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   1141篇
  免费   38篇
  国内免费   1篇
耳鼻咽喉   14篇
儿科学   93篇
妇产科学   50篇
基础医学   85篇
口腔科学   56篇
临床医学   91篇
内科学   224篇
皮肤病学   23篇
神经病学   47篇
特种医学   33篇
外科学   208篇
综合类   10篇
预防医学   23篇
眼科学   16篇
药学   23篇
中国医学   6篇
肿瘤学   178篇
  2024年   2篇
  2023年   8篇
  2022年   13篇
  2021年   33篇
  2020年   39篇
  2019年   38篇
  2018年   36篇
  2017年   24篇
  2016年   35篇
  2015年   38篇
  2014年   40篇
  2013年   58篇
  2012年   92篇
  2011年   76篇
  2010年   52篇
  2009年   60篇
  2008年   87篇
  2007年   93篇
  2006年   85篇
  2005年   70篇
  2004年   79篇
  2003年   55篇
  2002年   45篇
  2001年   3篇
  2000年   4篇
  1999年   2篇
  1997年   4篇
  1995年   1篇
  1994年   1篇
  1992年   4篇
  1991年   2篇
  1990年   1篇
排序方式: 共有1180条查询结果,搜索用时 187 毫秒
61.
The location and incidence of the zygomaticofacial foramen (ZFF) was studied in 80 dry skulls (160 sides) of unsexed adult skulls of West Anatolian people. The average distances from the ZFF to the frontozygomatic suture, to the zygomaticomaxillary suture, and to the inferior orbital rim were found to be 26.2 ± 3.2 mm, 18.6 ± 3.14 mm, and 5.94 ± 1.43 mm, respectively. The zygomas were evaluated for the number of foramina on their facial aspects. There was none in 25 (15.6%), one in 71 (44.4%), two in 45 (28.1%), three in 10 (6.3%), four in seven (4.4%), and five in two (1.3%) sides. The ZFF was also studied for its distribution around the zygoma by dividing the surface into four anatomical areas. There was no statistical difference between the morphometrical results on both sides. Data regarding the location and variation in the number of the ZFF is important in avoiding zygomatic nerve and vessel injury during surgery, but by virtue of the great variability found, ZFF is an unreliable landmark for maxillofacial surgery. Clin. Anat. 22:559–562, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   
62.
63.
BACKGROUND: To distinguish true local recurrences (TR) from new primary tumors (NP) and to assess whether this distinction has prognostic value in patients who develop ipsilateral breast tumor recurrences (IBTR) after breast-conserving surgery and radiotherapy. METHODS: Between 1970 and 1994, 1339 patients underwent breast-conserving surgery at The University of Texas M. D. Anderson Cancer Center for ductal carcinoma in situ or invasive carcinoma. Of these patients, 139 (10.4%) had an IBTR as the first site of failure. For the 126 patients with clinical data available for retrospective review, we classified the IBTR as a TR if it was located within 3 cm of the primary tumor bed and was of the same histologic subtype. All other IBTRs were designated NP. RESULTS: Of the 126 patients, 48 (38%) patients were classified as NP and 78 (62%) as TR. Mean time to disease recurrence was 7.3 years for NP versus 5.6 years for TR (P = 0.0669). The patients with NP had improved 10-year rates of overall survival (NP 77% vs. TR 46%, P = 0.0002), cause-specific survival (NP 83% vs. TR 49%, P = 0.0001), and distant disease-free survival (NP 77% vs. TR 26%, P < 0.0001). Patients with NP more often developed contralateral breast carcinoma (10-year rate: NP 29% vs. TR 8%, P = 0.0043), but were less likely to develop a second local recurrence after salvage treatment of the first IBTR (NP 2% vs. TR 18%, P = 0.008). CONCLUSIONS: Patients with NP had significantly better survival rates than those with TR, but were more likely to develop contralateral breast carcinoma. Distinguishing new breast carcinomas from local disease recurrences may have importance in therapeutic decisions and chemoprevention strategies. This is because patients with new carcinomas had significantly lower rates of metastasis than those with local disease recurrence, but were more likely to develop contralateral breast carcinomas.  相似文献   
64.
PURPOSE: The aim of this study was to evaluate the changes in salivary gland function in patients with chronic renal failure (CRF) undergoing hemodialysis. METHODS: The group consisted of 23 patients with CRF (13 female, 10 male; mean age: 40 +/- 13 yr) and 14 healthy control subjects (mean age: 40 +/- 13 yr). All underwent dynamic salivary gland scintigraphy with gustatory stimulation. After intravenous administration of 99mTc pertechnetate, first, perfusion images at 2 seconds per frame were acquired for 1 minute, then dynamic images at 1 minute per frame were acquired for 45 minutes. At 30 minutes after injection, 10 ml lemon juice was given for 15 minutes as a gustatory stimulus. We obtained time-activity curves derived from regions of interest centered over the four major salivary glands. The following functional indices were calculated for each gland: the time of maximum radioactivity (Tmax) for the prestimulated period, the time of minimum radioactivity (Tmin), as an indicator of velocity of secretion after stimulation, and the Lem E5% value as an indicator of the secretion function. RESULTS: When the patients with CRF undergoing hemodialysis were compared to the controls, there were statistically significant differences in Tmax, Tmin and Lem E5% values for bilateral parotid glands, and Tmin values for bilateral submandibular glands (p < 0.05), there were no statistically significant differences in Tmax and Lem E5% values for bilateral submandibular glands. There were also significant differences in Tmax and Lem E5% values for bilateral parotid glands between mild oral problems and severe oral problems in patients with CRF (undergoing hemodialysis). CONCLUSION: In this study, prolonged Tmax and Tmin values, and decreased Lem E5% values for parotid glands and prolonged Tmin values for submandibular glands on salivary scintigraphy pointed out decreased parenchymatous and excretory function in patients with CRF undergoing hemodialysis.  相似文献   
65.
BACKGROUND: Intracystic papillary carcinoma (IPC) of the breast is a rare form of noninvasive breast cancer. An appreciation of associated pathology with IPC may be critical in surgical decision-making. METHODS: The medical records of all patients with IPC treated between 1985 and 2001 were retrospectively reviewed. Three patient groups were identified according to the pathologic features of the primary tumor: IPC alone, IPC with associated ductal carcinoma in situ (DCIS), and IPC with associated invasion with or without DCIS. Types of treatment and outcomes were compared between groups. RESULTS: Forty patients were treated for IPC during the study period. Fourteen had pure IPC, 13 had IPC with DCIS, and 13 had IPC with invasion. The incidence of recurrence and the likelihood of dying of IPC did not differ between the three groups regardless of the type of surgery (mastectomy or segmental mastectomy) performed and whether radiation therapy was administered. The disease-specific survival rate was 100%. CONCLUSIONS: When IPC is identified, it is frequently associated with DCIS and or invasion. Standard therapy should be based on associated pathology. The role of radiation therapy in pure IPC remains to be determined.  相似文献   
66.
Background Our aim was to identify predictors of locoregional recurrence (LRR) in patients with early-stage breast cancer treated with breast-conserving therapy (BCT) and long-term follow-up. Methods From 1970 to 1994, 1153 patients with stage I to II breast cancer underwent BCT and radiotherapy at our institution. Patients with prior breast cancer or other primary malignancies were excluded. Clinical and pathologic characteristics evaluated were age, race, tumor size, stage, pathologic tumor margins, axillary nodal involvement, estrogen and progesterone receptor status, Black's nuclear grade, type of surgery, and use of adjuvant therapy. Results Of 1083 patients, 54% presented with stage I disease and 46% with stage II disease. Median age was 50 years, and median follow-up was 9 years. Axillary nodes were positive in 31% of the patients who underwent axillary dissection. LRR developed in 6%, LRR followed by systemic recurrence in 5%, and systemic recurrence alone in 13%, 76% had no evidence of recurrence at last follow-up. Age, tumor size, positive lymph nodes, and not receiving chemotherapy or hormonal therapy were independent predictors of LRR. Disease-specific survival among patients with LRR was similar to that among patients with no recurrence. Conclusions Multidisciplinary treatment strategies should be used to accomplish durable locoregional control after BCT. Presented at the 54th Annual Cancer Symposium of the Society of Surgical Oncology, Washington, DC, March 15–18, 2001.  相似文献   
67.
Background Breast-conservation surgery plus radiotherapy has become the standard of care for early-stage breast cancer; we evaluated its long-term complications. Methods We selected patients treated with surgery and radiotherapy between January 1990 and December 1992 (an era in which standard radiation dosages were used) with follow-up for at least 1 year. Patients were prospectively monitored for treatment-related complications. Median follow-up time was 89 months. Results A total of 294 patients met the selection criteria. Grade 2 or higher late complications were identified in 29 patients and included arm edema in 13 patients, breast skin fibrosis in 12, decreased range of motion in 4, pneumonitis in 2, neuropathy in 2, fat necrosis in 1, and rib fracture in 1. Arm edema was more common after lumpectomy plus axillary node dissection than after lumpectomy alone. Arm edema occurred in 18% of patients who underwent surgery plus irradiation of the lymph nodes and 10% who underwent surgery without nodal irradiation. Conclusions Breast-conservation surgery plus radiotherapy was associated with grade 2 or higher complications in only 9.9% of patients. Half of these complications were attributable to axillary dissection, it is hoped that lower complication rates can be achieved with sentinel lymph node biopsy.  相似文献   
68.
69.
Background: Although preoperative chemotherapy has become the standard of care for inoperable locally advanced breast cancer, its role for downstaging resectable primary tumors is still evolving. The purpose of this study was to determine whether the prognostic information from an axillary node dissection in patients with clinical T3N0 breast cancer was altered by preoperative chemotherapy compared with surgery de novo.Methods: Between 1976 and 1994, 91 patients with clinically node-negative operable T3 breast cancer received doxorubicin-based combination chemotherapy on protocol at one institution. Fifty-three patients received both preoperative and postoperative chemotherapy (PreopCT), and 38 received postoperative chemotherapy only (PostopCT). All patients underwent axillary lymph node dissection as part of their definitive surgical treatment. There were no differences between the PreopCT and PostopCT groups in median age (51 vs. 49 years), median tumor size at presentation (6 cm vs. 6 cm), tumor grade, or estrogen receptor status (estrogen receptor negative 38% vs. 32%). The median follow-up time was 7 years.Results: Patients in the PreopCT group had fewer histologically positive lymph nodes (median, 0 vs. 3, P < .01), and a lower incidence of extranodal extension (19% vs. 42%, P 5 .02). By univariate analysis, the number of pathologically positive lymph nodes (P < .01) and extranodal extension (P < .01) were predictors of disease-specific survival in PreopCT patients. Multivariate analysis showed that extranodal extension was the only independent prognostic factor in PreopCT patients (P < .01). Overall, PreopCT and PostopCT patients had similar 5-year disease-free survival rates (66% vs. 57%); however, PreopCT patients had worse disease-free (P 5 .01) and diseasespecific survival (P 5 .04) when survival was compared after adjustment for the number of positive lymph nodes. Furthermore, PreopCT patients with 4–9 positive lymph nodes had a lower 5-year disease-free survival rate than PostopCT patients with 4–9 positive nodes (17 vs. 48%, P 5 .04).Conclusions: Axillary lymph node status remains prognostic after chemotherapy. Pathologically positive lymph nodes after preoperative chemotherapy are associated with a worse prognosis than the same nodal status before chemotherapy.  相似文献   
70.
Background: This retrospective study was performed to assess the outcome among patients who underwent hepatic resection or tumor ablation after hepatic artery infusion (HAI) therapy downstaged previously unresectable hepatocellular carcinoma (HCC) or liver metastases from colorectal cancer (CRC).Methods: Between 1983 and 1998, 25 patients with HCC and 383 patients with hepatic CRC metastases were treated with HAI therapy for unresectable liver disease. We retrospectively reviewed the records of 26 (6%) of these patients who underwent subsequent surgical exploration for tumor resection or ablation.Results: At a median of 9 months (range 7–12 months) after HAI treatment, four patients (16%) with HCC underwent exploratory surgery; two underwent resection with negative margins, and the other two were given radiofrequency ablation (RFA) because of underlying cirrhosis. At a median postoperative follow-up of 16 months (range 6–48 months), all four patients were alive with no evidence of disease. At a median of 14.5 months (range 8–24 months) after HAI therapy, 22 patients with hepatic CRC metastases underwent exploratory surgery; 10 underwent resection, 6 underwent resection and RFA or cryotherapy, and 2 underwent RFA only. At a median follow-up of 17 months, 15 (83%) of the 18 patients with CRC who had received surgical treatment had developed recurrent disease; the other 3 died of other causes (1 of postoperative complications) within 7 months of the surgery. One patient in whom disease recurred underwent a second resection and was disease-free at 1 year follow-up.Conclusions: Hepatic resection or ablation after tumor downstaging with HAI therapy is a viable option for patients with unresectable HCC. However, given the high rate of recurrence of metastases from CRC, hepatic resection or ablation after downstaging with HAI should be used with caution.Presented at the 53rd Annual Meeting of the Society of Surgical Oncology, New Orleans, Louisiana, March 16–19, 2000.  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