mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Characteristics of coastline changes in mainland China since the early 1940s

Based on multi-temporal topographic maps, remote sensing images and field surveys covering the entire coastal zone of mainland China, the coastlines of six periods since the early 1940s were extracted. Coastline changes over the last 70 years were then analyzed in terms of coastline structure, coastline fractals, coastline change rates, land-sea patterns, and bay areas. The results showed that mainland coastline structure changed dramatically, and due to the significant coastline artificialization mainly driven by sea reclamation and coastal engineering, the remaining natural coastline merely accounts for less than one third at present. Coastline fractal dimension represented an overall spatial pattern of “north < entirety < south”; however, the discrepancy between the north and south coast was apparently narrowed due to dramatic coastline artificialization of northern China which in turn altered the whole pattern. Patterns and processes of land-sea interchange along the mainland coast were complex and varied spatially and temporally, with over 68% advancing toward sea and 22% retreating toward land. The net growth of land area was nearly 14.2 ×10~3 km~2 with an average growth rate of 202.82 km~2 a~(-1); and coast retreat was characterized by area decrease of 93 bays with a magnitude of 10.1 ×10~3 km~2 and an average shrinking rate up to 18.19% or an average shrinking speed up to 144.20 km~2 a~(-1), among which the total area of Bohai shrunk by 7.06%, with an average annual loss amounting to 82 km~2. The dramatic coastline changes along mainland China have brought about kinds of challenges to the coastal environment, therefore the integrated management, effective environment protection and sustainable utilization of coastlines is urgent.
Paleoclimate data assimilation: Its motivation, progress and prospects

Reconstructing past climate is beneficial for researchers to understand the mechanism of past climate change, recognize the context of modern climate change and predict scenarios of future climate change. Paleoclimate data assimilation (PDA), which was first introduced in 2000, is a promising approach and a significant issue in the context of past climate research. PDA has the same theoretical basis as the traditional data assimilation (DA) employed in the fields of atmosphere science, ocean science and land surface science. The main aim of PDA is to optimally estimate past climate states that are both consistent with the climate signal recorded in proxy and the dynamic understanding of the climate system through combining the physical laws and dynamic mechanisms of climate systems represented by climate models with climate signals recorded in proxies (e.g., tree rings, ice cores). After investigating the research status and latest advances of PDA abroad, in this paper, the background, concept and methodology of PAD are briefly introduced. Several special aspects and the development history of PAD are systematically summarized. The theoretical basis and typical cases associated with three frequently-used PAD methods (e.g., nudging, particle filter and ensemble square root filter) are analyzed and demonstrated. Finally, some underlying problems in current studies and key prospects in future research related to PDA are proposed to provide valuable thoughts on and a scientific basis for PDA research.
Hyperpolarizabilities of alkaline-earth metal ions Be~+, Mg~+, and Ca~+

The knowledge of the hyperpolarizabilities of atoms and ions is helpful for the analysis of the high order effects of the frequency shifts in precision spectroscopy experiments. Liu et al. [Phys. Rev. Lett. 114, 223001 (2015)] proposed to establish all-optical trapped ion clocks using laser at the magic wavelength for clock transition. To evaluate the high-order frequency shifts in this new scheme of optical clocks, hyperpolarizabilities are needed, but absent. Using the finite field method based on the B-spline basis set and model potentials, we calculated the electric-field-dependent energy shifts of the ground and low-lying excited states in Be~+, Mg~+, and Ca~+ in the field strength range of 0.0-6×10~(–5) a.u.. The scalar and tensor polarizabilities (α_0, α_2) and hyperpolarizabilities (γ_0, γ_2, γ_4) were deduced. The results of the hyperpolarizabilities for Be~+ showed good agreement with the values in literature, implying that the present method can be applied for the effective estimation of the atomic hyperpolarizabilities, which are rarely reported but needed in experiments. The feasibility of optical trapping of Ca~+ is discussed, and the contributions of hyperpolarizabilities to the transition frequency shift for Ca~+ in the optical dipole trap are estimated using quasi-electrostatic approximation.
Sonic hedgehog signaling in kidney fibrosis: a master communicator

The hedgehog signaling cascade is an evolutionarily conserved pathway that regulates multiple aspects of embryonic development and plays a decisive role in tissue homeostasis. As the best studied member of three hedgehog ligands, sonic hedgehog (Shh) is known to be associated with kidney development and tissue repair after various insults. Recent studies uncover an intrinsic link between dysregulated Shh signaling and renal fibrogenesis. In various types of chronic kidney disease (CKD), Shh is upregulated specifically in renal tubular epithelium but targets interstitial fibroblasts, thereby mediating a dynamic epithelial- mesenchymal communication (EMC). Tubule-derived Shh acts as a growth factor for interstitial fibroblasts and controls a hierarchy of fibrosis-related genes, which lead to the excessive deposition of extracellular matrix in renal interstitium. In this review, we recapitulate the principle of Shh signaling, its activation and regulation in a variety of kidney diseases. We also discuss the potential mechanisms by which Shh promotes renal fibrosis and assess the efficacy of blocking this signaling in preclinical settings. Continuing these lines of investigations will provide novel opportunities for designing effective therapies to improve CKD prognosis in patients.
Asymmetric construction of all-carbon quaternary stereocenters in the total synthesis of natural products

Structure units containing all-carbon quaternary stereogenic center are found in many bioactive natural products. However, enantioselective construction of this type of structure units has been a formidable challenge for synthetic community due to the steric hindrance enforced by all-carbon quaternary stereocenters. In this review, we present the achievements made by Chinese scientists in the area of asymmetric synthesis of all-carbon quaternary stereocenters in natural products during the past two years.
Plant pattern-recognition receptors controlling innate immunity

Unlike animals, plants lack an adaptive immune system, and entirely rely on innate immunity to resist numerous potential pathogens in their environment (Jones and Dangl, 2006; Boller and Felix, 2009). They have evolved diverse immune receptors to detect potential pathogenic microbes via recognition of pathogen-associated molecular patterns (PAMPs) and effectors encoded by pathogens. PAMPs can be detected by surface-localized pattern-recognition receptors (PRRs) that are receptor kinases (RKs) or receptor proteins (RPs), thereby activating pattern-triggered immunity (PTI). Plant PRRs are structurally and functionally analogous to animal Toll-like receptors (TLRs). In addition to microbial molecules, some PRRs can recognize damage-associated molecular patterns (DAMPs) that are plant derived molecules released during pathogen infection. Phytopathogens are capable of secreting effectors into plant apoplast or cytoplasm to enhance virulence. However, further evolution in plants has resulted in PRRs that recognize apoplastic effectors and intracellular immune receptors that recognize cytoplasmic effectors. Plant intracellular immune receptors contain nucleotide-binding, leucine-rich repeat domains and are homologous to animal NOD-like receptors (NLRs). Immunity initiated by NLRs is also referred to as effector-triggered immunity.
RLKs orchestrate the signaling in plant male-female interaction

Different from animals, sessile plants are equipped with a large receptor-like kinase (RLK) superfamily. RLKs are a family of single trans-membrane proteins with divergent N-terminal extracellular domains capped by a signal peptide and C-terminal intracellular kinase. Researches in the last two decades have uncovered an increasing number of RLKs that regulate plant development, stress response and sexual reproduction, highlighting a dominant role of RLK signaling in cell-to-cell communications. Sexual reproduction in flowering plants is featured by interactions between the male gametophyte and the female tissues to facilitate sperm delivery and fertilization. Emerging evidences suggest that RLKs regulate almost every aspect of plant reproductive process, especially during pollination. Therefore, in this review we will focus mainly on the function and signaling of RLKs in plant male-female interaction and discuss the future prospects on these topics.
中国东部夏季暴雨极端事件与水汽输送相关流型特征

1961~2010年中国东部夏季季风过程降水量与暴雨频数年际变化分析发现,两者年代际变化趋势相反,尤其90年代后暴雨频数年代际变化呈显著上升趋势,而中国东部夏季降水量却总体上呈下降趋势.分析1961~2010年夏季暴雨频数空间分布场,研究发现中国东部暴雨频数分布状态呈东南高频区向西北方向的大地形边缘带逐步递减,其可描述出50mm以上暴雨频数分布特征为“东南高,西北低”的与地形“阶梯式”分布相似的格局.另外,在全球气候变化背景下中国东部夏季降水变率与暴雨极端事件频数年际变率空间分布在中国“三阶梯”地形存在显著的区域性差异.研究发现中国东部夏季季风过程降水与暴雨极端事件频数相关的水汽输送通道及其水汽流型,水汽流汇合区的空间结构均呈显著差异.长江流域及华南等为暴雨高频区,中国东部暴雨过程整层水汽输送通道相关结构可描述出自中低纬海洋三支强水汽流 “汇合”及其整层水汽辐合特征,此暴雨高频区水汽流相关“汇合”较夏季季风过程降水或非暴雨类降水“偏南”,且水汽“辐合”结构更为显著.另外,中国东部夏季水汽流环流型特征亦对暴雨极端事件发生频数也有着重要的影响.整层水汽通量相关场暴雨类高频区对应矢气旋式涡旋结构环流型,对比分析非暴雨降水和暴雨频数与整层水汽输送通量相关矢场,可发现两者呈空间位置、尺度不同的相关气旋式环流型,其中暴雨类相关环流型“涡动”结构尺度小、位置偏南;非暴雨降水相关涡动结构尺度大、位置偏北.研究表明了夏季风强弱变化背景下整层水汽输送“涡动”环流的“驱动”及其水汽通量“辐合”的结构对中国东部暴雨高频区南-北位移格局变动有显著影响效应,中国东部暴雨高频区的年代际南北动态“摆动”与中国东部水汽输送“涡动”结构的涡度(正值中心)与散度高值区(负值中心)呈“同步”年代际变化特征.基于上述暴雨极端事件水汽输送及环流型影响综合分析研究,本文研究还提出了中国东部暴雨水汽输送流型结构的综合相关模型.
基于物候记录的中国中部关中地区公元600~902年冬半年温度重建

历史文献中的物候记录是揭示气候变化的重要证据.本文从隋唐时期历史文献中提取出周期性气象、水文事件(如初霜日期等)、农业物候记录(如春耕日期等)和观赏植物物候记录(如山桃始花等)等77个年份的87条历史物候记录.通过建立现代物候期与气温的转换方程,并代入上述历史物候期,重建了中国中部关中地区公元600~902年的冬半年(10月至次年4月)温度变化.关中地区600~902年气候可划分为前暖后冷等2个阶段,这一时期冬半年平均温度比1961~1990年高0.23℃.其中, 600~800年冬半年温度比现代高0.38℃,而800~902年比现代低0.08℃.上述重建结果与已有研究在整个时段内的平均温度和由暖转寒的阶段相一致,在各阶段的冷、暖程度上存在一定差异.本研究为进一步了解中国隋唐时期的温度变化提供了参考.
20世纪40年代初以来中国大陆海岸线变化特征

基于多时相地图资料、遥感影像以及覆盖整个大陆海岸带的野外考察,建立20世纪40年代初以来6个时相的中国大陆海岸线数据,并从岸线结构、岸线分形、岸线变化速率、陆海格局和海湾面积等角度分析过去70年来中国大陆海岸线的变化特征.结论如下:大陆海岸线结构变化显著,岸线人工化是最主要的特征,目前自然岸线的保有比例已经不足1/3;大陆海岸线分维数具有“北方<整体<南方”的宏观格局特征,但近年来北方海岸带急剧的岸线人工化过程通过大大缩小岸线分维数的南北差异而显著改变了中国大陆海岸线的分形特征;大陆沿海的陆海格局与过程特征复杂,超过68%的海岸总体向海扩张,超过22%的海岸总体向陆后退,而净变化结果是陆地面积增加了近1.42万km~2,平均增速为202.82km~2 a~(-1);大陆沿海93个主要海湾的面积萎缩量共约1.01万km~2,整体平均的萎缩率、萎缩速率分别高达18.19%、144.20km~2 a~(-1);渤海海域总面积减少了7.06%,年均减少82km~2.大陆海岸线的剧烈变化导致和加剧了海岸带和近海区域的多种问题,加强对大陆海岸线资源的保护、管理与可持续利用刻不容缓.
Asiatic Callosciurus squirrels as seed dispersers of exotic plants in the Pampas

Seed dispersal by exotic mammals exemplifies mutualistic interactions that can modify the habitat by facilitating the establishment of certain species. We examined the potential for endozoochoric dispersal of exotic plants by Callosciurus erythraeus introduced in the Pampas Region of Argentina. We identified and characterized entire and damaged seeds found in squirrel faeces and evaluated the germination capacity and viability of entire seeds in laboratory assays. We collected 120 samples of squirrel faeces that contained 883 pellets in seasonal surveys conducted between July 2011 and June 2012 at 3 study sites within the main invasion focus of C. erythraeus in Argentina. We found 226 entire seeds in 21% of the samples belonging to 4 species of exotic trees and shrubs. Germination in laboratory assays was recorded for Morus alba and Casuarina sp.; however, germination percentage and rate was higher for seeds obtained from the fruits than for seeds obtained from the faeces. The largest size of entire seeds found in the faeces was 4.2×4.0mm, whereas the damaged seeds had at least 1 dimension ≥ 4.7mm. Our results indicated that C. erythraeus can disperse viable seeds of at least 2 species of exotic trees. C. erythraeus predated seeds of other naturalized species in the region. The morphometric description suggested a restriction on the maximum size for the passage of entire seeds through the digestive tract of squirrels, which provides useful information to predict its role as a potential disperser or predator of other species in other invaded communities.
Seismic detections of the 15 February 2013 Chelyabinsk meteor from the dense ChinArray

ChinArray is a dense portable broadband seismic network to cover the entire continental China, and the Phase I is deployed along the north-south seismic belt in southwest China. In this study, we analyze seismic data recorded on the ChinArray following the February 15, 2013 Chelyabinsk (Russia) meteor. This was the largest known object entering the Earth's atmosphere since the 1908 Tunguska meteor. The seismic energy radiated from this event was recorded by seismic stations worldwide including the dense ChinArray that are more than 4000 km away. The weak signal from the meteor event was contaminated by a magnitude 5.8 Tonga earthquake occurred *20 min earlier. To test the feasibility of detecting the weak seismic signals from the meteor event, we compute vespagram and perform F-K analysis to the surface-wave data. We identify a seismic phase with back azimuth (BAZ) of 329.7° and slowness of 34.73 s/deg, corresponding to the surface wave from the Russian meteor event (BAZ *325.97°). The surface magnitude (MS) of the meteor event is 3.94 ± 0.18. We also perform similar analysis on the data from the broadband array F-net in Japan, and find the BAZ of the surface waves to be 316.61°. With the different BAZs of ChinArray and F-net, we locate the Russian meteor event at 58.80°N, 58.72°E. The relatively large mislocation (*438 km as compared with 55.15°N, 61.41°E by others) may be a result of the bending propagation path of surface waves, which deviates from the great circle path. Our results suggest that the dense ChinArray and its subarrays could be used to detect weak signals at teleseismic distances.
S-wave velocity structure in the SE Tibetan plateau

We use observations recorded by 23 permanent and 99 temporary stations in the SE Tibetan plateau to obtain the S-wave velocity structure along two profiles by applying joint inversion with receiver functions and surface waves. The two profiles cross West Yunnan block (WYB), the Central Yunnan sub-block (CYB), South China block (SCB), and Nanpanjiang basin (NPB). The profile at *25°N shows that the Moho interface in the CYB is deeper than those in the WYB and the NPB, and the topography and Moho depth have clear correspondence. Beneath the Xiaojiang fault zone (XJF), there exists a crustal low-velocity zone (LVZ), crossing the XJF and expanding eastward into the SCB. The NPB is shown to be of relatively high velocity. We speculate that the eastward extrusion of the Tibetan plateau may pass through the XJF and affect its eastern region, and is resisted by the rigid NPB, which has high velocity. This may be the main cause of the crustal thickening and uplift of the topography. In the Tengchong volcanic area, the crust is shown to have alternate high-and low-velocity layers, and the upper mantle is shown to be of low velocity. We consider that the magma which exists in the crust is from the upper mantle and that the complex crustal velocity structure is related to magmatic differentiation. Between the Tengchong volcanic area and the XJF, the crustal velocity is relatively high. Combining these observations with other geophysical evidence, it is indicated that rock strength is high and deformation is weak in this area, which is why the level of seismicity is quite low. The profile at *23°N shows that the variation of the Moho depth is small from the eastern rigid block to the western active block with a wide range of LVZs. We consider that deformation to the south of the SE Tibetan Plateau is weak.
Automatic GUI Test by Using SIFT Matching

In software development process, the last step is usually the Graphic User Interface( GUI) test, which is part of the final user experience (UE) test. Traditionally, there exist some GUI test tools in the market, such as Abbot Java GUI Test Framework and Pounder, in which testers pre-configure in the script all desired actions and instructions for the computer, nonetheless requiring too much of invariance of GUI environment; and they require reconfiguration in case of GUI changes, therefore still to be done mostly manually and hard for non-programmer testers to. Consequently, we proposed GUI tests by image recognition to automate the last process; we managed to innovate upon current algorithms such as SIFT and Random Fern, from which we develop the new algorithm scheme retrieving most efficient feature and dispelling inefficient part of each algorithm. Computers then apply the algorithm, to search for target patterns themselves and take subsequent actions such as manual mouse, keyboard and screen I/O automatically to test the GUI without any manual instructions. Test results showed that the proposed approach can accelerate GUI test largely compared to current benchmarks.
PLC-Oriented Access Point Location Planning Algorithm in Smart-Grid Communication Networks

In this study, we investigate the optimal location of access points (APs) to connect end nodes with a service provider through power-line communication in smartgrid communication networks. APs are the gateways of power-distribution communication networks, connecting users to control centers. Hence, they are vital for the reliable, safe, and economical operation of a power system. This paper proposes a planning method for AP allocation that takes into consideration economics, reliability, network delay, and (n-1) resilience. First, an optimization model for the AP location is established, which minimizes the cost of installing APs, while satisfying the reliability, network delay, and (n-1) resilience constraints. Then, an improved genetic algorithm is proposed to solve the optimization problem. The simulation results indicate that the proposed planning method can deal with diverse network conditions satisfactorily. Furthermore, it can be applied effectively with high flexibility and scalability.
超声检查在小儿肺炎诊断中的初步研究

小儿肺炎是导致小儿患者死亡的重要原因之一,特别是5岁以下小儿患者。以往临床诊断小儿肺炎的标准主要依据临床表现、胸部X线检查及实验室检查指标;但部分患者会出现仅有临床表现,而胸部X线片并未出现明显炎症表现的情况,同时对于小儿患者,在短时间内多次重复照射,明显增加患儿辐射剂量。超声检查具有简便、快捷、多方向性及少限制性等优点,对于小儿患者,其最重要的优点是无放射性损伤,可以很好的应用于小儿患者。本研究通过对小儿肺炎患者进行肺部超声检查,探讨肺部超声在小儿肺炎中的应用价值。
再次遇见MET:MET 14外显子突变的“中国特色”

继EGFR、ALK之后,MET驱动基因作为肺癌精准治疗的“后起之秀”走进了大众视野。然而, MET靶向治疗之路并非如EGFR或ALK一般顺利,最佳生物学标志物的寻找可谓“ 众里寻他千百度”。甚至,由于METLung 临床试验的失败,使 MET的研究一度陷入僵局。直至2014年,Camidge教授团队有关MET扩增研究的发表燃起了MET研究复兴的希望。去年,关于MET 14外显子突变在肺癌中的发现再次将MET的关注度推向顶峰。西方国家的研究结果显示,非鳞非小细胞肺癌(non-small cell lung cancer,NSCLC)患者MET 14外显子突变率为3%~4%,并可对克唑替尼产生良好的治疗效果。
The effi ciency of using a seismic base isolation system for a 2D concrete frame founded upon improved soft soil with rigid inclusions

2D fi nite element models were developed to analyze the effect of improved soft-soil foundation on the effi ciency of a base-isolated concrete frame. Static and dynamic analyses were performed for a frame on raft foundation. Non-improved and improved soft-soil foundation using rigid inclusions were considered, as well as the use of high damping rubber bearing as base isolation. Results show that the use of rigid inclusions increases the effi ciency of base isolation; base shear is reduced by 38% and maximum acceleration at the top of the frame by 30%.
胸腔镜肺癌切除术135例临床分析

目的探讨胸腔镜肺癌切除术的临床应用价值。方法回顾性分析2009年3月至2015年3月内蒙古医科大学附属医院行胸腔镜肺癌肺叶或亚肺叶切除术135例患者的临床资料,其中男86例、女49例,年龄56.3(44~ 81)岁。完成胸腔镜肺叶切除120例,右肺中下叶切除4例,肺楔形切除6例,肺段切除5例,同时行淋巴结清扫术。结果围手术期死亡1例,无支气管胸膜瘘及二次手术者。3例患者中转开胸,余均在腔镜下顺利完成手术。结论胸腔镜肺癌切除术安全有效,合理选择手术适应证可获得良好的治疗效果,值得在基层医院推广应用。
“防风”在中药组方配伍中的意义

防风性味辛温,归膀胱、肺、脾、肝经,具有祛风解表、胜湿止痛、止痉、止痒等功效,主治外感表证、风湿痹痛、破伤风、风疹瘙痒及脾虚湿盛等病证。历代医家依据其性味、归经及质轻上浮、发散、祛风、善行善走的特性,结合中医辨证,拓宽了其临床应用范围,笔者选取荆防败毒散、玉屏风散、泻黄散、消风散及痛泻药方等临床常用方剂,简述其防风的配伍用意,以了解此药在临床中的应用。
法国水定价及公私合作供水模式的经验和启示

法国采取市场与政府并举、公共部门与私人企业合作的供水模式,供水单位、政府和公众有序参与的水价定价程序和不同时期采用不同的主流水定价方法,使法国水价在调节水资源优化配置和节约用水中起到了重要的经济杠杆作用。以法国水定价及公私合作的供水模式为研究对象,分析总结其成功经验,以期为我国的供水事业改革提供参考。
低碳氮比污水旁路磷回收及强化脱氮耦合研究

以某低碳氮比污水处理厂为研究对象,通过不同泥源厌氧释磷能力对比分析,选择非化学协同除磷工艺的一期回流污泥作为磷回收泥源,建立以厌氧释磷为核心的旁路磷回收及释磷污泥反硝化强化脱氮耦合系统,其污泥中PO_4~(3-)-P释放率为9.53mgP/gDS,回收液中PO_4~(3-)-P浓度高于40mg/L,SS低于20mg/L,pH 为7.2~7.8。通过核算,该系统PO_4~(3-)-P回收率为68.7%,释磷污泥反硝化对主流系统脱氮的贡献率为4.3%,可增加1.5mg/L的TN 去除量,实现了“一碳多用”,在一定程度上减轻了低碳氮比污水处理系统碳源不足的问题。
住院服务质量对患者满意度、忠诚度的影响研究

目的了解出院患者对医院服务的感知,分析各指标对患者满意度和忠诚度的影响,为改善医院服务质量提供依据。方法每月采用第三方电话调查的方式收集满意度等数据,采用结构方程模型、优先矩阵分析、数据挖掘中神经网络等方法分析各指标对患者满意度和忠诚度的影响。结果本研究中出院患者总体满意度为94. 64± 7. 83分;该问卷能够较好反应患者住院期间的感知,结构方程模型拟合结果较好;护理维度指标对患者满意度的重要性普遍高于医疗维度指标,其中“生活照顾”和“护士反应”重要性高但满意度较低;“医生态度”是影响患者忠诚度的关键因素,其对患者忠诚度的贡献度达0. 32。结论提高患者满意度应该着重从护理维度入手,医生服务态度是影响患者忠诚度的关键因素,医患接触时间是改善患者忠诚度的关键时刻。
2007-2009年广州市六区PM_(2. 5)空气污染所致肺癌疾病负担研究

目的了解2007-2009年广州市六区居民肺癌的疾病负担情况,并估算其中由PM_(2. 5)污染所致的疾病负担部分。方法以2007-2009年广州市肿瘤登记年报数据为基础,将早死寿命损失年( years of life lost,YLL)作为疾病负担评价指标估算2007-2009年广州市六区居民因肺癌所致疾病负担;利用广州市环境保护局的PM_(2. 5)监测数据,以PM_(2. 5)与肺癌的暴露效应函数为依据,采用比较危险因素评估理论( comparative risk analysis,CRA),估算目标人群肺癌疾病负担中归因于PM_(2. 5)所致空气污染的部分。结果2007-2009年广州市六区居民由肺癌所带来的疾病负担分别为22974. 2YLLs、22128. 7YLLs、29473. 2YLLs,YLL率分别为每千人损失寿命10. 0年、9. 5年、12. 5年,三年总计带来早死寿命损失为74576. 1人年;其中归因于PM_(2. 5)污染的分别为8523. 4YLLs、7944. 2 YLLs、10286. 1YLLs,YLL率分别为每千人损失寿命3. 7年、3. 4年、4. 3年,总计带来早死寿命损失为26753. 7人年。肺癌所致的早死寿命损失年中约有35. 9%由PM_(2. 5)污染所致。结论PM_(2. 5)所致的空气污染威胁广州市居民的健康,所致肺癌给广州市居民带来了沉重的疾病负担。
超声诊断胎儿食管闭锁合并小脑下蚓部缺损、完全性心内膜垫缺损1例

本例EA为合并心脏、小脑等畸形,十分罕见。目前超声检查诊断EA主要通过以下三点:(1)反复观察胃泡小或不显示和羊水过多等间接征象;(2)于胎儿颈部及上纵隔部EA上方盲端无回声区等相对直接征象;(3)由于胎儿消化道充盈和排空等生理活动,可出现一过性食管扩张和胃泡不显示,其与EA超声征象类似,可反复观察胃泡变化予以鉴别,即观察时间至少为持续吞咽动作的30 min。此外,EA上方盲端无回声应与颈部水囊瘤、甲状舌骨囊肿等先天性疾病鉴别,因后者位于颈部及上纵隔部,且可压迫食管导致机械性梗阻,亦有胃泡小和羊水多等征象。
Role of Nd_2O_3 nanoparticles addition on microstructural and superconducting properties of YBa_2Cu_3O_(7–δ) ceramics

The effects of Nd_2O_3 nanoparticles addition on microstructure, transport and AC susceptibility properties of YBa_2Cu_3O_(7–δ) (Y123) superconductors were systematically investigated using X-ray diffraction (XRD), scanning electron micrograph (SEM), four point probe measurement and AC spectrometer. It was found that the added samples were predominant by Y-123 phase beside small amount of Y-211 and unreacted Nd_2O_3 secondary phases. All added samples preserved the orthorhombic structure similar to the pure sample and no orthorhombic-to-tetragonal transition occurred. The samples became more porous and their grain size significantly decreased with addition of Nd_2O_3. The addition of nano-Nd_2O_3 disturbed the grain growth of Y123, thus resulting in the degradation of superconducting properties of the samples. The superconducting transition temperature (T_(c onset)) of samples decreased from 92 K for x=0.0 to 78 K for x=1.0 wt.%, which could be attributable to oxygen vacancy disorder. From AC susceptibility result, the inter- and intra-granular loss peaks became wider and broader with increase of Nd_2O_3 addition due to the weakening of grains coupling. On the other hand, the inter-granular critical current density, J_(cm), was found to increase with Nd_2O_3 addition and had the highest value at x=0.6, confirming that Nd_2O_3 nanoparticles acted as pinning centers in Y123 matrix.
颈部孤立性纤维性肿瘤超声表现1例

讨论孤立性纤维性肿瘤(solitary fibrous tumors,SFTs)是一种少见的间叶来源梭形细胞肿瘤,多为良性,病因不明,好发于中年人,可见于肾脏、乳腺、胸膜、头面部等部位。其中发生于头颈部约6%~16%,而像本例这样发生于颈后肌间隙实属罕见。大部分SFTs生长缓慢、无疼痛等症状,体积较大者可能会因为产生类胰岛素生长因子发生类肿瘤性低血糖。其他组织器官的SFTs超声可表现为低或中等回声实性包块,边界清楚,边缘光滑,内部回声均匀或不均匀,CDFI多无血流信号。颈部SFTs的超声报道甚少,目前还未发现特征性的超声表现。本例超声误诊为先天性肌性斜颈,而术中显示肿块并非图左:二维横切面,内回声不均匀;图右:彩色多普勒下纵切面,未探及血流信号图1颈部实性包块声像图位于胸锁乳突肌内,分析可能由于肿块体积较大,胸锁乳突肌受压被向前推挤,导致病灶定位于胸锁乳突肌的误判。先天性肌性斜颈本质是胸锁乳突肌的血肿和肌炎。急性期超声表现为边界清晰、内部回声不均匀的低回声,血流丰富。随时间延长,血肿机化、胸锁乳突肌增生及纤维化,慢性期超声表现为边界不清的弥散低回声或边界清晰、内回声不均匀的条索状稍强回声,血流稀疏或无血流。由于颈部SFTs缺乏特征性的超声表现,故其与先天性肌性斜颈的鉴别需凭借位置和病史。