全文获取类型
收费全文 | 698篇 |
免费 | 112篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 50篇 |
妇产科学 | 13篇 |
基础医学 | 167篇 |
口腔科学 | 15篇 |
临床医学 | 58篇 |
内科学 | 179篇 |
皮肤病学 | 29篇 |
神经病学 | 26篇 |
特种医学 | 86篇 |
外科学 | 67篇 |
综合类 | 24篇 |
预防医学 | 19篇 |
眼科学 | 8篇 |
药学 | 29篇 |
中国医学 | 2篇 |
肿瘤学 | 32篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2019年 | 12篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 15篇 |
2013年 | 27篇 |
2012年 | 9篇 |
2011年 | 15篇 |
2010年 | 31篇 |
2009年 | 32篇 |
2008年 | 20篇 |
2007年 | 19篇 |
2006年 | 21篇 |
2005年 | 22篇 |
2004年 | 14篇 |
2003年 | 17篇 |
2002年 | 15篇 |
2001年 | 14篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 22篇 |
1997年 | 42篇 |
1996年 | 33篇 |
1995年 | 23篇 |
1994年 | 24篇 |
1993年 | 21篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 18篇 |
1989年 | 33篇 |
1988年 | 20篇 |
1987年 | 21篇 |
1986年 | 23篇 |
1985年 | 27篇 |
1984年 | 18篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 15篇 |
1979年 | 13篇 |
1978年 | 13篇 |
1977年 | 16篇 |
1976年 | 13篇 |
1975年 | 8篇 |
1974年 | 7篇 |
1970年 | 3篇 |
1963年 | 2篇 |
排序方式: 共有810条查询结果,搜索用时 15 毫秒
21.
22.
Failure of endotoxin to increase nonspecific resistance to infection of lipopolysaccharide low-responder mice. 总被引:10,自引:15,他引:10 下载免费PDF全文
In vitro and in vivo responses to lipopolysaccharide (LPS) and various other bacterial immunostimulants were compared in c3H/He low-responder mice. The principal findings were as follows. (i) Their splenic lymphocytes were stimulated by various gram-negative mitogens such as an Escherichia coli peptidoglycan, a detoxified derivative of LPS, and even endotoxins extracted by trichloroacetic acid that are known to contain protein; spleen cells of these mice were also transformed by two other B-cell mitogens extracted from acid-fast organisms. (ii) Their macrophages were refractory to LPS and weakly responsive to a mycobacterial prepartion. (iii) LPS failed to elicit nonspecific resistance in these mice against Klebsiella pneumoniae infection. (iv) Endotoxin extracted by trichloroacetic acid and a mycobacterial preparation that could increase nonspecific resistance to infection in other strains did not protect C3H/He mice against a challenge by K. pneumoniae, although both prepartions could evoke nonspecific responses of B cells in this low-responder subline. 相似文献
23.
Michel Ribeiro Fernandes Caroline Lorenzoni Almeida Ghezzi Tomaz JM Grezzana-Filho Fl via Heinz Feier Ian Leipnitz Aljamir Duarte Chedid Carlos Thadeu Schmidt Cerski Marcio Fernandes Chedid Cl ber Rosito Pinto Kruel 《World journal of gastrointestinal surgery》2021,13(3):315-322
BACKGROUNDPrimary extra-gastrointestinal stromal tumors (E-GIST) of the liver are rare. The clinical presentation may range from asymptomatic to bleeding or manifestations of mass effect. Oncologic surgery followed by adjuvant therapy with imatinib is the standard of care. However, under specific circumstances, a cytoreductive approach may represent a therapeutic option. We describe herein the case of an 84-year-old woman who presented with a tender, protruding epigastric mass. Abdominal computed tomography scan revealed a large, heterogeneous mass located across segments III, IV, V, and VIII of the liver. The initial approach was transarterial embolization of the tumor, which elicited no appreciable response. Considering the large size and central location of the tumor and the advanced age of the patient, non-anatomic complete resection was indicated. Due to substantial intraoperative bleeding and hemodynamic instability, only a near-complete resection could be achieved. Histopathology and immunohistochemical staining confirmed the diagnosis of primary E-GIST of the liver. Considering the risk/benefit ratio for therapeutic options, debulking surgery may represent a strategy to control pain and prolong survival.CASE SUMMARYHere, we present a case report of a patient diagnosed with E-GIST primary of the liver, which was indicated a cytoreductive surgery and adjuvant therapy with imatinib.CONCLUSIONE-GIST primary of the liver is a rare conditional, the treatment is with systemic therapy and total resection surgery. However, a cytoreductive surgery will be necessary when a complete resection is no possible. 相似文献
24.
We examined whether hormones would modify the carcinogenic action of aflatoxin B1 (AFB1). Four groups of inbred Fischer rats received AFB1, 125 mug per animal, weekly per os. In three of the groups, certain hormones were administered simultaneously: One group received 1 U growth hormone (GH) sc weekly, another was given 4 U adrenocorticotropin (ACTH) weekly, and a third received 0.5 U insulin weekly sc. AFB1, ACTH, and insulin were given for 20 weeks; GH was given for only 10 weeks. The control group did not receive hormone adjuvant. In each group, 4 animals were killed at 7, 14, 21, 28, and 35 weeks; the remaining rats were killed at 77 weeks. Their livers were carefully examined and samples prepared for light and electron microscopy. Animals receiving AFB1 and ACTH failed to exhibit hepatocellular carcinoma. On the other hand, malignant lymphoma appeared at 56 weeks in 3 of the 6 surviving males on this regime. AFB1, alone or when given with insulin or GH, caused hepatocellular carcinoma in all animals; in these, lymphoma was not observed. Lymphoma comprised two cell types, each with similar neclear characteristics but differing in their nucleocytoplasmic ratios and in the amount and distribution of cytoplasmic organelles. Alterations leading to hepatocellular carcinoma were examined at various stages of development. "Basophilic hyperplasia" reflected an increase in free ribosomes. "Hyperplastic nodules" were composed of hepatocyte aggregates with characteristics similar to those encountered in the earlier stage. Both the "neoplastic nodules" and hepatocellular carcinomas were formed by cells containing large, "smooth fingerprints" and free ribosomal aggregates. These features supported the concept that AFB1 impairs ribosomal binding to endoplasmic reticulum membranes. The failure of ACTH-treated animals to develop hepatocellular carcinoma was ascribed to the effect of adrenal cortical stimulation upon membrane-polysome binding. 相似文献
25.
Ionizing radiation is a carcinogen that induces oxidative DNA damage. 8-
Hydroxy-2'-deoxyguanosine (8-OHdG) is a relatively abundant, mutagenic
lesion that is widely regarded as a reliable index of oxidative DNA damage.
The purpose of this study was to examine the effects of X- radiation on
levels of 8-OHdG in the context of an experimental model for breast cancer
in which chronic radiation exposure has been shown to be carcinogenic in
Sprague-Dawley rats. A secondary objective of this study was to determine
if the use of phenol during DNA isolation affected the concentration of
8-OHdG subsequently measured. Our results indicate that a profoundly
carcinogenic dose of radiation induced a small but significant increase in
8-OHdG concentration in mammary gland DNA, and that the use of a
phenol-based versus a salt-based method of DNA isolation had no significant
impact on the levels of 8-OHdG detected in either control or irradiated
tissue.
相似文献
26.
27.
28.
Yamashita T; Wu N; Kupfer G; Corless C; Joenje H; Grompe M; D'Andrea AD 《Blood》1996,87(10):4424-4432
Fanconi anemia (FA) is an autosomal recessive disease characterized by congenital anomalies, aplastic anemia, and cancer susceptibility. Mutations within the FA complementation group C (FAC) gene account for approximately 14% of diagnosed FA cases. Two mutations, one in exon 1 (delG322) and one in exon 4 (IVS4 + 4 A to T), account for 90% of known FAC mutations. The delG322 mutation results in a mild FA phenotype, while the IVS4 + 4 A to T mutation results in severe FA phenotype. To determine the molecular basis for this clinical variability, we analyzed patient-derived cell lines for the expression of characteristic mutant FAC polypeptides. All cell lines with the delG322 mutation expressed a 50-kD FAC polypeptides, FRP-50 (FAC-related protein), shown to be an amino terminal truncated isoform of FAC reinitiated at methionine 55. All cell lines with the IVS4 + 4 A to T mutation lacked FRP-50. Overexpression of a cDNA encoding FRP-50 in an FA(C) cell line resulted in partial correction of mitomycin C sensitivity. In conclusion, expression of an amino terminal truncated FAC protein accounts, at least in part, for the clinical heterogeneity among FA(C) patients. 相似文献
29.
Who are they and what do they do? Profile of allied health professionals working with people with disabilities in rural and remote New South Wales 下载免费PDF全文
30.