全文获取类型
收费全文 | 128695篇 |
免费 | 44364篇 |
国内免费 | 278篇 |
专业分类
耳鼻咽喉 | 1985篇 |
儿科学 | 5894篇 |
妇产科学 | 1975篇 |
基础医学 | 22390篇 |
口腔科学 | 6085篇 |
临床医学 | 17930篇 |
内科学 | 34260篇 |
皮肤病学 | 8386篇 |
神经病学 | 18542篇 |
特种医学 | 3977篇 |
外国民族医学 | 4篇 |
外科学 | 20474篇 |
综合类 | 347篇 |
一般理论 | 63篇 |
预防医学 | 8302篇 |
眼科学 | 2041篇 |
药学 | 8653篇 |
1篇 | |
中国医学 | 1089篇 |
肿瘤学 | 10939篇 |
出版年
2023年 | 566篇 |
2022年 | 1086篇 |
2021年 | 3142篇 |
2020年 | 6032篇 |
2019年 | 12177篇 |
2018年 | 11730篇 |
2017年 | 12552篇 |
2016年 | 13365篇 |
2015年 | 13441篇 |
2014年 | 13898篇 |
2013年 | 14948篇 |
2012年 | 8200篇 |
2011年 | 8123篇 |
2010年 | 10936篇 |
2009年 | 7148篇 |
2008年 | 5403篇 |
2007年 | 4115篇 |
2006年 | 3865篇 |
2005年 | 3630篇 |
2004年 | 3226篇 |
2003年 | 2948篇 |
2002年 | 2839篇 |
2001年 | 1325篇 |
2000年 | 1202篇 |
1999年 | 769篇 |
1998年 | 448篇 |
1997年 | 333篇 |
1996年 | 318篇 |
1995年 | 288篇 |
1994年 | 256篇 |
1993年 | 225篇 |
1992年 | 387篇 |
1991年 | 353篇 |
1990年 | 341篇 |
1989年 | 325篇 |
1988年 | 266篇 |
1987年 | 258篇 |
1986年 | 242篇 |
1985年 | 236篇 |
1984年 | 194篇 |
1983年 | 141篇 |
1982年 | 117篇 |
1981年 | 110篇 |
1979年 | 140篇 |
1978年 | 137篇 |
1977年 | 121篇 |
1976年 | 110篇 |
1975年 | 101篇 |
1974年 | 138篇 |
1973年 | 101篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
The objective of this study was to compare the clinical and laboratory consequences of left and right displacement of the abomasum (LDA and RDA), short‐ and long‐term survival after surgery and the findings in cows, that could not be cured by omentopexy. Data from 564 cases of displaced abomasum (466 LDA, 98 RDA) were analysed retrospectively. Clinical and laboratory findings were compared between the two manifestations of DA. Survival was assessed after 10 days and after 15 months. Necropsy was carried out on cows that died or were killed. On arrival at the clinic, left displacement of the abomasum (LDA) cows had been recognized as diseased for longer. LDA occurred earlier in lactation, and more cows with right displacement of the abomasum (RDA) were pregnant. Overall clinical symptoms were more severe in RDA than in LDA cows. Heart rate was higher, body temperature was lower, inanition, abnormal faeces and ruminal stasis were more frequent in RDA cows. Leucocyte counts were higher, and potassium and chloride levels were lower in RDA cows. Acetonuria was more frequent in LDA cows. More LDA than RDA cows were released from the clinic as cured (82.0% versus 74.5%). However, survival after the early post‐surgical period was similar for RDA and LDA cows. At necropsy, diseases of the gastrointestinal system were the predominant finding in RDA cows, while in LDA cows, diseases of the liver and other concurrent diseases were more important. 相似文献
112.
Clinical trial of a prevention and treatment protocol for skin breakdown in two nursing homes. 总被引:1,自引:0,他引:1
Susan Hunter Julie Anderson Darlene Hanson Patricia Thompson Diane Langemo Marilyn G Klug 《Journal of wound, ostomy, and continence nursing》2003,30(5):250-258
OBJECTIVE: Our objective was to assess the effectiveness of skin care protocols, including a body wash and skin protectant, on skin breakdown in 2 nursing homes. DESIGN: This was a quasi-experimental pretest/posttest design study.Setting and subjects Adult residents (n = 136) of 2 skilled nursing homes consented to participate in this study. Seventy percent were women; the sample average age of 82 years. INSTRUMENTS: A researcher-designed data recording form documented resident demographics, incidence and type of skin breakdown or pressure ulcer, presence of urinary or fecal incontinence, and assessment of the effectiveness of body wash and skin protectant. METHODS: Baseline data on prevalence of pressure ulcers and skin protocol were collected weekly for a 3-month period followed by a week-long educational program by the researchers about skin care and the body wash and skin protectant. During the 3-month trial with the body wash and skin protectant incorporated into routine care, research assistants recorded resident data weekly and researchers again assessed prevalence and incidence of pressure ulcers and skin breakdown weekly. RESULTS: Incorporation of a body wash and skin protectant into a skin care prevention and early intervention protocol in 2 nursing homes documented a decrease in skin breakdowns from 68 pre-intervention to 40 postintervention; the decrease in agency B was statistically significant. There was a statistically significant decrease in stage I and II pressure ulcer incidence overall (pre-intervention = 19.9%, postintervention = 8.1%). Nurses evaluated the body wash and skin protectant as effective for 98% of the time used. CONCLUSION: Implementation of a protocol for skin care along with staff education, including the prophylactic use of a body wash and skin protectant, reduced the incidence of skin breakdown, including pressure ulcers and perineal dermatitis, in 2 long-term care facilities. 相似文献
113.
114.
115.
R. Kazi V. Prasad R. Venkitaraman C.M. Nutting P. Clarke P. Rhys‐Evans K.J. Harrington 《Clinical otolaryngology》2006,31(6):525-530
Objective: To determine the effects of a total laryngectomy on the swallow and subsequent quality of life in head and neck cancer patients. Design: Cross‐sectional single centre cohort study. Setting: Head and Neck Oncology Unit, Tertiary Referral Unit. Patients: Sixty‐two patients who underwent total laryngectomy at our centre participated in the study. Methods: Subjects were stratified by age, sex, tumour stage, other procedures such as myotomy and nerve re‐implantation. Pharyngectomy, glossectomy, flap reconstruction, neck dissection and previous radio‐ and chemotherapy were also assessed to see if they affected swallow and subsequent quality of life. Main outcome was measured using the MD Anderson Dysphagia Inventory questionnaire. Results: Responses were received from 46 males and 16 females (response rate of 80.5%) with a mean age of 64.7 years (SD 9.4). Median follow‐up in patients was 90 months (range 1–276). The mean MD Anderson Dysphagia Inventory total score in our series of patients was 77.7 (SD 16.6). MD Anderson Dysphagia Inventory global score was 79.4 (SD 22.6), Emotional score was 77.7 (SD 17.8), Functional score 81.3 (SD 15.9) and Physical score was 74.1(SD 18). Statistically significant differences were seen between the emotional scores of glossectomised and non‐glossectomised patients (Mann Whitney, P = 0.04). No significant correlation was seen between the subscale scores and the remaining treatment variables such as age, gender, site, tumour stage, myotomy, nerve implantation, radiotherapy, reconstruction and major complications. Conclusion: This questionnaire study is the largest of its type to assess the swallow of patients who have undergone laryngectomy at a single centre. The overall result confirmed that most patients had a subjectively good swallow. Only glossectomy and the method of PE segment closure were shown to significantly affect swallowing outcomes following surgery. We recommend further work especially prospective studies pre and post surgery using this or similarly validated instruments to fully assess swallow in the laryngectomy population. 相似文献
116.
Angelo Pan Placido Mondello Klara Posfay-Barbe Patrizia Catenazzi Annise Grandi Silvia Lorenzotti Andrea Patroni Nadia Poli Laura Soavi Giuseppe Carnevale 《Infection control and hospital epidemiology》2007,28(9):1099-1102
In an Italian hospital, we observed that hand hygiene was performed in 638 (19.6%) of 3,253 opportunities, whereas gloves were worn in 538 (44.2%) 1,218 of opportunities. We observed an inverse correlation between the intensity of care and the rate of hand hygiene compliance (R2=0.057; P<.001), but no such association was observed for the rate of glove use compliance (R2=0.014; P=.078). Rates of compliance with hand hygiene and glove use recommendations follow different behavioral patterns. 相似文献
117.
D L Lennon E R Shrago M Madden F J Nagle P Hanson 《The American journal of clinical nutrition》1986,43(2):234-238
The purpose of this investigation was to determine if there was any relationship between dietary carnitine intake and the concentrations of carnitine in skeletal muscle and blood plasma in healthy adult men and women. Subjects (14 men, 14 women, fasted 8 h) reported to the Biodynamics Laboratory where they completed a 24-h diet recall questionnaire. Resting muscle biopsy (vastus lateralis) and blood plasma samples were taken and assayed for free, short-chain, and long-chain acyl carnitine concentrations. Dietary carnitine intake was estimated from data on concentrations in food. There was no significant relationship between either protein or carnitine intake with skeletal muscle carnitine concentrations. There was a significant relationship between both dietary carnitine (r = 0.50) and protein (r = 0.48) intake with blood plasma total acid soluble carnitine concentrations (p less than 0.01) in all subjects. 相似文献
118.
Identification of the C-terminal flanking peptide of preprocholecystokinin in rat brain by a novel radioimmunoassay 总被引:1,自引:0,他引:1
The C-terminal flanking peptide of preprocholecystokinin (preproCCK) has been identified in extracts of rat brain using a novel radioimmunoassay. There is a single form of immunoreactive material on gel filtration, ion exchange and reversed-phase HPLC. The C-terminal preproCCK immunoreactivity had a similar pattern of distribution to CCK8 in different regions of rat brain. This assay should help in studies of neuronal CCK biosynthesis. 相似文献
119.
Photosensitivity and photodermatitis in childhood 总被引:1,自引:0,他引:1
G Kahn 《Dermatologic Clinics》1986,4(1):107-116
Photosensitivity disorders of children are uncommon, except for banal overexposure reactions to sunlight. Although the long-term sequelae of chronic or intense sun exposure are not often seen in children, physicians should advise patients of the harmful effects and irreversible skin damage that results from unduly prolonged sun exposure. Damage accumulates over the years to cause premature aging, senile elastosis, actinic keratoses, and squamous- and basal-cell carcinomas. Besides the pigmentary changes, wrinkles, and skin cancers--genuine sources of altered appearance and morbidity--we now know that sunburned children develop a higher incidence of melanoma, which is not a rare cause of death in young adults. In Australia, where the incidence of melanoma is highest, a strong correlation exists for melanoma in children who get sunburn before the age of 10. Also, the incidence of melanoma is 50 times as great in bikini wearers who get sunburn as in girls who wear one-piece bathing suits. 相似文献
120.
Characterization of binding and phosphorylation defects of erythrocyte insulin receptors in the type A syndrome of insulin resistance 总被引:7,自引:0,他引:7
The type A syndrome of insulin resistance and acanthosis nigricans is characterized by severe insulin resistance due to a cellular defect in insulin action. To better understand the molecular nature of this defect, we have investigated insulin binding to circulating monocytes, erythrocytes, and the Triton X-100-solubilized erythrocyte receptor, and insulin-stimulated receptor autophosphorylation using cells and receptor from three type A patients. Insulin binding in both circulating cells and the soluble extract of erythrocytes indicated a heterogeneity of defects. Patients A1 and A2 both presented a major decrease in tracer insulin binding to intact cells and soluble insulin receptor. Determination of stoichiometric binding parameters using a cooperative model indicated that in patient A1 this was due to a reduction in the number of receptors, whereas in patient A2 the affinity constant for binding was decreased. Patient A3 presented near-normal insulin binding to erythrocytes and normal binding in intact monocytes, solubilized erythrocyte receptors, and cultured fibroblasts. Affinity labeling of erythrocyte receptor from this patient revealed a normal alpha-subunit and also a normal relative distribution of the higher-molecular-weight, nonreduced oligomeric forms of the receptor. Receptor autophosphorylation was measured using the solubilized insulin receptor from erythrocytes. The maximal stimulated phosphorylation was reduced by 79%, 76%, and 52% in patients A1, A2, and A3, respectively, relative to the simultaneous control. In all three patients, the autophosphorylation was stimulated only 1.0-3.5 times the basal level compared with controls, in which the stimulation was 5.7-fold +/- 1.2 (mean +/- 1 SD, P less than 0.005). In addition, in patients A1 and A2 a decrease in basal phosphorylation was observed and in patient A2 there was a rightward shift of the dose-response curve for insulin stimulation. These data and the correlation of coupling of receptor phosphorylation with the fractional occupancy of the receptor measured in the same extract suggest that these patients exhibit three types of defects. In patient A1, there is a loss in receptor number manifested by a parallel decrease in insulin binding and receptor phosphorylation. In patient A2, there is an additional decrease in the affinity constant leading to a decrease in both binding and receptor phosphorylation with an almost linear coupling between receptor occupancy and receptor phosphorylation.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献