bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Stable CsPbX3/PbSO4 Core/Shell Nanocrystals Synthesized by a Simple Post‐Treatment Strategy
Authors: Zhong Qixuan , Liu Jun , Chen Shuhua , Li Pengli , Chen Jianian , Guan Wenhao , Qiu Yinghua , Xu Yong , Cao Muhan , Zhang Qiao
Published: December 2020

All‐inorganic lead halide perovskite (CsPbX3, X = Cl, Br, I, or their mixture) nanocrystals (NCs) have recently emerged as a promising photoelectric material; however, developing highly stable CsPbX3 NCs still remains a challenge due to their intrinsic ionic nature. This work presents a simple and facile post‐treatment strategy to encapsulate CsPbX3 NC with PbSO4 nanoshell at single‐particle level. Compared to pristine CsPbX3 NCs, the as‐prepared CsPbX3/PbSO4 NCs exhibit significant enhancement in the optical properties. Benefiting from the efficient protection of inert PbSO4 nanoshell, the obtained CsPbX3/PbSO4 core/shell NCs demonstrate great stability against polar solvents, including ethanol and acetone, and light irradiation. Furthermore, anion‐exchange reaction is strongly restricted upon the encapsulation of PbSO4 shell. This work provides an alternative approach for the synthesis of highly stable CsPbX3 NCs, and paves a new way for the preparation of core/shell heterostructures based on lead halide perovskite NCs.
Narrowband Emission from Organic Fluorescent Emitters with Dominant Low‐Frequency Vibronic Coupling
Authors: Qiu Xu , Tian Guangjun , Lin Chengwei , Pan Yuyu , Ye Xiyun , Wang Bohan , Ma Dongge , Hu Dehua , Luo Yi , Ma Yuguang
Published: December 2020

Organic fluorescent emitters with narrowband emissions are highly desirable for high‐resolution organic light‐emitting diode (OLED) display technology. In principle, this can be achieved by specifically controlling the intrinsic structural relaxation and vibronic coupling in the excited state. Here, a design strategy to realize narrowband emission of organic fluorescent emitters is proposed by significantly enhancing the low‐frequency vibronic coupling strength (Λ) while simultaneously reducing the high‐frequency Λ of the commonly involved stretching modes. The quinolino‐[3,2,1‐de]acridine‐5,9‐dione (QAO) species is found to be directly associated with this design principle. By introducing single bond‐linked peripheral moieties into the QAO core, the constructed QAO derivatives are shown to exhibit better performance, by achieving a full width at half‐maximum of 23 nm/0.13 eV in toluene for the narrowest band as well as 27 nm/0.15 eV in doped devices, with negligible dependence on the doping concentrations. The maximum external quantum efficiency of the fabricated blue OLED is 17.5%.
Spatio‐Spectral‐Temporal Imaging of Fast Transient Phenomena Using a Random Array of Pinholes
Authors: Anand Vijayakumar , Ng Soon Hock , Katkus Tomas , Juodkazis Saulius
Published: December 2020

Fast transient phenomena such as light–matter interactions, rapid electrical discharge, light scattering in tissues, and biochemical reactions that generate light signatures can be studied using high‐speed cameras. Herein, a lensless, single camera shot, spatio‐spectral‐temporal imaging technique based on chaotic waves is proposed and demonstrated. A random pinhole array is used as a chaotic wave generator to map every color point source in the object space to a unique random distribution. The spatio‐spectral signatures are recorded for two cases using a monochrome high‐speed camera, and an extensive library of spatio‐spectral signatures is synthesized by computational interpolation and extrapolation using the scaling factors of the Fresnel propagators. A spark generated by an abrupt electrical discharge is converted into a chaotic wave using the same pinhole array, and the hologram is recorded using the monochrome high‐speed camera in time. The recorded hologram of the spark is decomposed into spatio‐spectral 4D events in time with a temporal resolution of 40 μs using the semisynthetic spatio‐spectral signatures.
Threshold Size Effects in the Patterned Crystallization of Hybrid Halide Perovskites for Random Lasing
Authors: Hu Jingyun , Wang Meng , Tang Fawei , Liu Miao , Mu Yunyun , Fu Yulan , Guo Jinxin , Song Xiaoyan , Zhang Xinping
Published: December 2020

A threshold effect in the periodical patterning of the hybrid halide perovskites and a directional output coupling effect in the incoherent random lasing from the patterned materials are reported. Using 1D gratings, the random crystallization process is confined into the grating grooves, producing continuous microstrips of CH3NH3PbBr3 along the groove channels. However, the confinement is strongly dependent on the width of the grating grooves, which can be optimized by tuning the patterning periods. It is thus discovered that the most orderly arranged crystal strips are achieved for a grating period of 10 μm, corresponding to a channel width of about 5 μm, which is the lower limit for the formation of continuous crystal strips. Complicated interfaces inside such randomly organized multicrystals supplied scattering centers for optical gain mechanisms. Thus, incoherent random lasing actions are observed for all of these patterned structures, however, the best lasing performance is achieved for a grating period of 10 μm, which agrees with the highest quality of the crystal strips. The patterned substrate with a 1D grating supplies mechanisms for directional crystallization of hybrid halide perovskites and directional output coupling of random laser emission, enhancing significantly the practical application possibilities of such random lasers.
Enhanced Sampling Path Integral Methods Using Neural Network Potential Energy Surfaces with Application to Diffusion in Hydrogen Hydrates
Authors: Cendagorta Joseph R. , Shen Hengyuan , Bačić Zlatko , Tuckerman Mark E.
Published: December 2020

The high cost of ab initio molecular dynamics (AIMD) simulations to model complex physical and chemical systems limits its ability to address many key questions. However, new machine learning‐based representations of complex potential energy surfaces have been introduced in recent years to circumvent computationally demanding AIMD simulations while retaining the same level of accuracy. As these machine learning methods gain in popularity over the next decade, it is important to address the appropriate way to develop and integrate them with well‐established simulation methods. This paper details the parameterization and training, using accurate electronic structure calculations, of artificial neural network potentials (NNPs) to model the intermolecular interactions in a hydrogen clathrate hydrate, wherein hydrogen molecules are confined inside the cavities of the 3D crystalline framework of hydrogen‐bonded water molecules. This new NNP is used in conjunction with new path‐integral based enhanced sampling methods, for inclusion of nuclear quantum effects and promotion of free energy barrier crossing, in order to determine properties that are important for understanding the diffusion of hydrogen gas in the clathrate system. These simulations demonstrate the influence of cage occupancy on the free energy barriers that determine the diffusivity of hydrogen gas through the network of large cages.
Enhanced Thermoelectric Performance of Ba8Ga16Ge30 Clathrate by Modulation Doping and Improved Carrier Mobility
Authors: Zhang Yifei , Brorsson Joakim , Qiu Ren , Palmqvist Anders E. C.
Published: December 2020

Type‐I inorganic clathrates are promising high temperature thermoelectric materials. They are known for their intrinsic low thermal conductivity, but a moderate power factor leaves room for further improvement. In this paper, a new route for improving the power factor by enhanced carrier mobility achieved via modulation doping is reported. A series of clathrates with composition Ba8(AlxGa1−x)16Ge30 are synthesized through ball milling and spark plasma sintering of mixtures of Ba8Al16Ge30 and Ba8Ga16Ge30. Among the materials with x = 0.20, 0.23, and 0.25, it is found that the electrical conductivity is significantly enhanced with increasing x, while the Seebeck coefficient decreases slightly. It is further revealed that the carrier mobility of the sintered sample x = 0.25 is greatly increased, reaching a value that exceeds that for a single crystal. Electron microscopy analysis reveals that the material consists of a heterostructure and is composed of a Ga‐rich clathrate matrix phase and Al particles, suggesting that the power factor enhancement is due to modulation doping. As a result, the highest power factor is achieved for Ba8(Al0.25Ga0.75)16Ge30, with a value of 1.89 mW m−1 K−2 at 800 °C. Consequently, the maximum zT of sample x = 0.25 reaches 0.93 at 800 °C.
Counter‐Intuitive Structural Instability Aroused by Transition Metal Migration in Polyanionic Sodium Ion Host
Authors: Liu Rui , Zheng Shiyao , Yuan Yifei , Yu Pengfei , Liang Ziteng , Zhao Weimin , Shahbazian‐Yassar Reza , Ding Jianxu , Lu Jun , Yang Yong
Published: December 2020

The structure of polyanionic materials is conventionally known to be free of transition metal migration and structurally stable when storing/releasing sodium ions. Herein, the observation of enhanced cycling stability of a typical polyanionic cathode, Na3VCr(PO4)3 (NVCP) at lower temperature (−15 °C vs 30 °C), triggers the exploration of its structural origins with a surprising finding that the migratable nature of vanadium in NVCP leads to detrimental structural degradation of the polyanionic host upon cycling. The correlation between long range and short range structural change associated with this atomic migration is established via a strong combination of various in situ/ex situ characterization tools, revealing the essential V–to–Na1 site migration. Such transition metal migration is effectively suppressed when V atoms are pinned to their original position in the lattice by lowering the temperature. More importantly and practically, a room temperature‐based deep sodiation strategy is further developed to recover the structure. This work challenges the long‐standing assumption of the stability of the polyanionic framework structure and calls for urgent attention to the structural understanding of the NVCP system as well as strategy development for property enhancement.
DFT Mechanistic Study on Palladium‐Catalyzed Redox‐Neutral Hydroarylation of Unactivated Alkenes with Arylboronic Acids
Authors: Zhou Jianguo , Zhou Yongzhu , Li Yanxia , Zhang Jie , Zhang Lei
Published: December 2020

Density functional calculations were carried out on the mechanism of a palladium‐catalyzed hydroarylation reaction of β,γ‐unsaturated carbonyl compounds with arylboronic acids reported by Engle's group. The proposed reaction pathway consists of several key mechanistic steps, including the chelation of substrate 1 a, transmetalation of organoboron 2 a, migratory insertion, protodepalladation, and dechelation of product 3 a, among which the transmetalation step is rate‐determining with a free‐energy barrier of 27.0 kcal/mol. Experimental researchers proposed that the chelation of Daugulis's 8‐aminoquinoline (AQ) directing group facilitated the desired hydroarylation in a γ‐selective manner. However, the present study revealed that the chelation of AQ indeed retarded the delivery of the aryl group to the double bond and the regioselectivity was not necessarily the result of this group. Indeed, it could effectively prevent the homocoupling of 2 a, because the homocoupling was predicted to be easier than the desired hydroarylation in the absence of AQ. Additionally, some reductive coupling pathways between 1 a and 2 a were designed, and the competition of them was discussed in great detail. Lastly, the extension of this synthetic strategy to other types of alkenes was predicted.
Incorporating of layered double hydroxide/sepiolite to improve the performance of sulfonated poly(ether ether ketone) composite membranes for proton exchange membrane fuel cells
Authors: Charradi Khaled , Ahmed Zakarya , Thmaini Noura , Aranda Pilar , Al‐Ghamdi Youssef O. , Ocon Pilar , Keshk Sherif M. A. S. , Chtourou Radouane
Published: December 2020

Sulfonated poly(ether ether ketone) (SPEEK) with a low sulfonation degree was blended using nanofiller layered double hydroxide (LDH, Mg2AlCl)/sepiolite nanostructured material as additive to use as an electrolyte membrane for fuel cell application. Characterization assessments, that is, mechanical stability, thermal gravimetric analysis, ion exchange capability, swelling properties, water uptake capacities, electrochemical impedance spectroscopy analysis, and Fourier transform infrared spectroscopy of the composite membranes were conducted. The presence of LDH/sepiolite nanoarchitectured material within SPEEK was found to have the highest water retention and proton conductivity value at high temperature rather than LDH/SPEEK and pristine SPEEK membranes.
The lasting impact of colonial trauma in India: Links to Hindu nationalism
Authors: Rao Jyoti M.
Published: December 2020

Hindu supremacist ideology and Hindu nationalism are recently resurgent in India's far‐right government. This ideology has manifested itself in increased religious intolerance and human rights violations, including escalating oppression of religious and other minorities, journalists, civil rights advocates, and others. Using psychoanalytic theories of social trauma, groups, and prejudice, I link present‐day disturbances to the profound social trauma engendered by the colonial occupation of India by the British in multiple forms for nearly 200 years.
Pt Nanoparticles Supported on a Dynamic Boronate Ester‐Based G‐quadruplex Hydrogel as a Nanoreactor
Authors: Ghosh Tapas , Biswas Ankan , Bhowmik Sourav , Das Apurba K.
Published: December 2020

Herein, we have reported a dynamic boronic ester mediated guanosine (G) based G‐quadruplex hydrogel as an ideal template for in situ and ‘green chemical’ approach for the synthesis and stabilization of Pt NPs. 11B NMR and FT‐IR spectra reveal the formation of dynamic boronate ester bonds. The TEM images of the G‐quadruplex hydrogel reveal entangled three‐dimensional (3D) crosslink nanofibrillar networks with average diameter of 20 nm. Similarly, AFM images of the hydrogel show dense nanofibrillar assembly with an average height of 6 nm. The in situ generated Pt NPs have been characterized using TEM and XPS techniques. The average size of the nanofiber supported Pt NPs is 1.5 nm. The Pt NPs embedded G‐quadruplex hydrogel shows better mechanical stiffness than the native hydrogel as the storage modulus (G′) increases to 2250 Pa from 317.08 Pa after the in situ generation of Pt NPs. Furthermore, G‐quadruplex hydrogel supported Pt NPs have been used as a catalytic system for hydrogenation reaction of different aromatic nitro compounds in aqueous medium. The use of G‐quadruplex molecular system as a template for the synthesis and stabilization of metal NPs would be an interesting area of research.
In situ Polymerized FDU‐12/Poly(methyl methacrylate) and FDU‐12/polyamide 6 Nanocomposites for Cd2+ Adsorption
Authors: Zabihi Samyar , Jamshidian Sahar , Soltani Roozbeh , Pelalak Rasool , Heidari Zahra , Marjani Azam , Ghadiri Mahdi
Published: December 2020

Large‐pore mesoporous silica FDU‐12 was synthesized and functionalized with silane coupling agents bearing methacrylate and diamino groups. Diamino‐functionalized FDU‐12/polyamide 6 and methacrylate‐functionalized FDU‐12/poly(methyl methacrylate) nanocomposites were prepared via in situ polymerization approach. These two synthesized nanocomposites were used as potential adsorbents for the removal of Cd2+ cations from aqueous media. The impact of different adsorption factors affecting the adsorption process was investigated, and isotherm and kinetic studies were conducted to gain a better understanding of adsorption mechanisms involved in the removal process of Cd2+ by the adsorbents. Experimental and computational results demonstrated that the adsorbents have acceptable performance for Cd2+ uptake.
Numerical simulation of CO2 adsorption in a fluidized bed using solid‐supported amine sorbent
Authors: Esmaeili Rad Farnaz , Abbasian Javad , Arastoopour Hamid
Published: December 2020

The computational fluid dynamics (CFD) approach was used to simulate the gas‐solid flow in the carbonation section of a circulating fluidized bed designed by the National Energy Technology Laboratory for carbon capture. The extent of the carbon dioxide adsorption using particle‐supported amine sorbents was simulated using a two‐dimensional reactive CFD model. This study showed not only the predictive capability of our reacting CFD, but also the potential high carbon capture rate by solid sorbents using fluidized bed technology.
Versatile and Tunable Poly(Ethylene Glycol)‐Based Hydrogels Crosslinked through the Ugi Reaction
Authors: Padrão Inês , Fernandes Cláudia S. M. , Esteves Carina , Fernandes Tiago , Pina Ana S. , Roque Ana Cecília A.
Published: December 2020

The four‐component Ugi condensation reaction has been investigated to assemble chemically crosslinked hydrogels using multivalent star‐shaped poly(ethylene glycol) components. The resulting biocompatible hydrogels are highly versatile in composition and function. It is shown that acid, aldehyde, and cyanide components can be varied yielding materials with precise structure and tunable stiffness. Additionally, the resulting hydrogels were proven extremely robust to consecutive drying‐swelling cycles. This property was explored to develop a reversible humidity colorimetric sensor gel. Overall, this work demonstrates the application of the four‐component Ugi reaction as a powerful tool to quickly generate crosslinked gels with precise control in chemical composition.
Rational Design of Helix‐Stabilized Antimicrobial Peptide Foldamers Containing α,α‐Disubstituted Amino Acids or Side‐Chain Stapling
Authors: Hirano Motoharu , Saito Chihiro , Goto Chihiro , Yokoo Hidetomo , Kawano Ryuji , Misawa Takashi , Demizu Yosuke
Published: December 2020

Antimicrobial peptides (AMPs) are expected to be good candidate molecules for novel antimicrobial therapies. Most AMPs exert their antimicrobial activity through disruption of microbial membranes due to their amphipathic properties. Recently, the helical peptide ‘Stripe’ was reported by our group, a rationally designed amphipathic AMP focused on distribution of natural cationic and hydrophobic amino acid residues. In this study, a set of Stripe‐based AMP foldamers was designed, synthesized and investigated that contain α,α‐disubstituted amino acids or side‐chain stapling to stabilize their helical structures. Our results showed that a peptide containing 2‐aminoisobutyric acid (Aib) residues exhibited potent antimicrobial activity against both Gram‐positive S.aureus (MIC value: 3.125 μM) and Gram‐negative bacteria (including a multidrug‐resistant strain, MDRP, MIC value: 1.56 μM), without significant hemolytic activity (>100 μM). Electrophysiological measurements revealed that this peptide formed stable pores in a 1,2‐dioleoyl‐sn‐glycero‐3‐phosphoethanolamine (DOPE)/1,2‐dioleoyl‐sn‐glycero‐3‐phosphoglycerol (DOPG) bilayer but not in a dioleoylphosphocholine (DOPC) bilayer. The introduction of Aib residues into Stripe could be a promising way to increase the antimicrobial activity of AMP foldamers, and the peptide could represent a promising novel therapeutic candidate to treat multidrug‐resistant bacterial infection.
The effect of ceramic thickness on opalescence
Authors: Valizadeh Sara , Mahmoudi Nahavandi Alireza , Daryadar Marzieh , Özcan Mutlu , Hashemikamangar Sedighe Sadat
Published: December 2020

Objectives

Creating a tooth‐like appearance by use of dental ceramics is still a challenge. Opalescence is a unique property of dental enamel, attempted to be mimicked by dental restorative materials. This study aimed to assess the effect of ceramic thickness on opalescence.

Materials and methods

Twenty‐four discs were fabricated of feldspathic ceramic, IPS e.max, zirconia and Enamic ceramics with 10 mm diameter and 0.5 and 1 mm thicknesses (n = 12). The opalescence of ceramic specimens was calculated by measuring the difference in yellow‐blue axis (CIE ∆b*) and red‐green axis (CIE ∆a*) between the transmitted and reflected spectra. One‐way ANOVA was applied to compare the opalescence of different ceramic specimens with variable thicknesses at .05 level of significance.

Results

The opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramic specimens with 0.5 mm thickness was 1.06 ± 0.15, 3.39 ± 0.15, 1.98 ± 0.15 and 1.44 ± 0.15, respectively. By increasing the thickness to 1 mm, the opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramics changed to 1.12 ± 0.15, 1.47 ± 0.15, 3.85 ± 0.15 and 2.00 ± 0.15, respectively. In all groups except for IPS e.max, the mean opalescence of 1‐mm‐thick specimens was higher than that of 0.5‐mm‐thick specimens.

Conclusion

Type and thickness of ceramic affect its opalescence. The opalescence of all ceramic specimens tested in this study with 0.5 and 1 mm thicknesses was lower than that of the enamel.
Diagnostic value of urine cytology in detecting histologic variants of urothelial carcinomas in the urinary bladder: Cytopathologic correlation of 72 cases
Authors: Yoo Youngeun , Choi Euno , Lee Dong Hyeon , Park Sanghui , Sung Sun Hee
Published: December 2020

Background

Precise identification of histologic variants in urothelial carcinoma (UC) is important because some histologic types have a poor prognosis and clinical management varies. Urine cytology is used for bladder cancer screening, but the cytomorphologic features of histologic variants have not been well described. In the current study, we evaluate the effectiveness of urine cytology in detecting histologic variants of UC in the urinary bladder.

Methods

Seventy‐two urine cytology specimens from patients diagnosed with high‐grade UCs by radical cystectomy were retrospectively reviewed and correlated with histopathologic findings of subsequent radical cystectomy specimens.

Results

Of 72 total cases, 24 (33%) cases showed six histologic variants in corresponding surgical specimens, including squamous differentiation (13 cases), plasmacytoid variant (3 cases), micropapillary variant (3 cases), sarcomatoid variant (3 cases), giant cell variant (1 case), and glandular differentiation (1 case). Histopathology and cytomorphology were well correlated in 13 cases (54%), with squamous differentiation in 11 of 13 cases (85%), micropapillary features in 1 out of 3 cases (33%), and spindle cell/sarcomatoid features in 1 of 3 cases (33%). Furthermore, mucosal involvement by histologic variants, not amount of histologic variant, was related to high concordance rates between cytology and histology diagnosis.

Conclusions

The morphologic features of some histologic variants of high‐grade UCs, such as squamous differentiation, micropapillary variant, and sarcomatoid variant, are partially reflected on urine cytology. In addition, mucosal involvement by histologic variants was associated with a higher detection rate of histologic variants in urine cytology.
Water storage decisions will determine the distribution and persistence of imperiled river fishes
Authors: Dibble Kimberly L. , Yackulic Charles B. , Kennedy Theodore A. , Bestgen Kevin R. , Schmidt John C.
Published: December 2020

Managing the world’s freshwater supply to meet societal and environmental needs in a changing climate is one of the biggest challenges for the 21st century. Dams provide water security; however, the allocation of dwindling water supply among reservoirs could exacerbate or ameliorate the effects of climate change on aquatic communities. Here, we show that the relative sensitivity of river thermal regimes to direct impacts of climate change and societal decisions concerning water storage vary substantially throughout a river basin. In the absence of interspecific interactions, future Colorado River temperatures would appear to benefit both endemic and nonnative fish species. However, endemic species are already declining or extirpated in locations where their ranges overlap with warmwater nonnatives and changes in water storage may lead to warming in some of the coolest portions of the river basin, facilitating further nonnative expansion. Integrating environmental considerations into ongoing water storage negotiations may lead to better resource outcomes than mitigating nonnative species impacts after the fact.
Recent applications of plant cell culture technology in cosmetics and foods
Authors: Krasteva Gergana , Georgiev Vasil , Pavlov Atanas
Published: December 2020

Plants have been used as the main source of phytochemicals with nutritional, medicinal, cultural and cosmetic applications since times immemorial. Nowadays, achieving sustainable development, global climate change, restricted access to fresh water, limited food supply and growing energy demands are among the critical global challenges faced by humanity. Plant cell culture technology has the potential to address some of these challenges by providing effective tools for sustainable supply of phyto‐ingredients with reduced energy, carbon and water footprints. The main aim of this review is to discuss the recent trends in the development of plant cell culture technologies for production of plant‐derived substances with application in food products and cosmetic formulations. The specific technological steps and requirements for the final products are discussed in the light of the advances in cultivation technologies used for growing differentiated and undifferentiated plant in vitro systems. Future prospects and existing challenges of the commercialization of plant cell culture‐derived products have been outlined through the prism of the authors’ point of view. We expect this review will encourage scientists, policymakers and business enterprises to join efforts for speeding‐up the mass commercialization and popularization of plant cell culture technology as an eco‐friendly alternative method for sustainable production of plant‐derived additives with application in food and cosmetic products.
Recurrent chromosomal imbalances provide selective advantage to human embryonic stem cells under enhanced replicative stress conditions
Authors: Mus Liselot M. , Van Haver Stéphane , Popovic Mina , Trypsteen Wim , Lefever Steve , Zeltner Nadja , Ogando Yudelca , Jacobs Eva Z. , Denecker Geertrui , Sanders Ellen , Van Neste Christophe , Vanhauwaert Suzanne , Decaesteker Bieke , Deforce Dieter , Van Nieuwerburgh Filip , Mestdagh Pieter , Vandesompele Jo , Menten Björn , De Preter Katleen , Studer Lorenz , Heindryckx Björn , Durinck Kaat , Roberts Stephen , Speleman Frank
Published: December 2020

Human embryonic stem cells (hESCs) and embryonal tumors share a number of common features, including a compromised G1/S checkpoint. Consequently, these rapidly dividing hESCs and cancer cells undergo elevated levels of replicative stress, inducing genomic instability that drives chromosomal imbalances. In this context, it is of interest that long‐term in vitro cultured hESCs exhibit a remarkable high incidence of segmental DNA copy number gains, some of which are also highly recurrent in certain malignancies such as 17q gain (17q+). The selective advantage of DNA copy number changes in these cells has been attributed to several underlying processes including enhanced proliferation. We hypothesized that these recurrent chromosomal imbalances become rapidly embedded in the cultured hESCs through a replicative stress driven Darwinian selection process. To this end, we compared the effect of hydroxyurea‐induced replicative stress vs normal growth conditions in an equally mixed cell population of isogenic euploid and 17q + hESCs. We could show that 17q + hESCs rapidly overtook normal hESCs. Our data suggest that recurrent chromosomal segmental gains provide a proliferative advantage to hESCs under increased replicative stress, a process that may also explain the highly recurrent nature of certain imbalances in cancer.
Linear stability of convection in a vertical channel filled with nanofluid saturated porous medium
Authors: Srinivasacharya D. , Barman Dipak
Published: December 2020

The convection in a vertical channel filled with a porous medium saturated by a nanofluid is studied numerically. The effects of Brownian motion and thermophoresis are incorporated in the model used for nanofluid. Also, the flow within the porous region is governed by Brinkman's equation. The generalized eigenvalue problem for the perturbed state is obtained from a normal mode analysis and solved using the Chebyshev spectral collocation method. The Rayleigh number is expressed as an implicit function of the wavenumber with other parameters. The critical wavenumber and the critical Rayleigh number are calculated for different parameters. The preferred modes under critical conditions are detected.
The BTLA and PD‐1 signaling pathways independently regulate the proliferation and cytotoxicity of human peripheral blood γδ T cells
Authors: Hwang Hyun J. , Lee Jae J. , Kang Sung H. , Suh Jin K. , Choi Eun S. , Jang Seongsoo , Hwang Sang‐Hyun , Koh Kyung‐Nam , Im Ho J. , Kim Nayoung
Published: December 2020

Background

B‐ and T‐lymphocyte attenuator (BTLA) and programmed cell death‐1 (PD‐1) inhibit γδ T cell homeostasis and activation. This study aimed to determine whether BTLA and PD‐1 signaling pathways were convergent or independent in human peripheral blood γδ T cells. Herein we demonstrate that the signalings of BTLA and PD‐1 regulated proliferation and cytotoxicity of human γδ T cells, respectively.

Methods

Human peripheral blood γδ T cells were cultured with inactivated Jurkat cells in the presence of interleukin‐2 and zoledronate (Zol) for 14 days. Flow cytometry was performed to evaluate the phenotypes and functions of γδ T cells.

Results

The proliferation of the γδ T cells was increased when PBMCs were cocultured with inactivated herpes virus entry mediator (HVEM)low Jurkat cells. The cytotoxicity of the expanded γδ T cells was not affected by coculture with inactivated HVEMlow Jurkat cells and was further increased in the presence of anti‐PD‐L1 mAb. These results suggest that the inactivation of the BTLA signaling pathway during expansion could help produce more γδ T cells without compromising γδ T cell function. The inhibition of BTLA or PD‐1 signaling repressed phosphorylation of the src homology region 2‐containing protein tyrosine phosphatase 2 and increased the phosphorylation of protein kinase B in γδ T cells. However, there were no synergistic or additive effects by a combination of BTLA and PD‐1 blockade.

Conclusion

These results suggest that BTLA signaling is crucial in regulating γδ T cell proliferation and function and that the BTLA and PD‐1 signaling pathways act independently on the proliferation and cytotoxicity of human peripheral γδ T cells.
MicroRNA‐425‐3p inhibits myocardial inflammation and cardiomyocyte apoptosis in mice with viral myocarditis through targeting TGF‐β1
Authors: Li Junhua , Tu Jiehong , Gao Hong , Tang Lu
Published: December 2020

Objective

Emerging articles have profiled the relations between microRNAs and viral myocarditis. This research was unearthed to explore the capacity of miR‐425‐3p on cardiomyocyte apoptosis in mice with viral myocarditis and its mechanism.

Methods

A total of 120 mice were classified into 4 groups in a random fashion (n = 30). The mice were intraperitoneally injected with coxsackievirus type B3 (CVB3) to induce myocarditis. On the 7th day after CVB3 infection, 10 mice in each group were euthanized to assess the heart function indices of mice, observe the pathological conditions, detect myocardial tissue apoptosis, and measure the inflammatory factor levels in myocardial tissues. Expression of miR‐425‐3p, transforming growth factor (TGF‐β1), and apoptosis‐associated proteins in myocardial tissues was determined. The remaining 20 mice in each group were used for survival observation. The luciferase activity assay was implemented to validate the relationship between miR‐425‐3p and TGF‐β1. miR‐425‐3p mimic was transfected into mouse cardiomyocytes HL‐1 and then infected with CVB3 to further verify the regulatory effect of miR‐425‐3p on the cardiomyocyte apoptosis in viral myocarditis.

Results

miR‐425‐3p was lowly expressed in myocardial tissues of mice with viral myocarditis. Overexpressed miR‐425‐3p improved the cardiac function, alleviated pathological conditions, reduced cardiomyocyte apoptosis, decreased Bax and cleaved Caspase‐3 expression, elevated Bcl‐2 expression, decreased levels of inflammatory factors and improved survival rate of mice with viral myocarditis. Luciferase activity assay verified that miR‐425‐3p could bind to TGF‐β1, and overexpressed miR‐425‐3p suppressed TGF‐β1, p‐smad2/smad2 and p‐smad3/smad3 expression. In vitro experiments further verified that overexpression of miR‐425‐3p inhibited the apoptosis of CVB3‐HL‐1 cells, and the addition of TGF‐β1 would reverse this effect.

Conclusion

Our research indicates that miR‐425‐3p is poorly expressed in myocardial tissues of mice with viral myocarditis. Overexpressed miR‐425‐3p inhibits cardiomyocyte apoptosis and myocardial inflammation in mice with viral myocarditis as well as improves their survival rates through suppressing the TGF‐β1/smad axis.
Effect of growth hormone administration on ICSI outcomes in patients with polycystic ovary syndrome and recurrent implantation failure: A retrospective cross‐over study
Authors: Vitale Salvatore Giovanni , Palumbo Marco , Conde‐López Cristina , Mendoza Nicolas , Mendoza‐Tesarik Raquel , Tesarik Jan
Published: December 2020

Synopsis

The administration of growth hormone during ovarian stimulation in women with RIF and PCOS may improve intracytoplasmic sperm injection outcomes.
Your Fries are Less Fattening than Mine: How Food Sharing Biases Fattening Judgments Without Biasing Caloric Estimates
Authors: Taylor Nükhet , Noseworthy Theodore J.
Published: December 2020

Food sharing has become quite popular over the last decade, with companies offering food options specifically designed to be shared. As the popularity has grown, so too has concerns over the potential negative impact on consumer health. Despite companies’ explicit claims to the contrary, critics maintain that food sharing may be encouraging excessive caloric intake. The current article provides the first systematic exploration of why this may be happening. Three main and two supplementary studies suggest that food sharing reduces perceived ownership, which, in turn, leads people to mentally decouple calories from their consequence. Thus, sharing can reduce the perceived fattening potential of a consumption episode without biasing caloric estimates. This phenomenon persists even when explicit caloric information is provided, and it applies to both healthy and unhealthy foods. Importantly, we establish a relevant downstream consequence by illustrating that people tend to subsequently select calorie‐dense foods after underestimating the fattening potential of a shared consumption episode. A roadmap for future research and practical implications are discussed.
Historically recontextualizing Sidman's Tactics: How behavior analysis avoided psychology's methodological Ouroboros
Authors: Imam Abdulrazaq A.
Published: December 2020

Psychology is undergoing major cultural changes methodologically, with efforts to redefine how psychologists analyze and report their data. Davidson (2018) argued that psychology's methodological crises stem from mechanical objectivity involving the adoption of an analytic tool as source of dependable knowledge. This has led to institutionalization, and eventually uncritical ritualistic use, such as happened with null hypothesis statistical testing. Davidson invoked the mythological symbol of the Ouroboros to represent the endless churning of statistical fads. Sidman (1960), in his Tactics of Scientific Research provided a shield from these problems in terms of the premium he placed on the experience, expertise, judgement, and decision‐making of the scientist, that appear to be absent in psychology's ritualized processes.
Can serial cerebral MRIs predict the neuronopathic phenotype of MPS II?
Authors: Vollebregt Audrey A. M. , Ebbink Berendine J. , Rizopoulos Dimitris , Lequin Maarten H. , Aarsen Femke K. , Shapiro Elsa G. , van der Ploeg Ans T. , van den Hout Johanna M. P.
Published: December 2020

Objective

To advance the prediction of the neurocognitive development in MPS II patients by jointly analyzing MRI and neurocognitive data in mucopolysaccharidosis (MPS) II patients.

Methods

Cognitive ability scores (CAS) were obtained by neuropsychological testing. Cerebral MRIs were quantified using a disease‐specific protocol. MRI sumscores were calculated for atrophy, white‐matter abnormalities (WMA) and Virchow‐Robin spaces (VRS). To distinguish between atrophy and hydrocephalus the Evans' index and the callosal angle (CA) were measured. A random effects repeated measurement model was used to correlate CAS with the three MRI sumscores.

Results

MRI (n = 47) and CAS scores (n = 78) of 19 male patients were analyzed. Ten patients were classified as neuronopathic and nine as non‐neuronopathic. Neuronopathic patients had normal cognitive development until age 3 years. Mental age plateaued between ages 3 and 6, and subsequently declined with loss of skills at a maximum developmental age of 4 years. MRIs of neuronopathic patients showed abnormal atrophy sumscores before CAS dropped below the threshold for intellectual disability (<70). White‐matter abnormalities (WMA) and brain atrophy progressed. The calculated sumscores were inversely correlated with CAS (r = −.90 for atrophy and −.69 for WMA). This was not biased by the influence of hydrocephalus as shown by measurement of the Evans' and callosal angle. Changes over time in the Virchow‐Robin spaces (VRS) on MRI were minimal.

Conclusion

In our cohort, brain atrophy showed a stronger correlation to a decline in CAS when compared to WMA. Atrophy‐scores were higher in young neuronopathic patients than in non‐neuronopathic patients and atrophy was an important early sign for the development of the neuronopathic phenotype, especially when observed jointly with white‐matter abnormalities.
MR Measures of Small Bowel Wall T2 Are Associated With Increased Permeability
Authors: Scott Robert A. , Williams Hannah G. , Hoad Caroline L. , Alyami Ali , Ortori Catherine A. , Grove Jane I. , Marciani Luca , Moran Gordon W. , Spiller Robin C. , Menys Alex , Aithal Guruprasad P. , Gowland Penny A.
Published: December 2020

Background

Increased small bowel permeability leads to bacterial translocation, associated with significant morbidity and mortality. Biomarkers are needed to evaluate these changes in vivo, stratify an individual's risk, and evaluate the efficacy of interventions. MRI is an established biomarker of small bowel inflammation.

Purpose

To characterize changes in the small bowel with quantitative MRI measures associated with increased permeability induced by indomethacin.

Study Type

Prospective single‐center, double‐blind, two‐way crossover provocation study.

Subjects

A provocation cohort (22 healthy volunteers) and intrasubject reproducibility cohort (8 healthy volunteers).

Field Strength/Sequence

2D balanced turbo field echo sequences to measure small bowel wall thickness, T2, and motility acquired at 3T.

Assessment

Participants were randomized to receive indomethacin or placebo prior to assessment. After a minimum 2‐week washout, measures were repeated with the alternative allocation. MR measures (wall thickness, T2, motility) at each study visit were compared to the reference standard 2‐hour lactulose/mannitol urinary excretion ratio (LMR) test performed by a lab technician. All analyses were performed blind.

Statistical Tests

Normality was tested (Shapiro–Wilk's test). Paired testing (Student's t‐test or Wilcoxon) determined the significance of paired differences with indomethacin provocation. Pearson's correlation coefficient compared significant measures with indomethacin provocation to LMR. Intrasubject (intraclass correlation) and interrater variability (Bland–Altman) were assessed.

Results

Indomethacin provocation induced a significant increase in LMR compared to placebo (P < 0.05) and a significant increase in small bowel T2 (0.12 seconds compared to placebo 0.07 seconds, P < 0.05). Small bowel wall thickness (P = 0.17) and motility (P = 0.149) showed no significant change. T2 and LMR were positively correlated (r = 0.68, P < 0.05). T2 measurements were robust to interobserver (intraclass correlation 0.89) and intrasubject variability (Bland–Altman bias of 0.005 seconds, 95% confidence interval [CI] –0.04 to +0.05 seconds, and 0.0006 seconds, 95% CI –0.05 to +0.06 seconds).

Data Conclusion

MR measures of small bowel wall T2 were significantly increased following indomethacin provocation and correlated with 2‐hour LMR test results.

Level of Evidence

1

Technical Efficacy Stage

2
Dysregulation of the mevalonate pathway during SARS‐CoV‐2 infection: An in silico study
Authors: Gomez Marti Juan Luis , Wells Alan , Brufsky Adam M.
Published: December 2020

SARS‐CoV‐2 triggers a dysregulated innate immune system activation. As the mevalonate pathway (MVP) prevents the activation of inflammasomes and cytokine release and regulates endosomal transport, compromised signaling could be associated with the pathobiology of COVID‐19. Prior transcriptomic studies of host cells in response to SARS‐CoV‐2 infection have not reported to date the effects of SARS‐CoV‐2 on the MVP. In this study, we accessed public data sets to report in silico investigations into gene expression. In addition, we proposed candidate genes that are thought to have a direct association with the pathogenesis of COVID‐19, and which may be dependent on signals derived from the MVP. Our results revealed dysregulation of genes involved in the MVP. These results were not found when investigating the gene expression data from host cells infected with H3N2 influenza virus, H1N1 influenza virus, or respiratory syncytial virus. Our manually curated gene set showed significant gene expression variability in A549 cells infected with SARS‐CoV‐2, as per Blanco‐Melo et al. data set (GSE147507). In light of the present findings, SARS‐CoV‐2 could hijack the MVP, leading to hyperinflammatory responses. Prompt reconstitution of this pathway with available agents should be considered in future studies.
Periodontal and caries status in unexplained female infertility: A case–control study
Authors: Yildiz Telatar Gul , Gürlek Beril , Telatar Baris Can
Published: December 2020

Background

The aim of this study was to investigate the possible association between maternal periodontal disease and dental caries that affect oral health and unexplained infertility.

Methods

This cross‐sectional case‐control study included 50 fertile women and 50 women with unexplained infertility aged 21 to 39 years. Dental and periodontal parameters were examined to evaluate the oral health of the participants. According to the new periodontal disease classification, periodontitis severity was determined.

Results

In infertile women, the number of advanced caries lesions, the percentage of bleeding on probing (BOP), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were higher (P < 0.05). The DMFT and mean plaque index (PI) were not statistically different between the two groups. The PISA and PESA values were higher in women with unexplained infertility than in fertile women (P = 0.005 and P = 0.002, respectively). In multivariate analysis showed that association of DMFT and BOP variables with periodontitis was found to be significant for all women included in the study and for infertile women only (P = 0.000 and P = 0.012 for DMFT, respectively; P = 0.000 and P = 0.016 for BOP, respectively).

Conclusion

The chronic inflammatory environment caused by periodontitis and advanced carious lesions in women with unexplained infertility should be of great concern as it may have a role in the etiology of infertility.
Evaluating efficacy of a novel dentifrice in reducing probing depths in Stage I and II periodontitis maintenance patients: A randomized, double‐blind, positive controlled clinical trial
Authors: Kaur Maninder , Geurs Nicolaas C. , Cobb Charles M. , Otomo‐Corgel Joan , Takesh Thair , Lee June H. , Lam Tracie M. , Lin Kairong , Nguyen Audrey , Nguyen Brian L. , Wilder‐Smith Petra
Published: December 2020

Background

Compliance to periodontal maintenance therapy (PMT) is essential for long‐term periodontal health. Between PMT visits, patients must maintain good oral hygiene. A dentifrice with demonstrable clinical benefits for use between PMT visits would be highly desirable. The aim of this clinical study was to investigate the effect of a novel dental gel on probing depths (PD) and inflammation when used as a home care dentifrice in Stage I and II periodontitis patients.

Methods

This double‐blind clinical study randomized 65 subjects with Stage I and II periodontitis to the novel dental gel containing 2.6% EDTA, and a commercially available anti‐gingivitis dentifrice with 0.454% stannous fluoride. Primary endpoint was PD at 6 months for those sites with baseline PD ≥ 4 mm and secondary endpoints included whole mouth mean scores of modified gingival index (MGI), modified sulcus bleeding index (mSBI) and plaque index (PI). No SRP was performed at baseline.

Results

Subjects using the novel dentifrice showed significant PD reductions of 1.18 mm (from 4.27 mm at baseline to 3.09 mm at 6 months) compared to 0.93 mm (from 4.23 mm at baseline to 3.30 mm at 6 months) shown for those using the positive control dentifrice. Difference between treatments at 6 months was 0.21 mm with P‐value = 0.0126. Significant improvements in MGI (P = 0.0000), mSBI (P = 0.0000), and PI (P = 0.0102) were also observed in 6 months.

Conclusion

The novel dentifrice showed significant reductions in PD and gingival inflammation over 6 months solely as a home care dentifrice without baseline SRP in Stage I and II periodontitis maintenance patients.
Evaluating the correlation between different impact indicators for library and information science journals: Comparing the journal citation reports and scopus
Authors: Ali Mona Farouk
Published: December 2020

Library and information science (LIS) scholars are increasingly aware of the ranking of LIS journals in the Journal Citation Reports (JCR) and Scopus when deciding where to publish, especially scholars who belong to universities that rely on these rankings when making hiring or promotion decisions. However, it is not known which index presents the most appropriate indicator for the LIS discipline and whether Scopus ranking is a possible alternative to the impact factor (IF). This study analysed the 2018 indicators for 58 LIS journals that are included in both Clarivate Analytics' JCR and Elsevier's Scopus databases. The bivariate correlations were calculated using the Spearman correlation coefficient. Then, to examine the interchangeability among the selected indicators, each pair of correlations was compared using Fisher's R to Z transformation formula. The results showed that all bivariate correlations are positive and strong. The highest correlations are between the Total Cites and Eigenfactor Score (ES) (Rs = 0.962, R2 = 0.925) and between the IF and CiteScore (Rs = 0.952, R2 = 0.906). There were 71 combinations with P‐value >0.05, showing that there is no significant difference between the bivariate correlation, indicating interchangeability between those pairs. The best indicator which can be used interchangeably with the IF is the CiteScore. It is evident that, to measure the scientific quality of LIS journals, all stakeholders should take into consideration the correlations among the various indicators. Furthermore, they can rely on the CiteScore as an adequate alternative to the IF.