全文获取类型
收费全文 | 20491篇 |
免费 | 1276篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 332篇 |
儿科学 | 1107篇 |
妇产科学 | 497篇 |
基础医学 | 1784篇 |
口腔科学 | 360篇 |
临床医学 | 1613篇 |
内科学 | 4908篇 |
皮肤病学 | 334篇 |
神经病学 | 1035篇 |
特种医学 | 736篇 |
外科学 | 3695篇 |
综合类 | 454篇 |
一般理论 | 3篇 |
预防医学 | 1090篇 |
眼科学 | 904篇 |
药学 | 1549篇 |
1篇 | |
中国医学 | 71篇 |
肿瘤学 | 1354篇 |
出版年
2023年 | 164篇 |
2022年 | 341篇 |
2021年 | 758篇 |
2020年 | 404篇 |
2019年 | 604篇 |
2018年 | 704篇 |
2017年 | 491篇 |
2016年 | 497篇 |
2015年 | 503篇 |
2014年 | 785篇 |
2013年 | 993篇 |
2012年 | 1488篇 |
2011年 | 1350篇 |
2010年 | 848篇 |
2009年 | 669篇 |
2008年 | 999篇 |
2007年 | 1019篇 |
2006年 | 945篇 |
2005年 | 883篇 |
2004年 | 794篇 |
2003年 | 675篇 |
2002年 | 600篇 |
2001年 | 481篇 |
2000年 | 510篇 |
1999年 | 404篇 |
1998年 | 165篇 |
1997年 | 145篇 |
1996年 | 125篇 |
1995年 | 120篇 |
1994年 | 104篇 |
1993年 | 86篇 |
1992年 | 281篇 |
1991年 | 250篇 |
1990年 | 220篇 |
1989年 | 212篇 |
1988年 | 173篇 |
1987年 | 176篇 |
1986年 | 156篇 |
1985年 | 168篇 |
1984年 | 148篇 |
1983年 | 144篇 |
1982年 | 66篇 |
1981年 | 75篇 |
1979年 | 116篇 |
1978年 | 89篇 |
1977年 | 64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 31 毫秒
151.
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 |
152.
153.
CDX2 expression is progressively decreased in human gastric intestinal metaplasia, dysplasia and cancer. 总被引:1,自引:0,他引:1
Qiang Liu Ming Teh Kosei Ito Nilesh Shah Yoshiaki Ito Khay Guan Yeoh 《Modern pathology》2007,20(12):1286-1297
Intestinal metaplasia is a key event in multistep gastric carcinogenesis. CDX2, a master regulator of intestinal phenotype, was shown to play a tumor-suppressive role in colon cancer. However, it was reported to be expressed in nearly all gastric intestinal metaplasia and many gastric cancers. As CDX2 is differentially expressed in normal stomach and intestine, we sought to relate the CDX2 expression to gastrointestinal differentiation along gastric carcinogenesis. The expression of CDX2 protein in gastric intestinal metaplasia, dysplasia and cancer was examined and related to their gastrointestinal differentiation. CDX2 expression was significantly decreased in incomplete intestinal metaplasia, which expresses both gastric mucins (MUC5AC and MUC6) and intestinal mucin (MUC2), compared with complete intestinal metaplasia, which expresses intestinal mucin (MUC2) only. Although incomplete intestinal metaplasia morphologically resembles colon, its CDX2 expression was apparently lower than that in the normal colon. Moreover, CDX2 expression was progressively reduced in gastric dysplasia and cancer. The CDX2 expression in gastric cancer was also inversely correlated with the expression of gastric mucins. As incomplete intestinal metaplasia is associated with higher risk of gastric cancer, its lower CDX2 expression compared with that in complete intestinal metaplasia and normal colon epithelium resolved the current contradiction between the tumor-suppressive role of CDX2 in the colon and the high prevalence of CDX2 in intestinal metaplasia. Further decrease of CDX2 expression in gastric dysplasia and cancer suggests that CDX2 plays a similar anticarcinogenic role in intestinal metaplasia as it does in colon. Intestinal metaplasia or dysplasia with low expression of CDX2 may serve as predictive markers for gastric cancer. 相似文献
154.
Giardine B Riemer C Hardison RC Burhans R Elnitski L Shah P Zhang Y Blankenberg D Albert I Taylor J Miller W Kent WJ Nekrutenko A 《Genome research》2005,15(10):1451-1455
Accessing and analyzing the exponentially expanding genomic sequence and functional data pose a challenge for biomedical researchers. Here we describe an interactive system, Galaxy, that combines the power of existing genome annotation databases with a simple Web portal to enable users to search remote resources, combine data from independent queries, and visualize the results. The heart of Galaxy is a flexible history system that stores the queries from each user; performs operations such as intersections, unions, and subtractions; and links to other computational tools. Galaxy can be accessed at http://g2.bx.psu.edu. 相似文献
155.
Detection of human papillomavirus type 6/11 DNA in conjunctival papillomas by in situ hybridization with radioactive probes 总被引:7,自引:0,他引:7
Twenty-three conjunctival papillomas and 28 conjunctival dysplasias were examined for human papillomavirus (HPV)-DNA sequences by in situ hybridization with nick-translated 35S-labeled HPV probes. Adjacent paraffin sections were hybridized with HPV type 2, 6, 16, and 18 probes at Tm - 17 degrees C. Fifteen tissues, all papillomas, displayed positive hybridization with the HPV-6 probe. Infection with HPV-6 (or the closely related HPV-11) appeared to be responsible for most of the conjunctival papillomas of children and young adults. The presence of genital tract HPV-6 in these lesions suggests that some of the infections were acquired during passage through an infected birth canal. The lack of hybridization in adult conjunctival dysplasias indicates either that HPVs are not associated with this condition or that the probes and the technique utilized were not adequate for demonstration of this association. 相似文献
156.
157.
158.
159.
Wani T Kakru DK Shaheen R Nazir A Lone R Shakeel S Shah A 《Indian journal of pathology & microbiology》2004,47(1):76-77
Endocarditis is a rare complication of typhoid fever. We report a case in which Salmonella enterica serotype typhi was isolated from a case of endocarditis. The isolate was resistant to ampicillin, chloramphenicol and ciprofloxacin but sensitive to ceftriaxone, amikacin and gentamicin. 相似文献
160.
Experimental glomerulopathy alters renal cortical cholesterol,SR-B1, ABCA1, and HMG CoA reductase expression
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Previous studies indicate that acute tubular injury causes free cholesterol (FC) and cholesteryl ester (CE) accumulation within renal cortex/proximal tubules. This study assessed whether similar changes occur with glomerulopathy/nephrotic syndrome, in which high-circulating/filtered lipoprotein levels increase renal cholesterol supply. Potential adaptive changes in cholesterol synthetic/transport proteins were also assessed. Nephrotoxic serum (NTS) or passive Heymann nephritis (PHN) was induced in Sprague-Dawley rats. Renal injury (blood urea nitrogen, proteinuria) was assessed 2 and 7 days (NTS), or 10 and 30 days (PHN) later. FC and CE levels in renal cortex, isolated glomeruli, and proximal tubule segments were determined. SR-B1 (a CE influx protein), ABCA1 (a FC exporter), and HMG CoA reductase protein/mRNA levels were also assessed. FC was minimally elevated in renal cortex (0 to 15%), the majority apparently localizing to proximal tubules. More dramatic CE elevations were found ( approximately 5 to 15x), correlating with the severity of proteinuria at any single time point (r >/= 0.85). Cholesterol increments were associated with decreased SR-B1, increased ABCA1, and increased HMG CoA reductase (HMGCR) protein and its mRNA. Tubule (HK-2) cell culture data indicated that SR-B1 and ABCA1 levels are responsive to cholesterol supply. Experimental nephropathy can increase renal FC, and particularly CE, levels, most notably in proximal tubules. These changes are associated with adaptations in SR-B1 and ABCA1 expression, which are physiologically appropriate changes for a cholesterol overload state. However, HMGCR protein/mRNA increments can also result. These seem to reflect a maladaptive response, potentially contributing to a cell cholesterol overload state. 相似文献