全文获取类型
收费全文 | 5468篇 |
免费 | 406篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 162篇 |
妇产科学 | 175篇 |
基础医学 | 731篇 |
口腔科学 | 50篇 |
临床医学 | 584篇 |
内科学 | 1252篇 |
皮肤病学 | 131篇 |
神经病学 | 567篇 |
特种医学 | 138篇 |
外科学 | 849篇 |
综合类 | 46篇 |
一般理论 | 6篇 |
预防医学 | 511篇 |
眼科学 | 49篇 |
药学 | 359篇 |
中国医学 | 10篇 |
肿瘤学 | 212篇 |
出版年
2023年 | 52篇 |
2022年 | 52篇 |
2021年 | 86篇 |
2020年 | 88篇 |
2019年 | 98篇 |
2018年 | 110篇 |
2017年 | 93篇 |
2016年 | 100篇 |
2015年 | 110篇 |
2014年 | 117篇 |
2013年 | 226篇 |
2012年 | 298篇 |
2011年 | 275篇 |
2010年 | 151篇 |
2009年 | 138篇 |
2008年 | 264篇 |
2007年 | 275篇 |
2006年 | 252篇 |
2005年 | 194篇 |
2004年 | 199篇 |
2003年 | 164篇 |
2002年 | 164篇 |
2001年 | 158篇 |
2000年 | 173篇 |
1999年 | 148篇 |
1998年 | 49篇 |
1997年 | 48篇 |
1996年 | 47篇 |
1995年 | 32篇 |
1994年 | 44篇 |
1993年 | 43篇 |
1992年 | 138篇 |
1991年 | 121篇 |
1990年 | 124篇 |
1989年 | 119篇 |
1988年 | 112篇 |
1987年 | 105篇 |
1986年 | 109篇 |
1985年 | 89篇 |
1984年 | 85篇 |
1983年 | 66篇 |
1982年 | 43篇 |
1979年 | 37篇 |
1978年 | 41篇 |
1977年 | 38篇 |
1975年 | 44篇 |
1974年 | 39篇 |
1973年 | 39篇 |
1972年 | 40篇 |
1970年 | 33篇 |
排序方式: 共有5886条查询结果,搜索用时 15 毫秒
41.
J. K. Preiksaitis S. Rosno L. Rasmussen T. C. Merigan 《Journal of clinical immunology》1982,2(2):36S-41S
Cytomegalovirus (CMV) infection is a major problem during the first twelve weeks after cardiac transplantation. Reactivation of endogenous virus, blood transfusion, and the transplanted heart are sources for CMV infection. Not only can disseminated CMV infection contribute directly to mortality, but CMV infection predisposes to superinfection with bacterial and fungal pathogens. Studies in mice, the premature neonate, and bone marrow transplant recipients suggest that passive immunization with CMV antibody has a modifying effect on CMV infection. By prophylactic administration of intravenous immune globulin in a controlled randomized fashion to cardiac transplant recipients we will address the question of whether passively acquired antibody prevents or modifies infection with CMV or other viral, bacterial, and fungal infections. Thirteen patients undergoing cardiac transplantation at Stanford University were randomized to receive or not receive intravenous immune globulin (IGIV) at a dose of 20 ml/kg twenty-four hours post transplantation and then weekly thereafter for a period of 10 weeks. Six patients seronegative for CMV antibody were randomized separately from seven who were seropositive for CMV antibody. Seven patients randomly selected from these two groups received IGIV. In patients seronegative for CMV, administration of IGIV resulted in serum titers of 1:10,000–1:30,000 measured by radioimmunoassay. Antibody titers were maintained at levels of 1:10,000 to 1:30,000 throughout the 10 week period post transplantation. Antibody remained detectable up to 8 weeks after the last infusion. No significant increases in CMV antibody levels were detectable after IGIV administration in patients seropositive for CMV antibody prior to transplantation. The administration of IGIV in thirty-two large and repeated doses was safe and well tolerated in cardiac transplant recipients. Serum levels of CMV antibody comparable to those observed in normal CMV seropositive individuals were achieved in CMV seronegative transplant recipients and were maintained throughout the period of greatest risk for CMV infection. 相似文献
42.
The sensitivity and specificity of the Major Depression Inventory, using the Present State Examination as the index of diagnostic validity 总被引:4,自引:0,他引:4
Bech P Rasmussen NA Olsen LR Noerholm V Abildgaard W 《Journal of affective disorders》2001,66(2-3):159-164
BACKGROUND: A self-rating inventory has been developed to measure DSM-IV and ICD-10 diagnoses of major (moderate to severe) depression by the patients' self-reported symptoms. This Major Depression Inventory (MDI) can be scored both according to the DSM-IV and the ICD-10 algorithms for depressive symptomatology and according to severity scales by the simple total sum of the items. METHODS: The Schedule for Clinical Assessment in Neuropsychiatry (SCAN) was used as index of validity for the clinician's DSM-IV and ICD-10 diagnosis of major (moderate to severe) depression. The sensitivity and specificity of MDI was assessed in a sample of 43 subjects covering a spectrum of depressive symptoms. RESULTS: The sensitivity of the MDI algorithms for major depression varied between 0.86 and 0.92. The specificity varied between 0.82 and 0.86. When using the total score of MDI the optimal cut-off score was estimated 26 and the total score was shown to be a sufficient statistic. LIMITATIONS: The sample of subjects was limited. Patients with psychotic depression were not included. CONCLUSION: The MDI was found to have a sensitivity and specificity which is acceptable. The questionnaire is brief and can be scored diagnostically by the DSM-IV and ICD-10 algorithms as well as by its simple total score. 相似文献
43.
Rasmussen MS Simonsen JA Sandgaard NC Høilund-Carlsen PF Bie P 《Acta physiologica Scandinavica》2004,181(2):247-257
AIM: We tested the hypothesis that oxytocin in normal man causes natriuresis by means of nitric oxide and/or atrial natriuretic peptide. METHODS: Normal male subjects were investigated after 4 days of sodium controlled diets (30 mmol sodium chloride day(-1), n = 8 or 230 mmol sodium chloride day(-1), n = 6). Oxytocin was infused intravenously (1 pmol kg(-1) min(-1) for 240 min). RESULTS: Mean arterial blood pressure, heart rate and glomerular filtration rate by clearance of chromium-labelled ethylenediaminetetraacetate remained stable. Plasma oxytocin increased from 2 to 3 pg mL(-1) to around 50 pg mL(-1). Oxytocin decreased urine flow (4.2 +/- 0.2--0.75 +/- 0.11 and 4.6 +/- 1.3-1.4 +/- 0.6 mL min(-1), low- and high-salt diet, respectively). During low-salt conditions, oxytocin reduced sodium and potassium excretion (11 +/- 2--4 +/- 2 and 93 +/- 19--42 +/- 3 micromol min(-1), respectively). Plasma renin, angiotensin II, aldosterone and renal excretion of metabolites of nitric oxide (nitrate and nitrite) all decreased. Plasma atrial natriuretic peptide and cyclic guanosine monophosphate were unchanged. A similar pattern was obtained during high-salt conditions but in this case the antinatriuresis was not different from that occurring during the corresponding time control series. CONCLUSIONS: The data reject the hypothesis. In contrast, we found significant antinatriuretic, antikaliuretic and antidiuretic effects, which were not mediated by the renin-angiotensin-aldosterone system, atrial natriuretic peptide, systemic haemodynamics, or processes increasing urinary excretion of metabolites of nitric oxide. The natriuretic effect of oxytocin found in laboratory animals is species-specific. 相似文献
44.
45.
N Juul S Torp-Pedersen S Larsen F Rasmussen H H Holm 《Scandinavian journal of urology and nephrology》1986,20(4):275-278
A blind study comparing abdominal ultrasound and cystoscopy was carried out in 186 patients. 20 bladder tumours sized from 2 to 5 mm were overlooked. Combination with urine cytology increased the diagnostic sensitivity. In order to reduce costs and patient inconvenience in the bladder tumour control population abdominal ultrasound and urine cytology is advocated as an alternative to cystoscopy. This control modality seems safe in patients with "low-risk" bladder tumour disease. 相似文献
46.
47.
Tobias JD Holcomb GW Brock JW Morgan WM O'Dell N Lowe S Rasmussen GE 《The American journal of anesthesiology》1995,22(4):193-197
The authors prospectively evaluated the efficacy of caudal epidural block versus local infiltration combined with ilioinguinal/iliohypogastric block for analgesia after inguinal herniorrhaphy with laparoscopic inspection of the peritoneum. During standardized anesthetic care, 24 children were randomized to Group I (caudal epidural block with 1.2 mL/kg of 0.25% bupivacaine) or to Group II (local infiltration with an ilioinguinal/iliohypogastric block). Postoperative pain scores were significantly lower at all four evaluation points in Group I than in Group II. Patients in Group I had a significantly decreased requirement for supplemental intravenous fentanyl. Intra-operative requirements for isoflurane were decreased in Group I. The expired concentration of isoflurane was 0.4 +/- 0.1 (mean +/- SEM) in Group I and 1.5 +/- 0.3 in Group II. Time to extubation was 3.8 +/- 0.5 minutes in Group I and 8.2 +/- 1.1 minutes in Group II. The time from arrival in the postanesthesia care unit until discharge home was 113 +/- 3 minutes in Group I and 152 +/- 11 minutes in Group II. Caudal epidural block was more effective than local infiltration in controlling pain after herniorrhaphy with laparoscopy in children and resulted in earlier discharge home. 相似文献
48.
49.
50.
Various N--hydroxyalkyl derivatives of N-acyl amino acids and di- and tripeptides were prepared by hydrolysis or aminolysis of N-acyl 5-oxazolidinones. The stability of these derivatives was studied in aqueous solution as a function of pH. The compounds were all degraded quantitatively to their parent N-acylated amino acid or peptide and aldehyde but with vastly different rates. At pH 7.4 and 37°C the half-lives of decomposition ranged from 4 min to 1500 hr. The structural factors influencing the stability included both steric and polar effects within the acyl and N--hydroxyalkyl moieties as well as within the amino acid attached to the N--hydroxyalkylated N-acyl amino acid. Whereas the N-benzyloxycarbonyl (Z) derivatives of the dipeptides Gly-L-Leu and Gly-L-Ala were readily hydrolyzed by carboxypeptidase A, the N-hydroxymethylated compounds, i.e., Z-Gly(CH2OH)-Leu and Z-Gly(CH2OH)-Ala, were resistant to cleavage by the enzyme as revealed by their similar rates of decomposition in the presence or absence of the enzyme at pH 7.4 and 37°C. The results suggest that N--hydroxyalkylation of a peptide bond protects not only this bond but also an adjacent peptide bond against proteolytic cleavage. Since the N--hydroxyalkyl derivatives are readily bioreversible, undergoing spontaneous hydrolysis at physiological pH, this prodrug approach promises to overcome the enzymatic barrier to absorption of various peptides. 相似文献