2,645 research outputs found
ZnO:B back reflector with high haze and low absorption enhanced triple-junction thin film Si solar modules
AbstractWe present our development of a ZnO:B back reflector (BR) with high haze and low absorption for highly efficient triple-junction thin film Si solar modules over a large area (1.1×1.3m2). We try to maximize light trapping by the evaluation of the use of transparent conducting oxide (TCO) and BR for high efficiency. It was verified that the configuration of SnO2:F front TCO and ZnO:B BR shows better optical properties than typical configurations for light trapping due to its high transparency at the front and high haze at the back. In addition, we noticed that the absorption of the BR has a strong influence on the solar modules. We obtained a superior ZnO:B BR with high haze and low absorption by controlling the doping gas ratio (B2H6/DEZ). As the doping gas ratio of ZnO:B BR decreases, the haze increases due to a rougher surface morphology, and the absorption decreases due to reduced free carrier absorption. The solar modules with a ZnO:B BR in a lower doping gas ratio show relatively higher Pmax for the same i-μc-Si layer thickness. This results from an increased Isc due to higher haze and lower absorption. In addition, the ZnO:B BR with a low doping gas ratio was found to be effective in reducing the i-μc-Si layer thickness because there are more chances for trapping the light at the i-μc-Si layer. We could reduce the i-μc-Si layer thickness by about 28% for the equivalent Pmax level by lowering the doping gas ratio. We successfully applied the ZnO:B BR with high haze and low absorption into a triple-junction thin film silicon solar cell and achieved a new record, improving on our previous world record
Spontaneous Intraperitoneal Bladder Perforation Associated with Urothelial Carcinoma with Divergent Histologic Differentiation, Diagnosed by CT Cystography
Spontaneous bladder perforation is a very rare event. Prompt diagnosis of this injury is very important, particularly with intraperitoneal perforation, because mortality increases if surgical repair is delayed. Previous studies have reported that plain cystography is the primary modality of imaging study rather than relatively insensitive computed tomography (CT) when bladder perforation is suspected. We report here a rare case of spontaneous intraperitoneal perforation of the bladder associated with urothelial carcinoma with divergent histologic differentiation, as diagnosed with CT cystography
A machine-learning approach to predict postprandial hypoglycemia
Background For an effective artificial pancreas (AP) system and an improved therapeutic intervention with continuous glucose monitoring (CGM), predicting the occurrence of hypoglycemia accurately is very important. While there have been many studies reporting successful algorithms for predicting nocturnal hypoglycemia, predicting postprandial hypoglycemia still remains a challenge due to extreme glucose fluctuations that occur around mealtimes. The goal of this study is to evaluate the feasibility of easy-to-use, computationally efficient machine-learning algorithm to predict postprandial hypoglycemia with a unique feature set. Methods We use retrospective CGM datasets of 104 people who had experienced at least one hypoglycemia alert value during a three-day CGM session. The algorithms were developed based on four machine learning models with a unique data-driven feature set: a random forest (RF), a support vector machine using a linear function or a radial basis function, a K-nearest neighbor, and a logistic regression. With 5-fold cross-subject validation, the average performance of each model was calculated to compare and contrast their individual performance. The area under a receiver operating characteristic curve (AUC) and the F1 score were used as the main criterion for evaluating the performance. Results In predicting a hypoglycemia alert value with a 30-min prediction horizon, the RF model showed the best performance with the average AUC of 0.966, the average sensitivity of 89.6%, the average specificity of 91.3%, and the average F1 score of 0.543. In addition, the RF showed the better predictive performance for postprandial hypoglycemic events than other models. Conclusion In conclusion, we showed that machine-learning algorithms have potential in predicting postprandial hypoglycemia, and the RF model could be a better candidate for the further development of postprandial hypoglycemia prediction algorithm to advance the CGM technology and the AP technology further.11Ysciescopu
To Reduce the Incidence of Postoperative Intraabdominal Abscess, the Application of Nonoperative Management Should be Circumspect Considering Patient Factors and the Nature of Acute Appendicitis
Purpose Surgery and nonoperative management (NOM) are the treatment modalities for acute appendicitis (AA). There is little evidence to indicate which treatment method should be performed according to the patient's condition or disease severity, surgical extension, and timing after an appendectomy. This study aimed to evaluate postoperative intra-abdominal abscess (PIAA) associated with these factors. Methods The medical records of 839 patients who underwent appendectomy after a diagnosis of AA between 2019 and 2020 at Gangneung Asan Medical Centre were reviewed retrospectively. The factors associated with PIAA were evaluated. Results Postoperative complications occurred in 92 patients. Following appendectomy, 16 (1.9%), 83 (9.9%), and three (0.4%) patients developed PIAA, surgical site infection, and incisional hernia, respectively. The American Society of Anesthesiologists class, complicated appendicitis on preoperative abdominal computed tomography, failure of NOM, and extensive surgery above appendectomy were associated with the development of PIAA. However, a laparoscopic approach, irrigation, indwelling drain, ultrasonic dissection, and use of sterile bags were not associated with the development of PIAA. Conclusion NOM for some patients with complicated AA is an attractive treatment modality. However, to reduce the incidence of PIAA, the application of NOM should be circumspect considering patient factors and the nature of acute appendicitis. Furthermore, appendectomy should be performed as early as possible for patients not indicated for NOM
Red pepper seed water extract inhibits preadipocyte differentiation and induces mature adipocyte apoptosis in 3T3-L1 cells
BACKGROUND/OBJECTIVES: Reducing the number of adipocytes by inducing apoptosis of mature adipocytes as well as suppressing differentiation of preadipocytes plays an important role in preventing obesity. This study examines the anti-adipogenic and pro-apoptotic effect of red pepper seed water extract (RPS) prepared at 4°C (RPS4) in 3T3-L1 cells.
MATERIALS/METHODS: Effect of RPS4 or its fractions on lipid accumulation was determined in 3T3-L1 cells using oil red O (ORO) staining. The expressions of AMP-activated protein kinase (AMPK) and adipogenic associated proteins [peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding proteins α (C/EBP α), sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC)] were measured in 3T3-L1 cells treated with RPS4. Apoptosis and the expression of Akt and Bcl-2 family proteins [B-cell lymphoma 2 (Bcl-2), Bcl-2-associated death promoter (Bad), Bcl-2 like protein 4 (Bax), Bal-2 homologous antagonist/killer (Bak)] were measured in mature 3T3-L1 cells treated with RPS4.
RESULTS: Treatment of RPS4 (0-75 ug/mL) or its fractions (0-50 ug/mL) for 24 h did not have an apparent cytotoxicity on pre and mature 3T3-L1 cells. RPS4 significantly suppressed differentiation and cellular lipid accumulation by increasing the phosphorylation of AMPK and reducing the expression of PPAR-γ, C/EBP α, SREBP-1c, FAS, and ACC. In addition, all fractions except ethyl acetate fraction significantly suppressed cellular lipid accumulation. RPS4 induced the apoptosis of mature adipocytes by hypophosphorylating Akt, increasing the expression of the pro-apoptotic proteins, Bak, Bax, and Bad, and reducing the expression of the anti-apoptotic proteins, Bcl-2 and p-Bad.
CONCLUSIONS: These finding suggest that RPS4 can reduce the numbers as well as the size of adipocytes and might useful for preventing and treating obesity
DPY-17 and MUA-3 Interact for Connective Tissue-Like Tissue Integrity in Caenorhabditis elegans: A Model for Marfan Syndrome
mua-3 is a Caenorhabditis elegans homolog of the mammalian fibrillin1, a monogenic cause of Marfan syndrome. We identified a new mutation of mua-3that carries an in-frame deletion of 131 amino acids in the extracellular domain, which allows the mutants to survive in a temperature-dependent manner; at the permissive temperature, the mutants grow normally without obvious phenotypes, but at the nonpermissive temperature, more than 90% die during the L4 molt due to internal organ detachment. Using the temperature-sensitive lethality, we performed unbiased genetic screens to isolate suppressors to find genetic interactors of MUA-3. From two independent screens, we isolated mutations in dpy-17 as a suppressor. RNAi of dpy-17 inmua-3 rescued the lethality, confirming dpy-17 is a suppressor. dpy-17encodes a collagen known to genetically interact with dpy-31, a BMP-1/Tolloid-like metalloprotease required for TGFβ activation in mammals. Human fibrillin1 mutants fail to sequester TGFβ2 leading to excess TGFβ signaling, which in turn contributes to Marfan syndrome or Marfan-related syndrome. Consistent with that, RNAi of dbl-1, a TGFβ homolog, modestly rescued the lethality of mua-3 mutants, suggesting a potentially conserved interaction between MUA-3 and a TGFβ pathway in C. elegans. Our work provides genetic evidence of the interaction between TGFβ and a fibrillin homolog, and thus provides a simple yet powerful genetic model to study TGFβ function in development of Marfan pathology
DPY-17 and MUA-3 Interact for Connective Tissue-Like Tissue Integrity in Caenorhabditis elegans: A Model for Marfan Syndrome
mua-3 is a Caenorhabditis elegans homolog of the mammalian fibrillin1, a monogenic cause of Marfan syndrome. We identified a new mutation of mua-3 that carries an in-frame deletion of 131 amino acids in the extracellular domain, which allows the mutants to survive in a temperature-dependent manner; at the permissive temperature, the mutants grow normally without obvious phenotypes, but at the nonpermissive temperature, more than 90% die during the L4 molt due to internal organ detachment. Using the temperature-sensitive lethality, we performed unbiased genetic screens to isolate suppressors to find genetic interactors of MUA-3. From two independent screens, we isolated mutations in dpy-17 as a suppressor. RNAi of dpy-17 in mua-3 rescued the lethality, confirming dpy-17 is a suppressor. dpy-17 encodes a collagen known to genetically interact with dpy-31, a BMP-1/Tolloid-like metalloprotease required for TGFβ activation in mammals. Human fibrillin1 mutants fail to sequester TGFβ2 leading to excess TGFβ signaling, which in turn contributes to Marfan syndrome or Marfan-related syndrome. Consistent with that, RNAi of dbl-1, a TGFβ homolog, modestly rescued the lethality of mua-3 mutants, suggesting a potentially conserved interaction between MUA-3 and a TGFβ pathway in C. elegans. Our work provides genetic evidence of the interaction between TGFβ and a fibrillin homolog, and thus provides a simple yet powerful genetic model to study TGFβ function in development of Marfan pathology
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The Development of Web3D-based Open-pit Mine Monitoring System
Large-scale open-pit mines are critical infrastructure for acquiring natural resources. However, this type of mine can experience environmental and safety problems during operations and thus requires continuous monitoring. In this study, a web three-dimensional(3D)-based monitoring system is constructed using geospatial information open platform and open-source geospatial information software which targets open-pit mines in Gangwon-do, Korea. The purpose is to develop a monitoring system of open-pit mines that enables any person to monitor the topographic and environmental changes caused by mine operations and to develop and restore the area’s ecology. Open-pit mines were classified into active or inactive mines and monitoring items and methodologies were established for each type of mine. Cesium which is a WebGL-based open-source platform was chosen as it supports dynamic data visualization and hardware-accelerated graphics related to elapsed time which is the essential factor in the monitoring. The open-pit mine monitoring system was developed based on the geospatial database which contains information required for mine monitoring as time elapses, and by developing the open-source-based system software. The geospatial information database for monitoring consists of digital imagery and terrain data and also includes vector data and the restoration plan datas. The basic geospatial information used in the monitoring includes high resolution ortho image(GSD 0.5 m or above) for all areas of the mines. This is acquired by periodically using an airborne laser scanning system and a LiDAR DEM (grid size 1m × 1 m). In addition, geospatial information data were acquired by using an UAV and terrestrial LiDAR for small-scale areas; these tools are frequently used for rapid and irregular data acquisition. The geospatial information acquired for the monitoring of the open-pit mines represents various spatial resolutions and different terrain data. The database was constructed by converging this geospatial information with the Cesium-based geospatial information open platform of the ESRI World Imagery map and with SDK World Terrain meshes. The problems that resulted from the process of fusing aerial imagery and terrain data were solved in the Cesium-based open source environment. The prototype menu for the monitoring system was designed according to the monitoring item which was determined by the type of mine. The scene of the mine and changes in terrain were controlled and analyzed using the raster function of PostGIS according to the elapsed time. Using the GeoServer, the aerial imagery, terrain and restoration information for each period were serviced using the web standard interface, and the monitoring system was completed by visualizing these elements in Cesium in 3D format according to the elapsed time. This study has established a monitoring methodology for open-pit mines according to the type of mine and proposes a method for upgrading the imagery and terrain data required for monitoring. The study also showed the possibility of developing a Web3D-based open-pit mine monitoring system that is applicable to a wide range of mashup service developments
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