全文获取类型
收费全文 | 10304篇 |
免费 | 558篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 231篇 |
妇产科学 | 193篇 |
基础医学 | 1352篇 |
口腔科学 | 243篇 |
临床医学 | 1047篇 |
内科学 | 2447篇 |
皮肤病学 | 117篇 |
神经病学 | 1169篇 |
特种医学 | 363篇 |
外科学 | 1686篇 |
综合类 | 17篇 |
预防医学 | 307篇 |
眼科学 | 105篇 |
药学 | 619篇 |
中国医学 | 12篇 |
肿瘤学 | 912篇 |
出版年
2023年 | 54篇 |
2022年 | 156篇 |
2021年 | 223篇 |
2020年 | 134篇 |
2019年 | 182篇 |
2018年 | 262篇 |
2017年 | 214篇 |
2016年 | 255篇 |
2015年 | 237篇 |
2014年 | 363篇 |
2013年 | 500篇 |
2012年 | 782篇 |
2011年 | 718篇 |
2010年 | 407篇 |
2009年 | 394篇 |
2008年 | 684篇 |
2007年 | 650篇 |
2006年 | 693篇 |
2005年 | 666篇 |
2004年 | 696篇 |
2003年 | 605篇 |
2002年 | 514篇 |
2001年 | 110篇 |
2000年 | 85篇 |
1999年 | 91篇 |
1998年 | 119篇 |
1997年 | 89篇 |
1996年 | 94篇 |
1995年 | 81篇 |
1994年 | 70篇 |
1993年 | 73篇 |
1992年 | 70篇 |
1991年 | 73篇 |
1990年 | 51篇 |
1989年 | 60篇 |
1988年 | 41篇 |
1987年 | 40篇 |
1986年 | 46篇 |
1985年 | 31篇 |
1984年 | 41篇 |
1983年 | 31篇 |
1982年 | 37篇 |
1981年 | 34篇 |
1980年 | 28篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 11篇 |
1973年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Giancarlo Flati Donato Flati Barbara Porowska Giorgio Rossi Sandro Francavilla Emanuele Santoro M. Carboni 《Microsurgery》1993,14(9):628-633
Circumferential choledochoplasties with vascular grafts have rarely been attempted either experimentally or in clinical practice. In this study, choledochoplasties using autologous venous and arterial grafts were performed in rats. Sixty-four rats were randomly selected into five treatment groups: A) venous interpositional graft replacement of a choledochus gap without a stent; B) venous graft with prolene stent; C) venous graft with polyethylene stent; D) arterial graft; E) a control group with simple resection between ligatures in the choledochus. The operative mortality in treatment groups B, C, D, and E, was 0, and 13% in group A. At 12 weeks follow-up, all the rats in group E had died, whereas, 52.2% (P <.05) of the rats in group A, 30% of the rats in group B, 57% of the rats in group C, and 92.8% of the rats in group D survived treatment. Surviving animals were sacrificed at 3 months for further examination. The morphology and caliber of the common bile duct of these rats were normal in 25% of the rats in group A, 33% of the rats in group B, 25% of the rats in group C, and 84.6% of the rats in group D. Proximal dilations were found in the rats presenting with abnormal morphology. The dilations were less marked in the group treated by arterial choledochoplasties. Laboratory and clinical cholestatic parameters were within normal ranges in the presence of common bile duct dilations less than four times the normal duct caliber. Electron microscopic examination of the venous and arterial graft at 3 months follow-up revealed a fibrous ring composed of collagen fibers, fibroblasts, and remnants of elastic fibers. Regenerated ductal epithelium encompassed both types of grafts. Epithelialization was more pronounced in venous grafts as compared to arterial grafts. Biliary epithelium was able to colonize the venous grafts and resume cell specialization and function as in normal biliary epithelium. The most satisfactory results were obtained using venous grafts with stents or by using arterial grafts. © 1993 Wiley-Liss Inc. 相似文献
32.
Giuseppe Micieli Marco Magri Giorgio Sandrini Cristina Tassorelli Giuseppe Nappi 《Cephalalgia : an international journal of headache》1988,8(3):193-201
In this study the variations in pupil diameter induced by different stimuli (dark-light adaptation, light reflex, electric stimulation of the sural nerve) were investigated in episodic (in the active or remission phases) and in chronic cluster headache (CH) patients. Pupil size monitoring was performed with a monocular, infrared TV pupillometer, and sural nerve stimuli were applied after the pain threshold had been measured as the flexion reflex threshold of the biceps femoris muscle (RIII reflex). The results were compared with those obtained in patients with "peripheral" (third neuron) Horner's syndrome and in healthy sex- and age-matched controls. On the symptomatic side we found an impairment of pupil response to light flashes and nociceptive stimuli; similar findings were sometimes evident on the pain-free side, too. These results substantiate previous observations that in cluster headache a dysfunction of the integrative central nervous system pathways also exists intercritically and mostly bilaterally, involving both autonomic regulation and pain perception mechanisms. 相似文献
33.
A Giorgio P Amoroso G Francica G de Stefano P Fico G Lettieri L Tarantino L Finelli F Fiorentino P Pierri 《Gastrointestinal radiology》1988,13(4):336-340
To clarify the therapeutic role of echo-guided percutaneous puncture (EPP) in management of amebic liver abscess, 20 patients (24 abscesses) received metronidazole plus EPP. Fluid was aspirated through Chiba needles under real-time sonographic guidance so as to reduce cavity size to less than 3 cm. Not more than two EPPs were necessary in the majority of cases and no complication followed the procedure. This scheme resulted in a shortening of time of both hospitalization (less than or equal to 20 days) and liver lesion healing as assessed by ultrasound (less than or equal to 4 months). It is concluded that EPP is a valuable and safe therapeutic tool for hepatic amebic abscess. 相似文献
34.
Carmine M. Carapella Marco G. Paggi Fabio Cattani Giovanni B. Ciottoli Aristide Floridi Bruno Iandolo Laura Raus Antonio Riccio Antonio Caputo 《Journal of neuro-oncology》1989,7(1):103-108
Summary Up-to-date unsatisfactory results obtained in multimodality treatments of malignant glioma have prompted the research of new therapeutic modalities with unconventional modes of action. Lonidamine (LND) is a drug which reduces aerobic glycolytic activity in both human and experimental tumors. This effect mainly depends on the inhibition of mitochondrially-bound hexokinase (HK) which is present in large amounts in malignant cells. A Phase II study was conducted on patients with recurrent glioma; 12 patients were admitted to the study. Clinical side effects were moderate, necessitating a reduction of the dosage in only 1 case. The objective results were evaluated according to the indications of Levin. 2 responders and 3 cases of stable disease were observed out of 10 evaluable patients. The potential value of this new drug is discussed. 相似文献
35.
36.
Crosignani Pier Giorgio; De Cecco Luigi; Gastaldi Attilio; Venturini Pier Luigi; Oldani Sabina; Vegetti Walter; Semino Antonio; Commare Paolo La; Vercellini Paolo 《Human reproduction (Oxford, England)》1996,11(12):2732-2735
An open-label randomized pilot study was conducted to evaluatethe efficacy and acceptability of 6 months treatment with leuprolidein a 3-monthly versus a monthly i.m. depot injection for therelief of chronic pelvic pain in women with endometriosis. Atotal of 30 women aged 18-38 years were allocated to the 3-monthlydepot arm (n = 15) or to the monthly depot arm (n = 15) afterlaparoscopic diagnosis of pelvic endometriosis. Mean (SD) deepdys-pareunia scores according to a 03 point verbal ratingscale decreased from 1.8 (0.9) at baseline to 1.3 (0.7) at theend of treatment in the 3-monthly depot group and from 2.1 (1.2)to 13 (0.7) in the monthly depot group. Correspondingvalues in non-menstrual pain scores fell from 2.1 (0.6) to 1.1(03), and from 2.1 (0.8) to 1.2 (0.4) respectively, withoutstatistically significant differences between the groups. Serumluteinizing hormone (LH) and 17-oestradiol concentrations weresignificantly suppressed at 12 and 24 weeks compared with baselinevalues, without differences between the groups. The monthlydepot caused a slightly more marked inhibition of serum folliclestimulating hormone (FSH) levels with respect to the 3-monthlypreparation. Mean (SD) endometriosis scores at baseline andat 6-month follow-up laparoscopy were respectively 32.8 (25.1)and 12.2 (9.3) in the 3-monthly depot group and 29.0 (22.7)and 13.1 (15.3) in the monthly depot group (paired Mest, P 0.05). Mean percentage decrease in lumbar spine bone mineraldensity was 5.2% in the former and 4.9% in the latter subjects.In the 3-monthly depot group, 13 women graded the tolerabilityof their treatment schedule as good compared withseven in the monthly depot group (2 = 5.40, P = 0.02). 相似文献
37.
38.
Chiara Leoni Elizabeth Katherine Anna Triumbari Catello Vollono Roberta Onesimo Maria Podagrosi Valentina Giorgio Eliza Kuczynska Stefania Veltri Marco Tartaglia Giuseppe Zampino 《American journal of medical genetics. Part A》2019,179(6):940-947
Pain in individuals with RASopathies is a neglected topic in literature. In this article, we assessed prevalence and profile of pain in a sample of 80 individuals affected by RASopathies. The study sample included individuals with Noonan syndrome (N = 42), Costello syndrome (N = 17), and cardio‐facio‐cutaneous syndrome (N = 21). A set of standardized questionnaires and scales were administered (VAS/numeric scale, r‐FLACC, Wang‐Baker scale, NPSI, BPI, NCCPC‐R) to detect and characterize acute and chronic pain and to study the influence of pain on quality of life (PEDs‐QL, SF‐36) and sleeping patterns (SDSC); revision of past medical history and multisystemic evaluation was provided. Available clinical data were correlated to the presence of pain. High prevalence of acute (44%) and chronic (61%) pain was documented in the examined sample. Due to age and intellectual disability, acute pain was localized in 18/35 individuals and chronic pain in 33/49. Muscle‐skeletal and abdominal pain was more frequently reported. The intensity of acute and chronic pain interfered with daily activities in 1/3 of the sample. Pain negatively impacted on QoL and sleeping patterns. This work documents that pain is highly prevalent in RASopathies. Future studies including subjective and objective measures of pain are required to discriminate a somatosensory abnormality from an abnormal elaboration of painful stimuli at a central level. 相似文献
39.
This review was designed to determine from the best evidence whether there is an association between postmenopausal hormonal treatment and breast cancer risk. Also, if there is an association, does it vary according to duration and cessation of use, type of regimen, type of hormonal product or route of administration; whether there is a differential effect on risk of lobular and ductal cancer; and whether hormone treatment is associated with breast cancers that have better prognostic factors? Data sources for the review included Medline, the Cochrane Database of Systematic Reviews (Cochrane Library, 2005) and reference lists in the identified citations. Eligible citations addressed invasive breast cancer risk among postmenopausal women and involved use of the estrogen products with or without progestin that are used as treatment for menopausal symptoms. Abstracted data were demographic groupings, categories of hormone use, categories of breast cancer, two-by-two tables of exposure and outcome and adjusted odds ratios, relative risks (RRs) or hazard rates. Average estimates of risk were weighted by the inverse variance method, or if heterogeneous, using a random effects model. The average risk of invasive breast cancer with estrogen use was 0.79 [95% confidence interval (95% CI) = 0.61-1.02] in four randomized trials involving 12 643 women. The average breast cancer risk with estrogen-progestin use was 1.24 (95% CI = 1.03-1.50) in four randomized trials involving 19 756 women. The average risks reported in recent epidemiological studies were higher: 1.18 (95% CI = 1.01-1.38) with current use of estrogen alone and 1.70 (95% CI = 1.36-2.17) with current use of estrogen-progestin. The association of breast cancer with current use was stronger than the association with ever use, which includes past use. For past use, the increased breast cancer risk diminished soon after discontinuing hormones and normalized within 5 years. Reasonably adequate data do not show that breast cancer risk varies significantly with different types of estrogen or progestin preparations, lower dosages or different routes of administration, although there is a small difference between sequential and continuous progestin regimens. Epidemiological studies indicate that estrogen-progestin use increases risk of lobular more than ductal breast cancer, but the number of studies and cases of lobular cancer remains limited. Among important prognostic factors, the stage and grade in breast cancers associated with hormone use [corrected] do not differ significantly from those in non-users, but breast cancers in estrogen-progestin users are significantly more likely to be estrogen receptor (ER) positive. In conclusion, valid evidence from randomized controlled trials (RCTs) indicates that breast cancer risk is increased with estrogen-progestin use more than with estrogen alone. Epidemiological evidence involving more than 1.5 million women agrees broadly with the trial findings. Although new studies are unlikely to alter the key findings about overall breast cancer risk, research is needed, however, to determine the role of progestin, evaluate the risk of lobular cancer and delineate effects of hormone use on receptor presence, prognosis and mortality in breast cancer. 相似文献
40.
Fimognari C Berti F Cantelli-Forti G Hrelia P 《Environmental and molecular mutagenesis》2005,46(4):260-267
Isothiocyanates (ITCs) are commonly found in cruciferous vegetables. A variety of biological activities have been ascribed to ITCs, such as inhibition of cytochrome P450 enzymes and induction of phase II enzymes in animal models. ITCs are also able to block cell-cycle progression and induce apoptosis in human cancer cells in vitro. In this study, we evaluated the ability of the ITC sulforaphane to protect cultured human lymphocytes from micronucleus (MN) induction by four different mutagens: ethyl methanesulfonate (EMS), vincristrine (VIN), H(2)O(2) and mitomycin C (MMC). To understand the mechanisms of action of sulforaphane, the cultures were treated with the compound before, during and after treatment with the mutagens; in addition, the cultures were evaluated for the induction of apoptosis. Up to 10 microM, sulforaphane was non-genotoxic by itself, while 30 microM sulforaphane reduced the replicative index of the cells by more than 60%. Moreover, 1-10 microM sulforaphane reduced the MN frequency induced by EMS, VIN, H(2)O(2) and MMC in at least one of the treatment protocols; it had no effect on H(2)O(2)-MN induction in the post-treatment protocol, and it increased MN induction by MMC in the pre-treatment protocol. Apoptosis was produced in the cultures treated with sulforaphane alone. The fraction of apoptotic cells was increased after co- or post-treatment with sulforaphane and EMS and MMC, suggesting that sulforaphane-mediated apoptosis may remove highly damaged cells induced by these agents. Other mechanisms are involved in the anti-genotoxic activity of sulforaphane against VIN and H(2)O(2). Taken together, our findings indicate that under certain conditions sulforaphane possesses anti-genotoxic activity in vitro and that further studies are warranted to characterize this property in vivo. 相似文献