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   6228篇
  免费   302篇
  国内免费   45篇
耳鼻咽喉   93篇
儿科学   152篇
妇产科学   29篇
基础医学   914篇
口腔科学   122篇
临床医学   341篇
内科学   1689篇
皮肤病学   194篇
神经病学   415篇
特种医学   157篇
外科学   996篇
综合类   11篇
一般理论   1篇
预防医学   146篇
眼科学   131篇
药学   354篇
中国医学   5篇
肿瘤学   825篇
  2023年   43篇
  2022年   63篇
  2021年   138篇
  2020年   74篇
  2019年   89篇
  2018年   130篇
  2017年   101篇
  2016年   123篇
  2015年   144篇
  2014年   206篇
  2013年   207篇
  2012年   371篇
  2011年   348篇
  2010年   257篇
  2009年   206篇
  2008年   430篇
  2007年   416篇
  2006年   432篇
  2005年   473篇
  2004年   470篇
  2003年   455篇
  2002年   454篇
  2001年   70篇
  2000年   57篇
  1999年   64篇
  1998年   87篇
  1997年   87篇
  1996年   80篇
  1995年   70篇
  1994年   41篇
  1993年   55篇
  1992年   24篇
  1991年   37篇
  1990年   33篇
  1989年   35篇
  1988年   14篇
  1987年   11篇
  1986年   13篇
  1985年   17篇
  1984年   20篇
  1983年   9篇
  1982年   13篇
  1981年   13篇
  1980年   12篇
  1978年   14篇
  1977年   9篇
  1976年   6篇
  1975年   6篇
  1974年   13篇
  1972年   5篇
排序方式: 共有6575条查询结果,搜索用时 62 毫秒
941.
We performed targeted molecular therapy in a patient with a non-resectable pelvic gastrointestinal stromal tumor (GIST). Imatinib mesylate was administered at 400-600 mg/day for 6 months, and the tumor became resectable. The patient was a 58-year-old female who visited a gynecologic hospital with the chief complaint of a swollen feeling in the lower abdomen. A pelvic tumor was found by imaging, and the patient was referred to our hospital. Laparotomy was performed, but it was found that the tumor arose from the intestinal serous membrane, rather than from the uterus, and complete excision was difficult. A portion of the tumor tissue was excised, and the abdomen was closed. GIST was diagnosed on postoperative pathological examination, and the tissue was positive for c-kit protein on immunostaining. The tumor had markedly shrunk after oral administration of imatinib mesylate for 6 months, and excision by laparotomy became possible.  相似文献   
942.
Chlorhexidine gluconate (CHX) is an antiseptic that has been widely used for disinfection of cutaneous wound and gingivae. Recently, a patient who inhaled CHX solution died from acute respiratory distress syndrome (ARDS). Although it is highly possible that direct pulmonary damage might be the cause of ARDS, there is no preclinical information about the pulmonary toxicity of CHX. In the current study, the acute direct action of CHX to the lung was evaluated in rats. We successfully exposed the left but not the right lung either to CHX at concentrations of 1%, 0.1%, and 0.01% or to saline using a curved-tip administration tube. At the higher concentrations of CHX (0.1% and 1%), severe congestion to the alveoli and capillaries and perivascular and intra-alveolar hemorrhages were observed 1 day after exposure. Aniline blue-stained collagen fibers with an infiltration of inflammatory cells were present 7 days after exposure. The fibrotic changes and intra-alveolar inflammatory cells had decreased but were still observed sporadically 28 and 84 days after exposure. These detrimental effects were more severe at 1% than at 0.1% CHX. No remarkable effect was observed after exposures to 0.01% CHX and saline. We were able to evaluate the time-course changes in the pulmonary toxicity of CHX by exposures limited to the left lung. It is highly possible that CHX at a concentration of more than 0.1% might directly induce ARDS when aspirated and reaching to the alveoli.  相似文献   
943.
944.
A prospective clinical trial was undertaken in 121 patients with stomach cancer to compare immunochemotherapy with 5-fluorouracil and FT-207 combined with OK-432 or PS-K, immunostimulators, and plain chemotherapy with 5-fluororacil and FT-207. Of the 121 patients who received immunochemotherapy, 67 patients (group A) had undergone curative removal of the tumor. The other 54 patients had undergone non-curative tumor removal or had recurrence after non-curative tumor removal and they were divided into two groups (groups B and C) on the basis of lymphocyte reactivity induced with PHA. Although group A exhibited a significant increase in PHA-induced lymphocyte transformation and a trifling increase in lymphocyte counts, its survival rate within a 36 month period did not differ from that of the peer controls. Group B, composed of 21 patients showing improvement of PHA-induced lymphocyte transformation, significantly prolonged its survival compared to the peer controls. The survival of group C, composed of 33 patients showing a gradual drop in PHA-induced lymphocyte transformation, was not prolonged compared to the peer control patients; and they showed significant decreases in lymphocyte counts. The overall survival of group B and group C was not superior to that of the 48 peer controls.  相似文献   
945.
Murine macrophages treated with TGF-beta2 are capable of inducing anterior chamber-associated immune deviation (ACAID), and these macrophages are characterized by impaired IL-12 production and CD40 expression, consequently failing to promote Th1 cell differentiation. In this study, we investigated whether human monocytes can also acquire the specific functions by TGF-beta2 treatment, even when the monocytes are isolated from patients with Behcet's disease (BD). Adherent monocytes isolated from peripheral blood mononuclear cells (PBMC) of 16 BD patients and 16 healthy controls, were cultured overnight with or without 5 ng/ml of TGF-beta2. Then, TGF-beta2-treated or untreated adherent cells were co-cultured with allogeneic CD4(+) T cells obtained from healthy subjects. TGF-beta2 treatment inhibited the abilities of adherent monocytes obtained from BD patients to stimulate the proliferation and IFN-gamma production of allogeneic CD4(+) T cells. The reduced IFN-gamma production was also confirmed by IFN-gamma mRNA expression in the co-cultured T cells. IL-12 production and CD40 molecule expression by adherent monocytes obtained from BD patients were strikingly reduced by TGF-beta2 treatment. These results suggest a possibility that adherent monocytes isolated from BD patients may acquire a property to induce ACAID by treatment with TGF-beta2.  相似文献   
946.
BACKGROUND/AIMS: To determine the clinical significance of gene promoter methylation in hepatocellular carcinoma (HCC), we examined in clinical samples the methylation status of those promoters that showed elevated activity in hepatoma cell lines after 5-aza-2'-deoxycytidine treatment. METHODS: Regarding the genes with promoter hypermethylation in the cell lines, their expression levels and methylation status in HCC and non-HCC tissues were assessed by semiquantitive RT-PCR and methylation-specific PCR. To confirm the result, the expression levels and methylation status in 16 additional HCC and non-HCC tissues were assessed. RESULTS: The promoter regions of caveolin 1 (CAV1), cysteine and glycine-rich protein 1 (CSRP1), Kruppel-like factor 6 (KLF6), myosin (light polypeptide 9) (MYL9), and transgelin (TAGLN) were highly methylated in the cell lines. CAV1 and CSRP1 were methylated in HCC more frequently than in non-HCC. KLF6, MYL9, and TAGLN were fully methylated in both HCC and non-HCC. Using additional clinical samples, downregulation of CAV1 and CSRP1 was observed in 38 and 56%, respectively, of the 16 HCC samples and aberrant methylation of CAV1 and CSRP1 was observed in 56% of HCC in both cases. CONCLUSION: CAV1 and CSRP1 were inactivated in HCC by aberrant methylation and they may serve as important biomarkers of malignancy.  相似文献   
947.
Patients with end-stage renal disease (ESRD) develop various kinds of abnormalities in bone and mineral metabolism, widely known as renal osteodystrophy (ROD). Although the pathogenesis of ESRD may be similar in many patients, the response of the bone varies widely, ranging from high to low turnover. ROD is classified into several types, depending on the status of bone turnover, by histomorphometric analysis using bone biopsy samples [1,2]. In the mild type, bone metabolism is closest to that of persons with normal renal function. In osteitis fibrosa, bone turnover is abnormally activated. This is a condition of high-turnover bone. A portion of the calcified bone loses its lamellar structure and appears as woven bone. In the cortical bone also, bone resorption by osteoclasts is active, and a general picture of bone marrow tissue infiltration and the formation of cancellous bone can be observed. In osteomalacia, the bone surface is covered with uncalcified osteoid. This condition is induced by aluminum accumulation or vitamin D deficiency. The mixed type possesses characteristics of both osteitis fibrosa and osteomalacia. The bone turnover is so markedly accelerated that calcification of the osteoid cannot keep pace. In the adynamic bone type, bone resorption and bone formation are both lowered. While bone turnover is decreased, there is little osteoid. The existence of these various types probably accounts for the diversity in degree of renal impairment, serum parathyroid hormone (PTH) level, and serum vitamin D level in patients with ROD. However, all patients share a common factor, i.e., the presence of a uremic condition.  相似文献   
948.
Thin basement membrane nephropathy (TBMN) is characterized clinically by persistent hematuria, minimal proteinuria, normal renal function, another family member with hematuria, and a benign course. Especially in childhood TBMN, proteinuria of any degree is reported to be uncommon. We report on a boy with benign familial hematuria found by urinary screening at 3 years of age who presented with nephrotic syndrome (NS) at 15 years of age. His renal histology showed TBMN associated with minimal change disease (MCD). Treatment with corticosteroid resulted in complete remission of NS in a short period of time, while isolated hematuria persisted during the follow-up period despite this therapy. We speculate, therefore, that the nephrotic range proteinuria is not due to TBMN but rather is the manifestation of associated MCD. Several cases of TBMN with NS have been reported in adults, but it has not yet been reported in children in the literature. To our knowledge, this is the first case of childhood TBMN associated with NS resulting from coincidental MCD.  相似文献   
949.
We report a rare case of generalized peritonitis caused by nontraumatic, intraperitoneal rupture of the ureter. An 80-year-old woman with a history of bilateral vesicoureteral reflux and long-term urethral indwelling catheter drainage presented with a very distended abdomen. Computed tomography showed massive ascites and intraperitoneal free gas. We performed an emergency laparotomy, assuming a gastrointestinal perforation; but could not find a cause of generalized peritonitis. Postoperatively, she presented with anuria and massive peritoneal drainage. The findings of a cystogram confirmed intraperitoneal ureteral rupture. She was managed successfully with ureteral stenting. The diagnosis of this condition requires a high degree of clinical suspicion, along with radiographic evidence and peritoneal fluid analysis. Image-guided interventions play a crucial role in the management of ureteral urine leaks after a correct diagnosis has been made.  相似文献   
950.
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