全文获取类型
收费全文 | 1064篇 |
免费 | 84篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 85篇 |
妇产科学 | 9篇 |
基础医学 | 117篇 |
口腔科学 | 12篇 |
临床医学 | 111篇 |
内科学 | 182篇 |
皮肤病学 | 21篇 |
神经病学 | 109篇 |
特种医学 | 101篇 |
外科学 | 67篇 |
综合类 | 13篇 |
预防医学 | 150篇 |
眼科学 | 3篇 |
药学 | 94篇 |
中国医学 | 1篇 |
肿瘤学 | 71篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 14篇 |
2018年 | 19篇 |
2017年 | 16篇 |
2016年 | 14篇 |
2015年 | 23篇 |
2014年 | 30篇 |
2013年 | 49篇 |
2012年 | 58篇 |
2011年 | 48篇 |
2010年 | 50篇 |
2009年 | 36篇 |
2008年 | 42篇 |
2007年 | 30篇 |
2006年 | 46篇 |
2005年 | 43篇 |
2004年 | 39篇 |
2003年 | 34篇 |
2002年 | 37篇 |
2001年 | 31篇 |
2000年 | 23篇 |
1999年 | 22篇 |
1998年 | 28篇 |
1997年 | 36篇 |
1996年 | 29篇 |
1995年 | 35篇 |
1994年 | 25篇 |
1993年 | 39篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 22篇 |
1989年 | 17篇 |
1988年 | 27篇 |
1987年 | 18篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 15篇 |
1980年 | 6篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 13篇 |
1975年 | 4篇 |
1973年 | 5篇 |
1946年 | 2篇 |
排序方式: 共有1149条查询结果,搜索用时 0 毫秒
991.
Variability of 11q23 rearrangements in hematopoietic cell lines identified with fluorescence in situ hybridization 总被引:3,自引:0,他引:3
Kobayashi H; Espinosa R d; Thirman MJ; Davis EM; Diaz MO; Le Beau MM; Rowley JD 《Blood》1993,81(11):3027-3033
We mapped and ordered 17 cosmid, phage, and plasmid clones to chromosome 11, bands q22-q24, using fluorescence in situ hybridization (FISH). We then analyzed four hematopoietic cell lines with 11q23 rearrangements, Karpas 45, SUP-T13, RC-K8, and Karpas 422, using these probes. The studies showed that the translocation breakpoints of the Karpas 45 and SUP-T13 cell lines, which were derived from T-cell malignancies, were located in the same breakpoint cluster region of the MLL gene as the RS4; 11 cell line and patients with the t(9;11), t(11;19), and t(6;11) described previously. We confirmed that the translocation breakpoint of the RC-K8 cell line was located telomeric to the MLL gene, and found that the derivative 11 chromosome of the Karpas 422 cell line, which had been thought to contain a t(4;11) (q21;q23), was in fact formed through a deletion and an inverted tandem repeat of part of 11q. 相似文献
992.
MR Auroux EM Dulioust NY Nawar SG Yacoub EH Kempf AB Ebel 《Biomedicine & Pharmacotherapy》1990,44(10):519-523
Adult male Wistar rats were treated with cyclophosphamide either alone or with both cyclophosphamide and vinblastine. They were then mated with virgin non-treated females. Examination of their offspring showed an increased post-natal mortality rate; and diminished learning capacity and spontaneous activity in the adults. These disorders were also found in the second generation, resulting from mating between animals of the first generation. Biochemical analyses of the brains of the offspring of treated males in the first and second generations showed a diminished activity of hippocampal choline acetyl-transferase. Moreover, the second generation showed a diminution of fronto-parietal cortex norepinephrine. These biochemical results may correspond to the observed behavioral deficits. Furthermore, by studying experimental mutation, they add to our knowledge of the consequences of certain cytostatic treatments. 相似文献
993.
ME Malachowski ; RL Comenzo ; CD Hillyer ; KO Tiegerman ; EM Berkman 《Transfusion》1992,32(8):732-735
Large-volume leukapheresis (LVL, 15-35 L) was performed in two groups of patients (n = 10) with hematologic malignancies to obtain peripheral blood stem cells for bone marrow rescue following high-dose chemotherapy. The target cell count was 7 x 10(8) mononuclear cells (MNCs = lymphocytes and monocytes) per kg of body weight. Group A patients (n = 4) were studied on Day 1 of LVL, and components were collected from them as four sequential samples. Total MNCs collected averaged 1.29 x 10(10), total colony-forming-units granulocyte-macrophage (CFU-GM) averaged 12.1 x 10(6), and a 1.8-fold mobilization of CFU-GM was observed (p < 0.05, Sample 1 vs. Sample 4). Group B patients (n = 6) were studied throughout the three consecutive planned days of 5-hour LVL. An average of three LVL procedures per patient was performed (range, 1.25-4), and an average of 27 L (range, 24-33) of blood per LVL was processed. The blood:ACD-A ratio was 24:1 with 3000 units of heparin per 500 mL of ACD-A; heparin was also added to the collection bags. The component had an average hematocrit (Hct) of 0.02 and MNC content of 93 percent. The patients' pre-LVL and post-LVL average Hct varied significantly (before Day 1, 0.36 +/- 0.08; after Day 3, 0.28 +/- 0.06; p < 0.05). Platelet counts also decreased, with post-Day 3 counts averaging 19 percent of the average pre-Day 1 counts (p < 0.05). A decrease in the average MNC count after LVL was significant on Day 1 only (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
994.
The authors describe a method for freezing large amounts of peripheral blood lymphocytes (PBL) in a 20 percent glycerol solution. Between 0.6 and 4.3 X 10(9) cells in autologous plasma were frozen in polyethylene freezing bags in a final volume of 50 ml. The recovery after thawing averaged 89 +/- 14 percent with a mean viability by trypan blue dye exclusion of 80 +/- 7 percent (n = 11). In aliquots of fresh and frozen-thawed PBL from the same subjects radiolabeled with 111In, the radiolabeling efficiency for both fresh and thawed cells was 49 +/- 15 percent (p = 0.98, n = 5). The mitogen mean stimulation indices for glycerol-frozen cells (471 with phytohemagglutinin-M, 176 with pokeweed mitogen, and 380 with concanavalin A) were superior to those of cells frozen by a standard technique with dimethylsulfoxide (DMSO) (141, 47, and 123; p less than 0.05) and comparable to those of fresh PBL (403, 75, and 147). In a mixed lymphocyte culture, glycerol-frozen PBL showed significantly greater responsiveness to a pool of stimulator cells than did PBL frozen in DMSO (p = 0.03). Thawed cells are viable and functional as demonstrated by their response to mitogens and their ability to stimulate and respond in mixed lymphocyte culture. 相似文献
995.
Density gradient separation of peripheral blood stem cells: comparison of an automated cell processing device and manual methods 总被引:1,自引:0,他引:1
Peripheral blood stem cells were collected from normal donors by leukapheresis on a cell separator. The leukapheresis product contained 1.5 x 10(10) mononuclear cells (MNCs) and was divided into two aliquots that underwent either automated or manual density gradient separation with ficoll-hypaque and subsequent washing. In the automated process, recovery of MNCs was 85 percent, reduction in platelet content was 64 percent, and the final hematocrit (Hct) was less than 1 percent. The manual separation resulted in 76-percent MNC recovery, a 79-percent reduction in platelet content, and a final Hct of less than 1 percent. The purified MNCs were then placed in methylcellulose culture at a concentration of 4 x 10(5) MNCs per mL. Quadruplicate 1-mL aliquots were cultured, and colonies were counted and classified on Day 14. Comparison of automated and manual ficoll-hypaque separations demonstrated no differences in the total, erythroid, or granulocyte-macrophage colony numbers. The cell processor used is fast, reliable, uncomplicated, and provides a sterile product containing progenitor cells that are not adversely affected by the automated ficoll-hypaque separation. 相似文献
996.
Background
This study was conducted to assess the dental treatment requirements of psychiatric patients in comparison with the non psychiatric patients admitted in the hospital.Methods
A total of 103 hospitalised psychiatric patients were examined with an equal number of non psychiatric hospitalized patients.Result
73.22 % of psychiatric patients exhibited higher caries index along with higher decayed missing filled teeth (DMFT) as compared to 68.31 % in the control group. The incidence of periodontal diseases were significantly higher among the study group than the controls. There were statistically significant correlation between smoking, family pattern, calculus index and gingival index amongst psychiatric patients.Conclusion
There was a higher incidence of caries index, missing teeth and less filled teeth among psychiatric patients, indicating extensive dental treatment requirement for this group.Key Words: Dental caries, Periodontal disease, Psychiatric patients 相似文献997.
The investigation of the fine specificities of antinuclear antibodies (ANAs) has been fruitful in terms of the nosology and immunopathogenesis of human autoimmune syndromes. Particular reactivities serve as “markers,” in that patients with certain syndromes have a much higher incidence of such ANAs than do patients with other diseases. In this category is the almost exclusive against the nuclear acidic protein Sm. Reactivity to Sm can be detected by precipitation in agar, complement fixation, or passive hemagglutination (1,2). Autoimmune mouse strains have also provided a fertile field for the investigation of the basic phenomena of self-activity. In particular, the NZB strain and its hybrid NZB x NZW have been considered excellent models for human SLE and have therefore been studied in great detail (3,4). In addition, Murphy et al at The Jackson Laboratory, Bar Harbor, Maine, have developed several new inbred mouse strains that spontaneously develop SLE-like syndromes (5,6). These are the BXSB strain, which has a male dominant disease characterized by little antiative DNA antibody; the MRL/1, which develops massive, nonmalignant lymphadenopathy, associated with enormous increases in serum immunoglobulin levels and fulminant renal disease; and the MRL/n, which does not develop SLE-like disease until well into the 2nd yr of life, but like the MRL/1 develops high titers of ANA and fatal glomerulonephritis. The MRL/1 differs from MRL/n in only about 10 percent of its genome, including the gene responsible for the MRL/1’s lymphoproliferation. In the current study, we have used the technique of double immunodiffusion (ID) in agarose with standard human reference sera (of known ANA specificity) to survey a large number of mice from the NZB x NZW, MRL/1, MRL/n, BXSB, and other strains. We report here the finding of the anti-Sm marker” antibody almost uniquely in MRL/1 and MRL/n animals. These two related strains may serve as experimental models to explore the mechanism stimulating the production of this unique autoantibody in SLE. 相似文献
998.
PASSMORE AP; WHITEHEAD EM; CRAWFORD V; McVEIGH GE; JOHNSTON GD 《QJM : monthly journal of the Association of Physicians》1991,81(2):919-928
The antihypertensive efficacy and metabolic effects of cyclopenthiazide125 µg were compared with cyclopenthiazide 500 µgin patients with non-insulin dependent diabetes and hypertensionin a double blind, randomized crossover study. After a 6-weekplacebo period 24 patients with non-insulin dependent diabetesmellitus, stabilized on diet or oral hypoglycaemic agents, whohad a mean diastolic blood pressure between 90 and 120 mmHgafter receiving placebo for 6 weeks were given 125 µgor 500 µg cyclopenthiazide for 12 weeks. Patients thenreceived placebo for a further 6-week period, following whichthey received the alternate treatment dosage for 12 weeks. Therewere no differences between doses in their antihypertensiveeffects. While 500 µg significantly reduced systolic anddiastolic blood pressures, only diastolic pressure was significantlyreduced by 125 µg from pre-treatment values. The higherdose of cyclopenthiazide had greater effects on measures ofdiabetic control than did the 125 µg dose and the risein blood glucose after 12 weeks' treatment with 500 µgwas significantly different from pre-treatment values. Cyclopenthiazide125 µg had significantly less effect on triglycerides,potassium and urate, than did 500 µg. Cyclopenthiazide500 µg resulted in a significant fall in serum potassiumfrom pre-treatment values. There were no intertreatment differencesin the other variables measured. Cyclopenthiazide 125 µgis as effective as 500 µg in reducing diastolic bloodpressure in mildly hypertensive non-insulin dependent diabeticpatients. The higher dose had more pronounced adverse effectson glucose control and serum concentrations of triglycerides,potassium and urate. 相似文献
999.
Resistance of cloned cytotoxic T lymphocytes to cell-mediated cytotoxicity 总被引:7,自引:7,他引:7 下载免费PDF全文
A Blakely K Gorman H Ostergaard K Svoboda C C Liu J D Young W R Clark 《The Journal of experimental medicine》1987,166(4):1070-1083
Cloned CTLs show an unusually high resistance to lysis by effector CTLs. Several cloned CTL lines in our laboratories are absolutely refractory to lysis by other cloned CTLs, either (a) directly, (b) in the presence of lectin, or (c) by PMA-induced CTLs. They can be lysed to some extent by primary CTL, although they are less than 5% as sensitive as target cells normally used to assay primary CTL lytic activity. Lysis of cloned CTLs by primary CTL effector cells is not enhanced by the presence of lectin, and cloned T cells are also highly resistant to lysis by primary lymphokine-activated killer cells. Cloned CTLs are highly resistant to lysis by isolated CTL granules that contain the membranolytic pore-forming protein (PFP or perforin), while non-CTL targets are highly susceptible to granule-mediated killing, indicating that cloned CTLs resist lysis not only at the intact effector cell level but also when soluble effector proteins are used. This resistance mechanism may explain how CTLs kill but spare themselves from being killed during the cytolytic event. 相似文献
1000.