全文获取类型
收费全文 | 996篇 |
免费 | 52篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 8篇 |
妇产科学 | 5篇 |
基础医学 | 98篇 |
口腔科学 | 12篇 |
临床医学 | 41篇 |
内科学 | 79篇 |
皮肤病学 | 2篇 |
神经病学 | 18篇 |
特种医学 | 24篇 |
外科学 | 29篇 |
综合类 | 122篇 |
预防医学 | 344篇 |
眼科学 | 11篇 |
药学 | 181篇 |
中国医学 | 97篇 |
肿瘤学 | 6篇 |
出版年
2023年 | 4篇 |
2022年 | 30篇 |
2021年 | 39篇 |
2020年 | 36篇 |
2019年 | 22篇 |
2018年 | 26篇 |
2017年 | 18篇 |
2016年 | 35篇 |
2015年 | 39篇 |
2014年 | 59篇 |
2013年 | 93篇 |
2012年 | 86篇 |
2011年 | 77篇 |
2010年 | 48篇 |
2009年 | 58篇 |
2008年 | 49篇 |
2007年 | 50篇 |
2006年 | 34篇 |
2005年 | 21篇 |
2004年 | 30篇 |
2003年 | 20篇 |
2002年 | 18篇 |
2001年 | 10篇 |
2000年 | 15篇 |
1999年 | 19篇 |
1998年 | 12篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有1079条查询结果,搜索用时 15 毫秒
31.
Gianfranco Mamone 《International journal of food sciences and nutrition》2013,64(8):954-962
AbstractTriticum monococcum L. is one of the oldest ancestors of wheat. There is some evidence that einkorn encloses forms of gliadin-deriving peptides which may potentially exert a reduced toxicity to consumers with gluten-related disorders. Accordingly, ID331 and Monlis lines were comparatively investigated in this study. The biological effects of gastro-resistant peptides deriving from an in vitro simulated digestion were evaluated on 21 d differentiated Caco-2 cells. Triticum aestivum digested gliadin was included as the positive control. ID331 neither enhanced cell permeability nor induced zonulin release in Caco-2 monolayers. Monlis exerted a detectable toxicity as confirmed by the reorganisation of enterocyte cytoskeleton, in addition to changes both in monolayers permeability and apical release of zonulin. Differences in patterns of gastro-resistant prolamins may account for the differences. Outcomes support the use of ID331 as a prospective candidate for the development of innovative approaches to reduce wheat flour toxicity. 相似文献
32.
目的:分析注射用血栓通中三七从原料到成品全过程的元素迁移规律,以便更好地控制成品中元素杂质。方法:采用ICP-MS法全面分析三七药材、三七总皂苷(中间体)和注射用血栓通中21种元素的含量。结果:21种元素的标准曲线相关系数r均在0. 999以上,回收率在92. 71%~107. 07%之间,RSD均在5%以内。三七药材中铝、铁含量较高,铅、砷、汞、镉、铜符合中华人民共和国药典的相关规定,三七总皂苷(中间体)和注射用血栓通中多数元素均未检出或含量极低。结论:注射用血栓通的提取工艺可有效去除三七中大部分元素,重金属及有害元素也降到较低水平。 相似文献
33.
Najlae Mejrhit Ouarda Azdad Alae Chda Mohamed El Kabbaoui Amal Bousfiha Rachid Bencheikh 《Food and Agricultural Immunology》2017,28(6):969-980
The aim of this work was to evaluate the IgE-sensitivity to shrimp tropomyosin (ST) in a Moroccan population from Fez region, and then to study the effect of temperature and enzymatic digestion on the allergenicity of ST. This work was conducted with a questionnaire completed by a sera-bank, obtained from 500 patients recruited from Fez Hospitals. Their sera were analyzed for specific IgE-sensitivity to ST. From questionnaire, 9.8% reported allergy to fish and shellfish where shrimp was one of the most common species causing allergy in patients. Evaluation of specific IgE showed that 10.2% of patients present higher values. Further indirect ELISA and Dot-blot results indicated that ST showed a decrease in the human IgE binding under heating or pepsin hydrolysis. These results demonstrate that this population was sensitive to ST and the sensitivity could be reduced by heating and more where it was digested by pepsin. 相似文献
34.
Gastric and masticatory performances in full‐arch immediate loading rehabilitated patients
下载免费PDF全文
![点击此处可从《Journal of oral rehabilitation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
P. Pesce M. Menini M. Furnari F. Pera T. Tealdo P. Pera 《Journal of oral rehabilitation》2015,42(9):663-669
Full‐arch immediate loading implant rehabilitations provide patients with compromised dentition an effective treatment to improve their aesthetic and function. Aim of this prospective cohort study was to investigate the correlation between masticatory ability and gastric emptying rates among these patients. Ten subjects (five men and five women) with compromised dentition were tested in two occasions: before treatment and 30 days after the immediate loading rehabilitation. Masticatory ability was evaluated using the sieves test, and the gastric half emptying time (T1/2) was assessed by means of the 13C‐octanoic acid breath test. A statistically significant increment (P < 0·005) in masticatory ability was found only in reference to the particles smaller than or equal to 4·75 mm, whereas the gastric emptying rate showed a statistically significant reduction between pre‐ and post‐treatment (P = 0·003). A moderate negative correlation (rho = 0·64, P = 0·048) between the percentage change in masticatory ability and the percentage change in gastric emptying rate was evidenced. Patients with compromised dentition rehabilitated with full‐arch immediate implant prostheses present a significant improvement of the gastric process. 相似文献
35.
《Pancreatology》2014,14(5):415-418
Goals and backgroundWe evaluated ex and in vivo effect of streptokinase on pancreatic necrosum to improve the success rate of pigtail catheter drainage and irrigation in infected walled off pancreatic necrosis using step up approach and also looked at potential risk of bleeding.Experiment and clinical cases1000 IU/ml of streptokinase was added to 10 g. of intra-operatively obtained fresh tissue of peripancreatic necrosis and results compared to treatment with saline. Mixture was incubated for 12 h in thermostat at 37.5 °C and subjected to histopathology. Subsequently streptokinase (50,000 units thrice a day for 5 days through PCD) was used in two patients with walled off pancreatic necrosis (WOPN) not responding to step up approach and who were being considered for surgery.Grossly there was fragmentation of necrosum in streptokinase treated tissue. Microscopically complete loss of supportive collagenous framework was noted in streptokinase treated necrosum with clumping of necrotic tissue into structure-less mass. No such changes were discernible in saline treated tissue. In two patients with WOPN there was clearance of debris after streptokinase instillation. None of the patients was on thromboprophylaxis and bleeding was not noticed in any of the patients.ConclusionBased on ex vivo effect of streptokinase in dissolution of necrosum at periphery, we believe that in patients with walled off pancreatic necrosis (WOPN) not responding to pigtail catheter drainage and saline irrigation; streptokinase may prove to be useful adjunct. 相似文献
36.
Toong Long Jeng Yi Chen Chiang Chia Chi Lai Ting Chen Liao Su Yue Lin Tzu Che Lin Jih Min Sung 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2015,23(3):399
Several studies have reported the therapeutic use of caffeoylquinic acid (CQA) derivatives in the management of hyperglycemia. This study used a simulated in vitro gastrointestinal digestion model to assess the inhibitory effects of CQA derivatives-rich sweet potato leaf extract (SPLE) and a commercially produced green coffee bean extract (GCBE), each with total polyphenols contents of 452 mg g−1 and 278 mg g−1, respectively, against starch digestion. The changes in the amounts of total polyphenols and total CQA derivatives during in vitro gastrointestinal digestion were also examined. The results indicated that both extracts contained substantial levels of CQA derivatives (136 mg g−1 and 83.5 mg g−1 of extract for SPLE and GCBE, respectively). The amounts of total polyphenols and total CQA derivatives in 20 mg of SPLE and GCBE samples decreased from 9.04 mg to 0.58 mg and from 5.56 mg to 0.58 mg, and from 2.72 mg to 0.16 mg and from 1.67 mg to 0.10 mg, respectively, following in vitro gastrointestinal digestion and subsequent dialysis. When SPLE and GCBE were accompanied with starch for in vitro digestion test, they both exhibited inhibitory effect against starch digestion during simulated intestinal digestion, with estimated half maximal inhibitory concentration (IC50) values of 4.91 mg and 6.06 mg polyphenols, respectively. The amount of glucose permeated through dialysis membrane also decreased significantly in comparison with the extract-negative control. Thus, both SPLE and GCBE were capable of modulating the release of glucose from starch digestion in simulated intestinal tract. The observed inhibitory effects against glucose release were presumably due in part to the presence of CQA derivatives in the tested extracts. The SPLE had higher inhibitory effect against in vitro starch digestion than the commercially prepared reference GCBE. Therefore, the SPLE might be used to manage hyperglycemia over the long term. 相似文献
37.
Biological effect of food additive titanium dioxide nanoparticles on intestine: an in vitro study
下载免费PDF全文
![点击此处可从《Journal of applied toxicology : JAT》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Zheng‐Mei Song Ni Chen Jia‐Hui Liu Huan Tang Xiaoyong Deng Wen‐Song Xi Kai Han Aoneng Cao Yuanfang Liu Haifang Wang 《Journal of applied toxicology : JAT》2015,35(10):1169-1178
Titanium dioxide nanoparticles (TiO2 NPs) are widely found in food‐related consumer products. Understanding the effect of TiO2 NPs on the intestinal barrier and absorption is essential and vital for the safety assessment of orally administrated TiO2 NPs. In this study, the cytotoxicity and translocation of two native TiO2 NPs, and these two TiO2 NPs pretreated with the digestion simulation fluid or bovine serum albumin were investigated in undifferentiated Caco‐2 cells, differentiated Caco‐2 cells and Caco‐2 monolayer. TiO2 NPs with a concentration less than 200 µg ml–1 did not induce any toxicity in differentiated cells and Caco‐2 monolayer after 24 h exposure. However, TiO2 NPs pretreated with digestion simulation fluids at 200 µg ml–1 inhibited the growth of undifferentiated Caco‐2 cells. Undifferentiated Caco‐2 cells swallowed native TiO2 NPs easily, but not pretreated NPs, implying the protein coating on NPs impeded the cellular uptake. Compared with undifferentiated cells, differentiated ones possessed much lower uptake ability of these TiO2 NPs. Similarly, the traverse of TiO2 NPs through the Caco‐2 monolayer was also negligible. Therefore, we infer the possibility of TiO2 NPs traversing through the intestine of animal or human after oral intake is quite low. This study provides valuable information for the risk assessment of TiO2 NPs in food. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
38.
Bubenik GA 《Digestive diseases and sciences》2002,47(10):2336-2348
The gastrointestinal tract of vertebrate species is a rich source of extrapineal melatonin. The concentration of melatonin in the gastrointestinal tissues surpasses blood levels by 10–100 times and there is at least 400× more melatonin in the gastrointestinal tract than in the pineal gland. The gastrointestinal tract contributes significantly to circulating concentrations of melatonin, especially during the daytime and melatonin may serve as an endocrine, paracrine, or autocrine hormone influencing the regeneration and function of epithelium, enhancing the immune system of the gut, and reducing the tone of gastrointestinal muscles. As binding sites for melatonin exhibit circadian variation in various species, it has been hypothesized that some melatonin found in the gastrointestinal tract might be of pineal origin. Unlike the photoperiodically regulated production of melatonin in the pineal, the release of gastrointestinal melatonin seems to be related to the periodicity of food intake. Phylogenetically, melatonin and its binding sites were detected in the gastrointestinal tract of lower vertebrates, birds, and mammals. Melatonin was found also in large quantities in the embryonic tissue of the mammalian and avian gastrointestinal tract. Food intake and, paradoxically, also long-term food deprivation resulted in an increase of tissue and plasma concentrations of melatonin. Melatonin release may have a direct effect on many gastrointestinal tissues but may also well influence the digestive tract indirectly, via the central nervous system and the sympathetic and parasympathetic nerves. Melatonin prevents ulcerations of gastrointestinal mucosa by an antioxidant action, reduction of secretion of hydrochloric acid, stimulation of the immune system, fostering epithelial regeneration, and increasing microcirculation. Because of its unique properties, melatonin could be considered for prevention or treatment of colorectal cancer, ulcerative colitis, gastric ulcers, irritable bowel syndrome, and childhood colic. 相似文献
39.
Many physiological functions exhibit a diurnal rhythmicity that is influenced by biological clocks and feeding rhythms. In this review, we discuss the growing evidence showing the important role of circadian rhythms in regulating intestinal mucosa. First, we introduce the molecular timing system and the interrelationship between the master biological clock in the suprachiasmatic nuclei of the brain and the peripheral intestinal clock and provide evidence that the intestinal clock is entrained with the external environment. Second, we review the circadian rhythmicity of enterocyte proliferation and the largely unknown regulatory mechanisms behind these rhythms. Finally, we focus on the circadian clock control of food processing that functions by regulating the expression of digestive enzymes and intestinal nutrient and salt transporters. The concepts to be discussed highlight the ability of the intestinal epithelium to utilize self‐sustained clock signals together with signals associated with changes in the cellular environment and to use endogenous temporal control of the gastrointestinal functions to meet varying physiological and pathophysiological demands. The fact that internal de‐synchronizations within the body, such as those that occur in shift workers or with changes in food intake behaviour, are often associated with malfunctions of the gastrointestinal tract indicates that more information about the connections between the circadian clock and intestinal mucosa/transporting enterocytes could provide clues for future therapies. 相似文献
40.
Post-mortem diagnosis of drowning is a real challenge, especially in a decomposed body. The diatom test is considered a reliable scientific assessment in several countries including China. The lungs, liver, and kidneys are usually used in the diatom test, whereas the spleen and heart are rarely reported. In our study, we set up five water samples with different concentrations of diatoms. One-hundred and twenty adult SD rats were employed, assigned to the Drowning Group (DG), Post-mortem Submersion Group (PSG), Drowning Control Group (DG-Control), and Post-mortem Submersion Control Group (PSG-Control). Rats in DG and PSG were submerged in water samples, respectively. After the microwave digestion and vacuum filtration method for diatom enrichment, the diatom numbers were counted. The results showed no diatom was found in either the DG-Control or PSG-Control group. Although significant differences in the diatoms number were found between the DG and PSG groups, the heart and spleen revealed no significant differences. These two organs equally had high specificity and low sensitivity. Based on our data, we concluded that the heart and spleen can be used for the diagnosis of drowning, and detection of diatoms in systemic circulation organs may be more suitable for the diatom test, especially when exogenous contamination is avoided. 相似文献