全文获取类型
收费全文 | 2529篇 |
免费 | 144篇 |
国内免费 | 17篇 |
学科分类
医药卫生 | 2690篇 |
出版年
2023年 | 17篇 |
2022年 | 37篇 |
2021年 | 70篇 |
2020年 | 40篇 |
2019年 | 73篇 |
2018年 | 80篇 |
2017年 | 55篇 |
2016年 | 77篇 |
2015年 | 89篇 |
2014年 | 100篇 |
2013年 | 139篇 |
2012年 | 187篇 |
2011年 | 198篇 |
2010年 | 111篇 |
2009年 | 110篇 |
2008年 | 184篇 |
2007年 | 167篇 |
2006年 | 156篇 |
2005年 | 149篇 |
2004年 | 160篇 |
2003年 | 92篇 |
2002年 | 110篇 |
2001年 | 54篇 |
2000年 | 39篇 |
1999年 | 28篇 |
1998年 | 10篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 9篇 |
1991年 | 15篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 8篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1972年 | 3篇 |
1971年 | 11篇 |
1969年 | 5篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有2690条查询结果,搜索用时 31 毫秒
991.
Rajaei F Sari AE Bahramifar N Savabieasfahani M Ghasempouri M 《Bulletin of environmental contamination and toxicology》2011,87(6):678-683
Feather and muscle of 10 avian species (n = 46), were analyzed for polychlorinated biphenyls (PCBs) and organochlorine pesticides
(OCPs). Muscle contained significantly higher PCB and OCP than liver and feather. Mean muscle and feather PCB was 408.5 ± 134.5
and 32 ± 4.5 ng/g wet weight. Highly chlorinated PCBs were found in muscle and liver while feather had PCBs with less chlorination.
Gulls had highest levels of both pollutants. Gull feather PCB and OCP were strongly correlated with their levels in the liver
and muscle tissues (0.6 < r < 0.9, p < 0.01). Analysis of gull feather can be used as a non-invasive method for monitoring organic pollutants. 相似文献
992.
Frumkin A Raz AE Plesser-Duvdevani M Lieberman S 《Social science & medicine (1982)》2011,73(12):1741-1747
This article reports on attitudes of modern-religious Ashkenazi Jewish adults in Israel toward anonymous carrier matching for severe monogenic diseases by Dor Yesharim (the ultra-orthodox organization) and open individual carrier testing (through a medical center), examining how this important choice is being informed, communicated, made, and reflected on. Qualitative analysis of semi-structured interviews conducted with 23 modern-religious Ashkenazi Jews in 2009-2011 revealed social pressure to utilize Dor Yesharim; however, respondents considered its policy of advising against a marriage between partners who are carriers of the same genetic condition inappropriate for 'love marriages' where a couple's commitment may already be made. Confidential carrier testing was a stepping stone to open carrier testing for those advised not to marry. Respondents varied in their views on when open carrier tests should be conducted. Pre-implantation genetic diagnosis was considered religiously preferable to abortion; however most carrier couples opted for pre-natal testing and selective abortion, challenging stereotypes about the attitudes of religious Jews. It is discussed how carrier screening is contextualized and interpreted not just in terms of religious teachings, but in interaction with lay agency, personal experiences and knowledge of reproductive choices. We conclude by discussing the implications for the social analysis of the ethics of carrier screening in religious communities at risk. 相似文献
993.
Drinking Water Salinity and Maternal Health in Coastal Bangladesh: Implications of Climate Change 总被引:2,自引:0,他引:2
Aneire Ehmar Khan Andrew Ireson Sari Kovats Sontosh Kumar Mojumder Amirul Khusru Atiq Rahman Paolo Vineis 《Environmental health perspectives》2011,119(9):1328-1332
Background: Drinking water from natural sources in coastal Bangladesh has become contaminated by varying degrees of salinity due to saltwater intrusion from rising sea levels, cyclone and storm surges, and upstream withdrawal of freshwater.Objective: Our objective was to estimate salt intake from drinking water sources and examine environmental factors that may explain a seasonal excess of hypertension in pregnancy.Methods: Water salinity data (1998–2000) for Dacope, in rural coastal Bangladesh, were obtained from the Centre for Environment and Geographic Information System in Bangladesh. Information on drinking water sources, 24-hr urine samples, and blood pressure was obtained from 343 pregnant Dacope women during the dry season (October 2009 through March 2010). The hospital-based prevalence of hypertension in pregnancy was determined for 969 pregnant women (July 2008 through March 2010).Results: Average estimated sodium intakes from drinking water ranged from 5 to 16 g/day in the dry season, compared with 0.6–1.2 g/day in the rainy season. Average daily sodium excretion in urine was 3.4 g/day (range, 0.4–7.7 g/day). Women who drank shallow tube-well water were more likely to have urine sodium > 100 mmol/day than women who drank rainwater [odds ratio (OR) = 2.05; 95% confidence interval (CI), 1.11–3.80]. The annual hospital prevalence of hypertension in pregnancy was higher in the dry season (OR = 12.2%; 95% CI, 9.5–14.8) than in the rainy season (OR = 5.1%; 95% CI, 2.91–7.26).Conclusions: The estimated salt intake from drinking water in this population exceeded recommended limits. The problem of saline intrusion into drinking water has multiple causes and is likely to be exacerbated by climate change–induced sea-level rise. 相似文献
994.
Anneli Lauhio Johanna Hästbacka Ville Pettilä Taina Tervahartiala Sari Karlsson Tero Varpula Marjut Varpula Esko Ruokonen Timo Sorsa Elina Kolho 《Pharmacological research》2011,64(6):590-594
Recent evidence suggests that matrix metalloproteinases (MMPs) and their endogenous inhibitors are involved in the pathogenesis of sepsis. We studied serum levels of MMP-8, MMP-9 and TIMP-1 (tissue inhibitor of matrix metalloproteinase-1) in a multicentre, prospective cohort study of patients with sepsis treated in Intensive Care Units (ICUs). We analyzed serum samples taken on ICU admission from 248 critically ill sepsis patients. MMP-8, -9 and TIMP-1 serum levels were analyzed by enzyme-linked immunosorbent assays. Serum MMP-8, MMP-9 and TIMP-1 levels were significantly higher in patients with severe sepsis than in healthy controls. Serum MMP-8 levels among non-survivors (n = 33) were significantly (p = 0.006) higher than among survivors (n = 215). Serum TIMP-1 but not MMP-9 levels were significantly higher among non-survivors than survivors (p < 0.0001, p = 0.079, respectively). Systemic MMP-8 is upregulated in sepsis suggesting that MMP-8 may contribute to the host response during sepsis. High serum MMP-8 and TIMP-1 levels at ICU admission were seen among patients with fatal outcome. With this background, clinical studies examining the ability of MMP-inhibitors (such as the non-antimicrobial properties of tetracyclines) to diminish the MMP-mediated inflammatory response are needed to develop novel therapies in order to improve the outcome of sepsis. 相似文献
995.
996.
997.
Ramachandran B Mäkelä S Cravedi JP Berglund M Håkansson H Damdimopoulou P Maggi A 《Toxicology letters》2011,202(2):75-84
Cadmium (Cd), an environmental and dietary contaminant, has been described to mimic the effects of 17β-estradiol (E2) in selected model systems when studied as an inorganic salt. However, inorganic Cd salts do not represent the main form of Cd exposure in general human populations. The aims of this study were to compare the estrogen-like effects and the bioavailability of dietary Cd to inorganic CdCl2. Adult ovariectomized ERE-luc reporter mice were administered two bread based diets containing different concentrations of Cd (17.57 and 49.22 μg/kg, corresponding to oral intakes of 1.8 and 5.1 μg/kg body weight (bw) per day, respectively), inorganic CdCl2 (1 μg/kg bw per day by gavage) or E2 (5 μg/kg bw per day pellet) for 21 days. The effects on estrogen signaling were investigated by studying the uterine weights, luciferase activation, and expression of endogenous estrogen target genes. The uterine weight was significantly increased by both CdCl2 and E2 but not by the Cd containing diets. All treatments modulated the expression of luciferase and the endogenous estrogen target genes; however, there was no consistent overlap between the responses triggered by the bread diets and the responses stimulated by CdCl2 or E2. Oral exposure to Cd was calculated and the concentrations in liver and kidneys quantified to estimate the amount of absorbed Cd retained in tissues. The results suggest significantly lower absorption and/or tissue retention of dietary Cd compared to CdCl2 following oral exposure. Altogether, our results support previous reports on in vivo estrogenicity of CdCl2 but do not suggest the same activity for diet bound Cd. This study calls for caution when extrapolating results from pure compound studies (e.g. estrogenicity of CdCl2) to dietary exposure scenarios (e.g. estrogenicity of diet bound Cd). Further basic research is needed on the mechanisms of interaction between Cd and the estrogen signaling, biologically active species of Cd, and biomarkers of estrogen-like effects of Cd in vivo before human health risk assessment on the hormone disruptive effects of Cd can be carried out. 相似文献
998.
Haimi S Moimas L Pirhonen E Lindroos B Huhtala H Räty S Kuokkanen H Sándor GK Miettinen S Suuronen R 《Journal of biomedical materials research. Part A》2009,91(2):540-547
Human adipose stem cells (ASCs) combined with osteostimulative material provide an attractive approach for clinical bone regeneration. The effect of calcium phosphate (Ca-P) surface treatment of three-dimensional bioactive glass scaffolds on the attachment, proliferation, and osteogenic differentiation of ASCs was studied. Three types of bioactive glass scaffolds (nontreated, thick and thin Ca-P treated) were compared. All scaffold types supported ASC attachment, spreading, and proliferation equally as detected by scanning electron microscopy, fluorescence staining, and DNA measurement. Indices of osteogenic differentiation including the expression of osteopontin and alkaline phosphatase (ALP) were consistently higher in the nontreated and thin Ca-P-treated scaffolds when compared with thick Ca-P-treated scaffolds at 2 weeks. ASCs cultured on nontreated bioactive glass scaffolds showed significantly higher ALP activity when compared with both thin and thick Ca-P-treated scaffolds after 1 week in culture, but these differences equalized between the three scaffolds by the 2-week time point. In conclusion, osteogenic differentiation appears to be delayed on the Ca-P surface-treated scaffolds. This delay is more pronounced with thick Ca-P treatment of the scaffolds. 相似文献
999.
Sari?Suomela Virve?Koljonen Tiina?Skoog Heli?Kukko Tom?B?hling Ulpu?Saarialho-Kere 《Virchows Archiv : an international journal of pathology》2009,455(6):495-503
Merkel cell carcinoma (MCC) is an aggressive cutaneous tumor with poor outcome and increasing incidence. We examined by immunohistochemistry
the expression of three novel matrix metalloproteinases (MMPs)—MMP-21, MMP-26, and MMP-28—in 44 primary MCC tumors and six
lymph node metastases while MMP-10 served as a positive control. Their mRNA expression was also studied in the UISO MCC cell
line basally and after various stimulations using quantitative real-time PCR. MMP-28 was observed in tumor cells of 15/44
samples especially in tumors <2 cm in diameter (p = 0.015) while 21/44 specimens showed MMP-28 in the tumor stroma. Expression of MMP-21 was demonstrated in tumor cells of
13/43 samples. MMP-26, instead, was positive in stromal cells (17/44) and its expression associated with tumors ≥2 cm in diameter
(p = 0.006). Stromal expression of MMP-10 was the most frequent finding of the studied samples (31/44), but MMP-10 was detected
also in tumor cells (17/44). Most of the metastatic lymph nodes expressed MMP-10 and MMP-26. MMP-10, MMP-21, and MMP-28 mRNAs
were basally expressed by the UISO cells, and the corresponding proteins were detectable by immunostaining of cultured cells.
IFN-α and TNF-α downregulated MMP-21 and MMP-28 expression. Our results suggest that novel MMPs may have a role in MCC pathogenesis:
especially that MMP-26 expression in stroma is associated with larger tumors with poor prognosis. Expression of MMP-21 and
MMP-28 seems to associate with the tumors of lesser malignant potential. We also confirm the previous finding on the role
of MMP-10 in MCC pathogenesis. 相似文献
1000.