全文获取类型
收费全文 | 238篇 |
免费 | 8篇 |
国内免费 | 5篇 |
专业分类
儿科学 | 7篇 |
妇产科学 | 6篇 |
基础医学 | 15篇 |
口腔科学 | 8篇 |
临床医学 | 21篇 |
内科学 | 92篇 |
皮肤病学 | 5篇 |
神经病学 | 4篇 |
特种医学 | 42篇 |
外科学 | 22篇 |
综合类 | 8篇 |
预防医学 | 9篇 |
眼科学 | 1篇 |
药学 | 9篇 |
1篇 | |
肿瘤学 | 1篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 10篇 |
2011年 | 5篇 |
2010年 | 12篇 |
2009年 | 9篇 |
2008年 | 14篇 |
2007年 | 9篇 |
2006年 | 14篇 |
2005年 | 5篇 |
2004年 | 14篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 14篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有251条查询结果,搜索用时 15 毫秒
1.
In vitro and in vivo activity of murine lymphokine-activated killer cells after cryopreservation 总被引:1,自引:0,他引:1
The in vitro and in vivo effects of cryopreservation on the cytotoxic activity of murine lymphokine-activated killer (LAK) cells were studied. LAK cells were generated by incubation of spleen lymphocytes of BALB/c mice for 3 days with recombinant interleukin-2 (rIL-2) and subsequent cryopreservation. Cytotoxicity was determined in a 51Cr release assay. After thawing, cytotoxic activity was reduced (40.4% 51Cr release at an effector:target cell ratio of 40:1 as compared to 68.5% 51Cr release before freezing) and could be restored to precryopreserved levels by reincubation with rIL-2 for 2 days after thawing (78.8% 51Cr release). These cells were then tested in BALB/c mice injected with RAW 112 cells, a pre-B-cell lymphoma line. The results demonstrate that the survival rate of mice injected with cryopreserved and restimulated LAK cells (50% survival greater than 180 days after injection) did not differ significantly from that of mice injected with fresh unfrozen LAK cells (60% survival greater than 120 days, 50% survival greater than 180 days). Cryopreserved LAK cells have potential use in adoptive immunotherapy. 相似文献
2.
3.
Kulminski AM Ukraintseva SV Akushevich IV Arbeev KG Yashin AI 《Journal of the American Geriatrics Society》2007,55(6):935-940
OBJECTIVES: To describe the accumulation of aging-associated health disorders using a cumulative measure known as a frailty index (FI) and to evaluate its ability to differentiate long- and short-life phenotypes as well as the FI's connection to aging-associated processes in older people. DESIGN: Retrospective cross-sectional and longitudinal studies. SETTING: The National Long-Term Care Survey (NLTCS) data that assessed health and functioning of U.S. older individuals (> or =65) in 1982, 1984, 1989, 1994, and 1999 were analyzed. The NLTCS sample in each survey represents a mixture of longitudinal and cross-sectional components. PARTICIPANTS: Approximately 5,000 individuals in each survey. MEASUREMENTS: A cumulative index of health and well-being deficiencies (disabilities, signs, diseases) was calculated as a count of deficits observed in an individual divided by the total number of all considered deficits. RESULTS: Men and women who died before the age of 75 and those who died after the age of 85 exhibited remarkably similar FI frequency patterns despite the 10-year age difference between age profiles in these samples. Long life is consistently characterized in longitudinal analyses by lower FIs. FI dynamics are found to be strongly sex sensitive. CONCLUSION: The FI appears to be a sensitive age-independent indicator of sex-specific physiological decline in aging individuals and a sex-specific discriminator of survival chances. The FI is a promising characteristic suitable for improving sex-sensitive forecasts of risks of adverse health outcomes in older people. 相似文献
4.
5.
Bone marrow transplantation for patients with Philadelphia chromosome- positive acute lymphoblastic leukemia 总被引:1,自引:2,他引:1
Forman SJ; O'Donnell MR; Nademanee AP; Snyder DS; Bierman PJ; Schmidt GM; Fahey JL; Stein AS; Parker PM; Blume KG 《Blood》1987,70(2):587-588
We report the treatment outcome of allogeneic bone marrow transplantation in ten patients with Philadelphia chromosome-positive acute lymphoblastic leukemia. Six patients are alive and well for 6 to 30 months (median 19 months) after transplantation. Four patients died with transplant related complications. In view of the poor prognosis associated with this disease, marrow ablation followed by allogeneic or syngeneic marrow grafting may be the preferred treatment modality if a suitable marrow donor is available. 相似文献
6.
Golubovsky MD Weisman NY Arbeev KG Ukraintseva SV Yashin AI 《Experimental gerontology》2006,41(9):819-827
Recent studies suggest that downregulation of tumor suppressor genes might not only favor cancer development but also postpone organisms' aging and increase longevity. However, there is lack of population-based studies directly supporting this idea. We studied the lgl lethal alleles which are widespread in natural Drosophila populations. We demonstrate, for the first time, that animals heterozygous on the loss-of-function lgl tumor suppressor gene display a clear pre-adult viability advantage under stressful conditions (high 29 degrees C and low 16 degrees C temperatures). We found also the survival and longevity advantage effect of the lgl loss-of-function in the temperature stress conditions. The main features of this longevity influence are following. First, the lgl-dependent life span increase is sex-dependent; in all experimental combinations males are more sensitive than females of relevant genotypes. Second, the effect is stronger under the life-shortening temperature stress, 29 degrees C, where the hormesis was demonstrated. Third, the favoring effect of reduced dosage of tumor suppressor displays clearly in old but not young animals, delaying aging. Forth, the maternal or epigenetic inheritance of thermotolerance from mother to offspring appears to strengthen the observed longevity effects. One possible explanation of this stress-adaptive effect of reduced tumor suppressor dose might be a better resistance of Drosophila post-mitotic cells to a stress-associated apoptosis at old ages. 相似文献
7.
8.
Kulminski AM Ukraintseva SV Culminskaya IV Arbeev KG Land KC Akushevich L Yashin AI 《The journals of gerontology. Series A, Biological sciences and medical sciences》2008,63(10):1053-1059
We evaluated the predictive potential for long-term (24-year) survival and longevity (85+ years) of an index of cumulative deficits (DI) and six physiological indices (pulse pressure, diastolic blood pressure, pulse rate, serum cholesterol, blood glucose, and hematocrit) measured in mid- to late life (44-88 years) for participants of the 9th and 14th Framingham Heart Study examinations. For all ages combined, the DI, pulse pressure, and blood glucose are the strongest determinants of both long-term survival and longevity, contributing cumulatively to their explanation. Diastolic blood pressure and hematocrit are less significant determinants of both of these outcomes. The pulse rate is more relevant to survival, whereas serum cholesterol is more relevant to longevity. Only the DI is a significant predictor of longevity and mortality for each 5-year age group ranging from 45 to 85 years. The DI appears to be a more important determinant of long-term risks of death and longevity than are the physiological indices. 相似文献
9.
Platelet activation leads to the incorporation of 32[PO4(2-)] into bovine coagulation factor Va and recombinant human factor VIII. In the presence of the soluble fraction from thrombin-activated platelets and (gamma-32P) adenosine triphosphate, radioactivity is incorporated exclusively into the M(r) = 94,000 heavy chain (H94) of factor Va and into the M(r) = 210,000 to 90,000 heavy chains as well into the M(r) = 80,000 light chain of factor VIII. Proteolysis of the purified phosphorylated M(r) = 94,000 factor Va heavy chain by activated protein C (APC) gave products of M(r) = 70,000, 24,000, and 20,000. Only the intermediate M(r) = 24,000 fragment contained radioactivity. Because the difference between the M(r) = 24,000 and M(r) = 20,000 fragments is located on the COOH-terminal end of the bovine heavy chain, phosphorylation of H94 must occur within the M(r) = 4,000 peptide derived from the carboxyl-terminal end of H94 (residues 663 through 713). Exposure of the radioactive factor VIII molecule to thrombin ultimately resulted in a nonradioactive light chain and an M(r) = 24,000 radioactive fragment that corresponds to the carboxyl-terminal segment of the A1 domain of factor VIII. Based on the known sequence of human factor VIII, phosphorylation of factor VIII by the platelet kinase probably occurs within the acidic regions 337 through 372 and 1649 through 1689 of the procofactor. These acidic regions are highly homologous to sequences known to be phosphorylated by casein kinase II. Results obtained using purified casein kinase II gave a maximum observed stoichiometry of 0.6 mol of 32[PO4(2-)]/mol of factor Va heavy chain and 0.35 mol of 32[PO4(2-)]/mol of factor VIII. Phosphoamino acid analysis of phosphorylated factor Va by casein kinase II or by the platelet kinase showed only the presence of phosphoserine while phosphoamino acid analysis of phosphorylated factor VIII by casein kinase II showed the presence of phosphothreonine as well as small amounts of phosphoserine. The platelet kinase responsible for the phosphorylation of the two cofactors was found to be inhibited by several synthetic protein kinase inhibitors. Finally, partially phosphorylated factor Va was found to be more sensitive to APC inactivation than its native counterpart. Our findings suggest that phosphorylation of factors Va and VIIIa by a platelet casein kinase II- like kinase may downregulate the activity of the two cofactors. 相似文献
10.
The development of cellular immunity to Epstein-Barr virus after allogeneic bone marrow transplantation 总被引:7,自引:10,他引:7
Epstein-Barr virus-induced lymphoproliferative disease (EBV-LPD) is a potentially lethal complication during the first 6 months after allogeneic bone marrow transplantation (BMT). To determine whether deficiencies of EBV-specific cellular immunity contribute to EBV-LPD susceptibility and distinguish patients at risk, we performed limiting dilution analysis to quantify anti-EBV cytotoxic T-lymphocyte precursor (CTLp) frequencies in 26 recipients of unmodified or T-cell-depleted (TCD) grafts from EBV-seropositive donors. At 3 months post-BMT (n = 26), only five patients had EBV CTLp frequencies in the range of seropositive normal controls, irrespective of the type of transplant administered. By 6 months post-BMT, 9 of 13 patients tested had EBV CTLp frequencies within the normal range. The time period in which these patients had deficient cellular immunity to EBV corresponds to the period in which we have observed EBV-LPD in most prior patients. One patient with a low EBV CTLp frequency at 4 months post-BMT developed an EBV-LPD. Within 2 weeks of receiving an infusion of donor peripheral blood mononuclear cells (PBMC) providing less than 1,200 EBV- specific cytotoxic T-cell precursors, populations of EBV-specific CTL in the circulation were restored to levels detected in normal seropositive adults. Concurrently, the patient achieved a regression of the EBV-LPD, which has been sustained without further therapy. These studies indicate that recipients of both unmodified and TCD marrow grafts have profound deficiencies of EBV-specific T cell-mediated immunity early posttransplant, and that the period of risk for EBV-LPD closely corresponds to this interval of severe deficiency. Treatment of one patient with EBV-LPD with marrow donor-derived PBMC induced a rapid expansion of EBV-specific cytotoxic T-cell populations that occurred contemporaneously with the clinical regression of disease. 相似文献