首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   188734篇
  免费   1644篇
  国内免费   60篇
耳鼻咽喉   1406篇
儿科学   6994篇
妇产科学   3453篇
基础医学   18338篇
口腔科学   2622篇
临床医学   13106篇
内科学   33726篇
皮肤病学   1169篇
神经病学   17591篇
特种医学   9274篇
外科学   30872篇
综合类   2359篇
一般理论   3篇
预防医学   18902篇
眼科学   2909篇
药学   10133篇
中国医学   700篇
肿瘤学   16881篇
  2023年   114篇
  2022年   319篇
  2021年   525篇
  2020年   357篇
  2019年   438篇
  2018年   22350篇
  2017年   17653篇
  2016年   19804篇
  2015年   1347篇
  2014年   1421篇
  2013年   1465篇
  2012年   8009篇
  2011年   22094篇
  2010年   19453篇
  2009年   12069篇
  2008年   20411篇
  2007年   22572篇
  2006年   1435篇
  2005年   3036篇
  2004年   4019篇
  2003年   4903篇
  2002年   2992篇
  2001年   326篇
  2000年   456篇
  1999年   240篇
  1998年   290篇
  1997年   306篇
  1996年   164篇
  1995年   178篇
  1994年   150篇
  1993年   116篇
  1992年   69篇
  1991年   121篇
  1990年   151篇
  1989年   97篇
  1988年   80篇
  1987年   60篇
  1986年   43篇
  1985年   44篇
  1984年   41篇
  1983年   42篇
  1982年   44篇
  1980年   53篇
  1974年   32篇
  1969年   23篇
  1938年   61篇
  1937年   25篇
  1934年   30篇
  1932年   56篇
  1930年   48篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.

Introduction

Cervicovaginal decubitus ulceration is a well-known complication of advanced pelvic organ prolapse (POP). There is no consensus for its management. This case series describes the outcome of using repeated vaginal packs soaked with oestrogen cream to reduce POP and promote decubitus ulcer healing. We aimed to investigate the speed of ulcer healing and endometrial safety with this regimen.

Methods

This was a retrospective study of patients with stage 3 or 4 POP and intact uterus with decubitus ulcer who were planned for surgery that included hysterectomy after ulcer healing. Vaginal packs are replaced at least biweekly—or more frequently if extruded—until ulcer resolution.

Results

Thirteen patients were studied. Mean age was 69?±?6 years and mean duration of menopause was 19?±?6 years. Nine patients had a single ulcer and four had multiple ulcers. Mean ulcer diameter was 2.8?±?1.5 cm and mean duration for ulcer healing was 26?±?14 days. Hysterectomy and pelvic floor reconstruction was performed a median of 5 (range 0–153) days after ulcer healing was first noted. Histopathological examination of the endometrium following hysterectomy showed three specimens with endocervical hyperplasia; one had concurrent proliferative endometrium, two had simple endometrial hyperplasia and another two had proliferative endometrium.

Conclusion

Oestrogen-soaked vaginal packing is a viable option for managing a decubitus ulcer in advanced POP. We document a measurable impact on the endometrium with this short-term preoperative regimen. Further research is needed to evaluate its efficacy in promoting ulcer healing and endometrial safety.
  相似文献   
992.

Introduction

There is conflicting evidence on whether mediolateral episiotomy (MLE) reduces the risk of obstetric anal sphincter injuries (OASI) in spontaneous vaginal deliveries (SVD).

Objectives

A systematic review was undertaken to compare rates of OASI amongst women who had undergone mediolateral episiotomy versus those who did not.

Methods

?

Search strategy

Electronic searches were performed in literature databases: CINAHL, Cochrane, EMBASE, Medline and MIDIRS from database inception to July 2015. Studies were eligible if MLE was compared to spontaneous tears and if OASI was the outcome of interest.Two reviewers independently selected and extracted data on study characteristics, quality and results. We computed events of OASI in those who did and did not have an episiotomy from individual studies and pooled these results in a meta-analysis where possible.

Main results

Of the 2090 citations, 16 were included in the review. All were non-randomised, population based or retrospective cohort studies. There was great variation in quality amongst these studies. Data from 7 studies was used for meta-analysis. On collating data from these studies where the majority of women (636755/651114) were nulliparous, MLE reduced the risk of OASI (RR 0.67 95 % CI 0.49-0.92) in vaginal delivery.

Conclusion

The pooled analysis of a large number of women undergoing vaginal birth, most of who were nulliparous, indicates that MLE has a beneficial effect in prevention of OASI. An accurately given MLE might have a role in reducing OASI and should not be withheld, especially in nulliparous women. Caution is advised as the data is from non-randomised studies.
  相似文献   
993.

Introduction and hypothesis

The purpose of this study was to investigate the success and complication rates of single-incision sling for treating stress urinary incontinence (SUI), with a 3-year follow-up.

Methods

This study comprised 173 female patients with SUI or mixed urinary incontinence (MUI) with dominant SUI who underwent minisling procedure. All patients had positive cough stress test preoperatively; they were followed up for 3 years after surgery (1, 3, 6, 12 months, and yearly).

Results

Total follow-up was 36 months, and mean age 51 years (44–77); 128 (74 %) patients presented SUI and 45 (26 %) MUI. Objective and subjective cure and failure rates were 83.8 % (145 cases), 6.4 % (11 cases), and 9.8 % (17 cases), respectively. There were no differences in cure rates between 1 and 3 years. Mean body mass index was 28.7 (26.1–35.2), and mean operating time 7.9 min. (6.5–11.9). There were no major intraoperative complications. Eleven patients (6.4 %) had de novo urge incontinence that resolved using anticholinergic drugs; no patient had urinary retention. Vaginal mesh extrusion was reported in nine (5.2 %) patients.

Conclusions

The minisling system attained high success rates at 3 years’ follow-up. The procedure was easy to learn and has lower complication rate.
  相似文献   
994.

Introduction and hypothesis

Knowledge of the innervation of pelvic floor and sphincter muscles is of great importance to understanding the pathophysiology of female pelvic floor dysfunctions. This report presents our high-density intravaginal and intrarectal electromyography (EMG) probes and a comprehensive innervation zone (IZ) imaging technique based on high-density EMG readings to characterize the IZ distribution.

Methods

Both intravaginal and intrarectal probes are covered with a high-density surface electromyography electrode grid (8?×?8). Surface EMG signals were acquired in ten healthy women performing maximum voluntary contractions of their pelvic floor. EMG decomposition was performed to separate motor-unit action potentials (MUAPs) and then localize their IZs.

Results

High-density surface EMG signals were successfully acquired over the vaginal and rectal surfaces. The propagation patterns of muscle activity were clearly visualized for multiple muscle groups of the pelvic floor and anal sphincter. During each contraction, up to 218 and 456 repetitions of motor units were detected by the vaginal and rectal probes, respectively. MUAPs were separated with their IZs identified at various orientations and depths.

Conclusions

The proposed probes are capable of providing a comprehensive mapping of IZs of the pelvic floor and sphincter muscles. They can be employed as diagnostic and preventative tools in clinical practices.
  相似文献   
995.

Introduction

We present a video describing the technical considerations for performing a total colpocleisis in the management of symptomatic post-hysterectomy pelvic organ prolapse.

Methods

A 76-year old female presented with pelvic pressure and the presence of a palpable vaginal bulge. She had significant bother and had previously failed use of a pessary. She wasnot sexually active, with no plans for future sexual activity. Her medical history was significant for coronary artery disease with prior myocardial infarction. She had high-grade vaginal vault prolapse, without occult incontinence. After discussing observation, pessaries, restorative and obliterative procedures, she elected to undergo colpocleisis. Following hydrodissection with lidocaine with epinephrine, a quadrant-based dissection was performed to remove the vaginal epithelium circumferentially. Following this, serial purse string sutures were used to reduce the prolapse, with meticulous hemostasis. The vaginal epithelium was then closed transversely. Next, a perineorrhaphy was performed. The midline was plicated and the perineal body reconstructed.

Results

The patient had an uncomplicated postoperative course. At six-week follow-up she had no evidence of recurrent prolapse and was voiding without difficulty.

Conclusions

Colpocleisis can provide excellent anatomic and subjective outcomes. Our goal is to highlight pertinent technical considerations in order to optimize patient outcomes.
  相似文献   
996.

Introduction

In July 2011, the US Food and Drug Administration (FDA) issued a safety communication regarding serious complications associated with surgical mesh for pelvic organ prolapse, prompting increased media and public attention. This study sought to analyze internet search activity and news article volume after this FDA warning and to evaluate the quality of websites providing patient-centered information.

Methods

Google Trends? was utilized to evaluate search engine trends for the term “pelvic organ prolapse” and associated terms between 1 January 2004 and 31 December 2014. Google News? was utilized to quantify the number of news articles annually under the term “pelvic organ prolapse.” The search results for the term “pelvic organ prolapse” were assessed for quality using the Health On the Net Foundation (HON) certification.

Results

There was a significant increase in search activity from 37.42 in 2010 to 57.75 in 2011, at the time of the FDA communication (p?=?0.021). No other annual interval had a statistically significant increase in search activity. The single highest monthly search activity, given the value of 100, was August 2011, immediately following the July 2011 notification, with the next highest value being 98 in July 2011. Linear regression analysis of news articles per year since the FDA communication revealed r2?=?0.88, with a coefficient of 186. Quality assessment demonstrated that 42 % of websites were HON-certified, with .gov sites providing the highest quality information.

Conclusions

Although the 2011 FDA safety communication on surgical mesh was associated with increased public and media attention, the quality of relevant health information on the internet remains of poor quality. Future quality assurance measures may be critical in enabling patients to play active roles in their own healthcare.
  相似文献   
997.

Introduction and hypothesis

This committee opinion paper summarizes available evidence about recurrent pelvic organ prolapse (POP) to provide guidance on management.

Method

A working subcommittee from the International Urogynecological Association (IUGA) Research and Development Committee was formed. The literature regarding recurrent POP was reviewed and summarized by individual members of the subcommittee. Recommendations were graded according to the 2009 Oxford Levels of Evidence. The summary was reviewed by the Committee.

Results

There is no agreed definition for recurrent POP and evidence in relation to its evaluation and management is limited.

Conclusion

The assessment of recurrent POP should entail looking for possible reason(s) for failure, including persistent and/or new risk factors, detection of all pelvic floor defects and checking for complications of previous surgery. The management requires individual evaluation of the risks and benefits of different options and appropriate patient counseling. There is an urgent need for an agreed definition and further research into all aspects of recurrent POP.
  相似文献   
998.

Background

Different dosage protocols may be advocated by different clinicians for the same keloid lesion. The aim of this study was to determine the optimal frequency of injection of triamcinolone for the purpose of reducing the size of keloid, by monitoring volume change in lesions.

Methods

Volume of all lesions was measured, and 40 mg of triamcinolone was injected once. Lesion volume was thereafter monitored weekly for 6 weeks.

Results

Mean pretreatment volume was 6.4 ml. Following triamcinolone injection, mean lesion volume became 5.1, 3.7, 3.6, and 3.6 ml at 1, 2, 3, and 4 weeks postinjection, respectively. The mean lesion volume was 3.7 and 3.9 ml at 5 and 6 weeks postinjection. Mean lesion volume was 1.29 ml lower at 1 week than at pretreatment stage (SD?±?0.8797), 1.35 ml lower in volume at 2 weeks than 1 week (SD?±?1.0386), and 0.138 ml lower in volume at 3 weeks than 2 weeks (SD?±?0.159). Mean lesion volume was 0.0250 ml lower at 4 weeks than at 3 weeks (SD?±?0.3215), 0.1000 ml greater in volume at 5 weeks than 4 weeks (SD?±?0.1713), and 0.2000 ml greater in volume at 3 weeks than 2 weeks (SD?±?0.0418). There is a statistically significant difference between the mean volume at 1 week postinjection and that at pretreatment stage, between 2 and 1 week, and between 3 and 2 weeks (p?≤?0.05). Reduction in volume was found to be most profound and statistically significant within the first 2 weeks postinjection.

Conclusions

This study finds that the optimal frequency of intralesional injection of triamcinolone involves a 2-week injection interval.Level of Evidence: Level IV, therapeutic study
  相似文献   
999.

Background

Multidisciplinary management of orofacial clefts may lead to a successful treatment outcome. However, it is quite usual that lack of long-term treatment planning and collaboration among various specialists and lack of standardized surgical protocols result in poor esthetic and functional treatment outcomes. This article aims to hypothesize some critical determinants of outcome in cleft surgery.

Methods

Throughout a period of 18 years, 900 patients with different clinical types of congenital cleft anomaly were subject to primary repair of cleft lip, nose, and palate by single surgeon using various procedures, including preoperative nasoalveolar molding, two-stage and one-stage repair of complete cleft lip and palate, two-flap and one-flap palatoplasty, open tip rhinoplasty, and postoperative nasal molding.

Results

Clinical results of preoperative nasoalveolar molding and surgical repair of lip, nose, and palate were satisfactory for most patients, parents, and surgeon panel.

Conclusions

Treatment based on the individual patient’s facial assets and deficits must be the controlling factor in designing therapy. The essential key to successful management of clefts is to figure out the three-dimensional dynamics that govern the deformity and to recognize a fourth dimension for time along these dynamics in order to envision how a small difference in the position of a single suture during the first surgery can bring about a giant deformity upon completion of facial growth, hence the crucial role of the first surgery and its related concepts, techniques, and tactics in dictating the final outcome of the case.Level of Evidence: Level IV, therapeutic study.
  相似文献   
1000.

Background

Lip augmentation and changing contour lines have become more popular ways of improving the appearance. However, validated measures of lip fullness for quantification of outcomes are needed; ethnic background and personal goals can optimise outcomes while tailoring lip enhancement treatment to each individual’s anatomy. The aim of this study is to analyse the morphological features of the lip in detail and to clarify the objective parameters in related with the subjective ones regarding the lip augmentation and lip reconstruction.

Methods

Standard photographs of the lips of 200 young Anatolian adults were calculated with linear and angular components. The features of the lower third of the face were analysed with the software program. Linear analyses (heights of the upper lip, the upper vermilion, the lower lip height, the lower vermillion and the chin height) and angular analyses (the upper lip, the lower lip, the apex and Cupid’s bow angles) were measured as reference points. The lip shape was classified into five groups: thin, very thin, medium, full and very full.

Results

The lower third of the face was divided into three segments (Sn–Sto, Sm–Me and Sto–Sm), and the largest portion of the lower face was occupied by the chin and the smallest by the lower lip height in both genders. The upper vermilion height was 8.07?±?1.8 mm in males and 7.08?±?1.5 mm in females. The lower vermilion height was 10.1?±?2.4 mm in males and 9.7?±?1.9 mm in females. The upper lip angle was calculated as 30.3?±?9.6° in males and 24.2?±?6.2°mm in females. The lower lip angle was calculated as 38.3?±?9.7° in males and 36.5?±?6.4° in females. Meanwhile, the angular measurements of Cupid’s bow (i.e., the apex and the central angle of Cupid’s bow) were smaller in men than in women. When the lip was analyzed, the medium and full types in upper and lower lips accounted for substantial fractions in men, whereas medium and thin types were predominant also in women.

Conclusions

With the help of certain software, this research has made possible to define the best cosmetical redesign solution of lip construction and augmentation with a natural appearance for the patient.Level of Evidence: Level III, diagnostic study.
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号