全文获取类型
收费全文 | 475篇 |
免费 | 28篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 25篇 |
妇产科学 | 32篇 |
基础医学 | 51篇 |
口腔科学 | 12篇 |
临床医学 | 25篇 |
内科学 | 111篇 |
皮肤病学 | 6篇 |
神经病学 | 24篇 |
特种医学 | 9篇 |
外科学 | 78篇 |
综合类 | 13篇 |
预防医学 | 36篇 |
眼科学 | 5篇 |
药学 | 31篇 |
中国医学 | 6篇 |
肿瘤学 | 38篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 15篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 24篇 |
2012年 | 37篇 |
2011年 | 50篇 |
2010年 | 23篇 |
2009年 | 29篇 |
2008年 | 41篇 |
2007年 | 38篇 |
2006年 | 30篇 |
2005年 | 32篇 |
2004年 | 25篇 |
2003年 | 21篇 |
2002年 | 12篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1971年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1946年 | 1篇 |
1945年 | 1篇 |
排序方式: 共有505条查询结果,搜索用时 16 毫秒
51.
Jyotsna Bhatt Archana Mukherjee Aruna Korde Mukesh Kumar Haladhar Dev Sarma Ashutosh Dash 《Molecular imaging and biology》2017,19(1):59-67
Purpose
The present work was aimed at the development of prospective positron emission tomography (PET) agents for infection imaging. Towards this aim, ubiquicidin (UBI) fragments conjugated with the macrocyclic NODAGA chelator were radiolabeled with Ga-68 and evaluated.Procedures
Conformations of custom synthesized NODAGA-UBI (29–41) and NODAGA-UBI (31–38) conjugates were compared with UBI (29–41) by circular dichroism (CD) spectroscopy. Optimization of labeling of NODAGA conjugates of UBI peptides with Ga-68 was performed and quality control analysis was carried out by chromatography techniques. In vitro uptake of [68Ga] NODAGA-UBI (29–41) and [68Ga]NODAGA-UBI (31–38) was studied in Staphylococcus aureus cells. In vivo distribution of [68Ga]GaCl3 and [68Ga]NODAGA-UBI complexes was performed in normal Swiss mice.Results
Conformations of NODAGA-UBI (29–41) and NODAGA-UBI (31–38) conjugates were found to be similar to UBI (29–41). NODAGA-UBI conjugates could be consistently labeled with Ga-68 in high radiochemical yields (>95 %) with high radiochemical purity (>95 %). [68Ga]NODAGA-UBI (29–41) and [68Ga]NODAGA-UBI (31–38) complexes showed retention time of 14 and 14.5 min, respectively, by HPLC radiochromatogram. Specific uptake of [68Ga]NODAGA-UBI fragments was observed in S.aureus cells. Greater than 64 % of the injected dose was cleared via the renal route at 1 h post injection, and no significant uptake in vital organs of mice was observed with both the agents.Conclusion
This is the first report on Ga-68 labeled NODAGA-UBI fragments for infection imaging and the agents hold tremendous prospect in PET imaging.52.
53.
54.
Garg N Zivadinov R Ramanathan M Vasiliu I Locke J Watts K Lema J Rajeswary J Munschauer FE Ambrus J Weinstock-Guttman B 《Journal of neuroimmunology》2007,187(1-2):159-165
BACKGROUND: Autoreactive antibodies (ARAB) occur more frequently in patients with multiple sclerosis (MS) than in general population and the presence of these antibodies often causes uncertainty regarding the disease course, response to therapy and the diagnosis of MS. METHODS: Retrospective analyses of the ARAB, clinical and MRI data of a consecutive patient cohort of MS and clinically isolated syndrome (CIS) patients were conducted. The patients were evaluated for an extensive panel that included various subtypes of antiphospholipid antibody (APLA) including anti-phosphatidylethanolamine (APE), anti-phosphatidylserine (APS), anti-beta-2-glycoprotein-1 (ABGP), anti-cardiolipin (ACA), and several other ARAB such as antinuclear antibody (ANA), anti-neutrophilic cytoplasmic antibodies (ANCA), anti-thyroid peroxidase antibodies (ATA), anti-SS-A, and anti-SS-B antibodies. Quantitative MRI analysis was performed in a subgroup of MS patients measuring T2-lesion volume (LV), T1 black hole LV and brain parenchymal fraction (BPF). RESULTS: A total of 137 patients (mean age 44.7, 84% female) with either MS (n=111; age: mean 46.5+/-S.D. 10.3 years; disease duration: mean 13.0+/-S.D. 10.4 years; EDSS: mean 3.2+/-S.D. 1.9) or CIS (n=26; age: mean 37.7+/-S.D. 7.8 years; disease duration: mean 1.3+/-S.D. 1.1 years; EDSS: mean 1.0+/-S.D. 0.7) were enrolled. Among MS patients, 82 were RRMS, 26 SPMS, and 3 had PPMS. Seventy-seven (69%) of MS patients showed presence of one or more ARAB. The proportion of MS patients with APLA was 55% (61 patients); IgM subtype was most frequent. Co-occurrence of ACA and APE was more frequent in SPMS as compared to RRMS (15.4% vs. 1.2%, p=0.012). The proportion of CIS patients with ARAB was 75% with IgM subtype being the most frequent. However, the ARAB in majority of CIS patients (9 out of 14, 64%) were transient on repeated testing. In a subgroup of 62 MS patients, quantitative MRI analysis showed significantly higher T2-LV in patients with positive APLA (15.1 ml for APLA positive vs. 6.75 ml for APLA negative) after correcting for the disease duration (p=0.048). The patients with ATA also had significantly higher T2-LV after correction for disease duration (19.0 ml vs.8.5, p=0.044). CONCLUSIONS: ARAB were present in more than two thirds of MS and CIS patients although most of APLA in CIS were transient. The presence of APLA in MS patients was associated with higher T2-LV. 相似文献
55.
S. V. Mulgund M. S. Phoujdar S. V. Londhe P. S. Mallade T. S. Kulkarni A. S. Deshpande K. S. Jain 《Indian journal of pharmaceutical sciences》2009,71(1):35-40
A simple, specific, accurate and stability-indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of mephenesin and diclofenac diethylamine, using a Spheri-5-RP-18 column and a mobile phase composed of methanol: water (70:30, v/v), pH 3.0 adjusted with o-phosphoric acid. The retention times of mephenesin and diclofenac diethylamine were found to be 3.9 min and 14.5 min, respectively. Linearity was established for mephenesin and diclofenac diethylamine in the range of 50-300 μg/ml and 10-60 μg/ml, respectively. The percentage recoveries of mephenesin and diclofenac diethylamine were found to be in the range of 99.06-100.60% and 98.95-99.98%, respectively. Both the drugs were subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, photolytic and UV degradation. The degradation studies indicated, mephenesin to be susceptible to neutral hydrolysis, while diclofenac diethylamine showed degradation in acid, H2O2, photolytic and in presence of UV radiation. The degradation products of diclofenac diethylamine in acidic and photolytic conditions were well resolved from the pure drug with significant differences in their retention time values. This method can be successfully employed for simultaneous quantitative analysis of mephenesin and diclofenac diethylamine in bulk drugs and formulations. 相似文献
56.
Seasonality of cryptosporidiosis: A meta-analysis approach 总被引:1,自引:0,他引:1
Objectives
We developed methodology for and conducted a meta-analysis to examine how seasonal patterns of cryptosporidiosis, a primarily waterborne diarrheal illness, relate to precipitation and temperature fluctuations worldwide.Methods
Monthly cryptosporidiosis data were abstracted from 61 published epidemiological studies that cover various climate regions based on the Köppen Climate Classification. Outcome data were supplemented with monthly aggregated ambient temperature and precipitation for each study location. We applied a linear mixed-effect model to relate the monthly normalized cryptosporidiosis incidence with normalized location-specific temperature and precipitation data. We also conducted a sub-analysis of associations between the Normalized Difference Vegetation Index (NDVI), a remote sensing measure for the combined effect of temperature and precipitation on vegetation, and cryptosporidiosis in Sub-Saharan Africa.Results
Overall, and after adjusting for distance from the equator, increases in temperature and precipitation predict an increase in cryptosporidiosis; the strengths of relationship vary by climate subcategory. In moist tropical locations, precipitation is a strong seasonal driver for cryptosporidiosis whereas temperature is in mid-latitude and temperate climates. When assessing lagged relationships, temperature and precipitation remain strong predictors. In Sub-Saharan Africa, after adjusting for distance from the equator, low NDVI values are predictive of an increase in cryptosporidiosis in the following month.Discussion
In this study we propose novel methodology to assess relationships between disease outcomes and meteorological data on a global scale. Our findings demonstrate that while climatic conditions typically define a pathogen habitat area, meteorological factors affect timing and intensity of seasonal outbreaks. Therefore, meteorological forecasts can be utilized to develop focused prevention programs for waterborne cryptosporidiosis. 相似文献57.
Glickman SW Boulding W Staelin R Mulgund J Roe MT Lytle BL Rumsfeld JS Gibler WB Ohman EM Schulman KA Peterson ED 《American heart journal》2007,154(6):1206-1220
58.
Brookhart MA Schneeweiss S Avorn J Bradbury BD Rothman KJ Fischer M Mehta J Winkelmayer WC 《Journal of the American Society of Nephrology : JASN》2008,19(7):1389-1395
For poorly understood reasons, patients with end-stage renal disease (ESRD) differ substantially in their response to treatment with recombinant erythropoietin (EPO). Because hypoxia influences many of the biologic pathways involved in erythropoiesis, the altitude at which a patient lives may affect the dose-response relationship of EPO. In this retrospective cohort study, clinical data from 341,737 incident hemodialysis patients registered in the U.S. Renal Data System were combined with elevation data from the U.S. Geological Survey to address this question. Higher altitude was associated with smaller EPO doses and higher hematocrit levels. For example, compared with patients at sea level, patients living above 6000 ft received 19% less EPO (12.9 versus 15.9 thousand units/wk) but had hematocrit levels 1.1 points higher (35.7% versus 34.6%). These associations were found within subgroups defined by sex, race, age, calendar time, cause of ESRD, and dialysis center profit status, and persisted after adjustment for various potential confounding factors. Furthermore, resistance to EPO decreased with elevation. Our results suggest that ESRD patients living at high altitude either increase endogenous EPO production or respond better to endogenous and exogenous EPO. 相似文献
59.
60.
Background: The purpose of the study was to compare the success and ease of insertion of three techniques of laryngeal mask airway (LMA) insertion; the standard Brain technique, a lateral technique with cuff partially inflated and a rotational technique with cuff partially inflated.
Methods: One hundred and sixty-eight ASA I and II children aged 6 months to 6 years undergoing short elective surgical procedures lasting 40–60 min were included in the study. A standard anesthesia protocol was followed for all patients. Patients were randomly allocated into one of the three groups i.e. standard (S), rotational (R) and lateral (L). The primary outcome measure of the study was success rate at the first attempt using three techniques of LMA insertion. Secondary outcomes measures studied were overall success rate, time before successful LMA insertion, complications and maneuvers used to relieve airway obstruction.
Results: Successful insertion at the first attempt was significantly higher in group R (96%) compared with group L (84%) and group S (80%) ( P = 0.03). Overall success rate (i.e. successful insertion with two attempts) was 100% for group R, 93% for group L and 87% for group S ( P = 0.03). Time for successful insertion was significantly lower in group R compared with group L and S ( P < 0.001). The incidence of complications was lower in group R.
Conclusions: A rotational technique with partially inflated cuff is associated with the highest success rate of insertion and lowest incidence of complications and could be the technique of first choice for LMA insertion in pediatric patients. 相似文献
Methods: One hundred and sixty-eight ASA I and II children aged 6 months to 6 years undergoing short elective surgical procedures lasting 40–60 min were included in the study. A standard anesthesia protocol was followed for all patients. Patients were randomly allocated into one of the three groups i.e. standard (S), rotational (R) and lateral (L). The primary outcome measure of the study was success rate at the first attempt using three techniques of LMA insertion. Secondary outcomes measures studied were overall success rate, time before successful LMA insertion, complications and maneuvers used to relieve airway obstruction.
Results: Successful insertion at the first attempt was significantly higher in group R (96%) compared with group L (84%) and group S (80%) ( P = 0.03). Overall success rate (i.e. successful insertion with two attempts) was 100% for group R, 93% for group L and 87% for group S ( P = 0.03). Time for successful insertion was significantly lower in group R compared with group L and S ( P < 0.001). The incidence of complications was lower in group R.
Conclusions: A rotational technique with partially inflated cuff is associated with the highest success rate of insertion and lowest incidence of complications and could be the technique of first choice for LMA insertion in pediatric patients. 相似文献