bluuebunny/crossref_metadata_2025 huggingface dataset:
Biased auditory nerve central synaptopathy is associated with age‐related hearing loss
Authors: Wang Meijian , Zhang Chuangeng , Lin Shengyin , Wang Yong , Seicol Benjamin J. , Ariss Robert W. , Xie Ruili
Published: January 2021

Key points

Sound information is transmitted by different subtypes of spiral ganglion neurons (SGN) from the ear to the brain.

Selective damage of SGN peripheral synapses (cochlear synaptopathy) is widely recognized as one of the primary mechanisms of hearing loss, whereas the mechanisms at the SGN central synapses remain unclear.

We report that different subtypes of SGN central synapses converge at different ratios onto individual target cochlear nucleus neurons with distinct physiological properties, and show biased morphological and physiological changes during age‐related hearing loss (ARHL).

The results reveal a new dimension in cochlear nucleus neural circuitry that systematically reassembles and processes auditory information from different SGN subtypes, which is altered during ageing and probably contributes to the development of ARHL.

In addition to known cochlear synaptopathy, the present study shows that SGN central synapses are also pathologically changed during ageing, which collectively helps us better understand the structure and function of SGNs during ARHL.

Sound information is transmitted from the cochlea to the brain by different subtypes of spiral ganglion neurons (SGN), which show varying degrees of vulnerability under pathological conditions. Selective cochlear synaptopathy, the preferential damage of certain subtypes of SGN peripheral synapses, has been recognized as one of the main mechanisms of hearing loss. The organization and function of the auditory nerve (AN) central synapses from different subtypes of SGNs remain unclear, including how different AN synapses reassemble onto individual neurons in the cochlear nucleus, as well as how they differentially change during hearing loss. Combining immunohistochemistry with electrophysiology, we investigated the convergence pattern and subtype‐specific synaptopathy of AN synapses at the endbulb of Held, as well as the response properties of their postsynaptic bushy neurons in CBA/CaJ mice of either sex under normal hearing and age‐related hearing loss (ARHL). We found that calretinin‐expressing (type Ia) and non‐calretinin‐expressing (type Ib/Ic) endbulbs converged along a continuum of different ratios onto individual bushy neurons with varying physiological properties. Endbulbs degenerated during ageing in parallel with ARHL. Furthermore, the degeneration was more severe in non‐calretinin‐expressing synapses, which correlated with a gradual decrease in bushy neuron subpopulation predominantly innervated by these inputs. These synaptic and cellular changes were profound in middle‐aged mice when their hearing thresholds were still relatively normal and prior to severe ARHL. Our findings suggest that biased AN central synaptopathy and the correlated shift in cochlear nucleus neuronal composition play significant roles in weakened auditory input and altered central auditory processing during ARHL.
Effect of an office-based intervention on visceral adipose tissue: the WorkACTIVE-P randomized controlled trial
Authors: Dorling James L. , Höchsmann Christoph , Tudor-Locke Catrine , Beyl Robbie , Martin Corby K.
Published: January 2021

Office-based activity reduces sedentariness, yet no randomized controlled trials (RCTs) have assessed how such activity influences visceral adipose tissue (VAT). This study examined the effect of an office-based, multicomponent activity intervention on VAT. The WorkACTIVE-P RCT enrolled sedentary office workers (body mass index: 31.4 (standard deviation (SD) 4.4) kg/m2) to an intervention (n = 20) or control (n = 20) group. For 3 months, the intervention group received an office-based pedal desk, further to an intervention promoting its use and increased walking. The control group maintained habitual activity. At baseline and follow-up, VAT, cardiometabolic disease risk markers, physical activity, and food intake were measured. Steps/day were not altered relative to control (P ≥ 0.51), but the pedal desk was utilized for 127 (SD 61) min/day. The intervention reduced VAT relative to control (−0.15 kg; 95% confidence interval (CI) = −0.29 to −0.01; P = 0.04). Moreover, the intervention decreased fasting glucose compared with control (−0.29 mmol/L; 95% CI = −0.51 to −0.06; P = 0.01), but no differences in other cardiometabolic disease markers or food intake were revealed (P ≥ 0.11). A multicomponent intervention decreased VAT in office workers who were overweight or obese. Though longer-term studies are needed, office-based, multicomponent activity regimens may lower cardiometabolic disease risk. Trial registered at ClinicalTrials.gov (NCT02561611).

Novelty: In WorkACTIVE-P, a multicomponent activity intervention decreased visceral adipose tissue relative to control in office workers. The intervention also reduced glucose compared with control, though other metabolic risk markers and food intake were not altered. Such multicomponent interventions could help reduce cardiometabolic disease risk, but longer studies are needed.
Soft Chemical Mechanical Polishing Pad for Oxide CMP Applications
Authors: Kenchappa N. B. , Popuri Ramtej , Chockkalingam Ashwin , Jawali Puneet , Jayanath Shiyan , Redfield Daniel , Bajaj Rajeev
Published: January 2021

Chemical mechanical polishing (CMP) is widely accepted as the best planarization technique for fabricating nanoscale devices. A soft CMP pad that can enable higher oxide removal rates (RRs) and good planarity has been proposed for oxide CMP applications. In this study, three pads namely, Pad-1 (hard), Pad-2 (soft), and a commercial pad (hard) were used to polish blanket oxide, and STI patterned wafers. The Pad-2 demonstrated significantly higher RRs and better planarization than the hard pads. Post-polish pad texture analysis on Pad-2 showed a uniform surface asperity distribution. This is due to the novel method of pad manufacturing, which enables precise material placement and consistent pore construction.
Superconducting Polycrystalline Silicon Layer Obtained by Boron Implantation and Nanosecond Laser Annealing
Authors: Daubriac R. , Alba P. Acosta , Marcenat C. , Lequien S. , Vethaak T. D. , Nemouchi F. , Lefloch F. , Kerdilès S.
Published: January 2021

In this work, we report on the material properties of superconducting heavily boron-doped polycrystalline Silicon-On-Insulator (SOI) thin layers fabricated by pulsed laser induced recrystallization under experimental conditions compatible with high volume CMOS integration. This approach combines boron implantation and ultra-violet nanosecond laser annealing (UV-NLA) to reach maximum dopant activation by exceeding boron solid solubility in silicon. For our process conditions, material characterizations revealed five laser annealing regimes, including the SOI full-melt, which leads to the formation of superconducting polycrystalline layers. The average critical temperature was found to be around 170 mK, neither influenced by energy density nor the number of laser pulses. In addition, thanks to low temperature measurements coupled with magnetic field variations, we highlighted a type II superconductor behavior due to strong impurity effect. The deducted average effective coherence length of hole pairs in our layers was estimated around 85 nm.
Photocatalytic Application of TiO2-Loaded Viscose-Based Activated Carbon Fibers Composite Catalyst: Degradation of Low Concentration Formaldehyde and Simultaneous Anti-Microbe
Authors: Yan Shuhan , Yu Junwei , Zhu Bo , Qiao Kun , Cai Xun , Yuan Xiaomin , Li Chen
Published: January 2021

TiO2-loaded viscose-based activated carbon fibers (VACF) composite catalysts were successfully prepared by the load of anatase TiO2 nanoparticles (particle diameter 5–12 nm) on VACFs. Furthermore, the simultaneous photocatalytic applications of low concentration formaldehyde degradation and bacteriostasis were studied for the first time. In the structure of composite catalysts, titanium atoms exist at Ti4+ ions, and the combination mode of VACF and TiO2 nanoparticles is Ti–O–C bond. The results show that photocatalytic effect of TiO2 for low concentration formaldehyde (1 mg m−3) is further improved by the binding with VACFs in the composite catalysts, the HCHO conversion reach approximately 80% under the condition of visible light. Simultaneously, the composite catalysts with the optimal load coefficient of 3.57% have a high catalytic activity for bactericidal action (bacteriostasis rate reached 96%–98%).
High-Speed Etching of Silicon Carbide Wafer Using High-Pressure SF6 Plasma
Authors: Sano Yasuhisa , Tajiri Koki , Inoue Yuki , Mukai Risa , Nakanishi Yuma , Matsuyama Satoshi , Yamauchi Kazuto
Published: January 2021

Semiconductor silicon carbide (SiC) is proposed to be a promising material for power-saving devices. However, due to its hard and brittle properties, there is a need to develop a highly efficient strain-free thinning process for the backside thinning of vertical power transistors. As a method for thinning SiC wafers without crystallographic damages, plasma etching with high-pressure SF6 plasma was proposed and the dependence of different processing parameters on the removal rate was investigated. The results revealed that the removal rate was mainly influenced by the power density and relatively insensitive to processing parameters such as processing gap and gas flow rate. It was discovered that a high-speed etching of the entire surface of a commercially available 2-inch wafer at approximately 15 μm min−1 can be achieved by increasing the radio frequency power. Additionally, it was demonstrated that the thickness of the 2-inch wafer can be thinned to approximately 100 μm by only 20 min plasma etching.
Conduction Band Discontinuity in n-type Si/TiO2 Heterojunction Interfaces
Authors: Kavaliunas Vytautas , Hatanaka Yoshinori , Neo Yoichiro , Laukaitis Giedrius , Mimura Hidenori
Published: January 2021

The conduction band discontinuity between n-type Si substrates and anatase TiO2 films has been investigated. n-type Si substrates with three different dopant concentrations were used as a substrate for TiO2 thin-films: ND = 1015–16 cm−3 (as n-Si); ND = 1017–18 cm−3 (as n+-Si); ND = 1020–21 cm−3 (as n++-Si). The translation of X-ray photoelectron spectroscopy (XPS) results to an energy band diagram through the valence band offset (VBO) enables us to evaluate the conduction band discontinuities accurately: n-Si/TiO2—−0.22 eV, n+-Si/TiO2—−0.06 eV, and n++-Si/TiO2—+0.07 eV. Temperature–dependent current–voltage (I–V) characteristics were measured to evaluate the Fermi energy level (EF) of the TiO2 thin-films. Light transmittance was measured to evaluate the energy bandgap of the TiO2 thin-films. The band diagram of the n-type Si/TiO2 heterojunction was proposed. Deep-insight analysis of n-type Si/TiO2 was carried out on the basis of measured I–V characteristics.
Development of Molecularly Imprinted Quartz Crystal Microbalance (QCM) Sensor Including Two-Dimensional Hexagonal Boron Nitride (2D-hBN) Nanosheets and its Application to Ascorbic Acid Detection
Authors: Kotan Gül
Published: January 2021

A new quartz crystal microbalance (QCM) sensor based on two-dimensional hexagonal boron nitride (2D-hBN) nanosheets including molecular imprinted polymers (MIP) was formed for ascorbic acid (AA) sensing. Some characterization methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed for characterizations of sensor structure. After formation of AA imprinted QCM chip, AA imprinted QCM sensor showed high sensing performance and linear range of 1.00 × 10−10–1.00 × 10−7 M and detection limit (LOD) of 3.0 × 10−11 M were obtained. Finally, AA imprinted sensor was applied to plasma samples for AA analysis.
Aerobic Training Modulates the Increase in Plasma Concentrations of Cytokines in response to a Session of Exercise
Authors: Fonseca Tatiana Ramos , Mendes Thiago Teixeira , Ramos Guilherme Passos , Cabido Christian Emmanuel Torres , Morandi Rodrigo Figueiredo , Ferraz Fernanda Oliveira , Miranda Aline Silva , Mendonça Vanessa Amaral , Teixeira Antônio Lúcio , Silami-Garcia Emerson , Nunes-Silva Albená , Teixeira Mauro Martins
Published: January 2021

Acute physical exercise can modulate immune function. For example, acute exercise is known to increase the circulating concentration of cytokines. Exercise is also known to modulate immune function chronically. It is not known whether exercise training can result in training of the immune system. Here, we investigated the effects of six weeks of aerobic training on cytokine responses induced by acute exercise until fatigue. Twelve healthy men performed a fatiguing exercise at the anaerobic threshold (AT) intensity. After the training period, the participants performed another bout of acute exercise at the same duration and intensity of the pretraining situation. The analysis was made at the beginning, end, and at 10, 30, and 60 minutes during the recovery period. Training at AT induced a gain of 11.2% of exercise capacity. Before training, a single bout of acute exercise induced a significant increase in plasma levels of cytokines, including IL-6, TNF-α, sTNFR1, IL-10, CXCL10, BDNF, leptin, resistin, and adiponectin. After six weeks of aerobic training, levels of IL-6, sTNFR1, BDNF, and leptin increased to a lesser extent after an acute bout exercise at the same absolute intensity as the pretraining period. Responses to the same relative exercise intensity were similar to those observed before exercise. These results show that aerobic training is associated with training of acute immune responses to acute exercise until fatigue.
Pregnancy-Associated Chest Pain: A Case of Spontaneous Coronary Artery Dissection
Authors: Yogeswaran Vidhushei , Ramakrishna Satvik , MacGregor John S. , Zier Lucas , Goldschlager Nora
Published: January 2021

Spontaneous Coronary Artery Dissection (SCAD) is an important cause of myocardial infarction that typically affects women without traditional cardiovascular risk factors. It is the most common cause of myocardial infarction in pregnant and postpartum women. SCAD is often underdiagnosed due to the lack of clinician familiarity, and patients with pregnancy-associated SCAD often have more severe clinical presentations than those without. We present a case of SCAD in a multiparous woman who presented with acute chest pain in the postpartum period.
Exploration of the Immune-Related Signatures and Immune Infiltration Analysis in Melanoma
Authors: Li Ai-lan , Zhu Yong-mei , Gao Lai-qiang , Wei Shu-yue , Wang Ming-tao , Ma Qiang , Zheng You-you , Li Jian-hua , Wang Qing-feng
Published: January 2021

In the present study, we aimed to investigate immune-related signatures and immune infiltration in melanoma. The transcriptome profiling and clinical data of melanoma were downloaded from The Cancer Genome Atlas database, and their matched normal samples were obtained from the Genotype-Tissue Expression database. After merging the genome expression data using Perl, the limma package was used for data normalization. We screened the differentially expressed genes (DEGs) and obtained immune signatures associated with melanoma by an immune-related signature list from the InnateDB database. Univariate Cox regression analysis was used to identify potential prognostic immune genes, and LASSO analysis was used to identify the hub genes. Next, based on the results of multivariate Cox regression analysis, we constructed a risk model for melanoma. We investigated the correlation between risk score and clinical characteristics and overall survival (OS) of patients. Based on the TIMER database, the association between selected immune signatures and immune cell distribution was evaluated. Next, the Wilcoxon rank-sum test was performed using CIBERSORT, which confirmed the differential distribution of immune-infiltrating cells between different risk groups. We obtained a list of 91 differentially expressed immune-related signatures. Functional enrichment analysis indicated that these immune-related DEGs participated in several areas of immune-related crosstalk, including cytokine-cytokine receptor interactions, JAK–STAT signaling pathway, chemokine signaling pathway, and Th17 cell differentiation pathway. A risk model was established based on multivariate Cox analysis results, and Kaplan-Meier analysis was performed. The Kruskal-Wallis test suggested that a high risk score indicated a poorer OS and correlated with higher American Joint Committee on Cancer-TNM (AJCC-TNM) stages and advanced pathological stages (P<0.01). Furthermore, the association between hub immune signatures and immune cell distribution was evaluated in specific tumor samples. The Wilcoxon rank-sum test was used to estimate immune infiltration density in the two groups, and results showed that the high-risk group exhibited a lower infiltration density, and the dominant immune cells included M0 macrophages (P=0.023) and activated mast cells (P=0.005).
Ehretiquinone from Onosma bracteatum Wall Exhibits Antiaging Effect on Yeasts and Mammals through Antioxidative Stress and Autophagy Induction
Authors: Pan Yanjun , Liu Yanan , Fujii Rui , Farooq Umer , Cheng Lihong , Matsuura Akira , Qi Jianhua , Xiang Lan
Published: January 2021

The antiaging benzoquinone‐type molecule ehretiquinone was isolated in a previous study as a leading compound from the herbal medicine Onosma bracteatum wall. This paper reports the antiaging effect and mechanism of ehretiquinone by using yeasts, mammal cells, and mice. Ehretiquinone extends not only the replicative lifespan but also the chronological lifespan of yeast and the yeast‐like chronological lifespan of mammal cells. Moreover, ehretiquinone increases glutathione peroxidase, catalase, and superoxide dismutase activity and reduces reactive oxygen species and malondialdehyde (MDA) levels, contributing to the lifespan extension of the yeasts. Furthermore, ehretiquinone does not extend the replicative lifespan of Δsod1, Δsod2, Δuth1, Δskn7, Δgpx, Δcat, Δatg2, and Δatg32 mutants of yeast. Crucially, ehretiquinone induces autophagy in yeasts and mice, thereby providing significant evidence on the antiaging effects of the molecule in the mammalian level. Concomitantly, the silent information regulator 2 gene, which is known for its contributions in prolonging replicative lifespan, was confirmed to be involved in the chronological lifespan of yeasts and participates in the antiaging activity of ehretiquinone. These findings suggest that ehretiquinone shows an antiaging effect through antioxidative stress, autophagy, and histone deacetylase Sir2 regulation. Therefore, ehretiquinone is a promising molecule that could be developed as an antiaging drug or healthcare product.
Positive Periodic Solutions for a Class of Strongly Coupled Differential Systems with Singular Nonlinearities
Authors: Chen Ruipeng , Zhang Guangchen , Liu Jiayin
Published: January 2021

This article studies the existence of positive periodic solutions for a class of strongly coupled differential systems. By applying the fixed point theory, several existence results are established. Our main findings generalize and complement those in the literature studies.
Effect of Sample Volume Variation and Delay in Analysis on Plasma Glucose Concentration in Sri Lankan Healthy Adults
Authors: Dharmasena Isuru Anupama , Siriwardhana Deepani , Attanayake Anoja Priyadarshani
Published: January 2021

The correct volume of sample and time of storing prior to the analysis are important considerations in the estimation of plasma glucose concentration of patients. The present study was to determine the effect of sample volume variation and time delay in the analysis of plasma glucose results in healthy adults. A total of 30 individuals aged between 20 and 30 years were selected for the study. Blood samples were collected into three fluoride-oxalate collection tubes separately. The results revealed that the sample volume variation from 2.0 mL fluoride-oxalate tube to 1.0 mL and 3.0 mL did not significantly affect the plasma glucose concentration (

p

 > 0.05). However, the plasma glucose concentration in the sample significantly decreased upon delaying the analysis. The mean fasting plasma glucose concentration of analysis after one hour of collection and analysis after three hours of collection was not significantly different (

p

 > 0.05). The mean fasting plasma glucose concentrations between one hour and five hours timepoints after collection (

p

 < 0.001) and between three hours and five hours after collection (

p

 = 0.014) were significantly different. In conclusion, overfilling and underfilling (2.0 ± 1.0 mL) of fluoride-oxalate tubes did not affect the plasma glucose results significantly. If the samples are analyzed within three hours of collection, the time dependent change too is not statistically significant.
Multiobjective Optimization of Cable Forces and Counterweights for Universal Cable-Stayed Bridges
Authors: Wang Zhangming , Zhang Nan , Du Xianting , Wang Shilei , Sun Qikai
Published: January 2021

In cable-stayed bridges, especially asymmetric bridges, counterweights are always made to work together with cable pretension forces to get a reasonable finished state. To solve the optimization problem of the cable-stayed bridge considering the counterweights, the integrated optimization method (IOM) for estimating cable forces and counterweights is proposed. In this method, the counterweights are proposed to act on the anchor points. After that, the summary of the minimum weighted total bending energy and the summary of the counterweights are considered as two objective functions of a multiobjective problem. Finally, the dynamic weighted coefficient method is used to solve this problem and realize the Pareto solution set. IOM presents detailed procedures in a simple numerical model and is then applied to the Yong-ding special-shaped cable-stayed bridge. The results show that not only IOM can realize the priority selection of the loading position of the counterweights but also get a better reasonable finish state because of the introduction of the counterweight dimension; the dynamic weighted coefficient method can quickly find the Pareto optimal solution set and be further screened by decision-makers; counterweight is very helpful to reduce torsion and other spatial effects in cable-stayed bridges. IOM can be used as a universal optimization method for cable-stayed bridges.
Effect of Wheat Straw Ash on Fresh and Hardened Concrete Reinforced with Jute Fiber
Authors: Bheel Naraindas , Sohu Samiullah , Awoyera Paul , Kumar Ashok , Abbasi Suhail Ahmed , Olalusi Oladimeji B.
Published: January 2021

In the present era, a number of researchers are using either industrial or agricultural priceless products as a basic source of raw materials for the construction industry. These waste products are economical and helpful in producing a sustainable environment and reducing environmental pollution, which is called handling waste products. However, this research work was conducted on concrete containing 0.25%, 0.50%, 0.75%, and 1% of jute fiber as reinforcement material and 10%, 20%, 30%, and 40% of wheat straw ash (WSA) as replacement for fine aggregates. Moreover, the separate and combined effect of jute fiber and WSA as a replacement for sand ingredient in concrete is to determine the fresh and hardened properties of concrete. In this research, a number of concrete samples were prepared with 1 : 1.5 : 3 mix proportion at 0.54 water‐cement ratio and cured at 28 days. The experimental outcomes displayed that the compressive, splitting tensile, and flexural strengths improved by 32.88 MPa, 3.80 MPa, and 5.30 MPa at 0.50% of jute fiber along with 30% of WSA at 28 days consistently. Similarly, the modulus of elasticity was developed while the dosages of jute fiber and WSA increased together in concrete. Moreover, the permeability and workability of concrete were reduced while utilized jute fiber and WSA increased together in concrete.
Time Course of Lens Epithelial Cell Behavior in Rabbit Eyes following Lens Extraction and Implantation of Intraocular Lens
Authors: Kurosaka Daijiro , Imaizumi Toshiyasu , Kizawa Junya
Published: January 2021

Background. After cataract surgery, some lens epithelial cells (LECs) transdifferentiate into myofibroblast-like cells, which causes fibric posterior capsule opacification (PCO). Residual LECs differentiate into lens fiber cells, forming Elschnig pearls with PCO. This study was carried out to identify the time course of both types of LEC behavior in rabbit eyes following lens extraction and implantation of an intraocular lens (IOL). Methods. Phacoemulsification and implantation of posterior chamber IOLs were performed in rabbit eyes. Following enucleation, immunohistochemical methods were used to detect α-smooth muscle actin (α-SMA), a marker for myofibroblast-like cells, in the pseudophakic rabbit eyes. A mouse monoclonal antibody against α-SMA was used. Results. Soon after the operation, the LECs migrated and covered the lens capsule. Thereafter, the LECs around the anterior capsular margin were always positive for α-SMA. However, the distributions of these cells were not consistent. In some specimens, α-SMA-positive LECs were present around the IOL optic early after surgery, but most of them had disappeared several weeks after the surgery. The residual cells induced fibrotic PCO. In the other specimens, most LECs around the IOL optic except the anterior capsular margin were negative for α-SMA. In the peripheral region covered by the peripheral anterior and posterior capsules, LECs on the posterior capsule always differentiated into lens fiber cells and formed a Soemmering ring. Thereafter, migration of lens fiber cells from the Soemmering ring and differentiation of LECs in situ on the central posterior capsule consisted of Elschnig pearls type of PCO. Conclusions. Although postoperative LEC behavior is not consistent, residual α-SMA-positive LECs induced fibrotic PCO. The lens fiber cells that migrated from the peripheral capsular bag or that were differentiated in situ covered the central posterior capsule, forming Elschnig pearls with PCO.
Three‐Dimensional, Real‐Time, and Intelligent Data Acquisition of Large Deformation in Deep Tunnels
Authors: Zhao Yue-Mao , Han Yong , Kou Yong-Yuan , Li Lin , Du Jiu-Hua
Published: January 2021

Potential disasters of large deformation pose serious threats to deep underground projects such as tunnels and mines. Engineering with large deformation is typically characterized by high stress, complex engineering geology, strong disturbance, and squeezing deformation, posing a great challenge to the design of an effective and accurate monitoring system. To address this problem, it is necessary to grasp the three‐dimensional features of deformation and establish integrated monitoring of a support system. Monitoring equipment should be selected to obtain joint, stress, deformation, cracking process, and other information, and this information can be fed back to the warning and control module. The scheme of the monitoring system presented here was successfully applied to a deep metal mine. This intelligent monitoring system ensures safety during the construction and operation of the tunnel under complex surrounding rock conditions, allows the use of field monitoring data to guide construction and design, and provides a reference for future construction and project monitoring.
W196 and the β‐Hairpin Motif Modulate the Redox Switch of Conformation and the Biomolecular Interaction Network of the Apoptosis‐Inducing Factor
Authors: Romero-Tamayo Silvia , Laplaza Ruben , Velazquez-Campoy Adrian , Villanueva Raquel , Medina Milagros , Ferreira Patricia
Published: January 2021

The human apoptosis‐inducing factor (hAIF) is a moonlight flavoprotein involved in mitochondrial respiratory complex assembly and caspase‐independent programmed cell death. These functions might be modulated by its redox‐linked structural transition that enables hAIF to act as a NAD(H/+) redox sensor. Upon reduction with NADH, hAIF undergoes a conformational reorganization in two specific insertions—the flexible regulatory C‐loop and the 190‐202 β‐harpin—promoting protein dimerization and the stabilization of a long‐life charge transfer complex (CTC) that modulates its monomer‐dimer equilibrium and its protein interaction network in healthy mitochondria. In this regard, here, we investigated the precise function of the β‐hairpin in the AIF conformation landscape related to its redox mechanism, by analyzing the role played by W196, a key residue in the interaction of this motif with the regulatory C‐loop. Mutations at W196 decrease the compactness and stability of the oxidized hAIF, indicating that the β‐hairpin and C‐loop coupling contribute to protein stability. Kinetic studies complemented with computational simulations reveal that W196 and the β‐hairpin conformation modulate the low efficiency of hAIF as NADH oxidoreductase, contributing to configure its active site in a noncompetent geometry for hydride transfer and to stabilize the CTC state by enhancing the affinity for NAD+. Finally, the β‐hairpin motif contributes to define the conformation of AIF’s interaction surfaces with its physiological partners. These findings improve our understanding on the molecular basis of hAIF’s cellular activities, a crucial aspect for clarifying its associated pathological mechanisms and developing new molecular therapies.
Esophageal Balloon-Directed Ventilator Management for Postpneumonectomy Acute Respiratory Distress Syndrome
Authors: Sy Eric , Rao Jagadish , Zacharias Sherma , Ronco Juan J. , Lee James S.
Published: January 2021

Objective. Postpneumonectomy patients may develop acute respiratory distress syndrome (ARDS). There is a paucity of data regarding the optimal management of mechanical ventilation for postpneumonectomy patients. Esophageal balloon pressure monitoring has been used in traditional ARDS patients to set positive end-expiratory pressure (PEEP) and minimize transpulmonary driving pressure (

Δ

P

L

), but its clinical use has not been previously described nor validated in postpneumonectomy patients. The primary objective of this report was to describe the potential clinical application of esophageal pressure monitoring to manage the postpneumonectomy patient with ARDS. Design. Case report. Setting. Surgical intensive care unit (ICU) of a university-affiliated teaching hospital. Patient. A 28-year-old patient was involved in a motor vehicle collision, with a right main bronchus injury, that required a right-sided pneumonectomy to stabilize his condition. In the perioperative phase, they subsequently developed ventilator-associated pneumonia, significant cumulative positive fluid balance, and ARDS. Interventions. Prone positioning and neuromuscular blockade were initiated. An esophageal balloon was inserted to direct ventilator management. Measurements and Main Results.

V

T

was kept around 3.6 mL/kg PBW,

Δ

P

L

at ≤14 cm H2O, and plateau pressure at ≤30 cm H2O. Lung compliance was measured to be 37 mL/cm H2O. PEEP was optimized to maintain end-inspiratory transpulmonary

pressure
 

P

L

<
15

 cm H2O, and end-expiratory

P

L

between 0 and 5 cm H2O. The maximal

Δ

P

L

was measured to be 11 cm H2O during the care of this patient. The patient improved with esophageal balloon-directed ventilator management and was eventually liberated from mechanical ventilation. Conclusions. The optimal targets for

V

T

remain unknown in the postpneumonectomy patient. However, postpneumonectomy patients with ARDS may potentially benefit from very low

V

T

and optimization of PEEP. We demonstrate the application of esophageal balloon pressure monitoring that clinicians could potentially use to limit injurious ventilation and improve outcomes in postpneumonectomy patients with ARDS. However, esophageal balloon pressure monitoring has not been extensively validated in this patient population.
Synthesis and Characterization of Modified Kaolin‐Bentonite Composites for Enhanced Fluoride Removal from Drinking Water
Authors: Annan Ebenezer , Nyankson Emmanuel , Agyei-Tuffour Benjamin , Armah Stephen Kofi , Nkrumah-Buandoh George , Hodasi Joanna Aba Modupeh , Oteng-Peprah Michael
Published: January 2021

Fluoride‐contaminated drinking waters are known to cause severe health hazards such as fluorosis and arthritis. This paper presents the encapsulation of iron oxide nanoparticles in kaolin‐bentonite composites adsorbents (KBNPs) for the removal of fluoride from drinking water by adsorption compared with kaolin‐bentonite composite (KB). Adsorbents with an average weight of ∼200 mg and ∼7 mm diameter (granules) were prepared in the ratio of 10 : 10 : 0.1 for kaolinite, bentonite, and magnetite nanoparticles, respectively. The granules were air‐dried and calcined at 750°C and contacted with 2 mg/L sodium fluoride solution at varying time periods. The adsorbents were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) formulation, and Brunauer–Emmett–Teller (BET), whereas the adsorption mechanism and the kinetics were explained using the Langmuir isotherm, Freundlich models, and pseudo‐first‐order and pseudo‐second‐order models. The results showed that the BET surface areas for the granules were 10 m2/g and 3 m2/g for KBNPs and KB, respectively. The SEM images for the adsorbents before and after adsorption confirm the plate‐like morphology of kaolin and bentonite. The FTIR analyses of bentonite (3550 cm−1–4000 cm−1) and kaolin (400–1200 cm−1) correspond to the structural hydroxyl groups and water molecules in the interlayer space of bentonites and the vibrational modes of SiO4 tetrahedron of kaolin, respectively. The KBNPs composites also recorded a fluoride removal efficiency of ∼91% after 120 minutes compared with 64% for KB composites without Fe3O4 nanoparticles. The adsorptions of fluoride by the KBNPs and KB granules were found to agree with the Freundlich isotherm and a pseudo‐second‐order kinetic model, respectively. The results clearly show that the impregnation of clays with magnetite nanoparticles has significant effect in the removal of fluoride, and the implication of the results has been discussed to show the impact of clay‐magnetite nanoparticles composites in the removal of fluoride from contaminated water.
Energy‐Spectral Efficiency Optimization in Wireless Underground Sensor Networks Using Salp Swarm Algorithm
Authors: Ayedi Mariem , Eldesouky Esraa , Nazeer Jabeen
Published: January 2021

Achieving high data rate transmission is critically constrained by green communication metrics in Wireless Sensor Networks (WSNs). A unified metric ensuring a successful compromise between the energy efficiency (EE) and the spectral efficiency (SE) is, then, an interesting design criterion in such systems. In this paper, we focus on EE‐SE tradeoff optimization in Wireless Underground Sensor Networks (WUSNs) where signals penetrate through a challenging lossy soil medium and nodes’ power supply is critical. Underground sensor nodes gather and send sensory information to underground relay nodes which amplify‐and‐retransmit received signals to an aboveground sink node. We propose to optimize source and relay powers used for each packet transmission using an efficient recent metaheuristic optimization algorithm called Salp Swarm Algorithm (SSA). Thus, the optimal source and relay transmission powers, which maximize the EE‐SE tradeoff under the maximum allowed transmission powers and the initial battery capacity constraints, are obtained. Further, we study the case where the underground medium properties are dynamic and change from a transmission to another. For this situation, we propose to allocate different maximum node powers according to the soil medium conditions. Simulation results prove that our proposed optimization achieves a significant EE‐SE tradeoff and prolongs the network’s lifetime compared to the fixed allocation node power scheme. Additional gain is obtained in case of dynamic medium conditions.
In Vitro Evaluation of the Antifungal Activity of Ghassoul-Based Formulations with Oregano and Thyme Essential Oils against Penicillium sp.
Authors: Ziyat Hamid , Bennani Mohammed Naciri , Allaoui Safae , Houssaini Jamal , M’barek Hasna Nait , Arif Soukaina , Hajjaj Hassan
Published: January 2021

The essential oils from aromatic plants are today considered a suitable tool to protect stored grains from fungal attacks. The purpose of this work is to study the effect of formulations of thyme and oregano essential oil (EO) adsorbed on purified (Gh-P) and sulfuric acid-activated (Gh-A) ghassoul on the biological activity of fungal pathogens. Purified and activated ghassoul were characterized by XRD and FTIR, and EOs used in this study were issued from two medicinal plants known in Morocco and commercially available. Their chemical compositions were analyzed by the GC-MS technique. The main constituents of thyme EO were thymol (67.13%), ρ-cymene (4.85%), Z-caryophyllene (1.77%), and γ-terpinene (2.74%). Oregano EO contained carvacrol (59.82%), γ-terpinene (10.85%), and α-pinene (9.89%). This work focused on the study of the antifungal activity of EOs mixed with purified and sulfuric acid-activated ghassoul, in order to look for new natural bioactive products and assess their antifungal activity. Penicillium sp. was used as a pathogen agent for biological activity on Czapek agar medium. The results showed that the active ghassoul formulations had significant antifungal activity against Penicillium sp. Gh-A-thyme, Gh-A-thymol, and Gh-A-oregano had an inhibitory potential of more than 75% and excelled to retain it over time even after five months. On the other hand, the three purified ghassoul formulations (Gh-P-thyme, Gh-P-thymol, and Gh-P-oregano) showed an initial inhibitory power of less than 22%, which was decreasing over time.
Nonlinear Vibration Mechanism of the Marine Rotating Machinery with Airbag Isolation Device under Heaving Motion
Authors: Du Xiaolei , Li Ming
Published: January 2021

In this paper, we put an investigation into the nonlinear vibration mechanism of the marine rotating machinery with an airbag isolation device under heaving motion. First, we consider the effects of mass unbalance and heaving motion and propose a mathematical model of the marine rotating mechanical system with airbag vibration isolation. Then, the multiple‐scale method is conducted to analyze the nonlinear dynamic characteristics of the mechanical system; the frequency‐response curves are mainly studied under different parameters, such as the heave excitation, rotor speed, and damping; and the numerical method is also introduced to analyze its dynamic behaviors, such as the steady‐state response and its corresponding phase diagram, Poincaré section. The dynamic stability of the system is investigated based on the bifurcations and the largest Lyapunov exponent about rotor speed and heaving frequency. The obtained results indicate complex nonlinear characteristics of the system compared to the system without heaving excitation, which can help us fully understand the dynamic characteristics and parametric optimization as well as structural design of the marine mechanical isolation system.
A New Compensation Method for DRR of a Roll-Pitch Seeker Based on ESO
Authors: Li Yue , Li Wei , Liu Xiaodong , Xia Qunli
Published: January 2021

We propose a new DRR (Disturbance Rejection Rate) compensation method of a roll-pitch seeker based on ESO (extended state observer). The characteristics of a roll-pitch seeker and the DRR definition of two frames of a roll-pitch seeker are analyzed. The influence of different interference torques and different frequency bandwidths on the compensation effect is analyzed. Modeling and simulation of the guidance system of a roll-pitch seeker with the parasitic loop of DRR are carried out. Influence of the new DRR compensation method on dimensionless miss distance is analyzed. Mathematical simulation is established to compare the new ESO-based DRR compensation method with the existing methods such as the feedforward method and Kalman filter method. The analysis and simulation results show that the new ESO-based DRR compensation method has the advantages of high precision, good applicability, and easy adjustment, and the new method can effectively reduce the dimensionless miss distance with different types of input errors. The research of this proposed new method can provide a reference for the latest generation air-to-air missile operations in a high-altitude and high-speed environment and the high-precision research of a roll-pitch seeker.
Single Nucleotide Polymorphisms of Pfdhfr and Pfdhps Genes: Implications for Malaria Prophylactic Strategies in Maiduguri, Northeast Nigeria
Authors: Balogun Sulayman Tunde , Sandabe Umar Kyari , Sodipo Olufunke Adebola , Okon Kenneth Okwong , Akanmu Ayodele Oluwasoji
Published: January 2021

Background. The success of Intermittent Preventive Treatment in Pregnancy (IPTp), Intermittent Preventive Treatment in Infancy (IPTi), and Seasonal Malaria Chemoprevention (SMC) depends on sulfadoxine-pyrimethamine (SP) efficacy. Objective. The study determined Single Nucleotide Polymorphisms (SNPs) of Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) in Maiduguri, Northeast Nigeria. Materials and Methods. Giemsa-stained blood smears, capillary blood, and dried blood spot samples were collected from 63 subjects with uncomplicated malaria in Maiduguri between May and October 2018. Plasmodium species was determined and parasite density (PD) was estimated using the smears. Genomic DNA (gDNA) of P. falciparum was extracted from the dried blood spot samples using QIAamp DNA Mini Kit. The gDNA was subjected to nested PCR followed by restriction fragment length polymorphism (RFLP) to determine SNPs at Pfdhfr codons N51I, C59R, and S108N and Pfdhps codons S436A/F, A437G, and K540E. Results. The subjects’ mean age ± standard deviation was 23.6 ± 8.7 (2.0–67.0) years with a geometric mean PD of 8,948 (2,100–13,400) asexual parasites/µl blood. SNPs prevalence at any of the six Pfdhfr and Pfdhps codons was 85.7% (54/63); the prevalence was higher (

p
<
0.05

) in Pfdhfr (82.5%; 52/63) than Pfdhps (58.7%; 37/63). Pfdhfr allele 108N (82.5%; 52/63) was the highest (

p
<
0.05

) mutant when compared with alleles 51I (60.3%; 38/63) and 59R (66.7%; 42/63). Triple Pfdhfr mutation was observed in 60.3% (38/63) of the isolates and was higher (

p
<
0.05

) among female subjects and SP recipients. Prevalence of Pfdhps allele 436A (28.6%; 18/63) was similar (

p
>
0.05

) to allele 437G (34.9%; 22/63), with double mutation recorded in 4.8% (3/63). K540E mutation was not observed. Conclusion. Pfdhfr and Pfdhps mutations observed in Maiduguri are suggestive of SP resistance level, and this could constitute a setback to malaria prophylactic strategies in the region if unchecked. Thus, there is a need to investigate the clinical efficacy of SP.
Brain Networks Connectivity in Mild to Moderate Depression: Resting State fMRI Study with Implications to Nonpharmacological Treatment
Authors: Bezmaternykh Dmitry D. , Melnikov Mikhail Ye. , Savelov Andrey A. , Kozlova Lyudmila I. , Petrovskiy Evgeniy D. , Natarova Kira A. , Shtark Mark B.
Published: January 2021

Network mechanisms of depression development and especially of improvement from nonpharmacological treatment remain understudied. The current study is aimed at examining brain networks functional connectivity in depressed patients and its dynamics in nonpharmacological treatment. Resting state fMRI data of 21 healthy adults and 51 patients with mild or moderate depression were analyzed with spatial independent component analysis; then, correlations between time series of the components were calculated and compared between-group (study 1). Baseline and repeated-measure data of 14 treated (psychotherapy or fMRI neurofeedback) and 15 untreated depressed participants were similarly analyzed and correlated with changes in depression scores (study 2). Aside from diverse findings, studies 1 and 2 both revealed changes in within-default mode network (DMN) and DMN to executive control network (ECN) connections. Connectivity in one pair, initially lower in depression, decreased in no treatment group and was inversely correlated with Montgomery-Asberg depression score change in treatment group. Weak baseline connectivity in this pair also predicted improvement on Montgomery-Asberg scale in both treatment and no treatment groups. Coupling of another pair, initially stronger in depression, increased in therapy though was unrelated to improvement. The results demonstrate possible role of within-DMN and DMN-ECN functional connectivity in depression treatment and suggest that neural mechanisms of nonpharmacological treatment action may be unrelated to normalization of initially disrupted connectivity.
A Comparative Study of Landslide Susceptibility Mapping Using SVM and PSO-SVM Models Based on Grid and Slope Units
Authors: Zhao Shuai , Zhao Zhou
Published: January 2021

The main purpose of this study aims to apply and compare the rationality of landslide susceptibility maps using support vector machine (SVM) and particle swarm optimization coupled with support vector machine (PSO-SVM) models in Lueyang County, China, enhance the connection with the natural terrain, and analyze the application of grid units and slope units. A total of 186 landslide locations were identified by earlier reports and field surveys. The landslide inventory was randomly divided into two parts: 70% for training dataset and 30% for validation dataset. Based on the multisource data and geological environment, 16 landslide conditioning factors were selected, including control factors and triggering factors (i.e., altitude, slope angle, slope aspect, plan curvature, profile curvature, SPI, TPI, TRI, lithology, distance to faults, TWI, distance to rivers, NDVI, distance to roads, land use, and rainfall). The susceptibility between each conditioning factor and landslide was deduced using a certainty factor model. Subsequently, combined with grid units and slope units, the landslide susceptibility models were carried out by using SVM and PSO-SVM methods. The precision capability of the landslide susceptibility mapping produced by different models and units was verified through a receiver operating characteristic (ROC) curve. The results showed that the PSO-SVM model based on slope units had the best performance in landslide susceptibility mapping, and the area under the curve (AUC) values of training and validation datasets are 0.945 and 0.9245, respectively. Hence, the machine learning algorithm coupled with slope units can be considered a reliable and effective technique in landslide susceptibility mapping.