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   2042篇
  免费   96篇
  国内免费   18篇
耳鼻咽喉   21篇
儿科学   37篇
妇产科学   12篇
基础医学   276篇
口腔科学   45篇
临床医学   100篇
内科学   473篇
皮肤病学   23篇
神经病学   208篇
特种医学   99篇
外科学   436篇
综合类   6篇
预防医学   43篇
眼科学   18篇
药学   127篇
中国医学   11篇
肿瘤学   221篇
  2023年   11篇
  2022年   28篇
  2021年   38篇
  2020年   19篇
  2019年   33篇
  2018年   41篇
  2017年   38篇
  2016年   33篇
  2015年   43篇
  2014年   53篇
  2013年   60篇
  2012年   99篇
  2011年   152篇
  2010年   82篇
  2009年   69篇
  2008年   127篇
  2007年   128篇
  2006年   136篇
  2005年   117篇
  2004年   138篇
  2003年   125篇
  2002年   117篇
  2001年   55篇
  2000年   50篇
  1999年   32篇
  1998年   34篇
  1997年   14篇
  1996年   22篇
  1995年   17篇
  1994年   16篇
  1993年   12篇
  1992年   23篇
  1991年   13篇
  1990年   15篇
  1989年   16篇
  1988年   21篇
  1987年   20篇
  1986年   14篇
  1985年   13篇
  1984年   9篇
  1983年   12篇
  1982年   4篇
  1981年   6篇
  1980年   3篇
  1979年   13篇
  1978年   8篇
  1977年   3篇
  1975年   4篇
  1973年   3篇
  1961年   2篇
排序方式: 共有2156条查询结果,搜索用时 296 毫秒
1.
The aim of this study was to evaluate whether the lesion regression rate (ΔLR) based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria could be used for the prediction of treatment outcome in head and neck squamous cell carcinoma (HNSCC) patients treated with chemoradiotherapy (CRT) compared with FDG PET-CT. A total of 33 patients underwent MRI and PET-CT at pretreatment and at 8 weeks after CRT. We assessed the treatment outcome by analyzing the following parameters: the RECIST criteria, ΔLR, the European Organization for Research and Treatment of Cancer (EORTC) criteria, and pretreatment SUVmax of the primary tumor and node. The correlation between the analysis of the parameters and the results of the long-term follow-up of the patients was determined. The RECIST did not significantly correlate with locoregional control (LRC) or survival. The ΔLR was significantly lower for the lesions with locoregional failure (LRF) than for those with LRC. A threshold ΔLR of 48% revealed a sensitivity of 72.7% and specificity of 77.3% for the prediction of LRF. Progression-free survival (PFS) of patients with ΔLR ≥ 48% was significantly better than that of patients with ΔLR < 48% (P = 0.001), but not overall survival. There was a significant correlation between LRC and the EORTC (P = 0.02). The patients who achieved a complete response by the EORTC criteria showed significantly better PFS and overall survival (P = 0.01 and 0.04, respectively). The ΔLR was inferior to FDG PET-CT with respect to the prediction of patient survival; however, it may be useful for selecting patients in need of more aggressive monitoring after CRT.  相似文献   
2.
Background: Olfactory neuroblastoma is a rare sino‐nasal tumor arising from the olfactory epithelium and is often characterized by local invasion or metastasis. The role of chemotherapy in the treatment of this tumor is unclear. The purpose of this study was to review our institution’s experience of chemotherapy for advanced or recurrent olfactory neuroblastoma. Methods: Twenty‐one patients with histologically proven olfactory neuroblastoma were treated at our institution between 1992 and 2002. Twelve of these patients received chemotherapy in the setting of unresectable or recurrent disease and were retrospectively reviewed for clinical characteristics, treatment outcome or survival. Results: Eight patients of the 12 patients received cisplatin‐based chemotherapy and the remaining four patients received chemotherapy consisting of docetaxel plus irinotecan (three patients) or cyclophosphamide, doxorubicin, and vincristine (1 patient). A partial response was achieved in five patients, with an overall response rate of 42%, although the chemotherapeutic regimens were heterogeneous. Two partial responses were obtained among the three patients who received docetaxel plus irinotecan. The response rate to chemotherapy was 83% in the younger age group (<40 years), as opposed to 0% in the older age group (≥40 years), and the difference between the two groups was statistically significant (P = 0.02). Conclusion: Our study indicated that olfactory neuroblastoma would be sensitive to chemotherapy, especially with young patients. Docetaxel plus irinotecan has the possibility of showing favorable response, and warrants further investigation.  相似文献   
3.
Recently an essential role of interstitial cells of Cajal (ICC) within myenteric plexus (ICC-MY) was suggested in ascending contraction and descending relaxation in the mouse ileum. The role of ICC in these neural reflexes was examined in the distal colonic segments prepared from the wild type and c-kit mutant, W/W(V) mice, in the present study. Localized distension of the segments from the wild type mice by using a small balloon resulted in ascending contraction and descending relaxation. In the segments from the mutant mice, localized distension also induced these neural reflexes similar to those observed in the wild type mice. Immunohistochemical examination demonstrated that ICC-MY and ICC present in muscle layers (ICC-IM) were severely disrupted in the mutant mouse, but only ICC, present within submucosal plexus (ICC-SMP), remained unchanged. In the small strips with ICC-SMP absent prepared from the mutant mouse, electrical field stimulation induced contraction or relaxation in the absence or presence of atropine, respectively. It was suggested that ICC have no important role in the ascending and descending neural reflexes in the mouse distal colon, this is in direct contrast to the role of ICC-MY in the ileum.  相似文献   
4.
5.
Laparoscopic surgery has been widely performed for removing the gallbladder and the pelvic lymph-nodes in recent years. We have applied laparoscopy technique to nephrectomy and here we describe our procedures and the clinical results. The patient is placed in the supine position under general anesthesia. After a 4 liter CO2 pneumoperitoneum is induced, five trocars are inserted into the abdominal cavity through the ipsilateral abdominal wall. The patient is then turned to the lateral position to displace the bowel medially. The ipsilateral colon is reflected medially after incision of the parietal peritoneum was made along the line of Todt to expose the retroperitoneum. The ureter was identified and dissected. It was secured with 4 clips (2 clips on the renal side and 2 on the distal side) and then cut with scissors. The renal vein and artery were then dissected and separately ligated with clips as described above. These vessels were also cut. The upper pole of the kidney was dissected out and the adrenal gland was left in place. The kidney thus became completely free within the abdomen. It was then grasped by the forceps through a 10 mm sheath positioned below the umbilicus. After incising the abdominal wall, the kidney was removed from the abdominal cavity with the grasping forceps and the sheath. By this procedure right nephrectomy was completely performed in a 56-year-old female patient and left nephrectomy in a 56-year-old male patient. The underlying disease was recurrent pyelonephritis secondary to renal calculi in both cases. The operative times were 221 min and 346 min, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
6.
Abstract: Suitable evaluation systems are critical for ranking various biomaterials in order to develop a method to design and synthesize nonthrombogenic biomaterials. We have recently developed an in vitro test system to evaluate platelet/biomaterial interactions in whole blood. The system consists of a parallel plate flow cell and epifluorescent video microscopy (EVM). A glass coverslip coated with a polymer was incorporated into the flow cell, and blood was perfused using a syringe pump via a polymer–coated PVC tubing connected to the flow cell. Whole human blood was anticoagulated with heparin (2 U/ml), and the platelets were labeled with the fluorescent dye mepacrine (5 μM). This system permitted real–time and dynamic observations of platelet/biomaterial interactions in whole blood under a defined flow condition. In order to evaluate the feasibility of this system, two different segmented polyether–polyurethanes (SPEUs), PU–PTMG(650) and PU–PTMG(2000), were chosen as test polymers. Surface characteristics verified with electron spectroscopy for chemical analysis (ESCA) and contact angle measurements showed similar results in both SPEUs. Blood was perfused at a wall shear rate of 200 s–1 for 20 min. Excitation light was applied for 2 s at 1 min intervals. The real–time image was then analyzed at each time point for the percentage of surface area of platelet coverage. Plasma β–thromboglobulin (β–TG) levels were also measured before and after each run. PU–PTMG(650) showed a significantly higher number of adhered platelets than PU–PTMG(2000) at each time point. β–TG levels of PU–PTMG(650) were also higher than those of PU–PTMG(2000), which is comparable to the results of EVM. Thus, this EVM system has been proven to be an excellent and highly sensitive in vitro analytical method for evaluating platelet/biomaterial interactions.  相似文献   
7.
This report describes the use of transluminal endovascular grafting for the treatment of a presumed aortoduodenal fistula. The patient was a 71-year-old man who had undergone resection and graft replacement for an abdominal aortic aneurysm. Three years after operation, melena was caused by perforation of the duodenal wall by a pseudoaneurysm at the proximal graft anastomosis. The pseudoaneurysm was treated by transluminal endovascular grafting. The pseudoaneurysm was subsequently thrombosed and absorbed. The ulcer-like lesions at the site of the duodenal wall perforated by the pseudoaneurysm also resolved. Endovascular stent-grafts may have a role to play in management of aortoduodenal fistula.  相似文献   
8.
9.
The possibility that idiotypes (Ids) defined on anti-double stranded DNA (dsDNA) antibodies during active and inactive stages of lupus (1/84 Id and 4/90 Id, respectively) were expressed on anti-DNA antibodies during a subsequent active period (9/90) of the disease was investigated in a lupus patient with lupus cerebritis. Using rabbit (R)-anti-Ids specific to 1/84 Id and 4/90 Id in inhibition assays, the 4/90 Id was shown to be expressed on the framework regions of anti-single stranded DNA (ssDNA) but poorly on co-existing anti-dsDNA antibodies of active (9/90) stage. The 1/84 Id was poorly expressed on both types of 9/90 anti-DNA antibodies. While the 9/90 anti-ssDNA significantly bound to immobilized ssDNA and several single-stranded polynucleotides, only ssDNA inhibited the binding of the anti-ssDNA to ssDNA, suggesting its monospecificity toward ssDNA. Western blot analysis following isoelectric focusing showed that a spectrotype pattern of 4/90 Id-positive 9/90 anti-ssDNA IgG was similar to that of the 4/90 anti-dsDNA, suggesting that they are of related clonal origin. The present study suggests the idiotypic heterogeneity of anti-DNA antibodies and the shift of antigen specificity within an idiotypically related anti-DNA population during exacerbation of the disease.  相似文献   
10.
Objects We evaluated whether the presence of lacunar skull deformity (LSD) with myelomeningocele is a predictive factor for subsequent hydrocephalus development. Materials and methods We reviewed the clinical and radiological records of 18 infants with myelomeningocele, divided the patients into groups with (group A, n=9) and without (group B, n=9) ventriculomegaly at birth and assessed whether the presence of LSD was predictive of the necessity for ventriculoperitoneal shunt (VPS) placement. Results LSD was present in five group A patients. All nine group A patients underwent VPS placement. Among the group B patients, five had LSD; they underwent VPS placement. A significantly higher proportion of those with ventricle enlargement or LSD at birth required VPS placement (p=0.0001). Conclusion Adding to the ventriculomegaly at birth, the presence of LSD alerts to the necessity to monitor these infants closely to determine the necessity for VPS placement.  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