全文获取类型
收费全文 | 883篇 |
免费 | 44篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 11篇 |
妇产科学 | 12篇 |
基础医学 | 150篇 |
口腔科学 | 25篇 |
临床医学 | 78篇 |
内科学 | 165篇 |
皮肤病学 | 10篇 |
神经病学 | 99篇 |
特种医学 | 14篇 |
外科学 | 147篇 |
综合类 | 1篇 |
一般理论 | 1篇 |
预防医学 | 112篇 |
眼科学 | 1篇 |
药学 | 43篇 |
肿瘤学 | 58篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 17篇 |
2021年 | 26篇 |
2020年 | 15篇 |
2019年 | 26篇 |
2018年 | 25篇 |
2017年 | 19篇 |
2016年 | 16篇 |
2015年 | 24篇 |
2014年 | 40篇 |
2013年 | 52篇 |
2012年 | 66篇 |
2011年 | 59篇 |
2010年 | 45篇 |
2009年 | 36篇 |
2008年 | 45篇 |
2007年 | 41篇 |
2006年 | 50篇 |
2005年 | 41篇 |
2004年 | 40篇 |
2003年 | 41篇 |
2002年 | 44篇 |
2001年 | 10篇 |
2000年 | 12篇 |
1999年 | 12篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 2篇 |
1935年 | 6篇 |
1933年 | 2篇 |
排序方式: 共有930条查询结果,搜索用时 15 毫秒
1.
2.
F Marzatico P Gaetani V Silvani D Lombardi E Sinforiani R Rodriguez y Baena 《Surgical neurology》1990,34(5):294-300
Patients treated for aneurysmal subarachnoid hemorrhage show, in the long-term follow up, an elevated rate of cognitive disturbances that are mainly related to the impact of the initial bleeding: the neurotoxic effects of blood deposition in subarachnoidal spaces may result in a diffuse encephalopathy, but the intrinsic mechanism and the biochemical correlates are not known. In the present study we have evaluated mitochondrial function after experimental induction of subarachnoid hemorrhage. Mitochondrial function was evaluated in four different rat brain areas (frontal cortex, occipital cortex, hippocampus, and brain stem) after experimental isobaric subarachnoid hemorrhage in rats. Subarachnoid hemorrhage was induced by injecting 0.07 mL of arterial autologous blood into the cisterna magna. Intracranial pressure did not significantly increase. The nonsynaptic mitochondrial fraction was isolated from different rat brain areas, and the maximal rate of enzymatic reactions of some key enzymatic activities related to the Krebs cycle [nicotinamide adenine dinucleotide (oxidized form) (NAD+)-isocitrate dehydrogenase, citrate synthase, and succinate dehydrogenase] and of the electron transfer chain (cytochrome oxidase) were evaluated. The nonsynaptic mitochondrial fraction was utilized also to check parameters related to the mitochondrial respiration: state 3, state 4, uncoupled state, respiratory control ratio, and adenosine 5'-diphosphate/oxygen ratio. The biochemical parameters were measured at 1 and 72 hours after the subarachnoidal injection of blood. Subarachnoid hemorrhage did not affect the mitochondrial enzymatic activities both at 1 and 72 hours, while the mitochondrial enzymatic activities parameters were significantly affected: in particular, a significant decrease of respiratory control ratio in all tested brain areas was demonstrated. The increased mitochondrial vulnerability in the delayed phases could be one of the biochemical correlates of post-hemorrhagic encephalopathy. 相似文献
3.
The role of Serratia marcescens porins in antibiotic resistance 总被引:1,自引:0,他引:1
Ruiz N Montero T Hernandez-Borrell J Viñas M 《Microbial drug resistance (Larchmont, N.Y.)》2003,9(3):257-264
The outer membrane permeability of Serratia marcescens was studied by comparing porin-deficient mutants with their parental strains. Omp1-deficient strains were selected by moxalactam resistance, whereas mutants lacking the Omp2 porin were obtained by experimental infection with the SMP2 phage, whose primary receptor is the Omp2 porin. The role of porins was demonstrated in quinolone accumulation assays, where semiquantitative differences in accumulation were observed. Permeability coefficients to cephaloridine of Omp1 mutants were determined and compared with those of the parental strain. The clinical isolates S. marcescens HCPR1 and 866 showed 30- to 200-fold reduced permeability coefficients when Omp1 porin was absent. 相似文献
4.
Ischemic preconditioning increases the tolerance of Fatty liver to hepatic ischemia-reperfusion injury in the rat 总被引:16,自引:0,他引:16
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Serafín A Roselló-Catafau J Prats N Xaus C Gelpí E Peralta C 《The American journal of pathology》2002,161(2):587-601
Hepatic steatosis is a major risk factor in ischemia-reperfusion. The present study evaluates whether preconditioning, demonstrated to be effective in normal livers, could also confer protection in the presence of steatosis and investigates the potential underlying protective mechanisms. Fatty rats had increased hepatic injury and decreased survival after 60 minutes of ischemia compared with lean rats. Fatty livers showed a degree of neutrophil accumulation and microcirculatory alterations similar to that of normal livers. However, in presence of steatosis, an increased lipid peroxidation that could be reduced with glutathione-ester pretreatment was observed after hepatic reperfusion. Ischemic preconditioning reduced hepatic injury and increased animal survival. Both in normal and fatty livers, this endogenous protective mechanism was found to control lipid peroxidation, hepatic microcirculation failure, and neutrophil accumulation, reducing the subsequent hepatic injury. These beneficial effects could be mediated by nitric oxide, because the inhibition of nitric oxide synthesis and nitric oxide donor pretreatment abolished and simulated, respectively, the benefits of preconditioning. Thus, ischemic preconditioning could be an effective surgical strategy to reduce the hepatic ischemia-reperfusion injury in normal and fatty livers under normothermic conditions, including hepatic resections, and liver transplantation. 相似文献
5.
Ibáñez L Potau N Enriquez G Marcos MV de Zegher F 《Human reproduction (Oxford, England)》2003,18(8):1565-1569
BACKGROUND: Fetal growth restraint has been associated with FSH hypersecretion in early infancy and in early post-menarche, and with reduced uterine and ovarian size in adolescence. It is unknown whether these reproductive anomalies persist, respectively, into late infancy and into the reproductive age range. METHODS: We report follow-up findings in two age groups of girls. A cohort of infants [n=26; n=10 born appropriate-for-gestational-age (AGA) and n=16 born small-for-gestational-age (SGA)], who had been studied at the age of approximately 4 months, was assessed again at the age of 12 months. A cohort of teenagers (n=28), who had been studied at the age of approximately 14 years, was assessed again at the age of approximately 18 years; this group was complemented by a transversal cohort of similar age (n=19) for a total of 47 young women (n=27 AGA; n=20 SGA). In infants, only serum FSH was measured; adolescents underwent endocrine-metabolic screening, ultrasound assessment of uterine-ovarian size, and evaluation of body composition by dual X-ray absorptiometry. RESULTS: Serum FSH levels were higher in SGA than AGA infant girls at 4 and 12 months, and higher in SGA than AGA adolescents at 14 and 18 years (all P<0.01). Longitudinal ultrasound assessments disclosed a late-adolescent increment of uterine size that was less obvious in SGA than AGA girls. In contrast, ovarian volume remained stable in both subgroups. Compilation of longitudinal and transversal results at 18 years of age corroborated the persistent reduction in the uterine size of SGA girls (by approximately 20%; P<0.005) and in their ovarian volume (by approximately 40%; P<0.0001); moreover, SGA girls displayed not only a persistent elevation of FSH (by approximately 50%; P<0.001), but also a rise of LH and fasting insulin, as well as an excess of abdominal fat (all P<0.01). CONCLUSIONS: The gynaecology of young women born SGA was found to be characterized by hypergonadotrophinaemia and by a reduced uterine and ovarian size. 相似文献
6.
Zaffe D Rodriguez Y Baena R Rizzo S Brusotti C Soncini M Pietrabissa R Cavani F Quaglini V 《Journal of biomedical materials research. Part A》2003,64(2):365-371
Fourteen titanium dental implants (Tioblast) were implanted singly in the proximal tibia of New Zealand rabbits for 120 days. A bone defect was surgically produced and filled with Bio-Oss around six of these implants. After the animals were sacrificed and their organs harvested, bone segments were fixed and methacrylate embedded after the push-in test had been performed. Microradiography was performed on longitudinal sections of the implants, whereas scanning electron microscope analysis was performed on the remaining embedded half-implants using secondary electrons only. The results showed that the implants were apically and coronally surrounded by bone, whether Bio-Oss was used or not. Fractures were evident through the newly formed bone and between the pre-existing and newly formed bone. Some fracture lines propagated through the bone and stopped at the implant surface without continuing along the bone-titanium interface. Detachment between the implant and the bone occurred at the coronal extremity of the implants and along its cervical region. These results highlight the fact that the bone-titanium interface has a high resistance to loading. It exhibited greater resistance than the newly formed bone and seems to behave in a manner similar to the cement lines of osteons. 相似文献
7.
Baena N De Vigan C Cariati E Clementi M Stoll C Caballin MR Guitart M;EUROSCAN Working Group 《American journal of medical genetics. Part A》2003,(4):319-327
The aim of the present study was to evaluate the prenatal detection of rare chromosomal autosomal abnormalities by ultrasound (US) examination. Data were obtained from 19 congenital malformation registries from 11 European countries, between 01/07/96 and 31/12/98. A total of 664,340 births were covered and 7,758 cases with congenital malformations were recorded. Rare autosomal abnormalities were diagnosed in 114 cases (6.6%) from a total of 1,738 chromosome abnormalities. There were a wide variety of autosomal abnormalities: the most common were deletions (33 cases), duplications (32 cases), trisomies of chromosomes 8, 9, 10, 14, 15, and 16 (23 cases), and unbalanced rearrangements (19 cases). Out of these cases, 45.6% were detected prenatally by US examination due to the presence of congenital anomaly. As for the types of chromosomal anomaly, unbalanced rearrangements and deletions were the most frequently detected by US. A high percentage of cases with balanced rearrangements were associated with severe congenital anomalies. The most frequent congenital anomalies detected by US were cystic hygroma (20.6%), central nervous system defects (17.6%), cardiac defects (13.2%), and diaphragm defects (10.3%). This large series offers useful information about prenatal diagnosis by US of congenital defects associated with rare autosomal abnormalities and it provides a valuable knowledge about outcome. Fetal anomalies detected by US that were associated with rare autosomal abnormalities were significantly more frequent than those associated with common chromosomal abnormalities (45.6 vs. 34.7%). This study indicates the need to increase the detection of congenital anomalies by US. 相似文献
8.
Alessandro Morandi Marco Inzitari Cristina Udina Neus Gual Miriam Mota Elena Tassistro Anita Andreano Antonio Cherubini Simona Gentile Enrico Mossello Alessandra Marengoni Anna Olivé Francesc Riba Domingo Ruiz Elisabet de Jaime Giuseppe Bellelli 《Journal of the American Medical Directors Association》2021,22(6):1162-1167.e3
ObjectiveSensory deficits are important risk factors for delirium but have been investigated in single-center studies and single clinical settings. This multicenter study aims to evaluate the association between hearing and visual impairment or bi-sensory impairment (visual and hearing impairment) and delirium.DesignCross-sectional study nested in the 2017 “Delirium Day” project.Setting and ParticipantsPatients 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes, and hospices in Italy.MethodsDelirium was assessed with the 4AT (a short tool for delirium assessment) and sensory deficits with a clinical evaluation. We assessed the association between delirium, hearing and visual impairment in multivariable logistic regression models, adjusting for: Model 1, we included predisposing factors for delirium (ie, dementia, weight loss and autonomy in the activities of daily living); Model 2, we added to Model 1 variables, which could be considered precipitating factors for delirium (ie, psychoactive drugs and urinary catheters).ResultsA total of 3038 patients were included; delirium prevalence was 25%. Patients with delirium had a higher prevalence of hearing impairment (30.5% vs 18%; P < .001), visual impairment (24.2% vs 15.7%; P < .01) and bi-sensory impairment (16.2% vs 7.5%) compared with those without delirium. In the multivariable logistic regression analysis, the presence of bi-sensory impairment was associated with delirium in Model 1 [odds ratio (OR) 1.5, confidence interval (CI) 1.2–2.1; P = .00] and in Model 2 (OR 1.4; CI 1.1–1.9; P = .02), whereas the presence of visual and hearing impairment alone was not associated with delirium either in Model 1 (OR 0.8; CI 0.6–1.2, P = .36; OR 1.1; CI 0.8–1.4; P = .42) or in Model 2 (OR 0.8, CI 0.6–1.2, P = .27; OR 1.1, CI 0.8–1.4, P = .63).Conclusions and implicationsOur findings support the importance of routine screening and specific interventions by a multidisciplinary team to implement optimal management of sensory impairments and hence prevention and the management of the patients with delirium. 相似文献
9.
Mireia Ruiz-Castilla Bruce Dos Santos Claudia Vizcaíno Jacinto Baena Patricia Guilabert Judith Marin-Corral Joan R. Masclans Oriol Roca Juan P. Barret 《Burns : journal of the International Society for Burn Injuries》2021,47(4):906-913
IntroductionSeveral mechanisms play a role in the development of pneumonia after inhalation injury. Our aim was to analyze whether higher concentrations of inflammatory markers or of biomarkers of epithelial injury are associated with a higher incidence of pneumonia in patients with inhalation injury.Material and methodsSecondary analysis of a single-center prospective observational cohort pilot study, performed over a two-year period (2015–2017) at the Burns Unit of the Plastic and Reconstructive Surgery Department of Vall d’Hebron University Hospital. All patients aged 18 with suspected inhalation injury undergoing admission to the Burns Unit were included. Plasma biomarkers of the lung epithelium (RAGE and SP-D), inflammation markers (IL6, IL8), and IL33, as well as soluble suppression of tumorigenicity-2 (sST2) levels, were measured within the first 24 h of admission.ResultsTwenty-four patients with inhalation injury were included. Eight (33.3%) developed pneumonia after a median of 7 (4–8) days of hospital stay. Patients with pneumonia presented higher plasma concentrations of sST2 (2853 [2356–3351] ng/mL vs 1352 [865–1839] ng/mL; p < 0.001), IL33 (1.95 [1.31–2.59] pg/mL vs 1.26 [1.07–1.45] pg/mL; p = 0.002) and IL8 (325.7 [221.6–430.0] pg/mL vs 174.1 [95.2–253.0] pg/mL; p = 0.017) on day 1 of inclusion. Plasma sST2 concentration in the first 24 h demonstrated excellent diagnostic accuracy for predicting the occurrence of pneumonia in patients with smoke inhalation (AUROC 0.929 [95%CI 0.818–1.000]). A cutoff point of ≥2825 ng/mL for sST2 had a sensitivity of 75% and a specificity of 100%. The risk ratio of pneumonia in patients with sST2 ≥ 2825 ng/mL was 7.14 ([95% CI 1.56–32.61]; p = 0.016).ConclusionsPlasma sST2 in the first 24 h of admission predicts the occurrence of pneumonia in patients with inhalation injury. 相似文献
10.