全文获取类型
收费全文 | 4448篇 |
免费 | 340篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 195篇 |
妇产科学 | 82篇 |
基础医学 | 696篇 |
口腔科学 | 132篇 |
临床医学 | 424篇 |
内科学 | 944篇 |
皮肤病学 | 58篇 |
神经病学 | 399篇 |
特种医学 | 159篇 |
外国民族医学 | 1篇 |
外科学 | 503篇 |
综合类 | 69篇 |
一般理论 | 6篇 |
预防医学 | 390篇 |
眼科学 | 109篇 |
药学 | 304篇 |
中国医学 | 2篇 |
肿瘤学 | 306篇 |
出版年
2022年 | 29篇 |
2021年 | 68篇 |
2020年 | 33篇 |
2019年 | 56篇 |
2018年 | 69篇 |
2017年 | 55篇 |
2016年 | 52篇 |
2015年 | 69篇 |
2014年 | 79篇 |
2013年 | 152篇 |
2012年 | 237篇 |
2011年 | 235篇 |
2010年 | 144篇 |
2009年 | 122篇 |
2008年 | 264篇 |
2007年 | 273篇 |
2006年 | 266篇 |
2005年 | 302篇 |
2004年 | 300篇 |
2003年 | 290篇 |
2002年 | 273篇 |
2001年 | 106篇 |
2000年 | 91篇 |
1999年 | 92篇 |
1998年 | 66篇 |
1997年 | 52篇 |
1996年 | 41篇 |
1995年 | 39篇 |
1994年 | 44篇 |
1993年 | 46篇 |
1992年 | 50篇 |
1991年 | 59篇 |
1990年 | 51篇 |
1989年 | 49篇 |
1988年 | 35篇 |
1987年 | 47篇 |
1986年 | 43篇 |
1985年 | 38篇 |
1984年 | 38篇 |
1983年 | 33篇 |
1982年 | 34篇 |
1981年 | 48篇 |
1980年 | 38篇 |
1979年 | 28篇 |
1978年 | 22篇 |
1977年 | 26篇 |
1976年 | 34篇 |
1975年 | 27篇 |
1974年 | 23篇 |
1973年 | 23篇 |
排序方式: 共有4815条查询结果,搜索用时 15 毫秒
1.
2.
Burness Gene Wenberg MS RD December 《Journal of the American Dietetic Association》2004,104(8):1297-1299
3.
Gene M. Heyman 《Psychopharmacology》1993,112(2-3):259-269
A series of experiments evaluated the determinants of preference for mixtures of ethanol plus sucrose relative to sucrose in rats. One dipper served 10% ethanol mixed with 10% sucrose, and the second dipper served 10% sucrose. Lever presses operated each dipper according to a variable-interval 5-s schedule. In three experiments the subjects were given pre-session meals of sucrose (2.5–20 ml) or sucrose (20 ml) plus chow (5 or 10 g). Pre-session meals decreased responding maintained by sucrose but not responding maintained by ethanol mixture. In two experiments body weight was varied from 85% to 125% of the initial free-feeding values. Increases in body weight, like pre-session meals, decreased responding reinforced by sucrose, but typically did not decrease responding reinforced by ethanol mixture. Throughout most of the study, ethanol consumption remained at about 1.25 ml per half hour session (3–4 g/kg per 30 min). For example, pre-session access to ethanol mixture decreased within-session ethanol consumption, but total consumption, counting both sources, remained about 1.25 ml/session. The within-session patterns of responding also differed. Responding reinforced by ethanol mix decreased as a function of ethanol consumption, whereas responding reinforced by sucrose was relatively constant throughout the session. The simplest explanation of the results is that ethanol's pharmacological consequences regulated preference. 相似文献
4.
BACKGROUND CONTEXT: Paraspinal infections after zygapophyseal (facet) radiofrequency denervation (RFD) are a serious but rare complication of this procedure. We are aware of only one case report of an epidural abscess after facet joint injection. PURPOSE: To report post-procedure inflammatory changes after cervical facet RFD. STUDY DESIGN: Case report. PATIENT SAMPLE: A 35-year-old Caucasian female. METHODS: Retrospective case review. RESULTS: The patient underwent cervical RFD and was admitted to the hospital 7 days after her procedure with severe neck pain. Magnetic resonance imaging (MRI) with contrast revealed what appeared to be evidence of a paraspinal muscle abscess although blood tests were negative. She was treated with antibiotic therapy, yet she never developed systemic signs of infection. A follow-up MRI without contrast revealed no evidence of infection, and she was discharged home on hospital day 6. At her first follow-up visit, she was still experiencing scalp pain and paraspinal muscle spasm. During subsequent follow-up visits, she has continued to improve clinically without experiencing signs of infection. Another follow-up MRI 6 weeks after her discharge home revealed persistent minimal left paraspinal enhancement at C2-3, possibly representing post-procedure granulation tissue with no evidence of abscess. CONCLUSIONS: Post-procedural MRI findings after radiofrequency lesioning can resemble radiographic findings associated with a paraspinal abscess. Patients with radiographic findings consistent with abscess should only be treated if clinical signs or symptoms of systemic infection are present. 相似文献
5.
Early detection of myocardial contusion and its complications in patients with blunt trauma 总被引:4,自引:0,他引:4
MD Michael J. Norton MD Gregory G. Stanford MD John A. Weigelt 《American journal of surgery》1990,160(6):577-81; discussion 581-2
Myocardial contusion remains an elusive clinical entity, which consumes a disproportionate amount of scarce and expensive critical care resources for the purpose of cardiac monitoring. This study attempts to define a group of patients at high risk who can be identified from the available data present at the time of admission. All patients admitted with the suspicion of a myocardial contusion over a 3-year period were retrospectively studied. The records were examined for history, physical findings, electrocardiographic (ECG) results, creatine kinase levels, Injury Severity Score (ISS), and echocardiographic findings. A diagnosis of a myocardial contusion was made if patients had an ECG consistent with acute injury, increased creatine kinase-MB, or an abnormal echocardiogram consistent with acute injury. Patients were stratified into two groups: Group 1 patients satisfied the criteria for a myocardial contusion and Group 2 patients lacked sufficient evidence to substantiate this diagnosis. The records were then examined for the presence of factors available in the emergency room that might be predictive of a myocardial contusion or its complications. A total of 88 patients were evaluated; 27 of these were found to have a myocardial contusion (Group 1) with 61 patients placed in Group 2 (no myocardial contusion). Group 1 patients had an abnormal admission ECG (p less than 0.05), and an ISS greater than or equal to 10 (p less than 0.05). Multivariate analysis identified two factors predictive of a myocardial contusion: an abnormal ECG and an ISS greater than 10. When these two predictors were absent, the probability of a myocardial contusion was 1%. No predictors of a complication of a myocardial contusion were identified. These data suggest that a combination of easily obtained variables in the emergency department can be used to select a patient population at high risk for myocardial contusion. Prospective evaluation of these variables is necessary. 相似文献
6.
7.
A pharmacokinetic and pharmacodynamic comparison of plain and enteric-coated prednisolone tablets.
下载免费PDF全文
![点击此处可从《British journal of clinical pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
C G Adair O McCallion J C McElnay M G Scott B A Hamilton J P McCann C F Stanford D P Nicholls 《British journal of clinical pharmacology》1992,33(5):495-499
1. Eight healthy volunteers and eight patients suffering from chronic obstructive pulmonary disease (COPD) received 30 mg prednisolone as plain (P) and enteric-coated tablets (EP) in a randomised, cross-over manner. Plasma prednisolone and cortisol and blood glucose were measured over 24 h. 2. Although absorption of prednisolone was considerably slower when administered as the enteric-coated form, peak plasma drug concentrations and total AUC (0,24 h) were equivalent for the two formulations. Malabsorption of prednisolone was not observed. 3. The administration of EP was associated with significantly less adrenal suppression in volunteers than P as judged by measurement of AUC (0,24 h) values for endogenous cortisol. However, this difference did not reach statistical significance in the patient group. 4. Plasma cortisol concentrations declined more slowly following administration of the enteric-coated form to both groups. The difference in time taken (median and range) to maximum suppression of cortisol was statistically significant (P less than 0.05) between P (2.5 h; 2-4 h) and EP (4 h; 3-12 h) preparations administered to volunteers. There was a similar significant difference (P less than 0.05) between P (2.5 h; 1-4 h) and EP (7 h; 2-12 h) in the patients. 5. Plasma cortisol concentrations were significantly lower at 24 h in patients receiving the enteric-coated product in association with higher terminal prednisolone concentrations. 6. Blood glucose concentrations increased over an 8 h period in both groups.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
8.
9.
Dr. Stanford S. Jhee Pharm.D. Dr. Jack W. Kern Pharm.D. Dr. Jin-Pil Burm Ph.D. Dr. Albert E. Yellin M.D. Dr. Mark A. Gill Pharm.D. FASHP FCCP 《Pharmacotherapy》1995,15(4):472-478
Study Objective . To determine the appropriate compartmental and noncompartmental pharmacokinetic parameters for intravenous piperacillin and tazobactam. Design . Sequential selection of patients entered into a randomized, open-label clinical efficacy trial. Setting . Los Angeles County-University of Southern California Medical Center. Participants . Sequential sample of 18 patients admitted for intraabdominal infections and consented into a comparative antibiotic trial. Interventions . Patients received piperacillin 4 g plus tazobactam 500 mg by intravenous intermittent infusion every 8 hours. Measurements and Main Results . The estimated noncompartmental pharmacokinetic parameters (mean ± SD) for piperacillin and tazobactam, respectively, were as follows: maximum concentration in plasma 218.7 ± 48.9 μg/ml and 27.8 ± 9.1 μg/ml; half-life 1.07 ± 0.22 hours and 1.00 ± 0.27 hours; elimination rate constant 0.67 ± 0.13 hr−1 and 0.73 ± 0.18 hr−1; area under the concentration-time curve from zero hour to infinity 288.5 ± 71.25 mg·hr/L and 36.3 ± 9.55 mg·hr/L; total plasma clearance 14.75 ± 3.93 L/hour and 14.78 ± 4.39 L/hour; renal clearance 5.69 ± 1.94 L/hour and 7.85 ± 3.37 L/hour; volume of distribution at steady state 21.00 ± 4.18 L and 22.47 ± 8.27 L; and mean residence time 1.72 ± 0.29 hours and 1.79 ± 0.35 hours. Conclusion . Our findings were similar to those in other surgical patient models. The two-compartmental model best described piperacillin and tazobactam disposition in our patients. Bayesian analyses of the two-compartment models of piperacillin and tazobactam were able to predict trough, peak, and 2-hour postadministration levels without bias. 相似文献
10.