全文获取类型
收费全文 | 116篇 |
免费 | 11篇 |
国内免费 | 4篇 |
专业分类
儿科学 | 3篇 |
基础医学 | 8篇 |
口腔科学 | 18篇 |
临床医学 | 18篇 |
内科学 | 37篇 |
皮肤病学 | 3篇 |
特种医学 | 12篇 |
外科学 | 16篇 |
综合类 | 3篇 |
预防医学 | 6篇 |
药学 | 3篇 |
肿瘤学 | 4篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2009年 | 10篇 |
2008年 | 1篇 |
2007年 | 4篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2000年 | 1篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1984年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有131条查询结果,搜索用时 19 毫秒
1.
Circannual variation in lymphocyte subsets, revisited 总被引:2,自引:0,他引:2
BACKGROUND: Circadian and circannual variations in lymphocyte subsets, especially CD8+ T-lymphocytes, have been reported. This study focuses on CD4+ T-lymphocyte seasonal variation over a 6-year 8-month period. STUDY DESIGN AND METHODS: Lymphocyte subsets were quantitated monthly for four healthy individuals from 1986 through 1992 as part of a flow cytometry quality-control program. RESULTS: In general, there were no significant seasonal changes in the total number of white cells or in total lymphocyte counts. The absolute numbers of CD4+ T-lymphocytes were lowest in summer when the CD8+ T-lymphocytes were highest. Mean CD4+ T-lymphocyte counts were 846, 967, 618, and 695 per microL for Subjects 1 through 4, respectively, in winter and 432, 670, 355, and 766 per microL, respectively, in summer. Two healthy subjects had CD4+ T-lymphocyte counts lower than 300 per microL on one or more occasions during the study period. In three of the four subjects, the percentage of B-lymphocytes in winter was almost double that in summer. In one of the four subjects, no circannual rhythm was observed in these lymphocyte subpopulations. CONCLUSION: The seasonal variation in CD4+ T- lymphocyte counts demonstrated in three healthy individuals over almost 7 years is again of interest in light of renewed consideration of using surrogate tests, such as CD4+ T-lymphocyte counts, to screen for AIDS- like diseases that may be in the blood supply. 相似文献
2.
The family history in family practice: a questionnaire study 总被引:9,自引:7,他引:2
OBJECTIVES: Our aims were to investigate family medical history taking in
general practice, and to evaluate the value attached to the family medical
history as an aid to decision making in general practice. METHOD: A postal
questionnaire survey was conducted among all 291 GPs working within the
Calderdale and Kirklees Health Authority area. Each questionnaire was
followed by a reminder. The main outcome measures were answers to questions
on routine and opportunistic family history taking and a question about
transmitting knowledge about genetic risk to other members of the family.
Questions were also posed about the value attached to the family medical
history as an aid to decision making. RESULTS: A total of 193 GPs returned
the questionnaire (response rate 66.3%). On registration, 94.3% of GPs
indicated that enquiries were made about a family history of coronary heart
disease. Breast and colorectal cancer were specifically asked about by
48.4% and 30.7% of GPs, respectively. One-fifth of respondents indicated
that they asked a general question about family medical history. A little
over one-quarter of respondents indicated that they made opportunistic
enquiries about the family history or suggested that the patient should
inform other members of the family about possible risks. In the scenarios
highlighted in this study, the majority of respondents felt that the family
medical history had value as an aid to decision making. This was
particularly the case for checking a patient's cholesterol (92.1%) and for
initiating referrals in younger patients with possible cancer-related
symptoms (three-quarters of respondents). CONCLUSION: GPs value the family
medical history as an aid to decision making. Unfortunately, apart from
enquiries about coronary heart disease, routine or opportunistic family
history taking is not occurring in practice. Mechanisms need to be sought
to extract information from the family medical history so that it can be
more effectively used by GPs.
相似文献
3.
4.
Julie C. Sung Ciara Bosh Brooke Wyatt Mark Miller Alyson Harty David Del Bello Sterling Knight Douglas T. Dieterich Ponni V. Perumalswami Andrea D. Branch 《Journal of viral hepatitis》2020,27(4):350-359
Patient‐reported outcomes (PROs) are important measures of quality of life. Direct‐acting antiviral (DAA) drugs for hepatitis C virus (HCV) improved PROs in clinical trials. We prospectively evaluated the impact of DAA‐based HCV cure on PROs and liver‐related outcomes in real‐world patients at a large urban medical center. The short form (SF)‐36 and three additional validated instruments were used. F3‐4 fibrosis was defined as > 9.6 kPa by transient elastography (TE); S2‐3 steatosis was defined as > 270 dB/m by TE‐controlled attenuation parameter (CAP). Data were analysed by paired and unpaired t tests. Patients (n = 16) who did not achieve a sustained virologic response at 12 weeks (SVR12) were excluded. The study achieved its primary endpoint and showed a significant 30% improvement in the SF‐36 vitality score, measured baseline to SVR12: 63 versus 82, P < .001 (n = 111). Scores in 24 of 25 PRO domains improved at SVR12 (P < .05). Nearly all gains exceeded 5%, indicating their clinical significance. Transaminase values and liver stiffness improved (decreased) significantly, baseline to SVR12 (P < .005), but steatosis was unchanged (P = .58). Patients with baseline F0‐2 fibrosis and those with F3‐F4 fibrosis both improved in 22 domains. Patients with baseline S0‐S1 steatosis improved in more domains (23) than patients with S2‐S3 steatosis (19). At baseline, patients with F3‐F4 fibrosis and patients with S2‐3 steatosis had worse scores in certain PRO domains than patients with F0‐2 fibrosis or S0‐S1 steatosis, but this difference resolved by SVR12. HCV cure led to meaningful gains in PROs, and these findings may encourage patients to seek treatment. 相似文献
5.
Parikh N Martel-Laferriere V Zhang X Dieterich D Fiel MI Perumalswami P 《Seminars in liver disease》2012,32(2):186-192
A 59-year-old man with human immunodeficiency virus (HIV) was referred for persistently elevated liver enzyme activities. His HIV was well controlled on antiretroviral therapy and his viral load was undetectable. He had no history of chronic liver disease and had minimal alcohol intake. He was asymptomatic and his physical exam was unremarkable without any stigmata of liver disease. Beyond the elevations in alkaline phosphatase and gamma-glutamyl transferase, the rest of his laboratory work, including viral hepatitis serologies and serum α-fetoprotein, was within normal limits. A computed tomography (CT) scan revealed a mildly nodular liver but hepatic mass or ascites was not seen. He was subsequently followed every 3 to 6 months without any change in his clinical symptoms, laboratory values, or imaging tests. Two years after the original visit, the patient presented with acute onset of abdominal pain, an AFP of 15.8 ng/mL, and a 9-cm hepatic mass on imaging. Given his preserved liver function, he underwent right hepatic lobectomy. Histologic examination of the resected tissue was consistent with hepatocellular carcinoma (HCC). The uninvolved liver was noncirrhotic and unremarkable except for mild portal inflammation. As the vast majority of HIV patients who develop HCC have established chronic liver diseases such as hepatitis B and/or C along with cirrhosis, this case of HCC in an HIV patient without cirrhosis or viral hepatitis is rare. Although current screening guidelines recommend imaging only for patients with HIV and hepatitis B/C cirrhosis, closer monitoring may be important in HIV patients with even subtle liver dysfunction. 相似文献
6.
7.
8.
Alexander L Lundberg Ramon Lorenzo-Redondo Egon A Ozer Claudia A Hawkins Judd F Hultquist Sarah B Welch PV Vara Prasad James F Oehmke Chad J Achenbach Robert L Murphy Janine I White Robert J Havey Lori Ann Post 《JMIR Public Health and Surveillance》2022,8(1)
BackgroundVariants of the SARS-CoV-2 virus carry differential risks to public health. The Omicron (B.1.1.529) variant, first identified in Botswana on November 11, 2021, has spread globally faster than any previous variant of concern. Understanding the transmissibility of Omicron is vital in the development of public health policy.ObjectiveThe aim of this study is to compare SARS-CoV-2 outbreaks driven by Omicron to those driven by prior variants of concern in terms of both the speed and magnitude of an outbreak.MethodsWe analyzed trends in outbreaks by variant of concern with validated surveillance metrics in several southern African countries. The region offers an ideal setting for a natural experiment given that most outbreaks thus far have been driven primarily by a single variant at a time. With a daily longitudinal data set of new infections, total vaccinations, and cumulative infections in countries in sub-Saharan Africa, we estimated how the emergence of Omicron has altered the trajectory of SARS-CoV-2 outbreaks. We used the Arellano-Bond method to estimate regression coefficients from a dynamic panel model, in which new infections are a function of infections yesterday and last week. We controlled for vaccinations and prior infections in the population. To test whether Omicron has changed the average trajectory of a SARS-CoV-2 outbreak, we included an interaction between an indicator variable for the emergence of Omicron and lagged infections.ResultsThe observed Omicron outbreaks in this study reach the outbreak threshold within 5-10 days after first detection, whereas other variants of concern have taken at least 14 days and up to as many as 35 days. The Omicron outbreaks also reach peak rates of new cases that are roughly 1.5-2 times those of prior variants of concern. Dynamic panel regression estimates confirm Omicron has created a statistically significant shift in viral spread.ConclusionsThe transmissibility of Omicron is markedly higher than prior variants of concern. At the population level, the Omicron outbreaks occurred more quickly and with larger magnitude, despite substantial increases in vaccinations and prior infections, which should have otherwise reduced susceptibility to new infections. Unless public health policies are substantially altered, Omicron outbreaks in other countries are likely to occur with little warning. 相似文献
9.
Endodontic and periodontal diseases can provide many diagnostic and management challenges to clinicians, particularly when they occur concurrently. As with all diseases, a thorough history combined with comprehensive clinical and radiographic examinations are all required so an accurate diagnosis can be made. This is essential since the diagnosis will determine the type and sequence of treatment required. This paper reviews the relevant literature and proposes a new classification for concurrent endodontic and periodontal diseases. This classification is a simple one that will help clinicians to formulate management plans for when these diseases occur concurrently. The key aspects are to determine whether both types of diseases are present, rather than just having manifestations of one disease in the alternate tissue. Once it is established that both diseases are present and that they are as a result of infections of each tissue, then the clinician must determine whether the two diseases communicate via the periodontal pocket so that appropriate management can be provided using the guidelines outlined. In general, if the root canal system is infected, endodontic treatment should be commenced prior to any periodontal therapy in order to remove the intracanal infection before any cementum is removed. This avoids several complications and provides a more favourable environment for periodontal repair. The endodontic treatment can be completed before periodontal treatment is provided when there is no communication between the disease processes. However, when there is communication between the two disease processes, then the root canals should be medicated until the periodontal treatment has been completed and the overall prognosis of the tooth has been reassessed as being favourable. The use of non-toxic intracanal therapeutic medicaments is essential to destroy bacteria and to help encourage tissue repair. 相似文献
10.