全文获取类型
收费全文 | 1741篇 |
免费 | 96篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 90篇 |
妇产科学 | 84篇 |
基础医学 | 173篇 |
口腔科学 | 36篇 |
临床医学 | 120篇 |
内科学 | 496篇 |
皮肤病学 | 16篇 |
神经病学 | 178篇 |
特种医学 | 149篇 |
外科学 | 144篇 |
综合类 | 22篇 |
一般理论 | 1篇 |
预防医学 | 108篇 |
眼科学 | 20篇 |
药学 | 62篇 |
中国医学 | 1篇 |
肿瘤学 | 136篇 |
出版年
2024年 | 1篇 |
2023年 | 28篇 |
2022年 | 9篇 |
2021年 | 55篇 |
2020年 | 26篇 |
2019年 | 54篇 |
2018年 | 58篇 |
2017年 | 51篇 |
2016年 | 59篇 |
2015年 | 50篇 |
2014年 | 66篇 |
2013年 | 91篇 |
2012年 | 125篇 |
2011年 | 131篇 |
2010年 | 78篇 |
2009年 | 75篇 |
2008年 | 116篇 |
2007年 | 119篇 |
2006年 | 79篇 |
2005年 | 98篇 |
2004年 | 87篇 |
2003年 | 90篇 |
2002年 | 58篇 |
2001年 | 14篇 |
2000年 | 25篇 |
1999年 | 23篇 |
1998年 | 20篇 |
1997年 | 16篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有1842条查询结果,搜索用时 15 毫秒
1.
Jamaal L. Benjamin MD PhD Rebecca Dennis DO Stacy White Jr MD David Munson MD Sudha A. Anupindi MD Maciej Piskunowicz MD Kassa Darge MD PhD Ami Gokli MD Misun Hwang MD 《Journal of ultrasound in medicine》2020,39(5):1031-1036
Bowel diseases of prematurity, including necrotizing enterocolitis, are dreaded ailments of neonates. Early diagnosis is difficult, with clinical and radiographic findings often inconclusive. We present a novel use of contrast-enhanced ultrasound in detection of pediatric bowel disease. Early identification of compromised blood flow or an at-risk bowel can be quantitatively detected and monitored. This ability has implications for guidance of emerging therapies, allowing targeting of inflammation. These findings represent an advancement in detection of bowel disease in neonates. 相似文献
2.
3.
Mark A. Trimble Salvador Borges-Neto Stuart Smallhelser Ji Chen Emily F. Honeycutt Linda K. Shaw Jaekyeong Heo Robert A. Pagnanelli E. Lindsey Tauxe Ernest V. Garcia Fabio Esteves Frank Seghatol-Eslami G. Neal Kay Ami E. Iskandrian 《Journal of nuclear cardiology》2007,14(3):298-307
Background Cardiac resynchronization therapy (CRT) is approved for the treatment of patients with advanced systolic heart failure and
evidence of dyssynchrony on electrocardiograms. However, a significant percentage of patients do not demonstrate improvement
with CRT. Echocardiographic techniques have been used for more accurate determination of dyssynchrony. Single photon emission
computed tomography (SPECT) myocardial perfusion imaging has not previously been used to evaluate cardiac dyssynchrony. The
objective of this study is to evaluate mechanical dyssynchrony as described by phase analysis of gated SPECT images in patients
with left ventricular dysfunction, conduction delays, and ventricular paced rhythms.
Methods and Results A novel count-based method is used to extract regional systolic wall thickening amplitude and phase from gated SPECT images.
Five indices describing the phase dispersion of the onset of mechanical contraction are determined: peak phase, phase SD,
bandwidth, skewness, and kurtosis. These indices were determined in consecutive patients with left ventricular dysfunction
(n=120), left bundle branch block (n=33), right bundle branch block (n=19), and ventricular paced rhythms (n=23) and were
compared with normal control subjects (n=157). Phase SD, bandwidth, skewness, and kurtosis were significantly different between
patients with left ventricular dysfunction, left bundle branch block, right bundle branch block, and ventricular paced rhythms
and normal control subjects (all P<.001) Peak phase was significantly different between patients with right ventricular paced rhythms and normal control subjects
(P=.001).
Conclusions A novel SPECT technique for describing left ventricular mechanical dyssyn-chrony has been developed and may prove useful in
the evaluation of patients for CRT.
This study was funded in part by a research grant from the Medtronic-Duke Strategic Alliance, of which Dr Borges-Neto is the
primary investigator. 相似文献
4.
C N Mariash 《Endocrinology》1989,124(1):212-217
To determine whether the rapid response of hepatic mRNA-S14 to carbohydrate feeding was associated with an alteration in a specific hepatic nucleotide, acid extracts of liver tissue were analyzed by ion-paired reverse phase HPLC. A nucleotide present in nanomoles per g quantity correlated with the induction of this mRNA by sucrose. Four hours after sucrose feeding the content of this compound was 7 times greater than that in fasted rats. Furthermore, the response was rapid, attaining maximal levels 30 min after feeding, and remaining elevated for at least 4 h. The content of this nucleotide also correlated with the content of mRNA-S14 in the steady state, with the lowest levels of both mRNA-S14 and this nucleotide in fasted rats, intermediate levels in rats maintained on a regular chow diet, and the highest levels in rats fed a 60% sucrose diet for 4 days. Lastly, while the response of mRNA-S14 to thyroid hormone and sucrose is synergistic, the thyroidal state does not influence the response of this compound to sucrose. Thus, the interaction of thyroid hormone and sucrose on mRNA-S14 is distal to the generation of this compound. Based on the UV spectrum, HPLC retention, and [3H]adenosine labeling, this compound contains adenine. However, it is not any of the common adenine-containing mono- or oligonucleotides. These data indicate that a novel hepatic nucleotide is induced by sucrose and raise the possibility that this nucleotide is responsible for the induction of carbohydrate-responsive mRNAs. 相似文献
5.
背景日常生活中,自闭症患者核心社交不足的表现比外在实验任务中的表现要显著得多。为了使实验测量符合临床观察,我们介绍一种新方法,即在一个模拟日常需要的设置中采用社会监测的定量非典型性策略。把增强的社会生态有效性对这两组的影响最大化,同时评估实验变量相对的社会能力成果测量的效用。方法在观察社会场景时,用眼睛追踪技术测量目测定位,对象是15个有感知能力的自闭症男人和15个年龄、性别与言语IQ相称的控制主体。我们编码4个可靠的定位区域:嘴、眼睛、身体和目标。统计学分析把这两组定位在兴趣区域上的时间和社会能力成果测量作了比较。(比如日常社会调整和自闭症患者的社会症状的标准化测量)结果在四个区域中都观察到这两组间的重大不同。自闭症的最佳预报器是眼睛区域上的定位时间减少。定位在嘴巴上还是定位在目标上与社交机能紧密相关:增加对嘴的注意预示着改良的社会适应性和较少的自闭症社会损伤,而花更多时间注意目标则预示着相反的关系。结论在观察自然社会情形时,自闭症个体表现出社会视觉追击的反常模式,即眼睛不再那么突出,而嘴巴、身体和目标却越加突出。定位在嘴巴和目标(而不是眼睛)上的时间是社会能力的强有力指示器。 相似文献
6.
7.
Bombings and explosion incidents directed against innocent civilians are the primary instrument of global terror. In the present
review we highlight the major observations and lessons learned from these events. Five mechanisms of blast injury are outlined
and the different type of injury that they cause is described. Indeed, the consequences of terror bombings differ from those
of non-terrorism trauma in severity and complexity of injury, and constitute a new class of casualties that differ from those
of conventional trauma. The clinical implications of terror bombing, in treatment dilemmas in the multidimensional injury,
ancillary evaluation and handling of terror bombing mass casualty event are highlighted. All this leads to the conclusion
that thorough medical preparedness to cope with this new epidemic is required, and that understanding of detonation and blast
dynamics and how they correlate with the injury patterns is pivotal for revision of current mass casualty protocols. 相似文献
8.
Menahem Neuman Boris Friedman Avi Stein A. Ami Sidi Alexander Tsivian 《Gynecological surgery》2007,4(3):175-178
The objective of the study was to compare the clinical outcomes at the short-term follow-ups of two novel transobturator mid-urethral
sling procedures – the transobturator tape (TOT) procedure and the tension-free vaginal tape (TVT)-obturator procedure. The
study cohort consisted two groups of 40 women with urodynamically proven stress urinary incontinence (SUI). The patients in
one group underwent the TOT procedure, performed according to Delorme (Prog Urol 11:1306–1313, 2001); those in the second
group underwent the TVT-obturator operation, performed according to de Leval (Eur Urol 44:724–730, 2003). Intra-operative
diagnostic cystoscopy was not performed with either the TVT-obturator or the TOT procedures. The average follow-up was 12 months.
The two patient groups were similar in terms of demographic and therapeutic criteria, except for patient age, which was significantly
younger in the TVT-obturator group. Previously reported TVT-related operative complications, such as bladder penetration,
intra-operative bleeding, field infection and post-operative pelvic floor relaxation, were not observed in patients of either
group. Bowel and urethral injuries were also not recorded. The therapeutic failure rates were 10% for the TOT procedure and
5% for the TVT-obturator procedure. Urinary frequency and urgency post-operatively were reported in 25% of the TOT patients
and 19% of the TVT-obturator patients, pelvic or vaginal pain affected 10% of the TOT and 5% of the TVT-obturator patients,
while post-operative voiding difficulty was experienced by 12.5% of the TOT and 7.5% of the TVT-obturator patients. None of
the above-mentioned differences between the two patient groups were of statistical significance. The TVT-obturator and TOT
procedures, both minimally invasive, novel, mid-urethral sling procedures, seem to be safe, easy-to-perform and effective
in treating female SUI. The patients of both study groups suffered less intra- and post-operative surgical complications than
previously been reported in connection with the TVT operation. The TVT-obturator patients had fewer therapeutic failures,
less post-operative urinary frequency and urgency, less pelvic pain and less voiding difficulty. All of these findings, however,
had no statistical significance; consequently, long-term comparative data collection will be required before solid conclusions
can be drawn on the superiority of either of these two operative techniques. 相似文献
9.
10.