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961.
建立了用于在线估计高密度重组毕赤酵母培养过程中处于表达阶段的菌体密度软测量模型。分别对比了基于遗传算法(GA)的动力学软测量模型以及基于人工神经网络(ANN)的软测量模型,并对神经网络软测量模型的拓扑结构以及训练参数进行了初步探讨。当采用基于遗传算法(GA)的动力学模型,模型拟舍值的最大误差为7.63%;在采用神经网络软测量技术时,选取合适的模型结构和输入参数,最大误差为3.12%,而且软测量模型可以很好地反映菌体浓度实时变化趋势。该研究结果表明,在酵母细胞的高密度培养过程中采用基于神经网络的软测量模型具有较高的准确度,可以较好地实时反映发酵过程中菌体浓度的变化。  相似文献   
962.
Objective Deficiency of DNA mismatch repair (MMR) causes microsatellite instability (MSI) in a subset of colorectal cancers. Patients with these tumours have a better prognosis and may have an altered response to chemotherapy. Some of the tumours are caused by hereditary mutations (hereditary nonpolyposis colon cancer or Lynch syndrome), but most are epigenetic changes of sporadic origin. The aim of this study was to define a robust and inexpensive strategy for such classification in clinical practice. Method Tumours and blood samples from 262 successive patients with colorectal adenocarcinomas were collected. Expression of the MMR proteins MLH1, MSH2, and MSH6 by immunohistochemistry (IHC) was compared with MSI DNA analysis. Methylation analysis of MLH1 and mutation analysis for BRAF V600E were compared in samples with MSI and/or lack of MLH1 expression to determine if the tumour was likely to be sporadic. Results Thirty‐nine (14.9%) of the tumours showed MMR deficiency by IHC or by microsatellite analysis. Sporadic inactivation by methylation of MLH1 promoter was found in 35 patients whereby the BRAF activating V600E mutation, indicating sporadic origin, was found in 32 tumours. On the basis of molecular characteristics we found 223 patients with intact MMR, 35 patients with sporadic MMR deficiency, and four patients who were likely to have hereditary MMR deficiency. Conclusion To obtain the maximal benefit for patients and clinicians, MMR testing should be supplemented with MLH1 methylation or BRAF mutation analysis to distinguish sporadic patients from likely hereditary ones. MMR deficient patients with sporadic disease can be reassured of the better prognosis and the likely hereditary cases should receive genetic counselling.  相似文献   
963.
Advances in both access to and the technology underpinning next-generation sequencing have provided a formidable basis for the evaluation of individuals and families recognized as having a potential hereditary cancer. This article focuses on the most clinically relevant hereditary cancer predisposition syndromes such as hereditary breast and ovarian cancer syndromes and hereditary colorectal cancer. It also reviews current best practice in both surveillance for affected individuals as well as an providing an overview of the available risk-reduction strategies for affected individuals.  相似文献   
964.
目的对青少年发病的亨廷顿舞蹈病(Huntington disease)家系进行致病IT15基因早期诊断分析,为家系成员提供遗传咨询, 并为后续的HD发病机制及实验治疗研究提供依据。方法按照知情同意原则抽取家系成员外周血,提取基因组DNA,采用改良的降落PCR方法扩增IT15基因致病区域,DNA测序检测异常等位基因(CAG) n 三核苷酸重复次数。结果在该家系三代25名成员中,共发现8名致病IT15基因携带者,其中,III10、III12、III14、IV3和V2 CAG三核苷酸的拷贝数均为48,IV11和IV12均为(CAG) 67, IV14为(CAG) 63,而对照组35名正常人的CAG三核苷酸的拷贝数为8-25,两者之间没有重叠。结论家系中第四代致病基因携带者IV14与第三代患者III10比较,CAG三核苷酸重复次数增加15次,即本家系IT15基因在传递过程中发生了扩增突变。同时,扩增突变导致该家系出现青少年发病及遗传早现现象。  相似文献   
965.
Aim. Previous studies support the concept that obesity is a common comorbid condition in patients with epilepsy (PWE). In this study, we present the body mass index (BMI) and data from a survey to assess physical activity in a sample of PWE from an epilepsy clinic. Methods. Between June of 2011 and January of 2013, 100 PWE from an adult epilepsy clinic were included. We obtained BMI, waist circumference, and information regarding physical activity using a standardised questionnaire. Clinical, demographic, electrographic, and imaging parameters were collected from charts. Results. Mean age of patients was 40±14 (18–77) years. The BMI distribution was as follows: 2 patients (2%) underweight, 26 (26%) normal weight, 34 (34%) overweight, 25 (25%) obese, and 13 (13%) with morbid obesity. In our study, obesity was defined as having a BMI ≥30. We found 38 (38%) patients in this range. There was no difference in the rate of drug‐resistant epilepsy between obese and non‐obese patients (55 vs. 55%; p=0.05). Leisure time habit was reported in 82% of obese patients and 79% of patients without obesity. Overall, the most frequent activity was walking (70%). Factors associated with obesity were generalised epilepsy (OR: 2.7, 1.1–6.6; p=0.012), idiopathic syndrome (OR: 2.7, 1.04–7; p=0.018), and family history of epilepsy (OR: 6.1, 1.5–24.2; p=0.002). Conclusion. Our study suggests an association between obesity, idiopathic generalised epilepsy, and family history of epilepsy. Our study shows that PWE are physically active and there is no clear relation between exercise and obesity. We could not identify any association between drug‐resistant epilepsy and obesity. Absence of direct comparison with a control non‐epileptic population; a cross‐sectional design not allowing evaluation of a causal association among variables; and reliance on self‐reported physical activity are to be considered as limitations of the present study.  相似文献   
966.
目的 探讨家族性慢性进行性眼外肌瘫痪(CPEO)型线粒体肌病的临床、遗传和病理特点。方法 回顾性分析CPEO型线粒体肌病3个家系21例患者的临床表现、家系调查及5例肌活检病理学资料。结果 患者临床均表现为眼睑下垂和眼球运动障碍,伴或不伴有肌无力。1家系符合常染色体显性遗传规律,另2个家系符合母系遗传规律。病理改变:光镜下为破碎红纤维(RRFs)和细胞色素C氧化酶(COX)缺失纤维;电镜为肌膜下、肌原纤维间线粒体数量增多,嵴内可见电子致密颗粒或晶格样包涵体。结论 3个家系及其亲子代问临床与病理表现相似,提示不同遗传方式所致CPEO型线粒体肌病临床表现是相同的。  相似文献   
967.
目的 探讨儿茶酚胺氧位甲基转移酶(COMT)基因rs4680位点Val158Met多态性与帕金森病遗传易患性的相关性.方法 采用聚合酶链反应-连接酶检测反应(polymerase chain reaction-ligase detection reaction,PCR-LDR)基因多态性测序方法,分析COMT rs4680位点基因型及等位基因频率在帕金森病患者(437例)和健康对照者(530人)间的分布差异.结果 帕金森病患者G等位基因频率为77.2%,A等位基因频率为22.8%,而在健康对照者分别为74.7%、25.3%,两组间COMTrs4680位点Val158Met等位基因频率分布差异没有统计学意义(P =0.199).各基因型频率在帕金森病患者分别为G/G型57.4%、G/A型39.6%、A/A型3.0%,在健康对照者分别为54.9%、39.6%、5.5%,两组间基因型频率分布差异无统计学意义(P=0.156).在校正性别、年龄混杂因素后经二元Logistic回归分析,COMT rs4680位点各基因型与帕金森病发病风险之间仍无相关性.结论 COMT基因r4680位点Val158Met多态性与中国汉族人群帕金森病易患性可能无关,进一步扩大样本量及在其他不同种族中的研究能更好地确定COMT rs4680位点Val158Met多态性在帕金森病发病风险中的作用.  相似文献   
968.
研究背景亨廷顿病是一种常染色体显性遗传性神经系统退行性疾病.临床主要表现为舞蹈样动作、进行性认知功能减退及精神症状,神经影像学检查显示尾状核和大脑皮质萎缩.其致病基因IT15定位于4p16.3,由67个外显子组成编码亨廷顿蛋白,在其第1个外显子内存在一段多态胞嘧啶.腺嘌呤-鸟嘌呤(CAG)三核苷酸重复序列,正常范围为6~35次、异常36~250次.亨廷顿病多于成年期发病,具有外显不完全和延迟外显现象,而青少年型亨廷顿病临床较为少见.本研究针对一例少年期发病的亨廷顿病患者临床表型及其家系IT15基因CAG重复动态突变特征进行细致分析.方法 采用聚合酶链反应结合荧光标记毛细管电泳片段分析方法,对115例临床拟诊为亨廷顿病家系的先证者进行IT15基因CAG重复次数分析,经pMD18-T载体克隆测序验证部分阳性或携带中间重复等位基凶的样本.结果 经基因分析共发现109例患者携带异常扩展的IT15基因CAG重复序列,其中一例为少年期发病患者,临床以认知功能障碍和运动功能减退为首发症状,其父母临床表型正常.基因片段分析显示,患者IT15基因CAG重复次数为15/68次;其父母分别为17/37次和15117次.结论 (1)少年期发病的亨廷顿病与成年型临床表型不同,后者临床表现以舞蹈样运动、智能减退和精神异常为主,而少年型患者大多以认知功能障碍发病.(2)IT15基因扩展CAG重复序列在代问传递过程中会出现动态突变.引起发病年龄逐代提前,症状加重,即遗传早现.该家系患者之父携带中间等位基因37次重复,遗传给患者成为68次重复.在代间传递过程中发生了大幅度扩展,使CAG三核苷酸重复次数增加了31次,提示重复序列在父系遗传更不稳定.  相似文献   
969.
目的 探讨水通道蛋白4(AQP4)启动子区基因多态性与我国南方多发性硬化(MS)、视神经脊髓炎(NMO)患者血清抗AQP4抗体水平及遗传易患性的关系.方法 收集18例NMO、38例MS、13例复发性脊髓炎(RM)、6例复发性视神经炎(RON)患者及39名对照,PCR扩增AQP4外显子0及外显子1启动子基因(即AQP4-promoter0和AQP4-promoter 1),并行DNA测序.结果 共发现14个AQP4-promoter0及6个AQP4-promoter 1基因多态性位点.血清抗AQP4抗体阳性患者AQP4-promoter 0中-1003 bp多态性位点(A突变为G)发生率比血清抗AQP4抗体阴性患者(13/18与20/45,P=0.046)及对照组(13/18与10/39,P=0.001)高,差异有统计学意义.血清抗AQP4抗体阳性患者及血清抗AQP4抗体阴性患者AQP4-promoter 1中- 401 bp与-400 bp之间多态性位点(插入1个C)发生率均比对照组高(5/16与0/28,P=0.008; 8/38与0/28,P=0.027),差异有统计学意义.NMO及MS患者-1003bp多态性位点及-401 bp与-400 bp之间多态性位点发生率均比对照组高,差异有统计学意义(NMO:11/18与10/39,P=0.010;4/15与0/28,P=0.020;MS:19/38与10/39,P=0.027;8/34与0/28,P=0.018).结论 AQP4启动子区基因存在多态性位点,且与NMO、MS易患性有一定的关系;AQP4外显子0启动子中- 1003 bp多态性位点可能与血清抗AQP4抗体的出现有关.  相似文献   
970.
The SARS-CoV-2 pandemic has had a disastrous impact on global health. Although some vaccine candidates have been effective in combating SARS-CoV-2, logistical, economical, and sociological aspects still limit vaccine access globally. Recently, we reported on two room-temperature stable AAV-based COVID-19 vaccines that induced potent and protective immunogenicity following a single injection in murine and primate models. Obesity and old age are associated with increased mortality in COVID-19, as well as reduced immunogenicity and efficacy of vaccines. Here, we investigated the effectiveness of the AAVCOVID vaccine candidates in murine models of obesity and aging. Results demonstrate that obesity did not significantly alter the immunogenicity of either vaccine candidate. In aged mice, vaccine immunogenicity was impaired. These results suggest that AAV-based vaccines may have limitations in older populations and may be equally applicable in obese and non-obese populations.  相似文献   
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