Circuit Structure and Control Method to Reduce Size and Harmonic Distortion of Interleaved Dual Buck Inverter

A new circuit structure and control method for a high power interleaved dual-buck inverter are proposed. The proposed inverter consists of six switches, four diodes and two inductors, uses a dual-buck structure to eliminate zero-cross distortion, and operates in an interleaved mode to reduce the current stress of switch. To reduce the total harmonic distortion at low output power, the inverter is controlled using discontinuous-current-mode control combined with continuous-current-mode control. The experimental inverter had a power-conversion efficiency of 98.5% at output power = 1300 W and 98.3% at output power = 2 kW, when the inverter was operated at an input voltage of 400 V-DC, output voltage of 220 V-AC/60 Hz, and switching frequency of 20 kHz. The total harmonic distortion was < 0.66%, which demonstrates that the inverter is suitable for high-power dc-ac power conversion.11Ysciescopu

Enhancement on Radon Adsorption Property of GAC using Nano-size Carbon Colloids

Granular activated carbon (GAC) is well-known as an efficient adsorbent against a number of gaseous pollutants. Radon is one of those pollutants, and radon has been classified as the second leading cause of lung cancer in USA. This study was to enhance the radon removal efficiency with applying nano-technology. Nano-size carbon colloids (NCC) was produced through electrolysis which is simple and cheap. NCC was used for impregnation with activated carbon. Surface areas of both NCC-treated and non-treated activated carbon did not show a significant difference. However, the results of radon removal efficiency show that impregnated carbon with NCC could capture about 1.3 ~ 2 times of more radon gas compared to non-treated activated carbon. It is assumed that nano-size carbon colloids might have filled up meso-pores, and meso-pores turned into micro-pores eventually. Because meso-pores initially accounted for large portion of whole pores, more radon could be captured to NCC-impregnated activated carbon. Keywords: Radon, Nano-Size Carbon Collid, Activated Carbo

The pattern of bowel dysfunction in patients with rectal cancer following the multimodal treatment: anorectal manometric measurements at before and after chemoradiation therapy, and postoperative 1 year

Purpose Bowel dysfunction commonly occurs in patients with locally advanced rectal cancer treated with a multimodal approach of chemoradiation therapy (CRT) combined with sphincter-preserving rectal resection. This study investigated the decline in anorectal function using sequential anorectal manometric measurements obtained before and after the multimodal treatment as well as at a 1-year follow-up. Methods This was a retrospective cohort study conducted in a single center. The study population consisted of patients with locally advanced mid- to low rectal cancer who received the preoperative CRT followed by sphincter-preserving surgery from 2012 to 2016. The anorectal manometric value measured after each treatment modality was compared to demonstrate the degree of decline in anorectal function. A generalized linear model of repeated measures was performed using the manometric values measured pre- and post-CRT, and at 12 months postoperatively. Results Overall, 100 patients with 3 consecutive manometric data were included in the final analysis. In the overall cohort study, the mean resting and maximal squeezing pressures showed insignificant decrement post-neoadjuvant CRT. At a 1-year postoperative follow-up, the maximal squeezing pressure significantly decreased. The maximal rectal sensory threshold demonstrated significant reduction consecutively after each following treatment (P<0.001). Conclusion The short-term effect of neoadjuvant CRT on the anal sphincters was relatively trivial. The following sphincter-saving surgery resulted in a profound disruption of the anorectal function. Patients with rectal cancer should be consulted on the consequence of multimodal treatment

New-type of Multi-purpose Standard Radon Chamber in South Korea

Radon is an inert and a radioactive gas which is colorless, tasteless and odorless. As the radon decay proceeds, and if DNA damage continues beyond repair capacity of cells in the human body, it can cause severe health problems such as lung cancer in the long-term. There is a tendency that those countries where legal restriction on radon is strict, various studies related to radon are under way. In South Korea, radon has been regulated under recommendation level. Even though there are about 3 standard radon chambers in Korea, they have not been in an active use because of lack of demand. Also, most of them are specialized in calibration of radon detectors only. Recently, Korean government started giving some attention to radon issue and supporting radon research fields. Thus, this study was carried out to develop a new type of radon chamber for multi-purpose such as 1) radon emission rate from natural and artificial radon sources; 2) calibration of radon detectors; 3) evaluation of radon mitigation efficiency. Keywords: Radon, Radon Chamber, Indoor Air Quality, Chamber Desig

Case Report: Intellectual disability and borderline intellectual functioning in two sisters with a 12p11.22 loss

Multiple genome sequencing studies have identified genetic abnormalities as major causes of severe intellectual disability (ID). However, many children affected by mild ID and borderline intellectual functioning (BIF) lack a genetic diagnosis because known causative ID genetic mutations have not been identified or the role of genetic variants in mild cases is less understood. Genetic variant testing in mild cases is necessary to provide information on prognosis and risk of occurrence. In this study, we report two sibling patients who were 5 years 9 months old and 3 years 3 months old and presented to the hospital due to developmental delay. Clinical assessment and chromosomal microarray analysis were performed. The patients were diagnosed with mild intellectual disability (ID) and borderline intellectual functioning (BIF). Genetic analysis identified a loss of 12p11.22, including the OVCH1-AS1, OVCH1, and TMTC1 genes, which was the only variant that occurred in both sisters. Identical variants were found in their father with probable BIF. Neither patient presented any brain structural abnormalities or dysmorphism, and no exogenous factors or parenting problems were reported. Thus, loss of 12p11.22 may be associated with our patients’ cognitive impairment. The OVCH1, OVCH1-AS1 and TMTC1 variants identified in this study are the most likely disease-causing genes in the sisters. Our findings may expand as yet limited knowledge on mild ID and BIF causative variants, which would further support the diagnosis even if the severity is mild

A case of inflammatory myofibroblastic tumor originated from the greater omentum in young adult

Inflammatory myofibroblastic (IMF) tumor is a rare solid tumor that often affects children. IMF tumors occur primarily in the lung, but the tumor may affect any organ system with protean manifestations. A 22-year-old woman was evaluated for palpable low abdominal mass that had been increasing in size since two months prior. Abdominal computed tomography showed a lobulated, heterogeneous contrast enhancing soft tissue mass, 6.5 × 5.7 cm in size in the ileal mesentery. At surgery, the mass originated from the greater omentum laying in the pelvic cavity and was completely excised without tumor spillage. Histologically, the mass was a spindle cell lesion with severe atypism and some mitosis. Immunohistochemistry for anaplastic lymphoma kinase-1 revealed that the lesion was an IMF tumor. Because of its local invasiveness and its tendency to recur, this tumor can be confused with a soft tissue sarcoma. Increasing physician awareness of this entity should facilitate recognition of its clinical characteristics and laboratory findings

Sasa borealis Stem Extract Attenuates Hepatic Steatosis in High-Fat Diet-induced Obese Rats

The aim of the current study is to examine the improving effect of Sasa borealis stem (SBS) extract extracts on high-fat diet (HFD)-induced hepatic steatosis in rats. To determine the hepatoprotective effect of SBS, we fed rats a normal regular diet (ND), HFD, and HFD supplemented with 150 mg/kg body weight (BW) SBS extracts for five weeks. We found that the body weight and liver weight of rats in the HFD + SBS group were significantly lower than those in the HFD group. Significantly lower serum total cholesterol (TC) and triglyceride (TG) concentrations were observed in the SBS-supplemented group compared with the HFD group. We also found that the HFD supplemented with SBS group showed dramatically reduced hepatic lipid accumulation compared to the HFD alone group, and administration of SBS resulted in dramatic suppression of TG, TC in the HFD-induced fatty liver. In liver gene expression within the SBS treated group, PPARα was significantly increased and SREBP-1c was significantly suppressed. SBS induced a significant decrease in the hepatic mRNA levels of PPARγ, FAS, ACC1, and DGAT2. In conclusion, SBS improved cholesterol metabolism, decreased lipogenesis, and increased lipid oxidation in HFD-induced hepatic steatosis in rats, implying a potential application in treatment of non-alcoholic fatty liver disease