实体肿瘤血液动力学的三维数值模拟

目的数值研究实体肿瘤内外三维微血管网及间质内的血液动力学。方法数值生成实体肿瘤内外三维微血管网,根据Poiseuille定律和Darcy定律分别计算微血管内压强及肿瘤组织间质压、组织液流速。结果肿瘤外部微血管内压强迅速降低,肿瘤内部微血管压强变化很小,可视为常数;肿瘤组织间质压呈现‘内高且平,外低且陡’的分布,组织液流速与之相反。结论本模型得到了较为有效的肿瘤内外三维血管网结构;血液动力学计算结果与生理实际基本吻合,为研究肿瘤内药物输运提供了可信的模型及方法。

各向异性传导系数对实体肿瘤间质流体流动影响的二维边界元模拟

目的研究实体肿瘤组织间质各向异性传导系数对流体流动的影响。方法用图像处理方法建立具有实体肿瘤微血管形态和分布特征的二维微血管网络模型,应用边界元方法数值计算多连通区域内组织液的流动及水力传导系数变化的影响。结果横向与纵向间质水力传导系数的不同,对整个肿瘤内组织间质压强的分布有明显的影响;不同函数形式分布的水力传导系数,影响肿瘤局部区域内间质流体压强的分布。结论各向异性水力传导系数对实体肿瘤组织间质压强有明显影响,与传导系数变化的范围和肿瘤内微血管网络的形态有关。

肿瘤血管生成的二维数值模拟

血管生成(angiogenesis),指从已存在的血管网络中成长出新的血管网络。肿瘤毛细血管生成在肿瘤的生长、转移等阶段发挥着重要的作用。在此过程中内皮细胞积极参与其中的各个阶段:首先是各种各样的肿瘤促血管生成因子的释放(tumorangiogenesisfactors,TAF),激活内皮细胞;新生的内皮细胞在一系列的内部和外部因素的调节下向着肿瘤迁移,最终新生成的毛细血管到达肿瘤并穿越它。目前对肿瘤内及其周围的毛细血管网络了解很少,这给临床上对肿瘤的研究和治疗带来一定困难。本文考虑内皮细胞与胞外间质的相互作用、对TAF的响应,根据肿瘤内外的生理和病理条件描述肿瘤促血管生成的特点,并根据肿瘤内的复杂特性建立二维离散数学模型,研究肿瘤内部的毛细血管网络的生成。数值模拟的结果显示该模型在一定程度上可以产生符合真实的肿瘤内外的毛细血管分层特点的网络,同时也给后续的研究提供了一定的依据。

力学环境影响下肿瘤内外血管生成的数值模拟

目的考察肿瘤内外不同的力学环境对肿瘤血管生成过程中内皮细胞运动的影响,数值生成肿瘤内外血管网络。方法肿瘤外正常组织和肿瘤组织设为线性粘弹性体。肿瘤外正常组织内皮细胞扩散系数是常数;肿瘤内,肿瘤细胞的活性下降导致组织的黏附力降低,内皮细胞扩散系数设为离中心的幂次函数。建立内皮细胞运动的扩散方程,数值生成肿瘤内外血管网络。结果当考虑肿瘤内外不同力学环境对内皮细胞运动的影响时,可以获得相对真实的分层毛细血管网络:在肿瘤外层富含毛细血管,越靠近肿瘤中心,血管越稀少。在忽略力学环境的影响时,无法得到实验观测到的分层网络。结论肿瘤内外不同的力学环境对肿瘤血管生成的网络结构有着重要影响。

生理参数及药物注射方式对球形实体肿瘤中药物输运的影响

目的研究球形实体肿瘤中生理参数对药物输运的影响,以及探讨有较好效果的药物注射方式。方法设肿瘤中毛细血管网成球对称分布,肿瘤中的毛细血管表面积和肿瘤体积之比为半径的函数。肿瘤间质为多孔介质,化学药物透过毛细血管壁进入肿瘤间质,在肿瘤间质中输运满足扩散方程。肿瘤外正常组织富含血管和淋巴,药物能被淋巴管吸收,药物输运采用改进的药代动力学模型。用肿瘤中各部位药物浓度维持在最小药物浓度MEC水平以上的时间曲线面积(AUC)来衡量药物的效果。结果增大肿瘤间质中毛细血管对药物的通透性P,提高药物在肿瘤间质的扩散系数D,AUC的值均增大。在给出的六种给药方式中,分时段连续滴注和等时间间隔一次性注射的给药方式,它们的AUC值最大。结论增大肿瘤间质中毛细血管对药物的通透性,提高药物在肿瘤间质的扩散系数,以及采用分时段连续滴注和等时间间隔一次性注射的给药方式,有利于肿瘤的治疗。

空间弹性变形构件的李群和李代数分析方法

重点研究了具有三维空间弹性变形的杆件,即杆件同时受弯曲、拉伸和扭转等力作用而发生空间变形的李群和李代数理论描述问题。将杆件任意一点处的弹性变形与力的关系进行分析得到系统的空间变形柔度矩阵,并通过对弹性势能的分析,进一步得到了弹性杆件系统的空间变形的柔性密度。结合Rayleigh-Ritz法计算了系统的特征频率。阐明了所用理论方法解决空间弹性变形杆件问题的方便和有效性,并以空间变形简化处理为简单变形的传统方法进行了仿真结果的分析对比。

利用血管生成模型计算实体肿瘤内的血液动力学

肿瘤血管生成(Tumor-induced Angiogenesis)是指在实体肿瘤细胞诱导下毛细血管的生长以及肿瘤中血液微循环的建立。肿瘤内血液、组织液等流体流动在肿瘤药物输运过程中扮演着重要作用,而这些流动受到肿瘤内微血管网络结构的直接影响。目前要获得精确的肿瘤内外的毛细血管拓扑结构存在一定困难,因此给肿瘤内的血液动力学研究带来困难。本文根据肿瘤内外的复杂生理特性,建立肿瘤内外血管生成的二维离散模型,在获得相对真实的毛细血管网络拓扑结构基础上对肿瘤内的血液动力学进行初步计算,数值计算的结果加深了对肿瘤的复杂生理特性的理解,同时也给肿瘤内的药物输运给予一定的提示。

儿童大剂量移植HLA不相合双亲供者的纯化外周血CD34^+祖细胞

对于许多恶性和非恶性疾病来说,进行清髓性造血祖细胞异基因移植是唯一行之有效的治疗措施,但大多数需要移植的患者无组织相容性的同胞供者.与同胞移植相比,无关供者移植的移植物抗宿主病(GVHD)、移植排斥和感染的发病率及严重程度均增加,故移植效果较差 . 若能采用不用进行HLA配型的单倍体供者,由于其快捷的可用性,将提供一些优势.几乎所有可能进行异基因移植的患者都将会在一个特定的时间内找到供者.与应用脐血干细胞移植比较,单倍体供者在发生未植活或排斥反应的情况下仍然可以利用.其后如需要进行移植后免疫治疗如供体淋巴细胞输注时,也可以随时加以利用.然而在过去,清除T细胞的单倍体的移植使急慢性GVHD、未植活或移植物排斥的发病率增加以及免疫失调时间延长,这样就增加了致命性感染和淋巴细胞增殖性疾病的危险.

菠萝蛋白酶治疗心血管疾病的系统综述(英文)

背景:在2004年,全球估计有1710万人死于心血管疾病。根据美国心脏病协会的数据,心脏病与中风是2型糖尿病患者的首要致死及致残因素。寻找更多的安全有效的心血管疾病治疗方案对于该疾病的预防和治疗十分必要,营养补充品是可行方案之一。目的:探讨菠萝蛋白酶(一种食品补充品)对心血管疾病的预防和治疗作用。检索策略:2009年9月至2010年3月进行电子与手工检索。检索的数据库包括Ovid MEDLINE;All EBMReviews-Cochrane Database of Systematic Reviews(Cochrane DSR)、American College of Physicians(ACP)Journal Club、Database of Abstracts of Reviews of Effects(DARE)、Cochrane Central Register ofControlled Trials(CCTR)、Cochrane Methodology Register(CMR)、Health Technology Assessment(HTA)和National Health Service Economic Evaluation Database(NHSEED);Allied and ComplementaryMedicine(AMED)、British Nursing Index and Archive、EMBASE、Health Management InformationConsortium(HMIC)、ScienceDirect和Electronic Thesis Online Services(ETHOS)。检索语言限定为英文。纳入标准:有关菠萝蛋白酶用于预防或治疗心脑血管疾病的随机对照试验、人体研究、动物研究与实验性研究。资料提取与分析:3位作者分别对检索到的文章进行文献质量评估并提取文献资料。所收集的资料包括实验种类、用药剂量、治疗周期、测量指标、研究结果、菠萝蛋白酶的特征、结果的意义与研究结论。结果:在搜索到的223篇文章中,只有6篇文章符合纳入标准。包括3项动物实验和3项人体试验。菠萝蛋白酶可用来治疗急性血栓性静脉炎,因为它可减少血液中的纤维蛋白原含量,降低血小板聚集度,有保护心脏的作用,并能够改善动脉壁的结构,避免由凝血酶所诱发的血小板聚集,减少血栓的形成。结论:迄今为止,没有菠萝蛋白酶用于心血管疾病治疗的高质量的人体研究。在1948年至2010年间所发表的有关菠萝蛋白酶与心血管疾病的研究的数量极为有限。在未来的心血管疾病研究中这可能是一个值得探索的领域。

Iron and liver fibrosis: Mechanistic and clinical aspects

Liver fibrosis is characterised by excessive deposition of extracellular matrix that interrupts normal liver functionality. It is a pathological stage in several untreated chronic liver diseases such as the iron overload syndrome hereditary haemochromatosis, viral hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis and diabetes. Interestingly, regardless of the aetiology, iron-loading is frequently observed in chronic liver diseases. Excess iron can feed the Fenton reaction to generate unquenchable amounts of free radicals that cause grave cellular and tissue damage and thereby contribute to fibrosis. Moreover, excess iron can induce fibrosis-promoting signals in the parenchymal and non-parenchymal cells, which accelerate disease progression and exacerbate liver pathology. Fibrosis regression is achievable following treatment, but if untreated or unsuccessful, it can progress to the irreversible cirrhotic stage leading to organ failure and hepatocellular carcinoma, where resection or transplantation remain the only curative options. Therefore,understanding the role of iron in liver fibrosis is extremely essential as it can help in formulating iron-related diagnostic, prognostic and treatment strategies. These can be implemented in isolation or in combination with the current approaches to prepone detection, and halt or decelerate fibrosis progression before it reaches the irreparable stage. Thus, this review narrates the role of iron in liver fibrosis. It examines the underlying mechanisms by which excess iron can facilitate fibrotic responses. It describes the role of iron in various clinical pathologies and lastly,highlights the significance and potential of iron-related proteins in the diagnosis and therapeutics of liver fibrosis.

Maneuvering target tracking of UAV based on MN-DDPG and transfer learning

Tracking maneuvering target in real time autonomously and accurately in an uncertain environment is one of the challenging missions for unmanned aerial vehicles(UAVs).In this paper,aiming to address the control problem of maneuvering target tracking and obstacle avoidance,an online path planning approach for UAV is developed based on deep reinforcement learning.Through end-to-end learning powered by neural networks,the proposed approach can achieve the perception of the environment and continuous motion output control.This proposed approach includes:(1)A deep deterministic policy gradient(DDPG)-based control framework to provide learning and autonomous decision-making capability for UAVs;(2)An improved method named MN-DDPG for introducing a type of mixed noises to assist UAV with exploring stochastic strategies for online optimal planning;and(3)An algorithm of taskdecomposition and pre-training for efficient transfer learning to improve the generalization capability of UAV’s control model built based on MN-DDPG.The experimental simulation results have verified that the proposed approach can achieve good self-adaptive adjustment of UAV’s flight attitude in the tasks of maneuvering target tracking with a significant improvement in generalization capability and training efficiency of UAV tracking controller in uncertain environments.

学会在中国做生意：英美烟公司香烟经销网的演变，1902～1941

一从第一次世界大战开始直到第二次世界大战结束,英美烟公司在国外市场取得了其他公司难以企及的进展。其业务涉及40多个国家的市场,并在大多数情况下利用当地的生产设施,至1939年,英美烟公司已经名副其实地成为世界上销售地域最广、以机器生产为基础的跨国企业。

针刺作为辅助手段治疗精神分裂症的探索性病例研究(英文)

目的:探索个体针刺疗法作为常规治疗的辅助手段在精神分裂症患者中的效果;采用探索性病例研究的方法,使用定量和定性评价工具,以便能够对针刺治疗此类患者的确切疗效作出科学评价,并对未来采用针刺治疗此类患者的试验设计提供方法学建议。方法:共纳入11例精神分裂症患者,在予以10周的针刺治疗前,治疗过程中及治疗后分别采用多种有效的定量和定性评价工具对患者进行多方面的评价。这些评价手段包括对针刺治疗、全科医生及精神科医生病历的整理回顾。分析定性资料以评价受试者向研究者及其临床医生和护理人员报告的内容的可靠性。结果:11名受试者中共有8名完成了1个疗程的针刺治疗,全部11名受试者都报告了针刺治疗的积极作用,包括精神分裂症症状的改善,缓解药物的副作用,对精力、内在动机、睡眠、成瘾症状及其他身体机能的促进作用。但是,受试者向研究者和针刺医生报告的信息在不同治疗阶段有一定差别,且往往不一致;在研究结束后,受试者向研究者报告了更多的信息。结论:本研究表明,在常规疗法之外辅以针刺治疗能够给精神分裂症病人带来一定益处。对数据的三角测量表明了受试者报告内容的某些不一致性,而这些可以通过多种研究方法的混合使用得以克服。通过对数据的比较,推荐在将来的研究设计中使用阳性与阴性症状量表、针刺临床试验干预措施报告标准以及在问卷中增加对药物副作用、运动、睡眠以及日常作息的调查。在将来的研究中还应充分考虑到,恢复期患者容易复发,应该让他们可以方便地获得帮助。

An adaptive dwell time scheduling model for phased array radar based on three-way decision

Real-time resource allocation is crucial for phased array radar to undertake multi-task with limited resources,such as the situation of multi-target tracking,in which targets need to be prioritized so that resources can be allocated accordingly and effectively.A three-way decision-based model is proposed for adaptive scheduling of phased radar dwell time.Using the model,the threat posed by a target is measured by an evaluation function,and therefore,a target is assigned to one of the three possible decision regions,i.e.,positive region,negative region,and boundary region.A different region has a various priority in terms of resource demand,and as such,a different radar resource allocation decision is applied to each region to satisfy different tracking accuracies of multi-target.In addition,the dwell time scheduling model can be further optimized by implementing a strategy for determining a proper threshold of three-way decision making to optimize the thresholds adaptively in real-time.The advantages and the performance of the proposed model have been verified by experimental simulations with comparison to the traditional twoway decision model and the three-way decision model without threshold optimization.The experiential results demonstrate that the performance of the proposed model has a certain advantage in detecting high threat targets.

Challenges and facilitators for patient and public involvement in England;focus groups with senior nurses

The concepts of patient and public involvement (PPI) have been recognized and linked with quality in health services internationally and in Europe. In England, for more than a decade, NHS policies have increasingly quoted patient-centred services. Limited evidence exists about the implementation of PPI policies and strategies within organisations;three studies only have explored health professionals’ perceptions of PPI. Although nurses’ positive support for patient and public involvement has been noted, comparatively little is known about senior nurses’ experiences of embedding PPI. A national consultation utilising three focus groups aimed to explore senior nurses’ perceptions of challenges and facilitators for PPI implementation. Four Strategic Health Authorities (SHAs) and eleven Primary Care Trusts (PCTs) in England, with fifteen senior nurses with leadership roles and direct PPI experience, participated. Nurses’ perceptions on patient and public involvement, challenges and facilitators for its implementation were discussed. Focus groups were digitally recorded and transcribed verbatim;anonymised transcripts were validated by participants and analysed with thematic analysis. Limited resources, patient representation and recruitment, complexities of implementing PPI and national policy changes were challenging. Commissioning limitations, lack of feedback on patient experience, limited staff awareness, negative attitudes, management of patients and public expectations constituted further challenges. Nursing role characteristics and informal involvement activities, PPI policy and cultural change, commissioning PPI competencies, related service frameworks, providing feedback on patient experiences to staff and recognition of involvement benefits were recognised as facilitators. Findings provided new insights into senior nurses’ experiences and evidence that progress towards meaningful, effective PPI remains slow. However, recognition of existing nursing role characteristics and potential delivery problems created by expanded nursing roles, informal PPI practice and internal organisational sharing of patient feedback may bring an “emerging productive partnership” with nurses enabling and contributing to effective PPI.

Forecasting cryptocurrency returns and volume using search engines

In the context of the debate on the role of cryptocurrencies in the economy as well as their dynamics and forecasting,this brief study analyzes the predictability of Bitcoin volume and returns using Google search values.We employed a rich set of established empirical approaches,including a VAR framework,a copulas approach,and non-parametric drawings,to capture a dependence structure.Using a weekly dataset from 2013 to 2017,our key results suggest that the frequency of Google searches leads to positive returns and a surge in Bitcoin trading volume.Shocks to search values have a positive effect,which persisted for at least a week.Our findings contribute to the debate on cryptocurrencies/Bitcoins and have profound implications in terms of understanding their dynamics,which are of special interest to investors and economic policymakers.

All-Optical RZ to NRZ Format Conversion Using Single SOA Assisted by Optical Band-Pass Filter

We propose a novel all-optical format conversion from the return-to-zero （RZ） to the non-return-to-zero （NRZ） based on single semiconductor optical amplifier （SOA） and optical band-pass filter （OBE）. We demonstrate the proof of the principle experiment at 10 Gbps by using the test SOA and OBF converter. The format conversion can be achieved with output extinction ratio of 11.51 dB. The BER is 5.5×10^-9 when the power of NRZ is - 10 dBm. The proposed scheme is robust and potential for applications in optical networks.

Components of complex interventions for healthcare: A narrative synthesis of qualitative studies

Objective:Qualitative research on therapeutic components is necessary to evaluate the efficacy of complex interventions in healthcare.As few qualitative syntheses have been conducted,this study aimed to derive a new conceptual framework for understanding the components of complex interventions and provide evidence for the implementation and evaluation of complex healthcare interventions.Methods:A systematic search of seven databases was conducted to identify qualitative studies that explored components of complex healthcare interventions.Meta-ethnography was used to analyze the data and thematic analysis was used to build the conceptual framework.Results:Of the 35 included studies,most complex interventions were non-pharmacological,with cancer accounting for 22%,mental health for 14%,and stroke for 8%.Half of the studies were conducted in the United Kingdom.Three main categories emerged:what should healthcare workers do?what qualifications should they have?and what should patients do?Five main themes were identified:psychological,biological,cognitive and behavioral,environmental,and social support.Conclusion:This analysis provides a reference for designing components of complex interventions in further studies.

Recent progress and perspective on batteries made from nuclear waste

Sustainable energy sources are an immediate need to cope with the imminent issue of climate change the world is facing today.In particular,the long-lasting miniatured power sources that can supply energy continually to power handheld gadgets,sensors,electronic devices,unmanned airborne vehicles in space and extreme mining are some of the examples where this is an acute need.It is known from basic physics that radioactive materials decay over few years and some nuclear materials have their half-life until thousands of years.The past five decades of research have been spent harnessing the decay energy of the radioactive materials to develop batteries that can last until the radioactive reaction continues.Thus,an emergent opportunity of industrial symbiosis to make use of nuclear waste by using radioactive waste as raw material to develop bat-teries with long shelf life presents a great opportunity for sustainable energy resource development.However,the current canon of research on this topic is scarce.This perspective draws fresh discussions on the topic while highlighting future directions in this wealthy arena of research.Graphical abstract A long-lasting miniaturised nuclear battery utilising 14C radioactive isotope as fuel.

Evaluation of outcomes reported in randomized controlled trials for herbal remedies for adults with chronic hepatitis C

Background:Herbal remedies have been widely utilized in treating chronic hepatitis C (CHC) worldwide.Selecting appropriate outcomes to reflect both beneficial and harmful effects is a crucial step in designing randomized controlled trials (RCTs).This study evaluated the outcomes reported in RCTs on herbal remedies for CHC with comparison to the core outcomes recommended by the Cochrane Hepato-Biliary Group (CHBG),to check the consistency of the outcomes and to provide recommendation for future researches.Methods:A systematic literature search was conducted in Western and Chinese databases to identify RCTs on herbal remedies for adults with CHC.For each trial,all the outcomes reported in the results section were collected.Comparison between trial outcomes and CHBG core outcomes were evaluated and summarized with descriptive statistics.Results:A total of 116 RCTs involving 9154 participants were included;27 outcomes were identified.Commonly reported outcomes included alanine aminotransferase (64 trials,55.2%),adverse events (58 trials,50.0%),and end-of-treatment virological response (50 trials,43.1%).All trials indicated that the herbal remedies under investigation had a positive effect and was markedly more effective than the control.Nearly half of the trials reported that the combination of herbal medicine and antiviral drugs could ameliorate adverse events.Very few trials reported primary core outcomes relating survival and quality of life.The most frequently reported core outcomes are non-serious adverse events (54 trials,46.6%),viral response (27 trials,23.3%),and biochemical response (24 trials,20.7%).Conclusion:The variation and inconsistency in trial outcomes impedes research synthesis efforts,and indicate the need for comparable outcomes through the development of core outcome sets in CHC.The low concordance of outcome reporting could be improved by following CHBG core outcomes recommendation.