Children with urea cycle disorders present with hyperammonaemiaand its non-specific symptoms. Acute hyperammonaemia is a medicalemergency as the developmental and neurological outcome dependson the duration of hyperammonaemic coma [1]. The longer endogenousprotein catabolism continues, the more ammonia will be producedand accumulate and the greater is the risk of coma. To minimizepermanent brain damage, early diagnosis and appropriate therapyis mandatory. With diagnosis of hyperammonaemia, it is essentialto differentiate between urea cycle defects and other causesof encephalopathy. In Figure 1 a practicable flowchart for establishingthe correct diagnosis is depicted [2]. The emergency therapyin children with inborn metabolic disorders presenting  相似文献   
110.
Palliation of malignant rectal obstruction with self-expanding metal stents   总被引:4,自引:0,他引:4  
Hünerbein M  Krause M  Moesta KT  Rau B  Schlag PM 《Surgery》2005,137(1):42-47
BACKGROUND: Surgical management of patients with metastatic or recurrent rectal cancer remains controversial. Self-expanding metal stents are increasingly used for palliative treatment of advanced tumors, although long-term results are not yet available. METHODS: Between 1996 and 2003, 521 patients underwent surgery for rectal neoplasms. In the same time period, self-expanding metal stents were used for palliation of 34 patients with malignant rectal obstruction and incurable disease. The outcome of the patients was analyzed retrospectively. RESULTS: Rectal stents were successfully placed in 33 of 34 patients (97%) without major complications. Early failure occurred in 7 patients (21%) because of stent migration, pain, or incontinence. Long-term success with a mean patency of 5.3 months was observed in 26 patients (79%), but restenting was required in 2 patients. Despite the initial success of stenting, a colostomy was created in 2 other patients after 3.4 months and 9.2 months because of incontinence and rectovesical fistula. Overall, 6 of 33 patients (18%) underwent palliative surgery because of early complications (n = 4) or long-term failure of stent treatment (n = 2). CONCLUSIONS: Self-expanding metal stents are useful to avoid a colostomy in selected patients with incurable rectal cancer and limited life expectancy. Nonetheless, a considerable number (18%) of patients will require surgical palliation because of failure of stent treatment.  相似文献   
[首页] « 上一页 [6] [7] [8] [9] [10] 11 [12] [13] [14] [15] [16] 下一页 » 末  页»
  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   19371篇
  免费   1146篇
  国内免费   92篇
耳鼻咽喉   173篇
儿科学   268篇
妇产科学   209篇
基础医学   2660篇
口腔科学   655篇
临床医学   1817篇
内科学   4064篇
皮肤病学   520篇
神经病学   2025篇
特种医学   1283篇
外科学   3156篇
综合类   92篇
一般理论   6篇
预防医学   945篇
眼科学   385篇
药学   1015篇
中国医学   51篇
肿瘤学   1285篇
  2024年   15篇
  2023年   140篇
  2022年   288篇
  2021年   542篇
  2020年   361篇
  2019年   429篇
  2018年   546篇
  2017年   444篇
  2016年   592篇
  2015年   671篇
  2014年   817篇
  2013年   1040篇
  2012年   1610篇
  2011年   1520篇
  2010年   949篇
  2009年   815篇
  2008年   1345篇
  2007年   1431篇
  2006年   1328篇
  2005年   1238篇
  2004年   1115篇
  2003年   1009篇
  2002年   900篇
  2001年   192篇
  2000年   133篇
  1999年   181篇
  1998年   159篇
  1997年   142篇
  1996年   84篇
  1995年   54篇
  1994年   42篇
  1993年   47篇
  1992年   59篇
  1991年   36篇
  1990年   30篇
  1989年   27篇
  1988年   38篇
  1987年   19篇
  1986年   13篇
  1985年   9篇
  1984年   14篇
  1983年   9篇
  1982年   15篇
  1980年   11篇
  1977年   9篇
  1974年   10篇
  1973年   13篇
  1970年   8篇
  1969年   8篇
  1932年   7篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
101.

Background

The National Surgical Quality Improvement Program (NSQIP) is a risk-adjusted database designed to benchmark quality initiatives. NSQIP captures uniform morbidity variables for all operations and calculates expected morbidity probabilities. Given the frequent need for reoperation following breast-conserving surgery (BCS) and mastectomy, we hypothesized that NSQIP may inaccurately reflect surgical morbidity after breast cancer operations.

Methods

Using the 2008 NSQIP database, we identified 24,447 breast surgery patients. We calculated the observed versus expected (O/E) morbidity ratios, compared them to other general surgery procedures, and analyzed the O/E morbidity ratios among benign and malignant breast diagnoses.

Results

The NSQIP database shows that breast surgery has an O/E morbidity ratio of 3.11, which is higher than other general surgery procedures. Additionally, breast operations for malignancy have higher O/E morbidity ratios (3.22) than those performed for benign disease (2.59). Analysis of malignant patients by CPT code revealed that BCS patients had an O/E morbidity ratio of 7.75 and attributed 89?% of morbidity to reoperation, whereas mastectomy patients had an O/E morbidity ratio of only 1.7. Elimination of the reoperation variable from morbidity calculations in breast surgery reduces the O/E morbidity ratio to less than expected in all breast procedures.

Discussion

Breast surgery has a higher O/E morbidity ratio than other general surgery procedures. Reoperations are expected in BCS for positive margins and in mastectomy for completion ALND. Breast surgeons should advocate for benchmarking by surgical site-specific metrics, because current NSQIP criteria may negatively affect the quality assessment of high-volume breast centers.  相似文献   
102.

Purpose

Dysregulation of neurotransmitter receptors may contribute to bladder overactivity (OAB) symptoms. To address the question whether specific receptor expression patterns are associated with bladder pain syndrome/interstitial cystitis (BPS/IC), we examined the expression of muscarinic, purinergic and histamine receptors in the detrusor.

Methods

Detrusor receptor expression was investigated in bladder biopsies of female BPS/IC patients (n?=?44; age 60.64?±?13.78, mean?±?SD) and carcinoma patients (n?=?11; age 58.91?±?12.72) undergoing cystectomy. Protein expression of muscarinic (M2, M3), purinergic (P2X1–3) and histamine receptors (H1, H2) was analysed by confocal immunofluorescence, and gene expression was quantified by real-time polymerase chain reaction (qPCR).

Results

M2, P2X1, P2X2 and H1 receptor immunoreactivity (-IR) was significantly enhanced in BPS/IC compared to the control group, while there was no difference for M3-, P2X3- and H2-IR. We calculated a score, which separated BPS/IC from control patients with an AUC of 89.46%, showing 84.09% sensitivity and 90.91% specificity. Patients had a 9.25 times enhanced calculated risk for BPS/IC. In addition, two patient subgroups (M2?>?M3 and M3?>?M2) were observed, which differed in associated purinergic and histamine receptor expression.

Conclusions

M2, P2X1, P2X2 and H1 were significantly upregulated in BPS/IC patients, and H2 was occasionally highly overexpressed. There was no significant correlation between receptor protein and gene expression, implying posttranslational mechanisms being responsible for the altered receptor expressions. On the basis of individual receptor profiles, upregulated receptors could be targeted by monotherapy or combination therapy with already approved receptor inhibitors, thereby promoting tailored therapy for patients suffering from BPS/IC-like symptoms.  相似文献   
103.

Purpose

The increasing detection of adrenal tumors and the availability of a more sophisticated biochemical work-up leading to rising numbers of sub-clinical Conn’s and Cushing’s syndromes coincide with a rising number of adrenalectomies worldwide. The aim of our study was to report a single institution’s experience with adrenal surgery.

Methods

We report data of 528 adrenalectomies, operated at our institution before and after the onset of minimally invasive endoscopic surgery (1986–1994, 1995–2008). Gender, age, indication, imaging, surgical approach, operating time, histology, tumor size, hospital stay, and complications were analyzed retrospectively.

Results

A total of 478 patients underwent adrenal surgery during the time observed. The average number of yearly adrenalectomies increased from 14 to 21 (p?=?0.001) after the onset of laparoscopic surgery. Imaging techniques showed a significant shift towards magnetic resonance imaging (p?<?0.001) and preoperative assessment of tumor size was significantly correlated to malignancy: 10.8?% (11/102) and 42?% (21/50) of tumors measuring 4–6?cm and ≥6 cm, respectively, were malignant in the final histology report (p?<?0.001). Patients operated by minimally invasive endoscopy were significantly younger (mean 49.4?years, p?=?0.046), had significantly shorter operating times (mean 118?min, p?<?0.001), had shorter hospital stays (mean 7.1?days, p?<?0.001), and had less complications (6.9?%, p?=?0.004) compared to patients resected through open procedures.

Conclusion

Although adrenalectomy rates increased and minimally invasive endoscopic surgery reduced hospital stay and complications at our institution, the yearly number of procedures was still low with often high surgical complexity. We therefore believe that adrenal surgery remains a highly specialized procedure that should preferably be performed at endocrine surgery centers.  相似文献   
104.
Oelke M 《BJU international》2012,109(7):1044-1049
Study Type – Diagnostic (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? The diagnostic potential of ultrasound derived measurements of bladder wall thickness and bladder weight in men with LUTS and varying degrees of BOO have been explored. However, there is a paucity of such measurements in the asymptomatic population with which to compare such patients. This study investigates these measurements in community‐dwelling men with presumably normal bladder function.

OBJECTIVE

  • ? To identify measurements of ultrasonography (US)‐derived bladder wall thickness (BWT) and bladder weight in community‐dwelling men with presumably normal bladder function.

SUBJECTS AND METHODS

  • ? A total of 100 male volunteers underwent transabdominal US measurements of BWT and bladder weight, using the BVM 9500 bladder scanner (Verathon Medical, Bothell, WA, USA), at a variety of bladder filling volumes.
  • ? The data were explored for any correlation between measurements of BWT and US‐estimated bladder weight (UEBW) with subject age, height, weight, body mass index (BMI), International Consultation on Incontinence Questionnaire – Male Lower Urinary Tract Symptoms (ICIQ M‐LUTS) score, International Prostate Symptom Score (IPSS) and IPSS Quality of Life index (IPSS QoL).

RESULTS

  • ? Several statistically significant but weak correlations were observed: BWT and weight (r= 0.216, P= 0.032); BWT and BMI (r= 0.246, P= 0.014); UEBW and weight (r= 0.304, P= 0.002); and UEBW and BMI (r= 0.260, P= 0.009).
  • ? Bladder filling volume appeared to have a greater effect on BWT than on UEBW, although this could not be determined accurately.
  • ? There was a substantial difference in measurements of BWT and UEBW in the assessment of inter‐ and intra‐observer reliability testing.

CONCLUSION

  • ? Further studies are required to validate automated measurements of BWT and UEBW and to investigate such measurements in the symptomatic and asymptomatic male population.
  相似文献   
105.

Background

Tadalafil improved lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH; LUTS/BPH) in clinical studies but has not been evaluated together with an active control in an international clinical study.

Objective

Assess tadalafil or tamsulosin versus placebo for LUTS/BPH.

Design, setting, and participants

A randomised, double-blind, international, placebo-controlled, parallel-group study assessed men ≥45 yr of age with LUTS/BPH, International Prostate Symptom Score (IPSS) ≥13, and maximum urinary flow rate (Qmax) ≥4 to ≤15 ml/s. Following screening and washout, if needed, subjects completed a 4-wk placebo run-in before randomisation to placebo (n = 172), tadalafil 5 mg (n = 171), or tamsulosin 0.4 mg (n = 168) once daily for 12 wk.

Measurements

Outcomes were assessed using analysis of covariance (ANCOVA) or ranked analysis of variance (ANOVA) (continuous variables) and Cochran-Mantel-Haenszel test or Fisher exact test (categorical variables).

Results and limitations

IPSS significantly improved versus placebo through 12 wk with tadalafil (−2.1; p = 0.001; primary efficacy outcome) and tamsulosin (−1.5; p = 0.023) and as early as 1 wk (tadalafil and tamsulosin both −1.5; p < 0.01). BPH Impact Index significantly improved versus placebo at first assessment (week 4) with tadalafil (−0.8; p < 0.001) and tamsulosin (−0.9; p < 0.001) and through 12 wk (tadalafil −0.8, p = 0.003; tamsulosin −0.6, p = 0.026). The IPSS Quality-of-Life Index and the Treatment Satisfaction Scale–BPH improved significantly versus placebo with tadalafil (both p < 0.05) but not with tamsulosin (both p > 0.1). The International Index of Erectile Function–Erectile Function domain improved versus placebo with tadalafil (4.0; p < 0.001) but not tamsulosin (−0.4; p = 0.699). Qmax increased significantly versus placebo with both tadalafil (2.4 ml/s; p = 0.009) and tamsulosin (2.2 ml/s; p = 0.014). Adverse event profiles were consistent with previous reports. This study was limited in not being powered to directly compare tadalafil versus tamsulosin.

Conclusions

Monotherapy with tadalafil or tamsulosin resulted in significant and numerically similar improvements versus placebo in LUTS/BPH and Qmax. However, only tadalafil improved erectile dysfunction.

Trial registration

Clinicaltrials.gov ID NCT00970632  相似文献   
106.
Regulatory CD4+CD25+Foxp3+ T cells (Tregs) play an important role in the induction of allospecific tolerance. However tolerance in solid organ transplantation by mere transfer of Tregs has been difficult. Besides this the stability of the differentiation phenotype of Tregs has recently been questioned. We therefore aimed in generating large numbers of stable allospecific Tregs from naïve T cells by retroviral transduction with Foxp3. These were tested in an immunogenic skin transplantation model (C57BL/6→BALB/c). We established a system of transduction of mouse T cells with ecotropic retroviruses expressing Foxp3 and Thy1.1 as a surface marker to follow up transduced T cells. Alloantigen‐specific Tregs were generated by stimulating naïve recipient CD4+ T cells with irradiated donor splenocytes. CD25+ and/or CD69+ allospecific recipient CD4+ T cells were isolated and transduced with Foxp3. Alloantigen‐specific Foxp3 T cells (iTregs) showed high expression for the Treg markers Foxp3, CTLA4 and GITR. They could suppress a MLR in an alloantigen‐specific manner. Furthermore, they could be expanded up to 18 fold in vitro while maintaining their Treg phenotype and expression of lymph node homing markers like CCR7 and CD62L. iTregs prevented skin graft rejection without the need for chronic immunosuppression and recipients showed systemic allospecific allotolerance. Alloantigen‐specific Tregs were far more potent than polyspecific Tregs. Mechanisms of tolerance were graft specific homing, expansion and long‐term persistence of Tregs within the graft (>100 days, 90% of intragraft Tregs were alloantigen‐specific). In fact, tolerance could be transferred with re‐transplantation of the tolerant graft onto secondary recipients. Third party grafts were readily rejected demonstrating specificity of tolerance. Due to the Foxp3 transduction, iTregs did not lose their Treg phenotype. The results prove that large numbers of stable alloantigen‐specific Tregs can be generated from a polyclonal repertoire of naïve T cells. This is the first time that allotolerance was achieved in a non‐lymphopenic transplant model using skin grafts in an immunogenic strain combination. Therefore, antigen‐specific Tregs might have a huge therapeutic potential after solid organ transplantation.  相似文献   
107.
We studied interscapular brown adipose tissue (iBAT) activity in wild-type (WT) and glucagon-like peptide 1 receptor (GLP-1R)–deficient mice after the administration of the proglucagon-derived peptides (PGDPs) glucagon-like peptide (GLP-1), glucagon (GCG), and oxyntomodulin (OXM) directly into the brain. Intracerebroventricular injection of PGDPs reduces body weight and increases iBAT thermogenesis. This was independent of changes in feeding and insulin responsiveness but correlated with increased activity of sympathetic fibers innervating brown adipose tissue (BAT). Despite being a GCG receptor agonist, OXM requires GLP-1R activation to induce iBAT thermogenesis. The increase in thermogenesis in WT mice correlates with increased expression of genes upregulated by adrenergic signaling and required for iBAT thermogenesis, including PGC1a and UCP-1. In spite of the increase in iBAT thermogenesis induced by GLP-1R activation in WT mice, Glp1r−/− mice exhibit a normal response to cold exposure, demonstrating that endogenous GLP-1R signaling is not essential for appropriate thermogenic response after cold exposure. Our data suggest that the increase in BAT thermogenesis may be an additional mechanism whereby pharmacological GLP-1R activation controls energy balance.The increasing incidence of type 2 diabetes (T2D) and obesity worldwide has prompted the need for new therapies. Agonism of the receptor for glucagon-like peptide-1 (GLP-1) is currently one of the most successfully and widely used therapies for T2D. GLP-1 is a product of proglucagon that also gives rise to glucagon (GCG) and oxyntomodulin (OXM) (1). Both GLP-1 and its receptor (GLP-1R) are expressed in peripheral tissues and in areas of the central nervous system (CNS) involved in the control of energy balance. Treatment with GLP-1R agonists improves glycemic control and reduces body weight in diabetic humans (2). Studies in animals have demonstrated that CNS–GLP-1R signaling contributes to the body weight–reducing effect of these agonists (3).GCG is produced in the α cells of the pancreatic islets and is involved in the maintenance of euglycemia. Although its exogenous administration induces body weight loss associated with anorexia and increased energy expenditure (4), GCG has been traditionally dismissed as a potential drug target because of its diabetogenic effects. However, recent preclinical data have shown that simultaneous activation of both GLP-1R and GCG receptor (GCGR) leads to greater efficacy in both glycemic control and weight loss than the activation of GLP-1R alone (5,6).OXM can bind to and activate both GLP-1R and GCGR (7), and studies with rodents (8,9) and humans (10) suggest that it may be efficacious in treating obesity and diabetes. OXM regulates feeding, at least in part, through GLP-1R (7,11). There is evidence that OXM action in the CNS reduces body weight by increasing energy expenditure (12). This may involve activation of brown adipose tissue (BAT) metabolism, since intracerebroventricular (ICV) administration of OXM reduces the weight of interscapular BAT (iBAT) pads and increases body temperature in rats (12). The relative contribution of GLP-1R and GCGR to this process has never been investigated; however, it is known that GCG regulates iBAT activity, and this may be, at least in part, centrally mediated (13). The contribution of GLP-1R to the control of energy expenditure, and more specifically to BAT metabolism, remains largely unknown.The sympathetic nervous system (SNS) is essential for control of BAT metabolism by the CNS (14) and is involved in the CNS–GLP-1R control of lipid metabolism in white adipose tissue (WAT) (15). This, in addition to the evidence that GCG may increase BAT thermogenesis through actions in the CNS (13), led us to hypothesize that the action(s) of GCGR and GLP-1R in the brain controls BAT thermogenesis through the SNS. Here, we show that central administration of both GCGR and GLP-1R agonists increased SNS activity to iBAT and induced thermogenesis. Thus, we propose that CNS–GLP-1R may contribute to the control of energy balance by regulating BAT thermogenesis. The existence of functional BAT in adult humans has now been determined (1618), and effort needs to be directed toward a better understanding of the regulation of this tissue as a target for antiobesity therapeutics. The increase in BAT metabolism described here may contribute to the weight loss induced by GCGR and GLP-1R agonists in both animal models and humans.  相似文献   
108.
To determine changes in health-related quality of life (HRQOL) in patients treated with retropubic radical prostatectomy (RP) between two and seven years after surgery. A questionnaire from the University of California Los Angeles Prostate Index was sent to 142 patients previously treated with retropubic RP as mono-therapy for clinically localized prostate cancer. Patients were divided into five groups according to time from surgery. Demographics, clinical and pathological characteristics of patients were compared between these groups. Correlation coefficients controlled for age at the time of questionnaire between HRQOL scores and time from RP were assessed. A total of 105 patients (74%) returned the questionnaire. The mean time from surgery was 48 months (range 25–84). Demographics, clinical and pathological characteristics of patients were not statistically different between time groups. Several recoding items were found to decrease significantly with the time from RP including physical functioning, role limitations due to physical health problem, vitality, and general health. In contrary, urinary, bowel and sexual scores were not significantly correlated to time from RP. Although sexual, urinary and bowel scores seem to remain stable from 2 to 7 years following RP, general health appears to significantly deteriorate with time after RP, independent of the patient’s age at the time of the questionnaire.  相似文献   
109.
   Introduction
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