全文获取类型
收费全文 | 264篇 |
免费 | 10篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 23篇 |
妇产科学 | 1篇 |
基础医学 | 35篇 |
口腔科学 | 4篇 |
临床医学 | 15篇 |
内科学 | 38篇 |
皮肤病学 | 9篇 |
神经病学 | 60篇 |
特种医学 | 25篇 |
外科学 | 20篇 |
综合类 | 12篇 |
预防医学 | 5篇 |
眼科学 | 2篇 |
药学 | 25篇 |
肿瘤学 | 8篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 5篇 |
2011年 | 3篇 |
2010年 | 11篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 11篇 |
1998年 | 14篇 |
1997年 | 21篇 |
1996年 | 15篇 |
1995年 | 6篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1963年 | 1篇 |
1939年 | 3篇 |
1931年 | 1篇 |
排序方式: 共有283条查询结果,搜索用时 15 毫秒
61.
62.
The role of the area postrema in mediating taste aversions conditioned with the administration of lithium was examined in experiment 1. Rats with lesions of the area postrema or with sham lesions were given pairings of a novel taste with either intraperitoneally or intragastrically administered lithium chloride (LiCl; 10 mg/kg of a 0.15 M solution of lithium chloride) or a similar concentration of NaCl (control groups). Sham-lesioned rats exhibited strong taste aversions when lithium was used for the conditioning procedure and given intraperitoneally or intragastrically (P less than 0.01). Rats with lesions of the area postrema failed to develop taste aversions after the administration of lithium by either route. In experiment 2, rats with lesions of the area postrema and rats with sham lesions were given 30 min access to a 0.12 M solution of NaCl and 2 days later to a 0.12 M solution of lithium. The sham-lesioned animals drank less lithium than NaCl (P less than 0.02) and exhibited depressions in levels of activity following the ingestion of lithium. Rats with lesions of the area postrema drank more lithium than the sham-lesioned rats (P less than 0.01) and did not show behavioral depression after the ingestion of lithium. These data suggest that in the absence of the chemically-sensitive area postrema intragastrically administered lithium does not produce conditioned taste aversions or depression of activity in rats. 相似文献
63.
Erythropoietin and sexual dysfunction 总被引:7,自引:1,他引:6
Lawrence IG; Price DE; Howlett TA; Harris KP; Feehally J; Walls J 《Nephrology, dialysis, transplantation》1997,12(4):741-747
BACKGROUND: Erythropoietin (rHuEpo) therapy has been shown to improve
sexual function in the male dialysis population, with several studies
suggesting a direct effect upon endocrine function, as well as correction
of anaemia. Nevertheless many male dialysis patients receiving rHuEpo
continue to complain of sexual dysfunction. METHODS: At a dedicated renal
impotence clinic, 65 male dialysis patients were screened for endocrine
disturbances. Baseline serum sex hormones were compared between those
receiving and not receiving rHuEpo, using either the two-sample t test or
the Mann-Whitney U test, after assessing for normality. Results from four
patients were excluded on account of either medications (antiemetic
phenothiazines), hepatic dysfunction, or carcinomatosis. RESULTS:
Twenty-five patients (41.0%) were receiving rHuEpo, the recipients and
non-recipients being well matched for haemoglobin (10.19 +/- 0.29 vs 10.55
+/- 0.25 g/dl, n.s.), age (51.1 +/- 1.9 vs 53.6 +/- 2.1 years, n.s.) and
duration of sexual dysfunction (median, 3.0 vs 3.0 years, n.s.). The rHuEpo
recipients had a higher median creatinine (1090 vs 972 micromol/l, P <
0.02), but similar nutritional status to the non-recipients (albumin 41.0
vs 39.0 g/l, n.s.). The total duration of rHuEpo therapy was 0.85 +/- 0.14
years. Prolactin levels were similar in both the rHuEpo recipients and non-
recipients (440 vs 541 mu/l, n.s.), as were LH (11.0 vs 10.5 iu/l, n.s.)
and FSH (8.0 vs 6.5 iu/l, n.s.). However, there were significant elevations
of testosterone (19.8 +/- 1.3 vs 16.1 +/- 1.1 nmol/l, P < 0.05) and sex
hormone binding globulin (SHBG) (40.5 vs 26.0 nmol/l, P < 0.01), with a
trend toward elevated oestradiol (304 vs 248 pmol/l, P = 0.095) in the
rHuEpo-treated group. Forty-eight subjects (78.7%) received peritoneal
dialysis (PD), with the 19 rHuEpo recipients (39.6%) demonstrating
increased serum testosterone (21.0 +/- 1.5 vs 16.6 +/- 1.3 nmol/l, P <
0.05), SHBG (40.5 vs 26.5 nmol/l, P < 0.01), LH (15.0 vs 10.0 iu/l, P
< 0.01) and FSH (12.0 vs 5.3 iu/l, P < 0.05). These differences were
not demonstrated in the 13 haemodialysis (HD) subjects. CONCLUSIONS: Male
dialysis patients complaining of sexual dysfunction after correction of
anaemia with rHuEpo are characterized by higher levels of serum
testosterone and SHBG, but not suppression of hyperprolactinaemia or
hyperoestrogenism. Male PD subjects receiving rHuEpo also demonstrated
increased LH and FSH.
相似文献
64.
Exposure to rotating and elevated magnetic fields significantly reduced over three hours the ingestive effects of the opiate agonist, morphine (10 mg/kg), in free-feeding slugs, Limax maximus. Magnetic field exposure also inhibited the opioid-mediated increased ingestive responses of slugs that had been food-deprived for 24 hr. These results suggest that magnetic stimuli inhibit opiate-mediated behavioral and physiological functions in invertebrates in a similar manner as observed in vertebrates. 相似文献
65.
Ben Ariff Claire R Lloyd Sameer Khan Mohamed Shariff Andrew V Thillainayagam Devinder S Bansi Shahid A Khan Simon D Taylor-Robinson Adrian KP Lim 《World journal of gastroenterology : WJG》2009,15(11):1289-1300
Improvements in imaging technology allow exploitation of the dual blood supply of the liver to aid in the identification and characterisation of both malignant and benign liver lesions. Imaging techniques available include contrast enhanced ultrasound, computed tomography and magnetic resonance imaging. This review discusses the application of several imaging techniques in the diagnosis and staging of both hepatocellular carcinoma and cholangiocarcinoma and outlines certain characteristics of benign liver lesions. The advantages of each imaging technique are highlighted, while underscoring the potential pitfalls and limitations of each imaging modality. 相似文献
66.
狄柯坪 《中国组织工程研究与临床康复》2007,11(2):348-351
目的:综合分析核因子κΒ在血管增殖性疾病中的作用。
资料来源:应用计算机检索highwire1995—01/2004—12有关核因子κΒ对血管增殖性疾病影响的文献,检索词“nudear factor-Kappa B,vascular smooth muscle cell, proliferation, signal pathway”,并限定文章语言种类为English。
资料选择:对检索到的有关核因子κΒ对血管增殖性疾病影响方面的信息进行整理,选取针对性强的文章。同一领域的文献则选择近期发表或权威杂志的文章。
资料提炼:从检索到的203篇文献中初选符合要求的相关文献43篇。经过仔细研读,选择其中15篇文章作为参考。
资料综合:核因子κΒ或单独或与其他细胞因子协同作用.经过特定的信号转导途径,既可直接促进血管平滑肌细胞增殖也可通过抑制细胞凋亡而间接促进血管平滑肌细胞的增殖。选用能作用于核因子κΒ信号转导通路各个环节的抑制剂设法阻断导致核因子κΒ激活相关因子的表达,已经成为防治血管增殖性疾病的重要手段之一。
结论:核因子κΒ的激活确可通过不同途径促进血管增殖性疾病的发生,所以,如何适度有效地抑制核因子κΒ的激活将成为防治血管增殖性疾病面临的关键问题。 相似文献
67.
68.
The present study examined the dose related effects of low levels of the toxin, LiCl, on the ingestion of a palatable sucrose plus salt solution. Over five days (acquisition phase) rats were presented with a 0.3 M sucrose solution containing one of the following salt combinations: 0.12 M NaCl (n = 10 negative control group); 0.005 M LiCl + 0.115 NaCl (n = 10); 0.01 M LiCl + 0.11 NaCl (n = 10); 0.015 M LiCl + 0.105 M NaCl (n = 10); 0.02 M LiCl + 0.10 M NaCl (n = 10); and 0.12 M LiCl (n = 8 positive control group). During an extinction phase (5 days), all rats were presented with 0.3 M Sucrose + 0.12 M NaCl solution. Fluid intake levels and number of licks were quantified on each day. At low LiCl concentration levels rats exhibited a dose related reduction in amount consumed and number of licks of the sucrose plus salt solutions. This toxin related suppression of fluid intake and licking rapidly dissipated during the extinction phase. The present findings support the hypothesis that rats use a behavioral tolerance mechanism to regulate their intake of foods containing low levels of toxins. 相似文献
69.
Platelets contain mitogenic activities for MCF-7 human breast cancer cells when assayed under serum-free chemically defined conditions. Purification from outdated human platelets identified insulinlike growth factor I (IGF-I) as the most potent breast cancer cell mitogen in lysates (Karey KP, Sirbasku DA: see accompanying article, this issue). In this study the release and subcellular localization of IGF-I was investigated. Degranulation of platelets by thrombin treatment caused release of lysosomal enzymes (beta-glucuronidase and N-acetyl-D- glucosaminidase), alpha-granule proteins (beta-thromboglobulin and fibrinogen) as well as mitogenic activity for MCF-7 cells and IGF-I as measured by radioimmunoassay (RIA) and radioreceptor assay. Release of mitogenic activity and immunologically identified IGF-I was induced tenfold over controls by thrombin and was nearly complete as compared to platelets disrupted by repeated freezing and thawing. Disruption of platelets by nitrogen cavitation followed by separation of the organelles by sucrose density gradient sedimentation showed that IGF-I and mitogenic activity localized predominantly to fractions containing alpha-granules rather than soluble cellular components, lysosomes, or dense granules. The morphology of MCF-7 cells in serum-free medium supplemented with supernatants from thrombin-treated platelets also indicated the release of important cell-adhesion factors for human breast cancer cells. 相似文献
70.
Szilvassy SJ; Weller KP; Lin W; Sharma AK; Ho AS; Tsukamoto A; Hoffman R; Leiby KR; Gearing DP 《Blood》1996,87(11):4618-4628
Attempts to maintain or expand primitive hematopoietic stem cells in vitro without the concomitant loss of their differentiative and proliferative potential in vivo have largely been unsuccessful. To investigate this problem, we compared the ability of three cloned bone marrow (BM) stromal cell lines to support the growth of primitive Thy- 1lo Sca-1+H-2Khi cells isolated by fluorescence-activated cell sorting from the BM of Ly-5.2 mice treated 1 day previously with 5-fluo- rouracil. Sorted cells were highly enriched in cobblestone area-forming cells (CAFC), but their frequency was dependent on the stromal cell lines used in this assay (1 per 45 cells on SyS-1; 1 per 97 cells on PA6). In the presence of recombinant leukemia inhibitory factor (LIF), CAFC cloning efficiency was increased to 1 per 8 cells on SyS-1 and 1 per 11 cells on PA6, thus showing the high clonogenicity of this primitive stem cell population. More primitive stem cells with competitive repopulating potential were measured by injecting the sorted cells into lethally irradiated Ly-5.1 mice together with 10(5) radioprotective Ly-5.1 BM cells whose long-term repopulating ability has been "compromised" by two previous cycles of marrow transplantation and regeneration. Donor-derived lymphocytes and granulocytes were detected in 66% of animals injected with 50 sorted cells. To quantitate the maintenance of competitive repopulating units (CRU) by stromal cells, sorted cells were transplanted at limiting dilution before and after being cultured for 2 weeks on adherent layers of SyS-1, PA6, or S17 cells. CRU represented 1 per 55 freshly sorted cells. CRU could be recovered from cocultures supported by all three stromal cell lines, but their numbers were approximately-sevenfold less than on day 0. In contrast, the addition of LIF to stromal cultures improved CRU survival by 2.5-fold on S17 and PA6 cells (approximately two-fold to threefold decline), and enabled their maintenance on SyS-1. LIF appeared to act indirectly, because alone it did not support the proliferation of Thy- 1lo Sca-1+H-2Khi cells in stroma-free cultures. Polymerase chain reaction (RT-PCR) analysis revealed that Interleukin-1beta (IL-1 beta) IL-2, IL-6, granulocyte-colony stimulating factor, granulocyte macrophage-colony stimulating factor, transforming growth factors, LIF, and Steel Factor (SLF) mRNAs were upregulated in SyS-1 within 1 to 6 hours of LIF-stimulation. To determine if increased expression of SLF by LIF-stimulated SyS-1 cells could account for their capacity to support stem cells, sorted calls were cocultured on simian CV-E cells that were transfected with an expression vector encoding membrane-bound SLF, or supplemented with soluble SLF. In both cases, SLF synergized with IL-6 produced endogenously by CV-E cells enabling CAFC growth equivalent to that on LIF-stimulated SyS-1. CAFC development on LIF- stimulated SyS-1 could also be completely abrogated by an anti-SLF antibody. These data provide evidence for a role of LIF in the support of long-term repopulating stem cells by indirectly promoting cytokine expression by BM stroma. Furthermore, we have used quantitative assays to show a maintenance of CRU numbers, with retention of in vivo function following ex vivo culture. 相似文献