全文获取类型
收费全文 | 6396篇 |
免费 | 536篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 69篇 |
儿科学 | 254篇 |
妇产科学 | 188篇 |
基础医学 | 809篇 |
口腔科学 | 88篇 |
临床医学 | 728篇 |
内科学 | 1461篇 |
皮肤病学 | 139篇 |
神经病学 | 604篇 |
特种医学 | 300篇 |
外科学 | 974篇 |
综合类 | 80篇 |
一般理论 | 6篇 |
预防医学 | 549篇 |
眼科学 | 50篇 |
药学 | 380篇 |
中国医学 | 15篇 |
肿瘤学 | 259篇 |
出版年
2023年 | 49篇 |
2022年 | 54篇 |
2021年 | 97篇 |
2020年 | 94篇 |
2019年 | 104篇 |
2018年 | 144篇 |
2017年 | 135篇 |
2016年 | 137篇 |
2015年 | 143篇 |
2014年 | 153篇 |
2013年 | 285篇 |
2012年 | 324篇 |
2011年 | 296篇 |
2010年 | 210篇 |
2009年 | 191篇 |
2008年 | 291篇 |
2007年 | 302篇 |
2006年 | 268篇 |
2005年 | 205篇 |
2004年 | 210篇 |
2003年 | 175篇 |
2002年 | 172篇 |
2001年 | 175篇 |
2000年 | 180篇 |
1999年 | 154篇 |
1998年 | 108篇 |
1997年 | 101篇 |
1996年 | 102篇 |
1995年 | 81篇 |
1994年 | 72篇 |
1993年 | 83篇 |
1992年 | 154篇 |
1991年 | 139篇 |
1990年 | 143篇 |
1989年 | 134篇 |
1988年 | 136篇 |
1987年 | 126篇 |
1986年 | 124篇 |
1985年 | 99篇 |
1984年 | 97篇 |
1983年 | 82篇 |
1982年 | 46篇 |
1981年 | 47篇 |
1978年 | 43篇 |
1977年 | 48篇 |
1976年 | 40篇 |
1975年 | 47篇 |
1974年 | 39篇 |
1973年 | 39篇 |
1972年 | 40篇 |
排序方式: 共有6953条查询结果,搜索用时 15 毫秒
71.
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
72.
Constitutional and mosaic large NF1 gene deletions in neurofibromatosis type 1. 总被引:7,自引:1,他引:7 下载免费PDF全文
S A Rasmussen S D Colman V T Ho C R Abernathy P H Arn L Weiss C Schwartz R A Saul M R Wallace 《Journal of medical genetics》1998,35(6):468-471
A set of neurofibromatosis type 1 (NF1) patients was screened for large NF1 gene deletions by comparing patient and parent genotypes at 10 intragenic polymorphic loci. Of 67 patient/parent sets (47 new mutation patients and 20 familial cases), five (7.5%) showed loss of heterozygosity (LOH), indicative of NF1 gene deletion. These five patients did not have severe NF1 manifestations, mental retardation, or dysmorphic features, in contrast to previous reports of large NF1 deletions. All five deletions were de novo and occurred on the maternal chromosome. However, two patients showed partial LOH, consistent with somatic mosaicism for the deletion, suggesting that mosaicism may be more frequent in NF1 than previously recognised (and may have bearing on clinical severity). We suggest that large NF1 deletions (1) are not always associated with unusual clinical features, (2) tend to occur more frequently on maternal alleles, and (3) are an important mechanism for constitutional and somatic mutations in NF1 patients. 相似文献
73.
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
74.
KM Kanal NJ Hangiandreou AM Sykes HE Eklund PA Araoz JA Leon BJ Erickson 《Journal of digital imaging》2002,14(1):30-37
The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's
gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing
radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers,
and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed
with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant,
and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender
were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women
was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative
English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and
while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology
practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient
way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed
and sensitive manner. 相似文献
75.
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
76.
77.
The role of size, sequence and haplotype in the stability of FRAXA and FRAXE alleles during transmission 总被引:2,自引:5,他引:2
Murray A; Macpherson JN; Pound MC; Sharrock A; Youings SA; Dennis NR; McKechnie N; Linehan P; Morton NE; Jacobs PA 《Human molecular genetics》1997,6(2):173-184
Factors involved in the stability of trinucleotide repeats during
transmission were studied in 139 families in which a full mutation,
premutation or intermediate allele at either FRAXA or FRAXE was
segregating. The transmission of alleles at FRAXA, FRAXE and four
microsatellite loci were recorded for all individuals. Instability within
the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for
FRAXE) was extremely rare; only one example was observed, an increased in
size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in
the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were
unstably transmitted. Instability was more frequent for FRAXA intermediate
alleles that had a tract of pure CGG greater than 37 although instability
only occurred in two of 13 such transmissions: the changes observed were
limited to only one or two repeats. Premutation FRAXA alleles over 100
repeats expanded to a full mutation during female transmission in 100% of
cases, in agreement with other published series. There was no clear
correlation between haplotype and probability of expansion of FRAXA
premutations. Instability at FRAXA or FRAXE was more often observed in
conjunction with a second instability at an independent locus suggesting
genomic instability as a possible mechanism by which at least some FRAXA
and FRAXE mutations arise.
相似文献
78.
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
79.
80.
J Davies B Srinivasan PA Brennan 《Annals of the Royal College of Surgeons of England》2021,103(1):e42
Lipomas are common benign tumours that can occur in most parts of the body. Lipomas arising from the deep temporal fat pad, found between the two layers of the deep temporal fascia, are rare, however; there has been only one documented case report to our knowledge. We describe a second case arising from the temporal fat pad in a patient treated at our unit, having previously reported the first one, and discuss the relevant anatomy and management. 相似文献