bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of 3D Printing Parameters on Adhesion between Polylactic Acid (PLA) and Thermoplastic Polyurethane (TPU)
Authors: Brancewicz-Steinmetz Emila , Sawicki Jacek , Byczkowska Paulina
Published: October 2021

A 3D printer in FDM technology allows printing with two nozzles, which creates an opportunity to produce multi-material elements. Printing from two materials requires special consideration of the interface zone generated between their geometrical boundaries. This article aims to present the possibility of printing with PLA and TPU using commercially available filaments and software to obtain the best possible bond strength between two different polymers with respect to printing parameters, surface pattern (due to the material contact surface’s roughness), and the order of layer application. The interaction at the interface of two surfaces of two different filaments (PLA-TPU and TPU-PLA) and six combinations of patterns were tested by printing seven replicas for each. A total of 12 combinations were obtained. By analyzing pairs of samples (the same patterns, different order of materials), the results for the TPU/PLA samples were better or very close to the results for PLA/TPU. The best variants of pattern combinations were distinguished. Well-chosen printing parameters can prevent a drop in parts efficiency compared to component materials (depending on the materials combination).
Reaction Mechanism of ZrB2-ZrC Formation in Ni-Zr-B4C System Analyzed by Differential Scanning Calorimetry
Authors: Xu Jiaying , Ma Pengfei , Zou Binglin
Published: October 2021

The reaction mechanism of ZrB2-ZrC formation in a 30% Ni-Zr-B4C system under argon was revealed by using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the reaction mechanism in the Ni-Zr-B4C system was complex. Initially, NixZry and NixBy intermetallics were formed via solid-state diffusion reactions between Ni, B4C and Zr. Then, the eutectic reaction between Ni2B and Ni4B3 lead to the formation of Ni-B liquid. The free C atoms dissolved into the Ni-B liquid to form a Ni-B-C ternary liquid, and then part of the Zr powder dissolved into the surrounding Ni-B-C ternary liquid to form Ni-Zr-B-C quaternary liquid. Finally, ZrB2 and ZrC formed and precipitated out of the saturated liquid. The eutectic liquid plays an important role during the formation of ZrB2-ZrC.
Reactivity of Binary Construction and Demolition Waste Mix as Supplementary Cementitious Materials
Authors: Mencía Raquel Vigil de la Villa , Rojas Moisés Frías , Martínez-Ramírez Sagrario , Fernández-Carrasco Lucía , Cociña Ernesto Villar , García-Giménez Rosario
Published: October 2021

Calcareous and siliceous CDW wastes from concrete and glass wastes when mixed in binary mixtures has been analyzed in this study. Fine CDW fractions (<5 mm) of different sorts are selected: siliceous waste (HsT), calcareous waste (HcG) and laminated glass waste. The binary mixtures HsT/glass and HcG/glass at mix-proportions of 1:1, 2:1 and 1:2, respectively, are analyzed with a range of characterization techniques (XRD, TG/DTA, SEM-EDX, NMR, FT-IR) in the pure pozzolan/lime system over a reaction time of 90 days. The results showed that the incorporation of highly reactive recycled glass modified the pozzolanic reaction of the binary mixtures with respect to each particular concrete waste (of low activity). The principal mineralogical phases of the reaction were calcite and C–S–H gel, the latter modifying the C/S and A/S ratios as a function of either the silica or the lime-based concrete waste and the glass content of the mixtures. A higher degree of polymerization, morphology, and sodium content of C-H-S gel formed when glass was added.
Elastoplastic Model Framework for Saturated Soils Subjected to a Freeze–Thaw Cycle Based on Generalized Plasticity Theory
Authors: Cong Shengyi , Ling Xianzhang , Li Xinyu , Geng Lin , Xing Wenqiang , Li Guoyu
Published: October 2021

The failures of soil slopes during the construction of high-speed railway caused by the soil after the freeze–thaw (F–T) cycle and the subsequent threat to construction safety are critical issues. An appropriate constitutive model for soils accurately describing the deformation characteristics of soil slopes after the F–T cycle is very important. Few constitutive models of soils incorporate the F–T cycle, and the associated flow rule has always been employed in previous models, which results in an overestimation of the deformation of soil exposed to the F–T cycle. Generalized plasticity theory is widely used to predict the performance of geotechnical materials and is especially well adapted to deal with this type of generalized cyclic loading (such as a freeze–thaw cycle), and it overcomes the shortcomings of the associated flow rule that causes larger shear deformation. To this end, an elastoplastic model framework based on generalized plasticity theory with double yield surfaces for saturated soils subjected to F–T cycles was developed. Two types of plastic deformation mechanisms, i.e., plastic volumetric compression and plastic shear, were considered in this elastoplastic model. It was found that this model can accurately predict the mechanical behavior and deformation characteristics of saturated soils after F–T cycles.
Recent Advances in Deep Reinforcement Learning Applications for Solving Partially Observable Markov Decision Processes (POMDP) Problems Part 2—Applications in Transportation, Industries, Communications and Networking and More Topics
Authors: Xiang Xuanchen , Foo Simon , Zang Huanyu
Published: October 2021

The two-part series of papers provides a survey on recent advances in Deep Reinforcement Learning (DRL) for solving partially observable Markov decision processes (POMDP) problems. Reinforcement Learning (RL) is an approach to simulate the human’s natural learning process, whose key is to let the agent learn by interacting with the stochastic environment. The fact that the agent has limited access to the information of the environment enables AI to be applied efficiently in most fields that require self-learning. It’s essential to have an organized investigation—we can make good comparisons and choose the best structures or algorithms when applying DRL in various applications. The first part of the overview introduces Markov Decision Processes (MDP) problems and Reinforcement Learning and applications of DRL for solving POMDP problems in games, robotics, and natural language processing. In part two, we continue to introduce applications in transportation, industries, communications and networking, etc. and discuss the limitations of DRL.
Analytical Investigation of the Existence of Solutions for a System of Nonlinear Hadamard-Type Integro-Differential Equations Based upon the Multivariate Mittag-Leffler Function
Authors: Li Chenkuan , Srivastava Rekha , Gardiner Kyle
Published: October 2021

In this paper, the authors propose an investigation of the existence of solutions for a system of nonlinear Hadamard-type integro-differential equations in a Banach space. The result derived is new and based upon Babenko’s approach, Leray-Schauder’s nonlinear alternative, and the multivariate Mittag-Leffler function. Using an illustrative example, a demonstration of the application of the main theorem is also considered.
Dynamic Characteristics Analysis of Gear-Bearing System Considering Dynamic Wear with Flash Temperature
Authors: Xu Jinchi , Li Xiaopeng , Chen Renzhen , Wang Linlin , Yang Zemin , Yang Hexu
Published: October 2021

The influence of the dynamic wear model considering the tooth contact flash temperature on the dynamic characteristics of a gear-bearing system is studied. Firstly, the meshing stiffness model, based on flash temperature theory, is established. Then, the changing of tooth surface temperature and meshing stiffness in the process of gear meshing is analyzed. Next, the initial tooth surface wear is calculated based on the Archard theory, and the dynamic wear model of the system is established. Finally, the effects of initial wear, friction factors, and damping ratio on the system response are studied. The results show that with the increase of fractal dimension D, the uncertainty and the fluctuation amplitude of backlash decrease, and the meshing force decreases. Therefore, the initial tooth surface wear is reduced, and the stability of the system response with a dynamic wear model is improved; with the increase of the friction coefficient, the tooth surface flash temperature rises, and the root mean square value of the vibration displacement of the system amplifies, which indicates that the system tends to be unstable; with the increase of damping ratio, the system changes from unstable quasi-periodic and chaotic motion to the stable periodic motion. The increase of damping accelerates the energy loss of the system and makes the system prone to be stable.
Stability of Interval Type-3 Fuzzy Controllers for Autonomous Vehicles
Authors: Tian Man-Wen , Yan Shu-Rong , Mohammadzadeh Ardashir , Tavoosi Jafar , Mobayen Saleh , Safdar Rabia , Assawinchaichote Wudhichai , Vu Mai The , Zhilenkov Anton
Published: October 2021

Economic efficient Autonomous Road Vehicles (ARVs) are invariably subjected to uncertainties and perturbations. Therefore, control of vehicle systems requires stability to withstand the effect of variations in the nominal performance. Lateral path-tracking is a substantial task of ARVs, especially in critical maneuvering and cornering with variable speed. In this study, a new controller on the basis of interval type-3 (T3) fuzzy logic system (FLSs) is designed. The main novelties and advantages are as follows. (1) The uncertainty is a main challenge in the path-following problem of ARVs. However, in the fuzzy-based approaches, the bounds of uncertainty are assumed to be known. However, in the our suggested approach, the bounds of uncertainties are also fuzzy sets and type-3 FLSs with online adaptation rules are suggested to handle the uncertainties. (2) The approximation errors (AEs) and perturbations are investigated and tackled by the compensators. (3) The bounds of estimation errors are also uncertain and are estimated by the suggested adaptation laws. (4) The stability is ensured under unknown dynamics, perturbations and critical maneuvers. (5) Comparison with the benchmarking techniques and conventional fuzzy approaches verifies that the suggested path-following scheme results in better maneuver performance.
Pseudoalteromone A, a Ubiquinone Derivative from Marine Pseudoalteromonas spp., Suppresses Melanogenesis
Authors: Lim Su-Jin , Min Dae-jin , Kim Sohee , Lee Jihye , Lee Eun-Soo , Kim Hyuk , Cho Sung-Yoen , Beak Heung-Soo , Lee Chang-Seok , Nam Sang-Jip , Ko Jaeyoung
Published: October 2021

An ubiquinone derivative, pseudoalteromone A (1), has been isolated from two marine-derived Pseudoalteromonas spp., APmarine002 and ROA-050, and its anti-melanogenesis activity was investigated. The anti-melanogenic capacity of pseudoalteromone A was demonstrated by assessing the intracellular and extracellular melanin content and cellular tyrosinase activity in the B16 cell line, Melan-a mouse melanocyte cell line, and MNT-1 human malignant melanoma cell line. Treatment with pseudoalteromone A (40 μg/mL) for 72 h reduced α-melanocyte-stimulating hormone (α-MSH)-induced intracellular melanin production by up to 44.68% in B16 cells and 38.24% in MNT-1 cells. Notably, pseudoalteromone A induced a concentration-dependent reduction in cellular tyrosinase activity in B16 cell, and Western blot analyses showed that this inhibitory activity was associated with a significant decrease in protein levels of tyrosinase and tyrosinase-related protein 1 (Tyrp-1), suggesting that pseudoalteromone A exerts its anti-melanogenesis activity through effects on melanogenic genes. We further evaluated the skin-whitening effect of pseudoalteromone A in the three-dimensional (3D) pigmented-epidermis model, MelanoDerm, and visualized the 3D distribution of melanin by two-photon excited fluorescence imaging in this human skin equivalent. Collectively, our findings suggest that pseudoalteromone A inhibits tyrosinase activity and expression and that this accounts for its anti-melanogenic effects in melanocytes.
Extraction, Isolation and Characterization of Mycosporine-like Amino Acids from Four Species of Red Macroalgae
Authors: Sun Yingying , Han Xiu , Hu Zhijuan , Cheng Tongjie , Tang Qian , Wang Hui , Deng Xiaoqun , Han Xu
Published: October 2021

Marine macroalgae is known to be a good source of mycosporine-like amino acids (MAAs), especially red macroalgae. As a new type of active substance with commercial development prospects, the current progress in the extraction, isolation and characterization of MAAs is far from sufficient in terms of effectiveness in application. To determine the extraction processes of MAAs from four species of red macroalgae (Bangia fusco-purpurea, Gelidium amansii, Gracilaria confervoides, and Gracilaria sp.), a series of single-factor and orthogonal experiments were carried out in which the effects of solvents, the solid–liquid ratio, the time of extraction, the extraction degree and the temperature, on the yields of MAA extracts, were analyzed. Further, the isolation and identification of MAAs from Bangia fusco-purpurea and Gracilaria sp. were investigated. The results showed that the solid–liquid ratio, the time of extraction, the extraction degree and the temperature were 1:20 g/mL, 2 h, three times and 40 °C, respectively, when 25% methanol or 25% ethanol were used as the extraction solvent; these values were found to be suitable for the extraction of MAAs from four species of red macroalgae. Silica gel thin-layer chromatography was successfully used, for the first time, for the detection MAAs in this work, and it could be clearly seen that Bangia fusco-purpurea had the highest contents of MAAs among the four species of red macroalgae. MAA extracts from Bangia fusco-purpurea (or Gracilaria sp.) were isolated by silica gel column chromatography to obtain one fraction (or two fractions). The compositions and proportions of the MAAs in these fractions were determined via HPLC-ESI-MS spectra and by comparison with existing studies. Shinorine, palythine and porphyra-334 were found in 95.4% of the T1 fraction, and palythenic acid was found in 4.6% of this fraction, while shinorine, palythine and porphyra-334 were found in 96.3% of the J1 fraction, palythenic acid was found in 3.7% of the J2 fraction, and palythine was found in 100% of the J2 fraction, taken from the MAA extracts found in Bangia fusco-purpurea and Gracilaria sp., respectively. In addition, the relevant compositions and proportions of the MAA extracts taken from Gelidium amansii and Gracilaria confervoides were identified. This was the first study to report on the extraction process, isolation and identification of MAAs from Bangia fusco-purpurea, Gelidium amansii, Gracilaria confervoides, and Gracilaria sp.
Group-Based Lifestyle Intervention Strategies for Metabolic Syndrome: A Scoping Review and Strategic Framework for Future Research
Authors: Mahadzir Muhammad Daniel Azlan , Quek Kia Fatt , Ramadas Amutha
Published: October 2021

Background and Objectives: Group-based lifestyle interventions reap social support benefits and have been implemented among individuals with various chronic diseases. However, there is a lack of consolidated evidence on its approaches to prevent or manage metabolic syndrome (MetS). This scoping review aims to assess the group-based lifestyle interventional strategies for MetS and provide a strategic framework for future research in this area. Materials and Methods: Scholarly databases (OVID Medline, SCOPUS, PUBMED, PsycINFO, EMBASE, and Cochrane Central Register of Controlled Trials) and reference lists of included publications were systematically searched using appropriate keywords and MeSH terms. Peer-reviewed articles published from the start of indexing to 31 December 2020 focused on individuals with or at risk for MetS were included. Results: Thirteen interventions were identified, with seven conducted among adults with MetS and six in the population at risk for MetS. Three study designs were reported—randomised controlled trials (RCTs), pre–post interventions, and quasi-experiments. Most of the interventions were based in the community or community organisations, multifaceted, led by a multidisciplinary healthcare team, and assisted by peer educators. Waist circumference showed the most promising MetS-related improvement, followed by blood pressure. Conclusions: There is growing evidence supporting group-based lifestyle interventions to improve MetS-related risk factors. In summary, four strategies are recommended for future research to facilitate group-based interventions in preventing and managing MetS.
Analysis of Maternal and Neonatal Complications in a Group of Patients with Gestational Diabetes Mellitus
Authors: Preda Agnesa , Pădureanu Vlad , Moța Maria , Ștefan Adela-Gabriela , Comănescu Alexandru Cristian , Radu Lucrețiu , Mazilu Emilia Roxana , Vladu Ionela Mihaela
Published: October 2021

Background and Objectives: Gestational diabetes mellitus (GDM) represents one of the most common complications during pregnancy, being associated with numerous maternal and neonatal complications. The study aimed to analyze maternal and neonatal complications associated with GDM. The risk factors of GDM and of the maternal and neonatal complications were studied in order to prevent their occurrence. Materials and Methods: The study included 97 women in the study, who underwent an oral glucose tolerance test (OGTT) between weeks 24–28 of pregnancy, consequently being divided into two groups: pregnant women with and without GDM. Statistical analysis was performed using the SPSS 26.0 software and MATLAB fitglm, the results being considered statistically significant if p < 0.05. Results: We observed statistically significant differences between the group of women with and without GDM, regarding gestational hypertension (17.6% vs. 0%), preeclampsia (13.72% vs. 0%), and cesarean delivery (96.1% vs. 78,3%). Data on the newborn and neonatal complications: statistically significant differences were recorded between the two groups (GDM vs. no GDM) regarding the average weight at birth (3339.41 ± 658.12 g vs. 3122.83 ± 173.67 g), presence of large for gestational age (21.6% vs. 0%), macrosomia (13.7% vs. 0%), excessive fetal growth (35.3% vs. 0%), respiratory distress (31.4% vs. 0%), hospitalization for at least 24 h in the Neonatal Intensive Care Unit (9.80% vs. 0%), and APGAR score <7 both 1 and 5 min following birth (7.8% vs. 0%). Additionally, the frequency of neonatal hypoglycemia and hyperbilirubinemia was higher among newborns from mothers with GDM. Conclusions: The screening and diagnosis of GDM is vital, and appropriate management is required for the prevention of maternal and neonatal complications associated with GDM. It is also important to know the risk factors for GDM and attempt to prevent their appearance.
The Free Association Task: Proposal of a Clinical Tool for Detecting Differential Profiles of Semantic Impairment in Semantic Dementia and Alzheimer’s Disease
Authors: Zannino Gian Daniele , Perri Roberta , Marra Camillo , Caruso Gulia , Baroncini Matteo , Caltagirone Carlo , Carlesimo Giovanni Augusto
Published: October 2021

Backround and Objectives: It is widely agreed that patients suffering from Alzheimer’s disease (AD) and patients suffering from semantic dementia (SD) might fail clinically administered semantic tasks due to a different combination of underlying cognitive deficits: namely, degraded semantic representations in SD and degraded representations plus executive control deficit in AD. However, no easy administrable test or test battery for differentiating the semantic impairment profile in these populations has been devised yet. Materials and Methods: In this study, we propose a new easy administrable task based on a free association procedure (F-Assoc) to be used in conjunction with category fluency (Cat-Fl) and letter fluency (Lett-Fl) for quantifying pure representational and pure control deficits, thus teasing apart the semantic profile of SD and AD patients. Results: In a sample of 10 AD and 10 SD subjects, matched for disease severity, we show that indices of asymmetric performance contrasting F-Assoc and each of the two verbal fluency tasks yield a clearly distinguishable discrepancy pattern across SD and AD. We also provide empirical support for the validity of an asymmetry measure contrasting F-Assoc and Cat-FL as an index of control impairment. Conclusions: The present study suggests that the free association procedure provides a pure measure of degradation of semantic representations avoiding the confound of possible concomitant executive deficits.
Review of the Management of Obstructive Sleep Apnea and Pharmacological Symptom Management
Authors: Panahi Ladan , Udeani George , Ho Steven , Knox Brett , Maille Jason
Published: October 2021

Nearly a billion adults around the world are affected by a disease that is characterized by upper airway collapse while sleeping called obstructive sleep apnea or OSA. The progression and lasting effects of untreated OSA include an increased risk of diabetes mellitus, hypertension, stroke, and heart failure. There is often a decrease in quality-of-life scores and an increased rate of mortality in these patients. The most common and effective treatments for OSA include continuous positive airway pressure (CPAP), surgical treatment, behavior modification, changes in lifestyle, and mandibular advancement devices. There are currently no pharmacological options approved for the standard treatment of OSA. There are, however, some pharmacological treatments for daytime sleepiness caused by OSA. Identifying and treating obstructive sleep apnea early is important to reduce the risks of future complications.
Microstructure Characterization and Thermal Stability of TNM Alloy Fabricated by Powder Hot Isostatic Pressing
Authors: Wang Yichao , Xue Xiangyi , Kou Hongchao , Qiang Fengming , Yu Yonghao , Yin Zhongwei , Li Jinshan
Published: October 2021

A TNM alloy ingot was fabricated with powder hot isostatic pressing (P-HIP) and short-time exposure treatment conducted at 750–1050 °C for 2–5 h. The tensile mechanical properties were investigated at room temperature and 800 °C. The results revealed that a fully lamellar microstructure of P-HIPed TNM alloy with only 0.3 vol.% β0 phase could be obtained by hot isostatic pressing at 1260 °C, under the pressure of 170 MPa, held for 4 h. When the exposure temperature was below 850 °C, the α2 lamellae were transformed into nano-scaled (α2 + γ) lamellae (i.e., the α2→α2 + γ transformation). With increases in the exposure temperature, the β0 phase began to precipitate within the α2 lamellae (α2→β0 transformation) at 950 °C. The α2→γ and the α2→β0 transformation both happened at 950–1050 °C, and the higher exposure temperature accelerated the diffusion of Mo and facilitated the α2→β0 transformation. The yield strength and elongation at RT and 800 °C were both improved after short-time high-temperature exposure treatment. The uniform distribution and nano-scaled interfacial β0 phase provided precipitation strengthening and were not harmful to the elongation.
Influence of Nb on the Structure and High Temperature Performance of Billet for High-Rise Structural Steel
Authors: Zhou Jingyi , Zhu Liguang , Sun Ligen , Wang Bo , Xiao Pengcheng
Published: October 2021

Reasonable control of the niobium (Nb) content in steel slabs is of great significance for improving the surface quality of the slabs. In this study, a Gleeble-3500 thermal simulation testing machine was used to test the high-temperature mechanical properties of steel slabs with four different Nb contents (A: 0.006%, B: 0.031%, C: 0.050%, D: 0.065%) and to analyze the effect of Nb on the high-temperature performance of the steel slabs. Optical microscopy and transmission electron microscopy (TEM) were used to study the microstructure of the casting slabs with different Nb contents and the precipitation in the samples after heat treatment at different temperatures. The results of the study show that the microstructure of the cast slab is mainly composed of ferrite and pearlite. The distribution of each of the two structures was found to become more uniform and a significant improvement in yield strength was observed with increasing Nb content. After heat treatment, the precipitates in the high-rise structural steel were mainly square and star shaped Nb(C,N) precipitates. Increasing the Nb content was found to increase the amount of precipitates in steel. Beyond a threshold, increasing the Nb content did not increase the amount of precipitates. However, the size of the precipitates increased.
A Novel Mg–CaMgSn Master Alloy for Grain Refinement in Mg–Al-Based Alloys
Authors: Zhang Jianyue , Zhou Guanyu , Jiang Bin , Luo Alan , Zhao Xuzhe , Tang Aitao , Pan Fusheng
Published: October 2021

A novel grain refinement method using a CaMgSn intermetallic phase was investigated via adding a Mg–CaMgSn master alloy to an AZ31 magnesium alloy. The results showed a remarkable grain refinement effect in as-cast AZ31, with the average grain size reduced from approximately 260–93 μm after adding 0.45 wt.% CaMgSn particles. The added CaMgSn phase was found in grain interiors and acted as heterogeneous nucleation sites during solidification. The edge-to-edge matching model confirmed a low mismatch value of 2.3% for the {0002}Mg/{211}CaMgSn close-packed plane, suggesting that {211}CaMgSn was the possible matching plane for Mg nucleation. The microhardness and compressive yield strength were also improved by adding CaMgSn particles, confirming that adding Mg–CaMgSn master alloy was an effective method for refining the microstructure and improving the mechanical properties of Mg–Al-based alloys.
Ultra Low-Cycle Fatigue Behavior Comparison between Additively Manufactured and Rolled 17-4 PH (AISI 630) Stainless Steels
Authors: Gonzalez-Nino David , Strasser Timothy , Prinz Gary S.
Published: October 2021

This study investigates the mechanical behavior of additively manufactured (AM) 17-4 PH (AISI 630) stainless steels and compares their behavior to traditionally produced wrought counterparts. The goal of this study is to understand the key parameters influencing AM 17-4 PH steel fatigue life under ULCF conditions and to develop simple predictive models for fatigue-life estimation in AM 17-4 steel components. In this study, both AM and traditionally produced (wrought) material samples are fatigue tested under fully reversed (R = −1) strain controlled (2–4% strain) loading and characterized using micro-hardness, x-ray diffraction, and fractography methods. Results indicate decreased fatigue life for AM specimens as compared to wrought 17-4 PH specimens due to fabrication porosity and un-melted particle defect regions which provide a mechanism for internal fracture initiation. Heat treatment processes performed in this work, to both the AM and wrought specimens, had no observable effect on ULCF behavior. Result comparisons with an existing fatigue prediction model (the Coffin–Manson universal slopes equation) demonstrated consistent over-prediction of fatigue life at applied strain amplitudes greater than 3%, likely due to inherent AM fabrication defects. An alternative empirical ULCF capacity equation is proposed herein to aid future fatigue estimations in AM 17-4 PH stainless steel components.
Cord Blood Metabolome and BMI Trajectory from Birth to Adolescence: A Prospective Birth Cohort Study on Early Life Biomarkers of Persistent Obesity
Authors: Cao Tingyi , Zhao Jiaxuan , Hong Xiumei , Wang Guoying , Hu Frank B. , Wang Xiaobin , Liang Liming
Published: October 2021

There is increasing recognition on the role of early life metabolic programming in childhood obesity. This study sought to investigate whether newborn cord blood metabolome can predict future BMI. It included 946 children in the Boston Birth Cohort, a sample of high-risk yet understudied US urban, low-income, predominantly Black and Hispanic children, who were enrolled at birth and followed prospectively up to age 18 years. A total of 376 metabolites were measured in cord blood plasma. Longitudinal BMI trajectories were defined and categorized into three distinct patterns: early onset overweight and obesity (early-OWO), late onset OWO (late-OWO), and normal weight trajectory (NW). Multinomial logistic regression models were used to identify metabolites individually or as network modules associated with BMI trajectories. Of the 946 children, 388, 254, and 304 were classified as early-OWO, late-OWO, and NW, respectively. Of the seven co-metabolomic network modules defined, two were inversely correlated with early-OWO. Among the 68 metabolites within the two modules, 22 triacylglycerols and diacylglycerols were negatively associated with early-OWO; 5 cholesterol esters were positively associated with early-OWO. In this prospective birth cohort, we demonstrated distinctive longitudinal BMI trajectories and identified multiple cord plasma metabolites in relevant biological pathways that were associated with early-OWO.
Characterization of Flavonoids and Transcripts Involved in Their Biosynthesis in Different Organs of Cissus rotundifolia Lam
Authors: Gichuki Duncan Kiragu , Li Qingyun , Hou Yujun , Liu Yuanshuang , Ma Mengxue , Zhou Huimin , Xu Chen , Zhu Zhenfei , Wang Lina , Musila Fredrick Mutie , Wang Qingfeng , Xin Haiping
Published: October 2021

Cissus rotundifolia Lam. is used as a medicinal herb and vegetable. Flavonoids are the major components for the therapeutic effects. However, flavonoids constituents and expression profiles of related genes in C. rotundifolia organs are unknown. Colorimetric assay showed the highest flavonoid concentration in roots compared to the stem and leaf. Widely target-based metabolome analysis allowed tentative identification of 199 compounds in three organs. Flavonols and flavones were the dominant flavonoids subclasses. Among the metabolites, 171 were common in the three organs. Unique accumulation profile was observed in the root while the stem and leaf exhibited relatively similar patterns. In the root, six unique compounds (jaceosidin, licoagrochalcone D, 8-prenylkaempferol, hesperetin 7-O-(6″malonyl) glucoside, aureusidin, apigenin-4′-O-rhamnoside) that are used for medicinal purposes were detected. In total, 18,427 expressed genes were identified from transcriptome of the three organs covering about 60% of annotated genes in C. rotundifolia genome. Fourteen gene families, including 52 members involved in the main pathway of flavonoids biosynthesis, were identified. Their expression could be found in at least one organ. Most of the genes were highly expressed in roots compared to other organs, coinciding with the metabolites profile. The findings provide fundamental data for exploration of metabolites biosynthesis in C. rotundifolia and diversification of parts used for medicinal purposes.
Microneedles in Drug Delivery: Progress and Challenges
Authors: Avcil Muhammet , Çelik Ayhan
Published: October 2021

In recent years, an innovative transdermal delivery technology has attracted great interest for its ability to distribute therapeutics and cosmeceuticals for several applications, including vaccines, drugs, and biomolecules for skin-related problems. The advantages of microneedle patch technology have been extensively evaluated in the latest literature; hence, the academic publications in this area are rising exponentially. Like all new technologies, the microneedle patch application has great potential but is not without limitations. In this review, we will discuss the possible limitations by highlighting the areas where a great deal of improvements are required. Emphasising these concerns early on should help scientists and technologists to address the matters in a timely fashion and to use their resources wisely.
Probiotic Properties of Lactic Acid Bacteria with High Conjugated Linoleic Acid Converting Activity Isolated from Jeot-Gal, High-Salt Fermented Seafood
Authors: Song Nho-Eul , Kim Na-Jeong , Kim Young-Hun , Baik Sang-Ho
Published: October 2021

Conjugated linoleic acid (CLA) isomers are potent health-promoting fatty acids. This study evaluated the probiotic properties of 10 strains of high CLA-producing lactic acid bacteria (LAB) isolated from Jeot-gal, a high-salt, fermented seafood. Two isolates, Lactiplantibacillus plantarum JBCC105683 and Lactiplantibacillus pentosus JBCC105676, produced the largest amounts of CLA (748.8 and 726.9 μg/mL, respectively). Five isolates, L. plantarum JBCC105675, L. pentosus JBCC105676, L. pentosus JBCC105674, L. plantarum JBCC105683, and Lactiplantibacillus paraplantarum JBCC105655 synthesized more cis-9, trans-11-CLA than trans-10, cis-12-CLA (approximately 80:20 ratio). All the strains survived severe artificial acidic environments and showed antimicrobial activity and strong adhesion capability to Caco-2 cells as compared to the commercial strain Lactocaseibacillus rhamnosus GG. Among them, Pediococcus acidilactici JBCC105117, L. paraplantarum JBCC105655, and L. plantarum JBCC105683 strongly stimulated the immunological regulatory gene PMK-1 and the host defense antimicrobial peptide gene clec-60 in Caenorhabditis elegans. Moreover, three strains showed a significant induction of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-12, and IL-10 production in RAW 264.7 macrophages, indicating that they were promising candidates for probiotics with high CLA-converting activity. Our results indicate that the newly isolated CLA-producing LAB might be useful as a functional probiotic with beneficial health effects that modulate the immune system.
Complete Genome Analysis of Undecylprodigiosin Pigment Biosynthesizing Marine Streptomyces Species Displaying Potential Bioactive Applications
Authors: Ramesh Chatragadda , Anwesh Maile , Vinithkumar Nambali Valsalan , Kirubagaran Ramalingam , Dufossé Laurent
Published: October 2021

Marine Streptomyces species are underexplored for their pigment molecules and genes. In this study, we report the genome of the undecylprodigiosin biosynthesizing gene cluster carrying Streptomyces sp. strain BSE6.1, displaying antioxidant, antimicrobial, and staining properties. This Gram-positive obligate aerobic bacterium was isolated from the coastal sediment of the Andaman and Nicobar Islands, India. Pink to reddish pigmented colonies with whitish powdery spores on both agar and broth media are the important morphological characteristics of this bacterium. Growth tolerance to NaCl concentrations was 2 to 7%. The assembled genome of Streptomyces sp. BSE6.1 contains one linear chromosome 8.02 Mb in length with 7157 protein-coding genes, 82 tRNAs, 3 rRNAs and at least 11 gene clusters related to the synthesis of various secondary metabolites, including undecylprodigiosin. This strain carries type I, type II, and type III polyketide synthases (PKS) genes. Type I PKS gene cluster is involved in the biosynthesis of red pigment undecylprodigiosin of BSE6.1, similar to the one found in the S. coelicolor A3(2). This red pigment was reported to have various applications in the food and pharmaceutical industries. The genome of Streptomyces sp. BSE6.1 was submitted to NCBI with a BioProject ID of PRJNA514840 (Sequence Read Archive ID: SRR10849367 and Genome accession ID: CP085300).
The Role of Surfactin Production by Bacillus velezensis on Colonization, Biofilm Formation on Tomato Root and Leaf Surfaces and Subsequent Protection (ISR) against Botrytis cinerea
Authors: Stoll Alexandra , Salvatierra-Martínez Ricardo , González Máximo , Araya Michael
Published: October 2021

Many aspects regarding the role of lipopeptides (LPs) in bacterial interaction with plants are not clear yet. Of particular interest is the LP family of surfactin, immunogenic molecules involved in induced systemic resistance (ISR) and the bacterial colonization of plant surfaces. We hypothesize that the concentration of surfactin produced by a strain correlates directly with its ability to colonize and persist on different plant surfaces, which conditions its capacity to trigger ISR. We used two Bacillus velezensis strains (BBC023 and BBC047), whose antagonistic potential in vitro is practically identical, but not on plant surfaces. The surfactin production of BBC047 is 1/3 higher than that of BBC023. Population density and SEM images revealed stable biofilms of BBC047 on leaves and roots, activating ISR on both plant surfaces. Despite its lower surfactin production, strain BBC023 assembled stable biofilms on roots and activated ISR. However, on leaves only isolated, unstructured populations were observed, which could not activate ISR. Thus, the ability of a strain to effectively colonize a plant surface is not only determined through its production of surfactin. Multiple aspects, such as environmental stressors or compensation mechanisms may influence the process. Finally, the importance of surfactin lies in its impacts on biofilm formation and stable colonization, which finally enables its activity as an elicitor of ISR.
Cyanobacterial Communities of Carbonate Sediments and Biomineralization in Peterhof Fountains’ Water Supply System, Russia
Authors: Rodina Oksana A. , Vereshchagin Oleg S. , Vlasov Dmitry Yu. , Zelenskaya Marina S. , Pankin Dmitrii V. , Mitrofanov Nikita V. , Nikitin Michael Yu. , Vasileva Kseniia Yu. , Frank-Kamenetskaya Olga V.
Published: October 2021

The role of cyanobacterial communities in the formation of carbonate sediments (ancient and modern) is not completely clear. We studied the cyanobacterial communities connected with carbonate sediments of the freshwater bodies feeding the historical Peterhof fountains (Saint-Petersburg, Russia). Cyanobacterial communities were studied by metagenome analysis and optical microscopy. Carbonates associated with cyanobacterial communities (both in situ and in vitro) were studied by powder X-ray diffraction analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Raman spectroscopy. The interconnection between the mineral composition of carbonate sediments and inhabiting microorganism species was established. The leading role of cyanobacteria in carbonate biomineralization in fresh water of Peterhof fountains water supply system was shown. Cyanobacteria of 24 genera were revealed in sediments composed of calcite and aragonite. The crystallization of carbonates on the surface of 13 species of cyanobacteria was found. Using model experiments, a significant contribution of cyanobacterial species of the Oscillatoriaceae family (Phormidium spp., Lyngbya sp., Oscillatoria formosa) to carbonate biomineralization is demonstrated.
Effect of the Intake of Brown Rice for Six Months on the Cognitive Function in Healthy Elderly Persons: A Study Protocol for a Pilot, Non-Randomized Controlled Trial
Authors: Takano Yuji , Kokubun Keisuke , Saika Keiji , Nishiyama Naoki , Taki Yasuyuki
Published: October 2021

The nutritional components of brown rice have been reported to be effective against diabetes mellitus. Recent animal studies have suggested that it is also effective in maintaining cognitive function. Therefore, in this study, we examined the effect of a brown rice diet on cognitive function in individuals aged over 60 years. The study participants were recruited from a pool of individuals aged ≥60 years who were using elderly care facilities. The participants were provided with four servings of brown or white rice per week for 6 months, and their cognitive function was measured before and after the intervention period. Prior to the intervention, participants tasted the white and brown rice to determine which type they would like to be offered over the 6-month period. Since rice is the staple food of the participants in this study, they were allowed to decide whether they wanted to eat white or brown rice.
Fabrication and Characterization of a Thermophone Based on Laser-Scribed Graphene Intercalated with Multiwalled Carbon Nanotubes
Authors: Rabbani Moin , Syed Aashir Waheed , Khalid Syed , Mohammad Mohammad Ali
Published: October 2021

The low sound pressure level and high operating voltages of thermophones have limited their applications in the past. However, in recent years, utilizing nanomaterials in thermophones has improved their efficiency and applicability. Nanomaterials, especially carbon nanotubes and graphene, have the advantage of low heat capacity per unit area (HCPUA) and high electrical and thermal conductivity. Therefore, they require a low electrical input power and generate a high sound pressure level (SPL) by efficiently transferring heat to the surrounding fluid. Laser-scribed graphene (LSG) can generate smooth spectra acoustic emissions over a wide range of frequencies by means of thermoacoustic (TA) emission. In this work, a thermophone based on LSG intercalated with multiwalled carbon nanotubes (MWCNTs) is proposed. The effects of varying input power, duty cycle percentage and measuring distance on the sound pressure level (SPL) of thermophones are studied to extract maximum efficiency. The achieved SPL of LSG, normalized to the input power, has increased by approximately 11 dB by intercalating it with MWCNTs, which shows that our proposed material can be a potential candidate for an efficient thermophone.
Nutrition, Obesity and Asthma Inception in Children. The Role of Lung Function
Authors: Manuel Sanchez-Solís , Luis García-Marcos
Published: October 2021

Obesity is an important public health problem. WHO estimates that about 39 million children younger than 5 years of age are overweighted or obese. On the other hand, asthma is the most prevalent chronic disease in childhood, and thus, many children share those two conditions. In the present paper we review the epidemiology of children with asthma and obesity, as well as the consequences of being obese on the respiratory system. On the one hand obesity produces an underlying T-helper 2 (TH2) low inflammation state in which numerous cytokines, which could have an impact in the respiratory system play, a role. On the other hand, some respiratory changes have been described in obese children and, specially, the development of the so called “dysanapsis” (the disproportionate scaling of airway dimensions to lung volume) which seems to be common during the first stages of life, probably related to the early development of this condition. Finally, this review deals with the role of adipokines and insulin resistance in the inception and worsening of asthma in the obese child.
Intestinal Microbiota as a Contributor to Chronic Inflammation and Its Potential Modifications
Authors: Potrykus Marta , Czaja-Stolc Sylwia , Stankiewicz Marta , Kaska Łukasz , Małgorzewicz Sylwia
Published: October 2021

The gut microbiota is a crucial factor in maintaining homeostasis. The presence of commensal microorganisms leads to the stimulation of the immune system and its maturation. In turn, dysbiosis with an impaired intestinal barrier leads to accelerated contact of microbiota with the host’s immune cells. Microbial structural parts, i.e., pathogen-associated molecular patterns (PAMPs), such as flagellin (FLG), peptidoglycan (PGN), lipoteichoic acid (LTA), and lipopolysaccharide (LPS), induce inflammation via activation of pattern recognition receptors. Microbial metabolites can also develop chronic low-grade inflammation, which is the cause of many metabolic diseases. This article aims to systematize information on the influence of microbiota on chronic inflammation and the benefits of microbiota modification through dietary changes, prebiotics, and probiotic intake. Scientific research indicates that the modification of the microbiota in various disease states can reduce inflammation and improve the metabolic profile. However, since there is no pattern for a healthy microbiota, there is no optimal way to modify it. The methods of influencing microbiota should be adapted to the type of dysbiosis. Although there are studies on the microbiota and its effects on inflammation, this subject is still relatively unknown, and more research is needed in this area.
Does FGF21 Mediate the Potential Decrease in Sweet Food Intake and Preference Following Bariatric Surgery?
Authors: Nielsen Mette S. , Ritz Christian , Chenchar Anne , Bredie Wender L. P. , Gillum Matthew P. , Sjödin Anders
Published: October 2021

The liver-derived hormone fibroblast growth factor 21 (FGF21) has recently been linked to preference for sweet-tasting food. We hypothesized, that surgery-induced changes in FGF21 could mediate the reduction in sweet food intake and preference following bariatric surgery. Forty participants (35 females) with severe obesity (BMI ≥ 35 kg/m2) scheduled for roux-en-y gastric bypass (n = 30) or sleeve gastrectomy (n = 10) were included. Pre- and postprandial responses of intact plasma FGF21 as well as intake of sweet-tasting food assessed at a buffet meal test, the hedonic evaluation of sweet taste assessed using an apple juice with added sucrose and visual analog scales, and sweet taste sensitivity were assessed before and 6 months after bariatric surgery. In a cross-sectional analysis pre-surgery, pre- and postprandial intact FGF21 levels were negatively associated with the hedonic evaluation of a high-sucrose juice sample (p = 0.03 and p = 0.02). However, no changes in pre- (p = 0.24) or postprandial intact FGF21 levels were found 6 months after surgery (p = 0.11), and individual pre- to postoperative changes in pre- and postprandial intact FGF21 levels were not found to be associated with changes in intake of sweet foods, the hedonic evaluation of sweet taste or sweet taste sensitivity (all p ≥ 0.10). In conclusion, we were not able to show an effect of bariatric surgery on circulating FGF21, and individual postoperative changes in FGF21 were not found to mediate an effect of surgery on sweet food intake and preference.
A Single-Carbon Stable Isotope Ratio Model Prediction Equation Can Estimate Self-Reported Added Sugars Intake in an Adult Population Living in Southwest Virginia
Authors: Hedrick Valisa E. , Halliday Tanya M. , Davy Brenda M. , Zoellner Jamie M. , Jahren A. Hope
Published: October 2021

The δ13C value of blood is a novel proposed biomarker of added sugars (AS) intake. AS prediction equations using either a single- (δ13C) or dual-isotope model (δ13C and δ15N) were previously developed in an adult population with high AS intake living in southwest Virginia (reference group). The purpose of this investigation was to test the δ13C single- and δ13C and δ15N dual-isotope prediction equations for AS intake in adults with a lower mean AS intake and different demographic characteristics (test group). The blood samples for the reference (n = 257 for single-isotope, n = 115 for dual-isotope) and test groups (n = 56) were analyzed for δ13C and δ15N values using natural abundance stable isotope mass spectrometry and were compared to reported dietary AS intake. When the δ13C single-isotope equation was applied to the test group, predicted AS intake was not significantly different from reported AS intake (mean difference ± standard error = −3.6 ± 5.5 g, Z = −0.55, p = 0.51). When testing the dual-isotope equation, predicted AS was different from reported AS intake (mean difference ± SEM = 13.0 ± 5.4 g, Z = −2.95, p = 0.003). δ13C value was able to predict AS intake using a blood sample within this population subset. The single-isotope prediction equation may be an alternative method to assess AS intake and is more objective, cost-feasible, and efficient than traditional dietary assessment methods. However, more research is needed to assess this biomarker with rigorous study designs such as controlled feeding.