bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the effect of Baricitinib on the Course of COVID-19
Authors: Maslova Alina Yuryevna , Tskaeva Alla Aslanbekovna , Ashurova Zuleykha Abdulkerimkizi , Abazova AlinaTemrukovna , Ismailov Magomed Muradovich , Ismailova Maryam Muradovna , Baklanov Igor Spartakovich , Mishvelov Artem Evgenevich , Povetkin Sergey Nikolaevich , Baklanova Olga Aleksandrovna
Published: July 2021

The aim of the study was to determine the effect of the inhibitor of janus kinase – baricitinib ("Olumiant") on the course of COVID-19. This drug baricitinib is able to suppress the systemic inflammatory response, which is one of the common causes of death in COVID-19, is an urgent problem of the study. The study was carried out in the Regional Specialized Budget Infectious Diseases Hospital of Stavropol (Russian Federation, Stavropol Region). In a multivariate analysis, it was shown that the use of baricitinib was associated with a decrease in the frequency of the primary endpoint of death/need for invasive lung ventilation. The use of baricitinib was quite safe, but in some patients there was an increase in the level of transaminases. No cases of hypercoagulation have been reported while taking baricitinib. It was found that patients with a normal BMI are more sensitive to therapy than those who are overweight.75% of patients in the first group had a temperature above 38.0oC. However, against the background of taking the standard treatment regimen and baricitinib, it was noted that the temperature stabilized during the day and did not rise again. Against the background of taking baricitinib, the elimination of the phenomena of respiratory failure and the refusal of an oxygen mask occurred 3.1 times more often than without baricitinib. The authors concluded that the use of baricitinib can be considered as an additional therapy for moderate forms of pneumonia in patients over 65 years or in patients with concomitant chronic diseases in order to suppress the reactions of systemic inflammation and the development of serious respiratory and other system lesions caused by COVID-19.
An Observational Study on Drug Utilization Pattern in Chronic Kidney Disease Patients using Anti-Hypertensive Drugs in a Tertiary Care Teaching Hospital
Authors: Hadia Rajesh , Rajput Hemraj Singh , Mehta Vidhi , Shah Pushti , Muley Arti , Thakkar Jyoti , Muley Arti , Rathod Trupal , Joshi Dhaval , Maheshwari Rajesh , Chandrakar Vikas
Published: July 2021

Background: There is a strong relationship between Hypertension and chronic kidney disease. HTN is highly prevalent in CKD patients, contributing to high cardiovascular risk.

Objectives: This study aims drug utilization pattern of Antihypertensive drugs in CKD. The objective of the study to determine the occurrence of co-morbidities, the prevalence of CKD stages in chronic kidney patients and to prepare a protocol of anti-hypertensive in CKD.

Methodology: This was an observational/cross-sectional study that was carried out for six months at Dhiraj General Hospital, Vadodara. CKD patients who were prescribed antihypertensive agents were included as per study criteria. Data was collected by filling the patient medical record sheet.

Results: A total of 60 CKD patients with HTN were included in the study according to inclusion and exclusion criteria. Out of 60 patients, we noticed that number of inpatients was 67% while the number of OPD patients was just 33%. Comparing gender proportionality, male represents 63% and female represents 37% were found between the age group of 18-65 years. The recorded systolic BP in mild case in the overall study population was found to be 140-159 mmHg and diastolic BP was found to be 90-99 mmHg. In moderate case systolic BP was 160-179 mmHg and diastolic BP was found to be 100-109 mmHg. In severe cases systolic BP was ≥180 mmHg and diastolic BP was found to be ≥110 mmHg. Among antihypertensive Calcium channel blockers was prescribed in 34.18% of patients and mostly recommended drug for hypertensive chronic kidney patients was furosemide which was 19.34%. Most participants were treated with multi-drug therapy.

Conclusion: In Hypertensive CKD patients, calcium channel blockers and furosemide were highly recommended which do not diverge from National Kidney Foundation Kidney Disease, Outcome Quality Initiative guidelines.
Detection of Hookworm (Necator Americanus) and Other Intestinal Parasitic Infection among Primary School Children in Sokoto Metropolis
Authors: Mohammed K. , Emeagubor E. , Iduh M. U. , Garba M. K. , Nataala S. U. , Aschroft O. F.
Published: July 2021

Background: Hookworm is an intestinal parasite of human and is one of the major public health burdens in developing countries, particularly in Sub-Saharan Africa. It is estimated that about 3.5 billion people globally and 450 million people are thought to be ill as a result of such infections, the majority being children.

Aims: The study aimed to determine the prevalence of Hookworm and other intestinal parasitic infection among primary school children

Study Design: This was a cross-sectional, descriptive study

Place and Duration of Study: This study was conducted in among patients attending Usmanu Danfodiyo University, Teaching Hospital, Sokoto, Sokoto state, between March to November, 2017.

Methodology: A total of 224 participants were enrolled for the study. Standard parasitological  examination  was carried  out  on  stool  samples  using microscopy followed by formal  ether  concentration  methods

Results: Finding revealed, an overall prevalence of 4.5% out of 224 samples examined recorded for both Hookworm and other intestinal parasitic infection. There was high prevalence rate of Hookworm and other intestinal parasitic infection among males (5.3%) than females (3.6%).29 (12%) were positive for intestinal parasitic infections. Males  recorded  higher  prevalence  than  the  females  with 19 (11.9%)  and  10 (11.8%)  respectively

Conclusion: The total low prevalence rate of Hookworm and other intestinal parasitic infection may be as a result of improved standard of living and awareness of the Hookworm and other intestinal parasites in the study area. The government, non-governmental agencies and private individuals should help in the provision of social amenities to ensure total eradication of these diseases. The teaching of health education in both private schools should be encouraged by the government which will go a long way in  reducing  prevalence and  intensity  of  Hookworm  infections  among  the  study community.
O CAMINHO BRASILEIRO PARA O FASCISMO
Authors: Boito Jr. Armando
Published: July 2021

O artigo analisa a natureza do governo Bolsonaro, da sua base social de apoio mais ativa e da crise política que lhe deu origem. Polemiza com a bibliografia clássica e atual sobre o fascismo e, operando com um conceito de fascismo inserido na tradição marxista, caracteriza o governo e sua base social como (neo)fascistas. Sustenta a necessidade de construir uma tipologia das crises políticas nas sociedades capitalistas e procura mostrar que a natureza e a dinâmica da crise política brasileira de 2015-2018 são típicas da crise política que dá origem ao fascismo. Insere o bolsonarismo no contexto da democracia ainda existente no Brasil, que caracteriza como uma democracia burguesa em crise.

THE BRAZILIAN PATH TO FASCISM

The article analyzes the nature of the Bolsonaro Government, its most active social base of support, and the political crisis that gave rise to it. It polemizes with the classical and current bibliography on fascism and, operating with a concept of fascism embedded in the Marxist tradition, characterizes the government and its social base as (neo)fascists. It argues for the need to develop a typology of political crises in capitalist societies, showing that the nature and dynamics of the 2015-2018 Brazilian political crisis are typical of the political crisis that gives rise to fascism. Finally, it places bolsonarismo in the context of the democracy still existing in Brazil, which it characterizes as a bourgeois democracy in crisis.

Keywords: Brazilian Politics. Bolsonaro Government.Neo-fascism. Political Crisis.

LE CHEMIN BRÉSILIEN VERS LE FACISME

L’article analyse la nature du gouvernement Bolsonaro, sa base sociale de soutien la plus active et la crise politique qui les a engendrés. Il polémique avec la bibliographie classique et actuelle sur le fascisme et, opérant avec un concept de fascisme ancré dans la tradition marxiste, caractérise le gouvernement et sa base sociale comme (néo) fascistes. Il soutient le besoin de développer une typologie des crises politiques dans les sociétés capitalistes et entend montrer que la nature at dynamique de la crise politique brésilienne de 2015-2018 sont typiques de celle qui donne naissance au fascisme. Il place le bolsonarisme dans le contexte de la démocratie existant encore au Brésil, qu’il caractérise comme une démocratie bourgeoise en crise.

Mots-clés: Politique Brésilienne. Gouvernement Bolsonaro. Néofascisme. Crise Politique.
Revamping SiO2 Spheres by Core–Shell Porosity Endowment to Construct a Mazelike Nanoreactor for Enhanced Catalysis in CO2 Hydrogenation to Methanol
Authors: Kosari Mohammadreza , Anjum Uzma , Xi Shibo , Lim Alvin M. H. , Seayad Abdul Majeed , Raj Emmanuel A. J. , Kozlov Sergey M. , Borgna Armando , Zeng Hua Chun
Published: July 2021

Beyond the catalytic activity of nanocatalysts, the support with architectural design and explicit boundary could also promote the overall performance through improving the diffusion process, highlighting additional support for the morphology‐dependent activity. To delineate this, herein, a novel mazelike‐reactor framework, namely multi‐voids mesoporous silica sphere (MVmSiO2), is carved through a top‐down approach by endowing core‐shell porosity premade Stöber SiO2 spheres. The precisely‐engineered MVmSiO2 with peripheral one‐dimensional pores in the shell and interconnecting compartmented voids in the core region is simulated to prove combined hierarchical and structural superiority over its analogous counterparts. Supported with CuZn‐based alloys, mazelike MVmSiO2 nanoreactor experimentally demonstrated its expected workability in model gas‐phase CO2 hydrogenation reaction where enhanced CO2 activity, good methanol yield, and more importantly, a prolonged stable performance are realized. While tuning the nanoreactor composition besides morphology optimization could further increase the catalytic performance, it is accentuated that the morphological architecture of support further boosts the reaction performance apart from comprehensive compositional optimization. In addition to the found morphological restraints and size‐confinement effects imposed by MVmSiO2, active sites of catalysts are also investigated by exploring the size difference of the confined CuZn alloy nanoparticles in CO2 hydrogenation employing both in‐situ experimental characterizations and density functional theory calculations.
A Partial Sulfuration Strategy Derived Multi‐Yolk–Shell Structure for Ultra‐Stable K/Na/Li‐ion Storage
Authors: Shi Xiuling , Gan Yanmei , Zhang Qixin , Wang Chaoying , Zhao Yi , Guan Lunhui , Huang Wei
Published: July 2021

Metal sulfides are attractive anodes for alkali metal ion batteries due to the high theoretical capacity, while their practical implementation is hampered by the inherent poor conductivity and vast volume variation during cycles. Approaching rational designed microstructures with good stability and fast charge transfer is of great importance in response to these issues. Herein, a partial sulfuration strategy for the rational construction of multi‐yolk–shell (m‐Y–S) structures, from which multiple Fe1−xS nanoparticles are confined within hollow carbon nanosheet with tunable interior void space is reported. As anode materials, the m‐Y–S Fe1−xS@C composite can display high capacity and excellent rate capability (134, 365, and 447 mA h g−1 for K+, Na+, and Li+ storage at 20 A g−1). Remarkably, it exhibits ultra‐stable potassium storage up to 1200, 6000, and 20 000 cycles under current densities of 0.1, 0.5, and 1 A g−1, which is much superior to previous yolk–shell structures and metal‐sulfide anodes. Based on comprehensive experimental analysis and theoretical calculations, the exceptional performance of m‐Y–S structure can be ascribed to the optimized interior void space for good structure stability, as well as the multiple connection points and conductive carbon layer for superior electron/ion transportation.
3D Printing of Physical Organ Models: Recent Developments and Challenges
Authors: Jin Zhongboyu , Li Yuanrong , Yu Kang , Liu Linxiang , Fu Jianzhong , Yao Xinhua , Zhang Aiguo , He Yong
Published: July 2021

Physical organ models are the objects that replicate the patient‐specific anatomy and have played important roles in modern medical diagnosis and disease treatment. 3D printing, as a powerful multi‐function manufacturing technology, breaks the limitations of traditional methods and provides a great potential for manufacturing organ models. However, the clinical application of organ model is still in small scale, facing the challenges including high cost, poor mimicking performance and insufficient accuracy. In this review, the mainstream 3D printing technologies are introduced, and the existing manufacturing methods are divided into "directly printing" and "indirectly printing", with an emphasis on choosing suitable techniques and materials. This review also summarizes the ideas to address these challenges and focuses on three points: 1) what are the characteristics and requirements of organ models in different application scenarios, 2) how to choose the suitable 3D printing methods and materials according to different application categories, and 3) how to reduce the cost of organ models and make the process simple and convenient. Moreover, the state‐of‐the‐art in organ models are summarized and the contribution of 3D printed organ models to various surgical procedures is highlighted. Finally, current limitations, evaluation criteria and future perspectives for this emerging area are discussed.
Stretchable, Multifunctional Epidermal Sensor Patch for Surface Electromyography and Strain Measurements
Authors: Wang Chengjun , Cai Min , Hao Zengming , Nie Shuang , Liu Changying , Du Honggen , Wang Jian , Chen Weiqiu , Song Jizhou
Published: July 2021

The concurrent collection of surface electromyography (sEMG) and strain signals is important for many applications, such as human–machine interaction, sign language recognition, and clinical evaluation of muscle function. Nevertheless, the conventional sensor systems made of rigid, bulky components cannot provide a reliable, conformal interface for accurate, continuous measurements of the epidermal physiological signals. Herein, a skin‐interfaced, multifunctional epidermal sensor patch with characteristics of mechanical softness, large stretchability, and wearable conformability for multimodal measurements of sEMG signals and associated skin deformations from various muscle activities and joint motions is reported. The sensor patch features two pairs of stretchable sEMG electrodes and two thin, miniaturized strain sensors, which are connected by stretchable filamentary serpentine interconnects in an open‐meshed structure. Experimental and computational studies reveal the design and operation of the sensor patch, which exhibit stable and repetitive performance even under a 30% stretching strain level. Demonstrations of the sensor patch on the wrist for simple sign language recognition and on the lower back for the flexion‐relaxation phenomenon illustrate its potential for the comprehensive assessment of the muscle activities and related motions of muscle joints.
Early developmental impact of sex chromosome trisomies on attention deficit‐hyperactivity disorder symptomology in young children
Authors: Kuiper Kimberly , Swaab Hanna , Tartaglia Nicole , van Rijn Sophie
Published: July 2021

Individuals with sex chromosome trisomies ([SCT], XXX, XXY, and XYY)) are at increased risk for neurodevelopmental problems, given that a significant portion of the sex chromosome genes impact brain functioning. An elevated risk for psychopathology has also been described, including attention deficit‐hyperactivity disorder (ADHD). The present study aimed at identifying early markers of ADHD, providing the first investigation of ADHD symptomology in very young children with SCT. The variety, type, and severity of ADHD symptomology in 1–6‐year‐old children with SCT (n = 104) were compared with population‐based controls (n = 101) using the strengths and weaknesses of ADHD symptoms and normal‐behavior (SWAN) parent‐report questionnaire. ADHD symptomology was significantly more prevalent in SCT and already present from toddlerhood on, compared to controls. ADHD inattention symptoms were significantly increased in all karyotypes (XXX, XXY, and XYY), boys with XYY also showed significantly more hyperactivity/impulsivity symptoms than controls. Inattentiveness was more pronounced with increasing age for SCT, in contrast to controls. Within the SCT group, 24% of the children had significantly elevated ADHD symptoms at a clinical level. Already from an early age on, SCT is associated with a risk for ADHD, suggesting that its neurodevelopmental risk lies anchored in early brain maturation. Studying this genetically vulnerable population allows for the prospective study of risk markers to facilitate early and preventive interventions.
Activating Room‐Temperature Phosphorescence of Organic Luminophores via External Heavy‐Atom Effect and Rigidity of Ionic Polymer Matrix**
Authors: Yan Zi‐Ang , Lin Xiaohan , Sun Siyu , Ma Xiang , Tian He
Published: July 2021

Pure organic room‐temperature phosphorescence (RTP) materials have attracted wide attention for their easy preparation, low toxicity, and applications in various fields like bioimaging and anti‐counterfeiting. Developing phosphorescent systems with more universality and less difficulty in synthesis has long been the pursuit of materials scientists. By employing a polymeric quaternary ammonium salt with an ionic bonding matrix and heavy atoms, commercial fluorescent dyes are directly endowed with phosphorescence emission. In a single amorphous polymer, the external heavy‐atom effect generates excited triplet states and the rigid polymer matrix stabilizes them. This study put forward a new general strategy to design and develop pure organic RTP materials starting from existing library of organic dyes without complicated chemical synthesis.
The Controllable Reconstruction of Bi‐MOFs for Electrochemical CO2 Reduction through Electrolyte and Potential Mediation
Authors: Yao Dazhi , Tang Cheng , Vasileff Anthony , Zhi Xing , Jiao Yan , Qiao Shi‐Zhang
Published: July 2021

Monitoring and controlling the reconstruction of materials under working conditions is crucial for the precise identification of active sites, elucidation of reaction mechanisms, and rational design of advanced catalysts. Herein, a Bi‐based metal–organic framework (Bi‐MOF) for electrochemical CO2 reduction is selected as a case study. In situ Raman spectra combined with ex situ electron microscopy reveal that the intricate reconstruction of the Bi‐MOF can be controlled using two steps: 1) electrolyte‐mediated dissociation and conversion of Bi‐MOF to Bi2O2CO3, and 2) potential‐mediated reduction of Bi2O2CO3 to Bi. The intentionally reconstructed Bi catalyst exhibits excellent activity, selectivity, and durability for formate production, and the unsaturated surface Bi atoms formed during reconstruction become the active sites. This work emphasizes the significant impact of pre‐catalyst reconstruction under working conditions and provides insight into the design of highly active and stable electrocatalysts through the regulation of these processes.
Structure investigation, density functional theory, and biostudy of synthesized dihydrazone incorporating isatin moiety and its homo‐bimetallic complexes
Authors: Shakdofa Mohamad M. E. , Saleem Qaid M. , Shakdofa Adel M. E.
Published: July 2021

Seven homo‐bimetallic complexes derived from 3‐(‐(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)methylene)hydrazono)indolin‐2‐one with Fe3+, Co2+, Cu2+, and UO22+have been prepared and structurally investigated using elemental and thermo‐gravimetric analyses and spectral, magnetic, and molar conductivity measurements. This structural investigation leads us to conclude that the bis‐hydrazone has behaved as neutral tetradentate chelator chelated to the Fe3+, Co2+, Cu2+, and UO22+ions via the carbonyl and azomethine groups adopting distorted octahedral structure for Fe3+, Co2+, and Cu2+complexes (2–5), whereas the Cu2+complexes (6–7) have square planar structures. The structural characterization of bis‐hydrazone and its chelated compounds has been supported by density functional theory calculations. The optimized geometry, global reactivity descriptors, and lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) of the molecules have been calculated in accordance with the density functional theory (DFT)‐Beckee3eLeeeYangeParr (B3LYP) technique and 6e311G(d,p) basis set. The molecular electrostatic potential image was also drawn by the DFT‐B3LYP technique and 6e311G(d,p) basis set to envision the charge distribution and chemical reactivity on the molecules. The bioeffect of bis‐hydrazone and its chelated compounds was assessed against bacterial strainsBacillus subtilis,Escherichia coli, as well as fungal strainsCanadian albicansandAspergillus niger. The observed data imply encouraging bioeffect of some of these complexes in comparing with the free bis‐hydrazone or amphotericin B (AmB) against all fungalC. albicansandA. niger.
Numerical investigation on deposition rate of mechanically mixed ash particles in an entrained flow reactor
Authors: Wang Yibin , Wang Xiaoxiao , Tan Houzhang , Xu Xinwei
Published: July 2021

Homogeneous nucleation and heterogeneous condensation of salt vapors near the wall of superheater or reheater tubes greatly improve the sticky propensity of deposited surfaces or impacting particles and then lead to a fast‐growing rate of initial layer. Based on the deposition experiment of mechanically mixed KCl + SiO2 particles in an entrained flow reactor, a numerical model with considering the salt particle vaporization, salt vapor condensation, and its effect on SiO2 deposition is proposed for simulating impaction and adhesion behavior of molten and solid particles. The results show that deposits are mainly from the impaction of solid and molten particles and the condensation of salt vapors. The condensation rate of salt vapors in the stagnation zone at the windward side of metal probe is maximal. In comparison with the overall deposition rate, although the amount of salt vapors condensed on the probe surface can be negligible, it significantly affects the deposition rate of SiO2 particles. The coupled CFD model over a link between particle sticking and salt vapor condensation could well simulate the deposition behavior of mechanically mixed ash particles under rich‐salt‐vapor atmosphere.
The morphogenesis of porcine femoral head mammillary processes: A structural mechanism of biomechanical stability
Authors: Perrone Jr Ronald Vincent , Williams John Leicester
Published: July 2021

The capital femoral physis is a growth plate located between the head of the femur and femoral neck, which forms a temporary joint where growth plate cartilage is converted to bone by endochondral ossification. The bone‐cartilage‐bone interface develops a unique radial pattern of interdigitating mammillary processes that interlock the femoral head with the metaphysis, increasing biomechanical stability. The arrangement of these mammillary processes may not be a random occurrence and likely serves to provide mechanical mechanisms to enhance biomechanical stability. In this study, we provide a qualitative and quantitative analysis of porcine femoral head mammillary processes and focus on the analysis of six key points of development: the epiphyseal tubercle, epiphyseal cupping, growth plate slope angles, expansion of the epiphyseal subchondral bone plate, epiphyseal elongation, and the emergence of smaller, radially arranged mammillary processes. We introduce a metric of surface roughness analysis to quantify mammillary processes and apply it to analyze the development of the observed radial pattern of peripheral mammillary processes from birth to adolescence. We hypothesized that these processes develop to form a radial pattern with some degree of periodicity beginning relatively early in development of the joint and increase in prominence with age and weight of the animal. These findings may have important implications in the early diagnosis and treatment of the hip disorder slipped capital femoral epiphysis (SCFE). Underdevelopment of femoral head mammillary processes may reduce joint stability and could be a risk factor in SCFE.
Heed lessons learned from sex discrimination claims
Authors: O'Brien Timothy
Published: July 2021

The U.S. Court of Appeals for the Eighth Circuit issued a decision reinstating the sex discrimination claims brought by former members of the University of Minnesota's football team. The football players had filed suit alleging sex discrimination in violation of Title IX, race discrimination, and other claims related to an investigation into their participation in an alleged sexual assault and resulting discipline by the university for those actions. The District Court had dismissed all of the claims after the case was initially filed, but the Court of Appeals reversed the decision on the Title IX claims and remanded the case for further proceedings at the District Court level.
Identification of Bioactive Compounds against Aedes aegypti (Diptera: Culicidae) by Bioassays and in Silico Assays
Authors: de Brito Geisiane Amorim , Rocha de Oliveira Paulo Fernando , de Andrade Silva Caliene Melo , de Araújo Neto Moysés Fagundes , Leite Franco Henrique Andrade , Mesquita Paulo Roberto Ribeiro , Mota Tiago Feitosa , Magalhães‐Junior Jairo Torres
Published: July 2021

Most of the hematophagous insects act as disease vectors, including Aedes aegypti, responsible for transmitting some of the most critical arboviruses globally, such as Dengue. The use of repellents based on natural products is a promising alternative for personal protection compared to industrial chemical repellents. In this study, the repellent effect of essential oils extracted from Lippia thymoides, Lippia alba, Cymbopogon winterianus, and Eucalyptus globulus leaves was evaluated. Essential oils used showed repellent activity against Ae. aegypti in laboratory bioassays, obtaining protection rates above 70 % from 3.75 mg/mL and higher concentration for all analyzed oils. GC/MS identified 57 constituents, which were used in the ligand‐based pharmacophore model to expose compounds with requirements for repellents that modulate mosquitoes behavior through odorant‐binding protein 1 Ae. aegypti. Ligand‐based pharmacophore model approach results suggested that repellent activity from C. winterianus, L. alba, and L. thymoides essential oils’ metabolites is related to Citronelal (QFIT=26.77), Citronelol (QFIT=11.29), Citronelol acetate (QFIT=52.22) and Geranil acetate (QFIT=10.28) with synergistic or individual activity. E. globulus essential oil's repellent activity is associated with Ledol (0.94 %; QFIT=41.95). Molecular docking was applied to understand the binding mode and affinity of the essential oils’ data set at the protein binding site. According to molecular docking, Citronelol (ChemPLP=60.98) and geranyl acetate (ChemPLP=60.55) were the best‐classified compounds compared to the others and they can be explored to develop new repellents.
Engineered RebH Halogenase Variants Demonstrating a Specificity Switch from Tryptophan towards Novel Indole Compounds
Authors: Sana Barindra , Ho Timothy , Kannan Srinivasaraghavan , Ke Ding , Li Eunice H. Y. , Seayad Jayasree , Verma Chandra S. , Duong Hung A. , Ghadessy Farid J.
Published: July 2021

Activating industrially important aromatic hydrocarbons by installing halogen atoms is extremely important in organic synthesis and often improves the pharmacological properties of drug molecules. To this end, tryptophan halogenase enzymes are potentially valuable tools for regioselective halogenation of arenes, including various industrially important indole derivatives and similar scaffolds. Although endogenous enzymes show reasonable substrate scope towards indole compounds, their efficacy can often be improved by engineering. Using a structure‐guided semi‐rational mutagenesis approach, we have developed two RebH variants with expanded biocatalytic repertoires that can efficiently halogenate several novel indole substrates and produce important pharmaceutical intermediates. Interestingly, the engineered enzymes are completely inactive towards their natural substrate tryptophan in spite of their high tolerance to various functional groups in the indole ring. Computational modelling and molecular dynamics simulations provide mechanistic insights into the role of gatekeeper residues in the substrate binding site and the dramatic switch in substrate specificity when these are mutated.
Enhancement of the Catalytic Activity of Hammerhead Ribozymes by Organic Cations
Authors: Nakano Shu‐ichi , Yamashita Hirofumi , Sugimoto Naoki
Published: July 2021

Catalytic turnover is important for the application of ribozymes to biotechnology. However, the turnover is often impaired because of the intrinsic high stability of base pairs with cleaved RNA products. Here, organic cations were used as additives to improve the catalytic performance of hammerhead ribozyme constructs that exhibit different kinetic behaviors. Kinetic analysis of substrate cleavage demonstrated that bulky cations, specifically tetra‐substituted ammonium ions containing pentyl groups or a benzyl group, have the ability to greatly increase the turnover rate of the ribozymes. Thermal stability analysis of RNA structures revealed that the bulky cations promote the dissociation of cleaved products and refolding of incorrectly folded structures with small disruption of the catalytic structure. The use of bulky cations is a convenient method for enhancing the catalytic activity of hammerhead ribozymes, and the approach may be useful for advancing ribozyme technologies.
Structure Elucidation of Complex Endotaxially Intergrown Lanthanum Barium Oxonitridosilicate Oxides by Combination of Microfocused Synchrotron Radiation and Transmission Electron Microscopy
Authors: Gamperl Lisa , Neudert Lukas , Schultz Peter , Durach Dajana , Schnick Wolfgang , Oeckler Oliver
Published: July 2021

Single‐crystalline domains in intergrown microcrystalline material of the new compounds Ba22.5+xLa55−x[Si129N240−xOx]O3:Ce3+ and Ba25.5+xLa77−x[Si170N312−xO9+x]O4:Ce3+ were identified by transmission electron microscopy (TEM). Precise diffraction data from these domains were collected with microfocused synchrotron radiation so that crystal structure elucidation of the complex disordered networks became possible. They are composed of two different interconnected slabs of which one is similar in both compounds, which explains their notorious intergrowth. The distribution of Ba and La is indicated by the analysis of bond‐valence sums and by comparison with isostructural Sr28.5+xLa75−x[Si170N312−xO9+x]O4. Ce3+ doping leads to yellow luminescence. This is a showcase that highlights the discovery and accurate characterization of new compounds relevant for luminescence applications from heterogeneous microcrystalline samples by exploiting the capability of the combination of TEM and diffraction using the latest focusing techniques for synchrotron radiation.
Triplet Exciton Upconverting Blue Exciplex Host for Deep Blue Phosphors
Authors: Hui Yun Ju , Lim Junseop , Yeob Lee Jun , Lee Yoonkyoo , Chu Changwoong
Published: July 2021

A thermally activated delayed fluorescence (TADF)‐type exciplex host employing a novel electron‐transport type (n‐type) type host managing positive polarons and stabilizing excitons was developed to elongate the device lifetime of deep blue phosphorescent organic light‐emitting diodes (PhOLEDs). The bipolar n‐type host was designed to prevent hole leakage and secure hole stability while being stabilized under excitons by introducing a CN‐modified carbazole moiety as a weak donor. The TADF‐type exciplex host‐based blue PhOLEDs showed high (above 20 %) quantum efficiency with a deep blue color coordinate of (0.14, 0.16) and elongated device lifetime. The device operational lifetime of the blue PhOLEDs bearing the TADF‐type exciplex host was extended by more than twice compared to that of the exciplex‐free unipolar host. This work suggested a design concept of the n‐type host to develop the TADF‐type exciplex host for deep blue phosphors to reach a long lifespan in the deep blue PhOLEDs.
Regioselective trans‐Hydrostannation of Boron‐Capped Alkynes
Authors: Melot Romain , Saiegh Tomas J. , Fürstner Alois
Published: July 2021

Alkynyl‐B(aam) (aam=anthranilamidato) derivatives are readily available bench‐stable compounds that undergo remarkably selective reactions with Bu3SnH in the presence of [Cp*RuCl]4 as the catalyst. The addition follows a stereochemically unorthodox trans‐selective course; in terms of regioselectivity, the Bu3Sn‐ unit is delivered with high fidelity to the C‐atom of the triple bond adjacent to the boracyclic head group (“alpha,trans‐addition”). This outcome is deemed to reflect a hydrogen bonding interaction between the protic −NH groups of the benzo‐1,3,2‐diazaborininone ring system and the polarized [Ru−Cl] bond in the loaded catalyst, which locks the substrate in place in a favorable orientation relative to the incoming reagent. The resulting isomerically (almost) pure gem‐dimetalated building blocks are amenable to numerous downstream functionalizations; most remarkable is the ability to subject the −B(aam) moiety to Suzuki‐Miyaura cross coupling without need for prior hydrolysis while keeping the adjacent Bu3Sn‐ group intact. Alternatively, the tin residue can be engaged in selective tin/halogen exchange without touching the boron substituent; the fact that the two ‐NH entities of −B(aam) do not protonate organozinc reagents and hence do not interfere with Negishi reactions of the alkenyl halides thus formed is another virtue of this so far underutilized boracycle. Overall, the ruthenium catalyzed trans‐hydrostannation of alkynyl‐B(aam) derivatives opens a practical gateway to isomerically pure trisubstituted alkenes of many different substitution patterns by sequential functionalization of the 1‐alkenyl‐1,1‐heterobimetallic adducts primarily formed.
An Optimized Protocol for the Synthesis of Peptides Containing trans‐Cyclooctene and Bicyclononyne Dienophiles as Useful Multifunctional Bioorthogonal Probes
Authors: La–Venia Agustina , Dzijak Rastislav , Rampmaier Robert , Vrabel Milan
Published: July 2021

Despite the great advances in solid‐phase peptide synthesis (SPPS), the incorporation of certain functional groups into peptide sequences is restricted by the compatibility of the building blocks with conditions used during SPPS. In particular, the introduction of highly reactive groups used in modern bioorthogonal reactions into peptides remains elusive. Here, we present an optimized synthetic protocol enabling installation of two strained dienophiles, trans‐cyclooctene (TCO) and bicyclononyne (BCN), into different peptide sequences. The two groups enable fast and modular post‐synthetic functionalization of peptides, as we demonstrate in preparation of peptide‐peptide and peptide‐drug conjugates. Due to the excellent biocompatibility, the click‐functionalization of the peptides can be performed directly in live cells. We further show that the introduction of both clickable groups into peptides enables construction of smart, multifunctional probes that can streamline complex chemical biology experiments such as visualization and pull‐down of metabolically labeled glycoconjugates. The presented strategy will find utility in construction of peptides for diverse applications, where high reactivity, efficiency and biocompatibility of the modification step is critical.
Hierarchical Nanoporous C/C Composite from Humic Fulvic Acid and Sulfonated Pitch for High‐Energy‐Density EDLC Electrodes
Authors: Chang Panpan , Yang Fan , Cen Yongbing , Zheng Jie , Li Xuguang , Xie Qingruo , Dong Jinshi
Published: July 2021

As a new type of energy storage device, electric double layer capacitors (EDLCs) possess fast charge/discharge speed and good cycling stability. However, the low energy density and high production cost of EDLC electrodes are still big challenges. Herein, a hierarchical nanoporous C/C composite is synthesized by chemical recombination and subsequent activation strategy from low‐cost carbon resources, namely renewable humic fulvic acid (FA) and industrial sulfonated pitch (SP). Profiting from the abundant polycyclic aromatic hydrocarbons in SP and plentiful oxygen‐containing groups in FA, the resultant nanoporous C/C composite has both high e‐conductivity and high specific surface area (SSA). Thus, this porous C/C composite can be directly fabricated as EDLC electrode without any conductive agent. By fully exploiting the synergistic effect between high e‐conductivity and high SSA, it shows excellent electrochemical stability in EMIMBF4 ionic liquid electrolyte. Furthermore, it possesses a higher specific gravimetric capacitance (117 F g−1) than that of pure FA‐based porous carbon (92.5 F g−1) at a current density of 1 A g−1. More importantly, the maximum energy density can be as high as 55.4 Wh kg−1, largely better than commercial activated carbon.
Dose‐dependent effects of aerobic exercise on clinically relevant biomarkers among healthy women at high genetic risk for breast cancer: A secondary analysis of a randomized controlled study
Authors: Ehret Christopher J. , Zhou Shouhao , Tchou Julia C. , Schmitz Kathryn H. , Sturgeon Kathleen M.
Published: July 2021

Background

Excess adiposity and dysregulated metabolism are associated with increased cancer risk. Triglycerides, cholesterol, glucose, insulin, HOMA‐IR, and VO2max are robust clinical‐metabolic biomarkers of overall health.

Aims

Aerobic exercise may improve clinical‐metabolic biomarkers and decrease cancer risk. This secondary analysis of the WISER Sister randomized controlled trial investigated dose‐dependent effects of aerobic exercise on clinical biomarker levels in women at high genetic risk for breast cancer.

Methods and Results

One hundred thirty‐nine participants were randomized to: control (<75 min/week), low‐dose (150 min/week), and high‐dose (300 min/week) aerobic exercise intervention groups. Intervention adherence was assessed via heart monitor. Fasting blood draws, cardio‐pulmonary tests, and demographical surveys were taken at baseline and 5 months. Triglyceride, cholesterol, glucose, insulin, and VO2max changes were assessed for 80 of the 122 study completers. Ninety‐six percent of assayed‐completers adhered to >80% of their exercise dose. A significant dose‐dependent increase in VO2max was observed for the low‐dose and high‐dose groups compared to control. No intervention effects were observed for plasma biomarkers. Overweight women (BMI > 25) showed a significant decrease in insulin levels and a trend for decreased triglycerides following exercise intervention. Significant increases in VO2max were independent of BMI stratification.

Conclusion

Women at high genetic risk for breast cancer should maintain healthy weights and aerobic capacities through aerobic exercise to achieve measurable benefits on overall health. For overweight women, exercise appears to improve subclinical metabolic dysregulation. However, normal weight women were unaffected by aerobic exercise as their biomarker levels may be below the threshold for improvement. VO2max increases solely quantified the benefits of exercise in already healthy women at high‐risk for breast cancer.
Effect of occlusal anatomy of CAD/CAM feldspathic posterior crowns in the stress concentration and fracture load
Authors: Borges Alexandre Luiz Souto , Tribst João Paulo Mendes , de Lima Aline Lins , Dal Piva Amanda Maria de Oliveira , Özcan Mutlu
Published: July 2021

Objectives

This study evaluated the effect of restoration occlusal design on the maximum fracture load and stress distribution of a feldspathic ceramic crown.

Materials and Methods

Twenty dentin analogues were used to simulate a full‐crown preparation. Next, 20 feldspathic crowns were milled according to the occlusal design parameter available in the CAD database (Young or Adult). The crowns were cemented with dual cure resin‐cement and loaded until fracture at 1 mm/min crosshead speed. Data were analyzed by using one‐way ANOVA and Tukey tests (p < 0.05). The same geometry and experimental setup was modeled and exported to the computer aided engineering software and tensile stress concentration was calculated using the finite element method with 300 N occlusal load simulation.

Results

The occlusal anatomy significantly influenced the load‐to‐fracture (p < 0.05). Adult design showed higher mean values (1149 ± 201 N) than Young design (454 ± 77 N). The maximum principal stress criteria showed similar stress pattern for both designs, however, the highest stress concentration was calculated for Young design (91 MPa) in the occlusal surface.

Conclusions

An anatomy design with reduced cusp angulation and less evident occlusal sulcus can reduce the stress concentration and increase the fracture load for feldspathic CAD/CAM posterior crowns.
A study of the effect of self‐generated pressure gradient sources on the resistive filamentation instability
Authors: Mahdavi Mohammad , Khanzadeh Hengameh
Published: July 2021

In the field of fast ignition scheme, self‐generated magnetic fields via beam resistive filamentation have a significant role in the angular divergence of the relativistic electron beam, which can be affected by the intensity of other self‐generated magnetic fields. In this context, the effects of pressure gradient sources arising from temperature and density gradient of the pellet along the beam flow direction are investigated. The results showed that the resistive filamentation instability can be strongly amplified compared to the fully homogeneous plasma. In this respect, for the distance away from the critical surface, the instability is protected for a longer wave number. Also, the beam and plasma properties such as the beam relativistic factor, the beam number density, and the degree of the plasma temperature anisotropy might be effective.
Variation of filamentation phenomenon in strongly magnetized plasma with various discharge parameters
Authors: Menati Mohamad , Konopka Uwe , Thomas Edward
Published: July 2021

Filamentation phenomenon is one of the most important outcomes of applying a strong magnetic field to low‐pressure plasmas and dusty plasmas. In this article, the variation of filamentation phenomenon with neutral gas pressure and plasma density will be investigated using numerical simulations. It will be shown through these simulations how the formation of the filamentary patterns in the magnetized plasma results in a localized electric field structure that strongly contributes to the properties of the filamentary patterns. Based on the results of the simulations, a theoretical model is derived that relates the width of the filamentary patterns to the plasma density. The model has been successfully employed to predict the width of the patterns emerging in various simulations of the magnetized plasma.
Petrophysics and sediment variability in a mixed alluvial to lacustrine carbonate system (Miocene, Madrid Basin, Central Spain)
Authors: Reijmer John J. G. , Blok Carlette N. , El‐Husseiny Ammar , Kleipool Lucas M. , Hogendorp Yanto C. K. , Alonso‐Zarza Ana María
Published: July 2021

This study evaluates variations in petrophysical properties within a mixed alluvial to lacustrine carbonate system (Miocene, Madrid Basin, Central Spain). The transition from alluvial environments to lake margins settings displays a shift from alluvial, siliciclastic red sandstones and mudstones to palustrine–lacustrine mudstones to packstones. Fluctuations in lake‐water level enabled land plants to occupy the lake margins during periods of low lake levels. The palustrine carbonates include features like pseudo‐microkarst, nodular and mottled limestones; the lacustrine deposits include enlarged root cavities, desiccation cracks and channel bodies. Scarce fresh water biota comprises charophytes, gastropods and ostracods. The sediments possess high natural, irregular varying, gamma‐ray values at the alluvial–lacustrine transition, and low, but constant values at full lacustrine sites. Acoustic properties agree with lithological variations within individual facies. Porosity is the most important parameter influencing P‐wave and S‐wave velocities. The scatter in the velocity–porosity relationship links to the porosity type; macro‐porosity or microporosity. The wide range of pore types and pore sizes results in a weak porosity to permeability relationship for the carbonate‐dominated rocks with low permeability for microporous and high permeability for macro‐porous carbonates. The sandstones (probably only inhibiting interparticle porosity), and to a lesser extent the sandy wackestones to packstones, show quite a strong relationship between porosity and permeability. Elastic properties of mixed alluvial–lacustrine deposits (this study) and marine deposits (literature data) overlap as variations in pore structures and porosity values are similar. Only 16% of the marine and lacustrine carbonate sediments display Equivalent Pore Aspect Ratio values above 0.2. In travertine deposits, 83% of the samples exceed Equivalent Pore Aspect Ratio values above 0.2, which highlights that travertine deposits are dominated by larger Equivalent Pore Aspect Ratios compared to lacustrine and marine carbonate deposits. Travertines display other rock frameworks with different pore types, pore distribution and amount of porosity.
Carotenoids‐based reddish pelvic spines in nonreproducing female and male sticklebacks (Gasterosteus aculeatus) – Signalling social dominance?
Authors: Kroken Karl Kristian , Sæthre Axel Aas , Nicolaisen Ove , Egeland Torvald Blikra , Nordeide Jarle Tryti
Published: July 2021

Conspicuous ornaments are often considered a result of evolution by sexual selection. According to the social selection hypothesis, such conspicuous traits may also evolve as badges of status associated with increased boldness or aggression toward conspecifics in conflicts about ecological resources. This study tested predictions from the social selection hypothesis to explain evolution of conspicuous red color of the pelvic spines of the three‐spine stickleback (Gasterosteus aculeatus). Wild nonreproducing sticklebacks were presented to pairs of dummies which differed at their pelvic spines, having either (i) normal‐sized gray or red pelvic spines or (ii) normal‐sized gray or large red pelvic spines. The experimental tank was illuminated by white or green light, since green light impedes the sticklebacks’ ability to detect red color. The dummies moved slowly around in circles at each end of the experimental tank. We quantified the parameters (i) which of the two dummies was visited first, (ii) time taken before the first visit to a dummy, (iii) distribution of the focal sticklebacks in the two zones close to each of the two dummies and in the neutral zone of the tank, (iv) close to which of the two dummies did the focal fish eat its first food‐piece, and (v) time spent until the first piece of food was eaten. This was carried out for 22 females and 29 males sticklebacks. The results suggested no effect of the color or size of the dummies’ pelvic spines, on none of the five behavioral parameters. Moreover, neither the color of the pelvic spines of the focal sticklebacks themselves (as opposed to redness of the dummies’ spines) nor their body length was associated with behavior toward the dummies. Thus, this study did not support predictions from the social selection hypothesis to explain evolution of red pelvic spines in sticklebacks.