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1.
茶多酚抗突变和消除自由基作用的研究   总被引:6,自引:0,他引:6  
曹明富  袁妙葆 《科技通报》1994,10(5):301-305
采用E.ColiSOS显色法,小鼠骨髓细胞微核及染色体畸变试验和体外自由基消除实验等方法测定了茶多酚复合物(TP)的抗突变和消除自由基作用.结果表明:(1)TP的终浓度在2.5和5mg/ml时,对由阳性致突变物MNNG,EMS和NaN_3诱导的SOS应答反应均具有明显的抑制作用;(2)小鼠每日ig40、80和120mg/kg剂量的TP能明显抑制由环磷酰胺(CP)诱发的骨髓PCE的MNCF,三种剂量TP的抑制率分别为40.98%、66.76%和65.94%;(3)TP对MMC诱发的骨髓细胞染色体畸变(CA)的抑制率分别为62.56%、55.71%和47.95%;(4)在X/XO-ESR、X/XO/Luminol-BCL和IR/NBT-SPM三种模型中TP对超氧阴离子O_2自由基均具有极强的消除作用,消除率分别为98±6%、98±1.2%和95±1.5%,对O_2的消除效率明显强于维生素C和E,对不同工艺制备的TP消除活性氧自由基作用的测定结果显示:脱咖啡碱程度高,EGC和L-EGCG含量比例高的TP-3制剂消除O_2的效率最高.因此,TP消除有害自由基,中断或终止自由基的氧化反应是抗突变,抗肿瘤作用的主要机制  相似文献   

2.
美国研究开发政策和投入的新发展   总被引:3,自引:0,他引:3  
1997年美国全国用于研究与发展(R&D)的经费首次突破了2000亿美元大关,达到了2057亿美元,比1996年增长了125亿美元,比1984年的1019.40亿美元翻了一番。这是美国长期重视R&D的结果。这一数字使美国的R&D在国内生产总值(GDP)中所占的比例达到了2.6%(扣除国防方面的因素后,R&D在GDP中占2.2%),创历史最高水平。根据1996年度的统计,世界各国科研经费占国民生产总值的比例,居第一位的是瑞典3.6%,其次是日本2.96%,美国2.52%,法国2.31%,德国2.2…  相似文献   

3.
朱岩  李刚 《科技通报》1994,10(5):297-300
采用梯度淋洗离子色谱法对碱金属、碱土金属及其铵类进行分析,该方法采用CG3分离柱,0.3mmol/LHCl为淋洗剂,4min后改用3.0mmol/L盐酸间苯二胺和5.0mmo1/LHCl作淋洗剂(流速2.0ml/min)采用微膜抑制柱,再生液为50mmol/LKOH(流速2.0ml/min),用电导检测法分别检测Li ̄+、Na ̄+、NH、K ̄+和Mg ̄(2+)、Ca ̄(2+)、Sr ̄(2+)、Ba ̄(2+).对分析条件进行了探讨.  相似文献   

4.
边平凤 《科技通报》1998,14(2):94-97
用TRP技术考察了不同负载量及不同焙烧温度的Co3O4/CeO2催化剂的还原性能和还原催化剂的再氧化性能.结果表明,Co3O4/CeO2催化剂有4个还原峰(α1、α2、γ1、γ2),α1、α2还原峰归属为分散在CeO2表面与CeO2发生相互作用的氧化钴的还原,γ1、γ2归属为晶相氧化钴的还原,随着焙烧温度升高,α1、α2峰消失.Co3O4/CeO2催化剂经还原后,α2物种最易氧化,其次是γ1物种,γ2物种最难被氧化.  相似文献   

5.
吴红丽  朱波 《科技通报》1997,13(2):103-106
采用浸渍法制备了一系列γ-Al2O3负载的Cr-Ag双金属氧化物催化剂,并考察了对CO的氧化活性.结果表明,由Cr(NO3)3、CrO3、Cr2(C2O4)3作为Cr源制备的单组分Cr-/γ-Al2O3催化剂对CO的氧化活性基本相同,且均较差;但添加少量Ag(<2wt%)却能明显提高Cr/γ-Al2O3催化剂对CO的氧化活性,且分步浸渍法制备的Cr-Ag/γ-Al2O3双组分催化剂的活性明显优于用其浸渍法制备的催化剂  相似文献   

6.
吴楚绶 《科技通报》1997,13(3):193-196
观察了力平脂对高脂血症者的治疗作用和安全性.确诊高脂血症者68例,力平脂,0.1,Tid,服一个月为一疗程后,血清总胆固醇(TC)平均降低20.98%,甘油三酯平均降低51.88%,HDL-C平均升高10.26%,LDL-C平均降低12.57%,ApoA1平均升高2.24%,ApoB平均降低21.10%,从调血脂的个体疗效分析,力平脂降低TC的总有效率84.61%,降低TG的总有效率95.24%,升高HDL-C的总有效率61.77%,降低LDL-C的总有效率为55.88%,升高ApoA1的总有效率38.24%,降低ApoB的总有效率77.94%.提示:力平脂治疗高脂血症者,对降低TC,TG,LDL-C,ApoB和升高HDL-C,ApoA1均有明显效果,其中降低TG的疗效尤为突出,副作用轻微.临床实践表明:力平脂是一个疗效高、安全、服用方便的调血脂新药  相似文献   

7.
对自然数k≤n-1,F(n,k)定义为:存在长为F(n,k)的由1,2,…,组成的数列Sn,k使对每个k,1≤i≤k,Sn,k的前F(n,i)项以1,2,…,n的全部i-排列为其子排列且任何长小于F(n,k)的数列不满足这一条件,对此:1982年,CaiMaocheng犤1犦证明了F(n,k)≤k(n-1)+1-犤k4犦。1989年,单?犤2犦证明了F(n,k)≤k(n-1)+1-犤k+26犦-犤k6犦。1992年,徐士达犤3犦证明了F(n,k)≤k(n-1)+1-犤k+26犦-犤k6犦-犤k-26犦。同时猜想:F(n,k)=k(n-1)+1-犤k+2…  相似文献   

8.
CK—A型单向楔块式超越离合器基本参数和主要尺寸(其它暂略)型号公称转矩(Nm)D(h7)键槽bxtLCKA1CKA2CKA3CKA4CKA531.5506310014050556063633×1.84×2.56×3.56×3.56×3.522222224301218202525252825303538354045503×1.44×1.86×2.86×2.86×2.82424242632250022502000180018000.300.360.390.440.50d(H7)键槽b1xt1L1超越极限转速(rpm)质量…  相似文献   

9.
胡建文 《科技通报》1997,13(5):349-351
对以上消化道症状而就诊的321例慢性胃炎患者行胃镜及幽门螺杆菌(HP)检测和胃粘膜病理学检查,结果显示慢性萎缩性胃炎的HP检出率为76.1%,显著高于慢性浅表性胃炎的检出率56.3%(P<0.01),HP感染患者胃粘膜萎缩和肠化生的发生率分别为26.3%和29.9%,显著高于无HP感染者胃粘膜萎缩和肠化生的发生率12.6%及19.7%(P<0.01和P<0.05).且HP感染与胃粘膜萎缩程度有显著关系,而与肠化生程度和不典型增生无显著关系(P>0.05).提示HP感染可以使胃粘膜萎缩和肠化生的发病率升高,并认为HP感染可能为胃癌发生的危险因素之一.  相似文献   

10.
土地资源形势严峻我国是土地资源大国,又是土地资源小国。我国人均土地面积只有12亩,不到世界人均的1/3;人均耕地1.2亩,为世界人均的1/4。土地沙化面积不断扩大。沙漠与沙漠化面积已达153.3万km2,占国土面积的15.9%。预计今后10年,沙漠化...  相似文献   

11.
Appropriate therapeutic measures can improve the life expectancy of patients with ovarian malignancy. There has been a pressing need for serodiagnostic assays to enable, the close patient monitoring. Cancer Antigen 125 (CA125) has been described as a useful marker in patient monitoring for ovarian malignancy. Keeping this in view, the present study was planned. 40 consecutive female patients of ovarian carcinoma (mean age 52.4±10.7 years) were selected for serum CA125 analysis during the period of year 1995–2001. The tumour marker concentration was compared with histologic types of ovarian tumour and the FIGO staging of the disease. 25 healthy females (mean age 35.2–10.4 years) served as control. Mean serum CA125 concentrations in patients with papillary serous adenocarcinoma(Mean±%CV 1571±121.5 U/ml) was much higher than patients with mucinous adenocarcinoma(775±78U/ml). Mean serum CA125 concentration in endometrioid carcinoma was very high(2853±136 U/ml). The patient with clear cell carcinoma however had shown moderate increase(60 U/ml). No correlation was found between serum CA125 concentration and the FIGO staging of disease. Quantitation of CA125 was most helpful in monitoring the response of treatment and followup of the patients after completion of their treatment. Posttherapeutically its concentration showed more than 50% reduction in almost all (91.4%) patients (P<0.001). Importantly these patients had also shown significant regression of the disease clinically and radiologically. 8.6% of patients had shown static or increase in serum CA125 concentration which was associated with either clinically static or progressive disease. Recurrence of the disease was noted in patients who had shown increase in serum CA125 concentration (biochemical recurrence) in the followup However, in our test population biochemical recurrence(increase in serum marker concentration) preceded the clinical or radiological recurrence by an average of 6.5 months. Kaplan meier survival analysis for evaluation of overall survival in our test subjects showed an overall survival of 32% at one year and median survival of 9 months with confidence interval of 6.34 to 11.66. We conclude that serum CA125 is a useful marker for monitoring the treatment and predicting an early recurrence of the disease in ovarian carcinoma patients. A study in larger number of patients is needed to define its exact role in the management of the carcinoma ovary.  相似文献   

12.
许沈华  冯文华 《科技通报》1992,8(4):244-248
用单克隆抗体MC_3在福尔马林固定的48例大肠癌、31例癌变腺瘤、42例伴有不典型增生腺瘤、40例腺瘤、13例息肉以及48例正常肠粘膜组织切片上用免疫组化(PAP)法检测,结果MC_3相应抗原的表达阳性率分别为93.8%(45/48)、80.65% (25/31)、47.62% (20/42)、37.5%(15/40),其阳性率差异有非常显著性(P<0.001).48例正常肠粘膜均为阴性.MC_3在大肠癌组织中的反应程度与患者3年生存率有关,差异有显著意义(P<0.05).MC_3反应强度在高分化肠癌组与中~低分化肠癌组比较差异有显著意义(P<0.05).在绒毛状腺瘤、混合性腺瘤和管状腺瘤中MC_3相应抗原表达阳性率分别为71.4%(25/35)、60.0%(9/15)、41.3(26/63),差异有显著性(p<0.05).绒毛状腺瘤、混合性腺瘤和管状腺瘤其癌变率分别为45.7%(16/35)、13.3%(2/15)、20.6%(13/63),其癌变率比较差异有显著性(P<0.05).  相似文献   

13.
目的:制作乳腺癌调强放疗计划时,采用分段逆向调强优化方法以达到更好的靶区剂量和保护肺、心脏等危及器官。方法:应用Eclipse8.6计划系统针对10例乳腺癌患者(肿瘤原发部位左右侧各5例)分别制定T1,T2模式调强放疗计划,处方剂量均为DT50Gy/25次。T1模式采用左乳300°、330°、0°、30°、60°、90°和120°方向射野,右乳60°、30°、0°、330°、300°、270°和240°方向射野,设置优化参数进行逆向优化和剂量运算。T2模式采用与T1模式相同的角度方向设野,第一段总剂量24Gy,分次剂量2Gy,分12次治疗,设置优化参数进行逆向优化和剂量运算;第二段总剂量26Gy,分次剂量2Gy,分13次照射,设置优化参数,采用"Base dose plan"功能选择基于第一段治疗计划以总量50Gy来逆向优化和剂量运算。将两段计划相加作为T2模式的治疗计划,通过剂量体积直方图比较两种模式下计划的靶体积和危及器官剂量分布。结果:T1、T2模式调强放疗计划的靶体积均满足临床剂量要求,对于左侧乳腺癌,适形指数分别为0.727±0.034、0.751±0.034(t=-6.20,P=0.003);对于右侧乳腺癌,适形指数分别为0.691±0.058、0.729±0.048(t=-5.39,P=0.006)。对左侧乳腺癌,T2模式的左肺V10(%)、左肺V20(%)、左肺V30(%)、全肺V10(%)、全肺V20(%)、全肺V30(%)和心脏V10(%)均大于T1模式,分别增大5.0%、2.7%、3.7%、4.6%、2.6%、3.8%和4.4%。对于右侧乳腺癌,无充分证据说明危及器官各指标有差别。结论:与T1模式相比,采用分段逆向调强优化方法能更好的优化靶区的剂量分布,但对左侧乳腺癌而言,会略微增加左肺、全肺和心脏剂量受量。  相似文献   

14.
Circulating levels of gonadotropins (FSH,LH), prolactin (PRL), estradiol and progesterone were measured by radioimmunoassay in the sera of 60 patients with histopathologically proven breast cancer. 30 patients belonged to the post and 30 to the premenopausal group. 30 healthy women, 15 each in the pre and post menopausal groups served as controls for the study. Prolactin was elevated in 33% and 26% of pre and post menopausal breast cancer patients respectively. Lower levels of estradiol and progesterone were observed during the luteal phase of the menstrual cycle in premenopausal breast cancer patients. Among postmenopausal patients with breast cancer, LH was elevated in 32%, FSH in 15% and estradiol in 30% of the patients studied.  相似文献   

15.
The early diagnosis of bladder cancer is important for effective treatment of the disease. This study aimed to evaluate the nuclear matrix protein 22 (NMP 22), soluble epithelial cadherin (E-cadherin), cathepthin-D and total protein with clinico-pathological features of bladder cancer, and to determine the relation between each marker and tumor progression after treatment. The study includes 65 patients with bladder cancer, 14 benign urinary diseases and 11 healthy volunteers. Patients were categorized according to bilharzial infestation, T stage, tumor grade, size and the presence of lymph node metastasis. Forty patients were followed for disease progression after surgery. There was a significant increase of NMP22, E-cadherin, cathepthin-D and total protein detected in cancer group compared to healthy and benign groups. It was found that NMP 22 and E-cadherin had highest sensitivity (84.4, 76.9 %, respectively) while, total ddedprotein showed highest specificity (77.4 %). Tumor size correlated with urinary NMP22 (r = 0.3, p = 0.02), although, E-cadherin, cathepsin-D and total protein correlated with tumor size (r = 0.3, 0.28, 0.2; p = 0.01, p = 0.01, 0.04, respectively) and lymph node metastasis (r = 0.32, 0.34, 0.2; p = 0.003, 0.005, 0.04, respectively). Elevated pretreatment urinary NMP22, E-cadherin and total protein levels was associated significantly with bladder cancer recurrence (p = 0.02, 0.001, 0.005, respectively). In conclusion, determination of urinary NMP22, E-cadherin and total protein in bladder cancer patients or persons at risk of developing bladder cancer will help in early detection of the disease and prediction of recurrence. The use of a combination of tumor markers is markedly useful than the assessment of single one.  相似文献   

16.
中国东部地区春季降水与气温异常型的联合EOF分析   总被引:1,自引:0,他引:1  
郝振华  余锦华 《资源科学》2013,35(9):1898-1907
利用中国东部地区(100°E以东)140个气象观测站1951-2010年的逐月降水和地面气温资料,在去除气温的线性趋势的基础上采用联合EOF分析等方法,对春季(3-5月)的降水异常型和气温异常型之间的关系进行了诊断研究,结果表明:①在第一典型场(方差贡献率为28.13%)中,降水异常型态为南方型,存在3个暖异常区域:华北中部和北部的部分地区、陕西汉中地区以及西南地区;3个冷异常中心:一个位于长江以南地区,一个位于东北地区,一个位于西北地区的内蒙古西部。时间系数存在准3年、4~5年和8年尺度振荡周期;②在第二典型场(方差贡献率为16.57%)中,降水异常型态为中间型,气温异常偏高区基本位于南岭以南地区和西南地区的云南、贵州、四川,气温异常偏低区处在南岭以北地区。时间系数存在3年和18年为明显的时间振荡周期;③在第三典型场(方差贡献率为7.94%)中,降水异常型态近似表现为北方型,气温异常场,从南向北表现为“+-+”交替分布型。时间系数存在24~26年、4年为明显的时间振荡周期。通过3个模态的分析发现降水异常偏多与气温异常偏低、降水异常偏少与气温异常偏高的一致性特征在长江以南地区表现得尤为显著,当降水偏多时,云量增多,地表吸收的太阳辐射减少,再加上异常偏多的降水改变了地表的湿度(增大),进一步使地面放出的长波辐射相应减少,从而导致了地面气温降低。  相似文献   

17.
BackgroundSpermatogonial stem cells (SSCs) are important for the production of interspecies germ line chimeras. The interspecies germ cell transfer technique has been suggested as a way to conserve endangered birds. Our objective was to develop a technique for restoring endangered birds by developing interspecies germ line chimeras between pheasant (Phasianus colchicus) and chicken (Gallus gallus) with SSCs.ResultsSSCs were isolated from the surgically removed testis of a pheasant. Growth conditions for pheasant SSCs were established by co-culturing STO (SIM mouse embryo-derived thioguanine and ouabain resistant) cells and pheasant SSCs. The colony-forming cells divided and proliferated stably to yield an established SSC line. Pheasant SSCs showed strong reactivity for GDNF family receptor alpha1 (GFRα1) marker. Finally, production of germ line chimeras was attempted by transferring pheasant SSCs into recipient embryos. Although final embryo survival was 5.6% (20/354), the initial survival rate was 88% (312/354). To measure the percent transfer of donor SSC to gonads, the pheasant SSCs were labeled with PKH 26 fluorescent dye. We observed 30% donor cells and 9.48% c-kit/CD117-positive cells in the gonads of recipient chickens. Donor SSCs were thus stably engrafted in the recipient gonads.ConclusionsThis study showed that SSCs can be used as a tool for the conservation of endangered birds and the production of germ line chimeras. Our findings yield insights into how we may use the pheasant spermatogonial stem cell line for efficient production of interspecies germ line chimeras and ultimately, to the restoration of endangered birds.  相似文献   

18.
BackgroundTP73 antisense RNA 1 (TP73-AS1), a newly discovered long non-coding RNA (lncRNA), has been reported to be upregulated in various kinds of tumors, and shows a variable influence on living quality and prognosis of patients. Thus, we conducted a meta-analysis to evaluate the overall prognostic value of the lncRNA TP73-AS1 in cancer patients.ResultsA systematic literature retrieval was carried out using the PubMed, Cochrane Library, EMBASE, and Web of Science databases. We calculated the pooled hazard ratio (HR) and odds ratio (OR) with 95% confidence intervals (CIs) to evaluate the association of TP73-AS1 expression with prognostic and clinicopathological parameters. A total of 15 studies including 1057 cancer patients were finally selected for the meta-analysis. The results demonstrated that high TP73-AS1 expression was significantly associated with shorter overall survival (OS) (HR = 1.97, 95% CI: 1.68–2.31, P < 0.001). According to a fixed-effects or random-effects model, elevated TP73-AS1 expression markedly predicted advanced clinical stage (OR = 3.30, 95% CI: 2.35–4.64, P < 0.001), larger tumor size (OR = 2.37, 95% CI: 1.75–3.22, P < 0.001), earlier lymph node metastasis (OR = 3.28, 95% CI: 1.59–6.76, P = 0.001), and distant metastasis (OR = 4.94, 95% CI: 2.61–9.37, P < 0.001).ConclusionsHigh lncRNA TP73-AS1 expression appears to be predictive of a worse OS and clinicopathologic features for patients with various types of malignant tumors. These results provide a basis for utilizing TP73-AS1 expression as an unfavorable indicator to predict survival outcomes.How to cite: Wang X, Shu K, Wang Z, et al. Prognostic value of long non-coding RNA TP73-AS1 expression in different types of cancer: A systematic review and meta-analysis. Electron J Biotechnol 2020;43. https://doi.org/10.1016/j.ejbt.2019.12.005.  相似文献   

19.
A metabolomic study for determination of certain urinary metabolomes, 1-methyladenosine (1-MA), 1-methylguanosine (1-MG), and 8-hydroxy-2′ deoxyguanosine (8-OHdG) in urine specimens of breast cancer patients. The accuracy of these metabolites and their combined score with cancer antigen 15-3 (CA15-3) was developed to improve the early detection of breast cancer. This study recruited 52 healthy individuals, 47 benign breast tumors, and 167 malignant breast tumor patients. Urine samples were handled to adjust the creatinine concentrations to 8 mg/dL (0.7 mmol/L) and analyzed using GC–MS to detect and quantify the selected urinary metabolomes in urine samples of all participants. The accuracy of individual urinary metabolomes and their combination with CA15-3 were evaluated using multivariate statistical analysis. The cutoff value of CA15-3 was 32.5 U/mL. Cutoff values of 1-MA, 1-MG, and 8-OHdG were 2.19, 2.1, and 7.3 µmol/mmol creatinine, respectively. The concentrations of 1-MA, 1-MG, and 8-OHdG were significantly higher in breast cancer patients, especially in the early-stage. The combination of three urinary metabolomes with CA15-3 improves the diagnostic sensitivity of breast cancer. For the combined score, the area under the curve (AUC) value of combined score ranged from 0.820 to 0.950, with high accuracy, ranged from 77.0 to 95.5%. The most significant AUC (0.973), sensitivity (90.1%), selectivity (94.0%) was recorded at comparing the healthy control with the early-stage of malignant breast cancer. In conclusion, the combination of three urinary metabolomes with serum CA15-3 improves the diagnostic sensitivity of breast cancer.  相似文献   

20.
李铁  陆玲 《大众科技》2013,(6):171-173,164
中药治疗乳腺癌有着广泛的临床适应证,尤其在内分泌治疗毒副反应研究方面有着显著的优势。对提高患者生存率,降低复发转移率,改善患者的生活质量具有极其重要的临床意义和广泛的应用前景。  相似文献   

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