全文获取类型
收费全文 | 3017篇 |
免费 | 159篇 |
国内免费 | 18篇 |
学科分类
医药卫生 | 3194篇 |
出版年
2023年 | 27篇 |
2022年 | 75篇 |
2021年 | 118篇 |
2020年 | 55篇 |
2019年 | 92篇 |
2018年 | 107篇 |
2017年 | 58篇 |
2016年 | 85篇 |
2015年 | 80篇 |
2014年 | 117篇 |
2013年 | 129篇 |
2012年 | 219篇 |
2011年 | 213篇 |
2010年 | 118篇 |
2009年 | 114篇 |
2008年 | 172篇 |
2007年 | 186篇 |
2006年 | 162篇 |
2005年 | 179篇 |
2004年 | 164篇 |
2003年 | 135篇 |
2002年 | 120篇 |
2001年 | 38篇 |
2000年 | 29篇 |
1999年 | 29篇 |
1998年 | 24篇 |
1997年 | 16篇 |
1996年 | 23篇 |
1995年 | 15篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 27篇 |
1991年 | 26篇 |
1990年 | 23篇 |
1989年 | 11篇 |
1988年 | 24篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1972年 | 6篇 |
1971年 | 9篇 |
1968年 | 13篇 |
1967年 | 10篇 |
排序方式: 共有3194条查询结果,搜索用时 15 毫秒
1.
Albert J. Moreno Allan L. Parker Peter Fredericks Gottlieb L. Turnbull 《European journal of nuclear medicine and molecular imaging》1986,12(5-6):309-310
A 58-year-old man with a pectus excavatum demonstrated a photon-deficient defect within the left lobe of the liver on liver-spleen scintigraphy using Tc-99m SCOL. Computed tomography of the liver clearly revealed the abnormal defect seen on the liver-spleen scan to be due to the pectus excavatum. This case confirms the impression that these skeletal aberrations may cause false-positive hepatic defects.The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense 相似文献
2.
C Lee R Salim D Ofili-Yebovi J Yazbek A Davies D Jurkovic 《Ultrasound in obstetrics & gynecology》2006,28(6):837-841
OBJECTIVE: To determine the intraobserver and interobserver reproducibility of measurement of the percentage of protrusion of submucous fibroids into the uterine cavity using three-dimensional saline contrast sonohysterography (3D-SCSH). METHODS: Women diagnosed with submucous uterine fibroids on B-mode two-dimensional (2D) ultrasound scan were invited to join the study and 3D-SCSH was carried out. 3D volume datasets were stored digitally and were examined later using the technique of planar reformatted sections. The reproducibilities of the measurement of fibroid diameter and protrusion ratio into the uterine cavity (ratio of the size of the segment of the fibroid protruding into the cavity to the total diameter of the fibroid) were examined by two independent observers who were unaware of the initial 2D scan findings. Interobserver reproducibility was assessed by calculating the difference between measurements taken by the two operators (limits of agreement) and interclass correlation coefficient. Intraobserver repeatability was assessed by calculating the difference between two measurements for each variable (limits of agreement) and further expressed as an intraclass correlation coefficient. RESULTS: Thirty-three 3D ultrasound volumes were examined. There was a good agreement between the observers in classifying the fibroids as greater or less than 50% confined to the myometrium (Cohen's kappa 0.81). There was no bias in measurements for both variables either between observers or with repeated measurements by each observer. For fibroid diameter and protrusion ratio the inter- and intraclass correlation coefficients were high (0.984-0.995), with narrow limits of agreement. CONCLUSION: 3D-SCSH is a reproducible method for the quantification of the percentage of a submucous fibroid protruding into the uterine cavity. 相似文献
3.
4.
A S Salim 《Clinical science (London, England : 1979)》1991,80(1):59-64
1. Reserpine (5 mg/kg intraperitoneally) produced gastric mucosal vasoconstriction and injury in all rats within 6 h (injury score 38.8 +/- 2.1 mm2, mean +/- SEM). Coeliac ganglionectomy or the beta-adrenoceptor-blocking drug propranolol (5-15 mg/kg) did not influence these effects of reserpine, but vagotomy protected the rats against them. The alpha-adrenoceptor-blocking drugs phenoxybenzamine and phentolamine at 5 mg/kg were protective against injury. However, a 10 mg/kg dose of either blocker was more effective (2.2 +/- 0.5 mm2 and 3 +/- 0.8 mm2, respectively, versus 38.8 +/- 2.1 mm2, mean +/- SEM, P less than 0.01) and a dose of 15 mg/kg afforded complete protection. 2. Methysergide, a 5-hydroxytryptamine receptor antagonist, produced a dose-dependent increase in the reserpine-induced injury; a significant (P less than 0.05) increase was noted with 15 and 20 mg/kg (47.5 +/- 2.9 mm2 and 49.4 +/- 2.2 mm2, respectively, versus 38.8 +/- 2.1 mm2, mean +/- SEM). 3. The results suggest that, in the rat, reserpine causes vagal alpha-adrenoceptor stimulation producing gastric mucosal vasoconstriction and injury. 5-Hydroxytryptamine is not implicated in the mechanism of this injury and affords protection against it. 相似文献
5.
A S Salim 《Journal of pharmaceutical sciences》1992,81(7):698-700
Reserpine (intraperitoneal, 5 mg/kg every day for 5 days) produced chronic ulceration of the rat stomach 2 weeks postdose. Gavage with 1% DL-cysteine or DL-methionine-S-methylsulfonium chloride at 1 mL/day for 2 weeks and 5 days protected against ulceration in 30% of the rats, and this protection extended to 80% of cases with 2% solutions. Similar gavage with 5% solutions protected all rats against ulceration without significantly influencing the basal H+ output [13.1 +/- 0.3 and 14.2 +/- 0.2 mumol for DL-cysteine and DL-methionine-S-methylsulfonium chloride, respectively, versus 15.1 +/- 0.4 mumol (mean +/- standard error of the mean; n = 10)]; that is, cytoprotection was achieved. 相似文献
6.
E. M. Fredericks M. J. Lopez J. C. Magee V. Shieck L. Opipari-Arrigan 《American journal of transplantation》2007,7(8):1974-1983
The present study empirically assessed the relationships between adherence behaviors and HRQOL, parent and child psychological functioning and family functioning, and investigated the relationship between adherence behaviors and health outcomes in children who were within 5 years of their liver transplantation. Participants included 38 children (mean = 8.5 years, range 28 months to 16 years) and their parent/guardian(s). HRQOL and psychological functioning were examined using well-validated assessment measures. Measures of adherence included the rate of clinic attendance and standard deviations (SDs) of consecutive tacrolimus blood levels, which were collected and evaluated retrospectively. Measures of child health status included the frequency of hospital admissions, liver biopsies, episodes of rejection and graft function for the year prior to study participation. Results indicated that nonadherence was related to lower physical HRQOL, more limitations in social and school activities related to emotional and behavioral problems, parental emotional distress and decreased family cohesion. Nonadherence was also related to frequency and duration of hospitalizations, liver biopsies and rejection episodes. These results suggest that empirically based assessment of HRQOL, parenting stress and family functioning may help identify patients at risk for nonadherence, and may allow for the need-based delivery of appropriate clinical interventions. 相似文献
7.
8.
The validity and use of psychosocial assessments in occupational therapy are ongoing concerns (Moyer, 1984) and were the focus of this study. Fifty African patients with schizophrenia and 10 nondysfunctional African volunteers took an an assessment battery that included the Schroeder, Block, Campbell Adult Psychiatric Sensory Integration Evaluation (SBC) (Schroeder, Block, Trottier, & Stowell, 1978), a daily activity, work, and leisure activity interview based on the Model of Human Occupation (Kielhofner, 1985), and a culture-specific test of functional performance. Data on subjects' psychiatric histories and demographics were collected. Rationale for the assessments used, methods for devising the functional assessment, methods and procedures for data collection, and analysis are presented. A stronger relationship was found to exist between subjects' performances on the SBC and the functional activity test than between interviews based on the Model of Human Occupation and the functional activity test, both for patients and for the whole sample. All assessments were found to differentiate between patients and nonpatients, although the SBC was the best discriminator. Among psychiatric history variables, the strongest relationships were between measures of seriousness of illness and both the SBC and functional activity assessment. The most effective way to measure performance dysfunction and seriousness of illness in persons with schizophrenia was to measure the underlying sensorimotor impairment or to use a culture-specific test of functional performance. 相似文献
9.
Salim H. Khalil Mohammed H. Qari John M. Jackson Robert Haywood Pyle Hassan El-Solh Abdallah Al-Nasser 《Leukemia research》1994,18(12):881-883
Geographical variations in the incidence of disease are of considerable theoretical and practical importance. It has been claimed that the distribution of acute lymphoblastic leukemia (ALL) phenotypes in Saudi Arabia is different from that recorded in the Western literature. One hundred and twelve (112) patients under 15 years of age, diagnosed as ALL between January 1992 and May 1994 had immunophenotypes performed on their blast cells. Common ALL (cALL) together with pre-B-ALL, formed 86.5% of the total; B-cell 3%, T-cell 6% and null cell 4.5%. These figures are not significantly different from the Western literature. A previous claim from this institution in 1990, that both null and B-cell ALL were significantly increased compared with elsewhere, is not supported by the present figures. Age and sex distribution, and FAB classification, L1 77%, L2 20% and L3 3%, were also of the same order as described elsewhere and, in particular, there was no increase in the frequency of L3 subtype. 相似文献
10.
Quantitative antimicrobial susceptibility test for Streptococcus pneumoniae using inoculum supplemented with whole defibrinated sheep blood. 总被引:2,自引:1,他引:2 下载免费PDF全文
R F D'Amato J M Swenson G A McKinley L Hochstein A A Wallman D J Cleri A J Mastellone L Fredericks L Gonzalez D H Pincus et al. 《Journal of clinical microbiology》1987,25(9):1753-1756
The National Committee for Clinical Laboratory Standards recommends the use of lysed horse blood-supplemented Mueller-Hinton broth for determining the quantitative antimicrobial susceptibility of Streptococcus pneumoniae. This procedure may be difficult for laboratories using previously prepared or commercial MIC systems. Therefore, a study was undertaken to determine whether previously prepared microdilution trays containing Mueller-Hinton broth without blood could be used for determining the antimicrobial susceptibility of S. pneumoniae by adding whole defibrinated sheep blood to the bacterial suspension used to inoculate the trays. The presence of alpha-hemolysis was used as an indicator of bacterial growth. One hundred isolates of S. pneumoniae selected to represent a distribution of susceptibility patterns were tested by the National Committee for Clinical Laboratory Standards method and the sheep blood-supplemented-inoculum method. Greater than 94% agreement between the two methods was achieved. The sheep-blood-supplemented-inoculum procedure was highly reproducible and easy to perform and provides an acceptable alternative for determining the MICs for S. pneumoniae for laboratories using previously prepared or commercial microdilution systems. 相似文献