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血清25(OH)D水平与痴呆发病风险的剂量—反应Meta分析
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作者 周巧 汤瑶 罗兴梅 《疑难病杂志》 CAS 2022年第3期297-301,共5页
目的系统分析血清25羟基维生素D[25(OH)D]与痴呆发病风险的剂量—反应关系。方法检索中国学术期刊全文数据库(CNKI)、万方数据知识服务平台、PubMed、Embase、Cochrane Library、Web of Science数据库中研究血清25(OH)D与痴呆发病风险... 目的系统分析血清25羟基维生素D[25(OH)D]与痴呆发病风险的剂量—反应关系。方法检索中国学术期刊全文数据库(CNKI)、万方数据知识服务平台、PubMed、Embase、Cochrane Library、Web of Science数据库中研究血清25(OH)D与痴呆发病风险的剂量—反应关系的相关文献,检索时限从数据库创建到2021年9月,采用Stata 16.0软件使用广义最小二乘估计方法(GLST)分析血清25(OH)D与痴呆发病风险的剂量—反应关系。结果共纳入9篇文献,含11项研究,包括42054例研究对象,其中发生痴呆3480例。基于随机效应模型对各原始研究最高剂量组相对于最低剂量组的RR值及95%CI进行合并,Meta分析结果显示,血清25(OH)D水平与痴呆发病风险呈负相关[RR(95%CI)=0.751(0.615~0.916),P=0.005]。剂量—反应Meta分析显示,随着血清维生素D水平升高,痴呆发病风险逐渐降低;血清维生素D水平每增加1 nmol/L,痴呆发病风险降低0.3%(OR=0.997,95%CI 0.996~0.999,P<0.001),血清维生素D水平与痴呆发病风险相关,且可能存在线性负相关(RR=-0.003,P<0.001)。结论血清25(OH)D水平与痴呆发病风险呈线性负相关。 展开更多
关键词 痴呆 25-羟基维生素D 阿尔茨海默病 剂量—反应关系 META分析
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生物活化黄曲霉毒素对病毒干扰素诱生的抑制作用
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作者 陈家坤 Hahon N. 《广州医学院学报》 1993年第1期10-14,共5页
用鼠肝匀浆(S_9)代谢活化黄曲霉毒素B族和G族,研究它们对流感病毒在恒河猴肾细胞(LLC-MK_2)诱导干扰素-α/β的抑制作用。结果显示活化与未活化的黄曲霉毒素对干扰素诱生都有抑制作用。但代谢活化后,抑制作用增强,抑制作用的大小按B_1&g... 用鼠肝匀浆(S_9)代谢活化黄曲霉毒素B族和G族,研究它们对流感病毒在恒河猴肾细胞(LLC-MK_2)诱导干扰素-α/β的抑制作用。结果显示活化与未活化的黄曲霉毒素对干扰素诱生都有抑制作用。但代谢活化后,抑制作用增强,抑制作用的大小按B_1>G_1>B_2>G_2顺序排列,显示有结构-活性关系。而干扰素赋予细胞的抗病毒能力并不受黄曲霉毒素的影响。 展开更多
关键词 干扰素 黄曲霉毒素 生物活化 剂量—反应
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职业性皮肤病
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《中国医学文摘(皮肤科学)》 2003年第3期160-160,共1页
关键词 职业性接触 砷中毒患者 视网膜母细胞瘤蛋白 高砷煤 RB蛋白 临床分级 皮肤 羽毛尘 剂量—反应关系 变态反应性疾病
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Dietary Leucine Requirement for Juvenile Large Yellow Croaker Pseudosciaena crocea (Richardson,1846) 被引量:4
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作者 LI Yan AI Qinghui MAI Kangsen XU Wei CHENG Zhenyan HE Zhigang 《Journal of Ocean University of China》 SCIE CAS 2010年第4期371-375,共5页
Dietary leucine requirement for juvenile large yellow croaker, Pseudosciaena crocea Richardson 1846 (initial body weight 6.0 g±0.1 g) was determined using dose-response method.Six isonitogenous (crude protein 43%... Dietary leucine requirement for juvenile large yellow croaker, Pseudosciaena crocea Richardson 1846 (initial body weight 6.0 g±0.1 g) was determined using dose-response method.Six isonitogenous (crude protein 43%) and isoenergetic (19 kJ g-1) practical diets containing six levels of leucine (Diets 1-6) ranging from 1.23% to 4.80% (dry matter) were made at about 0.7% increment of leucine.Equal amino acid nitrogen was maintained by replacing leucine with glutamic acid.Triplicate groups of 60 individuals were fed to apparent satiation by hand twice daily (05:00 and 17:30).The water temperature was 26-32℃, salinity 26-30 and dissolved oxygen approximately 7 mg L-1 during the experimental period.Final weight (FW) of large yellow croaker initially increased with increasing level of dietary leucine but then decreased at further higher level of leucine.The highest FW was obtained in fish fed diet with 3.30% Leucine (Diet 4).FW of fish fed the diet with 4.80% Leucine (Diet 6) was significantly lower than those fed Diet 4.However, no significant differences were observed between the other dietary treatments.Feed efficiency (FE) and whole body composition were independent of dietary leucine contents (P>0.05).The results indicated that leucine was essential for growth of juvenile large yellow croaker.On the basis of FW, the optimum dietary leucine requirement for juvenile large yellow croaker was estimated to be 2.92% of dry matter (6.79% of dietary protein). 展开更多
关键词 Pseudosciaena crocea LEUCINE REQUIREMENT DIETS
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Effects of two medicinal plants Psidium guajava L. (Myrtaceae) and Diospyros mespiliformis L. (Ebenaceae) leaf extracts on rat skeletal muscle cells in primary culture 被引量:4
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作者 BELEMTOUGRI R.G. CONSTANTIN B. +2 位作者 COGNARD C. RAYMOND G. SAWADOGO L. 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2006年第1期56-63,共8页
Crude decoction, aqueous and ethanolic extracts of two medicinal plants (Psidiura guajava and Diospyros raespiliformis), widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for t... Crude decoction, aqueous and ethanolic extracts of two medicinal plants (Psidiura guajava and Diospyros raespiliformis), widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release. 展开更多
关键词 Psidium guajava Diospyros mespiliformis MYRTACEAE EBENACEAE Medicinal plants Intracellular calcium Sarcoplasmic reticulum CAFFEINE
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Long-term omeprazole and esomeprazole treatment does not significantly increase gastric epithelial cell proliferation and epithelial growth factor receptor expression and has no effect on apoptosis and p53 expression 被引量:7
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作者 Istvan Hritz Laszlo Herszenyi +2 位作者 Bela Molnar Zsolt Tulassay Laszlo Pronai 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第30期4721-4726,共6页
AIM: To study the effect of proton pump inhibitor (PPI) treatment on patients with reflux esophagitis and its in vivo effect on apoptosis, p53- and epidermal growth factor receptor (EGFR) expression. METHODS: Af... AIM: To study the effect of proton pump inhibitor (PPI) treatment on patients with reflux esophagitis and its in vivo effect on apoptosis, p53- and epidermal growth factor receptor (EGFR) expression. METHODS: After informed consent was obtained, gastric biopsies of the antrum were taken from patients with reflux oesophagitis prior to and after 6 mo of 20 mg omeprazole (n = 24) or 40 mg esomeprazole (n = 22) therapy. Patients did not take any other medications known to affect the gastric mucosa. All patients were Helicobacter pylori negative as confirmed by rapid urease test and histology, respectively. Cell proliferation, apoptosis, EGFR, and p53 expression were measured by immunohistochemical techniques. At least 600 glandular epithelial cells were encountered and results were expressed as percentage of total cells counted. Was considered statistically significant. RESULTS: Although there was a trend towards increase of cell proliferation and EGFR expression both in omeprazole and esomeprazole treated group, the difference was not statistically significant. Neither apoptosis nor p53 expression was affected. CONCLUSION: Long-term PPI treatment does not significantly increase gastric epithelial cell proliferation and EGFR expression and has no effect on apoptosis and p53 expression. 展开更多
关键词 Proton pump inhibibor OMEPRAZOLE ESOMEPRAZOLE Cell proliferation APOPTOSIS p53 expression Epidermal growth factor receptor
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Influence of Carbon Content on S Zorb Sorbent Activity 被引量:4
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作者 Xu Li 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第2期6-10,共5页
The reaction activity of S Zorb sorbents with different sulfur contents was investigated, and the structure and composition of carbon-containing sorbents were characterized by XRD, FT-IR and TG-MS in order to delve in... The reaction activity of S Zorb sorbents with different sulfur contents was investigated, and the structure and composition of carbon-containing sorbents were characterized by XRD, FT-IR and TG-MS in order to delve into the kind and morphology of carbon on the sorbent. Test results have revealed that coke could be deposited on the S Zorb sorbent during the operating process, and the coke content was an important factor influencing the reaction performance of the S Zorb sorbent. Retention of a definite amount of coke on the sorbent while securing the desulfurization activity of the S Zorb sorbent would be conducive to the reduction of octane loss of reaction product. 展开更多
关键词 S Zorb sorbent carbon content desulfurization activity octane loss
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Apparent dose dependent antibody response in chickens immunized with orthopox virus antigens
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作者 张小莺 Rüdiger Schade Heinz Ellerbrok 《Journal of Chinese Pharmaceutical Sciences》 CAS 2008年第4期337-339,共3页
Dose-dependent IgY antibody response to different amounts oforthopox virus (OPV) antigen has been studied in immunized chickens for two different OPV strains (vaccinia virus, 7.0× 10^6 PFU and cowpox virus, 9.... Dose-dependent IgY antibody response to different amounts oforthopox virus (OPV) antigen has been studied in immunized chickens for two different OPV strains (vaccinia virus, 7.0× 10^6 PFU and cowpox virus, 9.2× 10^7PFU). The antibody responses to different immunizations were tested and compared by indirect immunofluorescence antibody test. Our results, together with the literature, show that the antigen dose used for immunization plays an important role for the production of specific Abs. An increase in antigen concentration may achieve higher Ab titers but, dependent on the immunogenicity of OPV antigen, it can also lead to an immune depression. However, in this study we found that OPV played a positive correlation between antigen concentration and Ab-titer. 展开更多
关键词 IGY Orthopox virus Antigen dose Immune response
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Single dose of intra-muscular platelet rich plasma reverses the increase in plasma iron levels in exercise-induced muscle damage:A pilot study 被引量:1
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作者 Zekine Punduk Onur Oral +2 位作者 Nadir Ozkayin Khalid Rahman Rana Varol 《Journal of Sport and Health Science》 SCIE 2016年第1期109-114,共6页
Background:Platelet rich plasma(PRP) therapy is widely used in enhancing the recovery of skeletal muscle from injury.However,the impact of intramuscular delivery of PRP on hematologic and biochemical responses has not... Background:Platelet rich plasma(PRP) therapy is widely used in enhancing the recovery of skeletal muscle from injury.However,the impact of intramuscular delivery of PRP on hematologic and biochemical responses has not been fully elucidated in exercise-induced muscle damage.The purpose of this investigation the effects of intramuscular delivery of PRP on hematologic and biochemical responses and recovery strategy muscle damage induced by high intensity muscle exercise(exercise-induced muscle damage,EIMD).Methods:Moderately active male volunteers participated in this study and were assigned to a control group(control,n = 6) and PRP administration group(PRP,n = 6).The subjects performed exercise with a load of 80% one repetition maximum(1RM) maximal voluntary contraction of the elbow flexors until point of exhaustion of the non-dominant arm was reached.The arms were treated with saline or autologous PRP post-24 h EIMD.Venous blood samples were obtained in the morning to establish a baseline value and 1–4 days post-exercise and were analyzed for serum ferritin,iron,iron binding capacity(IBC),creatinine kinase(CK),lactate dehydrogenase(LDH),aspartate aminotransferase(AST),and alanine aminotransferase(ALT).Results:The baseline levels of plasma iron,ferritin,IBC,CK,LDH,AST,and ALT were similar in both the control and PRP groups.However,24-h following exercise a significant increase in these parameters was observed in both groups between 1 and 4 days during the recovery period.Interestingly,PRP administration decreased plasma iron levels compared to the control on the second day post-exercise.Plasma IBC increased in PRP group from Days 2 to 4 post-exercise compared to the control group whilst PRP administration had no effect on plasma ferritin,CK,AST,ALT,or LDH.Conclusion:Acute exhaustive exercise increased muscle damage markers,including plasma iron,IBC,and ferritin levels,indicating muscle damage induced by exercise.PRP administration improves inflammation by reversing the increase in the iron levels post-exercise without displaying any myotoxicity and may have a role to play in the recovery of exercise-induced muscle damage. 展开更多
关键词 Exercise-induced muscle damage Ferritin Plasma iron Platelet rich plasma
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Rifaximin in the treatment of inflammatory bowel disease 被引量:4
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作者 Mario Guslandi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第42期4643-4646,共4页
The gut microbiota plays a role in promoting and maintaining inflammation in inflammatory bowel diseases (IBD), hence the rationale for the use of antibiotics in the treatment of those disorders. Antibiotics, howeve... The gut microbiota plays a role in promoting and maintaining inflammation in inflammatory bowel diseases (IBD), hence the rationale for the use of antibiotics in the treatment of those disorders. Antibiotics, however, may induce untoward effects, especially during longterm therapy. Rifaximin α polymer is an antibacterial agent that is virtually unabsorbed after oral administration and is devoid of systemic side effects. Rifaximin has provided promising results in inducing remission of Crohn's disease (up to 69% in open studies and significantly higher rates than placebo in double blind trials) and ulcerative colitis (76% in open studies and significantly higher rates than placebo in controlled studies) and might also have a role in maintaining remission of ulcerative colitis and pouchitis. The potential therapeutic activity of rifaximin in IBD deserves to be further investigated and confirmed in larger, controlled studies. The optimal dosage still needs to be better defined. 展开更多
关键词 ANTIBIOTICS Gut microbiota Inflammatorybowel disease RIFAXIMIN
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Detection of Acetyl-CoA Carboxylase (ACCase) Inhibitor Herbicides Resistance in Sterile Wild Oat (Avena sterilis L.) Using Agar Quick Test
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作者 Abdullatief Mohammed Abdurruhman Sibel Uygur and Feyzullah Nezihi Uygur 《Journal of Agricultural Science and Technology(A)》 2018年第1期10-17,共8页
This study was conducted using seeds in Petri dish containing agar medium in order to determine acetyl-CoA carboxylase (ACCase) herbicides resistance (R) in Avena sterilis that was grown in wheat fields at Adana p... This study was conducted using seeds in Petri dish containing agar medium in order to determine acetyl-CoA carboxylase (ACCase) herbicides resistance (R) in Avena sterilis that was grown in wheat fields at Adana province, Turkey. Seeds were collected from one large suspected field, where clodinafop-propargyl (Aryloxyphenoxypropionate “FOPs”) and pinoxaden (Phenylpyrazoline “DEN”) have been applied for many years. Susceptible (S) population was collected from the road side on the same region. Agar media of concentration 14 g/L was prepared and it was melted in microwave. Then the amount of 20 mL agar media was added into each Petri dish. Five seeds were placed on agar mediums containing discriminating dose of clodinafop and pinoxaden. Petri dishes were placed in growth incubator operating at 10 °C. After 15 d, both radicle and hypocotyl length were measured. The percentage of germinated seed and dose-response curves were determined. At these different concentration levels, there were more than 50% of R and less than 40% of S seed germinated for pinoxaden. However, for clodinafop, more than 60% of R and less than 50% of S seeds were germinated. At higher concentration levels, the populations of resistant and susceptible were not germinated for both herbicides. The resistance value of R population was then compared with that of the S biotype. From the resistance index (RI), the population was more resistant to pinoxaden (7.43 for radicle and 2.47 for hypocotyl) than the clodinafop-propagyl (1.39 for radicle and 3.77 for hypocotyl). The method provided a simple, quick and cost effective way to identify ACCase herbicides resistance in most grass weeds. 展开更多
关键词 Acetyl-CoA carboxylase herbicides resistance Avena sterilis L. CLODINAFOP-PROPARGYL pinoxaden.
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High doses of α-galactosylceramide potentiate experimental autoimmune encephalomyelitis by directly enhancing Th17 response 被引量:3
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作者 Gaochao Qian Xia Qin +5 位作者 Ying Qin Zang Baoxue Ge Taylor B Guo Bing Wan Lei Fang Jingwu Z Zhang 《Cell Research》 SCIE CAS CSCD 2010年第4期480-491,共12页
α-Galactosylceramide (u-GC) is widely known to activate invariant natural killer T (iNKT) cells to suppress my- elin antigen-specific Thl responses, protecting susceptible mice against experimental antoimmune enc... α-Galactosylceramide (u-GC) is widely known to activate invariant natural killer T (iNKT) cells to suppress my- elin antigen-specific Thl responses, protecting susceptible mice against experimental antoimmune encephalomyelitis 0EAE). Here, we demonstrate an unexpected finding that high doses of α-GC exacerbated, rather than ameliorated, EAE. Similar results were observed when MOG35.ss-specific T cells treated with high-dose α-GC were transferred into naive syngeneic recipient mice. Further study showed that high doses of a-GC directly enhance the Thl7 and Thl re- sponse by activation of CD4+CD44+ memory T cells through phosphorylation of STAT3 and activation of NF-kB. Un- like the activation of iNKT cells by low doses of a-GC, high doses of a-GC directly interacted with CDld expressed on T ceils and activated Thl7 and Thl cells. Furthermore, antigen-presenting cells (APCs) predominantly express CDldl, whereas the majority of CD4~ T cells express CDld2. Knockdown of CDldl or CDld2 gene expression by RNAi interfered with the activation of iNKT or Thl7/Thl cells, respectively. Therefore, α-GC treatment could im- prove or worsen EAE by engaging either APCs or Thl7/Thl cells depending on the dose used. 展开更多
关键词 α-GC experimental autoimmune encephalomyelitis IL-17
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Synthesis of Methyl 3-Hydroxypropanoate by Hydroesterification of Ethylene Oxide over Dicobalt Octacarbonyl Catalyst
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作者 Zhang Ye Zhou Haijun +1 位作者 Xie Xianmei Chen Xiaoping 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第4期48-51,共4页
Methyl 3-hydroxypropanoate was synthesized via hydroesterification of ethylene oxide with CO in the presence of dicobalt octacarbonyl catalyst and methanol solvent. The catalyst exhibited high catalytic activity. The ... Methyl 3-hydroxypropanoate was synthesized via hydroesterification of ethylene oxide with CO in the presence of dicobalt octacarbonyl catalyst and methanol solvent. The catalyst exhibited high catalytic activity. The effect of reaction temperature, CO pressure, methanol dosage, catalyst dosage and reaction time on catalytic reaction was investigated. The test results revealed that this reaction was greatly affected by reaction temperature, but it was not significantly affected by the CO pressure, the methanol dosage, the catalyst dosage and the reaction time. Under the optimal conditions, the conversion of ethylene oxide was equal to 92.24%, while the selectivity and yield of methyl 3-hydroxypropanoate reached 88.99% and 84.35%, respectively. 展开更多
关键词 ethylene oxide methyl 3-hydroxypropanoate dicobalt octacarbonyl hydroesterification.
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Influences of the [Co^2+]/[Co^3+] Ratio on the Process of Liquid-phase Oxidation of Toluene by Air 被引量:8
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作者 唐盛伟 沈伟 梁斌 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第4期613-617,共5页
Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid.In a φ48mm bubble column reactor,the commercial process of toluene liquid phase oxidation was conducted with Co(CH... Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid.In a φ48mm bubble column reactor,the commercial process of toluene liquid phase oxidation was conducted with Co(CH3COO)2.4H2O as catalyst.The Co2+ concentration [Co2+] was determined by extraction spectrophotometry and hereby the Co3+ concentration [Co3+] was obtained by mass balance.The results showed that [Co3+] reached the maximum at about 25-30min.[Co3+] increased with increasing Co catalyst amount at total Co concentration<150 mg.L-1 of toluene.The conversion of toluene,yield and selectivity of benzoic acid increased with the increasing [Co3+/Co2+] max.A high [Co3+] and a high [Co3+]/[Co2+] ratio are beneficial to the reaction. 展开更多
关键词 TOLUENE benzoic acid liquid-phase oxidation cobaltous acetate
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Effect of Operating Conditions on Olefin Distribution in FCC Gasoline as Part of an Olefin Reduction Process 被引量:1
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作者 Ouyang Fusheng Pei Xu +2 位作者 Zhao Xuhong Liu Xuan Weng Huixin (Research Institute of Petroleum Processing,East China University of Science and Technology,Shanghai 200237) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2010年第4期34-42,共9页
The effects of operating conditions on the distribution of olefins in the FCC gasoline, obtained during catalytic cracking reaction in the presence of the GOR-Q catalyst and conventional MLC-500 catalyst, have been st... The effects of operating conditions on the distribution of olefins in the FCC gasoline, obtained during catalytic cracking reaction in the presence of the GOR-Q catalyst and conventional MLC-500 catalyst, have been studied in detail. The test results showed that the GOR-Q catalyst could obviously reduce the content of several kinds of olefins in FCC gasoline. Olefins in the FCC gasoline consist mainly of C5- C7 compounds, that are composed of C=C bond with normal or mono- branched chains. The reduction of gasoline olefin content could be achieved by decreasing the content of above-mentioned olefins. Lower reaction temperature, lower weight hourly space velocity (WHSV) and higher catalyst to oil ratio would help to reduce the content of olefins with a C = C double bond, normal olefins, mono-branched-chain olefins and diolefins. To decrease the loss of gasoline octane number, the operation for olefin reduction should be firstly focused on increasing the catalyst to oil ratio. 展开更多
关键词 operating conditions FCC gasoline olefin CATALYST
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Synthesis of Vanillin 1, 2-Propylene Glycol Acetal Catalyzed by H3PMo6W6O40·nH2O 被引量:1
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作者 Zongrui Liu Zhe Dong Xiaohong Wang Lijuan Xie Limei Duan 《Journal of Chemistry and Chemical Engineering》 2010年第2期22-26,共5页
Vanillin 1, 2-propylene glycol acetal was synthesized from vanillin and 1, 2-propylene glycol using H3PMo6W6O40·nH2O as catalyst, The factors influencing the synthesis were discussed and the better reaction condi... Vanillin 1, 2-propylene glycol acetal was synthesized from vanillin and 1, 2-propylene glycol using H3PMo6W6O40·nH2O as catalyst, The factors influencing the synthesis were discussed and the better reaction conditions were found as follows: The amount of vanillin was 3.8 g, the molar ratio of vanillin was 1, 2-propylene glycol 1.0 to 2.4, the amount of catalyst was 1.6% in proportion to the total reacting materials, the volume ofcyclohexane as the water-carrying agent 4 mL, the refluxing time was 2 h at 88-96℃ and thus the product yield reached over 87%. The results show that the catalyst's activity is high and the reaction time is short. 展开更多
关键词 Vanillin 1 2-propylene glycol acetal H3PMo6W6O40 polyoxometalate catalysis.
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Effect of Operation Variables on Hydrodenitrogenation and Hydrodesulfurization over NiMo/Al_2O_3 Catalysts 被引量:2
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作者 段爱军 徐春明 林世雄 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第6期743-746,共4页
Using the JQ-II high pressure hydrogenation micro-reactor unit, the reactivity of Athabasca bitumen derived heavy gas oil was studied over commercial and homemade hydrotreating catalysts. The effects of catalyst prepa... Using the JQ-II high pressure hydrogenation micro-reactor unit, the reactivity of Athabasca bitumen derived heavy gas oil was studied over commercial and homemade hydrotreating catalysts. The effects of catalyst preparation variables and the influences of operation conditions, such as pressure, temperature, hydrogen/oil ratio and space velocity were also examined. It was shown that the optimal concentrations of the active components were 5% of NiO, 20% of MoO3 and 3.5% of phosphorus (by mass), and the suitable operation conditions were determined experimentally. 展开更多
关键词 HYDROTREATMENT heavy gas oil HYDRODESULFURIZATION HYDRODENITROGENATION
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Technology and kinetics of free fatty acids esterification in tung oil
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作者 甘孟瑜 潘登 《Journal of Chongqing University》 CAS 2009年第2期133-138,共6页
We studied the esterification of free fatty acids (FFA) in tung oil with methanol by using activated carbon treated with sulfuric acid as a catalyst, and investigated the effect of different temperatures, methanol/o... We studied the esterification of free fatty acids (FFA) in tung oil with methanol by using activated carbon treated with sulfuric acid as a catalyst, and investigated the effect of different temperatures, methanol/oil mole ratio and catalyst amount on the conversion of FFA. Results show that the optimal reaction condition is when the reaction time is 2 h, the mass fraction of the catalyst to total material is 5%, the molar ratio of menthol to FFA is 15 : 1, and the reaction temperature is 368.15 K. We also investigated the kinetics of estefification at various temperatures. Results indicate that the rate-control step could be attributed to the surface reaction, and within the range of the experimental conditions, the as-calculated kinetics formula can depict the esterification processes well. 展开更多
关键词 b-iodiesel KINETICS ESTERIFICATION tung oil supported catalyst
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Study on Fractionated Total Body Irradiation before Hematopoietic Stem Cell Transplantation
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作者 Tong Fang Bo Liu Hong Gao 《Chinese Journal of Clinical Oncology》 CSCD 2009年第1期47-50,共4页
OBJECTIVE To observe the dose and the complicationsfrom total body irradiation before hematopoietic stem celltransplantation.METHODS This study involved 312 patients with total bodyirradiation before hematopoietic ste... OBJECTIVE To observe the dose and the complicationsfrom total body irradiation before hematopoietic stem celltransplantation.METHODS This study involved 312 patients with total bodyirradiation before hematopoietic stem cell transplantation. Theywere entered into the treated research from May 1999 to October2005. All patients had received the irradiation from ^(60)Co of anabsorbed dose rate of (5.2 ± 1.13) cGy/min. The total dose of TBIwas 7~12 Gy, 1 f/d × 2 d. A high-dose rate group (≥10 Gy) included139 cases and a low-dose rate group (< 10 Gy) included 173 cases.RESULTS The probability of acute gastrointestinal reactionsin the high-dose rate group was more compared with that in thelow-dose rate group. The differences for other reactions, such ashematopoietic reconstitution and graft survival rate, between thetwo groups were insignificant.CONCLUSION Using fractional total body irradiation at a doserate of 5 cGy/min, with a total dose of 7~12 Gy, 1 f/d × 2 d , withthe lung receiving under 7.5 Gy is a safe and effective pretreatmentfor hematopoietic stem cell transplantation. 展开更多
关键词 hematopoietic stem cell TRANSPLANTATION PRETREATMENT total body irradiation absorbed dose rate.
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Kinetic Study of Esterification of Lactic Acid with Isobutanol and n-Butanol Catalyzed by Ion-exchange Resins 被引量:3
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作者 屈一新 彭少君 +2 位作者 王水 张志强 王际东 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第5期773-780,共8页
The esterification reactions of lactic acid with isobutanol and n-butanol have been studied in the presence of acid ion-exchange resin Weblyst D009. The influences of catalyst loading, stirrer speed, catalyst particle... The esterification reactions of lactic acid with isobutanol and n-butanol have been studied in the presence of acid ion-exchange resin Weblyst D009. The influences of catalyst loading, stirrer speed, catalyst particle size, initial reactant molar ratio and temperature on the reaction rate have been examined. Experimental kinetic data were correlated by using the pseudo-homogeneous, Langnluir-Hinshelwood and Eley-Rideal models. Nonideality of the liquid phase was taken into account by using activities instead of molar fractions. The activity coefficients were calculated according to the group contribution method UNIFAC. Provided that the nonideality of the liquid is taken into account, the esterification kinetics of lactic acid with isobutanol and n-butanol catalyzed by the acid ion-exchange resin can be described using all threemodels with reasonable errors. 展开更多
关键词 KINETICS ESTERIFICATION lactic acid ISOBUTANOL N-BUTANOL ion exchange resin
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