全文获取类型
收费全文 | 65542篇 |
免费 | 5967篇 |
国内免费 | 4903篇 |
专业分类
耳鼻咽喉 | 640篇 |
儿科学 | 701篇 |
妇产科学 | 618篇 |
基础医学 | 7764篇 |
口腔科学 | 1114篇 |
临床医学 | 8628篇 |
内科学 | 9755篇 |
皮肤病学 | 600篇 |
神经病学 | 3595篇 |
特种医学 | 2525篇 |
外国民族医学 | 34篇 |
外科学 | 6895篇 |
综合类 | 11131篇 |
现状与发展 | 16篇 |
一般理论 | 1篇 |
预防医学 | 4479篇 |
眼科学 | 1883篇 |
药学 | 6851篇 |
54篇 | |
中国医学 | 3350篇 |
肿瘤学 | 5778篇 |
出版年
2024年 | 213篇 |
2023年 | 1080篇 |
2022年 | 2728篇 |
2021年 | 3428篇 |
2020年 | 2515篇 |
2019年 | 2197篇 |
2018年 | 2311篇 |
2017年 | 2039篇 |
2016年 | 1946篇 |
2015年 | 3101篇 |
2014年 | 3723篇 |
2013年 | 3160篇 |
2012年 | 4956篇 |
2011年 | 5476篇 |
2010年 | 3524篇 |
2009年 | 2590篇 |
2008年 | 3295篇 |
2007年 | 3447篇 |
2006年 | 3353篇 |
2005年 | 3465篇 |
2004年 | 2208篇 |
2003年 | 2102篇 |
2002年 | 1759篇 |
2001年 | 1399篇 |
2000年 | 1576篇 |
1999年 | 1617篇 |
1998年 | 1079篇 |
1997年 | 1010篇 |
1996年 | 760篇 |
1995年 | 707篇 |
1994年 | 675篇 |
1993年 | 394篇 |
1992年 | 473篇 |
1991年 | 426篇 |
1990年 | 365篇 |
1989年 | 312篇 |
1988年 | 232篇 |
1987年 | 227篇 |
1986年 | 170篇 |
1985年 | 114篇 |
1984年 | 66篇 |
1983年 | 59篇 |
1982年 | 43篇 |
1981年 | 31篇 |
1980年 | 14篇 |
1979年 | 23篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1975年 | 4篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
51.
用改良的ELISA检测25例正常对照组和32例急性脑血管病患者的血清和脑脊液(CSF)中的脑型肌酸激酶同功酶BB(creatine kinase isoenzyme BB)浓度。32例急性脑血管病患者CSF CKBB平均水平为16.62±8.3ng/ml,明显高于对照组(7.5—4.8ng/ml)。发病24h内CSFCKBB轻微增高,24~48h达高峰,以后下降,7天左右尚未恢复正常。病初CSF CKBB水平明显高于恢复期。9例高血压性脑出血的血肿出血量(按CT片上血肿大小计算)与患者CSF CKBB有密切关系(r=0.8127,P<0.01)。血肿体积(X)与CSF CKBB浓度(y)的回归方程y—7.945±0.872X。 相似文献
52.
Dr.DavidJiang 《中国听力语言康复科学杂志》2004,(4):58-60
听力学是一门刚刚兴起的学科,在我国尚属起步阶段,许多专业词汇都是从英语翻译过来的。为了使广大读者对听力学基本概念有更清晰的认识和理解,本刊特别开辟专栏。约请加拿大达尔豪斯大学教授Dr.David Jiang撰写系列文章,对相关词汇及英语术语加以解释和界定。此间,Dr.David Jiang将选择一些容易混淆和误读的、有代表性的术语和词语,结合现实情况。给大家做更为详尽的介绍。以期我国听力语言康复科学学术界同仁对一些英文专业词汇有更为准确和精当的理解与应用。 相似文献
53.
良性淋巴上皮病、淋巴上皮癌、MALT淋巴瘤的关系 总被引:1,自引:0,他引:1
李江 《中国口腔颌面外科杂志》2007,5(5):379-380
良性淋巴上皮病(benign lymphoepithelial lesion)、淋巴上皮癌(lymphoepithelial carcinoma)、黏膜相关淋巴组织型结外边缘区B细胞淋巴瘤(MALT淋巴瘤)(extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue,MALT lymphoma)是3种性质不同但又存在某些关联的病变,本文对3种病变的病因、组织病理学表现及三者之间的关系进行了介绍,并结合叶为民等论文中的一些内容进行了简要探讨。 相似文献
54.
55.
Jiang He Mary Rusckowski Yi Wang Shuping Dou Xinrong Liu Surong Zhang Guozheng Liu Donald J. Hnatowich 《Molecular imaging and biology》2007,9(1):17-23
Objective Pretargeting with radioactivity has significantly improved tumor to normal tissue radioactivity ratios over conventional antibody
imaging in both animal studies and clinical trials. This laboratory is investigating DNA analogues such as phosphorodiamidate
morpholinos (MORFs) for pretargeting using technetium-99m (99mTc) for detection. However, the unique properties of fluorescence activation and quenching combined with oligomers with their
unique properties of hybridization may be particularly useful when used together for pretargeting with optical detection.
The use of linear fluorophore-conjugated oligomer duplexes have been little used in animals, and to our knowledge, have not
previously been considered for pretargeting applications.
Methods A MORF/cDNA pair was selected such that when hybridized, the fluorescence of the Cy5.5-conjugated 25 mer MORF (Cy5.5–MORF25)
is inhibited with a BHQ3-conjugated 18 mer complementary DNA (BHQ3–cDNA18). The short BHQ3–cDNA18 was selected to dissociate
in the presence of a long cMORF25 in the pretargeted tumor, thus releasing the inhibitor from the Cy5.5 emitter. In this manner,
the Cy5.5 fluorescence will be inhibited everywhere but in the target. The dissociation was first examined in vitro by adding the duplex to the cMORF25 both in solution and immobilized on polystyrene microspheres and by surface plasmon resonance
(SPR). Thereafter, biotinylated cMORF25 immobilized on streptavidin polystyrene microspheres were administered intramuscularly
in one thigh of hairless SKH-1 mice as target while an identical weight of the identical microspheres but without the cMORF25
was administered in the contralateral thigh as control. The animals then received IV the Cy5.5–MORF25/BHQ3–cDNA18 duplex or
equal molar dosage of single-chain Cy5.5–MORF25 and were imaged.
Results The SPR studies showed that the immobilized cDNA18 rapidly captured the flowing MORF25 to provide a duplex with a slow dissociation
rate constant. Furthermore, when cMORF25 was next allowed to flow over the now immobilized duplex, the cDNA18 was unable to
prevent dissociation of the heteroduplex and the formation and release of the cMORF25-MORF25 homoduplex. Images of animals
obtained soon after receiving the Cy5.5–MORF25 singlet showed intense whole body fluorescence obscuring the target thigh.
However, only 5 minutes after receiving the Cy5.5–MORF25/BHQ3–cDNA18 duplex, the target thigh was clearly visible along with
only the kidneys.
Conclusions This first study of optical pretargeting provides a proof of concept that oligomer pretargeting found to be useful with radioactivity
detection is applicable with fluorescent detection as well. In addition, our results demonstrate that by using linear oligomers
for optical pretargeting, chain lengths (and base sequences) may be manipulated to provide duplexes with stabilities and fluorescence
inhibition optimized for pretargeting and other in vivo applications of optical imaging. 相似文献
56.
The C fibre reflex of the cat urinary bladder 总被引:5,自引:3,他引:2
57.
Allen Cato III Linda E. Gustavson Jiang Qian Tawakol El-Shourbagy Edward A. Kelly 《Epilepsia》1998,39(1):43-47
Summary: Purpose: We wished to determine the effect of renal impairment on the pharmacokinetics and tolerability of the new antiepileptic drug tiagabine (TGB).
Methods: We assessed TGB pharmacokinetics and tolerability in 25 subjects with various degrees of renal function (based on creatinine clearance, n = 4–6 per group) from healthy (group I) to requiring hemodialysis (group V) in a single and multiple dose (every 12h), one-period (groups I-IV) or a single dose, two-period (group V) study (4-mg oral doses of TGB · HCl). Blood samples were collected after the first dose (both periods for group V) and after the last dose on day 5 (groups I-IV). TGB plasma concentrations and plasma protein binding were determined by high-performance liquid chromatography (HPLC) and ultrafiltration, respectively.
Results: TGB was well tolerated by all study subjects. The pharmacokinetics of TGB were similar in all subjects; no pharmacokinetic parameter (based on either total or unbound concentrations) was statistically correlated with creatinine clearance. For total TGB in plasma, single-dose mean values of the maximum plasma concentration, clearance, and half-life (t1/2) ranged from 52 to 108 ng/ml, from 7.14 to 11.02 I/h, and from 6.4 to 8.4 h, respectively.
Conclusions: TGB pharmacokinetics and tolerability were independent of renal function; therefore, dosage adjustment is unnecessary for epilepsy patients with renal impairment. 相似文献
Methods: We assessed TGB pharmacokinetics and tolerability in 25 subjects with various degrees of renal function (based on creatinine clearance, n = 4–6 per group) from healthy (group I) to requiring hemodialysis (group V) in a single and multiple dose (every 12h), one-period (groups I-IV) or a single dose, two-period (group V) study (4-mg oral doses of TGB · HCl). Blood samples were collected after the first dose (both periods for group V) and after the last dose on day 5 (groups I-IV). TGB plasma concentrations and plasma protein binding were determined by high-performance liquid chromatography (HPLC) and ultrafiltration, respectively.
Results: TGB was well tolerated by all study subjects. The pharmacokinetics of TGB were similar in all subjects; no pharmacokinetic parameter (based on either total or unbound concentrations) was statistically correlated with creatinine clearance. For total TGB in plasma, single-dose mean values of the maximum plasma concentration, clearance, and half-life (t1/2) ranged from 52 to 108 ng/ml, from 7.14 to 11.02 I/h, and from 6.4 to 8.4 h, respectively.
Conclusions: TGB pharmacokinetics and tolerability were independent of renal function; therefore, dosage adjustment is unnecessary for epilepsy patients with renal impairment. 相似文献
58.
采用反相HPLC荧光测定法对大鼠肾脏N-乙酰氨基葡萄糖转移酶(GnT)Ⅲ活性测定时二价金属离子及氨基糖的影响进行了研究。结果表明:GnTⅢ必须有二价金属离子激活,最佳激活离子为Mn ̄(2+)离子,其次为Mg ̄(2+)离子;二协金属离子对GnTⅢ的激活作用依次为Mn ̄(2+)>Mg(2+)>Co(2+)>Ca ̄(2+)>Ni ̄(2+)>Ba ̄(2+)>Zn ̄(2+)。四种氨基糖(N-乙酰氨基葡萄糖GlcNAc,N-乙酰氨基半轧糖GaINAc,氨基葡萄糖GlcN,氨基半乳糖GalN),除GlcN使GnT活性增加外,其余三种对GnTⅢ均有不同程度的抑制作用。 相似文献
59.
60.
猪卵透明带单克隆抗体的研制 总被引:1,自引:1,他引:0
用热溶猪卵透明带抗原免疫BALB/C 小鼠,取其脾细胞和SP2/O 细胞融合产生的杂交瘤。用间接免疫荧光和ELISA 方法筛选,经四次克隆化后,获得三株分泌猪卵透明带单克隆抗体杂交瘤细胞株(LPD_8,LPC_4,LPD_2)。通过间接免疫荧光试验,其中二株单克隆抗体(LPD_8,LPC_4)与人卵透明带有交叉反应。但它们在猪与人卵透明带上呈现的荧光部位有明显的不同,LPD_8位于整个透明带上,而LPC_4只见于透明带外层。LPD_2荧光位于透明带内层且与人卵无交叉反应。我们认为这种差别是由于抗原决定簇的不同所致。 相似文献