全文获取类型
收费全文 | 106079篇 |
免费 | 29593篇 |
国内免费 | 1149篇 |
专业分类
耳鼻咽喉 | 2470篇 |
儿科学 | 2785篇 |
妇产科学 | 2449篇 |
基础医学 | 3720篇 |
口腔科学 | 5318篇 |
临床医学 | 26589篇 |
内科学 | 27081篇 |
皮肤病学 | 3420篇 |
神经病学 | 12933篇 |
特种医学 | 3843篇 |
外科学 | 19105篇 |
综合类 | 130篇 |
现状与发展 | 40篇 |
一般理论 | 4篇 |
预防医学 | 13614篇 |
眼科学 | 2245篇 |
药学 | 1524篇 |
中国医学 | 33篇 |
肿瘤学 | 9518篇 |
出版年
2024年 | 746篇 |
2023年 | 5082篇 |
2022年 | 1259篇 |
2021年 | 2945篇 |
2020年 | 5473篇 |
2019年 | 2184篇 |
2018年 | 7105篇 |
2017年 | 7487篇 |
2016年 | 8097篇 |
2015年 | 8240篇 |
2014年 | 10727篇 |
2013年 | 12523篇 |
2012年 | 4440篇 |
2011年 | 4167篇 |
2010年 | 7182篇 |
2009年 | 9431篇 |
2008年 | 4048篇 |
2007年 | 2978篇 |
2006年 | 4128篇 |
2005年 | 2660篇 |
2004年 | 2012篇 |
2003年 | 1578篇 |
2002年 | 1479篇 |
2001年 | 1871篇 |
2000年 | 1184篇 |
1999年 | 1746篇 |
1998年 | 2147篇 |
1997年 | 1968篇 |
1996年 | 2025篇 |
1995年 | 1736篇 |
1994年 | 1127篇 |
1993年 | 946篇 |
1992年 | 771篇 |
1991年 | 664篇 |
1990年 | 528篇 |
1989年 | 535篇 |
1988年 | 513篇 |
1987年 | 387篇 |
1986年 | 362篇 |
1985年 | 303篇 |
1984年 | 277篇 |
1983年 | 321篇 |
1982年 | 243篇 |
1981年 | 214篇 |
1980年 | 128篇 |
1978年 | 128篇 |
1977年 | 123篇 |
1976年 | 95篇 |
1974年 | 81篇 |
1972年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Joan C. Engebretson RN DrPH Diane Wind Wardell RNC PhD 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1997,26(6):660-664
Nonnutritive sucking can provide low-birth-weight infants with an opportunity to organize their behavior, an important component of developmental care. A pacifier specifically designed for low-birth-weight infants facilitates their nonnutritive sucking to more fully meet their needs. The research and development of a pacifier for low-birth-weight infants incorporated a naturalistic approach and used the best model, the infant thumb, in the design. Clinical trials with infants randomized to control and experimental groups were conducted to compare the prototype pacifier to a commercially available pacifier. Observations using the Anderson Behavioral State Scale demonstrated that infants using the prototype pacifier more often were found to be in an alert state. This pacifier may contribute to infants' state organization for optimum feeding and could be a component in developmental care planning. 相似文献
992.
Niklas Zethraeus PhD Student Magnus Johannesson Associate Professor Peter Henriksson Head of Department Roland T. Strand Consultant 《BJOG : an international journal of obstetrics and gynaecology》1997,104(10):1191-1195
Objective To measure the gain in quality of life due to hormone replacement therapy for women with mild and severe menopausal symptoms.
Design Prospective study where data on quality of life and willingness to pay were collected by interview.
Setting Department of Gynaecology at Sodertalje Hospital near Stockholm.
Participants One hundred and four women aged 45 to 65 years treated for menopausal symptoms for at least one month.
Methods Quality oflife was measured by the time tradeoff and rating scale methods. The willingness to pay for hormone replacement therapy was investigated using the contingent valuation method.
Main outcome measures The quality adjusted life year weight measured with the rating scale and time tradeoff methods, and willingness to pay.
Results The increase in the quality adjusted life year weight due to hormone replacement therapy for women with mild symptoms was 0.26 according to the rating scale method and 0.18 according to the time tradeoff method. For women with severe symptoms the quality adjusted life year weight increased by 0.50 according to the rating scale method and by 0.42 according to the time tradeoff method. The mean willingness to pay for hormone replacement therapy per month was 2300 Swedish krone for women with mild symptoms and 4800 Swedish krone for women with severe symptoms (£1 = 10.3 Swedish krone).
Conclusions Hormone replacement therapy leads to a major improvement in quality of life for women with menopausal symptoms. Both for women with mild and severe menopausal symptoms the willingness to pay for the treatment also greatly exceeds the costs, indicating that hormone replacement therapy is economically beneficial for women with menopausal symptoms. 相似文献
Design Prospective study where data on quality of life and willingness to pay were collected by interview.
Setting Department of Gynaecology at Sodertalje Hospital near Stockholm.
Participants One hundred and four women aged 45 to 65 years treated for menopausal symptoms for at least one month.
Methods Quality oflife was measured by the time tradeoff and rating scale methods. The willingness to pay for hormone replacement therapy was investigated using the contingent valuation method.
Main outcome measures The quality adjusted life year weight measured with the rating scale and time tradeoff methods, and willingness to pay.
Results The increase in the quality adjusted life year weight due to hormone replacement therapy for women with mild symptoms was 0.26 according to the rating scale method and 0.18 according to the time tradeoff method. For women with severe symptoms the quality adjusted life year weight increased by 0.50 according to the rating scale method and by 0.42 according to the time tradeoff method. The mean willingness to pay for hormone replacement therapy per month was 2300 Swedish krone for women with mild symptoms and 4800 Swedish krone for women with severe symptoms (£1 = 10.3 Swedish krone).
Conclusions Hormone replacement therapy leads to a major improvement in quality of life for women with menopausal symptoms. Both for women with mild and severe menopausal symptoms the willingness to pay for the treatment also greatly exceeds the costs, indicating that hormone replacement therapy is economically beneficial for women with menopausal symptoms. 相似文献
993.
Andreas Lee M.D. Michael Sator M.D. Alfred Kratochwil Professor Josef Deutinger Professor Elisabeth Vytiska-Binsdorfer PhD Gerhard Bernaschek Professor 《Fertility and sterility》1997,68(5):831-835
Objective: At present, only limited data are available on endometrial volume during the menstrual cycle. Most of these studies deal with animal models and use magnetic resonance imaging for volume measuring. The application of three-dimensional ultrasound in endometrial volume estimation is the subject of this study.Setting: Patients visiting the outpatient unit of the division of endocrinology and reproductive medicine of a university hospital.Patient(s): Twenty patients with a history of a normal menstrual cycle were selected.Intervention(s): Ultrasound examinations were performed during a single menstrual cycle in addition to routine laboratory tests.Main Outcome Measure(s): Uterus-endometrial volume ratio.Result(s): Data from 18 patients could be evaluated. In 81 examinations the endometrium volume could be determined. Mean endometrial volume measured by three-dimensional ultrasound was 1.23 cm'. Mean uterus volume was 48.93 cm3. The change of the uterus-endometrial volume ratio showed a good correlation with the day of menstrual cycle. Quadratic regression analysis of volume and cycle length was R2 = 0.432.Conclusion(s): Three-dimensional ultrasound allows assessment of volume data of the female internal genitalia. In this study changes of the endometrial volume in menstrual cycles were measured. Additional studies are required to give information on the clinical impact of this new technique of endometrial volume estimation. 相似文献
994.
Margaret K. Hargreaves PhD Maciej S. Buchowski PhD Robert E. Hardy MD MPH Susan R. Rossi RN PhD Joseph S. Rossi PhD 《American journal of obstetrics and gynecology》1997,176(6):s255
Modification of dietary fat and fiber could help prevent cancers of the breast, endometrium, and ovary that are prevalent in African-American women. Dietary intervention programs aimed at reducing fat intake have had mixed results in this population. The transtheoretic model is proposed for achieving dietary change. Strategies for changing health behaviors in African-American women include heightening sensitivity to cultural values among health educators and the use of multiple strategies to reinforce messages. To stimulate healthier eating, it is important to incorporate the distinct habitual eating patterns into innovative intervention methods, using effective behavioral change methods. (Am J Obstet Gynecol 1997;176:S255-64.) 相似文献
995.
Kathleen M. Hanlon-Lundberg MD Russell S. Kirby PhD Sweeta Gandhi MD Fredrik F. Broekhuizen MD 《American journal of obstetrics and gynecology》1997,176(6):1149-1156
OBJECTIVE: This study aims to establish normal values for nucleated red blood cells in term singletons and factors associated with their elevation.STUDY DESIGN: Cord blood was prospectively collected from term singleton gestations from Feb. 1 to July 31, 1995. Umbilical vein white blood cells and nucleated red blood cells were counted and umbilical arterial pH was determined. Medical records provided maternal and neonatal information.RESULTS: Cord blood from 1112 cases was obtained and evaluated for nucleated red blood cells per 100 white blood cells. Nine outliers were censored (nucleated red blood cells per 100 white blood cells = 126 to 830); five cases were excluded because of missing data. The mean value of nucleated red blood cells per 100 white blood cells was 8.55, the SD was 10.27, and the range was 0 to 89. The value did not vary by maternal tobacco or drug use, anemia, fetal presentation, or mode of delivery. Both maternal diabetes and meconium were associated with elevated values, p < 0.01. Apgar scores and cord pHs showed trends toward inverse proportionality to the number of nucleated red blood cells per 100 white blood cells.CONCLUSION: The mean number of nucleated red blood cells per 100 white blood cells was 8.55, with a wide range and SD. Elevated values may be associated with markers of intrauterine hypoxia such as meconium, lower Apgar scores, and lower pH values. (Am J Obstet Gynecol 1997;176:1149-56.) 相似文献
996.
J. Bornstein MD D. Zarfati MD N. Goldshmid MD Z. Stolar MA N. Lahat PhD H. Abramovici MD 《American journal of obstetrics and gynecology》1997,177(6):1439-1443
OBJECTIVE: Our purpose was to recognize special features of women with both vestibulitis and constant vulvar pain (vestibulodynia) and to determine whether vestibulodynia is a separate disease entity or a subset of vestibulitis. STUDY DESIGN: Ninety-one women with severe vulvar vestibulitis underwent perineoplasty by a single surgeon during 1992 to 1995. Twenty-five (27%) of them who had vestibulodynia were compared with 66 (73%) who had dyspareunia alone. With univariate and then multivariate analysis, the two groups were compared with regard to demographic, social, and medical variables, the presence of human papillomavirus deoxyribonucleic acid, physical findings in the vestibule, and surgical outcome. RESULTS: The vestibulodynia and vestibulitis groups differed in age (30.5 ± 10.6 years vs 24.7 ± 6.2 years respectively), as well as in marital status (married, 44% vs 18%, respectively), nonuse of contraception (20% vs 1%, respectively), presence of human papillomavirus deoxyribonucleic acid in the vestibule (80% vs 48%, respectively), and failure of surgical treatment (incomplete response rate, 64% vs 2%, respectively). With multivariate analysis, patients with human papillomavirus deoxyribonucleic acid present in the vestibule have an odds ratio of 5.44 (95% confidence interval, 1.45 to 20.33) of belonging to the group with vestibulodynia, whereas dysuria and age have odds ratios of 3.70 (95% confidence interval 1.09 to 12.55) and 1.14 (95% confidence interval 1.04 to 1.24), respectively. CONCLUSIONS: Vestibulodynia is a unique syndrome in that it affects women who are older than those who have vestibulitis alone and it is associated with human papillomavirus deoxyribonucleic acid, dysuria, and a higher surgical failure rate than that for vestibulitis.(Am J Obstet Gynecol 1997;177:43) 相似文献
997.
An Australian study of functional status after childbirth 总被引:1,自引:0,他引:1
998.
W.Edward Richards MD Sheila M. Dobin PhD Vicki Malone CLSp Alfred B. Knight MD Thomas J. Kuehl PhD 《American journal of obstetrics and gynecology》1997,176(6):1172-1180
OBJECTIVE: Although most methods for selecting the sex of offspring by sorting spermatozoa are ineffective at shifting the ratio of Y- to X-containing cells, some commercial sources continue to offer such services. Our objective was to evaluate commercially “sorted” samples with use of dual-color fluorescence in situ hybridization and to identify variations in assessment by comparing motile and total sperm populations, donors, observers, and fluorescence in situ hybridization probes.STUDY DESIGN: Cryopreserved sperm from seven anonymous donors were processed as for insemination. Sperm cells from each total sample or motile subfraction were prepared for fluorescence in situ hybridization by incubation with disulfide-reducing agents to expand sperm nuclei. Two sets of X and Y chromosome–specific, fluorophore-labeled deoxyribonucleic acid probes were used. At least 400 nuclei from each preparation were classified independently by three blinded observers. Hybridization efficiency, aneuploidy, and sex chromosome content were evaluated in subsets of five unsorted, five female-oriented, and five male-oriented samples. Total and motile subfractions were compared with eight samples. Fluorescence in situ hybridization probes were compared in five paired unsorted samples.RESULTS: No differences were detected between washed samples and paired motile subfractions. No differences in hybridization and aneuploidy were detected between groups of sorted samples. The Y/X ratio was significantly different between the sorted groups. However, male-oriented samples had a lower Y/X ratio than female-oriented samples did. Observer and probe choice accounted for small but significant variations that did not alter conclusions about the Y/X ratio for sorted samples.CONCLUSION: In a series of 10 sorted samples from one commercial source, dual-color fluorescence in situ hybridization demonstrated a small but significant shift in the sex chromosome ratios among samples. However, this shift was opposite to that expected by the orientation of the sorted samples. (Am J Obstet Gynecol 1997;176:1172-80.) 相似文献
999.
Judith McFarlane RN DrPH FAAN Barbara Parker RN PhD FAAN Karen Soeken PhD Connie Silva RN PhD Sally Reel RN PhD 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1998,27(1):64-69
Objective: To evaluate an intervention protocol, administered during pregnancy, for increasing safety-seeking behaviors of abused women.
Design: Prospective, ethnically stratified cohort analysis.
Setting: Public prenatal clinics.
Participants: Pregnant women reporting physical or sexual abuse in the year before or during the present pregnancy. One hundred thirty-two women met study criteria, received the intervention, and were followed for 1 year after the completion of the pregnancy.
Intervention: Three education, advocacy, and community referral sessions that included information on safety behaviors.
Main outcome Measure: Adoption of safety behaviors by abused women. Safety behaviors were measured before the intervention, twice during pregnancy, and at 2, 6, and 12 months after completion of the pregnancy.
Results: Repeated measures analysis of variance showed a significant increase in adoption of each safety behavior (p < .0001), with most behaviors showing a significant increase after the first intervention session.
Conclusions: Pregnant women who were abused and were offered an intervention protocol report a significant increase in safety behavior adoption during and after pregnancy. Abuse during pregnancy is common. Identification of abuse and immediate clinical intervention that includes information about safety behaviors can result in safety behavior adoption that may prevent future abuse and increase the safety and well-being of women and infants. 相似文献
Design: Prospective, ethnically stratified cohort analysis.
Setting: Public prenatal clinics.
Participants: Pregnant women reporting physical or sexual abuse in the year before or during the present pregnancy. One hundred thirty-two women met study criteria, received the intervention, and were followed for 1 year after the completion of the pregnancy.
Intervention: Three education, advocacy, and community referral sessions that included information on safety behaviors.
Main outcome Measure: Adoption of safety behaviors by abused women. Safety behaviors were measured before the intervention, twice during pregnancy, and at 2, 6, and 12 months after completion of the pregnancy.
Results: Repeated measures analysis of variance showed a significant increase in adoption of each safety behavior (p < .0001), with most behaviors showing a significant increase after the first intervention session.
Conclusions: Pregnant women who were abused and were offered an intervention protocol report a significant increase in safety behavior adoption during and after pregnancy. Abuse during pregnancy is common. Identification of abuse and immediate clinical intervention that includes information about safety behaviors can result in safety behavior adoption that may prevent future abuse and increase the safety and well-being of women and infants. 相似文献
1000.