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   16163篇
  免费   873篇
  国内免费   102篇
耳鼻咽喉   89篇
儿科学   408篇
妇产科学   252篇
基础医学   1862篇
口腔科学   303篇
临床医学   988篇
内科学   4393篇
皮肤病学   437篇
神经病学   1155篇
特种医学   555篇
外科学   3089篇
综合类   89篇
预防医学   394篇
眼科学   119篇
药学   987篇
中国医学   31篇
肿瘤学   1987篇
  2023年   110篇
  2022年   232篇
  2021年   423篇
  2020年   255篇
  2019年   339篇
  2018年   379篇
  2017年   306篇
  2016年   351篇
  2015年   404篇
  2014年   502篇
  2013年   566篇
  2012年   1036篇
  2011年   1062篇
  2010年   616篇
  2009年   509篇
  2008年   885篇
  2007年   944篇
  2006年   991篇
  2005年   919篇
  2004年   947篇
  2003年   916篇
  2002年   943篇
  2001年   294篇
  2000年   225篇
  1999年   273篇
  1998年   223篇
  1997年   191篇
  1996年   160篇
  1995年   131篇
  1994年   118篇
  1993年   96篇
  1992年   154篇
  1991年   150篇
  1990年   166篇
  1989年   125篇
  1988年   141篇
  1987年   153篇
  1986年   134篇
  1985年   134篇
  1984年   103篇
  1983年   67篇
  1982年   38篇
  1981年   35篇
  1980年   32篇
  1979年   55篇
  1978年   33篇
  1977年   32篇
  1975年   26篇
  1974年   27篇
  1971年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
We reported an autopsy case of Down's syndrome with moyamoya syndrome. A 30-year-old male with Down's syndrome suffered from a cerebral infarction and died of brain herniation. Cerebral angiography showed vascular abnormalities that were the same as moyamoya disease. Pathological findings revealed multiple stenosis of main trunk of the cerebral arteries. Pathologically, the stenosed vessels showed eccentric intimal thickness with cholesterin deposit, unlike moyamoya disease. There are only two previous reports of autopsied cases of Down's syndrome with moyamoya syndrome. We postulate that a protein encoded on chromosome 21 may be related to the pathogenesis of Down's syndrome with moyamoya syndrome.  相似文献   
972.
973.
AIM: To investigate the efficacy of tissue adhesives for closing the orifice of the inguinal hernia sac (IHS) as an alternative method for treating inguinal hernia. METHODS: Five-week-old male Lewis rats (n=4) were used, because Lewis rats have a large patent IHS. The rats were divided into 9 groups (n=6 in each) according to the type of tissue adhesive used: G1, fibrin glue (Beriplast); G1b, Beriplast plus blood; G2, microfibrillar collagen hemostat (Avitene); G2b, Avitene plus blood; G3, fibrinogen-based sealant (TachoComb); G3b, TachoComb plus blood; G4, synthetic absorbable sealant (Advaseal); G5, bilateral single port laparoscopic injection of octylcyanoacrylate (Dermabond); and G6, sham operation (control group). In G1-G4, surgery was performed through a midline lower abdominal incision. In G5, a 5-mm laparoscope was inserted in the epigastrium, a fine catheter was passed through the side port of the laparoscope into the right HIS, and 0.2 mL Dermabond was injected. The left IHS was treated in the same way. All rats were sacrificed 3 months after treatment, and IHS patency was examined macroscopically. All rats in G5 and G6 were mated 50 days after treatment to check fertility. RESULTS: All rats survived until sacrifice. At sacrifice, all IHS were patent in G6. All IHS were also patent in G1-G4, but all IHS were closed at the internal ring in G5. In G5 there were no adhesions between the orifice of the closed sac and the small bowel in 5/6, and only minor adhesions in 1/6. G5 fertility (5/6: 83%) was the same as for the control group (G6). CONCLUSION: Our results suggest that laparoscopic injection of Db into the IHS is simple, safe, reliable, virtually scarless, and may be a reasonable alternative to standard open surgical inguinal hernia repair.  相似文献   
974.
PURPOSE: To evaluate the efficacy of hand-assisted laparoscopic radical nephrectomy (HALRN) in patients with localized stage T(1)/T(2) renal-cell carcinoma, we analyzed the clinical results of our patients treated in this way. PATIENTS AND METHODS: From March 1999 to March 2003, a total of 96 patients aged 28 to 86 years (mean 61 years) with clinical stage T(1)/T(2)N(0)M(0), pathologically confirmed renal-cell carcinoma underwent HALRN. The outcomes were compared with those of open radical nephrectomy, which was performed in 86 patients from November 1991 to February 1999 in our institution. Kaplan-Meier analysis was used to analyze survival. RESULTS: Ten patients (10.4%) had perioperative complications. During a mean follow-up of 25 months (range 6-54 months), no patients died of the cancer, although three patients had metastatic disease. The 4-year disease- free and overall survival rates were 88% and 100%, respectively. Seventy-eight patients who underwent open radical nephrectomy were followed for 38 to 156 months (median 86 months). Seventy-three survived without any recurrent disease, five survived with metastasis, and no patient died of metastatic disease. The 4-year disease-free and overall survival rates were 93% and 100%, respectively. CONCLUSIONS: Hand-assisted laparoscopic surgical management of T(1)/T(2) renal-cell carcinoma is feasible and safe. At our institution, HALRN confers long-term oncologic effectiveness equivalent to that of open radical nephrectomy.  相似文献   
975.
PURPOSE: Vascular endothelial growth factor (VEGF) is known as a multifunctional protein with roles in angiogenesis stimulation and apoptosis inhibition. We hypothesized that intracavernous administration of VEGF would recover erectile dysfunction due to diabetes by protection from apoptosis in the penile cavernosum. MATERIALS AND METHODS: A total of 30, 6-month-old male Sprague-Dawley rats were divided into 2 large groups, namely 20 with diabetes and 10 healthy controls. The diabetic group received intraperitoneal injection of streptozotocin (STZ) to induce diabetes. Intracavernous injection of VEGF was administered to randomly selected STZ diabetic rats 6 weeks after STZ injections. Erectile functional studies were performed in 10 STZ and 10 STZ plus VEGF rats at 12 weeks. After completion of the functional study the penile crura were collected for molecular and immunohistochemical studies. RESULTS: Mean intracavernous pressure in the diabetic group was significantly lower than in controls and low pressure was significantly recovered by VEGF treatment. Gene expression of pro-apoptotic and anti-apoptotic factors were present in the control, diabetic and VEGF treated groups. However, anti-apoptotic protein expression was lacking in the diabetic group and it was recovered by VEGF treatment. The apoptotic index in the diabetic group was significantly higher than in controls and this index was significantly decreased in the VEGF treated group. CONCLUSIONS: The decrease in and recovery of intracavernous pressure correlated significantly with a variation in anti-apoptotic protein expression in the diabetic and VEGF treated groups. To our knowledge this is the first study to show that intracavernous injection of VEGF restores erectile dysfunction through the inhibition of apoptosis in diabetic rats.  相似文献   
976.

Purpose:

We report the difference in quality of life (QOL) between patients with an orthotopic neobladder and normative values in the age matched Japanese population.

Materials and Methods:

Between November 1996 and June 2003, 75 patients underwent orthotopic neobladder construction at our institution, of whom 47 males and 9 females were enrolled in this study. A total of 19 patients were excluded because of death or insufficient followup (less than 6 months). Two types of questionnaire, namely the RAND 36-Item Health Survey, version 2 and the Functional Assessment of Cancer Therapy-Bladder Cancer, were mailed to all 56 patients. The 48 patients (86%) who returned the completed forms were included in our analysis. Postoperative QOL was compared with age matched normative values in the control Japanese population.

Results:

Overall there was no significant difference in any scale between patients with a neobladder and the age matched control Japanese population. The patient bodily pain score in the seventh decade of life and the role-physical score in those older than 70 years were better than age matched normative values in the Japanese population (p <0.005 and p <0.05, respectively). Male patients in the seventh decade of life were more likely to have better QOL in the physical functioning, role-physical and role-emotional subscales in addition to the bodily pain subscale compared to age matched control values (p <0.05, <0.05, <0.001 and <0.001, respectively). Likewise in male patients older than 70 years role-physical scores remained better than age matched normative values in the Japanese population (p <0.01). Further analysis of bladder cancer related QOL showed that patients followed more than 24 months were more likely to have a lower incontinence score than those followed less than 24 months (p <0.05). In addition, the continence related QOL change alone did not affect any health related QOL scales, as analyzed by RAND 36-Intem Health Survey.

Conclusions:

Our study shows that there is no essential difference in health related QOL between patients with a neobladder and the age matched Japanese control population. The current results provide some primary evidence to help in decision making and eliminate potential anxiety about worse QOL after cystectomy.  相似文献   
977.
PURPOSE: Urokinase-type plasminogen activator (uPA) has an important role in tumor progression through the degradation of extracellular matrix. In addition, uPA receptor (uPAR) and plasminogen activator inhibitors (PAIs), composed of PAI-1 and 2, are also known to affect such activities. Tumor associated macrophage (TAM) is an important regulator of tumor progression that is associated with the uPA system in various cancers. However, to our knowledge the clinical significance of PAI-2 and the relationship between the uPA system and TAM in human renal cell carcinoma (RCC) tissues have not been investigated. We investigated and clarified these issues. MATERIALS AND METHODS: The subjects of the current study were 106 consecutive surgically resected specimens from patients with RCC. The expression of uPA, uPAR, PAI-1 and PAI-2 was determined by immunohistochemistry. We also examined the relationships among these molecules, survival and TAM. RESULTS: The mean immunoreactive scores (range 0 to 6) of uPA, uPAR, PAI-1 and PAI-2 were 3.09, 2.22, 1.99 and 0.56, respectively. These scores correlated with the grade and presence of metastasis. The expression of uPA, uPAR and PAI-1 but not PAI-2 correlated negatively with cause specific survival. Of uPA family members multivariate analysis showed that PAI-1 independently influenced cause specific survival. TAM counts correlated with PAI-1 only (p <0.001). CONCLUSIONS: Our results suggest that PAI-1 is an important regulator of tumor progression and survival, and PAI-1 may modulate them via TAM. On the other hand, PAI-2 has a minimum role in survival. Our results may help discussions of treatment strategy in patients with RCC.  相似文献   
978.
Background Messenger RNA of liver fatty acid-binding protein (L-FABP) is expressed in proximal tubules of the kidney, and a certain amount is excreted into urine. We analyzed factors relating to the urinary L-FABP excretion in health-check participants.Methods We measured L-FABP in the first morning urine by ELISA in 715 men and 193 women 30–79 years of age who entered a 2-day hospitalized health checkup program. In addition to the routine physical examination and laboratory tests, plasma high-sensitivity C-reactive protein (HSCRP) was assayed.Results In 150 healthy subjects, urinary L-FABP averaged 3.6 ± 0.2µg/g creatinine, whereas the values were significantly increased in patients with hypertension (5.2 ± 0.4, P = 0.010), diabetes mellitus (5.5 ± 0.5, P < 0.001), and chronic hepatitis (5.8 ± 1.0, P = 0.022). Urinary L-FABP excretion was significantly greater in women than in men when the value was related to creatinine. In regression analysis in men, urinary L-FABP was positively correlated with fasting plasma glucose (r = 0.103, P = 0.033) and plasma HSCRP (r = 0.135, P = 0.006).Conclusions It is suggested that renal production and urinary excretion of L-FABP are increased in situations in which arteriosclerosis is promoted, such as hypertension, diabetes mellitus, and cardiovascular inflammation.  相似文献   
979.
Purpose We compared the clinicopathologic features affecting outcome after surgery for hepatocellular carcinoma (HCC) between patients with concurrent and previous chronic hepatitis B.Methods Group A consisted of 58 patients with concurrent chronic hepatitis B, defined by seropositivity for the hepatitis B surface antigen (HBsAg), and group B consisted of 18 patients whose HCC was detected after disappearance of the HBsAg. We assessed the influence of various characteristics on outcome.Results The mean age and percentage of patients suffering from alcohol abuse or diabetes mellitus were significantly greater in group B than in group A, whereas histologic hepatitis activity, hepatic fibrosis, and alanine aminotransferase activity were significantly lower in group B than in group A. The tumor-free survival rates were similar between the two groups, but the risk factors of recurrence differed. In group A, relative youth, high aspartate aminotransferase activity, low platelet count, multiple tumors, large tumor size, portal invasion, cirrhosis, nonanatomic resection, and positive surgical margin were risk factors. In group B, large tumor size and poor differentiation were risk factors.Conclusion Hepatitis B status, tumor factors, and the type of operation affected cancer recurrence after surgery for HCC in patients with concurrent chronic HBV, as opposed to only tumor factors in patients with previous chronic hepatitis B.  相似文献   
980.
The International Society for the Study of the Aging Male (ISSAM) recommends that a diagnosis be based on a patient's total testosterone (TT), calculated free testosterone (cFT), or calculated bioavailable testosterone (cBT) for partial androgen deficiency of the aging male (PADAM). The purpose of this study was to confirm whether hypogonadism of patients with PADAM is related to symptoms and clarify which criteria of testosterone recommended by ISSAM is suitable for Japanese patients. A total of 90 patients with PADAM symptoms were included in this study. Endocrinologic profiles were reviewed as appropriate, and PADAM symptoms were judged by means of several questionnaires. Laboratory values and symptoms were compared between patients with and without hypogonadism. Even when any criterion of testosterone was used for diagnosis of hypogonadism, AMS (total and subscales), IIEF-5, or SDS scores of PADAM symptoms did not differ significantly between patients classified as having and not having hypogonadism. No other endocrinologic variables than testosterone differed significantly between them, either. PADAM symptoms are not related to testosterone level and it is still obscure whether ISSAM's criterion can be adopted for Japanese patients with PADAM. Other pathology needs to be addressed for evaluation and diagnosis of PADAM in Japan.  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