全文获取类型
收费全文 | 315篇 |
免费 | 4篇 |
国内免费 | 12篇 |
学科分类
医药卫生 | 331篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2014年 | 4篇 |
2013年 | 9篇 |
2012年 | 6篇 |
2011年 | 4篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 3篇 |
2007年 | 13篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 13篇 |
1997年 | 22篇 |
1996年 | 24篇 |
1995年 | 15篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 22篇 |
1988年 | 13篇 |
1987年 | 18篇 |
1986年 | 17篇 |
1985年 | 20篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 6篇 |
排序方式: 共有331条查询结果,搜索用时 0 毫秒
1.
PADGEM (GMP140) is a component of Weibel-Palade bodies of human endothelial cells 总被引:65,自引:10,他引:55
PADGEM protein (PADGEM), also known as GMP140, is a platelet alpha- granule membrane protein that is translocated to the external membrane after platelet activation. Although the biosynthesis of this protein was originally thought to be confined to megakaryocytes, the synthesis of PADGEM in endothelial cells was recently demonstrated (McEver et al: Blood 70:1974a, 1987). We now describe the subcellular localization of this protein in endothelial cells. Immunofluorescence staining of permeabilized human umbilical vein endothelial cells with KC4, a well characterized monoclonal antibody to PADGEM, showed positively stained elongated structures similar in distribution and shape to Weibel-Palade bodies. Their identity as Weibel-Palade bodies was confirmed by double label immunofluorescence using KC4 and a polyclonal antiserum to von Willebrand factor (vWf), a protein known to be specifically stored in these organelles. All Weibel-Palade bodies were found to contain PADGEM. In contrast to strong perinuclear staining produced with anti- vWf antibodies, no significant perinuclear staining was obtained with KC4, indicating that relatively little PADGEM is present in the endoplasmic reticulum and in the Golgi apparatus. In endothelial cells treated with secretagogues that stimulate vWf release the elongated structures positive for PADGEM disappeared, further identifying these structures as Weibel-Palade bodies. This observation extends the parallels between Weibel-Palade bodies and alpha-granules and suggests a possible functional association between vWf and PADGEM. 相似文献
2.
Advanced primary breast cancer: assessment at mammography of response to induction chemotherapy 总被引:2,自引:0,他引:2
The response to induction chemotherapy is an important prognostic factor in patients with nonmetastatic, locally advanced breast carcinomas. Assessment at mammography of the response of 60 breast cancers in 59 women was performed between 1974 and 1986. Responses were excellent in 13 tumors, moderate in 34, and poor in 13 (excellent moderate = 78%). Assessment of response of discrete masses in a fatty breast was easiest; assessment of response of tumor areas that were poorly defined-such as a focal area of architectural distortion or mass in dense breast parenchyma-was more difficult. Of 17 patients with excellent pathologic responses-that is, minimal or no residual tumor-15 (88%) had complete responses (no residual tumor) as determined with mammography, physical examination, or both. Mammography provides information complementary to physical examination and is essential in the accurate assessment of the response to chemotherapy of locally advanced breast cancer. 相似文献
3.
4.
The effects of co-culture with human fibroblasts on human embryo development in vitro and implantation 总被引:5,自引:0,他引:5
Wetzels AM; Bastiaans BA; Hendriks JC; Goverde HJ; Punt-van der Zalm AP; Verbeet JG; Braat DD 《Human reproduction (Oxford, England)》1998,13(5):1325-1330
In a human in-vitro fertilization (IVF) programme, the effect of co-
culture of embryos with human fibroblasts was evaluated with respect to
pregnancy rate and embryo development. Patients were included in the study
after giving informed written consent. The IVF treatments were randomly
assigned by stratification of both age (<36 versus > or =36 years)
and previous IVF attempts (yes versus no). After fertilization was
established, the zygotes were transferred to a 4-well dish with or without
fibroblasts and cultured for 2 days. On the third day after ovum pick-up
(OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were
scored and a maximum of three embryos was transferred. Supernumerary
embryos of good quality were cryopreserved. The design of this study was a
group sequential trial with the objective of detecting differences between
pregnancy rates following IVF with conventional incubation or incubation in
co-culture with fibroblasts. This design included one evaluation at
half-way data collection. In the study, 148 patients had an OPU, of whom 77
were allocated to the co-culture group. There was no statistically
significant difference in pregnancy rate, cell number and embryo quality
between the two groups. The ongoing pregnancy rate per embryo transfer was
27% in co-culture and 30% in the conventional culture group. The
implantation rates per transferred embryo were 17 and 18% respectively.
Using a multivariate logistic regression model for the probability of
ongoing pregnancies, the odds ratio of co-culture, adjusted for age and
previous IVF attempts, was not statistically significant. In conclusion,
co-culture with human fibroblasts does not contribute to an improvement of
embryo quality nor to a higher pregnancy rate after IVF in an unselected
group of patients.
相似文献
5.
Dohle GR; Ramos L; Pieters MH; Braat DD; Weber RF 《Human reproduction (Oxford, England)》1998,13(3):620-623
Male genital tract obstructions may result from infections, previous
inguinal and scrotal surgery (vasectomy) and congenital bilateral absence
of the vas deferens (CBAVD). Microsurgery can sometimes be successful in
treating the obstruction. In other cases and in cases of failed surgical
intervention, the patient can be treated by microsurgical or percutaneous
epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction
(TESE) and intracytoplasmic sperm injection (ICSI). We present the results
of 39 ICSI procedures for obstructive azoospermia in 24 couples. The
aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD
in nine and genital infections in four. Sperm retrieval was accomplished
via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was
only applied when PESA failed to produce enough spermatozoa for
simultaneous ICSI. In six patients, the ICSI procedure was performed with
cryopreserved spermatozoa after an initial PESA procedure. Fertilization
occurred in 47% of the metaphase II oocytes; embryo transfer was performed
in 92% of procedures and resulted in a clinical pregnancy in 13/39
procedures. Ongoing pregnancy was achieved in 10/39 procedures. One
pregnancy was terminated early after prenatal investigation showed a
cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine
pregnancies resulted in the live birth of 10 children, without any
congenital abnormalities. Epididymal and testicular retrieved spermatozoa
were successfully used for ICSI to treat obstructive azoospermia, and
resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI
procedures, a success rate of 25.6% per treatment cycle and of 27.7% per
embryo transfer.
相似文献
6.
7.
Congenital pulmonary atresia with ventricular septal defect: angiographic and surgical correlates 总被引:1,自引:0,他引:1
Of 181 patients with severe congenital pulmonary atresia and ventricular septal defect or "type IV truncus" (an obsolete term), all but 11% had true central pulmonary arteries. These arteries were demonstrable by large serial biplane angiograms using multiple selective injections into collateral vessels, frequent photographic subtraction, and occasional pulmonary vein-wedge angiograms. These techniques are extremely important for accurate diagnosis and in planning corrective or palliative surgery, which was done in 77% of patients with pulmonary arteries. 相似文献
8.
von Willebrand factor released from Weibel-Palade bodies binds more avidly to extracellular matrix than that secreted constitutively 总被引:8,自引:5,他引:8
Large multimers of von Willebrand factor (vWf) are released from the Weibel-Palade bodies of cultured endothelial cells following treatment with a secretagogue (Sporn et al, Cell 46:185, 1986). These multimers were shown by immunofluorescent staining to bind more extensively to the extracellular matrix of human foreskin fibroblasts than constitutively secreted vWf, which is composed predominantly of dimeric molecules. Increased binding of A23187-released vWf was not due to another component present in the releasate, since releasate from which vWf was adsorbed, when added together with constitutively secreted vWf, did not promote binding. When iodinated plasma vWf was overlaid onto the fibroblasts, the large forms bound preferentially to the matrix. These results indicated that the enhanced binding of the vWf released from the Weibel-Palade bodies was likely due to its large multimeric size. It appears that multivalency is an important component of vWf interaction with the extracellular matrix, just as has been shown for vWf interaction with platelets. The pool of vWf contained within the Weibel-Palade bodies, therefore, is not only especially suited for platelet binding, but also for interaction with the extracellular matrix. 相似文献
9.
Hematologic and immunomodulatory effects of an interleukin-1 receptor antagonist coinfusion during low-dose endotoxemia in healthy humans 总被引:3,自引:0,他引:3
Granowitz EV; Porat R; Mier JW; Orencole SF; Callahan MV; Cannon JG; Lynch EA; Ye K; Poutsiaka DD; Vannier E 《Blood》1993,82(10):2985-2990
Endotoxin is a component of gram-negative bacteria that causes hematologic and immunologic changes through its induction of cytokines. Interleukin-1 receptor antagonist (IL-1Ra) is a naturally occurring inhibitor of IL-1 that competes with IL-1 for occupancy of cell-surface receptors but possesses no agonist activity. We investigated the ability of human recombinant IL-1Ra to block the effects of low-dose endotoxin. Fourteen healthy male volunteers between 18 and 30 years old were injected intravenously with 3 ng/kg Escherichia coli endotoxin. Concurrent with the injections, nine volunteers received a 3-hour continuous intravenous infusion of IL-1Ra. The other five subjects were given a 3-hour infusion of saline. Volunteers injected with endotoxin experienced a threefold increase in circulating neutrophils over baseline. This neutrophilia was significantly reduced by 48% in subjects administered endotoxin plus IL-1Ra (P = .0253). Ex vivo mitogen-induced peripheral blood mononuclear cell proliferation decreased by greater than 60% at 3 and 6 hours after endotoxin injection (P = .0053). This endotoxin-induced reduction in mitogen response was reversed in subjects coinjected with IL-1Ra (P = .0253). Endotoxin-induced symptoms, fever, and tachycardia were unaffected by IL-1Ra. IL-1 appears to be an important mediator in endotoxemia because some of its hematologic and immunomodulatory effects can be blocked by IL-1Ra. 相似文献
10.
软骨修复组织蛋白多糖代谢与一氧化氮合酶抑制剂的影响 总被引:3,自引:0,他引:3
目的:应用一氧化氮合酶抑制剂可改善骨性关节炎和风湿性关节炎软骨的代谢,作者前期的实验也证明一氧化氮合酶抑制剂能提高软骨修复组织的质量。实验进一步观察一氧化氮合酶抑制剂对软骨修复组织蛋白多糖代谢的影响。方法:实验于1999-06/2002-02在南方医科大学完成。①实验分组:取雄性新西兰兔24只,8月龄,体质量(2.5±0.2)kg。随机抽签法分为对照组、骨形态发生蛋白组和S-甲基异硫脲组,每组8只。②实验方法:将大白兔双侧股骨髁间关节面造成全层软骨缺损,对照组:软骨缺损不充填任何物质;骨形态发生蛋白组:缺损用骨形态发生蛋白纤维蛋白凝胶复合物充填;S-甲基异硫脲组:缺损应用胶原复合骨形态发生蛋白充填,术后按5mg/(kg·12h)皮下注射S-甲基异硫脲。术后1年麻醉后处死动物。③实验评估:应用组织切片番红O-快绿染色和图像分析技术,按照染色百分率、平均灰度(平均染色程度)和染色厚度(软骨厚度)指标来检测糖胺聚糖含量;应用Na235SO4掺入法检测软骨修复组织蛋白多糖合成。结果:纳入新西兰兔24只,均进入结果分析。①术后1年,对照组几乎无红色染色区域;骨形态发生蛋白组可见到少量的不均匀红色区域;S-甲基异硫脲组可见到较多均匀一致的红色染色区域。②S-甲基异硫脲组软骨修复组织番红O染色百分率为89.28%,明显高于骨形态发生蛋白组36.54%和对照组13.4%,S-甲基异硫脲组修复组织番红O-快绿染色平均灰度值134.5,分别为骨形态发生蛋白组平均灰度值56.8的2.5倍,为对照组26.4的7倍。软骨平均厚度S-甲基异硫脲组1.75cm分别为骨形态发生蛋白组0.76cm和对照组0.25cm的2倍和6倍。③Na235SO4掺入法结果显示,S-甲基异硫脲组[35S]摄入量明显高于骨形态发生蛋白组和对照组(P<0.01)。结论:诱导型一氧化氮合酶抑制剂S-甲基异硫脲的应用能明显增加软骨修复组织糖胺聚糖含量和蛋白多糖合成,对于软骨修复质量的提高有积极意义。 相似文献