全文获取类型
收费全文 | 31366篇 |
免费 | 1948篇 |
国内免费 | 702篇 |
专业分类
耳鼻咽喉 | 162篇 |
儿科学 | 675篇 |
妇产科学 | 1116篇 |
基础医学 | 1280篇 |
口腔科学 | 539篇 |
临床医学 | 10518篇 |
内科学 | 4776篇 |
皮肤病学 | 397篇 |
神经病学 | 1263篇 |
特种医学 | 1711篇 |
外国民族医学 | 3篇 |
外科学 | 2619篇 |
综合类 | 4990篇 |
现状与发展 | 1篇 |
预防医学 | 970篇 |
眼科学 | 620篇 |
药学 | 1296篇 |
12篇 | |
中国医学 | 419篇 |
肿瘤学 | 649篇 |
出版年
2024年 | 131篇 |
2023年 | 482篇 |
2022年 | 707篇 |
2021年 | 878篇 |
2020年 | 927篇 |
2019年 | 917篇 |
2018年 | 749篇 |
2017年 | 750篇 |
2016年 | 776篇 |
2015年 | 807篇 |
2014年 | 1607篇 |
2013年 | 1707篇 |
2012年 | 1529篇 |
2011年 | 1878篇 |
2010年 | 1625篇 |
2009年 | 1555篇 |
2008年 | 1606篇 |
2007年 | 1699篇 |
2006年 | 1759篇 |
2005年 | 1605篇 |
2004年 | 1374篇 |
2003年 | 1166篇 |
2002年 | 1032篇 |
2001年 | 977篇 |
2000年 | 776篇 |
1999年 | 701篇 |
1998年 | 647篇 |
1997年 | 556篇 |
1996年 | 499篇 |
1995年 | 441篇 |
1994年 | 367篇 |
1993年 | 291篇 |
1992年 | 261篇 |
1991年 | 236篇 |
1990年 | 190篇 |
1989年 | 118篇 |
1988年 | 113篇 |
1987年 | 93篇 |
1986年 | 83篇 |
1985年 | 93篇 |
1984年 | 66篇 |
1983年 | 48篇 |
1982年 | 54篇 |
1981年 | 33篇 |
1980年 | 19篇 |
1979年 | 19篇 |
1978年 | 20篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Jakub Pazdrowski Aleksandra Daczak‐Pazdrowska Adriana Polaska Joanna Ka
mierska Wojciech Barczak Mateusz Szewczyk Pawe Golusiski Zygmunt Adamski Ryszard aba Wojciech Golusiski 《Skin research and technology》2019,25(6):857-861
Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy. 相似文献
4.
Aaron Pitzele Mohammad Rahimi Eric Armbrecht 《The journal of maternal-fetal & neonatal medicine》2015,28(15):1770-1773
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion. 相似文献
5.
Improvement in Tricuspid Annular Plane Systolic Excursion with Pulmonary Hypertension Therapy in Pediatric Patients
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
6.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS. 相似文献
7.
Dynamic LVOT Obstruction and Aortic Stenosis in the Same Patient: A Case of Challenging Doppler Hemodynamics
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Matthew W. Parker M.D. Francis J. Kiernan M.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(6):1030-1032
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction. 相似文献
8.
Gian Eugenio Tontini Guido Manfredi Stefania Orlando Helmut Neumann Maurizio Vecchi Elisabetta Buscarini Luca Elli 《Digestive endoscopy》2019,31(6):627-643
Over the last decade, impressive technological advances have occurred in ultrasonography and small‐bowel endoscopy. Nowadays, endoscopic ultrasonography is an essential diagnostic tool and a therapeutic weapon for pancreatobiliary disorders. Capsule endoscopy and device‐assisted enteroscopy have quickly become the reference standard for the diagnosis of small‐bowel luminal diseases, thereby leading to radical changes in diagnostic and therapeutic pathways. We herein provide an up‐to‐date overview of the latest advances in endoscopic ultrasonography and small‐bowel endoscopy, focusing on the emerging paradigms and technological innovations that might improve clinical practice in the near future. 相似文献
9.
目的:探讨彩色多普勒超声诊断卵巢肿瘤蒂扭转的临床意义。方法方便选取2012―2015年该院收治的58例疑似卵巢肿瘤蒂扭转患者作为观察目标,入选病例均应用彩色多普勒超声进行检查,并将检查结果同术后病理检查结果进行比较。结果58例患者中,术后病理证实卵巢肿瘤蒂扭转者51例,彩色多普勒超声共确诊49例,检查准确率为96.1%;囊壁增厚、腹腔或盆腔积液、可见混合型团块是卵巢肿瘤蒂扭转的主要彩超表现。结论卵巢肿瘤蒂扭转应用彩色多普勒超声诊断,可显著提高诊断准确率,具有积极的临床使用和推广价值。 相似文献
10.
Moises Rodriguez-Gonzalez Antonio Moruno Tirado Reza Hosseinpour Jose Santos de Soto 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2015,42(4):350-356
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic. 相似文献