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81.
Rene E Sotomayor Melissa Washington Linh Nguyen Rahma Nyang'anyi Dennis M Hinton Ming Chou 《Toxicological sciences》2003,73(2):329-338
We studied the effects of intermittent exposure to aflatoxin B1 (AFB1) on hepatic DNA and RNA adduct formation. Fisher-344 male rats were fed 0.01, 0.04, 0.4, or 1.6 ppm of AFB1 intermittently for 8, 12, 16, and 20 weeks, alternating with 4 weeks of dosing and 4 weeks of rest. Other groups of rats were fed 1.6 ppm of AFB1 continuously for 4, 8, 12, and 16 weeks. Control rats received AFB1-free NIH-31 meal diet. AFB1-DNA and -RNA adducts were measured by HPLC with fluorescence detection. The data are presented as total DNA or RNA adducts. The DNA and RNA adduct levels increased or decreased depending on the cycles of dosing and rest. Rats removed from treatment 1 month after 1 or 2 dosing cycles (8 and 16 weeks of intermittent exposure) showed approximately a twofold decrease in DNA adduct levels and a two- to elevenfold decrease in RNA adduct levels compared with rats euthanized immediately after the last dosing cycle (12 and 20 weeks of intermittent exposure). Our data indicate that DNA and RNA adducts increased linearly, from 0.01 ppm to 1.6 ppm of AFB1 after 12 and 20 weeks of intermittent treatment. A linear dose response was also apparent for DNA but not for RNA adducts after 8 and 16 weeks of treatment. As biomarkers of exposure, AFB1-RNA adducts were three to nine times more sensitive than AFB1-DNA adducts but showed greater variability. These results suggest that binding of AFB1 to hepatic DNA is a linear function of the dose, regardless of the way this is administered. The dose-response relationship for RNA adducts depends on the length of the no-dosing cycles and on the turnover rate of RNA. 相似文献
82.
Thomas C Neylan Maryanne Lenoci Melissa L Maglione Nicholas Z Rosenlicht Thomas J Metzler Christian Otte Frank B Schoenfeld Rachel Yehuda Charles R Marmar 《Neuropsychopharmacology》2003,28(9):1666-1676
Metyrapone blocks cortisol synthesis, which results in the stimulation of hypothalamic cortiocotropin-releasing factor (CRF) and a reduction in delta sleep. We examined the effect of metyrapone administration on endocrine and sleep measures in male subjects with and without chronic PTSD. We hypothesized that metyrapone would result in a decrease in delta sleep and that the magnitude of this decrease would be correlated with the endocrine response. Finally, we utilized the delta sleep response to metyrapone as an indirect measure of hypothalamic CRF activity and hypothesized that PTSD subjects would have decreased delta sleep at baseline and a greater decrease in delta sleep induced by metyrapone. Three nights of polysomnography were obtained in 24 male subjects with combat-related PTSD and 18 male combat-exposed normal controls. On day 3, metyrapone was administered during normal waking hours until habitual sleep onset preceding night 3. Endocrine responses to metyrapone were measured in plasma obtained the morning following sleep recordings, the day before and after administration. Repeated measures ANOVAs were conducted to compare the endocrine and sleep response to metyrapone in PTSD and controls. PTSD subjects had significantly less delta sleep as indexed by stages 3 and 4, and total delta integrated amplitude prior to metyrapone administration. There were no differences in premetyrapone cortisol or ACTH levels in PTSD vs controls. PTSD subjects had a significantly decreased ACTH response to metyrapone compared to controls. Metyrapone caused an increase in awakenings and a marked decrease in quantitative measures of delta sleep that was significantly greater in controls compared to PTSD. The decline in delta sleep was significantly associated with the magnitude of increase in both 11-deoxycortisol and ACTH. The results suggest that the delta sleep response to metyrapone is a measure of the brain response to increases in hypothalamic CRF. These data also suggest that the ACTH and sleep EEG response to hypothalamic CRF is decreased in PTSD. 相似文献
83.
Carl A. Latkin Wei Hua Melissa A. Davey Susan G. Sherman 《The International journal on drug policy》2003,14(5-6):449
Syringe exchange programmes (SEPs) are a fundamental source of sterile syringes and other health services for injection drug users (IDUs). However, various obstacles prevent many individuals from obtaining syringes from this source. As a result, some IDUs acquire syringes from “secondary exchangers”. The current study assessed the acquisition of syringes from the Baltimore City Needle Exchange Program (BNEP) as well as factors associated with obtaining syringes from the BNEP. Participants were asked to identify the colour of the cap of the most recently obtained syringe (red or grey cap suggested BNEP origins). In addition, support and risk network variables were examined. Although 38% reported using a syringe with a grey or red cap, only 7% reported that the BNEP was their primary source of syringes. Multivariate analyses showed that reporting the most recent syringe cap as red or grey was associated with obtaining syringes from the BNEP, obtaining syringes from a spouse, obtaining syringes from friends/neighbours, and number of drug users in their network. Based on these findings, encouraging secondary exchange is an effective method of providing injectors with syringes. 相似文献
84.
85.
Irene D Fischer Melissa J Krauss William Claiborne Dunagan Stanley Birge Eileen Hitcho Shirley Johnson Eileen Costantinou Victoria J Fraser 《Infection control and hospital epidemiology》2005,26(10):822-827
OBJECTIVES: Most research on hospital falls has focused on predictors of falling, whereas less is known about predictors of serious fall-related injury. Our objectives were to characterize inpatients who fall and to determine predictors of serious fall-related injury. METHODS: We performed a retrospective observational study of 1,082 patients who fell (1,235 falls) during January 2001 to June 2002 at an urban academic hospital. Multivariate analysis of potential risk factors for serious fall-related injury (vs no or minor injury) included in the hospital's adverse event reporting database was conducted with logistic regression to calculate adjusted odds ratios (aORs) with 95% confidence intervals (CI95) RESULTS: The median age of patients who fell was 62 years (interquartile range, 49-77 years), 50% were women, and 20% were confused. The hospital fall rate was 3.1 falls per 1,000 patient-days, which varied by service from 0.86 (women and infants) to 6.36 (oncology). Some (6.1%) of the falls resulted in serious injury, ranging by service from 3.1% (women and infants) to 10.9% (psychiatry). The most common serious fall-related injuries were bleeding or laceration (53.6%), fracture or dislocation (15.9%), and hematoma or contusion (13%). Patients 75 years or older (aOR, 3.2; CI95, 1.3-8.1) and those on the geriatric psychiatry floor (aOR, 2.8; CI95, 1.3-6.0) were more likely to sustain serious fall-related injuries. CONCLUSIONS: There is considerable variation in fall rates and fall-related injury percentages by service. More detailed studies should be conducted by floor or service to identify predictors of serious fall-related injury so that targeted interventions can be developed to reduce them. 相似文献
86.
Bernard F. Fuemmeler Larry L. Mullins Jill Van Pelt Melissa Y. Carpentier Joan Parkhurst 《Children's Health Care》2005,34(4):289-303
In this study, we compared levels of posttraumatic stress symptoms (PTSS) and general psychological distress between parents of childhood cancer survivors and parents of children with Type 1 diabetes mellitus (DM1). In this study, we also examined potential risk factors for PTSS. Participants included 47 parents of childhood cancer survivors and 31 parents of children with DM1. Participants completed self-report measures of posttraumatic stress, general psychological distress, coping strategies, social network size, and perceived illness uncertainty. Findings revealed that parents of children surviving cancer reported higher levels of PTSS and general distress than parents of children with DM1. In the total sample, lower levels of emotion-focused coping and greater perceived uncertainty were associated with increased frequency of both PTSS and general psychological distress after we accounted for demographic and illness variables. Having a child with cancer may increase the risk for experiencing PTSS. Interventions are warranted that focus specifically on the reduction of PTSS in parents of children surviving cancer. 相似文献
87.
88.
Erin M Kane Reina M Turcios Melissa L Arvay Salvador Garcia Joseph S Bresee Roger I Glass 《Pan American journal of public health》2004,16(6):371-377
OBJECTIVE: To assess the disease burden and characterize the epidemiology of rotavirus diarrhea in Latin America. METHODS: We conducted a literature review of studies of children < 5 years of age who were hospitalized or seen as outpatients for diarrhea and for whom rotavirus was sought as the etiologic agent of the diarrhea. This review included inpatient and outpatient studies published since 1998 that included at least 100 children and reported surveillance activities lasting at least 12 consecutive months. RESULTS: A total of 18 inpatient and 10 outpatient studies met the criteria for inclusion in this review. Rotavirus was detected in a median of 31% of inpatients (range, 16%-52%) and 30.5% of outpatients (range, 4%-42%). The median detection rate was higher in studies that used an enzyme-linked immunosorbent assay (ELISA) (inpatients 38%, outpatients 33%) versus less sensitive methods of detection. The age distribution of rotavirus disease varied among countries, with 65%-85% of children hospitalized in the first year of life. Most countries had rotavirus admissions year round, and rotavirus generally exhibited a winter seasonal peak in both temperate and tropical climates. CONCLUSIONS: The heavy burden of disease attributable to rotavirus in Latin America suggests that vaccines currently being tested could have considerable impact in preventing hospitalizations, clinic visits, and deaths. The findings of the young age distribution of patients highlight the importance of early immunization for the success of a vaccine program. The data suggest that future surveillance for rotavirus diarrhea in Latin America should use a standardized surveillance protocol with an ELISA for detection. Data from surveillance studies will be critical to monitor the impact of the future introduction of vaccines. 相似文献
89.
Melissa Wake Elizabeth K Hughes Christy M Collins Zeffie Poulakis 《Ambulatory Pediatrics》2004,4(5):411-417
OBJECTIVE: To report 1) health-related quality of life (HRQoL) in 7- to 8-year-old children with congenital hearing loss and 2) effects of severity and age of diagnosis on parent-reported child HRQoL. METHODS: Setting: State of Victoria, Australia. Design: Two population-based cohorts of 7- to 8-year-old children. Participants: Cohort 1 consisted of 83 children (51 boys) fitted with hearing aids or cochlear implants for congenital hearing loss by 4.5 years, born before universal newborn hearing screening, and without intellectual disability (the Children with Hearing Impairment in Victoria Outcome Study). Cohort 2 consisted of 895 children representative of the Victorian 7- to 8-year-old school population (the 1997 Health of Young Victorians Study). Outcome: The 28-item parent-proxy Child Health Questionnaire measure of HRQoL. RESULTS: Response rate for cohort 1 was 67%; 22% had mild, 33% had moderate, 17% had severe, and 29% had profound hearing loss; and the mean nonverbal IQ was 105.4 (SD = 16.5). Children with hearing loss scored significantly more poorly than the normative sample on 6 Child Health Questionnaire scales (Role/Social-Physical, Behavior, Mental Health, Parent Impact-Emotional, Parent Impact-Time, and Family Activities) and on the Psychosocial Summary Score. HRQoL was poorer with milder losses, accounting for 10% and 11% of variance in the Physical and Psychosocial Summary scores, respectively. Age at diagnosis did not contribute significantly to the Summary scores, but only 11 children were diagnosed <6 months of age. CONCLUSIONS: Parent-reported psychosocial well-being of 7- to 8-year-old children with hearing loss is poorer than that of their hearing peers. Future studies should determine whether HRQoL has improved after introduction of universal newborn hearing screening. 相似文献
90.
Goldberg MC Landa R Lasker A Cooper L Zee DS 《Journal of autism and developmental disorders》2000,30(6):519-524
The effect of tilt-suppression on post-rotatory vestibular nystagmus was investigated to assess the function of the caudal cerebellar vermis (lobules IX and X, or nodulus and uvula) in 13 school-age children with high-functioning autism (HFA) and 10 normal controls. Tilt-suppression of the vestibulo-ocular reflex (VOR) refers to the decreasing of the duration of post-rotatory vestibular nystagmus that occurs when the head is moved out of the plane in which it was located during the previous sustained constant-velocity rotation. The participant is rotated in a vestibular chair with the head upright and then the head is tilted forward just after the chair stops rotating. Such tilt-suppression is impaired with lesions of the cerebellar nodulus and portions of the uvula. Results show that children with HFA have normal post-rotatory nystasmus with the head upright and normal attenuation of post-rotatory nystagmus induced by head tilt. These behavioral findings suggest that lobules IX and X of the cerebellum are spared in high-functioning autism. 相似文献