全文获取类型
收费全文 | 1127篇 |
免费 | 62篇 |
国内免费 | 133篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 40篇 |
妇产科学 | 58篇 |
基础医学 | 117篇 |
口腔科学 | 10篇 |
临床医学 | 164篇 |
内科学 | 178篇 |
皮肤病学 | 13篇 |
神经病学 | 52篇 |
特种医学 | 62篇 |
外科学 | 286篇 |
综合类 | 61篇 |
一般理论 | 2篇 |
预防医学 | 55篇 |
眼科学 | 16篇 |
药学 | 142篇 |
1篇 | |
中国医学 | 16篇 |
肿瘤学 | 40篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 23篇 |
2020年 | 8篇 |
2019年 | 18篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 16篇 |
2015年 | 22篇 |
2014年 | 20篇 |
2013年 | 39篇 |
2012年 | 56篇 |
2011年 | 52篇 |
2010年 | 42篇 |
2009年 | 40篇 |
2008年 | 62篇 |
2007年 | 154篇 |
2006年 | 64篇 |
2005年 | 51篇 |
2004年 | 38篇 |
2003年 | 33篇 |
2002年 | 39篇 |
2001年 | 54篇 |
2000年 | 38篇 |
1999年 | 28篇 |
1998年 | 24篇 |
1997年 | 31篇 |
1996年 | 26篇 |
1995年 | 11篇 |
1994年 | 22篇 |
1993年 | 22篇 |
1992年 | 26篇 |
1991年 | 38篇 |
1990年 | 22篇 |
1989年 | 33篇 |
1988年 | 21篇 |
1987年 | 22篇 |
1986年 | 22篇 |
1985年 | 14篇 |
1984年 | 5篇 |
1983年 | 10篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 2篇 |
1973年 | 2篇 |
1966年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有1322条查询结果,搜索用时 15 毫秒
61.
输精管结扎术后附睾瘀积—发生机制及其防治方法的研究 总被引:10,自引:1,他引:10
木文对输精管结扎后的“附睾瘀积”进行了系统研究。选用金黄地鼠为实验动物,结扎组84只,对照组76只。采用微穿刺、微量分析方法证实扎管后附睾功能受损。组织学检查示附睾管扩张,间质充血,有大量慢性炎细胞浸润。临床收集49例病人,39例微波治疗,10例手术,效果优良。采用B超、C超、MRI观察瘀积附睾,发现附睾瘀积多位于附睾尾部。人类标本的光镜及电镜检查证实,附睾瘀积的病理实质是附睾对外渗精子的一种无菌性炎症反应。本文根据研究资料,阐明了附睾瘀积的发生机制,提出了防治方法,并定名为“附睾瘀积综合征”。 相似文献
62.
Correction of penile curvature using the 16-dot plication technique: a review of 132 patients 总被引:3,自引:0,他引:3
PURPOSE: We review the results of 132 cases of congenital and acquired penile curvature corrected with our 16 or 24-dot, minimal tension technique using multiple parallel plications performed under papaverine induced erection. MATERIALS AND METHODS: Chart and telephone interviews were conducted on 132 consecutive patients 16 to 79 years old who underwent penile plication between December 1995 and November 2000. Patient data as well as outcomes were analyzed. RESULTS: We were unable to contact 8 patients. Of the patients 16 had congenital penile curvature, including 4 in whom the Nesbit procedure performed elsewhere had failed, and 116 had Peyronie's disease, including 8 in whom a previous Nesbit procedure had failed. Preoperative complaints included persistent penile pain with erection for more than 1 year in 15 of 132 cases, difficult intercourse or partner discomfort in 106 and poor self-image in 11. Curvature ranged from 30 to 120 degrees. Erections were evaluated preoperatively with duplex ultrasound after intracavernous injection and self-stimulation. Of the patients 63% had good erections, 25% moderate erections requiring sildenafil and 12% poor erections requiring injection therapy. Foreskin edema necessitating subsequent circumcision and an organized hematoma requiring evacuation occurred in 1 case each. At 6 months 93% of patients reported straight erections and 7% reported almost straight but acceptable erections. Recurrence of curvature was reported by 15% of patients at a mean of 2.6 years of followup. Four patients reported worsening of erectile function after the procedure. CONCLUSIONS: Penile plication is a simple, safe method to correct congenital and acquired penile curvature. Using a minimal tension parallel plication technique, excellent durable results can be attained. This simplified repair avoids the neurovascular bundles and has a minimal to no detrimental affect on erectile function. Preoperative counseling must be given regarding penile shortening and the palpable small bumps from the nonabsorbable sutures. 相似文献
63.
Long-term survival of autotransplanted major pelvic ganglion in the corpus cavernosum of adult rats 总被引:2,自引:0,他引:2
Graziottin TM Resplande J Nunes L Rogers R Gholami S Lue T 《The Journal of urology》2002,168(1):362-366
PURPOSE: Neurogenic impotence is a common complication after radical pelvic surgery, irradiation or perineal trauma. Neuronal transplantation is a new frontier for treating neurological disorders. We investigated whether the major pelvic ganglion can survive and become functional after being implanted into the corpus cavernosum in adult rats. MATERIALS AND METHODS: Adult male rats (13) were divided into 3 groups and sacrificed at 3 time points, namely 30 (4), 60 (5) and 90 (4) days. All rats underwent excision of the right major pelvic ganglion and left cavernous nerve. The right ganglion was implanted into the right crus of the penis. Electrostimulation was applied to the left major pelvic ganglion and cavernous nerve (1.5 mA.) and right crus (10 mA.) at sacrifice. The crural region and left ganglion were then excised for immunostaining of neuronal nitric oxide synthase (nNOS), protein gene product 9.5 and growth associated protein 43. Image analysis was used to calculate the area stained in pixels. Electron microscopy of the implanted area was performed to assess neuronal survival. RESULTS: Although the degree varied, all neuronal implants survived after transplantation. The response to electrostimulation was insufficient to produce erection. No difference was noted among the areas of nNOS staining when specimens from the 3 time points were compared. The area of expression of nNOS, protein gene product 9.5 and growth associated protein 43 was larger in the implanted area than in the surrounding cavernous tissue. Under electron microscopy most surviving implants showed normal ultrastructure, although areas of fibrotic replacement were seen in several implants. CONCLUSIONS: Our results show that the autotransplanted major pelvic ganglion expresses nNOS, protein gene product 9.5 and growth associated protein 43, and survived up to 90 days after implantation into the corpus cavernosum. Further studies with fetal neuronal tissue seem warranted. 相似文献
64.
Long-term effect of ovariectomy and simulated birth trauma on the lower urinary tract of female rats 总被引:8,自引:0,他引:8
Resplande J Gholami SS Graziottin TM Rogers R Lin CS Leng W Lue TF 《The Journal of urology》2002,168(1):323-330
PURPOSE: Using an animal model we studied the long-term effects of ovariectomy and simulated birth trauma in the development of apoptosis as well as the urodynamic, histological and ultrastructural findings 9 months after such procedures. MATERIALS AND METHODS: A total of 24 pregnant Sprague-Dawley female rats were used. Immediately after delivery 14 animals underwent vaginal ballooning and ovariectomy, while the remaining 10 served as controls. At 9 months the animals underwent urodynamic evaluation, which included the urethral pressure profile. The rats were then sacrificed and urogenital tissue was obtained for immunostaining using terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end-labeling, histomorphometry evaluation and electron microscopy. RESULTS: Immunostaining demonstrated a significant increase in the apoptotic index in the urethra of castrated/ballooning rats with a predominance in the submucosa layer. Maximum urethral closure pressure was significantly lower in that group, although there was no correlation of apoptosis with maximum urethral closure pressure measurement. Urodynamic evaluation revealed only discrete alterations in cystometric parameters. Morphometric evaluation showed increased connective tissue in the vagina. Electron microscopy of urethral smooth muscle demonstrated altered cellular shape, increased intercellular space with collagen deposition and some degeneration of the mitochondria. CONCLUSIONS: Apoptosis in the urethra occurs 9 months after castration and simulated birth trauma. However, this finding was not seen in the muscle layers or in other urogenital tissues. Some ultrastructural changes also occurred that may explain some symptoms that women have after vaginal childbirth and menopause. 相似文献
65.
The induction of an antibody response to amyloid beta (Abeta) peptide has become a strategy for the treatment of Alzheimer's disease (AD). This has proven effective in reducing the plaque burden in transgenic mice that develop Abeta plaques similar to human AD patients. The mechanism for enhanced clearance of Abeta is partly due to the interaction of immunoglobulin Fcgamma receptor-expressing microglia and specific antibody-opsonized Abeta deposits. This interaction can stimulate Fcgamma receptor-mediated phagocytosis, but also results in inflammatory activation of these cells. Consequently, interaction of microglia with antibody-antigen complexes could exacerbate the existing inflammation in the brains of AD patients. In this study, we used substrate-bound Abeta and cultured human microglia from AD and non-demented cases to model interaction of microglia and antibody-opsonized plaques in AD brains. Enhanced production of tumor necrosis factor-alpha, macrophage colony stimulating factor, interleukin-10, and superoxide ions was detected. We also demonstrated enhanced uptake of opsonized Abeta by microglia, which was reduced significantly in the presence of excess IgG, indicative of the involvement of Fcgamma receptor-mediated mechanisms. Human microglia were shown in this study to express mRNA for Fcgamma receptors I, IIa, IIb, and III. The expression of Fcgamma receptor II was augmented by proinflammatory stimulation. These results suggest that initial interactions of human microglia with antibody-opsonized amyloid could result in increased inflammation. The consequence of this on inflammatory pathology in AD brains needs to be considered before immunization is used as a strategy for treating AD. 相似文献
66.
The N-ras proto-oncogene can suppress the malignant phenotype in the presence or absence of its oncogene 总被引:3,自引:0,他引:3
Diaz R Ahn D Lopez-Barcons L Malumbres M Perez de Castro I Lue J Ferrer-Miralles N Mangues R Tsong J Garcia R Perez-Soler R Pellicer A 《Cancer research》2002,62(15):4514-4518
ras proto-oncogenes have traditionally been associated with the regulation and promotion of cell growth. We have induced thymic lymphomas in N-ras(-/-) mice and in transgenic mice that overexpress wild-type N-ras and found that the lack of wild-type N-ras alleles favors the development of thymic lymphomas,whereas overexpression of wild-type N-ras protects against thymic lymphomagenesis in the presence or absence of its oncogene. To investigate the inhibitory role of wild-type N-ras in in vitro transformation, we introduced wild-type N-ras in N-ras-deficient tumor cells that lack ras activating mutations and found decreased growth in both low serum and soft agar. Taken together, our results indicate that wild-type N-ras has "tumor suppressor" activity, even in the absence of its oncogenic allele. 相似文献
67.
68.
Persistent perfluorinated organic compounds, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are used in a variety of industrial applications. They are very stable in the environment, distribute widely in the global environment and in wild life, and are detected in human sera. 相似文献
69.
Tang HF Yi YH Li L Sun P Zhang SQ Zhao YP 《第二军医大学学报》2005,26(8):902-902
Two new sulfated steroidal pentaglycosides(asterosaponins),novaeguinosides Ⅰ(2) and (Ⅱ)2,along with the known regularoside B(1)were isolated from the starfish Culcita novaeguineae.Their structures were elucidated by extensive NMR techniques as well as chemical evidence. 相似文献
70.
Delayed testosterone replacement restores nitric oxide synthase-containing nerve fibres and the erectile response in rat penis 总被引:2,自引:0,他引:2
OBJECTIVE: To elucidate the effect of testosterone on penile innervation. Materials and methods Three groups of six rats each were assessed; two groups (1 and 2) were castrated and the third (group 3) underwent a sham operation (control). Eight weeks after castration, group 2 received a subcutaneous injection with testosterone. At 8 weeks, the rats in group 1 and 3 underwent a final functional analysis while those in group 2 did so at 12 weeks. The evaluation included a subcutaneous injection with apomorphine to study centrally mediated erection, and cavernosal nerve electrostimulation and papaverine injection to study peripherally mediated erection. At death a penile mid-shaft specimen was taken for NADPH-diaphorase staining. RESULTS: In the apomorphine study, castration resulted in significantly fewer yawns and erections than in the control, and those in group 2 significantly better central erectile function than in the controls. The mean (SEM) number of nitric oxide synthase (NOS)-containing nerve fibres in the corpora cavernosa and both dorsal nerves of castrated rats, at 46.2 (9.1) and 203 (32.1), respectively, were significantly lower than in rats in group 2, at 84.1 (11.2) and 300.6 (17.1), and than in the controls, at 88.6 (10.9) and 306.3 (22.9), respectively. The intracavernosal pressure decreased significantly in the absence of testosterone, both after electrostimulation and intracavernosal papaverine injection. However, there was no difference between the control and group 2 rats in either the number of NOS-containing nerve fibres or in the peripheral erectile functional study. CONCLUSIONS: Testosterone acts on the nervous system to mediate erection; when it is absent there may be down-regulation of both the production and activity of NO, thereby decreasing the response to peripheral stimulation via the NO pathway. The restoration of erectile function seen in rats in group 2 supports this phenomenon. Delayed testosterone replacement has no detrimental effect on the restoration of the erectile mechanism after castration. 相似文献