全文获取类型
收费全文 | 522篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
儿科学 | 58篇 |
妇产科学 | 4篇 |
基础医学 | 48篇 |
口腔科学 | 12篇 |
临床医学 | 63篇 |
内科学 | 101篇 |
皮肤病学 | 7篇 |
神经病学 | 7篇 |
特种医学 | 149篇 |
外科学 | 22篇 |
综合类 | 5篇 |
预防医学 | 20篇 |
眼科学 | 3篇 |
药学 | 26篇 |
肿瘤学 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 12篇 |
2013年 | 17篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 29篇 |
2009年 | 22篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 11篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 7篇 |
2000年 | 10篇 |
1999年 | 9篇 |
1998年 | 32篇 |
1997年 | 27篇 |
1996年 | 25篇 |
1995年 | 26篇 |
1994年 | 26篇 |
1993年 | 19篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 17篇 |
1988年 | 18篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 20篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 14篇 |
1975年 | 8篇 |
1973年 | 1篇 |
排序方式: 共有543条查询结果,搜索用时 7 毫秒
61.
Diaziquone given as a bolus has not been effective in patients with relapsed or refractory leukemia. Because of in vitro data suggesting enhancement of diaziquone-induced cytotoxicity for human and murine leukemia cells with increased duration of drug exposure and the relatively short terminal plasma half-life of diaziquone, 49 patients (34 acute nonlymphocytic leukemia [ANLL], six chronic myelogenous leukemia in blast crisis [CML-B], five acute lymphocytic leukemia [ALL], four 2 degrees ANLL) with leukemia were given diaziquone as a continuous infusion for seven days. The maximum tolerated dose was 28 mg/m2/d for seven days. The dose-limiting toxicity was the duration of bone marrow aplasia (median, 49 days to greater than 500 PMNs in responders; range, 28 to 101 days). Nonhematologic toxicity was minimal. Responses occurred only in patients with relapsed ANLL, of whom 26 were treated at effective doses. There were six complete responses (CR) (23%) and two partial responses (PR) (8%), although five of eight responders never achieved platelet counts greater than 100,000/microL. Thrombocytopenia in these patients was felt to be a manifestation of diaziquone effect, not persistence of leukemia. The median duration of CR was 195 days (range, 88 to 860+). One patient had active CNS leukemia at the start of treatment and has had a durable (28+ month) CR in both sites of disease. Diaziquone produced prolonged aplasia in patients with secondary ANLL and CML-B (five of ten patients died aplastic), whereas patients with ALL all had regrowth of leukemia and two failed to become aplastic. The lack of significant nonhematologic toxicity and the activity in patients with relapsed ANLL render diaziquone of interest as second-line therapy or consolidation therapy in first remission for patients with ANLL. 相似文献
62.
Targeting ASCT2‐mediated glutamine uptake blocks prostate cancer growth and tumour development 下载免费PDF全文
Qian Wang Rae‐Anne Hardie Andrew J Hoy Michelle van Geldermalsen Dadi Gao Ladan Fazli Martin C Sadowski Seher Balaban Mark Schreuder Rajini Nagarajah Justin J‐L Wong Cynthia Metierre Natalia Pinello Nicholas J Otte Melanie L Lehman Martin Gleave Colleen C Nelson Charles G Bailey William Ritchie John EJ Rasko Jeff Holst 《The Journal of pathology》2015,236(3):278-289
63.
64.
Serial evaluations of lymphocytotoxic antibody (LCTAb) and responsiveness to random donor platelet transfusion were reviewed in 234 patients who had developed LCTAb at some time during their treatment course. Seventy (30%) of these patients had significant falls in antibody levels. In 44 patients these declines occurred after further antigenic exposure was reduced either because no transfusions were administered or only histocompatible platelets were transfused. Forty patients with declines in LCTAb levels who were previously refractory to platelet transfusion were rechallenged with random donor platelets. Thirty-four of 35 clinically evaluable patients had good responses to these unmatched transfusions for 2 weeks to 36 months, and in 21 patients antibody did not return despite repeated transfusions. Thus, serial LCTAb measurements are helpful in the management of alloimmunized patients. Many patients will have decreases or a loss of LCTAb, either permanently or transiently, and can be successfully supported with more easily available unmatched random donor platelet transfusions. 相似文献
65.
Because there was a possibility that activated factor XIII (factor XIIIa) might stabilize a platelet-fibrinogen aggregate through its crosslinking action, we have isolated plasma factor XIII, activated it, and studied the effect of factor XIIIa at a concentration of 3.3 micrograms/ml on aggregation and 125I-fibrinogen binding of rabbit platelets stimulated with 9 microM ADP. Factor XIIIa did not cause aggregation in the absence of ADP, nor did it enhance ADP-induced aggregation or substantially stabilize the platelet aggregate. The presence of factor XIIIa did not affect the amount of fibrinogen bound to platelets immediately after stimulation with ADP, but it appeared to cause a slow specific binding of 125I-fibrinogen to platelets whether or not they were stimulated with ADP. This binding, which was not inhibited by prostaglandin E1, did not lead to aggregation and was accompanied by crosslinking of fibrinogen through its A alpha and gamma chains, either to other fibrinogen molecules or to a platelet protein or proteins. 相似文献
66.
Cobalamin (vitamin B12) deficiency detection by urinary methylmalonic acid quantitation 总被引:2,自引:0,他引:2
A study was made to assess the value of cobalamin deficiency detection through quantitation of urinary methylmalonic acid (MMA). Urinary MMA was measured in 1118 patients suffering from megaloblastic anemia, other anemias, elevated red cell mean corpuscular volume, or unexplained neurologic disorders. Patients without proven cobalamin deficiency had urinary MMA levels less than 20 micrograms/ml. All patients (n = 27) confirmed to have cobalamin deficiency showed MMA levels greater than 20 micrograms/ml. Data are presented showing the Schilling test results, the comparison of serum cobalamin to urinary MMA levels, and other basic hematologic data. MMA levels are a good indication of cobalamin distribution and function since they are directly related to a cobalamin-dependent metabolic pathway. With rapid, reliable quantitation by mass spectrometry, urinary MMA can now be a useful clinical test. 相似文献
67.
Effects of the cell adhesion peptide, Arg-Gly-Asp-Ser, on responses of washed platelets from humans, rabbits, and rats 总被引:5,自引:0,他引:5
Fibrinogen is a cofactor in the aggregation of human platelets, and is required for ADP-induced aggregation of washed platelets; however, exogenous fibrinogen is not required for ADP-induced aggregation of washed platelets from rabbits or rats. Because with human platelets the cell adhesion peptide, Arg-Gly-Asp-Ser (RGDS), inhibits aggregation and the binding of 125I-fibrinogen to ADP-stimulated platelets, its effects on rabbit and rat platelets were studied to investigate the differences in the fibrinogen requirements of platelets from the three species. RGDS (50 mumol/L) caused greater than 80% inhibition of thrombin- induced or (ADP + fibrinogen)-induced aggregation of human platelets, but only 3% to 9% inhibition of the aggregation of rabbit or rat platelets, regardless of whether fibrinogen was added. RGDS inhibited the binding of 125I-fibrinogen to ADP-stimulated human platelets by 80% to 90%, but by only 15% to 27% in the case of rabbit or rat platelets. The differences were due to the species of platelets, since human and rabbit fibrinogens gave similar results. In addition, RGDS failed to displace fibrinogen from the surface of rabbit platelets that had been stimulated with ADP. Thus, there are species differences in the ability of the cell adhesion peptide, RGDS, to block the platelet fibrinogen receptor, even within the mammalian species. 相似文献
68.
Neutrophil elastase produces 52-kD and 30-kD glucocorticoid receptor fragments in the cytosol of human leukemia cells 总被引:1,自引:0,他引:1
Characterization of glucocorticoid receptors in leukemia cells is important to understand mechanisms of glucocorticoid resistance but has been impeded by receptor fragmentation in cytosol extracts. We recently found that formation of 52- and 30-kilodalton (kD) glucocorticoid receptor fragments in cytosol of leukemia cells is due to proteolysis and is blocked by diisopropylfluorophosphate (DFP). In the present study, we identify a 28-kD serine protease in cytosol of leukemia cells that binds [3H]DFP and correlates with the formation of 52- and 30-kD receptor fragments. This protease is immunoprecipitated by antiserum to neutrophil elastase. Limited digestion of [3H]dexamethasone-21-mesylate- labeled receptors by purified neutrophil elastase produces 52- and 30- kD receptor fragments. Receptor fragmentation in the cytosol of leukemia cells in inhibited by methoxysuccinyl-alanyl-alanyl-prolyl- valyl-chloromethylketone, a highly specific inhibitor of neutrophil elastase. The addition of as few as 5% neutrophils to a lymphoid cell suspension provides sufficient elastase to produce receptor fragmentation. Our findings indicate that neutrophil elastase is responsible for receptor fragmentation in the cytosol of leukemia cells. The neutrophil elastase may be endogenous to the leukemia cells or may come from neutrophils that contaminate leukemia cell suspensions. 相似文献
69.
We report a new bleeding disease--storage pool deficiency (SPD) of platelets--in pigs from the Mayo swine colony of homozygous von Willebrand's disease (vWD) and of heterozygous carriers of vWD. Levels of factor VIII, von Willebrand factor antigen (vWF:Ag), and ristocetin cofactor (RCof) were similar in the vWD carriers and SPD pigs. The latter pigs, however, had bleeding times of 15 minutes or more and were severe bleeders, in contrast to clinically normal vWD carriers. Platelet aggregation in response to collagen was reduced in most SPD pigs. Total platelet content of ADP, ATP, and serotonin was less than that of normal pigs. While the initial uptake of 14C-labeled serotonin into platelets was similar in SPD and normal pigs, retention of serotonin was reduced in platelets of SPD pigs. Transmission electron microscopy showed a large decrease of dense bodies in the platelets of SPD pigs. These findings support a diagnosis of SPD. Genetic analyses suggest an autosomal recessive mode of inheritance. A breeding program is under way to produce pigs affected only at the SPD gene, thus allowing further characterization of SPD and SPD-carrier pigs. 相似文献
70.
Shpall EJ; Stemmer SM; Hami L; Franklin WA; Shaw L; Bonner HS; Bearman SI; Peters WP; Bast RC Jr; McCulloch W 《Blood》1994,83(11):3132-3137
4-Hydroperoxycyclophosphamide (4-HC), a commonly used marrow-purging agent, is active against many tumors, but is also toxic to normal marrow progenitors. Amifostine (WR-2721) is a sulfhydryl compound with chemoprotectant activity. Preclinical studies using suspensions of bone marrow and breast cancer cells demonstrated that ex vivo treatment with amifostine followed by 4-HC resulted in protection of marrow progenitors, with no compromise in the antitumor effect of 4-HC. This fact stimulated the development of a clinical trial. Bone marrow was harvested from 15 poor-prognosis breast cancer patients and randomly assigned to ex vivo treatment with amifostine followed by 4-HC (amifostine + 4-HC), or treatment with 4-HC alone. High-dose chemotherapy was then administered followed by infusion of the purged autologous bone marrow support (ABMS). Leukocyte engraftment, defined as a white blood cell count > or = 1 x 10(9)/L, was achieved in an average of 26 days for patients whose marrow was purged with amifostine + 4-HC versus 36 days for patients whose marrow was purged with 4-HC alone (P = .032). The average number of platelet transfusions (12 v 29; P = .017) and days of antibiotic therapy (28 v 40; P = .012) were significantly less for patients whose marrow was exposed to amifostine + 4-HC, compared with 4-HC alone. Unpurged backup marrow fractions were infused into three patients whose marrow was purged with 4-HC alone, because of inadequate marrow recovery. None of the patients who received amifostine + 4-HC-purged marrow required a backup marrow fraction. Complete remissions were achieved in 83% of patients with measurable disease, with no difference between the two cohorts. Forty- three percent of patients remained alive and progression-free at a mean of 13 months posttransplant. There was no significant difference in the rate or pattern of relapse for patients whose marrow was purged with amifostine + 4-HC compared with those whose marrow was purged with 4-HC alone. Ex vivo treatment of marrow with amifostine significantly shortens the time to marrow recovery, thereby reducing the risk of myelosuppressive complications in breast cancer patients receiving high- dose chemotherapy and 4-HC-purged ABMS. Since supportive care requirements are also significantly decreased, amifostine may reduce the cost of such therapy. 相似文献