全文获取类型
收费全文 | 8661篇 |
免费 | 780篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 309篇 |
妇产科学 | 272篇 |
基础医学 | 1069篇 |
口腔科学 | 379篇 |
临床医学 | 768篇 |
内科学 | 1685篇 |
皮肤病学 | 113篇 |
神经病学 | 1023篇 |
特种医学 | 492篇 |
外科学 | 1153篇 |
综合类 | 143篇 |
一般理论 | 9篇 |
预防医学 | 896篇 |
眼科学 | 162篇 |
药学 | 563篇 |
中国医学 | 5篇 |
肿瘤学 | 381篇 |
出版年
2022年 | 75篇 |
2021年 | 150篇 |
2020年 | 112篇 |
2019年 | 136篇 |
2018年 | 135篇 |
2017年 | 120篇 |
2016年 | 130篇 |
2015年 | 140篇 |
2014年 | 207篇 |
2013年 | 303篇 |
2012年 | 365篇 |
2011年 | 393篇 |
2010年 | 214篇 |
2009年 | 272篇 |
2008年 | 372篇 |
2007年 | 439篇 |
2006年 | 381篇 |
2005年 | 399篇 |
2004年 | 363篇 |
2003年 | 352篇 |
2002年 | 336篇 |
2001年 | 272篇 |
2000年 | 283篇 |
1999年 | 272篇 |
1998年 | 115篇 |
1997年 | 100篇 |
1996年 | 101篇 |
1995年 | 111篇 |
1994年 | 79篇 |
1993年 | 89篇 |
1992年 | 200篇 |
1991年 | 175篇 |
1990年 | 161篇 |
1989年 | 127篇 |
1988年 | 144篇 |
1987年 | 137篇 |
1986年 | 156篇 |
1985年 | 140篇 |
1984年 | 127篇 |
1983年 | 98篇 |
1982年 | 74篇 |
1980年 | 59篇 |
1979年 | 94篇 |
1978年 | 70篇 |
1975年 | 64篇 |
1974年 | 70篇 |
1973年 | 58篇 |
1972年 | 60篇 |
1969年 | 59篇 |
1968年 | 56篇 |
排序方式: 共有9492条查询结果,搜索用时 15 毫秒
41.
Does teaching audit improve standards,and affect MCQ results in undergraduate trauma and orthopaedic tuition? 下载免费PDF全文
Over the study period from 1981 to 1987 inclusive, student critiques were scored to indicate the undergraduates' perception of the quality of teaching they received on each 2-month attachment to the trauma and orthopaedic surgical departments of two teaching hospitals. The medical staff and the environment in the two teaching hospitals were different. It was found that while the mean MCQ results did not change significantly throughout the study period, an improvement was noticed in the perceived quality of undergraduate tuition, especially at one hospital. 相似文献
42.
D P Wood M Spencer B J Hocevar J E Montie R Kay 《The Urologic clinics of North America》1988,15(4):753-767
The postoperative care of stoma patients is truly life long. With the excellent stoma equipment available, no patient should be a "stoma cripple." New advances in continent reservoirs will improve patient acceptance and lessen the fear associated with stomas. Finally, close follow-up by both the enterostomal therapy nurse and the surgeon is essential for the complete care of the stoma patient. 相似文献
43.
Event-related potentials (ERPs) from 134 children were obtained at 3 and 8 years of age and recorded to a series of consonant-vowel speech syllables and their nonspeech analogues. The HOME inventory was administered to these same children at 3 and 8 years of age and the sample was divided into 2 groups (low vs. high) based on their HOME scores. Discriminant functions analyses using ERP responses to speech and non-speech analogues successfully classified HOME scores obtained at 3 and 8 years of age and discriminated between children who received low vs. high levels of stimulation for language and reading. 相似文献
44.
45.
Jacques R. Caldwell David E. Pearce Craig Spencer Rosmarie Leder Robert H. Waldman 《The Journal of allergy and clinical immunology》1973,52(4):225-230
Immunologic studies were performed on 5 patients with pigeon breeders' disease. Intradermal injection of pigeon serum produced an immediate wheal-and-flare reaction within 15 minutes and a secondary Arthus-type reaction within 4 to 8 hours. Immunofluorescent studies of the secondary reaction site showed IgG, C3, and C4 in 2 patients. Patients' sera produced multiple precipitin bands with pigeon serum when reacted by double diffusion in gel. IgG antibody isolated from each of the patients' serum formed precipitating immune complexes that fixed large amounts of complement (C4) when added to fresh human serum. Peripheral blood lymphocytes from 4 of the 5 patients produced macrophage migration inhibitory factor (MIF) when challenged with dilute pigeon serum. These studies are the first to show complement fixing antibodies and macrophage MIF production by lymphocytes from patients with hypersensitivity lung disease and suggest that both humoral and cellular immunity may be important in the pathogenesis of these disorders. 相似文献
46.
47.
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 |
48.
49.
Boursier L Farstad IN Mellembakken JR Brandtzaeg P Spencer J 《European journal of immunology》2002,32(9):2427-2436
The contribution of peritoneal B cells to the intestinal lamina propria plasma cell population is well documented in mice, but unknown in humans. We have analyzed immunoglobulin (Ig) genes of human peritoneal B cells, because such genes show distinctive characteristics in mucosal B cells, particularly highly mutated variable regions. Here, we report the characteristics of variable region genes used by IgM, IgA and IgG in peritoneal cells. We focused on the properties of IgV(H)4-34 to allow comparisons of like-with-like between different isotypes and cells from different immune compartments. We observed that the IgM genes were mostly unmutated, and that the mutated subset had less mutations than would be expected in a mucosal B cell population. Likewise, the IgV(H)4-34 genes used by IgA and IgG from peritoneal B cells had significantly lower numbers of mutations than observed in the mucosal counterparts. Other trends observed, while not reaching statistical significance, followed the trend of peripheral B cells. The peritoneal B cell population had more IgA1 than IgA2 sequences, and there was no dominance of J(H)4 in the IgA from peritoneum or spleen, in contrast to the mucosal sequences. Overall, this study suggested that human peritoneal B cell are either peripheral or mixed in origin; they are unlikely to represent an inductive compartment for the mucosal B cell system. 相似文献
50.