全文获取类型
收费全文 | 3455篇 |
免费 | 183篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 153篇 |
妇产科学 | 71篇 |
基础医学 | 427篇 |
口腔科学 | 63篇 |
临床医学 | 201篇 |
内科学 | 672篇 |
皮肤病学 | 38篇 |
神经病学 | 173篇 |
特种医学 | 136篇 |
外科学 | 719篇 |
综合类 | 17篇 |
预防医学 | 52篇 |
眼科学 | 103篇 |
药学 | 249篇 |
中国医学 | 31篇 |
肿瘤学 | 542篇 |
出版年
2024年 | 2篇 |
2023年 | 19篇 |
2022年 | 33篇 |
2021年 | 105篇 |
2020年 | 48篇 |
2019年 | 79篇 |
2018年 | 98篇 |
2017年 | 85篇 |
2016年 | 82篇 |
2015年 | 102篇 |
2014年 | 137篇 |
2013年 | 148篇 |
2012年 | 193篇 |
2011年 | 247篇 |
2010年 | 132篇 |
2009年 | 128篇 |
2008年 | 204篇 |
2007年 | 239篇 |
2006年 | 213篇 |
2005年 | 225篇 |
2004年 | 244篇 |
2003年 | 197篇 |
2002年 | 213篇 |
2001年 | 59篇 |
2000年 | 53篇 |
1999年 | 43篇 |
1998年 | 37篇 |
1997年 | 39篇 |
1996年 | 34篇 |
1995年 | 30篇 |
1994年 | 25篇 |
1993年 | 13篇 |
1992年 | 18篇 |
1991年 | 13篇 |
1990年 | 24篇 |
1989年 | 13篇 |
1988年 | 13篇 |
1987年 | 12篇 |
1986年 | 12篇 |
1985年 | 11篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1969年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有3664条查询结果,搜索用时 46 毫秒
51.
Taro Maeda Yukihiro Shintani Kanako Nakano Kazuhiro Terashima Yoshiyasu Yamada 《Pediatrics international》2004,46(2):122-125
BACKGROUND: The efficacy of inactivated influenza vaccine in healthy infants and children younger than 24 months has not been confirmed. The aim of the present study was to determine the prophylactic effect of inactivated influenza vaccine against influenza A in healthy children aged 6-24 months. METHODS: Healthy infants and young children (6-24 months old) were immunized by subcutaneous injection of inactivated influenza vaccine before influenza seasons. Age matched children were randomly assigned as the control. These children were followed up from January to April in each year (2000, 2001 and 2002). The attack rates of influenza A infection was compared and statistically assessed. RESULTS: The attack rate of influenza A virus infection in the vaccine group and the control group were 14.8% (n = 27) vs 12.5% (n = 32) in 2000 (P = 0.526); 2.8% (n = 72) vs 7.2% (n = 69) in 2001 (P = 0.203); and 3.4% (n = 52) vs 8.9% (n = 56) in 2002 (P = 0.205). The attack rates of influenza A between the two groups were not significantly different. CONCLUSIONS: Inactivated influenza vaccine did not reduce the attack rate of influenza A infection in 6-24 month old children. 相似文献
52.
Junko Miyamoto Hiroshi Asanuma Hideo Nakai Tomonobu Hasegawa Hajime Nawata Yukihiro Hasegawa 《Clinical Pediatric Endocrinology》2006,15(4):151-162
The prevalence of abnormalities in androgen receptor gene (AR) among patients with
ambiguous genitalia is unknown. Moreover, endocrinological data from prepubertal patients
with AR mutation are very limited. Thus, the aim of this study was to examine the
prevalence of abnormalities in AR among patients with both ambiguous genitalia, which was
defined as a combination of two or more genital abnormalities (i.e. hypospadias,
microphallus (penile length < 25 mm), hypoplastic scrotum, bifid scrotum, undescended
testis) in this study, and normal to elevated T levels. We also compared the
endocrinological data of prepubertal patients with AR mutation and ambiguous genitalia
with that of those without the AR mutation. We screened 26 Japanese prepubertal 46,XY
patients (five from three families were included) with both ambiguous genitalia and normal
to elevated T levels. Mutations in AR were found in three (two of the three were related).
Among the 23 patients without mutation in AR, the steroid 5-alpha-reductase 2 gene
(SRD5A2) was also examined in eight patients with elevated T/dehydrotestosterone ratio
after the hCG (>10) or with undervirilized family members. No mutation in SRD5A2 was
found. Characteristics of the three patients with mutation in AR were compared with the 23
patients without mutation. In two patients, basal T levels (0.3, 0.2 ng/ml) and peak T
levels after the hCG tests (8.3, 8.5 ng/ml) tended to be higher, and the peak LH/ peak FSH
ratios after the GnRH tests (4.6, 4.0) were higher than in patients without mutation, at
the ages of 1 yr and 9 mo and 3 yr and 8 mo, respectively. In conclusion, an abnormality
in either AR or SRD5A2 was not common among patients with ambiguous genitalia and normal
testosterone secretion. Elevated peak LH/peak FSH ratio (≥4) after the GnRH test in
addition to detectable basal T levels and elevated peak T levels after the hCG test may
infer AR abnormality in prepubertal patients with ambiguous genitalia at the age of one
and over, although further study is needed, because our data were limited. 相似文献
53.
No Improvement of Adult Height in Non-growth Hormone (GH) Deficient Short
Children with GH Treatment
Toshiaki Tanaka Kenji Fujieda Susumu Yokoya Akira Shimatsu Katsuhiko Tachibana Hiroyuki Tanaka Takakuni Tanizawa Akira Teramoto Toshiro Nagai Yoshikazu Nishi Yukihiro Hasegawa Kunihiko Hanew Keinosuke Fujita Reiko Horikawa Goro Takada Masao Miyashita Tadashi Ohno Kazuo Komatsu 《Clinical Pediatric Endocrinology》2006,15(1):15-21
It is still in doubt whether the standard-dose growth hormone (GH) used in Japan (0.5
IU/kg/week, 0.167 mg/kg/week) for growth hormone deficiency is effective for achieving
significant adult height improvement in non-growth hormone deficient (non-GHD) short
children. We compared the growth of GH-treated non-GHD short children with that of
untreated short children to examine the effect of standard-dose GH treatment on non-GHD
short children. GH treatment with recombinant human growth hormone (rhGH) was started
before the age of 11 yr in 64 boys and 76 girls with non-GHD short stature registered at
the Foundation for Growth Science who have now reached their adult height. In 119
untreated boys and 127 untreated girls whose height standard deviation score (SDS) was
below –2 SD at the age of 6 yr, height growth was followed until 17 yr. Height SDS was
significantly lower before GH treatment in the GH-treated group than at the age of 6 yr in
the untreated group, in both sexes. Adult height and adult height SDS were significantly
greater in the untreated group than in the GH-treated group, in both sexes, although the
change in height SDS did not differ significantly. Height SDS was significantly lower
before GH treatment in the GH-treated group than at the age of 6 yr in the untreated
group, so 57 boys and 57 girls whose height SDS at the age of 6 yr in the untreated group
closely matched the height SDS before GH treatment in the GH-treated group were chosen for
comparison. Height SDS did not differ significantly between the GH-treated group before GH
treatment and the untreated group at the age of 6 yr, nor were there differences between
these subgroups in adult height, adult height SDS, or height SDS change, in either sex.
The effect of GH treatment is reported to be dose-dependent and doses over 0.23 mg/kg/week
are reported to be necessary to improve adult height in non-GHD short children. Currently,
the GH dose is fixed at 0.175 mg/kg/week in Japan, and we expected to find, and indeed
concluded, that ordinary GH treatment in Japanese, non-GHD short children does not improve
adult height. 相似文献
54.
Gaku Matsumoto Jun-ichi Namekawa Mariko Muta Tadahiko Nakamura Hiroko Bando Kazumi Tohyama Masakazu Toi Kazuo Umezawa 《Clinical cancer research》2005,11(3):1287-1293
We previously designed and synthesized the new nuclear factor kappaB (NF-kappaB) inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) derived from the structure of the antibiotic epoxyquinomicin C. We looked into the effect of DHMEQ on cellular phenotypes and tumor growth in mice injected with human breast carcinoma cell line MDA-MB-231 or MCF-7. In estrogen-independent breast adenocarcinoma cell line MDA-MB-231, NF-kappaB is constitutively activated. The addition of DHMEQ (10 microg/mL) completely inhibited the activated NF-kappaB for at least 8 hours. On the other hand, NF-kappaB is not activated in estrogen-dependent MCF-7 cells. In this cell line, DHMEQ completely inhibited the tumor necrosis factor-alpha-induced activation of NF-kappaB. DHMEQ did not inhibit the degradation of IkappaB but inhibited the nuclear translocation of NF-kappaB by both p65/p50 and RelB/p52 pathways. MDA-MB-231 cells secrete interleukin (IL)-6 and IL-8 without stimulation, and DHMEQ decreased the secretion levels of both cytokines. When MDA-MB-231 or MCF-7 cells were stimulated by tumor necrosis factor-alpha, the inhibitory effects of DHMEQ were still maintained. I.p. administration of DHMEQ (thrice a week) significantly inhibited the tumor growth of MDA-MB-231 (12 mg/kg) or MCF-7 (4 mg/kg) in severe combined immunodeficiency mice. No toxicity was observed during the experiment, including the loss of body weight. An immunohistological study on resected MCF-7 tumors showed that DHMEQ inhibited angiogenesis and promoted apoptosis. Furthermore, in Adriamycin-resistant MCF-7 cells highly expressing multidrug resistance gene-1, DHMEQ also exhibited the above capability, including down-regulation of IL-8. Thus, DHMEQ might be a potent drug for the treatment of various breast carcinomas by inhibiting the NF-kappaB activity. 相似文献
55.
Kusnandar Anggadiredja Masanori Nakamichi Takato Hiranita Hiroyuki Tanaka Yukihiro Shoyama Shigenori Watanabe Tsuneyuki Yamamoto 《Neuropsychopharmacology》2004,29(8):1470-1478
We clarified the modulating action of the endocannabinoid system, and its possible mediation by the arachidonic acid cascade, on the reinstatement of methamphetamine (METH)-seeking behavior, using the intravenous self-administration paradigm in rats. Following 12 days of self-administration of METH, the replacement of METH with saline resulted in a gradual decrease in lever press responses (extinction). Under extinction conditions, METH-priming or re-exposure to cues previously paired with METH infusion markedly increased the responses (reinstatement of drug-seeking). The cannabinoid CB1 receptor antagonist, SR141716A, blocked this behavior. Although the cannabinoid agonist, Delta8-tetrahydrocannabinol (THC), had no effects by itself, coadministration of the agonist and METH at small doses reinstated the drug-seeking behavior. THC attenuated the effects of the reinstatement-inducing dose of METH, but enhanced the effect of cues. Either given repeatedly during the extinction or singly, 24 h before the first METH-priming or cues challenge, THC suppressed the reinstatement. In another set of experiments, we found that diclofenac, a cyclooxygenase inhibitor, also attenuated the reinstatement induced by exposure to cues or drug-priming. These results suggest that the endocannabinoid system, through possible mediation by the arachidonic acid cascade, serves as a modulator of the reinstating effects of METH-priming and cues. Extending the current view on the treatment of drug dependence, these results indicate that endocannabinoid-activating substances as well as cyclooxygenase inhibitors may be promising as antirelapse agents. 相似文献
56.
The present review focused the involvement of N-methyl-d-aspartate (NMDA) receptors in morphine physical dependence. The increased levels of extracellular glutamate, NMDA receptor ζ subunit (NR1) mRNA, NMDA receptor 1 subunit (NR2A) protein, phosphorylated Ca2+/calmodulin kinase II (p-CaMKII) protein, c-fos mRNA, c-Fos protein, are observed in the specific brain areas of mice and/or rats showing signs of naloxone-precipitated withdrawal. In preclinical and clinical studies, a variety of NMDA receptor antagonists and pretreatment with an antisense oligonucleotide of the NR1 have been reported to inhibit the development, expression and/or maintenance of opiate physical dependence. In contrast to data obtained in adult animals, NMDA receptor antagonists are neither effective in blocking the development of opiate dependence nor the expression of opiate withdrawal in neonatal rats. In the NMDA receptor-deficient mice, the NR2A knockout mice show the marked loss of typical withdrawal abstinence behaviors precipitated by naloxone. The rescue of NR2A protein by electroporation into the nucleus accumbens of NR2A knockout mice reverses the loss of abstinence behaviors. The activation of CaMKII and increased expression of c-Fos protein in the brain of animals with naloxone-precipitated withdrawal syndrome are prevented by NMDA receptor antagonists, whereas the increased levels of extracellular glutamate are not prevented by them. These findings indicate that glutamatergic neurotransmission at the NMDA receptor site contributes to the development, expression and maintenance of opiate dependence, and suggest that NMDA receptor antagonists may be a useful adjunct in the treatment of opiate dependence. 相似文献
57.
Kyohei Takahashi Yukihiro Tohdoh Takeo Matsubayashi Vladimír Jellúš Katsuya Maruyama 《Clinical imaging》2012,36(6):816-820
Longitudinal relaxation time (T1) determined by 3.0-T magnetic resonance imaging of the tibialis anterior and extensor digitorum longus muscles increased gradually with muscle fatigue caused by three 120-s periods of repeated ankle dorsiflexion separated by 5-min rest periods. T1 values decreased in the recovery period, although they remained higher than the preexercise values. T1 values for the soleus muscle were unchanged throughout the experiment. Results suggest that muscle T1 values increase with increasing muscle fatigue. 相似文献
58.
59.
Monoclonal antibodies (MAbs) against natural products with low?molecular weights have become an important tool when combined with
other analytical systems. Eastern blotting involves a typical staining system wherein, for example, glycosides can be blotted to a membrane
and cross?linked and stained using MAbs. An immunoaffinity column combined with a monoclonal antibody allows a one?step purification
of hapten compounds or preparation of a knockout extract that removes only the target hapten molecules from a crude extract. Here, we
discuss the application of these extracts. Single?chain variable fragment (scFv) proteins have led to novel assay systems such as fluobodies or
antibodies coupled with green fluorescent protein for natural products. A typical novel application of a scFv gene would be in the context of
plant breeding; this is designated “missile?type” molecular breeding, intended to increase hapten molecule concentrations in transgenic plants 相似文献