全文获取类型
收费全文 | 12017篇 |
免费 | 781篇 |
国内免费 | 55篇 |
专业分类
耳鼻咽喉 | 107篇 |
儿科学 | 309篇 |
妇产科学 | 168篇 |
基础医学 | 1647篇 |
口腔科学 | 272篇 |
临床医学 | 1080篇 |
内科学 | 2318篇 |
皮肤病学 | 286篇 |
神经病学 | 898篇 |
特种医学 | 405篇 |
外科学 | 1664篇 |
综合类 | 79篇 |
预防医学 | 1810篇 |
眼科学 | 265篇 |
药学 | 829篇 |
中国医学 | 29篇 |
肿瘤学 | 687篇 |
出版年
2023年 | 56篇 |
2022年 | 105篇 |
2021年 | 242篇 |
2020年 | 133篇 |
2019年 | 197篇 |
2018年 | 215篇 |
2017年 | 211篇 |
2016年 | 225篇 |
2015年 | 296篇 |
2014年 | 347篇 |
2013年 | 432篇 |
2012年 | 716篇 |
2011年 | 758篇 |
2010年 | 399篇 |
2009年 | 438篇 |
2008年 | 708篇 |
2007年 | 759篇 |
2006年 | 652篇 |
2005年 | 610篇 |
2004年 | 638篇 |
2003年 | 589篇 |
2002年 | 493篇 |
2001年 | 238篇 |
2000年 | 281篇 |
1999年 | 223篇 |
1998年 | 99篇 |
1997年 | 85篇 |
1996年 | 127篇 |
1995年 | 238篇 |
1994年 | 233篇 |
1993年 | 204篇 |
1992年 | 272篇 |
1991年 | 242篇 |
1990年 | 193篇 |
1989年 | 106篇 |
1988年 | 87篇 |
1987年 | 113篇 |
1986年 | 108篇 |
1985年 | 77篇 |
1984年 | 53篇 |
1983年 | 47篇 |
1982年 | 40篇 |
1981年 | 38篇 |
1980年 | 34篇 |
1979年 | 55篇 |
1978年 | 43篇 |
1977年 | 30篇 |
1975年 | 37篇 |
1974年 | 33篇 |
1973年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Increasing evidence suggests that human epidermal melanocytes play an important role in the skin immune system; however, a role of their pigmentation in immune and inflammatory responses is poorly examined. In the study, the expression of Toll‐like receptor 4 (TLR4) and inflammatory cytokines and chemokines by cultured normal melanocytes derived from lightly and darkly pigmented skin was investigated after cell stimulation with lipopolysaccharide (LPS). The basal TLR4 mRNA level in heavily pigmented cells was higher as compared to their lightly pigmented counterparts. Melanocyte exposure to LPS upregulated the expression of TLR4 mRNA and enhanced the DNA‐binding activity of NF‐κB p50 and p65. We found substantial differences in the LPS‐stimulated expression of numerous genes encoding inflammatory cytokines and chemokines between the cells with various melanin contents. In lightly pigmented melanocytes, the most significantly upregulated genes were nicotinamide phosphoribosyltransferase (NAMPT/visfatin), the chemokines CCL2 and CCL20, and IL6, while the genes for CXCL12, IL‐16 and the chemokine receptor CCR4 were the most significantly upregulated in heavily pigmented cells. Moreover, the lightly pigmented melanocytes secreted much more NAMPT, CCL2 and IL‐6. The results of our study suggest modulatory effect of melanogenesis on the immune properties of normal epidermal melanocytes. 相似文献
3.
Edyta C Pirog Rebecca N Baergen Robert A Soslow Diane Tam Amy E DeMattia Yao-Tseng Chen Christina Isacson 《The American journal of surgical pathology》2002,26(1):70-75
There is considerable interobserver variation in the diagnosis of low-grade squamous intraepithelial lesion that involves mature squamous epithelium. Our aim was to evaluate the utility of MIB-1 immunostaining as an adjunct test to increase diagnostic accuracy. Consecutive cervical biopsies originally diagnosed as normal (n = 26) or low-grade squamous intraepithelial lesion (n = 23) were reviewed by three pathologists to obtain a consensus diagnosis. MIB-1 immunostaining was performed, and positive staining was defined as a cluster of at least two stained nuclei in the upper two thirds of the epithelial thickness. Human papillomavirus (HPV) DNA detection was performed using a polymerase chain reaction assay. All cases were subsequently reclassified as low-grade squamous intraepithelial lesion (LSIL) or normal (NL) when two or three of three gold standard criteria were satisfied (LSIL gold standard criteria = consensus diagnosis of LSIL, HPV+, MIB-1+; NL gold standard criteria = consensus diagnosis of NL, HPV-, MIB-1-). Using the gold standard diagnoses, we have identified that 14 normal cases (36%) were originally overdiagnosed as LSIL, and one LSIL case (10%) was originally underdiagnosed as normal. All MIB-1-positive cases were HPV+ and identified as LSIL in the consensus review. All MIB-1-negative cases were NL by gold standard criteria. The sensitivity (1.0) and the specificity (1.0) of MIB-1 staining for identifying LSIL were superior to the sensitivity (0.9) and the specificity (0.8) of HPV testing. In conclusion, MIB-1 is a highly sensitive and specific marker for identifying low-grade squamous intraepithelial lesion and is helpful in verifying the diagnosis of equivocal cases. 相似文献
4.
5.
6.
Lindemann-Sperfeld Lutz Marintschev Ivan Zeugner Andreas Otto Wieland 《Trauma und Berufskrankheit》2002,4(1):S87-S90
Trauma und Berufskrankheit - Zusammenfassung Der Processus coronoideus ist der wichtigste knöcherne Stabilisator des Ellbogengelenks, der vordere Anteil des Lig. collaterale ulnae, welcher am... 相似文献
7.
8.
9.
William P. Grant DPM Laurence G. Rubin DPM Guy R. Pupp DPM George Vito DPM Dwayne Jacobus DPM Erin A. Jerlin DPM Harry S. Tam DPM 《The Journal of foot and ankle surgery》2007,46(5):325-335
The purpose of this study was to assess 7 methods of fixation for a midtarsal osteotomy. Polyurethane foam models (N = 6) and cadaver specimens (N = 4-7) were used to examine the force generated by the different constructs of fixation. A midtarsal osteotomy was performed on each specimen in the test groups. The osteotomies were fixated either with 2 parallel 0.062-in Kirschner wires and 40-mm-long, 4-mm partially threaded, cancellous, cannulated titanium screws, an external ring fixator (frame), a frame with wires tensioned (tension), a frame with wires tensioned and compressed toward the osteotomy (tension and compression), a frame with tension, compression, and parallel Kirschner wires, or a frame with tension, compression, and two 4.0 cannulated parallel screws, respectively. Each model was fixated, and the force generated by the construct across the osteotomy was recorded via the use of pressure-sensitive film. Statistical analysis of the data in the polyurethane foam group determined that the use of frame with tension, compression, and two 4.0 parallel cannulated screws was statistically superior to 1) frame, 2) frame with tension, 3) 2 parallel Kirschner wires, 4) two 4.0 cannulated parallel screws, and 5) frame with tension and compression. A cadaver study determined that the frame with tension, compression, and 2 parallel Kirschner wires was statistically superior to 1) frame and 2) two parallel Kirschner wires. These findings suggest that there is a difference in the force generated by the type of fixation construct across a midtarsal osteotomy. 相似文献
10.
Background contextLumbar zygapophyseal joint (Z-joint) synovial cysts can cause low back pain (LBP), spinal stenosis, and lower extremity radiculopathy. In the literature, there are several minimally invasive techniques described with mixed results. Typical recommended treatment is surgical resection of the cyst. Currently, there is little information available concerning the efficacy and outcome with treatment of Z-joint synovial cyst by percutaneous, fluoroscopic, contrast-enhanced distention, and rupture.PurposeTo evaluate the therapeutic value and safety of Z-joint cyst rupture in symptomatic patients.Study design/settingRetrospective cohort study in an academic outpatient physiatric spine practice.Patient sampleThirty-two patients with moderate-to-severe LBP and leg pain (18 women and 14 men with an age range of 46–86 y; mean age, 66 y) with an average preprocedure symptom duration of 5 months. The patient's clinical symptoms correlated with magnetic resonance imaging studies documenting the presence of a synovial cyst at the corresponding level and side of symptoms. Patients had at least 6 months follow-up (range, 6–24).Outcome measuresNumerical Pain Rating Scale, Roland-Morris Disability Questionnaire, North American Spine Society four-point patient satisfaction survey, recurrence of synovial cyst requiring repeat rupture, and need for surgical intervention.MethodsPatients with symptomatic lumbar Z-joint synovial cyst were identified and their charts were reviewed. Patients included in the study either had symptomatic lumbar LBP or LBP with associated lower extremity radiculopathy. All patients in the study had magnetic resonance imaging's documenting Z-joint synovial cyst that corresponded with the patients' clinical symptoms. All patients received fluoroscopically guided, contrast-enhanced, percutaneous facet cyst distention and rupture followed by an intra-articular facet joint injection of 1 cc kenalog and 1 cc of 1% lidocaine. Seventeen of the patients also received a transforaminal epidural steroid injection just before facet cyst rupture. Telephone follow-up was conducted on all patients.ResultsExcellent long-term (average follow-up 1 y; range, 6–24 mo) pain relief was achieved in 23 (72%) of 32 patients undergoing facet cyst rupture. Twelve patients (37.5%) had synovial cyst recurrence and 11 chose to undergo repeat rupture, which resulted in 5 patients (45%) obtaining complete relief of symptoms and 6 patients (55%) requiring surgical intervention for cyst removal. Fisher exact test demonstrated that all patients who did not have a cyst recurrence were a success and obtained complete relief of symptoms (p<.0002). Patients who underwent a repeat rupture had a 50% chance of a successful outcome. There was no statistical significance between a successful outcome and level of facet cyst rupture, the presence of spondylolisthesis, sex, age, or having a transforaminal epidural steroid injection at the time of the procedure. Wilcoxon signed-rank test demonstrated that the difference in Numerical Pain Rating Scale and Roland-Morris Disability Questionnaire scores before and after the procedure was statistically significant (p<.0001). No complications were reported.ConclusionsFluoroscopic percutaneous Z-joint cyst rupture appears to be a safe and effective minimally invasive treatment option. This procedure should be considered before surgical intervention. 相似文献