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   6162篇
  免费   409篇
  国内免费   31篇
耳鼻咽喉   93篇
儿科学   151篇
妇产科学   70篇
基础医学   752篇
口腔科学   118篇
临床医学   474篇
内科学   1388篇
皮肤病学   118篇
神经病学   341篇
特种医学   173篇
外国民族医学   2篇
外科学   1006篇
综合类   121篇
一般理论   9篇
预防医学   454篇
眼科学   178篇
药学   559篇
中国医学   56篇
肿瘤学   539篇
  2023年   74篇
  2022年   209篇
  2021年   335篇
  2020年   157篇
  2019年   189篇
  2018年   243篇
  2017年   168篇
  2016年   172篇
  2015年   228篇
  2014年   305篇
  2013年   288篇
  2012年   477篇
  2011年   513篇
  2010年   332篇
  2009年   247篇
  2008年   355篇
  2007年   358篇
  2006年   328篇
  2005年   315篇
  2004年   273篇
  2003年   275篇
  2002年   214篇
  2001年   58篇
  2000年   44篇
  1999年   42篇
  1998年   51篇
  1997年   29篇
  1996年   37篇
  1995年   24篇
  1994年   22篇
  1993年   19篇
  1992年   23篇
  1991年   14篇
  1990年   12篇
  1989年   12篇
  1988年   15篇
  1987年   8篇
  1985年   13篇
  1984年   9篇
  1983年   14篇
  1982年   17篇
  1981年   9篇
  1980年   9篇
  1979年   5篇
  1978年   10篇
  1975年   4篇
  1974年   4篇
  1973年   5篇
  1972年   4篇
  1971年   5篇
排序方式: 共有6602条查询结果,搜索用时 15 毫秒
31.
Pure gonadal dysgenesis or Swyer syndrome is a sex-reversal disorder resulting from embryonic testicular regression sequences especially during the first few weeks of fetal life and is induced by mutations in the SRY gene. In the present report, we describe a nonmosaic XY sex-reversed female with pure gonadal dysgenesis. Molecular analysis using sequential PCR to detect Y chromosomal microdeletions showed the presence of SRY, ZFY and AZFa, b and c regions. Automated sequencing of the SRY region revealed a new mutation (deletion of A (adenine) in codon 82 at position +244), leading to a frame shift mutation within the helix I of the HMG-box domain. This mutation generates a truncated protein and is very likely to produce an impairment of SRY DNA binding activity. The present findings further support the functional importance of the putative DNA binding activity of the SRY HMG-box domain.  相似文献   
32.
BackgroundHyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.ObjectiveTo address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.MethodsWe reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.ResultsA total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).ConclusionsAs this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures.  相似文献   
33.
International Urology and Nephrology - To evaluate the acute renal colic score (ARC) in predicting the need of emergency intervention (EI) in patients with ureteric colic secondary to a ureteral...  相似文献   
34.
International Urology and Nephrology - We aimed to determine the potential relationship between atherosclerotic cardiovascular disease (ASCVD) score, which equates to 10-year risk of...  相似文献   
35.
This study reports the first evaluation of sperm hyaluronan binding assay (HBA) for predicting the fertility of Nili-Ravi buffalo bulls in relation to standard parameters of sperm quality. Cryopreserved semen doses of low (n = 6), medium (n = 3) and high fertility (n = 8) bulls based on their respective return rates were used. Significantly, more spermatozoa bound to hyaluronan from the most fertile bulls (57.15% ± 1.44) compared with medium (42.46% ± 1.08) and low fertility bulls (29.70% ± 0.78). A strongly positive correlation (r = .824, p < .01) was found between HBA and fertility that predicts a 67.9% variability (r2 = .679, p < .01) in fertility. HBA was also strongly positively correlated with sperm viability (r = .679, p < .01) followed by their live/dead ratio (r = .637, p < .01), uncapacitated spermatozoa (r = .631, p < .01), normal apical ridge (r = .459, p < .01), motility (r = .434, p < .01), mature spermatozoa with low residual histones (r = .364, p < .01), high plasma membrane integrity (r = .316, p < .01) and nonfragmented DNA levels (r = .236, p < .05). It was negatively correlated with spermatozoa having reacted acrosome (r = −.654, p < .01). A fertility model built using a combination of sperm HBA and either sperm livability or viability predicts, respectively, 86.1% (r2 = .861, p < .01) and 85.9% (r2 = .859, p < .01) variability in buffalo bull fertility. In conclusion, sperm HBA may prove to be a single robust predictor of Nili-Ravi buffalo bull fertility.  相似文献   
36.
37.
BackgroundInjuries involving upper cervical spine are serious and fatal injuries which are associated with alteration of normal occipital–cervical anatomy. These injuries may result in permanent neurologic deficits or neck deformity if not treated in a timely and appropriate manner.ObjectiveTo evaluate the outcomes of neglected upper cervical spine injuries treated by various methods.Study designRetrospective study.Materials and methodsTwelve patients attending ER or OPD with a history of neck trauma and who were diagnosed with fractures and fracture dislocations C1 and C2 were included in the study. Fresh injuries sustained within a week were excluded from study. The outcomes were measured in terms of improvement in VAS, ODI Scores and correction of the neck deformity. Surgical parameters like duration of surgery and blood loss were also observed.ResultsEleven males and one female. The mean age was 40.9 ± 16.9 (07–67 years). Eleven patients underwent posterior instrumentation, while one patient was treated anteriorly. The mean delay in presentation was 28 ± 8.67 days (15–42 days). The mean duration of surgery was 188.3 ± 34.35 min (120–240 min), average blood loss was 350 ± 111.8 ml (150–600 ml). The mean VAS improved from 8.45 ± 0.89 to 3.9 ± 0.51 (p < 0.05). The mean ODI Pre-operatively was 88.45 ± 5.89 which improved to 31.9 ± 4.01 (p < 0.05). The neck deformity/torticollis was corrected in all the patients.ConclusionsNeglected upper cervical spine injuries are difficult to treat and a posterior approach is helpful in reducing the subluxations indirectly and to obtain a posterior fusion.  相似文献   
38.
PurposeWe examined the role of obesity and intraoperative red blood cell (RBC) and platelet transfusion in early allograft dysfunction (EAD) following liver transplantation (LT).MethodsThis is a retrospective analysis of 239 adult deceased-donor LT recipients over a 10-year period. EAD was defined by Olthoff’s criteria. Data collection included donor (D) and recipient (R) age, body mass index (BMI) ≥ 35 kg/m2, diabetes mellitus, allograft macrosteatosis, and intraoperative (RBC) and platelet administration. We employed logistic regression to evaluate associations of these factors with EAD. Results are presented as odds ratios (OR) and 95% confidence intervals (CI) with corresponding P values. A P ≤ .05 was considered statistically significant.ResultsEAD occurred in 85 recipients (36%). Macrosteatosis data were available for 199 donors. In the multivariate analyses, BMI-D ≥ 35 kg/m2 increased the odds of developing EAD by 156% in the entire cohort (OR 2.56, 95% CI 1.09-6.01) and by 187% in recipients with macrosteatosis data (n = 199, OR 2.87, 95% CI 1.15-7.15). Each unit of RBCs increased the odds for EAD by 8% (OR 1.08, 95% CI 1.02-1.14) and, for the subgroup of 238 recipients with macrosteatosis data, by 9% (OR 1.09, 95% CI 1.02-1.16).ConclusionWe found a significant independent association of donor obesity and intraoperative RBC transfusion with EAD but no such association for platelet administration, MELD score, age, recipient obesity, and diabetes.  相似文献   
39.
ObjectivesTo examine how postoperative pain control after robotic thoracoscopic surgery varies with liposomal bupivacaine (LipoB) versus 0.5% bupivacaine/1:200,000 epinephrine (Bupi/Epi) intercostal nerve blocks within the context of an enhanced recovery after thoracic surgery (ERATS) protocol.DesignA retrospective analysis of a prospectively maintained database of patients undergoing robotic thoracoscopic procedures between September 1, 2018 and October 31, 2019 was conducted.SettingUniversity of Miami, single-institutional.ParticipantsPatients.InterventionsTwo hundred fifty-two patients had either LipoB intercostal nerve blocks (n = 129) or Bupi/Epi intercostal nerve blocks (n = 123) when undergoing robotic thoracic surgery.Measurements and Main ResultsComparative analysis of patient-reported pain levels, in-hospital and post-discharge opioid requirements, 90-day operative complications, length of hospital stay, and hospital costs was performed. Data were stratified to either anatomic lung resection or pulmonary wedge resection/mediastinal-pleural procedures. Bupi/Epi patients reported significantly more acute postoperative pain than LipoB patients, which correlated with higher in-hospital and post-discharge opioid requirements. There were no differences in postoperative complications, length of hospital stay, or hospital costs between the two groups.ConclusionsAs part of an ERATS protocol, infiltration of intercostal spaces and surgical wounds with LipoB for robotic thoracoscopic procedures afforded better postoperative subjective pain control and decreased opioid requirements without an increase in hospital costs as compared with use of Bupi/Epi.  相似文献   
40.
BackgroudDue to extensive fibrosis during revision surgery, adequate exposure is essential and it can be achieved with several extensile approach options, such as tibial tubercle osteotomy. Information regarding surgical exposure during revision arthroplasty is limited in developing countries, such as Pakistan, due to the lack of adequate data collection and follow-up. Therefore, the purpose of this study was to evaluate the impact of tibial tubercle osteotomy on final outcome of revision total knee arthroplasty (TKA).MethodsA total of 231 revision TKAs were performed between January 2008 and December 2017. Twenty-nine patients underwent tibial tubercle osteotomy for adequate exposure during revision surgery. Of these, 27 patients with complete follow-up were included in our study. Factors examined include age at the time of revision surgery, gender, comorbidities, arthroplasty site (right or left), body mass index (BMI), and primary indications for the tibial tubercle osteotomy during revision TKA. Functional outcome was measured by using Knee Society score (KSS) at 3 months and the final follow-up. All statistical analysis was done using SPSS version 20.0 with a p-value < 0.05 considered significant.ResultsOut of 27 patients, 6 patients (22.2%) were men and 21 patients (77.7%) were women. Right knee revision arthroplasty was performed in 15 patients (55.5%), left knee revision arthroplasty was performed in 12 patients (44.4%), and bilateral revision surgery was performed in only 1 patient (3.7%). The mean BMI was 29.2 kg/m2. We used a constrained condylar knee in 20 patients (74%), a rotating hinge knee in 5 patients (18.5%), and mobile bearing tray plus metaphyseal sleeves in 2 patients (7.4%). The KSS was 52.21 ± 4.05 preoperatively, and 79.42 ± 2.2 and 80.12 ± 1.33 at 3 months and 12 months, respectively. Radiological union was achieved in all patients at 3 months. Of 27 patients, only 1 patient (3.7%) had proximal migration of the osteotomy site at 6 months: the patient was asymptomatic and union was also achieved and, therefore, no surgical intervention was performed.ConclusionsTibial tubercle osteotomy during revision TKA can be a safe and reliable technique with superior outcomes and minimal complication rates.  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