全文获取类型
收费全文 | 2551篇 |
免费 | 197篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 63篇 |
妇产科学 | 67篇 |
基础医学 | 267篇 |
口腔科学 | 176篇 |
临床医学 | 269篇 |
内科学 | 485篇 |
皮肤病学 | 83篇 |
神经病学 | 197篇 |
特种医学 | 45篇 |
外科学 | 319篇 |
综合类 | 69篇 |
一般理论 | 4篇 |
预防医学 | 235篇 |
眼科学 | 131篇 |
药学 | 175篇 |
中国医学 | 12篇 |
肿瘤学 | 147篇 |
出版年
2023年 | 30篇 |
2022年 | 57篇 |
2021年 | 117篇 |
2020年 | 77篇 |
2019年 | 116篇 |
2018年 | 85篇 |
2017年 | 70篇 |
2016年 | 80篇 |
2015年 | 88篇 |
2014年 | 102篇 |
2013年 | 145篇 |
2012年 | 183篇 |
2011年 | 173篇 |
2010年 | 101篇 |
2009年 | 81篇 |
2008年 | 126篇 |
2007年 | 144篇 |
2006年 | 111篇 |
2005年 | 113篇 |
2004年 | 99篇 |
2003年 | 96篇 |
2002年 | 52篇 |
2001年 | 34篇 |
2000年 | 44篇 |
1999年 | 35篇 |
1998年 | 15篇 |
1997年 | 18篇 |
1995年 | 8篇 |
1992年 | 22篇 |
1991年 | 28篇 |
1990年 | 22篇 |
1989年 | 35篇 |
1988年 | 21篇 |
1987年 | 17篇 |
1986年 | 14篇 |
1985年 | 18篇 |
1984年 | 9篇 |
1983年 | 11篇 |
1981年 | 8篇 |
1979年 | 13篇 |
1977年 | 6篇 |
1975年 | 7篇 |
1974年 | 10篇 |
1973年 | 7篇 |
1972年 | 9篇 |
1971年 | 12篇 |
1969年 | 16篇 |
1968年 | 8篇 |
1967年 | 7篇 |
1966年 | 7篇 |
排序方式: 共有2757条查询结果,搜索用时 46 毫秒
51.
Sibling and friend relationships have significant impact on individuals' socio-emotional development. Hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN) synthesize and secrete neuropeptides, including oxytocin, associated with attachment behaviors. Here, using fMRI, we investigate the implication of these two hypothalamic nuclei in the visual processing of personally known faces. Faces of same-sex sibling, best friend, celebrity, and unknown person appear in the middle of the screen while participants perform a task requiring a button click each time a central white dot turns red. Ratings of familiarity (time spent together) and emotionality (feelings toward individual) toward the four individuals are recorded. Local activation within the hypothalamus is assessed via two complementary methods: (1) voxel-based analyses within inclusive mask of the hypothalamus; (2) region-of-interest (ROI) analysis of partial hypothalamic volumes using SON and PVN as center of mass coordinates, with percent signal change extracted and analyzed within these ROIs. Results suggest that the SON responds to all familiar individuals while the PVN has increased response to sibling compared to friend faces and is correlated to familiarity but not emotionality. These findings support differential involvement of local hypothalamic substructures SON and PVN in response to faces of individuals with different social relationships. 相似文献
52.
53.
Helicobacter pylori and the prevention of gastric cancer. 总被引:2,自引:0,他引:2
Terrence Sullivan Fredrick D Ashbury Carlo A Fallone Farah Naja Richard Schabas Philip C Hébert Richard Hunt Nicola Jones 《Journal canadien de gastroenterologie》2004,18(5):295-302
BACKGROUND: Helicobacter pylori is an important cause of stomach cancer that infects a substantial proportion of the Canadian adult population. H pylori can be detected by noninvasive tests and effectively eradicated by medical treatment. Screening for and treatment of H pylori may represent a significant opportunity for preventive oncology. METHODS: Cancer Care Ontario organized a workshop held in Toronto, Ontario, on October 24 and 25, 2002, to: review the current state of knowledge regarding H pylori treatment and cancer prevention; determine if there is currently sufficient evidence to consider the promotion of H pylori treatment for the purpose of cancer prevention; identify critical areas for research; and advise Cancer Care Ontario on H pylori and cancer prevention. RESULTS: Workshop participants developed a number of recommendations for research into the relationship between H pylori and stomach cancer, including determining the prevalence of infection in different regions of Canada, the pathogenetic sequence of carcinogenesis from H pylori infection, and the implementation of a prospective observational study. INTERPRETATION: Although the rate of H pylori infection is declining in Canada and the treatment of H pylori is generally accepted to be safe, the evidence to date may not warrant the implementation of population screening for H pylori infection to prevent gastric carcinoma in average-risk populations. Rather, a demonstration project is needed to estimate prevalence, evaluate the merits of screening, measure patient compliance and physician participation, develop education materials, establish a registry for monitoring and evaluation, and develop a quality assurance framework. 相似文献
54.
Over the last 7 years we have seen more than 200 severe aplastic anemia patients at this centre. Three of them developed an unusual complication in the form of thymic hemorrhage. Following this complication, all 3 patients recovered partially from their aplastic anemia, without any need for further immunosuppression. These cases show possible ways to manipulate the thymus gland as a management strategy for this disease. 相似文献
55.
Accumulation and toxicity of CuO and ZnO nanoparticles through waterborne and dietary exposure of goldfish (Carassius auratus) 下载免费PDF全文
Mehmet Ates Zikri Arslan Veysel Demir James Daniels Ibrahim O. Farah 《Environmental toxicology》2015,30(1):119-128
Dietary and waterborne exposure to copper oxide (CuO) and zinc oxide (ZnO) nanoparticles (NPs) was conducted using a simplified model of an aquatic food chain consisting of zooplankton (Artemia salina) and goldfish (Carassius auratus) to determine bioaccumulation, toxic effects, and particle transport through trophic levels. Artemia contaminated with NPs were used as food in dietary exposure. Fish were exposed to suspensions of the NPs in waterborne exposure. ICP‐MS analysis showed that accumulation primarily occurred in the intestine, followed by the gills and liver. Dietary uptake was lower, but was found to be a potential pathway for transport of NPs to higher organisms. Waterborne exposure resulted in about a 10‐fold higher accumulation in the intestine. The heart, brain, and muscle tissue had no significant Cu or Zn. However, concentrations in muscle increased with NP concentration, which was ascribed to bioaccumulation of Cu and Zn released from NPs. Free Cu concentration in the medium was always higher than that of Zn, indicating CuO NPs dissolved more readily. ZnO NPs were relatively benign, even in waterborne exposure (p ≥ 0.05). In contrast, CuO NPs were toxic. Malondialdehyde levels in the liver and gills increased substantially (p < 0.05). Despite lower Cu accumulation, the liver exhibited significant oxidative stress, which could be from chronic exposure to Cu ions. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 119–128, 2015. 相似文献
56.
Vincenti Marie Farah Charlotte Amedro Pascal Scheuermann Valerie Lacampagne Alain Cazorla Olivier 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》2022,36(5):793-803
Cardiovascular Drugs and Therapy - Duchenne muscular dystrophy (DMD) is associated with a progressive alteration in cardiac function. The aim of this study was to detect early cardiac dysfunction... 相似文献
57.
Staiger H Machicao F Werner R Guirguis A Weisser M Stefan N Fritsche A Häring HU 《Metabolism: clinical and experimental》2008,57(5):637-643
Angiopoietin-like protein 4 (ANGPTL4) represents an adipokine with metabolic effects within adipose tissue, such as inhibition of lipoprotein lipase activity and stimulation of lipolysis. These effects were convincingly demonstrated in mice. Therefore, we asked whether genetic variation within the ANGPTL4 gene contributes to prediabetic phenotypes, such as dyslipidemia, insulin resistance, or beta-cell dysfunction, in white subjects at an increased risk for type 2 diabetes mellitus. We genotyped 629 subjects with and without a family history of diabetes for the 4 single nucleotide polymorphisms (SNPs) rs4076317, rs2278236, rs1044250, and rs11672433 and performed correlational analyses with metabolic traits. For metabolic characterization, all subjects underwent an oral glucose tolerance test; a subset was additionally characterized by hyperinsulinemic-euglycemic clamp. The 4 SNPs rs4076317, rs2278236, rs1044250, and rs11672433 cover 100% of common genetic variation (minor allele frequency>or=0.05) within the ANGPTL4 gene (r2>or=0.8). None of these SNPs revealed significant correlation with anthropometric data (sex, age, body mass index, body fat, and waist-hip ratio) or with family history of diabetes. Furthermore, no reliable correlations were found with fasting triglycerides, fasting nonesterified fatty acids, and area under the curve of nonesterified fatty acids during oral glucose tolerance test or with parameters of insulin sensitivity and insulin secretion. Finally, haplotype analysis revealed the existence of 8 common diplotypes. None of these, however, was significantly correlated with insulin sensitivity, insulin secretion, or plasma lipid measures. We conclude that common genetic variation within the ANGPTL4 gene may not play a major role in the development of prediabetic phenotypes in our white population. 相似文献
58.
Hassan Boskabadi Farah Ashrafzadeh Hassan Doosti Maryam Zakerihamidi 《Iranian journal of pediatrics.》2015,25(4)
Background:
Asphyxia is considered an important cause of morbidity and mortality in neonates. This condition can affect many vital organs including the central nervous system and may eventually lead to death or developmental disorders.Objectives:
Considering the high prevalence of asphyxia and its adverse consequences, the present study was conducted to evaluate the risk factors for birth asphyxia and assess their correlation with prognosis in asphyxiated infants.Patients and Methods:
This two-year follow-up cohort study was conducted on 260 infants (110 asphyxiated infants and 150 healthy neonates) at Mashhad Ghaem Hospital during 2007 - 2014. Data collection tools consisted of a researcher-designed questionnaire including maternal and neonatal information and clinical/laboratory test results. The subjects were followed-up, using Denver II test for 6, 12, 18, and 24 months (after discharge). For data analysis, t-test was performed, using SPSS version 16.5. P value ≤ 0.05 was considered statistically significant.Results:
Of 260 neonates, 199 (76.5%) and 61 (23.5%) cases presented with normal neonatal outcomes and with abnormal neonatal outcomes (developmental delay), respectively. Variables such as the severity of asphyxia (P = 0.000), five-minute Apgar score (P = 0.015), need for ventilation (P = 0.000), and severity of acidosis at birth (P = 0.001) were the major prognostic factors in infants with asphyxia. Additionally, prognosis was significantly poorer in boys and infants with dystocia history (P = 0.000).Conclusions:
Prevalence of risk factors for developmental delay including the severity of asphyxia need for mechanical ventilation, and severity of acidosis at birth, dystocia, and Apgar score were lower in surviving infants; therefore, controlling these risk factors may reduce asphyxia-associated complications. 相似文献59.
Conwell DL Vargo JJ Zuccaro G Dews TE Mekhail N Scheman J Walsh RM Grundfest-Broniatowski SF Dumot JA Shay SS 《The American journal of gastroenterology》2001,96(2):431-436
OBJECTIVES: Chronic pancreatic pain is difficult to treat. Surgical and medical therapies directed at reducing pain have met with little long-term success. In addition, there are no reliable predictors of response including pancreatic duct diameter. A differential neuroaxial blockade allows characterization of chronic abdominal pain into visceral and nonvisceral pain origins and may be useful as a guide to the treatment. Pain from an inflamed, and scarred pancreas should be visceral in origin. The purpose of our study was to determine the frequency with which patients with chronic pancreatitis have visceral pain and whether our modified differential neuroaxial blockade technique using thoracic epidural analgesia can accurately predict which patients will respond to medical or surgical therapy. METHODS: We retrospectively reviewed the medical records of patients with a firmly established diagnosis of chronic pancreatitis (Cambridge classification, calcifications) who had undergone a differential neuroaxial block for their chronic abdominal pain evaluation. Patient demographics and medical or surgical treatment for pancreatic pain was recorded. Response to therapy was defined by a 50% reduction in pain by verbal response score. RESULTS: A total of 23 patients were identified. Alcohol was the most common etiology for chronic pancreatitis (15 of 23, 55%). Surprisingly, the majority of chronic pancreatitis patients had nonvisceral pain (18 of 23, 78%) and only 22% (5 of 23) had visceral pain by differential neuroaxial block. Four of five patients (80%) with visceral pain responded to therapy, whereas only 5 of 17 (29%) of patients with nonvisceral pain responded. CONCLUSIONS: Surprisingly, patients with chronic pancreatitis commonly have nonvisceral pain. Differential neuroaxial blockade can predict which patients will respond to therapy. 相似文献
60.
Calcium deposition in photocrosslinked poly(Pro‐Hyp‐Gly) hydrogels encapsulated rat bone marrow stromal cells 下载免费PDF全文
Farah Nurlidar Keisuke Yamane Mime Kobayashi Kayo Terada Tsuyoshi Ando Masao Tanihara 《Journal of tissue engineering and regenerative medicine》2018,12(3):e1360-e1369
Reproducing the features of the extracellular matrix is important for fabricating three‐dimensional (3D) scaffolds for tissue regeneration. A collagen‐like polypeptide, poly(Pro‐Hyp‐Gly), is a promising material for 3D scaffolds because of its excellent physical properties, biocompatibility, and biodegradability. In this paper, we present a novel photocrosslinked poly(Pro‐Hyp‐Gly) hydrogel as a 3D scaffold for simultaneous rat bone marrow stromal cell (rBMSC) encapsulation. The hydrogels were fabricated using visible‐light photocrosslinking at various concentrations of methacrylated poly(Pro‐Hyp‐Gly) (20–50 mg/ml) and irradiation times (3 or 5 min). The results show that the rBMSCs encapsulated in the hydrogels survived 7 days of incubation. Calcium deposition on the encapsulated rBMSCs was assessed with scanning electron microscope observation, Alizarin Red S, and von Kossa staining. The most strongly stained area was observed in the hydrogel formed with 30 mg/ml of methacrylated poly(Pro‐Hyp‐Gly) with 5‐min irradiation. These findings demonstrate that poly(Pro‐Hyp‐Gly) hydrogels support rBMSC viability and differentiation, as well as demonstrating the feasibility of using poly(Pro‐Hyp‐Gly) hydrogels as a cytocompatible, biodegradable 3D scaffold for tissue regeneration. 相似文献