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排序方式: 共有729条查询结果,搜索用时 15 毫秒
51.
Ottinger MA Lavoie E Thompson N Barton A Whitehouse K Barton M Abdelnabi M Quinn M Panzica G Viglietti-Panzica C 《Brain Research Reviews》2008,57(2):376-385
Endocrine disrupting chemicals (EDCs) exert hormone-like activity in vertebrates and exposure to these compounds may induce both short- and long-term deleterious effects including functional alterations that contribute to decreased reproduction and fitness. An overview of the effects of a number of EDCs, including androgenic and estrogenic compounds, will be considered. Many studies have been conducted in the precocial Japanese quail, which provides an excellent avian model for testing these compounds. Long-term impacts have also been studied by raising a subset of animals through maturation. The EDCs examined included estradiol, androgen active compounds, soy phytoestrogens, and atrazine. Effects on behavior and hypothalamic neuroendocrine systems were examined. All EDCs impaired reproduction, regardless of potential mechanism of action. Male sexual behavior proved to be a sensitive index of EDC exposure and embryonic exposure to a variety of EDCs consistently resulted in impaired male sexual behavior. Several hypothalamic neural systems proved to be EDC responsive, including arginine vasotocin (VT), catecholamines, and gonadotropin releasing hormone system (GnRH-I). Finally, EDCs are known to impact both the immune and thyroid systems; these effects are significant for assessing the overall impact of EDCs on the fitness of avian populations. Therefore, exposure to EDCs during embryonic development has consequences beyond impaired function of the reproductive axis. In conclusion, behavioral alterations have the advantage of revealing both direct and indirect effects of exposure to an EDC and in some cases can provide a valuable clue into functional deficits at different physiological levels. 相似文献
52.
《Clinical toxicology (Philadelphia, Pa.)》2013,51(5):446-447
AbstractBackground. Diphenidine (1-(1,2-diphenylethyl)piperidine) and its 2-methoxylated derivative methoxphenidine (MXP, 2-MeO-diphenidine) are substances with dissociative effects that were recently introduced for “recreational” purpose through the online-based sale of new psychoactive substances (NPS). A number of analytically confirmed non-fatal intoxications associated with diphenidine or MXP have occurred in Sweden and were included in the STRIDA project. Study design. Observational case series of consecutive patients with admitted or suspected intake of NPS and requiring intensive treatment in an emergency room and hospitalization in Sweden. Patients and methods. Blood and urine samples were collected from intoxicated patients presenting at emergency departments all over the country. NPS analysis was performed by multi-component liquid chromatography–mass spectrometry methods. Data on clinical features were collected during telephone consultations with the Poisons Information Centre and retrieved from medical records. Information was also obtained from online drug discussion forums. Case series. Over a 12-month period from January to December 2014, 750 cases of suspected NPS intoxication originating from emergency departments were enrolled in the STRIDA project of which 14 (1.9%) tested positive for diphenidine and 3 (0.4%) tested positive for MXP. Co-exposure to several other NPS (e.g., 5-/6-(2-aminopropyl)benzofuran, 2-4-bromomethcathinone, butylone, 3,4-dichloromethylphenidate, 5-methoxy-N-isopropyltryptamine, methiopropamine, and α-pyrrolidinopentiothiophenone), also including other dissociative substances (3-/4-methoxyphencyclidine), and classical drugs of abuse (e.g., cannabis and ethanol) was documented in 87% of these cases. The 17 patients were aged 20–48 (median: 32) years, and 13 (76%) were men. They commonly presented with hypertension (76%), tachycardia (47%), anxiety (65%), and altered mental status (65%) including confusion, disorientation, dissociation, and/or hallucinations. Eight patients (47%) displayed severe intoxication (Poisoning Severity Score 3). The diphenidine- or MXP-positive patients required hospitalization for 1–3 (median: 2) days. In addition to standard supportive therapy, half of the cases were treated with benzodiazepines and/or propofol. Conclusion. The adverse effects noted in analytically confirmed cases of NPS intoxication involving diphenidine or MXP were similar to those reported for other dissociative substances such as ketamine and methoxetamine. However, the high proportion of polysubstance use might have played a role in the intoxication and clinical features in some cases. 相似文献
53.
Ronald Bartzatt Ph.D. Donald Nagel Ph.D. 《Archives of environmental & occupational health》2013,68(5):313-315
Potassium ferrate (K2FeO4) is useful in the advanced treatment of waste water. Additional evidence of this capability is presented in this study. Potassium ferrate is a very strong oxidant and is highly soluble in water. The nitrosamine studied in this work was toxic and was a potent pancreatic tumorigen in laboratory animals. Nitrosamines, which are potent carcinogens, are widespread throughout the environment and can be eliminated from waste water effluent by the action of potassium ferrate. Potassium ferrate and the nitrosamine was placed in aqueous solution and allowed to react to completion. Analysis by photospectroscopy revealed that the nitrosamine was completely degraded. This result suggests that potassium ferrate is useful for decontamination of some waste water collections. 相似文献
54.
目的 探讨女工芳香烃溶剂暴露和细胞色素P450氧化酶MSP1基因和谷胱甘肽S转移酶GSTM1基因的多态性对自然流产的影响。方法 采用回顾性流行病学调查方法。使用统一调查表,由经过培训的调查员在北京燕山地区调查了276个女工,其中有自然流产史者58人,无自然流产史者218人。结果 单因素分析发现;GSTM1缺失基因型可致女工自然流产的危险度显著增加[OR=2.07(95%CI:1.15-3.71)],但未观察到MSP1基因及芳香烃溶剂暴露对女工自然流产的影响,采用多元Logistic回归模型。经文化程度,年龄,倒班,体重指数,被动吸烟,职业紧张混杂因素调整后,可见GSTM1缺失基因型能显著致女工自然流产危险度增加[OR=2.15(95%CI;1.17-3.98)]。以GSTM1存在基因型和MSP1野生基因型为参照组。采用多元Logistic回归模型。并将文化程度,年龄,倒班,体重指数,被动吸烟,职业紧张混杂因素放入回归模型进行调整,在调整混杂因素前后,与参照组比较,均可见MSP1杂合子/突变基因型合并GSTM1缺失基因型使女工自然流失基因型与MSP1突变纯合子/杂合子基因型之间对自然流产的影响存在相加的联合作用。 相似文献
55.
Evaluation of contact sensitivity of rubber chemicals using the murine local lymph node assay 总被引:1,自引:0,他引:1
The sensitizing abilities of 4 rubber additives, tetramelhylthiuram disulfide (TMTD), 2-mercaplob-enzothiazole (MBT), V-isopropyl-N'-phenyl-p-phenylenediamine (IPPD) and zinc diethyldithiocar-bamate (ZDEC), were evaluated using the murine local lymph node assay. Exposure to IPPD induced a significant increase of lymph node cell proliferation in the draining lymph nodes even at a low concentration. Exposure to TMTD and MBT induced moderate proliferation responses, while ZDEC induced a weak proliferation even at the higher concentrations. The sensitizing potency of each chemical was described in terms of the concentration that increased lymph node cell proliferation by a factor of 2 over that in the vehicle-treated control group. The concentrations of IPPD, TMTD. MBT and ZDEC were 0.14%. 10%, respectively. 相似文献
56.
Chronic inflammatory disease, embracing rheumatoid arthritis (RA), inflammatory bowel disease (IBD), hepatitis, asthma, atherosclerosis,
multiple system organ failure (MSOF), etc., is mediated by reactive oxygen species (ROS). These ROS originate from activated
neutrophils in infections and in immune and autoimmune reactions, from tissue deposits of ferritin, and from futile cycling
of cytochrome P450 (CYP) following exposure to persistent chemicals, and may be perpetuated by the actions of complement,
cytokines and eicosanoids. Acute inflammation is normally arrested by removal of ROS by tissue glutathione (GSH) and the antioxidant
vitamins, A, C and E, all of which are regenerated by NADH and NADPH. Failure of this antioxidant defence system can lead
to oxidative stress and to chronic inflammatory disease, including surgical shock and MSOF. The roles of oxidative stress
and microcirculatory arrest in promoting MSOF, and of GSH, the antioxidant defence system, and fibronectin in preventing this,
are reviewed in the light of recent experimental studies of surgical shock, including fasting, anaesthesia, hepatic ischaemia
and reperfusion. 相似文献
57.
Wenyue Hu Paul D Jones Brad L Upham James E Trosko Christopher Lau John P Giesy 《Toxicological sciences》2002,68(2):429-436
Gap junctional intercellular communication (GJIC) is the major pathway of intercellular signal transduction, and is thus important for normal cell growth and function. Recent studies have revealed a global distribution of some perfluorinated organic compounds, especially perfluorooctane sulfonic acid (PFOS) in the environment. Because other perfluoroalkanes had been shown to inhibit GJIC, the effects of PFOS and related sulfonated fluorochemicals on GJIC were studied using a rat liver epithelial cell line (WB-F344) and a dolphin kidney epithelial cell line (CDK). In vivo effects on GJIC were studied in Sprague-Dawley rats orally exposed to PFOS for 3 days or 3 weeks. Effects on GJIC were measured using the scrape loading dye technique. PFOS, perfluorooctane sulfonamide (PFOSA), and perfluorohexane sulfonic acid (PFHA) were found to inhibit GJIC in a dose-dependent fashion, and this inhibition occurred rapidly and was reversible. Perfluorobutane sulfonic acid (PFBS) showed no significant effects on GJIC within the concentration range tested. A structure activity relationship was established among all 4 tested compounds, indicating that the inhibitory effect was determined by the length of fluorinated tail and not by the nature of the functional group. The results of the studies of the 2 cell lines and the in vivo exposure were comparable, suggesting that the inhibitory effects of the selected perfluorinated compounds on GJIC were neither species- nor tissue-specific and can occur both in vitro and in vivo. 相似文献
58.
Man-made endocrine-disrupting chemicals (EDCs) range across all continents and oceans. Some geographic areas are potentially more threatened than others: one of these is the Mediterranean Sea. Levels of some xenobiotics are much higher here than in other seas and oceans. In this paper we review the final results of a project supported by the Italian Ministry of the Environment, in which the hypothesis that Mediterranean top predator species (such as large pelagic fish and marine mammals) are potentially at risk due to EDCs was investigated. We illustrate the need to develop and apply sensitive methodological tools, such as biomarkers (Vitellogenin, Zona Radiata proteins and CYP1A activities) for evaluation of toxicological risk in large pelagic fish top predators (Swordfish, (Xiphias gladius), Bluefin Tuna (Thunnus thynnus thynnus)) and nondestructive biomarkers (CYP1A activities and fibroblast cell culture in skin biopsy), for the hazard assessment of threatened marine mammals species (Striped Dolphin, (Stenella coeruleoalba), Bottlenose Dolphin (Tursiops truncatus), Common Dolphin (Delphinus delphis) and Fin Whale (Balaenoptera physalus))exposed to EDCs. Differential gender susceptibility to EDCs is also explored both in large pelagic fish and in cetaceans. In cetaceans, male specimens showed higher cytochrome P450 induction (BPMO in skyn biopsies, CYP2B in fibroblasts cell cultures) by xenobiotics with respect to females. 相似文献
59.
K. Sankaranarayanan 《Journal of cancer research and clinical oncology》1981,99(1-2):87-102
Summary Mutagenicity test systems play a dual role in public health: (1) to identify chemicals in our environment that are capable of causing genetic alterations and thus pose a threat of genetic damage to generations yet unborn and (2) as a faster screen (than many of the conventional carcinogenicity tests) to identify chemicals with carcinogenic potentials. In this paper the different mutagenicity test systems currently available are reviewed together with a discussion of their advantages and disadvantages. It is argued that our current data base does not permit a realistic quantitative assessment of genetic hazards ensuing from exposure to environmental chemicals and that only qualitative conclusions are possible. A framework which may be useful in the context of the latter is briefly outlined. 相似文献
60.
L Costas C Infante-Rivard J-P Zock M Van Tongeren P Boffetta A Cusson C Robles D Casabonne Y Benavente N Becker P Brennan L Foretova M Maynadié A Staines A Nieters P Cocco S de Sanjosé 《British journal of cancer》2015,112(7):1251-1256