移动云服务环境中办公资源的安全访问控制技术研究（英文）

由于云计算环境中无线办公网络环境的复杂性,导致移动端用户的数据资源存在较大的安全性隐患,因此为了提高移动云服务环境中办公数据访问的安全性,提出了一种基于改进CP-ABE(ciphertext-policy attributed-based encryption)的安全访问控制机制。该方法通过结合电子签章技术,对传统属性加密方案进行了改进,实现了更加高效的移动云计算安全访问控制。仿真实验结果显示:相比其他方法,提出方法所需计算开销和存储更小,且运算效率更高,适用于云服务环境中移动端用户的多种办公应用。

基于谐响应分析的水环境下核主泵叶轮动应力研究

准确计算核主泵叶轮在流体介质中的动应力对核主泵安全可靠运行具有十分重要的意义。本文开展了基于谐响应分析的叶轮动应力的研究,完成了叶轮模态分析、阻尼比分析,压力脉动分析以及动应力分析。得到了叶轮各阶模态频率、叶轮阻尼比以及压力荷载,并对比了缩尺模型实验与数值模拟水力性能,计算了叶轮动应力。结果表明,叶轮湿模态频率比干模态频率低;叶轮流体介质阻尼比比材料阻尼比大一个数量级,并且基本不随着振幅变化;缩尺模型试验与数值模拟水力性能最大误差为2.8%;叶片表面压力脉动主要表现为转频及其谐频振动;叶轮共振模态为1节径1模态,最大动应力为2.02MPa。本文通过分析叶轮模态、阻尼比、压力荷载以及动应力,提供了水环境下叶轮动应力分析方法。

基于小波变换和算术编码的无损图像压缩方法研究（英文）

为了提高图像压缩的性能以便实现更好的无损图像压缩,提出了一种基于小波变换和算术编码的无损图像压缩方法。首先,该方法对图像的所有高频和低频分量进行整数小波变换。然后利用期望最大化算法和最大似然估计对几何分布有限混合模型的参数进行了估计。最后结合直方图截断方法完成算术编码。多组图像数据的测试结果显示相比于其他方法,提出压缩方法表现出较好的压缩性能(主观和客观保真度指标),即更高的压缩比和峰值信噪比。

Henoch-Schonlein purpura with intestinal perforation and cerebral hemorrhage: A case report

Henoch-Schonlein purpura (HSP) with intestinal perforation and cerebral hemorrhage is a very rare clinical condition. There has been no report of HSP complicated with both intestinal perforation and cerebral hemorrhage until October 2012. Here we describe a case of HSP with intestinal perforation and cerebral hemorrhage in a 5-year-old girl. Plain abdominal radiograph in the erect position showed heavy gas in the right subphrenic space with an elevated diaphragm. Partial resection of the small intestine was performed, and pathological analysis suggested chronic suppurative inflammation in all layers of the ileal wall and mesentery. Seventeen days after surgery, cerebral hemorrhage developed and the patient died.

Procalcitionin as a diagnostic marker to distinguish upper and lower gastrointestinal perforation

AIM To assess the accuracy of serum procalcitionin(PCT)as a diagnostic marker in verifying upper and lower gastrointestinal perforation(GIP).METHODS This retrospective study included 46 patients from the surgical intensive care unit(ICU)of the Second Affiliated Hospital of Harbin Medical University who were confirmed to have GIP between June 2013 and December 2016.Demographic and clinical patient data were recorded on admission to ICU.Patients were divided into upper(n=19)and lower(n=27)GIP groups according to the perforation site(above or below Treitz ligament).PCT and WBC count was obtained before laparotomy and then compared between groups.Meanwhile,the diagnostic accuracy of PCT was analyzed.RESULTS Patients with lower GIP exhibited significantly higher APACHE II score,SOFA score and serum PCT level than patients with upper GIP(P=0.017,0.004,and0.001,respectively).There was a significant positive correlation between serum PCT level and APACHE II score or SOFA score(r=0.715 and r=0.611,respectively),while there was a significant negative correlation between serum PCT level and prognosis(r=-0.414).WBC count was not significantly different between the two groups,and WBC count showed no significant correlation with serum PCT level,APACHE II score,SOFA score or prognosis.The area under the receiver operating characteristic curve of PCT level to distinguish upper or lower GIP was 0.778.Patients with a serum PCT level above 17.94 ng/d L had a high likelihood of lower GIP,with a sensitivity of 100%and a specificity of 42.1%.CONCLUSION Serum PCT level is a reliable and accurate diagnostic marker in identifying upper or lower GIP before laparotomy.

Management of procedural pain in the intensive care unit

Pain is a common experience for inpatients,and intensive care unit(ICU)patients undergo more pain than other departmental patients,with an incidence of 50%at rest and up to 80%during common care procedures.At present,the management of persistent pain in ICU patients has attracted considerable attention,and there are many related clinical studies and guidelines.However,the management of transient pain caused by certain ICU procedures has not received sufficient attention.We reviewed the different management strategies for procedural pain in the ICU and reached a conclusion.Pain management is a process of continuous quality improvement that requires multidisciplinary team cooperation,painrelated training of all relevant personnel,effective relief of all kinds of pain,and improvement of patients'quality of life.In clinical work,which involves complex and diverse patients,we should pay attention to the following points for procedural pain:(1)Consider not only the patient's persistent pain but also his or her procedural pain;(2)Conduct multimodal pain management;(3)Provide combined sedation on the basis of pain management;and(4)Perform individualized pain management.Until now,the pain management of procedural pain in the ICU has not attracted extensive attention.Therefore,we expect additional studies to solve the existing problems of procedural pain management in the ICU.

微信平台系统在心血管内科临床教学中的应用

目的评价微信平台在心血管内科临床教学中的应用效果。方法本研究抽选2017年5月至2018年5月心血管内科本科实习生48名为观察对象。数字随机将实习生分为对照组与实验组,每组24名,对照组采用传统教学模式,实验组利用微信平台进行个体化教学。比较两组实习生的理论知识和实践能力评分,分析两组实习生对教学模式的满意度。结果实验组学生的理论知识评分和实践能力评分均明显高于对照组,其对教学模式的满意度亦明显较对照组高(P < 0.01)。结论在心血管内科临床教学中,恰当应用微信网络平台有利于巩固实习生理论知识,提高临床实践能力,增加学习兴趣。

密封口环间隙对核主泵CAP1400瞬态特性的影响

核主泵密封口环间隙泄漏流会与过流部件主流流道形成交互作用,进而影响核主泵内部载荷,带来不稳定的瞬态流动,给核主泵的安全可靠性带来致命的威胁。为此本文利用RNG k-ε湍流模型来数值求解CAP1400核主泵三维内部流场,并分析密封口环间隙对内部非定常流动特性的影响,该数值方法得到了试验验证。研究结果表明:密封口环间隙流会很大程度上影响核主泵动叶与导叶之间的压力脉动干涉,还会通过叶轮上盖板腔室反馈到叶轮进口,并且增大相应频域上的压力脉动幅值,其最大增幅可达到74.5左右,同时还会导致叶轮叶片径向载荷发生周期性突变,影响核主泵的安全可靠性。

Standardization of critical care management of non-critically ill patients with COVID-19

The large global outbreak of coronavirus disease 2019(COVID-19)has seriously endangered the health care system in China and globally.The sudden surge of patients with severe acute respiratory syndrome coronavirus 2 infection has revealed the shortage of critical care medicine resources and intensivists.Currently,the management of non-critically ill patients with COVID-19 is performed mostly by non-intensive care unit(ICU)physicians,who lack the required professional knowledge,training,and practice in critical care medicine,especially in terms of continuous monitoring of the respiratory function,intervention,and feedback on treatment effects.This clinical problem needs an urgent solution.Therefore,here,we propose a series of clinical strategies for non-ICU physicians aimed at the standardization of the management of non-critically ill patients with COVID-19 from the perspective of critical care medicine.Isolation management is performed to facilitate the implementation of hierarchical monitoring and intervention to ensure the reasonable distribution of scarce critical care medical resources and intensivists,highlight the key patients,timely detection of disease progression,and early and appropriate intervention and organ function support,and thus improve the prognosis.Different management objectives are also set based on the high-risk factors and the severity of patients with COVID-19.The approaches suggested herein will facilitate the timely detection of disease progression,and thus ensure the provision of early and appropriate intervention and organ function support,which will eventually improve the prognosis.

Recent advances in non-Pb-based group-Ⅳ chalcogenides for environmentally-friendly thermoelectric materials

Pb-based group-IV chalcogenides including Pb Te and Pb Se have been extensively studied as high performance thermoelectric materials during the past few decades.However,the toxicity of Pb inhibits their applications in vast fields due to the serious harm to the environment.Recently the Pb-free group-IV chalcogenides have become an extensive research subject as promising thermoelectric materials because of their unique thermal and electronic transport properties as well as the enviromentally friendly advantage.This paper briefly summarizes the recent research advances in Sn-,Ge-,and Sichalcogenides thermoelectrics,showing the unexceptionally high thermoelectric performance in Sn Se single crystal,and the significant improvement in thermoelectric performance for those polycrystalline materials by successfully modulating the electronic and thermal transport through using some well-developed strategies including band engineering,nanostructuring and defect engineering.In addition,some important issues for future device applications,including N-type doping and mechanical and chemical stabilities of the new thermoelectrics,are also discussed.

带内部支撑结构的低压排汽缸气动性能分析

The static pressure recovery of low-pressure exhaust hood is important for the overall effectiveness of steam turbines.The tubular and plate stiffeners inside the exhaust contribute to the structural safety of exhaust,which affect the aerodynamic performance.Given the complicated exhaust model coupled with the last stage of turbine,this paper intends to investigate the aerodynamic performance of exhaust hood with individual stiffeners using highfidelity numerical simulations in order to figure out the corresponding effects.The results show that(1)the types of stiffeners have different effects on the aerodynamic performance;and(2)different installation positions and types of plate stiffeners have different effects on aerodynamic performance.The above investigations highlight the future demand regarding reasonable layout and quantity of stiffeners to improve the aerodynamic performance of exhaust as well as maintaining the structural safety.

Two-micrometer thulium laser resection of the prostate-tangerine technique in benign prostatic hyperplasia patients with previously negative transrectal prostate biopsy

The 2-1μm thulium laser resection of the prostate-tangerine technique （TmLRP-TT） has been introduced as a minimally invasive treatment for benign prostatic hyperplasia （BPH）. This study was undertaken to assess the clinical efficacy and safety of TmLRP-TT for the treatment of BPH patients with previously negative transrectal prostate biopsy. A prospective analysis of 51 patients with previously negative transrectal prostate biopsy who underwent surgical treatment using TmLRP-TT was performed from December 2011 to December 2013. Preoperative status, surgical details, and perioperative complications were recorded. The follow-up outcome was evaluated with subjective and objective tests at I and 6 months. TmLRP-TT was successfully completed in all patients. Mean prostate volume, operative duration, and catheterization time were 93.3 ± 37.9 ml, 69.5 ± 39.5 min, and 6.5 ± 1.3 days, respectively. The mean International Prostate Symptom Score, quality of life score, maximum urinary flow rate, and post-void residual urine volume changed notably at 6-month follow-up （22.5 ± 6.9 vs 6.1 ± 3.2, 4.8 ± 1.3 vs 1.1 ± 0.9, 7.3 ± 4.5 vs 18.9 ± 7.1 ml s^-1, and 148.7 ± 168.7 vs 28.4 ± 17.9 ml）. Two （3.9%） patients required blood transfusion perioperatively, while 3 （5.9%） patients experienced transient hematuria postoperatively, and 2 （3.9%） patients received 3 days recatheterization due to clot retention. TmLRP-TT is a safe and effective minimally invasive technique for patients with previously negative transrectal prostate biopsy during the 6-month follow-up. This promising technology may be a feasible surgical method for previously negative transrectal prostate biopsy in the future.

The infection kinetics and transmission potential of two Guaico Culex viruses in Culex quinquefasciatus mosquitoes

Guaico Culex virus(GCXV)is a newly identified segmented Jingmenvirus from Culex spp.mosquitoes in Central and South America.The genome of GCXV is composed of four or five single-stranded positive RNA segments.However,the infection kinetics and transmission capability of GCXV in mosquitoes remain unknown.In this study,we used reverse genetics to rescue two GCXVs(4S and 5S)that contained four and five RNA segments,respectively,in C6/36 cells.Further in vitro characterization revealed that the two GCXVs exhibited comparable replication kinetics,protein expression and viral titers.Importantly,GCXV RNAs were detected in the bodies,salivary glands,midguts and ovaries of Culex quinquefasciatus at 4–10 days after oral infection.In addition,two GCXVs can colonize Cx.quinquefasciatus eggs,resulting in positive rates of 15%–35%for the second gonotrophic cycle.In conclusion,our results demonstrated that GCXVs with four or five RNA segments can be detected in Cx.quinquefasciatus eggs during the first and second gonotrophic cycles after oral infection.

Quantitative and HPLC fingerprint analysis combined with chemometrics for quality evaluation of Codonopsis Radix processed with different methods

Objective: To observe the effect of different processing methods on the quality of Codonopsis Radix and provide data reference for the reasonable processing in the producing areas.Methods: An analytical strategy that combined quantitative and HPLC fingerprint analysis with chemometrics was developed for the quality evaluation of Codonopsis Radix. Lobetyolin, polysaccharide, sucrose,glucose, and fructose were detected simultaneously in Codonopsis Radix samples treated with different processing methods including dryer-drying, sun-drying, shade-drying, sulfur fumigation, and kneading,etc.Results: The results showed that different processing methods had an obvious impact on the quality of Codonopsis Radix. Sun-drying or shade-drying was recommended, and sulfur fumigation should be avoided. And dryer-drying at 40 °C-50 °C was suggested to meet the requirement for large scale processing. In addition, based on the content of polysaccharide, glucose, and fructose, it was advised to knead for three times. As for lobetyolin and sucrose, kneading should be avoided.Conclusions: Our findings demonstrated that processing method had a big impact on the quality of Codonopsis Radix. Based on the results, the appropriate processing methods directed at different requirements were recommended. The study could lay a foundation for the reasonable processing of Codonopsis Radix in producing areas.

Simultaneous determination of 15 flavonoids from different parts of Scutellaria baicalensis and its chemometrics analysis

Objective: The aerial parts of Scutellaria baicalensis were used as Huangqin Tea for thousands of years and mainly contain flavonoids which contribute to its bioactivities. However, there is no appropriate quality evaluation method of Huangqin Tea, and three flavanones of isocarthamidin-7-O-β-D-glucuronide,carthamidin-7-O-β-D-glucuronide, and isoscutellarein-8-O-β-D-glucuronide with high contents in the aerial parts have never been defined quantitatively. Here, an HPLC-DAD method for simultaneous determination of 15 flavonoids and systematically compared their contents and distribution in the roots,stems, leaves, and flowers of S. baicalensis was established.Methods: Under the HPLC-DAD chromatographic conditions, 77 batches of samples of S. baicalensis were analyzed. Meanwhile, the chromatographic fingerprint of different parts of S. baicalensis was established.Subsequently, principal component analysis(PCA), orthogonal projections to latent structures discriminant analysis(OPLS-DA), and clustering heat map were performed based on the contents of 15 flavonoids in different parts of S. baicalensis.Results: The results showed significant differences in the contents and distributions of 15 flavonoids among the different parts of S. baicalensis. The chemical composition of stems showed some similarities to leaves, and their contents were all lower than leaves. The contents of isocarthamidin-7-O-β–glucuronide [(106.66 66 ± 22.68) mg/g], carthamidin-7-O-β-D-glucuronide [(19.82 ± 11.17) mg/g],and isoscutellarein-8-O-β-D-glucuronide [(3.10 ± 1.73) mg/g] were the highest in leaves. The content of apigenin-7-O-β-D-glucopyranoside and chrysin-7-O-β-D-glucuronide were the highest in flowers. The contents of baicalin, baicalein, wogonoside, wogonin, alpinetin, and oroxylin A were higher in roots than in other parts.Conclusion: The method was fully validated and could be effectively used to characterize the contents and distributions of main flavonoids in the different parts of S. baicalensis. It may lay a foundation to establish the quality evaluation system for Huangqin Tea.

Chemical Constituents in Plants of Genus Kadsura Kaempf. ex Juss.

Genus Kadsura Kaempf. ex Juss. includes important medicinal plants widely used in the south and southwest of China. The stems and roots are effective in activating blood and resolving stasis, promoting q/circulation to relieve pain, dispelling wind and eliminating dampness, in which lignans and triterpenoids are the major bioactive constituents. Here we summarized the chemical constituents isolated from genus Kadsura Kaempf. ex Juss., which would provide a primary and strategic platform for further exploiting the medicinal value and resources of genus Kadsura Kaempf. ex Juss.

Native Medicinal Plant Richness Distribution Patterns and Environmental Determinants of Xinjiang, Northwest China

Objective To comprehensively map the distribution patterns of native medicinal plants of Xinjiang Uygur Autonomous Region, China; To find the environmental determinants and to give suggestions for the conservation planning of medicinal plants in Xinjiang region. Methods Firstly, we compiled the distribution data of native medicinal plants at a county level in Xinjiang region, including the source plants of Chinese Materia Medica （CMM）, Uygur Medicine （UM）, and Kazak Medicine （KM）; Secondly, we divided the distribution data into grid with a resolution of 0.1~ x 0.1~ and overlaid it on the topography and climate data in Arcgis 10.0; Finally, we analyzed the correlations of medicinal plant richness and environmental variables with ordinary least square （OLS） regressions and partial regressions. Results UM has more non-native species in Xinjiang region than KM. The species richness of medicinal plants is high in Altay Mountains, western Tianshan Mountains, and part of Kunlun Mountains. The richness of medicinal plants is highly correlated with the vascular plant species richness and climate, and further, the independent effects of vascular plant species richness are higher than the independent effects of climate. The whole plant, root ＆ rhizome, and seed ＆ fruit are more frequently used than stem and leaf for CMM in Xinjiang region. Conclusion The distribution patterns of medicinal plants are concordant with vascular plant species, which could be carefully considered in the conservation planning of this region. Taking full advantage of current nature reserves is a low-costing approach to the conservation of medicinal plants although they were not originally established for medicinal plant protection. Nevertheless, it is urgent to further study the distributions and protection status of medicinal plants in the nature reserves of Xinjiang region.

A multi-center cross-sectional study on blood purification among adult patients in intensive care unit in China: a study protocol

Background: Blood purification (BP) is one of the most important rescue measures for patients with critical illness in the intensive care unit (ICU), espedally for those with acute kidney injury. The purpose of this nationwide survey was to reveal the real world of current BP practice in different ICUs all over China. This study was designed to be a multi-center cross-sectional study. Methods: All adult patients (over 18 years of age), who were admitted to ICU and required BP in 35 sub-centers across China were included during 30-day survey period in 2018. Demographic characteristics and clinical data were recorded including the timing of treatment initiation, indications, modality, relative contraindication, establishment of vascular access, selection of filter/membrane, settings, anti-coagulation, executive department, complication, intake, and output. Discussion: This nationwide survey may contribute to reveal the real world of current BP practice in different ICUs all over China.

Towards a scientific rationale for traditional properties of Chinese medicinal plants: “natures” and “flavors”

Objective: According to theory of Chinese medicine property, the ecological environment shapes properties(natures and flavors) of Chinese materia medica(CMM) and there are close relationships between certain natures and flavors. However, to date these observations have not been validated scientifically in the context of the whole flora of a region. The present study aims to address this gap.Methods: We collected geographical distributions of 3637 vascular plant species native to the Xinjiang region of northwest China, of which around 812 are medicinal plants. The CMM property characters of these medicinal plants were also collected. All medicinal plants were then analyzed in the occurrence of their natures(cold, cool, neutral, warm, and hot) and flavors(sweet, bitter, sour, salty, and pungent). Possible correlations between these properties and environmental factors, notably climate, as well as correlations with plant species richness of the wider native flora of Xinjiang were then investigated using permutation test and regression.Results: Cold species(38.5%) were more numerous than warm(21.0%) and neutral(22.3%), while bitter species(43.3%) were more numerous than pungent(25.6%), sweet(22.4%) and sour(6.7%) ones. Species with bitter flavor were most commonly also cold(48.6%) in nature, sour flavor usually coincided with cold(44.2%) or cool nature(26.0%), whereas pungent or sweet species tended to be warm(34.4%, 28.4%) or neutral(27.8%, 28.4%). The percentages of species of cold/cool nature, bitter flavor were higher in mountainous regions, and the percentages of warm/neutral and pungent/sweet/sour were higher in basins. The percentages of species of cold/cool, bitter were positively correlated with actual evapotranspiration(AET),and also plant species richness but had a bell-shaped relationship with potential evapotranspiration(PET),whereas the inverse situation was shown for warm/neutral and pungent/sweet/sour species.Conclusion: Analysis of the data in Xinjiang region of China supports the qualitative observations concerning natures and flavors in traditional theory of Chinese medicine property. Specifically,(i) certain natures and flavors co-occur more frequently than if randomly distributed;(ii) correlations between proportions of natures and flavors and climatic variables suggest a role for the environment in shaping the properties of CMM.

Ten Basic Principles about Critical Ultrasonography： Critical Care Practitioners Need to Know

With the noninvasive, convenient, and unique value in tile quick diagnosis and dynamic monitoring during the course of treatment, critical ultrasonography has been widely used in critical care medicine, regarded as the ＂visual stethoscope＂ and applied in medical education and training system. Based on years of experience in the application and promotion of critical ultrasonography, the authors of this study suggested that a proper understanding of critical ultrasonography is of most importance, and a consistent quality control system is required to minimize misdiagnosis,