全文获取类型
收费全文 | 2203篇 |
免费 | 234篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 5篇 |
妇产科学 | 18篇 |
基础医学 | 167篇 |
口腔科学 | 389篇 |
临床医学 | 142篇 |
内科学 | 150篇 |
皮肤病学 | 26篇 |
神经病学 | 79篇 |
特种医学 | 82篇 |
外科学 | 335篇 |
综合类 | 256篇 |
预防医学 | 81篇 |
眼科学 | 476篇 |
药学 | 67篇 |
2篇 | |
中国医学 | 51篇 |
肿瘤学 | 115篇 |
出版年
2024年 | 6篇 |
2023年 | 51篇 |
2022年 | 96篇 |
2021年 | 141篇 |
2020年 | 95篇 |
2019年 | 106篇 |
2018年 | 104篇 |
2017年 | 99篇 |
2016年 | 94篇 |
2015年 | 116篇 |
2014年 | 141篇 |
2013年 | 120篇 |
2012年 | 119篇 |
2011年 | 116篇 |
2010年 | 97篇 |
2009年 | 88篇 |
2008年 | 113篇 |
2007年 | 103篇 |
2006年 | 83篇 |
2005年 | 67篇 |
2004年 | 56篇 |
2003年 | 50篇 |
2002年 | 31篇 |
2001年 | 49篇 |
2000年 | 30篇 |
1999年 | 26篇 |
1998年 | 17篇 |
1997年 | 18篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 17篇 |
1993年 | 16篇 |
1992年 | 18篇 |
1991年 | 13篇 |
1990年 | 15篇 |
1989年 | 17篇 |
1988年 | 15篇 |
1987年 | 6篇 |
1986年 | 19篇 |
1985年 | 13篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 4篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有2473条查询结果,搜索用时 78 毫秒
41.
42.
Background We examined the current status and diagnostic accuracy of currently available techniques for tumor staging and assessed treatment
outcomes in patients with superficial esophageal cancer who received esophaguspreserving therapy, such as endoscopic mucosal
resection (EMR) alone or combined with chemoradiotherapy (CRT).
Methods In 274 patients with superficial esophageal cancer, we examined the depth of tumor invasion and the degree of lymph node metastasis
by means of endoscopy, magnifying endoscopy, endoscopic ultrasonography (EUS), computed tomography (CT), and cervical and
abdominal ultrasonography (US). We compared treatment outcomes among treatment groups according to the depth of tumor invasion.
Results The rates of correctly diagnosing the depth of tumor invasion were 89.6% on conventional endoscopy, 90.1% on magnifying endoscopy,
and 85% on scanning with a high-frequency miniature ultrasonic probe (miniature US probe). Diagnostic accuracy for the m3
or sm1 cancers was poor. Magnifying endoscopy allowed invasion to be more precisely estimated, thereby improving diagnostic
accuracy. However, lesions that maintained their surface structure despite deep invasion were misdiagnosed on magnifying endoscopy.
A miniature US probe was useful for the assessment of such lesions. The diagnostic accuracy of EUS for lymph node metastasis
was 83%, with a sensitivity of 76%. The sensitivity of CT was 29%, and that of cervical and abdominal US was 17%. Patients
with m1 or m2 cancer had good outcomes after esophagus-preserving therapy. Although there were no significant differences
in survival rates, many patients with sm2 or sm3 cancer who received CRT died of their disease. Nodal recurrence was diagnosed
by EUS. In patients who received CRT, the time to the detection of recurrence was slightly prolonged.
Conclusions Long-term follow-up at regular intervals is essential in patients with m3 or sm esophageal cancers who receive esophagus-preserving
treatment. At present, EUS is the most reliable technique for the diagnosis of lymph node metastasis and is therefore essential
for pretreatment evaluation as well as for follow-up. Earlier detection of recurrence at a level that would potentially salvage
treatment remains a topic for future research.
Review articles on this topic also appeared in the previous issue (Volume 4 Number 3). An editorial related to this article
is available at . 相似文献
43.
Parisa Akhlaghi Hashem Miri-Hakimabad Laleh Rafat-Motavalli 《Journal of radiation research》2015,56(4):646-655
In order to establish an organ and effective dose database for Iranian children undergoing computed tomography (CT) examinations, in the first step, two Iranian 11-year-old phantoms were constructed from image series obtained from CT and magnetic resonance imaging (MRI). Organ and effective doses for these phantoms were calculated for head, chest, abdomen–pelvis and chest–abdomen–pelvis (CAP) scans at tube voltages of 80, 100 and 120 kVp, and then they were compared with those of the University of Florida (UF) 11-year-old male phantom. Depth distributions of the organs and the mass of the surrounding tissues located in the beam path, which shield the internal organs, were determined for all phantoms. From the results, it was determined that the main organs of the UF phantom receive smaller doses than the two Iranian phantoms, except for the urinary bladder of the Iranian girl phantom. In addition, the relationship between the anatomical differences and the size of the dose delivered was also investigated and the discrepancies between the results were examined and justified. 相似文献
44.
Carol L Shields Janet Manalac Chandana Das Jarin Saktanasate Jerry A Shields 《Indian journal of ophthalmology》2015,63(2):117-121
Background:Spectral domain enhanced depth imaging optical coherence tomography (EDI-OCT) can provide anatomic localization of intraocular tumors.Aims:The aim was to identify topographical and intrinsic patterns of choroidal tumors on EDI-OCT.Results:Using EDI-OCT, choroidal nevus displayed a smooth, dome-shaped topography with overlying retinal pigment epithelium alterations, drusen, and occasional subretinal cleft demonstrating photoreceptor loss. Small choroidal melanoma showed smooth, moderately dome-shaped topography, commonly with overlying shallow subretinal fluid that often depicted “shaggy” photoreceptors. Choroidal metastasis showed a minimally “lumpy, bumpy” surface topography and with overlying subretinal fluid and shaggy photoreceptors. Choroidal hemangioma showed a smooth, dome-shaped topography, with expansion of the affected small, medium, and large choroidal vessels. Choroidal lymphoma showed varying topography with increasing tumor thickness as “flat, rippled, or undulating (seasick)” surface. Choroidal osteoma displayed a smooth undulating surface with visible intralesional horizontal lines suggestive of bone lamellae and occasional horizontal and vertical tubules with intralesional “spongy” flecks. Choroidal melanocytosis appeared as uniformly thickened choroid with increased stromal density surrounding the normal choroidal vascular structures.Conclusions:Enhanced depth imaging-OCT can depict characteristic patterns that are suggestive of various choroidal tumors. 相似文献
45.
Fatih Ula? ümit Dogan O?uz Dikba? Serdal ?elebi Asena Kele? 《Indian journal of ophthalmology》2015,63(3):244-249
Purpose:
The effect of hypothyroidism on the choroidal thickness (CT) was investigated in patients with subclinical hypothyroidism and overt hypothyroidism, and biochemically and clinically euthyroid patients receiving levothyroxine treatment. The patients were compared with healthy subjects.Materials and Methods:
One eye of 71 hypothyroid and 22 healthy subjects between 20 and 40 years of age were included in this study. CT measurements were taken at the fovea and at 2 points that were 1500 μm nasal and temporal to the fovea using spectral-domain optical coherence tomography. Independent sample t-test''s and was used for statistical analysis of the data.Results:
The CT was significantly thicker in hypothyroid patients compared to healthy subjects (P values were 0.013 for subfoveal, 0.015 for temporal and 0.020 for nasal segments). The intraocular pressure (IOP) and body mass index (BMI) were also significantly higher in hypothyroid patients (P values were 0.021 and 0.003, respectively). There was not a statistically significant difference in the BMI and IOP measurements between healthy subjects and euthyroid patients (P > 0.05). However, there was a statistically significant difference in the subfoveal, temporal and nasal CT measurements between healthy subjects and euthyroid patients (P values were 0.006, 0.031 and 0.013, respectively).Conclusions:
All subgroups of hypothyroid patients had thicker CT compared to healthy subjects. Euthyroid patients receiving levothyroxine treatment had lower IOP, BMI levels, and serum lipid levels than patients with subclinical hypothyroidism and overt hypothyroidism. 相似文献46.
Enhanced Depth Imaging of Central Laminar Thickness in Optic Neuropathy: Comparison with Normal Eyes
Suntaree Thitiwichienlert Hitoshi Ishikawa Ken Asakawa Tetsuya Ikeda Kimiya Shimizu 《Neuro-ophthalmology (Aeolus Press)》2015,39(4):166-174
The purpose of this study was to compare central laminar thickness (LT) among patients with glaucomatous optic neuropathy (GON), patients with non-GON, and normal subjects using enhanced-depth imaging optical coherence tomography (EDI-OCT). Enrolled were 57 patients (n = 64 eyes), including 30 women and 27 men. Three groups were identified: GON (n = 18 eyes), non-GON (n = 16 eyes), and control (n = 30 eyes). The GON group comprised eyes with primary open-angle glaucoma (POAG) (n = 9) and normal-tension glaucoma (NTG) (n = 9). The non-GON group comprised eyes with demyelinating optic neuritis (n = 9), anterior ischemic optic neuropathy (AION) (n = 2), compressive ON (n = 2), Leber hereditary ON (n = 2), and traumatic ON (n = 1). GON and non-GON groups were further divided into mild, moderate, and severe subgroups. Inclusion in the GON group was based on mean deviations (MDs) of visual fields; inclusion in the non-GON group was based on critical flicker frequency (CFF) responses. Intraclass correlation coefficients (ICCs) were used to verify reproducibility of measurements. LTs of GON and non-GON group eyes were thinner than those of control group eyes (p < 0.01); LTs of GON group eyes were thinner than those of non-GON group eyes (p = 0.01). LTs of severe GON subgroup eyes were thinner than those of moderate and mild GON subgroup eyes (p < 0.001; p = 0.024, respectively). LTs of severe non-GON subgroup eyes were thinner than those of mild non-GON subgroup eyes (p = 0.002). These results show that EDI-OCT is valuable for documenting structural abnormalities in optic neuropathy (ON). 相似文献
47.
48.
49.
Dong Yoon Kim Soo Geun Joe Sung Jae Yang Joo Yong Lee June-Gone Kim Young Hee Yoon 《Korean journal of ophthalmology : KJO》2015,29(3):160-167
PurposeTo analyze differences in the subfoveal choroidal thickness (SFChT) between bevacizumab responders (BevRs) and nonresponders (BevNRs) in patients with idiopathic central serous chorioretinopathy (CSC).MethodsThe medical records of 30 unilateral chronic CSC patients who were treated with intravitreal bevacizumab (IVB) as a first line treatment were reviewed. Patients were categorized as BevNRs when CSC did not completely resolve after a minimum of 3 IVB treatments. Enhanced depth imaging-optical coherence tomography was used and SFChT was measured before and after treatment. Choroidal hyperpermeability was also evaluated using indocyanine angiography.ResultsTwenty and 10 eyes were classified as BevRs or BevNRs, respectively. The mean number of IVB treatments was 2.22 ± 0.89 in BevRs, and 4.80 ± 1.03 in BevNRs. Compared with BevNRs, BevRs demonstrated significantly greater pretreatment SFChT (441.25 ± 88.09 vs. 364.10 ± 61.97 µm); SFChT reduction following IVB was significantly greater in BevRs than BevNRs. SFChT in the unaffected eyes was also greater in BevRs than BevNRs. Choroidal hyperpermeability was detected less frequently in BevNRs (hypofluorescence on late-phase, 0.0% and 33.3% in BevNRs and BevRs, respectively; p= 0.049).ConclusionsCompared with CSC eyes that did not respond well to IVB, BevRs demonstrated significantly thicker SFChT at baseline, greater reduction in SFChT after IVB treatment, and hyperfluorescence on late-phase indocyanine green angiography. We recommend IVB injection as the first-line therapy for CSC eyes with relatively high SFChT and hyperfluorescence on late-phase indocyanine green angiography. 相似文献
50.
目的::观察哈萨克族与汉族大学生正视眼的角膜中央厚度、前房深度、角膜前后表面曲率的差异性,并分析角膜厚度与角膜前、后曲率的相关性。方法:对新疆医科大学一年级500多名学生进行近视眼筛查,选取正视眼的汉族学生55名和哈萨克族学生51名,应用Sirius角膜地形图对其进行测量。结果:哈萨克族与汉族大学生角膜中央厚度(哈:0.52±0.03mm,汉:0.54±0.03mm )、前房深度(哈:2.97±0.31mm,汉:3.14±0.25mm)有显著性差异(P<0.05)。角膜前、后表面曲率(K1,K2)无显著性差异(P>0.05)。汉族的角膜厚度与角膜前曲率相关分析r<0,与角膜后曲率相关分析r<0.1。哈萨克族的角膜厚度与角膜前曲率相关分析r<0,与角膜后曲率相关分析r<0.1。结论:哈萨克族与汉族大学生正视眼的生物学测量指标中,角膜厚度、前房深度是有差异的。两个民族的角膜厚度与角膜前、后曲率(K1,K2)无相关性。 相似文献