首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9862篇
  免费   831篇
  国内免费   16篇
耳鼻咽喉   139篇
儿科学   359篇
妇产科学   252篇
基础医学   1225篇
口腔科学   148篇
临床医学   1263篇
内科学   1660篇
皮肤病学   229篇
神经病学   1291篇
特种医学   197篇
外科学   1046篇
综合类   53篇
一般理论   16篇
预防医学   1450篇
眼科学   103篇
药学   518篇
  1篇
中国医学   5篇
肿瘤学   754篇
  2024年   38篇
  2023年   225篇
  2022年   326篇
  2021年   637篇
  2020年   417篇
  2019年   604篇
  2018年   655篇
  2017年   416篇
  2016年   443篇
  2015年   425篇
  2014年   535篇
  2013年   703篇
  2012年   916篇
  2011年   859篇
  2010年   441篇
  2009年   340篇
  2008年   489篇
  2007年   423篇
  2006年   423篇
  2005年   349篇
  2004年   265篇
  2003年   222篇
  2002年   228篇
  2001年   26篇
  2000年   14篇
  1999年   32篇
  1998年   32篇
  1997年   23篇
  1996年   28篇
  1995年   17篇
  1994年   15篇
  1993年   19篇
  1992年   10篇
  1991年   9篇
  1990年   9篇
  1989年   7篇
  1988年   6篇
  1987年   5篇
  1986年   6篇
  1985年   9篇
  1984年   5篇
  1983年   5篇
  1982年   7篇
  1981年   4篇
  1980年   7篇
  1979年   7篇
  1977年   3篇
  1976年   4篇
  1975年   3篇
  1971年   5篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Sleep spindles are important for sleep quality and cognitive functions, with their coordination with slow oscillations (SOs) potentially organizing cross-region reactivation of memory traces. Here, we describe the organization of spindles on the electrode manifold and their relation to SOs. We analyzed the sleep night EEG of 34 subjects and detected spindles and SOs separately at each electrode. We compared spindle properties (frequency, duration, and amplitude) in slow wave sleep (SWS) and Stage 2 sleep (S2); and in spindles that coordinate with SOs or are uncoupled. We identified different topographical spindle types using clustering analysis that grouped together spindles co-detected across electrodes within a short delay (±300 ms). We then analyzed the properties of spindles of each type, and coordination to SOs. We found that SWS spindles are shorter than S2 spindles, and spindles at frontal electrodes have higher frequencies in S2 compared to SWS. Furthermore, S2 spindles closely following an SO (about 10% of all spindles) show faster frequency, shorter duration, and larger amplitude than uncoupled ones. Clustering identified Global, Local, Posterior, Frontal-Right and Left spindle types. At centro-parietal locations, Posterior spindles show faster frequencies compared to other types. Furthermore, the infrequent SO-spindle complexes are preferentially recruiting Global SO waves coupled with fast Posterior spindles. Our results suggest a non-uniform participation of spindles to complexes, especially evident in S2. This suggests the possibility that different mechanisms could initiate an SO-spindle complex compared to SOs and spindles separately. This has implications for understanding the role of SOs-spindle complexes in memory reactivation.  相似文献   
52.
53.
54.
The healthcare workforce in the United States is becoming increasingly diverse, gradually shifting society away from the historical overrepresentation of White men among physicians. However, given the long-standing underrepresentation of people of color and women in the medical field, patients may still associate the concept of doctors with White men and may be physiologically less responsive to treatment administered by providers from other backgrounds. To investigate this, we varied the race and gender of the provider from which White patients received identical treatment for allergic reactions and measured patients’ improvement in response to this treatment, thus isolating how a provider’s demographic characteristics shape physical responses to healthcare. A total of 187 White patients experiencing a laboratory-induced allergic reaction interacted with a healthcare provider who applied a treatment cream and told them it would relieve their allergic reaction. Unbeknownst to the patients, the cream was inert (an unscented lotion) and interactions were completely standardized except for the provider’s race and gender. Patients were randomly assigned to interact with a provider who was a man or a woman and Asian, Black, or White. A fully blinded research assistant measured the change in the size of patients’ allergic reaction after cream administration. Results indicated that White patients showed a weaker response to the standardized treatment over time when it was administered by women or Black providers. We explore several potential explanations for these varied physiological treatment responses and discuss the implications of problematic race and gender dynamics that can endure “under the skin,” even for those who aim to be bias free.

The face of medicine is changing. Women and people of color make up an increasing percentage of health care providers (13). In 2017, for the first time in history, women were the majority of accepted medical school applicants in the United States and the number of non-White accepted applicants rose to above 50%. Here, we ask whether this recent demographic shift in the race and gender of doctors is also shifting long-held, societally pervasive notions of what a doctor “looks like.”Despite the increasing diversity of the medical field, for most people in most contexts, the association between “doctor” and “White man” is still likely strong and pervasive. This is hardly surprising. For most of medical history in North America, the majority of physicians fit this profile (see Fig. 1 A and B), and even now the majority of practicing physicians are still men and nearly half are White (see Fig. 1 C and D). Consequently, the emerging links between “Doctor and Woman” and between “Doctor and Black person,” for example, are likely weak. Moreover, to the extent that those associations exist, they are likely to have to compete for attention with an array of strong, frequent, and negative associations that undermine the links between women and competence and African Americans and competence (46).Open in a separate windowFig. 1.The change in the representation of women (A) and people color (B) in the number of accepted applicants to US medical schools, as well as the current representation of professionally active women physicians (C) and physicians of color (D). (A and B) From the Association of American Medical Colleges (AAMC). (C) From the Henry J. Kaiser Family Foundation. (D) From 2013 from the Association of American Medical Colleges (AAMC). AAMC data on race/ethnicity were not available for 2013 or 2014, hence explaining the gaps in the graph around these years in B.In patient–provider interactions, as in every social encounter, people bring with them a set of learned associations about social groups that have been formed by their various life experiences (e.g., personal interactions, media exposure) (612). Mirroring the historical representation of doctors in actual medical practice, representations of doctors in popular media have overwhelmingly been as White men (1315). Patients who have learned this societally pervasive “Doctor = White man” association through their actual encounters with physicians as well as through movies, television, books, and advertising may respond less positively to care from Black and women providers. These associations may exist at an implicit level even in the context of positive explicit attitudes toward Black doctors and women doctors (16, 17), and they are potentially powerful, influencing the course of medical care. Also, while it is clear from past research that being a target of bias can be harmful to health (e.g., people who face race-based discrimination face adverse physical and mental health consequences) (18), it is unclear whether viewing another social group in light of societally pervasive associations (e.g., about doctors on the basis of gender and race) can be harmful to the health of the perceiver.Here, we focus on how the race and gender of doctors may impact patients’ responses to the expectations doctors set about medical treatment. Previous research shows that a provider’s expressed expectations for a medical treatment (i.e., that it will benefit patients) can improve patient engagement, adherence, and physiological responses to treatment (1925). Based on these findings, we anticipate that patients who interact with a doctor whose personal characteristics (e.g., race, gender) do not conform to dominant societal representations of what a doctor looks like may be less responsive to such expectations. We hypothesize that patients may be less responsive to the exact same medical treatment when the doctor who sets expectations that this treatment will be beneficial is not a White man.This hypothesis draws on a large and growing body of research suggesting that the total effect of a healthcare treatment depends on the social context in which that treatment takes place (2529). The realization that the social context can influence treatment and medical outcomes is bolstered by a large body of research on the placebo effect (26). Although people may sometimes assume that actual pharmaceutical properties of a medication or treatment are solely responsible for its total benefit, placebo paradigms show that the total effect of treatment is in fact a combined product of the drug and their medical properties (e.g., acetaminophen, antihistamines), the body’s natural healing abilities (e.g., endogenous opioids and antihistamines), and the psychological and social context (e.g., what a patient believes about treatment and the qualities of the person who administers the treatment) (SI Appendix, Fig. S1). For example, past research suggests that a physician’s characteristics, such as their projected warmth and competence, influences how much a patient improves in response to treatment. In one recent study (22), the researchers independently manipulated whether a provider acted more or less warm, and more or less competent, toward a patient during an allergy skin prick test that induced a mild allergic reaction. The provider set positive expectations about a placebo cream (i.e., unscented hand lotion) placed on the reaction, informing patients that this cream was an antihistamine that would reduce the reaction. When the provider was both warm and competent, patients showed a stronger physiological response to the placebo treatment over time; their allergic reaction decreased the most rapidly in size, in response to the positive expectations that the provider had set. Thus, aspects of social interactions with providers can influence the degree to which the positive expectations that a provider sets about treatment ultimately influence physiological treatment response.As in most social interactions in the United States, race and gender are likely salient aspects of the social context in patient–provider interactions (30, 31, 32). Previous research has found, for example, that patient race can influence the quality of care received from doctors in myriad ways (3336). Here, we focus on provider race and provider gender as features of the social context that can influence patients’ response to treatment. Specifically, we ask the following: will White patients exhibit a weaker physiological response to the expectations set about treatment by doctors who are not White and men?  相似文献   
55.
Background:Burnout in people with diabetes and healthcare professionals (HCPs) is at an all-time high. Spotlight AQ, a novel “smart” adaptive patient questionnaire, is designed to improve consultations by rapidly identifying patient priorities and presenting these in the context of best-practice care pathways to aid consultations. We aimed to determine Spotlight AQ’s feasibility in routine care.Materials and Methods:The Spotlight prototype tool was trialed at three centers: two UK primary care centers and one US specialist center (June-September 2020). Participants with type 1 (T1D) or type 2 diabetes (T2D) completed the questionnaire prior to their routine consultations. Results were immediately available and formed the basis of the clinical discussion and decision-making within the clinic visit.Results:A convenience sample of 49 adults took part, n=31 T1D, (n=18 female); and n=18 T2D (n=10 male, n=4 female, n=4 gender unreported). Each identified two priority concerns. “Psychological burden of diabetes” was the most common priority concern (T1D n = 27, 87.1%) followed by “gaining more skills about particular aspects of diabetes” (T1D n=19, 61.3%), “improving support around me” (n=8, 25.8%) and “diabetes-related treatment issues” (n=8, 25.8%). Burden of diabetes was widespread as was lack of confidence around self-management. Similarly, psychological burden of diabetes was the primary concern for participants with T2D (n=18,100%) followed by “gaining more skills about aspects of diabetes” (n=7, 38.9%), “improving support around me” (n=7, 38.9%) and “diabetes-related treatment issues” (n=4; 22.2%).Conclusions:Spotlight AQ is acceptable and feasible for use in routine care. Gaining more skills and addressing the psychological burden of diabetes are high-priority areas that must be addressed to reduce high levels of distress.  相似文献   
56.
Chondroblastoma is a rare, benign primary cartilaginous bone tumor that typically arises in the epiphyses of the long bones. Radiologically, a well-defined lytic lesion with thin sclerotic margins is commonly found. The tumor is characterized histologically as an admixture of chondroblasts and multinucleated giant cells with chondroid matrix and pericellular calcifications. We present a case of a chondroblastoma of the hand with an unusual large extraosseous soft tissue component. The mass demonstrated diffuse calcifications and radiolucent lesions in the dorsal aspect of the hamate and metacarpals. Differential diagnoses included synovial chondromatosis, soft tissue chondroma, and tenosynovial giant cell tumor. The patient underwent open biopsy of the mass with plans for excision. Final histopathologic diagnosis was of chondroblastoma of the hamate with a large soft tissue component. A marginal excision of the lesion with curettage and cementation was performed.  相似文献   
57.
58.
OBJECTIVE: To examine the hypothesis that pregnancy is associated with vascular remodeling, leading to an increased vascular compliance that can be observed in subsequent pregnancies. STUDY DESIGN: Chart review of41 multiparous deliveries at our institution from a 2-month period in 2004. Charts examined were from patients with uncomplicated, singleton pregnancies who were nulliparous during their prior delivery. Patients with blood pressure recordings in all 3 trimesters during both pregnancies were included. The mean arterial pressure (MAP) in the index and prior pregnancy was compared. RESULTS: There were no significant MAP differences noted, other than in the late third trimester (MAP, 85.05 vs. 80.15, p < 0.001). When we plotted the difference in >34 weeks MAP against the time between pregnancies, we did not see any statistically significant correlation (Pearson Correlation -0.147, p = 0.35). We examined the mean pulse pressure at >34 weeks. We found no statistically significant differences between the first and second pregnancies (mean pulse pressure, 42.27 vs. 43.55, p = 0.5). CONCLUSION: Our data does not support the hypothesis that pregnancy is associated with vascular remodeling, leading to an increased vascular compliance that can be observed in subsequent pregnancies. This could be due to demographic differences between our population and previously studied populations.  相似文献   
59.
60.
PurposeTo explore the impact of the extent of reticular pseudodrusen (RPD) on mesopic visual sensitivity in individuals with intermediate age-related macular degeneration (AMD).MethodsIn total, 570 eyes from 285 participants with bilateral large drusen underwent microperimetry testing to assess the visual sensitivity of the central 3.6-mm region and multimodal imaging to determine the extent of RPD in the central 20° × 20° region (at the eye level). Mean visual sensitivity within five sectors in the central 3.6-mm region sampled on microperimetry and the extent of RPD in these sectors were derived. Linear mixed models were used to examine the association between the extent of RPD on overall mean visual sensitivity and sector-based mean sensitivity.ResultsAn increasing extent of RPD at the eye level and within sectors was associated with a significant reduction in overall and sector-based mean sensitivity, respectively (P < 0.001 for both). However, when both RPD parameters were considered together in a multivariable model, only an increasing extent of RPD at the eye level (P < 0.001) and not within each sector (P = 0.178) was independently associated with reduced sector-based mean sensitivity.ConclusionsMesopic visual sensitivity is generally reduced in eyes with large drusen and coexistent RPD compared to eyes without RPD, with greater reductions with an increasing extent of RPD. However, reduced sector-based visual sensitivities are explained by the overall extent of RPD present, rather than their extent within the sector itself. These findings suggest that there are generalized pathogenic changes in eyes with RPD accounting for the observed mesopic visual dysfunction.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号