首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3872篇
  免费   241篇
  国内免费   18篇
耳鼻咽喉   36篇
儿科学   136篇
妇产科学   51篇
基础医学   561篇
口腔科学   107篇
临床医学   242篇
内科学   954篇
皮肤病学   101篇
神经病学   347篇
特种医学   174篇
外科学   467篇
综合类   10篇
预防医学   148篇
眼科学   73篇
药学   291篇
中国医学   8篇
肿瘤学   425篇
  2023年   34篇
  2022年   60篇
  2021年   109篇
  2020年   79篇
  2019年   102篇
  2018年   120篇
  2017年   99篇
  2016年   105篇
  2015年   99篇
  2014年   147篇
  2013年   152篇
  2012年   300篇
  2011年   280篇
  2010年   159篇
  2009年   117篇
  2008年   221篇
  2007年   219篇
  2006年   175篇
  2005年   203篇
  2004年   175篇
  2003年   183篇
  2002年   165篇
  2001年   56篇
  2000年   48篇
  1999年   71篇
  1998年   30篇
  1997年   32篇
  1996年   20篇
  1995年   21篇
  1994年   20篇
  1993年   19篇
  1992年   50篇
  1991年   41篇
  1990年   28篇
  1989年   55篇
  1988年   37篇
  1987年   44篇
  1986年   43篇
  1985年   39篇
  1984年   42篇
  1983年   24篇
  1982年   10篇
  1981年   7篇
  1980年   9篇
  1979年   17篇
  1978年   7篇
  1977年   11篇
  1976年   11篇
  1972年   5篇
  1966年   6篇
排序方式: 共有4131条查询结果,搜索用时 15 毫秒
81.
A 61-year-old woman was admitted to our hospital with a fever, nausea, diarrhea, and back pain. Her condition rapidly deteriorated, and she was transferred to the intensive-care unit for mechanical circulatory support and antibiotics, but she died 40 hours after admission. Autopsy findings showed necrotic and suppurative myocardial changes due to group B Streptococcus (GBS). To date, only one case of bacterial myocarditis caused by GBS has been reported. We herein report a case of GBS myocarditis, the etiology of which is poorly understood due to the limited number of cases. Bacterial myocarditis should be considered in patients with sepsis and myocardial dysfunction.  相似文献   
82.
Methotrexate (MTX), the anchor drug in the current treatment strategy for rheumatoid arthritis (RA), was first approved for treatment of RA in Japan in 1999 at the recommended dose of 6–8?mg/week; it was approved as first-line drug with the maximum dose of 16?mg/week in February 2011. However, more than half of Japanese patients with RA are unable to tolerate a dose of 16?mg/week of MTX. Moreover, some serious adverse events during the treatment with MTX, such as pneumocystis pneumonia (PCP) and lymphoproliferative disorders (LPD) have been observed much more frequently in Japan than in other countries. Therefore, this article, an abridged English translation summarizing the 2016 update of the Japan College of Rheumatology (JCR) guideline for the use of MTX in Japanese patients with RA, is not intended to be valid for global use; however, it is helpful for the Japanese community of rheumatology and its understanding might be useful to the global community of rheumatology.  相似文献   
83.
84.
BACKGROUND/AIMS: Obstructive jaundice (OJ) is associated with increased surgical morbidity and infectious complication. The aim of the current study was to clarify the mechanism of excessive inflammation and susceptibility to infection in OJ. METHODS: C57/BL6 mice were subjected to bile duct ligation (BDL) or sham surgery. Expression tumor necrosis factor-alpha, macrophage inflammatory protein-2, monocyte chemoattractant protein-1, inducible protein-10, and interleukin (IL)-10, activation of nuclear factor kappa B, fluorescence activated cell sorter analysis, serum alanine aminotransferase levels, and histology were examined. Survival after lipopolysaccharide (LPS) administration or cecal ligation and puncture 3 or 14 d after surgery was determined. IL-1beta and interferon-gamma expression was examined after LPS administration. RESULTS: OJ induced nuclear factor kappa B activation and increased expression of macrophage inflammatory protein-2, which caused significant increases in neutrophil recruitment. Serum alanine aminotransferase levels increased consistent with histological observations in OJ. Mononuclear cells were recruited in the liver after BDL associated with monocyte chemoattractant protein-1 up-regulation. The recruitment of NK and T cells was varied, consistent with IP-10 expression during the time course of OJ. IL-10 expression was significantly up-regulated 14 d after BDL. After LPS administration, the mice at 3 d after BDL and at 3 and 14 d after sham surgery were all still alive, but all mice at 14 d after BDL died. After LPS administration, IL-1beta significantly increased in the mice at 14 d after BDL. CONCLUSIONS: Immune response such as expression of pro- and anti-inflammatory mediators and recruitment of immune cells may thus differ over the time course of OJ. Prolonged OJ may cause excessive inflammation, thus result in susceptibility to infection.  相似文献   
85.
86.
To investigate the seroprevalence of severe fever with thrombocytopenia syndrome (SFTS) among wild and companion animals on Tsushima Island, Japan, SFTS virus (SFTSV)-specific ELISA and virus-neutralizing tests were conducted on 50 wild boars, 71 Sika deer, 84 dogs, 323 domestic cats, and 6 Tsushima leopard cats. In total, 1 wild boar (1.8%), 2 dogs (2.4%), 7 domestic cats (2.2%), and 1 Tsushima leopard cat (16.7%) were positive for anti-SFTSV antibodies. Among the 11 positive animals, 10 were collected after 2019, and all were found on the southern part of the island. SFTSV, thus far, seems to be circulating within a limited area of Tsushima Island. To protect humans and animals, including endangered Tsushima leopard cats, from SFTSV infection, countermeasures are needed to prevent the spread of SFTSV on Tsushima Island.  相似文献   
87.
Roles of Fos in apoptosis of epithelia in the mouse male accessory sex organs and uterus were investigated using Fos-deficient mice. Normal 30- and 50-day-old and Fos-deficient 50-day-old male and female mice were castrated, and testosterone propionate and estradiol-17 beta were daily injected into male and female mice, respectively, for 5 days. An apoptotic index (a percentage of apoptotic cells) in the epithelium was examined from the day following the last injection (day 1) to day 8. The body weights and the weights of the ventral prostate (VP), coagulating gland (C), seminal vesicle (SV) and epididymis (Ep) and uterus of 50-day-castrated Fos-deficient mice on day 1 suggested that the development of these mice corresponded to that of 30-day-castrated normal mice at the most. The extents of apoptosis estimated by an apoptotic index in the VP, C, SV, Ep and uterus in 50-day-castrated Fos-deficient mice were comparable to those in 30-day-castrated normal mice. The extents of apoptosis in the SV, Ep and uterus in 30-day-castrated normal and 50-day-castrated Fos-deficient mice were similar to those in 50-day-castrated normal mice, while the extents of apoptosis in the VP and C in the former two groups of mice were less than those in the latter mice. The present results show that Fos-deficiency does not affect apoptosis in the SV, EP and uterus. However, the extents of apoptosis in the VP and C were less in 50-day-castrated Fos-deficient mice than in 50-day-castrated normal mice. This seems to be due to the retarded development of 50-day-castrated Fos-deficient mice, but not to a role of Fos in apoptosis.  相似文献   
88.
Objective Dilatation of the pulmonary artery itself (PAD: pulmonary artery diameter) or in relation to the ascending aorta (PAD/AAD: pulmonary artery diameter to ascending aortic diameter ratio) has been reported to be associated with pulmonary hypertension and with a prognostic outcome of either heart failure or cardiovascular events. We herein aimed to assess the correlations between pulmonary hypertension-related parameters PAD (or PAD/AAD) and left ventricular (LV) remodeling and LV function. Methods This retrospective study included 193 patients (ages: 67±12 years) who underwent both coronary CT angiography (CCTA) and echocardiography. The PAD and the AAD were measured on a transaxial non-contrast CCTA image at the level of the pulmonary artery bifurcation. Left ventricular mass (LVM), relative wall thickness ratio (RWT), left ventricular ejection fraction (LVEF), left atrial volume (LAV), and early mitral inflow velocity to mitral annular early diastolic velocity ratio (E/e'') were evaluated by echocardiography. The relationships between PAD (or PAD/AAD) and echocardiography parameters were assessed, and adjusted for the demographic data and cardiovascular disease (CVD) risk factors by a multivariable linear regression analysis. Results PAD (mean±SD: 2.6±0.4 cm) was positively correlated with LVM (r=0.34, p<0.001), LAV (r=0.41, p<0.001), and E/e'' (r=0.29, p<0.001). PAD/AAD (mean±SD: 0.76±0.12 cm) was positively correlated with LVM (r=0.12, p=0.09), LAV (r=0.24, p<0.001), and E/e'' (r=0.15, p=0.04). These correlations remained significant after adjusting for demographic data and CVD risk factors. PAD (or PAD/AAD) did not correlate with LVEF or RWT (p>0.05). Conclusion Greater PAD or PAD/AAD is significantly associated with LV remodeling and an impaired LV function.  相似文献   
89.
Immunohistochemisty with RD3, a monoclonal antibody specific for three‐repeat (3R) tau, is sometimes hampered by diffuse neuronal staining on formalin‐fixed, paraffin‐embedded sections pretreated with formic acid and heating. Additional pretreatment with potassium permanganate followed by oxalic acid completely eliminated this diffuse RD3‐immunoreactivity (IR) in neurons. Furthermore, this additional pretreatment uniformly enhanced RD3‐IR, as well as RD4‐IR, a monoclonal antibody specific for four‐repeat (4R) tau, on pathological deposits with tau IR. This enhanced sensitivity and specificity may allow more reliable identification of 3R and 4R tau in pathological deposits, which may be variable dependent on disease and regions. Cerebral cortex and midbrain from 8 patients [5 progressive supranuclear palsy (PSP) and 3 corticobasal degeneration (CBD)] were screened for RD3‐ and RD4‐IR with this improved procedure. In addition to RD4‐positive structures found both in cerebral cortex and brainstem, RD3‐positive neurofibrillary tangles (NFTs) were also found in midbrain in 7 of these 8 cases but not in the cortex. Multi‐labeling study demonstrated that most of RD3‐negative neurons were positive for RD4. This reliable demonstration of pathological 3R tau deposits in the brainstem of PSP/CBD, so far presumably characterized by deposition of 4R tau, is useful to map tau‐positive lesions according to their biochemical composition.  相似文献   
90.
There are marked increases in noradrenaline (NA) release during emergence from general anesthesia induced with volatile anesthetics. These changes in NA in the posterior hypothalamus of the rat were assessed by intracranial microdialysis. Sevoflurane and halothane in equipotent concentrations were used to obtain the same depth of anesthesia. NA release increased similarly with the two agents during recovery. However, NA release remained elevated longer with halothane, from which recovery was also slower.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号