全文获取类型
收费全文 | 3584篇 |
免费 | 217篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 78篇 |
妇产科学 | 94篇 |
基础医学 | 630篇 |
口腔科学 | 135篇 |
临床医学 | 321篇 |
内科学 | 797篇 |
皮肤病学 | 52篇 |
神经病学 | 378篇 |
特种医学 | 85篇 |
外科学 | 230篇 |
综合类 | 32篇 |
一般理论 | 2篇 |
预防医学 | 273篇 |
眼科学 | 64篇 |
药学 | 318篇 |
中国医学 | 20篇 |
肿瘤学 | 297篇 |
出版年
2024年 | 4篇 |
2023年 | 33篇 |
2022年 | 119篇 |
2021年 | 190篇 |
2020年 | 104篇 |
2019年 | 127篇 |
2018年 | 121篇 |
2017年 | 84篇 |
2016年 | 129篇 |
2015年 | 125篇 |
2014年 | 187篇 |
2013年 | 224篇 |
2012年 | 307篇 |
2011年 | 328篇 |
2010年 | 178篇 |
2009年 | 115篇 |
2008年 | 249篇 |
2007年 | 219篇 |
2006年 | 215篇 |
2005年 | 183篇 |
2004年 | 151篇 |
2003年 | 134篇 |
2002年 | 113篇 |
2001年 | 18篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1998年 | 14篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有3828条查询结果,搜索用时 15 毫秒
991.
Bozicevic I Rode OD Lepej SZ Johnston LG Stulhofer A Dominkovic Z Bacak V Lukas D Begovac J 《AIDS and behavior》2009,13(2):303-309
We used respondent-driven sampling among men who have sex with men (MSM) in Zagreb, Croatia in 2006 to investigate the prevalence
of HIV, other sexually transmitted infections and sexual behaviours. We recruited 360 MSM. HIV infection was diagnosed in
4.5%. The seroprevalence of antibodies to viral pathogens was: herpes simplex virus type-2, 9.4%; hepatitis A, 14.2%; hepatitis
C, 3.0%. Eighty percent of participants were susceptible to HBV infection (HBs antigen negative, and no antibodies to HBs
and HBc antigen). Syphilis seroprevalence was 10.6%. Prevalence of Chlamydia and gonorrhoea was 9.0%, and 13.2%, respectively.
Results indicate the need for interventions to diagnose, treat and prevent sexually transmitted infections among this population. 相似文献
992.
993.
Mazzini L Mareschi K Ferrero I Vassallo E Oliveri G Boccaletti R Testa L Livigni S Fagioli F 《Neurological research》2006,28(5):523-526
OBJECTIVES: Our study was aimed to evaluate the feasibility and safety of intraspinal cord implantation of autologous mesenchymal stem cells (MSCs) in a few well-monitored amyotrophic lateral sclerosis (ALS) patients. METHODS: Seven patients affected by definite ALS were enrolled in the study and two patients were treated for compassionate use and monitored for at least 3 years. Bone marrow was collected from the posterior iliac crest according to the standard procedure and MSCs were expanded ex vivo according to Pittenger's protocol. The cells were suspended in 2 ml autologous cerebrospinal fluid and transplanted into the spinal cord by a micrometric pump injector. RESULTS: The in vitro expanded MSCs did not show any bacterial o fungal contamination, hemopoietic cell contamination, chromosomic alterations and early cellular senescence. No patient manifested major adverse events such as respiratory failure or death. Minor adverse events were intercostal pain irradiation and leg sensory dysesthesia, both reversible after a mean period of 6 weeks. No modification of the spinal cord volume or other signs of abnormal cell proliferation were observed. A significant slowing down of the linear decline of the forced vital capacity was evident in four patients 36 months after MSCs transplantation. CONCLUSIONS: Our results demonstrate that direct injection of autologous expanded MSCs into the spinal cord of ALS patients is safe, with no significant acute or late toxicity, and well tolerated. The clinical results seem to be encouraging. 相似文献
994.
Brinar VV Petelin Z Brinar M Djaković V Zadro I Vranjes D 《Clinical neurology and neurosurgery》2006,108(3):318-326
Autoimmune diseases represent a diverse group of disorders that have generally of unknown etiology and poorly understood pathogenesis. They may be organ-specific or systemic, giving rise to overlapping syndromes; more than one autoimmune disease may occur in the same patient. Numerous case reports have documented that multiple sclerosis (MS) may be present concurrently with other autoimmune diseases, most commonly rheumatoid arthritis, autoimmune thyroid disease, type I diabetes mellitus and pernicious anemia. Case reports of disseminated encephalomyelitis (DEM) coincidental with other autoimmune diseases are rare. Many of systemic autoimmune diseases cause central nervous system (CNS) demyelination and are frequently then diagnosed as MS, whereas they often are instances of DEM, the result of vascular, granulomatous or postinfectious manifestations. We have reviewed 15 patients with autoimmune diseases and CNS demyelination in order to determine the nature of the demyelinating process. 相似文献
995.
Branchi I D'Andrea I Sietzema J Fiore M Di Fausto V Aloe L Alleva E 《Journal of neuroscience research》2006,83(6):965-973
Early experiences affect brain function and behavior at adulthood. Being reared in a communal nest (CN), consisting of a single nest where three mothers keep their pups together and share care-giving behavior from birth to weaning (postnatal day [PND] 25), provides an highly socially stimulating environment to the developing pup. Communal nest characterizes the natural ecologic niche of many rodent species including the mouse. At adulthood, CN reared mice, compared to mice reared in standard nesting laboratory condition (SN), show an increase in BDNF protein levels and longer survival of BrdU-positive cells in the hippocampus. Open field and elevated plus maze results indicate that CN mice, although showing levels of exploratory and locomotor activity similar to those of SN mice, displayed increased anxiety-like behavior, performing more thigmotaxis in the open field and spending less time in the open arms of the plus maze. Furthermore, CN mice displayed higher levels of immobility behavior in the forced swim test. Overall, these findings show that CN, an highly stimulating early social environment, increases adult neuronal plasticity, as suggested by high BDNF levels and augmented number of newly generated cells in the hippocampus, which is associated to an increased anxiety- and "depression"-like behavior. These findings are discussed in the framework of the neurotrophin hypothesis of depression. 相似文献
996.
997.
Manuela Vaneckova Zdenek Seidl Barbara Goldova Ivana Vitkova Alice Baxova Pavel Petrovicky Vaclav Sebron Pavel Calda 《Brain & development》2010
Post-mortem magnetic resonance appears to be a method supplementary to classic pathological–anatomical autopsy in determining foetal abnormalities. Frequently, it plays a key role, primarily where autopsy options are in some way limited (developed autolysis, dilatation of the ventricular system). This case report demonstrates that post-mortem magnetic resonance imaging can precisely determine the type of congenital malformation (hydranencephaly), by contrast to ultrasound, with which alobar holoprosencephaly has been described, often presenting a differential diagnosis problem. Pathological–anatomical autopsy was significantly limited due to this diagnosis and this methodology was incapable of unequivocally determining the type of malformation. We would like to demonstrate by this case report the necessity of performing post-mortem magnetic resonance imaging so that we may precisely determine the diagnosis as requested by the parents and also be able to answer the question posed by risks for future pregnancies. 相似文献
998.
Brakus SM Govorko DK Vukojevic K Jakus IA Carev D Petricevic J Saraga-Babic M 《European journal of oral sciences》2010,118(6):537-546
The regulators of apoptosis Bcl-2, Bax, caspase-3, p53, and Hsp70 were analyzed immunohistochemically in the developing human mandible of eight human conceptuses from weeks 5 to 10 of gestation. During this period, all proteins displayed an increased pattern of expression in the mandible ectomesenchyme and in newly formed bone, except for caspase-3, which showed decreased expression in the ectomesenchyme, but appeared first in the ossification zone at the 7th wk of development. Simultaneously, the oral epithelium showed weak (p53) to strong (hsp70) expression of all proteins investigated, while in Meckel's cartilage cells, bcl-2 was expressed weakly and hsp70 was expressed moderately. Cells on the surface of the forming bone were predominantly bax positive, and only occasionally bcl-2 positive. Only a few cells on the surface and inside the bony spicules co-expressed bax and bcl-2. Terminal deoxynucleotidyl transferase (TdT)-mediated biotin-dUTP nick-end labelling (TUNEL)-positive cells were found to be apoptotic osteoblasts. The expression of all proteins investigated changed dynamically during early mandible development and the subsequent differentiation of Meckel's cartilage and bone. While interactions between those factors might be associated with the survival of Meckel's cartilage, in the ossification zone they might participate in the control of cell numbers, mineralization, and bone remodelling. Among many other factors, precise orchestration of pro- and anti-apoptotic factors contributes to normal mandible development. 相似文献
999.
Bilen Emek Abali Michele Zecchini Gilda Daiss Ivana Czabany Wolfgang Gindl-Altmutter Roman Wan-Wendner 《Materials》2021,14(14)
Thermosetting polymers are used in building materials, for example adhesives in fastening systems. They harden in environmental conditions with a daily temperature depending on the season and location. This curing process takes hours or even days effected by the relatively low ambient temperature necessary for a fast and complete curing. As material properties depend on the degree of cure, its accurate estimation is of paramount interest and the main objective in this work. Thus, we develop an approach for modeling the curing process for epoxy based thermosetting polymers. Specifically, we perform experiments and demonstrate an inverse analysis for determining parameters in the curing model. By using calorimetry measurements and implementing an inverse analysis algorithm by using open-source packages, we obtain 10 material parameters describing the curing process. We present the methodology for two commercial, epoxy based products, where a statistical analysis provides independence of material parameters leading to the conclusion that the material equation is adequately describing the material response. 相似文献
1000.
Izzotti A De Flora S Cartiglia C Are BM Longobardi M Camoirano A Mura I Dore MP Scanu AM Rocca PC Maida A Piana A 《Carcinogenesis》2007,28(4):892-898
Infection by Helicobacter pylori is the most important risk factor for gastric cancer. However, only a small fraction of colonized individuals, representing at least half of the world's population, develop this malignancy. In order to shed light on host-microbial interactions, gastric mucosa biopsies were collected from 119 patients suffering from dyspeptic symptoms. 8-Hydroxy-2'-deoxyguanosine (8-oxo-dG) levels in the gastric mucosa were increased in carriers of H.pylori, detected either by cultural method or by polymerase chain reaction, and were further increased in subjects infected with strains positive for the cagA gene, encoding the cytotoxin-associated protein, cagA. Oxidative DNA damage was more pronounced in males, in older subjects, and in H.pylori-positive subjects suffering from gastric dysplasia. Moreover, 8-oxo-dG levels were significantly higher in a small subset of subjects having a homozygous variant allele of the 8-oxoguanosine-glycosylase 1 (OGG1) gene, encoding the enzyme removing 8-oxo-dG from DNA. Conversely, they were not significantly elevated in glutathione S-transferase M1 (GSTM1)-null subjects. Thus, both bacterial and host gene polymorphisms affect oxidative stress and DNA damage, which is believed to represent a key mechanism in the pathogenesis of gastric cancer. The interplay between bacterial and host gene polymorphisms may explain why gastric cancer only occurs in a small fraction of H.pylori-infected individuals. 相似文献