全文获取类型
收费全文 | 307篇 |
免费 | 23篇 |
专业分类
330篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 11篇 |
2013年 | 17篇 |
2012年 | 28篇 |
2011年 | 28篇 |
2010年 | 24篇 |
2009年 | 14篇 |
2008年 | 16篇 |
2007年 | 23篇 |
2006年 | 20篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有330条查询结果,搜索用时 0 毫秒
111.
Effects of purified herbal extract of Salvia miltiorrhiza on ischemic rat myocardium after acute myocardial infarction 总被引:6,自引:0,他引:6
Sun J Huang SH Tan BK Whiteman M Zhu YC Wu YJ Ng Y Duan W Zhu YZ 《Life sciences》2005,76(24):2849-2860
In the current study, we compared purified Salvia miltiorrhiza extract (PSME) with Angiotensin-converting enzyme inhibitor, Ramipril, in in vitro experiments and also in vivo using animal model of myocardial infarction. PSME was found to have a significantly higher trolox equivalent antioxidant capacity which indicated a great capacity for scavenging free radicals. PSME could also prevent pyrogallo red bleaching and DNA damage. After 2 weeks treatment with PSME or Ramipril, survival rates of rats with experimental myocardial infarction were marginally increased (68.2% and 71.4%) compared with saline (61.5%). The ratios of infarct size to left ventricular size in both PSME-and Ramipril-treated rats were significantly less than that in the saline-treated group. Activity of cardiac antioxidant enzyme superoxide dismutase (SOD) was significant higher while level of Thiobarbituric acid-reactive substances (TBARs) was lower in the PSME treated group. Purified and standardized Chinese herb could provide an alternative regimen for the prevention of ischemic heart disease. 相似文献
112.
Lobosporangium is proposed as a new name for Echinosporangium Malloch, a later homonym of Echinosporangium Kylin. Lobosporangium transversale was isolated from arid soils on three occasions between 1964 and 1968 but has not been reported again. Observations on sporangium development in culture revealed rapid sporangiospore germination, rapidly growing hyphae forming anastomoses, threefold dichotomously branching aerial sporangiophores and formation of clusters of eight sporangia. The sporangia of L. transversale are illustrated, and the placement of Lobosporangium in the Mortierellaceae is discussed. A new genus, Gamsiella, is proposed that is based on Mortierella multidivaricata. Sporangial ontogeny of Gamsiella is compared with that presented here for Lobosporangium. 相似文献
113.
An assay for beta-glucuronidase is described. The assay uses 1-(beta-D-glucopyranuronosyl)pyridinium hydroxide, inner salt, as substrate and the quantitative determination is performed with headspace gas chromatography, measuring one of the products, pyridine, in the gas phase. The assay has been developed utilizing commercially available beta-glucuronidase (EC 3.2.1.31.) from Escherichia coli, and has been applied to various sources of beta-glucuronidase. Crude homogenates can be assayed directly with a minimum of manipulative steps and the method is suited for automation. 相似文献
114.
Osteoarthritis (OA) mainly affects older populations; however, it is possible that early life factors contribute to the development of OA in later life. The aim of this review is to describe the association between childhood or early adulthood risk factors and knee pain, structural imaging markers and development of knee OA in later life. A narrative overview of the literature synthesising the findings of literature retrieved from searches of computerised databases and manual searches was conducted. We found that only a few studies have explored the long-term effect of childhood or early adulthood risk factors on the markers of joint health that predispose people to OA or joint symptoms. High body mass index (BMI) and/or overweight status from childhood to adulthood were independently related to knee pain and OA in later life. The findings regarding the association between strenuous physical activity and knee structures in young adults are still conflicting. However, a favourable effect of moderate physical activity and fitness on knee structures is reported. Childhood physical activity and performance measures had independent beneficial effects on knee structures including knee cartilage in children and young adults. Anterior knee pain syndrome in adolescence could lead to the development of patellofemoral knee OA in the late 40s. Furthermore, weak evidence suggests that childhood malalignment, socioeconomic status and physical abuse are associated with OA in later life. The available evidence suggests that early life intervention may prevent OA in later life. 相似文献
115.
Paolo Fusar-Poli Andrés Estradé Giovanni Stanghellini Cecilia Maria Esposito René Rosfort Milena Mancini Peter Norman Julieann Cullen Miracle Adesina Gema Benavides Jimenez Caroline da Cunha Lewin Esenam A. Drah Marc Julien Muskan Lamba Edwin M. Mutura Benny Prawira Agus Sugianto Jaleta Teressa Lawrence A. White Stefano Damiani Candida Vasconcelos Ilaria Bonoldi Pierluigi Politi Eduard Vieta Jennifer Radden Thomas Fuchs Matthew Ratcliffe Mario Maj 《World psychiatry》2023,22(3):352-365
We provide here the first bottom-up review of the lived experience of depression, co-written by experts by experience and academics. First-person accounts within and outside the medical field were screened and discussed in collaborative workshops involving numerous individuals with lived experience of depression, family members and carers, representing a global network of organizations. The material was enriched by phenomenologically informed perspectives and shared with all collaborators in a cloud-based system. The subjective world of depression was characterized by an altered experience of emotions and body (feeling overwhelmed by negative emotions, unable to experience positive emotions, stuck in a heavy aching body drained of energy, detached from the mind, the body and the world); an altered experience of the self (losing sense of purpose and existential hope, mismatch between the past and the depressed self, feeling painfully incarcerated, losing control over one's thoughts, losing the capacity to act on the world; feeling numb, empty, non-existent, dead, and dreaming of death as a possible escape route); and an altered experience of time (experiencing an alteration of vital biorhythms, an overwhelming past, a stagnation of the present, and the impossibility of the future). The experience of depression in the social and cultural context was characterized by altered interpersonal experiences (struggling with communication, feeling loneliness and estrangement, perceiving stigma and stereotypes), and varied across different cultures, ethnic or racial minorities, and genders. The subjective perception of recovery varied (feeling contrasting attitudes towards recovery, recognizing recovery as a journey, recognizing one's vulnerability and the need for professional help), as did the experience of receiving pharmacotherapy, psychotherapy, and social as well as physical health interventions. These findings can inform clinical practice, research and education. This journey in the lived experience of depression can also help us to understand the nature of our own emotions and feelings, what is to believe in something, what is to hope, and what is to be a living human being. 相似文献
116.
Ren M Rajendran R Ning P Tan Kwong Huat B Choon Nam O Watt F Jenner A Halliwell B 《Free radical biology & medicine》2006,41(2):222-225
Developing atherosclerotic plaques in cholesterol-fed rabbits are enriched in iron but depleted in zinc. In order to examine further the role of zinc, New Zealand White rabbits were fed a high-cholesterol 1% (w/w) diet with zinc (1 g/kg) supplementation for 8 weeks. After the 8-week period, the average atherosclerotic lesion cross-sectional areas in the aortas of the animals fed with the zinc supplement were significantly decreased (1.0 mm2) compared with lesion areas of the animals fed only on the high-cholesterol diet (3.1 mm2). Using nuclear microscopy, a technique for mapping and measuring trace elements in tissue sections, lesion zinc levels (24 ppm) were observed to be unchanged in the zinc-fed rabbits compared to controls. However, average lesion Fe levels in the zinc-fed group were measured at 32 ppm, whereas in the control group the average Fe levels were significantly higher at 43 ppm (P = 0.03). Our data support the concept that zinc may have an antiatherogenic effect by decreasing iron levels in the lesion, possibly leading to inhibition of iron-catalyzed free radical reactions. 相似文献
117.
Summary The aim of the present study has been to assess the therapeutic efficacy of various cytokines, singly or in combination, with and without chemotherapy (cyclophosphamide, Cy), in mice carrying advanced, weakly immunogenic tumors (MCA-105 sarcoma, M109 carcinoma). Treatment of animals with i.p. growths or experimental pulmonary metastases began 8–18 days after i.p. or i.v. tumor cell inoculation respectively. None of the cytokines tested [interleukin-2 (IL-2), interferon (IFN), tumor necrosis factor (TNF) and macrophage-colony-stimulating factor (M-CSF)] nor Cy had by itself a significant curative effect. A synergistic therapeutic effect was obtained with IL-2 or IFN (but not with TNF or M-CSF) in combination with Cy. The most efficacious regimen (65%–90% cure of mice carrying i.p. tumors) was the combination of Cy+IL-2+IFN. Preliminary experiments suggested that sequential administration of these cytokines might be more beneficial than concurrent administration. Following successful immunotherapy, long-term (3–6 months) survivors showed a tumor-specific resistance to a second tumor challenge and their spleen contained an increased number of specific antitumor cytotoxic T lymphocyte precursors (5- to 20-fold, compared to control mice). In vitro and in vivo cell-depletion experiments using monoclonal antibodies revealed that T cells (primarily CD8), but not NK cells, are crucial for the therapeutic effects. This study indicates that a potent specific antitumor T cell immunity can be elicited against advanced weakly immunogenic tumors by combining chemotherapy (Cy) with IL-2 and IFN. 相似文献
118.
Chen JJ Qian W Biswas K Viswanadhan VN Askew BC Hitchcock S Hungate RW Arik L Johnson E 《Bioorganic & medicinal chemistry letters》2008,18(16):4477-4481
Replacement of the core beta-amino acid in our previously reported piperidine acetic acid and beta-phenylalanine-based Bradykinin B1 antagonists by dihydroquinoxalinone acetic acid increases the in vitro potency and metabolic stability. The most potent compounds from this series have IC(50)s<0.2 nM in a human B1 receptor functional assay. A molecular modeling study of the binding modes of key compounds, based on a B1 homology model, explains the structure-activity relationship (SAR) for these analogs. 相似文献
119.
Benny J. Chen Yiqun Jiao Ping Zhang Albert Y. Sun Geoffrey S. Pitt Divino Deoliveira Nicholas Drago Tong Ye Chen Liu Nelson J. Chao 《PloS one》2013,8(1)
Two-photon microscopy has enabled the study of individual cell behavior in live animals. Many organs and tissues cannot be studied, especially longitudinally, because they are located too deep, behind bony structures or too close to the lung and heart. Here we report a novel mouse model that allows long-term single cell imaging of many organs. A wide variety of live tissues were successfully engrafted in the pinna of the mouse ear. Many of these engrafted tissues maintained the normal tissue histology. Using the heart and thymus as models, we further demonstrated that the engrafted tissues functioned as would be expected. Combining two-photon microscopy with fluorescent tracers, we successfully visualized the engrafted tissues at the single cell level in live mice over several months. Four dimensional (three-dimensional (3D) plus time) information of individual cells was obtained from this imaging. This model makes long-term high resolution 4D imaging of multiple organs possible. 相似文献
120.