全文获取类型
收费全文 | 175307篇 |
免费 | 979篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 1129篇 |
儿科学 | 6648篇 |
妇产科学 | 2995篇 |
基础医学 | 16458篇 |
口腔科学 | 1545篇 |
临床医学 | 12290篇 |
内科学 | 30853篇 |
皮肤病学 | 658篇 |
神经病学 | 16378篇 |
特种医学 | 8915篇 |
外科学 | 28941篇 |
综合类 | 2308篇 |
预防医学 | 18034篇 |
眼科学 | 2770篇 |
药学 | 9402篇 |
中国医学 | 625篇 |
肿瘤学 | 16355篇 |
出版年
2021年 | 52篇 |
2019年 | 42篇 |
2018年 | 21934篇 |
2017年 | 17384篇 |
2016年 | 19519篇 |
2015年 | 912篇 |
2014年 | 812篇 |
2013年 | 748篇 |
2012年 | 6938篇 |
2011年 | 20982篇 |
2010年 | 18800篇 |
2009年 | 11501篇 |
2008年 | 19460篇 |
2007年 | 21656篇 |
2006年 | 502篇 |
2005年 | 2143篇 |
2004年 | 3338篇 |
2003年 | 4327篇 |
2002年 | 2455篇 |
2001年 | 275篇 |
2000年 | 410篇 |
1999年 | 172篇 |
1998年 | 203篇 |
1997年 | 206篇 |
1996年 | 91篇 |
1995年 | 106篇 |
1994年 | 103篇 |
1993年 | 58篇 |
1992年 | 44篇 |
1991年 | 97篇 |
1990年 | 133篇 |
1989年 | 87篇 |
1988年 | 65篇 |
1987年 | 53篇 |
1986年 | 30篇 |
1985年 | 34篇 |
1984年 | 23篇 |
1983年 | 25篇 |
1982年 | 27篇 |
1980年 | 43篇 |
1974年 | 21篇 |
1970年 | 25篇 |
1969年 | 21篇 |
1939年 | 20篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 22篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Gong K Zhang N He Z Zhou L Lin G Na Y 《Journal of cancer research and clinical oncology》2008,134(4):433-437
In order to increase our knowledge and understanding about multilocular cystic renal cell carcinoma (MCRCC), including diagnosis,
surgical management, pathologic and prognostic characteristics, clinical data of patients who suffered with MCRCC were reviewed
retrospectively. From 1998 to 2005, among 770 patients diagnosed with renal cell carcinoma (RCC) at our institute, 31 cases
(4.0%) were identified as MCRCC. The average age of patients suffered with RCC and MCRCC was 58.1 ± 3.6 and 45.9 ± 2.7, respectively
(P < 0.01), whereas the gender ratio of male to female in RCC and MCRCC is 2.12:1 and 2.88:1(P < 0.01). Surprisingly, 28 of those 31 renal masses (90.3%) were first discovered on the radiographic image, and the size
of tumors in maximum diameter ranged from 1.7 to 11.0 cm (mean 4.1 ± 2.2 cm). All those patients were treated with open nephrectomy,
including 21 radical and 10 partial. The stages of tumor were classified as pT1N0M0, pT2N0M0, and pT3bN0M0 following the 1997
criteria of tumor-node-metastasis (TNM) classification in the number of 27(87.1%), 3(9.7%) and 1(3.2%), respectively. By contrast,
according to the tumor nuclear grading system, those tumors were classified as Grades 1 and 2 in 13 (42%) and 18 patients
(58%), respectively. Only 29 cases from those patients have been followedup for a period of 9 to 81 months so far (mean 32.6 ± 11),
while no tumor recurrence occurred except for 1 case who died of causes other than MCRCC. In general, MCRCC is a frequent
subtype of RCC in the clinic. A nephron-sparing procedure should be considered in the preoperative plan when a complex multicystic
renal mass with enhanced density is observed. 相似文献
992.
OBJECTIVES: Liver biopsy is a valuable clinical tool, but for the interpretation to be meaningful a certain core size should be obtained. This study examines the changes the liver biopsy core undergoes during processing steps. METHODS: A total of 61 consecutive percutaneous liver biopsies were obtained between November 2004 and April 2005. The needle type utilized was the 16-gauge automatic tru-cut. A measurement was made while each liver biopsy core specimen resided in the cartridge, then a measurement was made with the core placed on the tray, and a final measurement was made after the pathologist received the formalin-fixed specimen. RESULTS: The mean size of the biopsy core in the cartridge measured 15 +/- 2 mm, compared to a mean size on the tray of 19.6 +/- 3.5 mm, and a mean size after fixation of 18.3 mm. All mean sizes were statistically different from one another. The compressive effect of the cartridge was 23%. The shrinkage effect of formalin fixation was 7%. CONCLUSIONS: The liver biopsy core size changes significantly through the processing steps. It is imperative that the operator is aware of these changes so that appropriate decisions are made. As an example, if the operator underestimates the core size when measured in the cartridge, a second pass may be completed when in fact adequate tissue had been obtained on the first pass. 相似文献
993.
Mégraud F 《Current infectious disease reports》2005,7(2):115-120
Triple therapy including clarithromycin, amoxicillin, and a proton pump inhibitor (PPI) has been recommended as the treatment
of choice for Helicobacter pylori eradication. This regimen is now challenged by an increasing level of clarithromycin resistance that jeopardizes the treatment
success. When clarithromycin resistance has been detected, or when its rate is known to be high in the geographic area, this
drug cannot be used. It can be replaced by metronidazole, the resistance of which has a limited clinical relevance. Another
option is to prescribe tetracycline and metronidazole with a PPI or ranitidine bismuth citrate. New antibiotics such as levofloxacin
or rifabutin can also be used in combination with amoxicillin and a PPI. Probiotics can be added to all of these regimens
to improve compliance by decreasing adverse events. But some authors advocate a quadruple therapy as a first-line treatment.
Solutions to improve the limitations of this last regimen are now being proposed. Clarification of the controversial treatment
indications such as gastroesophageal reflux disease or prevention of nonsteroidal anti-inflammatory drug gastroduodenal symptoms
has been made. The question of prevention of gastric carcinoma by H. pylori eradication remains unanswered. 相似文献
994.
The aim of this study was to examine optimal self-management in osteoarthritis and its association with patient-reported outcomes.
We recruited a population-based sample of Medicare beneficiaries (n = 551) residing in Allegheny County, PA, USA and elicited an expanded set of self-management behaviors using open-ended inquiry.
We defined optimal self-management according to clinical recommendations, including use of hot compresses on affected joints,
alteration of activity, and exercise. Only 20% practiced optimal self-management as defined by two or more of these criteria.
Optimal and suboptimal self-managers did not differ in sociodemographic features. Both white and African–Americans who practiced
optimal self-management reported significantly less pain, but the benefit was greatest in severe disease for whites and for
mild-moderate disease among African–Americans. This backdrop of naturally occurring self-management behaviors may be important
to recognize in planning programs that seek to bolster self-management skills. 相似文献
995.
Hauner H 《Treatments in endocrinology》2004,3(4):223-232
Obesity is the most important modifiable risk factor for type 2 diabetes mellitus and most patients with diabetes are overweight or obese. It is well known that excess bodyweight induces or aggravates insulin resistance, which is a characteristic feature of type 2 diabetes. Thus, bodyweight plays a central role in the prevention and treatment of diabetes. Recent data suggest that lifestyle intervention in patients with impaired glucose tolerance results in an impressive reduction in the conversion to overt diabetes, which is greater than the effect of early intervention with drugs such as metformin or acarbose. The prevention of diabetes has been shown to be associated with the extent of weight loss. In patients with type 2 diabetes, weight loss by any means is followed by an improvement of metabolic control and associated risk factors. The most appropriate recommendation for obese patients with type 2 diabetes is a nutritionally balanced, moderately hypocaloric diet with a reduced intake of saturated fat and an increase in physical activity. If this standard approach is only partly successful or not at all, additional strategies such as weight-lowering drugs, very low-calorie diets for limited periods of up to 12 weeks, and, for severely obese patients, bariatric surgery should be carefully considered. A large body of data suggests that such measures can be very effective in this patient group by improving metabolic disturbances and blood pressure. However, it is extremely important for the long-term outcome that the treatment is tailored to the needs and wishes of the individual patient. There is growing agreement that due to the low success rate of conventional therapies and the overwhelming benefit from weight loss, more determined and aggressive strategies may be appropriate to achieve the central goal of weight reduction in obese patients with type 2 diabetes. 相似文献
996.
Glycyrrhizin enhances interleukin-10 production by liver dendritic cells in mice with hepatitis 总被引:4,自引:0,他引:4
Background Glycyrrhizin (GL), an aqueous extract of licorice root, is known to have various immune-modulating and biological response-modifier activities. GL is used in patients with hepatitis to reduce the activity of liver inflammation; however, the mechanism underlying the anti-inflammatory activity of GL is poorly understood. As antigen-presenting dendritic cells (DC) in the tissue play a major role in the regulation of the inflammatory mucosal milieu during tissue inflammation, we studied whether the function of liver DC was altered by GL therapy in a murine model of concanavalin-A (Con A)-induced hepatitis.Methods Liver DC were propagated from control mice or mice with Con-A-induced hepatitis, and the effect of GL on liver DC was evaluated in vivo and in vitro.Results The levels of interleukin (IL)-10 produced by liver DC were significantly lower in mice with Con-A-induced hepatitis compared with control mice. However, treatment with GL caused increased production of IL-10 in mice with Con A-induced hepatitis. The increased production of IL-10 by mice with Con A-induced hepatitis was also confirmed in vitro by culturing liver DC with GL.Conclusions This study indicates that increased production of IL-10 by liver DC due to GL administration may be involved in downregulation of the levels of liver inflammation in mice with Con A-induced hepatitis. 相似文献
997.
Nicolas Beysard Bertrand Yersin Pascal Meylan Olivier Hugli Pierre-Nicolas Carron 《Internal and emergency medicine》2018,13(2):251-256
The morbidity and mortality of the 2014–2015 influenza season were more important than those in previous years. We assessed the impact of the 2014–2015 influenza season on the length of stay (LOS) and workload in an academic emergency department (ED). This is a monocentric retrospective study. The database of the microbiology laboratory was used to identify influenza nasal swabs performed during the influenza seasons from 2010 to 2015. Patients admitted to the ED during these periods were identified through the administrative database and cross-checked with patients who underwent an influenza nasal swab in the ED. Median LOS was used to estimate the impact of the isolation procedures on ED LOS. Bed occupancy rate and mean LOS in the ED were calculated as proxy of the ED workload. During the 2014–2015 influenza season, 55.9% of ED patients (n = 123) with confirmed influenza were hospitalised. In terms of workload, despite that influenza patients represented only 2.2% of all ED patients during the season, they occupied 28% of ED beds with respiratory isolation during the delay to realise and obtain the test results, as well as during the delay before being discharged home or transferred to a hospital ward. The median ED LOS for influenza-confirmed patients was significantly longer in comparison with all ED patients (21.6 h vs 4.0 for ambulatory patients and 24.7 h vs 12.3 for hospitalised patients). The 2014–2015 influenza season had significant consequences in terms of ED LOS and bed use. It dramatically increased the workload in the ED. 相似文献
998.
Qun He Ye Wang Yan Li Yurun Zhang Peng Lin Fang Yang Xiaobing Fu Jie Li H. Fisher Raymond Li Ling Willi McFarland 《AIDS and behavior》2008,12(1):93-96
Men who have sex with men (MSM) may account for an increasing proportion of China’s HIV epidemic, but remain difficult to access for epidemiological studies due to high stigma. We compare the composition of two samples of MSM obtained in Guangzhou, China. The first survey, conducted in 2004, recruited MSM through convenience sampling. The second survey in 2006 used long-chain referral recruitment in the context of respondent-driven sampling. Compared to convenience sampling, the long-chain referral method included higher proportions of subgroups of MSM thought to be at elevated risk for HIV infection and more difficult to reach, including internal migrants and those engaging in commercial sex. Long-chain referral also recruited more MSM who were under 25 years, unemployed, and had lower education. We conclude that long-chain referral recruitment will be more effective in tracking the leading edge of the epidemic among MSM in China than convenience sampling. 相似文献
999.
Ian T. MacQueen Melinda Maggard-Gibbons Gina Capra Laura Raaen Jesus G. Ulloa Paul G. Shekelle Isomi Miake-Lye Jessica M. Beroes Susanne Hempel 《Journal of general internal medicine》2018,33(2):191-199
Background
Rural areas have historically struggled with shortages of healthcare providers; however, advanced communication technologies have transformed rural healthcare, and practice in underserved areas has been recognized as a policy priority. This systematic review aims to assess reasons for current providers’ geographic choices and the success of training programs aimed at increasing rural provider recruitment.Methods
This systematic review (PROSPERO: CRD42015025403) searched seven databases for published and gray literature on the current cohort of US rural healthcare practitioners (2005 to March 2017). Two reviewers independently screened citations for inclusion; one reviewer extracted data and assessed risk of bias, with a senior systematic reviewer checking the data; quality of evidence was assessed using the GRADE approach.Results
Of 7276 screened citations, we identified 31 studies exploring reasons for geographic choices and 24 studies documenting the impact of training programs. Growing up in a rural community is a key determinant and is consistently associated with choosing rural practice. Most existing studies assess physicians, and only a few are based on multivariate analyses that take competing and potentially correlated predictors into account. The success rate of placing providers-in-training in rural practice after graduation, on average, is 44% (range 20–84%; N = 31 programs). We did not identify program characteristics that are consistently associated with program success. Data are primarily based on rural tracks for medical residents.Discussion
The review provides insight into the relative importance of demographic characteristics and motivational factors in determining which providers should be targeted to maximize return on recruitment efforts. Existing programs exposing students to rural practice during their training are promising but require further refining. Public policy must include a specific focus on the trajectory of the healthcare workforce and must consider alternative models of healthcare delivery that promote a more diverse, interdisciplinary combination of providers.1000.
Epidemiology of anaphylaxis in the united states 总被引:2,自引:0,他引:2
Anaphylaxis is a potentially life-threatening allergic reaction characterized by a syndrome of dermatologic and systemic signs
and symptoms, at times including cardiovascular collapse from distributive shock. Although it is recognized that the incidence
of anaphylaxis is increasing, the extent of its prevalence, both from individual causes and in toto, remains unclear. Common
causes include pharmacologic agents, such as antibiotics and radiocontrast media, as well as foods, insect stings, and latex
exposure. The available literature suffers from methodologic shortcomings, limiting the accuracy of estimated prevalence.
However, current data suggest that there are approximately 1500 annual deaths from anaphylaxis, and between 2.8 million and
42.7 million Americans are at risk of experiencing an episode of anaphylaxis during their lives. 相似文献