全文获取类型
收费全文 | 12722篇 |
免费 | 562篇 |
国内免费 | 93篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 152篇 |
妇产科学 | 163篇 |
基础医学 | 1531篇 |
口腔科学 | 177篇 |
临床医学 | 722篇 |
内科学 | 3853篇 |
皮肤病学 | 276篇 |
神经病学 | 942篇 |
特种医学 | 460篇 |
外科学 | 1870篇 |
综合类 | 36篇 |
一般理论 | 3篇 |
预防医学 | 344篇 |
眼科学 | 170篇 |
药学 | 672篇 |
中国医学 | 19篇 |
肿瘤学 | 1783篇 |
出版年
2023年 | 89篇 |
2022年 | 180篇 |
2021年 | 299篇 |
2020年 | 163篇 |
2019年 | 199篇 |
2018年 | 257篇 |
2017年 | 216篇 |
2016年 | 250篇 |
2015年 | 271篇 |
2014年 | 337篇 |
2013年 | 411篇 |
2012年 | 751篇 |
2011年 | 777篇 |
2010年 | 473篇 |
2009年 | 424篇 |
2008年 | 769篇 |
2007年 | 807篇 |
2006年 | 820篇 |
2005年 | 821篇 |
2004年 | 849篇 |
2003年 | 795篇 |
2002年 | 760篇 |
2001年 | 218篇 |
2000年 | 179篇 |
1999年 | 196篇 |
1998年 | 196篇 |
1997年 | 139篇 |
1996年 | 122篇 |
1995年 | 103篇 |
1994年 | 84篇 |
1993年 | 85篇 |
1992年 | 114篇 |
1991年 | 114篇 |
1990年 | 101篇 |
1989年 | 91篇 |
1988年 | 105篇 |
1987年 | 87篇 |
1986年 | 95篇 |
1985年 | 96篇 |
1984年 | 68篇 |
1983年 | 50篇 |
1982年 | 35篇 |
1980年 | 29篇 |
1979年 | 26篇 |
1978年 | 27篇 |
1977年 | 26篇 |
1975年 | 25篇 |
1973年 | 26篇 |
1969年 | 24篇 |
1968年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Shigekazu Fujioka Yasushi Kitaura 《BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy》2001,15(12):791-799
Idiopathic dilated cardiomyopathy (IDC) is a myocardial disease characterised by ventricular dilatation, impaired contractility, and the symptoms of congestive heart failure. Although the causes of IDC remain uncertain, much interest has been focused on the enteroviral infection in the myocardium in the pathogenesis of this disease. Enteroviral RNA has been demonstrated in the myocardium at all stages of IDC. Recent studies using sequence analysis of enteroviral polymerase chain reaction (PCR) products have shown that the viruses detected in hearts of patients with IDC are coxsackie B. In addition, active coxsackieviral RNA replication in the myocardium has been demonstrated by strand-specific detection of viral RNA. Viral antigen has also been found in hearts with IDC by immunohistochemical techniques. In tissue culture experiments and transgenic mice, it has been shown that restricted coxsackieviral RNA replication, and not infectious virus progeny, in the myocardium can impair cardiac contractile function and lead to dilated cardiomyopathy. Coxsackieviral RNA in the myocardium can be a marker of a poor clinical outcome after partial left ventriculectomy, and might influence prognosis after heart transplantation. Therefore, there is a therapeutic need to detect replicating coxsackieviral RNA in the myocardium, and a specific therapy for coxsackie B viruses is indicated in the management of patients with virus-positive IDC. 相似文献
992.
ABSTRACT: Facial hyperpigmentation is usually a reflection of an increased amount of melanin either within the epidermis, the dermis, or both (mixed pattern). The increase in melanin content is due to an increased number of functioning melanocytes (melanocytosis), an increased amount of melanin production without a numerical alteration of melanocytes (melanosis), or both. Topical hypo/depigmenting agents are most effective in those disorders where the increased melanin pigment (secondary to melanocytosis or melanosis) is within the epidermis. In patients with melasma, one of the more common causes of facial hyperpigmentation, two major groups of hypo/depigmenting agents have been used: phenolic derivatives and nonphenolic compounds. Hydroquinone, a phenolic derivative, has been used most extensively. It is applied to areas of involvement, either alone or in combination with one or two of the following: tretinoin, salicylic acid, glycolic acid, or corticosteroid. Phenolic thioethers are a new class of phenolic derivatives, and they exhibit both cytocidal and cytostatic effects selectively on melanocytes. Nonphenolic depigmenting agents include azelaic acid and kojic acid. If the facial hyperpigmentation is not improved by first-line topical therapies, chemical peels may be used in combination. The precise cause of melasma is not known, and multiple factors have been implicated. However, a genetic predisposition and exposure to ultraviolet (UV) light are very important factors. Avoidance of direct exposure to sunlight and application of broad-spectrum sunscreens are required during and after the period of active treatment. In addition to melasma, other causes of facial hyperpigmentation include Riehl's melanosis, photocontact dermatitis, the sequelae of inflammatory diseases such as acne vulgaris and cutaneous lupus, and nevus of Ota. 相似文献
993.
994.
Tetsuya Takao Akira Tsujimura Hiroshi Kiuchi Kazuhiko Komori Kazutoshi Fujita Yasushi Miyagawa Shingo Takada Norio Nonomura Akihiko Okuyama 《International journal of urology》2008,15(9):789-793
Objectives: To investigate changes in the management of cases over time, we undertook a retrospective analysis of urological surgeries carried out in patients aged 80 years and older in a single institution over the last 30 years. Methods: Between 1975 and 2004, 402 patients aged 80 years and older underwent 412 surgeries in our department. We reviewed the clinical records and analyzed changes in clinical data over time. We evaluated the observed comorbidities and postoperative complications in selected patients for whom complete clinical records were available. We then identified risk factors for postoperative complications by means of multiple logistic regression analysis. Results: The number of surgeries carried out in patients aged 80 years and older increased every 5 years. Over time, the number of endourological and laparoscopic surgeries increased. Of 255 patients, 225 (88.3%) had at least one comorbidity, and 51 patients had postoperative complications. The number of observed comorbidities, such as cardiovascular disorder, central nervous system disorder, and diabetes mellitus, increased over the most recent 10‐year period. However, there were no differences in postoperative complications over time. Male sex and open surgery were found to be independent risk factors for postoperative complications. Conclusions: Although elderly patients had various comorbidities, the postoperative morbidity rate was acceptable in our selected cases. This study may provide useful detailed information for patients 80 years and older who will undergo urological surgery. 相似文献
995.
996.
Yasushi Matsumoto Hisashi Nagashima Toshihide Toriyama Shigeaki Kobayashi Kazuhiro Hongo 《Journal of clinical neuroscience》2008,15(6):700-703
Intracranial arterial dissections of the vertebrobasilar system are recognized as a cause of stroke. Although the pathogenic mechanism underlying this phenomenon is unknown, in some cases the stroke originates from subarachnoid hemorrhage, while in others ischemia is the cause. In cases where hemorrhage occurs, occlusion of the lesion is effective in reducing the risk of re-bleeding. However, deciding on treatment is difficult in uncommon cases in which occlusion occurs immediately after hemorrhage. Intracranial arterial dissections of the vertebrobasilar system often present as subarachnoid hemorrhage, and the most appropriate surgical treatment remains controversial. In this report, we describe a rare case of vertebral artery dissection in which occlusion occurred immediately after subarachnoid hemorrhage. Serial angiography revealed spontaneous recanalization of the right vertebral artery dissection, as well as enlargement. The progressive angiographic changes of the ruptured vertebral artery dissection and the endovascular treatment of such arterial dissections are discussed. 相似文献
997.
998.
Go Takahashi Hiroyuki Tanaka Keiko Wakahara Reishi Nasu Mikiko Hashimoto Kosuke Miyoshi Hirohisa Takano Hirotaka Yamashita Naoki Inagaki Hiroichi Nagai 《Journal of pharmacological sciences》2010,112(2):192-202
Recent research has focused on the effects of ambient particulate pollution and much evidence has indicated that particulate pollution is associated with the onset of asthma and allergy; however, the effect of diesel exhaust particles (DEP) on the development of allergen-induced airway remodeling has not been fully investigated in vivo. In the present study, we examined the effects of DEP on Dermatophagoides farinae allergens (Der f)–induced asthma-like phenotypes in mice. Mice were administered i.t. 8 times with Der f. DEP were injected i.t. with Der f 4 times throughout the experiment or twice at the sensitization period. In both cases, DEP aggravated Der f–induced increases in airway responsiveness to acetylcholine, the number of eosinophils and neutrophils in the bronchoalveolar lavage fluid (BALF), serum Der f–specific IgG1 levels, Th2 cytokines and transforming growth factor-β 1 levels in BALF, and amount of hydroxyproline in the right lungs. Furthermore, goblet cell hyperplasia and subepithelial fibrosis were also markedly aggravated. These findings indicate that DEP can potentiate airway remodeling induced by repeated allergen challenge as well as Th2-drived airway hyperresponsiveness, eosinophilic inflammation, and IgG1 production and that DEP can exhibit adjuvant activity for airway remodeling, probably due to the enhancement of allergen sensitization and/or of Th2 polarizing pathways. 相似文献
999.
Yuichi Miyazaki Kazunori Toyoda Yasuyuki Iguchi Teruyuki Hirano Norifumi Metoki Masanori Tomoda Masayuki Shiozawa Junpei Koge Yasushi Okada Yuka Terasawa Muneaki Kikuno Haruko Okano Joji Hagii Masanori Nakajima Teppei Komatsu Masahiro Yasaka 《Journal of atherosclerosis and thrombosis》2021,28(5):544
Aim: This study aimed to investigate the diagnostic yield of 7-day Holter monitoring for detecting covert atrial fibrillation (AF) in patients with recent embolic stroke of undetermined source (ESUS) and to identify the pre-entry screening biomarkers that had significant associations with later detection of AF (clinicaltrials.gov. ). Methods: A total of 206 patients who have recent ESUS without previously documented AF underwent Holter electrocardiography using a chest strap-style monitor. External validation of biomarkers predictive of AF was performed using 83 patients with ESUS who were implanted with insertable cardiac monitors. Results: The 7-day Holter monitoring started at a median of 13 days after the onset of stroke. AF was detected in 14 patients, and three of these showed a single AF episode lasting <2 min. The median time delay to the first documented AF was 50 h. Each of serum brain natriuretic peptide ≥ 66.0 pg/mL (adjusted odds ratio 5.23), atrial premature contractions (APCs) ≥ 345 beats (3.80), and APC short runs ≥ 13 (5.74) on 24-h Holter prior to the 7-day Holter showed a significant association with detection of AF, independent of age and physiological findings in this derivation cohort, and all of these showed a significant association in the validation cohort (adjusted odds ratio 6.59, 7.87, and 6.16, respectively). Conclusions: In recent ESUS patients, the detection rate of AF using the 7-day Holter monitoring was 6.8% (95% CI 4.1%–11.1%). Brain natriuretic peptide, APC count, and APC short runs in the standard clinical workup seemed to be predictors of covert AF. NCT02801708相似文献
1000.
Koichi Matsumoto MD Shigeru Moriyama Yasushi Iwata Tohru Masuda Kazuo Matsumoto Keiji Iriyama 《Surgery today》1986,16(6):456-459
Histopathological examination, specific mucin staining and analysis of cellular DNA content of rectal mucosa were carried
out in twenty-eight tissue specimens biopsied from ten adult and eight adolescent patients with ulcerative colitis. There
was an increase in proliferative activity in the rectal mucosa in both groups with active colitis, but, there were no significant
differences in the potential for malignant transformation of rectal mucosa in these groups. 相似文献