338 research outputs found
Bidirectional two colored light emission from stress-activated ZnS-microparticles-embedded polydimethylsiloxane elastomer films
Bidirectional two-colored mechanoluminescent light emission has been demonstrated by unifying two polydimethylsiloxane elastomer layers functionalized with zinc sulfide doped with Cu (ZnS:Cu) or Cu and Mn (ZnS:Cu,Mn). The bilayered composite films are simply fabricated by dispensing uncured ZnS:Cu,Mn + PDMS onto previously spin-coated and ardened ZnS:Cu + PDMS film. The robust PDMS-PDMS bonding yields a ilm which can simultaneously emit light with color coordinates of (0.25, 0.56) and (0.50, 0.48), similar to the intrinsic colors of ZnS:Cu and ZnS:Cu,Mn, respectively. Composite films can emit light in upper and lower directions without fracture when it is stretched. © 2013 Optical Society of America.1
A Case of Cushing's Syndrome Presenting as Endometrial Hyperplasia
We describe here the case of a 39-year-old woman with a cortisol-producing adrenal adenoma and she presented with endometrial hyperplasia and hypertension without the specific characteristics of Cushing's syndrome. The patient had consulted a gynecologist for menometrorrhagia 2 years prior to her referral and she was diagnosed with endometrial hyperplasia and hypertension. Her blood pressure and the endometrial lesion were refractory despite taking multiple antihypertensives and repetitive dilation and curettage and progestin treatment. On admission, the clinical examination revealed mild central obesity (a body mass index of 22.9 kg/m2, a waist circumference of 85 cm and a hip circumference of 94cm), but there was no hirsutism and myopathy. She showed impaired glucose tolerance on an oral glucose tolerance test. The biochemical hypercortisolemia together with the prolactin and androgen levels were evaluated to explore the cause of her anovulation. Adrenal Cushing's syndrome was confirmed on the basis of the elevated urinary free cortisol (454 µg/24h, normal range: 20-70) with a suppressed ACTH level (2.0 pg/mL, normal range: 6.0-76.0) and the loss of circadian cortisol secretion. A CT scan revealed a 3.1 cm, hyperechoic, well-marginated mass in the left adrenal gland. Ten months post-adrenalectomy, the patient had unintentionally lost 9 kg of body weight, had regained a regular menstrual cycle and had normal thickness of her endometrium
Cardiac Resynchronization Therapy for Left Ventricular Dysfunction Induced by Chronic Right Ventricular Pacing in a Child
Cardiac resynchronization therapy (CRT) has been proven its value in adult patients with congestive heart failure of low ejection fraction and wide QRS duration. Contrast to adult patients, CRT has been rarely applied for young patients. We report on a 9-yr-old boy with progressive left ventricular (LV) dilatation and dysfunction following chronic VVI pacemaker therapy for congenital complete atrioventricular block associated with maternal anti-SSA/Ro and SSB/La antibody. His LV dysfunction was improved after epicardially established CRT
Subchronic oral toxicity of silver nanoparticles
<p>Abstract</p> <p>Background</p> <p>The antibacterial effect of silver nanoparticles has resulted in their extensive application in health, electronic, consumer, medicinal, pesticide, and home products; however, silver nanoparticles remain a controversial area of research with respect to their toxicity in biological and ecological systems.</p> <p>Results</p> <p>This study tested the oral toxicity of silver nanoparticles (56 nm) over a period of 13 weeks (90 days) in F344 rats following Organization for Economic Cooperation and Development (OECD) test guideline 408 and Good Laboratory Practices (GLP). Five-week-old rats, weighing about 99 g for the males and 92 g for the females, were divided into four 4 groups (10 rats in each group): vehicle control, low-dose (30 mg/kg), middle-dose (125 mg/kg), and high-dose (500 mg/kg). After 90 days of exposure, clinical chemistry, hematology, histopathology, and silver distribution were studied. There was a significant decrease (P < 0.05) in the body weight of male rats after 4 weeks of exposure, although there were no significant changes in food or water consumption during the study period. Significant dose-dependent changes were found in alkaline phosphatase and cholesterol for the male and female rats, indicating that exposure to more than 125 mg/kg of silver nanoparticles may result in slight liver damage. Histopathologic examination revealed a higher incidence of bile-duct hyperplasia, with or without necrosis, fibrosis, and/or pigmentation, in treated animals. There was also a dose-dependent accumulation of silver in all tissues examined. A gender-related difference in the accumulation of silver was noted in the kidneys, with a twofold increase in female kidneys compared to male kidneys.</p> <p>Conclusions</p> <p>The target organ for the silver nanoparticles was found to be the liver in both the male and female rats. A NOAEL (no observable adverse effect level) of 30 mg/kg and LOAEL (lowest observable adverse effect level) of 125 mg/kg are suggested from the present study.</p
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Direct Reprogramming of Rat Neural Precursor Cells and Fibroblasts into Pluripotent Stem Cells
Background: Given the usefulness of rats as an experimental system, an efficient method for generating rat induced pluripotent stem (iPS) cells would provide researchers with a powerful tool for studying human physiology and disease. Here, we report direct reprogramming of rat neural precursor (NP) cells and rat embryonic fibroblasts (REF) into iPS cells by retroviral transduction using either three (Oct3/4, Sox2, and Klf4), four (Oct3/4, Sox2, Klf4, and c-Myc), or five (Oct3/4, Sox2, Klf4, c-Myc, and Nanog) genes. Methodology and Principal Findings: iPS cells were generated from both NP and REF using only three (Oct3/4, Sox2, and Klf4) genes without c-Myc. Two factors were found to be critical for efficient derivation and maintenance of rat iPS cells: the use of rat instead of mouse feeders, and the use of small molecules specifically inhibiting mitogen-activated protein kinase and glycogen synthase kinase 3 pathways. In contrast, introduction of embryonic stem cell (ESC) extracts induced partial reprogramming, but failed to generate iPS cells. However, when combined with retroviral transduction, this method generated iPS cells with significantly higher efficiency. Morphology, gene expression, and epigenetic status confirmed that these rat iPS cells exhibited ESC-like properties, including the ability to differentiate into all three germ layers both in vitro and in teratomas. In particular, we found that these rat iPS cells could differentiate to midbrain-like dopamine neurons with a high efficiency. Conclusions/Significance: Given the usefulness of rats as an experimental system, our optimized method would be useful for generating rat iPS cells from diverse tissues and provide researchers with a powerful tool for studying human physiology and disease
Analysis of Exercise Intensity Based on Cardiorespiratory Response in a Virtual Reality-Based Exercise Program for Firefighter Physical Fitness Enhancement
OBJECTIVES Current regulations for Korean firefighters primarily emphasize exercise during working hours without specifying particular exercise methods. This study aims to evaluate the exercise intensity of the stepwise Korean Firefighter Fitness Program (KFFP) using Kinect-based mixed reality device (Virtual mate, VM), considering the demanding 24-hour shift work and high physical strength requirements. The objective is to assess its potential as one of the exercise methods and provide valuable insights. METHODS CResearchers recruited 30 participants to evaluate the exercise intensity based on the cardiopulmonary responses induced by the Stepwise Korean Firefighter Fitness Program (KFFP) using Virtual Mate (VM). Initially, the participants' resting heart rate, maximum heart rate (HRmax), and maximum oxygen consumption (VO2max) were measured. Subsequently, researchers monitored the participants' cardiopulmonary responses by employing portable gas analyzers and wireless heart rate monitors while implementing the Stepwise KFFP with VM. Exercise intensity related to cardiopulmonary responses was recorded using both absolute parameters (VO2, HR) and relative parameters (%VO2max, %HRR, %HR). Researchers utilized repeated measures analysis of variance for statistical analysis. RESULTS The analysis of the stepwise KFFP using VM showed significant increases all parameters as the program advanced(p<.001). VO2 increased from around 19.4 ml/kg/min in Step 1 to approximately 22.8 ml/kg/min in Step 3. Similarly, %HRR rose from roughly 40.6% in Step 1 to about 53.9% in Step 3. CONCLUSIONS Upon evaluating the stepwise KFFP based on the exercise intensity levels recommended by ACSM, it is confirmed that the stepwise KFFP using VM comprises both moderate-intensity and highintensity exercises. This approach is deemed effective and can serve as a fitness management method for firefighters working in 24-hour shift patterns that demand high fitness levels
Differences in salient beliefs associated with voluntary exercise training among South Korean firefighters before and after COVID-19
Background : Participating in voluntary exercise training is important to meet occupational requirements as well as firefighters’ health and safety. The purpose of this study is to identify salient beliefs associated with voluntary exercise training among firefighters in the pandemic era by comparing outcomes with those from a previous elicitation study, which was carried out before the COVID-19 outbreak.
Methods : A total of 57 firefighters are recruited to participate in an elicitation study. Participants are requested to respond to six open-ended questions related to voluntary exercise training. Content analysis is used to create categories that combine similar factors in each belief. Beliefs mentioned by more than 30% of participants are used for comparison with the results of the previous research.
Results : “Improves my physical ability” (n = 44) and “cause injury” (n = 17) are identified as behavioral beliefs in the present study, whereas “makes me tired” and “takes too much time” were also elicited in Lee’s study. Normative beliefs are “family members” (n = 45) and “colleagues” (n = 27) and these results are consistent with those in Lee’s study. “Lack of time” (n = 28), “exercise facilities” (n = 19), and “COVID-19” (n = 19) are elicited as control beliefs in the present study, whereas “physical condition” (n = 21) and “exercise partners” (n = 14) were elicited as other control beliefs, and “COVID-19” was not mentioned in Lee’s study.
Conclusion : This study can contribute valuable information about salient beliefs associated with exercise training behavior among firefighters, particularly under pandemic conditions. Future researchers should develop tailored exercise training programs for firefighters based on current elicited beliefs.This research was supported by the Emergency Response to Disaster sites Research and Development Program funded by National Fire Agency(20013968)
A Case of Hypothyroidism and Type 2 Diabetes Associated with Type V Hyperlipoproteinemia and Eruptive Xanthomas
Primary hypothyroidism and type 2 diabetes are both typically associated with the increased level of triglycerides. To date, there have been only a few case reports of type 2 diabetes patients with both type V hyperlipoproteinemia and eruptive xanthomas, but there have been no reports of hypothyroidism patients associated with eruptive xanthomas. We report here on a case of a 48-yr old female patient who was diagnosed with type 2 diabetes and primary hypothyroidism associated with both type V hyperlipoproteinemia and eruptive xanthomas. We found rouleaux formation of RBCs in peripheral blood smear, elevated TSH, and low free T4 level, and dyslipidemia (total cholesterol 18.1 mM/L, triglyceride 61.64 mM/L, HDL 3.0 mM/L, and LDL 2.54 mM/L). She has taken fenofibrate, levothyroxine, and oral hypoglycemic agent for 4 months. After treatment, both TSH level and lipid concentration returned to normal range, and her yellowish skin nodules have also disappeared
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