Numerical Simulation and Entropy Production Analysis of Centrifugal Pump with Various Viscosity

The fluid’s viscosity significantly affects the performance of a centrifugal pump.The entropy production method and leakage are employed to analyze the performance changes under various viscosities by numerical simulation and validated by experiments.The results showed that increasing viscosity reduces both the pump head and efficiency.In addition,the optimal operating point shifts to the left.Leakage is influenced by vortex distribution in the front chamber and boundary layer thickness in wear-ring clearance,leading to an initial increase and subsequent decrease in leakage with increasing viscosity.The total entropy production Spro,Total inside the pump rises with increasing viscosity.The different mechanisms dominate under varying conditions:Turbulent dissipation dominates at low viscosity.Under high-viscosity conditions,energy loss is primarily caused by direct dissipation Spro,D and wall entropy production Spro,W.This study provides a deeper and more objective understanding of the energy characteristics of centrifugal pumps handling fluids of various viscosity,potentially aiding in optimizing pump design and improving energy conversion efficiency.

Optimal Design of High-Speed Partial Flow Pumps using Orthogonal Tests and Numerical Simulations

To investigate the influence of structural parameters on the performances and internal flow characteristics of partial flow pumps at a low specific speed of 10000 rpm,special attention was paid to the first and second stage impeller guide vanes.Moreover,the impeller blade outlet width,impeller inlet diameter,blade inclination angle,and number of blades were considered for orthogonal tests.Accordingly,nine groups of design solutions were formed,and then used as a basis for the execution of numerical simulations(CFD)aimed at obtaining the efficiency values and heads for each design solution group.The influence of impeller geometric parameters on the efficiency and head was explored,and the“weight”of each factor was obtained via a range analysis.Optimal structural parameters were finally chosen on the basis of the numerical simulation results,and the performances of the optimized model were verified accordingly(yet by means of CFD).Evidence is provided that the increase in the efficiency and head of the optimized model was 12.11%and 23.5 m,respectively,compared with those of the original model.

Association between Mental Health Literacy and Workplace Well-Being of Chinese Grassroots Civil Servants:The Chain Mediating Effects of Regulatory Emotional Self-Efficacy and Resilience

This study aimed to investigate the relationship between mental health literacy(MHL)and workplace well-being(WWB)of Chinese grassroots civil servants,with regulatory emotional self-efficacy(RESE)and resilience as mediating variables.A questionnaire survey was conducted among Chinese grassroots civil servants,with a valid sample size of 2673 after excluding missing values and conducting relevant data processing.The PROCESS was used to examine the relationship between MHL,RESE,resilience,and WWB.The study found that MHL among grassroots civil servants was positively and significantly correlated with WWB(r=0.73,p<0.01).RESE partially mediated the relationship between MHL and WWB(β=0.25,95%CI[0.22,0.28]).Resilience partially mediated the relationship between MHL and WWB(β=0.22,95%CI[0.19,0.26]).MHL had a positive effect on WWB through the chain mediating effect of RESE and resilience(β=0.05,95%CI[0.03,0.07]).There is a close relationship between MHL and WWB,where Chinese grassroots civil servants with higher levels of MHL can develop stronger RESE and resilience,leading to higher WWB.The results of this study remind organizational institutions of Chinese grassroots civil servants that enhancing MHL,RESE,and resilience is an important pathway to promoting their WWB.

Determination of metastable zone and induction time of analgin for cooling crystallization

The solubility, metastable zone width, and induction time of analgin for unseeded batch cooling crystallization in ethanol–aqueous system were experimentally determined. The solubility data could be well described by the van't Hoff equation model. The metastable zone width at various cooling rates was measured, and some parameters of nucleation kinetic were calculated using the Ny'vlt theory. Furthermore, the induction period of various temperatures and supersaturation ratios was also measured. According to classical nucleation theory, some nucleation parameters and interfacial energy was calculated through the induction time(t_(ind)) data. Homogeneous nucleation tended to occur when the supersaturation is high, whereas heterogeneous nucleation was more likely to occur when the supersaturation is low.

Ubiquitin-specific protease 15 contributes to gastric cancer progression by regulating the Wnt/β-catenin signaling pathway

BACKGROUND Ubiquitin-specific protease 15(USP15)is an important member of the ubiquitinspecific protease family,the largest deubiquitinase subfamily,whose expression is dysregulated in many types of cancer.However,the biological function and the underlying mechanisms of USP15 in gastric cancer(GC)progression have not been elucidated.AIM To explore the biological role and underlying mechanisms of USP15 in GC progression.METHODS Bioinformatics databases and western blot analysis were utilized to determine the expression of USP15 in GC.Immunohistochemistry was performed to evaluate the correlation between USP15 expression and clinicopathological characteristics of patients with GC.A loss-and gain-of-function experiment was used to investigate the biological effects of USP15 on GC carcinogenesis.RNA sequencing,immunofluorescence,and western blotting were performed to explore the potential mechanism by which USP15 exerts its oncogenic functions.RESULTS USP15 was up-regulated in GC tissue and cell lines.The expression level of USP15 was positively correlated with clinical characteristics(tumor size,depth of invasion,lymph node involvement,tumor-node-metastasis stage,perineural invasion,and vascular invasion),and was related to poor prognosis.USP15 knockdown significantly inhibited cell proliferation,invasion and epithelialmesenchymal transition(EMT)of GC in vitro,while overexpression of USP15 promoted these processes.Knockdown of USP15 inhibited tumor growth in vivo.Mechanistically,RNA sequencing analysis showed that USP15 regulated the Wnt signaling pathway in GC.Western blotting confirmed that USP15 silencing led to significant down-regulation ofβ-catenin and Wnt/β-catenin downstream genes(c-myc and cyclin D1),while overexpression of USP15 yielded an opposite result and USP15 mutation had no change.Immunofluorescence indicated that USP15 promoted nuclear translocation ofβ-catenin,suggesting activation of the Wnt/β-catenin signaling pathway,which may be the critical mechanism promoting GC progression.Finally,rescue experiments showed that the effect of USP15 on gastric cancer progression was dependent on Wnt/β-catenin pathway.CONCLUSION USP15 promotes cell proliferation,invasion and EMT progression of GC via regulating the Wnt/β-catenin pathway,which suggests that USP15 is a novel potential therapeutic target for GC.

Global Stability in a Graph p-Laplacian SIR Epidemic ModelS

A p-Laplacian ( p > 2 ) reaction-diffusion system on weighted graphs is introduced to a networked SIR epidemic model. After overcoming difficulties caused by the nonlinear p-Laplacian, we show that the endemic equilibrium is globally asymptotically stable if the basic reproduction number r0 is greater than 1, while the disease-free equilibrium is globally asymptotically stable if r0 is lower than 1. We extend the stability results of SIR models with graph Laplacian ( p = 2 ) to general graph p-Laplacian.

Dynamics of two levitated nanospheres nonlinearly coupling with non-Markovian environment

The dynamics of two nanospheres nonlinearly coupling with non-Markovian reservoir is investigated. A master equation of the two nanospheres is derived by employing quantum state diffusion method. It is shown that the nonlinear coupling can improve the non-Markovianity. Due to the sharing of the common non-Markovian environment, the state transfer between the two nanospheres can be realized. The entanglement and the squeezing of the individual mode, as well as the jointed two-mode are analyzed. The present system can be realized by trapping two nanospheres in a wideband cavity, which might provide a method to study adjustable non-Markovian dynamics of mechanical motion.

Measurement and correlation of solubility of 9-fluorenone in 11 pure organic solvents from T = 283.15 to 323.15 K

In this work, the solubility data of 9-fluorenone in 11 pure solvents(methanol, ethanol, n-propanol, isopropanol, n-butanol, iso-butanol, acetonitrile, ethyl formate, ethyl acetate, dimethyl sulfoxide, n-hexane)were measured by the gravimetric method from 278.15 K to 318.15 K under atmospheric pressure. The results showed that the solubility of 9-fluorenone in all tested solvents increased with the raised temperature. The solubility data were correlated by the modified Apelblat equation, λh model and NRTL(nonradom two fluid) model. The average relative deviation(ARD) correlated by three thermodynamic models in different solvents was all below 5%, which indicated that the three thermodynamic models fit the solubility data well. Furthermore, the mixing thermodynamic properties of 9-fluorenone in pure solvent systems were calculated via NRTL model. The results indicated the dissolution process of 9-fluorenone is spontaneous and entropically favorable. The solubility and the mixing thermodynamic properties provided in this paper would play an important role in industrial manufacture and follow-up operation of 9-fluorenone.

卤代烷反应中取代和消去竞争的教学设计

在卤代烷的取代和消去反应中,进攻试剂均为带负电的实体或多电子基团,因此取代和消去的竞争是卤代烷教学内容的重点和难点。本文介绍我们对这部分教学内容的组织和设计,使学生更好地理解反应底物、进攻试剂和反应条件对优势反应及产物的影响。该教学设计对培养学生的分析能力、思考能力和灵活应用知识的能力具有重要作用。

超声乳化联合房角黏连分离术与小梁切除术治疗APACG的疗效比较

目的:对比分析原发性急性闭角型青光眼(APACG)合并早期白内障患者行白内障超声乳化联合房角黏连分离术(GSL+PPI术)及小梁切除术后的生活质量并分析相关因素。方法:前瞻性随机性病例对照研究。将符合纳入标准的APACG患者分为A(PPI+GSL术组,29例)、B(小梁切除术组,30例)两组,术后随访6mo,采用NEI-VFQ-25量表评估生活质量,同时记录患者眼压、最佳矫正视力(BCVA)、返院复查频率及基本信息。结果:术后6mo,两组眼压均较术前降低,A组BCVA较术前明显改善(均P<0.05),B组手术前后BCVA无明显差异(P>0.05),且B组复诊频率高于A组(P<0.05)。两组术后NEI-VFQ-25量表评分均较术前增高(均P<0.05),与B组比较,A组术后总体视觉、眼痛、远距离工作、社交功能、角色限制等方面的生活质量评分更高,且A组术后生活质量评分提高的幅度较B组更高(P<0.05),其与A组术后BCVA改善及复查频率较少有关(R2=0.48,F=5.00,P<0.05)。结论:与小梁切除术相比,PPI+GSL术后APACG合并早期白内障患者能获得更好的生活质量。

成人全身麻醉苏醒期躁动危险因素的Meta分析

目的对成人全身麻醉苏醒期躁动的危险因素进行Meta分析。方法检索中国期刊全文数据库(CNKI)、中国生物医学文献数据库(CBM)、维普中文科技期刊数据库(VIP)、万方数据库、The Cochrane Library、PubMed、Embase、Web ofScience,收集2010年1月—2020年1月公开发表的关于全身麻醉苏醒期躁动危险因素的文献,按照纳入与排除标准进行筛选,应用Review Manager 5.3软件对纳入文献进行Meta分析。结果共纳入12篇文献,其中英文文献3篇,中文文献9篇;累计合并EA组1520例,Non-EA组13800例。Meta分析结果显示:男性[OR=1.57(95%CI:1.17,2.10)]、ASA分级高[OR=2.39(95%CI:1.80,3.17)]、有吸烟史[OR=1.87(95%CI:1.23,2.84)]、有酗酒史[OR=2.34(95%CI:1.79,3.05)]、合并糖尿病[OR=1.63(95%CI:1.02,2.59)、手术时间长[OR=22.78(95%CI:5.64,39.92)]、留置导尿管[OR=8.27(95%CI:2.89,23.65)]、镇痛不足[OR=6.26(95%CI:1.59,24.66)]、使用催醒药[OR=1.85(95%CI:1.08,3.16)]、使用静吸复合麻醉[OR=2.26(95%CI:1.34,3.82)]为成人全身麻醉苏醒期躁动的主要危险因素。结论成人全身麻醉苏醒期躁动的主要危险因素为男性、ASA分级高、有吸烟及酗酒史、合并糖尿病、手术时间长、留置导尿管、镇痛不足、使用催醒药、使用静吸复合麻醉。在临床工作中,针对上述危险因素采取防治措施,可降低苏醒期躁动的发生率。

靶向miRNA前体不同类型sgRNA的丰度及特异性评估

CRISPR/Cas技术能高效进行基因组定点编辑,但不同细菌来源或人工改造的Cas9以及Cpf1等核酸酶识别的PAM(protospacer adjacent motif)有差异,因此不同的基因编辑核酸酶可能采用不同类型的sgRNAs(small guide RNAs)。Micro RNAs(miRNAs)是一类调控性的小分子非编码RNAs,为了研究miRNA前体中是否可能存在特异性高的sgRNAs靶点,本文利用本课题组前期开发的生物信息学软件CRISPR-offinder,对靶向28 645条miRNA前体的11种不同类型sgRNA的丰度及特异性进行了分析,并利用CRISPR/Cas9慢病毒技术构建了猪miR-302/367基因簇敲除细胞系,对构建的猪miRNA敲除细胞系的效率进行了检测。结果表明,每个miRNA前体中平均存在约8种不同类型sgRNA的靶点;通过评估靶向猪miRNA前体sgRNA的脱靶效应,发现其中特异性高的sgRNA仅占18.2%;通过CRISPR/Cas9慢病毒技术成功构建了猪miR-302/367基因簇敲除细胞系,发现通过该技术构建miRNA敲除细胞系的效率为40%。本研究为利用CRISPR/Cas技术靶向敲除miRNA提供了重要资源。

Optimization of a Centrifugal Pump Used as a Turbine Impeller By Means of an Orthogonal Test Approach

A prototype centrifugal pump with a specific speed of 110 is used to investigate and optimize the performances of a turbine for power generation.Particular attention is given to the design of the internal impeller.The internal flow field is simulated in the framework of a commercial computational fluid dynamics software(ANSYS).Four geometrical parameters of the impeller are considered,i.e.,the inlet diameter,the inlet width,the blade number,and the blade angle.The optimization is carried out on the basis of a three-level approach relying on an orthogonal test method.The results of the numerical simulations show good agreement with the experimental tests under different flow conditions.In accordance with the L9(34)design table,the head and efficiency under the rated flow rate of the nine designed schemes are calculated and processed with the method of range analysis to obtain an optimized model.

Health Economic Assessment for Screening of Gastric Cancer in AHigh Risk Population in Northeastern China

Objective：To assess economic cost-effects for the screening programs of gastric cancer in a high risk population in northeastern China.Methods：The data were collected from November 2001 to December 2003.The multi-stage sampling to define the screening group and the control group was applied in this study.Two stage screening programs were used in the study.An epidemiological survey and serum PG test were carried out in the first stage.The endoscopy and pathological examination were performed in the second stage screening.Effectiveness was assessed by the increased quality adjusted life-year（QALY） because of reduced gastric cancer deaths in screening.Results：A total of 27,970 participants（n=7,128 screening group,n=20,842 control group） were enrolled in the survey.Twenty nine gastric cancer cases were detected in the screening group with 20 cases in the early stage and 9 cases in the advanced stage,respectively.Eighty six gastric cancer cases were detected in the control group,all of whom were in the advanced stage and had died before the study finished.The screening and treatment of 29 cases cost $152,227 and $5,249 per each case,respectively.The costs were $459 to gain per QALY.Conclusion：The screening program of gastric cancer used in our study is an economic and society-beneficial measure to detect gastric cancer in high risk area.The methods fit China＇s present economic development level.

Integration of human papillomavirus 18 DNA in esophageal carcinoma 109 cells

AIM:To detect human papillomavirus(HPV) DNA in esophageal carcinoma(EC) 109 cells and investigate the relationship between HPV and EC.METHODS:Genomic DNA and total RNA from EC109 cells were isolated.HPV DNA was detected by polymerase chain reaction(PCR) with the general primer sets of My09/11 and GP5 +/6 + for the HPV L1 gene and type-specific primer sets for HPV18 E6 and HPV18 E6-E7.Reverse transcription(RT) of mRNA isolated from EC109 cells was performed to produce a cDNA.And then a PCR-based protocol for the amplification of papillomavirus oncogene transcripts was used to analyze HPV18 DNA and integrated transcripts of HPV18 in the chromosomes of EC109 cells.The final nested PCR products were cloned into a pMD-18T vector and sequenced to analyze the chromosomal location of HPV integration.RESULTS:HPV18 DNA was detected in EC109 cells by PCR using the general primer sets of My09/11 and GP5 +/6 + for HPV L1 and the type-specif ic primer sets for HPV18 E6 and E6-E7 to generate products of 450 bp,150 bp,335 bp and 944 bp,respectively.Approximately 600 bp of integrated HPV18-specific transcript was identified.The final nested PCR product of integrated HPV18 DNA was cloned into a pMD-18T vector and sequenced to analyze the chromosomal location of HPV integration.Sequence alignment showed that the HPV18 sequence from EC109 cells was identical to that of the encoded early protein E7-E1 of the standard HPV18 strain X05015,and another partial gene sequence was identical to a partial sequence of human chromosome 8.CONCLUSION:Integration of the HPV genome into the host cell chromosome suggests that persistent HPV infection is vital for malignant cell transformation and carcinogenesis.

Relationship between Occurrence and Progression of Lung Cancer and Nocturnal Intermittent Hypoxia, Apnea and Daytime Sleepiness

The possible relationship between lung cancer and nocturnal intermittent hypoxia,apnea and daytime sleepiness,especially the possible relationship between the occurrence and progression of lung cancer and obstructive sleep apnea syndrome (OSAS) was explored.Forty-five cases of primary lung cancer suitable for surgical resection at the Third Affiliated Hospital of Kunming Medical University between January 2017 and December 2017 were recruited (lung cancer group),and there were 45 patients in the control group who had no significant differences in age,sex and other general data from lung cancer group.The analyzed covariates included general situation,snore score,the Epworth Sleeping Scale (ESS),Pittsburgh Sleep Quality Index (PSQI),apnea and hypopneas index (AHI),oxygen desaturation index 4 (ODk),lowest arterial oxygen saturation [LSpCh (%)],oxygen below 90% of the time [T90%(min)],the percentage of the total recorded time spend below 90% oxygen saturation (TS90%),to explore the possible relationship between lung cancer and above indicators.The participants were followed up for one year.The results showed that:(1) There was significant difference in body mass index (BMI),ESS,AHI,T90%(min),TS90%,ODh,snore score and LSpCh (%) between lung cancer group and control group (P<0.05).There was no statistically significant difference in age,gender,PSQI score,incidence of concurrent hypertension,diabetes and coronary heart disease (CHD),and smoking history between the two groups (P>0.05);(2) Patients in the lung cancer group were divided into OSAS subgroup and non- OSAS subgroup according to the international standard for the diagnosis of OSAS.There was significant difference in BMI,age,staging,incidence of concurrent hypertension and concurrent CHD,snore score,ESS score,T90%(min),TS90%,ODh and LSpCh (%) between OSAS subgroup and non-OSAS subgroup (P<0.05).There was no statistically significant difference in gender,PSQI score,incidence of concurrent diabetes,smoking history and lung cancer type between the two groups (P>0.05);(3) AHI was strongly negatively correlated with the LSpCh (%) and positively with ESS,staging,snoring score,T90%(min),TS90%,ODh and BMI (P<0.05);(4) There were 3 deaths,5 cases of recurrence,and 4 cases of metastasis in OSAS subgroup;and there was 1 death,4 cases of recurrence and 2 cases of metastasis in non-OSAS subgroup during the follow-up period of one year,respectively.There was no significant difference in mortality,recurrence rate and metastasis rate between the two subgroups,and the total rate of deterioration in OSAS subgroup was significantly increased compared to the non-OSAS subgroup (P<0.05).It was concluded that the patients with lung cancer are prone to nocturnal hypoxemia,apnea,snoring and daytime sleepiness compared to control group.The incidence of OSAS in patients with lung cancer was higher,and the difference in the hypoxemia-related indicators was statistically significant.The mortality,recurrence rate,and metastasis rate increases in lung cancer patients with OSAS during the one-year follow-up period,suggesting that OSAS may be a contributing factor to the occurrence and progression of lung cancer.

The role of autophagic and lysosomal pathways in ischemic brain injury

Autophagy is involved in neural cell death after cerebral ischemia. Our previous studies showed that rapamycin-induced autophagy decreased the rate of apoptosis, but the rate of apoptosis was in- creased after the autophagy inhibitor, 3-methyladenine, was used. In this study, a suture-occluded method was performed to generate a rat model of brain ischemia. Under a transmission electron microscope, autophagic bodies and autophagy lysosomes were markedly accumulated in neurons at 4 hours post brain ischemic injury, with their numbers gradually reducing over time. Western blotting demonstrated that protein levels of light chain 3-11 and cathepsin B were significantly in- creased within 4 hours of ischemic injury, but these levels were not persistently upregulated over time. Confocal microscopy showed that autophagy was mainly found in neurons with positive light chain 3 signal. Injection of rapamycin via tail vein promoted the occurrence of autophagy in rat brain tissue after cerebral ischemia and elevated light chain 3 and cathepsin B expression. However, in- jection of 3-methyladenine significantly diminished light chain 3-11 and cathepsin B expression. Results verified that autophagic and lysosomal activity is increased in ischemic neurons. Abnormal components in cells can be eliminated through upregulating cell autophagy or inhibiting autophagy after ischemic brain injury, resulting in a dynamic balance of substances in cells. Moreover, drugs that interfere with autophagy may be potential therapies for the treatment of brain injury.

Application of the back-error propagation artificial neural network(BPANN) on genetic variants in the PPAR-γ and RXR-α gene and risk of metabolic syndrome in a Chinese Han population

This study was aimed to explore the associations between the combined effects of several polymorphisms in the PPAR-γ and RXR-α gene and environmental factors with the risk of metabolic syndrome by back-error propaga- tion artificial neural network （BPANN）. We established the model based on data gathered from metabolic syndrome patients （n = 1012） and normal controls （n = 1069） by BPANN. Mean impact value （MIV） for each input variable was calculated and the sequence of factors was sorted according to their absolute MIVs. Generalized multifactor dimensionality reduction （GMDR） confirmed a joint effect of PPAR-9＂ and RXR-a based on the results from BPANN. By BPANN analysis, the sequences according to the importance of metabolic syndrome risk fac- tors were in the order of body mass index （BMI）, serum adiponectin, rs4240711, gender, rs4842194, family history of type 2 diabetes, rs2920502, physical activity, alcohol drinking, rs3856806, family history of hypertension, rs1045570, rs6537944, age, rs17817276, family history of hyperlipidemia, smoking, rs1801282 and rs3132291. However, no polymorphism was statistically significant in multiple logistic regression analysis. After controlling for environmental factors, A1, A2, B1 and B2 （rs4240711, rs4842194, rs2920502 and rs3856806） models were the best models （cross-validation consistency 10/10, P = 0.0107） with the GMDR method. In conclusion, the interaction of the PPAR-γ and RXR-α gene could play a role in susceptibility to metabolic syndrome. A more realistic model is obtained by using BPANN to screen out determinants of diseases of multiple etiologies like metabolic syndrome.

Tagging single nucleotide polymorphisms in the PPAR-γ and RXR-α gene and type 2 diabetes risk:a case-control study of a Chinese Han population

Peroxisome proliferator-activated receptor （PPAR-γ）,which is mainly involved in adipocyte differentiation, has been suggested to play an important role in the pathogenesis of insulin resistance and atherosclerosis. We investigated the frequencies of two common tagging polymorphisms of the PPAR-γ gene and two of PPAR-α with minor allele frequency （MAF）≥ 0.05 in the Chinese Han population and analyzed the correlation between the different genotypes and the risk of type 2 diabetes mellitus （T2DM）. TaqMan assay was performed to test the genotypes in T2DM patients （n = 1,105） and normal controls （n = 1,107）. Serum adiponectin concentration was measured by ELISA kit. The variant genotypes rs17817276GG, rs3856806CT and rs3856806CT/TT of PPAR-γ were associated with T2DM, P = 0.023,0.037 and 0.018, respectively. Furthermore, the prevalence of haplotype GT in PPAR-γ was less frequent in the case subjects （0.3%） than in the controls （1.9%） [P 0.001,OR（95%CI）=0.13 （0.06-0.31）]. Patients with genotype TT of rs3856806 had a higher serum level of adiponectin than those with the genotype CC and CT （P = 0.031 and 0.038, respectively）. There was no statistically significant difference between patients and controls in genotype distribution of rs6537944 and rs1045570 of the RXR-α gene. The present study suggests that the variant genotypes in the PPAR-γ gene could decrease the risk for the development of T2DM in the Chinese Han population.

Do neural precursor cells exist in a distal neurogenic region following cerebral hemorrhage?

BACKGROUND： Cerebral injury in adult mammals can induce neural precursor cells （NPCs） to proliferate and migrate towards the focal zone, but it is unclear whether endogenous NPCs can migrate towards regions distal to the hemorrhagic focus or whether NPCs differentiate in the peripheral hemorrhagic region. OBJECTIVE： To investigate the distribution of endogenous NPCs in different brain regions of rats with experimental cerebral hemorrhage, as well as NPC proliferation and differentiation with time. DESIGN, TIME AND SE＇B＇ING： A randomized, controlled animal experiment was performed at the Department of Neurobiology, Luzhou Medical College, between January 2007 and October 2008. MATERIALS： Bromodeoxyuridine （BrdU） was purchased from Roche, Germany. Mouse anti-rat BrdU monoclonal antibody, rabbit anti-nestin polyclonal antibody, rabbit anti-neuron specific enolase （NSE） polyclonal antibody were purchased from Wuhan Boster, China. Rabbit anti-glial fibrillary acidic protein （GFAP） polyclonal antibody was purchased from Sigma, USA. METHODS： Thirty-five adult Sprague Dawley rats were randomly divided into three groups： （1） cerebral hemorrhage group （n = 25）, rats were stereotaxically administered 50 p L autologous arterial blood via the dorsal caudate putamen to induce cerebral hemorrhage; （2） sham-surgery group （n = 5）, rats underwent surgery but did not receive blood injection; （3） blank control group （n = 5）, rats received no surgery and blood administration. At 2 hours after surgery, all rats were intraperitoneally administered BrdU. MAIN OUTCOME MEASURES： Distribution and proliferation of BrdU-positive cells were observed by immunohistochemical staining. BrdU-positive cell differentiation into neurons and glial cells in the peripheral hemorrhagic region was detected by double-label immunofluorescence. RESULTS： Immunohistochemistry results revealed that BrdU-positive cells existed not only in the peripheral hemorrhagic region, such as the subependymal layer and hippocampal dentate gyrus, but also in the lateral septal nucleus, diagonal band, habenular nucleus, and cerebral cortex. Following cerebral hemorrhage, BrdU-positive cells in the peripheral hemorrhagic region gradually increased （P 〈 0.05）, and peaked at 7 14 days. Double-label immunofluorescence showed that with time after cerebral hemorrhage, BrdU/nestin-positive cells decreased, but BrdU/GFAP- and BrdU/NSE-positive cells increased in the peripheral cerebral hemorrhagic region （P 〈 0.05）. CONCLUSION： Cerebral hemorrhage can induce the proliferation of endogenous NPCs, which peaks at 1-2 weeks after hemorrhage. NPCs can also migrate towards the regions distal to the hemorrhagic focus, such as a diagonal band or lateral septal nucleus. NPCs can gradually differentiate with increasing time after hemorrhage.