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   5693篇
  免费   274篇
  国内免费   34篇
耳鼻咽喉   109篇
儿科学   268篇
妇产科学   130篇
基础医学   475篇
口腔科学   235篇
临床医学   505篇
内科学   1323篇
皮肤病学   104篇
神经病学   279篇
特种医学   110篇
外科学   918篇
综合类   350篇
一般理论   4篇
预防医学   359篇
眼科学   200篇
药学   393篇
中国医学   32篇
肿瘤学   207篇
  2024年   4篇
  2023年   87篇
  2022年   280篇
  2021年   401篇
  2020年   184篇
  2019年   205篇
  2018年   232篇
  2017年   153篇
  2016年   186篇
  2015年   244篇
  2014年   291篇
  2013年   292篇
  2012年   428篇
  2011年   401篇
  2010年   233篇
  2009年   195篇
  2008年   303篇
  2007年   288篇
  2006年   297篇
  2005年   277篇
  2004年   227篇
  2003年   213篇
  2002年   170篇
  2001年   46篇
  2000年   49篇
  1999年   35篇
  1998年   28篇
  1997年   18篇
  1996年   19篇
  1995年   13篇
  1994年   15篇
  1993年   7篇
  1992年   22篇
  1991年   18篇
  1990年   19篇
  1989年   13篇
  1988年   14篇
  1987年   13篇
  1986年   5篇
  1985年   10篇
  1984年   5篇
  1983年   6篇
  1980年   5篇
  1979年   5篇
  1977年   5篇
  1974年   6篇
  1973年   4篇
  1972年   4篇
  1970年   5篇
  1969年   4篇
排序方式: 共有6001条查询结果,搜索用时 0 毫秒
71.
A total of 90 cases of pneumococcal infections were identified at a major referral hospital in Kuala Lumpur, Malaysia during a study period of four years. Pneumonia was the most common clinical presentation (41 cases) followed by meningitis (19 cases). Of 48 patients who were followed-up during the microbiology consultation round, 11 died, 9 were children below two years old. Capsular typing was carried out on 57 strains of Streptococcus pneumoniae isolated from blood and body fluids of 43 children and 14 adults. 38 strains isolated from pharyngeal specimens were also typed. Types 6A (11 strains), 6B (7 strains), 14 (8 strains) and 19A (8 strains) predominated in children. The strains from older patients comprised 3 isolates from cerebrospinal fluid (types 18B, 6B and 14), five from blood (4 strains, type 1 and 1 strain, type 4) and six from pus (1 strain, type 14, 3 strains type 23F and 2 strains type 34). The isolates from pharyngeal specimens belonged to capsular type similar to those implicated in infections. 90% of the types reported in this study are included in the 23 valent pneumococcal vaccines. Minimum inhibitory concentrations of penicillin, cefuroxime, chloramphenicol and rifampicin were determined for selected strains. 4.1% of isolates were resistant to penicillin (3/74), 4.5% to cefuroxime (2/44), 6.5% to chloramphenicol (3/46) and 14.6% to rifampicin (6/41).  相似文献   
72.
Thrombotic microangiopathies (TMAs) are rare, but life-threatening disorders characterized by microangiopathic hemolytic anemia and thrombocytopenia (MAHAT) associated with multiorgan dysfunction as a result of microvascular thrombosis and tissue ischemia. The differentiation of the etiology is of utmost importance as the pathophysiological basis will dictate the choice of appropriate treatment.We retrospectively evaluated 154 (99 females and 55 males) patients who received therapeutic plasma exchange (TPE) due to a presumptive diagnosis of TMA, who had serum ADAMTS13 activity/anti-ADAMTS13 antibody analysis at the time of hospital admission. The median age of the study cohort was 36 (14-84). 67 (43.5%), 32 (20.8%), 27 (17.5%) and 28 (18.2%) patients were diagnosed as thrombotic thrombocytopenic purpura (TTP), infection/complement-associated hemolytic uremic syndrome (IA/CA-HUS), secondary TMA and TMA-not otherwise specified (TMA-NOS), respectively. Patients received a median of 18 (1­75) plasma volume exchanges for 14 (153) days. 81 (52.6%) patients received concomitant steroid therapy with TPE. Treatment responses could be evaluated in 137 patients. 90 patients (65.7%) achieved clinical remission following TPE, while 47 (34.3%) patients had non-responsive disease. 25 (18.2%) non-responsive patients died during follow-up. Our study present real-life data on the distribution and follow-up of patients with TMAs who were referred to therapeutic apheresis centers for the application of TPE.  相似文献   
73.

Background

Once a disease of developed countries, type 2 diabetes mellitus (T2DM) has become widespread worldwide. For people with T2DM, achievement of therapeutic outcomes demands the rational and quality use of medicine.

Aims

The primary aim of this study was to examine the prevalence of diabetes and prescribing patterns of anti-diabetic medications in Australia and Malaysia.

Methods

The most recent, publicly available, statistical reports (2004–2008) on the use of medicines published in Australia and in Malaysia were evaluated. Defined daily doses (DDDs/1,000 population/day) were derived from the reports and used to rank and compare individual drug use.

Results

There was an increasing trend in the prevalence of diabetes in Australia, although there is a greater predicted increase in prevalence for Malaysia. While drugs used for the treatment of diabetes were not the most highly used drugs in Australia, their use increased during the study period, from 42.64 to 48.61 DDD/1,000/day. Anti-diabetic drugs were the most frequently dispensed class of drugs in Malaysia. Although the total consumption of anti-diabetic drugs in Malaysia decreased between 2006 and 2007 (from 40.30 to 39.72), this was followed by a marked increase to 46.69 in 2008. There was a marked reduction in the dispensing of insulin in Malaysia from 2004 to 2007 (7.77 to 3.23).

Conclusion

The use of drugs to treat diabetes does not reflect the usage patterns found in Australia. Effective drug use reviews are required to ensure impartial access in middle- and low-income countries.  相似文献   
74.
Clinical Rheumatology - Although latent tuberculosis infection (LTBI) treatment is given before anti-tumor necrosis factor (TNF) treatment, tuberculosis (TB) still develops in these patients and...  相似文献   
75.
激素敏感脂酶基因高度表达对泡沫细胞形成的作用   总被引:3,自引:0,他引:3  
中国仓鼠卵细胞在给予β-VLDL后,细胞内蓄积胆固醇酯,形成泡沫样细胞。以腺病毒基因转移方法书激素敏感脂酶基因转染到中国仓鼠卵细胞中,得到了来自激素敏感脂酶的胆固醇酯水解活性高度表达,此时,β-VLDL导致的胆固醇酯蓄积作用被阻断,提示增加胆固醇酯水解可以防止泡沫细胞形成。  相似文献   
76.
It has been commonly recognized that circadian rhythm and sleep/wake cycle are causally involved in bipolar disorder. There has been a paucity of systematic research considering the relations between sleep and mood states in bipolar disorder. The current study examines the possible influences of sleep deprivation on mood states and endocrine functions among first-degree relatives of patients with bipolar disorder and healthy controls. Blood samples were taken at two time points in the consecutive mornings at predeprivation and postdeprivation periods. Participants simultaneously completed the Profiles of Mood States at two time points after giving blood samples. Plasma T3 and TSH levels increased after total sleep deprivation in both groups. Sleep deprivation induced TSH levels were reversely associated with depression–dejection among healthy controls. A paradoxical effect was detected for only the first-degree relatives of the patients that changes in plasma cortisol levels negatively linked to depression–dejection and anger–hostility scores after total sleep deprivation. Plasma DHEA levels became correlated with vigor-activity scores after sleep deprivation among first-degree relatives of bipolar patients. On the contrary, significant associations of depression–dejection, anger–hostility, and confusion–bewilderment with the baseline plasma DHEA levels became statistically trivial in the postdeprivation period. Findings suggested that first-degree relatives of patients with bipolar disorder had completely distinct characteristics with respect to sleep deprivation induced responses in terms of associations between endocrine functions and mood states as compared to individuals whose relatives had no psychiatric problems. Considering the relationships between endocrine functions and mood states among relatives of the patients, it appears like sleep deprivation changes the receptor sensitivity which probably plays a pivotal role on mood outcomes among the first-degree relatives of patients with bipolar disorder.  相似文献   
77.
The self-renewal versus differentiation choice of Drosophila and mammalian neural stem cells (NSCs) requires Notch (N) signaling. How N regulates NSC behavior is not well understood. Here we show that canonical N signaling cooperates with a noncanonical N signaling pathway to mediate N-directed NSC regulation. In the noncanonical pathway, N interacts with PTEN-induced kinase 1 (PINK1) to influence mitochondrial function, activating mechanistic target of rapamycin complex 2 (mTORC2)/AKT signaling. Importantly, attenuating noncanonical N signaling preferentially impaired the maintenance of Drosophila and human cancer stem cell-like tumor-forming cells. Our results emphasize the importance of mitochondria to N and NSC biology, with important implications for diseases associated with aberrant N signaling.  相似文献   
78.
79.
Clinical Oral Investigations - 3D cephalometric analysis performed on cone-beam or multi-slice computed tomography (CBCT, MSCT) has superior diagnostic value compared to 2D cephalometry based on...  相似文献   
80.
BackgroundThe coronavirus diseases of 2019 (COVID-19) pandemic was classified as one of the worst pandemics in the 21st century. Its rapid transmission, unpredicted mortality rate, and the uncertainty surrounding its transmission method have evoked additional fear and anxiety. Nonetheless, to the best of our knowledge, no prior study has explored PTSD prevalence three months after the start of the quarantine procedures in Saudi Arabia nor has examined PTSD prevalence by three different methods.ObjectiveThis observational cross-sectional study aimed to identify the prevalence, severity, and influencing factors of PTSD in different regions of Saudi Arabia three months after the onset of the quarantine procedures related to the COVID-19 pandemic.MethodsThrough the month of June 2020, 1374 people (49.05% men and 50.95% women) completed a 35-item, 10-minute online. The prevalence of PTSD was measured using PCL-S (specific for COVID-19) that assesses the 17 symptoms of PTSD. Resilience was measured using 2-items Arabic version of the Connor-Davidson Resilience Scale 2 (CD-RISC 2).ResultsWe calculated the prevalence by three methods, namely, PTSD cut-off score, criteria, and combined, and the prevalence was 22.63%, 24.8%, and 19.6%, respectively. Female participants showed higher prevalence than male. As well, participants who were either tested positive or suspected of having been infected with COVID-19 showed higher PTSD prevalence. Higher resilience was associated with lower PTSD prevalence.ConclusionsThis was the first study to report PTSD prevalence by three differential methods three months after the onset of the quarantine procedures related to the COVID-19 pandemic in Saudi Arabia. We observed a significant impact of the COVID-19 pandemic in the Saudi population; therefore, great attention should be performed in implementing new procedures that deal with the highlighted risk factors, especially in vulnerable groups, to overcome the psychological impact of the COVID-19 pandemic.  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