The combustion characteristics and thermal performance of a premixed H2/air combustion in the micro-combustor with a backward-facing step is studied through experimental tests and numerical ...simulations. The effects of step length and wall thickness on the flame stability and thermal performance of the micro-combustor are presented and compared. The results show that the outer wall temperature can be improved by the reduction of wall thickness and modified through the relocation of the high temperature zone. With the decrease of the step length, the flame location is reduced in the combustion chamber, while the same location of peak temperature is obtained in the combustors with varied wall thicknesses. The efficiency of the micro thermophotovoltaic (micro-TPV) system with GaSb and InGaAsSb PV cells are calculated and compared. The micro-TPV system with GaInAsSb PV cells and the micro-combustor with step length 5 mm and outer diameter 3.6 mm produced the highest energy output and efficiency.
•Flame location and temperature of combustion in micro combustors are presented.•Flame stability is enhanced by setting backward-facing step and reducing step length.•Power output and efficiency of the MTPV system is improved by reducing wall thickness.
A hybrid metal–dielectric nanoantenna promises to harness the large Purcell factor of metallic nanostructures while taking advantage of the high scattering directivity and low dissipative losses of ...dielectric nanostructures. Here, we investigate a compact hybrid metal–dielectric nanoantenna that is inspired by the Yagi-Uda design. It comprises a metallic gold bowtie nanoantenna feed element and three silicon nanorod directors, exhibiting high unidirectional in-plane directivity and potential beam redirection capability in the visible spectral range. The entire device has a footprint of only 0.38 λ2, and its forward directivity is robust against fabrication imperfections. We use the photoluminescence from the gold bowtie nanoantenna itself as an elegant emitter to characterize the directivity of the device and experimentally demonstrate a directivity of ∼49.2. In addition, we demonstrate beam redirection with our device, achieving a 5° rotation of the main emission lobe with a feed element displacement of only 16 nm. These results are promising for various applications, including on-chip wireless communications, quantum computing, display technologies, and nanoscale alignment.
Objective
Electroconvulsive therapy (ECT) is commonly used to treat patients with treatment‐resistant depression. We aimed to investigate whether combining an antidepressant agent with ECT might ...enhance therapeutic efficacy and prevent early relapse.
Method
During the acute ECT phase, patients (N = 97) with treatment‐resistant depression were randomized to receive ECT plus agomelatine 50 mg/day (n = 48) or ECT plus placebo (n = 49). Symptom severity measures, including the 17‐item Hamilton Depression Rating Scale (HAMD‐17) and other scales, functional impairment, quality of life, neuropsychological tests, adverse events and attitudes toward ECT, were assessed regularly. Remission was defined as a HAMD‐17 score ≤7. If patients achieved post‐ECT remission, they were prescribed agomelatine 50 mg/day and participated in a 12‐week follow‐up trial. HAMD‐17 was rated at 4‐week intervals. Relapse was defined as a HAMD‐17 score ≥14, or rehospitalization for a psychiatric reason.
Results
The two treatment groups were comparable at (i) baseline variables; (ii) score changes in all symptom measures, functional impairment, quality of life, and neuropsychological tests; (iii) frequency of adverse events and attitudes toward ECT; and (iv) post‐ECT response/remission rates. There were no statistically significant differences following ECT in relapse rates and time to relapse between these two groups.
Conclusion
Adding agomelatine to ECT yielded comparable response/remission rates to ECT without agomelatine in the acute ECT phase. Starting agomelatine in combination with ECT did not seem to be more efficacious in preventing relapse than starting agomelatine after the acute ECT course. More research is needed to guide clinical recommendations.
TET proteins, by converting 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), are hypothesized, but not directly shown, to protect promoter CpG islands (CGIs) against abnormal DNA methylation ...(DNAm) in cancer. We define such a protective role linked to DNA damage from oxidative stress (OS) known to induce this abnormality. TET2 removes aberrant DNAm during OS through interacting with DNA methyltransferases (DNMTs) in a “Yin-Yang” complex targeted to chromatin and enhanced by p300 mediated TET2 acetylation. Abnormal gains of DNAm and 5hmC occur simultaneously in OS, and knocking down TET2 dynamically alters this balance by enhancing 5mC and reducing 5hmC. TET2 reduction results in hypermethylation of promoter CGIs and enhancers in loci largely overlapping with those induced by OS. Thus, TET2 indeed may protect against abnormal, cancer DNAm in a manner linked to DNA damage.
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•TET2 is acetylated at K110 by p300 and deacetylated by HDAC1/2•Acetylation increases TET2 activity, protein stability, and partnering with DNMT1•Oxidative stress targets TET2/DNMTs to chromatin, increases DNAm and 5hmC•TET2 KO induces DNA hypermethylation in a manner similar to oxidative stress
TETs trigger active DNA demethylation by converting 5mC to 5hmC, and dysfunction of TET2 is frequently observed in cancers. Zhang et al. define a TET2-DNMTs “Yin-Yang” complex that is targeted to chromatin during oxidative stress to prevent abnormal DNA methylation and identify a post-translational modification that positively regulates this process.
Summary
A growing elderly population is expected worldwide, and the burden of hip fractures on health care system will continue to increase. By 2035, there will be a 2.7-fold increase in the number ...of hip fractures in Taiwan. The study provides quantitative basis for the future distribution of medical resources.
Introduction
Hip fractures have long been recognized as a major public health concern. The study aimed to determine time trends in the incidence of hip fractures and to forecast the number of hip fractures expected in Taiwan up to 2035.
Methods
A nationwide survey was conducted using data from the Taiwan National Health Insurance Research Database from 2004 to 2011. A total of 141,397 hip fractures were identified, with a mean of 17,675 fractures/year. Annual incidences of hip fractures were calculated and tested for trends. Projections of the incidence rates of hip fractures and bed days associated with hip fractures were calculated using Poisson regression on the historical incidence rates in combination with population projections from 2012 to 2035.
Results
The incidence rates of hip fracture during 2004–2011 were 317 and 211 per 100,000 person-years among women and men, respectively. Over this 8-year period, the age-standardized incidence of hip fracture decreased by 13.4 % among women and 12.2 % among men. Despite the decline in the age-standardized incidence, the absolute number of hip fractures increased owing to the aging population. The number of hip fractures is expected to increase from 18,338 in 2010 to 50,421 in 2035—a 2.7-fold increase. The number of bed days for 2010 and 2035 was estimated at 161,248 and 501,995, respectively, representing a 3.1-fold increase.
Conclusions
The socioeconomic impact of hip fractures will be high in the near future. This study provides a quantitative basis for future policy decisions to serve this need.
Small, stand-alone, direct methanol fuel cells (DMFCs) that have no auxiliary liquid pumps and gas blowers/compressors are known as passive DMFCs. The devices are ideal for powering portable ...electronic devices, as this type of fuel cell uniquely has a simple and compact system and no parasitic power losses. This article provides a comprehensive review of experimental and numerical studies of heat and mass transport in passive DMFCs. Emphasis is placed on the mechanisms and key issues of the mass transport of each species through the fuel cell structure under the influence of passive forces. It is shown that the key issue regarding the methanol supply is how to feed high-concentration methanol solution but with minimum methanol crossover through the membrane so that both the system specific energy and cell performance can be maximized. The key issue regarding the oxygen supply is how to enhance the removal of liquid water from the cathode under the air-breathing condition. For water transport, the aim is to transport the water produced on the cathode through the membrane to the anode by optimizing the design of the membrane electrode assembly so that the fuel cell can be operated with pure methanol and with minimum flooding at the cathode. The heat loss from a passive DMFC is usually large and it is therefore critically important to reduce this feature so that the fuel cell can be operated at a sufficiently high temperature, which critically affects the cell performance.
Clean and highly efficient energy production has long been sought to solve energy and environmental problems. Fuel cells, which convert the chemical energies stored in fuel directly into electrical ...energy, are expected to be a key enabling technology for this century. This article is concerned with one of the most advanced fuel cells – direct methanol fuel cells (DMFCs). We present a comprehensive review of the state-of-the-art studies of mass transport of different species, including the reactants (methanol, oxygen and water) and the products (water and carbon dioxide) in DMFCs. Rather than elaborating on the details of the previous numerical modeling and simulation, the article emphasizes: i) the critical mass-transport issues that need to be addressed so that the performance and operating stability of DMFCs can be upgraded, ii) the basic mechanisms that control the mass-transport behaviors of reactants and products in this type of fuel cell, and iii) the previous experimental and numerical findings regarding the correlation between the mass transport of each species and cell performance.
Aims
Available bacterins, commercial or autogenous, for Actinobacillus pleuropneumoniae disease control have, thus far, shown debatable protective efficacy and only in homologous challenges. Our ...study sought to determine whether the addition of reombinant protein ApxIV to the multicomponent vaccine could enhance protection against homologous and heterologous challenge of A. pleuropneumoniae.
Methods and Results
The virulence of ApxI, ApxII, ApxIV and OMP were cloned and expressed using a prokaryotic system; these recombinant proteins were combined with inactivated A. pleuropneumoniae serovar 1 to formulate different multicomponent vaccines. Immune response and protective efficacy of the vaccines were evaluated in mice and pigs. A protection rate of 67% was observed against heterologous challenge in mice vaccinated with the rApxIV formulation. Piglets vaccinated with vaccine containing ApxIV produced significantly higher antibody titre and provided complete protection and reduced gross lesions by 67% when compared with the nonimmunized group after homologous challenge. Additionally, flow cytometry analysis showed significant cellular immune response.
Conclusions
The results of our vaccination experiments revealed that a combination of inactivated bacteria and the recombinant antigens rApxI, rApxII, rApxIV and rOMP can provide effective protection against heterologous A. pleuropneumoniae challenge.
Significance and Impact of the Study
The addition of ApxIV to the multicomponent vaccine could enhance homologous and heterologous protection in mice and pigs, respectively, against challenge by A. pleuropneumoniae.
► Impact of engine load on engine’s performance, combustion and emission characteristics. ► The brake specific fuel consumption (BSFC) increases significantly at partial load conditions. ► The brake ...thermal efficiency (BTE) drops at lower engine loads, and increases at higher loads. ► The partial load also influences the trend of CO emissions.
This paper investigated the performance, combustion and emission characteristics of diesel engine fueled by biodiesel at partial load conditions. Experiments were conducted on a common-rail fuel injection diesel engine using ultra low sulfur diesel, biodiesel (B100) and their blend fuels of 10%, 20%, 50% (denoted as B10, B20 and B50 respectively) under various loads. The results show that biodiesel/blend fuels have significant impacts on the engine’s brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) at partial load conditions. The increase in BSFC for B100 is faster than that of pure diesel with the decrease of engine load. A largest increase of 28.1% in BSFC is found at 10% load. Whereas for BTE, the results show that the use of biodiesel results in a reduced thermal efficiency at lower engine loads and improved thermal efficiency at higher engine loads. Furthermore, the characteristics of carbon monoxide (CO) emissions are also changed at partial load conditions. When running at lower engine loads, the CO emission increases with the increase of biodiesel blend ratio and the decrease of engine speed. However, at higher engine loads, an opposite trend is obtained.
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