282 research outputs found
Spectro-Polarimetric Observation of an Emerging Flux Region: Triggering Mechanism of Ellerman Bombs
High spatial resolution observation of an emerging flux region (EFR) was done
using a vector magnetograph and a H-alpha Lyot filtergraph with Domeless Solar
Telescope at Hida Observatory on October 22, 2006. In H-alpha wing images, we
could see many Ellerman bombs (EBs) in the EFR. Two observation modes, slit
scan and slit fixed, were performed with the vector magnetograph, along with
H-alpha filtergraph. Using H-alpha wing images, we detected 12 EBs during slit
scan observation period and 9 EBs during slit fixed observation period. With
slit scan observation, we found that all the EBs were distributed in the area
where the spatial gradient of vertical field intensity was large, which
indicates the possibility of rapid topological change in magnetic field in the
area of EBs. With slit fixed observation, we found that EBs were distributed in
the areas of undulatory magnetic fields, both in vertical and horizontal
components. This paper is the first to report the undulatory pattern in
horizontal components of magnetic field, which is also evidence for emerging
magnetic flux by Parker instability. These results allow us to confirm the
association between EBs and emerging flux tubes. Three triggering mechanism of
EBs is discussed with respect to emerging flux tubes: 9 out of 21 EBs occurred
at the footpoints of emerging flux tubes, 8 out of 21 EBs occurred at the top
of emerging flux tubes, and 4 out of 21 EBs occurred at unipolar region. Each
case can be explained by magnetic reconnection in the low chromosphere.Comment: 30 pages, 17 figure
Dioxin Toxicity In Vivo Results from an Increase in the Dioxin-Independent Transcriptional Activity of the Aryl Hydrocarbon Receptor
The Aryl hydrocarbon receptor (Ahr) is the nuclear receptor mediating the toxicity of dioxins -widespread and persistent pollutants whose toxic effects include tumor promotion, teratogenesis, wasting syndrome and chloracne. Elimination of Ahr in mice eliminates dioxin toxicity but also produces adverse effects, some seemingly unrelated to dioxin. Thus the relationship between the toxic and dioxin-independent functions of Ahr is not clear, which hampers understanding and treatment of dioxin toxicity. Here we develop a Drosophila model to show that dioxin actually increases the in vivo dioxin-independent activity of Ahr. This hyperactivation resembles the effects caused by an increase in the amount of its dimerisation partner Ahr nuclear translocator (Arnt) and entails an increased transcriptional potency of Ahr, in addition to the previously described effect on nuclear translocation. Thus the two apparently different functions of Ahr, dioxin-mediated and dioxin-independent, are in fact two different levels (hyperactivated and basal, respectively) of a single function
Heat Treatment Inhibits Skeletal Muscle Atrophy of Glucocorticoid- Induced Myopathy in Rats
Summary The purpose of this study was to investigate the influence of heat treatment on glucocorticoid (GC)-induced myopathy. Eight-weekold Wistar rats were randomly assigned to the control, Dex, and Dex + Heat groups. Dexamethasone (2 mg/kg) was injected subcutaneously 6 days per week for 2 weeks in the Dex and Dex + Heat group. In the Dex + Heat group, heat treatment was performed by immersing hindlimbs in water at 42 °C for 60 min, once every 3 days for 2 weeks. The extensor digitorum longus muscle was extracted following 2 weeks of experimentation. In the Dex + Heat group, muscle fiber diameter, capillary/muscle fiber ratio, and level of heat shock protein 72 were significantly higher and atrogene expression levels were significantly lower than in the Dex group. Our results suggest that heat treatment inhibits the development of GC-induced myopathy by decreasing atrogene expression and increasing angiogenesis
Factors considered by medical students when formulating their specialty preferences in Japan: findings from a qualitative study
<p>Abstract</p> <p>Background</p> <p>Little research addresses how medical students develop their choice of specialty training in Japan. The purpose of this research was to elucidate factors considered by Japanese medical students when formulating their specialty choice.</p> <p>Methods</p> <p>We conducted qualitative interviews with 25 Japanese medical students regarding factors influencing specialty preference and their views on roles of primary versus specialty care. We qualitatively analyzed the data to identify factors students consider when developing specialty preferences, to understand their views about primary and subspecialty care, and to construct models depicting the pathways to specialization.</p> <p>Results</p> <p>Students mention factors such as illness in self or close others, respect for family member in the profession, preclinical experiences in the curriculum such as labs and dissection, and aspects of patient care such as the clinical atmosphere, charismatic role models, and doctor-patient communication as influential on their specialty preferences. Participating students could generally distinguish between subspecialty care and primary care, but not primary care and family medicine. Our analysis yields a "Two Career" model depicting how medical graduates can first train for hospital-based specialty practice, and then switch to mixed primary/specialty care outpatient practice years later without any requirement for systematic training in principles of primary care practice.</p> <p>Conclusion</p> <p>Preclinical and clinical experiences as well as role models are reported by Japanese students as influential factors when formulating their specialty preferences. Student understanding of family medicine as a discipline is low in Japan. Students with ultimate aspirations to practice outpatient primary care medicine do not need to commit to systematic primary care training after graduation. The Two Career model of specialization leaves the door open for medical graduates to enter primary care practice at anytime regardless of post-graduate residency training choice.</p
Does community-based education increase students' motivation to practice community health care? - a cross sectional study
<p>Abstract</p> <p>Background</p> <p>Community-based education has been introduced in many medical schools around the globe, but evaluation of instructional quality has remained a critical issue. Community-based education is an approach that aims to prepare students for future professional work at the community level. Instructional quality should be measured based on a program's outcomes. However, the association between learning activities and students' attitudes is unknown. The purpose of this study was to clarify what learning activities affect students' attitudes toward community health care.</p> <p>Methods</p> <p>From 2003 to 2009, self-administered pre- and post-questionnaire surveys were given to 693 fifth-year medical students taking a 2-week clinical clerkship. Main items measured were student attitudes, which were: "I think practicing community health care is worthwhile" ("worthwhile") and "I am confident about practicing community health care" ("confidence") using a visual analogue scale (0-100). Other items were gender, training setting, and learning activities. We analyzed the difference in attitudes before and after the clerkships by paired <it>t </it>test and the factors associated with a positive change in attitude by logistic regression analysis.</p> <p>Results</p> <p>Six hundred forty-five students (93.1%), 494 (76.6%) male and 151(23.4%) female, completed the pre- and post-questionnaires. The VAS scores of the students' attitudes for "worthwhile" and "confidence" after the clerkship were 80.2 ± 17.4 and 57.3 ± 20.1, respectively. Both of the scores increased after the clerkship. Using multivariate logistic regression analysis, "health education" was associated with a positive change for both attitudes of "worthwhile" (adjusted RR: 1.71, 95% CI: 1.10-2.66) and "confidence" (1.56, 1.08-2.25).</p> <p>Conclusions</p> <p>Community-based education motivates students to practice community health care. In addition, their motivation is increased by the health education activity. Participating in this activity probably produces a positive effect and improves the instructional quality of the program based on its outcomes.</p
Inhibition of intestinal polyp growth by oral ingestion of bovine lactoferrin and immune cells in the large intestine
Hypertensive patients' perceptions of their physicians' knowledge about them: a cross-sectional study in Japan
<p>Abstract</p> <p>Background</p> <p>In order to evaluate the difference in quality of primary care provided by physicians between the types of medical institutions in Japan, we examined whether the physicians' comprehensive knowledge of their patients is perceived differently by the patients seen at clinics and hospitals.</p> <p>Methods</p> <p>Patients with prescriptions for hypertensive drugs were approached sequentially at 13 pharmacies, and were administered a questionnaire on their perception of their physician's knowledge about them. Data were obtained for 687 patients (362 from clinics and 325 from hospitals). A physician's knowledge of his or her patients was assessed according to six aspects: their medical history, their current medications, history of allergy, what worries patients most about their health, patients' values and beliefs on their health, and patients' roles and responsibilities at work, home, or school. Responses were scored from 1 through 6 (1: knows very well; 6: doesn't know at all).</p> <p>Results</p> <p>Patients treated in clinics were seen more frequently, for a longer period, and had fewer complications than the patients who were treated in hospitals. Among the six aspects of physicians' knowledge assessed, 79.3% of the patients reported that their physicians knew their complete list of medications "very well or well," while 28.3% reported the same about their roles and responsibilities at work, home, or school. Physicians in clinics were considered to know their patients' worries about their health (p = 0.004) and the roles and responsibilities of the patients at work, home, or school (p = 0.028) well. Multiple regression analysis showed that the type of medical institutions remained as a significant variable only for the aspect of patients' worries about their health. The factor that consistently affected the patients' perception of physicians' knowledge about them was the patients' age.</p> <p>Conclusions</p> <p>Hypertensive patients' perceptions of their physicians' knowledge about them did not differ significantly between clinics and hospitals in Japan for most of the aspects. In order to differentiate the roles of physicians in hospitals and clinics better and ensure the quality of primary care, the establishment of a standardized educational system to train primary care physicians better is recommended.</p
Undergraduate educational environment, perceived preparedness for postgraduate clinical training, and pass rate on the National Medical Licensure Examination in Japan
<p>Abstract</p> <p>Background</p> <p>We investigated the views of newly graduating physicians on their preparedness for postgraduate clinical training, and evaluated the relationship of preparedness with the educational environment and the pass rate on the National Medical Licensure Examination (NMLE).</p> <p>Methods</p> <p>Data were obtained from 2429 PGY-1 physicians-in-training (response rate, 36%) using a mailed cross-sectional survey. The Dundee Ready Education Environment Measure (DREEM) inventory was used to assess the learning environment at 80 Japanese medical schools. Preparedness was assessed based on 6 clinical areas related to the Association of American Medical Colleges Graduation Questionnaire.</p> <p>Results</p> <p>Only 17% of the physicians-in-training felt prepared in the area of general clinical skills, 29% in basic knowledge of diagnosis and management of common conditions, 48% in communication skills, 19% in skills associated with evidence-based medicine, 54% in professionalism, and 37% in basic skills required for a physical examination. There were substantial differences among the medical schools in the perceived preparedness of their graduates. Significant positive correlations were found between preparedness for all clinical areas and a better educational environment (all p < 0.01), but there were no significant associations between the pass rate on the NMLE and perceived preparedness for any clinical area, as well as pass rate and educational environment (all p > 0.05).</p> <p>Conclusion</p> <p>Different educational environments among universities may be partly responsible for the differences in perceived preparedness of medical students for postgraduate clinical training. This study also highlights the poor correlation between self-assessed preparedness for practice and the NMLE.</p
Deregulated expression of hnRNP A/B proteins in human non-small cell lung cancer: parallel assessment of protein and mRNA levels in paired tumour/non-tumour tissues
<p>Abstract</p> <p>Background</p> <p>Heterogeneous nuclear ribonucleoproteins (hnRNPs) of the A/B type (hnRNP A1, A2/B1, A3) are highly related multifunctional proteins participating in alternative splicing by antagonising other splicing factors, notably ASF/SF2. The altered expression pattern of hnRNP A2/B1 and/or splicing variant B1 alone in human lung cancer and their potential to serve as molecular markers for early diagnosis remain issues of intense investigation. The main objective of the present study was to use paired tumour/non-tumour biopsies from patients with non-small cell lung cancer (NSCLC) to investigate the expression profiles of hnRNP A1, A2/B1 and A3 in conjunction with ASF/SF2.</p> <p>Methods</p> <p>We combined western blotting of tissue homogenates with immunohistochemical examination of fixed tissue sections and quantification of mRNA expression levels in tumour versus adjacent normal-looking areas of the lung in the same patient.</p> <p>Results</p> <p>Our study, in addition to clear evidence of mostly uncoupled deregulation of hnRNPs A/B, has revealed hnRNP A1 to be the most deregulated protein with a high frequency of over-expression (76%), followed by A3 (52%) and A2/B1 (43%). Moreover, direct comparison of protein/mRNA levels showed a lack of correlation in the case of hnRNP A1 (as well as of ASF/SF2), but not of A2/B1, suggesting that different mechanisms underlie their deregulation.</p> <p>Conclusion</p> <p>Our results provide strong evidence for the up-regulation of hnRNP A/B in NSCLC, and they support the existence of distinct mechanisms responsible for their deregulated expression.</p
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