PERFORMANCE EVALUATION OF HYBRID SOLAR AIRWATER HEATER WITH VARIOUS INLET AIR TEMPERATURE DURING HEATING PROCESS

Research about hybrid solar air-water heater that can heating both air and liquid has been conducted for enhancing the usage of solar thermal energy. In the previous study, thermal efficiency of this collector was investigated with many operating and external conditions, but all of previous experiment conducted using outdoor air as inlet air of collector. Thus, in this study, the performance change of hybrid solar air-water heater was investigated with change of inlet air temperature during air and liquid were heated simultaneously. As a result, thermal efficiency for liquid heating was increased with increment of the inlet air temperature. On the contrary to this, thermal efficiency for air heating of collector was decreased with increment of inlet air temperature. In case of total thermal efficiency of collector considered air and liquid heat gain, it was also decreased with increment of inlet air temperature. From these results, it was confirmed that using outdoor air directly as inlet air of collector is better for the use of solar energy. However it is hard to conclude that which is better between using outdoor air and heated air on the perspective of energy saving of building because heat storage performance was increased if the return air or any heated air is used as inlet air of hybrid solar air-water heater when air and liquid was heated simultaneously even air and total thermal efficiency is decreased. Thus, the necessity of more profound study and consideration about this as a further study was also confirmed

Acidic pH shock induces the expressions of a wide range of stress-response genes

<p>Abstract</p> <p>Background</p> <p>Environmental signals usually enhance secondary metabolite production in <it>Streptomycetes </it>by initiating complex signal transduction system. It is known that different sigma factors respond to different types of stresses, respectively in <it>Streptomyces </it>strains, which have a number of unique signal transduction mechanisms depending on the types of environmental shock. In this study, we wanted to know how a pH shock would affect the expression of various sigma factors and shock-related proteins in <it>S. coelicolor </it>A3(2).</p> <p>Results</p> <p>According to the results of transcriptional and proteomic analyses, the major number of sigma factor genes were upregulated by an acidic pH shock. Well-studied sigma factor genes of <it>sigH </it>(heat shock), <it>sigR </it>(oxidative stress), <it>sigB </it>(osmotic shock), and <it>hrdD </it>that play a major role in the secondary metabolism, were all strongly upregulated by the pH shock. A number of heat shock proteins including the DnaK family and chaperones such as GroEL2 were also observed to be upregulated by the pH shock, while their repressor of <it>hspR </it>was strongly downregulated. Oxidative stress-related proteins such as thioredoxin, catalase, superoxide dismutase, peroxidase, and osmotic shock-related protein such as vesicle synthases were also upregulated in overall.</p> <p>Conclusion</p> <p>From these observations, an acidic pH shock was considered to be one of the strongest stresses to influence a wide range of sigma factors and shock-related proteins including general stress response proteins. The upregulation of the sigma factors and shock proteins already found to be related to actinorhodin biosynthesis was considered to have contributed to enhanced actinorhodin productivity by mediating the pH shock signal to regulators or biosynthesis genes for actinorhodin production.</p

Clinical Efficacy of Primary Tumor Volume Measurements: Comparison of Different Primary Sites

ObjectivesThe purpose of study was to determine the clinical efficacy of primary tumor volume measurements of different primary sites in the oropharynx compared to the oral cavity.MethodsA retrospective analysis of 85 patients with oral cavity or oropharynx cancer. The tumor area was manually outlined from axial magnetic resonance (MR) series. The software calculated the tumor volumes, automatically. The values of the primary tumor volumes were then subdivided into separate groups (≤3,500 mm3, >3,500 mm3).ResultsThe prognostic indicators were the cT and cN (oral cavity); age, primary site, cT, cN, and primary tumor volume (oropharynx) on the univariate analysis. There was no significant prognostic factor for oral cavity cancer on the multivariate analysis. Primary site, cN, and primary tumor volume were independent prognostic indicators for oropharynx cancer by multivariate analysis.ConclusionPrimary tumor volume measurement is a reliable way to stratify outcome, and make up for the weak points in the American Joint Committee on Cancer staging system with oropharynx cancer

A novel family VII esterase with industrial potential from compost metagenomic library

<p>Abstract</p> <p>Background</p> <p>Among the vast microbial genomic resources now available, most microbes are unculturable in the laboratory. A culture-independent metagenomic approach is a novel technique that circumvents this culture limitation. For the screening of novel lipolytic enzymes, a metagenomic library was constructed from compost, and the clone of <it>estCS2 </it>was selected for lipolytic properties on a tributyrin-containing medium.</p> <p>Results</p> <p>The <it>estCS2 </it>sequence encodes a protein of 570 amino acid residues, with a predicted molecular mass of 63 kDa, and based on amino acid identity it most closely matches (45%) the carboxylesterase from <it>Haliangium ochraceum </it>DSM 14365. EstCS2 belong to family VII, according to the lipolytic enzyme classification proposed by Arpigny and Jaeger, and it retains the catalytic triad Ser₂₄₅-Glu₃₆₃-His₄₆₆that is typical of an α/β hydrolase. The Ser₂₄₅residue in the catalytic triad of EstCS2 is located in the consensus active site motif GXSXG. The EstCS2 exhibits strong activity toward <it>p</it>-nitrophenyl caproate (C6), and it is stable up to 60°C with an optimal enzymatic activity at 55°C. The maximal activity is observed at pH 9, and it remains active between pH 6-10. EstCS2 shows remarkable stability in up to 50% (v/v) dimethyl sulfoxide (DMSO) or dimethylformamide (DMF). The enzyme has the ability to cleave sterically hindered esters of tertiary alcohol, as well as to degrade polyurethanes, which are widely used in various industries.</p> <p>Conclusions</p> <p>The high stability of EstCS2 in organic solvents and its activity towards esters of ketoprofen and tertiary alcohols, and in polyurethane suggests that it has potential uses for many applications in biotransformation and bioremediation.</p

The Benefits and Risks of Prophylactic Central Neck Dissection for Papillary Thyroid Carcinoma: Prospective Cohort Study

Objectives. This study evaluated the benefits of performing prophylactic central neck dissection (CND) with total thyroidectomy (TT) in management of papillary thyroid carcinoma (PTC) patients who were clinically node-negative at presentation. Methods. A total of 257 patients with stage T1 or T2 PTC and without preoperative evidence of lymph node involvement (N0) were enrolled in this prospective study. The patients were randomly assigned to two groups: (1) a total thyroidectomy (TT) group (n=104) or (2) a TT plus CND group (n=153). The two groups were compared for their perioperative data, complication rates, disease recurrence rates, and clinical outcomes. Results. The two groups of patients were similar in age, sex ratio, follow-up duration, and tumor size (P=0.227, 0.359, 0.214, and 0.878, resp.). The two groups showed similar rates of disease recurrence (3.9% in the TT group versus 3.3% in the TT plus CND group); however, complications occurred more frequently in the TT plus CND group; especially transient hypocalcemia (P=0.043). Conclusions. Patients treated with TT plus CND had a higher rate of complications with similar recurrence rate. We believe that CND may not be routinely recommended when treating patients with PTC

Use of Magnetic Nanoparticles to Visualize Threadlike Structures Inside Lymphatic Vessels of Rats

A novel application of fluorescent magnetic nanoparticles was made to visualize a new tissue which had not been detectable by using simple stereomicroscopes. This unfamiliar threadlike structure inside the lymphatic vessels of rats was demonstrated in vivo by injecting nanoparticles into lymph nodes and applying magnetic fields on the collecting lymph vessels so that the nanoparticles were taken up by the threadlike structures. Confocal laser scanning microscope images of cryosectioned specimens exhibited that the nanoparticles were absorbed more strongly by the threadlike structure than by the lymphatic vessels. Further examination using a transmission electron microscope revealed that the nanoparticles had been captured between the reticular fibers in the extracellular matrix of the threadlike structures. The emerging technology of nanoparticles not only allows the extremely elusive threadlike structures to be visualized but also is expected to provide a magnetically controllable means to investigate their physiological functions

The Role of Transnasal Esophagoscopy in ENT Office: A Prospective, Multicenter Study in Korea

ObjectivesThe purpose of study was to report the current role of transnasal esophagoscopy (TNE) in Korea.MethodsOne hundred thirty-seven patients who underwent TNE at Soonchunhyang University Bucheon Hospital (n=69) and Korea University Anam Hospital (n=68) from July 2007 to February 2009 were prospectively analyzed. Laryngopharyngeal reflux disease (LPRD) patients without any response to proton-pump inhibitor (n=102), and patients with complaints that require esophagoscopy as part of their evaluation (n=35) were included in this study; investigation of metachronous lesions or routine follow-up screening of head and neck cancer patients, n=17; dysphagia, n=9; blood tinged saliva, n=4; to determine the cause of vocal fold paralysis as screening tool, n=4; suspicious esophageal foreign body, n=1.ResultsFifty-three patients (38.7%) had positive findings on TNE. Positive finding ratio was highest in group of dysphagia (7 among 9 patients, 78%). Forty-two patients (41.1%) were found to have pathology (esophagitis, n=41; esophageal diverticulum, n=1) during the screening examination for LPRD. There were no significant complications in any of the patients.ConclusionTNE is a high-yield diagnostic and therapeutic modality available to otolaryngologists for use on awake patients in the office setting

Fasting Plasma Glucose Cutoff Value for the Prediction of Future Diabetes Development: A Study of Middle-Aged Koreans in a Health Promotion Center

We determined optimal fasting plasma glucose (FPG) cutoff values predictive of future diabetes development in a group of middle-aged Koreans who visited a health promotion center. The medical records of 2,964 subjects, who attended the Health Promotion Center in 1998 and 2003, were examined. Subjects were classified into four groups according to their baseline FPG values (Group 1:FPG <5.0 mM/L; Group 2: 5.0≤FPG <5.6 mM/L; Group 3: 5.6≤FPG <6.1 mM/L; Group 4: 6.1≤FPG <7.0 mM/L). No significant difference was observed between Group 1 and Group 2 in terms of diabetes incidence. However, incidence in Group 3 was significantly higher than that in Group 1 [hazards ratio 4.88 (1.65-14.41), p=0.004] and the hazards ratio in Group 4 for diabetes was 36.91 (13.11-103.61), p<0.001, versus Group 1. Receiver operator characteristics curve analysis showed that an FPG of 5.97 mM/L represents the lower limit and gives the best combination of sensitivity and specificity. Our data shows that the risk of future diabetes development started to increase below an FPG of 6.1 mM/L and suggests the importance of efforts to modify diabetes development risk factors at lower impaired fasting glucose levels

The ancient phosphatidylinositol 3-kinase signaling system is a master regulator of energy and carbon metabolism in algae

Algae undergo a complete metabolic transformation under stress by arresting cell growth, inducing autophagy and hyperaccumulating biofuel precursors such as triacylglycerols and starch. However, the regulatory mechanisms behind this stress-induced transformation are still unclear. Here, we use biochemical, mutational, and “omics” approaches to demonstrate that PI3K signaling mediates the homeostasis of energy molecules and influences carbon metabolism in algae. In Chlamydomonas reinhardtii, the inhibition and knockdown (KD) of algal class III PI3K led to significantly decreased cell growth, altered cell morphology, and higher lipid and starch contents. Lipid profiling of wild-type and PI3K KD lines showed significantly reduced membrane lipid breakdown under nitrogen starvation (-N) in the KD. RNA-seq and network analyses showed that under -N conditions, the KD line carried out lipogenesis rather than lipid hydrolysis by initiating de novo fatty acid biosynthesis, which was supported by tricarboxylic acid cycle down-regulation and via acetyl-CoA synthesis from glycolysis. Remarkably, autophagic responses did not have primacy over inositide signaling in algae, unlike in mammals and vascular plants. The mutant displayed a fundamental shift in intracellular energy flux, analogous to that in tumor cells. The high free fatty acid levels and reduced mitochondrial ATP generation led to decreased cell viability. These results indicate that the PI3K signal transduction pathway is the metabolic gatekeeper restraining biofuel yields, thus maintaining fitness and viability under stress in algae. This study demonstrates the existence of homeostasis between starch and lipid synthesis controlled by lipid signaling in algae and expands our understanding of such processes, with biotechnological and evolutionary implications.Ministry of Science, ICT and Future Planning 2015M3A6A2065697Ministry of Oceans and Fisheries 2015018