AIM:To evaluate potential risk factors in the development of ulcerative colitis(UC) in China.METHODS:A total of 1308 patients with UC and 1308 age-matched and sex-matched controls were prospectively studied in China.T...AIM:To evaluate potential risk factors in the development of ulcerative colitis(UC) in China.METHODS:A total of 1308 patients with UC and 1308 age-matched and sex-matched controls were prospectively studied in China.The UC cases were collected from 17 hospitals in China from April 2007 to April 2010.Uniform questionnaires were designed to investigate risk factors including smoking,appendectomy,stress,socio-economic conditions,nonsteroidal antiinflammatory drugs(NSAIDs),oral contraceptives,diet,breastfeeding,infections and family sanitary conditions.Group comparisons by each factor were done using simple logistic regression analysis.Conditional logistic regression was used for multivariate analysis.RESULTS:By univariate analysis,the variables predictive of UC included feeling stress,light and heavy alcoholic drinking,spicy food,sugar consumption and infectious diarrhea,while heavy tea intake and tap water consumption were protective against UC.On multivariate analysis,the protective factor for UC was tap water consumption [odds ratios(OR) = 0.424,95%CI:0.302-0.594,P < 0.001];while the potential risk factors for UC were heavy sugar consumption(OR = 1.632,95%CI:1.156-2.305,P < 0.001),spicy food(light intake:OR = 3.329,95%CI:2.282-4.857,P < 0.001;heavy intake:OR = 3.979,95%CI:2.700-5.863,P < 0.001),and often feeling stress(OR = 1.981,95%CI:1.447-2.711,P < 0.001).Other factors,such as smoking habit,appendectomy,breastfeeding,a history of measles,rural or urban residence,education,oral contraceptives,and NSAID use have not been found to have a significant association with the development of UC in the present study.CONCLUSION:Our study showed tap water consumption was a protective factor for UC,while spicy food,heavy sugar consumption and often feeling stress were risk factors for UC in this Chinese population.展开更多
Thermal barrier coatings(TBCs)can effectively protect the alloy substrate of hot components in aeroengines or land-based gas turbines by the thermal insulation and corrosion/erosion resistance of the ceramic top coat....Thermal barrier coatings(TBCs)can effectively protect the alloy substrate of hot components in aeroengines or land-based gas turbines by the thermal insulation and corrosion/erosion resistance of the ceramic top coat.However,the continuous pursuit of a higher operating temperature leads to degradation,delamination,and premature failure of the top coat.Both new ceramic materials and new coating structures must be developed to meet the demand for future advanced TBC systems.In this paper,the latest progress of some new ceramic materials is first reviewed.Then,a comprehensive spalling mechanism of the ceramic top coat is summarized to understand the dependence of lifetime on various factors such as oxidation scale growth,ceramic sintering,erosion,and calcium–magnesium–aluminium–silicate(CMAS)molten salt corrosion.Finally,new structural design methods for high-performance TBCs are discussed from the perspectives of lamellar,columnar,and nanostructure inclusions.The latest developments of ceramic top coat will be presented in terms of material selection,structural design,and failure mechanism,and the comprehensive guidance will be provided for the development of next-generation advanced TBCs with higher temperature resistance,better thermal insulation,and longer lifetime.展开更多
AIM To investigate the value of the gamma-glutamyltraspeptidase(GGT)-to-platelet(PLT) ratio(GPR) in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B(CHB). METHODS We included 390 untreated CHB pa...AIM To investigate the value of the gamma-glutamyltraspeptidase(GGT)-to-platelet(PLT) ratio(GPR) in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B(CHB). METHODS We included 390 untreated CHB patients in this study. The GPR, aspartate aminotransferase(AST)-to-PLT ratio index(APRI), and fibrosis-4(FIB-4) of all patients were analysed to determine if these parameter were correlated with age, gender, medical history, liver function [total bilirubin(TBil), alanine aminotransferase(ALT), and AST], GGT, PLT count, or hepatic fibrosis stage. The GPR, APRI, and FIB-4, as well as the combination of the GPR and APRI or the GPR and FIB-4 were assessed in different cirrhosis stages using receiver operating characteristic(ROC) curve analysis to evaluate their value in diagnosing hepatic fibrosis in CHB patients. RESULTS The GPR, APRI, and FIB-4 were not correlated withCHB patients' age, gender, or disease duration(P > 0.05), but all of these parameters were positively correlated with serum ALT, AST, GGT, and PLT count(P < 0.01). Additionally, the GPR, APRI, and FIB-4 were positively correlated with hepatic fibrosis(P < 0.01); the areas under the ROC curve for the GPR in F1, F2, F3, and F4 stages were 0.723, 0.741, 0.826, and 0.833, respectively, which were significantly higher than the respective values for the FIB-4 and APRI(F1: 0.581, 0.612; F2: 0.706, 0.711; F3: 0.73, 0.751; and F4: 0.799, 0.778). The respective diagnostic cut-off points for each stage were 0.402, 0.448, 0.548, and 0.833, respectively. The diagnostic sensitivity and specificity were, respectively, 88.8% and 87.5% in F1, 72.7% and 89.7% in F2, 81.3% and 98.6% in F3, and 80% and 97.4% in F4 when the GPR and APRI were connected in parallel; 86.6% and 90.2%, 78.4% and 96%, 78.6% and 97.4%, and 73.2% and 97.9%, respectively, when the GPR and APRI were connected in series; 80.2% and 89%, 65% and 89%, 70.3% and 98.5%, and 78.8% and 96.8%, respectively, when the GPR and FIB-4 were connected in parallel; and 83.6% and 87.9%, 76.8% and 96.6%, 展开更多
AIM:To assess the effect of age at diabetes onset and uncontrollable high Hb A1 c levels on the development of diabetic retinopathy(DR)among Chinese type 2 diabetes mellitus(DM)patients.METHODS:This was a cross-sectio...AIM:To assess the effect of age at diabetes onset and uncontrollable high Hb A1 c levels on the development of diabetic retinopathy(DR)among Chinese type 2 diabetes mellitus(DM)patients.METHODS:This was a cross-sectional survey of diabetic patients in Subei district,China.Data covering physical measurements,fasting blood-glucose(FBG),glycosylated hemoglobin(Hb A1 c),blood lipid,urinary albumin/creatinine ratio(UACR),ocular fundus examination,and diabetes treatment records were collected.An independent sample t-test were used to analyze differences.A Logistic regression analysis was applied to study the independent risk factors of DR.RESULTS:A total of 1282 patients with type 2 DM were enrolled,and 191 cases had DR(14.9%).The age at diabetes onset,education level,alcohol consumption,Hb A1 c level,UACR level,and hypoglycemic drugs were independent influencing factors for DR.The older the onset of diabetes,the less likely to develop DR(OR:0.958,95%CI:0.942-0.975,P=0.000).Patients were then divided in terms of age at diabetes onset as follows:<50 y,50-59 y,60-69 y,and≥70 y.Compared with diabetes onset age<50 y,50-59 y(OR:0.463,95%CI:0.306-0.699,P=0.000),60-69 y(OR:0.329,95%CI:0.203-0.535,P=0.000)and≥70 y(OR:0.232,95%CI:0.094-0.577,P=0.002)were at a lower risk of DR.The prevalence of DR was highest in patients with diabetes onset age<50 y(29.5%,P<0.05).The Hb A1 c level(8.67±1.97)%and proportion of insulin injection(52.5%)in patients with diabetes onset<40 y were higher than in patients with older diabetes onset age(P<0.05).CONCLUSION:Diabetes onset at an earlier age and uncontrollable high Hb A1 c level could be independent risk factors for DR.展开更多
AIM:To investigate the hepatoprotective effects and mechanisms of an extract of Salvia miltiorrhiza and Carthamus tinctorius in vivo.METHODS:C57BL/6J mice were randomly assigned to five groups and intraperitoneally ad...AIM:To investigate the hepatoprotective effects and mechanisms of an extract of Salvia miltiorrhiza and Carthamus tinctorius in vivo.METHODS:C57BL/6J mice were randomly assigned to five groups and intraperitoneally administered 0.9% saline,Salvia miltiorrhiza and Carthamus tinctorius extract [Danhong injection(DHI),0.75 and 3 g/kg mixed extract] or reduced glutathione for injection(RGI,300 mg/kg) for 30 min before exposure to lipopolysaccharide(LPS,16 mg/kg). After intraperitoneal LPS stimulation for 90 min or 6 h,the mice were sacrificed by ether anaesthesia,and serum and liver samples were collected. Histological analysis(H&E) and terminal deoxynucleotidyl transferase-mediated d UTP nick end-labelling(TUNEL) staining were performed. Alanine transferase(ALT),aspartate transaminase(AST),total bilirubin(TBil),glutathione-S-transferase(GST),malondialdehyde(MDA),tumour necrosis factor(TNF)-α,interleukin(IL)-6,and caspase-3 levels were measured. Bax,Bcl-2,P-IκBα,IκBα,P-NF-κB p65,and NF-κB p65 protein levels were determined by Western blot. TNF-α,IL-6,caspase-3,Bax and Bcl-2 m RNA expression was measured by real-time reverse transcription-polymerase chain reaction(RT-PCR).RESULTS:Hematoxylin-eosin staining and TUNEL results suggested that DHI(3 g/kg) treatment alleviated inflammatory and apoptotic(P < 0.01) injury in the liver of mice. DHI treatment dose-dependently blunted the abnormal changes in biochemical parameters such as ALT(72.53 ± 2.83 for 3 g/kg,P < 0.01),AST(76.97 ± 5.00 for 3 g/kg,P < 0.01),TBil(1.17 ± 0.10 for 3 g/kg,P < 0.01),MDA(0.81 ± 0.36 for 3 g/kg,P < 0.01),and GST(358.86 ± 12.09 for 3 g/kg,P < 0.01). Moreover,DHI(3 g/kg) remarkably decreased LPS-induced protein expression of TNF-α(340.55 ± 10.18 for 3 g/kg,P < 0.01),IL-6(261.34 ± 10.18 for 3 g/kg,P < 0.01),and enzyme activity of caspase-3(0.93 ± 0.029 for 3 g/kg,P < 0.01). The LPS-induced m RNA expression of TNF-α,IL-6 and caspase-3 was also decreased by DHI. Western blot analysis revealed that DHI antagonised LPS-stimulated decre展开更多
为量化评估饰面人造板材生产过程中所产生的环境影响,探索产品的低碳优化方向,本文运用生命周期评价法,聚焦产品碳足迹这一环境属性,对饰面人造板材产品生命周期过程的碳足迹进行了量化分析。以某公司产品的碳足迹评价过程为例,以0.5 m...为量化评估饰面人造板材生产过程中所产生的环境影响,探索产品的低碳优化方向,本文运用生命周期评价法,聚焦产品碳足迹这一环境属性,对饰面人造板材产品生命周期过程的碳足迹进行了量化分析。以某公司产品的碳足迹评价过程为例,以0.5 mm重组装饰单板为评价对象,进行实地数据收集与计算。结果表明:该重组装饰单板1 m^(2)的产品碳足迹总和值为2.79 kg CO_(2)eq,其高碳排放单元过程为生产制造阶段,碳足迹为1.13 kg CO_(2)eq。热蒸汽能源的使用对碳排放贡献的影响最大,主要发生于染色漂白和单板干燥工序。因此,针对染色漂白和单板干燥工序进行低碳优化,对于降低产品碳足迹具有重要的意义。展开更多
Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the different...Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors,the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located.Accordingly,the optimal microenvironment for inducing stem cell differentiation is a hot topic.EGb761 is extracted from the leaves of the Ginkgo biloba tree.It is used worldwide and is becoming one of the focuses of stem cell research.Studies have shown that EGb761 can antagonize oxygen free radicals,stabilize cell membranes,promote neurogenesis and synaptogenesis,increase the level of brain-derived neurotrophic factors,and replicate the environment required during the differentiation of stem cells into nerve cells.This offers the possibility of using EGb761 to induce the differentiation of stem cells,facilitating stem cell transplantation.To provide a comprehensive reference for the future application of EGb761 in stem cell therapy,we reviewed studies investigating the influence of EGb761 on stem cells.These started with the composition and neuropharmacology of EGb761,and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.展开更多
基金Supported by A Grant from Chinese Medical Association Re-search Special Funds,No. 07040490057 (to Professor Ou-yang Q)
文摘AIM:To evaluate potential risk factors in the development of ulcerative colitis(UC) in China.METHODS:A total of 1308 patients with UC and 1308 age-matched and sex-matched controls were prospectively studied in China.The UC cases were collected from 17 hospitals in China from April 2007 to April 2010.Uniform questionnaires were designed to investigate risk factors including smoking,appendectomy,stress,socio-economic conditions,nonsteroidal antiinflammatory drugs(NSAIDs),oral contraceptives,diet,breastfeeding,infections and family sanitary conditions.Group comparisons by each factor were done using simple logistic regression analysis.Conditional logistic regression was used for multivariate analysis.RESULTS:By univariate analysis,the variables predictive of UC included feeling stress,light and heavy alcoholic drinking,spicy food,sugar consumption and infectious diarrhea,while heavy tea intake and tap water consumption were protective against UC.On multivariate analysis,the protective factor for UC was tap water consumption [odds ratios(OR) = 0.424,95%CI:0.302-0.594,P < 0.001];while the potential risk factors for UC were heavy sugar consumption(OR = 1.632,95%CI:1.156-2.305,P < 0.001),spicy food(light intake:OR = 3.329,95%CI:2.282-4.857,P < 0.001;heavy intake:OR = 3.979,95%CI:2.700-5.863,P < 0.001),and often feeling stress(OR = 1.981,95%CI:1.447-2.711,P < 0.001).Other factors,such as smoking habit,appendectomy,breastfeeding,a history of measles,rural or urban residence,education,oral contraceptives,and NSAID use have not been found to have a significant association with the development of UC in the present study.CONCLUSION:Our study showed tap water consumption was a protective factor for UC,while spicy food,heavy sugar consumption and often feeling stress were risk factors for UC in this Chinese population.
文摘Thermal barrier coatings(TBCs)can effectively protect the alloy substrate of hot components in aeroengines or land-based gas turbines by the thermal insulation and corrosion/erosion resistance of the ceramic top coat.However,the continuous pursuit of a higher operating temperature leads to degradation,delamination,and premature failure of the top coat.Both new ceramic materials and new coating structures must be developed to meet the demand for future advanced TBC systems.In this paper,the latest progress of some new ceramic materials is first reviewed.Then,a comprehensive spalling mechanism of the ceramic top coat is summarized to understand the dependence of lifetime on various factors such as oxidation scale growth,ceramic sintering,erosion,and calcium–magnesium–aluminium–silicate(CMAS)molten salt corrosion.Finally,new structural design methods for high-performance TBCs are discussed from the perspectives of lamellar,columnar,and nanostructure inclusions.The latest developments of ceramic top coat will be presented in terms of material selection,structural design,and failure mechanism,and the comprehensive guidance will be provided for the development of next-generation advanced TBCs with higher temperature resistance,better thermal insulation,and longer lifetime.
基金Supported by National Natural Science Foundation of China,No.81460301 and No.81760363Key Project of Natural Science Foundation of Ningxia,No.NZ15134
文摘AIM To investigate the value of the gamma-glutamyltraspeptidase(GGT)-to-platelet(PLT) ratio(GPR) in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B(CHB). METHODS We included 390 untreated CHB patients in this study. The GPR, aspartate aminotransferase(AST)-to-PLT ratio index(APRI), and fibrosis-4(FIB-4) of all patients were analysed to determine if these parameter were correlated with age, gender, medical history, liver function [total bilirubin(TBil), alanine aminotransferase(ALT), and AST], GGT, PLT count, or hepatic fibrosis stage. The GPR, APRI, and FIB-4, as well as the combination of the GPR and APRI or the GPR and FIB-4 were assessed in different cirrhosis stages using receiver operating characteristic(ROC) curve analysis to evaluate their value in diagnosing hepatic fibrosis in CHB patients. RESULTS The GPR, APRI, and FIB-4 were not correlated withCHB patients' age, gender, or disease duration(P > 0.05), but all of these parameters were positively correlated with serum ALT, AST, GGT, and PLT count(P < 0.01). Additionally, the GPR, APRI, and FIB-4 were positively correlated with hepatic fibrosis(P < 0.01); the areas under the ROC curve for the GPR in F1, F2, F3, and F4 stages were 0.723, 0.741, 0.826, and 0.833, respectively, which were significantly higher than the respective values for the FIB-4 and APRI(F1: 0.581, 0.612; F2: 0.706, 0.711; F3: 0.73, 0.751; and F4: 0.799, 0.778). The respective diagnostic cut-off points for each stage were 0.402, 0.448, 0.548, and 0.833, respectively. The diagnostic sensitivity and specificity were, respectively, 88.8% and 87.5% in F1, 72.7% and 89.7% in F2, 81.3% and 98.6% in F3, and 80% and 97.4% in F4 when the GPR and APRI were connected in parallel; 86.6% and 90.2%, 78.4% and 96%, 78.6% and 97.4%, and 73.2% and 97.9%, respectively, when the GPR and APRI were connected in series; 80.2% and 89%, 65% and 89%, 70.3% and 98.5%, and 78.8% and 96.8%, respectively, when the GPR and FIB-4 were connected in parallel; and 83.6% and 87.9%, 76.8% and 96.6%,
基金Supported by the Health and Family Planning Commission Project from Jiangsu Province,China(No.H201672)Xuzhou Medical Innovation(Technical Breakthrough)Team from Xuzhou Health and Planning Committee(No.XWCX201610)。
文摘AIM:To assess the effect of age at diabetes onset and uncontrollable high Hb A1 c levels on the development of diabetic retinopathy(DR)among Chinese type 2 diabetes mellitus(DM)patients.METHODS:This was a cross-sectional survey of diabetic patients in Subei district,China.Data covering physical measurements,fasting blood-glucose(FBG),glycosylated hemoglobin(Hb A1 c),blood lipid,urinary albumin/creatinine ratio(UACR),ocular fundus examination,and diabetes treatment records were collected.An independent sample t-test were used to analyze differences.A Logistic regression analysis was applied to study the independent risk factors of DR.RESULTS:A total of 1282 patients with type 2 DM were enrolled,and 191 cases had DR(14.9%).The age at diabetes onset,education level,alcohol consumption,Hb A1 c level,UACR level,and hypoglycemic drugs were independent influencing factors for DR.The older the onset of diabetes,the less likely to develop DR(OR:0.958,95%CI:0.942-0.975,P=0.000).Patients were then divided in terms of age at diabetes onset as follows:<50 y,50-59 y,60-69 y,and≥70 y.Compared with diabetes onset age<50 y,50-59 y(OR:0.463,95%CI:0.306-0.699,P=0.000),60-69 y(OR:0.329,95%CI:0.203-0.535,P=0.000)and≥70 y(OR:0.232,95%CI:0.094-0.577,P=0.002)were at a lower risk of DR.The prevalence of DR was highest in patients with diabetes onset age<50 y(29.5%,P<0.05).The Hb A1 c level(8.67±1.97)%and proportion of insulin injection(52.5%)in patients with diabetes onset<40 y were higher than in patients with older diabetes onset age(P<0.05).CONCLUSION:Diabetes onset at an earlier age and uncontrollable high Hb A1 c level could be independent risk factors for DR.
基金Supported by National Natural Science Foundation of China,No.81173469 and No.81273891the Key New Drug Creation and Manufacturing Program,No.2012ZX09304007
文摘AIM:To investigate the hepatoprotective effects and mechanisms of an extract of Salvia miltiorrhiza and Carthamus tinctorius in vivo.METHODS:C57BL/6J mice were randomly assigned to five groups and intraperitoneally administered 0.9% saline,Salvia miltiorrhiza and Carthamus tinctorius extract [Danhong injection(DHI),0.75 and 3 g/kg mixed extract] or reduced glutathione for injection(RGI,300 mg/kg) for 30 min before exposure to lipopolysaccharide(LPS,16 mg/kg). After intraperitoneal LPS stimulation for 90 min or 6 h,the mice were sacrificed by ether anaesthesia,and serum and liver samples were collected. Histological analysis(H&E) and terminal deoxynucleotidyl transferase-mediated d UTP nick end-labelling(TUNEL) staining were performed. Alanine transferase(ALT),aspartate transaminase(AST),total bilirubin(TBil),glutathione-S-transferase(GST),malondialdehyde(MDA),tumour necrosis factor(TNF)-α,interleukin(IL)-6,and caspase-3 levels were measured. Bax,Bcl-2,P-IκBα,IκBα,P-NF-κB p65,and NF-κB p65 protein levels were determined by Western blot. TNF-α,IL-6,caspase-3,Bax and Bcl-2 m RNA expression was measured by real-time reverse transcription-polymerase chain reaction(RT-PCR).RESULTS:Hematoxylin-eosin staining and TUNEL results suggested that DHI(3 g/kg) treatment alleviated inflammatory and apoptotic(P < 0.01) injury in the liver of mice. DHI treatment dose-dependently blunted the abnormal changes in biochemical parameters such as ALT(72.53 ± 2.83 for 3 g/kg,P < 0.01),AST(76.97 ± 5.00 for 3 g/kg,P < 0.01),TBil(1.17 ± 0.10 for 3 g/kg,P < 0.01),MDA(0.81 ± 0.36 for 3 g/kg,P < 0.01),and GST(358.86 ± 12.09 for 3 g/kg,P < 0.01). Moreover,DHI(3 g/kg) remarkably decreased LPS-induced protein expression of TNF-α(340.55 ± 10.18 for 3 g/kg,P < 0.01),IL-6(261.34 ± 10.18 for 3 g/kg,P < 0.01),and enzyme activity of caspase-3(0.93 ± 0.029 for 3 g/kg,P < 0.01). The LPS-induced m RNA expression of TNF-α,IL-6 and caspase-3 was also decreased by DHI. Western blot analysis revealed that DHI antagonised LPS-stimulated decre
文摘为量化评估饰面人造板材生产过程中所产生的环境影响,探索产品的低碳优化方向,本文运用生命周期评价法,聚焦产品碳足迹这一环境属性,对饰面人造板材产品生命周期过程的碳足迹进行了量化分析。以某公司产品的碳足迹评价过程为例,以0.5 mm重组装饰单板为评价对象,进行实地数据收集与计算。结果表明:该重组装饰单板1 m^(2)的产品碳足迹总和值为2.79 kg CO_(2)eq,其高碳排放单元过程为生产制造阶段,碳足迹为1.13 kg CO_(2)eq。热蒸汽能源的使用对碳排放贡献的影响最大,主要发生于染色漂白和单板干燥工序。因此,针对染色漂白和单板干燥工序进行低碳优化,对于降低产品碳足迹具有重要的意义。
基金funded by the National Natural Science Foundation of China,No.81501185(to CR)the Key Research&Development Project of Shandong Province of China,No.2017GSF218043(to CR)the Science and Technology Planning Project of Yantai of China,No.2016WS017(to LNG),2017WS105(to HL)
文摘Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors,the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located.Accordingly,the optimal microenvironment for inducing stem cell differentiation is a hot topic.EGb761 is extracted from the leaves of the Ginkgo biloba tree.It is used worldwide and is becoming one of the focuses of stem cell research.Studies have shown that EGb761 can antagonize oxygen free radicals,stabilize cell membranes,promote neurogenesis and synaptogenesis,increase the level of brain-derived neurotrophic factors,and replicate the environment required during the differentiation of stem cells into nerve cells.This offers the possibility of using EGb761 to induce the differentiation of stem cells,facilitating stem cell transplantation.To provide a comprehensive reference for the future application of EGb761 in stem cell therapy,we reviewed studies investigating the influence of EGb761 on stem cells.These started with the composition and neuropharmacology of EGb761,and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.
