Electro-absorption Modulator with Dual Carrier Accumulation Layers Based on Epsilon-Near-Zero ITO

An electro-absorption modulator based on indium tin oxide is proposed by constructing a waveguide consisting of metal-dielectric-ITO-dielectric-Si stack. Applying a negative voltage bias on the ITO layer, carrier accumulation occurs at both dielectric-ITO interfaces, which dramatically changes the guided mode properties due to the epsilon-near-zero effect. By tuning the real part of the permittivity around zero, the guided plasmonic mode concentrates in either ITO or dielectric layers, resulting in a high propagation loss. These dual carrier accumulation layers significantly improve the extinction ratio of the modulator. A further improvement is obtained by using high refractive index dielectric thin layers, which provides a strong optical confinement in the carrier accumulation layers. The dual carrier accumulation layer device shows a 200 % increase of the modulation efficiency compared to a single accumulation layer design. A modulation depth of 9.9 dB/μm can be achieved by numerical simulation.     

The Effect of Polymeric Nanoparticles on Biocompatibility of Carrier Red Blood Cells

Red blood cells (RBCs) can be used for vascular delivery of encapsulated or surface-bound drugs and carriers. Coupling to RBC prolongs circulation of nanoparticles (NP, 200 nm spheres, a conventional model of polymeric drug delivery carrier) enabling their transfer to the pulmonary vasculature without provoking overt RBC elimination. However, little is known about more subtle and potentially harmful effects of drugs and drug carriers on RBCs. Here we devised high-throughput in vitro assays to determine the sensitivity of loaded RBCs to osmotic stress and other damaging insults that they may encounter in vivo (e.g. mechanical, oxidative and complement insults). Sensitivity of these tests is inversely proportional to RBC concentration in suspension and our results suggest that mouse RBCs are more sensitive to damaging factors than human RBCs. Loading RBCs by NP at 1:50 ratio did not affect RBCs, while 10–50 fold higher NP load accentuated RBC damage by mechanical, osmotic and oxidative stress. This extensive loading of RBC by NP also leads to RBCs agglutination in buffer; however, addition of albumin diminished this effect. These results provide a template for analyses of the effects of diverse cargoes loaded on carrier RBCs and indicate that: i) RBCs can tolerate carriage of NP at doses providing loading of millions of nanoparticles per microliter of blood; ii) tests using protein-free buffers and mouse RBCs may overestimate adversity that may be encountered in humans.     

The Effect of Ringing on Cytokinin Distribution in Salix baylonica

Although quantitative differences were observed in the cytokinin content of mature leaves and bark of Salix babylonica it would appear as if these tissues contained the same cytokinin complement. Ringing resulted in a decrease in the level of cytokinins in the leaves and an increase in the bark, both above and below the girdle. In the leaves the decrease was due mainly to a drop in the level of those compounds that co-chromatographed with the cytokinin glucosides. These compounds were also almost undetectable in the bark above the girdle, where callus was formed. The observed increase in the cytokinin content of the bark above the girdle was due to higher activity in those parts of the chromatograms where zeatin and zeatin riboside occurred. Ringing stimulated the growth of lateral buds below the girdle. These developing buds as well as the bark below the girdle contained very high levels of cytokinins that cochromatographed with zeatin and zeatin riboside.     

The Predictive Performance and Stability of Six Species Distribution Models

Background

Predicting species’ potential geographical range by species distribution models (SDMs) is central to understand their ecological requirements. However, the effects of using different modeling techniques need further investigation. In order to improve the prediction effect, we need to assess the predictive performance and stability of different SDMs.

Methodology

We collected the distribution data of five common tree species (Pinus massoniana, Betula platyphylla, Quercus wutaishanica, Quercus mongolica and Quercus variabilis) and simulated their potential distribution area using 13 environmental variables and six widely used SDMs: BIOCLIM, DOMAIN, MAHAL, RF, MAXENT, and SVM. Each model run was repeated 100 times (trials). We compared the predictive performance by testing the consistency between observations and simulated distributions and assessed the stability by the standard deviation, coefficient of variation, and the 99% confidence interval of Kappa and AUC values.

Results

The mean values of AUC and Kappa from MAHAL, RF, MAXENT, and SVM trials were similar and significantly higher than those from BIOCLIM and DOMAIN trials (p<0.05), while the associated standard deviations and coefficients of variation were larger for BIOCLIM and DOMAIN trials (p<0.05), and the 99% confidence intervals for AUC and Kappa values were narrower for MAHAL, RF, MAXENT, and SVM. Compared to BIOCLIM and DOMAIN, other SDMs (MAHAL, RF, MAXENT, and SVM) had higher prediction accuracy, smaller confidence intervals, and were more stable and less affected by the random variable (randomly selected pseudo-absence points).

Conclusions

According to the prediction performance and stability of SDMs, we can divide these six SDMs into two categories: a high performance and stability group including MAHAL, RF, MAXENT, and SVM, and a low performance and stability group consisting of BIOCLIM, and DOMAIN. We highlight that choosing appropriate SDMs to address a specific problem is an important part of the modeling process.     

The Effect of Nanoemulsion as a Carrier of Hydrophilic Compound for Transdermal Delivery

The purpose of the present study was to investigate the effect of nanoemulsions as a carrier vehicle of hydrophilic drug for transdermal delivery. The response surface methodology with a mixture design was used to evaluate the effect of ingredient levels of nanoemulsion formulations including cosurfactant (isopropyl alcohol, 20∼30%), surfactant (mixed of Brij 30 and Brij 35, 20∼30%), and distilled-water (34.5∼50.0%) on properties of the drug-loaded nanoemulsions including physicochemical characters and drug permeability through rat skin. The result showed that the hydrophilic drug in aqueous solution with or without penetration enhancer could not transport across rat skin after 12 h of application. Used nanoemulsions as carrier vehicle, the permeation rate of drug was significantly increased from 0 to 63.23 µg/cm²/h and the lag time was shortened from more than 12 h to about 2.7∼4.0 h. Moreover, the drug-loaded nanoemulsion formulation also showed physicochemical stability after 3 month storage at 25°C and 40°C.     

Treatment of Salmonella Enteritis and its Effect on the Carrier State

During an outbreak of Salmonella enteritis, 113 symptomatic and asymptomatic patients were assigned to different treatment groups: 43 received ampicillin; 41 were given trimethoprim-sulfamethoxazole; and 29 received no specific therapy. During the four-week observation period no statistically significant benefit from treatment with either ampicillin or trimethoprim-sulfamethoxazole was apparent in relation to duration and severity of symptoms or duration of the carrier state. However, the impression that trimethoprim-sulfamethoxazole might have shortened the period of fecal Salmonella excretion in the few asymptomatic patients may warrant further controlled studies.There was no significant alteration in hematological or biochemical values, or urine constituents, in patients receiving trimethoprim-sulfamethoxazole. Side effects probably attributable to this drug developed in only 5% of the 41 patients.It is concluded that uncomplicated salmonellosis is best treated without using currently available chemotherapeutic agents.     

The Effect of Time Distribution Shape on a Complex Epidemic Model

In elaborating a model of the progress of an epidemic, it is necessary to make assumptions about the distributions of latency times and infectious times. In many models, the often implicit assumption is that these times are independent and exponentially distributed. We explore the effects of altering the distribution of latency and infectious times in a complex epidemic model with regional divisions connected by a travel intensity matrix. We show a delay in spread with more realistic latency times. More realistic infectiousness times lead to faster epidemics. The effects are similar but accentuated when compared to a purely homogeneous mixing model.     

The Effect of Infant Body Mass on Carrier Travel Speed in Cotton-top Tamarins (Saguinus oedipus)

Infant carrying is common in primates and may be the second most costly activity related to reproduction, after lactation. In cooperative breeding groups of callitrichids, all group members carry and care for twin infants. Previous studies have described the costs of infant carrying in terms of body mass loss and reduced locomotor capability. However, infant carrying may also influence travel speed, an important potential cost because slower speed may handicap foraging, energetic budgets, and predator avoidance. We evaluated the impact of infant carrying on the travel speed of 27 adult and 9 subadult cotton-top tamarins (Saguinus oedipus) of both sexes in large outdoor enclosures. We compared carrier speed to speed when not carrying during the 10 weeks after nine births. Subadult tamarins, which have a lower body mass than adults do, moved faster than adults when not carrying. We found no difference between the mean speeds of subadults and adults while carrying. However, the speed of carriers decreased as infant mass increased, and the slope of this negative relationship was more pronounced in subadult carriers. For every 80 g of extra mass load (the body mass of newborn twins), adults reduced their speed by 6 % and subadults by 19 % relative to noncarrying speed. We also observed a reduction in speed while carrying two infants in adult tamarins as carrying time increased. Our results contribute to an understanding of the costs of infant carrying, and serve to emphasize the importance of cooperative breeding systems in coping with these costs.     

The Structural Basis of ATP as an Allosteric Modulator

Adenosine-5’-triphosphate (ATP) is generally regarded as a substrate for energy currency and protein modification. Recent findings uncovered the allosteric function of ATP in cellular signal transduction but little is understood about this critical behavior of ATP. Through extensive analysis of ATP in solution and proteins, we found that the free ATP can exist in the compact and extended conformations in solution, and the two different conformational characteristics may be responsible for ATP to exert distinct biological functions: ATP molecules adopt both compact and extended conformations in the allosteric binding sites but conserve extended conformations in the substrate binding sites. Nudged elastic band simulations unveiled the distinct dynamic processes of ATP binding to the corresponding allosteric and substrate binding sites of uridine monophosphate kinase, and suggested that in solution ATP preferentially binds to the substrate binding sites of proteins. When the ATP molecules occupy the allosteric binding sites, the allosteric trigger from ATP to fuel allosteric communication between allosteric and functional sites is stemmed mainly from the triphosphate part of ATP, with a small number from the adenine part of ATP. Taken together, our results provide overall understanding of ATP allosteric functions responsible for regulation in biological systems.     

The Relative Age Effect and Its Influence on Academic Performance

Introduction and Purpose

The policy of school organisation for grouping students in the same academic year is based on date of birth. The differences in the experiences and maturation of older students involve a relatively better performance in academic settings, which is known as the relative age effect (RAE). This effect is more important the younger the student is. The goal of this study is to identify the connections of influence that RAE, socioeconomic status (SES), and type of institution have on academic performance in a school population of eighth graders.

Methods

The study is based on a population-based, representative sample of 15,234 8th graders (50.4% female; average age = 13.61 years) in the 2011 National System of Quality Assessment in Education Survey (SIMCE) from Chile. The SIMCE for global academic performance consists of 4 tests: reading, mathematics, social studies, and science. All tests consist of multiple-choice and closed questions. In addition, in order to have the information of general academic performance, an extra variable expressing the average score of each student was created. Also, the SIMCE includes additional variables for the evaluation process such as SES or type of school. Students were assigned to one of five age groups in terms of date of birth (G1, G2, G3, G4, and G5), in which students belonging to G1 are the oldest and students belonging to G5 are the youngest.

Results

The results achieved in the structural equation modelling indicate a good global fit. Individual relationships show significant effects of the three variables observed on academic performance, although SES received the highest values. The influence of RAE took place both in the full sample and sub-samples composed according to the SES and academic performance, showing higher values for students with lower scores. Although the influence of RAE decreases when SES is controlled, its effect is still significant and contributes to additionally explain the performance.

Conclusions

The RAE remains, even with residual values, an explanatory factor in academic performance even in eighth graders. Since the RAE decreases as the influence of schooling increases, the potential adverse effects for some students would be placed in previous and initial moments of formal schooling. These findings may be useful into taking steps towards flexibilisation on age of entry in compulsory schooling. Moreover, the need to implement early, comprehensive evaluation systems which include aspects related to neurodevelopment in order to provide maximum information to parents and educators is also drawn.     

The Effect of Low-Frequency Road Noise on Driver Sleepiness and Performance

It is a well-known fact today that driver sleepiness is a contributory factor in crashes. Factors considered as sleepiness contributor are mostly related to time of the day, hours being awake and hours slept. Factors contributing to active and passive fatigue are mostly focusing on the level of cognitive load. Less is known what role external factors, e.g. type of road, sound/noise, vibrations etc., have on the ability to stay awake both under conditions of sleepiness and under active or passive fatigue. The aim of this moving base driving simulator study with 19 drivers participating in a random order day and night time, was to evaluate the effect of low-frequency road noise on driver sleepiness and performance, including both long-term and short-term effects. The results support to some extent the hypothesis that road-induced interior vehicle sound affects driving performance and driver sleepiness. Increased low-frequency noise helps to reduce speed during both day- and night time driving, but also contributes to increase the number of lane crossings during night time.     

临床医师薪酬分配与绩效实证研究

目的 研究基于绩效的临床医师薪酬分配办法和适当拉开薪酬差距是否能有效提升医院的绩效水平。方法 采用变异系数衡量临床医师的薪酬差距,采用对照研究的方法评估医院的绩效提升水平。结果 外科医师薪酬差距拉开幅度最大,其余依次为儿科、内科和医技科,2006—2010年医院绩效优于对照医院。结论 通过薪酬分配制度改革的实践,基于绩效适当拉开薪酬差距,激发临床医师的积极性,增强医疗团队活力,提高绩效水平,提升医院综合实力。     

肌酸提高运动能力的作用

介绍了肌酸在机体的分布与合成及其在肌肉能量代谢中的作用。综述了补充肌酸对提高体内肌酸含量和运动能力的作用 ,并介绍了肌酸提高运动能力作用的机制研究情况     

纳米粒载体研究进展

目的:介绍纳米粒载体的制备、优点和应用进展,为纳米粒在新的领域的应用提供依据.方法:以纳米粒制备方法和基质材料的不断发展以及各个领域的应用为线索来综述.结果:纳米粒的制备方法有离子交换法、乳化法和自组装法,基质材料有蛋白质和多糖等,纳米粒本身无毒性,能增加所载物的溶解度和生物利用度,提高靶向性及效率,在抗肿瘤治疗、神经系统治疗和药物检测等多方面有广泛的应用.结论:纳米粒作为一种载体,在药物临床研究、药理研究和生物分析等方面都得到了广泛应用,并有可能开发为其他领域的运送体系,有广阔的应用前景.     

Effect of Adjuvants on the Antibody Response to a Hapten on a Thymus-independent Carrier

IT has been demonstrated in mice that levan (polyfructose), an antigen which interacts only with B lymphocytes¹, can function as a carrier and produce a thymus-independent response to dinitrophenol (DNP)². Using this conjugate, antibody-production against the hapten is totally unaffected in thymectomized animals and is abolished in mice tolerant to levan. The DNP-levan conjugate produces only 19S antibody against DNP.     

The Effect of Mineral Nutrition on the Distribution of Growth in Lolium perenne

Ramets of Lolium perenne from the same genotypes were grownin nutrient solutions of two concentrations. Additional mineralnutrition increased the rate of production of new tillers, therate of increase in size of tillers and the rate of productionof new roots, but not the rate of growth of individual mainroots. The genotypes differed considerably from each other intheir rates of growth, especially of shoot growth. When thegrowth-rate of the same population of genotypes was alteredby changing the environmental conditions it was found that thelower the mean rate of shoot growth, the greater its coefficientof variation. Variation in the rate of shoot growth, due tomineral nutrition and genetic constitution of the plants growingin a dilute nutrient solution, was accompanied by a similarbut smaller variation in the number of roots.