全文获取类型
收费全文 | 567篇 |
免费 | 37篇 |
国内免费 | 23篇 |
专业分类
儿科学 | 35篇 |
妇产科学 | 12篇 |
基础医学 | 95篇 |
口腔科学 | 7篇 |
临床医学 | 66篇 |
内科学 | 93篇 |
皮肤病学 | 2篇 |
神经病学 | 7篇 |
特种医学 | 172篇 |
外科学 | 18篇 |
综合类 | 11篇 |
预防医学 | 18篇 |
眼科学 | 5篇 |
药学 | 29篇 |
肿瘤学 | 57篇 |
出版年
2023年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 15篇 |
2013年 | 21篇 |
2012年 | 9篇 |
2011年 | 8篇 |
2010年 | 16篇 |
2009年 | 17篇 |
2008年 | 8篇 |
2007年 | 24篇 |
2006年 | 11篇 |
2005年 | 20篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 31篇 |
1997年 | 29篇 |
1996年 | 42篇 |
1995年 | 23篇 |
1994年 | 18篇 |
1993年 | 28篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 13篇 |
1989年 | 25篇 |
1988年 | 24篇 |
1987年 | 25篇 |
1986年 | 10篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 21篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 9篇 |
1976年 | 18篇 |
1975年 | 7篇 |
排序方式: 共有627条查询结果,搜索用时 0 毫秒
51.
The pharmacology of a new pasteurized factor VIII (FVIII) concentrate derived from human blood plasma was studied in 23 adults with hemophilia A. In Part 1 of the study involving six nonbleeding subjects, the mean increase in FVIII activity was 1.43 +/- 0.34 U per ml 10 minutes after an intravenous dose of 50 U per kg. The intravascular survival kinetics in these six patients showed a biphasic decay curve with an initial mean half-life of 5.1 +/- 1.2 hours probably representing early redistribution, and a late half-life of 13.3 +/- 4.9 hours. In Part 2 of the study, the activity at 10 minutes was measured in another 17 patients, as well as in one patient already studied in Part 1. The mean increase in activity with the 24 observations was 1.13 +/- 0.37 U per ml with a mean FVIII dosage of 51.0 +/- 2.6 U per kg of body weight. Only one patient had an allergic reaction, which did not recur when the patient was given a second lot. 相似文献
52.
Percutaneous umbilical blood samples (PUBS), obtained under ultrasound guidance, are used for prenatal diagnosis and management of hemolytic disease of the newborn (HDN) and other fetal disorders. Rapid testing at the time of sampling is vital to distinguish fetal from maternal blood. Blood typing was performed by slide technique in the treatment room during 38 procedures on 25 patients. Anti-I was used to test 50 presumed PUBS; venous I-positive maternal blood was tested in parallel. Because anti-I cannot detect fetal blood after umbilical vein transfusion (UVT) of I-positive donor blood, ABO and Rh blood typing reagents were used to test 29 samples when maternal and fetal or donor blood groups differed. Monoclonal reagents were used for optimal detection of weak AB antigens in fetal blood. Avid, chemically modified anti-D was used for Rh typing. Blood typing showed 27 (34%) of 79 samples to be maternal blood. Fetal blood was obtained in 8 of 10 cases investigated for fetal disorder and in 16 cases of potential HDN (anti-D, 5; -CD, 5; -cE, 2; -K, 2; -c; -E). The absence of HDN (antigen-negative fetus) was determined in 4 cases. UVT afforded live birth of 9 of 10 infants with HDN and was not indicated in two cases. 相似文献
53.
54.
Herkert JC Niessen RC Olderode-Berends MJ Veenstra-Knol HE Vos YJ van der Klift HM Scheenstra R Tops CM Karrenbeld A Peters FT Hofstra RM Kleibeuker JH Sijmons RH 《European journal of cancer (Oxford, England : 1990)》2011,47(7):965-982
BackgroundBi-allelic germline mutations of one of the DNA mismatch repair genes, so far predominantly found in PMS2, cause constitutional MMR-deficiency syndrome. This rare disorder is characterised by paediatric intestinal cancer and other malignancies. We report the clinical, immunohistochemical and genetic characterisation of four families with bi-allelic germline PMS2 mutations. We present an overview of the published gastrointestinal manifestations of CMMR-D syndrome and propose recommendations for gastro-intestinal screening.Methods and ResultsThe first proband developed a cerebral angiosarcoma at age 2 and two colorectal adenomas at age 7. Genetic testing identified a complete PMS2 gene deletion and a frameshift c.736_741delinsTGTGTGTGAAG (p.Pro246CysfsX3) mutation. In the second family, both the proband and her brother had multiple intestinal adenomas, initially wrongly diagnosed as familial adenomatous polyposis. A splice site c.2174+1G>A, and a missense c.137G>T (p.Ser46Ile) mutation in PMS2 were identified. The third patient was diagnosed with multiple colorectal adenomas at age 11; he developed a high-grade dysplastic colorectal adenocarcinoma at age 21. Two intragenic PMS2 deletions were found. The fourth proband developed a cerebral anaplastic ganglioma at age 9 and a high-grade colerectal dysplastic adenoma at age 10 and carries a homozygous c.2174+1G>A mutation.Tumours of all patients showed microsatellite instability and/or loss of PMS2 expression.ConclusionsOur findings show the association between bi-allelic germline PMS2 mutations and severe childhood-onset gastrointestinal manifestations, and support the notion that patients with early-onset gastrointestinal adenomas and cancer should be investigated for CMMR-D syndrome. We recommend yearly follow-up with colonoscopy from age 6 and simultaneous video-capsule small bowel enteroscopy from age 8. 相似文献
55.
Risk of colorectal and endometrial cancers in EPCAM deletion-positive Lynch syndrome: a cohort study
Kempers MJ Kuiper RP Ockeloen CW Chappuis PO Hutter P Rahner N Schackert HK Steinke V Holinski-Feder E Morak M Kloor M Büttner R Verwiel ET van Krieken JH Nagtegaal ID Goossens M van der Post RS Niessen RC Sijmons RH Kluijt I Hogervorst FB Leter EM Gille JJ Aalfs CM Redeker EJ Hes FJ Tops CM van Nesselrooij BP van Gijn ME Gómez García EB Eccles DM Bunyan DJ Syngal S Stoffel EM Culver JO Palomares MR Graham T Velsher L Papp J Oláh E Chan TL Leung SY van Kessel AG Kiemeney LA Hoogerbrugge N 《The lancet oncology》2011,12(1):49-55
56.
57.
58.
59.
Kersten MJ; Evers LM; Dellemijn PL; van den Berg H; Portegies P; Hintzen RQ; van Lier RA; von dem Borne AE; van Oers RH 《Blood》1996,87(5):1985-1989
Diagnosis of meningeal localization of lymphoid malignancies by means of cytologic examination of the cerebrospinal fluid (CSF) can be difficult. Thus far no reliable CSF tumor markers have been identified. CD27 is a transmembrane disulfide-linked 55-kD homodimer present on most peripheral blood T cells and on a subset of B cells. CD27 is also expressed on human malignant B cells and high levels of soluble CD27 can be present in the serum of patients with B-cell malignancies. The aim of this study is to determine prospectively the diagnostic value of CSF sCD27 as a tumor marker in patients with meningeal localization of lymphoid malignancies. CSF sCD27 levels were determined by sandwich enzyme-linked immunosorbent assay. The optimal cut-off value using receiver operator characteristics curves was found to be 10 U/mL. sCD27 levels were normal in all 50 control patients (lumbar disc protrusion) and in 39 of 40 samples obtained from patients with either solid tumors or acute myeloid leukemia. Of 104 CSF samples from 70 children with acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) undergoing routine central nervous system (CNS) staging, sCD27 was false positive and false negative in only one sample each. In 70 samples from 45 patients suspected of meningeal localization of ALL or NHL, the sCD27 test had an excellent sensitivity (100%) and specificity (82%). In 7 patients with positive CSF studied longitudinally, sCD27 levels correlated very well with remission and relapse. sCD27 levels were not nonspecifically increased by the administration of cytostatic drugs. Finally, sCD27 was also elevated in the 4 patients studied with primary central nervous system lymphoma (PCNSL). CSF sCD27 is a promising tumor marker in patients with either meningeal localization of lymphoid malignancies or PCNSL, and can be useful in the differential diagnosis of CNS involvement by either lymphoid malignancies or solid tumors. 相似文献
60.
CJ Barry AIIP CRA AAIMBI RL Cooper FRACO FRACS RH Eikelboom BE PhD 《Clinical & experimental ophthalmology》1997,25(2):137-143
Purpose: To retrospectively examine the optic disc photographs of a glaucoma population for optic disc haemorrhages, vascular occlusions and vascular abnormalities. Methods: The optic disc photographs of 906 eyes of glaucoma and suspect glaucoma patients were examined. Optic disc photographs were taken annually, where possible, with the follow-up period varying between 1 and 14 years duration (mean, 2.89). Glaucoma patients are regularly reviewed every 4–6 months and glaucoma suspects every 1–2 years, depending on the ophthalmologist. Low-tension glaucoma patients were reviewed more frequently (mean, every 2.6 months). The results of the findings were compared to a control group of 39 subjects with a mean follow-up period of 7 years, using Fisher's exact test. Results: It was found that during the period under review, 7.4% (n= 67) of eyes had optic disc haemorrhages. The highest frequency of optic disc haemorrhages (37.5%) was found in the low tension glaucoma group (P= 0.0001) followed by 11.4% of primary open-angle glaucoma eyes (P= 0.03). In the normal group there were three eyes with optic disc haemorrhages and one with a disc collateral, which constitutes 5.1% vascular changes in this sub-group. Of the study eyes 2.8% had central retinal vein occlusions, 1.3% branch vein occlusion, 1.2% disc vessel abnormalities (loops) and 1.1% disc collaterals. Discrete nerve fibre layer haemorrhages and microaneurysms were found in 0.8% and 1.8% of eyes, respectively. Conclusions: A total of 16.8% of the eyes observed in this study had either disc haemorrhages or vascular changes. The underlying trend of vascular and haemorrhagic changes in glaucoma are demonstrated in this sample, which is in general agreement with previous studies. The high percentage of optic disc haemorrhages in low tension glaucoma is highlighted. The presence of microaneurysms and nerve fibre layer haemorrhages is interesting but of unknown significance. 相似文献