全文获取类型
收费全文 | 650篇 |
免费 | 42篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 9篇 |
妇产科学 | 8篇 |
基础医学 | 66篇 |
口腔科学 | 25篇 |
临床医学 | 44篇 |
内科学 | 133篇 |
皮肤病学 | 9篇 |
神经病学 | 61篇 |
特种医学 | 13篇 |
外科学 | 79篇 |
综合类 | 19篇 |
预防医学 | 93篇 |
眼科学 | 20篇 |
药学 | 65篇 |
中国医学 | 8篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 24篇 |
2021年 | 35篇 |
2020年 | 19篇 |
2019年 | 29篇 |
2018年 | 26篇 |
2017年 | 21篇 |
2016年 | 26篇 |
2015年 | 23篇 |
2014年 | 35篇 |
2013年 | 33篇 |
2012年 | 70篇 |
2011年 | 63篇 |
2010年 | 32篇 |
2009年 | 28篇 |
2008年 | 39篇 |
2007年 | 43篇 |
2006年 | 38篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 15篇 |
2002年 | 9篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有692条查询结果,搜索用时 12 毫秒
1.
Farzad Mostashari Annie Fine Debjani Das John Adams Marcelle Layton 《Journal of urban health》2003,80(1):i43-i49
In 1998, the New York City Department of Health and the Mayor’s Office of Emergency Management began monitoring the volume of ambulance dispatch calls as a surveillance tool for biologic terrorism. We adapted statistical techniques designed to measure excess influenza mortality and applied them to outbreak detection using ambulance dispatch data. Since 1999, we have been performing serial daily regressions to determine the alarm threshold for the current day. In this article, we evaluate this approach by simulating a series of 2,200 daily regressions. In the influenza detection implementation of this model, there were 71 (3.2%) alarms at the 99% level. Of these alarms, 64 (90%) occurred shortly before or during a period of peak influenza in each of six influenza seasons. In the bioterrorism detection implementation of this methodology, after accounting for current influenza activity, there were 24 (1.1%) alarms at the 99% level. Two occurred during a large snowstorm, 1 is unexplained, and 21 occurred shortly before or during a period of peak influenza activity in each of six influenza seasons. Our findings suggest that this surveillance system is sensitive to communitywide respiratory outbreaks with relatively few false alarms. More work needs to be done to evaluate the sensitivity of this approach for detecting nonrespiratory illness and more localized outbreaks. 相似文献
2.
Thomas A. Krenitsky John Dillberger Elena Zotova Joseph C. Arezzo James B. Koprich Farzad Mortazavi Timothy A. Gates Gary L. Dunbar 《Drug development research》2004,62(1):60-70
In cultured cells, KP544 [2‐amino‐5‐(4‐chlorophenylethynyl)‐4‐(4‐trans‐hydroxycyclohexyl amino) pyrimidine] amplifies differentiation initiated by nerve growth factor (NGF) or cAMP. This report describes the pharmacokinetics, safety, and neuroprotective efficacy of KP544 in rats. After an oral dose of 10 mg/kg KP544 was 25% bioavailable with a plasma half‐life of 1.3 h and brain levels 6‐fold higher than plasma levels at 4 and 8 h post‐dose. In a safety study, daily oral dosing for 30 days at 10 and 100 mg/kg was well tolerated. The favorable pharmacokinetic and safety profiles, together with its amplification of NGF in vitro, prompted evaluation of KP544 in two models involving NGF deficiencies. In the first model, brains were lesioned with intrastriatal injections of quinolinic acid. KP544 at oral doses of 0.02 to 1.0 mg/kg/day almost completely prevented the resulting learning deficits as evaluated using a radial‐arm‐water maze. At the lowest dose, there was a slower onset of functional improvement. These effects were accompanied by reductions (16–34%) in the striatal lesion size that were greatest at the highest dose and comparable to those seen with NGF therapy. The second model involved a peripheral neuropathy induced by taxol that is associated with decreases in NGF. KP544 at oral doses of 0.1–10 mg/kg/day decreased the severity of the neuropathy as measured by caudal nerve conduction velocities (30–70% return to control values). In both models, KP544 had a large therapeutic index suggesting its potential as a new approach for treating clinical disorders involving deficiencies in NGF. Drug Dev. Res. 62:60–70, 2004. © 2004 Wiley‐Liss, Inc. 相似文献
3.
Smoking practices in New York City: The use of a population-based survey to guide policy-making and programming 总被引:4,自引:0,他引:4
Farzad Mostashari Bonnie D. Kerker Anjum Hajat Nancy Miller Thomas R. Frieden 《Journal of urban health》2005,82(1):58-70
To inform New York City’s (NYC’s) tobacco control program, we identified the neighborhoods with the highest smoking rates,
estimated the burden of second-band smoke exposure, assessed the early response to state taxation, and examined cessation
practices. We used a stratified random design to conduct a digit-dialed telephone survey in 2002 among 9,674 New York City
adults. Our main outcome measures included prevalence of cigarette smoking, exposure to second-hand smoke, the response of
smokers to state tax increases, and cessation practices. Even after controlling for sociodemographic factors (age, racelethnicity,
income, education, marital status, employment status, and foreign-born status) smoking rates were highest in Central Harlem
and in the South Bronx. Sixteen percent of nonsmokers reported frequent exposure to second-hand smoke at home or in a workplace.
Among smokers with a child with asthma, only 33% reported having a no-smoking policy in their homes. More than one fifth of
smokers reported reducing the number of cigarettes they smoked in response to the state tax increase. Of current smokers who
tried to quit, 65% used no cessation aid. These data were used to inform New York City’s smoke-free legislation, taxation,
public education, and a free nicotine patch give-away program. In conclusion, large, local surveys can provide essential data
to effectively advocate for, plan, implement, and evaluate a comprehensive tobacco control program.
Dr. Mostashari (the guarantor) made substantial contributions to the conception, design, and supervision of this paper, the
analysis and interpretation of data, the drafting of the paper, critical revisions of the paper for important intellectual
content, and the acquisition of data and funding for this research. Dr. Kerker made substantial contributions to the analysis
and interpretation of data, the drafting of the paper and critical revisions of the paper for important intellectual content.
Ms. Hajat made substantial contributions to the acquisition of data and critical revisions of the paper for important intellectual
content. Dr. Miller made substantial contributions to the conception of this paper and critical revisions of the paper for
important intellectual content. Dr. Frieden made substantial contributions to the conception, design, and supervision of this
paper and critical revisions of the paper for important intellectual content. 相似文献
4.
Azadeh Nasiri Shaya Mokhtari Reza Jahani Bahram Daraie Hassan Yazdanpanah Mehrdad Faizi Farzad Kobarfard 《RSC advances》2022,12(27):17096
Liquid chromatography-tandem mass spectroscopy (LC-MS/MS) is an accurate and specific technique for drug residue analysis in different matrices. The high specificity and sensitivity of the multiple reaction monitoring (MRM) approach for detecting drugs such as aldehydes, which have the potential to change mass during the sample preparation phase, becomes a drawback during the analysis process. In this study, concerns about the intrusion of solvent molecules into spiramycin''s chemical structure as an aldehydic drug as well as the stability of spiramycin in the milk matrix were addressed. Furthermore, the binding sites where the solvent molecules could bind to spiramycin molecules were investigated through nuclear magnetic resonance (NMR) spectroscopy. It was revealed that water, ethanol, and methanol as protic solvents can add to the formyl group of spiramycin molecules during standard solutions preparation while there was no evidence for the addition of acetonitrile and dimethyl sulfoxide (aprotic solvents). In addition, as time passed, the peak area of spiramycin decreased either in the spiked aqueous sample or milk sample while an increase in the peak area of H2O-bound spiramycin was observed. After 96 h, more than 90% of spiramycin was converted to H2O-bound spiramycin. In conclusion, we can propose the use of aprotic solvents for the preparation of spiramycin standard solutions especially when the prepared solutions are not used instantly. Moreover, ion transitions for both spiramycin and its H2O-added form (843.6 m/z to 173.9 m/z and 861.5 m/z to 173.9 m/z, respectively) should be considered for the accurate quantification of spiramycin residue in aqueous samples such as milk.Water, ethanol, and methanol as protic solvents can add to the formyl group of spiramycin molecules during standard solutions preparation while there was no evidence for the addition of acetonitrile and dimethyl sulfoxide as aprotic solvents. 相似文献
5.
Maryam Farzad Fereydoun Layeghi Ali Asgari Seyed Ali Hosseini Mehdi Rassafiani 《Journal of hand and microsurgery》2014,6(1):27-34
The objective of the study is to provide information about non disease specified outcome measures which evaluate disability in patients who have impairments in hand and upper extremity and to find the extent to which they are evaluating “disability” based on ICF hand Core Set (activity limitation and participation restriction). MEDLINE, CINAHL, GOOGLE SCHOLAR , OVID and SCIENCE DIRECT databases were systematically searched for studies on non disease specified outcome measures used to evaluate upper extremity function; only studies written in English were considered. We reviewed titles and abstracts of the identified studies to determine whether the studies met predefined eligibility criteria (eg, non disease specified out come measures used in hand injured patients). All the outcome measures which had eligibility included. After full text review ,7 non disease specified outcome measures in hand were identified. Studies were extracted, and the information retrieved from them. All the outcome measures which had incuded, were linked with ICF hand core set disability part (activity and participation). All of them only linked to 16 (42 %) components of ICF hand Core Set, which were most activity and less participation from ICF. None of the non disease specified out come measures in hand injuries cover all domains of disability from the ICF Hand Core Set. 相似文献
6.
7.
Anatomical variants of lower limb vasculature and implications for free fibula flap: Systematic review and critical analysis
下载免费PDF全文
![点击此处可从《Microsurgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sound knowledge of the anatomical patterns of lower limb vasculature is crucial for raising the free fibula flap (FFF). The tibial arteries are particularly susceptible to anatomical variations with a dominant role of peroneal artery (PR) for lower leg perfusion, and hence precluding fibular flap harvest. In this systematic review we study the prevalence of lower limbs with dominant peroneal artery (dPR). A systematic review of the MEDLINE and EMBASE databases was conducted using a comprehensive combination of keywords and search algorithm according to PRISMA guidelines. Articles describing the branching patterns of lower limb arteries, in cadaveric or angiographic studies, were included. A total of 5,790 limbs were included from 26 studies. dPR was found in 5.2% of all limbs. The combination of dPR with hypoplastic or aplastic posterior tibial artery was the most common pattern (3.3%) followed by hypoplastic anterior tibial artery (1.5%). Peronea arteria magna (PAM) was seen in 0.4% of limbs. Bilateral variants were seen in 20% of all cases with a dPR. A greater awareness of dPR as anatomical variation and its prevalence among healthy subjects can prevent ischemic donor‐site complications after FFF harvest. Clinical examination alone may not suffice to detect anatomical variations, hence preoperative imaging of lower limb vascular system is recommended. © 2015 Wiley Periodicals, Inc. Microsurgery 36:165–172, 2016. 相似文献
8.
9.
Microscopy with ultraviolet surface excitation (MUSE): A novel approach to real‐time inexpensive slide‐free dermatopathology
下载免费PDF全文
![点击此处可从《Journal of cutaneous pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Amir Qorbani Farzad Fereidouni Richard Levenson Sana Y. Lahoubi Zachary T. Harmany Austin Todd Maxwell A. Fung 《Journal of cutaneous pathology》2018,45(7):498-503
Traditional histology relies on processing and physically sectioning either frozen or formalin‐fixed paraffin‐embedded (FFPE) tissue into thin slices (typically 4‐6 μm) prior to staining and viewing on a standard wide‐field microscope. Microscopy using ultraviolet (UV) surface excitation (MUSE) represents a novel alternative microscopy method that works with UV excitation using oblique cis‐illumination, which can generate high‐quality images from the cut surface of fresh or fixed tissue after brief staining, with no requirement for fixation, embedding and histological sectioning of tissue specimens. We examined its potential utility in dermatopathology. Concordance between MUSE images and hematoxylin and eosin (H&E) slides was assessed by the scoring of MUSE images on their suitability for identifying 10 selected epidermal and dermal structures obtained from minimally fixed tissue, including stratum corneum, stratum granulosum, stratum spinosum, stratum basale, nerve, vasculature, collagen and elastin, sweat glands, adipose tissue and inflammatory cells, as well as 4 cases of basal cell carcinoma and 1 case of pseudoxanthoma elasticum deparaffinized out of histology blocks. Our results indicate that MUSE can identify nearly all normal skin structures seen on routine H&E as well as some histopathologic features, and appears promising as a fast, reliable and cost‐effective diagnostic approach in dermatopathology. 相似文献
10.