bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Numerical Simulation and Experiment Validation of Dynamic Damage Characteristics of Anisotropic Shale for Percussive-Rotary Drilling with a Full-Scale PDC Bit
Authors: Dong Guangjian , Chen Ping
Published: May 2018

The lower rate of penetration (ROP) is one of the key technical difficulties during drilling of shale reservoirs. Percussive-rotary drilling (PRD) is crucial for increasing ROP. One of the core problems of ROP optimization for PRD are the dynamic damage characteristics of rock fragmentation. By considering the dynamic drilling parameters, a new model for estimating the PRD with a full-scale polycrystalline diamond compact (PDC) bit is established. The mechanical parameters of shale are measured by a wave velocity method. Rock damage characteristics are simulated by using the finite element method. The numerical simulation model is verified by the actual drilling case in LMX shale reservoir in Sichuan (China). The results indicate that rock element damage occurs along the direction of maximum principal stress. The order of decreasing rock damage rate is impact-static load, static load and impact load. When the impact load has the same peak value, and the rock elements in contact with the cutters obtain more energy with load frequency increasing. The rock fragmentation efficiency under a sine wave is higher than rectangular and pulse waves. The rock can obtain more energy to be broken with the increasing impact load duration and peak values. When the impact-static load goes over the rock damage threshold value, the higher the peak value of the impact load is, the more energy the rock will obtain. The higher the lateral vibration amplitude of the drill bit, the lower the efficiency of rock fragmentation. Repetitions of drill bit axial vibration at one indentation point will reduce the ROP, and the axial vibration energy of the drill bit is consumed. Therefore, a small lateral movement and reasonable axial vibration frequency increase the rock breaking efficiency. The ROP was increased through the suppression of drill string and the application of vibration. The study results can be used in the optimization designs of bit trajectory and ROP for PRD tools.
ICT Based Performance Evaluation of Primary Frequency Control Support from Renewable Power Plants in Smart Grids
Authors: Shahid Kamal , Altin Müfit , Mikkelsen Lars Møller , Løvenstein Olsen Rasmus , Iov Florin
Published: May 2018

The increased penetration of Renewable Energy Generation (ReGen) plants in future power systems poses several challenges to the stability of the entire system. In future green energy rich power systems, the responsibility for providing ancillary services will be shifted from conventional power plants towards ReGen plants, such as wind and photovoltaic power plants. Frequency control support from the Wind Power Plants (WPPs) is one of the crucial ancillary services in order to preserve operational stability in case of grid disturbances. Among other requirements, the ability to provide fast frequency control support from ReGen plants will highly depend on the underlying communication infrastructure that allows an exchange of information between different ReGen plants and the control centers. This paper, therefore, focuses on the evaluation of the impact of communication and the related aspects to provide online frequency control support from ReGen (with special focus on WPP). The performance evaluation is based on an aggregated WPP model that is integrated into a generic power system model. This generic power system model is specifically designed to assess the ancillary services in a relatively simple yet relevant environment. Several case studies with different wind speeds at a particular wind-power penetration level and communication scenarios are considered to evaluate the performance of power system frequency response. The article provides the Transmission System Operator (TSO) and other communication engineers insights into the importance and various aspects of communication infrastructure for general service coordination between WPPs and specifically primary frequency control coordination from WPPs in future power systems.
Research on the Neutral-Point Voltage Balance for NPC Three-Level Inverters under Non-Ideal Grid Conditions
Authors: Lyu Jian Guo , Wang Ji Dong , Hu Wen Bin , Wu Zhao Feng
Published: May 2018

In order to solve the neutral-point voltage unbalancing problem for neutral-point clamped (NPC) three-level inverters under non-ideal grid conditions, a novel zero-sequence component injection method for modulation signals was proposed in this paper. Based on the mathematical expressions of neutral-point voltage unbalancing, the fluctuation of the neutral-point voltage under different grid conditions was studied. The proposed method dynamically calculates the zero-sequence component for modulation signals by region selections based on sinusoidal pulse width modulation (DCR-SPWM). Under non-ideal grid conditions, this DCR-SPWM method can control the neutral-point voltage balance for NPC three-level inverters with different grid and output power conditions, and improves the grid current quality. The simulation results verified the correctness of the theoretical analysis in this paper, and the feasibility and effectiveness of this method were verified by the experiments in the experimental platform of the NPC three-level grid-connected inverter based on DSP-CPLD controllers.
Automatic Detection of Single Trees in Airborne Laser Scanning Data through Gradient Orientation Clustering
Authors: Dong Tianyang , Zhou Qizheng , Gao Sibin , Shen Ying
Published: May 2018

Currently, existing methods for single-tree detection based on airborne laser scanning (ALS) data usually require some thresholds and parameters to be set manually. Manually setting threshold or parameters is laborious and time-consuming, and for dense forests, the high commission and omission rate make most existing single-tree detection techniques inefficient. As a solution to these problems, this paper proposed an automatic single-tree detection method in ALS data through gradient orientation clustering (GOC). In this method, the rasterized Canopy Height Model (CHM) was derived from ALS data using surface interpolation. Then, potential trees were assumed as approximate conical shapes and extracted based on the GOC. Finally, trees were identified from the potential trees based on the compactness of the crown shape. This method used the gradient orientation information of rasterized CHM, thus increasing the generalization of single-tree detection method. In order to verify the validity and practicability of the proposed method, twelve 1256 m2 circular study plots of different forest types were selected from the benchmark dataset (NEWFOR), and the results from nine different methods were presented and compared for these study plots. Among nine methods, the proposed method had the highest root mean square matching score (RMS_M = 43). Moreover, the proposed method had excellent detection (M > 47) in both single-layer coniferous and single-layered mixed stands.
Models for Predicting Specific Gravity and Ring Width for Loblolly Pine from Intensively Managed Plantations, and Implications for Wood Utilization
Authors: Dahlen Joseph , Auty David , Eberhardt Thomas L.
Published: May 2018

Loblolly pine (Pinus taeda L.) is increasingly grown on intensively managed plantations that yield high growth rates. Wood properties, including specific gravity (SG), change with cambial age, and thus intensively managed trees contain a high proportion of low density corewood when harvested because of reduced rotation lengths. This study was undertaken to develop models of ring-level properties (SG and width) in intensively managed loblolly pine plantations. Ninety-three trees from five stands aged from 24 to 33 years were harvested, and 490 disks were obtained from in between the 5.2-m logs that were cut, and at the merchantable top. The disks were cut into pith-to-bark radial strips that were scanned on an X-ray densitometer, and the resultant data analyzed using non-linear mixed-effects models. The fixed effects of the models, which included cambial age and for some models disk height and ring width, were able to explain 56, 46, 54, 16, and 46 percent of the within-tree variation for ring SG, ring width, latewood SG, earlywood SG, and latewood percent, respectively. To assess implications for wood utilization, a modeled tree was built by using height, diameter, and taper equations and these models were linked with the developed ring SG model to produce a tree properties map. The linked information was also used to generate tree and log SG and proportion of corewood values for different rotation ages. The results from this study are a step towards integrating wood quality models into growth-and-yield modeling systems that are important for loblolly pine plantation management.
Legacy Lead from Past Mining Activity and Gasoline Additives: Evidence from Lead Isotopes and Trace Element Geochemical Studies in the White River Basin, Southern Ozark Region, USA
Authors: Potra Adriana , Ruhl Laura S. , Samuelsen John R.
Published: May 2018

Lead isotope compositions and Pb, Cu, Zn, and As concentrations in stream sediment leachates in the White River Basin, southern Ozark Region, have been determined to discriminate between natural and anthropogenic sources of Pb and to assess the metal loads that are transported by streams draining the Mississippi Valley-type (MVT) Zn-Pb mines in the Northern Arkansas district. The samples that were collected downstream of and closest to the mines have trace element concentrations well above those in soils from Arkansas. The trace element concentrations are lower in samples that were collected upstream of the mines. Most of the analyzed samples have trace metal concentrations above the United States Environmental Protection Agency (USEPA) Sediment Quality Guidelines Threshold Effects Level. The Pb isotope values of the downstream samples and the MVT ores are similar, suggesting a similar Pb source. The Pb isotope values of the upstream samples are similar to those that were defined by soils from the Ozark Plateau, suggesting that Pb from historic mining does not dominate upstream sediments. However, a linear regression line through the leachate data indicates that mixing between two end-members represented by leaded gasoline and ores could generate the Pb isotope ratios that were noticed in the upstream leachates.
A Cross-Sectional Examination of Physical Activity Levels and Their Socio-Demographic Determinants in Southern Tanzania
Authors: Msambichaka Beverly , Abdul Ramadhani , Abdulla Salim , Klatser Paul , Tanner Marcel , Kaushik Ramaiya , Bringolf-Isler Bettina , Geubbels Eveline , Eze Ikenna C.
Published: May 2018

Physical activity is essential for healthy aging. Evidence suggests that vigorous-intensity physical activity (VPA) may be more beneficial than moderate-intensity physical activity (MPA). We examined physical activity levels (MPA, VPA and total physical activity), and their socio-demographic determinants in 2311 participants (15–93 years; 68% women) of the MZIMA Open Community Cohort, who had complete relevant data. Physical activity levels were estimated in minutes per week across three domains—work, leisure and transport. We created three outcome variables: low MPA (<150 min per week of MPA), low VPA (<75 min per week of VPA) and insufficient physical activity (IPA: <150 min per week of total physical activity) and applied sample-weighted multivariable logistic regression to assess associations with potential socio-demographic determinants. Prevalence of IPA, low MPA and low VPA were 25%, 26% and 65% respectively. IPA and low MPA were correlated (Spearman R = 0.98; p < 0.001). Work, leisure and transport contributed 54%, 25% and 21% to total physical activity respectively. IPA and low VPA were significantly associated with female sex, lower education, non-manual occupation and frequent fruit consumption. We observed significant differences by sex (Pheterogeneity < 0.001), on the associations between education and IPA, and between age, occupation and low VPA. In conclusion, low levels of VPA, which were more pronounced in women, support the monitoring and promotion of VPA alongside overall physical activity. Leisure-related activities should also be promoted towards gains in vigorous-intensity and total physical activity in this setting.
Risk and Benefit of Different Cooking Methods on Essential Elements and Arsenic in Rice
Authors: Mwale Tasila , Rahman Mohammad Mahmudur , Mondal Debapriya
Published: May 2018

Use of excess water in cooking of rice is a well-studied short-term arsenic removal technique. However, the outcome on the nutritional content of rice is not well addressed. We determined the benefit of different cooking techniques on arsenic removal and the associated risk of losing the essential elements in rice. Overall, we found 4.5%, 30%, and 44% decrease in the arsenic content of rice when cooked with rice-to-water ratios of 1:3, 1:6 (p = 0.004), and 1:10 (parboiling; p < 0.0001), respectively. All the essential elements (except iron, selenium, and copper) incurred a significant loss when rice was cooked using the 1:6 technique: potassium (50%), nickel (44.6%), molybdenum (38.5%), magnesium (22.4%), cobalt (21.2%), manganese (16.5%), calcium (14.5%), selenium (12%), iron (8.2%), zinc (7.7%), and copper (0.2%) and further reduction was observed on parboiling, except for iron. For the same cooking method (1:6), percentage contribution to the recommended daily intake (RDI) of essential elements was highest for molybdenum (154.7%), followed by manganese (34.5%), copper (33.4%), selenium (13.1%), nickel (12.4%), zinc (10%), magnesium (8%), iron (6.3%), potassium (1.8%), and calcium (0.5%). Hence, cooked rice as a staple is a poor source for essential elements and thus micronutrients.
Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay
Authors: Huang Faming , Huang Boqiang , Huang Jinliang , Li Shenghui
Published: May 2018

Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A), while land change was fastest during the second time interval 2002–2009 in a separate terrestrial area within coastal zone (zone B). Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban sustainability in similar coastal areas.
Do Physical Activity Friendly Neighborhoods Affect Community Members Equally? A Cross-Sectional Study
Authors: Stappers Nicole E. H. , Van Kann Dave H. H. , De Vries Nanne K. , Kremers Stef P. J.
Published: May 2018

An activity-friendly environment may increase physical activity (PA) levels and decrease sedentary behavior (SB). This study investigated associations between socio-demographic characteristics, health-related quality of life (HRQoL), perceived environment and objectively measured PA outcomes. Socio-demographic characteristics were assessed using a questionnaire and HRQoL was measured using the EQ-5D. The Neighborhood Environment Walkability Scale (NEWS-A) was used to assess the perceived environment. SB, light PA (LPA) and moderate-to-vigorous PA (MVPA) were measured using the Actigraph GT3X+. Data from 622 Dutch adults were used in multivariate linear regression analyses to investigate associations between NEWS-A and PA outcomes. Analyses were controlled for socio-demographic characteristics and HRQoL. The presence of attractive buildings was associated with less SB (β = −0.086, p < 0.01) and more MVPA (β = 0.118, p < 0.01). Presence of destinations within walking distance was also positively associated with MVPA (β = 0.106, p < 0.01). Less crime was associated with less MVPA (β = 0.092, p < 0.05). Interactions between personal and environmental characteristics showed that the absence of PA-hindering characteristics (e.g., heavy traffic) was associated with less SB and more MVPA, but only for residents with problems regarding pain and usual activities. The presence of PA-facilitating characteristics (e.g., aesthetics and destinations) was associated with less SB, more LPA and more MVPA but only for the more advantaged people in society. Results suggest that to reduce health inequalities, it would be more helpful to remove barriers rather than introduce PA facilitating characteristics.
The Cold-Regulated Genes of Blueberry and Their Response to Overexpression of VcDDF1 in Several Tissues
Authors: Walworth Aaron , Song Guo-qing
Published: May 2018

Expression of blueberry cold-regulated genes (VcCORs) could play a role in the variable cold hardiness of blueberry tissues. In this study, transcriptome comparisons were conducted to reveal expression of VcCORs in non-acclimated leaves, flower buds, and flowers of both non-transgenic and transgenic blueberries containing an overexpressed blueberry DWARF AND DELAYED FLOWERING gene (VcDDF1) as well as in fully chilled flower buds of non-transgenic blueberry. In non-transgenic blueberries, 57.5% of VcCOR genes showed differential expression in at least one of the three pairwise comparisons between non-acclimated leaves, flower buds, and flowers, and six out of nine dehydration-responsive element-binding factors showed differential expression. In addition, expression of VcDDF1 was not cold-inducible in non-transgenic blueberries and had higher expression in flowers than in leaves or non-acclimated flower buds. In transgenic blueberries, overexpression of VcDDF1 resulted in higher VcDDF1 expression in leaves than in flower buds and flowers. VcDDF1 overexpression enhanced expression of blueberry CBF1 and CBF3 in leaves and repressed expression of CBF3 in both flower buds and flowers. Overall, the results revealed tissue-specific expression patterns of VcCORs. The responses of VcCORs to overexpression of VcDDF1 suggest that it is possible to increase plant cold hardiness through overexpression of a non-cold-inducible gene.
Immunological Processes Driving IgE Sensitisation and Disease Development in Males and Females
Authors: Leffler Jonatan , Stumbles Philip A. , Strickland Deborah H.
Published: May 2018

IgE sensitisation has increased significantly over the last decades and is a crucial factor in the development of allergic diseases. IgE antibodies are produced by B cells through the process of antigen presentation by dendritic cells, subsequent differentiation of CD4+ Th2 cells, and class switching in B cells. However, many of the factors regulating these processes remain unclear. These processes affect males and females differently, resulting in a significantly higher prevalence of IgE sensitisation in males compared to females from an early age. Before the onset of puberty, this increased prevalence of IgE sensitisation is also associated with a higher prevalence of clinical symptoms in males; however, after puberty, females experience a surge in the incidence of allergic symptoms. This is particularly apparent in allergic asthma, but also in other allergic diseases such as food and contact allergies. This has been partly attributed to the pro- versus anti-allergic effects of female versus male sex hormones; however, it remains unclear how the expression of sex hormones translates IgE sensitisation into clinical symptoms. In this review, we describe the recent epidemiological findings on IgE sensitisation in male and females and discuss recent mechanistic studies casting further light on how the expression of sex hormones may influence the innate and adaptive immune system at mucosal surfaces and how sex hormones may be involved in translating IgE sensitisation into clinical manifestations.
Effect of Melatonin on Rat Heart Mitochondria in Acute Heart Failure in Aged Rats
Authors: Odinokova Irina , Baburina Yulia , Kruglov Alexey , Fadeeva Irina , Zvyagina Alena , Sotnikova Linda , Akatov Vladimir , Krestinina Olga
Published: May 2018

Excessive generation of reactive oxygen species (ROS) in mitochondria and the opening of the nonselective mitochondrial permeability transition pore are important factors that promote cardiac pathologies and dysfunction. The hormone melatonin (MEL) is known to improve the functional state of mitochondria via an antioxidant effect. Here, the effect of MEL administration on heart mitochondria from aged rats with acute cardiac failure caused by isoprenaline hydrochloride (ISO) was studied. A histological analysis revealed that chronic intake of MEL diminished the age-dependent changes in the structure of muscle fibers of the left ventricle, muscle fiber swelling, and injury zones characteristic of acute cardiac failure caused by ISO. In acute heart failure, the respiratory control index (RCI) and the Ca2+ retention capacity in isolated rat heart mitochondria (RHM) were reduced by 30% and 40%, respectively, and mitochondrial swelling increased by 34%. MEL administration abolished the effect of ISO. MEL partially prevented ISO-induced changes at the subunit level of respiratory complexes III and V and drastically decreased the expression of complex I subunit NDUFB8 both in control RHM and in RHM treated with ISO, which led to the inhibition of ROS production. MEL prevents the mitochondrial dysfunction associated with heart failure caused by ISO. It was shown that the level of 2′,3′-cyclicnucleotide-3′-phosphodiasterase (CNPase), which is capable of protecting cells in aging, increased in acute heart failure. MEL also retained the CNPase content in RHM both in control experiments and after ISO-induced heart damage. We concluded that an increase in the CNPase level promotes cardioprotection.
Pannexin-1 in Human Lymphatic Endothelial Cells Regulates Lymphangiogenesis
Authors: Boucher Jonathan , Simonneau Claire , Denet Golthlay , Clarhaut Jonathan , Balandre Annie-Claire , Mesnil Marc , Cronier Laurent , Monvoisin Arnaud
Published: May 2018

The molecular mechanisms governing the formation of lymphatic vasculature are not yet well understood. Pannexins are transmembrane proteins that form channels which allow for diffusion of ions and small molecules (<1 kDa) between the extracellular space and the cytosol. The expression and function of pannexins in blood vessels have been studied in the last few decades. Meanwhile, no studies have been conducted to evaluate the role of pannexins during human lymphatic vessel formation. Here we show, using primary human dermal lymphatic endothelial cells (HDLECs), pharmacological tools (probenecid, Brilliant Blue FCF, mimetic peptides [10Panx]) and siRNA-mediated knockdown that Pannexin-1 is necessary for capillary tube formation on Matrigel and for VEGF-C-induced invasion. These results newly identify Pannexin-1 as a protein highly expressed in HDLECs and its requirement during in vitro lymphangiogenesis.
Comparison of Three Extraction Approaches for the Isolation of Neurotransmitters from Rat Brain Samples
Authors: Miękus Natalia , Olędzka Ilona , Harshkova Darya , Liakh Ivan , Plenis Alina , Kowalski Piotr , Bączek Tomasz
Published: May 2018

The determination of neurotransmitters (NTs) as relevant potential biomarkers in the study of various central nervous system (CNS) pathologies has been demonstrated. Knowing that NTs-related diseases mostly occupy individual regions of the nervous system, as observed, for instance, in neurodegenerative diseases (Alzheimer’s and Parkinson’s Diseases), the analysis of brain slices is preferred to whole-brain analysis. In this report, we present sample preparation approaches, such as solid-phase extraction, solid-phase microextraction, and dispersive liquid–liquid microextraction, and discuss the pitfalls and advantages of each extraction method. The ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate)-assisted solid-phase microextraction (IL-SPME) is found to be, in our research, the relevant step towards the simultaneous determination of six NTs, namely, dopamine (DA), adrenaline (A), noradrenaline (NA), serotonin (5-HT), l-tryptophan (l-Trp), l-tyrosine (l-Tyr) in rat brain samples. The development of a novel bioanalytical technique for the evaluation of biomarkers in the context of green chemistry might be accelerated just with the use of IL, and this approach can be considered an advantageous strategy.
Enhancement of Recombinant Protein Production in Transgenic Nicotiana benthamiana Plant Cell Suspension Cultures with Co-Cultivation of Agrobacterium Containing Silencing Suppressors
Authors: Huang Ting-Kuo , Falk Bryce W. , Dandekar Abhaya M. , McDonald Karen A.
Published: May 2018

We have previously demonstrated that the inducible plant viral vector (CMViva) in transgenic plant cell cultures can significantly improve the productivity of extracellular functional recombinant human alpha-1-antiryspin (rAAT) compared with either a common plant constitutive promoter (Cauliflower mosaic virus (CaMV) 35S) or a chemically inducible promoter (estrogen receptor-based XVE) system. For a transgenic plant host system, however, viral or transgene-induced post-transcriptional gene silencing (PTGS) has been identified as a host response mechanism that may dramatically reduce the expression of a foreign gene. Previous studies have suggested that viral gene silencing suppressors encoded by a virus can block or interfere with the pathways of transgene-induced PTGS in plant cells. In this study, the capability of nine different viral gene silencing suppressors were evaluated for improving the production of rAAT protein in transgenic plant cell cultures (CMViva, XVE or 35S system) using an Agrobacterium-mediated transient expression co-cultivation process in which transgenic plant cells and recombinant Agrobacterium carrying the viral gene silencing suppressor were grown together in suspension cultures. Through the co-cultivation process, the impacts of gene silencing suppressors on the rAAT production were elucidated, and promising gene silencing suppressors were identified. Furthermore, the combinations of gene silencing suppressors were optimized using design of experiments methodology. The results have shown that in transgenic CMViva cell cultures, the functional rAAT as a percentage of total soluble protein is increased 5.7 fold with the expression of P19, and 17.2 fold with the co-expression of CP, P19 and P24.
Connexin43 Carboxyl-Terminal Domain Directly Interacts with β-Catenin
Authors: Spagnol Gaelle , Trease Andrew J. , Zheng Li , Gutierrez Mirtha , Basu Ishika , Sarmiento Cleofes , Moore Gabriella , Cervantes Matthew , Sorgen Paul L.
Published: May 2018

Activation of Wnt signaling induces Connexin43 (Cx43) expression via the transcriptional activity of β-catenin, and results in the enhanced accumulation of the Cx43 protein and the formation of gap junction channels. In response to Wnt signaling, β-catenin co-localizes with the Cx43 protein itself as part of a complex at the gap junction plaque. Work from several labs have also shown indirect evidence of this interaction via reciprocal co-immunoprecipitation. Our goal for the current study was to identify whether β-catenin directly interacts with Cx43, and if so, the location of that direct interaction. Identifying residues involved in direct protein–protein interaction is of importance when they are correlated to the phosphorylation of Cx43, as phosphorylation can modify the binding affinities of Cx43 regulatory protein partners. Therefore, combining the location of a protein partner interaction on Cx43 along with the phosphorylation pattern under different homeostatic and pathological conditions will be crucial information for any potential therapeutic intervention. Here, we identified that β-catenin directly interacts with the Cx43 carboxyl-terminal domain, and that this interaction would be inhibited by the Src phosphorylation of Cx43CT residues Y265 and Y313.
Cutaneous Melanoma—A Long Road from Experimental Models to Clinical Outcome: A Review
Authors: Coricovac Dorina , Dehelean Cristina , Moaca Elena-Alina , Pinzaru Iulia , Bratu Tiberiu , Navolan Dan , Boruga Ovidiu
Published: May 2018

Cutaneous melanoma is a complex disorder characterized by an elevated degree of heterogeneity, features that place it among the most aggressive types of cancer. Although significant progress was recorded in both the understanding of melanoma biology and genetics, and in therapeutic approaches, this malignancy still represents a major problem worldwide due to its high incidence and the lack of a curative treatment for advanced stages. This review offers a survey of the most recent information available regarding the melanoma epidemiology, etiology, and genetic profile. Also discussed was the topic of cutaneous melanoma murine models outlining the role of these models in understanding the molecular pathways involved in melanoma initiation, progression, and metastasis.
An Interactive Multiobjective Optimization Approach to Supplier Selection and Order Allocation Problems Using the Concept of Desirability
Authors: Lee Pyoungsoo , Kang Sungmin
Published: May 2018

In supply chain management, selecting the right supplier is one of the most important decision-making processes for improving corporate competitiveness. In particular, when a buyer considers selecting multiple suppliers, one should consider the issue of order allocation with supplier selection. In this article, an interactive multiobjective optimization approach is proposed for the supplier selection and order allocation problem. Also, the concept of desirability is incorporated into the optimization model to take into account the principles of diminishing marginal utility. The results are presented by comparing them with the solutions from the weighting methods. This study shows the advantage of the proposed method in that the decision-maker directly checks the degree of desirability and learns his/her preference structure through improved solutions.
S–H Bond Activation in Hydrogen Sulfide by NHC-Stabilized Silyliumylidene Ions
Authors: Porzelt Amelie , Schweizer Julia I. , Baierl Ramona , Altmann Philipp J. , Holthausen Max C. , Inoue Shigeyoshi
Published: May 2018

Reactivity studies of silyliumylidenes remain scarce with only a handful of publications to date. Herein we report the activation of S–H bonds in hydrogen sulfide by mTer-silyliumylidene ion A (mTer = 2,6-Mes2-C6H3, Mes = 2,4,6-Me3-C6H2) to yield an NHC-stabilized thiosilaaldehyde B. The results of NBO and QTAIM analyses suggest a zwitterionic formulation of the product B as the most appropriate. Detailed mechanistic investigations are performed at the M06-L/6-311+G(d,p)(SMD: acetonitrile/benzene)//M06-L/6-311+G(d,p) level of density functional theory. Several pathways for the formation of thiosilaaldehyde B are examined. The energetically preferred route commences with a stepwise addition of H2S to the nucleophilic silicon center. Subsequent NHC dissociation and proton abstraction yields the thiosilaaldehyde in a strongly exergonic reaction. Intermediacy of a chlorosilylene or a thiosilylene is kinetically precluded. With an overall activation barrier of 15 kcal/mol, the resulting mechanistic picture is fully in line with the experimental observation of an instantaneous reaction at sub-zero temperatures.
The Emerging Role of Biomarkers in the Diagnosis of Gestational Diabetes Mellitus
Authors: Rodrigo Natassia , Glastras Sarah J.
Published: May 2018

Gestational diabetes mellitus (GDM) is a common complication of pregnancy; its rising incidence is a result of increased maternal obesity and older maternal age together with altered diagnostic criteria identifying a greater proportion of pregnant women with GDM. Its consequences are far-reaching, associated with poorer maternal and neonatal outcomes compared to non-GDM pregnancies, and GDM has implications for metabolic health in both mother and offspring. Objective markers to identify women at high risk for the development of GDM are useful to target therapy and potentially prevent its development. Established clinical risk factors for GDM include overweight/obesity, age, ethnicity, and family history of diabetes, though they lack specificity for its development. The addition of biomarkers to predictive models of GDM may improve the ability to identify women at risk of GDM prior to its development. These biomarkers reflect the pathophysiologic mechanisms of GDM involving insulin resistance, chronic inflammation, and altered placental function. In addition, the role of epigenetic changes in GDM pathogenesis highlights the complex interplay between genetic and environmental factors, potentially offering further refinement of the prediction of GDM risk. In this review, we will discuss the clinical challenges associated with the diagnosis of GDM and its current pathophysiologic basis, giving rise to potential biomarkers that may aid in its identification. While not yet validated for clinical use, we explore the possible clinical role of biomarkers in the future. We also explore novel diagnostic tools, including high throughput methodologies, that may have potential future application in the identification of women with GDM.
Special Issue: Zinc Oxide Nanostructures: Synthesis and Characterization
Authors: Baskoutas Sotirios
Published: May 2018

Zinc oxide (ZnO) is a wide band gap semiconductor with an energy gap of 3.37 eV at room temperature. It has been used considerably for its catalytic, electrical, optoelectronic, and photochemical properties. ZnO nanomaterials, such as quantum dots, nanorods, and nanowires, have been intensively investigated for their important properties. Many methods have been described in the literature for the production of ZnO nanostructures, such as laser ablation, hydrothermal methods, electrochemical deposition, sol–gel methods, Chemical Vapour Deposition, molecular beam epitaxy, the common thermal evaporation method, and the soft chemical solution method. The present Special Issue is devoted to the Synthesis and Characterization of ZnO nanostructures with novel technological applications.
Polymerizable Microsphere-Induced High Mechanical Strength of Hydrogel Composed of Acrylamide
Authors: Wang Zhiyong , Lin Meiqin , Wang Menghan , Song Xia , Zhang Chuqiao , Dong Zhaoxia , Zhang Juan , Yang Zihao
Published: May 2018

Polymerizable microspheres are introduced into acrylamide to prepare the high mechanical strength hydrogels with a novel three-dimensional pore structure. Rheological properties, compressive stress–strain, tensile property, and compression strength of three different types of hydrogels were investigated. Moreover, a scanning electron microscope (SEM) was adopted to observe the three-dimension network structure of three different types of hydrogels. The test results illustrated that viscous moduli (G″) and elastic moduli (G′) of a hydrogel containing polymerizable microspheres (P) reached maximum values, compared to the normal hydrogel (N) and the composite hydrogel containing ordinary microspheres (O). When the hydrogels were squeezed, the N was easily fractured under high strain (99%), whereas the P was not broken, and quickly recovered its initial morphology after the release of load. The P showed excellent tensile properties, with an elongation at break up to 90% and a tensile strength greater than 220 g. The compression strength of the N was 100.44 kPa·m−1, while the resulting strength of P was enhanced to be 248.00 kPa·m−1. Therefore, the various performances of N were improved by adding polymerizable microspheres. In addition, the SEM images indicated that N has a general three-dimensional network structure; the conventional network structure did not exist in the P, which has a novel three-dimensional pore structure in the spherical projection and very dense channels, which led to the compaction of the space between the three-dimensional pore network layers and reduced the flowing of free water wrapped in the network. Therefore, the mechanical strength of hydrogel was enhanced.
N-Hyper Sets
Authors: Jun Young , Song Seok-Zun , Kim Seon
Published: May 2018

To deal with the uncertainties, fuzzy set theory can be considered as one of the mathematical tools by Zadeh. As a mathematical tool to deal with negative information, Jun et al. introduced a new function, which is called a negative-valued function, and constructed N -structures in 2009. Since then, N -structures are applied to algebraic structures and soft sets, etc. Using the N -structures, the notions of (extended) N -hyper sets, N -substructures of type 1, 2, 3 and 4 are introduced, and several related properties are investigated in this research paper.
Structural Elucidation of Irish Organic Farmed Salmon (Salmo salar) Polar Lipids with Antithrombotic Activities
Authors: Tsoupras Alexandros , Lordan Ronan , Demuru Martina , Shiels Katie , Saha Sushanta , Nasopoulou Constantina , Zabetakis Ioannis
Published: May 2018

While several marine polar lipids (PL) have exhibited cardioprotective properties through their effects on the platelet-activating factor (PAF) pathways, salmon PL have not been tested so far. In this study, the antithrombotic activities of salmon PL were assessed in human platelets and the structural characterisation of bioactive salmon PL was performed by GC-MS and LC-MS analyses. PL from fillets of Irish organic farmed salmon (Salmo salar) were extracted and separated into several lipid subclasses by thin-layer chromatography (TLC), while their fatty acid profile was fully characterised by GC-MS. Salmon total lipids (TL), total neutral lipids (TNL), total polar lipids (TPL), and each PL subclass obtained by TLC were further assessed for their in vitro effects towards PAF-induced and thrombin-induced platelet aggregation in human platelets. Salmon PL exhibited antithrombotic effects on human platelet aggregation, mostly through their strong inhibitory effects against the PAF pathway with IC50 values comparable to other marine PL, but with lower effects towards the thrombin pathway. PL fractions corresponding to phosphatidylcholine and phosphatidylethanolamine derivatives exhibited the most potent anti-PAF effects, while LC-MS analysis putatively elucidated their structure/function relationship. Several diacyl-PC/PE and alkyl-acyl-PC/PE species containing mostly docosahexaenoic acid at their sn-2 glycerol-backbone may be responsible for the bioactivity. The data presented suggests that salmon contains PL with strong antithrombotic bioactivities.
Asperversins A and B, Two Novel Meroterpenoids with an Unusual 5/6/6/6 Ring from the Marine-Derived Fungus Aspergillus versicolor
Authors: Li Huaqiang , Sun Weiguang , Deng Mengyi , Qi Changxing , Chen Chunmei , Zhu Hucheng , Luo Zengwei , Wang Jianping , Xue Yongbo , Zhang Yonghui
Published: May 2018

Asperversins A (1) and B (2), two novel meroterpenoids featuring an uncommon 5/6/6/6 ring system, along with five new analogues (3–7) and a known compound asperdemin (8), were obtained from the marine-derived fungus Aspergillus versicolor. Their structures and absolute configurations were confirmed by extensive spectroscopic analyses, single-crystal X-ray diffraction studies, and electronic circular dichroism (ECD) calculation. All new compounds were tested for their acetylcholinesterase enzyme (AChE) inhibitory activities and cytotoxic activities, of which compound 7 displayed moderate inhibitory activity against the AChE with an IC50 value of 13.6 μM.
A Marine Isolate of Bacillus pumilus Secretes a Pumilacidin Active against Staphylococcus aureus
Authors: Saggese Anella , Culurciello Rosanna , Casillo Angela , Corsaro Maria Michela , Ricca Ezio , Baccigalupi Loredana
Published: May 2018

Producing antimicrobials is a common adaptive behavior shared by many microorganisms, including marine bacteria. We report that SF214, a marine-isolated strain of Bacillus pumilus, produces at least two different molecules with antibacterial activity: a molecule smaller than 3 kDa active against Staphylococcus aureus and a molecule larger than 10 kDa active against Listeria monocytogenes. We focused our attention on the anti-Staphylococcus molecule and found that it was active at a wide range of pH conditions and that its secretion was dependent on the growth phase, medium, and temperature. A mass spectrometry analysis of the size-fractionated supernatant of SF214 identified the small anti-Staphylococcus molecule as a pumilacidin, a nonribosomally synthesized biosurfactant composed of a mixture of cyclic heptapeptides linked to fatty acids of variable length. The analysis of the SF214 genome revealed the presence of a gene cluster similar to the srfA-sfp locus encoding the multimodular, nonribosomal peptide synthases found in other surfactant-producing bacilli. However, the srfA-sfp cluster of SF214 differed from that present in other surfactant-producing strains of B. pumilus by the presence of an insertion element previously found only in strains of B. safensis.
Fabrication of a Porous Metal via Selective Phase Dissolution in Al-Cu Alloys
Authors: Vargas-Martínez Juan , Estela-García John E. , Suárez Oscar Marcelo , Vega Carmen A.
Published: May 2018

Through free corrosion, a new low cost porous material was successfully fabricated by removing a single phase of a binary aluminum-copper alloy. This selective phase dissolution was carried out an Al-Al2Cu eutectic alloy of the Al-Cu binary system and additionally for two hypereutectic compositions. The porosity of the material depends on the microstructure formed upon solidification. For this reason, several solidification methods were studied to define the most convenient in terms of uniformity and refinement of the average pore and ligament sizes. The samples were corroded in a 10% v/v NaOH aqueous solution, which demonstrated to be the most convenient in terms of time involved and resulting porosity conditions after the corrosion process. The porosity was measured through analysis of secondary electron images. The effectiveness of the process was verified using X-ray diffraction, which showed that, under the proposed methodology, there was complete removal of one of the phases, namely the aluminum one.
Metal Matrix Composites
Authors: Gupta Manoj
Published: May 2018

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A Low Power Energy-Efficient Precision CMOS Temperature Sensor †
Authors: Wei Rongshan , Bao Xiaotian
Published: May 2018

This paper presents a low power, energy-efficient precision CMOS temperature sensor. The front-end circuit is based on bipolar junction transistors, and employs a pre-bias circuit and bipolar core. To reduce measurement errors arising from current ratio mismatch, a new dynamic element-matching mode is proposed, which dynamically matches all current sources in the front-end circuit. The first-order fitting and third-order fitting are used to calibrate the output results. On the basis of simulation results, the sensor achieves 3σ-inaccuracies of +0.18/−0.13 °C from −55 °C to +125 °C. Measurement results demonstrate sensor 3σ-inaccuracies of ±0.2 °C from 0 °C to +100 °C. The circuit is implemented in 0.18 μm CMOS, and consumes 6.1 μA with a 1.8 V supply voltage.
Relationship between Mineral and Organic Matter in Shales: The Case of Shahejie Formation, Dongying Sag, China
Authors: Zeng Xiang , Cai Jingong , Dong Zhe , Bian Lizeng , Li Yuanfeng
Published: May 2018

Types of organic matter and mineral associations and microstructures of shales can reflect the depositional mechanism and sedimentary environment. Therefore, analysis of organic matter and mineral associations is a prerequisite for research on fine-grained sedimentary rocks. Shales from the Eocene Shahejie Formation in the Dongying Sag of China were selected to classify their lithofacies and to investigate the characteristics of their organic matter and mineral associations. This analysis identified six lithofacies (e.g., laminated shales and massive mudstones); in all the lithofacies, clay minerals exhibit a positive correlation with detrital minerals, thus indicating that they were derived from the same source. The comprehensive analysis of mineral and organic matter associations reveals that detrital minerals were deposited with low-hydrogen index (HI) OM. The deposition of detrital minerals was mainly a physical process. Clay minerals can undergo deposition in one of two ways due to their surface charge: they can either aggregate with high-HI OM via chemical deposition, thus forming organic-rich laminae, or they can be deposited together with low-HI OM via physical deposition, thus forming clay-rich laminae or a massive matrix. Carbonate minerals, which often coexist with high-HI OM, are biological sediments. The analysis of the sedimentary characteristics of these organic matter and mineral associations indicates that the sedimentary processes differ between various lithofacies: e.g., the discontinuous laminated shale represents the product of biophysical processes. Differences in depositional mechanisms are also present in each sub-member. Therefore, it is important to analyze the properties of minerals and organic matter, as well as their associations, to more deeply understand the classification of lithofacies and the depositional processes of shales and mudstones.
Production of Minor Ginenosides from Panax notoginseng by Microwave Processing Method and Evaluation of Their Blood-Enriching and Hemostatic Activity
Authors: Liu Huiying , Pan Jun , Yang Ye , Cui Xiuming , Qu Yuan
Published: May 2018

A green solvent extraction technology involving a microwave processing method was used to increase the content of minor ginsenosides from Panax notoginseng. This article aims to investigate the optimization of preparation of the minor ginsenosides by this microwave processing method using single-factor experiments and response surface methodology (RSM), and discuss the blood-enriching activity and hemostatic activity of the extract of microwave processed P. notoginseng (EMPN) The RSM for production of the minor ginsenosides was based on a three-factor and three-level Box-Behnken design. When the optimum conditions of microwave power, temperature and time were 495.03 W, 150.68 °C and 20.32 min, respectively, results predicted that the yield of total minor ginsenosides (Y9) would be 93.13%. The actual value of Y9 was very similar to the predicted value. In addition, the pharmacological results of EMPN in vivo showed that EMPN had the effect of enriching blood in N-acetylphenylhydrazine (APH) and cyclophosphamide (CTX)-induced blood deficient mice because of the increasing content of white blood cells (WBCs) and hemoglobin (HGB) in blood. Hemostatic activity in vitro of EMPN showed that it had significantly shortened the clotting time in PT testing (p < 0.05). The hemostatic effect of EMPN was mainly caused by its components of Rh4, 20(S)-Rg3 and 20(R)-Rg3. This microwave processing method is simple and suitable to mass-produce the minor ginsenosides from P. notoginseng.