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   1670篇
  免费   79篇
  国内免费   3篇
耳鼻咽喉   4篇
儿科学   67篇
妇产科学   12篇
基础医学   172篇
口腔科学   30篇
临床医学   119篇
内科学   551篇
皮肤病学   48篇
神经病学   118篇
特种医学   40篇
外科学   278篇
综合类   9篇
预防医学   55篇
眼科学   11篇
药学   69篇
中国医学   2篇
肿瘤学   167篇
  2023年   10篇
  2022年   13篇
  2021年   26篇
  2020年   18篇
  2019年   27篇
  2018年   33篇
  2017年   23篇
  2016年   25篇
  2015年   14篇
  2014年   32篇
  2013年   43篇
  2012年   52篇
  2011年   53篇
  2010年   37篇
  2009年   26篇
  2008年   61篇
  2007年   59篇
  2006年   60篇
  2005年   90篇
  2004年   73篇
  2003年   55篇
  2002年   70篇
  2001年   77篇
  2000年   95篇
  1999年   72篇
  1998年   21篇
  1997年   12篇
  1996年   14篇
  1995年   18篇
  1994年   20篇
  1993年   17篇
  1992年   40篇
  1991年   65篇
  1990年   48篇
  1989年   34篇
  1988年   41篇
  1987年   27篇
  1986年   31篇
  1985年   32篇
  1984年   17篇
  1983年   19篇
  1979年   9篇
  1978年   10篇
  1975年   14篇
  1974年   8篇
  1973年   11篇
  1971年   16篇
  1970年   15篇
  1969年   9篇
  1966年   7篇
排序方式: 共有1752条查询结果,搜索用时 15 毫秒
61.
In this study, we investigated the process of supernumerary upper incisor formation in the Pax6 mutant rat, rSey(2)/rSey(2), which exhibits a facial cleft between the medial nasal and maxillary processes. Histological investigation and epithelial labeling studies of wild type rat embryos indicated that the upper incisor develops by fusion of two primary dental placodes (PDPs) in the medial nasal process with a contribution from the epithelium of the maxillary process. In the rSey(2)/rSey(2) embryo, both PDPs are formed but they stay apart, then subsequently these PDPs independently develop into upper incisor tooth buds. In order to examine if the failure of the two placodes to fuse is due to the cleft between the maxillary and medial nasal processes, maxillary and medial nasal process fusion was inhibited with a barrier in wild type embryos. This resulted in the maintenance of the two distinct PDPs. These results demonstrate that fusion of the facial processes reduces the number of odontogenic placodes and is required to assemble all components at one site for rat upper incisor formation. The results also provide further insight into the mechanism of supernumerary incisor formation in human cleft lip conditions.  相似文献   
62.
T Maeda  M Eto  Y Nishimura  K Nomoto  Y Y Kong    K Nomoto 《Immunology》1993,78(1):113-121
It has previously been reported that a single i.p. injection of 200 mg/kg cyclophosphamide (CP) 2 days after priming with 10(8) donor spleen cells (SC) leads to donor-specific skin allograft tolerance in H-2 compatible, multiminor antigen incompatible murine strain combinations. It is speculated that the i.v. injection of donor cells may result in synchronized proliferation of donor-reactive host T cells and subsequently administered CP may specifically destroy these proliferating T cells in the periphery. Although this unique action of CP is considered to be a principal mechanism in this method, direct evidence has not yet been obtained. In the present article, this in vivo destructive effect of CP is clearly demonstrated by assessing detailed kinetics of host-derived blastoid T cells and donor (Mls-1a)-reactive V beta 6+ T cells in the model system of C3H mice rendered tolerant to AKR. Frequencies of the blastoid cells and V beta 6+ cells, which increased as a result of AKR priming, decreased rapidly with the administration of CP. C3H mice, which received AKR SC alone, also exhibited partial deletion of V beta 6+ T cells, but both tempo and magnitude of decrease in the frequency of V beta 6+ cells were quite different from those of the C3H mice given AKR SC and CP, which showed more rapid and profound elimination of V beta 6+ T cells. In accordance with these kinetic studies, in vitro proliferative response to Mls-1a antigens was greatly impaired in mice treated with SC and CP, whereas a low but appreciable response was detected in mice given SC alone.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
63.

Objective

We previously reported on the role of cytoreduction in 248 patients with surgical stage IVb endometrial cancer (EMCA). This study aimed to evaluate the clinical characteristics, prognosis according to initial treatment, and impact of preoperative chemotherapy in the overall population of patients with clinical and surgical stage IVb EMCA.

Methods

A multi-institutional retrospective analysis was performed in 426 patients diagnosed with clinical and surgical stage IVb EMCA from 1996 to 2005. Factors associated with overall survival (OS) were identified using univariate and multivariate analyses.

Results

The median OS for all 426 patients was 14 months. Patients were divided into three groups according to their initial treatment: primary surgery group (n = 279), primary chemotherapy group (n = 125), and palliative care group (n = 22). The median OS times for these groups were 21, 12, and 1 month, respectively (p < 0.0001). Patients in the primary surgery group had better performance status (PS) and lower numbers of extra-abdominal metastases than those in the primary chemotherapy group. Multivariate analysis identified good PS, endometrioid histology, absence of clinical intra-abdominal stage IVb metastasis, hysterectomy, and chemotherapy as independent predictors of OS. In the primary chemotherapy group, 59 patients subsequently underwent surgery, and these patients had similar OS to those in the primary surgery group.

Conclusions

Hysterectomy and chemotherapy may prolong OS in selected patients with stage IVb EMCA. Our data suggest that primary chemotherapy followed by surgery may be a useful treatment choice in patients not suitable for primary surgery.  相似文献   
64.
This study aimed to evaluate the optimal method for planning computed tomography (CT) for prostate cancer radiotherapy to avoid a dose difference of ≥3% between the actual and planned treatments using multiple acquisition planning CT (MPCT). We calculated the 3-dimensional (3D) displacement error between the pelvic bone and matching fiducial marker on MPCT and cone-beam CT scans of 25 patients who underwent prostate volumetric-modulated arc therapy for prostate cancer. The correlation of the 3D displacement error and the dose difference between planned and actual treatments was calculated using least squares second-order polynomial model. The 3D displacement error showed a moderate correlation with differences between planned and accumulated treatment doses (r = 0.587, p < 0.0001). Moreover, the improvement rate of the minimum 3D displacement error showed a strong correlation with the relative error between each MPCT image (r = 0.793, p < 0.0001). Significant differences were observed between planned and actual treatment doses (p < 0.0001) in the relative 3D displacement errors of <1 mm, 1 to 3 mm, and >3 mm. The 3D displacement error on MPCT (as the selection estimation index for optimal planning CT) is useful for monitoring patient-specific intensity-modulated radiation therapy quality assurance. This new method allows to estimate dose differences from the planned dose before commencing treatment, thereby ensuring high-quality therapy. As radiotherapy quality is critical for patient outcome, these findings may contribute to better management of prostate cancer.  相似文献   
65.
66.
Identification of the proteinaceous components of the pathological inclusions is an important step in understanding the associated disease mechanisms. We immunohistochemically examined two previously reported cases with eosinophilic neuronal cytoplasmic inclusions (NCIs) (case 1, Mori et al. Neuropathology 2010; 30: 648–53; case 2, Kojima et al. Acta Pathol Jpn 1990; 40: 785–91) using 67 antibodies against proteins related to cytoskeletal constituents, ubiquitin‐proteasome system, autophagy‐lysosome pathway and stress granule formation. Regional distribution pattern of eosinophilic NCIs in case 1 was substantially different from that in case 2. However, NCIs in both cases were immunonegative for ubiquitin and p62 and were immunopositive for stress granule markers as well as autophagy‐related proteins, including valosin‐containing protein. Considering that eukaryotic stress granules are cleared by autophagy and valosin‐containing protein function, our findings suggest that eosinophilic NCIs in the present two cases may represent the process of autophagic clearance of stress granules.  相似文献   
67.
M. Eto    K. Watanabe  K. Ishii 《Clinical genetics》1986,30(5):422-427
We have examined the apo E phenotype frequencies in the Japanese population (n = 576, 16-78 years of age). Apo E phenotypes were determined by the rapid flat gel isoelectric focusing method that we previously reported. The apo E phenotype frequencies in the Japanese were 0.3% for E2/2, 6.1% for E3/2, 71.9% for E3/3, 0.7% for E4/2, 19.3% for E4/3 and 1.7% for E4/4. The apo E allele frequencies were 0.037, 0.846 and 0.117 for the epsilon 2, epsilon 3 and epsilon 4 alleles, respectively. These frequencies were compared with those in the Caucasian populations (n = 3033) reported by Sing & Davignon (1985). There was a significant difference in the apo E phenotype frequencies between the Japanese and Caucasian populations. In addition, a significantly lower frequency of the epsilon 2 and epsilon 4 alleles and a significantly higher frequency of the epsilon 3 allele were found in the Japanese than those reported for the Caucasian populations. It is concluded that there is a racial difference in the apo E allele frequencies between the Japanese and Caucasian populations.  相似文献   
68.
BackgroundPerforming total hip arthroplasty (THA) as early as possible is recommended for rapidly destructive coxarthrosis (RDC) as it causes pain that becomes progressively more severe. However, acetabular bone loss remains an issue in THA. Special devices, such as a Kerboull-type plate, may be used for acetabular bone defects, but the procedure is highly invasive and often the patients are elderly, further complicating matters. We retrospectively investigated the clinical and radiographic results of THA using conventional hydroxyapatite-coated cementless cup in RDC.MethodsA total of 32 patients (35 hips) with RDC were enrolled in the study with a minimum 10-year follow-up. All THAs were performed using conventional hydroxyapatite-coated cementless cup. All patients were evaluated clinically according to the Harris hip score (HHS). Acetabular bone deficiency was classified according to the American Academy of Orthopaedic Surgeons (AAOS) classification.ResultsEleven hips (31%) were AAOS type III, and none were type IV. Total HHS significantly improved from 36.5 to 79.4 (p < 0.01). Two cups exhibited loosening. The overall implant-associated survival rate after 10 years was 91.4%.ConclusionsClinical results of THA using conventional cementless implants for patients with RDC were acceptable. Thus, THA using conventional cementless implant is an effective and safe surgery for patients with RDC, minimizing surgical stress.  相似文献   
69.

Purpose

Currently, several therapeutic options for castration-resistant prostate cancer (CRPC) are available, for which predictive biomarkers have not been established. Therefore, we aimed to reveal the association between pretreatment serum testosterone level and antitumor outcomes when treated with androgen receptor axis-targeting agents and taxane chemotherapies for CRPC.

Patients and methods

The present study included Japanese patients with metastatic prostate cancer whose serum testosterone levels during androgen-deprivation therapy were available. The antitumor outcomes when treated with enzalutamide, abiraterone, docetaxel, and cabazitaxel with clinicopathological parameters including serum testosterone levels during androgen-deprivation therapy, as well as prognoses including progression-free survival and overall survival, were examined.

Results

Progression-free survival among men with higher serum testosterone level was superior to that among men with lower serum testosterone level when treated with enzalutamide. On the contrary, progression-free survival and overall survival among men with higher serum testosterone level were significantly inferior to those among men with lower serum testosterone level when treated with docetaxel and cabazitaxel, respectively.

Conclusions

The present study indicated distinct prognostic values of serum testosterone level when treated with androgen receptor axis-targeting agent and taxane chemotherapy for CRPC, suggesting that serum testosterone level may be useful predictive biomarker to navigate the appropriate therapy in patients with CRPC.  相似文献   
70.
PURPOSE: Much attention has been paid to nonmyeloablative allogeneic stem cell transplantation for the treatment of renal cancer. We recently proposed a cyclophosphamide-using nonmyeloablative cell therapy in which donor lymphocyte infusion (DLI) was carried out after the tolerance induction to donor cells. In considering the clinical application of the cyclophosphamide-using cell therapy, attempts to reduce graft-versus-host disease (GVHD) are crucial. The aim of the present study was to modify the cyclophosphamide-using cell therapy to reduce the risk of GVHD while preserving the antitumor activity against renal cancer. EXPERIMENTAL DESIGN: We assessed whether a delay in performing DLI from day 1 to day 5 after the cyclophosphamide treatment could reduce the risk of GVHD while preserving antitumor activity against RENCA, a murine carcinogen-induced renal cell carcinoma, in the cyclophosphamide-using cell therapy. RESULTS: Regarding the in vivo antitumor effect, there was no difference between DLI on day 1 and day 5 after the cyclophosphamide treatment, whereas the histologic findings of the small intestine showed that the cyclophosphamide-using cell therapy with DLI on day 5 decreased the risk of GVHD. In addition, the acquired immunity against RENCA was also observed in the RENCA-rejected mice that had been treated with DLI on day 5. CONCLUSIONS: Our results show that a delay in DLI during cyclophosphamide-using nonmyeloablative cell therapy can dissociate graft-versus-tumor effects from GVHD by reducing the risk of GVHD.  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