全文获取类型
收费全文 | 1267篇 |
免费 | 55篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 36篇 |
妇产科学 | 87篇 |
基础医学 | 171篇 |
口腔科学 | 25篇 |
临床医学 | 65篇 |
内科学 | 239篇 |
皮肤病学 | 48篇 |
神经病学 | 62篇 |
特种医学 | 39篇 |
外科学 | 198篇 |
综合类 | 64篇 |
预防医学 | 56篇 |
眼科学 | 24篇 |
药学 | 132篇 |
中国医学 | 17篇 |
肿瘤学 | 67篇 |
出版年
2022年 | 8篇 |
2021年 | 15篇 |
2020年 | 14篇 |
2019年 | 13篇 |
2018年 | 30篇 |
2017年 | 16篇 |
2016年 | 29篇 |
2015年 | 32篇 |
2014年 | 45篇 |
2013年 | 54篇 |
2012年 | 64篇 |
2011年 | 77篇 |
2010年 | 45篇 |
2009年 | 31篇 |
2008年 | 37篇 |
2007年 | 76篇 |
2006年 | 58篇 |
2005年 | 69篇 |
2004年 | 57篇 |
2003年 | 76篇 |
2002年 | 52篇 |
2001年 | 41篇 |
2000年 | 41篇 |
1999年 | 33篇 |
1998年 | 14篇 |
1997年 | 9篇 |
1996年 | 5篇 |
1992年 | 12篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 18篇 |
1987年 | 9篇 |
1986年 | 22篇 |
1985年 | 8篇 |
1983年 | 7篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 10篇 |
1974年 | 14篇 |
1973年 | 12篇 |
1972年 | 22篇 |
1971年 | 16篇 |
1970年 | 7篇 |
1969年 | 18篇 |
1968年 | 13篇 |
1967年 | 9篇 |
1965年 | 4篇 |
排序方式: 共有1351条查询结果,搜索用时 0 毫秒
51.
Yi-Ling Yang Po-Kuan Chao Long-Sun Ro Yu-Yuan P Wo Kwok-Tung Lu 《Neuropsychopharmacology》2007,32(5):1042-1051
Recent results show that brain glucocorticoids are involved in the dysregulation of fear memory extinction in post-traumatic stress disorder patients. The present study was aimed to elucidate the possible mechanism of glucocorticoids on the conditioned fear extinction. To achieve these goals, male SD rats, fear-potentiated startle paradigm, and Western blot were used. We found that (1) systemic administration of the synthetic glucocorticoid agonist dexamethasone (DEX) facilitated extinction of conditioned fear in a dose-dependent manner (0.05, 0.1, 0.5, or 1.0 mg/kg, i.p.); (2) systemic administration of the glutamate NMDA receptor antagonist (+/-)-HA966 (6.0 mg/kg, i.p.) and intra-amygdala infusion of the NMDA receptor antagonists MK801 (0.5 ng/side, bilaterally) or D,L-2-amino-5-phosphonovaleric acid (AP5, 2.0 ng/side, bilaterally) blocked the DEX facilitation effect; (3) the corticosteroid synthesis inhibitor metyrapone (25 mg/kg. s.c.) blocked extinction and this was prevented by co-administration of NMDA receptor agonist D-cycloserine (DCS, 5.0 mg/kg, i.p.); (4) co-administration of DEX and DCS in subthreshold doses provided a synergistic facilitation effect on extinction (0.2 and 5 mg/kg, respectively). Control experiments indicated that co-administration of DEX and DCS did not alter the expression of conditioned fear and the effect was not due to lasting damage to the amygdala. These results suggest that glutamate NMDA receptors within the amygdala participate in the modulatory effect of glucocorticoids on extinction. 相似文献
52.
半导体激光不同累积能量照射后牙本质的改变 总被引:4,自引:0,他引:4
目的:探讨临床应用半导体激光治疗牙本质过敏症的最佳参数值。方法:选择离体上下颌第一、二恒磨牙,用单面金刚砂片垂直于牙长轴在面牙尖下1.0mm和2.5mm二处切断,制成1.5mm厚的牙片15张。选用不同功率的激光照射牙本质片,每种功率激光分别照射180s、240s和300s。牙本质片经常规固定、包埋、切片、染色后,光学显微镜下观察牙本质的组织学变化。结果:不同功率的激光经不同照射时间照射牙本质片后,均可封闭牙本质小管。激光功率不变时,牙本质小管的封闭厚度随照射时间的增加而增加;照射时间相同时,牙本质小管的封闭厚度随激光功率的增加而增加,且具有显著性差异。在激光功率为0.5W时,个别样本在激光照射区域牙本质中心处有凹坑出现。结论:激光功率0.4W,照射时间300s条件下,牙本质小管封闭厚度较厚,且不出现凹坑现象,可作为半导体激光脱敏的最佳参考数值。 相似文献
53.
Sniegocki M Sosnowski S Woźniak B Kasprzak HA Beuth W Bierwagen M Drawi AS 《Ortopedia, traumatologia, rehabilitacja》2000,2(2):25-27
Spinal fractures at the craniocervical function require surgical treatment. Surgical can be preceded by direct traction of the cranium in order to set the fragments prior to fixation. This paper presents various methods of fixation from the posterior titanium loops. 相似文献
54.
Walter Z Mankiewicz J Woźniak K Majewska E Baj Z 《International journal of occupational medicine and environmental health》2000,13(3):205-213
The aim of this work was to investigate the possibility of apoptosis in the human peripheral blood lymphocytes after treatment with potassium dichromate (K2Cr2O7), a potential occupational carcinogenic and mutagenic agent. Lymphocytes were stimulated by phytohemagglutinin, cultured for 72 h and incubated with either 0.2 mM or 0.4 mM K2Cr2O7 for the last 24 h or 48 h of culture. The condensation and margination of chromatin with emerging 'half-moon' structure, characteristic of apoptosis were observed. Phosphatidylserine displaced from the inner to outer side of the cellular membrane in 54% of cells after a 48-h incubation with 0.4 mM K2Cr2O7 (annexin-V+/PI-); 39% of these cells were of late apoptotic--secondary necrotic form (annexin-V+/PI+). Following the agarose gel electrophoresis of DNA, a 'ladder pattern' typical of apoptosis, was found. The results of the present study demonstrate that K2Cr2O7 can induce in the human peripheral blood lymphocytes changes similar to apoptotic ones. 相似文献
55.
M Szamatowicz W Kuczyński M Kulikowski J Radwan E Sola S Wo?czyński 《Ginekologia polska》1988,59(5):263-268
56.
Tubulointerstitial nephritis with uveitis: clinico-pathological and immunological study 总被引:1,自引:0,他引:1
Litwin M Michałkiewicz J Jarmuek W Woźniewicz B Grenda R Iwanicka K Madaliński K 《Pediatric nephrology (Berlin, Germany)》2002,17(8):683-688
A 10-year-old boy was evaluated for fever, weight loss, uveitis, normocytic, normochromic anemia, renal insufficiency, and hypergammaglobulinemia of 8 weeks' duration. Infectious and neoplastic causes of fever were excluded. A renal biopsy performed in the 4th week of disease revealed diffuse plasmocytic interstitial nephritis. No treatment was prescribed and the patient was transferred to another hospital. Because clinical symptoms and renal insufficiency were still present, in the 8th week of disease a second biopsy was performed, which showed lympho-monocytic interstitial nephritis. At the same time, phenotypic analysis of peripheral blood mononuclear cells was carried out, revealing a significantly decreased number of CD3(+), CD4(+), and CD3(+)/CD8(+) cells, increased non-T CD3(-)/CD8(+) and CD56(+) NK cells, and decreased "na?ve" (CD45RA(+)/CD4(+)) and memory (CD45RO(+)/CD8(+)) T lymphocytes. A 6-month course of oral prednisone was prescribed. Clinical symptoms and laboratory findings quickly returned to normal values. After 13 days of corticosteroid therapy, a second phenotypic analysis of peripheral blood mononuclear cells was performed, which revealed normalization of CD3(+), CD4(+), and CD3(+)/CD8(+) cells as well as proportions of non-T CD8(+) and CD56(+) NK lymphocytes, "na?ve" and memory cells. This case shows spontaneous evolution of tubulointerstitial infiltrates from plasmacytic to lympho-monocytic, profound disturbances of the immunological system, and the beneficial effect of corticosteroids on both the clinical course and immunological disturbances. 相似文献
57.
Woźniak A Kasprzak HA Woźniak B Drewa G Beuth W Sniegocki M Grzelak L 《Neurologia i neurochirurgia polska》2003,37(5):1025-35; discussion 1036
The aim of the study was to evaluate the intensity of oxygen-derived free radicals generation (expressed as the lipid peroxidation process), as well as antioxidant potential changes in patients with cervical spinal cord injury. Subjects in the study were 32 patients treated in the Neurosurgery and Neurotraumatology Clinic, Medical University in Bydgoszcz. Malondialdehyde (MDA) concentration and conjugated dienes (CD) level in the patients' blood plasma and erythrocytes, as well as their plasma antioxidant potential in reaction with a stable free radical--1.1-diphenyl-2-picryl-hydrazyl were assayed. Intensification of the lipid peroxidation process as well as a decrement of plasma antioxidant potential were found in the patients with cervical spinal cord injury. A strong correlation was also shown between severity of cervical spinal cord injury assessed using the ASIA impairment scale on the one hand and intensification of the lipid peroxidation process and plasma antioxidant potential decrease on the other hand. 相似文献
58.
In vitro infrared thermographic assessment of root surface temperature rises during thermafil retreatment using system B 总被引:1,自引:0,他引:1
The purpose of this in vitro study was to measure the temperature rise on the outer root surface during retreatment of Thermafil using the System B HeatSource. Twenty extracted human maxillary premolars were filled with Thermafil with plastic carriers and divided into two groups of 10 teeth each. In group 1, Thermafil obturators were retrieved using System B HeatSource fitted with a medium plugger at a temperature of 225 degrees C. The plugger was placed first on the buccal, then on the lingual of the plastic carrier for 5 s each. This melted the gutta-percha and softened the plastic carrier. In group 2, Thermafil obturators were retrieved in the same manner except that the heated plugger was placed for 8 s. The temperature changes on the outer root surfaces were recorded using a thermal imaging camera. Thermafil retreatment in vitro using a System B HeatSource causes temperature rises ranging from 26.7 degrees C to 46.0 degrees C. This finding could possibly have implications for creating injury of the periodontal tissues. 相似文献
59.
Wo JM Jabbar A Winstead W Goudy S Cacchione R Allen JW 《Digestive diseases and sciences》2002,47(11):2579-2585
Hypopharyngeal pH artifacts have been a concern in the detection of laryngopharyngeal reflux. Our purpose was to analyze and quantify artifacts from dual-sensor hypopharyngeal pH monitoring. In all, 42 hypopharyngeal and 58 esophageal pH studies were reviewed. Type 1 (out of range), type 2 (pH drift), and type 3 (isolated pH drop) artifacts were identified. The proportion of proximal-sensor pH drop to <4 that was artifactual was determined. The median number (range) of artifacts was 1 (0–17) and 2 (0–28) for hypopharyngeal and esophageal pH studies, respectively (P = NS). The median proportion of artifactual pH drop to <4 was 1% (0–84%) and 2% (0–74%) for hypopharyngeal and esophageal pH studies, respectively (P = NS). The diagnosis did not change in any patient after excluding pH artifacts. In all, 19% of the combined 2432 hypopharyngeal pH drops of <4 were artifacts. In conclusion, hypopharyngeal pH artifacts per study were uncommon but can be prominent in a few patients. One can identify these artifacts and exclude them from analysis. 相似文献
60.
P Rzymski T Opala M Wilczak J Wo?niak S Sajdak 《International journal of gynaecology and obstetrics》2005,88(3):292-298
OBJECTIVE: Early ovarian cancer detection is still very difficult and patients are mostly in advanced stages, with obvious influence on poor prognosis. METHOD: Fifty-one ovarian cancer patients and 16 healthy controls had the serum concentrations of TNF alpha receptor p55, p75 and CA-125 measured prospectively and preoperatively. RESULT: Mean concentrations of TNF alpha receptor p55, p75 and CA-125 in patients with ovarian cancer were higher than in controls. The ratios of p55 and p75 receptor in ovarian cancer and controls were 0.73+/-0.38 and 0.55+/-0.06 respectively. The areas under ROC curve in detecting malignancy (all FIGO stages) were 0.73, 0.65, 0.88 and 0.85 for p55, p75, p55/p75 ratio and CA-125 respectively. The areas under ROC curve in detecting stage I of ovarian cancer were 0.52, 0.60, 0.84 and 0.66 for p55, p75, p55/p75 ratio and CA-125 respectively. CONCLUSION: Serum TNF alpha p55/p75 ratio showed promising value in ovarian cancer detection. 相似文献