Design, Analysis and Empirical Researches for Solar Heat Collecting System based on Flat Mirrors Combination

There has been a dramatic increase of research on energy production using solar energy. This research aims to examine development of concentrating solar collector that is related to mid-high solar energy field. Although the use of dish type solar thermal system has been common in the existing high-efficiency collector technology, several problems have been raised. In order to solve these issues, the frame has been designed as flat plate type with Fresnel lens and the structural stability has been proved by analysis. Furthermore, the experiment that checks collectorrsquos temperature has been performed for the correct works of the stirling engine

Clinical Characteristics and Genotypes of Rotaviruses in a Neonatal Intensive Care Unit

BackgroundThere are few reports on the symptoms of rotavirus infections in neonates. This study aims to describe clinical signs of rotavirus infections among neonates, with a particular focus on preterm infants, and to show the distribution of genotypes in a neonatal intensive care unit (NICU).MethodsA prospective observational study was conducted at a regional NICU for 1 year. Stool specimens from every infant in the NICU were collected on admission, at weekly intervals, and from infants showing symptoms. Rotavirus antigens were detected by enzyme-linked immunosorbent assay (ELISA), and genotypes were confirmed by Reverse transcription-Polymerase chain reaction (RT-PCR). The infants were divided into three groups: symptomatic preterm infants with and without rotavirus-positive stools [Preterm(rota+) and Preterm(rota–), respectively] and symptomatic full- or near-term infants with rotavirus-positive stools [FT/NT(rota+)]. Demographic and outcome data were compared among these groups.ResultsA total of 702 infants were evaluated for rotaviruses and 131 infants were included in this study. The prevalence of rotavirus infections was 25.2%. Preterm(rota+) differed from Preterm(rota–) and FT/NT(rota+) with respect to frequent feeding difficulty (p = 0.047 and 0.034, respectively) and higher percentage of neutropenia (p = 0.008 and 0.011, respectively). G4P[6] was the exclusive strain in both the Preterm(rota+) (97.7%) and FT/NT(rota+) (90.2%), and it was the same for nosocomial, institutional infections, and infections acquired at home.ConclusionSystemic illness signs such as feeding difficulty and neutropenia are specific for preterm infants with rotavirus infections. G4P[6] was exclusive, regardless of preterm birth or locations of infections. This study might be helpful in developing policies for management and prevention of rotavirus infections in NICUs

Comparison of postoperative changes in the distal and proximal segments between conventional and sliding mini-plate fixation following mandibular setback

The purpose of the present study was to evaluate the postoperative three-dimensional (3D) changes in the proximal segments after mandibular setback sagittal split ramus osteotomy and to compare the changes between the conventional mini-plate fixation and semi-rigid sliding plate fixation

Remineralization Property of an Orthodontic Primer Containing a Bioactive Glass with Silver and Zinc

White spot lesions (WSLs) are irreversible damages in orthodontic treatment due to excessive etching or demineralization by microorganisms. In this study, we conducted a mechanical and cell viability test to examine the antibacterial properties of 0.2% and 1% bioactive glass (BAG) and silver-doped and zinc-doped BAGs in a primer and evaluated their clinical applicability to prevent WSLs. The microhardness statistically significantly increased in the adhesive-containing BAG, while the other samples showed no statistically significant difference compared with the control group. The shear bond strength of all samples increased compared with that of the control group. The cell viability of the control and sample groups was similar within 24 h, but decreased slightly over 48 h. All samples showed antibacterial properties. Regarding remineralization property, the group containing 0.2% of the samples showed remineralization properties compared with the control group, but was not statistically significant; further, the group containing 1% of the samples showed a significant difference compared with the control group. Among them, the orthodontic bonding primer containing 1% silver-doped BAG showed the highest remineralization property. The new orthodontic bonding primer used in this study showed an antimicrobial effect, chemical remineralization effect, and WSL prevention as well as clinically applicable properties, both physically and biologically

Difficult evaluation of thyroid cancer due to cervical paraffin injection

Paraffinoma is a well known complication of previous paraffin injection into the subcutaneous layer that presents as various conditions including firm mass formation, edema, induration, ulceration, and skin necrosis. Paraffinoma can mimic neoplasm on physical examination and imaging studies and may complicate ultrasonographic diagnoses due to typical posterior shadowing and high echogenicity. When paraffinomas involve around the thyroid gland, the diagnosis of thyroid tumors is very difficult. We present a case of thyroid cancer, the evaluation of which was complicated by the presence of cervical paraffinoma

Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea

The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser83→Arg83 or Ser83→Asn83. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida

Effect of DPSS laser on the shear bond strength of orthodontic brackets

Purpose—To test the bonding of orthodontic brackets to teeth using a diode-pumped solid state (DPSS) laser. Methods—A total of 60 extracted human teeth were divided randomly into four groups: Group 1 (control) - the brackets were bonded to teeth using the quartz-tungsten-halogen (QTH) light (800 mW/cm2) for 40 seconds; Groups 2–4 - the brackets were bonded to teeth using the DPSS laser (500 mW/cm2) for 40 seconds, 20 seconds, and 10 seconds, respectively. The teeth were debonded using shear force in a universal testing machine, and the amount of residual adhesive remaining on each tooth was evaluated. Statistical analysis was carried out for the shear bond strength (SBS) and Adhesive Remnant Index (ART). Results—The brackets bonded using the DPSS laser for 40 seconds showed the highest mean SBS (13.1±1.2 MPa) among the groups. Furthermore, the DPSS laser with 10 seconds light-curing could achieve 83% of the mean SBS obtained using the QTH light for 40 seconds. The ARI scores showed no differences among all four groups suggesting a similar failure mode