首页 | 官方网站   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   10898篇
  免费   469篇
  国内免费   73篇
医药卫生   11440篇
  2023年   67篇
  2022年   132篇
  2021年   242篇
  2020年   109篇
  2019年   165篇
  2018年   230篇
  2017年   176篇
  2016年   239篇
  2015年   249篇
  2014年   307篇
  2013年   391篇
  2012年   637篇
  2011年   671篇
  2010年   418篇
  2009年   311篇
  2008年   590篇
  2007年   618篇
  2006年   623篇
  2005年   671篇
  2004年   646篇
  2003年   586篇
  2002年   604篇
  2001年   207篇
  2000年   193篇
  1999年   209篇
  1998年   159篇
  1997年   126篇
  1996年   129篇
  1995年   103篇
  1994年   107篇
  1993年   70篇
  1992年   116篇
  1991年   131篇
  1990年   135篇
  1989年   125篇
  1988年   124篇
  1987年   102篇
  1986年   92篇
  1985年   94篇
  1984年   64篇
  1983年   58篇
  1982年   41篇
  1981年   36篇
  1980年   37篇
  1979年   40篇
  1978年   31篇
  1977年   23篇
  1973年   23篇
  1970年   18篇
  1969年   27篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
PURPOSE: Recent studies reported that clinical responsiveness to gefitinib was associated with somatic mutation of epidermal growth factor receptor (EGFR) gene in non-small cell lung cancers (NSCLC). Here, we investigated the relationship between EGFR mutation and clinicopathologic features. EXPERIMENTAL DESIGN: EGFR mutational status of 120 NSCLCs was determined mainly in EGFR exons 18 to 21 by direct sequence and correlated with clinicopathologic parameters. RESULTS: EGFR mutations were present in 38 cases (32%) and the majority of mutations were in-frame deletions of exon 19 (19 cases) and a missense mutation in exon 21 (18 cases). EGFR mutations were frequently associated with adenocarcinoma (P < 0.0001), never smoker (P < 0.0001), and female gender (P = 0.0001). Of interest, increasing smoke exposure was inversely related to the rate of EGFR mutation (P < 0.0001). Multivariate analysis showed that smoking and histology were independent variables. Furthermore, gender difference was observed for the mutational location (P = 0.01) dominance of exon 19 for males and exon 21 for females. Twenty-one cases were treated with gefitinib and found that EGFR mutation was significantly related to gefitinib responsiveness (P = 0.002). In addition, median survival times of patients with and without EGFR mutations treated with gefitinib were 25.1 and 14.0 months, respectively. Patients with EGFR mutations had approximately 2-fold survival advantage; however, the difference was not significant. CONCLUSIONS: We show that EGFR mutations were significantly related to histology and smoke exposure and were a strong predictive factor for gefitinib responsiveness in NSCLC.  相似文献   
103.
Supplement of ulinastatin on renal function after cardiopulmonary bypass   总被引:14,自引:0,他引:14  
The effects of Miraclid (ulinastatin) on renal tubular function after open thorax surgery under cardiopulmonary bypass were investigated. On the 3rd day after open thorax surgery, which had lasted more than 127 min under cardiopulmonary bypass, the levels of urinary ulinastatin in the Miraclid group and control (without Miraclid) were 170 IU.mg Cr-1 and 95 IU.mg Cr-1, respectively. In the Miraclid group, 300,000 units.day-1 of Miraclid was administrated for three postoperative days. N-acetyl-beta-d-glucosaminidase in urine as a marker of tubular function rose significantly on the seventh postoperative day in the control group but not in patients with Miraclid group. These data suggested that Miraclid 300,000 units.day-1 was needed to protect renal tubular function and more than that dose was needed to prevent the deterioration of renal function after open thorax surgery after cardiopulmonary bypass lasting more than 127 min.  相似文献   
104.
The accumulation of cisplatin is decreased in many cisplatin-resistant cell lines, and an active efflux pump for cisplatin exists in some of them, but it has not yet been identified. In this study, we transfected the copper-transporting P-type ATPase cDNA (ATP7B) into human epidermoid carcinoma KB-3-1 cells. The transfectant, KB/WD cell line, which overexpressed the P-type ATPase, ATP7B, was resistant to both cisplatin (8.9-fold) and copper (2.0-fold). The accumulation of cisplatin in KB/WD cells was lower than in mock-transfected KB/CV cells, and the efflux of cisplatin from KB/WD cells was enhanced compared with KB/CV cells. KB/WD cells were sensitive to other heavy metals, such as antimony, arsenate, arsenite, cadmium, and cobalt. ATP7B was overexpressed in cisplatin-resistant prostate carcinoma PC-5 cells but not in the parental PC-3 cells and the revertant PC-5R cells. ATP7B may be involved in cisplatin resistance in some tumors.  相似文献   
105.
Cancer‐associated fibroblasts (CAFs) are reportedly involved in invasion and metastasis in several types of cancer, including gastric cancer (GC), through the stimulation of CXCL12/CXCR4 signaling. However, the mechanisms underlying these tumor‐promoting effects are not well understood, which limits the potential to develop therapeutic targets against CAF‐mediated CXCL12/CXCR4 signaling. CXCL12 expression was analyzed in resected GC tissues from 110 patients by immunohistochemistry (IHC). We established primary cultures of normal fibroblasts (NFs) and CAFs from the GC tissues and examined the functional differences between these primary fibroblasts using co‐culture assays with GC cell lines. We evaluated the efficacy of a CXCR4 antagonist (AMD3100) and a FAK inhibitor (PF‐573,228) on the invasive ability of GC cells. High CXCL12 expression levels were significantly associated with larger tumor size, increased tumor depth, lymphatic invasion and poor prognosis in GC. CXCL12/CXCR4 activation by CAFs mediated integrin β1 clustering at the cell surface and promoted the invasive ability of GC cells. Notably, AMD3100 was more efficient than PF‐573,228 at inhibiting GC cell invasion through the suppression of integrin β1/FAK signaling. These results suggest that CXCL12 derived from CAFs promotes GC cell invasion by enhancing the clustering of integrin β1 in GC cells, resulting in GC progression. Taken together, the inhibition of CXCL12/CXCR4 signaling in GC cells may be a promising therapeutic strategy against GC cell invasion.  相似文献   
106.
Since the prognosis of small cell lung cancer (SCLC) remains poor, development of new therapeutic approaches, including immunotherapies, would be desirable. In the current study, to evaluate immunological responses in refractory SCLC patients, we conducted a small scale phase II clinical trial of personalized peptide vaccination (PPV), in which vaccine antigens are selected based on pre-existing host immunity. Ten refractory SCLC patients, who had failed to respond to chemo- and/or chemoradiotherapies (median number of regimens, 2.5; median duration, 20.5 months), were enrolled. A maximum of four human leukocyte antigen (HLA)-matched peptides showing higher antigen-specific humoral responses were subcutaneously administered (weekly for six consecutive weeks and then bi-weekly thereafter). PPV was terminated before the 3rd administration in four patients because of rapid disease progression, whereas the remaining six patients completed at least one cycle (six times) of vaccinations. Peptide-specific immunological boosting was observed in all of the six patients at the end of the first cycle of vaccinations, with their survival time of 25, 24.5 (alive), 10 (alive), 9.5, 6.5, and 6 months. Number of previous chemotherapy regimens and frequency of CD3(+) CD26(+) cells in peripheral blood were potentially prognostic in the vaccinated patients (hazard ratio [HR] = 2.540, 95% confidence interval [CI] = 1.188-5.431, P = 0.016; HR = 0.941, 95% CI = 0.878-1.008, P = 0.084; respectively). Based on the feasible immune responses in refractory SCLC patients who received at least one cycle (six times) of vaccinations, PPV could be recommended for a next stage of larger-scale, prospective clinical trials.  相似文献   
107.
A 58-year-old man was diagnosed as having type 3 gastric cancer (poorly differentiated adenocarcinoma). He underwent total gastrectomy with splenectomy, as well as D3 dissection, and received postoperative chemotherapy combining oral uracil and futrafur (UFT) with cisplatin (CDDP), but results showed recurrence of multiple abdominal lymph node metastases around the aorta. He therefore received various anticancer drug regimens (irinotecan [CPT-11]/CDDP; 1 M tegafur-0.4 M gimeracil-1 M oteracil potassium [TS-1], methotrexate (MTX)/5-fluorouracil); however, final results showed growth of lymph node metastasis and simultaneous worsening of his general condition. The patient then received combined administration of doxifluridine (5′-DFUR)/docetaxel (5′-DFUR, 1000 mg/body [666.7 mg/m 2 ], given by consecutive daily administration, orally, for days 1–14; and docetaxel, 80 mg/body [60 mg/m 2 ], on day 8, by venous drip, every 3 weeks). Three courses of this regimen resulted in approximately 90% reduction of the abdominal lymph node size, disappearance of the right cervical lymph node metastasis, reductions of the levels of two tumor markers (carcinoembryonic antigen [CEA] and carbohydrate antigen [CA]19-9), and improvement of his general condition. In total, seven courses of the regimen were carried out. The patient died on day 298 after starting this combined regimen and showed a response period of 126 days. The primary toxicity identified was neutropenia (grade 4), as well as other low-grade (grade 1, 2) hematological and nonhematological toxicities. In the field of gastric cancer treatment, especially for patients showing multiple resistance to anticancer drugs, an effective therapy is critically needed. Received: January 15, 2002 / Accepted: July 8, 2002 Offprint requests to: A. Sato  相似文献   
108.
Our previous studies demonstrated that specific inhibition of the BIG3‐PHB2 complex, which is a critical modulator in estrogen (E2) signaling, using ERAP, a dominant negative peptide inhibitor, leads to suppression of E2‐dependent estrogen receptor (ER) alpha activation through the reactivation of the tumor suppressive activity of PHB2. Here, we report that ERAP has significant suppressive effects against synergistic activation caused by the crosstalk between E2 and growth factors associated with intrinsic or acquired resistance to anti‐estrogen tamoxifen in breast cancer cells. Intrinsic PHB2 released from BIG3 by ERAP effectively disrupted each interaction of membrane‐associated ERα and insulin‐like growth factor 1 receptor beta (IGF‐1Rβ), EGFR, PI3K or human epidermal growth factor 2 (HER2) in the presence of E2 and the growth factors IGF or EGF, followed by inhibited the activation of IGF‐1Rβ, EGFR or HER2, and reduced Akt, MAPK and ERα phosphorylation levels, resulting in significant suppression of proliferation of ERα‐positive breast cancer cells in vitro and in vivo. More importantly, combined treatment with ERAP and tamoxifen led to a synergistic suppression of signaling that was activated by crosstalk between E2 and growth factors or HER2 amplification. Taken together, our findings suggest that the specific inhibition of BIG3‐PHB2 is a novel potential therapeutic approach for the treatment of tamoxifen‐resistant breast cancers activated by the crosstalk between E2 and growth factor signaling, especially in premenopausal women.  相似文献   
109.
Aims/IntroductionThe bone mineral density in patients with type 1 diabetes mellitus is reduced due to impaired insulin secretion. However, it is unclear whether the rate of bone mineral density reduction is affected by the type 1 diabetes mellitus subtype. This study aimed to clarify the difference in bone mineral density across type 1 diabetes mellitus subtypes: slowly progressive (SP), acute‐onset (AO), and fulminant (F).MethodsThis was a retrospective, single‐center, cross‐sectional study conducted on 98 adult type 1 diabetes mellitus patients. The main outcome included the bone mineral density Z‐score (BMD‐Z) measured at the lumbar spine and femoral neck.ResultsThe lumbar spine BMD‐Z was lower in the acute‐onset than in the slowly progressive subtype (P = 0.03). No differences were observed when compared with the fulminant subtype. The femoral neck BMD‐Z tended to be higher in the slowly progressive than in the acute‐onset and fulminant subtypes. Multiple regression analyses showed that the lumbar spine BMD‐Z was associated with subtypes (AO vs SP) (P = 0.01), but not subtypes (F vs SP), adjusted for sex, duration, retinopathy, and C‐peptide immunoreactivity (CPR). When the patients were divided into disease duration tertiles, in the first and second tertiles, the CPR levels were lower in the acute‐onset or fulminant than in the slowly progressive subtype. In contrast, the lumbar spine and femoral neck BMD‐Z differed between the acute‐onset and slowly progressive only in the second tertiles (both P < 0.01), with a similar tendency between the fulminant and slowly progressive subtypes.ConclusionsAmong the type 1 diabetes mellitus subtypes, bone mineral density undergoes time‐dependent changes, which reveals that the bone mineral density decline follows the impaired insulin secretion. These results provide novel insights into the association between the low insulin exposure duration and bone mineral density.  相似文献   
110.
Objective To examine the continuation of antibody prevalence status after 12 months and background factors in antibody-positive subjects following asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods We initially determined the SARS-CoV-2 anti-nucleocapsid protein immunoglobulin G (anti-N IgG) antibody prevalence in 1,603 patients, doctors, and nurses at 65 medical institutions in Kanagawa Prefecture, Japan. We then obtained consent from 33 of the 39 subjects who tested positive and performed follow-up for 12 months. Results Follow-up for up to 12 months showed that a long-term response of the anti-N IgG antibody could be detected in 6 of the 33 participants (18.2%). The proportions with hypertension, using an angiotensin-receptor blocker, and without a drinking habit were higher among the participants with a long-term anti-N IgG antibody response for up to 12 months than among those without a long-term antibody response. Conclusions The proportion of individuals with subclinical COVID-19 who continuously had a positive result for the anti-N IgG antibody at 12 months was low.  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-23

京公网安备 11010802026262号