全文获取类型
收费全文 | 55579篇 |
免费 | 5692篇 |
国内免费 | 1540篇 |
专业分类
耳鼻咽喉 | 441篇 |
儿科学 | 1956篇 |
妇产科学 | 1079篇 |
基础医学 | 3860篇 |
口腔科学 | 1332篇 |
临床医学 | 6048篇 |
内科学 | 10986篇 |
皮肤病学 | 644篇 |
神经病学 | 2539篇 |
特种医学 | 1217篇 |
外国民族医学 | 32篇 |
外科学 | 5217篇 |
综合类 | 8204篇 |
现状与发展 | 11篇 |
预防医学 | 6669篇 |
眼科学 | 531篇 |
药学 | 3016篇 |
64篇 | |
中国医学 | 1381篇 |
肿瘤学 | 7584篇 |
出版年
2024年 | 214篇 |
2023年 | 1399篇 |
2022年 | 2686篇 |
2021年 | 4032篇 |
2020年 | 3251篇 |
2019年 | 2762篇 |
2018年 | 2621篇 |
2017年 | 2335篇 |
2016年 | 2439篇 |
2015年 | 2514篇 |
2014年 | 4020篇 |
2013年 | 3843篇 |
2012年 | 3165篇 |
2011年 | 3314篇 |
2010年 | 2620篇 |
2009年 | 2558篇 |
2008年 | 2398篇 |
2007年 | 2454篇 |
2006年 | 1978篇 |
2005年 | 1792篇 |
2004年 | 1454篇 |
2003年 | 1270篇 |
2002年 | 950篇 |
2001年 | 922篇 |
2000年 | 700篇 |
1999年 | 620篇 |
1998年 | 512篇 |
1997年 | 506篇 |
1996年 | 398篇 |
1995年 | 407篇 |
1994年 | 394篇 |
1993年 | 270篇 |
1992年 | 279篇 |
1991年 | 252篇 |
1990年 | 188篇 |
1989年 | 190篇 |
1988年 | 158篇 |
1987年 | 146篇 |
1986年 | 114篇 |
1985年 | 123篇 |
1984年 | 104篇 |
1983年 | 84篇 |
1982年 | 93篇 |
1981年 | 73篇 |
1980年 | 54篇 |
1979年 | 33篇 |
1978年 | 34篇 |
1977年 | 24篇 |
1976年 | 27篇 |
1975年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
By substituting the saturated vapour phase tension of the pure normal hydrocarbons described by the Clausius-Clapeyron law into the accepted expression of the specific retention volume (Vg,T), a theoretically coherent and relatively simple mathematical evidence of the elution behaviour of the homologous members has been deduced. It gives exponential retention time dependence on carbon number for isothermal, and nearly equidistant (i.e., approximately linear retention-time dependence on carbon number) elution for linear temperature programmed gas chromatographic runs. The final equations are in close correlation with the experimental results. Special emphasis is placed on the fact that a good approximation—not strict physical laws—have been found. 相似文献
72.
目的肥胖易伴发多种慢性疾病。本文探讨肥胖者体重与体成份(脂肪、肌肉)之间的关系及其对临床减重的意义。方法经临床确诊系单纯性肥胖者45例,男17例,女28例。使用美国LunarDPX-L型双能X线吸收测量仪(DXA),测量全身骨、第2~4腰椎、股骨颈骨矿密度(BMD)及体脂肪和肌肉量,并计算体重指数(BMI=W/H2)、体重(kg)/身高(m)即W/H数值进行比较分析。结果男性体重平均94.54±17.41kg,BMI33±4.87。女性体重平均124.37±14.0kg,BMI35.41±6.39。男女两性全身BMD与体重相关,分别为r=0.415,P<0.05,r=0.529,P<0.0025。女性体重与脂肪、肌肉之间呈正相关分别为r=0.522,P<0.0025、r=0.612,P<0.005。男性体重与BMI、W/H及全身肌肉量相关,与脂肪组织无明显相关。男女性W/H较BMI相关系数高。男性全身BMD与全身肌肉量正相关r=0.421,P<0.05。女性全身及股骨颈BMD与脂肪量相关r=0.360,P<0.05、r=0.323,P<0.05。女性全身肌肉量与股骨颈BMD呈正相关r=0.373,P<0.05。结论①肥胖者体重增加,男性以肌肉增加为主,女性脂肪和肌肉都增加;②男性全身骨密度增高与肌肉量增加有关,而女性则主要为脂肪量增加;③女性肌肉、脂肪量与股骨颈BMD密切相关;④体重(kg)/身高(m)比计算体重指数能更准确地反映总体肥胖的程度。 相似文献
73.
体重指数分级标准应用方法的探讨 总被引:1,自引:0,他引:1
目的探讨按照体重指数分级标准计算出的体重值应用表的实用价值。方法将身高作为选定变量,其变量值间距为1 cm,按照体重指数分级标准上、下限值,分别乘以身高2(m2),即求出相对应的体重(kg),依此制成应用表。判定时依据身高和实测的体重,对照应用表得出其体重指数分级范围。结果制成并列出以体重值查对其相对应危险值应用表。结论本查对表适用于大规模的预防性健康体检。在人体生长发育阶段能做到自身动态监测,对早期预防肥胖症具有积极作用。 相似文献
74.
K. HELLMAN M. LUNDELL† C. SILFVERSWÄRD‡ B. NILSSON§ A.-C. HELLSTRÖM & B. FRANKENDAL 《International journal of gynecological cancer》2006,16(3):1201-1211
The goal of this retrospective study concerning primary carcinoma of the vagina (PCV) was to analyze clinical and histopathologic prognostic factors in one of the largest known material, which comprised 314 patients. PCV is a rare disease, and the majority of published studies are based on small materials; therefore, the established knowledge concerning prognostic factors is insufficient. Routine treatment is based on irradiation with risk for undertreatment or overtreatment, which leads to unnecessary complications in the absence of prognostic factors. The overall 5-year disease-specific survival rate in this study was 45% and in stage I 75%. In the univariate statistical analysis, several factors correlated significantly with disease-specific survival. However, in the multivariate analysis, there were only three factors that independently could predict poor survival-high age at diagnosis, large tumors (> or =4 cm), and advanced stage. Common background factors with no prognostic significance were prior hysterectomy, other gynecological malignancies, and pelvic irradiation. In conclusion, this study has elucidated three strong prognostic factors that might be considered in the choice of therapy and also for modification of the FIGO guidelines. Increased knowledge concerning complementary biologic markers to discriminate between low- and high malignant tumors is however of great importance. 相似文献
75.
BACKGROUND: Diffuse peritubular capillary (PTC) C4d deposition has been shown to be associated with relatively poor graft outcome. The significance of focal PTC C4d staining in the early post-transplant period is uncertain. METHODS: Sixty-five biopsies from 53 patients with acute rejection were graded (Banff '97 criteria), stained for C4d, monocytes and T cells, and divided into three groups according to PTC C4d: (i) focal C4d (F) (14 biopsies, 14 patients), (ii) diffuse C4d (D) (23 biopsies, 15 patients) and (iii) no C4d (N) (28 biopsies, 24 patients). The three groups were compared with respect to a variety of biopsy and clinical parameters including outcome. RESULTS: The incidence of transplant glomerulitis and glomerular monocyte infiltration were significantly greater in F (64% and 2.0+/-2.0) and D (57% and 3.4+/-2.0) than in N (11% and 0.2+/-0.2). A significantly higher proportion of F (93%) demonstrated acute cellular rejection (Banff '97 grade > or = 1A) than did D (35%). The F and D groups included significantly more females (50 and 67%, respectively) than did N (21%). The percentage of patients with a second or third transplant was higher in F (29%) and D (40%) than in N (8%) (P = 0.0589). The proportion of patients with glomerular filtration rate < 30 ml/min at 12, 24 and 48 months was higher in the D and F groups than in the N, and there was a statistically significant increasing trend in odds of this outcome occurring at 48 months across the three groups (D > F > N group) (P = 0.0416). CONCLUSION: The results suggest that the biopsy findings and clinical course in patients with focal PTC C4d staining are similar to those associated with diffuse C4d. 相似文献
76.
目的 检测亚硒酸钠是否能够削弱或解除顺铂对植物血球凝激素(PHA)刺激的人体外周血淋巴细胞的增殖抑制。方法 用顺铂和亚硒酸钠单独或联合处理PHA刺激的人体外周血淋巴细胞,顺铂(0.05,0.20,0.50mg/L)在细胞培养24h时加入,亚硒酸钠(0.05mg/L)在不同处理中分别在细胞培养开始时加入或与顺铂同时加入;培养72h后检测转化淋巴细胞的有丝分裂指数。结果0.05mg/L亚硒酸钠在培养开始时加入,PHA刺激转化的淋巴细胞有丝分裂指数较对照增长42.8%(P<0.05),与顺铂同时加入,有丝分裂指数增长13.7%(P>0.05)。0.05与0.20mg/L顺铂处理细胞,有丝分裂指数未发生显性改变,当顺铂剂量为0.50mg/L时,细胞有丝分裂指数较对照降低54.5%(P<0.001)。亚硒酸钠预处理细胞可以解除0.50mg/L顺铂所致的细胞增殖抑制,使有丝分裂指数恢复正常,但亚硒酸钠与顺铂同时加入时,被顺铂抑制的有丝分裂指数只能部分提高。结论0.05mg/L亚硒酸钠单独作用于淋巴细胞可直接促进细胞增殖,与顺铂联合处理细胞时,可降低顺铂毒性,拮抗顺铂的抗增殖作用。亚硒酸钠在细胞培养开始时加入培养体系效果更佳。 相似文献
77.
本文报道了我院收治的卵巢恶性畸胎瘤31例,随访中2例失访,随访率为93.53%。并讨论了卵巢恶性畸瘤的治疗方式为手术加联合化疗,对年轻的I期患者可行患侧单侧附件切除术,术后化疗极为重要。化疗方法采用VAC或PVB方案联合化疗,本文还 影响预后的重要因素为临床分期期和病理学特点. 相似文献
78.
Health-related quality of life assessed before and during chemotherapy predicts for survival in multiple myeloma 总被引:5,自引:0,他引:5
Measurement of health-related quality of life was integrated into a randomized trial (NMSG 4/90) comparing melphalan/prednisone to melphalan/prednisone + interferon α-2b in newly diagnosed multiple myeloma. One of the aims of the study was to assess the prognostic significance of quality-of-life scores, using the EORTC QLQ-C30 questionnaire. Univariate analysis showed a highly significant association with survival from the start of therapy for physical functioning as well as role and cognitive functioning, global quality of life, fatigue and pain. In multivariate analysis, physical functioning and W.H.O. performance status were independent prognostic factors ( P values=0.001 for both) when analysed in a Cox regression model with the somatic variables β-2 microglobulin, skeletal disease and age. The best prediction for survival from the start of therapy was obtained by combining the β-2 microglobulin and physical functioning scores in a variable consisting of three risk factor levels with an estimated median survival of 17, 29 and 49 months, respectively. At a 12 months landmark analysis, the relative risk for patients with physical functioning score 0–20 v 80–100 was 5.63 (99% CI 2.76–11.49), whereas the relative risk for patients without an objective response to chemotherapy compared to those with at least a minor response was 2.32 (99% CI 1.44–3.74). Quality-of-life assessment may be an independent and valuable addition to the known prognostic factors in multiple myeloma. 相似文献
79.
In 112 comatose patients somatosensory, visual and auditory evoked potentials were registered within 36 hours after the onset of coma or admission. Main causes of coma were head injury, and intracerebral and subarachnoid haemorrhage. The initial bilateral loss of any evoked potential was associated with a mortality of 98%. Normal somatosensory evoked potentials were associated with a survival rate of 74%, while normal visual and normal auditory evoked potentials had a survival rate of 60% and 66%, respectively. It is concluded that SEPs can be valuable for the prognosis of coma after primary brain lesions. 相似文献
80.