全文获取类型
收费全文 | 1601篇 |
免费 | 108篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 60篇 |
妇产科学 | 42篇 |
基础医学 | 186篇 |
口腔科学 | 78篇 |
临床医学 | 147篇 |
内科学 | 386篇 |
皮肤病学 | 30篇 |
神经病学 | 83篇 |
特种医学 | 243篇 |
外科学 | 156篇 |
综合类 | 16篇 |
预防医学 | 90篇 |
眼科学 | 28篇 |
药学 | 76篇 |
中国医学 | 5篇 |
肿瘤学 | 85篇 |
出版年
2023年 | 23篇 |
2022年 | 31篇 |
2021年 | 52篇 |
2020年 | 38篇 |
2019年 | 43篇 |
2018年 | 54篇 |
2017年 | 30篇 |
2016年 | 36篇 |
2015年 | 55篇 |
2014年 | 54篇 |
2013年 | 69篇 |
2012年 | 84篇 |
2011年 | 70篇 |
2010年 | 59篇 |
2009年 | 52篇 |
2008年 | 61篇 |
2007年 | 69篇 |
2006年 | 63篇 |
2005年 | 45篇 |
2004年 | 38篇 |
2003年 | 20篇 |
2002年 | 29篇 |
2001年 | 22篇 |
2000年 | 15篇 |
1999年 | 19篇 |
1998年 | 48篇 |
1997年 | 58篇 |
1996年 | 55篇 |
1995年 | 48篇 |
1994年 | 47篇 |
1993年 | 32篇 |
1992年 | 14篇 |
1991年 | 16篇 |
1990年 | 15篇 |
1989年 | 24篇 |
1988年 | 35篇 |
1987年 | 16篇 |
1986年 | 30篇 |
1985年 | 29篇 |
1984年 | 16篇 |
1983年 | 18篇 |
1982年 | 19篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1978年 | 6篇 |
1977年 | 10篇 |
1976年 | 15篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有1718条查询结果,搜索用时 31 毫秒
1.
Alejandra Gordillo Hernández Eduardo Dominguez-Adame Lanuza Auxiliadora Cano Matias Rosario Perez Huertas Katherine Maria Gallardo Rodriguez Purificacion Gallinato Perez Fernando Oliva Mompean 《World journal of gastrointestinal surgery》2015,7(8):170-173
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence. 相似文献
2.
3.
Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
4.
5.
6.
Herpes simplex virus type 1 infection induces upregulation of interleukin-23 (p19) mRNA expression in trigeminal ganglia of BALB/c mice. 总被引:2,自引:0,他引:2
Eeva K Broberg Niko Set?l? Juha-Pekka Er?linna Aimo A Salmi Matias R?ytt? Veijo Hukkanen 《Journal of interferon & cytokine research》2002,22(6):641-651
We investigated the expression kinetics of several cytokines in trigeminal ganglia (TG) and in brains of BALB/c mice during the course of ocular herpes simplex virus type 1 (HSV-1) infection. All mice recovered from the infection within 2 weeks. The quantitative rapid real-time RT-PCR method was used to analyze interleukin-4 (IL-4), interferon-gamma (IFN-gamma), IL-12p35, IL-12p40, and the recently described IL-23 (p19) mRNA in TG, brain, and splenocyte samples. In TG, we found elevated expression of mRNA for IL-23 (p19) from early acute infection (day 3) to the beginning of the latent phase (day 14). The increase was not detected in brain or in the spleen. IL-4 expression occurred in both TG and brain from the beginning of the experiment to the latent phase. During the latent phase (days 14 and 31), IL-4 expression was significantly elevated in the brain when compared with the uninfected controls (p < 0.05). Considerable expression of IFN-gamma mRNA was detected in TG of mice during acute HSV-1 infection. The expression of IL-23 was detected also in the brains of the mice, even though no significant changes were found during the acute HSV-1 infection. This is, to our knowledge, the first report to show elevated expression of IL-23 (p19) mRNA (p < 0.05) during viral infection in TG of mice. 相似文献
7.
Ralls PW; Johnson MB; Kanel G; Dobalian DM; Colletti PM; Boswell WD Jr; Radin DR; Halls JM 《Radiology》1986,161(2):451-454
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease. 相似文献
8.
Objective . To describe the importance of migraine in Santiago, Chile, by analyzing its prevalence, clinical features and impact by age, gender and socioeconomic status. Methods . In 1993, a representative sample of 1,540 adults of the province of Santiago were interviewed using a standard questionnaire. A total of 1,385 (89.9%) subjects responded to the survey. Initially, a designated member of each household responded to the questionnaire. Subsequently, each household member with headaches was asked to respond to questions about severity, frequency, location, duration, associated symptoms and impact in work and social activities of their most frequent headaches. Migraine diagnoses were determined in accordance with the International Headache Society (IHS) criteria of 1988. Results. Recurrent headaches in the past year were found in 516 (36.82%) respondents, 145 (28.1%) males and 371 (71.9%) females. Total prevalence of migraine was found to be 7.3% (95%, CI 5.9–8.6); 11.9% (95% CI 9.6–14.2) in females and 2.0% (95% CI 0.9–3.0) in males. Overall, migraine constituted 19.6% (101/516) of all headaches reported in this sample. The prevalence did not vary significantly by age groups or socioeconomic status (SES). Migraine with aura had an overall prevalence of 3.5% (CI 0.8–7.1), and was significantly more frequent in females. In 60–70% of cases the attacks lasted 2–6 h and the frequency was 3.3 and 3.4 per month in females and males respectively. Both males and females reported significantly high percentages of attacks during work. Conclusions . Migraine prevalence in a sample of adults of Santiago is similar to that reported in previous studies using IHS criteria. Women of all socioeconomic levels are at an increased risk. 相似文献
9.
10.