全文获取类型
收费全文 | 4302篇 |
免费 | 339篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 130篇 |
妇产科学 | 58篇 |
基础医学 | 814篇 |
口腔科学 | 73篇 |
临床医学 | 270篇 |
内科学 | 898篇 |
皮肤病学 | 65篇 |
神经病学 | 414篇 |
特种医学 | 118篇 |
外国民族医学 | 1篇 |
外科学 | 619篇 |
综合类 | 285篇 |
预防医学 | 176篇 |
眼科学 | 86篇 |
药学 | 314篇 |
中国医学 | 62篇 |
肿瘤学 | 327篇 |
出版年
2024年 | 7篇 |
2023年 | 37篇 |
2022年 | 71篇 |
2021年 | 116篇 |
2020年 | 87篇 |
2019年 | 86篇 |
2018年 | 124篇 |
2017年 | 99篇 |
2016年 | 109篇 |
2015年 | 139篇 |
2014年 | 159篇 |
2013年 | 171篇 |
2012年 | 281篇 |
2011年 | 287篇 |
2010年 | 174篇 |
2009年 | 142篇 |
2008年 | 221篇 |
2007年 | 241篇 |
2006年 | 235篇 |
2005年 | 226篇 |
2004年 | 264篇 |
2003年 | 270篇 |
2002年 | 265篇 |
2001年 | 144篇 |
2000年 | 114篇 |
1999年 | 90篇 |
1998年 | 73篇 |
1997年 | 47篇 |
1996年 | 35篇 |
1995年 | 33篇 |
1994年 | 35篇 |
1993年 | 24篇 |
1992年 | 40篇 |
1991年 | 22篇 |
1990年 | 26篇 |
1989年 | 27篇 |
1988年 | 32篇 |
1987年 | 34篇 |
1986年 | 29篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 19篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1979年 | 9篇 |
1977年 | 8篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1970年 | 4篇 |
1969年 | 6篇 |
排序方式: 共有4740条查询结果,搜索用时 15 毫秒
1.
目的:在原核系统中表达并纯化大肠杆菌胞嘧啶脱氨酶(cytosine deaminase,CD),制备鼠抗大肠杆菌CD多克隆抗体,方法:亚克隆CD基因到原核表达载体pMAL-c2和pBV222中,并转化入大肠杆菌DH5α内,诱导表达并纯化MBP-CD和6his-CD融合蛋白,用纯化的MBP-CD融合蛋白免疫小鼠制备多克隆抗体。结果:通过重组质粒的酶切筛选出重组阳性克隆,成功地表达和纯化出MBP-CD和6his-CD融合蛋白,用纯化的MBP-CD成功制备了鼠抗CD多克隆抗体,并用6his-CD和GST-CD重组蛋白进行Western印迹分析,证实了抗体的正确性,结论:应用多克隆抗体可以检测体内外CD基因的表达,为临床前和临床上深入开展CD基因的生物治疗研究提供重要的实验材料。 相似文献
2.
目的:分析胃癌大肠转移的X线钡灌肠表现。方法:104例胃癌入院术前检查发现结肠转移或胃癌术后转移入院治疗的病例。分析钡灌肠初次发现大肠转移征象的年龄、发现胃癌原发病变距初次发现大肠转移的间隔时间、转移病变的发生部位和病变造成的X线钡灌肠图像上的肠管变形和粘膜面的改变。结果:104例胃癌结肠转移,男67例,女37例。胃癌术前检查中发现结肠转移者32例,术后发现的大肠转移中,多数转移发生在手术后3年内(占91.3%)。胃癌原发灶的肉眼形态BorrmannⅢ型(28例)和BorrmannⅣ型(65例)者占89.4%,组织学中以低分化腺癌和印戒细胞癌为主要成分者占91.3%。X线钡灌肠检查显示大肠转移的好发部位为横结肠(80),其次为直肠(50)。转移灶可累及多节段肠管,其中横结肠中1/3段(47),横结肠左1/3(44),横结肠右1/3(39)和直肠腹膜返折之上(39)。X线显示肠管单侧变形者227处,双侧变形者96处。黏膜面表现为梳齿状黏膜纹聚集改变253处,颗粒结节状改变23处,外压性改变20处,弥漫性改变62处。结论:胃癌大肠转移的好发部位为横结肠和直肠,结肠黏膜面的梳齿状黏膜纹聚集为胃癌大肠转移的主要X线钡剂灌肠表现。 相似文献
3.
4.
Shinhiro Takeda Kazuhiro Nakanishi Teruo Takano Gen Ishikawa Ryo Ogawa 《Journal of anesthesia》1997,11(2):83-87
Effective gas exchange can be maintained in animals without endotracheal intubation using external high-frequency oscillation
(EHFO). The aim of this study was to evaluate the effect of EHFO in patients with respiratory failure due to severe cardiogenic
pulmonary edema. Seven patients were ventilated with EHFO for 2h at 60 oscillations·min−1, with a cuiras pressure of 36 cmH2O (−26 to +10) and an inspiratory to expiratory ratio of 1:1, with EHFO. Blood gas values and hemodynamic parameters were
measured. Significant increases were noted in cardiac index (2.3±0.5 to 2.5±0.5 l·m−2;P<0.05), stroke volume index (24±7 to 28±8 ml·m−2;P<0.05), and arterial O2 pressure (Pao2) (70±4 to 95±23 mmHg;P<0.01) without a change in pulmonary artery wedge pressure at 1 h after EHFO. The respiratory rate decreased from 28±3 to
22 ±3 breaths·min−1 at 5 min after the termination of EHFO (P <0.01). Arterial CO2 pressure (Paco2) did not, however, decrease. Increased stroke volume without a change in pulmonary artery wedge pressure (preload) suggests
either improved inotropic function of the left ventricle or reduced left ventricular afterload with EHFO. The use of EHFO
may be effective not only for gas exchange but also for left ventricular function in patients with severe cardiogenic pulmonary
edema. 相似文献
5.
目的 :观察血清保存方法对促甲状腺激素 (TSH)结果的影响。方法 :将甲状腺功能正常、异常患者共 10份血清 ,采用不同血清量、不同条件分组保存后测定 TSH。结果 :保存方法对 TSH结果有一定的影响。结论 :用于 TSH血清的保存量要多、要密封管口、低温保存。 相似文献
6.
Chihaya Maesawa Gen Tamura Yasushi Suzuki Kaoru Ishida Kazuyoshi Saito Ryoichi Satodate 《Cancer science》1992,83(12):1253-1256
For the rapid and sensitive detection of p53 gene mutations in esophageal endoscopic biopsy specimens, we combined cell sorting with the polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analysis. Mutations in exons 5–8 of the p53 gene were investigated by FCR-SSCF analysis using 103 sorted nuclei obtained from each endoscopic biopsy specimen of 16 patients with esophageal cancer. DNAs extracted from their respective surgical specimens were investigated by a conventional method of PCR-SSCP analysis. Mutations in the biopsy specimens were detected in 6 of the 12 aneuploid tumors but in none of the 4 diploid tumors. After tumor cell enrichment by cell sorting, one mutation in exon 8 became apparent, which could not be detected from the surgical specimen by a conventional method of PCR-SSCP analysis. This method should improve the sensitivity of detecting p53 gene mutations, and provides additional information concerning the DNA ploidy pattern in the tumors. 相似文献
7.
Comparison of p53 expression in proximal and distal gastric cancer: Histopathologic correlation and prognostic significance 总被引:2,自引:0,他引:2
Huihuan Tang MD Shuichi Hokita MD PhD Xiangming Che MD Masamichi Baba MD PhD Kuniaki Aridome MD PhD Fumio Kijima MD Gen Tanabe MD PhD Sonshin Takao MD PhD Dr. Takashi Aikou MD PhD 《Annals of surgical oncology》1997,4(6):470-474
Background: The overexpression of p53 has been found to be correlated with prognosis of some carcinomas, including gastric cancer, but
no studies have reported on its relationship to the location of gastric cancer. In the present study, we compared the p53
expression of proximal and distal gastric cancer concerning histopathology and prognosis.
Methods: A total of 170 tumors in the patients with proximal (80 cases) and distal (90 cases) gastric cancer were studied by immunohistochemical
methods.
Results: p53 immunopositivity was detected in 28.8% of all tumors. The p53-positive expression in proximal gastric cancer was higher
than in distal gastric cancer (38.8% vs. 20.0%, p<0.05). A 5-year survival analysis showed that there is no significant difference
between tumors that are p53 positive and p53 negative. No correlation was found between p53 expression and histopathology
of gastric cancer.
Conclusion: p53 nuclear staining is not useful as a prognostic indicator or as a parameter in gastric cancer. 相似文献
8.
病毒性心肌炎心肌肌钙蛋白Ⅰ检测的临床意义 总被引:1,自引:0,他引:1
目的:对病毒性心肌炎患儿血中肌钙蛋白I(cTn I)含量进行检测,探讨与临床的关系。方法:采用放射免疫法对24例病毒性心肌炎患儿血中cTn I进行定量检测,同时检测血清心肌酶谱的改变情况,并就两种指标进行相关性探讨。结果:病毒性心肌炎患儿血中cTn I含量明显增高(4.5±2.2 )vs(2.3±0.3)ng/ml,P<0.01),并与CKMB,LDH_1的含量呈明显的正相关。结论:cTnl I是诊断病毒性心肌炎的敏感指标,可以反映出心肌受损的程度。 相似文献
9.
Masatoshi Kubo Shigeharu Moriyama Tomohiro Nogami Tadayoshi Kunitomo Sugato Nawa 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(9):435-438
This paper presents a case of intercostal hemangioma, in which a complete surgical resection was accomplished based upon a
tentative diagnosis provided by magnetic resonance imaging (MRI). A 27-year-old man visited our hospital for the evaluation
of chest pain and shortness of breath after exertion. Computed tomography showed a soft tissue mass, 5.5×3.5 cm in size, arising
from the right lateral 7th intercostal space. Dynamic MRI showed that the mass was enhanced rapidly in the early phase and
that this early enhancement was maintained during the delayed phase, which was compatible with a diagnosis of intercostal
hemangioma. The patient underwent surgery, and a complete resection of the tumor with the right 7th and 8th ribs and their
intercostal muscles was accomplished. Histopathological examination confirmed the diagnosis of intramuscular hemangioma of
the large-vessel type. Presently, 6 months after the operation, the patient is doing well, without any evidence of local recurrence. 相似文献
10.
采用显微外科技术行阴囊纵膈皮瓣尿道下裂修复术18例,均获成功。其手术要点为:将阴茎腹侧纤维索条切除,充分伸展阴茎,皮瓣保留足够长度与宽度,克保血运;在显微镜下采用7-0尼龙丝线缝合,形成皮管,不缝皮肤,只缝皮下。硅胶管支架引流,加压包扎阴茎。本文对手术成功的原因进行了初步讨论。 相似文献