bluuebunny/crossref_metadata_2025 huggingface dataset:
Blocking Activin Receptor Ligands Is Not Sufficient to Rescue Cancer-Associated Gut Microbiota—A Role for Gut Microbial Flagellin in Colorectal Cancer and Cachexia?
Authors: Pekkala Satu , Keskitalo Anniina , Kettunen Emilia , Lensu Sanna , Nykänen Noora , Kuopio Teijo , Ritvos Olli , Hentilä Jaakko , Nissinen Tuuli A. , Hulmi Juha J.
Published: November 2019

Colorectal cancer (CRC) and cachexia are associated with the gut microbiota and microbial surface molecules. We characterized the CRC-associated microbiota and investigated whether cachexia affects the microbiota composition. Further, we examined the possible relationship between the microbial surface molecule flagellin and CRC. CRC cells (C26) were inoculated into mice. Activin receptor (ACVR) ligands were blocked, either before tumor formation or before and after, to increase muscle mass and prevent muscle loss. The effects of flagellin on C26-cells were studied in vitro. The occurrence of similar phenomena were studied in murine and human tumors. Cancer modulated the gut microbiota without consistent effects of blocking the ACVR ligands. However, continued treatment for muscle loss modified the association between microbiota and weight loss. Several abundant microbial taxa in cancer were flagellated. Exposure of C26-cells to flagellin increased IL6 and CCL2/MCP-1 mRNA and IL6 excretion. Murine C26 tumors expressed more IL6 and CCL2/MCP-1 mRNA than C26-cells, and human CRC tumors expressed more CCL2/MCP-1 than healthy colon sites. Additionally, flagellin decreased caspase-1 activity and the production of reactive oxygen species, and increased cytotoxicity in C26-cells. Conditioned media from flagellin-treated C26-cells deteriorated C2C12-myotubes and decreased their number. In conclusion, cancer increased flagellated microbes that may promote CRC survival and cachexia by inducing inflammatory proteins such as MCP-1. Cancer-associated gut microbiota could not be rescued by blocking ACVR ligands.
Mouse Models for Immunotherapy in Hepatocellular Carcinoma
Authors: Li Enya , Lin Li , Chen Chia-Wei , Ou Da-Liang
Published: November 2019

Liver cancer is one of the dominant causes of cancer-related mortality, and the survival rate of liver cancer is among the lowest for all cancers. Immunotherapy for hepatocellular carcinoma (HCC) has yielded some encouraging results, but the percentage of patients responding to single-agent therapies remains low. Therefore, potential directions for improved immunotherapies include identifying new immune targets and checkpoints and customizing treatment procedures for individual patients. The development of combination therapies for HCC is also crucial and urgent and, thus, further studies are required. Mice have been utilized in immunotherapy research due to several advantages, for example, being low in cost, having high success rates for inducing tumor growth, and so on. Moreover, immune-competent mice are used in immunotherapy research to clarify the role that the immune system plays in cancer growth. In this review paper, the advantages and disadvantages of mouse models for immunotherapy, the equipment that are used for monitoring HCC, and the cell strains used for inducing HCC are reviewed.
Developmental Study of Soot-Oxidation Catalysts for Fireplaces: The Effect of Binder and Preparation Techniques on Catalyst Texture and Activity
Authors: Nevalainen Pauliina , Kinnunen Niko , Suvanto Mika
Published: November 2019

An awareness of increasing climate and health problems has driven the development of new functional and affordable soot-oxidation catalysts for stationary sources, such as fireplaces. In this study, Al(OH)3, water glass and acidic aluminium phosphate binder materials were mixed with soot-oxidation catalysts. The effect of the binder on the performance of the Ag/La-Al2O3 catalyst was examined, while the Pt/La-Al2O3 catalyst bound with Al(OH)3 was used as a reference. Soot was oxidised above 340 °C on the Ag/La-Al2O3 catalyst, but at 310 °C with same catalyst bound with Al(OH)3. The addition of water glass decreased the catalytic performance because large silver crystals and agglomeration resulted in a blockage of the support material’s pores. Pt/La-Al2O3 bound with Al(OH)3 was ineffective in a fireplace environment. We believe that AgOx is the active form of silver in the catalyst. Hence, Ag/La-Al2O3 was shown to be compatible with the Al(OH)3 binder as an effective catalyst for fireplace soot oxidation.
The Potential Applications of Bacillus sp. and Pseudomonas sp. Strains with Antimicrobial Activity against Phytopathogens, in Waste Oils and the Bioremediation of Hydrocarbons
Authors: Soare (Vladu) Mariana-Gratiela , Lakatos Elena Simina , Ene Nicoleta , Malo (Dalanaj) Nereida , Popa Ovidiu , Babeanu Narcisa
Published: November 2019

Biodegradation is one of the primary mechanisms for the elimination of petroleum and other hydrocarbon pollutants from the environment. This study presents the results obtained with two newly isolated microorganisms and their potential applications in bioremediation, agriculture, and industrial fields. Twenty-five strains of microorganisms were isolated from plant materials and were subject to a selection process on the basis of antimicrobial activity. Two bacterial strains, respectively Bacillus mycoides (Bm) and Pseudomonas putida (B1), were selected for further experiments, based on the largest inhibition zones against the phytopathogens Erwinia carotovora and Xanthomonas campestris. The production of biosurfactants and enzymes was evaluated in specific media. In order to assess the production of biosurfactants, submerged bioprocesses were carried out on Yeast Malt Peptone Glucose (YMPG), M44, Luria-Bertani (LB), and King B media (KB); the supernatants were used to form emulsions with heptane, octane, and sunflower oil, and the emulsifying indices were determined.
Clostridium sp. as Bio-Catalyst for Fuels and Chemicals Production in a Biorefinery Context
Authors: Liberato Vanessa , Benevenuti Carolina , Coelho Fabiana , Botelho Alanna , Amaral Priscilla , Pereira Nei , Ferreira Tatiana
Published: November 2019

Clostridium sp. is a genus of anaerobic bacteria capable of metabolizing several substrates (monoglycerides, diglycerides, glycerol, carbon monoxide, cellulose, and more), into valuable products. Biofuels, such as ethanol and butanol, and several chemicals, such as acetone, 1,3-propanediol, and butyric acid, can be produced by these organisms through fermentation processes. Among the most well-known species, Clostridium carboxidivorans, C. ragsdalei, and C. ljungdahlii can be highlighted for their ability to use gaseous feedstocks (as syngas), obtained from the gasification or pyrolysis of waste material, to produce ethanol and butanol. C. beijerinckii is an important species for the production of isopropanol and butanol, with the advantage of using hydrolysate lignocellulosic material, which is produced in large amounts by first-generation ethanol industries. High yields of 1,3 propanediol by C. butyricum are reported with the use of another by-product from fuel industries, glycerol. In this context, several Clostridium wild species are good candidates to be used as biocatalysts in biochemical or hybrid processes. In this review, literature data showing the technical viability of these processes are presented, evidencing the opportunity to investigate them in a biorefinery context.
Cholest-4,6-Dien-3-One Promote Epithelial-To-Mesenchymal Transition (EMT) in Biliary Tree Stem/Progenitor Cell Cultures In Vitro
Authors: Nevi Lorenzo , Costantini Daniele , Safarikia Samira , Di Matteo Sabina , Melandro Fabio , Berloco Pasquale Bartolomeo , Cardinale Vincenzo
Published: November 2019

Human biliary tree stem/progenitor cells (hBTSCs), reside in peribiliary glands, are mainly stimulated by primary sclerosing cholangitis (PSC) and cholangiocarcinoma. In these pathologies, hBTSCs displayed epithelial-to-mesenchymal transition (EMT), senescence characteristics, and impaired differentiation. Here, we investigated the effects of cholest-4,6-dien-3-one, an oxysterol involved in cholangiopathies, on hBTSCs biology. hBTSCs were isolated from donor organs, cultured in self-renewal control conditions, differentiated in mature cholangiocytes by specifically tailored medium, or exposed for 10 days to concentration of cholest-4,6-dien-3-one (0.14 mM). Viability, proliferation, senescence, EMT genes expression, telomerase activity, interleukin 6 (IL6) secretion, differentiation capacity, and HDAC6 gene expression were analyzed. Although the effect of cholest-4,6-dien-3-one was not detected on hBTSCs viability, we found a significant increase in cell proliferation, senescence, and IL6 secretion. Interestingly, cholest-4.6-dien-3-one impaired differentiation in mature cholangiocytes and, simultaneously, induced the EMT markers, significantly reduced the telomerase activity, and induced HDAC6 gene expression. Moreover, cholest-4,6-dien-3-one enhanced bone morphogenic protein 4 (Bmp-4) and sonic hedgehog (Shh) pathways in hBTSCs. The same pathways activated by human recombinant proteins induced the expression of EMT markers in hBTSCs. In conclusion, we demonstrated that chronic exposition of cholest-4,6-dien-3-one induced cell proliferation, EMT markers, and senescence in hBTSC, and also impaired the differentiation in mature cholangiocytes.
The Envelope Residues E152/156/158 of Zika Virus Influence the Early Stages of Virus Infection in Human Cells
Authors: Bos Sandra , Viranaicken Wildriss , Frumence Etienne , Li Ge , Desprès Philippe , Zhao Richard Y. , Gadea Gilles
Published: November 2019

Emerging infections of mosquito-borne Zika virus (ZIKV) pose an increasing threat to human health, as documented over the recent years in South Pacific islands and the Americas in recent years. To better understand molecular mechanisms underlying the increase in human cases with severe pathologies, we recently demonstrated the functional roles of structural proteins capsid (C), pre-membrane (prM), and envelop (E) of ZIKV epidemic strains with the initiation of viral infection in human cells. Specifically, we found that the C-prM region contributes to permissiveness of human host cells to ZIKV infection and ZIKV-induced cytopathic effects, whereas the E protein is associated with viral attachment and early infection. In the present study, we further characterize ZIKV E proteins by investigating the roles of residues isoleucine 152 (Ile152), threonine 156 (Thr156), and histidine 158 (His158) (i.e., the E-152/156/158 residues), which surround a unique N-glycosylation site (E-154), in permissiveness of human host cells to epidemic ZIKV infection. For comparison purpose, we generated mutant molecular clones of epidemic BeH819015 (BR15) and historical MR766-NIID (MR766) strains that carry each other’s E-152/156/158 residues, respectively. We observed that the BR15 mutant containing the E-152/156/158 residues from MR766 was less infectious in A549-Dual™ cells than parental virus. In contrast, the MR766 mutant containing E-152/156/158 residues from BR15 displayed increased infectivity. The observed differences in infectivity were, however, not correlated with changes in viral binding onto host-cells or cellular responses to viral infection. Instead, the E-152/156/158 residues from BR15 were associated with an increased efficiency of viral membrane fusion inside infected cells due to conformational changes of E protein that enhance exposure of the fusion loop. Our data highlight an important contribution of E-152/156/158 residues to the early steps of ZIKV infection in human cells.
CCN2 Mediates S1P-Induced Upregulation of COX2 Expression in Human Granulosa-Lutein Cells
Authors: Hu Liao-Liao , Chang Hsun-Ming , Yi Yuyin , Liu Yingtao , Taylor Elizabeth L. , Zheng Li-Ping , Leung Peter C.K.
Published: November 2019

CCN1 and CCN2 are members of the CCN family and play essential roles in the regulation of multiple female reproductive functions, including ovulation. Cyclooxygenase-2 (COX2) is a critical mediator of ovulation and can be induced by sphingosine-1-phosphate (S1P) through the S1P1/3-mediated Yes-associated protein (YAP) signaling. However, it is unclear whether CCN1 or CCN2 can mediate S1P-induced upregulation of COX2 expression and increase in prostaglandin E2 (PGE2) production in human granulosa-lutein (hGL) cells. In the present study, we investigated the effects of S1P on the expressions of CCN1 and CCN2 in hGL cells. Additionally, we used a dual inhibition approach (siRNA-mediated silencing and small molecular inhibitors) to investigate the molecular mechanisms of S1P effects. Our results showed that S1P treatment significantly upregulated the expression of CCN1 and CCN2 in a concentration-dependent manner in hGL cells. Additionally, inhibition or silencing of S1P1, but not S1P3, completely abolished the S1P-induced upregulation of CCN2 expression. Furthermore, we demonstrated that S1P-induced nuclear translocation of YAP and inhibition or silencing of YAP completely abolished the S1P-induced upregulation of CCN1 and CCN2 expression. Notably, silencing of CCN2, but not CCN1, completely reversed the S1P-induced upregulation of COX2 expression and the increase in PGE2 production. Thus, CCN2 mediates the S1P-induced upregulation of COX2 expression through the S1P1-mediated signaling pathway in hGL cells. Our findings expand our understanding of the molecular mechanism underlying the S1P-mediated cellular activities in the human ovary.
Dissecting Aging and Senescence—Current Concepts and Open Lessons
Authors: Schmeer Christian , Kretz Alexandra , Wengerodt Diane , Stojiljkovic Milan , Witte Otto W.
Published: November 2019

In contrast to the programmed nature of development, it is still a matter of debate whether aging is an adaptive and regulated process, or merely a consequence arising from a stochastic accumulation of harmful events that culminate in a global state of reduced fitness, risk for disease acquisition, and death. Similarly unanswered are the questions of whether aging is reversible and can be turned into rejuvenation as well as how aging is distinguishable from and influenced by cellular senescence. With the discovery of beneficial aspects of cellular senescence and evidence of senescence being not limited to replicative cellular states, a redefinition of our comprehension of aging and senescence appears scientifically overdue. Here, we provide a factor-based comparison of current knowledge on aging and senescence, which we converge on four suggested concepts, thereby implementing the newly emerging cellular and molecular aspects of geroconversion and amitosenescence, and the signatures of a genetic state termed genosenium. We also address the possibility of an aging-associated secretory phenotype in analogy to the well-characterized senescence-associated secretory phenotype and delineate the impact of epigenetic regulation in aging and senescence. Future advances will elucidate the biological and molecular fingerprints intrinsic to either process.
An Investigation of the Polishing Behavior of Calcined Bauxite Aggregate
Authors: Yang Fa , Guan Bowen , Liu Jingyi , Wu Jiayu , Liu Jianan , Xie Chao , Xiong Rui
Published: November 2019

The application of top-grade calcined bauxite to improve the skid resistance of pavement surface coatings increases construction costs and causes excessive tire wear. Therefore, it is necessary to investigate the polishing behavior of different grades of calcined bauxite aggregate. The polished stone value of calcined bauxite was measured after the standard polishing time and the extended polishing time. The Los Angeles (L.A.) abrasion and the crushing value, profile roughness, hardness, X-ray diffraction, and micromorphology were also tested. The results showed that the calcined bauxite above 75# (the ratio of corundum to mullite by weight, C/M > 1) satisfied the requirement of the ultra-thin friction course. Compared with basalt, the calcined bauxite above 80# (C/M > 3) has better long-term skid resistance, even though the pavement surface is subject to heavier traffic. Due to the higher cohesion of lower porosity, more hard minerals to keep the surface roughness, and less soft minerals to smooth the surface roughness, calcined bauxite with a higher corundum content has the better skid resistance. There is a power law relationship between C/M and Polished Stone Value (PSV). Considering the diminishing returns of higher-grade calcined bauxite, it is necessary to accurately select the appropriate C/M of calcined bauxite before use in pavement surface coatings.
Evaluation of the Factors Affecting the Wear Resistance of Calcined Bauxite Aggregates
Authors: Wu Xirong , Zhen Nanxiang , Kong Fansheng
Published: November 2019

The continuous use of load-bearing road surfaces often results in degradation over time, particularly if they are constructed from cement or aggregates that were poorly polished. Surfaces prepared from calcined bauxite exhibit good skid resistance properties, and this work describes a comparison of the wear resistance of six different kinds of calcined bauxite with the aim of identifying the best material for road construction. Our results suggest that wear resistance of calcined bauxite is not only related to its hardness, but also dependent on the hardness dispersion throughout the aggregate and its elastic modulus. These data provide important information to enable the correct grade of bauxite clinker to be chosen for constructing high-friction road surfaces with good wear and skid resistance properties.
A New Modular Petri Net for Modeling Large Discrete-Event Systems: A Proposal Based on the Literature Study
Authors: Davidrajuh Reggie
Published: November 2019

Petri net is a highly useful tool for modeling of discrete-event systems. However, Petri net models of real-life systems are enormous, and their state-spaces are usually of infinite size. Thus, performing analysis on the model becomes difficult. Hence, slicing of Petri Net is suggested to reduce the size of the Petri nets. However, the existing slicing algorithms are ineffective for real-world systems. Therefore, there is a need for alternative methodologies for slicing that are effective for Petri net models of large real-life systems. This paper proposes a new Modular Petri Net as a solution. In modular Petri net, large Petri net models are decomposed into modules. These modules are compact, and the state spaces of these modules are also compact enough to be exhaustively analyzed. The research contributions of this paper are the following: Firstly, an exhaustive literature study is done on Modular Petri Nets. Secondly, from the conclusions drawn from the literature study, a new Petri net is proposed that supports module composition with clearly defined syntax. Thirdly, the new Petri net is implemented in the software GPenSIM, which is crucial so that real-life discrete-event systems could be modeled, analyzed, and performance-optimized with GPenSIM.
Symmetry Breaking Induced Pockels Effect in a Tilted Field Switching BPIII Cell
Authors: Chen Hui-Yu , Wang Yen-Wen
Published: November 2019

In this study, we propose driving the amorphous blue phase III (BPIII) with a tilted electric field to enhance or magnify its inherent linear electro-optical properties. The electro-optical properties of in-plane-switching (IPS) BPIII and tilted-field-switching (TFS) BPIII cells are compared here. According to the change in the induced birefringence with varying the strength of the electric field in the TFS-BPIII cell, the Kerr effect occurs in the low electric field and the Pockels effect dominates in the high electric field. In addition, the transmittance of the TFS-BPIII cell depends on the polarity of the applied field from 1 Hz to 10 kHz. It also results in the rise time of the TFS-BPIII cell being almost half of that of the IPS-BPIII cell. These experimental results and discussion allowed us to unravel the mystery of the amorphous BPIII step by step and provide the potential application of BPIII in photonic devices.
Unexpected Increase in Benzodiazepine Prescriptions Related to the Introduction of an Electronic Prescribing Tool: Evidence from Multicenter Hospital Data
Authors: Del Giorno Rosaria , Schneiders Carmen , Stefanelli Kevyn , Ceschi Alessandro , Gyoerik-Lora Sandor , Aletto Irene , Gabutti Luca
Published: November 2019

Electronic Prescribing tools (e-prescribing) have shown several benefits in terms of prescribing process adequacy and health care quality in hospital settings. We hypothesize however, that an undesired effect of digitalisation, due to the easier and faster prescribing process allowing patients to skip face-to-face conversations with patients and nurses, is that it could facilitate the prescription of medications at high risk of overuse or abuse, such as benzodiazepines (BZDs). We conducted a panel data study to investigate, the impact of the introduction of an e-prescribing system on new BZD prescriptions in hospitalised patients in a network of five teaching hospitals. During the observation period 1 July 2014–30 April 2019, 43,320 admissions were analysed. A fixed-effects model was adopted to estimate the effect of e-prescribing on new BZD prescriptions. E-prescribing implementation was associated with a significant increase of new BZD prescriptions: absolute +1.5%, and relative +43% (p < 0.001). The effect was similar in males and females (respectively, absolute +2.3%, relative +65% (p < 0.001); absolute +1.8%, relative +58% (p = 0.01)) and in patients ≥70 years old (absolute +1.6%, relative +59% (p < 0.001)). After controlling for time-varying explanatory variables, the implementation of the e-prescribing tool showed similar significant effects. E-prescribing implementation was associated with a significant increase of new in-hospital BZD prescriptions. For classes of drugs at risk of overuse or abuse, e-prescribing should be used cautiously, to minimize the risk of over-prescriptions. Further research in other settings and countries is needed to analyse causal interactions between e-prescribing and BZD prescriptions in the hospital setting, and to promote the ultimate goal of high-value care.
Antimicrobial Susceptibility Test for the Determination of Resistant and Susceptible S. aureus and Enterococcus spp. Using a Multi-Channel Surface Plasmon Resonance Device
Authors: Ucak Ozkaya Gulsum , Durak Muhammed Zeki , Akyar Isin , Karatuna Onur
Published: November 2019

The objective of this study was to investigate the development of a surface plasmon resonance (SPR) sensor platform equipped with multiple channels for the simultaneous determination of methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA) and vancomycin-resistant Enterococcus (VRE), and vancomycin-susceptible Enterococcus (VSE). Drug resistance of S. aureus strains against cefoxitin and Enterococcus strains against vancomycin were investigated both using the minimum inhibitory concentration method (MIC) assay and the SPR system equipped with single and multiple channels. The MIC values of MRSA and MSSA ranged from 32 µg/mL to >128 µg/mL and from 1 µg/mL to 4 µg/mL, respectively. The MIC values of VRE and VSE were between 64 to >128 µg/mL and 2–4 µg/mL, respectively. With the multiple-channel system, the angle shifts of MRSA, MSSA, VRE and VSE were found to be −0.030° and −0.260°, −0.010° and −0.090° respectively. The antibiotic-resistant and susceptible strains were distinguished within 3 h for S. aureus strains and within 6 h for Enterococcus strains.
A Note on Graphs with Prescribed Orbit Structure
Authors: Mowshowitz Abbe , Dehmer Matthias , Emmert-Streib Frank
Published: November 2019

This paper presents a proof of the existence of connected, undirected graphs with prescribed orbit structure, giving an explicit construction procedure for these graphs. Trees with prescribed orbit structure are also investigated.
A Novel Residual Dense Pyramid Network for Image Dehazing
Authors: Yin Shibai , Wang Yibin , Yang Yee-Hong
Published: November 2019

Recently, convolutional neural network (CNN) based on the encoder-decoder structure have been successfully applied to image dehazing. However, these CNN based dehazing methods have two limitations: First, these dehazing models are large in size with enormous parameters, which not only consumes much GPU memory, but also is hard to train from scratch. Second, these models, which ignore the structural information at different resolutions of intermediate layers, cannot capture informative texture and edge information for dehazing by stacking more layers. In this paper, we propose a light-weight end-to-end network named the residual dense pyramid network (RDPN) to address the above problems. To exploit the structural information at different resolutions of intermediate layers fully, a new residual dense pyramid (RDP) is proposed as a building block. By introducing a dense information fusion layer and the residual learning module, the RDP can maximize the information flow and extract local features. Furthermore, the RDP further learns the structural information from intermediate layers via a multiscale pyramid fusion mechanism. To reduce the number of network parameters and to ease the training process, we use one RDP in the encoder and two RDPs in the decoder, following a multilevel pyramid pooling layer for incorporating global context features before estimating the final result. The extensive experimental results on a synthetic dataset and real-world images demonstrate that the new RDPN achieves favourable performance compared with some state-of-the-art methods, e.g., the recent densely connected pyramid dehazing network, the all-in-one dehazing network, the enhanced pix2pix dehazing network, pixel-based alpha blending, artificial multi-exposure image fusions and the genetic programming estimator, in terms of accuracy, run time and number of parameters. To be specific, RDPN outperforms all of the above methods in terms of PSNR by at least 4.25 dB. The run time of the proposed method is 0.021 s, and the number of parameters is 1,534,799, only 6% of that used by the densely connected pyramid dehazing network.
Sub-Graph Regularization on Kernel Regression for Robust Semi-Supervised Dimensionality Reduction
Authors: Liu Jiao , Zhao Mingbo , Kong Weijian
Published: November 2019

Dimensionality reduction has always been a major problem for handling huge dimensionality datasets. Due to the utilization of labeled data, supervised dimensionality reduction methods such as Linear Discriminant Analysis tend achieve better classification performance compared with unsupervised methods. However, supervised methods need sufficient labeled data in order to achieve satisfying results. Therefore, semi-supervised learning (SSL) methods can be a practical selection rather than utilizing labeled data. In this paper, we develop a novel SSL method by extending anchor graph regularization (AGR) for dimensionality reduction. In detail, the AGR is an accelerating semi-supervised learning method to propagate the class labels to unlabeled data. However, it cannot handle new incoming samples. We thereby improve AGR by adding kernel regression on the basic objective function of AGR. Therefore, the proposed method can not only estimate the class labels of unlabeled data but also achieve dimensionality reduction. Extensive simulations on several benchmark datasets are conducted, and the simulation results verify the effectiveness for the proposed work.
Study on the Possibility of Improving the Environmental Performance of Diesel Engine Using Carbon Nanotubes as a Petroleum Diesel Fuel Additive
Authors: Markov Vladimir , Kamaltdinov Vyacheslav , Zherdev Anatoliy , Furman Viktor , Sa Bowen , Neverov Vsevolod
Published: November 2019

The relevance of this article is due to the need for improving indicators of exhaust gas toxicity of diesel engines. One of the modern directions of achieving the required environmental performance of diesel engines is the addition of various nanomaterials to petroleum diesel fuel. The aim of the present study was to investigate the possibility of improving the environmental performance of a diesel engine for a generator set using carbon nanotubes as an additive to petroleum diesel fuel in an amount of up to 500 mg/L. Experimental studies were carried out on a D-243 diesel engine operating in a wide range of loads from idle to full load with the addition of 125, 250, and 500 mg/L of carbon nanotubes in the diesel fuel. The mixing of petroleum diesel fuel with nanotubes was done using an ultrasonic unit. The possibility of improving the environmental performance of the studied diesel engine fueled with carbon nanotube-blended petroleum diesel fuel was examined. Results showed that, in the full-load mode of diesel operation, the addition of 500 mg/L of carbon nanotubes to diesel fuel enabled the engine to reduce exhaust smoke from 26.0% to 11.2% on the Hartridge scale.
Thermal Performance Analysis of a Direct-Heated Recompression Supercritical Carbon Dioxide Brayton Cycle Using Solar Concentrators
Authors: Wang Jinping , Wang Jun , Lund Peter D. , Zhu Hongxia
Published: November 2019

In this study, a direct recompression supercritical CO2 Brayton cycle, using parabolic trough solar concentrators (PTC), is developed and analyzed employing a new simulation model. The effects of variations in operating conditions and parameters on the performance of the s-CO2 Brayton cycle are investigated, also under varying weather conditions. The results indicate that the efficiency of the s-CO2 Brayton cycle is mainly affected by the compressor outlet pressure, turbine inlet temperature and cooling temperature: Increasing the turbine inlet pressure reduces the efficiency of the cycle and also requires changing the split fraction, where increasing the turbine inlet temperature increases the efficiency, but has a very small effect on the split fraction. At the critical cooling temperature point (31.25 °C), the cycle efficiency reaches a maximum value of 0.4, but drops after this point. In optimal conditions, a cycle efficiency well above 0.4 is possible. The maximum system efficiency with the PTCs remains slightly below this value as the performance of the whole system is also affected by the solar tracking method used, the season and the incidence angle of the solar beam radiation which directly affects the efficiency of the concentrator. The choice of the tracking mode causes major temporal variations in the output of the cycle, which emphasis the role of an integrated TES with the s-CO2 Brayton cycle to provide dispatchable power.
Experimental Study on Flat-Glass Heating and Edge-Sealing Using Multiple Microwave Sources
Authors: Kim Jae Kyung , Kim Young Shin , Jeon Euy Sik
Published: November 2019

There has been a recent surge of interest in vacuum insulating glass (VIG) due to its excellent thermal insulation performance. Vacuum glazing is necessary for high-performance sealing solders and various applications in sealing technology. This paper describes experimental studies into heating and edge-sealing of flat glass using microwaves. Electric–thermal coupled analysis using ANSYS was employed and heating and edge-sealing experiments were conducted on flat glass. In order to ensure a uniform electric field distribution in the microwave chamber, the electric field and temperature distributions were analyzed according to waveguide patterns. In addition, the electric field and temperature distribution were analyzed with the inclusion of carbon susceptor plates. Based on the electric simulation results by waveguide pattern, a microwave heating chamber was fabricated, and a basic experiment was conducted on both heating and edge-sealing of the glass. The cross-section of the sealed glass confirmed that it was sealed without cracks or breakage.
Active Disturbance Rejection Control Scheme for Reducing Mutual Current and Harmonics in Multi-Parallel Grid-Connected Inverters
Authors: Saleem Muhammad , Ko Byoung-Sun , Kim Si-Hwan , Kim Sang-il , Chowdhry Bhawani , Kim Rae-Young
Published: November 2019

With the increasing penetration of renewable energy sources into modern power systems, parallel inverters with LCL filters are commonly employed in the grid interface, giving rise to potential resonance problems. Among the different resonances, interactive resonance is triggered by interaction among inverters when different current references are applied to parallel inverters. It may also feature a mutual current that circulates among inverters instead of flowing into the grid and introduces harmonics or instability in the control system. In this paper, active disturbance rejection control based on a reduced-order extended state observer (RESO) was proposed for parallel inverters. With the proposed scheme, the interaction between inverters is considered as an exogenous disturbance caused by other parallel inverters, estimated by the RESO, and rejected by the controller. In the results, the mutual current and interactive harmonics, calculated via fast Fourier transform, were reduced with the proposed control scheme. Thus, the lower total harmonic distortion of each current was achieved. Additionally, the robust stability and less model-dependent control design are the other additive advantages over the derivative filtered capacitor voltage feedforward-based active damping using PI control. The simulation and real-time experimental results of the conventional and proposed scheme, obtained using the hardware-in-loop, were presented to verify the theoretical analysis under the similar and different current reference cases.
Effects of Bounded Uncertainties on the Dynamic Characteristics of an Overhung Rotor System with Rubbing Fault
Authors: Fu Chao , Zhen Dong , Yang Yongfeng , Gu Fengshou , Ball Andrew
Published: November 2019

This paper investigated the nonlinear vibrations of an uncertain overhung rotor system with rub-impact fault. As the clearance of the rotor and stator is getting smaller, contact between them often occurs at high rotation speeds. Meanwhile, inherent uncertainties in the rubbing can be introduced for a variety of reasons, and they are typically restricted to small-sample variables. It is important to gain a robust understanding of the dynamics of such a system under non-probabilistic uncertainties. A non-intrusive uncertainty quantification scheme, coupled with the Runge-Kutta method, was used to study the effects of the rub-impact related interval uncertainties on the dynamical response individually and simultaneously, including the uncertainties in the contact stiffness, clearance, and friction coefficient. Moreover, the numerical validation of the developed analysis method was verified through comparisons with the scanning approach. The results obtained provide some guidance for investigating the uncertain dynamics of rubbing rotors and diagnosing the rub-impact fault under non-random uncertainty.
Workers with Active Implantable Medical Devices Exposed to EMF: In Vitro Test for the Risk Assessment
Authors: Mattei Eugenio , Calcagnini Giovanni , Censi Federica , Pinto Iole , Bogi Andrea , Falsaperla Rosaria
Published: November 2019

The occupational health and safety framework identifies workers with an active implantable medical device (AIMD), such as a pacemaker (PM) or an implantable defibrillator (ICD), as a particularly sensitive risk group that must be protected against the dangers caused by the interference of electromagnetic field (EMF). In this paper, we describe the results of in vitro testing/measurements performed according to the EN50527-2-1:2016 standard, for the risk assessment of employees with a PM exposed to three EMF sources: (1) An electrosurgical unit (ESU); (2) a transcranial stimulator (TMS); and (3) an arc welder. The ESU did not affect the PM behavior in any of the configurations tested. For the TMS and the arc welder, interference phenomena were observed in limited experimental configurations, corresponding to the maximum magnetic field coupling between the EMF source and the implant. The in vitro measurements presented can be considered an example of how the specific risk assessment for a worker with a PM can be performed, according to one of the methodologies proposed in the EN50527-2-1:2016, and can be used as scientific evidence and literature data for future risk assessments on the same EMF sources.
Factors Affecting the Chipping Operation Based on the Screen Size of the Drum Chipper
Authors: Choi Yun-Sung , Cho Min-Jae , Paik Seung-Ho , Mun Ho-Seong , Kim Dae-Hyun , Han Sang-Kyun , Oh Jae-Heun
Published: November 2019

Forest biomass has recently been highlighted as a renewable energy source in South Korea. As the Renewable Energy Certificate weight has been revised to encourage the use of forest biomass for energy production, forest operations have focused on the development of new technologies and harvesting methods for the extraction and utilization of forest biomass. This study examined the application of a drum chipper to forest biomass and analyzed the effects of screen size (40, 50, 65, and 80 mm) on productivity, cost, and particle size distribution. When the screen size was 40 mm to 65 mm, the chipping productivity improved by up to 3.6 times, the fuel consumption decreased by up to 29.7%, and the chipping cost was reduced by up to 31.9%. The fines content tended to decrease with an increase in screen size. The size of woodchips was less than 100 mm in length and ranged from 10 to 63 mm. The 65 mm screen was the most effective (e.g., producing optimal wood chip size at an acceptable production rate) for the chipping operation. Harvesting methods and drying time are also important factors that determine the utilization efficiency of forest biomass. Therefore, further research should be focused on the effect of moisture content on chipping productivity, power required, and fine particle size in forest biomass productions.
Climate Change Vulnerability Assessment for Forest Management: The Case of the U.S. Forest Service
Authors: Timberlake Thomas J. , Schultz Courtney A.
Published: November 2019

Forest managers need access to targeted scientific information about the impacts of climate change in order to adapt to climate change. Vulnerability assessments address this need and are common across a range of disciplines and geographies; however, the practice of vulnerability assessment has revealed challenges that warrant further examination in a specific context. The U.S. Forest Service, a national forest-management agency in charge of 78 million hectares, has developed a collection of climate change vulnerability assessments to support adaptation by forest managers. We conducted a qualitative document analysis, informed by a series of research interviews with scientists, of 44 vulnerability assessments developed for the U.S. Forest Service. We found that partnerships between research scientists and land managers were central to the development of vulnerability assessments in the U.S. Forest Service. Assessment processes vary across settings. As the practice has developed, vulnerability assessments increasingly cover larger spatial extents and a broader range of resources associated with forest management. We identified ways in which vulnerability assessments can support decision-making, including approaches already in use and opportunities to improve practice. In particular, we discuss how vulnerability assessments are well-positioned to support the development of land-management plans, which set strategic management direction for periods of at least a decade. This paper provides baseline knowledge on a fundamental aspect of a large national forestry agency’s climate change adaptation strategy, with many findings transferable to the study of other forest-management organizations.
Lessons Learned from the Water Producer Project in the Atlantic Forest, Brazil
Authors: Viani Ricardo A. G. , Bracale Henrique , Taffarello Denise
Published: November 2019

Forest and landscape restoration (FLR) is a powerful strategy for large-scale tropical forest recovery, and payment for ecosystem services (PES) is used to support FLR programs and projects on privately-owned land. In this article, we discuss the lessons learned from the Water Producer Project, a pioneer, multiple-stakeholder, and PES-supported FLR project in the Atlantic Forest, south-eastern Brazil. The project was implemented in four landscapes located in two municipalities. Altogether, 41 PES contracts with landowners were signed, resulting in various FLR practices being implemented in a total of 342.4 ha (64.2 ha for riparian forest restoration, 90.8 ha for soil conservation, and 187.4 for forest conservation) of land, which represents 39% of the project goal. As of the end of the project, only 50% (USD 49,250) of the available PES funds had been spent. However, funds spent on project planning, implementation, communication, and monitoring were 12 times greater than those spent on PES. Several challenges restricted the progress and monitoring of the project. The main issue was landowner participation and/or engagement. In terms of lessons learned, we highlight that PES schemes are more complex than initially thought, and that sufficient funding does not guarantee the success of FLR projects. It is essential to promote landowner participation and engagement by considering them key players in FLR projects. Finally, acceptance from landowners was higher and implementation was easier for forest conservation practices that required no land-use changes. Thus, we suggest that similar future projects should focus on targeting private properties in marginal agricultural lands with a high probability of natural regeneration. Alternatively, future projects could focus on lands with remnant forest cover of high conservation value.
Post-Harvest Evaluation of Soil Physical Properties and Natural Regeneration Growth in Steep-Slope Terrains
Authors: Sohrabi Hadi , Jourgholami Meghdad , Tavankar Farzam , Venanzi Rachele , Picchio Rodolfo
Published: November 2019

Protection of forest soils during harvesting operations is necessary to reduce damage and accelerate recovery time. The current study aims to evaluate soil physical properties, natural regeneration, and its recovery process in treatments including slope gradient, traffic intensity and skid trail after long periods of time, after ceasing the timber harvesting operations. The most recent skidding operations within each 5 years recovery period were studied for a chronosequence of 20 years. Soil samples were taken in abandoned skid trails and data were recorded on naturally regenerated species and density. The results revealed that most soil disturbances occurred on the slopes >20%, as well as the highest levels of traffic intensity. Bulk density and penetration resistance were still higher than the control area, with a significant difference between them, while total porosity was partially recovered. Twenty years after the skidding operation, soil bulk density and penetration resistance were 13.2% and 23.7% higher than the control area, while total porosity was 9.78% lower the than value of the control area. Seedlings of 50–150 cm and >150 cm in height on skid trails had significantly lower density than those in the control. The number of seedlings per m2 was less than the control area in all skid trails and for all height classes. The proportion of seedlings present in low traffic intensity was higher than in medium and high traffic intensities. The findings confirmed that full recovery rates are lengthy, and more time than 20 years is required to fully recover, especially with regards to penetration resistance.
Inhibition of Escherichia coli O157:H7 and Salmonella enterica Isolates on Spinach Leaf Surfaces Using Eugenol-Loaded Surfactant Micelles
Authors: Ruengvisesh Songsirin , Kerth Chris R. , Taylor T. Matthew
Published: November 2019

Spinach and other leafy green vegetables have been linked to foodborne disease outbreaks of Escherichia coli O157:H7 and Salmonella enterica around the globe. In this study, the antimicrobial activities of surfactant micelles formed from the anionic surfactant sodium dodecyl sulfate (SDS), SDS micelle-loaded eugenol (1.0% eugenol), 1.0% free eugenol, 200 ppm free chlorine, and sterile water were tested against the human pathogens E. coli O157:H7 and Salmonella Saintpaul, and naturally occurring microorganisms, on spinach leaf surfaces during storage at 5 °C over 10 days. Spinach samples were immersed in antimicrobial treatment solution for 2.0 min at 25 °C, after which treatment solutions were drained off and samples were either subjected to analysis or prepared for refrigerated storage. Whereas empty SDS micelles produced moderate reductions in counts of both pathogens (2.1–3.2 log10 CFU/cm2), free and micelle-entrapped eugenol treatments reduced pathogens by >5.0 log10 CFU/cm2 to below the limit of detection (<0.5 log10 CFU/cm2). Micelle-loaded eugenol produced the greatest numerical reductions in naturally contaminating aerobic bacteria, Enterobacteriaceae, and fungi, though these reductions did not differ statistically from reductions achieved by un-encapsulated eugenol and 200 ppm chlorine. Micelles-loaded eugenol could be used as a novel antimicrobial technology to decontaminate fresh spinach from microbial pathogens.
Antioxidant and Antimicrobial Potential of Phenolic Metabolites from Traditionally Used Mediterranean Herbs and Spices
Authors: Generalić Mekinić Ivana , Skroza Danijela , Ljubenkov Ivica , Katalinić Višnja , Šimat Vida
Published: November 2019

The phenolic extracts of fifteen Mediterranean medicinal plants, as well as their antioxidant and antimicrobial activities were investigated to grade their potential as additives in the food industry. Phenolic profiles of plant extracts were determined spectrophotometrically (total phenolics and phenolic subgroups) while individual compounds were identified using chromatographic assays. The biological activity of samples was determined using five antioxidant assays, while the antibacterial potential was determined against six foodborne pathogens (Camplyobacter coli, Escherichia coli, Salmonela Infantis, Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus). The results showed significant variations in phenolic profile of plants and consequently their biological activity. Bearberry contained the highest concentration of phenolics, was extremely rich in non-flavonoids and also had the highest amount of catechins that resulted with good reducing and free radical scavenging properties and low chelating activity. All extracts were not effective against tested microorganisms with Gram-positive bacteria being more sensitive (especially S. aureus). The most effective extracts were St. Johns wort against S. aureus with minimal inhibitory concentration (MIC) of 1.00 mg/mL), bay laurel and nettle against B. cereus (MICs of 1.67 mg/mL), and woodland strawberry against L. monocytogenes (MIC of 3.33 mg/mL).