全文获取类型
收费全文 | 1458篇 |
免费 | 96篇 |
国内免费 | 219篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 56篇 |
妇产科学 | 42篇 |
基础医学 | 158篇 |
口腔科学 | 48篇 |
临床医学 | 125篇 |
内科学 | 244篇 |
皮肤病学 | 42篇 |
神经病学 | 122篇 |
特种医学 | 285篇 |
外科学 | 335篇 |
综合类 | 58篇 |
预防医学 | 58篇 |
眼科学 | 8篇 |
药学 | 141篇 |
肿瘤学 | 38篇 |
出版年
2022年 | 8篇 |
2021年 | 45篇 |
2020年 | 13篇 |
2019年 | 12篇 |
2018年 | 23篇 |
2017年 | 11篇 |
2016年 | 17篇 |
2015年 | 21篇 |
2014年 | 25篇 |
2013年 | 30篇 |
2012年 | 28篇 |
2011年 | 28篇 |
2010年 | 36篇 |
2009年 | 42篇 |
2008年 | 27篇 |
2007年 | 60篇 |
2006年 | 46篇 |
2005年 | 59篇 |
2004年 | 49篇 |
2003年 | 44篇 |
2002年 | 65篇 |
2001年 | 95篇 |
2000年 | 66篇 |
1999年 | 73篇 |
1998年 | 74篇 |
1997年 | 68篇 |
1996年 | 64篇 |
1995年 | 61篇 |
1994年 | 40篇 |
1993年 | 46篇 |
1992年 | 20篇 |
1991年 | 28篇 |
1990年 | 34篇 |
1989年 | 54篇 |
1988年 | 42篇 |
1987年 | 41篇 |
1986年 | 26篇 |
1985年 | 31篇 |
1984年 | 19篇 |
1983年 | 13篇 |
1982年 | 18篇 |
1981年 | 20篇 |
1980年 | 19篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 19篇 |
1976年 | 13篇 |
1975年 | 13篇 |
1971年 | 6篇 |
1970年 | 11篇 |
排序方式: 共有1773条查询结果,搜索用时 15 毫秒
71.
72.
This report describes the production and characterization of 13 rodent monoclonal antibodies to the human erythrocyte anion transport protein AE1 (syn. band 3). Eleven antibodies (4 murine and 7 rat) recognize epitopes dependent on the integrity of the third extracellular loop of the protein. Two antibodies (1 murine and 1 rat) recognize epitopes on the N-terminal cytoplasmic domain. Quantitative binding studies using radioiodinated IgG and Fab fragments of antibodies to extracellular epitopes on AE1 ranged from 77,000 to 313,000 (IgG) and from 241,000 to 772,000 (Fab) molecules bound at saturation. The results indicate that the epitopes recognized by different antibodies vary in their accessibility and suggest that there is heterogeneity in the organization of individual AE1 molecules in the red blood cell membrane. Quantitative binding studies on South East Asian ovalocytes using several antibodies to AE1 and an anti-Wrb show a marked reduction in the number of antibody molecules bound at saturation. These results are consistent with the existence of highly cooperative interactions between transmembrane domains of AE1 in normal erythrocytes and the disruption of these interactions in the variant AE1 found in South East Asian ovalocytes. 相似文献
73.
Maternal administration of granulocyte colony-stimulating factor improves neonatal rat survival after a lethal group B streptococcal infection 总被引:2,自引:0,他引:2
Novales JS; Salva AM; Modanlou HD; Kaplan DL; del Castillo J; Andersen J; Medlock ES 《Blood》1993,81(4):923-927
Maternally administered recombinant human granulocyte colony- stimulating factor (rhG-CSF) has been shown to cross the placenta and induce a peripheral neutrophilia and increases in the marrow and spleen neutrophil storage pools in fetal and newborn rats. In the present study, we have used this model system to investigate the efficacy of prenatally administered rhG-CSF on neonatal defense to a lethal challenge with Group B-beta hemolytic Streptococcus (GBS). Pregnant rats were injected with rhG-CSF twice daily beginning 6 days before parturition. At birth, all pups were infected with a dose of GBS that is lethal for 90% of infected pups (LD90). Survival was monitored daily for 5 days. Survival of infected pups from saline-treated mothers beyond 60 hours after infection was 10%. No difference in survival was observed among pups from mothers treated 2 and 4 days before parturition. In contrast, we determined that survival was 82.5% among infected pups from mothers treated for 6 days before parturition with rhG-CSF. Our results demonstrate that maternal administration of rhG- CSF augments neonatal defenses against a lethal bacterial challenge. 相似文献
74.
The effects of granulocyte-macrophage colony-stimulating factor (GM- CSF) are not confined to cells of the myeloid lineage. GM-CSF has been shown to have effects on mature T cells and both mature and immature T- cell lines. We therefore examined the GM-CSF responsiveness of murine thymocytes to investigate whether GM-CSF also affected normal immature T lymphocytes. The studies presented here indicate that GM-CSF augments accessory cell (AC)-dependent T-cell receptor (TCR)-mediated proliferation of unseparated thymocyte populations. To identify the GM- CSF responsive cell type, thymic AC and T cells were examined for GM- CSF responsiveness. We found that GM-CSF augmentation of TCR-induced thymocyte proliferation appears to be mediated via augmentation of AC function, and not via direct effects on mature single-positive (SP) thymocytes. Enriched double-negative (DN) thymocytes were also tested for GM-CSF responsiveness. GM-CSF induced the proliferation of adult and fetal DN thymocytes in an AC-independent and TCR-independent single- cell assay. Thus, in contrast to the SP thymocytes, a DN thymocyte population was directly responsive to GM-CSF. GM-CSF therefore may play a direct role in the expansion of DN thymocytes and an indirect role in the expansion of SP thymocytes. 相似文献
75.
Weisdorf DJ; Verfaillie CM; Davies SM; Filipovich AH; Wagner JE Jr; Miller JS; Burroughs J; Ramsay NK; Kersey JH; McGlave PB 《Blood》1995,85(12):3452-3456
Delay in hematologic recovery after bone marrow transplantation (BMT) can extend and amplify the risks of infection and hemorrhage, compromise patients' survival, and increase the duration and cost of hospitalization. Because current studies suggest that granulocyte- macrophage (GM) colony-stimulating factor (CSF) may potentiate the sensitivity of hematopoietic progenitor cells to G-CSF, we performed a prospective, randomized trial comparing GM-CSF (250 micrograms/m2/d x 14 days) versus sequential GM-CSF x 7 days followed by G-CSF (5 micrograms/kg/d x 7 days) as treatment for primary or secondary graft failure after BMT. Eligibility criteria included failure to achieve a white blood cell (WBC) count > or = 100/microL by day +21 or > or = 300/microL by day +28, no absolute neutrophil count (ANC) > or = 200/microL by day +28, or secondary sustained neutropenia after initial engraftment. Forty-seven patients were enrolled: 23 received GM-CSF (10 unrelated, 8 related allogeneic, and 5 autologous), and 24 received GM- CSF followed by G-CSF (12 unrelated, 7 related allogeneic, and 5 autologous). For patients receiving GM-CSF alone, neutrophil recovery (ANC > or = 500/microL) occurred between 2 and 61 days (median, 8 days) after therapy, while those receiving GM-CSF+G-CSF recovered at a similar rate of 1 to 36 days (median, 6 days; P = .39). Recovery to red blood cell (RBC) transfusion independence was slow, occurring 6 to 250 days (median, 35 days) after enrollment with no significant difference between the two treatment groups (GM-CSF: median, 30 days; GM-CSF+G- CSF; median, 42 days; P = .24). Similarly, platelet transfusion independence was delayed until 4 to 249 days (median, 32 days) after enrollment, with no difference between the two treatment groups (GM- CSF: median, 28 days; GM-CSF+G-CSF: median, 42 days; P = .38). Recovery times were not different between patients with unrelated donors and those with related donors or autologous transplant recipients. Survival at 100 days after enrollment was superior after treatment with GM-CSF alone. Only 1 of 23 patients treated with GM-CSF died versus 7 of 24 treated with GM-CSF+G-CSF who died 16 to 84 days (median, 38 days) after enrollment, yielding Kaplan-Meier 100-day survival estimates of 96% +/- 8% for GM-CSF versus 71% +/- 18% for GM-CSF+G-CSF (P = .026). These data suggest that sequential growth factor therapy with GM-CSF followed by G-CSF offers no advantage over GM-CSF alone in accelerating trilineage hematopoiesis or preventing lethal complications in patients with poor graft function after BMT.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
76.
Marketa Marvanova Paul Jacob Henkel 《Journal of the American Pharmacists Association》2019,59(3):361-368
ObjectivesTo summarize select continuing pharmacy education (CPE) topics and hours related to geriatric care completed by community, hospital/clinic, and long-term care (LTC)/consultant pharmacists in the previous 12 months, whether pharmacy workplace influenced topic selection or completion, and to describe CPE sources used by community versus hospital/clinic pharmacists.DesignCross-sectional survey (2017).Setting and participantsLicensed pharmacists in North Dakota, South Dakota, Minnesota, Iowa, and Nebraska with primary practice settings in community pharmacies, hospitals, or clinics or those practicing as consultant pharmacists.Main outcome measuresCPE on geriatric-related topics and hours completed in the previous 12 months, CPE providers and sources used, and differences in CPE topic completion and CPE providers and sources by primary pharmacy practice setting.ResultsPharmacists’ response rates for states ranged from 10.5% to 17.1%. Pharmacists (n = 1082) reported limited completion of geriatric-related topics. Almost one-third completed CPE credit in Alzheimer disease (AD) but fewer than 20% of pharmacists in selected age-related chronic diseases (e.g., Parkinson disease, dementia with Lewy bodies, epilepsy, vascular dementia, geriatric syndrome). LTC/consultant pharmacists completed significantly more hours in geriatric-related topics compared with other pharmacists. In contrast, diabetes mellitus, hypertension, asthma, and heart failure were completed by 34% to 64% of the pharmacists. Pharmacist’s Letter (57.2%), Power-Pak CE (42.4%), conferences, conventions, and symposia (32.5%), and Pharmacy Times (21.8%), were the most used CPE sources. Other sources were used by fewer than 18% of the pharmacists. Online CPE providers used by high numbers of study participants offered limited AD- or dementia-related topics and hours.ConclusionFindings revealed modest to minimal CPE completion in select geriatric care topics among pharmacists in the Upper Midwest. Completion rates were higher for LTC pharmacists compared with hospital, clinic, and community pharmacists. Only a few CPE sources were heavily used, and those offered minimal CPE in AD/dementia-related care. Given current findings and previous research, current CPE use habits and CPE offerings from major providers and sources seem insufficient for ensuring continued high-quality patient-centered care for growing U.S. aging populations. 相似文献
77.
78.
AMP-18,一种新发现的胃黏膜保护因子 总被引:3,自引:0,他引:3
AMP-18是一种新发现的由胃腺体上皮细胞合成的小分子蛋白质,独特表达于胃黏膜,机体其他部位少见,胃癌组织中表达缺失.AMP-18 由185个氨基酸组成,除去N端信号肽(20个氨基酸)后大小约18 ku,第54-150个氨基酸组成高度保守的结构域(BRICHOS区域)承担主要的生理功能.AMP-18由胃腺体上皮细胞以胞吐的方式分泌到胃黏液中,他的合成和分泌与个体生长发育有关,并受福斯高林、吲哚美辛、地塞米松等药物的影响.目前发现 AMP-18的生理功能主要有促进胃黏膜上皮细胞的有丝分裂,促进细胞的迁徙,促胃肠黏膜损伤的修复,保持胃肠黏膜的完整等. 相似文献
79.
EG Burden RW Walker DJ Ferguson AMF Goubran JR Howell JB John F Khan JS McGrath JP Evans 《Annals of the Royal College of Surgeons of England》2021,103(3):173
IntroductionWith the emergence of the COVID-19 pandemic, all elective surgery was temporarily suspended in the UK, allowing for diversion of resource to manage the anticipated surge of critically unwell patients. Continuing to deliver time-critical surgical care is important to avoid excess morbidity and mortality from pathologies unrelated to COVID-19. We describe the implementation and short-term surgical outcomes from a system to deliver time-critical elective surgical care to patients during the COVID-19 pandemic.Materials and methodsA protocol for the prioritisation and safe delivery of time-critical surgery at a COVID-19 ‘clean’ site was implemented at the Nuffield Health Exeter Hospital, an independent sector hospital in the southwest of England. Outcomes to 30 days postoperatively were recorded, including unplanned admissions after daycase surgery, readmissions and complications, as well as the incidence of perioperative COVID-19 infection in patients and staff.ResultsA total of 128 surgical procedures were performed during a 31-day period by a range of specialties including breast, plastics, urology, gynaecology, vascular and cardiology. There was one unplanned admission and and two readmissions. Six complications were identified, and all were Clavien-Dindo grade 1 or 2. All 128 patients had preoperative COVID-19 swabs, one of which was positive and the patient had their surgery delayed. Ten patients were tested for COVID-19 postoperatively, with none testing positive.ConclusionThis study has demonstrated the implementation of a safe system for delivery of time-critical elective surgical care at a COVID-19 clean site. Other healthcare providers may benefit from implementation of similar methodology as hospitals plan to restart elective surgery. 相似文献
80.