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   3618篇
  免费   118篇
  国内免费   14篇
耳鼻咽喉   44篇
儿科学   25篇
妇产科学   33篇
基础医学   421篇
口腔科学   179篇
临床医学   197篇
内科学   982篇
皮肤病学   49篇
神经病学   256篇
特种医学   148篇
外科学   467篇
综合类   12篇
预防医学   193篇
眼科学   40篇
药学   240篇
中国医学   9篇
肿瘤学   455篇
  2023年   27篇
  2022年   55篇
  2021年   65篇
  2020年   32篇
  2019年   50篇
  2018年   62篇
  2017年   59篇
  2016年   65篇
  2015年   73篇
  2014年   95篇
  2013年   110篇
  2012年   209篇
  2011年   210篇
  2010年   140篇
  2009年   117篇
  2008年   218篇
  2007年   235篇
  2006年   243篇
  2005年   253篇
  2004年   228篇
  2003年   195篇
  2002年   173篇
  2001年   79篇
  2000年   85篇
  1999年   72篇
  1998年   58篇
  1997年   44篇
  1996年   44篇
  1995年   42篇
  1994年   25篇
  1993年   30篇
  1992年   45篇
  1991年   46篇
  1990年   39篇
  1989年   15篇
  1988年   31篇
  1987年   11篇
  1986年   26篇
  1985年   21篇
  1984年   18篇
  1983年   8篇
  1982年   7篇
  1980年   6篇
  1979年   20篇
  1978年   8篇
  1975年   6篇
  1972年   7篇
  1970年   6篇
  1969年   9篇
  1966年   5篇
排序方式: 共有3750条查询结果,搜索用时 15 毫秒
91.
92.
Background Although delayed union or pseudoarthrosis after lumbar arthrodesis has been recognized as a major radiographic complication, little has been known about the effect of fusion status on the patient’s quality-of-life (QOL) outcome. The purpose of this study was to investigate the effects of fusion status after posterior lumbar interbody fusion (PLIF) on QOL outcomes by using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ).Methods Among 100 patients who underwent single level PLIF for spinal canal stenosis, 29 who had not achieved fusion (incomplete fusion group) and 29 age- and sex ratio-matched patients who had achieved fusion (fusion group) 6 months after surgery were enrolled. Overall clinical evaluation was performed before and 6 months after surgery: the physician determined the Japanese Orthopaedic Association Score for Low Back Pain (JOA score); the JOABPEQ and visual analogue scale (VAS) values were collected. The recovery rate of the JOA score, changes in all JOABPEQ subdomain scores and in the VAS values were calculated. All variables were compared between the groups.Results The preoperative JOA scores, JOABPEQ scores of all subdomains, and VAS values of all categories did not differ between the groups. The recovery rate was higher in the fusion group than the incomplete fusion group (p = 0.0185). The changes in the JOABPEQ scores for walking ability and social life function were significantly greater in the fusion group than the incomplete fusion group (walking ability, p = 0.0172; social life function, p = 0.0191). The postoperative VAS values and changes in the VAS values for all categories did not differ between the groups.Conclusions Incomplete fusion after PLIF correlated with poor improvement in walking ability and social life function. Therefore, the achievement of fusion after PLIF is essential to obtain better patient QOL outcomes.  相似文献   
93.
94.
Background: Desquamative gingivitis (DG) is a clinical manifestation common to several diseases. It is known that most cases of DG are caused by mucous membrane pemphigoid (MMP), oral lichen planus (OLP), or pemphigus vulgaris (PV). Early recognition and treatment of these diseases can improve the prognosis, but diagnostic delays are common in patients with DG because obtaining a diagnostic biopsy is technically challenging. A biopsy technique designed to maintain the gingival epithelium for patients with DG was developed. The usefulness of this technique is discussed. Methods: This study is based on a retrospective review of 27 DG cases. A stab‐and‐roll technique was used to obtain gingival tissue. This technique is designed to reduce lateral forces on the epithelium during the procedure and to thereby prevent the inadvertent removal of the epithelium from the biopsy specimen. A total of 52 biopsies comprising 27 for hematoxylin and eosin (H&E)–stained samples and 25 for direct immunofluorescence (DIF) testing were reviewed. Results: Fifty‐one of the 52 biopsies (98.1%) maintained the epithelium. Only one biopsy (1.9%) showed that the epithelium was totally absent. Therefore, H&E and DIF features of 51 biopsies were analyzed. Definitive diagnoses of the diseases causing DG included MMP (13 cases), PV (eight cases), and OLP (six cases). Conclusions: A diagnostic biopsy was obtained from the gingiva of patients with DG using the stab‐and‐roll technique. The gingival epithelium was well maintained, and the relationship with the underlying connective tissue was diagnostic. In the future, this stab‐and‐roll biopsy technique may facilitate early diagnosis and treatment of diseases causing DG.  相似文献   
95.

Objective

Minor salivary gland sialolithiasis occurs in ~1 % of all sialolithiasis cases. We report a case of sialolithiasis considered to have occurred in the minor salivary gland in two areas of the upper lip, with special emphasis on the findings from image examinations.

Case report

A 33-year-old male complained of a painless mass on the left upper lip. At the first examination, there was a nodular, hard swelling that involved the left cuspid area of the upper lip. Although a panoramic radiograph revealed no abnormality, an intraoral radiograph showed a small radiopaque body with a laminar pattern. Computed tomography images indicated that a calcified body was present in two areas of the upper lip. On magnetic resonance imaging, the lesion was observed as a lower-signal area than the surrounding soft tissue. The mass had a high signal in the central area in the T2 and short T1 inversion recovery images. The sonogram showed a hypoechoic mass with an echogenic structure in the central area. An excisional biopsy of the left upper lip was performed under local anesthesia. A well-demarcated mass with a calcified body was enucleated. The histopathologic diagnosis was sialoadenitis with sialolithiasis.

Conclusion

Most cases of minor salivary gland sialolithiasis are solitary, with multiple sialolithiasis being extremely rare. Sonograms are useful in the diagnosis of minor salivary gland sialolithiasis. Careful imaging examination is necessary to identify multiple lesions and select appropriate treatments.  相似文献   
96.
97.
To evaluate the effect of the extended lymphadenectomy for thoracic esophageal carcinoma, the pattern of recurrence in the 50 patients with pT3 tumors who underwent esophagectomy with cervical, mediastinal, and abdominal lymph node dissection (3-F) (group A) was compared with that of 100 patients at pT3 who underwent esophagectomy without upper mediastinal and cervical lymphadenectomy (2-F) (group B). The cumulative 5-year survival rate for 115 patients who underwent 3-F was 50.9%. Cumulative 5-year survival rates for patients in groups A and B were 36.8% and 22.0%, respectively. The survival curve for group A was significantly better than group B (P = 0.02332). Lymphatic recurrence was noted less frequently in group A (8/23) than in group B (31/49) (χ2 = 5.1149), whereas the rate of hematogenous recurrence was similar. Extension of the field of lymph node dissection reduced the lymph node recurrence in patients with thoracic esophageal carcinoma, which may have positively affected patient survival. © 1996 Wiley-Liss, Inc.  相似文献   
98.
BackgroundDespite the progress in endoscopic hemostasis and pharmacological treatment, the mortality rate of peptic ulcer bleeding remains at 5–10%. Rebleeding after peptic ulcer bleeding is believed to be a risk factor for mortality. This study aimed to evaluate whether renal dysfunction is a predictor of rebleeding after endoscopic hemostasis in patients with peptic ulcer bleeding.Methods: In this retrospective study, consecutive patients with peptic ulcer bleeding who underwent endoscopic hemostasis at our Hospital from January 2010 to December 2018 were enrolled. The relationship between rebleeding within 30 days after endoscopic hemostasis and the patients’ admission and endoscopic characteristics were analyzed using univariate and multivariate regression models.ResultsOut of 274 patients with peptic ulcer bleeding, 17 (6.2%) patients experienced rebleeding. In the analysis of the patients’ admission characteristics, estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2 was an independent risk factor for rebleeding (odds ratio 4.77, 95% confidence interval 1.168-18.211, p = 0.03). Patients with eGFR < 15 mL/min/1.73 m2 with or without hemodialysis had the highest rebleeding rate at 36.8%. With respect to endoscopic characteristics, the rate of rebleeding was associated with combination therapy (p < 0.0001) and active bleeding (p = 0.03).Conclusion: Renal dysfunction might be an independent risk factor for rebleeding after endoscopic hemostasis in patients with peptic ulcer bleeding.  相似文献   
99.
In the present study, we analyzed the kinetics of serum soluble interleukin-2 receptor (sIL-2R) using data from 77 patients undergoing HLA-haploidentical transplantation using reduced-intensity conditioning (RIC), who were at an advanced stage or at high risk for relapse, to clarify the usefulness of sIL-2R as a biomarker of acute graft-versus-host disease (GVHD). Anti-T-lymphocyte globulin and methylprednisolone were used as GVHD prophylaxis. While the median sIL-2R in 38 patients not developing GVHD was suppressed at levels <740 U/ml, sIL-2R in 25 patients developing severe GVHD peaked on day 11 (1,663 U/ml), and thereafter decreased to <1,000 U/ml after day 30. The occurrence of GVHD was not limited to times of high sIL-2R level, but occurred at any time point on the sIL-2R curve. Most patients developing GVHD, however, experienced a higher sIL-2R level early in their transplant course. The combination of RIC and glucocorticoids sufficiently suppressed sIL-2R levels after HLA-haploidentical transplantation. In a multivariate analysis to identify factors associated with GVHD, day 7 sIL-2R >810 U/ml was the only factor significantly associated with the occurrence of severe GVHD (p = 0.0101).  相似文献   
100.
BACKGROUND: Toxic nitrite and N-nitroso compounds due to gastric bacterial growth are often detected in the stomach of patients with atrophic gastritis and partial gastrectomy. The aim of this study is to investigate whether breath N2O, a major metabolite of denitrification, detected after ingestion of nitrate is associated with atrophic gastritis and partial gastrectomy. METHODS: Nine young, 16 normal older, nine atrophic gastritis and six partial gastrectomy subjects ingested 100 g lettuce, equal to 130 mg nitrate, and breath N2O was measured at 15-min intervals for 5 h. N2O was analyzed using an infrared-photoacoustic analyzer, and atrophic gastritis was diagnosed by pepsinogen test. RESULTS: The mean breath N2O concentrations were higher in the following order at all times: partial gastrectomy>atrophic gastritis>normal>young. The maximum N2O concentrations in the patients with partial gastrectomy and atrophic gastritis were 1655 +/- 296 and 1350 +/- 200 (mean +/- S.E.) ppb, respectively, which were higher than that of the normal subjects, 827 +/- 91 ppb (P < 0.05). The maximum N2O concentration in young people was 527 +/- 86 ppb, which was lower than that of the normal older people (P < 0.051). CONCLUSION: These higher N2O concentrations in gastric patients reflect bacterial growth in the stomach due to the reduction of gastric acid.  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