全文获取类型
收费全文 | 501篇 |
免费 | 19篇 |
国内免费 | 3篇 |
专业分类
儿科学 | 4篇 |
基础医学 | 38篇 |
口腔科学 | 2篇 |
临床医学 | 50篇 |
内科学 | 40篇 |
皮肤病学 | 2篇 |
神经病学 | 62篇 |
特种医学 | 4篇 |
外科学 | 11篇 |
综合类 | 79篇 |
预防医学 | 43篇 |
眼科学 | 1篇 |
药学 | 176篇 |
中国医学 | 8篇 |
肿瘤学 | 3篇 |
出版年
2022年 | 7篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 12篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 21篇 |
2013年 | 52篇 |
2012年 | 21篇 |
2011年 | 33篇 |
2010年 | 24篇 |
2009年 | 23篇 |
2008年 | 33篇 |
2007年 | 28篇 |
2006年 | 25篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 13篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1995年 | 4篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 5篇 |
1972年 | 2篇 |
1971年 | 7篇 |
1970年 | 5篇 |
1968年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有523条查询结果,搜索用时 31 毫秒
11.
Summary: When using a spectrophotometric method to measure cholinesterase activity in carbamate-treated tissues, precautions must be taken to limit the reactivation of the inhibited cholinesterase. Many testing laboratories use automated instruments to measure cholinesterase activity, instruments that usually employ a spectrophotometric method. To date, there has been no systematic investigation of the validity of the cholinesterase data obtained from carbamate-treated tissues using these automated instruments. The purpose of this study was to compare the cholinesterase data obtained using an automated analyzer with those obtained using a radiometric assay (i.e., the optimal method for unstable inhibitors). Using both an automated analyzer and the radiometric method, cholinesterase activity was measured in whole blood and brain tissue taken from rats treated with various dosages of carbaryl. Reactivation occurred when using the automated instrument. In the brain tissue, cholinesterase activity of the treated tissues was as much as 16% higher with the automated method than with the radiometric method. In the whole blood, there was an 18-26% reactivation using the automated method. Further detailed analyses indicate that this reactivation is not due to the initial dilution required of the tissue sample for automated analysis. The results indicate that the length of the preincubation may be a major factor that encourages the reactivation of the cholinesterase activity; however, even when the preincubation period is minimized, reactivation still occurs. 相似文献
12.
Summary Preparations from alloxan diabetic rats showed a reduced sensitivity to the neuromuscular blocking action of (+)-tubocurarine
but no alteration in sensitivity to the deplolarizing neuromuscular blocking drug decamethonium. Physostigmine was less effective
in augmenting twitch height in preparations from alloxan diabetic rats and such preparations had a significantly lowered total
cholinesterase activity compared with control preparations. An additional observation was a reduction in the effectiveness
of the pre-junctionally active agent β-bungarotoxin in producing neuromuscular blockade in physostigmine-treated preparations
from alloxan diabetic rats. All the changes produced by alloxan administration were prevented by treatment with insulin. 相似文献
13.
AIM:To understand the correlation of serum cholinesterase (CHE) activity with gastric cancer and to assess their clinical significance. METHODS:The velocity method was adopted to detect the activity of serum CHE in patients with gastric cancer and in patients with non-malignant tumor as controls. RESULTS:The serum CHE activity in the treatment group was significantly lower than that in the control group with a very significant difference between the two groups (83.3:113.1,P=0.0003). Age was significantly associated with the incidence of gastric caner. CONCLUSION:Serum CHE activity has a close relation with the incidence of gastric cancer. 相似文献
14.
目的研究辛硫磷农药中毒患者病情变化与血清胆碱酯酶(ChE)恢复的关系。方法95例重度有机磷中毒(AOPP)患者,包括A组辛硫磷中毒患者45例,B组其他有机磷中毒患者50例,入院后均给予洗胃、清除毒物、解磷定、阿托品及积极的对症支持治疗。分别于入院时、治疗后1、2、3、4、5、6~8、8~11、11~13天……及出院时抽血测定血清ChE,计算阿托品用量。结果血清ChE在两组患者治疗前无统计学意义(P〉0.05),治疗后1—3天部分有下降趋势,第1天降至最低,3天后B组血清ClE逐渐上升,而A组ChE持续低水平。6—9天后缓慢回升,部分患者出院时仍低于甚至明显低于正常,但两组预后无显著差异.A组胆碱酯酶恢复时间13—44天,较B组7—25天明显延迟。阿托品用量大,治疗时间长。结论辛硫磷中毒患者ChE恢复明显延迟.对AOPP患者合理治疗具有重要指导意义。 相似文献
15.
目的观察分析南京市某有机磷农药生产企业人员外周血象(包括WBC、PLT、RBC和Hb)、丙氨酸转氨酶(ALT)和胆碱酯酶(CHE)结果的变化情况,探讨不同工种、不同工龄、不同性别与研究指标之间的关系,为减少职业危害提供科学依据。方法对2013年某有机磷农药生产企业1 138名人员和某外厂692名未接触有机磷农药的工人进行外周血象、ALT和CHE检测分析。结果有机磷组的WBC为(6.0±1.47)×10^9/L,PLT为(158.2±52.29)×10^9/L,RBC为(4.59±0.49)×10^12/L,Hb为(137.3±15.93)g/L,ALT为(24.9±19.78)U/L,CHE为(248.3±85.43)U/L,均在正常参考范围内;但WBC、PLT、RBC、Hb和CHE均低于对照组,差异有统计学意义(均P〈0.01)。不同工种间,PLT、Hb、RBC、ALT和CHE的差异有统计学意义(P〈0.01),操作工的WBC为(5.97±1.47)×10^9/L,PLT为(155.7±51.55)×10^9/L,RBC为(4.58±0.49)×10^12/L,Hb为(137.1±16.0)g/L,ALT为(24.1±17.33)U/L,CHE为(236.3±86.06)U/L,均低于管理人员,差异均有统计学意义。随着接害工龄的增加,血液检查的各项指标有逐渐降低的趋势,其中,5-15 a组的CHE为(213.6±83.85)U/L,RBC(4.49±0.52)×10^12/L,Hb为(133.9±16.99)g/L,显著低于〈5 a组,差异有统计学意义。CHE的异常率在性别间差异有统计学意义。结论长期接触有机磷农药对生产工人的外周血象,ALT和CHE有一定的负面影响,对工龄5-15年的影响尤为明显。 相似文献
16.
David DAndrea Francesco Soria Mohammad Abufaraj Kilian Gust Beat Foerster Mihai D. Vartolomei Shoji Kimura Andrea Mari Alberto Briganti Mesut Remzi Christian K. Seitz Romain Mathieu Pierre I. Karakiewicz Shahrokh F. Shariat 《Urologic oncology》2018,36(12):528.e7-528.e13
Purpose
To evaluate the predictive and prognostic role as well as the clinical impact on decision-making of serum cholinesterase (ChoE) levels in patients treated with radical prostatectomy for clinically nonmetastatic prostate cancer.Materials and methods
We conducted a retrospective analysis of our multi institutional database. Preoperative ChoE was evaluated as continuous and dichotomized variable using a visual assessment of the functional form of the association of ChoE with biochemical recurrence (BCR)-free survival. We assessed its association with perioperative clinicopathologic characteristics and outcomes. Multivariable models established its independent prognostic value for BCR. Cox proportional hazard coefficients were used to build nomograms for the prediction of early and late BCR. Decision curve analysis was used to assess the clinical impact on decision making of preoperative ChoE.Results
In all, 6,041 patients were available for the analysis. Decreased ChoE was associated with higher biopsy Gleason score, preoperative PSA levels, pathologic Gleason score, pathological stage, lymph node metastasis, positive surgical margin, and lymphovascular invasion at radical prostatectomy (all P < 0.01). Preoperative ChoE ≤ 6.52 U/ml was associated with higher probability of BCR (HR 1.72, 95% CI 1.48–1.99, P < 0.001). Preoperative and postoperative multivariable models that adjusted for the effects of established clinicopathologic features confirmed its independent association with BCR. In decision curve analysis inclusion of preoperative ChoE did not improve the net benefit of preoperative and postoperative models for the prediction of BCR.Conclusions
Despite independent association with clinicopathologic features and BCR, preoperative serum ChoE has no impact on clinical decision making. Future studies should investigate the possible relationship between ChoE activity and neoplastic cell transformation with a rational for targeting. 相似文献17.
《Current medical research and opinion》2013,29(8):1221-1225
SUMMARYObjective: To assess the impact of donepezil treatment compared with placebo on caregiver time spent assisting patients with Alzheimer's disease (AD).Research design and methods: Patient and caregiver data were collected as part of a 1-year, prospective, double-blind, randomized, placebo-controlled trial. The Resource Utilization in Dementia (RUD) questionnaire was used to record caregiver time at study baseline and at Weeks 12, 24, 36, and 52. This analysis focuses solely on those caregivers who were actively (> 0?h/day reported on the RUD) providing care at study baseline.Main outcome measures: The change in time relative to baseline that caregivers spent assisting patients over the course of the study.Results: The active caregiver population was composed of 96 caregivers of donepezil-treated patients and 94 caregivers of patients receiving placebo. Over the course of the 1-year study, and as the condition of the AD patients deteriorated, it was expected that caregiver time would increase. As expected, after 52?weeks, caregivers of placebo patients were providing almost 2?h each day (106.8?min) more care than they had done at study baseline. For those caregivers of donepezil-treated patients, although they were spending more time caring than they had done at study baseline, their time burden had only increased by 42.6?min more each day. This difference in caring time between the 2 groups, relative to baseline at Week 52, was 1.1?h (64.2?min) each day, and was significant (?p = 0.03).Conclusion: Caregiver time devoted to helping an AD patient typically increases with the severity of the disease. By helping the patient maintain his/her ability to perform activities of daily living for longer, treatment with donepezil is not only beneficial to the patient, but also has positive time-burden implications for the caregiver. 相似文献
18.
《Clinical toxicology (Philadelphia, Pa.)》2013,51(4):243-253
Methyl parathion (MP) was used illegally to spray homes for insect control over approximately an 8-yr period. In an attempt to determine if there were any adverse health effects from this, health-screening evaluations were performed on 353 individuals living in homes that were illegally sprayed. The average subject spent 15.5 h a day in the home. Subjects from homes with high levels of MP (exposure group) were compared to controls that lived in homes with minimal or no MP. Subjects were aware of the levels of MP found in their homes and recall bias was likely. There were no significant differences in the symptoms reported or by the physician assessment of subacute or chronic toxicity between those in the exposure group and controls. No significant differences were found in growth and developmental evaluations. Three subjects were identified who most likely suffered acute toxicity from the initial exposure and were not appropriately diagnosed and treated. Cholinesterase determinations also did not differ between those in the exposure group and controls. When subjects from the exposure group were stratified by the level of MP in their home, those from homes with the highest levels appeared to have an increased likelihood of subacute toxicity and reported an increased number of neuropsychiatric symptoms (OR 2 for both evaluations). 相似文献
19.
The two distinct molecular forms of cholinesterase (ChE) are acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Our previous studies have reported that ChE is involved in tooth development. However, further experiments are needed to understand the precise action of ChE in tooth development. This study aimed to localise types of ChE in human tooth germs, and identify their distribution pattern.ChE were localised in frozen sections of jaws which were prepared from dead fetuses, neonates and stillborns who were free from visible abnormalities by Karnovsky and Root method.AChE was identified in the inner and outer enamel epithelia including the cervical loop region, stratum intermedium and preameloblasts of tooth germs at bell stage. Secretory ameloblasts were free from staining. The bud and cap stages of permanent tooth germs showed AChE activity on the lingual aspect and top surface of the epithelial ingrowths, respectively. BuChE activity was localised in the degenerating dental lamina.Our study reported the first evidence of localisation of ChE in human tooth development and identified the possible molecular form of ChE in tooth germs as AChE. Also, our results have provided strong evidence to speculate the action of AChE is on the cells of enamel organ during tooth development. 相似文献
20.