bluuebunny/crossref_metadata_2025 huggingface dataset:
A History of Molecular Chaperone Structures in the Protein Data Bank
Authors: Bascos Neil Andrew D. , Landry Samuel J.
Published: December 2019

Thirty years ago a class of proteins was found to prevent the aggregation of Rubisco. These proteins’ ability to prevent unwanted associations led to their being called chaperones. These chaperone proteins also increased in expression as a response to heat shock, hence their label as heat shock proteins (Hsps). However, neither label encompasses the breadth of these proteins’ functional capabilities. The term “unfoldases” has been proposed, as this basic function is shared by most members of this protein family. Onto this is added specializations that allow the different family members to perform various cellular functions. This current article focuses on the resolved structural bases for these functions. It reviews the currently available molecular structures in the Protein Data Bank for several classes of Hsps (Hsp60, Hsp70, Hsp90, and Hsp104). When possible, it discusses the complete structures for these proteins, and the types of molecular machines to which they have been assigned. The structures of domains and the associated functions are discussed in order to illustrate the rationale for the proposed unfoldase function.
Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review
Authors: Tang Guo-Yi , Meng Xiao , Gan Ren-You , Zhao Cai-Ning , Liu Qing , Feng Yi-Bin , Li Sha , Wei Xin-Lin , Atanasov Atanas G. , Corke Harold , Li Hua-Bin
Published: December 2019

Tea is widely consumed all over the world. Generally, tea is divided into six categories: White, green, yellow, oolong, black, and dark teas, based on the fermentation degree. Tea contains abundant phytochemicals, such as polyphenols, pigments, polysaccharides, alkaloids, free amino acids, and saponins. However, the bioavailability of tea phytochemicals is relatively low. Thus, some novel technologies like nanotechnology have been developed to improve the bioavailability of tea bioactive components and consequently enhance the bioactivity. So far, many studies have demonstrated that tea shows various health functions, such as antioxidant, anti-inflammatory, immuno-regulatory, anticancer, cardiovascular-protective, anti-diabetic, anti-obesity, and hepato-protective effects. Moreover, it is also considered that drinking tea is safe to humans, since reports about the severe adverse effects of tea consumption are rare. In order to provide a better understanding of tea and its health potential, this review summarizes and discusses recent literature on the bioactive components, bioavailability, health functions, and safety issues of tea, with special attention paid to the related molecular mechanisms of tea health functions.
Study on the Preparation of Ionic Liquid Doped Chitosan/Cellulose-Based Electroactive Composites
Authors: Wang Fang , Xie Chong , Qian Liying , He Beihai , Li Junrong
Published: December 2019

Electro-actuated polymer (EAP) can change its shape or volume under the action of an external electric field and shows similar behavioral characteristics with those of biological muscles, and so it has good application prospects in aerospace, bionic robots, and other fields. The properties of cellulose-based electroactive materials are similar to ionic EAP materials, although they have higher Young’s modulus and lower energy consumption. However, cellulose-based electroactive materials have a more obvious deficiency—their actuation performance is often more significantly affected by ambient humidity due to the hygroscopicity caused by the strong hydrophilic structure of cellulose itself. Compared with cellulose, chitosan has good film-forming and water retention properties, and its compatibility with cellulose is very excellent. In this study, a chitosan/cellulose composite film doped with ionic liquid, 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac), was prepared by co-dissolution and regeneration process using [EMIM]Ac as the solvent. After that, a conductive polymer, poly(3,4-ethylenedioxythiophene)/poly (styrene sulfonate) (PEDOT: PSS), was deposited on the surface of the resulted composite, and then a kind of cellulose-based electroactive composites were obtained. The results showed that the end bending deformation amplitude of the resulted material was increased by 2.3 times higher than that of the pure cellulose film under the same conditions, and the maximum deformation amplitude reached 7.3 mm. The tensile strength of the chitosan/cellulose composite film was 53.68% higher than that of the cellulose film, and the Young’s modulus was increased by 72.52%. Furthermore, in comparison with the pure cellulose film, the water retention of the composite film increased and the water absorption rate decreased obviously, which meant that the resistance of the material to changes in environmental humidity was greatly improved.
Assessment of Radio-Induced Damage in Endothelial Cells Irradiated with 40 kVp, 220 kVp, and 4 MV X-rays by Means of Micro and Nanodosimetric Calculations
Authors: Tang Nicolas , Bueno Marta , Meylan Sylvain , Perrot Yann , Tran Hoang N. , Freneau Amélie , Dos Santos Morgane , Vaurijoux Aurélie , Gruel Gaëtan , Bernal Mario A. , Bordage Marie-Claude , Emfietzoglou Dimitris , Francis Ziad , Guatelli Susanna , Ivanchenko Vladimir , Karamitros Mathieu , Kyriakou Ioanna , Shin Wook-Geun , Incerti Sébastien , Villagrasa Carmen
Published: December 2019

The objective of this work was to study the differences in terms of early biological effects that might exist between different X-rays energies by using a mechanistic approach. To this end, radiobiological experiments exposing cell monolayers to three X-ray energies were performed in order to assess the yields of early DNA damage, in particular of double-strand breaks (DSBs). The simulation of these irradiations was set in order to understand the differences in the obtained experimental results. Hence, simulated results in terms of microdosimetric spectra and early DSB induction were analyzed and compared to the experimental data. Human umbilical vein endothelial cells (HUVECs) were irradiated with 40, 220 kVp, and 4 MV X-rays. The Geant4 Monte Carlo simulation toolkit and its extension Geant4-DNA were used for the simulations. Microdosimetric calculations aiming to determine possible differences in the variability of the energy absorbed by the irradiated cell population for those photon spectra were performed on 10,000 endothelial cell nuclei representing a cell monolayer. Nanodosimetric simulations were also carried out using a computation chain that allowed the simulation of physical, physico-chemical, and chemical stages on a single realistic endothelial cell nucleus model including both heterochromatin and euchromatin. DNA damage was scored in terms of yields of prompt DSBs per Gray (Gy) and per giga (109) base pair (Gbp) and DSB complexity was derived in order to be compared to experimental data expressed as numbers of histone variant H2AX (γ-H2AX) foci per cell. The calculated microdosimetric spread in the irradiated cell population was similar when comparing between 40 and 220 kVp X-rays and higher when comparing with 4 MV X-rays. Simulated yields of induced DSB/Gy/Gbp were found to be equivalent to those for 40 and 220 kVp but larger than those for 4 MV, resulting in a relative biological effectiveness (RBE) of 1.3. Additionally, DSB complexity was similar between the considered photon spectra. Simulated results were in good agreement with experimental data obtained by IRSN (Institut de radioprotection et de sûreté nucléaire) radiobiologists. Despite differences in photon energy, few differences were observed when comparing between 40 and 220 kVp X-rays in microdosimetric and nanodosimetric calculations. Nevertheless, variations were observed when comparing between 40/220 kVp and 4 MV X-rays. Thanks to the simulation results, these variations were able to be explained by the differences in the production of secondary electrons with energies below 10 keV.
Assessment of the Effects of Bisphenol A on Dopamine Synthesis and Blood Vessels in the Goldfish Brain
Authors: Wang Qing , Lin Fangmei , He Qi , Liu Xiaochun , Xiao Shiqiang , Zheng Leyun , Yang Huirong , Zhao Huihong
Published: December 2019

Bisphenol A (BPA) is an abundant contaminant found in aquatic environments. While a large number of toxicological studies have investigated the effects of BPA, the potential effects of BPA exposure on fish brain have rarely been studied. To understand how BPA impacts goldfish brains, we performed a transcriptome analysis of goldfish brains that had been exposed to 50 μg L−1 and 0 μg L−1 BPA for 30 days. In the analysis of unigene expression profiles, 327 unigenes were found to be upregulated and 153 unigenes were found to be downregulated in the BPA exposure group compared to the control group. Dopaminergic signaling pathway-related genes were significantly downregulated in the BPA exposure group. Furthermore, we found that serum dopamine concentrations decreased and TUNEL (terminal deoxynucleotidyl transferase 2-deoxyuridine, 5-triphosphate nick end labeling) staining was present in dopamine neurons enriched regions in the brain after BPA exposure, suggesting that BPA may disrupt dopaminergic processes. A KEGG analysis revealed that genes involved in the fluid shear stress and atherosclerosis pathway were highly significantly enriched. In addition, the qRT-PCR results for fluid shear stress and atherosclerosis pathway-related genes and the vascular histology of the brain showed that BPA exposure could damage blood vessels and induce brain atherosclerosis. The results of this work provide insights into the biological effects of BPA on dopamine synthesis and blood vessels in goldfish brain and could lay a foundation for future BPA neurotoxicity studies.
Profiles of Long Non-Coding RNAs and mRNA Expression in Human Macrophages Regulated by Interleukin-27
Authors: Hu Xiaojun , Goswami Suranjana , Qiu Ju , Chen Qian , Laverdure Sylvain , Sherman Brad T. , Imamichi Tomozumi
Published: December 2019

Macrophages play an essential role in the immune system. Recent studies have shown that long non-coding RNAs (lncRNAs) can regulate genes encoding products involved in the immune response. Interleukin (IL)-27 is a member of the IL-6/IL-12 family of cytokines with broad anti-viral effects that inhibits human immunodeficiency virus (HIV) type-1 and herpes simplex virus (HSV). However, little is known about the role of lncRNAs in macrophages affected by IL-27. Therefore, we investigated the expression profiles of mRNA and lncRNA in human monocyte-derived macrophages (MDMs) regulated by IL-27. Monocytes were differentiated in the presence of macrophage-colony stimulatory factor (M-CSF)- or human AB serum with or without IL-27, and these cells were the subject for the profile analysis using RNA-Seq. We identified 146 lncRNAs (including 88 novel ones) and 434 coding genes were differentially regulated by IL-27 in both M-CSF- and AB serum-induced macrophages. Using weighted gene co-expression network analysis, we obtained four modules. The immune system, cell cycle, and regulation of complement cascade pathways were enriched in different modules. The network of mRNAs and lncRNAs in the pathways suggest that lncRNAs might regulate immune activity in macrophages. This study provides potential insight into the roles of lncRNA in macrophages regulated by IL-27.
Single Molecule Imaging of T-DNA Intermediates Following Agrobacterium tumefaciens Infection in Nicotiana benthamiana
Authors: Pereman Idan , Melamed-Bessudo Cathy , Dahan-Meir Tal , Herz Elad , Elbaum Michael , Levy Avraham A.
Published: December 2019

Plant transformation mediated by Agrobacterium tumefaciens is a well-studied phenomenon in which a bacterial DNA fragment (T-DNA), is transferred to the host plant cell, as a single strand, via type IV secretion system and has the potential to reach the nucleus and to be integrated into its genome. While Agrobacterium-mediated transformation has been widely used for laboratory-research and in breeding, the time-course of its journey from the bacterium to the nucleus, the conversion from single- to double-strand intermediates and several aspects of the integration in the genome remain obscure. In this study, we sought to follow T-DNA infection directly using single-molecule live imaging. To this end, we applied the LacO-LacI imaging system in Nicotiana benthamiana, which enabled us to identify double-stranded T-DNA (dsT-DNA) molecules as fluorescent foci. Using confocal microscopy, we detected progressive accumulation of dsT-DNA foci in the nucleus, starting 23 h after transfection and reaching an average of 5.4 and 8 foci per nucleus at 48 and 72 h post-infection, respectively. A time-course diffusion analysis of the T-DNA foci has demonstrated their spatial confinement.
Polyglycerol Hyperbranched Polyesters: Synthesis, Properties and Pharmaceutical and Biomedical Applications
Authors: Zamboulis Alexandra , Nakiou Eirini A. , Christodoulou Evi , Bikiaris Dimitrios N. , Kontonasaki Eleana , Liverani Liliana , Boccaccini Aldo R.
Published: December 2019

In a century when environmental pollution is a major issue, polymers issued from bio-based monomers have gained important interest, as they are expected to be environment-friendly, and biocompatible, with non-toxic degradation products. In parallel, hyperbranched polymers have emerged as an easily accessible alternative to dendrimers with numerous potential applications. Glycerol (Gly) is a natural, low-cost, trifunctional monomer, with a production expected to grow significantly, and thus an excellent candidate for the synthesis of hyperbranched polyesters for pharmaceutical and biomedical applications. In the present article, we review the synthesis, properties, and applications of glycerol polyesters of aliphatic dicarboxylic acids (from succinic to sebacic acids) as well as the copolymers of glycerol or hyperbranched polyglycerol with poly(lactic acid) and poly(ε-caprolactone). Emphasis was given to summarize the synthetic procedures (monomer molar ratio, used catalysts, temperatures, etc.,) and their effect on the molecular weight, solubility, and thermal and mechanical properties of the prepared hyperbranched polymers. Their applications in pharmaceutical technology as drug carries and in biomedical applications focusing on regenerative medicine are highlighted.
Development of Thiazolidinedione-Based HDAC6 Inhibitors to Overcome Methamphetamine Addiction
Authors: Sharma Chiranjeev , Oh Yong Jin , Park Byoungduck , Lee Sooyeun , Jeong Chul-Ho , Lee Sangkil , Seo Ji Hae , Seo Young Ho
Published: December 2019

Thiazolidinedione is a five-membered heterocycle that is widely used in drug discovery endeavors. In this study, we report the design, synthesis, and biological evaluation of a series of thiazolidinedione-based HDAC6 inhibitors. In particular, compound 6b exerts an excellent inhibitory activity against HDAC6 with an IC50 value of 21 nM, displaying a good HDAC6 selectivity over HDAC1. Compound 6b dose-dependently induces the acetylation level of α-tubulin via inhibition of HDAC6 in human neuroblastoma SH-SY5Y cell line. Moreover, compound 6b efficiently reverses methamphetamine-induced morphology changes of SH-SY5Y cells via regulating acetylation landscape of α-tubulin. Collectively, compound 6b represents a novel HDAC6-isoform selective inhibitor and demonstrates promising therapeutic potential for the treatment of methamphetamine addiction.
A Comprehensive Evaluation of the Community Environment Adaptability for Elderly People Based on the Improved TOPSIS
Authors: Zhang Shen-Cheng , Wang Hui , Liu Zhi , Zeng Shouzhen , Jin Yun , Baležentis Tomas
Published: December 2019

As the main way of providing care for elderly people, home-based old-age care puts forward higher requirements for the environmental adaptability of the community. Five communities in Wuhu were selected for a comprehensive assessment of environmental suitability. In order to ensure a comprehensive and accurate assessment of the environmental adaptability of the community, we used the analytic hierarchy process (AHP) to calculate the weight of each indicator and the technique for order preference by similarity to ideal solution (TOPSIS) method to evaluate the adaptability of community, as well as further analyses using a two-dimensional data space map. The results show that the Weixing community is the most suitable for the elderly and outdoor activities of the community.
Interspecific Competition between the House Fly, Musca domestica L. (Diptera: Muscidae) and Black Soldier Fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) When Reared on Poultry Manure
Authors: Miranda Chelsea D. , Cammack Jonathan A. , Tomberlin Jeffery K.
Published: December 2019

Few studies have examined the competitive interaction between the house fly (HF) and the black soldier fly (BSF). The fact that the BSF deters HF oviposition is widely cited in BSF literature, but this interaction has not been assessed in over three decades. In this study, the competitive interaction of BSF and HF larvae was observed on fresh (day 0) and aged poultry manure (manure aged for two, four, six, or eight days). Specifically, a priority effect study was conducted to determine if colonization sequence influences time to first pupariation (HF) or pre-pupation (BSF), survivorship, and weight. Results show >70% of HFs reached pupariation in all treatments except when placed on manure eight days after the initial inoculation with BSF. However, age of the resource negatively impacted time to first pupariation and puparium weight when HFs were reared alone or introduced two to eight days after BSF. No BSF pre-pupae resulted from treatments in which HFs were the pioneering species. BSFs reached the highest percent pre-pupation when reared alone on fresh manure, but BSFs may be more susceptible to the negative impacts of an aging resource, as no pre-pupae were observed when provided with six- or eight-day-old manure. Similar to HFs, age of the resource may have impacted development and survivorship; other factors such as moisture content, chemical composition, and amount of resource provided may have also impacted our results. These data may be useful in implementing BSFs as biological control agents of the HF, as well provide valuable information for facilities mass-producing HFs or BSFs for food or feed.
Bioresorbable Vascular Scaffolds—Dead End or Still a Rough Diamond?
Authors: Jeżewski Mateusz P. , Kubisa Michał J. , Eyileten Ceren , De Rosa Salvatore , Christ Günter , Lesiak Maciej , Indolfi Ciro , Toma Aurel , Siller-Matula Jolanta M. , Postuła Marek
Published: December 2019

Percutaneous coronary interventions with stent-based restorations of vessel patency have become the gold standard in the treatment of acute coronary states. Bioresorbable vascular scaffolds (BVS) have been designed to combine the efficiency of drug-eluting stents (DES) at the time of implantation and the advantages of a lack of foreign body afterwards. Complete resolution of the scaffold was intended to enable the restoration of vasomotor function and reduce the risk of device thrombosis. While early reports demonstrated superiority of BVS over DES, larger-scale application and longer observation exposed major concerns about their use, including lower radial strength and higher risk of thrombosis resulting in higher rate of major adverse cardiac events. Further focus on procedural details and research on the second generation of BVS with novel properties did not allow to unequivocally challenge position of DES. Nevertheless, BVS still have a chance to present superiority in distinctive indications. This review presents an outlook on the available first and second generation BVS and a summary of results of clinical trials on their use. It discusses explanations for unfavorable outcomes, proposed enhancement techniques and a potential niche for the use of BVS.
Acute Respiratory Distress Syndrome (ARDS): Pathophysiological Insights and Lung Imaging
Authors: Perchiazzi Gaetano , Wrigge Hermann
Published: December 2019

Acute respiratory distress syndrome (ARDS) is in the center of the scientific debate both for its complex pathophysiology and for the discussion about the remedies that could contribute to its healing. The intricate interplay of different body systems that characterizes ARDS is mirrored by two main research threads, one centered on the pathophysiological mechanisms of the disease and the other on the new approaches to lung imaging. In this Special Issue of the Journal of Clinical Medicine are presented studies using imaging technologies based on electrical impedance tomography, synchrotron radiation computed tomography and intravital probe-based confocal laser endomicroscopy. The studies on the pathophysiological mechanisms pertain to the evaluation of the biomarkers of the disease and the platelet disfunction during extracorporeal membrane oxygenation. These contributions witness the intensity of ARDS research as many of the key problems of the disease are only in part resolved.
Clinical and Ultrasound Thyroid Nodule Characteristics and Their Association with Cytological and Histopathological Outcomes: A Retrospective Multicenter Study in High-Resolution Thyroid Nodule Clinics
Authors: Molina-Vega María , Rodríguez-Pérez Carlos Antonio , Álvarez-Mancha Ana Isabel , Baena-Nieto Gloria , Riestra María , Alcázar Victoria , Romero-Lluch Ana Reyes , Galofré Juan C. , Fernández-García José C.
Published: December 2019

Introduction: Thyroid nodules are a common finding. A high-resolution thyroid nodule clinic (HR-TNC) condenses all tests required for the evaluation of thyroid nodules into a single appointment. We aimed to evaluate the clinical outcomes at HR-TNCs. Design and Methods: A retrospective cross-sectional multicenter study including data from four HR-TNCs in Spain. We evaluated fine-needle aspiration (FNA) indications and the association between clinical and ultrasound characteristics with cytological and histopathological outcomes. Results: A total of 2809 thyroid nodules were included; FNA was performed in 82.1%. Thyroid nodules that underwent FNA were more likely larger, isoechoic, with microcalcifications, and in younger subjects. The rate of nondiagnostic FNA was 4.3%. A solid component, irregular margins or microcalcifications, significantly increased the odds of Bethesda IV-V-VI (vs. Bethesda II). Irregular margins and a solid component were independently associated with increased odds of malignancy. Thyroid nodules <20 mm and ≥20–<40 mm had a 6.5-fold and 3.3-fold increased risk for malignancy respectively in comparison with those ≥40 mm. Conclusion: In this large multicenter study, we found that the presence of a solid component and irregular margins are factors independently related to malignancy in thyroid nodules. Since nodule size ≥40 mm was associated with the lowest odds of malignancy, this cut-off should not be a factor leading to indicate thyroid surgery. HR-TNCs were associated with a low rate of nondiagnostic FNA.
Reduction of Fat to Muscle Mass Ratio Is Associated with Improvement of Liver Stiffness in Diabetic Patients with Non-Alcoholic Fatty Liver Disease
Authors: Osaka Takafumi , Hashimoto Yoshitaka , Okamura Takuro , Fukuda Takuya , Yamazaki Masahiro , Hamaguchi Masahide , Fukui Michiaki
Published: December 2019

Body weight reduction leads to improvement of nonalcoholic fatty liver disease (NAFLD), but the contributions of body composition modification on its improvement have not been clarified yet. We performed a retrospective cohort study in a Japanese university hospital to clarify the effect of body fat reduction on the improvement of hepatic stiffness as well as hepatic steatosis. The skeletal muscle mass index (SMI, kg/m2), fat to muscle mass ratio, and the change in fat to muscle mass ratio after 1 year from baseline were calculated. Controlled attenuation parameter (CAP, dB/m) and liver stiffness measurement (LSM, kPa) were evaluated by elastography. Primary outcome was set as the association of the change of fat to muscle mass ratio after 1 year from baseline with the change of liver stiffness measurement. One hundred and seventeen patients (59 men and 58 women) completed the study. The average age was 63.5 years, and baseline CAP and LSM were 273.4 ± 53.5 dB/m and 6.3 ± 3.4 kPa, respectively. After 1 year, body mass index (BMI), SMI, and LSM decreased. Multiple regression analyses demonstrated that change in fat to muscle mass ratio was associated with the change in CAP (ß = 0.38, p < 0.001) or LSM (ß = 0.21, p = 0.026). The reduction of fat to muscle mass ratio was associated with improvement in liver stiffness, but the reduction of BMI was not.
Impact of Antiplatelet Therapies on Patients Outcome in Osteosynthetic Surgery of Proximal Femoral Fractures
Authors: Humenberger Michael , Stockinger Matthias , Kettner Stephan , Siller-Matula Jolanta , Hajdu Stefan
Published: December 2019

Background: Proximal femoral fractures should be treated in a timely manner. Affected patients often require antiplatelet therapy (APT) due to cardiovascular diseases. Guidelines recommend 5-7 days APT interruption for elective surgery. Early osteosynthetic surgery of proximal femoral fractures despite of APT should be considered. Aim of the study: To evaluate whether early osteosynthetic surgery despite of APT is associated with increased blood loss, complications and mortality. Methods: Data of patients with proximal femoral fractures, who were treated by osteosynthesis at the Department of Trauma Surgery at the Medical University of Vienna were collected retrospectively. Study groups were formed by time to surgery and APT interruption. The primary endpoint of the study was the perioperative blood loss. Secondary endpoints were complications, 30-day and 1-year mortality, time to surgery, and the total length of hospital stay. Results: The osteosynthetic treatment of proximal femoral fractures despite of APT resulted in a shorter time to surgery (13.8 vs. 66.0 h; p < 0.01). In patients on APT, the TBL (total perioperative blood loss) was higher without need for revision or an increase in the need for packed red blood cells if surgery was performed within 24 h after admission. APT had no significant influence on mortality. Patients who underwent surgery within 24 h after admission had a lower mortality. The complication rate was higher in patients who underwent surgery later than 24 h after admission. Conclusions: Surgery within 24 h after admission, regardless of APT, resulted in a shorter hospitalization length and was associated with less common complications and a lower mortality.
Machine Vision Systems in Precision Agriculture for Crop Farming
Authors: Mavridou Efthimia , Vrochidou Eleni , Papakostas George A. , Pachidis Theodore , Kaburlasos Vassilis G.
Published: December 2019

Machine vision for precision agriculture has attracted considerable research interest in recent years. The aim of this paper is to review the most recent work in the application of machine vision to agriculture, mainly for crop farming. This study can serve as a research guide for the researcher and practitioner alike in applying cognitive technology to agriculture. Studies of different agricultural activities that support crop harvesting are reviewed, such as fruit grading, fruit counting, and yield estimation. Moreover, plant health monitoring approaches are addressed, including weed, insect, and disease detection. Finally, recent research efforts considering vehicle guidance systems and agricultural harvesting robots are also reviewed.
Dynamic Bankruptcy Prediction Models for European Enterprises
Authors: Korol Tomasz
Published: December 2019

This manuscript is devoted to the issue of forecasting corporate bankruptcy. Determining a firm’s bankruptcy risk is one of the most interesting topics for investors and decision-makers. The aim of the paper is to develop and to evaluate dynamic bankruptcy prediction models for European enterprises. To conduct this objective, four forecasting models are developed with the use of four different methods—fuzzy sets, recurrent and multilayer artificial neural network, and decision trees. Such a research approach will answer the question of whether changes in indicators are relevant predictors of a company’s coming financial crisis because declines or increases in values do not immediately indicate that the company’s economic situation is deteriorating. The research relies on two samples of firms—the learning sample of 50 bankrupt and 50 non-bankrupt enterprises and the testing sample of 250 bankrupt and 250 non-bankrupt firms.
A Displaced Community’s Perspective on Land-Grabbing in Africa: The Case of the Kalimkhola Community in Dwangwa, Malawi
Authors: Bae Yuh Jin
Published: December 2019

In recent years, the sugar industry in Malawi has been criticized for its connections to land-grabbing. The general trend in the current literature has been the attempt to identify the main actors and factors that were instrumental in the displacement of local communities. These studies often neglect the importance of each community’s in-depth perspectives on land-grabbing, which is essential in obtaining a comprehensive understanding of land-grabbing. By conducting field research based on in-depth interviews with the Kalimkhola community, this study had two main objectives: (1) to analyze the wider implications and effects of land-grabbing and displacement, other than its often-cited economic aspects; and (2) to analyze more specific reasons behind the community’s complaints and strong resistance to land-grabbing. The main findings of this research are that (1) land-grabbing leads to a loss of traditional cultural practices, and (2) the main reason for discontentment amongst community members is not the process of displacement, per se, but the worsening of their living and working environments. For those who were forcibly moved twice, their environmental change for the worse contributed to community resistance. These findings, along with the others in this paper, show that land-grabbing studies have the potential to broaden the research area. This can only be achieved by engaging in close interactions and in-depth interviews with specific local communities, which will lead to a more comprehensive understanding of land-grabbing in Dwangwa.
Innovating Along the Continuum of Land Rights Recognition: Meridia’s “Documentation Packages” for Ghana
Authors: Salifu Fuseini , Abubakari Zaid , Richter Christine
Published: December 2019

Documentation of land rights can ensure tenure security and facilitate smooth land transactions, but in most countries of the global south this has been difficult to achieve. These difficulties are related to the high transaction cost, long transaction times, and procedural rigidity of land registration processes. In response to these problems, innovative approaches of tenure documentation have been conceived at a global level and are being promoted in many countries of the global south. Little is known yet about how such innovative land tenure documentation approaches unfold in various contexts and to what effect. The implementation of innovative approaches is challenging, due to the legal pluralistic nature of land governance and administrative hybridity in many countries of the global south, including the West African region. This qualitative study explores how Meridia, a small for-profit company, develops innovative approaches to register land rights in the form of “documentation packages” within the existing institutional setting of Ghana. In the paper, we describe both the processes of preparing the documentation packages and respective actors involved, as well as the nature of encounters between innovative interventions and existing institutions. Meridia develops specific products in response to both the regional diversity of land tenure, uses, and market demands, as well as in response to the challenges that the institutional context poses to the process of land tenure registration. As such, the case illustrates how innovation evolves in step-by-step fashion through negotiations with existing land institutions. The various documentation packages developed in this manner differ in terms of cost and complexity of preparation, in terms of recognition by customary and statutory institutions, as well as in the usability of the issued certificates and the extent of exchangeability of associated land parcels. Therefore, Meridia’s product innovation reflects the continuum of land rights, but it also poses questions for future research regarding the political economy of land tenure certification and regarding the actual uses and benefits of issued certificates.
Synthesis and Characterization of Novel Ti3SiC2 Reinforced Ni-Matrix Multilayered Composite-Based Solid Lubricants
Authors: Tran Quan , Fuka Matt , Dey Maharshi , Gupta Surojit
Published: December 2019

We report the synthesis and characterization of two different types of Ni-based laminated composites (Types I and II). In Type-I composites, layers of Ni and Ti3SiC2 (Ni–Ti3SiC2) were interleaved with Ni, whereas in Type-II composites, Ni–Ti3SiC2 layers were interleaved with Al and Ni. The laminate thickness and Ti3SiC2 content in the individual Ni–Ti3SiC2 layers were systematically varied in both the composites. Detailed SEM studies showed that Ti3SiC2 particulates are well distributed in the Ni-matrix with little or no interfacial reactions with interparticle porosity. However, there were interfacial reactions between Ni and Al in Type II composites. In general, Type I multilayered composites had higher ultimate compressive strength (UCS) in parallel orientation as compared to perpendicular orientation (layers are aligned parallel or perpendicular to the wear surface then it will be referred to as parallel or perpendicular orientation). Comparatively, in Type II composites, the UCS was greater in perpendicular orientation as compared to parallel due to the presence of Al layers as bonding layers. Both the composite designs showed triboactive behavior against alumina disks and sensitivity to laminate thickness and orientation. In Type-I composites, the decrease in µ and wear rate (WR) with laminate thickness was more pronounced in the perpendicular orientation as compared to the parallel orientation. Comparatively, Ni–Ti3SiC2/Al/Ni composites showed that the parallel orientation was more effective in enhancing the triboactive performance. SEM analysis of tribosurfaces showed signs of triboxidation and abrasion, which led to the formation of O-rich tribofilms.
Novel Therapeutic Strategies Applied to Pseudomonas aeruginosa Infections in Cystic Fibrosis
Authors: Chirgwin Michael E. , Dedloff Margaret R. , Holban Alina Maria , Gestal Monica C.
Published: December 2019

Cystic fibrosis (CF) is one of the most prevalent genetic diseases and a total of 1700 different genetic mutations can cause this condition. Patients that suffer this disease have a thickening of the mucus, creating an environment that promotes bacterial infections. Pseudomonas aeruginosa is a ubiquitous bacterium, which is frequently found in the lungs of CF patients. P. aeruginosa is known for its high level of antibiotic resistance as well as its high rate of mutation that allows it to rapidly evolve and adapt to a multitude of conditions. When a CF lung is infected with P. aeruginosa, the decay of the patient is accelerated, but there is little that can be done apart from controlling the infection with antibiotics. Novel strategies to control P. aeruginosa infection are imperative, and nanotechnology provides novel approaches to drug delivery that are more efficient than classic antibiotic treatments. These drug delivery systems are offering new prospects, especially for these patients with special mucus conditions and bacterial characteristics that limit antibiotic use.
PffBT4T-2OD Based Solar Cells with Aryl-Substituted N-Methyl-Fulleropyrrolidine Acceptors
Authors: Gaspar Hugo , Figueira Flávio , Strutyński Karol , Melle-Franco Manuel , Ivanou Dzmitry , Tomé João P. C. , Pereira Carlos M. , Pereira Luiz , Mendes Adélio , Viana Júlio C. , Bernardo Gabriel
Published: December 2019

Novel C60 and C70 N-methyl-fulleropyrrolidine derivatives, containing both electron withdrawing and electron donating substituent groups, were synthesized by the well-known Prato reaction. The corresponding highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) energy levels were determined by cyclic voltammetry, from the onset oxidation and reduction potentials, respectively. Some of the novel fullerenes have higher LUMO levels than the standards PC61BM and PC71BM. When tested in PffBT4T-2OD based polymer solar cells, with the standard architecture ITO/PEDOT:PSS/Active-Layer/Ca/Al, these fullerenes do not bring about any efficiency improvements compared to the standard PC71BM system, however they show how the electronic nature of the different substituents strongly affects the efficiency of the corresponding organic photovoltaic (OPV) devices. The functionalization of C70 yields a mixture of regioisomers and density functional theory (DFT) calculations show that these have systematically different electronic properties. This electronic inhomogeneity is likely responsible for the lower performance observed in devices containing C70 derivatives. These results help to understand how new fullerene acceptors can affect the performance of OPV devices.
Statistical Features and Expert Knowledge for Monitoring Operating Efficiency and Conditions of Wastewater Treatment Pumps
Authors: Lin Chang-Ming , Lin Sheng-Fuu
Published: December 2019

Wastewater treatment requires energy-intensive technology. The demand for industrial and residential wastewater treatment is increasing, and it has been widely accepted that low energy consumption and high operating efficiencies are essential to achieve high operating benefits in wastewater treatment plants (WWTPs). In this study, characteristic parameters of equipment operation were collected and subject to statistical analysis for trend observations in combination with expert knowledge to monitor equipment operating conditions. A methodology was developed to monitor and assess operating efficiencies of industrial equipment while not interfering with the existing operation. The proposed methodology was applied to monitor the pump efficiency in a WWTP. The results showed that the new methodology resulted in real-time acquisition of statistical operating data and enabled online detection of abnormal pump operation. The energy loss to low operating efficiencies of a malfunctioning pump was prevented, thereby allowing the pump to operate at high efficiency with an extended equipment life.
Numerical and Experimental Investigation of Morphological Modification on Fused Silica Using CO2 Laser Ablation
Authors: Zhou Li , Jiang Youen , Zhang Peng , Wei Hui , Fan Wei , Li Xuechun , Zhu Jianqiang
Published: December 2019

In this paper, a numerical model based on the finite-element method for predicting the morphological evolution during CO2 laser ablation on fused silica is developed and examined experimentally. Adopting the optimized parameters that were obtained from the model, a typical cone-shaped multi-stage structure with a diameter of 2 mm and a slope angle of 10.4° was sufficiently polished. Both the roughness and the transparency of the surface structure were significantly improved. The characterized slope angle of the continuous surface is exactly consistent with the predicted value, and the ablation depth is 32 ± 1.247 µm with a deviation of 1.7% (RMS, root mean square). The deviation is principally caused by the neglect of melting displacement in simulation and the irregularity in actual stepping structures. These results indicate that the numerical model can simulate morphological modification of CO2 laser ablation with a high degree of reliability. It could further be used to optimize processing parameters for customizing continuous fused silica surfaces, which could facilitate industrial manufacturing of freeform optics.
Temperature Effects on the Dielectric Properties and Breakdown Performance of h-BN/Epoxy Composites
Authors: Tang Yongzhe , Zhang Peng , Zhu Mingxiao , Li Jiacai , Li Yuxia , Wang Ziguo , Huang Liangsong
Published: December 2019

Epoxy–boron nitride composites are promising insulating materials, and it is highly important to understand their insulating performances at different temperatures with different nano-doping amounts. In this study, we investigated the effects of different mass fractions of epoxy–micron hexagonal boron nitride composites on their thermal conductivity, as well as the effects of temperature and mass fraction on their insulating performances. The results demonstrated that the thermal conductivity of epoxy–micron hexagonal boron nitride composites was superior to that of neat epoxy. The thermal conductivity of epoxy–micron hexagonal boron nitride composites increased with the mass fraction of hexagonal boron nitride, and their dielectric constant and dielectric loss increased with temperature. The dielectric constant of epoxy–micron hexagonal boron nitride composites decreased as the mass fraction of hexagonal boron nitride increased, while their dielectric losses decreased and then increased as the mass fraction of hexagonal boron nitride increased. Due to internal heat accumulation, the alternating current breakdown strength of epoxy–micron hexagonal boron nitride composites increased and then decreased as the mass fraction of hexagonal boron nitride increased. Additionally, as the temperature increased, the composites transitioned from the glassy state to the rubbery or viscous state, and the breakdown strength significantly degraded.
Effect of Thermal Conductive Fillers on the Flame Retardancy, Thermal Conductivity, and Thermal Behavior of Flame-Retardant and Thermal Conductive Polyamide 6
Authors: Wang Fang , Shi Wenbo , Mai Yuliang , Liao Bing
Published: December 2019

In this work, polyamide 6 (PA6) composites with improved flame retardancy and thermal conductivity were prepared with different thermal conductive fillers (TC fillers) such as aluminum nitride (AlN) and boron nitride (BN) in a PA6 matrix with aluminum diethylphosphinate (AlPi) as a fire retardant. The resultant halogen-free flame retardant (HFFR) and thermal conductive (TC) PA6 (HFFR-TC-PA6) were investigated in detail with a mechanical property test, a limiting oxygen index (LOI), the vertical burning test (UL-94), a cone calorimeter, a thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of the impact fracture surface and char residue of the composites were analyzed by scanning electron microscopy (SEM). It was found that the thermal conductivity of the HFFR-TC-PA6 composite increased with the amount of TC fillers. The TC fillers exerted a positive effect for flame retardant PA6. For example, the HFFR-TC-PA6 composites with the thickness of 1.6 mm successfully passed the UL-94 V-0 rating with an LOI of more than 29% when the loading amount of AlN-550RFS, BN-SW08 and BN-NW04 was 30 wt%. The morphological structures of the char residues revealed that TC fillers formed a highly integrated char layer surface (without holes) during the combustion process, as compared to that of flame retardant PA6/AlPi composites. In addition, the thermal stability and crystallization behavior of the composites were studied.
Piezoelectric Characteristics of 0.55Pb(Ni1/3Nb2/3)O3-0.45Pb(Zr,Ti)O3 Ceramics with Different MnO2 Concentrations for Ultrasound Transducer Applications
Authors: Kang Myeongcheol , Kang Lae-Hyong
Published: December 2019

In this study, we investigate the piezoelectric characteristics of 0.55Pb(Ni1/3Nb2/3)O3-0.45Pb(Zr,Ti)O3 (PNN-PZT) with MnO2 additive (0, 0.25, 0.5, 1, 2, and 3 mol%). We focus on the fabrication of a piezoelectric ceramic for use as both actuator and sensor for ultrasound transducers. The actuator and sensor properties of a piezoelectric ceramic depend on the piezoelectric strain coefficient d and piezoelectric voltage coefficient g, related as g = d/εT. To increase g, the dielectric constant εT must be decreased. PNN-PZT with MnO2 doping is synthesized using the conventional solid-state reaction method. The electrical properties are determined based on the resonant frequencies and vibration modes measured by using an impedance analyzer. The MnO2 addition initially improves the tetragonality of the PNN-PZT ceramic, which then saturates at a MnO2 content of 1 mol%. Therefore, the dielectric constant and piezoelectric coefficient d33 steadily decrease, while the mechanical properties (Qm, Young’s modulus), tanδ, electromechanical coupling coefficient k, and piezoelectric voltage coefficient g were improved at 0.5–1 mol% MnO2 content.
Non-Destructive Testing of Steel Corrosion Fluctuation Parameters Based on Spontaneous Magnetic Flux Leakage and Its Relationship with Steel Bar Diameter
Authors: Zhao Qingyuan , Zhou Jianting , Xia Qianwen , Zhang Senhua , Zhang Hong
Published: December 2019

In an actual structure, the arrangement of steel bars is complicated, there are many factors affecting the corrosion of steel bars, and these factors affect each other. However, accurately reflecting the corrosion of steel bars in actual engineering through theoretical calculations is difficult. Besides, it is impossible to detect and evaluate steel bars rust completely and accurately. This article is based on spontaneous magnetic leakage detection technology and adopts the method of stage corrosion and scanning along the reinforcing bar. Based on spontaneous magnetic flux leakage detection technology, the linear change rate of the tangential component curve of the magnetic flux leakage signal generated after the corrosion of a steel bar is studied, and a comparison is made between the steel bar coated concrete samples with different steel bar diameters. In this paper, the “origin of magnetic flux leakage signal” is defined as a reference point, which is convenient for effectively comparing the magnetic signal curves under all operating conditions. Besides, the “rust-magnetic fluctuation parameter” is proposed to accurately reflect the sudden change of leakage magnetic field caused by disconnection due to the corrosion of a steel bar. A new data processing method is provided for the non-destructive testing of steel corrosion using the spontaneous magnetic flux leakage effect, which can effectively reduce the influence of steel bar diameter on magnetic flux leakage signal and improve the precision of non-destructive testing technology of steel bar corrosion using the metal magnetic memory effect.
The Effect of Selected Parameters of Vibro-Abrasive Processing on the Surface Quality of Products Made of 6082 Aluminium Alloy
Authors: Stańczyk Marcin , Figlus Tomasz
Published: December 2019

Vibro-abrasive processing is the basic method for the mass finishing of parts and components in various industries. Continuous progress in the development of processing media and machine design solutions means that every research effort into vibro-abrasive processing broadens the scope of knowledge in the selection of media, parameters, and applications in various industry fields. In this paper, an attempt is made to parametrize the vibratory grinding process, which is one of the three stages of high gloss finishing. Samples of the 6082 aluminium alloy intended for use in loaded machine parts and forged car wheel rims were subject to a research analysis. The samples were processed in a rotary vibrator equipped with a sample fixing system, using resin media and auxiliary com-pounds. On the basis of the analysis, the processing capacities were determined for the selected conditions and abrasive media. The influence of time and applied processing media on the change in samples’ roughness was determined. The effects of processing were examined with the use of laser devices measuring surface roughness in the areas of 3D and 2D analysis. The analysis of the test results showed that the use of S12TZ type resin media in a 12-hour finishing process of the 6082 aluminium alloy allowed for a 75.5% reduction in surface roughness, which corresponds to approximately 6.3% per hour of processing.