging stress, which was calculated from the numerical calculation was close to the effect stress in stress relaxation tests

Cost-effectiveness of public-health policy options in the presence of pretreatment NNRTI drug resistance in sub-Saharan Africa: a modelling study.

Science.gov (United States)

Phillips, Andrew N; Cambiano, Valentina; Nakagawa, Fumiyo; Revill, Paul; Jordan, Michael R; Hallett, Timothy B; Doherty, Meg; De Luca, Andrea; Lundgren, Jens D; Mhangara, Mutsa; Apollo, Tsitsi; Mellors, John; Nichols, Brooke; Parikh, Urvi; Pillay, Deenan; Rinke de Wit, Tobias; Sigaloff, Kim; Havlir, Diane; Kuritzkes, Daniel R; Pozniak, Anton; van de Vijver, David; Vitoria, Marco; Wainberg, Mark A; Raizes, Elliot; Bertagnolio, Silvia

2018-03-01

There is concern over increasing prevalence of non-nucleoside reverse-transcriptase inhibitor (NNRTI) resistance in people initiating antiretroviral therapy (ART) in low-income and middle-income countries. We assessed the effectiveness and cost-effectiveness of alternative public health responses in countries in sub-Saharan Africa where the prevalence of pretreatment drug resistance to NNRTIs is high. The HIV Synthesis Model is an individual-based simulation model of sexual HIV transmission, progression, and the effect of ART in adults, which is based on extensive published data sources and considers specific drugs and resistance mutations. We used this model to generate multiple setting scenarios mimicking those in sub-Saharan Africa and considered the prevalence of pretreatment NNRTI drug resistance in 2017. We then compared effectiveness and cost-effectiveness of alternative policy options. We took a 20 year time horizon, used a cost effectiveness threshold of US$500 per DALY averted, and discounted DALYs and costs at 3% per year. A transition to use of a dolutegravir as a first-line regimen in all new ART initiators is the option predicted to produce the most health benefits, resulting in a reduction of about 1 death per year per 100 people on ART over the next 20 years in a situation in which more than 10% of ART initiators have NNRTI resistance. The negative effect on population health of postponing the transition to dolutegravir increases substantially with higher prevalence of HIV drug resistance to NNRTI in ART initiators. Because of the reduced risk of resistance acquisition with dolutegravir-based regimens and reduced use of expensive second-line boosted protease inhibitor regimens, this policy option is also predicted to lead to a reduction of overall programme cost. A future transition from first-line regimens containing efavirenz to regimens containing dolutegravir formulations in adult ART initiators is predicted to be effective and cost-effective in

RIMS (real-time imprint monitoring by scattering of light) study of pressure, temperature and resist effects on nanoimprint lithography

International Nuclear Information System (INIS)

Yu Zhaoning; Gao He; Chou, Stephen Y

2007-01-01

To optimize nanoimprint lithography (NIL), it is essential to be able to characterize and control the NIL process in situ and in real time. Recently we have developed a real-time imprint monitoring by the scattering-of-light (RIMS) approach, which allows us to detect the degree of resist deformation and the duration of resist penetration by a mould during the imprint process in real time. In this paper we report the performances of RIMS under a broad range of working conditions. RIMS data shows that the resist penetration is facilitated by increasing processing temperature, pressure and the resist film thickness; a prolonged pre-NIL resist baking step, on the other hand, has the effect of slowing it down. Our results provide further demonstration of the effectiveness of this method under different working conditions. RIMS measurements show not only how long an imprint takes to complete, but also how an imprint progresses with time and how it is affected by differences in processing parameters. These measurements provide information crucial for a better understanding and process optimization in NIL

Dinitroaniline herbicide resistance in a multiple-resistant Lolium rigidum population.

Science.gov (United States)

Chen, Jinyi; Yu, Qin; Owen, Mechelle; Han, Heping; Powles, Stephen

2018-04-01

The pre-emergence dinitroaniline herbicides (such as trifluralin and pendimethalin) are vital to Australian no-till farming systems. A Lolium rigidum population collected from the Western Australian grain belt with a 12-year trifluralin use history was characterised for resistance to dinitroaniline, acetyl CoA carboxylase (ACCase)- and acetolactate synthase (ALS)-inhibiting herbicides. Target-site resistance mechanisms were investigated. This L. rigidum population exhibited 32-fold resistance to trifluralin, as compared with the susceptible population. It also displayed 12- to 30-fold cross-resistance to other dinitroaniline herbicides (pendimethalin, ethalfluralin and oryzalin). In addition, this population showed multiple resistance to commonly used post-emergence ACCase- and ALS-inhibiting herbicides. Two target-site α-tubulin gene mutations (Val-202-Phe and Thr-239-Ile) previously documented in other dinitroaniline-resistant weed species were identified, and some known target-site mutations in ACCase (Ile-1781-Leu, Asp-2078-Gly and Cys-2088-Arg) and ALS (Pro-197-Gln/Ser) were found in the same population. An agar-based Petri dish screening method was established for the rapid diagnosis of resistance to dinitroaniline herbicides. Evolution of target-site resistance to both pre- and post-emergence herbicides was confirmed in a single L. rigidum population. The α-tubulin mutations Val-202-Phe and Thr-239-Ile, documented here for the first time in L. rigidum, are likely to be responsible for dinitroaniline resistance in this population. Early detection of dinitroaniline herbicide resistance and integrated weed management strategies are needed to maintain the effectiveness of dinitroaniline herbicides. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Influence of glutamine on the effect of resistance exercise on cardiac ANP in rats

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Romeu Rodrigues de Souza

2015-03-01

Full Text Available Various nutritional supplements (herbs, vitamins, and micronutrients improve responses and adaptations to resistance exercise. ANP is a heart hormone that contributes to fluid, electrolyte and blood pressure homeostasis through its natriuretic and vasodilative actions. In the present study, the adaptation of ANP in response to resistance exercise was investigated in rats supplemented with glutamine for five weeks. The results showed that supplementation with glutamine did not influence the number of ANP granules per atrial cardiocyte in sedentary animals. In exercised-trained rats, the number and diameter of the granules was significantly higher in comparison with the control group and in exercised animals supplemented with glutamine there was significant increase in the number and diameter of ANP granules compared with controls. Altogether, these data indicated that in resistance exercise rats, glutamine significantly enhances cardiac ANP thus implicating the beneficial effects of glutamine supplementation to the ANP system.

Tuning the resistive switching memory in a metal–ferroelectric–semiconductor capacitor by field effect structure

Energy Technology Data Exchange (ETDEWEB)

Wang, S.Y., E-mail: shouyu.wang@yahoo.com [College of Physics and Electronic Information Science, Tianjin Normal University, Tianjin 300074 (China); Guo, F.; Wang, X. [College of Physics and Electronic Information Science, Tianjin Normal University, Tianjin 300074 (China); Liu, W.F., E-mail: wfliu@tju.edu.cn [Department of Applied Physics, Faculty of Science, Tianjin University, Weijin Road, Nankai District, Tianjin 300072 (China); Gao, J., E-mail: jugao@hku.hk [Department of Physics, the University of Hong Kong, Pokfulam Road (Hong Kong)

2015-11-30

Highlights: • Bistable or tristable electrically conducting state is observed. • Coefficient can be tuned in situ by modulating carrier's density. • The RS effects may be of significance for multi-source controlled memory devices. - Abstract: Resistive switching (RS) effects based on a correlation between ferroelectric polarization and conductivity might become of particular interest for nonvolatile memory applications, because they are not subjected to the scaling restrictions. Here we report on RS behaviors modulated by a reversal of ferroelectric polarization in heterostructures comprising of a ferroelectric layer and a semiconducting manganite film. It is found that electrically conducting state is bistable or even tristable; and via the polarization flipping, a maximum resistive switching coefficient (R{sub max}/R{sub min}) is found to be larger than 3000 with bias of 6 V in Ag/BaTiO{sub 3}/La{sub 0.8}Ca{sub 0.2}MnO{sub 3} at room temperature. More importantly, employing field-effect structure with ferroelectric PMN-PT as substrate, we found that the resistive switching behaviors can be tuned in situ by modulating the concentration of carriers in the semiconducting manganite layer. Possible mechanisms are discussed on the basis of the interplay of bound ferroelectric charges, charged defects in ferroelectric layer and mobile carriers in manganite thin films. The giant RS effects observed here may be of significance for memory devices by combing electronic conduction with magnetic, spintronic, and optical functionalities.

Resistive transition of two-dimensional arrays of proximity-effect Josephson junctions

International Nuclear Information System (INIS)

Abraham, D.W.

1983-01-01

Results of measurements on large arrays of PbBi/Cu proximity-effect junctions are presented. Extrapolation of the critical current measured at low temperature to the region at and above T/sub c/ allows us to describe the initial drop in resistance by a simple model of the proximity effect, and also to define an effective temperature T' = E/sub J/(T/sub c/)T/E/sub J/(T) for describing the vortex-unbinding transition. This extrapolation has also allowed comparison of the magnitude of the universal jump in the renormalized coupling strength E/sub J/(T) with prediction, after allowance for renormalization effects. A simple decomposition of the vortex population above T/sub c/ into a sum of thermally-generated and currents-split components allows us to compare data taken at finite voltage sensitivity with theory. This idea is used to understand the broadened universal scaling of this data in a form consistent with the theory of Halperin and Nelson, suitably modified for array samples. Except for temperatures very near the transition temperature, these results can differ significantly from the continuum results of Halperin and Nelson and may be more appropriate for description of junction arrays and some granular films. New experimental data are also presented which show a periodic variation of the resistance of these arrays with the magnetic flux per cell in units of the flux quantum, including a secondary minimum at the half-quantum points. A simple model is presented which accounts for the existence, shape, and magnitude of this periodic variation in terms of vortex core energies. Observations of the current dependence of this periodic variation are presented, and a qualitative model of this effect is discussed

Researching Effective Strategies to Improve Insulin Sensitivity in Children and Teenagers - RESIST. A randomised control trial investigating the effects of two different diets on insulin sensitivity in young people with insulin resistance and/or pre-diabetes.

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De Sukanya

2010-09-01

Full Text Available Abstract Background Concomitant with the rise in childhood obesity there has been a significant increase in the number of adolescents with clinical features of insulin resistance and prediabetes. Clinical insulin resistance and prediabetes are likely to progress to type 2 diabetes and early atherosclerosis if not targeted for early intervention. There are no efficacy trials of lifestyle intervention in this group to inform clinical practice. The primary aim of this randomised control trial (RCT is to determine the efficacy and effectiveness of two different structured lifestyle interventions differing in diet composition on insulin sensitivity, in adolescents with clinical insulin resistance and/or prediabetes treated with metformin. Methods/design This study protocol describes the design of an ongoing RCT. We are recruiting 108 (54 each treatment arm 10 to 17 year olds with clinical features of insulin resistance and/or prediabetes, through physician referral, into a multi-centred RCT. All participants are prescribed metformin and participate in a diet and exercise program. The lifestyle program is the same for all participants except for diet composition. The diets are a high carbohydrate, low fat diet and a moderate carbohydrate, increased protein diet. The program commences with an intensive 3 month dietary intervention, implemented by trained dietitians, followed by a 3 month intensive gym and home based exercise program, supervised by certified physical trainers. To measure the longer term effectiveness, after the intensive intervention trial participants are managed by either their usual physician or study physician and followed up by the study dietitians for an additional 6 months. The primary outcome measure, change in insulin sensitivity, is measured at 3, 6 and 12 months. Discussion Clinical insulin resistance and prediabetes in the paediatric population are rapidly emerging clinical problems with serious health outcomes. With

EFFECTS OF MINERAL ADMIXTURE ON THE CARBONIC ACID LEACHING RESISTANCE OF CEMENT-BASED MATERIALS

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Yun Dong

2017-07-01

Full Text Available In order to reveal the degradation process and deterioration mechanism of cement-based materials, this paper analyzes the effects of carbonic acid leaching on the mechanical strength of mortars, as well as relative mass loss, microstructure, and composition of various cement pastes. The results indicate that cement pastes containing less than 20 % fly ash have higher carbonic acid leaching resistance than cement pastes without fly ash. However, after carbonic acid leaching, the compressive strength of the samples with fly ash is lower than that of the cement pastes without fly ash. The leaching resistance is good for samples cured at an early age before leaching. Carbonic acid leaching proceeds from the paste surface to the interior. The incorporation of an appropriate amount of slag powder helps to increase the density of the paste. Due to the pozzolanic activity of fly ash at late-stage leaching, a mixture of fly ash (≤ 20 % and slag powder (≤ 20 % effectively improves carbonic acid leaching resistance. The products of early-stage leaching were mainly CaCO₃ and small amounts of SiO₂ and Fe₂O₃. The C-S-H phase at the paste surface suffered serious damage after long periods of leaching, and the main products of leaching were SiO₂ and Fe₂O₃.

Fracture resistance of metal-free composite crowns-effects of fiber reinforcement, thermal cycling, and cementation technique.

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Lehmann, Franziska; Eickemeyer, Grit; Rammelsberg, Peter

2004-09-01

The improved mechanical properties of contemporary composites have resulted in their extensive use for the restoration of posterior teeth. However, the influence of fiber reinforcement, cementation technique, and physical stress on the fracture resistance of metal-free crowns is unknown. This in vitro study evaluated the effect of fiber reinforcement, physical stress, and cementation methods on the fracture resistance of posterior metal-free Sinfony crowns. Ninety-six extracted human third molars received a standardized tooth preparation: 0.5-mm chamfer preparation and occlusal reduction of 1.3 to 1.5 mm. Sinfony (nonreinforced crowns, n=48) and Sinfony-Vectris (reinforced crowns, n=48) crowns restoring original tooth contour were prepared. Twenty-four specimens of each crown type were cemented, using either glass ionomer cement (GIC) or resin cement. Thirty-two crowns (one third) were stored in humidity for 48 hours. Another third was exposed to 10,000 thermal cycles (TC) between 5 degrees C and 55 degrees C. The remaining third was treated with thermal cycling and mechanical loading (TCML), consisting of 1.2 million axial loads of 50 N. The artificial crowns were then vertically loaded with a steel sphere until failure occurred. Significant differences in fracture resistance (N) between experimental groups were assessed by nonparametric Mann-Whitney U-test (alpha=.05). Fifty percent of the Sinfony and Sinfony-Vectris crowns cemented with glass ionomer cement loosened after thermal cycling. Thermal cycling resulted in a significant reduction in the mean fracture resistance for Sinfony crowns cemented with GIC, from 2037 N to 1282 N (P=.004). Additional fatigue produced no further effects. Fiber reinforcement significantly increased fracture resistance, from 1555 N to 2326 N (P=.001). The minimal fracture resistance was above 600 N for all combinations of material, cement and loading. Fracture resistance of metal-free Sinfony crowns was significantly increased by

Effect of transmission reduction by insecticide-treated bednets (ITNs on antimalarial drug resistance in western Kenya.

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Monica Shah

Full Text Available Despite the clear public health benefit of insecticide-treated bednets (ITNs, the impact of malaria transmission-reduction by vector control on the spread of drug resistance is not well understood. In the present study, the effect of sustained transmission reduction by ITNs on the prevalence of Plasmodium falciparum gene mutations associated with resistance to the antimalarial drugs sulfadoxine-pyrimethamine (SP and chloroquine (CQ in children under the age of five years was investigated during an ITN trial in Asembo area, western Kenya. During the ITN trial, the national first line antimalarial treatment changed from CQ to SP. Smear-positive samples collected from cross sectional surveys prior to ITN introduction (baseline, n = 250 and five years post-ITN intervention (year 5 survey, n = 242 were genotyped for single nucleotide polymorphisms (SNPs at dhfr-51, 59, 108, 164 and dhps-437, 540 (SP resistance, and pfcrt-76 and pfmdr1-86 (CQ resistance. The association between the drug resistance mutations and epidemiological variables was evaluated. There were significant increases in the prevalence of SP dhps mutations and the dhfr/dhps quintuple mutant, and a significant reduction in the proportion of mixed infections detected at dhfr-51, 59 and dhps-437, 540 SNPs from baseline to the year 5 survey. There was no change in the high prevalence of pfcrt-76 and pfmdr1-86 mutations. Multivariable regression analysis further showed that current antifolate use and year of survey were significantly associated with more SP drug resistance mutations. These results suggest that increased antifolate drug use due to drug policy change likely led to the high prevalence of SP mutations 5 years post-ITN intervention and reduced transmission had no apparent effect on the existing high prevalence of CQ mutations. There is no evidence from the current study that sustained transmission reduction by ITNs reduces the prevalence of genes associated with malaria

Ameliorative effects of polyunsaturated fatty acids against palmitic acid-induced insulin resistance in L6 skeletal muscle cells

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Sawada Keisuke

2012-03-01

Full Text Available Abstract Background Fatty acid-induced insulin resistance and impaired glucose uptake activity in muscle cells are fundamental events in the development of type 2 diabetes and hyperglycemia. There is an increasing demand for compounds including drugs and functional foods that can prevent myocellular insulin resistance. Methods In this study, we established a high-throughput assay to screen for compounds that can improve myocellular insulin resistance, which was based on a previously reported non-radioisotope 2-deoxyglucose (2DG uptake assay. Insulin-resistant muscle cells were prepared by treating rat L6 skeletal muscle cells with 750 μM palmitic acid for 14 h. Using the established assay, the impacts of several fatty acids on myocellular insulin resistance were determined. Results In normal L6 cells, treatment with saturated palmitic or stearic acid alone decreased 2DG uptake, whereas unsaturated fatty acids did not. Moreover, co-treatment with oleic acid canceled the palmitic acid-induced decrease in 2DG uptake activity. Using the developed assay with palmitic acid-induced insulin-resistant L6 cells, we determined the effects of other unsaturated fatty acids. We found that arachidonic, eicosapentaenoic and docosahexaenoic acids improved palmitic acid-decreased 2DG uptake at lower concentrations than the other unsaturated fatty acids, including oleic acid, as 10 μM arachidonic acid showed similar effects to 750 μM oleic acid. Conclusions We have found that polyunsaturated fatty acids, in particular arachidonic and eicosapentaenoic acids prevent palmitic acid-induced myocellular insulin resistance.

Dichromatic and monochromatic laser radiation effects on antibiotic resistance, biofilm formation, and division rate of Pantoea agglomerans

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Thomé, A. M. C.; Souza, B. P.; Mendes, J. P. M.; Cardoso, A. F. R.; Soares, L. C.; Trajano, E. T. L.; Fonseca, A. S.

2018-06-01

Since infection is a common cause of delayed wound healing, it is important to understand the effect of low-level laser therapy (LLLT) in bacterial mechanisms. In this study we evaluated the effects of LLLT on antibiotic resistance, division rate, and biofilm formation of Pantoea agglomerans. P. agglomerans samples were isolated from human pressure injuries in humans and cultures were exposed to low-level monochromatic and simultaneous dichromatic laser radiation to study the susceptibility of an antimicrobial to ampicillin and piperacillin  +  tazobactam, quantification of areas of bacterial colonies, and biofilm formation of bacterial cells. Fluence, wavelength, and emission mode were used in the therapeutic protocols for wound healing. The data showed no changes in the areas of the colonies, but dichromatic laser radiation decreased biofilm formation, while a monochromatic red laser at low dose increased biofilm formation and infrared at high dose decreased antibiotic resistance to ampicillin. LLLT modulates antibiotic resistance and biofilm formation of P. agglomerans, but these depend on the laser irradiation parameters, since dichromatic laser radiation induces biological effects that differ from those induced by monochromatic laser radiation. Thus, simultaneous dichromatic low-level red and infrared lasers could be a new option for the treatment of infected wounds, reducing biofilm formation, without altering antibiotic resistance and the division rate of P. agglomerans cultures.

Seasonal Variations in Resistivity at a Police Forensic Site and the Effectiveness of Unconventional Array Types

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Edwards, S.; Bank, C. G.

2016-12-01

Geophysical studies involving the detection of buried organic material can be affected by the passage of time and environmental changes such as temperature and, in more importantly, water content in the ground. These effects can be of particular concern for police forensic investigations. This study involved conducting multiple resistivity surveys across 4 months to determine how time and environmental variations affected the detection of porcine carcasses buried four years previous at a provincial police training and research site. Our research also explored survey results of non-conventional grid and square arrays versus traditional linear arrays. The study site is located in Bolton, Ontario, and measures 16 m by 30 m. It contains 18 graves plus other buried objects. Studies were conducted approximately every other week. The resistivity lines used Wenner arrays of 24 m (0.5 m electrode spacing) and 48 m (1 m spacing) in length. Environmental data was obtained from Environment Canada and through simple observations. Preliminary findings indicated that time and environmental changes affected the detection of the porcine bodies by either being too dry and having too high a resistivity to survey effectively, or too wet and having the site flushed with water making the surrounding ground similar in resistivity to the bodies. Future research is needed to further explore how best to minimize environmental changes from resistivity results to enable reliable detection of buried organic material such as human remains In regard to array configurations, the square array in particular shows promise in that it can be set up and executed in less time than running several linear arrays over the same area. The application of such unconventional arrays to police forensic work may prove valuable if the area of interest is off-limits for resistivity surveys due to physical obstructions.

Effect of berberine on insulin resistance in women with polycystic ovary syndrome: study protocol for a randomized multicenter controlled trial.

Science.gov (United States)

Li, Yan; Ma, Hongli; Zhang, Yuehui; Kuang, Hongying; Ng, Ernest Hung Yu; Hou, Lihui; Wu, Xiaoke

2013-07-18

Insulin resistance and hyperinsulinemia play a key role in the pathogenesis of polycystic ovary syndrome (PCOS), which is characterized by hyperandrogenism, ovulatory dysfunction, and presence of polycystic ovaries on pelvic scanning. Insulin resistance is significantly associated with the long-term risks of metabolic syndrome and cardiovascular disease. Berberine has effects on insulin resistance but its use in women with PCOS has not been fully investigated. In this paper, we present a research design evaluating the effects of berberine on insulin resistance in women with PCOS. This is a multicenter, randomized, placebo-controlled and double-blind trial. A total of 120 patients will be enrolled in this study and will be randomized into two groups. Berberine or placebo will be taken orally for 12 weeks. The primary outcome is the whole body insulin action assessed with the hyperinsulinemic-euglycemic clamp. We postulate that women with PCOS will have improved insulin resistance following berberine administration. This study is registered at ClinicalTrials.gov, NCT01138930.

Study of the effectiveness of the US safety standard for child resistant cigarette lighters

OpenAIRE

Smith, L; Greene, M; Singh, H

2002-01-01

Objective: The purpose of this research is to evaluate the effectiveness of the US Consumer Product Safety Commission's (CPSC) Safety Standard for Cigarette Lighters, which requires that disposable cigarette lighters be resistant to operation by children younger than age 5.

Effectiveness of small daily amounts of progressive resistance training for frequent neck/shoulder pain

DEFF Research Database (Denmark)

Andersen, Lars; Saervoll, Charlotte A; Mortensen, Ole S

2011-01-01

Regular physical exercise is a cornerstone in rehabilitation programs, but adherence to comprehensive exercise remains low. This study determined the effectiveness of small daily amounts of progressive resistance training for relieving neck/shoulder pain in healthy adults with frequent symptoms...

Research surface resistance of copper normal and abnormal skin-effects depending on the frequency of electromagnetic field

International Nuclear Information System (INIS)

Kutovyi, V.A.; Komir, A.I.

2013-01-01

The results of the frequency dependence of surface resistance of copper in diffuse and specular reflection of electrons from the conductive surface of the high-frequency resonance of the system depending on the frequency of the electromagnetic field in the normal and anomalous skin effect. Found, the surface resistance of copper is reduced by more than 10 times at the temperature of liquid helium, as compared with a surface resistivity at room temperature, at frequencies f ≤ 173 MHz, for diffuse reflection of conduction electrons from the surface of the conductive layer, and the specular reflection - at frequencies f ≤ 346 MHz

Effect of pinacidil on norepinephrine- and potassium-induced contractions and membrane potential in rat and human resistance vessels and in rat aorta

International Nuclear Information System (INIS)

Videbaek, L.M.; Aalkjaer, C.; Mulvany, M.J.

1988-01-01

The effect of pinacidil on contractile responses to norepinephrine, potassium, and membrane potential was examined in rat and human resistance vessels. In some experiments rat aorta was also used. Pinacidil (0.1-30 microM) caused a concentration-dependent relaxation of norepinephrine-induced contractions in all vessels studied. In the same concentration range, pinacidil had only little effect on potassium (125 mM) activated rat mesenteric and femoral resistance vessels. In denervated rat mesenteric resistance vessels, a depolarization with potassium (125 mM) before superimposing a norepinephrine tone markedly diminished the effect of pinacidil. In resting rat mesenteric resistance vessels, pinacidil (1-10 microM) caused a hyperpolarization of 10-15 mV. In rat aorta, pinacidil (10 microM) caused a significant (p less than 0.001) increase in 86 Rb+ efflux rate constant whereas 1 microM had no effect. The results of these experiments indicate that the vasodilating effect may be caused by a hyperpolarization of the vascular smooth muscle cell membrane

Effectiveness of a Glycylcycline Antibiotic for Reducing the Pathogenicity of Superantigen-Producing Methicillin-Resistant Staphylococcus aureus in Burn Wounds.

Science.gov (United States)

Nosanov, Lauren B; Jo, Daniel Y; Randad, Pranay R; Moffatt, Lauren T; Carney, Bonnie C; Ortiz, Rachel T; Shupp, Jeffrey W

2017-01-01

Objective : Burn-injured patients are highly susceptible to infectious complications, which are often associated with increased morbidity and mortality. Rates of antibiotic resistance have increased, and resistant species such as methicillin-resistant Staphylococcus aureus provide additional challenges in the form of virulence factors. Proteins can disrupt local healing, leading to systemic immune disruption. To optimize outcomes, treatments that reduce pathogenicity must be identified. This study aims to compare a glycylcycline antibiotic-tigecycline-with clindamycin for effectiveness in treating superantigenic methicillin-resistant Staphylococcus aureus in burn wounds. Methods : Sprague-Dawley rats received paired 2 × 2-cm burn wounds, which were subsequently inoculated with known virulence factor-producing methicillin-resistant Staphylococcus aureus or media alone on postinjury day 1. Infected animals received twice-daily tigecycline (high or low dose), twice-daily clindamycin (high or low dose), or saline alone (positive controls). Daily sampling and imaging assessments were performed. Results : Bacterial counts and toxin levels were reduced significantly in antibiotic-treated groups relative to positive controls ( P study supports the use of tigecycline in the treatment of methicillin-resistant Staphylococcus aureus -infected burn wounds. While both protein synthesis inhibitors are effective, tigecycline appears to be superior in controlling toxin levels, enabling better wound healing.

Resistive switching effect of N-doped MoS2-PVP nanocomposites films for nonvolatile memory devices

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Wu, Zijin; Wang, Tongtong; Sun, Changqi; Liu, Peitao; Xia, Baorui; Zhang, Jingyan; Liu, Yonggang; Gao, Daqiang

2017-12-01

Resistive memory technology is very promising in the field of semiconductor memory devices. According to Liu et al, MoS2-PVP nanocomposite can be used as an active layer material for resistive memory devices due to its bipolar resistive switching behavior. Recent studies have also indicated that the doping of N element can reduce the band gap of MoS2 nanosheets, which is conducive to improving the conductivity of the material. Therefore, in this paper, we prepared N-doped MoS2 nanosheets and then fabricated N-doped MoS2-PVP nanocomposite films by spin coating. Finally, the resistive memory [C. Tan et al., Chem. Soc. Rev. 44, 2615 (2015)], device with ITO/N-doped MoS2-PVP/Pt structure was fabricated. Study on the I-V characteristics shows that the device has excellent resistance switching effect. It is worth mentioning that our device possesses a threshold voltage of 0.75 V, which is much better than 3.5 V reported previously for the undoped counterparts. The above research shows that N-doped MoS2-PVP nanocomposite films can be used as the active layer of resistive switching memory devices, and will make the devices have better performance.