全文获取类型
收费全文 | 600篇 |
免费 | 48篇 |
国内免费 | 61篇 |
学科分类
医药卫生 | 709篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 9篇 |
2018年 | 11篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 11篇 |
2014年 | 22篇 |
2013年 | 30篇 |
2012年 | 9篇 |
2011年 | 13篇 |
2010年 | 28篇 |
2009年 | 28篇 |
2008年 | 29篇 |
2007年 | 49篇 |
2006年 | 20篇 |
2005年 | 20篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 14篇 |
2001年 | 18篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 35篇 |
1997年 | 37篇 |
1996年 | 24篇 |
1995年 | 25篇 |
1994年 | 29篇 |
1993年 | 20篇 |
1992年 | 5篇 |
1991年 | 10篇 |
1990年 | 3篇 |
1989年 | 18篇 |
1988年 | 18篇 |
1987年 | 11篇 |
1986年 | 4篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1975年 | 4篇 |
1966年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有709条查询结果,搜索用时 15 毫秒
1.
Balloon dacryocystoplasty: indications and contraindications 总被引:3,自引:0,他引:3
2.
3.
Survey of CAG/CTG repeats in human cDNAs representing new genes: candidates for inherited neurological disorders 总被引:3,自引:2,他引:3
Neri C; Albanese V; Lebre AS; Holbert S; Saada C; Bougueleret L; Meier-Ewert S; Le Gall I; Millasseau P; Bui H; Giudicelli C; Massart C; Guillou S; Gervy P; Poullier E; Rigault P; Weissenbach J; Lennon G; Chumakov I; Dausset J; Lehrach H; Cohen D; Cann HM 《Human molecular genetics》1996,5(7):1001-1009
4.
New serological assay for detection of putative Helicobacter pylori virulence factors 总被引:4,自引:0,他引:4 下载免费PDF全文
Park CY Cho YK Kodama T El-Zimaity HM Osato MS Graham DY Yamaoka Y 《Journal of clinical microbiology》2002,40(12):4753-4756
We evaluated a new immunoblot assay (Helicoblot 2.1) for Helicobacter pylori infection and CagA and VacA status by using serum samples from 222 patients. The test accurately detected H. pylori infection and VacA status, but improvements in the interpretation criteria are required before it can be recommended for determination of CagA status. 相似文献
5.
Graham DY Hoffman J Anderson SY Qureshi W Osato MS El-Zimaity HM 《Alimentary pharmacology & therapeutics》1999,13(2):169-172
BACKGROUND: Although many combination therapies have been proposed, there is still interest in identifying simple, inexpensive, effective protocols that have high rates of success. AIM: To investigate the role of the new soluble form of bismuth, ranitidine bismuth citrate, in twice-a-day therapy for Helicobacter pylori infection. METHODS: Patients with histologically and culture proven H. pylori infection received ranitidine bismuth citrate 400 mg, tetracycline HCl 500 mg, and clarithromycin 500 mg, each b.d. for 14 days, followed by 300 mg ranitidine once a day for 4 additional weeks. Outcome was assessed 4 or more weeks after the end of antimicrobial therapy by repeat endoscopy with histology and culture (49 patients) or urea breath testing (14 patients). RESULTS: Sixty-three patients completed the therapy, 59 men and four women (average age 56.7 years; range 31-75 years). All patients had clarithromycin-susceptible strains prior to therapy. H. pylori infection was cured in 94% (95% CI: 85-98%). There was a therapy failure in one patient who took the medicine for only 1 day and stopped because of side-effects. Three of the isolates from treatment failures were available post-failure; two were clarithromycin-resistant and one was susceptible. Side-effects were severe in two patients (3%) and moderate in three (primarily diarrhoea). CONCLUSIONS: Twice-a-day ranitidine bismuth citrate, tetracycline, clarithromycin triple therapy was well tolerated and effective for the treatment of H. pylori infection in patients with clarithromycin-susceptible H. pylori. 相似文献
6.
OBJECTIVES: To determine the spectrum of N and G genotypes of respiratory syncytial virus (RSV) causing respiratory tract infection and whether particular genotypes are associated with severity of infection. PATIENTS AND METHODS: Nasopharyngeal aspirates (NPAs) were obtained from 114 infants with acute respiratory tract infection due to RSV over two seasons. Viral mRNA was extracted from NPAs or cultured virus, reverse transcribed, and the cDNA amplified by the polymerase chain reaction using primers directed to parts of the N and G gene respectively. Amplicons were separately digested with four different restriction endonucleases for each gene. The fragments were separated by agarose gel, electrophoresis, and the electrophoretic patterns used to assign the various genotypes. Disease severity was assessed as very mild (upper respiratory tract signs only), mild (coryza and signs of lower respiratory tract infection), moderate (requiring nasogastric or intravenous fluids), and severe (requiring oxygen or ventilation). RESULTS: Five of the six known N genotypes were detected, but NP4 and NP2 were found most frequently. There was no association between N genotype and disease severity. Six G (SHL) genotypes were detected. Significantly (p = 0.04) more of the infants infected with the SHL2 genotype had severe or moderate disease. CONCLUSIONS: During the seasonal peaks of RSV respiratory tract infection at least 10 different RSV genotypes cocirculated. While there is no association between N genotypes and disease severity, infection with the SHL2 G genotype appears to result in moderate to severe disease. 相似文献
7.
8.
Arianne C Lim Kitty WM Bloemenkamp Kees Boer Johannes J Duvekot Jan Jaap HM Erwich Tom HM Hasaart Pieter Hummel Ben WJ Mol Jos PM Offermans Charlotte M van Oirschot Job G Santema Hubertina CJ Scheepers Willem A Schöls Frank PHA Vandenbussche Maurice GAJ Wouters Hein W Bruinse 《BMC pregnancy and childbirth》2007,7(1):1-6
Background
Adequate vitamin D concentrations during pregnancy are necessary to neonatal calcium homeostasis, bone maturation and mineralization. The aim of study is to evaluate serum vitamin D concentrations in mothers and their newborns and effect of vitamin D deficiency on pregnancy outcomes.Methods
552 pregnant women were recruited from Tehran University educating hospitals in the winter of 2002. Maternal and cord blood samples were taken at delivery. The serum was assayed for 25-hydroxyvitamin D3, calcium, phosphorus and parathyroid hormone.Results
The prevalence of vitamin D deficiency in maternal and cord blood samples were 66.8% and 93.3%, respectively (<35 nmol/l). There was significant correlation between maternal and cord blood serum concentrations of vitamin D. In mothers with vitamin D deficiency, cord blood vitamin D concentrations was lower than those from normal mothers (P = .001). Also, a significant direct correlation was seen between maternal vitamin D intake and weight gain during pregnancy.Conclusion
Consideration to adequate calcium and vitamin D intake during pregnancy is essential. Furthermore, we think it is necessary to reconsider the recommendation for vitamin D supplementation for women during pregnancy. 相似文献9.
Background
Breathlessness causes significant burden in our community but the underlying socio-demographic and lifestyle factors that may influence it are not well quantified. This study aims to define these predictors of chronic breathlessness at a population level. 相似文献10.
Primary tumor cells of myeloma patients induce interleukin-6 secretion in long-term bone marrow cultures 总被引:6,自引:9,他引:6
Lokhorst HM; Lamme T; de Smet M; Klein S; de Weger RA; van Oers R; Bloem AC 《Blood》1994,84(7):2269-2277
Long-term bone marrow cultures (LTBMC) from patients with multiple myeloma (MM) and normal donors were analyzed for immunophenotype and cytokine production. Both LTBMC adherent cells from myeloma and normal donor origin expressed CD10, CD13, the adhesion molecules CD44, CD54, vascular cell adhesion molecule 1, very late antigen 2 (VLA-2), and VLA- 5, and were positive for extracellular matrix components fibronectin, laminin, and collagen types 3 and 4. LTBMC from myeloma patients and normal donors spontaneously secreted interleukin-6 (IL-6). However, levels of IL-6 correlated with the stage of disease; highest levels of IL-6 were found in LTBMC from patients with active myeloma. To identify the origin of IL-6 production, LTBMC from MM patients and normal donors were cocultured with BM-derived myeloma cells and cells from myeloma cell lines. IL-6 was induced by plasma cell lines that adhered to LTBMC such as ARH-77 and RPMI-8226, but not by nonadhering cell lines U266 and FRAVEL. Myeloma cells strongly stimulated IL-6 secretion in cocultures with LTBMC adherent cells from normal donors and myeloma patients. When direct cellular contact between LTBMC and plasma cells was prevented by tissue-culture inserts, no IL-6 production was induced. This implies that intimate cell-cell contact is a prerequisite for IL-6 induction. Binding of purified myeloma cells to LTBMC adherent cells was partly inhibited by monoclonal antibodies against adhesion molecules VLA-4, CD44, and lymphocyte function-associated antigen 1 (LFA-1) present on the plasma cell. Antibodies against VLA-4, CD29, and LFA-1 also inhibited the induced IL-6 secretion in plasma cell-LTBMC cocultures. In situ hybridization studies performed before and after coculture with plasma cells indicated that LTBMC adherent cells produce the IL-6. These results suggest that the high levels of IL-6 found in LTBMC of MM patients with active disease are a reflection of their previous contact with tumor cells in vivo. These results provide a new perspective on tumor growth in MM and emphasize the importance of plasma cell-LTBMC interaction in the pathophysiology of MM. 相似文献