全文获取类型
收费全文 | 381篇 |
免费 | 76篇 |
国内免费 | 4篇 |
专业分类
461篇 |
出版年
2023年 | 10篇 |
2022年 | 17篇 |
2021年 | 18篇 |
2020年 | 20篇 |
2019年 | 24篇 |
2018年 | 18篇 |
2017年 | 26篇 |
2016年 | 14篇 |
2015年 | 28篇 |
2014年 | 39篇 |
2013年 | 40篇 |
2012年 | 36篇 |
2011年 | 33篇 |
2010年 | 9篇 |
2009年 | 14篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 6篇 |
2005年 | 10篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有461条查询结果,搜索用时 15 毫秒
451.
The paper examines the ethical and legal challenges of making decisions for previously competent patients and the role of advance directives and legal representatives in light of the Oviedo Convention. The paper identifies gaps in the Convention that result in conflicting instructions in cases of a disagreement between the expressed prior wishes of a patient, and the legal representative. The authors also examine the legal and moral status of informally expressed prior wishes of patients unable to consent. The authors argue that positivist legal reasoning is insufficient for a consistent interpretation of the relevant provisions of the Convention and argue that ethical argumentation is needed to provide guidance in such cases. Based on the ethical arguments, the authors propose a way of reconciling the apparent inconsistencies in the Oviedo Convention. They advance a culturally sensitive approach to the application of the Convention at the national level. This approach understands autonomy as a broader, relational consent and emphasizes the social and cultural embeddedness of the individual. Based on their approach, the authors argue that there exists a moral obligation to respect the prior wishes of the patient even in countries without advance directives. Yet it should be left to the national legislations to determine the extent of this obligation and its concrete forms. 相似文献
452.
Hae Young Song Mi Jeong Lee Min Young Kim Kyung Hye Kim Il Hwan Lee Sang Hun Shin Jung Sub Lee Jae Ho Kim 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2010,1801(1):23-30
Migration of mesenchymal stem cells plays a key role in regeneration of injured tissues. Rheumatoid arthritis (RA) is a chronic inflammatory disease and synovial fluid (SF) reportedly contains a variety of chemotactic factors. This study was undertaken to investigate the role of SF in migration of human bone marrow-derived mesenchymal stem cells (hBMSCs) and the molecular mechanism of SF-induced cell migration. SF from RA patients greatly stimulated migration of hBMSCs and the SF-induced migration was completely abrogated by pretreatment of the cells with the lysophosphatidic acid (LPA) receptor antagonist Ki16425 and by small interfering RNA- or lentiviral small hairpin RNA-mediated silencing of endogenous LPA1/Edg2. Moreover, SF from RA patients contains higher concentrations of LPA and an LPA-producing enzyme autotoxin than normal SF. In addition, SF from RA patients increased the intracellular concentration of calcium through a Ki16425-sensitive mechanism and pretreatment of the cells with the calmodulin inhibitor W7 or calmodulin-dependent protein kinase II inhibitor KN93 abrogated the SF-induced cell migration. These results suggest that LPA-LPA1 plays a key role in the migration of hBMSCs induced by SF from RA patients through LPA1-dependent activation of calmodulin-dependent protein kinase II. 相似文献
453.
《Endocrine practice》2022,28(11):1140-1145
ObjectiveThe aim of this study was to compare the “time to euthyroidism” and “time spent in euthyroidism” following methimazole (MMI) and radioactive iodine (RAI) treatments.MethodsThree hundred fifty-eight patients with hyperthyroidism, 178 who underwent long-term MMI treatment and 180 patients who underwent RAI treatment, were analyzed. The time to normalization of increased serum values of free thyroxine and triiodothyronine and suppressed serum thyroid-stimulating hormone (TSH) values as well as the percentage of time that the thyroid hormone levels remained within normal ranges during a mean follow-up time of 12 years were compared.ResultsThe mean time to euthyroidism was 4.59 ± 2.63 months (range, 2-16 months) in the MMI group and 15.39 ± 12.11 months (range, 2-61 months) in the RAI group (P < .001). During follow-up, the percentage of time spent in euthyroidism was 94.5% ± 7.3% and 82.5% + 11.0% in the MMI and RAI groups, respectively (P < .001). Serum TSH values above and below the normal range were observed in 5.3% and 0.2% of patients, respectively, in the MMI group and 9.8% and 7.7% of patients, respectively, in the RAI group (P < .001). The time to euthyroidism and the percentage of time spent in euthyroidism in 40 RAI-treated patients with euthyroidism were similar to those in the MMI group and significantly shorter than those in the RAI-treated hypothyroid and relapsed subgroups. In patients who continued MMI therapy for >10 years, the percentage of time spent in euthyroidism was >99%.ConclusionIn our cohort of selected patients, MMI therapy was accompanied by faster achievement of the euthyroid state and more sustained normal serum TSH levels during long-term follow-up compared with RAI therapy. 相似文献
454.
Moritz Späth Martin Hohmann Maximilian Rohde Benjamin Lengenfelder Florian Stelzle Florian Klämpfl 《Journal of biophotonics》2021,14(4):e202000465
Multiple diseases are associated with a wide spectrum of microvascular dysfunctions, microangiopathies and microcirculation disorders. Monitoring the microcirculation could thus be useful to diagnose many local and systemic circulatory disorders and to supervise critically ill patients. Many of the scores currently available to help identify the condition of a microcirculation disorder are invasive or leave scope for interpretation. Thus, the present study aims to investigate with Monte-Carlo simulations (as numerical solutions of the radiative transfer equation) whether shifted position-diffuse reflectance imaging (SP-DRI), a non-invasive diagnostic technique, reveals information on the capillary diameter to assess the state of the microcirculation. To quantify the SP-DRI signal, the modulation parameter K is introduced. It proves to correlate almost perfectly with the capillary diameter (), making it a valid parameter for reliably assessing microcirculation. SP-DRI is emerging as an important milestone on the way to early and conveniently diagnosing microcirculation associated diseases. 相似文献
455.
Multielement analysis in serum of thyroid cancer patients before and after a surgical operation 总被引:1,自引:0,他引:1
Concentrations of trace elements Zn, Cu, Fe, Mn, Mg, and Sr in the serum of 50 thyroid cancer patients and 50 healthy controls
were analyzed comprehensively by Pattern Recognition Analysis Method. Based on the Principal Component Analysis Method, Zn,
Cu, and Sr were found to be the principal elements with significant variations between patients and healthy controls. According
to the Mahalanolis Distance Decision and Nonlinear Mapping Methods, the trace elements levels in the serum of cancerous patients
were found significantly different from that of controls.
For 16 thyroid malignant tumor patients who underwent surgery, sample points of patients after surgery were directional away
from corresponding points before surgery. However, an overlapping was found and separation between two groups of points was
not complete. This finding suggests that there may be a latency period for the restoration of trace element levels after removal
of the malignant tumorous tissue. 相似文献
456.
《Endocrine practice》2023,29(7):509-516
ObjectiveThe cardiovascular (CV) and renal benefits of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in people with type 2 diabetes are well known. However, similar beneficial effects of SGLT2i in combination with dipeptidyl peptidase-4 inhibitors (DPP4i) are unknown. It is of interest to explore a trial-level meta-analysis to fill this knowledge gap.MethodsA literature search was conducted in the PubMed and Embase databases until January 31, 2023. All CV outcome trials (CVOTs) reporting the CV and renal outcomes of SGLT2i with or without background DPP4i therapy against the placebo were retrieved. A meta-analysis was subsequently conducted by applying the inverse variance-weighted averages of pooled logarithmic hazard ratio using primarily random-effects analysis.ResultsThis meta-analysis showed that the beneficial 3-point major adverse cardiovascular events composite (3 CVOTs; N = 32 418), the composite of CV death or heart failure hospitalization (hHF) (4 CVOTs; N = 37 687), hHF (3 CVOTs; N = 27 545), CV death (4 CVOTs; N = 34 565), and renal outcomes (2 CVOTs; N = 25 406) with SGLT2i were similar with or without background DPP4i therapy against the placebo (Pheterogeneity = .71, .07, .87, .72, and .25; respectively). However, against the placebo, the summary estimates for the 3-point major adverse cardiovascular events composite, hHF, and renal outcomes were stronger with SGLT2i alone, whereas the summary estimates for CV death or hHF composite were larger with SGLT2i with background DPP4i therapy.ConclusionBeneficial CV and renal effects of SGLT2i are similar against the placebo regardless of background DPP4i therapy. 相似文献
457.
Chrisna Veldsman Marleen M. Kock Theresa Rossouw Martin Nieuwoudt Mark Maeurer Anwar A. Hoosen & Marthie M. Ehlers 《FEMS immunology and medical microbiology》2009,57(3):269-273
Tuberculosis is a life-threatening infection worldwide. Despite improvements in therapy, it results in 2 million deaths and 9 million new cases annually. This study evaluated the use of the QuantiFERON-TB GOLD enzyme-linked immunosorbent assay in a high HIV/TB burden setting in an ARV clinic at the Tshwane District Hospital, South Africa. The sensitivity and specificity of the QF assay in the clinic were 30% (9/30) and 63% (19/30), respectively, when compared with the gold standard culture results. Analysis also suggested that the sensitivity of the QuantiFERON assay is determined by a limiting patient CD4 value between 150 and 200. 相似文献
458.
Luz P. Blanco Cecilia S. Toro Jaime M. Romero Carlos A. Santiviago Guido C. Mora 《Microbiology and immunology》1997,41(12):999-1003
The immunogenic effect of Salmonella typhi OmpC porin during typhoid fever in humans was evaluated in vitro. Peripheral blood mononuclear cells from 17 patients were challenged with outer membrane preparations from Escherichia coli UH302 and UH302/pSTP2K2 strains, both lacking E. coli OmpF and OmpC porins, although UH302/pSTP2K2 expressed a plasmid-encoded S. typhi Ty2 OmpC. The mononuclear cell supernatants, immunized in vitro with OmpC antigen, derived from 10 out of 17 patients activated U937 bactericidal capacity. In contrast, the supernatants from the immunization with outer membrane preparation lacking S. typhi Ty2 OmpC induced a significantly reduced bactericidal capacity of U937 cells. This procedure should prove useful for in vitro characterization of cellular immunogens from exclusive human pathogens. 相似文献
459.
L. Magni D.M. Raimondo C. Dalla Man G. De Nicolao B. Kovatchev C. Cobelli 《Biomedical signal processing and control》2009,4(4):338-346
In this paper, the feedback control of glucose concentration in type I diabetic patients using subcutaneous insulin delivery and subcutaneous continuous glucose monitoring is considered. A recently developed in silico model of glucose metabolism is employed to generate virtual patients on which control algorithms can be validated against interindividual variability. An in silico trial consisting of 100 patients is used to assess the performances of a linear output feedback and a nonlinear state-feedback model predictive controller, designed on the basis of the in silico model. More than satisfactory results are obtained in the great majority of virtual patients. The experiments highlight the crucial role of the anticipative feedforward action driven by the meal announcement information. Preliminary results indicate that further improvements may be achieved by means of a nonlinear model predictive control scheme. 相似文献
460.
Mantovani G. Macciò A. Lai P. Turnu E. Del Giacco G. S. 《Cell biochemistry and biophysics》1994,24(1-3):301-305
The aim of the study was to evaluate the subset distribution and the IL-2 R p55–p75 subunit expression on unstimulated and
phytohemagglutinin (PHA)-stimulated (at 3-d) peripheral blood mononuclear cells (PBMC), of patients with solid cancers of
different sites. Indeed the expression of the two subunits of IL-2R is an essential prerequisite for The action of the IL-2
on CD8+, CD16+ lymphocytes as effectors in antitumor activity (LAK-cells). The subset distribution (CD3, CD4, CD8, CD16, DR) was assessed
by cytofluorometry with specific monoclonal antibodies (MAbs); the p55 (CD25) and p75 subunit expression was evaluated by
specific MAb (OKT26a and anti-p75). Ninety patients with advanced cancer (mainly non-small cell lung cancer [NSCLC], head
and neck cancer, and gynecological cancer; mean age 55 yr; range 27–80) were studied. Thirty-five age- and sex-matched healthy
subjects were studied as controls. Our data show that there is no significant difference in the subset distribution between
cancer patients and controls. Furthermore, no difference has been found in the expression of p55 subunits on unstimulated
PBMC between cancer patients and controls. No difference has been found in the expression of both p55 and p75 subunits on
PHA-stimulated PBMC between cancer patients and controls. Our results can support the rationale for further clinical trials
with IL-2 in solid malignancies. 相似文献