bluuebunny/crossref_metadata_2025 huggingface dataset:
Natural biopolymers as proton conductors in bioelectronics
Authors: Jia Manping , Kim Jinhwan , Nguyen Tiffany , Duong Thi , Rolandi Marco
Published: May 2021

Bioelectronic devices sense or deliver information at the interface between living systems and electronics by converting biological signals into electronic signals and vice‐versa. Biological signals are typically carried by ions and small molecules. As such, ion conducting materials are ideal candidates in bioelectronics for an optimal interface. Among these materials, ion conducting polymers that are able to uptake water are particularly interesting because, in addition to ionic conductivity, their mechanical properties can closely match the ones of living tissue. In this review, we focus on a specific subset of ion‐conducting polymers: proton (H+) conductors that are naturally derived. We first provide a brief introduction of the proton conduction mechanism, and then outline the chemical structure and properties of representative proton‐conducting natural biopolymers: polysaccharides (chitosan and glycosaminoglycans), peptides and proteins, and melanin. We then highlight examples of using these biopolymers in bioelectronic devices. We conclude with current challenges and future prospects for broader use of natural biopolymers as proton conductors in bioelectronics and potential translational applications.
Modulation of high mannose levels in N‐linked glycosylation through cell culture process conditions to increase antibody‐dependent cell‐mediated cytotoxicity activity for an antibody biosimilar
Authors: Rameez Shahid , Gowtham Yogender K. , Nayar Gautam , Mostafa Sigma S.
Published: May 2021

The regulatory approval of a biosimilar product is contingent on the favorable comparability of its safety and efficacy to that of the innovator product. As such, it is important to match the critical quality attributes of the biosimilar product to that of the innovator product. The N‐glycosylation profile of a monoclonal antibody (mAb) can influence effector function activities such as antibody‐dependent cell‐mediated cytotoxicity (ADCC) and complement‐dependent cytotoxicity. In this study, we describe efforts to modulate the high‐mannose (HM) levels of a biosimilar mAb produced in a Chinese hamster ovary cell fed‐batch process. Because the HM level of the mAb was observed to impact ADCC activity, it was desirable to match it to the innovator mAb's levels. Several cell culture process related factors known to modulate the HM content of N‐glycosylation were investigated, including osmolality, ammonium chloride (NH4Cl) addition, glutamine concentration, monensin addition, and the addition of alternate sugars and amino sugars to the feed medium. The process conditions evaluated varied in impact on HM levels, process performance and product quality. One condition, the addition of alternate sugars and amino sugars to feed medium, was identified as the preferred method for increasing HM levels with minimal disruptions to process performance or other product quality attributes. Interestingly, a secondary interaction between sugar and amino sugar supplemented feeds and osmolality was observed during process scale‐up. These studies demonstrate sugar and amino sugar concentrations and osmolality are critical variables to evaluate to match HM content in biosimilar and their innovator mAbs.
Sn and Na Co‐doping to Suppress Voltage Decay of Li‐rich Layered Oxide
Authors: Hu Yongyuan , Qin Zhongzheng , Cong Bowen , Pei Jian , Sun Shanfu , Chen Gang
Published: May 2021

Li‐rich layered oxides (LLOs) as cathode materials are expected to be applied to advanced lithium‐ion batteries (LIBs) with great potential. However, the electrochemical instability and large voltage decay seriously restrict their development. In this work, a novel LLO cathode material (SN‐LLO) with Sn and Na co‐doping is fabricated through a co‐precipitation process with subsequent calcination, which exhibits enhanced electrochemical stability and suppressed voltage decay. Structural characterizations indicate that with the regulation of Na doping, the impurity Li2SnO3 is inhibited and layered SN‐LLO solid solution with the
arrangement of Sn in layers and stacking faults along c axis is obtained. DFT calculations demonstrate that the enhanced electrochemical stability results from the increase in the energy barrier of Mn migration in the slabs due to the steric effect of Sn. This study provides a rational design idea to improve the electrochemical stability of advanced Li‐rich layered oxides.
Metal‐Free Deoxygenation of Chiral Nitroalkanes: An Easy Entry to α‐Substituted Enantiomerically Enriched Nitriles
Authors: Pirola Margherita , Faverio Chiara , Orlandi Manuel , Benaglia Maurizio
Published: May 2021

A metal‐free, mild and chemodivergent transformation involving nitroalkanes has been developed. Under optimized reaction conditions, in the presence of trichlorosilane and a tertiary amine, aliphatic nitroalkanes were selectively converted into amines or nitriles. Furthermore, when chiral β‐substituted nitro compounds were reacted, the stereochemical integrity of the stereocenter was maintained and α‐functionalized nitriles were obtained with no loss of enantiomeric excess. The methodology was successfully applied to the synthesis of chiral β‐cyano esters, α‐aryl alkylnitriles, and TBS‐protected cyanohydrins, including direct precursors of four active pharmaceutical ingredients (ibuprofen, tembamide, aegeline and denopamine).
Use of immobilized zinc oxide photocatalysts for wastewater treatment: Application to methylene blue degradation
Authors: Karavasilis Michalis V. , Tsakiroglou Christos D.
Published: May 2021

Zinc‐oxide (ZnO) nanoparticles were immobilized on borosilicate glass spheres with treatment of zinc acetate dihydrate (ZAC) solution, and calcination at 400–450°C. The isotherm and kinetic parameters of methylene blue (MB) sorption on ZnO‐coated glass beads were estimated from batch sorption tests in darkness. An ultraviolet (UV)‐lamp with nominal power of 6 W and emission peak at 375 nm was used as a light source. Batch experiments of MB photodegradation were performed in a double‐wall glass reactor. Continuous flow tests were conducted in a poly(methyl methacrylate) (PMMA) annular photoreactor by recirculating the MB solution between it and a feed tank. All results were interpreted with dynamic models based on a two‐step process consisting of MB adsorption/desorption, and adsorbed MB surface reaction. The intense stirring caused by air bubbling or aqueous phase flow triggers the detachment of catalyst mass from substrate, the partial renewal of immobilized catalyst surface exposed to UV‐radiation, and the enhancement of the apparent maximum MB sorption capacity by total ZnO mass. The fast MB adsorption leads to an almost constant concentration of adsorbed MB at equilibrium, while the surface photocatalytic reaction is the MB degradation rate‐controlling step. Comparable values of the kinetic constant of surface reaction are estimated from batch and continuous flow tests, for repeated cycles of photocatalysis.
Reprogramming oral epithelial keratinocytes into a pluripotent phenotype for tissue regeneration
Authors: Bazina Fayrouz , Brouxhon Sabine M. , Kyrkanides Stephanos
Published: May 2021

Objectives

We set out to reprogram adult somatic oral epithelial keratinocytes into pluripotent cells for regenerative dentistry.

Setting and Sample population

Immortalized murine oral keratinocyte cell (IMOK) line raised from adult mouse mucosa were cultured in vitro in our studies.

Materials and Methods

Adult murine oral epithelial keratinocytes were chronically treated with TGF‐β1 in vitro, and the expression of Oct4, Nanog, Sox2 and Nestin, as well as specific homeobox Gata and Pax gene family members were investigated.

Results

We documented the induction of stem factors linked with pluripotency and/or the maintenance and regulation of stem‐cell self‐renewal in oral epithelial keratinocytes by TGFβ1. Moreover, we discovered that this TGF‐β1‐induced increase in Oct4, Nanog, Sox2 and Nestin was inhibited by SB431542, suggesting that TGF‐β1 signals via the TGF‐βRI receptor to induce pluripotency and stemness.

Conclusions

Adult oral epithelial keratinocytes treated chronically with TGF‐β1 acquired phenotypic characteristics consistent with pluripotent stem cells, highlighting the facileness of reprogramming adult oral keratinocytes into an unlimited supply of pluripotent stem cells.
Peace education in secondary schools of Mizoram
Authors: Mishra Lokanath
Published: May 2021

Peace education aims to equip future citizens with the necessary knowledge, attitudes, and skills to acknowledge and respect all kinds of diversity and understanding with human dignity. This article is based on empirical research to examine the practices of peace‐related activities in secondary schools of Mizoram. Mixed method was employed in this study. The secondary school students and the teachers of Mizoram were the target populations of the study. The total sample of the study comprised of 200 students: 100 boys and 100 girls of class IX; 100 teachers from 20 government secondary schools of Mizoram were drawn through a simple random sampling technique. A self‐made questionnaire consisting of 23 items, semi‐structured interview, and Focus Group Discussion were used as the techniques of data collection. The study showed that peace education components embedded in the existing curriculum were being taught through cocurricular and extracurricular activities. This article concludes by suggesting that teachers need to consider and include the guiding principles of peace and should encourage students to develop their critical thinking, reasoning, awareness of societal problems and issues, broadening their outlook, and concentrating on studies and to be associated with cocurricular activities.
A novel RANKL‐targeted flavonoid glycoside prevents osteoporosis through inhibiting NFATc1 and reactive oxygen species
Authors: Hong Guoju , Chen Zhenqiu , Han Xiaorui , Zhou Lin , Pang Fengxiang , Wu Rishana , Shen Yingshan , He Xiaoming , Hong Zhinan , Li Ziqi , He Wei , Wei Qiushi
Published: May 2021

Background and purpose

Osteoporosis is characterized by excessive bone resorption due to enhanced osteoclast activation. Stimulation of nuclear factor of activated T cells 1 (NFATc1) and accumulation of reactive oxygen species (ROS) are important mechanisms underlying osteoclastogenesis. Robinin (Rob) is a flavonoid glycoside that has shown anti‐inflammatory and antioxidative effects in previous studies, but little is known about its effects on bone homeostasis. The purpose of our research was to investigate whether Rob could prevent bone resorption in ovariectomized (OVX) mice by suppressing osteoclast production through its underlying mechanisms.

Methods

The docking pose of Rob and RANKL was identified by protein‐ligand molecular docking. Rob was added to bone marrow macrophages (BMMs) stimulated by nuclear factor‐κB (NF‐κB) ligand (RANKL). The effects of Rob on osteoclastic activity were evaluated by positive tartrate resistant acid phosphatase (TRAcP) staining kit and hydroxyapatite resorption assay. RANKL‐induced ROS generation in osteoclasts was detected by H2DCFDA and MitoSox Red staining. The classic molecular cascades triggered by RANKL, such as NF‐κB, ROS, calcium oscillations, and NFATc1‐mediated signaling pathways, were investigated using Fluo4 staining, western blot, and quantitative real‐time polymerase chain reaction. In addition, an OVX mouse model mimicking estrogen‐deficient osteoporosis was created to evaluate the therapeutic effects of Robin vivo.

Results

Computational docking results showed that Rob could bind specifically to RANKL's predicted binding sites.In vitro, Rob inhibited RANKL‐mediated osteoclastogenesis dose‐dependently without obvious cytotoxicity at low concentrations. We also found that Rob attenuated RANKL‐induced mitochondrial ROS production or enhanced activities of ROS‐scavenging enzymes, and ultimately reduced intracellular ROS levels. Rob abrogated the RANKL‐induced mitogen‐activated protein kinase (MAPK) and NF‐κB signaling pathways, and subsequently blocked NFATc1 signaling and TRAcP expression. In addition, Rob inhibited osteoclast proliferation by downregulating the expression of osteoclast target genes (Acp5,Cathepsin K,Atp6v0d2, Nfact1,c‐Fos, andMmp9) and reducing Ca2+oscillations. Ourin vivoresults showed that Rob reduced bone resorption in OVX animal model by repressing osteoclast activity and function.

Conclusions

Rob inhibits the activation of osteoclasts by targeting RANKL and is therefore a potential osteoporosis drug.
Interaction of CSF α‐synuclein and amyloid beta in cognition and cortical atrophy
Authors: Lee Young‐gun , Jeon Seun , Kang Sung Woo , Park Mincheol , Baik Kyoungwon , Yoo Han Soo , Chung Seok Jong , Jeong Seong Ho , Jung Jin Ho , Lee Phil Hyu , Sohn Young Ho , Evans Alan C. , Ye Byoung Seok ,   and the Alzheimer's Disease Neuroimaging Initiative
Published: May 2021

Introduction

Lewy body–related pathology is commonly observed at autopsy in individuals with dementia, but in vivo biomarkers for α‐synucleinopathy are lacking.

Methods

Baseline cerebrospinal fluid (CSF) biomarkers, polygenic risk score (PRS) for Parkinson's disease (PRS‐PD) and Alzheimer's disease (PRS‐AD), longitudinal cognitive scores, and magnetic resonance imaging were measured in 217 participants from the Alzheimer's Disease Neuroimaging Initiative. Linear mixed models were used to find the relationship of CSF biomarkers and the PRS with cognition and cortical atrophy.

Results

Higher PRS‐PD and PRS‐AD were associated with lower CSF α‐synuclein and amyloid beta (Aβ), respectively. Lower CSF α‐synuclein and the interaction of CSF α‐synuclein and Aβ were associated with lower cognitive scores and global cortical atrophy most prominently in the occipital cortex.

Discussion

Lower CSF α‐synuclein could be a biomarker for α‐synucleinopathy, and the simultaneous evaluation of CSF biomarkers for AD and CSF α‐synuclein could reveal the independent and interactive effects on cognition and cortical atrophy.
Valorization of CO2 into N‐alkyl Oxazolidin‐2‐ones Promoted by Metal‐Free Porphyrin/TBACl System: Experimental and Computational Studies
Authors: Damiano Caterina , Sonzini Paolo , Manca Gabriele , Gallo Emma
Published: May 2021

The cycloaddition of CO2 to N‐alkyl aziridines was efficiently promoted by the convenient TPPH2/TBACl binary catalytic system. The metal‐free procedure was effective for the synthesis of differently substituted N‐alkyl oxazolidin‐2‐ones in yields up to 100 % and excellent regioselectivities (up to 99 %). The mechanism of the reaction was proposed based on a DFT study which indicated the formation of an adduct between TPPH2 and TBACl as the effective catalytic active species.
Stereoselective Visible‐Light Catalyzed Cyclization of Bis(enones): A Viable Approach to the Synthesis of Enantiomerically Enriched Cyclopentane Rings
Authors: Medici Fabrizio , Resta Simonetta , Presenti Piero , Caruso Lucia , Puglisi Alessandra , Raimondi Laura , Rossi Sergio , Benaglia Maurizio
Published: May 2021

Photoredox catalytic cyclization of aryl enones in the presence of visible light, promoted either by metals or organic dyes, represent a valuable strategy for the synthesis of cycloalkanes. The development of a stereoselective version of such transformation, in the presence of the metal‐free catalyst Eosin Y was studied, with the aim to realize an efficient protocol for the in‐flow synthesis of enantiomerically enriched functionalized cyclopentane rings, taking advantage of the flow reactors technology. The use of a chiral auxiliary on the bisenone to be cyclized offers a straightforward and convenient option to exert a stereocontrol on the light‐driven cyclization. By exploiting Evans’ oxazolidinones, the stereoselective light‐driven cyclization affords, after the removal of the chiral auxiliary, a functionalized 1,2‐trans cyclopentane ring in up to 83/17 enantiomeric ratio. When the reaction was performed in continuo, in a homemade coil photoreactor, high yields were observed. The cyclization was also successfully realized in a 3D‐printed mesoreactor, without any change in the diastereoseletctivity of the process.
Visible Light‐Induced Metal‐Free and Oxidant‐Free Radical Cyclization of (2‐Isocyanoaryl)(methyl)sulfanes with Ethers
Authors: Xie Xiao‐Yu , Li Yang , Xia Yun‐Tao , Luo Kai , Wu Lei
Published: May 2021

A novel cascade cyclization of (2‐isocyanoaryl) (methyl)sulfanes and ethers is developed. With 4CzIPN as a photocatalyst and the irradiation of blue LED light, ether radicals are efficiently generated without adding any oxidant, endowing the strategy with features of oxidant‐free, metal‐free, mild reaction conditions, and operational simplicity. This strategy provides efficient approach to access various ether‐containing benzothiazoles in acceptable to good yields.
Increasing the Stability of LiMn2O4 Against Harsh Conditions During Lithium Recovery from Real Brine Solutions
Authors: Hippauf Felix , Abendroth Thomas , Neidhardt Julia , Althues Holger , Aljlil Saad A. , Alrasheed Radwan A. , Alyousef Yousef M. , Kaskel Stefan
Published: May 2021

Brines are abundant waste products from desalination plants and have higher lithium contents than sea water (0.17 ppm). Herein, electrochemical lithium recovery from real brine solutions using Li‐selective LiMn2O4 is reported. Free‐standing electrodes are prepared completely solvent‐free. At low current densities, the complete theoretical capacity of 148 mAh g−1 can be utilized. The process is highly rate dependent due to the lithium concentration in the mm range. The high salt content of the brine depicts a challenging environment for electrodes and reactor materials. Competing earth‐alkali metals lead to scale formation blocking the electrode surface and reducing the electrode capacity for lithium uptake. The high chloride concentration enables the formation of chlorine Cl2 at potentials < 1 V versus Ag/AgCl competing with the deintercalation of lithium. A combination of commercial antiscalants was used to suppress the formation of CaCO3 at the electrode prolonging its cycle life. It is shown that a cation exchange membrane not only effectively blocks chloride ions from the electrode but also decreases the Li‐diffusion. Finally, the selectivity of the process is proven in a real brine with a low lithium content (0.7 mm), and an actual recovery experiment is conducted in a flow setup.
Binding Li3PO4 to Spinel LiNi0.5Mn1.5O4 via a Surface Co‐Containing Bridging Layer to Improve the Electrochemical Performance
Authors: Wu Yida , Ben Liubin , Zhan Yuanjian , Yu Hailong , Qi Wenbin , Zhao Wenwu , Huang Xuejie
Published: May 2021

Coating the surface of cathode materials with Li3PO4 to improve the cycling performance is commonly practiced; however, obtaining an effective and uniform coating of Li3PO4 on cathode materials is extremely difficult due to the lack of strong bonds between them. Herein, this issue is solved by coating the surface of LiNi0.5Mn1.5O4 with Li3PO4 via a novel hydrothermal method. It is shown that a uniform Li3PO4 surface coating can only be obtained by introducing a small amount of additional metal ions, such as Co, in the starting solution. X‐ray photoelectron microscopy combined with scanning transmission electron microscopy reveals that the Co ions diffuse into the 16c sites of the surface of the spinel LiNi0.5Mn1.5O4 structure, making the surface layer act as a bridging layer that connects olivine Li3PO4 with bulk spinel LiNi0.5Mn1.5O4. The high‐voltage LiNi0.5Mn1.5O4 half‐cell with the optimal Li3PO4 coating shows a discharge capacity retention of 95.8% after 50 cycles at 55 °C, compared with the only 81.1% discharge capacity retention of the bare counterpart.
Dynamic rocking response of a rigid planar block on a nonlinear hysteretic Winkler foundation
Authors: Lu Yang , Xiong Feng , Ge Qi
Published: May 2021

A new design philosophy termed “rocking isolation” has been advocated in recent studies on soil–structure interaction (SSI) toward utilizing nonlinear foundation response for seismic protection of structures. Allowing structures to rock on their foundation enables nonlinearities arising from base uplifting and soil yielding to limit seismic actions on structures, contributing to resilient SSI systems with controllable residual deformation. The current work presents an improved Winkler‐based rocking foundation model as an efficient practical tool to calculate the dynamic response of a rocking isolation system idealized as a rigid rectangular block rocking on a nonlinear hysteretic foundation allowing for base uplift. Compared with existing Winkler models where coupled shear‐compressive soil behavior is usually ignored, improvements are made by using smooth biaxial hysteretic elements to describe the point‐wise constitutive relation between tractions and displacements at the base. The foundation model is calibrated and validated against published experimental and numerical simulation data on clayey foundations. Analytical expressions are derived to estimate foundation rocking stiffness and failure envelope which describes the interaction between ultimate resultant forces developed on the foundation. The free‐vibrational and seismic responses of a class of flexibly supported rigid rocking blocks are examined using the proposed model through nonlinear response‐history analyses. It is found that sliding due to the coupled shear‐compressive soil behavior tends to reduce free‐vibrational rocking response of blocks with smaller slenderness ratios, while it may increase or decrease seismic overturning potential of blocks on heavily loaded foundations.
Structural optimal hybrid control strategies employing dynamic dual units: inerter and spring
Authors: Liang Qigang , Li Luyu , Zhang Yu
Published: May 2021

The concepts of optimal hybrid control strategies in the time and frequency domains are proposed herein. The time‐domain optimal hybrid control (also called GangGang strategy) consists of two dynamic units, an inerter and a spring, which work with different force mechanisms at different time phases of vibrations. The inerter acts on the structure when the vibration phase is accelerated, whereas the spring works when the structure deviates from its initial position. The combination of the two piecewise working units achieves better performance than their individual full‐time operations. The working time phases of the two units are complementary, covering the entire vibration period. The hysteresis loops of them are also complementary in the quadrant coordinate system. Owing to the piecewise properties of the two units, the equivalent linearization system (ELS) of such systems is formulated, and a statistical linearization procedure is developed to obtain the equivalent linearization parameters. Then, a parametric study on the equivalent damping is performed through sensitivity analysis and a comparative analysis of the ELS was performed in terms of the standard deviation and peak displacement levels under stationary stochastic excitations. The frequency‐domain optimal hybrid control conforms with the concept of intelligent isolation. The inerter and spring units can be switched according to the excitation frequency by an on–off control benefitting structures subjected to excitations with definite frequency range.
On stock volatility forecasting based on text mining and deep learning under high‐frequency data
Authors: Lei Bolin , Liu Zhengdi , Song Yuping
Published: May 2021

Few existing literatures used the text information of the public opinions as the input index for volatility forecasting. This paper uses the text comment information of stockholders to construct a text sentiment factor that integrates the influence of comments and then combines other transaction information on volatility forecasting based on high‐frequency finance data with the deep learning model long short‐term memory (LSTM). The study finds that under the framework of the LSTM model, the forecasting accuracy for the volatility with the sentiment index is better than that of the LSTM model without the sentiment index and 10 traditional econometric models under the six loss functions. When compared with the traditional econometric model for multistep forecasting, the LSTM model is robust. With the addition of the public opinion index, the accuracy of LSTM is improved by 9.3%, 4.7%, 6.2%, 9.2%, 7.9%, and 16.9%, respectively, under the six evaluation criteria. The research in this article provides a more accurate, robust, and sustainable method for volatility forecasting in the context of big data.
Stock markets and exchange rate behavior of the BRICS
Authors: Salisu Afees A. , Cuñado Juncal , Isah Kazeem , Gupta Rangan
Published: May 2021

Relying on the uncovered equity parity (UEP), we formulate a predictive model that links movements in exchange rate to stock return differential between the domestic market and the foreign (US) market. We also test for any probable asymmetric relationship between the two variables while also accounting for the role of observed common (global) factor such as oil price. We find a positive relationship between stock return differential and exchange rate return for three of the BRICS countries namely Brazil, India and South Africa, thus validating the UEP hypothesis, whereas a contrasting evidence is observed for China and Russia. We further establish the out‐of‐sample predictability of stock return differential for exchange rates of the BRICS while accounting for the role of observed common (global) factor, and asymmetry may further improve the forecast accuracy. The implications of our findings for portfolio diversification and foreign exchange management are highlighted.
Early Jurassic palaeoclimate in Southwest China and its implications for dinosaur fossil distribution
Authors: Shen Huan , Zhang Laiming , Wang Chengshan , Amiot Romain , Wang Xu , Cui Linlin , Song Peng
Published: May 2021

Lufeng County in Southwest China is one of the most famous lagerstätten in which Early Jurassic dinosaurs can be found. The reason for the burial of large body size dinosaur fossils at this site is still an enigma, although it could be attributed to either suitable habitats or good preservation conditions. Both of these factors are indirectly regulated by climatic conditions. Therefore, a quantitative reconstruction of the terrestrial palaeoclimate of the Lufeng area during the Early Jurassic could help shed new light on this issue. In this study, we analysed the stable isotope compositions of oxygen and carbon (δ13C and δ18O) in apatite phosphate and carbonate from the tooth enamel and compact bones of basal sauropodiform andSinosaurusfossils. The oxygen isotopes provided a mean annual temperature (MAT) of ≥21 ± 3°C, and the carbon isotopes allowed us to estimate a mean annual precipitation (MAP) of 965 ± 460 mm/yr during the Early Jurassic in Lufeng County. These conditions correspond to a relatively arid tropical savanna climate hospitable to vertebrate life. We also compared the spatial relationship between the global distribution of dinosaur fossils and climatically sensitive deposits during the Jurassic. The dinosaur fossil distribution reveals a strong preference for arid regions. We therefore suggest that ‘savanna‐like’ tropical conditions helped accommodate a large number of dinosaurs and preserve their carcasses in the Lufeng area during the Early Jurassic.
Neural evidence for recognition of naturalistic videos in monkey hippocampus
Authors: Sakon John J. , Suzuki Wendy A.
Published: May 2021

The role of the hippocampus in recognition memory has long been a source of debate. Tasks used to study recognition that typically require an explicit probe, where the participant must make a response to prove they remember, yield mixed results on hippocampal involvement. Here, we tasked monkeys to freely view naturalistic videos, and only tested their memory via looking times for two separate novel versus repeat video conditions on each trial. Notably, a large proportion (>30%) of hippocampal neurons differentiated these videos via changes in firing rates time‐locked to the duration of their presentation on screen, and not during the delay period between them as would be expected for working memory. Many of these single neurons (>15%) contributed to both retrieval conditions, and differentiated novel from repeat videos across trials with trial‐unique content, suggesting they detect familiarity. The majority of neurons contributing to the classifier showed an enhancement in firing rate on repeat compared with novel videos, a pattern which has not previously been shown in hippocampus. These results suggest the hippocampus contributes to recognition memory via familiarity during free‐viewing.
Assessment of CHADFDM satellite‐based input dataset for the groundwater recharge estimation in arid and data scarce regions
Authors: Salehi Siavashani Nafiseh , Jimenez‐Martinez Joaquin , Vaquero Guillermo , Elorza Francisco J. , Sheffield Justin , Candela Lucila , Serrat‐Capdevila Aleix
Published: May 2021

Aquifer natural recharge estimations are a prerequisite for understanding hydrologic systems and sustainable water resources management. As meteorological data series collection is difficult in arid and semiarid areas, satellite products have recently become an alternative for water resources studies. A daily groundwater recharge estimation in the NW part of the Lake Chad Basin, using a soil–plant‐atmosphere model (VisualBALAN), from ground‐ and satellite‐based meteorological input dataset for non‐irrigated and irrigated land and for the 2005–2014 period is presented. Average annual values were 284 mm and 30°C for precipitation and temperature in ground‐based gauge stations. For the satellite‐model‐based Lake Chad Basin Flood and Drought Monitor System platform (CHADFDM), average annual precipitation and temperature were 417 mm and 29°C, respectively. Uncertainties derived from satellite data measurement could account for the rainfall difference. The estimated mean annual aquifer recharge was always higher from satellite‐ than ground‐based data, with differences up to 46% for dryland and 23% in irrigated areas. Recharge response to rainfall events was very variable and results were very sensitive to: wilting point, field capacity and curve number for runoff estimation. Obtained results provide plausible recharge values beyond the uncertainty related to data input and modelling approach. This work prevents on the important deviations in recharge estimation from weighted‐ensemble satellite‐based data, informing in decision making to both stakeholders and policy makers.
Ecohydrological modelling in a deciduous boreal forest: Model evaluation for application in non‐stationary climates
Authors: Marshall Adrienne M. , Link Timothy E. , Flerchinger Gerald N. , Nicolsky Dmitry J. , Lucash Melissa S.
Published: May 2021

Soil moisture is an important driver of growth in boreal Alaska, but estimating soil hydraulic parameters can be challenging in this data‐sparse region. Parameter estimation is further complicated in regions with rapidly warming climate, where there is a need to minimize model error dependence on interannual climate variations. To better identify soil hydraulic parameters and quantify energy and water balance and soil moisture dynamics, we applied the physically based, one‐dimensional ecohydrological Simultaneous Heat and Water (SHAW) model, loosely coupled with the Geophysical Institute of Permafrost Laboratory (GIPL) model, to an upland deciduous forest stand in interior Alaska over a 13‐year period. Using a Generalized Likelihood Uncertainty Estimation parameterisation, SHAW reproduced interannual and vertical spatial variability of soil moisture during a five‐year validation period quite well, with root mean squared error (RMSE) of volumetric water content at 0.5 m as low as 0.020 cm3/cm3. Many parameter sets reproduced reasonable soil moisture dynamics, suggesting considerable equifinality. Model performance generally declined in the eight‐year validation period, indicating some overfitting and demonstrating the importance of interannual variability in model evaluation. We compared the performance of parameter sets selected based on traditional performance measures such as the RMSE that minimize error in soil moisture simulation, with one that is designed to minimize the dependence of model error on interannual climate variability using a new diagnostic approach we call CSMP, which stands for Climate Sensitivity of Model Performance. Use of the CSMP approach moderately decreases traditional model performance but may be more suitable for climate change applications, for which it is important that model error is independent from climate variability. These findings illustrate (1) that the SHAW model, coupled with GIPL, can adequately simulate soil moisture dynamics in this boreal deciduous region, (2) the importance of interannual variability in model parameterisation, and (3) a novel objective function for parameter selection to improve applicability in non‐stationary climates.
Assessment and treatment of tracheostomy tube manipulation: Effects of competing stimuli and protective equipment
Authors: Falligant John M. , Hardesty Samantha L. , Pierce David , Kurtz Patricia F.
Published: May 2021

Functional analyses (FA) are widely used in the assessment and treatment of problem behavior. However, with limited exceptions, the procedures are rarely applied to potentially dangerous behaviors involving medical equipment. The current study replicated and extended procedures previously used by Kurtz and Chin (2004) to assess and treat tracheostomy tube manipulation in a 5‐year‐old boy diagnosed with extensive medical and developmental conditions. FA results indicated that tracheostomy tube manipulation (i.e., touching, pulling, occluding) was automatically maintained. An augmented competing stimulus assessment was conducted to identify stimuli associated with low levels of tracheostomy tube manipulation and elevated levels of item engagement. A treatment package consisting of noncontingent access to competing stimuli with prompting and continuous application of protective equipment produced significant reductions in tracheostomy tube manipulation, as well as significant increases in toy engagement.
Prosthetic meshes for hernia repair: State of art, classification, biomaterials, antimicrobial approaches, and fabrication methods
Authors: Serrano‐Aroca Ángel , Pous‐Serrano Salvador
Published: May 2021

Worldwide, hernia repair represents one of the most frequent surgical procedures encompassing a global market valued at several billion dollars. This type of surgery usually requires the implantation of a mesh that needs the appropriate chemical, physical and biological properties for the type of repair. This review thus presents a description of the types of hernias, current hernia repair methods, and the state of the art of prosthetic meshes for hernia repair providing the most important meshes used in clinical practice by surgeons working in this area classified according to their biological or chemical nature, morphology and whether bioabsorbable or not. We emphasise the importance of surgical site infection in herniatology, how to deal with this microbial problem, and we go further into the future research lines on the production of advanced antimicrobial meshes to improve hernia repair and prevent microbial infections, including multidrug‐resistant strains. A great deal of progress has been made in this biomedical field in the last decade. However, we are still far from an ideal antimicrobial mesh that can also provide excellent integration to the abdominal wall, mechanical performance, low visceral adhesion and minimal inflammatory or foreign body reactions, among many other problems.
Suicidal ideation among active and nonactive/former Latter‐day Saint sexual minorities
Authors: Lefevor G. Tyler , McGraw James S. , Skidmore Samuel J.
Published: May 2021

Sexual minorities (SMs) in the Church of Jesus Christ of Latter‐day Saints (LDS) experience a number of unique risks related to their religious/spiritual and SM experience that may increase their likelihood of experiencing suicidal ideation (SI) and ultimately dying by suicide. However, it is unclear which aspects of these experiences are responsible for elevated SI. It is further unclear whether religiousness/spirituality and minority stress relate to SI similarly for active and nonactive/former LDS SMs. To address this gap, we examined data from 602 active and nonactive/former LDS SMs. Active and nonactive LDS SMs reported similar degrees of SI and minority stress but differing degrees of religiousness/spirituality with active LDS SMs reporting more religiousness/spirituality than nonactive/former LDS SMs. Several variables were associated with increased SI in both groups including positive religious coping, interpersonal religious struggles, internalized homonegativity, and concealment. Other variables were associated with decreased SI in both groups including resolving conflict between sexual and religious identities, family support, and friend support. Our results suggest that whether LDS SMs are active in their faith is an important factor to consider when understanding how religiousness/spirituality and minority stress relate to SI.
Utility of lignin‐modifying enzymes: a green technology for organic compound mycodegradation
Authors: Dhagat Swasti , Jujjavarapu Satya Eswari
Published: May 2021

Organic compounds such as heavy metals, polychlorinated biphenyls, petroleum hydrocarbons, pesticides and phenolic derivatives have become major environmental pollutants. These compounds are also known as xenobiotics as they are not produced or essentially utilized by any organism for its biological function. Xenobiotics are degraded by many microorganisms owing to the presence of enzymes that break down these complex compounds and utilize them as substrates. One group of enzymes commonly produced by microorganisms that have a major role in the degradation of xenobiotic organic compounds are lignin‐modifying enzymes, as the chemical structure of xenobiotic compounds resembles lignin. Lignin‐modifying enzymes are oxidative enzymes that have an important role in degrading abundant lignocellulosic wastes present in the environment. These enzymes include laccase, lignin peroxidase, manganese‐dependent peroxidase and versatile peroxidase, and are produced by bacteria and fungi, with white rot fungi being the major producer. They have a wide range of applications in detoxification of industrial and agricultural wastes and xenobiotic organic compounds. Mycodegradation or fungal degradation forms an important part of the ecosystem, as fungi can degrade many toxic substances because the fungal mycelia penetrate deep into substrates and help colonize the substrates rapidly. In this review, the problems associated with xenobiotic compounds are explained. Fungal lignin‐modifying enzymes, as a probable solution to xenobiotic degradation, have also been discussed in detail, along with their mechanism of action. © 2021 Society of Chemical Industry (SCI).
High gestational folic acid supplementation prevents hypoxia‐ischemia‐induced caspase‐3 augmenting without changing synapsin and H3 methylation levels in the rat hippocampus
Authors: Deniz Bruna Ferrary , Confortim Heloísa Deola , Miguel Patrícia Maidana , Bronauth Loise , Fernandes Isabela R. , Muotri Alysson R. , Pereira Lenir Orlandi
Published: May 2021

Perinatal asphyxia is a peripartum event that can cause permanent sequelae to the newborns, affecting the brain development. Recently, it has been demonstrated that epigenetics mechanisms play an important role in this injury and that folic acid (FA) supplementation during pregnancy can affect these epigenetics modifications as well as gene expression. We have identified both positive and negative effects of FA treatment in rats submitted to a model of neonatal hypoxia‐ischemia (HI). Considering that FA supplementation is already used in pregnant women and that HI occurs in the peripartum period, this study was designated to evaluate how gestational FA supplementation and neonatal HI affect: apoptosis (caspase‐3) and expression of synaptic proteins (synapsin and PSD‐95) and the methylation of histone H3 lysine (K) 4 and 27 in the rat hippocampus. Pregnant Wistar rats were divided according to the diets: standard (SD), supplemented with 2 mg/kg of FA or with 20 mg/kg of FA. HI procedure was performed at the 7th PND. Protein expression and H3 methylation were evaluated at the 60th PND in the rats’ hippocampus. Neonatal HI increased caspase‐3 expression decreased synapsin expression and reduced H3K4me2, ‐me3 and H3K27me2, ‐me3 in the ipsilateral hippocampus. FA only prevented the augment in caspase‐3 expression. In conclusion, neonatal HI caused lasting effects on caspase‐3‐mediated cell death (prevented by the FA) and synaptic proteins in the rats’ hippocampus. This is the first study to show that histone modifications may contribute to these pathological findings in the hippocampus of HI animals.
Micro‐ and nano‐tomography analysis of mouse soleus muscle using radiation
Authors: Jang Sang‐Hun , Lee Jiwon , Lee Onseok
Published: May 2021

In this study, we analyze radiation images of muscle structure of mice soleus muscles using radiation source‐based microtomography and nanotomography. Soleus muscle samples were collected for analysis from 8‐week‐old male Institute of Cancer Research mice. First, phase‐contrast X‐ray microtomography was employed in these experiments. Then to obtain images with excellent contrast, imaging was performed using monochromatic light with excellent transmission power. To analyze additional muscle structures in higher magnification images than these images, nanotomography was performed, which facilitated obtaining high‐magnification and high‐resolution images. Muscle tissue microstructures were confirmed through three‐dimensional images obtained from phase‐contrast X‐ray microtomography. Thus, the muscle tissue's overall shape at microscopic level can be captured. Additionally, a single muscle fiber was examined using hard X‐ray nano‐imaging, through which we could observe the alignment of countless myofibrils, that is, actin and myosin filaments in the muscle fibers. Thus, the methodology adopted here proved to be advantageous in analyzing the muscle tissue's overall structure with microtomography and in observing the myofibrils in detail using nanotomography.
Circulating tumor DNA as a predictive marker for occult metastases in pancreatic cancer patients with radiographically non‐metastatic disease
Authors: Hata Tatsuo , Mizuma Masamichi , Iseki Masahiro , Takadate Tatsuyuki , Ishida Masaharu , Nakagawa Kei , Hayashi Hiroki , Morikawa Takanori , Motoi Fuyuhiko , Unno Michiaki
Published: May 2021

Purpose

To elucidate the effectiveness of circulating tumor DNA (ctDNA) for predicting occult metastases in patients with pancreatic cancer without apparent metastases.

Methods

Circulating tumor DNA was obtained from plasma samples of 165 patients with pancreatic cancer and analyzed using droplet digital PCR. The prevalence and allele frequencies of ctDNA were compared across different patterns and degrees of metastatic spread.

Results

Of the 142 patients without apparent metastases who underwent abdominal exploration, 39 (27.5%) harbored occult metastases including positive peritoneal lavage cytology. The prevalence of ctDNA was significantly higher in patients with occult metastases than in those without (41.0% vs 14.6%, P = .001). A markedly high prevalence of ctDNA was observed in patients with radiographically visible metastases (78.3%). ctDNA was found to be an independent predictor of the presence of occult metastases (odds ratio: 3.113, P = .039), and its diagnostic performance in combination with tumor markers had a sensitivity of 66.7% and a specificity of 81.6%. In 62 treatment‐naïve patients without metastases, multivariate analysis identified the presence of ctDNA as an independent prognostic factor (hazard ratio: 6.311, P = .001).

Conclusion

Circulating tumor DNA can help predict the presence of occult metastases in pancreatic cancer patients with radiographically non‐metastatic disease.
Clinical impact of recombinant thrombomodulin administration on disseminated intravascular coagulation due to severe acute cholangitis (Recover‐AC study)
Authors: Ogura Takeshi , Eguchi Takaaki , Nakahara Kazunari , Kanno Yoshihide , Omoto Shunsuke , Itonaga Masahiro , Kuroda Taira , Hakoda Akitoshi , Ikeoka Seitaro , Takagi Megumi , Okada Akihiko , Sato Junya , Morita Ryo , Michikawa Yousuke , Ito Kei , Koshita Shinsuke , Takenaka Mamoru , Kitano Masayuki , Koizumi Mitsuhito , Higuchi Kazuhide
Published: May 2021

Background and Aim

Recombinant thrombomodulin (rhTM) is potentially effective in the treatment of disseminated intravascular coagulation (DIC). Several studies related to drugs for the treatment of acute cholangitis have shown negative results in improvement of overall survival (OS) with rhTM. The aim of this multicenter study was to evaluate the clinical effectiveness of rhTM in patients with acute cholangitis and sepsis‐induced DIC who underwent biliary drainage.

Methods

A total of 284 consecutive patients, who were complicated with sepsis‐induced DIC due to severe acute cholangitis, were included (rhTM group, n = 173; non‐rhTM, n = 111) in this study. The primary outcome was the DIC resolution rate at 7 days after starting treatment. The 28‐day survival rate was secondarily evaluated.

Results

DIC scores in the rhTM group improved significantly compared with the non‐rhTM group on day 7 (P = .020). According to multivariate analysis, etiology of cholangitis (malignant, HR 2.28), rhTM (non‐administration, HR 4.13), and DIC score (≥5, HR 2.46) were significant factors associated with failed DIC resolution on day 7. Propensity score matching created 103 matched pairs. Survival rate at day 28 was significantly higher in rhTM group (94.3%) compared with non‐rhTM group (82.6%; P = .048) after propensity score matching. rhTM (non‐administration, HR 2.870), DIC score (≥5, HR 2.751), and APACHE II score (≥20, HR 9.310) were significant factors associated with decreasing survival rate at day 28.

Conclusion

In conclusion, rhTM seemed to improve patient survival, but future studies should only include patients with benign or malignant disease and should be performed according to APACHE II scores.