全文获取类型
收费全文 | 20447篇 |
免费 | 1225篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 331篇 |
儿科学 | 1104篇 |
妇产科学 | 496篇 |
基础医学 | 1776篇 |
口腔科学 | 356篇 |
临床医学 | 1604篇 |
内科学 | 4890篇 |
皮肤病学 | 327篇 |
神经病学 | 1034篇 |
特种医学 | 721篇 |
外科学 | 3684篇 |
综合类 | 451篇 |
一般理论 | 3篇 |
预防医学 | 1087篇 |
眼科学 | 904篇 |
药学 | 1546篇 |
1篇 | |
中国医学 | 71篇 |
肿瘤学 | 1346篇 |
出版年
2023年 | 164篇 |
2022年 | 344篇 |
2021年 | 758篇 |
2020年 | 402篇 |
2019年 | 604篇 |
2018年 | 703篇 |
2017年 | 488篇 |
2016年 | 496篇 |
2015年 | 502篇 |
2014年 | 783篇 |
2013年 | 988篇 |
2012年 | 1487篇 |
2011年 | 1346篇 |
2010年 | 847篇 |
2009年 | 663篇 |
2008年 | 997篇 |
2007年 | 1015篇 |
2006年 | 942篇 |
2005年 | 880篇 |
2004年 | 788篇 |
2003年 | 672篇 |
2002年 | 599篇 |
2001年 | 479篇 |
2000年 | 510篇 |
1999年 | 403篇 |
1998年 | 161篇 |
1997年 | 138篇 |
1996年 | 117篇 |
1995年 | 116篇 |
1994年 | 104篇 |
1993年 | 82篇 |
1992年 | 279篇 |
1991年 | 250篇 |
1990年 | 219篇 |
1989年 | 211篇 |
1988年 | 172篇 |
1987年 | 176篇 |
1986年 | 155篇 |
1985年 | 168篇 |
1984年 | 147篇 |
1983年 | 141篇 |
1982年 | 65篇 |
1981年 | 75篇 |
1979年 | 116篇 |
1978年 | 86篇 |
1977年 | 63篇 |
1974年 | 75篇 |
1973年 | 110篇 |
1972年 | 100篇 |
1971年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Anand Shah Danny O Jacobs Henrique Martins Matthew Harker Andreia Menezes Mariana McCready Ricardo Pietrobon 《BMC medical informatics and decision making》2006,6(1):34
Background
The Internet has been increasingly utilized in biomedical research. From online searching for literature to data sharing, the Internet has emerged as a primary means of research for many physicians and scientists. As a result, Web-based surveys have been employed as an alternative to traditional, paper-based surveys. We describe DADOS-Survey, an open-source Web-survey application developed at our institution that, to the best of our knowledge, is the first to be compliant with the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). DADOS-Survey was designed with usability as a priority, allowing investigators to design and execute their own studies with minimal technical difficulties in doing so. 相似文献62.
63.
Y F Posey D Shah J E Ulm K T Bastin F F Parl J A Phillips 《American journal of clinical pathology》1989,92(3):347-351
The prenatal diagnosis of sickle cell anemia (hemoglobin SS) can be established by DNA analysis using two highly sensitive techniques (Southern blot and polymerase chain reaction [PCR]). Hemoglobin electrophoresis provides a third, simpler and more rapid, technique to analyze blood from a fetus at risk for sickle cell anemia. The authors present examples of prenatal diagnostic studies using both DNA analysis techniques and hemoglobin electrophoresis. Hemoglobin electrophoresis of fetal hemolysate can provide a simple and rapid alternative method to PCR analysis for the prenatal exclusion of sickle cell anemia, and it is especially useful in cases in which rapid results are needed because of advanced gestational age. 相似文献
64.
Bradley Q. Fox Peninah F. Benjamin Ammara Aqeel Emily Fitts Spencer Flynn Brian Levine Elizaveta Maslak Rebecca L. Milner Benjamin Ose Michael Poeschla Meghna Ray Maeve Serino Sahaj S. Shah Kelly L. Close 《Clinical Diabetes》2021,39(2):160
To the best of our knowledge, there are no published data on the historical and recent use of CGM in clinical trials of pharmacological agents used in the treatment of diabetes. We analyzed 2,032 clinical trials of 40 antihyperglycemic therapies currently on the market with a study start date between 1 January 2000 and 31 December 2019. According to ClinicalTrials.gov, 119 (5.9%) of these trials used CGM. CGM usage in clinical trials has increased over time, rising from <5% before 2005 to 12.5% in 2019. However, it is still low given its inclusion in the American Diabetes Association’s latest guidelines and known limitations of A1C for assessing ongoing diabetes care.The availability of reliable continuous glucose monitoring (CGM) systems has proven to be a major innovation in diabetes management and research. Most current CGM systems are approved for 7- to 14-day use and use a wire-tipped glucose oxidase sensor inserted in subcutaneous tissue to monitor glucose concentrations in interstitial fluid. One implanted CGM system is approved for longer-term use (90–180 days); it operates with fluorescence-based technology. CGM sensors record a glucose data point every 1–15 minutes (depending on the system), collecting far more granular data and information on glycemic patterns than self-monitoring of blood glucose (SMBG) alone. Real-time CGM or intermittently scanned CGM systems send data continuously or intermittently to dedicated receivers or smartphones, whereas professional CGM systems provide retrospective data, either blinded or unblinded, for analysis and can be used to identify patterns of hypo- and hyperglycemia. Professional CGM can be helpful to evaluate patients when other CGM systems are not available to the patient or the patient prefers a blinded analysis or a shorter experience with unblinded data.In the 20 years since CGM systems first became available to people with diabetes, technological improvements, particularly pertaining to accuracy and form factor, have made CGM increasingly viable for both patient use and clinical investigation (1,2). Average sensor MARD (mean absolute relative difference; a summary accuracy statistic) has decreased from >20 to <10% (3–10), including two systems that do not require fingerstick calibrations and three that are approved to be used for insulin dosing (11). Concurrently, size, weight, and cost of CGM systems have all decreased, while user-friendliness and convenience have increased (12).To encourage use of CGM-derived data, researchers and clinicians have worked to develop a standard set of glycemic metrics beyond A1C. In 2017, two international groups of leading diabetes clinical and research organizations published consensus definitions for key metrics, including clinically relevant glycemic cut points for hypoglycemia (<70 and <54 mg/dL), hyperglycemia (>180 and >250 mg/dL), and time in range (TIR; 70–180 mg/dL) (13,14).CGM-derived metrics provide far greater precision and granularity than is possible with SMBG or A1C data alone (Table 1), enabling clinicians and investigators to better represent inter- and intraday glycemic differences with metrics such as TIR, glycemic variability, and time in hypoglycemia and hyperglycemia (15). Crucially, CGM also allows for the accurate measurement and detection of nocturnal glycemia (16). The use of these metrics enables a more comprehensive understanding of glycemic management that can facilitate individualized treatment for people with diabetes or prediabetes. Although A1C is a useful estimate of mean glucose over the previous 2–3 months, especially when evaluating population health, it is important to include other glycemic outcomes in clinical trials. Furthermore, there is emerging evidence suggesting that TIR predicts the development of microvascular complications at least as well as A1C (17,18).TABLE 1Benefits of CGM Compared With A1C Alone in Assessing Glycemia
Open in a separate windowDespite recent standardization of metrics and an emerging consensus around the importance of including CGM-derived outcomes in clinical trials, to our knowledge, there has been no attempt to estimate the historical and current use of CGM in clinical trials of pharmacological agents for diabetes. We sought to analyze the use of CGM in trials of currently available pharmaceutical agents for the treatment of diabetes. 相似文献
CGM | A1C Alone |
---|---|
Facilitates real-time readings of blood glucose levels | Requires SMBG |
Provides information on glucose variability, including duration of hypo- and hyperglycemia and nocturnal glycemia | Does not provide information on acute glycemic excursions and time in biochemical hypoglycemia and hyperglycemia |
Correlates strongly with 3 months of mean glucose, TIR, and hyperglycemia metrics | Measures average glucose during the past 2–3 months |
Provides information on direction of and rate of change in glucose levels | Does not provide information on direction of or rate of change in glucose levels |
Provides TIR data (time spent between 70 and 180 mg/dL) | Does not have TIR measurement capability |
65.
66.
67.
68.
Self-assembly of in vitro-translated human papillomavirus type 16 L1 capsid protein into virus-like particles and antigenic reactivity of the protein. 下载免费PDF全文
S Iyengar K V Shah K L Kotloff S J Ghim R P Viscidi 《Clinical and Vaccine Immunology : CVI》1996,3(6):733-739
The human papillomavirus type 16 (HPV-16) L1 capsid protein is the major component of the HPV virion. We prepared L1 protein of HPV-16 in a cell-free system. The L1 gene was cloned in an expression plasmid and transcribed and translated in vitro in a rabbit reticulocyte lysate. The expressed protein had the molecular mass (55 kDa) expected for the L1 protein, and it assembled into virus-like particles that closely resembled papillomavirus virions. The protein retained conformational epitopes, as evidenced by its reactivity with monoclonal antibodies which recognize only intact viral particles. In radioimmunoprecipitation assays with sera from college women grouped by their genital tract HPV DNA status, high reactivity was found in 68% of HPV-16 DNA-positive women, in 23% of women with other HPVs, and in 19% of HPV-negative women. In comparison, none of the sera of children were reactive. The results of the radioimmunoprecipitation assays showed a significant correlation with results obtained with the same sera in an enzyme-linked immunosorbent assay with virus-like particles produced in baculovirus (chi-square test for linear trend, P = 0.0023). Although the amounts of L1 protein obtained are small, the ability to produce virus-like particles by in vitro translation may be useful in the study of virus assembly, virus binding, and the immunological response to HPV infection. 相似文献
69.
An IFN-beta-albumin fusion protein that displays improved pharmacokinetic and pharmacodynamic properties in nonhuman primates. 总被引:6,自引:0,他引:6
Cynthia Sung Bernardetta Nardelli David W LaFleur Erich Blatter Marta Corcoran Henrik S Olsen Charles E Birse Oxana K Pickeral Junli Zhang Devanshi Shah Gordon Moody Solange Gentz Lisa Beebe Paul A Moore 《Journal of interferon & cytokine research》2003,23(1):25-36
The long half-life and stability of human serum albumin (HSA) make it an attractive candidate for fusion to short-lived therapeutic proteins. Albuferon (Human Genome Sciences [HGS], Inc., Rockville, MD) beta is a novel recombinant protein derived from a gene fusion of interferon-beta (IFN-beta ) and HSA. In vitro, Albuferon beta displays antiviral and antiproliferative activities and triggers the IFN-stimulated response element (ISRE) signal transduction pathway. Array analysis of 5694 independent genes in Daudi-treated cells revealed that Albuferon beta and IFN-beta induce the expression of an identical set of 30 genes, including 9 previously not identified. In rhesus monkeys administered a dose of 50 microg/kg intravenously (i.v.) or subcutaneously (s.c.) or 300 microg/kg s.c., Albuferon beta demonstrated favorable pharmacokinetic properties. Subcutaneous bioavailability was 87%, plasma clearance at 4.7-5.7 ml/h/kg was approximately 140-fold lower than that of IFN-beta, and the terminal half-life was 36-40 h compared with 8 h for IFN-beta. Importantly, Albuferon beta induced sustained increases in serum neopterin levels and 2',5' mRNA expression. At a molar dose equivalent to one-half the dose of IFN-beta, Albuferon beta elicited comparable neopterin responses and significantly higher 2',5'-OAS mRNA levels in rhesus monkeys. The enhanced in vivo pharmacologic properties of IFN-beta when fused to serum albumin suggest a clinical opportunity for improved IFN-beta therapy. 相似文献
70.
Shah P Patkar D Patankar T Shah J Srinivasa P Krishnan A 《Journal of postgraduate medicine》1999,45(3):84-86
Hypothalamic hamartomas are rare tumours of particular interest because of their unusual symptoms. Three cases of hypothalamic hamartomas are reported in children, who presented with precocious puberty and gelastic seizures. 相似文献