全文获取类型
收费全文 | 1574篇 |
免费 | 90篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 29篇 |
妇产科学 | 152篇 |
基础医学 | 177篇 |
口腔科学 | 17篇 |
临床医学 | 157篇 |
内科学 | 155篇 |
皮肤病学 | 13篇 |
神经病学 | 296篇 |
特种医学 | 138篇 |
外科学 | 260篇 |
综合类 | 21篇 |
预防医学 | 72篇 |
眼科学 | 5篇 |
药学 | 79篇 |
肿瘤学 | 84篇 |
出版年
2021年 | 18篇 |
2019年 | 21篇 |
2018年 | 30篇 |
2016年 | 17篇 |
2015年 | 24篇 |
2014年 | 27篇 |
2013年 | 45篇 |
2012年 | 52篇 |
2011年 | 60篇 |
2010年 | 28篇 |
2009年 | 24篇 |
2008年 | 53篇 |
2007年 | 53篇 |
2006年 | 49篇 |
2005年 | 53篇 |
2004年 | 49篇 |
2003年 | 46篇 |
2002年 | 58篇 |
2001年 | 47篇 |
2000年 | 55篇 |
1999年 | 43篇 |
1998年 | 18篇 |
1997年 | 25篇 |
1996年 | 21篇 |
1995年 | 29篇 |
1994年 | 18篇 |
1992年 | 39篇 |
1991年 | 40篇 |
1990年 | 35篇 |
1989年 | 33篇 |
1988年 | 36篇 |
1987年 | 31篇 |
1986年 | 37篇 |
1985年 | 28篇 |
1984年 | 25篇 |
1983年 | 23篇 |
1982年 | 26篇 |
1981年 | 15篇 |
1979年 | 22篇 |
1978年 | 16篇 |
1977年 | 15篇 |
1976年 | 22篇 |
1974年 | 26篇 |
1973年 | 22篇 |
1972年 | 17篇 |
1971年 | 26篇 |
1970年 | 23篇 |
1969年 | 19篇 |
1968年 | 17篇 |
1966年 | 15篇 |
排序方式: 共有1664条查询结果,搜索用时 31 毫秒
1.
2.
We sought to determine if chronic endurance training would increase mitochondrial respiration or protein content in rat diaphragm muscle. To this end, 20 male Wistar rats were randomly assigned to control (C) or an 8-week endurance training (T) group, n = 10 per group. At the end of T, VO2 max was 13% greater in T (83.3 vs 73.8 ml X kg-1 X min-1) and peak max power output was 32% greater (2.63 vs 1.98 kg X m X min-1). Mitochondrial specific activities of pyruvate-malate and cytochrome oxidase (expressed per mg mitochondrial protein) in both plantaris and diaphragm were similar in C and T rats, as were ADP/O and respiratory control ratios. When expressed per gram wet weight, whole muscle homogenate oxygen uptake (pyruvate + malate) and cytochrome oxidase activity increased 36 and 23%, respectively (P less than 0.05) in plantaris from T rats but did not change in diaphragm. Control oxidative capacity and mitochondrial protein content in the diaphragm were ca. 2-fold those in control plantaris. Plantaris mitochondrial protein content increased ca. 50% with T while the diaphragm was unaffected. We conclude that: plantaris muscle oxidative capacity adapts to training by increasing mitochondrial protein content, since there was no evidence for functional improvement of existing mitochondria, and in the face of a substantial training effect in whole animal and plantaris, the T stimulus was not sufficient to induce mitochondrial protein changes in the diaphragm. This finding is the result of either a 'pre-adaptation' secondary to the diaphragm's high chronic activity, or a sub-threshold increase in diaphragm recruitment during the exercise conditions studied. 相似文献
3.
John D Paulson Melissa Delgado 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(2):175-181
OBJECTIVE: This study was designed to determine the relationship between interstitial cystitis (IC), endometriosis (endo), and chronic pelvic pain (CPP) in individuals in whom nongynecological and nonurological problems had been previously ruled out. METHODS: A prospective study of 162 consecutive women with a complaint of chronic pelvic pain seen in the clinic was performed between August 2002 and December 2005. These patients underwent a workup to exclude other causes of pelvic pain, had PUF (Pain Urgency and Frequency) questionnaires filled out, and underwent a laparoscopy and a cystoscopy with hydrodistention. Pain levels were determined, and treatment was reviewed and enumerated. Results were obtained and quantified. RESULTS: In this study, 123 (76%) patients were diagnosed with active endometriosis, 133 (82%) were diagnosed with interstitial cystitis, and 107 (66%) had both disease entities simultaneously. Thirteen (8%) patients were diagnosed with pathologies unrelated to endometriosis and interstitial cystitis. Pain levels were seen to decrease at 6 months in all groups of patients with the exception of those patients with endometriosis only. CONCLUSION: CPP is a difficult, taxing, and frustrating concern for many women in the United States. These individuals have traditionally been difficult to treat. A large number of women with CPP in our patient population have been shown to have endometriosis, interstitial cystitis, or both. Therefore, a workup for premenopausal individuals with CPP involves obtaining a history that keys into possible nongynecologic causes of pain, a complete accounting of urinary problems, and a thorough history of gynecological problems. A physical examination with a comprehensive history should be performed, and the investigation may include the possibility of a simultaneous laparoscopy and cystoscopy if warranted. These procedures can serve as both a means for diagnosis and treatment of these problems when encountered. 相似文献
4.
A group of 159 patients previously reported as having margins positive for disease after radical prostatectomy with or without adjunctive postoperative radiation was reanalyzed to determine whether the reported benefit did indeed exist. Upon re-examination of the 159 patients 15 were identified who did not receive radical prostatectomy but who were analyzed as if they had received this therapy. An updated review of the total pool of 159 patients with analysis as to failure, death of any cause or death of prostatic cancer demonstrated no benefit of postoperative radiation therapy for margin positive disease. Exclusion of patients who did not receive radical prostatectomy and analysis as described also failed to identify any benefit of postoperative adjunctive radiation therapy. 相似文献
5.
6.
7.
STUDY OBJECTIVE: To assess the clinical utility of measuring urinary pregnanediol glucuronide in random samples in an infertility practice. DESIGN: Samples of urine were collected from patients approximately 3 weeks from their last menstrual period to ascertain if ovulation had occurred. Each sample was tested for specific gravity before analyzing for pregnanediol glucuronide. Simultaneous venipuncture was performed to compare results from the urinary assay to quantitative measures of serum progesterone (P). SETTING: All patients were randomly sampled. PATIENTS: Three hundred ninety women undergoing pituitary down regulation with leuprolide acetate were chosen for study because they routinely initiate medication after documentation of ovulation. OUTCOME MEASURES: The performance of the urinary pregnanediol glucuronide was evaluated as to its sensitivity, specificity, predictive value, and test efficiency compared with a serum measurement of 2.5 ng/mL and 10.0 ng/mL. RESULTS: The performance characteristics of the pregnanediol glucuronide assay were directly related to the hydration status of the patient at the time of sample collection. Regardless of urine specific gravity, if pregnanediol glucuronide was qualitatively detected (greater than 3 micrograms/mL), serum P was greater than 2.5 ng/mL. However, in cases in which pregnanediol glucuronide was undetected (less than 3 micrograms/mL), results were only accurate when the specific gravity was greater than or equal to 1.020. When comparing urinary pregnanediol glucuronide values to serum greater than 10 ng/mL, both specificity and predictive value of a positive test decreased because of increased numbers of false-positive results. CONCLUSIONS: The enzyme immunoassay measurement for pregnanediol glucuronide may replace the use of serum P in documenting the ovulatory status of many patients. However, all specimens must be checked for specific gravity and if less than 1.020, a serum P should be used to ensure accuracy. 相似文献
8.
Summary A retrospective review was performed on all patients with stage D1 prostate cancer treated at Duke University Medical Center between 1975 and 1989. A total of 156 patients underwent staging pelvic lymph-node dissection for clinically organ-confined prostate cancer (stage A or B) but were found to have disease metastatic to the pelvic lymph nodes (stage D1). Of this population, 42 patients also underwent radical prostatectomy (group 1), leaving 114 who did not have their prostate removed (group 2). The median cancer-specific survival was 11.2 years for group 1 versus 5.8 years for group 2 (P=0.005). In patients with one or two positive lymph nodes the median cancer-specific survival was 10.2 years for group 1 versus 5.9 years for group 2 (P=0.015). There was no difference in survival if three or more lymph nodes were positive. Adjuvant treatment with immediate androgen deprivation and/or postoperative radiation therapy failed to improve the survival experience. The incidence of local problems, including stricture formation, bleeding, or regrowth of cancer requiring dilation or surgical intervention (transurethral prostatectomy) averaged 9.5% in group 1 and 24.6% in group 2. These data show that patients with limited node-positive disease selected for radical prostatectomy experience a survival advantage over those denied such therapy and that this advantage is independent of adjunctive therapy.This research was performed while Dr. Frazier was serving as a fellow in Urologic Oncology with funding from the United States Navy. The opinions herein represent those of the authors and do not necessarily reflect those of the United States Navy or the Department of Defense 相似文献
9.
10.