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Serum hepatitis B virus RNA is a predictor of HBeAg seroconversion and virological response with entecavir treatment in chronic hepatitis B patients 被引量:18
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作者 Hao Luo Xia-Xia Zhang +5 位作者 Li-Hua Cao Ning Tan Qian Kang Hong-Li Xi Min Yu Xiao-Yuan Xu 《World Journal of Gastroenterology》 SCIE CAS 2019年第6期719-728,共10页
BACKGROUND Characteristics of alterations of serum hepatitis B virus(HBV) RNA in different chronic hepatitis B(CHB) patients still cannot be fully explained. Whether HBV RNA can predict HBeAg seroconversion is still c... BACKGROUND Characteristics of alterations of serum hepatitis B virus(HBV) RNA in different chronic hepatitis B(CHB) patients still cannot be fully explained. Whether HBV RNA can predict HBeAg seroconversion is still controversial.AIM To investigate whether HBV RNA can predict virological response or HBeAg seroconversion during entecavir(ETV) treatment when HBV DNA is undetectable.METHODS The present study evaluated 61 individuals who were diagnosed and treated with long-term ETV monotherapy at the Department of Infectious Diseases of Peking University First Hospital(China) from September 2006 to December 2007.Finally, 30 treatment-naive individuals were included. Serum HBV RNA were extracted from 140 μL serum samples at two time points. Then they were reverse transcribed to cDNA with the HBV-specific primer. The product was quantified by real-time quantitative PCR(RT-PCR) using TAMARA probes. Statistical analyses were performed with IBM SPSS 20.0.RESULTS Level of serum HBV RNA at baseline was 4.15 ± 0.90 log10 copies/mL. HBV RNA levels showed no significant difference between the virological response(VR)and partial VR(PVR) groups at baseline(P = 0.940). Serum HBV RNA significantly decreased among patients who achieved a VR during ETV therapy(P < 0.001). The levels of HBV RNA in both HBeAg-positive patients with seroconversion group and those with no seroconversion increased after 24 wk of treatment. Overall, HBV RNA significantly but mildly correlated to HBsAg(r =0.265, P = 0.041), and HBV RNA was not correlated to HBV DNA(r = 0.242, P =0.062). Furthermore, serum HBV RNA was an independent indicator for predicting HBeAg seroconversion and virological response. HBeAg seroconversion was more likely in CHB patients with HBV RNA levels below4.12 log10 copies/mL before treatment.CONLUSION The level of serum HBV RNA could predict HBeAg seroconversion and PVR during treatment. In the PVR group, the level of serum HBV RNA tends to be increasing. 展开更多
关键词 Chronic HEPATITIS b HEPATITIS b virus RNA Virological response HbeAg seroconversion ENTECAVIR
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Mutations of pre-core and basal core promoter before and after hepatitis B e antigen seroconversion 被引量:4
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作者 Nozomi Kamijo Akihiro Matsumoto +5 位作者 Takeji Umemura Soichiro Shibata Yuki Ichikawa Takefumi Kimura Michiharu Komatsu Eiji Tanaka 《World Journal of Gastroenterology》 SCIE CAS 2015年第2期541-548,共8页
AIM: To investigate the role of pre-core and basal core promoter(BCP) mutations before and after hepatitis Be antigen(HBe Ag) seroconversion.METHODS: The proportion of pre-core(G1896A) and basal core promoter(A1762T a... AIM: To investigate the role of pre-core and basal core promoter(BCP) mutations before and after hepatitis Be antigen(HBe Ag) seroconversion.METHODS: The proportion of pre-core(G1896A) and basal core promoter(A1762T and G1764A) mutant viruses and serum levels of hepatitis B virus(HBV) DNA, hepatitis B surface antigen(HBs Ag), and HB core-related antigen were analyzed in chronic hepatitis B patients before and after HBe Ag seroconversion(n = 25), in those who were persistently HBe Ag positive(n = 18), and in those who were persistently anti-HBe positive(n = 43). All patients were infected with HBV genotype C and were followed for a median of 9 years.RESULTS: Although the pre-core mutant became predominant(24% to 65%, P = 0.022) in the HBe Ag seroconversion group during follow-up, the proportion of the basal core promoter mutation did not change. Median HBV viral markers were significantly higher in patients without the mutations in an HBe Ag positive status(HBV DNA: P = 0.003; HBs Ag: P < 0.001; HB core-related antigen: P = 0.001). In contrast, HBV DNA(P = 0.012) and HBs Ag(P = 0.041) levels were significantly higher in patients with the pre-core mutation in an anti-HBe positive status.CONCLUSION: There is an opposite association of the pre-core mutation with viral load before and after HBe Ag seroconversion in patients with HBV infection. 展开更多
关键词 seroconversion HEPATITIS b core-related ANTIGEN Pr
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Hepatitis B surface antigen seroconversion after HBV reactivation in non-Hodgkin's lymphoma 被引量:4
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作者 Wei-Ping Liu Wen Zheng +3 位作者 Yu-Qin Song Ling-Yan Ping Gui-Qiang Wang Jun Zhu 《World Journal of Gastroenterology》 SCIE CAS 2014年第17期5165-5170,共6页
Reactivation of hepatitis B virus(HBV)can occur in lymphoma patients infected with HBV when they receive chemotherapy or immunotherapy.Prophylactic administration of lamivudine(LAM)reduces the morbidity and mortality ... Reactivation of hepatitis B virus(HBV)can occur in lymphoma patients infected with HBV when they receive chemotherapy or immunotherapy.Prophylactic administration of lamivudine(LAM)reduces the morbidity and mortality associated with HBV reactivation.However,what defines HBV reactivation and the optimal duration of treatment with LAM have not yet been clearly established.HBV reactivation may occur due to the cessation of prophylactic LAM,although re-treatment with nucleoside analogs may sometimes result in hepatitis B surface antigen(HBsAg)seroconversion,which is a satisfactory endpoint for the management of HBV infection.We report a case of HBV reactivation in a 68-year-old HBsAg-positive patient who received rituximab-based immunochemotherapy for follicular lymphoma.HBV reactivation developed following cessation of prophylactic LAM therapy.The patient subsequently received treatment with entecavir(ETV),which led to a rapid and sustained suppression of HBV replication and HBsAg seroconversion.We also appraised the literature concerning HBV reactivation and the role of ETV in the management of HBV reactivation in lymphoma patients.A total of 28 cases of HBV reactivation have been reported as having been treated with ETV during or after immunosuppressive chemotherapy in lymphoma patients.We conclude that ETV is an efficacious and safe treatment for HBV reactivation following LAM cessation in lymphoma patients treated with rituximab-based immunochemotherapy. 展开更多
关键词 Hepatitis b surface antigen seroconversion Non-Hodgkin’ s lymphoma Rituximab Entecavir
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Serum hepatitis B core-related antigen as a surrogate marker of hepatitis B e antigen seroconversion in chronic hepatitis B 被引量:5
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作者 Xiu-Mei Chi Xiao-Mei Wang +5 位作者 Zhong-Feng Wang Rui-Hong Wu Xiu-Zhu Gao Hong-Qin Xu Yan-Hua Ding Jun-Qi Niu 《World Journal of Gastroenterology》 SCIE CAS 2021年第40期6927-6938,共12页
BACKGROUND Quantitative hepatitis B core-related antigen(qHBcrAg)has a better correlation with intrahepatic hepatitis B virus(HBV)covalently closed circular DNA(cccDNA)than HBV DNA or hepatitis B e antigen(HBeAg),but ... BACKGROUND Quantitative hepatitis B core-related antigen(qHBcrAg)has a better correlation with intrahepatic hepatitis B virus(HBV)covalently closed circular DNA(cccDNA)than HBV DNA or hepatitis B e antigen(HBeAg),but data are still lacking for its clinical application.AIM The aim was to investigate serum qHBcrAg levels in patients with chronic hepatitis B and assess the correlation of serum qHBcrAg with pregenomic RNA(pgRNA),cccDNA,and HBeAg seroconversion.METHODS This study was a secondary analysis of patients who underwent percutaneous liver biopsy between July 2014 and June 2019 in two multicenter randomized controlled clinical trials of peginterferon vs nucleos(t)ide analog(NUC)-based therapy(NCT03509688 and NCT03546530).Serum qHBcrAg,pgRNA,HBV DNA,hepatitis B core antigen,HBeAg,liver cccDNA,and HBV DNA were measured.The correlations of serum qHBcrAg with other biomarkers were analyzed.RESULTS A total of 139 patients were included.The mean qHBcrAg levels were 5.32±1.18 log10 U/mL at baseline and decreased during treatment(all P<0.0001).Serum qHBcrAg levels were positively correlated with pgRNA(r=0.597,P<0.0001)and cccDNA(r=0.527,P<0.0001)levels.The correlation of serum qHBcrAg level and intrahepatic HBV DNA levels at baseline was weak but significant(r=0.399,P<0.0001).HBcrAg predicted HBeAg seroconversion,with areas under the receiver operating characteristics curve of 0.788 at 24 wk and 0.825 at 48 wk.Log HBcrAg at wk 24 and 48 was independently associated with HBeAg seroconversion[odds ratio(OR)=2.402,95%confidence interval(CI):1.314-4.391,P=0.004;OR=3.587,95%CI:1.315-9.784,P=0.013].CONCLUSION Serum HBcrAg levels were correlated with HBV virological markers and could be used to predict HBeAg seroconversion. 展开更多
关键词 Hepatitis b virus Hepatitis b core antigen Hepatitis b virus DNA Detection Liver biopsy Pregenomic RNA Quantitative hepatitis b core-related antigen Receiver operating characteristic seroconversion Correlation
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Liver Histopathological Features Influencing HBeAg Seroconversion in Patients with HBeAg-positive Chronic Hepatitis B Treated with Pegylated Interferon α
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作者 Yao-ren Hu Hua-dong Yan +2 位作者 Guo-sheng Gao Cheng-liang Zhu Ji-fang Cheng 《国际感染病学(电子版)》 CAS 2014年第1期10-15,共6页
Objective To investigate the efficiency of pegylated interferon α therapy for patients with HBe Ag-positive chronic hepatitis B(CHB) and explore whether liver histopathological features and other factors might influe... Objective To investigate the efficiency of pegylated interferon α therapy for patients with HBe Ag-positive chronic hepatitis B(CHB) and explore whether liver histopathological features and other factors might influence HBe Ag seroconversion.Methods Total of 80 HBe Ag-positive CHB patients who received liver puncture were treated with pegylated interferon α once a week for 48 weeks. The rate of HBe Ag seroconversion was determined after therapy, and the factors influencing HBe Ag seroconversion were analyzed.Results The rate of HBe Ag seroconversion was 30.00% at the end of treatment. The rate of HBe Ag seroconversion gradually increased with the elevation of liver inflammatory activity(χ2 = 9.170, P = 0.027). But liver fibrosis has little correlation with the rate of HBeA g seroconversion(χ2 = 5.917, P = 0.116). Except HBeA g, other baseline indexes including gender, age, serum ALT and serum HBV DNA 1evels had no statistical difference between the patients with HBe Ag seroconversion and the patients without HBe Ag seroconversion. By binary logistic regression analysis, liver inflammation and HBeA g were influencing factors for HBeA g seroconversion. Conclusions Pegylated interferon α therapy induces a higher rate of HBeA g seroconversion in HBeA g-positive chronic hepatitis B patients with severe liver inflammation, so the liver biopsies should be performed in time. 展开更多
关键词 Chronic hepatitis b Pegylated interferon α Hepatitis b e antigen seroconversion
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Factors Associated with Antigen HBs Seroconversion among Blood Donors in Ouagadougou from 2008 to 2017
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作者 Abdoul-Guaniyi Sawadogo T. Isidore Traore +13 位作者 Salam Sawadogo Kompingnin Nebie Lucien Désiré Dahourou Juste Some Hervé Kpoda Ahmed Kabore Dahourou Honorine Arzouma Paul Yooda Bia Emile Drabo Jean-Etienne Koanda Alain Konseybo Eléonore Kafando Nicolas Meda Léon Blaise Savadogo 《Advances in Infectious Diseases》 2021年第3期278-289,共12页
<strong>Introduction: </strong>The risk of transmission of pathogens such as hepatitis B virus threatens the safety of transfused patients especially in high endemic areas. The aim of this study was to det... <strong>Introduction: </strong>The risk of transmission of pathogens such as hepatitis B virus threatens the safety of transfused patients especially in high endemic areas. The aim of this study was to determine the incidence and factors associated with hepatitis B virus surface antigen (HBsAg) seroconversion in blood donors at the Regional Blood Transfusion Centre of Ouagadougou. <strong>Methods:</strong> A retrospective cohort study of voluntary non-remunerated blood donors (VNRBD), was conducted from 2008 to 2017. Data on HBsAg seroconversion were collected. The Kaplan-Meier method and the Log-Rank test were used to estimate the survival curves. Cox’s regression identified the factors associated with this seroconversion. <strong>Results:</strong> Of 23,494 donors, 559 had HBsAg seroconversion. The number of donor years was 58,637.50 and the HBV incidence rate was 9.53 per 1000 donor years. The median seroconversion time was 75.73 months with extremes of 2.7 months and 107.12 months. The risk of seroconversion was 1.30 times higher among donors aged 21 to 24 years old (p = 0.007) and 2.49 times higher among those over 24 years old (p < 0.0001) than among donors under 21 years old. Female donors were 1.11 times more likely to seroconvert than male donors (p = 0.33). Donor residence was not significantly associated with HBsAg seroconversion (Hazard ratio = 1.12;p = 0.36). The risk of seroconversion decreased significantly with the number of blood donations (Hazard ratio = 0.58;p = 0.006). <strong>Conclusion: </strong>The incidence of HBsAg remains high among blood donors, which could have a negative impact on transfusion safety. The age of the blood donor was significantly associated to AgHBs seroconversion. 展开更多
关键词 Time to onset Viral Hepatitis b blood Donors seroconversion
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Eu掺杂ZnO多孔片状材料的制备及其降解印刷染料RhB
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作者 吴娟 王晶 +3 位作者 王刚 李丹婷 李英豪 王健俐 《当代化工》 CAS 2024年第4期764-768,共5页
采用常温络合-水解法构筑Eu掺杂Zn O多孔片状材料。通过SEM、TEM、XRD、EDS等表征手段证明稀土元素Eu成功掺杂到Zn O之中,Eu-Zn O的形貌为多孔片状结构。研究了Eu-Zn O多孔片状材料对染料的光催化性能。结果表明:该材料对Rh B具有较好... 采用常温络合-水解法构筑Eu掺杂Zn O多孔片状材料。通过SEM、TEM、XRD、EDS等表征手段证明稀土元素Eu成功掺杂到Zn O之中,Eu-Zn O的形貌为多孔片状结构。研究了Eu-Zn O多孔片状材料对染料的光催化性能。结果表明:该材料对Rh B具有较好的降解效率,降解效率高达99.2%,循环稳定性能高达98.3%,远大于商用Zn O的76.2%的降解效率和82.3%的循环稳定性能,由以上数据说明Eu-Zn O具有很好的光催化降解效率和循环稳定性能。其优异的光催化性能归因于稀土元素Eu掺杂和多孔片状结构。 展开更多
关键词 Eu-Zn o Rh b 常温络合-水解法 光催化
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g-C_(3)N_(4)/Ag/Ag_(2)O复合材料低功率紫外照射下降解罗丹明B 被引量:1
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作者 苏春雨 秦娇 +4 位作者 常璐 耿悦 虞阿芳 吕东军 张晓蕾 《山东化工》 CAS 2024年第10期13-16,共4页
光催化降解技术高效、环保、节能的优点使其在环保领域具有广泛应用前景,为解决环境污染问题提供了新的思路。其中高效催化剂是实现污染物高效光催化降解的关键。g-C_(3)N_(4)半导体材料因优良的热稳定性和化学稳定性、易于合成以及能... 光催化降解技术高效、环保、节能的优点使其在环保领域具有广泛应用前景,为解决环境污染问题提供了新的思路。其中高效催化剂是实现污染物高效光催化降解的关键。g-C_(3)N_(4)半导体材料因优良的热稳定性和化学稳定性、易于合成以及能带结构易调控等优点在催化领域具有广阔的应用前景,但由于纯g-C_(3)N_(4)可见光利用率低、表面积小、导带位置较低,限制了其实际应用中的催化活性。本文通过光诱导还原方法实现了g-C_(3)N_(4)材料表面Ag/Ag_(2)O的原位负载,系统研究了Ag/Ag_(2)O负载量对材料催化性能的影响,实现低功率紫外光催化下水中罗丹明B的快速高效去除,研究发现50 mg的g-C_(3)N_(4)中在0.24 g/L的AgNO3溶液还原得到的g-C_(3)N_(4)/Ag/Ag_(2)O复合材料具有最佳的催化性能。同时将复合材料应用于实际水体中罗丹明B染料的催化降解,取得了良好催化效果。本研究为去除水环境有机物污染提供了一种高效、绿色的解决方法。 展开更多
关键词 g-C_(3)N_(4) AG Ag_(2)o 罗丹明b 光催化
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CsBa_(2)ScB_(8)O_(16):首例结构中同时含有零维[B_(3)O_(6)]基元和一维B—O链的稀土硼酸盐
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作者 焦思慧 吴红萍 俞洪伟 《人工晶体学报》 CAS 北大核心 2024年第9期1550-1559,共10页
利用高温溶液法合成了首例结构中同时含有零维[B_(3)O_(6)]基元和一维B—O链的稀土硼酸盐晶体CsBa_(2)ScB_(8)O_(16),该晶体属于三斜晶系,空间群为P1,晶胞参数为a=6.6985Å,b=7.216Å,c=14.798Å,α=97.563°,β=95.226... 利用高温溶液法合成了首例结构中同时含有零维[B_(3)O_(6)]基元和一维B—O链的稀土硼酸盐晶体CsBa_(2)ScB_(8)O_(16),该晶体属于三斜晶系,空间群为P1,晶胞参数为a=6.6985Å,b=7.216Å,c=14.798Å,α=97.563°,β=95.226°,γ=95.546°,Z=2。该晶体中的[BO3]与[B4 O9]基元通过共享氧原子连接形成一维[B_(5)O_(10)]_(∞)链,[Sc(1)O_(6)]八面体与一维[B5 O_(10)]_(∞)链通过共享氧原子形成二维[Sc(1)(B_(4)O_(9))]_(∞)层,层间由[Sc(2)O_(6)]八面体连接形成Sc—B—O三维框架。孤立的[B_(3)O_(6)]基元与Cs^(+)、Ba^(2+)填充在三维孔道内维持电荷平衡。为了进一步探索CsBa_(2)ScB_(8)O_(16)结构的新颖性,将该晶体与其他含有碱金属或碱土金属的稀土硼酸进行比较,讨论了阳离子与硼的摩尔比(n(A)/n(B))对B—O基元的聚合度及B—O阴离子框架维度的影响。此外,对化合物进行了红外光谱、紫外-可见-近红外漫反射光谱,以及热学行为等表征测试,并基于第一性原理计算对化合物微观电子层面进行了计算分析。结果表明CsBa_(2)ScB_(8)O_(16)的紫外截止边小于190 nm,双折射为0.072@1064 nm,其光学特性主要由[B3O6]基元、[B5O10]基元和[ScO6]多面体贡献。 展开更多
关键词 稀土硼酸盐 高温溶液法 晶体结构 bo框架 第一性原理计算 双折射
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O型血孕妇产前血清IgG抗A(B)抗体效价积分评估HDN发生价值
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作者 何烁晴 洪立闩 +1 位作者 吴永美 孙月娥 《中国计划生育学杂志》 2024年第7期1687-1691,共5页
目的:探究产前O型血孕妇血清中免疫球蛋白G(IgG)抗A(B)抗体效价积分对新生儿溶血(HDN)发生的预测价值。方法:回顾性选取2022年1月-2023年12月本院收治的101例O型血孕妇临床资料,根据新生儿是否发生HDN分为为HDN组(n=26)和非HDN组(n=75)... 目的:探究产前O型血孕妇血清中免疫球蛋白G(IgG)抗A(B)抗体效价积分对新生儿溶血(HDN)发生的预测价值。方法:回顾性选取2022年1月-2023年12月本院收治的101例O型血孕妇临床资料,根据新生儿是否发生HDN分为为HDN组(n=26)和非HDN组(n=75)。比较两组临床资料、产前血清中IgG抗A(B)抗体效价积分等。采用Spreaman相关分析分析孕妇血清中IgG抗A(B)抗体效价积分与HDN发生的相关性,受试者工作曲线(ROC)分析O型血孕妇血清中IgG抗A(B)抗体效价积分对HDN发生的预测价值。结果:HDN组孕妇产前血清IgG抗A(B)抗体效价均高于非HDN组,当产前血清的IgG抗A(B)抗体效价相同时,HDN组孕妇的血清IgG抗A(B)抗体效价积分明显于非HDN组(均P<0.05);Spearman相关分析,孕妇产前血清IgG抗A(B)抗体效价积分与HDN发生呈正相关(r=0.666,P<0.001);ROC曲线分析,O型血孕妇血清中IgG抗A(B)抗体效价积分预测HDN发生曲线下面积0.874,截断值54.88,灵敏度84.0%、特异度94.7%。结论:产前O型血孕妇血清中IgG抗A(B)抗体效价积分新生儿发生HDN概率呈正相关,且对HDN的发生有一定预测价值。 展开更多
关键词 o型血孕妇 血清IgG抗A(b)抗体效价 效价积分 新生儿溶血症 临床评估
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Heteroatom tuning in agarose derived carbon aerogel for enhanced potassium ion multiple energy storage
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作者 Kaijun Xie Xin Liu +5 位作者 Haolin Li Long Fang Kai Xia Dongjiang Yang Yihui Zou Xiaodong Zhang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期239-254,共16页
The incorporation of heteroatoms into carbon aerogels(CAs)can lead to structural distortions and changes in active sites due to their smaller size and electronegativity compared to pure carbon.However,the evolution of... The incorporation of heteroatoms into carbon aerogels(CAs)can lead to structural distortions and changes in active sites due to their smaller size and electronegativity compared to pure carbon.However,the evolution of the electronic structure from single-atom doping to heteroatom codoping in CAs has not yet been thoroughly investigated,and the impact of codoping on potassium ion(K+)storage and diffusion pathways as electrode material remains unclear.In this study,experimental and theoretical simulations were conducted to demonstrate that heteroatom codoping,composed of multiple heteroatoms(O/N/B)with different properties,has the potential to improve the electrical properties and stability of CAs compared to single-atom doping.Electronic states near the Fermi level have revealed that doping with O/N/B generates a greater number of active centers on adjacent carbon atoms than doping with O and O/N atoms.As a result of synergy with enhanced wetting ability(contact angle of 9.26°)derived from amino groups and hierarchical porous structure,ON-CA has the most optimized adsorption capacity(−1.62 eV)and diffusion barrier(0.12 eV)of K^(+).The optimal pathway of K^(+)in ON-CA is along the carbon ring with N or O doping.As K^(+)storage material for supercapacitors and ion batteries,it shows an outstanding specific capacity and capacitance,electrochemical stability,and rate performance.Especially,the assembled symmetrical K^(+)supercapacitor demonstrates an energy density of 51.8 Wh kg^(−1),an ultrahigh power density of 443Wkg^(−1),and outstanding cycling stability(maintaining 83.3%after 10,000 cycles in 1M KPF6 organic electrolyte).This research provides valuable insights into the design of highperformance potassium ion storage materials. 展开更多
关键词 AGARoSE carbon aerogels o/N/b codoping potassium-ion battery potassium-ion supercapacitor
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Mo_(2)B_(2)O_(2) MBene for Efficient Electrochemical CO Reduction to C_(2) Chemicals:Computational Exploration
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作者 Bikun Zhang Jianwen Jiang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第6期342-350,共9页
Emerging as a new class of two-dimensional materials with atomically thin layers,MBenes have great potential for many important applications such as energy storage and electrocatalysis.Toward mitigating carbon footpri... Emerging as a new class of two-dimensional materials with atomically thin layers,MBenes have great potential for many important applications such as energy storage and electrocatalysis.Toward mitigating carbon footprint,there has been increasing interest in CO_(2)/CO conversion on MBenes,but mostly focused on C_(1) products.C^(2+) chemicals generally possess higher energy densities and wider applications than C_(1) counterparts.However,C–C coupling is technically challenging because of high energy requirement and currently few catalysts are suited for this process.Here,we explore electrochemical CO reduction reaction to C_(2) chemicals on Mo_(2)B_(2)O_(2) MBene via density-functional theory calculations.Remarkably,the most favorable CO–COH coupling is revealed to be a spontaneous and barrierless process,making Mo_(2)B_(2)O_(2) an efficient catalyst for C–C coupling.Among C_(1) and C_(2) chemicals,ethanol is predicted to be the primary product.Furthermore,by charge and bond analysis,it is unraveled that there exist significantly more unbonded electrons in the C atom of intermediate*COH than other C_(1) intermediates,which is responsible for the facile C–C coupling.From an atomic scale,this work provides microscopic insight into C–C coupling process and suggests Mo_(2)B_(2)O_(2) a promising catalyst for electrochemical CO reduction to C_(2) chemicals. 展开更多
关键词 C_(2) chemicals C-C coupling density-functional theory Mbene Mo2b2o2
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“O+B”域数据分析应用定位纯3G用户分析探讨
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作者 赵宇 田经化 《新潮电子》 2024年第11期10-12,共3页
在3G退网过程中,地市一线市场前端针对通过B域数据分类的“非VOLTE语音用户”进行迁转营销和投诉处理时,发现数据准确性存在偏差,贯通数据底座并融合B域和O域数据后,精准识别定位“纯3G语音用户”模型,可以更精准指导一线市场营销迁转。
关键词 3G退网 非VoLTE用户 用户迁转 b域(业务域) o域(运营域)
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B→O血型转变工具酶α-半乳糖苷酶cDNA克隆及表达 被引量:20
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作者 杨军 宫锋 +4 位作者 季守平 任会明 刘泽澎 高新 章扬培 《中国生物化学与分子生物学报》 CAS CSCD 2000年第4期438-442,共5页
α-半乳糖苷酶是实现 B→O血型转变、制备通用型血的关键工具酶 .利用反转录 PCR方法从中国海南 Catimor咖啡豆中克隆α-半乳糖苷酶 c DNA,插入嗜甲基酵母 P.pastoris分泌表达载体 p PIC9K中 ,转化 P.pastoris GS1 1 5,筛选高表达重组菌... α-半乳糖苷酶是实现 B→O血型转变、制备通用型血的关键工具酶 .利用反转录 PCR方法从中国海南 Catimor咖啡豆中克隆α-半乳糖苷酶 c DNA,插入嗜甲基酵母 P.pastoris分泌表达载体 p PIC9K中 ,转化 P.pastoris GS1 1 5,筛选高表达重组菌株 .经甲醇诱导表达 7d后 ,发酵液总蛋白分泌量约 1 .2 mg/ml,SDS- PAGE呈现约 41 k D特异表达带 ,与专一性底物对 -硝基 -苯基 -α- D-吡喃半乳糖苷反应证明 ,表达产物具有 α-半乳糖苷酶活性 ,最高达到 1 8U/ml.初步实验表明 ,表达的 α-半乳糖苷酶可酶解 B型红细胞 ,成功实现 B→O血型转变 . 展开更多
关键词 b→o血型转变 α-半乳糖苷酸 基因克隆 输血疗法
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原核基因工程制备新型重组α-半乳糖苷酶应用于人B→O血型改造的研究 被引量:12
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作者 高红伟 李素波 +6 位作者 鲍国强 檀英霞 王玲燕 金泗虎 王颖丽 季守平 宫锋 《中国实验血液学杂志》 CAS CSCD 2011年第2期503-507,共5页
本研究利用基因工程方法制备脆弱类杆菌来源的新型α-半乳糖苷酶并将其应用于人B→O血型改造。在获得了能够表达细菌α-半乳糖苷酶工程菌株的基础上,从诱导时间、诱导剂浓度两个方面对工程菌株的诱导条件进行优化,获得细菌α-半乳糖苷... 本研究利用基因工程方法制备脆弱类杆菌来源的新型α-半乳糖苷酶并将其应用于人B→O血型改造。在获得了能够表达细菌α-半乳糖苷酶工程菌株的基础上,从诱导时间、诱导剂浓度两个方面对工程菌株的诱导条件进行优化,获得细菌α-半乳糖苷酶的最佳可溶性表达条件;超声上清经过阳离子交换层析和阴离子交换层析等方法进行纯化。利用纯化后的α-半乳糖苷酶在磷酸盐缓冲液(pH 6.8)中处理B型红细胞2小时,制备O型红细胞。结果表明细菌α-半乳糖苷酶最佳诱导表达条件为:37℃、起始D600为0.8,IPTG浓度为0.1 mmol/L,诱导时间为2小时。纯化后α-半乳糖苷酶的纯度为电泳纯,比活由纯化前的0.42 U/mg提高到了2.1 U/mg。该酶在26℃、接近中性的pH条件(6.8)下经2小时可将B型红细胞改造成O型红细胞,需要的酶量为225μg/ml红细胞。结论:建立了重组细菌α-半乳糖苷酶的表达纯化工艺,制备的重组α-半乳糖苷酶可有效地将B型红细胞改造成O型红细胞,为B→O血型改造提供了更有效的工具酶。 展开更多
关键词 基因重组α-半乳糖苷酶 血型改造 b→o血型改造
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K_2B_4O_7-Na_2B_4O_7-Li_2B_4O_7-H_2O四元体系288K相平衡研究 被引量:10
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作者 桑世华 唐明林 +1 位作者 殷辉安 张允湘 《化学工程》 CAS CSCD 北大核心 2003年第4期68-70,6,共3页
采用等温溶解平衡法研究了K2 B4O7 Na2 B4O7 Li2 B4O7 H2 O四元体系在 2 88K时的相平衡及平衡液相的主要物化性质(密度、电导率、pH值 )。研究发现 :该四元体系为简单共饱和型 ,无复盐及固溶体形成 ,根据溶解度数据绘制了相图 ,相图中... 采用等温溶解平衡法研究了K2 B4O7 Na2 B4O7 Li2 B4O7 H2 O四元体系在 2 88K时的相平衡及平衡液相的主要物化性质(密度、电导率、pH值 )。研究发现 :该四元体系为简单共饱和型 ,无复盐及固溶体形成 ,根据溶解度数据绘制了相图 ,相图中有一个共饱点E ,三条单变度曲线E3 E ,E2 E ,E1 E ;三个结晶区平衡固相分别为K2 B4O7·4H2 O ,Na2 B4O7·10H2 O和Li2 B4O7·3H2 O。实验结果表明K2 B4O7对Na2 B4O7有增溶作用 。 展开更多
关键词 K2b4o7-Na2b4o7-Li2b4o7-H2o四元体系 288K相平衡 水盐体系 硼酸盐 盐湖卤水
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地表UV-B辐射增强对土壤-冬小麦系统N_2O排放的影响机理研究 被引量:14
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作者 蒋静艳 牛传坡 +2 位作者 胡正华 杨玉峰 黄耀 《环境科学》 EI CAS CSCD 北大核心 2006年第9期1712-1716,共5页
为了解UV-B增强条件下农田N2O响应规律,采用室外盆栽实验,研究了地表UV-B辐射增强20%对土壤-冬小麦系统N2O排放的影响及其影响机理.结果表明,在小麦返青期,UV-B辐射增强处理对该系统N2O的排放影响不显著;在小麦的拔节期,UV-B辐射增强处... 为了解UV-B增强条件下农田N2O响应规律,采用室外盆栽实验,研究了地表UV-B辐射增强20%对土壤-冬小麦系统N2O排放的影响及其影响机理.结果表明,在小麦返青期,UV-B辐射增强处理对该系统N2O的排放影响不显著;在小麦的拔节期,UV-B辐射增强处理显著降低了土壤-小麦系统N2O的排放,并减少了该系统的呼吸速率.UV-B辐射增强对N2O的影响机理主要表现在对小麦植株N代谢过程的影响,如显著增加了植株叶片中可溶性蛋白质、TN、TP的含量.UV-B辐射增强对土壤产N2O的影响表现为间接影响,主要是显著增加了小麦根区土壤有效氮和土壤微生物碳、氮的量,并改变了土壤微生物的C/N,使之由5.0增至6.8. 展开更多
关键词 UV—b 土壤-小麦系统 N2o排放 N代谢
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孕母O型血清ABO抗体效价对新生儿溶血的影响分析 被引量:5
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作者 杨庆 应海燕 +2 位作者 张冬梅 付玉童 周佩珊 《陕西医学杂志》 CAS 2015年第12期1617-1619,共3页
目的:探讨孕母O型血清中IgG抗(A)B抗体效价对ABO新生儿溶血的影响。方法:选取进行产前检查的198例O型Rh阳性血孕妇(丈夫为非O型Rh阳性血)及其分娩的新生儿,检测所有孕妇的IgG抗(A)B抗体效价,同时对新生儿进行溶血病血清学检查。结果:O-... 目的:探讨孕母O型血清中IgG抗(A)B抗体效价对ABO新生儿溶血的影响。方法:选取进行产前检查的198例O型Rh阳性血孕妇(丈夫为非O型Rh阳性血)及其分娩的新生儿,检测所有孕妇的IgG抗(A)B抗体效价,同时对新生儿进行溶血病血清学检查。结果:O-A组孕妇血清IgG抗(A)B抗体效价≤1∶32者8例,占9.09%,显著低于O-B组(25.04%)和O-AB组(25.81%P<0.05),而O-B组和O-AB组之间无显著性差异(P>0.05);孕妇血清IgG抗(A)B抗体效价越高,HDN发生率越高,不同抗体效价组别间比较,差异具有统计学意义(P<0.05)。结论:孕母O型血清中IgG抗(A)B抗体效价与ABO-HDN高度相关,动态监测孕母O型血清中IgG抗(A)B抗体效价,对预防和治疗新生儿溶血疾病具有非常重要的临床价值。 展开更多
关键词 新生儿溶血 o型血 孕妇 IgG抗(A)b抗体效价 Abo血型
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A、B、AB型全血加入O型全血37℃对血型鉴定、抗体效价及抗球蛋白试验的影响 被引量:3
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作者 肖瑞卿 赵树铭 +6 位作者 林武存 曾杰 许聃 陈英 吴建君 胡建 刘景汉 《第三军医大学学报》 CAS CSCD 北大核心 2005年第18期1885-1887,共3页
目的了解A、B、AB型全血加入O型全血不同剂量后血型正反鉴定、抗-A、抗-B抗体效价、直接与间接抗人-IgG实验变化。方法完全随机抽取4℃保存24 h A、B、AB型全血分别60 m l,按不同比例加入O型抗-A、抗-B效价1∶64的全血9、12、15、18 m ... 目的了解A、B、AB型全血加入O型全血不同剂量后血型正反鉴定、抗-A、抗-B抗体效价、直接与间接抗人-IgG实验变化。方法完全随机抽取4℃保存24 h A、B、AB型全血分别60 m l,按不同比例加入O型抗-A、抗-B效价1∶64的全血9、12、15、18 m l置入100 m l塑料血袋内混匀后,置37℃孵箱,间隔15 m in摇动1次。分别在1、2、4、8、12、24 h留取标本,做血型正反鉴定、抗-A、抗-B抗体效价、直接与间接抗人-IgG实验。结果不同型全血加入不同剂量O型全血,37℃不同时间血型正反鉴定相符;相对应抗-A、抗-B抗体效价逐渐下降到消失;直接与间接抗人-IgG实验的变化,以B型接受O型的反应最小,在接受600 m l直接与间接抗人-IgG均为阴性,800 m l同1 200 m l反应基本一致。A、AB型接受O型后直接与间接抗人-IgG反应基本一致,实验结果均为阳性。结论以B型接受O型的反应最小,在接受600 m l直接与间接抗人-IgG均为阴性。800 m l同1 200 m l反应基本一致,A、AB型直接与间接抗人-IgG均为阳性。原则上最好不输O型全血,从直接抗人-IgG实验分析,只要红细胞上存在不完全抗体,就一定会影响红细胞的寿命与质量。 展开更多
关键词 A、b、Ab型全血加入o型全血 血型鉴定 抗体效价 抗人-IgG试验
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Fe_3O_4/C纳米粒子的制备及其对水中罗丹明B的去除 被引量:19
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作者 张春荣 闫李霞 +1 位作者 申大忠 陈令新 《环境化学》 CAS CSCD 北大核心 2012年第11期1669-1675,共7页
采用溶剂热-水热法合成了碳覆盖的Fe3O4纳米粒子Fe3O4/C,利用扫描电镜(SEM)与红外光谱(FT-IR)对其进行了表征,并研究了其对水中罗丹明B的吸附性能.系统考察了吸附动力学、吸附等温线、吸附剂用量对吸附性能的影响.Fe3O4/C对罗丹明B的吸... 采用溶剂热-水热法合成了碳覆盖的Fe3O4纳米粒子Fe3O4/C,利用扫描电镜(SEM)与红外光谱(FT-IR)对其进行了表征,并研究了其对水中罗丹明B的吸附性能.系统考察了吸附动力学、吸附等温线、吸附剂用量对吸附性能的影响.Fe3O4/C对罗丹明B的吸附在3 h内即可达到平衡,最大吸附量可达13.23 mg.g-1.分别用Langmuir和Freundlich吸附模型解释了Fe3O4/C对罗丹明B的作用机理,吸附反应过程符合准二级动力学方程.结果表明,该吸附剂具有良好的磁效应和吸附性能,可快速去除罗丹明B,去除率高达90%以上;吸附剂可重复利用,成本低,具有环境友好的优势. 展开更多
关键词 FE3o4纳米粒子 活性炭 罗丹明b 吸附
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