全文获取类型
收费全文 | 43883篇 |
免费 | 4741篇 |
国内免费 | 1199篇 |
专业分类
耳鼻咽喉 | 202篇 |
儿科学 | 1730篇 |
妇产科学 | 351篇 |
基础医学 | 5609篇 |
口腔科学 | 635篇 |
临床医学 | 4773篇 |
内科学 | 10296篇 |
皮肤病学 | 1017篇 |
神经病学 | 2479篇 |
特种医学 | 751篇 |
外国民族医学 | 6篇 |
外科学 | 2905篇 |
综合类 | 6815篇 |
现状与发展 | 5篇 |
一般理论 | 1篇 |
预防医学 | 2951篇 |
眼科学 | 591篇 |
药学 | 4019篇 |
28篇 | |
中国医学 | 2964篇 |
肿瘤学 | 1695篇 |
出版年
2024年 | 207篇 |
2023年 | 1012篇 |
2022年 | 1497篇 |
2021年 | 2322篇 |
2020年 | 2167篇 |
2019年 | 1862篇 |
2018年 | 1778篇 |
2017年 | 1902篇 |
2016年 | 1996篇 |
2015年 | 1827篇 |
2014年 | 3266篇 |
2013年 | 3395篇 |
2012年 | 3065篇 |
2011年 | 3195篇 |
2010年 | 2364篇 |
2009年 | 2302篇 |
2008年 | 2191篇 |
2007年 | 1976篇 |
2006年 | 1717篇 |
2005年 | 1525篇 |
2004年 | 1186篇 |
2003年 | 951篇 |
2002年 | 831篇 |
2001年 | 736篇 |
2000年 | 568篇 |
1999年 | 488篇 |
1998年 | 447篇 |
1997年 | 364篇 |
1996年 | 354篇 |
1995年 | 268篇 |
1994年 | 243篇 |
1993年 | 223篇 |
1992年 | 219篇 |
1991年 | 171篇 |
1990年 | 152篇 |
1989年 | 129篇 |
1988年 | 112篇 |
1987年 | 120篇 |
1986年 | 99篇 |
1985年 | 124篇 |
1984年 | 90篇 |
1983年 | 58篇 |
1982年 | 65篇 |
1981年 | 54篇 |
1980年 | 44篇 |
1979年 | 34篇 |
1978年 | 28篇 |
1977年 | 26篇 |
1976年 | 28篇 |
1974年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Hossam B El-Zawawy Corey S Gill Rick W Wright Linda J Sandell 《Journal of orthopaedic research》2006,24(12):2150-2158
Smoking delays the healing process and increases morbidity associated with many common musculoskeletal disorders, including long bone fracture. In the current study, a murine model of tibial fracture healing was used to test the hypothesis that smoking delays chondrogenesis after fracture. Mice were divided into two groups, a nonsmoking control group and a group exposed to cigarette smoke for 1 month prior to surgical tibial fracture. Mice were euthanized at 7, 14, and 28 days after surgery. The outcomes measured were immunohistochemical staining for type II collagen protein expression as a marker of cartilage matrix and proliferating cell nuclear antigen (PCNA) staining to measure proliferation at the site of injury. Toluidine blue staining and histomorphometry were used to quantify areas of cartilaginous and noncartilaginous fracture callus. Radiographs were analyzed for evidence of remodeling after injury. At day 7 after injury, mice exposed to cigarette smoke had a smaller fracture callus with less cartilage matrix compared to controls. Proliferation was present at high levels in both groups at this time point, but proliferating cells had a more immature morphology in the smoking group. At day 14, chondrogenesis was more active in smokers compared to controls, while a higher percentage of bone was present in the control animals. At day 28, X-ray analysis revealed a larger fracture callus remaining in the smoking animals. Together, these findings show that the chondrogenic phase of tibial fracture healing is delayed by smoking. This study represents, to our knowledge, the first analysis of molecular and cellular mechanisms of healing in a smoking mouse fracture model. 相似文献
92.
Natural history of extensive Mongolian spots in mucopolysaccharidosis type II (Hunter syndrome): a survey among 52 Japanese patients 总被引:1,自引:0,他引:1
T Ochiai† Y Suzuki‡ T Kato‡ H Shichino§ M Chin§ H Mugishima§ T Orii¶ 《Journal of the European Academy of Dermatology and Venereology》2007,21(8):1082-1085
BACKGROUND: Recent reports have shown a correlation between extensive Mongolian spots and mucopolysaccharidosis type II (Hunter syndrome). However, a statistical survey of the incidence and natural history of extensive Mongolian spots among the patients with Hunter syndrome is lacking. OBJECTIVES: To determine the prevalence of extensive Mongolian spots, to determine the natural course of the spots according to age in Japanese patients with Hunter syndrome, and to compare them with the results obtained from the patients' brothers who did not have Hunter syndrome. PATIENTS/METHODS: Fifty-two males with Hunter syndrome aged 3 to 40 years were studied. Twenty-five patients were examined in two clinics to determine the existence and characteristics of the spots. We interviewed their families about the spots in their neonates and the natural course of the spots according to their ages. The same survey was done among another 27 patients using a mailed questionnaire to their families. As control, we investigated 21 brothers of the patients by a mailed questionnaire to their families. RESULTS: The extensive Mongolian spots are identified in almost all the infants with Hunter syndrome and disappear extremely later in their life. The lesions had a high incidence of deep-blue hyperpigmentation. Regardless of age, the overall incidence was 78%. All of the brothers who did not have Hunter syndrome had common-type Mongolian spots in neonates, which regressed during their childhood. CONCLUSION: Our results confirm a strong correlation between extensive Mongolian spots and Hunter syndrome for the Japanese population. The presence of extensive Mongolian blue spots should alert the physician to the possibility of Hunter syndrome. 相似文献
93.
Hiroaki YOSHIDA Tetsuya KAWAMURA Iekuni ICHIKAWA Osamu SAKAI 《Nephrology (Carlton, Vic.)》1997,3(S2):s719-s723
Summary: Clinical studies revealed that angiotensin converting enzyme (ACE) inhibitor reduces proteinuria and attenuates progressive decline in renal function in IgA nephropathy. Recent studies by us and others have demonstrated that the homozygote of the D allele (DD) of the ACE insertion/deletion (I/D) polymorphism is a potential risk factor for poor prognosis in IgA nephropathy, and that this deletion polymorphism predicts the therapeutic efficacy of ACE inhibition on proteinuria and, potentially, on progressive deterioration of renal function in patients with the nephropathy. 相似文献
94.
报告5例对胰岛素抵抗的糖尿病特殊类型病例,其均具有胰岛素应用指征,但使用胰岛素后血糖却反而上升,逐渐增加胰岛素用量,则血糖值亦呈上升趋势。对该类病人的治疗,首先停用胰岛素,改用自制中药制剂及优降糖、降糖灵治疗,取得了良好效果。 相似文献
95.
Clinicopathologlc and mucin histochemical characteristics of 90 cases of ovarian mucinous borderline tumors (MBT) of Intestinal (IMET) and müllerian types (MMBT) were studied to determine whether IMBT and MMBT constitute distinct tumor subtypes. The IMBT (77 cases, 78 lesions) contained goblet cells, absorptive cells and endocrine cells, which represented Intestinal differentiation. The average diameter of IMBT was 13.4 cm. Five patients (6.5%) had stage III disease wtth pseudomyxoma perltonel and one of them died from tumor. Approximately 50% of IMBT demonstrated gastrointestinal characteistics on mucin histochemistry. The MMBT (13 cases, 14 lesions) consisted of mumus columnar cells and eosinophilic cells, with no Intestinal differentiation. MMBT accounted for 15.2% of MBT. MMBT averaged 8.4 cm in diameter, and 29% were associated with endometriosls of the ipsilateral ovary. All patients with MMBT had stage I disease, and none suffered from pseudomyxoma peritonel. All patients whose follow-up data were available were alive and well, without evidence of tumor recurrence. The mucin histochemical findings in MMBT resembled those of noml endocervix. Results of the present study suggest that IMBT and MMBT have different characteristics and constitute distinct subtypes of MBT. 相似文献
96.
Nobutaka Eiraku Shinji Ijichi Shinji Yashiki Mitsuhiro Osame Shunro Sonoda 《Journal of neuroimmunology》1992,37(3):223-228
The in vitro proliferation of peripheral blood lymphocytes (PBLs) without any mitogenic stimulation is one of the hallmarks of human T lymphotropic virus type I (HTLV-I) infection. Recent evidence suggests a difference in the degree of the phenomenon between HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and asymptomatic HTLV-I carriers (AC). In this article, we demonstrated several alterations in the features of the in vitro transformed lymphocytes between patients with HAM/TSP (n = 16) and AC (n = 8). The percentages of total CD8+ and CD8+CD28+ cells were significantly increased in the in vitro proliferating T lymphocytes derived from the patients with HAM/TSP when compared to those from AC. HAM/TSP was segregated from AC by the high degree of the proliferation of CD8+CD28+ cells. The expression of HTLV-I-specific antigens on the cultured PBLs was detected only in the subjects which showed low CD8+CD28+/CD4+ ratio of the in vitro proliferating lymphocytes. These findings suggest that this phenomenon distinguishes HAM/TSP from AC, not only in quantity but also in quality. 相似文献
97.
对114例不同类型和级别的结肠癌进行银染核仁形成区嗜银蛋白(Ag-NORs)形态定量研究.结果表明,Ag-NORs数量、大小和分布在结肠未分化癌和印戒细胞癌组与管状腺癌和粘液腺癌组比较,有明显差异.管状腺癌随分化程度的降低,Ag-NORs的数量、形态、大小和分布也发生等级性变化.结果提示,Ag-NORs形态定量的数量、形态、大小和分布4项指标对结肠癌分型有一定意义,对管状腺癌分级有较好的诊断价值。 相似文献
98.
Akira Fukushima 《Psychiatry and clinical neurosciences》1994,48(Z1):1-4
Abstract: Historical changes in forensic psychiatric evaluation on criminal responsibility and proceedings in psychopathological findings of amphetamine psychosis are reviewed at first. The classification of amphetamine related mental disorders are proposed in 6 types. Among them, the clinical characteristics and psychopathological features of “Anxiety-situational reaction type” (Fukushima) are described. According to some reasonable grounds, offenders diagnosed as anxiety-situational reaction type should be evaluated as diminished responsibility in place of irresponsibility. Finally, two cases of murder committed under the influence of amphetamine, are reported in detail. 相似文献
99.
It has recently been shown that it is possible to discriminate accurately among myoelectric signals underlying different muscle
contraction types, specifically elbow flexion and extension and forearm pronation and supination. It was reported that once
a number of distinctive features had been extracted from the myoelectric signals, a neural network could be trained to distinguish
the contraction types with an impressively high accuracy. In the present paper, we show that a technique known as parallel
cascade identification can be used to construct classifiers that can also accurately, differentiate the contraction types.
The use of parallel cascades has the benefit of dispensing with the need for feature extraction, so that raw myoelectric signal
data can be used directly. In addition, very little data are required to train the parallel cascades to distinguish accurately
novel incoming myoelectric signals. Results of using parallel cascades to distinguish foream pronation, supination, and elbow
flexion are presented. 相似文献
100.
Emilio Bombardieri Antonia Martinetti Rosalba Miceli Luigi Mariani Maria Rita Castellani Ettore Seregni 《European journal of nuclear medicine and molecular imaging》1997,24(11):1349-1355
Bone scintigraphy plays a major role in the diagnosis of bone metastases. The clinical utility of new biochemical markers
of bone metabolism has recently been investigated in various bone diseases. This study evaluated the role of some bone metabolism
markers in comparison with bone scan in the follow-up of breast cancer patients. We studied 149 patients with breast cancer,
33 (22%) of whom had bone metastases. IRMAs were used for the evaluation of blood levels of osteocalcin, bone alkaline phosphatase
(BAP), the C-terminal propeptide of type I procollagen and the C-terminal cross-linked telopeptide of type I collagen (ICTP).
Multivariate regression analysis showed that menopausal status (P=0.007) and metastatic bone lesions (P=0.001) affected bone marker levels. When considering post-menopausal women, the only subset in which bone metabolism marker
behaviour could be reliably investigated, we found a high degree of overlap in marker distribution for scan-positive and scan-negative
patients. Discrimination between scan-negative and scan-positive patients based on the above markers, taken singly or jointly,
was assessed by means of logistic discriminant analysis. The best discrimination was achieved with BAP, closely followed by
ICTP. BAP and ICTP together gave a slight improvement over the use of the two markers separately. However, even in this case
the degree of discrimination was poor and its clinical utility was limited. In fact, to achieve a specificity of 95%, the
sensitivity of the test was about 20%; conversely, with a sensitivity of 95%, the specificity was below 10%. In conclusion,
based on our findings, we believe that blood levels of the investigated markers cannot replace bone scintigraphy in the follow-up
of breast cancer patients for the early detection of bone metastases.
Received 14 April and in revised form 5 July 1997 相似文献