全文获取类型
收费全文 | 2025篇 |
免费 | 245篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 85篇 |
妇产科学 | 47篇 |
基础医学 | 225篇 |
口腔科学 | 44篇 |
临床医学 | 194篇 |
内科学 | 336篇 |
皮肤病学 | 76篇 |
神经病学 | 141篇 |
特种医学 | 104篇 |
外科学 | 371篇 |
综合类 | 58篇 |
一般理论 | 5篇 |
预防医学 | 355篇 |
眼科学 | 9篇 |
药学 | 115篇 |
中国医学 | 1篇 |
肿瘤学 | 100篇 |
出版年
2021年 | 23篇 |
2020年 | 21篇 |
2019年 | 30篇 |
2018年 | 31篇 |
2017年 | 38篇 |
2016年 | 41篇 |
2015年 | 43篇 |
2014年 | 56篇 |
2013年 | 95篇 |
2012年 | 95篇 |
2011年 | 84篇 |
2010年 | 77篇 |
2009年 | 81篇 |
2008年 | 79篇 |
2007年 | 83篇 |
2006年 | 67篇 |
2005年 | 68篇 |
2004年 | 71篇 |
2003年 | 67篇 |
2002年 | 69篇 |
2001年 | 58篇 |
2000年 | 58篇 |
1999年 | 42篇 |
1998年 | 48篇 |
1997年 | 45篇 |
1996年 | 46篇 |
1995年 | 35篇 |
1994年 | 33篇 |
1993年 | 28篇 |
1992年 | 34篇 |
1991年 | 34篇 |
1990年 | 37篇 |
1989年 | 42篇 |
1988年 | 41篇 |
1987年 | 41篇 |
1986年 | 33篇 |
1985年 | 30篇 |
1984年 | 21篇 |
1983年 | 22篇 |
1981年 | 18篇 |
1979年 | 16篇 |
1978年 | 25篇 |
1977年 | 17篇 |
1976年 | 16篇 |
1974年 | 28篇 |
1972年 | 23篇 |
1970年 | 17篇 |
1969年 | 16篇 |
1968年 | 15篇 |
1966年 | 19篇 |
排序方式: 共有2281条查询结果,搜索用时 15 毫秒
991.
Fluorescent protease histochemical analysis of muscle biopsy specimens from two patients with nemaline myopathy revealed the apparent absence of one proteolytic enzyme, dipeptidyl peptidase. Although the function of peptidases in normal muscle is obscure, this abnormality suggests that proteases may participate in posttranslational modification of proteins that are to be assembled into Z lines or, alternatively, in the disassembly and degradation of Z-line material. 相似文献
992.
Screening tests for blood donors presumed to have transmitted the acquired immunodeficiency syndrome
McDougal JS; Jaffe HW; Cabridilla CD; Sarngadharan MG; Nicholson JK; Kalyanaraman VS; Schable CA; Kilbourne B; Evatt BL; Gallo RC 《Blood》1985,65(3):772-775
We investigated 18 sets of blood donors from 12 to 50 months after they donated blood to recipients who subsequently developed the acquired immunodeficiency syndrome (AIDS). Within each donor set, only one donor was suspected of having transmitted the disease (ie, member of an AIDS risk group). The other donors (n = 189) were not risk group members and served as controls. A number of laboratory tests distinguished suspected from nonsuspected donors, including determination of T helper/T suppressor cell ratio, antibody to hepatitis B core antigen, and immune complexes, but none of these was as sensitive and specific as tests for antibody to the human retrovirus, HTLV-III/LAV. 相似文献
993.
994.
Gregory Crosby 《Journal canadien d'anesthésie》1988,35(4):359-363
The authors used the 2-[14C]deoxyglucose method to study local spinal and cerebral glucose utilization simultaneously during 1.2 per cent halothane anaesthesia in adult Sprague-Dawley rats. In conscious animals (n = 5) the rate of glucose utilization in lumbar spinal gray matter was about 50 per cent lower than that of cerebral cortex. Halothane anaesthesia (n = 6) reduced spinal cord and cerebral metabolic rate. Spinal glucose utilization was reduced 12-35 per cent, but this was less than the 45-70 per cent decrease halothane produced in 8 of 16 cerebral structures examined and was independent of the hypotension produced. These results indicate that halothane is a spinal metabolic depressant but that its effects on this tissue are substantially less than those it has on many cerebral structures. 相似文献
995.
This five-year retrospective study reviews our experience with epidural obstetric analgesia in patients with previous Harrington rod instrumentation (HRI) for correction of idiopathic scoliosis. Patients were identified by the presence of an antepartum anaesthetic consultation for HRI. The anaesthetic record was examined to determine the frequency of epidural catheter insertion and any problems related to this procedure. Nine epidural insertions were attempted in the 16 patients identified. Five were uncomplicated but four were complicated by one or more of: failure to identify the epidural space, blood vessel trauma, dural puncture, failure to obtain analgesia or the need for multiple attempts before successful insertion. There were no sequelae related to epidural insertion. There were no sequelae related to epidural insertion. We conclude that patients with HRI may be offered epidural anaesthesia for labour and delivery provided that they are informed of the increased risk of complications. 相似文献
996.
Meloni-Ehrig AM Tirado CA Chen K Jahn J Suchan S Scheerle J Crosby MG Meany H Seibel N Leitenberg D Heritage DW Mowrey PN 《Cancer Genetics and Cytogenetics》2005,161(1):82-85
We present a case of del(14)(q21) as a sole abnormality in a 4-year-old boy diagnosed with precursor B-cell acute lymphoblastic leukemia (pre-B ALL). To our knowledge, this is the first case of isolated del(14)(q21) in pre-B ALL. Two pretreatment bone marrow samples obtained 5 days apart were analyzed by cytogenetics. The G-banded karyotypes of the two samples were similar, differing only in the ratio of normal/abnormal metaphases detected. Both samples showed a del(14)(q21) as the only abnormality. Fluorescence in situ hybridization performed using the probes TEL/AML1 and immunoglobulin heavy chain (IGH) showed no fusion involving the TEL and AML1 genes and only a single IGH signal in 20% of the interphase cells analyzed. 相似文献
997.
Binford RB Mussell MP Crosby RD Peterson CB Crow SJ Mitchell JE 《Journal of consulting and clinical psychology》2005,73(6):1089-1096
This study's purpose was to examine the extent to which participants (N = 143) receiving cognitive-behavioral therapy for bulimia nervosa (BN) reported implementing therapeutic strategies to abstain from BN behaviors, and to assess whether use of specific strategies predicts outcome at treatment end and 1- and 6-month follow-up. Frequency of outcome expectancies (OE), stimulus-response prevention (SRP), and social support-seeking (SSS) strategies significantly increased by end of treatment. By 1-month follow-up, use of SSS, not OE or SRP, declined significantly relative to treatment end. Although frequency of coping strategy use at treatment end did not predict 1-month BN symptom remission, SSS use at 1-month follow-up predicted 6-month remission. Findings highlight the importance of social support to maintain treatment gains. 相似文献
998.
Huw?P?Jones Stella?Karuri Catherine?MG?Cronin Arne?Ohlsson Abraham?Peliowski Anne?Synnes Shoo?K?LeeEmail author The Canadian Neonatal Network 《BMC pediatrics》2005,5(1):40
Background
The increased survival of preterm and very low birth weight infants in recent years has been well documented but continued surveillance is required in order to monitor the effects of new therapeutic interventions. Gestation and birth weight specific survival rates most accurately reflect the outcome of perinatal care. Our aims were to determine survival to discharge for a large Canadian cohort of preterm infants admitted to the neonatal intensive care unit (NICU), and to examine the effect of gender on survival and the effect of increasing postnatal age on predicted survival. 相似文献999.
Adenosine A2A receptor activation reduces inflammation and preserves pulmonary function in an in vivo model of lung transplantation 总被引:2,自引:0,他引:2
Reece TB Ellman PI Maxey TS Crosby IK Warren PS Chong TW LeGallo RD Linden J Kern JA Tribble CG Kron IL 《The Journal of thoracic and cardiovascular surgery》2005,129(5):1137-1143
BACKGROUND: Reperfusion injury continues to significantly affect patients undergoing lung transplantation. Isolated lung models have demonstrated that adenosine A 2A receptor activation preserves function while decreasing inflammation. We hypothesized that adenosine A 2A receptor activation by ATL-146e during the initial reperfusion period preserves pulmonary function and attenuates inflammation in a porcine model of lung transplantation. METHODS: Mature pig lungs preserved with Viaspan (Barr Laboratories, Pomona, NY) underwent 6 hours of cold ischemia before transplantation and 4 hours of reperfusion. Animals were treated with (ATL group, n = 7) and without (IR group, n = 7) ATL-146e (0.05 microg kg -1 . min -1 ATL-146e administered intravenously for 3 hours). With occlusion of the opposite pulmonary artery, the animal was maintained for the final 30 minutes on the allograft alone. Recipient lung physiology was monitored before tissue evaluation of pulmonary edema (wet-to-dry weight ratio), myeloperoxidase assay, and tissue tumor necrosis factor alpha by means of enzyme-linked immunosorbent assay. RESULTS: When the ATL group was compared with the IR group, the ATL group had better partial pressure of carbon dioxide (43.8 +/- 4.1 vs 68.9 +/- 6.3 mm Hg, P < .01) and partial pressure of oxygen (272.3 +/- 132.7 vs 100.1 +/- 21.4 mm Hg, P < .01). ATL-146e-treated animals exhibited lower pulmonary artery pressures (33.6 +/- 2.1 vs 47.9 +/- 3.5 mm Hg, P < .01) and mean airway pressures (16.25 +/- 0.08 vs 16.64 +/- 0.15 mm Hg, P = .04). ATL-146e-treated lungs had lower wet-to-dry ratios (5.9 +/- 0.39 vs 7.3 +/- 0.38, P < .02), lower myeloperoxidase levels (2.9 x 10 -5 +/- 1.2 x 10 -5 vs 1.3 x 10 -4 +/- 4.0 x 10 -5 DeltaOD mg -1 . min -1 , P = .03), and a trend toward decreased lung tumor necrosis factor alpha levels (57 +/- 12 vs 96 +/- 15 pg/mL, P = .06). The ATL group demonstrated significantly less inflammation on histology. CONCLUSION: Adenosine A 2A activation during early reperfusion attenuated lung inflammation and preserved pulmonary function in this model of lung transplantation. ATL-146e and similar compounds could play a significant role in improving outcomes of pulmonary transplantation. 相似文献
1000.
Yarber WL Milhausen RR Crosby RA Torabi MR 《Perspectives on sexual and reproductive health》2005,37(3):148-154
CONTEXT: Public opinion is important in determining condom and condom education policies in public high schools.
METHODS: A random telephone survey of 517 Indiana residents was conducted from July through October 2003 to assess public opinion about education on correct condom use for HIV and STD prevention; condom availability in Indiana public high schools; and issues related to condom use, effectiveness and promotion. Data were analyzed using bivariate and linear regression techniques.
RESULTS: A majority of respondents strongly or somewhat agreed that instruction on correct condom use for HIV and STD prevention should be provided in public high schools (77%), classroom instruction should include condoms (71%), only medically accurate information about condoms should being given (94%) and the federal government should promote condoms (70%). Fewer than half (48%) strongly or somewhat agreed that condoms should be made available to teenagers in public high schools without parental permission. Nearly all (92%) considered condoms at least somewhat effective in preventing HIV and other STDs. Non-Republican party affiliation, younger age and condom use within the previous five years were each significantly associated with having positive opinions on many of the condom-related statements.
CONCLUSIONS: Public opinion appears to support the provision of correct condom use information in Indiana public schools. Schools should consider providing only medically accurate information about condoms and including condoms in instruction so students can see and touch them. 相似文献
METHODS: A random telephone survey of 517 Indiana residents was conducted from July through October 2003 to assess public opinion about education on correct condom use for HIV and STD prevention; condom availability in Indiana public high schools; and issues related to condom use, effectiveness and promotion. Data were analyzed using bivariate and linear regression techniques.
RESULTS: A majority of respondents strongly or somewhat agreed that instruction on correct condom use for HIV and STD prevention should be provided in public high schools (77%), classroom instruction should include condoms (71%), only medically accurate information about condoms should being given (94%) and the federal government should promote condoms (70%). Fewer than half (48%) strongly or somewhat agreed that condoms should be made available to teenagers in public high schools without parental permission. Nearly all (92%) considered condoms at least somewhat effective in preventing HIV and other STDs. Non-Republican party affiliation, younger age and condom use within the previous five years were each significantly associated with having positive opinions on many of the condom-related statements.
CONCLUSIONS: Public opinion appears to support the provision of correct condom use information in Indiana public schools. Schools should consider providing only medically accurate information about condoms and including condoms in instruction so students can see and touch them. 相似文献