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念珠菌菌血症病原菌特点及短期预后风险预测评分模型的构建与验证

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解放军医学杂志 2024年第3期49卷 280-287页

作者：马建新林小强蔡明池许玉珍彭俊梁声强解放军联勤保障部队第909医院(厦门大学附属东南医院)检验科福建漳州363000 中南大学湘雅医学院附属株洲医院检验科湖南株洲413007

目的分析念珠菌菌血症的病原菌特征,构建并验证其短期死亡风险预测评分模型。方法回顾性分析2011年1月1日-2020年12月31日联勤保障部队第909医院收治的念珠菌菌血症患者的临床资料,分析病原菌构成、药敏试验结果和住院患者发生率。选取... 详细信息

目的分析念珠菌菌血症的病原菌特征,构建并验证其短期死亡风险预测评分模型。方法回顾性分析2011年1月1日-2020年12月31日联勤保障部队第909医院收治的念珠菌菌血症患者的临床资料,分析病原菌构成、药敏试验结果和住院患者发生率。选取念珠菌菌血症324例随机纳入建模组(190例)、验证组(134例),采用二元logistic回归筛选危险因素,依据比值比(OR)赋分,构建30d死亡风险预测评分模型。运用预测评分模型对建模组、验证组进行评分,验证预测模型的预测效能。结果336例念珠菌菌血症患者共检出念珠菌356株,其中白色念珠菌126株(35.39%),热带念珠菌79株(22.19%),近平滑念珠菌74株(20.79%),光滑念珠菌48株(13.48%),季也蒙念珠菌14株(3.93%),克柔念珠菌8株(2.25%),其他念珠菌7株(1.97%);住院患者念珠菌菌血症发生率从2011年的0.20‰上升到2020年的0.48‰。念珠菌对两性霉素B耐药率明显低于氟康唑、伏立康唑、伊曲康唑(P<0.05)。纳入模型分析的324例中,确诊后30d死亡95例,病死率29.32%;建模组男性、发热、肠外营养占比明显高于验证组(P<0.05),慢性肺病、1个月内手术史占比均低于验证组(P<0.05)。Logistic回归分析结果显示,慢性肾衰竭、机械通气、重度中性粒细胞降低、72h内未接受抗真菌治疗、急性生理和慢性健康状况Ⅱ评分(APACHEⅡ)≥20分为念珠菌菌血症短期死亡的危险因素(P<0.05),OR值分别为3.179、1.970、2.979、2.080、2.399,风险赋分分别为6、4、6、4、5。风险评分模型对建模组ROC曲线下面积(AUC)为0.792(95%CI 0.721~0.862),Hosmer-Lemeshow(H-L)检验结果为P=0.305;验证组AUC为0.796(95%CI 0.735~0.898),H-L检验结果为P=0.329。风险评分≤8分为短期死亡低风险组,评分9~15分为中风险组,评分≥16分为高风险组。结论住院患者念珠菌菌血症发生率呈上升趋势,病死率较高;构建的念珠菌菌血症短期死亡风险预测评分模型预测效能较好。

关键词：念珠菌菌血症药敏试验危险因素预测评分模型

Gold Catalysts Supported on Crystalline Fe_2O_3 and CeO_2/Fe_2O_3 for Low-temperature CO Oxidation

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Chemical Research in Chinese Universities 2010年第1期26卷 98-104页

作者： LIU Rui-hui ZHANG Cun-man ma jian-xin School of Environmental Science and Engineering Tongii University Shanghai 200092 P. R. China Clean Energy Automotive Engineering Center School of Automotive Studies Tongji University Shanghai 201804 P. R. China

High active and stable gold catalysts supported on crystalline Fe203 and CeO2/Fe2O3 were prepared via the deposition-precipitation method. The catalyst with a Au load of 1.0% calcined at 180 ℃ showed a CO conversion of 100% at -8.9℃, while Au/CeO2/Fe2O3 converted CO completely at -16.1 ℃. Even having been calcined at 500 ℃, Au/Fe2O3 still exhibited significant catalytic activity, achieving full conversion of CO at 61.6℃. The catalyst with a low Au load of 0.5% could convert CO completely at room temperature and kept the activity unchanged for at least 150 h. N2 adsorption-desorption measurements show that the crystalline supports possessed a high specific surface area of about 200 m2/g. Characterizations of X-ray diffraction and transmission electron microscopy indicate that gold species were highly dispersed as nano or sub-nano particles on the supports. Even after the catalyst was calcined at 500 ℃, the Au particles remained in a nano-size of about 6--10 nm. X-ray photoelectron spectra reveal that the supported Au existed in metallic state Au0. The modification of Au/Fe2O3 by CeO2 proved to be beneficial to the inhibition of crystallization of Fe2O3 and the stabilization of gold particles in dispersed state, consequently promoting catalytic activity.

关键词： Gold catalyst Low-temperature CO oxidation Iron oxide Nanoparticle Additive

LAMINAR DEVELOPING FLOW IN THE ENTRANCE REGION OF ROTATING CURVED PIPES

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Journal of Hydrodynamics 2006年第4期18卷 418-423页

作者： ma jian-feng SHEN xin-rong ZHANG Ming-kan ZHANG Ben-Zhao Department of Mechanics Zhejiang University Hangzhou 310027 China

Three-dimensional laminar flow in the entrance region of rotating curved pipes was investigated. The governing equations were written in an orthogonal curvilinear coordinate system and solved with a fully three-dimensional numerical method. The development of secondary flow, axial velocity, local and average friction factors for different cases of rotation were given and discussed in detail. The results show that rotation influences the flow structure and friction factor greatly and that the secondary flow is sink-type in the early stage of development and then turns to vortex structure. The average friction factor and the intensity of secondary flow have drastic decrease near the entrance. At some proper rotation, the average friction factor can be noticeably reduced.

关键词： developing flow secondary flow rotating curved pipe

A STUDY ON THE FLOW IN HELICAL ELLIPTICAL PIPES WITH GALERKIN METHOD

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Journal of Hydrodynamics 2006年第1期18卷 70-76页

作者： ma jian-feng SHEN xin-rong ZHANG Ben-zhao ZHANG Ming-kan Department of Mechanics Zhejiang University Hangzhou 310027 China

The fully developed laminar flow in helical elliptical pipes is influenced by curvature, torsion and aspect ratio of cross-section. With the aid of the symbolic manipulation technique, the governing equations were solved by the Galerkin method, The procedures of implementing the Galerkin method for flows in curvilinear pipes were discussed. The effects of the aspect ratio and torsion on the flow structure, wall shear stress and flow ratio were examined in detail. The results show that the flow characteristic for aspect ratio larger than unit is quite different from those for the aspect ratio smaller than unit.

关键词： Galerkin method helical elliptical pipe secondary flow

Transesterified Chinese Spicehush (Lindera communis) seed oil as a biodiesel fuel

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Forestry Studies in China 2007年第2期9卷 132-136页

作者： Wang Wei-gang ma Lei jiang jian-xin jiang Li Zhang Zhi-xiang College of materials Science and Technology Beijing Forestry University Beijing 100083 P. R. China

Studies were carried out on the transesterification of the Chinese Spicehush （Lindera communis） seed （LCS） oil with methanol for the production of biodiesel. The methyl esters of LCS oil were compared with soybean esters to determine biodiesel fuel performance and properties. The fatty acids content in the seed kernel oil （LKO） and coat oil （LCO） were quantified by gas chromatography and mass spectrometry method （C-C-MS）. LKO contains 95.1% saturated acids （capric, lauric, myristic and palmitic） and 2.3% unsaturated acids （oleic）. LCO contains 24.6% saturated acids （palmitic and stearic） and 73.6% unsaturated acids （oleic, linoleic and palmitoleic）. The kinematic viscosity, cold filter plugging point, cloud point, flash point and cetane index were determined. The methyl esters of LKO had a higher kinematic viscosity and a lower cold filter plugging point value, so it has better performance in cold weather. The biodiesel of LCS oil has fuel properties within the limits prescribed by American （ASTM D 6751-02） standards, except for a slightly lower flash point of LKO biodiesel than that prescribed by these standards （130℃）. Thus, LKO and LCO biodiesel have great potential to be used on a large scale as fuel for diesel engines.

关键词： biodiesel Lindera communis oil transesterification property

Ventricular synchronicity： observations comparing pulse flow and tissue Doppler assessment in a Chinese healthy adult cohort

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Chinese Medical Journal 2012年第1期125卷 27-32页

作者： QUAN xin ZHU Tian-gang GUO Shi ma jian-xin WANG xin GUO Ji-hong Heart Center Peking University People＇s Hospital Beijing100044 China Department of Cardiology Dongzhimen Hospital BeijingUniversity of Chinese Medicine Beijing 100700 China No. 305 Hospital of People＇s Liberation Army Beijing 100034China

Background Mechanical asynchrony is an important parameter in predicting the response to cardiac resynchronization therapy, but detailed knowledge about cardiac timing in healthy persons is scarce. Therefore, in the current study, we sought to investigate the physiological status of interventricular synchronicity using pulse wave flow and tissue Doppler imaging in a healthy Chinese population. Methods Eighty-eight healthy volunteers underwent standard flow and tissue Doppler echocardiographic examinations. Ventricular inflow and outflow pulse wave flow Doppler patterns were recorded together with annulus pulse tissue Doppler imaging. Time intervals from the beginning of the QRS complex to the onset, peak and end of each wave were measured. Results The onsets of systole between left and right ventricles were highly synchronized by both imaging modalities. However, the left ventricle reached the peak flow ejection and peak mechanical contraction earlier than the right ventricle, （165.61±26.23） ms vs. （204.3±34.55） ms （P 〈0.01） and （133.62±26.19） ms vs. （191.25±38.47） ms （P 〈0.01）. Time to peak early diastolic relaxation was earlier in the left ventricle than in the right heart, （500.23±56.52） ms vs. （524.94±47.42） ms （P 〈0.01 ）. Conclusions Left and right ventricles were well synchronized at the onsets of systole and diastole even though interventricular peak systolic and peak early diastolic dyssynchrony was observed in healthy people by pulse wave Doppler imaging. In addition, diastolic timing events were slightly affected by age and gender.

关键词： systolic diastolic Doppler synchronicity

Grain refinement of 5A06 aluminum alloy welds caused by tungsten inert gas welding arc characteristics under Ar-He alternating gas supply conditions:a coupled method of water-cooled copper plate test/numerical simulation

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Journal of Iron and Steel Research International 2024年第3期31卷 767-777页

作者： Hong-bin Dai jian Miao Jia-xin Lin School of materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and *** the tungsten inert gas(TIG)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change *** FLUENT software was used to numerically simulate the characteristics of the TIG arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were *** with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIG arc has obvious dynamic characteristics under the condition of Ar-He alternating gas *** unique dynamic TIG arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply Grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property

Tuning Surface Molecular Design of Porous Carbon for Blue Energy Harvesting

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Research 2024年第1期2023卷 651-662页

作者： jian Yu Zhong-Lin Wang Tianwei ma Department of Civil and Environmental Engineering University of Hawaii at MānoaHonoluluHI 96822USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Engineering Texas A&M University-Corpus ChristiCorpus ChristiTX 78412USA

Capacitive mixing is a promising blue energy technology due to its membrane-free electricity generation and long electrode life ***,because of limited performance,existing systems do not lend themselves to practical *** it is a crucial factor directly influencing electrode behavior,surface chemistry has largely been overlooked in capacitive ***,we show that manipulating surface functionalization alone can tune the responses of electrodes to produce a high voltage rise without altering the pore structure of the *** findings reveal that the spontaneous electrode potential of a surface-modified carbon electrode shifts negatively proportional to the surface charge due to the surface groups,which explains why and how manipulating the surface chemistry can improve the power generation capacity.

关键词： electrode Porous mixing

1,25-Dihydroxyvitamin D3 pretreatment enhances the efficacy of allergen immunotherapy in a mouse allergic asthma model

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Chinese Medical Journal 2010年第24期123卷 3591-3596页

作者： ma jian-xin XIA Jun-bo CHENG Xiao-ming WANG Chang-zheng Institute of Respiratory Diseases the Second Affiliated Hospital of the Third Military Medical University Chongqing 400037 China

Background Allergen-specific immunotherapy can induce immune tolerance to specific allergens by regulating immune status of individuals. However, its clinical application is limited due to individual differences in efficacy among patients and un-confirmed safety. 1,25 Dihydroxyvitamin D3 （1,25（OH）2D3） has been shown to be involved in a variety of physiological processes, including immune response regulation. In the present study we explored the role of 1,25（OH）2D3 pretreatment for *** Seventy-five BALB/c mice were randomly divided into five groups （15 mice per group）. The mouse allergic asthma model was established by intra-peritoneal injection of ovalbumin （OVA, 10 μg） and aluminium hydroxide （2 mg）as an adjuvant. Intra-peritoneal injection of 50 ng of 1,25（OH）2D3 served as a pretreatment, subcutaneous injection of OVA （100 μg） as an immunotherapy, and 1% OVA inhalation as a challenge. Histopathological analysis was performed on four mice per group. The number of cells and their classification in bronchoalvolar lavage （BAL） fluid were *** of serum OVA-specific immunoglobulin E （slgE） and IFN-Y, IL-4, IL-5 and IL-10 in BAL fluid were measured by *** After 1,25（OH）2D3 pretreatment, immunotherapy could significantly inhibit the infiltration of inflammatory cells into lung tissues and BAL fluid of mice with allergic asthma when compared with un-treated animals （eosinophils：（7.46±1.34）×104/ml vs. （13.41±1.67）×104/ml, P ＜0.05）. In addition, levels of IL-4 （（36.g1±7.87） pg/ml vs. （43.70±6.42）pg/ml, P ＞0.05） and IL-5 （（41.97±7.93） pg/ml vs. （60.14±8.35） pg/ml, P ＜0.05） in BAL fluid and serum slgE （（0.42±0.05）vs. （0.75±0.06） OD units, P ＜0.05） were profoundly reduced. However, the IL-10 level in BAL fluid was significantly increased （（67.74±6.57） pg/ml vs. （44.62±8.81） pg/ml, P ＜0.05）.Conclusions These results indicated that 1,25（OH）2D3 pretreatment enhanced the inhibitory effects of immunotherapy on allergic airway inflammation. In th

关键词： asthma airway inflammation immunotherapy vitamin D3