全文获取类型
收费全文 | 188279篇 |
免费 | 1625篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 1308篇 |
儿科学 | 6890篇 |
妇产科学 | 3173篇 |
基础医学 | 18526篇 |
口腔科学 | 1877篇 |
临床医学 | 13533篇 |
内科学 | 33212篇 |
皮肤病学 | 1179篇 |
神经病学 | 17454篇 |
特种医学 | 9468篇 |
外科学 | 30607篇 |
综合类 | 2360篇 |
一般理论 | 2篇 |
预防医学 | 18628篇 |
眼科学 | 3078篇 |
药学 | 10588篇 |
中国医学 | 810篇 |
肿瘤学 | 17330篇 |
出版年
2023年 | 101篇 |
2022年 | 319篇 |
2021年 | 513篇 |
2020年 | 281篇 |
2019年 | 370篇 |
2018年 | 22270篇 |
2017年 | 17629篇 |
2016年 | 19908篇 |
2015年 | 1515篇 |
2014年 | 1509篇 |
2013年 | 1535篇 |
2012年 | 8152篇 |
2011年 | 22041篇 |
2010年 | 19430篇 |
2009年 | 12048篇 |
2008年 | 20190篇 |
2007年 | 22420篇 |
2006年 | 1188篇 |
2005年 | 2745篇 |
2004年 | 3837篇 |
2003年 | 4702篇 |
2002年 | 2825篇 |
2001年 | 561篇 |
2000年 | 688篇 |
1999年 | 368篇 |
1998年 | 262篇 |
1997年 | 256篇 |
1996年 | 122篇 |
1995年 | 150篇 |
1994年 | 120篇 |
1993年 | 76篇 |
1992年 | 118篇 |
1991年 | 150篇 |
1990年 | 203篇 |
1989年 | 142篇 |
1988年 | 114篇 |
1987年 | 85篇 |
1986年 | 71篇 |
1985年 | 73篇 |
1984年 | 48篇 |
1983年 | 53篇 |
1982年 | 39篇 |
1980年 | 58篇 |
1979年 | 39篇 |
1978年 | 52篇 |
1975年 | 35篇 |
1974年 | 46篇 |
1938年 | 60篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Jie Shang Jeanette C. Reece Daniel D. Buchanan Graham G. Giles Jane C. Figueiredo Graham Casey Steven Gallinger Stephen N. Thibodeau Noralane M. Lindor Polly A. Newcomb John D. Potter John A. Baron John L. Hopper Mark A. Jenkins Aung Ko Win 《International journal of colorectal disease》2016,31(8):1451-1457
Purpose
Gallbladder diseases and cholecystectomy may play a role in the development of colorectal cancer (CRC). Our aim was to investigate the association between cholecystectomy and CRC risk overall and by sex, family history, anatomical location, and tumor mismatch repair (MMR) status.Methods
This study comprised 5847 incident CRC cases recruited from population cancer registries in Australia, Canada, and the USA into the Colon Cancer Family Registry between 1997 and 2012 and 4970 controls with no personal history of CRC who were either randomly selected from the general population or were spouses of the cases. The association between cholecystectomy and CRC was estimated using logistic regression, after adjusting for confounding factors.Results
Overall, there was no evidence for an association between cholecystectomy and CRC (odds ratio [OR] = 0.88, 95 % confidence interval 0.73, 1.08). In the stratified analyses, there was no evidence for a difference in the association between women and men (P = 0.54), between individuals with and without family history of CRC in first-degree relative (P = 0.64), between tumor anatomical locations (P = 0.45), or between MMR-proficient and MMR-deficient cases (P = 0.54).Conclusion
Cholecystectomy is not a substantial risk factor for CRC, regardless of sex, family history, anatomical location, or tumor MMR status.992.
Shyam S. Sharma Bir Singh Mukesh Jain Sudhir Maharshi Sandeep Nijhawan Bharat Sapra Ashok Jhajharia 《Indian journal of gastroenterology》2016,35(1):40-47
Aim
To determine long-term outcome of endoscopic management of pancreatic pseudocyst/walled-off pancreatic necrosis (WOPN) without necrosectomy.Methods
One-hundred and sixty-five pancreatic pseudocysts/WOPN managed endoscopically over a period of 22 years were analyzed retrospectively for technical success, complications, and recurrence.Results
Symptomatic 118 males and 47 females with mean age of 35.8 years were included. Alcohol was the most common etiology (41.2 %). Transmural endoscopic drainage was done in 144 patients, while 21 patients underwent transpapillary drainage. All the patients were subjected to contrast computed tomography (CT) abdomen or routine/Doppler ultrasound. Endoscopic ultrasound was done in last 11 patients. One or two double pigtail 7 Fr stents were placed when clear watery fluid came out from cyst (130 patients, 78.8 %), and nasocystic drainage (NCD) tubes were placed in addition to two 7 Fr stents when there were frank pus, thick dark fluid, or solid components inside the cyst (35 patients). All these patients settled on this treatment. Thirty-three of 35 patients of WOPN could be managed endoscopically without necrosectomy. Complications occurred in 9.2 % of pseudocysts and 40 % of WOPN. Thirty-five patients were followed up for more than 5 years (3 patients more than 10 years), and 130 patients were followed up for up to 5 years. Recurrence occurred in 8.1 % of pseudocysts and 5.7 % of WOPN.Conclusion
Majority of pancreatic pseudocysts/WOPN can be managed with endoscopic drainage without necrosectomy with high success, low complication, and recurrence rates.993.
Danjo K Sakamoto J Iwane S Tamura K Nakaji S Fukuda S Murakami H Shimoyama T Takahashi I Umeda T 《Digestive diseases and sciences》2008,53(3):712-718
We investigated the effects of cellulose supplementation on fecal consistency and fecal weight. About 26 women were classified into two groups-normal defecation and constipation groups. All subjects ate the following meals during the experiment: ordinary meals (first week), experimental meals (second week), and experimental meals mixed with 4 g (third week) and 8 g (fourth week) cellulose. The experimental meal contained 16.7 g fiber. Fecal weights, fecal water content, fecal consistency, and defecation frequency were measured during the experimental period. As a result, in the normal defecation group, the mean fecal weight was 222.9 g day(-1) in the first week, and thereafter decreased. Although 20/24 g of fiber intake in the third/fourth week increased the fecal weight to over 150 g, the fecal consistency was still lower than the optimal consistency of around 300 g cm(-2). However, these changes were not observed in the constipated group. 相似文献
994.
Unsafe Drug Use and Arrhythmic Events in Brugada Patients with ICD: Results of a Long-Term Follow-Up
Diogo de Almeida Fernandes Natália António Marta Madeira Pedro Sousa Miguel Ventura João Cristóvão José Nascimento Luís Elvas Lino Gonçalves Guilherme Mariano Pego 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》2018,32(1):23-28
Purpose
Brugada syndrome is a hereditary disease linked with an increased risk of sudden death that may require an implantable cardioverter-defibrillator (ICD) in order to halt the arrhythmic events. The aim of this study was to identify possible triggers for appropriate ICD therapies in patients with Brugada syndrome, focusing on their past and current therapeutic profiles.Methods
Thirty patients with high-risk Brugada syndrome, with ICD implanted at the Coimbra Hospital and University Center, were enrolled. Patients were questioned about their Brugada syndrome history, previous cardiac events, comorbidities, present and past medications, and physical activity. Patients were followed up during 5.8?±?5.3 years. The ICD was interrogated, and arrhythmic events and device therapies were recorded. The cohort who received appropriate ICD therapies was compared with the remaining patients to determine the potential link between clinical variables and potentially fatal arrhythmic events.Results
More than half of the patients (53.3%) took at least one non-recommended drug, and 16.7% received appropriate ICD therapies, with a long-term rate of 4.0%/year. There was a tendency for more appropriate ICD therapies in patients who took unsafe drugs (85.7 versus 45.5%, p?=?0.062), and the mean time between unsafe drug intake and appropriate ICD therapies was 3.8?±?7.5 days.Conclusions
This study revealed that the medical community is still unaware of the pharmacological restrictions imposed by Brugada syndrome. Patients who took non-recommended drugs seem to have a higher risk of ventricular arrhythmic events.995.
Background
The worldwide spread of multidrug-resistant Gram-negative bacteria (MDR-GN) continues. Treatment options for infections caused by MDR-GN remain scarce and only few new substances are currently in clinical phase II/III studies or have already been granted market approval.Objectives
To provide an overview about current data on new β?lactam antibiotics and β?lactamase inhibitor combinations, respectively. New macrolides, ketolides and aminoglycosides are not addressed.Materials and methods
Selective literature research regarding published data on ceftazidim/avibactam, ceftolozan/tazobactam, imipenem/cilastatin?+?relebactam, meropenem/vaborbactam, aztreonam/avibactam and cefiderocol, as well as registered trials.Results
The development of new antimicrobials for the treatment of MDR-GN infections offers new options for attending physicians. β?Lactamase producers are inhibited by these new substances, though with varying efficacy; however, there are still no adequate treatment options for metallo-β-lactamase (MBL) producers.Conclusions
Clinical data are still indifferent and come from heterogeneous patient collectives. Direct comparisons with established treatment strategies, such as the “last-resort use” of polymyxins are hardly possible. Cases of early development of resistance have already been described. Finally, the importance of toxicity and optimal dosing—in organ failure or organ replacement procedures such as dialysis—remain unclear.996.
Derek Leong Ali A. Sovari Ashkan Ehdaie Tarun Chakravarty Qiang Liu Hasan Jilaihawi Rajendra Makkar Xunzhang Wang Eugenio Cingolani Michael Shehata 《Journal of interventional cardiac electrophysiology》2018,52(1):111-116
Background
Damage to the cardiac conduction system requiring permanent pacemaker (PPM) implantation is a known adverse outcome of transcatheter aortic valve replacement (TAVR). A permanent-temporary pacemaker (PTPM) is a device that involves an active-fixation lead attached to an external pulse generator taped to the skin. We reviewed the utility of PTPMs as a temporary bridge measure after TAVR in patients with conduction abnormalities that do not meet conventional criteria for PPM placement.Methods
Between January 01, 2013 and December 31, 2015, we analyzed 67 patients who received PTPM after TAVR. Baseline demographics, comorbidities, type and size of the valve, pre-TAVR electrocardiograms (ECGs), post-TAVR ECGs at 1 day, 1 month, and 6 months, and pacemaker interrogation results were reviewed for each patient if available.Results
The mean age of patients was 80.5?±?9.1 years. PTPM were placed for 2.3?±?2.4 days. Among these patients, 44.8% (n?=?30) received a PPM prior to discharge. Male gender (OR 2.84, 95% CI 1.05–7.69, p?=?0.05) and an increase in QRS duration post-TAVR (p?=?0.01) were associated with PPM placement. Pacemaker interrogation data of 11 patients with PPM revealed that 27% (n?=?3) had <?1% V-pacing requirements and <?10% A-pacing requirements.Conclusions
In post-TAVR patients who develop conduction abnormalities that do not meet conventional PPM implantation indications, PTPM safely provides a time period for further assessment and may prevent unnecessary PPM implantation. Male gender and an increase in QRS duration post-TAVR are associated with PPM implantation. Additionally, some patients may recover from their conduction disturbances and demonstrate low pacemaker utilization.997.
Sheri K. Palejwala Andrew R. Conger Amy A. Eisenberg Pejman Cohan Chester F. Griffiths Garni Barkhoudarian Daniel F. Kelly 《Pituitary》2018,21(6):584-592
Purpose
In most clinical series of Cushing’s disease (CD), over 80% of patients are women, many of whom are of reproductive age. The year following pregnancy may be a common time to develop CD. We sought to establish the incidence of CD onset associated with pregnancy.Methods
A retrospective review was conducted for patients with biochemically-proven CD. Demographics, clinical history, biochemistry, imaging, pathology, and outcomes were reviewed. Pregnancy-associated CD was defined as symptom onset within 1 year of childbirth.Results
Over 10 years, 77 patients including 64 women (84%), with CD underwent endonasal surgery. Of the 64 women, 64% were of reproductive age (15–45 years) at the time of diagnosis, and 11 (27%) met criteria for pregnancy-associated CD. Of these 11 women, median number of pregnancies prior to onset of CD was 2 (range 1–4) compared to zero (range 0–7) for 30 other women with CD onset during reproductive age (p?=?0.0024). With an average follow-up of 47?±?34 months, sustained surgical remission rates for woman with pregnancy-associated CD, other women of reproductive age, and women not of reproductive age were 91%, 80% and 83%, respectively. The average lag-time from symptom onset to diagnosis for women with pregnancy-associated CD was 4?±?2 years.Conclusions
In this exploratory study, over one quarter of women of reproductive age with CD appeared to have symptomatic disease onset within 1 year of childbirth. This relatively high rate of pregnancy-associated CD suggests a possible causal relationship related to the stress of pregnancy and pituitary corticotroph hyperactivity in the peripartum period. This possible association suggests a heightened degree of clinical suspicion and biochemical testing for CD may be warranted after childbirth. Further study of this possible link between pregnancy and CD is warranted.998.
Introduction
REM sleep deprivation (SD) decreases tolerance of the rat heart to ischemia-reperfusion (IR) injury; the underlying mechanisms, however, are unknown. This study aimed at determining whether changes in iNOS, Bax, and Bcl-2 gene expression are involved in this detrimental effect.Method
SD was induced by flowerpot technique for a period of 4 days. This method is simple and able to induce sleep fragmentation which occurs as one of the sleep disorder symptoms in clinical conditions. The hearts of control and SD rats were perfused in Langendorff apparatus and subjected to 30 min ischemia, followed by 90 min reperfusion. The hemodynamic parameters (left ventricular developed pressure (LVDP), and ± dp/dt), NOx (nitrite + nitrate) level, infarct size, and mRNA expression of iNOS, Bax, and Bcl-2 were measured after IR.Results
SD rats had lower recovery of post-ischemic LVDP (32.8 ± 2.5 vs. 51.5 ± 2.1 mmHg; P < 0.05), + dp/dt (1555 ± 66 vs. 1119.5 ± 87 mmHg/s; P < 0.05) and ? dp/dt (1437 ± 65 vs. 888 ± 162 mmHg/s; P < 0.05). SD rats also had higher NOx levels (41.4 ± 3.1 vs. 22.4 ± 3.6 μmol/L; P < 0.05) and infarct size (64.3 ± 2.3 vs. 38.3 ± 1.6%; P < 0.05) after IR, which along with LVDP, ± dp/dt restored to near normal status in the presence of aminoguanidine, a selective iNOS inhibitor. Following IR, expression of iNOS and Bax increased and Bcl-2 decreased (502, 372, and 54%, respectively) in SD rats; whereas in the presence of aminoguanidine, expression of iNOS and Bax significantly decreased and Bcl-2 increased (165, 168, and 19%, respectively).Conclusion
Higher expression of iNOS and subsequent increase in apoptosis in the hearts after IR may contribute to less tolerance to myocardial IR injury in SD rats.999.
Purpose of Review
Chronic inflammation, adipokines, and hepatokines have been identified as basis of insulin resistance and β cell failure in animal models. We present our current knowledge concerning the potential relationship between these cytokines, inflammation, metabolic syndrome (MetS), and type 2 diabetes mellitus (T2DM) in the pediatric population.Recent Findings
Pro-inflammatory cytokines related to insulin resistance and MetS in children are tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1β, interferon gamma, pigment epithelium-derived factor, chemerin, vaspin, and fetuin A. Anti-inflammatory cytokines associated with insulin resistance and MetS in children are leptin, adiponectin, omentin, fibroblast growth factor (FGF)-21, osteocalcin, and irisin. These anti-inflammatory cytokines are decreased (adiponectin, omentin, and osteocalcin) or increased (leptin, FGF-21, and irisin) in obesity suggesting a resistance state. TNF-α, fetuin A, and FGF-21 are altered in obese children with T2DM suggesting an involvement in β cell failure.Summary
These cytokines, adipokines, and hepatokines may be able to predict development of MetS and T2DM and have a potential therapeutic target ameliorating insulin resistance.1000.