An investigation of solar cell interconnection schemes within CPV modules using a validated temperature‐dependent SPICE network model

In this paper, we present a temperature‐dependent network model of a concentrator photovoltaic (CPV) module. The ability of this network model to calculate different interconnection schemes within CPV modules is validated, and there is good agreement between the measured and calculated data. The model is used to quantify the influence of an inhomogeneous current and of a temperature distribution between the solar cells on the power output of a module. The different interconnection schemes that combine parallel and series connections are compared. The optimal interconnection scheme strongly depends on the variations in the short current densities and temperature differences between the solar cells as well as on the risk of ‘sudden death’ of individual solar cells. Optimal interconnection schemes for several scenarios are developed. A combination of parallel and series interconnections is found to be the most robust interconnection. Copyright © 2012 John Wiley & Sons, Ltd.     

Evaluation of the inhibitory effect of dimethyl dicarbonate (DMDC) against wine microorganisms

Several microbial species associated with wine were challenged against increasing concentrations of dimethyl dicarbonate (DMDC). The concentration inducing complete cell death upon addition to red wine was regarded as the minimum inhibitory concentration (MIC). In dry red wines with 12% (v/v) ethanol and pH 3.50, the inactivation depended on the initial cell concentration. For an initial inoculum of 500 CFU/ml, the MIC of the yeasts species Schizosaccharomyces pombe, Dekkera bruxellensis, Saccharomyces cerevisiae and Pichia guilliermondii was 100mg/l. The most sensitive strains belong to Zygosaccharomyces bailii, Zygoascus hellenicus and Lachancea thermotolerans, with MIC of 25mg/l DMDC. For inoculation rates of about 10(6)CFU/ml, the maximum dose of DMDC legally authorized (200mg/l) was not effective against the most resistant species. The addition of 100mg/l potassium metabisulphite (PMB), equivalent to 1mg/l molecular sulphur dioxide, increased the inactivation effect of 100mg/l DMDC over initial yeast populations of 10(6)CFU/ml but did not fully kill S. pombe and S. cerevisiae. Lactic acid and acetic acid bacteria were not killed by the addition of 300 mg/l of DMDC. Trials performed in wines before bottling showed that in most samples indigenous bacterial populations were not affected by 200mg/l DMDC. Therefore, under winery practice, DMDC at the maximum dose legally permitted may be regarded as an efficient preservative to control low contamination rates of yeasts but ineffective against lactic acid and acetic acid bacteria.     

Neuroprotective Effects of Sigma 1 Receptor Ligands on Motoneuron Death after Spinal Root Injury in Mice

Loss of motor neurons (MNs) after spinal root injury is a drawback limiting the recovery after palliative surgery by nerve or muscle transfers. Research based on preventing MN death is a hallmark to improve the perspectives of recovery following severe nerve injuries. Sigma-1 receptor (Sig-1R) is a protein highly expressed in MNs, proposed as neuroprotective target for ameliorating MN degenerative conditions. Here, we used a model of L4–L5 rhizotomy in adult mice to induce MN degeneration and to evaluate the neuroprotective role of Sig-1R ligands (PRE-084, SA4503 and BD1063). Lumbar spinal cord was collected at 7, 14, 28 and 42 days post-injury (dpi) for immunohistochemistry, immunofluorescence and Western blot analyses. This proximal axotomy at the immediate postganglionic level resulted in significant death, up to 40% of spinal MNs at 42 days after injury and showed markedly increased glial reactivity. Sig-1R ligands PRE-084, SA4503 and BD1063 reduced MN loss by about 20%, associated to modulation of endoplasmic reticulum stress markers IRE1α and XBP1. These pathways are Sig-1R specific since they were not produced in Sig-1R knockout mice. These findings suggest that Sig-1R is a promising target for the treatment of MN cell death after neural injuries.     

Evaluating the Effects of Subnormothermic Perfusion with AP39 in a Novel Blood-Free Model of Ex Vivo Kidney Preservation and Reperfusion

The use of blood for normothermic and subnormothermic kidney preservation hinders the translation of these approaches and promising therapeutics. This study evaluates whether adding hydrogen sulfide donor AP39 to Hemopure, a blood substitute, during subnormothermic perfusion improves kidney outcomes. After 30 min of renal pedicle clamping, porcine kidneys were treated to 4 h of static cold storage (SCS-4 °C) or subnormothermic perfusion at 21 °C with Hemopure (H-21 °C), Hemopure + 200 nM AP39 (H200nM-21 °C) or Hemopure + 1 µM AP39 (H1µM-21 °C). Then, kidneys were reperfused with Hemopure at 37 °C for 4 h with metabolic support. Perfusate composition, tissue oxygenation, urinalysis and histopathology were analyzed. During preservation, the H200nM-21 °C group exhibited significantly higher urine output than the other groups and significantly higher tissue oxygenation than the H1µM-21 °C group at 1 h and 2h. During reperfusion, the H200nM-21 °C group exhibited significantly higher urine output and lower urine protein than the other groups. Additionally, the H200nM-21 °C group exhibited higher perfusate pO₂ levels than the other groups and significantly lower apoptotic injury than the H-21 °C and the H1µM-21 °C groups. Thus, subnormothermic perfusion at 21 °C with Hemopure + 200 nM AP39 improves renal outcomes. Additionally, our novel blood-free model of ex vivo kidney preservation and reperfusion could be useful for studying other therapeutics.     

Aminomethylphosphonic Acid and Methoxyacetic Acid Induce Apoptosis in Prostate Cancer Cells

Aminomethylphosphonic acid (AMPA) and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA) is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145) through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2), leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer.     

整体顶升钢屋盖网壳结构卸载过程模拟分析

针对大跨度钢屋盖网壳结构杆系众多、受力复杂,采用整体顶升施工方法时主体结构下方必须设置临时支撑,结构成型后拆除支撑会使结构体系发生重大转变及杆件内力重分布的问题,以天水市体育中心体育馆钢屋盖结构为例,建立精细化有限元模型,对所有节点和杆件按照不同规格分类分别赋予实际质量。利用ANSYS中的生死单元法跟踪模拟顶升施工全过程,以结构完全成型且未拆撑时的状态作为卸载过程的初始状态。采用约束方程法对整体分级同步和分区分步2种卸载方式进行模拟,对比不同卸载方式下所有千斤顶的内力值及应力值较大杆件的应力随卸载步的变化趋势。结果表明:受力复杂的大跨度网壳结构需制定合理的卸载方案并进行模拟分析,确保结构卸载过程的安全; 卸载时支撑处的部分拉杆变为压杆,应引起足够重视; 此类刚性大跨度结构的杆件应力在分区分步卸载过程中对位移变化较敏感,所以要严格控制每一步的卸载位移量; 约束方程法能实现对主体结构和临时支撑脱离再接触过程的真实模拟,为类似工程提供了可靠的卸载分析方法。     

Verification of Cooking Endpoint Temperatures in Beef by Immunoassay of Lactate Dehydrogenase Isozyme 5

ABSTRACT: Ground beef Semimembranosus muscle was inoculated with Escherichia coli , and aliquots were left raw or cooked to 1 of 24 time/temperature combinations. Samples were analyzed by aerobic plate counts for surviving bacteria, total extractable protein, and immunoblot quantification of lactate dehydrogenase isozyme 5 (LDH5). Bacterial thermal death curves exhibited a consistent log decline with increasing temperature and cooking times at a given temperature, which were paralleled by decreases in LDH5 at 61 °C and above. Total protein exhibited a linear time/temperature decline. Immunologic analysis of LDH5 may be suitable for development into a rapid assay method for the verification in beef of cooking endpoint temperatures from 61 °C to 69 °C.     

食源性致病菌菌株多相异质性对微生物风险评估的影响研究进展

微生物风险评估是当前保障食品安全的重要科学工具之一,被广泛应用于食品安全政策、法规和标准的制定。菌株多相异质性是微生物的固有特性,普遍存在于各类致病菌之中,影响着风险评估的准确性和不确定性。本文概述了国内外食品微生物菌株多相异质性的相关研究,总结了菌株多相异质性的概念,从生长和失活异质性、被膜形成异质性、毒力异质性和耐药异质性4 个方面全面系统地分析了菌株多相异质性的存在形式。在此基础上探讨了菌株多相异质性对微生物风险评估的影响,进一步展望了降低该影响的4 种解决措施,提出微生物风险评估宏模型的概念,以期提高食品安全风险评估的准确性和可靠性。     

2012—2017年江西省毒蘑菇中毒事件流行病学分析

目的 分析2012—2017年江西省毒蘑菇中毒事件流行病学特征,为制定预防毒蘑菇中毒措施提供依据。方法 通过“国家食源性疾病事件报告系统”查询2012—2017年江西省上报的毒蘑菇中毒事件,并进行描述性分析。结果 2012—2017年江西省共报告野生毒蘑菇中毒事件起数120起,发病人数463人,死亡人数19人,病死率为4.1%;事件起数最多的是2015年,占事件总起数的33.3%(40/120);中毒事件主要发生在5～8月份;九江市、鹰潭市、吉安市和抚州市是毒蘑菇中毒的高发地区;家庭是毒蘑菇中毒的主要发生场所,家庭毒蘑菇中毒事件占中毒事件总起数的92.5%(111/120);农村毒蘑菇中毒事件发生率高于城市;误采误食是毒蘑菇中毒的主要原因。中毒类别主要以灰花纹鹅膏菌和铅绿褶菇为主。结论 毒蘑菇中毒是造成江西省食源性疾病死亡的主要原因。     

基于ANSYS单元生死技术的焊接模拟

以开V型坡口钢板为例,利用ANSYS软件对其焊接过程进行有限元模拟,建立了合理的三维实体模型,使用单元"生死"技术模拟焊接焊缝的依次生成,获得了焊接温度场及残余应力场的分布规律,并对结果进行了分析和讨论,得出计算结果与实测结果比较吻合,说明ANSYS的单元生死技术能有效地模拟焊接过程,本方法对各种关键问题的处理比较得当。