全文获取类型
收费全文 | 3545篇 |
免费 | 213篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 62篇 |
妇产科学 | 29篇 |
基础医学 | 492篇 |
口腔科学 | 66篇 |
临床医学 | 381篇 |
内科学 | 1069篇 |
皮肤病学 | 70篇 |
神经病学 | 158篇 |
特种医学 | 137篇 |
外科学 | 461篇 |
综合类 | 13篇 |
预防医学 | 118篇 |
眼科学 | 42篇 |
药学 | 315篇 |
中国医学 | 7篇 |
肿瘤学 | 334篇 |
出版年
2022年 | 27篇 |
2021年 | 55篇 |
2020年 | 30篇 |
2019年 | 40篇 |
2018年 | 58篇 |
2017年 | 41篇 |
2016年 | 60篇 |
2015年 | 50篇 |
2014年 | 101篇 |
2013年 | 93篇 |
2012年 | 150篇 |
2011年 | 152篇 |
2010年 | 86篇 |
2009年 | 69篇 |
2008年 | 151篇 |
2007年 | 152篇 |
2006年 | 140篇 |
2005年 | 122篇 |
2004年 | 150篇 |
2003年 | 148篇 |
2002年 | 176篇 |
2001年 | 168篇 |
2000年 | 187篇 |
1999年 | 174篇 |
1998年 | 60篇 |
1997年 | 45篇 |
1996年 | 38篇 |
1995年 | 39篇 |
1994年 | 23篇 |
1993年 | 37篇 |
1992年 | 115篇 |
1991年 | 90篇 |
1990年 | 73篇 |
1989年 | 82篇 |
1988年 | 69篇 |
1987年 | 65篇 |
1986年 | 58篇 |
1985年 | 61篇 |
1984年 | 42篇 |
1983年 | 30篇 |
1979年 | 21篇 |
1977年 | 14篇 |
1973年 | 14篇 |
1971年 | 14篇 |
1970年 | 18篇 |
1969年 | 15篇 |
1968年 | 19篇 |
1967年 | 14篇 |
1966年 | 23篇 |
1965年 | 16篇 |
排序方式: 共有3783条查询结果,搜索用时 15 毫秒
991.
SEA0400, a novel and selective inhibitor of the Na+-Ca2+ exchanger, attenuates reperfusion injury in the in vitro and in vivo cerebral ischemic models. 总被引:16,自引:0,他引:16
T Matsuda N Arakawa K Takuma Y Kishida Y Kawasaki M Sakaue K Takahashi T Takahashi T Suzuki T Ota A Hamano-Takahashi M Onishi Y Tanaka K Kameo A Baba 《The Journal of pharmacology and experimental therapeutics》2001,298(1):249-256
The effect of the newly synthesized compound 2-[4-[(2,5-difluorophenyl)methoxy]phenoxy]-5-ethoxyaniline (SEA0400) on the Na+-Ca2+ exchanger (NCX) was investigated and compared against that of 2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea (KB-R7943). In addition, the effects of SEA0400 on reperfusion injury in vitro and in vivo were examined. SEA0400 was extremely more potent than KB-R7943 in inhibiting Na+-dependent Ca2+ uptake in cultured neurons, astrocytes, and microglia: IC50s of SEA0400 and KB-R7943 were 5 to 33 nM and 2 to 4 microM, respectively. SEA0400 at the concentration range that inhibited NCX exhibited negligible affinities for the Ca2+ channels, Na+ channels, K+ channels, norepinephrine transporter, and 14 receptors, and did not affect the activities of the Na+/H+ exchanger, Na+,K+-ATPase, Ca2+-ATPase, and five enzymes. SEA0400, unlike KB-R7943, did not inhibit the store-operated Ca2+ entry in cultured astrocytes. SEA0400 attenuated dose- dependently paradoxical Ca2+ challenge-induced production of reactive oxygen species, DNA ladder formation, and nuclear condensation in cultured astrocytes, whereas it did not affect thapsigargin-induced cell injury. Furthermore, administration of SEA0400 reduced infarct volumes after a transient middle cerebral artery occlusion in rat cerebral cortex and striatum. These results indicate that SEA0400 is the most potent and selective inhibitor of NCX, and suggest that the compound may exert protective effects on postischemic brain damage. 相似文献
992.
Takayanagi R Nakamura Y Nakajima Y Shimizu A Nakamura H Yamada Y Suzuki H Arakawa Y Omata M Iga T 《Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan》2004,124(4):225-229
During performance of clinical trials in medical institutions, information regarding the safety of investigational drugs is submitted by trial sponsors according to guidelines for good clinical practice. In the present study, reports of clinical trials conducted at the University of Tokyo Hospital were examined, focusing on the safety information provided to the Institutional Review Board (IRB). Two hundred two reports (52 protocols) of safety information were submitted to the IRB by clinical trial sponsors between April 2000 and March 2001, of which 185 contained a total of 3021 cases of adverse events. Of those, 194 reports were judged by clinical investigators/physicians not to be associated with any significant problems and the trials were continued. For 157 of those 194 reports, it was considered unnecessary to inform the test subjects of the report contents, including the adverse events. The decision of whether or not the test subjects should be informed of such contents tended to depend on the causal relationship between the adverse events and drug intake, as well as the predictability of the adverse events. For 8 of those 194 reports, the IRB recommended that the clinical investigators/ physicians provide information to the test subjects and/or submit detailed information on the status of these subjects to the IRB. From these results, we suggest that establishment of a system to unify and evaluate drug safety information is necessary to provide safe and efficient clinical trials. 相似文献
993.
Takuji Kawamura Shiho Nakamura Daiki Sone Hiroaki Sakai Kana Amamiya Naonori Inoue Naokuni Sakiyama Atsushi Shirakawa Yusuke Okada Kasumi Sanada Kojiro Nakase Koichiro Mandai Azumi Suzuki Atsuhiro Morita Kiyohito Tanaka Koji Uno Kenjiro Yasuda 《Journal of gastroenterology and hepatology》2019,34(3):532-536
994.
We herein report a 31-year-old woman with progressive hemifacial atrophy. The atrophy at her left face began about ten years ago. She had been in a traffic accident one year before the onset of her facial atrophy. Neurological examination revealed anisocoria (right < left) and retraction of the left eyelid, which thus suggested the presence of Pourfour de Petit syndrome. The pupillary reaction to both cocaine and tyramine were reduced bilaterally. Thermography of the face showed slightly lower surface temperature on the left side. A facial thermal sweat test was normal. These findings indicated local hyperactivity of the sympathetic nervous system at the Th 1-Th2 levels on the left side. A left stellate ganglion block effectively induced an accumulation of the subcutaneus tissue of her face on the left side. This is a very rare case in which local sympathetic hyperactivity is present and has caused progressive hemifacial atrophy. 相似文献
995.
A case of neuro-Beh?et's disease manifested as chronic progressive cerebellar ataxia is reported. A 56-year-old woman had suffered from recurrent oral aphthous ulcers, genital ulcers and polyarthritis since her late twenties. At age 53, she noticed small stepped-gait; at age 55, she developed scanning speech, a wide-based gait and memory disturbance. On admission she had oral aphthous ulcers, scarring of genital ulcers and polyarthralgia. A neurological examination revealed memory disturbance, saccadic eye movement, scanning speech, a slow tongue wiggle, moderate limb and truncal ataxia and moderate hyperreflexia in four limbs without pathological reflexes. Relevant laboratory examination data showed a positive HLA-B51. The cerebrospinal fluid (CSF) had a mild elevation of the cell counts and the amounts of protein. Brain magnetic resonance imaging showed mild atrophy of the cerebellum and brainstem. Fluoro-2-deoxyglucose-positron emission tomography showed a decreased glucose metabolism in the cerebellum and brainstem. Methylprednisolone pulse therapy (1 g x 3 days) followed by oral corticosteroids (50 mg/day) with gradual tapering markedly alleviated the cerebellar ataxia. The presence of oral and genital ulcers and CSF pleocytosis as well as effectiveness of corticosteroids in relieving the neurologic symptoms suggested neuro-Beh?et's disease. We propose the existence of a new subtype of neuro-Beh?et's disease characterized by chronic progressive cerebellar involvement possibly due to microvasculitis for which corticosteroids may be effective. 相似文献
996.
Arakawa T Hayashi S Kinugasa Y Murakami G Fujimiya M 《Okajimas folia anatomica Japonica》2010,87(2):49-58
To investigate intergender differences in muscle cleavage and joining during development of the external anal sphincter (EAS), we examined semiserial sections of 16 fetuses between 15 and 30 weeks of gestation (6 males and 10 females). The subcutaneous part of the EAS (EASsc) developed along the male perineal raphe and extended posteriorly. Thus, the male EAS was characterized by anterior protrusion of the subcutaneous muscle, in contrast to the almost circular female EAS. In both genders, the bulbospongiosus anlage (or the levator ani anlage) issued muscle fibers to form the superficial (or deep) part of the EAS. The EASsc communicated with the superficial part in males, whereas the female bulbospongiosus tended to communicate with the levator ani rather than the EAS. In both genders, the longitudinal muscle bundle(s) of the anorectum contributed to perineal body formation. However, the male perineal body also had a thick fascia between the rhabdosphincter and the levator. The bulbospongiosus seems to play a critical role in forming the EAS. A strict intergender difference in subcutaneous muscle development is evident along the perineal raphe, as the raphe is not evident in females. These results help to explain variations in the EAS, including anal malformations. 相似文献
997.
Animals are known to recognize a specific odorant informing conspecific health condition, which plays a significant role in regulating their social communication. Here, we assess neural mechanisms regulating innate approach/avoidance response toward such conspecific odor cues in rats. Odor scent from healthy conspecifics induced approach behavior, while those from sick conspecifics produced avoidance response in odor-recipient male rats. Analysis of mRNA expression in several brain sites of odor recipient rats illustrated that induction of c-fos mRNA expression was found in the olfactory bulb (OB), the medial amygdala (MeA), the bed nucleus of stria terminalis (BnST), and the paraventricular nucleus of the hypothalamus (PVN), when exposed to conspecific odor. Moreover, in the MeA, expression of oxytocin (OT) receptor mRNA was increased when rats were exposed to healthy conspecific odor, while induction of arginine vasopressin (AVP) receptor 1a and 1b mRNA were found only when exposed to sick conspecific odor. Bilateral infusion of OT receptor (OTR) antagonist, (d(CH2)5(1),Tyr(Me)(2),Thr(4),Orn(8),des-Gly-NH2(9))-Vasotocin, into the MeA blocked approach behavior to healthy odor, while those of AVP receptor antagonists, V1a selective: (Phenylac(1),D-Tyr(Me)(2),Arg(6.8),Lys-NH2(9))-Vasopressin, and type 1 receptor antagonist: (Deamino-Pen(1), Try(Me)(2), Arg(8))-Vasopressin, into the MeA inhibited avoidance response to sick odor. These findings provide evidence for an essential role of OT and AVP receptors, especially type 1a, in the MeA in regulating approach/avoidance behaviors, respectively, in social odorant communication. 相似文献
998.
Hasegawa A Takenobu T Kasumi H Komori S Koyama K 《American journal of reproductive immunology (New York, N.Y. : 1989)》2008,60(3):187-191
Problem Early studies have shown that an antibody to male reproductive tissue CD52 is a pathogenic factor of infertility. The molecule contains a unique carbohydrate antigen that induces antibodies interfering with sperm function. However, the characteristic properties of CD52 in female reproductive tissues are not known. We examined the expression and localization of CD52 in mature expanded cumulus masses. Method of study Mouse cumulus oocyte complexes were collected from [C57B1/6; DBA/2] F1 female mice having a superovulation treatment. Human cumulus cells were obtained from infertile patients taking in vitro fertilization-embryo transfer treatment under informed consent. CD52 messenger RNA (mRNA) and protein were detected using RT-PCR, quantitative PCR, western blotting and immunohistochemical methods. Results CD52 mRNA was found both in the human and mouse cumulus cells. Mouse CD52 mRNA was detected in cumulus cells but not oocytes and significantly increased after ovulation. The expression of the molecule was also confirmed at the protein level. Immunostaining with anti CD52 peptide antibody revealed that CD52 is present in cumulus cells and the extracellular matrix. Conclusion We first showed the expression of CD52 in human cumulus cells. CD52 has some functional roles around fertilization in females as well as in males. 相似文献
999.
Relationship of serological subtype, basic core promoter and precore mutations to genotypes/subgenotypes of hepatitis B virus 总被引:4,自引:0,他引:4
Using phylogenetic analysis and pairwise comparison of 670 complete hepatitis B virus (HBV) genomes, we demonstrated that nucleotide divergence greater than 7.5% can be used to separate strains into genotypes A-H. Strains can be separated into subgenotypes when two criteria are met: nucleotide divergence of about 4% but less than 7.5% and good bootstrap support. There is a highly statistically significant association between serological subtypes and genotypes (chi2-test for association, P < 0.0001): adw is associated with genotypes A, B, F, G, and H, adr with C and ayw with D and E. The logistic regression method showed that 1802-1803CG are characteristic of genotypes A, D, and E whereas 1802-1803TT are characteristic of genotypes B, C, and F. 1858C is positively associated with genotypes A, F, and H and 1858T with genotypes B, D, and E. Subgenotypes C2, F1/F4 can be differentiated from subgenotypes C1, F2/F3, respectively, because the latter have 1858C as opposed to 1858T in the former. 1888A was positively associated with subgenotype A1 and TAA at 1817 with genotype G. The Haploplot method revealed high linkage between loci 1858 and 1896 but strong evidence of recombination between loci 1862 and 1896. Loci 1809-1812, 1862, and 1888 may have co-evolved. Using a computer program, we showed that serological subtype deduced from the S region (position 155-835) and mutations/variations within the basic core promoter/precore region (1653-1900), allowed genotyping of HBV with 97% sensitivity and 99% specificity. Certain subgenotypes or subgenotype groups could also be differentiated. 相似文献
1000.
Arakawa T Sekiya S Kumaki K Terashima T 《Anatomical science international / Japanese Association of Anatomists》2006,81(3):187-196
To understand which layer of the intrinsic muscles of the foot the adductor hallucis muscle belongs to, it is essential to investigate the innervation patterns of this muscle. In the present study, we examined the innervation patterns of the adductor hallucis muscles in 17 feet of 15 Japanese cadavers. We investigated the intramuscular nerve supplies of the adductor hallucis muscles in six feet and performed nerve fiber analysis in three feet. The results indicate that: (i) the oblique head of the adductor hallucis muscle is divided into three compartments (i.e. lateral, dorsal and medial parts) or two compartments (i.e. dorsal and medial parts) based on its intramuscular nerve supplies, but we could not classify the transverse head into any parts; (ii) the communicating twig between the lateral and medial plantar nerves penetrated the oblique head of the adductor hallucis muscle in 13 of 17 feet (76.5%); (iii) the penetrating twig entered between the lateral and dorsal parts of the oblique head, passed between the lateral and medial parts of this muscle and then connected with the medial plantar nerve; and (iv) the majority of the nerve fibers of the penetrating twig derived from the lateral plantar nerve. The present study demonstrated that only the lateral part of the oblique head of the adductor hallucis muscle had a unique innervating pattern different from other parts of this muscle, suggesting that the lateral part of the oblique head has a different origin from other parts of this muscle. 相似文献