全文获取类型
收费全文 | 1538篇 |
免费 | 66篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 71篇 |
妇产科学 | 12篇 |
基础医学 | 155篇 |
口腔科学 | 21篇 |
临床医学 | 164篇 |
内科学 | 448篇 |
皮肤病学 | 52篇 |
神经病学 | 75篇 |
特种医学 | 300篇 |
外科学 | 66篇 |
综合类 | 33篇 |
预防医学 | 110篇 |
眼科学 | 15篇 |
药学 | 71篇 |
中国医学 | 2篇 |
肿瘤学 | 65篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 21篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 19篇 |
2014年 | 24篇 |
2013年 | 55篇 |
2012年 | 51篇 |
2011年 | 33篇 |
2010年 | 49篇 |
2009年 | 79篇 |
2008年 | 57篇 |
2007年 | 108篇 |
2006年 | 63篇 |
2005年 | 44篇 |
2004年 | 48篇 |
2003年 | 27篇 |
2002年 | 32篇 |
2001年 | 26篇 |
2000年 | 27篇 |
1999年 | 42篇 |
1998年 | 72篇 |
1997年 | 82篇 |
1996年 | 102篇 |
1995年 | 63篇 |
1994年 | 58篇 |
1993年 | 54篇 |
1992年 | 17篇 |
1991年 | 17篇 |
1990年 | 22篇 |
1989年 | 40篇 |
1988年 | 36篇 |
1987年 | 34篇 |
1986年 | 45篇 |
1985年 | 41篇 |
1984年 | 8篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1975年 | 13篇 |
1973年 | 2篇 |
排序方式: 共有1661条查询结果,搜索用时 15 毫秒
41.
Ian J Majewski Lorenza Mittempergher Nadia M Davidson Astrid Bosma Stefan M Willems Hugo M Horlings Iris de Rink Liliana Greger Gerrit KJ Hooijer Dennis Peters Petra M Nederlof Ingrid Hofland Jeroen de Jong Jelle Wesseling Roelof JC Kluin Wim Brugman Ron Kerkhoven Frank Nieboer Paul Roepman Annegien Broeks Thomas R Muley Jacek Jassem Jacek Niklinski Nico van Zandwijk Alvis Brazma Alicia Oshlack Michel van den Heuvel René Bernards 《The Journal of pathology》2013,230(3):270-276
42.
Marieke de Vries Angela Fagerlin Holly O. Witteman Laura D. Scherer 《Patient education and counseling》2013
Objective
To review the strengths and weaknesses of deliberative and intuitive processes in the context of patient decision support and to discuss implications for decision aid (DA) design.Methods
Conceptual review of the strengths and weaknesses of intuitive and analytical decision making and applying these findings to the practice of DA design.Results
DAs combine several important goals: providing information, helping to clarify treatment related values, supporting preference construction processes, and facilitating more active engagement in decision making. Many DAs encourage patients to approach a decision analytically, without solid theoretical or empirical grounding for this approach. Existing research in other domains suggests that both intuition and deliberation may support decision making. We discuss implications for patient decision support and challenge researchers to determine when combining these processes leads to better outcomes.Conclusions
Intuitive and analytical decision processes may have complementary effects in achieving the desired outcomes of patient decision support.Practice implications
DA developers should be aware that tools solely targeted at supporting deliberation may limit DA effectiveness and harm preference construction processes. Patients may be better served by combined strategies that draw on the strengths and minimize the weaknesses of both deliberative and intuitive processes. 相似文献43.
Nynke D Scherpbier-de Haan Gerald MM Vervoort Chris van Weel Jozé CC Braspenning Jan Mulder Jack FM Wetzels Wim JC de Grauw 《The British journal of general practice》2013,63(617):e798-e806
Background
Chronic kidney disease (CKD) is highly prevalent in patients with diabetes or hypertension in primary care. A shared care model could improve quality of care in these patientsAim
To assess the effect of a shared care model in managing patients with CKD who also have diabetes or hypertension.Design and setting
A cluster randomised controlled trial in nine general practices in The Netherlands.Method
Five practices were allocated to the shared care model and four practices to usual care for 1 year. Primary outcome was the achievement of blood pressure targets (130/80 mmHg) and lowering of blood pressure in patients with diabetes mellitus or hypertension and an estimated glomerular filtration rate (eGFR)<60ml/min/1.73m2.Results
Data of 90 intervention and 74 control patients could be analysed. Blood pressure in the intervention group decreased with 8.1 (95% CI = 4.8 to 11.3)/1.1 (95% CI = −1.0 to 3.2) compared to −0.2 (95% CI = −3.8 to 3.3)/−0.5 (95% CI = −2.9 to 1.8) in the control group. Use of lipid-lowering drugs, angiotensin-system inhibitors and vitamin D was higher in the intervention group than in the control group (73% versus 51%, 81% versus 64%, and 15% versus 1%, respectively, [P = 0.004, P = 0.01, and P = 0.002]).Conclusion
A shared care model between GP, nurse practitioner and nephrologist is beneficial in reducing systolic blood pressure in patients with CKD in primary care. 相似文献44.
Angela Fagerlin Michael Pignone Purva Abhyankar Nananda Col Deb Feldman-Stewart Teresa Gavaruzzi Jennifer Kryworuchko Carrie A Levin Arwen H Pieterse Valerie Reyna Anne Stiggelbout Laura D Scherer Celia Wills Holly O Witteman 《BMC medical informatics and decision making》2013,13(Z2):S8
Background
Consensus guidelines have recommended that decision aids include a process for helping patients clarify their values. We sought to examine the theoretical and empirical evidence related to the use of values clarification methods in patient decision aids.Methods
Building on the International Patient Decision Aid Standards (IPDAS) Collaboration’s 2005 review of values clarification methods in decision aids, we convened a multi-disciplinary expert group to examine key definitions, decision-making process theories, and empirical evidence about the effects of values clarification methods in decision aids. To summarize the current state of theory and evidence about the role of values clarification methods in decision aids, we undertook a process of evidence review and summary.Results
Values clarification methods (VCMs) are best defined as methods to help patients think about the desirability of options or attributes of options within a specific decision context, in order to identify which option he/she prefers. Several decision making process theories were identified that can inform the design of values clarification methods, but no single “best” practice for how such methods should be constructed was determined. Our evidence review found that existing VCMs were used for a variety of different decisions, rarely referenced underlying theory for their design, but generally were well described in regard to their development process. Listing the pros and cons of a decision was the most common method used. The 13 trials that compared decision support with or without VCMs reached mixed results: some found that VCMs improved some decision-making processes, while others found no effect.Conclusions
Values clarification methods may improve decision-making processes and potentially more distal outcomes. However, the small number of evaluations of VCMs and, where evaluations exist, the heterogeneity in outcome measures makes it difficult to determine their overall effectiveness or the specific characteristics that increase effectiveness.45.
Enhancement of neutrophil function by granulocyte-macrophage colony- stimulating factor involves recruitment of a less responsive subpopulation 总被引:3,自引:0,他引:3
Human granulocyte-macrophage colony-stimulating factor (GM-CSF) enhances numerous functions of mature neutrophils (PMN) including phagocytosis, superoxide responses to chemotaxins, antibody-dependent cellular cytotoxicity, and expression of complement receptors. A central question concerns whether the mechanism of enhancement involves quantitative increases in the response of all cells v subpopulation recruitment. The effects of GM-CSF on individual cell light scatter changes, membrane potential, and oxidant responses induced by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP) were assessed by flow cytometry and by scoring individual cells for nitroblue tetrazolium dye (NBT) reduction. GM-CSF produced a dose- and time-dependent shift in forward light scatter that was very similar in character to that seen with FMLP or leukotriene B4 stimulation. Although not capable of depolarizing the cells directly, GM-CSF primed PMNs for enhanced membrane potential responses to FMLP by significantly increasing the proportion of depolarizing cells when compared with diluent-treated controls after a 60-minute incubation at 37 degrees C (79.4% +/- 3.4% v 29.5% +/- 4.7% GM-CSF v diluent, mean +/- SE, P less than .005, n = 11). Subpopulation recruitment by GM-CSF treatment was also demonstrated by the FMLP-elicited NBT test. Taken together, these results indicate that GM-CSF can modulate the function of mature PMN by enhancing the proportion of responsive cells. 相似文献
46.
Thrombopoietin (TPO) or MpI ligand is known to stimulate megakaryocyte (MK) proliferation and differentiation. To identify the earliest human hematopoietic cells on which TPO acts, we cultured single CD34+Thy- 1+Lin- adult bone marrow cells in the presence of TPO alone, with TPO and interleukin-3 (IL-3), or with TPO and c-kit ligand (KL) in the presence of a murine stromal cell line (Sys1). Two distinct growth morphologies were observed: expansion of up to 200 blast cells with subsequent differentiation to large refractile CD41b+ MKs within 3 weeks or expansion to 200-10,000 blast cells, up to 25% of which expressed CD34. The latter blast cell expansions occurred over a 3- to 6-week period without obvious MK differentiation. Morphological staining, analysis of surface marker expression, and colony formation analysis revealed that these populations consisted predominantly of cells committed to the myelomonocytic lineage. The addition of IL-3 to TPO-containing cultures increased the extent of proliferation of single cells, whereas addition of KL increased the percentage of CD34+ cells among the expanding cell populations. Production of multiple colony- forming unit-MK from single CD34+Thy-1+Lin- cells in the presence of TPO was also demonstrated. In limiting dilution assays of CD34+Lin- cells, TPO was found to increase the size and frequency of cobblestone areas at 4 weeks in stromal cultures in the presence of leukemia inhibitory factor and IL-6. In stroma-free cultures, TPO activated a quiescent CD34+Lin-Rhodamine 123lo subset of primitive hematopoietic progenitor cells into cycle, without loss of CD34 expression. These data demonstrate that TPO acts directly on and supports division of cells more primitive than those committed to the MK lineage. 相似文献
47.
48.
49.
Kirsten Boonstra Robin Bokelaar Paul H. Stadhouders Hans A. Tuynman Alexander C. Poen Karin M. van Nieuwkerk Ellen M. Witteman Dörte Hamann Ben J. Witteman Ulrich Beuers Cyriel Y. Ponsioen 《Hepatology International》2014,8(2):266-274
Background and aims
The natural history of primary biliary cirrhosis (PBC) has so far mainly been studied in tertiary referral centres. The aim of the present investigation was to describe the natural history of PBC in a large population-based cohort in order to identify risk factors for development of malignancies and disease progression.Methods
Four independent hospital databases were searched in 44 hospitals in a geographically defined area, after which all medical records were evaluated on site. In addition, PBC registries in the three liver transplant centers were checked for missed referrals from the area of interest.Results
In total, 992 cases fulfilled the inclusion criteria. The median follow-up was 73 months (range 0–434). Mortality was similar to the age- and gender matched population (SMR 1.1; 95 % CI 0.9–1.4). Male gender, smoking, and elevated bilirubin, decreased albumin, and elevated AST at time of diagnosis, were associated with an increased risk for the combined end point PBC-related death or liver transplantation. In total, 133 (13 %) patients developed one or more malignancies (SIR 1.5; 95 % CI 1.1–1.9). There was a ninefold increased risk of developing hepatobiliary malignancies (SIR 9.4; 95 % CI 3.04–21.8), a fivefold increased risk of developing urinary bladder cancer (SIR 5.0; 95 % CI 1.6–11.6), and a 1.8-fold increased risk of developing breast cancer (SIR 1.8; 95 % CI 1.08–2.81).Conclusion
PBC is associated with an increased risk of hepatobiliary, bladder and breast cancer. Still, survival—under treatment with ursodeoxycholic acid (UDCA)—was comparable to the general population in this population-based study. 相似文献50.
Objective:To investigate the wound healing properly of Napoleona vogelii leaf extract in folkloric medicine.Methods:Roth sexes of adult albino rats(n=25) were used in this study and another group(n=30) were subjected to acute toxicity test(LD_(50)) of the plant extract.For the LD_(50),three randomized groups of 5 rats were first treated with 10,100,1 000 mg/kg body weight(bw),orally.This w as followed by a second treatment of 1500,3000,and 5 000 mg/kg bw of the leaf extract with continual monitoring of the animals for mortality or non-mortality.Incision wounds(1.3cm) were created on the skin of five groups of 5 rals using surgical blade under anesthesia.The first group was topically treated with petroleum jelly alone,group 2 was topically applied 400 mg/mL w/v of the reference drug,Neobaein,while group 3-5 were topically treated with 5-50 mg/mL w/v of the plant extract,respectively.Results:The percentage yield of the extract was 49.80%w/w dry matter.The phytochemical analysis revealed several bioactive constituents including glycosides,tannins,alkaloids,perpenoids.saponins,steroids,proteins,and carbohydrates.The LD_(50) was beyond our experimental limit and was not determined.Increased concentrations(5,20,and 50mg/mL w/v) of the extract had significant(ANOVA,P0.05) healing effect on the incision wounds giving rise to 125%-140% while treatmentawith Neobacin resulted in 150% healing effect on the third treatment regimen compared to the control(100%).Conclusions:These data indicate that Napoleona vogelii leaf extract contains potent bioactive compounds containing wound healing activity,substantiating its use as a wound healer in folkloric medicine. 相似文献