Resetting biological oscillators—A stochastic approach

We present a stochastic approach to phase-resetting of an ensemble of oscillators. In order to describe stimulation-induced dynamical phenomena we develop a stochastic model which consists of an ensemble of phase oscillators interacting via random forces. Every single oscillator is submitted to a phase stimulus. The ensemble's dynamics is determined by a Fokker-Planck equation. The stationary states are calculated explicitly, whereas the transients are analysed numerically. If the stimulus of a given (non-vanishing) intensity is administered at a critical initial cluster phase for a critical duration T _crit the ensemble's synchronized oscillation is annihilated. A transition from type 1 resetting to type 0 resetting occurs when the stimulation duration exceeds T _crit. Stimulation causes a shift of the mean frequency of every single oscillator. This frequency shift is explicitly calculated by deriving the mean first passage time. The model shows that there is a subcritical intensity which is connected with an enhanced vulnerability to stimulation. The desynchronized states, the so-called black holes, are typically associated with a double peak in the ensemble's phase distribution. This is important for analysing experimental data because simple peak-detection algorithms are not able to extract the underlying dynamics.Our results are discussed from the experimentator's point of view so that the insights derived from our model can improve data analysis and design of stimulation experiments.     

MORBILLIVIRUS INFECTION IN BOTTLENOSE DOLPHINS: EVIDENCE FOR RECURRENT EPIZOOTICS IN THE WESTERN ATLANTIC AND GULF OF MEXICO

Morbillivirus infection is widespread among odontocetes of the western Atlantic and Gulf of Mexico. Serologic evidence of infection in bottlenose dolphins, Tursiops truncatus , was first detected during an epizootic along the mid-Atlantic coast in 1987. Here, we report recurrent epizootics in the coastal dolphin population since at least the early 1980s based on serological surveys and regional stranding frequencies. The first observed epizootic of this series occurred in the Indian and Banana Rivers in 1982 and was followed by others on the mid-Atlantic coast in 1987–1988 and in the Gulf of Mexico between 1992 and 1994. This temporal pattern of infection is likely facilitated by the population size and its fragmentation into relatively discrete coastal communities. Introduction of morbillivirus into a community with a sufficient number of naive hosts may precipitate an epizootic, depending on the potential for transmission within the group. Propagation of an epizootic along the coast is probably determined by frequency of contact between adjacent communities and seasonal migrations.
Morbillivirus antibodies were also detected in serum from offshore bottlenose dolphins. The sero-prevalence in the latter may be higher than in coastal dolphins because of their close association with enzootically infected pilot whales ( Globicephala spp.). Occasional contact between offshore and coastal dolphins may provide an epizootiologic link between pilot whales and coastal dolphin communities.     

Dopamine Semiquinone Radical Doped PEDOT:PSS: Enhanced Conductivity,Work Function and Performance in Organic Solar Cells

Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been is applied as hole transport material in organic electronic devices for more than 20 years. However, the redundant sulfonic acid group of PEDOT:PSS has often been overlooked. Herein, PEDOT:PSS‐DA is prepared via a facile doping of PEDOT:PSS with dopamine hydrochloride (DA·HCl) which reacts with the redundant sulfonic acid of PSS. The PEDOT:PSS‐DA film exhibits enhanced work function and conductivity compared to those of PEDOT:PSS. PEDOT:PSS‐DA‐based devices show a power conversion efficiency of 16.55% which is the highest in organic solar cells (OSCs) with (poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)‐4‐fluorothiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithio‐phene))‐co‐(1,3‐di(5‐thiophene‐2‐yl)‐5,7‐bis(2‐ethylhexyl)‐benzo[1,2‐c:4,5‐c′]dithiophene‐4,8‐dione))] (PM6):(2,2′‐((2Z,2′Z)‐((12,13‐bis(2‐ethylhexyl)‐3,9‐diundecyl‐12,13‐dihydro‐[1,2,5]thiadiazolo[3,4‐e]thieno[2′′,3′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2‐g]thieno[2′,3′:4,5]thieno[3,2‐b]indole‐2,10‐diyl)bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile) (Y6) as the active layer. Furthermore, PEDOT:PSS‐DA also exhibits enhanced performance in three other donor/acceptor systems, exhibiting high compatibility in OSCs. This work demonstrates that doping PEDOT:PSS with various amino derivatives is a potentially efficient strategy to enhance the performance of PEDOT:PSS in organic electronic devices.     

Development of Dopant‐Free Organic Hole Transporting Materials for Perovskite Solar Cells

There has been considerable progress over the last decade in development of the perovskite solar cells (PSCs), with reported performances now surpassing 25.2% power conversion efficiency. Both long‐term stability and component costs of PSCs remain to be addressed by the research community, using hole transporting materials (HTMs) such as 2,2′,7,7′‐tetrakis(N,N′‐di‐pmethoxyphenylamino)‐9,9′‐spirbiuorene(Spiro‐OMeTAD) and poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] (PTAA). HTMs are essential for high‐performance PSC devices. Although effective, these materials require a relatively high degree of doping with additives to improve charge mobility and interlayer/substrate compatibility, introducing doping‐induced stability issues with these HTMs, and further, additional costs and experimental complexity associated with using these doped materials. This article reviews dopant‐free organic HTMs for PSCs, outlining reports of structures with promising properties toward achieving low‐cost, effective, and scalable materials for devices with long‐term stability. It summarizes recent literature reports on non‐doped, alternative, and more stable HTMs used in PSCs as essential components for high‐efficiency cells, categorizing HTMs as reported for different PSC architectures in addition to use of dopant‐free small molecular and polymeric HTMs. Finally, an outlook and critical assessment of dopant‐free organic HTMs toward commercial application and insight into the development of stable PSC devices is provided.     

中心静脉导管引流对单孔胸腔镜肺癌根治术患者术后胸腔引流的应用分析

目的:探讨中心静脉导管引流对单孔胸腔镜肺癌根治术患者术后胸腔引流的应用效果。方法:回顾性选取2019年1月至2019年12月期间我院收治的行单孔胸腔镜肺癌根治术患者80例的临床资料,根据引流方式的不同分为A组(n=40,传统引流)和B组(n=40,中心静脉导管引流),对比两组患者临床指标、生活质量、炎性因子及并发症发生情况。结果:B组引流操作时间、术后住院时间短于A组(P0.05)。两组术后3个月生活质量简表(SF-36)各维度评分均较术前升高,且B组高于A组(P0.05)。两组术前、术后3d、术后7d白介素-6(IL-6)、C反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)呈先升高后下降趋势,且术后3d、术后7d B组以上指标低于A组(P0.05)。两组术后并发症发生率比较无差异(P0.05)。结论:与传统引流相比,单孔胸腔镜肺癌根治术患者术后采用中心静脉导管引流,效果显著,可减少炎性刺激,安全可靠,有效改善患者术后生活质量。     

单孔、两孔及三孔胸腔镜下早期非小细胞肺癌根治术的效果比较研究

目的:通过比较不同胸腔镜手术方式治疗早期非小细胞肺癌根治术术后的相关临床指标,为临床手术方式提供经验。方法:收集我院2017年1月～2019年12月收治的行肺癌根治术的早期非小细胞肺癌病例共100例,分别采用单孔胸腔镜(40例),两孔胸腔镜(32例)及三孔胸腔镜(28例)手术方式,比较三组手术术中及术后的相关指标。结果:单孔胸腔镜组术中出血量、术后引流量明显少于两孔胸腔镜组和三孔胸腔镜组(P0.05),而两孔胸腔镜组明显少于三孔胸腔镜组(P0.05);单孔胸腔镜组术后胸管留置时间和术后住院时间均短于两孔胸腔镜组和三孔胸腔镜组(P0.05),而两孔胸腔镜组明显短于三孔胸腔镜组(P0.05)。三组组内疼痛评分术后24h低于术后12h,术后48h低于术后24h,差异均有统计学意义(P0.05)。三组组间不同时间点疼痛评分比较发现,单孔胸腔镜组疼痛评分低于两孔胸腔镜组和三孔胸腔镜组(P0.05),而两孔胸腔镜组低于三孔胸腔镜组(P0.05)。三组清扫淋巴结数目、淋巴结站数和术后并发症发生率差异均无统计学意义(P0.05)。结论:单孔胸腔镜早期非小细胞肺癌根治术与两孔、三孔胸腔镜手术相比优势明显,且不会显著增加术后并发症,可作为临床首选。     

中国首批国家公园体制试点的经验与成效、问题与建议

建立国家公园体制是建设生态文明制度的重要内容,是解决我国自然保护地发展过程中存在的重叠设置、多头管理、边界不清、权责不明、保护与发展矛盾突出等问题的重大举措。根据国家统一部署,2020年要设立一批国家公园,分级统一的管理体制基本建立。在跨时2年的资料收集、实地考察基础上,全面总结首批10个国家公园体制试点的经验与成效,梳理试点过程中存在的问题,并提出针对性建议,以期全面展现国家公园体制试点的最新进展,为国家公园深化建设提供参考和依据。结果显示,各试点区基本建立起分级统一的管理体制,创新了运行机制,保护力度持续加强,资金投入不断加大,科研合作不断深化,社会参与逐渐扩大。体制试点产生了明显的生态成效,民生改善初步显现,社会效益充分彰显。但是,仍然存在管理机构级别和类型参差不齐,法律制度不健全,资金保障长效机制未建立,人才队伍建设滞后,保护与发展的矛盾突出,空间范围不合理等问题。建议采取必要措施改进存在的问题,积极推广有效经验,加快健全国家公园体制。     

基于UPLC-MS/MS定量检测法优化灵芝三萜热回流提取工艺的研究

基于超高效液相-三重四级杆质谱联用（UPLC-MS/MS）定量检测法优化出一种灵芝三萜热回流提取的工艺。通过本实验建立的灵芝三萜UPLC-MS/MS精确方法检测不同来源的7个栽培品种灵芝子实体中19个三萜化合物的含量,筛选出三萜含量较高的sd-2灵芝子实体作为提取原料,以三萜含量和提取物得率为指标,通过单因素和响应面实验对灵芝三萜的热回流工艺进行优化,获得的最佳条件为：乙醇浓度75%、提取时间2.5h、液料比14:1、提取次数2次。对获得的最佳提取工艺进行中试实验,灵芝子实体乙醇提取物的得率为6.10%,三萜含量为11.8591mg/g。研究结果可为灵芝三萜的工业大规模提取提供理论依据,为灵芝高附加值产品的开发利用提供技术支撑。     

Phytoremediation of 1,4-Dioxane-Containing Recovered Groundwater

The results of a pilot-scale phytoremediation study are reported in this paper. Small plots of trees established on a closed municipal waste landfill site were irrigated with recovered groundwater containing 1,4-dioxane (dioxane) and other volatile organic compounds (VOCs). The plots were managed to minimize the leaching of irrigation water, and leaching was quantified by the use of bromide tracer. Results indicated that the dioxane (2.5 μg/L) was effectively removed, probably via phytovolatilization, and that a full-scale phytoremediation system could be used. A system is now in place at the site in which the recovered groundwater can be treated using two different approaches. A physical treatment system (PTS) will be used during the winter months, and a 12 ha phytoremediation system (stands of coniferous trees) will be used during the growing season. The PTS removes VOCs using an air-stripper, and destroys dioxane using a photo-catalytic oxidation process. Treated water will be routed to the local sewer system. The phytoremediation system, located on the landfill, will be irrigated with effluent from the PTS air-stripper containing dioxane. Seasonal use of the phytoremediation system will reduce reliance on the photo-catalytic oxidation process that is extremely energy consumptive and expensive to operate.