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   1040篇
  免费   101篇
  国内免费   22篇
耳鼻咽喉   5篇
儿科学   45篇
妇产科学   100篇
基础医学   126篇
口腔科学   26篇
临床医学   99篇
内科学   185篇
皮肤病学   17篇
神经病学   95篇
特种医学   32篇
外科学   193篇
综合类   4篇
预防医学   42篇
眼科学   4篇
药学   39篇
肿瘤学   151篇
  2023年   5篇
  2022年   8篇
  2021年   15篇
  2020年   13篇
  2019年   18篇
  2018年   19篇
  2017年   24篇
  2016年   19篇
  2015年   42篇
  2014年   22篇
  2013年   44篇
  2012年   71篇
  2011年   57篇
  2010年   24篇
  2009年   34篇
  2008年   60篇
  2007年   58篇
  2006年   88篇
  2005年   70篇
  2004年   70篇
  2003年   68篇
  2002年   70篇
  2001年   7篇
  2000年   7篇
  1999年   7篇
  1998年   17篇
  1997年   7篇
  1996年   16篇
  1995年   14篇
  1994年   13篇
  1993年   12篇
  1992年   10篇
  1991年   11篇
  1990年   14篇
  1989年   6篇
  1988年   7篇
  1987年   9篇
  1986年   5篇
  1985年   8篇
  1984年   8篇
  1983年   8篇
  1982年   12篇
  1980年   4篇
  1978年   8篇
  1977年   4篇
  1976年   5篇
  1975年   6篇
  1974年   8篇
  1973年   8篇
  1967年   6篇
排序方式: 共有1163条查询结果,搜索用时 15 毫秒
91.
92.
93.
BACKGROUND: The authors conducted a randomized controlled trial to determine whether parental presence during induction of anesthesia (PPIA) is associated with parental physiologic and behavioral manifestations of stress. METHODS: Children and their parents (N = 80) were randomly assigned to one of three groups: (1) PPIA; (2) PPIA plus 0.5 mg/kg oral midazolam; and (3) control (no PPIA or midazolam). The effect of the group assignment on parental heart rate (HR), parental blood pressure, and parental skin conductance level (SCL) were assessed. Both parental HR and parental SCL were monitored continually. Anxiety of the parent and child was also assessed. RESULTS: Parental HR increased from baseline until the induction of anesthesia (P = 0.001). A group-by-time effect ( P= 0.005) was also found. That is, throughout the induction period there were several time points at which parents in the two PPIA groups had a significantly higher HR than did parents in the control group (P < 0.05). Similarly, SCL was found to increase in all parents from baseline until induction of anesthesia (P = 0.001). Significant group differences in SCL changes over time were found as well (P = 0.009). State anxiety and blood pressure following induction of anesthesia did not differ significantly between groups ( P= nonsignificant). Examination of parental Holter data revealed no rhythm abnormalities and no electrocardiogram changes indicating ischemia. CONCLUSIONS: The authors found that PPIA is associated with increased parental HR and SCL. However, no increased incidence of electrocardiogram abnormalities were found in parents present during induction of anesthesia.  相似文献   
94.
Wang SM  Caldwell-Andrews AA  Kain ZN 《Anesthesia and analgesia》2003,97(4):1010-5, table of contents
In a previous study, we indicated that 42% of surgical outpatients are interested in using acupuncture as a treatment modality for preoperative anxiety. We designed this follow-up survey to assess differences in attitude toward complementary-alternative medical therapies (CAM) between patients undergoing outpatient surgeries and those undergoing inpatient surgeries. The results indicate that most surgical patients (57.4%) use some form of CAM, including self-prayer (praying for their own health; 29%), chiropractic treatment (23%), massage therapy (15%), relaxation (14%), herbs (13%), megavitamins (9%), and acupuncture (7%). Inpatient surgical respondents reported using self-prayer more than outpatient surgical respondents, but no other differences in CAM use were found between inpatient and outpatient respondents. More inpatient respondents reported disclosing their usage of CAM to perioperative physicians than did outpatient respondents. Most surgical patients were willing to accept CAM as part of their perioperative management but were not willing to pay out-of-pocket for CAM treatment. The leading CAM therapies that fewer of the respondents were willing to pay for out-of-pocket included relaxation, massage, chiropractic medicine, herbs, and acupuncture. IMPLICATIONS: Most surgical patients use some form of complementary-alternative medical therapies (CAM) and are willing to accept CAM therapy as part of their perioperative management.  相似文献   
95.
Elevated fasting plasma total homocysteine concentration (tHcy) and lower vitamin status are associated with atherosclerotic states. Silent brain ischemic lesions and brain atrophy, prevailing in the elderly, are affected by tHcy and vitamin status. The study was performed on 56 outpatients who had undergone brain computed tomography (CT) before the onset of the study. According to brain CT evaluation, three groups were set: minor brain ischemia, brain atrophy and control. Brain CT, tHcy, plasma pyridoxal phosphate (PLP), vitamin B(12), folic acid and cognitive and functional capacities were measured or evaluated in all of the subjects. Plasma vitamin score for three vitamins was calculated. In subjects with minor brain ischemic lesions (n = 21), tHcy was higher by 5.6 microM, whereas vitamin score and cognitive function were lower than in controls (n = 24). In subjects with brain atrophy (n = 11), plasma PLP and cognitive function were lower. Particular attention should be paid to tHcy monitoring, vitamin status assessment and brain impairment evaluation.  相似文献   
96.
The expression of DCC protein in female breast cancer   总被引:5,自引:0,他引:5  
Background. The deleted in colorectal cancer (DCC) gene has been shown to be frequently deleted or its expression reduced or absent in glioblastomas, colorectal, gastro-intestinal, pancreatic and prostatic tumors. In the present study, we investigated the expression of DCC in surgical specimen from 75 patients with primary breast cancer. Methods. The expression of the DCC, estrogen receptors (ER), and progesterone receptors (PR) was studied in 75 surgical specimens of primary breast cancer using an immunohistochemical method. To evaluate the outcomes of the breast cancer patients, we followed up the patients during minimum of 10 years. Results. Reduced or loss of expression of DCC was identified in 45 out of 75 samples. There were significant differences between cases without metastasis or local recurrences versus these with metastasis or local recurrences (p = 0.006), and between patients alive with no evidence of malignancy versus those with recurrence or dead of disease (p = 0.005). There were no significant differences between the DCC status and age, sex, tumor location, stage, grade, or proportion of patients who received adjuvant therapy. Conclusions. These findings suggest that a decrease in DCC expression may influence the prognosis of breast carcinoma patients.  相似文献   
97.
BRAF oncogenic mutations have been identified in significant numbers of melanocytic lesions. To correlate BRAF mutation and melanoma progression, we screened BRAF mutations in 65 melanocytic lesions, including nevi, radial growth phase (RGP), vertical growth phase (VGP) melanomas, and melanoma metastases, as well as 25 melanoma cell lines. PCR and direct sequencing were used to analyze DNA samples extracted from laser capture microdissected tissues. A similar high frequency (62-72%) of BRAF oncogenic mutations was identified in melanocytic nevi, VGP, metastatic melanomas, and melanoma cell lines [H. Davies et al., Nature (Lond.), 417: 949-954, 2002; P. M. Pollock et al., Nat. Genet., 33: 19-20, 2002; and M. S. Brose et al., Cancer Res., 62: 6997-7000, 2002]. In striking contrast, we found BRAF lesions in only 10% of the earliest stage or RGP melanomas. These findings imply that BRAF mutations cannot be involved in the initiation of the great majority of melanomas but instead reflect a progression event with important prognostic implications in the transition from the great majority of RGP melanomas to VGP and/or metastatic melanoma.  相似文献   
98.
Background: Gastric slippage is a well-described complication of gastric banding. The Heliogast? band is equipped with a locking mechanism that enables its straightforward reopening and repositioning. Our experience with Heliogast? band salvage after anterior slippage is reported. Methods: The study sample comprised 418 consecutive patients who underwent 2-step laparoscopic gastric banding with the Lap-Band? first (n=235) followed with the Heliogast? band (n=183). Gastric slippage was diagnosed by symptoms of dysphagia and vomiting and was confirmed with Gastrografin? swallow. Patients who did not respond to conservative treatment were laparoscopically reoperated. In the Heliogast? group, the band was dissected free, unlocked, and repositioned. In the Lap-Band? group, when reopening proved impossible, the band was removed with or without replacement. Results: 10 patients (2.4%) underwent reoperation for anterior slippage, 5 with a Lap-Band? (2.1%) and 5 with a Heliogast? band (2.7%). Band repositioning was feasible in all 5 patients in the Heliogast? group, but in only one of the patients in the Lap-Band? group; in the others, the band was removed. Band repositioning was confirmed radiologically. No postoperative complications were recorded, and all patients were discharged on the first day after surgery. At a median 10 months' follow-up after Heliogast? repositioning, all patients had satisfactory weight loss. Conclusion: Laparoscopic Heliogast? band salvage after anterior slippage is comparatively simple and safe, with excellent postoperative results and no interference with continued weight loss. This constitutes an important means of management for the bariatric surgeon.  相似文献   
99.
We recently reported that immunization of mice with certain self-prion protein peptides induced specific T-cell and B-cell immune responses; importantly, this immunization was associated with a decrease in the number of protease-resistant PrP(Sc) particles recoverable in a transplanted, scrapie-infected syngeneic tumor. The present study was carried out to determine whether immunization with the immunogenic PrP peptides might influence the natural history of experimental scrapie in mice. We immunized C57BL/6 mice with self-prion peptides in complete Freund's adjuvant (CFA) or with CFA alone as a control and then infected the mice with mouse-adapted scrapie by injection either intraperitoneally or intracerebrally. We report here that immunization with CFA, irrespective of whether prion peptides were present in the inoculum, resulted in marked prolongation of survival of the mice, whether the challenge was intracerebral or intraperitoneal. Mice in the immunized and control groups that died contained equivalent amounts of PrP(Sc). Thus, CFA immunization has a therapeutic effect in experimental scrapie in mice, possibly by reducing the rate of PrP(Sc) accumulation in the brain.  相似文献   
100.
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