全文获取类型
收费全文 | 1505篇 |
免费 | 56篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 46篇 |
妇产科学 | 19篇 |
基础医学 | 213篇 |
口腔科学 | 13篇 |
临床医学 | 108篇 |
内科学 | 341篇 |
皮肤病学 | 24篇 |
神经病学 | 91篇 |
特种医学 | 161篇 |
外科学 | 187篇 |
综合类 | 4篇 |
预防医学 | 33篇 |
眼科学 | 12篇 |
药学 | 198篇 |
中国医学 | 24篇 |
肿瘤学 | 103篇 |
出版年
2023年 | 10篇 |
2022年 | 29篇 |
2021年 | 60篇 |
2020年 | 23篇 |
2019年 | 29篇 |
2018年 | 43篇 |
2017年 | 49篇 |
2016年 | 45篇 |
2015年 | 94篇 |
2014年 | 105篇 |
2013年 | 96篇 |
2012年 | 138篇 |
2011年 | 149篇 |
2010年 | 84篇 |
2009年 | 70篇 |
2008年 | 80篇 |
2007年 | 81篇 |
2006年 | 58篇 |
2005年 | 71篇 |
2004年 | 54篇 |
2003年 | 50篇 |
2002年 | 58篇 |
2001年 | 33篇 |
2000年 | 29篇 |
1999年 | 19篇 |
1998年 | 10篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1987年 | 1篇 |
1982年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1586条查询结果,搜索用时 31 毫秒
91.
Distribution of porcine reproductive and respiratory syndrome virus in stillborn and liveborn piglets from experimentally infected sows. 总被引:2,自引:0,他引:2
Four pregnant sows were infected 3 weeks before their expected farrowing date with a Korean isolate (North American genotype) of porcine reproductive and respiratory syndrome virus (PRRSV). The distribution of virus in their stillborn and liveborn (killed 7 days after birth) offspring was assessed immunohistochemically and by in-situ hybridization. PRRSV antigen and nucleic acid were detected in lung, thymus, liver, tonsil, spleen, heart, kidney and lymph nodes from both stillborn and liveborn piglets. Positive cells typically exhibited a red (immunohistochemistry) or dark brown (in-situ hybridization) reaction product in the cytoplasm, without background staining. The most consistent labelling for PRRSV was in the thymus, tonsil and lymph nodes. The experiment suggested that, in prenatal piglets, PRRSV replicates primarily in lymphoid tissues, having gained access to them from the placenta via the bloodstream. 相似文献
92.
Jung Hwa Kim Sun A Lee Tae-Beom Ahn Sung Sang Yoon Key Chung Park Dae-Il Chang Kyung Cheon Chung 《JOURNAL OF CLINICAL NEUROLOGY》2008,4(1):36-39
We describe a 64-year-old man with scrub typhus who presented with both polyneuropathy and cerebral infarction. A eurological examination revealed a confused mental state, stiff neck, hearing impairment, symmetric weakness, sensory loss, and ataxia. Electrophysiologic studies showed demyelinating sensorimotor polyneuropathy and sensorineural hearing loss. Brain magnetic resonance imaging showed multiple infarctions. Brain involvement or polyneuropathy associated with scrub typhus has been rarely reported, and the pathogenic mechanism underlying the multiple neurological complications remains to be elucidated. 相似文献
93.
94.
Background Optic gliomas may unpredictably stabilize or progress. Prognosis was known to be better in patients with neurofibromatosis
1 (NF1) than those with non-NF1. The confusion over management is caused, at least in part, by the uncertain disease course
of the tumor.
Case history We report here a 13-year-old girl presented with a 1-month history of a gradual decline of vision in her left eye. She was
diagnosed by clinical examination and magnetic resonance imaging as having a left optic-nerve glioma and was followed by serial
magnetic resonance imaging over 3 years. She and her family did not show any stigmata of NF1. Approximately 3 years after
the onset of her symptoms, visual acuity, color testing, and visual fields have markedly improved with tumor regression by
magnetic resonance imaging.
Conclusions The possibility of spontaneous regression of an optic-nerve glioma should be considered even in the planning of treatment
for a non-NF1 patient with this tumor. 相似文献
95.
S J Oh K S Won D H Moon J H Cheon H-J Ha J M Jeong H K Lee 《Nuclear medicine communications》2002,23(1):75-81
This study was undertaken in order to prepare 188Re labelled ethylenediamine-N,N,N',N'-tetrakis(methylene phosphonic acid) (EDTMP), and to determine its potential as a therapeutic radiopharmaceutical for the palliation of metastatic bone pain. The effects of pH, incubation methods, and concentrations of stannous chloride, EDTMP, and ammonium perrhenate as a carrier on radiochemical yield and stability were evaluated. Biodistribution studies were performed in male Wistar rats after intravenous injection of 188Re-EDTMP and compared with those of hydroxyethylidene diphosphonate (HEDP). Greater than 95% radiochemical yield of 188Re-EDTMP was obtained under the optimal conditions (0.1 mmol x ml(-1) of EDTMP, 0.5 mg x ml(-1) of stannous chloride, and pH 1.0). Heating the reaction mixture (boiling water for 15 min, and microwave heating for 15 s) and the addition of ammonium perrhenate increased the radiochemical stability (>90% at 3 h, and >80% at 48 h). The biodistribution of 188Re-EDTMP showed high bony uptake and rapid clearance from other organs, and high bone-to-soft tissue ratios, which are similar to 188Re-HEDP. In conclusion, 188Re-EDTMP was prepared with high radiochemical yield and stability, and showed favourable biological characteristics. Microwave heating was a convenient and rapid method for the preparation of 188Re-EDTMP. It is considered that 188Re-EDTMP is a potential therapeutic agent for bone metastasis. 相似文献
96.
Kyung-Sub Moon Shin Jung Min-Cheol Lee Hyo-Cheol Cheon In-Young Kim Jung-Kil Lee Tae-Sun Kim Sam-Suk Kang 《Journal of clinical neuroscience》2005,12(3):310-313
We report two cases of pineal germinoma with remarkable chronic granulomatous inflammation. In the first case, the pineal mass was totally removed via an occipital transtentorial approach as symptoms were due to direct mass effect. In the second case, endoscopic third ventriculostomy and tissue biopsy was performed to alleviate worsening hydrocephalus. Pathological examination of specimens of both cases showed chronic granulomatous inflammation associated with a few germ cell tumor nests, which demonstrated positive staining for placental alkaline phosphatase. Both patients received post-operative craniospinal irradiation with no subsequent neurological deficits. Follow-up magnetic resonance imaging (MRI) of the second case showed an asymptomatic, shrunken residual tumor mass. MRI of the first case showed no residual or recurrent disease. Thus, a pineal mass with unusual features on MRI and chronic granulomatous inflammation on histopathology, should raise the suspicion of germinoma. In cases with symptomatic mass effect, open resection can be considered. In cases with lesser mass effect, conventional therapeutic modalities without resection can achieve a good outcome, as for other germinomas. 相似文献
97.
Kwak HJ Song JS Heo JY Yang SD Nam JY Cheon HG 《The Journal of pharmacology and experimental therapeutics》2005,315(3):1188-1195
Roflumilast, a potent and selective phosphodiesterase 4 (PDE4) inhibitor, has been demonstrated to be an effective anti-inflammatory agent in airway inflammatory diseases. In the present study, we investigated the mechanism of anti-inflammatory effects of roflumilast in murine macrophage cell line RAW264.7 cells. Roflumilast inhibited NO, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1beta production via suppression of their gene expressions in lipopolysaccharide (LPS)-stimulated macrophages. To elucidate the mechanism by which roflumilast inhibits the production of inflammatory mediators, we examined the effect of roflumilast on the activation of nuclear factor-kappaB (NF-kappaB) in these cells. Roflumilast inhibited the DNA binding activity of NF-kappaB by preventing inhibitor kappaBalpha phosphorylation and degradation. The phosphorylation of mitogen-activated protein (MAP) kinases, including stress-activated protein kinase/c-Jun NH2-terminal kinase (JNK) and p38 MAP kinase, was also markedly inhibited by roflumilast. Similar to the effects of roflumilast, treatment of either SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)imidazole] or SP600125 [anthra(1,9-cd)pyrazol-6(2H)-one 1,9-pyrazoloanthrone], specific inhibitors of p38 MAP kinase and JNK, respectively, suppressed NO, TNF-alpha, and IL-1beta production. Consistent with in vitro results, administration of roflumilast recovered the survival rate of LPS-treated mice, with concurrent suppression of plasma levels of nitrite/nitrate, TNF-alpha, and IL-1beta. These results suggest that the inhibitory activity of roflumilast on the production of inflammatory mediators seems to be mediated via inhibition of NF-kappaB, p38 MAP kinase, and JNK activation in macrophages. 相似文献
98.
99.
Chang Mo Moon Jae Hee Cheon Jae Kook Shin Soung Min Jeon Hyun Jung Bok Jin Ha Lee Jae Jun Park Sung Pil Hong Tae Il Kim Nam Kyu Kim Won Ho Kim 《Digestive diseases and sciences》2010,55(10):2904-2911
Background
Gastrointestinal tract involvement in Behçet’s disease (BD) often requires surgical intervention due to serious complications such as intestinal perforation, fistula formation, or massive bleeding.Aim
The aims of this study were to investigate the clinical and surgical features of free bowel perforation and to determine the risk factors associated with this complication in intestinal BD patients.Methods
We reviewed the medical records of 129 patients with intestinal BD treated from September 1988 to September 2008. Among them, 33 patients had intestinal perforations and all underwent emergent or elective laparotomy.Results
The mean age of the patients with bowel perforation was 34.8 ± 15.6 years (range 12–70 years) with a sex ratio of 2.3:1 (male:female). Twenty-seven (81.8%) patients were diagnosed with intestinal BD preoperatively, whereas six (18.2%) patients were diagnosed by pathological examination after operation. Fourteen (42.4%) patients experienced postoperative recurrence of intestinal BD and 11 (33.3%) underwent reoperation. Multivariate Cox hazard regression analysis identified younger age (≤25 years) at diagnosis (HR = 3.25; 95% CI, 1.41–7.48, p = 0.006), history of prior laparotomy (HR = 5.53; 95% CI, 2.25–13.56, p = 0.0001), and volcano-shaped intestinal ulcers (HR = 2.84; 95% CI, 1.14–7.08, p = 0.025) as independent risk factors for free bowel perforation in intestinal BD.Conclusions
According to the results of our study, patients diagnosed with intestinal BD younger than 25 years, who had a history of prior laparotomy or volcano-shaped intestinal ulcers have an increased risk of free bowel perforation. 相似文献100.
Sung Jae Shin Sang Kil Lee Tae Il Kim Jae Hee Cheon Eun Soo Kim Byung Chang Kim Sooyoung Park Won Ho Kim 《International journal of colorectal disease》2010,25(11):1371-1376