全文获取类型
收费全文 | 557篇 |
免费 | 38篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 34篇 |
妇产科学 | 6篇 |
基础医学 | 74篇 |
口腔科学 | 26篇 |
临床医学 | 47篇 |
内科学 | 94篇 |
皮肤病学 | 37篇 |
神经病学 | 22篇 |
特种医学 | 44篇 |
外科学 | 99篇 |
综合类 | 35篇 |
预防医学 | 26篇 |
眼科学 | 8篇 |
药学 | 26篇 |
中国医学 | 1篇 |
肿瘤学 | 29篇 |
出版年
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 6篇 |
2015年 | 12篇 |
2014年 | 20篇 |
2013年 | 25篇 |
2012年 | 19篇 |
2011年 | 26篇 |
2010年 | 24篇 |
2009年 | 31篇 |
2008年 | 25篇 |
2007年 | 27篇 |
2006年 | 19篇 |
2005年 | 22篇 |
2004年 | 7篇 |
2003年 | 13篇 |
2002年 | 11篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 35篇 |
1997年 | 28篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 12篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1966年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有610条查询结果,搜索用时 15 毫秒
71.
Sabina Luisa Campanelli Giuseppe Casalino Caterina Casavola Vincenzo Moramarco 《Materials》2013,6(12):5923-5941
Friction Stir Welding (FSW) is a solid-state joining process; i.e., no melting occurs. The welding process is promoted by the rotation and translation of an axis-symmetric non-consumable tool along the weld centerline. Thus, the FSW process is performed at much lower temperatures than conventional fusion welding, nevertheless it has some disadvantages. Laser Assisted Friction Stir Welding (LAFSW) is a combination in which the FSW is the dominant welding process and the laser pre-heats the weld. In this work FSW and LAFSW tests were conducted on 6 mm thick 5754H111 aluminum alloy plates in butt joint configuration. LAFSW is studied firstly to demonstrate the weldability of aluminum alloy using that technique. Secondly, process parameters, such as laser power and temperature gradient are investigated in order to evaluate changes in microstructure, micro-hardness, residual stress, and tensile properties. Once the possibility to achieve sound weld using LAFSW is demonstrated, it will be possible to explore the benefits for tool wear, higher welding speeds, and lower clamping force. 相似文献
72.
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
73.
Comparison of clinical and self-reported diagnoses for participants on a community-based arthritis self-management programme 总被引:2,自引:0,他引:2
OBJECTIVE: With the advent of community-based arthritis education
programmes, it is important to determine the accuracy of participants'
self-reported diagnoses. The purpose of this study was to determine the
level of agreement between general practitioner (GP)-recorded and self-
reported diagnoses of participants attending an Arthritis Self- Management
Programme (ASMP). METHODS: Participants enrolling on the ASMP were asked to
(a) identify their type of arthritis via a self- administered postal
questionnaire and (b) obtain a written confirmation of their diagnosis from
their GP. The sample (n = 613) comprised mainly women (83%) with a mean age
of 58.8 yr (S.D. 12.6) and a mean disease duration of 15.4 yr (S.D. 12.5).
RESULTS: Participants' self-reported diagnoses were confirmed by GPs in 534
cases [87.1%, 95% confidence interval (CI): 84.4 89.8%]. Confirmed
diagnoses were reported by 86.9% (95% CI: 83.1-90.7%) of those with
osteoarthritis (OA) and 96.1% (95% CI: 93.6 98.6%) of those with rheumatoid
arthritis (RA). The concordance rate for all other types of arthritis
combined was lower at 60.5% (95% CI: 49.5-71.5%). There were no significant
differences with respect to age, gender, education, physical functioning,
duration of disease and number of GP visits between those who correctly
identified their type of arthritis and those who did not. CONCLUSIONS: This
study suggests that the majority of RA and OA participants attending an
arthritis education programme can correctly identify their specific type of
arthritis.
相似文献
74.
Factors predicting survival in chronic lymphocytic leukemia patients developing Richter syndrome transformation into Hodgkin lymphoma 下载免费PDF全文
Francesca Romana Mauro Piero Galieni Alessandra Tedeschi Luca Laurenti Giovanni Del Poeta Gianluigi Reda Marina Motta Alessandro Gozzetti Roberta Murru Maria Denise Caputo Melissa Campanelli Anna Maria Frustaci Idanna Innocenti Sara Raponi Anna Guarini Fortunato Morabito Robin Foà Massimo Gentile 《American journal of hematology》2017,92(6):529-535
We hereby report the clinical and biologic features of 33 of 4680 (0.7%) patients with chronic lymphocytic leukemia (CLL), managed at 10 Italian centers, who developed Hodgkin lymphoma (HL), a rare variant of Richter syndrome. The median age at CLL and at HL diagnosis were 61 years (range 41‐80) and 70 years (range 46‐82), respectively, with a median interval from CLL to the diagnosis of HL of 90 months (range 0‐258). In 3 cases, CLL and HL were diagnosed simultaneously. Hl was characterized by advanced stage in 79% of cases, International Prognostic Score (IPS) ≥4 in 50%, extranodal involvement in 39%, B symptoms in 70%. Prior treatment for CLL had been received by 82% of patients and included fludarabine in 67%. Coexistence of CLL and HL was detected in the same bioptic tissue in 87% of cases. The most common administered treatment was the ABVD regimen given to 22 patients (66.6%). The complete response (CR) rate after ABVD was 68%, and was influenced by the IPS (P = .03) and interval from the last CLL treatment (P = .057). Survival from HL was also influenced by the IPS (P = .006) and time from the last CLL treatment (P = .047). The achievement of CR with ABVD was the only significant and independent factor predicting survival (P = .037). Taken together, our results show that the IPS and the interval from the prior CLL treatment influence the likelihood of achieving CR after ABVD, which is the most important factor predicting survival of patients with CLL developing HL. 相似文献
75.
The activation of factor XI initiates the intrinsic coagulation pathway. Until recently it was believed that the main activator of factor XI is factor XIIa in conjunction with the cofactor high molecular weight kininogen on a negatively charged surface. Two recent reports have presented evidence that in a purified system factor XI is activatable by thrombin together with the soluble polyanion dextran sulfate. To assess the physiological relevance of these findings we studied the activation of factor XI in normal and factor XII-deficient plasma. We used either kaolin/cephalin or dextran sulfate as a surface for the intrinsic coagulation pathway, tissue factor to generate thrombin via the extrinsic pathway, or the addition of alpha-thrombin directly. 125I-factor XI, added to factor XI-deficient plasma at physiologic concentrations (35 nmol/L), is rapidly cleaved on incubation with kaolin. The kinetics appear to be exponential with half the maximum cleavage at 5 minutes. Similar kinetics of factor XI cleavage are seen when 40 nmol/L factor XIIa (equal to 10% of factor XII activation) is added to factor XII-deficient plasma if an activating surface is provided. Tissue factor (1:500) added to plasma did not induce cleavage of factor XI during a 90-minute incubation, although fibrin formation within 30 seconds indicated that thrombin was generated via the extrinsic pathway. Adding 1 mumol/L alpha-thrombin (equivalent to 50% prothrombin activation) directly to factor XII deficient or normal plasma (with or without kaolin/cephalin/Ca2+ or dextran sulfate) led to instantaneous fibrinogen cleavage, but again no cleavage of factor XI was observable. We conclude that in plasma surroundings factor XI is not activated by thrombin, and that proposals of thrombin initiation of the intrinsic coagulation cascade are not supportable. 相似文献
76.
77.
78.
Surgical bacterial infections and antimicrobial susceptibility patterns at Lilongwe Central Hospital
RM Banda AS Muula GR Gwaza DC Namarika KC Ng'oma FE Chintolo H Yamakazi AP Muyco 《Malawi medical journal : the journal of Medical Association of Malawi》2001,13(3):27-29
A cross sectional study was done between October 1999 and February 2000 to determine antimicrobial susceptibility patterns of consecutive bacterial isolates of 102 clinical samples among surgical in-patients at Lilongwe Central Hospital (LCH), Malawi. Antimicrobial susceptibility was determined using comparative disc diffusion techniques. 83 (81.4%) samples were culture positive for bacterial growth while 19 (18.6%) grew nothing. Of the 93 culture positive specimens, Staphylococcus aureus was the predominant organism 43(51.8%) followed by Proteus species 8(9.6%) and E. coli 7(8.4%). Overall, 98.6% of all isolates tested against ciprofloxacin were susceptible, and against gentamicin and flucloxacin were 84.8% and 66.7% respectively. 59.3% of isolates tested against chloramphenicol were resistant. We recommend a review on the use of chloramphenicol as first-line antimicrobial therapy among surgical in-patients at Lilongwe Central Hospital. We also recommend restricted use of antimicrobials so as to minimise development of drug resistance. Periodic susceptibility studies are necessary to guide judicious use of antibiotics. 相似文献
79.
本文应用直接、间接双色免疫荧光染色,流体细胞测定仪技术,观察了经~(131)碘治疗的23例Graves′病患者的循环活性T细胞亚群的动态变化。~(131)碘治疗后的第一个月至第三个月,HLA-DR、Ta_1和UCHL_1活性T细胞亚群数目明显增加,以Vicia-villosa为标志的抗抑制细胞亚群较治疗前明显增加。实验结果提示:Graves′病患者经~(131)碘治疗后的抗甲状腺自身抗体浓度增加可能是由于T细胞的激活和抗抑制细胞亚群增加的共同结果。 相似文献
80.
Cloning of cDNA for proteinase 3: a serine protease, antibiotic, and autoantigen from human neutrophils 总被引:10,自引:0,他引:10 下载免费PDF全文
D Campanelli M Melchior Y Fu M Nakata H Shuman C Nathan J E Gabay 《The Journal of experimental medicine》1990,172(6):1709-1715
Closely similar but nonidentical NH2-terminal amino acid sequences have been reported for a protein or proteins in human neutrophils whose bioactivities is/are diverse (as a serine protease, antibiotic, and Wegener's granulomatosis autoantigen) but that share(s) several features: localization in the azurophil granules, a molecular mass of approximately 29 kD, reactivity with diisopropylfluorophosphate, and the ability to degrade elastin. We previously purified one such entity, termed p29b. Using a monospecific antibody, we have cloned from human bone marrow a cDNA encoding the complete p29b protein in its mature form, along with pre- and pro-sequences. The predicted amino acid sequence agrees closely with the NH2-terminal sequence obtained previously from purified p29b, as well as with sequences newly obtained from CNBr fragments. The primary structure is highly homologous to elastase, cathepsin G, T cell granzymes, and other serine proteases, and shares both the catalytic triad and substrate binding pocket of elastase. Hybridization of the full-length cDNA with restriction enzyme digests of human genomic DNA revealed only one fragment. This suggests that the closely related species described previously are the same, and can be subsumed by the term used for the first-described activity, proteinase 3. Proteinase 3 is more abundant in neutrophils than elastase and has a similar proteolytic profile and specific activity. Thus, proteinase 3 may share the role previously attributed to neutrophil elastase in tissue damage, and has the potential to function as an antimicrobial agent. 相似文献