全文获取类型
收费全文 | 401153篇 |
免费 | 27279篇 |
国内免费 | 15514篇 |
专业分类
耳鼻咽喉 | 5389篇 |
儿科学 | 9976篇 |
妇产科学 | 5740篇 |
基础医学 | 41730篇 |
口腔科学 | 9222篇 |
临床医学 | 40673篇 |
内科学 | 65970篇 |
皮肤病学 | 6071篇 |
神经病学 | 19322篇 |
特种医学 | 17720篇 |
外国民族医学 | 149篇 |
外科学 | 54193篇 |
综合类 | 51128篇 |
现状与发展 | 63篇 |
预防医学 | 21452篇 |
眼科学 | 5800篇 |
药学 | 37251篇 |
106篇 | |
中国医学 | 8092篇 |
肿瘤学 | 43899篇 |
出版年
2023年 | 3982篇 |
2022年 | 7550篇 |
2021年 | 16632篇 |
2020年 | 10853篇 |
2019年 | 16030篇 |
2018年 | 10783篇 |
2017年 | 10562篇 |
2016年 | 13395篇 |
2015年 | 16974篇 |
2014年 | 29009篇 |
2013年 | 26627篇 |
2012年 | 29773篇 |
2011年 | 27598篇 |
2010年 | 24172篇 |
2009年 | 23816篇 |
2008年 | 22880篇 |
2007年 | 23069篇 |
2006年 | 20160篇 |
2005年 | 15671篇 |
2004年 | 10533篇 |
2003年 | 9179篇 |
2002年 | 7420篇 |
2001年 | 6561篇 |
2000年 | 5817篇 |
1999年 | 4535篇 |
1998年 | 4561篇 |
1997年 | 4130篇 |
1996年 | 3529篇 |
1995年 | 3197篇 |
1994年 | 2982篇 |
1993年 | 2295篇 |
1992年 | 2374篇 |
1991年 | 2105篇 |
1990年 | 1984篇 |
1989年 | 1816篇 |
1988年 | 1715篇 |
1987年 | 1480篇 |
1986年 | 1218篇 |
1985年 | 2222篇 |
1984年 | 2275篇 |
1983年 | 1608篇 |
1982年 | 1757篇 |
1981年 | 1651篇 |
1980年 | 1433篇 |
1979年 | 1195篇 |
1978年 | 918篇 |
1977年 | 884篇 |
1976年 | 767篇 |
1975年 | 489篇 |
1974年 | 490篇 |
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
991.
目的 探讨Survivin和PCNA在脑膜瘤组织中的表达及临床意义。方法 采用免疫组织化学sP法检测97例脑膜瘤组织和18例正常脑膜组织中Survivin和PCNA的表达。结果 Survivin在正常脑膜和脑膜瘤组织中阳性表达率为0%和65.9%(64/97),差异具有显著性(P〈0.001)。Survivln表达阳性率在脑膜瘤Ⅱ级(85.7%)和Ⅰ级(51、7%)之间、Ⅲ级(93.8%)和Ⅰ级之间差异具有显著性(P〈0.001)。PCNA蛋白在正常脑膜和脑膜瘤组织中表达阳性率为0%和55.7%(54/97),差异具有显著性(P〈0.001)。PC—NA表达阳性率在脑膜瘤Ⅱ级(71.4%)和Ⅰ级(41、7%)之间,Ⅲ级(87.5%)同Ⅰ级之间差异具有显著性(P〈0.001)。Survivin与PCNA蛋白在脑膜瘤中的表达呈正相关关系(rs=0.640,P〈0.01)。结论 Survivin过度表达和脑膜瘤发生及PCNA的表达密切相关,两者参与了脑膜瘤发生、增殖和发展。 相似文献
992.
目的探讨不同摄食控制方法对荷瘤小鼠生存期的影响。方法摄食控制组分别为每日限食2.0 g(DR)、隔1日断食限食4.0 g(IF)、隔2日断食限食6.0 g(SF)和隔1日断食不限食(IF1)4种方法,正常摄食为空白对照组(AL)。观察各组小鼠的体重变化和平均存活天数。结果DR组和IF组平均存活天数分别为19.52±5.24 d和17.96±4.49 d,比对照AL组15.75±1.83 d明显延长(P<0.001和P<0.01)。结论摄食控制恰当,可明显抑制肿瘤细胞的生长、延长荷瘤小鼠的生存期并提高生存质量。 相似文献
993.
杨允娇 《新疆医科大学学报》1986,(1)
我科6年中对子宫颈及阴道恶性肿瘤施行腹壁下动脉插管化疗共34例,作为配合放疗及争取手术的综合疗法之一,提高晚期宫颈癌的放疗效果,对Ⅱ期早宫颈癌施行根治术者6例,但对腺癌、肉瘤及恶性黑色素瘤等效果差。 相似文献
994.
K. W. Stephen J. I. Russell S. L. Creanor C. K. Burchell 《Community dentistry and oral epidemiology》1987,15(2):90-94
Fibre optic transillumination (FOTI) has been employed during the course of a 3-yr clinical dentifrice trial which initially involved 3003 children. At the initial examination, a subgroup of 813 13-yr-olds, and at the following annual visit, 2247 14-yr-olds, were examined using a 150 W lamp and 0.5 mm diameter probe. Routine clinical and radiographic examinations were performed separately. Compared to the clinical scores for anterior teeth, FOTI detected an additional 64% of interproximal lesions at the first visit while, for the larger number of children at the second visit, the increase in lesion detection level using FOTI was 37%. For the posterior teeth the comparable figure at the second examination was 92%. When FOTI data were compared to radiographic data for more than 52,000 posterior interproximal surfaces, FOTI could only detect 17% of radiographic Grade 2 lesions and 48% Grade 3 lesions. Thus any assumption that FOTI diagnoses may be a substitute for bitewing radiography appears premature. 相似文献
995.
Attempts have been made to culture the mucosa from various parts of the gastrointestinal tract. In this study, using an explant culture method, epithelial cells have been successfully cultured from all major regions of the gastrointestinal tract. The success rate, as judged by outgrowth of epithelial cells for at least 4 weeks, varied with the tissue studied with 19/50 colonic biopsies, 5/11 small intestinal biopsies, 9/12 stomach biopsies and 42/47 gallbladder biopsies yielding outgrowth of epithelial cells. Differentiation of the epithelial cells along the mucus cell pathway could be demonstrated on the monolayer cultures using Periodic acid Schiff or Alcian blue staining. Because the cultures were very heterogeneous and many morphological cell types were present in most cultures, differentiation along the other known differentiation pathways of the gastrointestinal mucosa, such as development of absorptive cells and endocrine cells, could not be excluded.
The problem of bacterial contamination, which has hindered previous studies on tissue from these sites, was overcome by decontaminating the biopsy by soaking in dilute sodium hypochlorite (0.04%). 相似文献
The problem of bacterial contamination, which has hindered previous studies on tissue from these sites, was overcome by decontaminating the biopsy by soaking in dilute sodium hypochlorite (0.04%). 相似文献
996.
Summary The histogenesis of stromal cells in capillary hemangioblastoma has been the subject of debate. The light and electron microscopic studies of hemangioblastomas presented here showed pericytic and leiomyoblastic features in stromal cells. Cells cultured by the monolayer method showed similar features to those of the original tumors. Immunohistochemical studies for glial fibrillary acidic protein and factor VIII/von Willebrand factor indicated that stromal cells were antigenically distinct from astrocytes and endothelial cells. These findings suggest that stromal cells are closely related to pericytes and smooth muscle cells, and support Rhodin's speculation that pericytes serve as a precursor to smooth muscle cells. 相似文献
997.
The usefulness of intra-operative antiemetics and postoperative oral fluid restriction in the prevention of vomiting following anaesthesia for ophthalmic surgery, was studied in 200 patients. They were allocated into four groups of 50 and given either saline (as control), droperidol, metoclopramide or prochlorperazine. Oral intake was restricted postoperatively in half of the patients of each group. Anaesthesia comprised morphine and atropine premedication and a halothane, nitrous oxide and oxygen spontaneous breathing technique. No significant beneficial effects resulted from intra-operative antiemetics; vomiting incidences of 26% after saline and droperidol, 28% after metoclopramide and 14% after prochlorperazine were observed. Younger patients and females vomited most frequently. Restriction of oral fluids did not decrease the incidence of vomiting but demonstrated that approximately half of those patients who vomit do so with their first postoperative oral intake. Vomiting was observed more frequently after non intra-ocular surgery than after intra-ocular surgery (37% cf. 16%, p less than 0.01) and postoperative analgesics were required by more non intra-ocular patients than by intra-ocular patients (25% cf. 5%, p less than 0.001). Squint patients vomited most frequently (48%) and most frequently required postoperative analgesia (35%). 相似文献
998.
G. Adebahr 《International journal of legal medicine》1986,97(3):207-212
Zusammenfassung Die verschiedenen Aspekte des Hirntodes werden besprochen. Dabei wird auf die Möglichkeit hingewiesen, eine den Hirntod verursachende Vergiftung durch chemisch-toxikologische Untersuchungen von Gehirn und Sinusblut zu sichern, da in Gehirn und Sinusblut der Stoff-wechsel maximal gedrosselt bzw. aufgehoben ist, in den übrigen Körperorganen Arzneimittel oder toxische Substanzen aber abgebaut werden. Ein sehr wichtiger Aspekt ist gegeben, wenn durch Gewalteinwirkung die Voraussetzungen für den Hirntod geschaffen wurden und die Wertigkeit einer folgenden zweiten Gewaltanwendung, z.B. in Form eines Stiches mit Blutung, beurteilt werden soll. In dieser Konstellation hat die vitale Reaktion in Form der Blutung nämlich dann keinen Beweiswert, wenn nicht mit an Sicherheit grenzender Wahrscheinlichkeit ausgeschlossen werden kann, daß der Hirntod eingetreten war, als die zweite Gewalteinwirkung erfolgte. Andererseits kann der Hirntod — bei Befunden, die ihn verursachen können — für den Zeitpunkt der zweiten Gewalteinwirkung ausgeschlossen werden, wenn komplizierte Vitalreaktionen, z.B. in Form einer Entzündung, vorhanden sind.Hernn Prof. Dr. med. J. Gerchow zur Vollendung des 65. Lebensjahres gewidmet 相似文献
999.
体外培养诱导外周血淋巴细胞促进大鼠面神经再生的实验研究 总被引:1,自引:0,他引:1
目的:通过在神经缺损处局部回输体外分离培养纯化的淋巴细胞,了解此种方法促进面神经损伤修复的效果。方法:将20只Wistar大鼠的面神经颊支剪断并立即缝合(其余3支反折缝合)制成面神经损伤模型大鼠,将其分成淋巴细胞组和对照组,每组10只,每组再分成2周组和8周组。淋巴细胞组局部回输体外分离培养的外周血淋巴细胞,对照组作对照。于2周和8周测定面神经颊支-触须肌复合动作电位传导速度,辣根过氧化物酶(HRP)神经逆行示踪测定面神经核团的神经元阳性数目。结果:淋巴细胞组面神经颊支-触须肌复合动作电位传导速度8周时为0.64±0.07,与对照组(0.56±0.07)相比,差异有统计学意义(P<0.05)。HRP神经逆行示踪测定面神经核团神经元阳性数目,淋巴细胞组2周及8周与对照组同时间段相比差异均无统计学意义(均P>0.05)。结论:体外分离培养纯化的淋巴细胞在局部应用于神经损伤处对面神经再生修复可起一定的促进作用。 相似文献
1000.
Ferritin immunohistochemistry as a marker for microglia 总被引:1,自引:1,他引:0
Summary An immunohistochemical analysis of formalin-fixed, paraffin-embedded brain sections was performed with antisera against holoferritin and the light(L)-subunit of ferritin. Sections immunostained using anti-glial fibrillary acidic protein (GFAP), Ricinus communis agglutinin-1 (RCA-1) stain for microglia and iron stain (Berlin blue stain) were compared. The L-subunit of ferritin was purified from normal human spleen according to the modified scrapie-associated fibrils purification, and the antiserum was raised in a rabbit. Both ferritin antisera positively stained resting and, more markedly, reactive microglia, both of which were also stained with RCA-1 but not with GFAP. Ferritin-positive resting microglia were seen more abundantly in cerebral and cerebellar cortices than in white matter. The advantages of ferritin antisera over RCA-1 are as follows. (1) RCA-1 heavily stains blood vessels, while anti-ferritin does not, hence the microglial cells are more readily visualized with ferritin immunohistochemistry. (2) Reactive microglia and macrophages are more strongly stained with anti-ferritin. (3) The staining intensity of ferritin is independent of the length of tissue fixation in formalin. However, anti-ferritin is inferior to RCA-1 in staining resting microglia with a scanty cytoplasm, especially in the white matter, probably because the former recognizes cytoplasmic components, while the latter recognizes cell membrane. Iron stain only gave a reaction to microglial cells in brains with neurosyphilis and to hemosiderin-laden macrophages. Thus, in addition to RCA-1, ferritin antisera are useful as a microglia marker in formalin-fixed, paraffin-embedded sections.Supported in part by Dr. A. Kondo, Department of Neuropathology, Neurological Institute, Kyushu University 相似文献