bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Iridium Catalytic System Compatible with Inorganic and Organic Nitrogen Sources for Dual Asymmetric Reductive Amination Reactions
Authors: Gao Zhaofeng , Liu Jingwen , Huang Haizhou , Geng Huiling , Chang Mingxin 
Published: October 2021

AbstractAsymmetric reductive amination (ARA) is one of the most promising methods for the synthesis of chiral amines. Herein we report our efforts on merging two ARA reactions into a single‐step transformation. Catalyzed by a complex formed from iridium and a steric hindered phosphoramidite, readily available and inexpensive aromatic ketones initially undergo the first ARA with ammonium acetate to afford primary amines, which serve as the amine sources for the second ARA, and finally provide the enantiopure C2‐symmetric secondary amine products. The developed process competently enables the successive coupling of inorganic and organic nitrogen sources with ketones in the same reaction system. The Brønsted acid additive plays multiple roles in this procedure: it accelerates the formation of imine intermediates, minimizes the inhibitory effect of N‐containing species on the iridium catalyst, and reduces the primary amine side products.
Designing new nanoliposomal formulations and evaluating their effects on myeloid‐derived suppressor cells and regulatory T cells in a colon cancer model aiming to develop an efficient delivery system for cancer treatment; an in vitro and in vivo study
Authors: Taheri Ramezan Ali , Bahramifar Ali , Jaafari Mahmoud Reza , Fasihi‐Ramandi Mahdi , Emameh Reza Zolfaghari , Mohammadian Haftcheshmeh Saeed , Ebrahimi Nik Maryam 
Published: October 2021

AbstractRegulfatory T cells (Tregs) and myeloid‐derived suppressor cells (MDSCs) are common immunosuppressive cells in the tumor microenvironment. These cells, through various mechanisms, inhibit antitumor immune responses and impede effective therapies. Therefore, designing an efficient protocol for inducing immune surveillance in tumors is highly recommended. Recently, nanoliposomes have provided broad‐spectrum and state‐of‐the‐art vehicles to deliver antigens or immune system compartments in immunotherapies. It has been shown that different lipids in the structure of liposomes and various liposomal formulations can affect immune responses in the tumor microenvironment. This study was aimed to evaluate the effects of four different liposomal formulations on MDSCs and Tregs in C26 tumor‐bearing mice. To this end, after preparing liposomes, they were injected into tumor‐inoculated mice and analyzed MDSC and Treg population and functions in spleen and tumor tissues. Results showed that 1,2‐dioleoyl‐3‐trimethylammonium propane (DOTAP)‐containing liposomes reduced MDSC population and activity in the spleen, but not tumor, compared with other groups significantly (p < 0.05 and p < 0.01, respectively). Moreover, DOTAP‐containing liposomes reduced the expression of S100A8 and arginase‐1 genes in splenic MDSCs (p < 0.05). In conclusion, we provided evidence that DOTAP‐containing liposomes contributed to stimulating immune responses and provided a situation to inhibit immunosuppression in the tumor microenvironment.
Orthogonal Peptide‐Templated Labeling Elucidates Lateral ETAR/ETBR Proximity and Reveals Altered Downstream Signaling
Authors: Wolf Philipp , Mohr Alexander , Gavins Georgina , Behr Victoria , Mörl Karin , Seitz Oliver , Beck‐Sickinger Annette G. 
Published: October 2021

AbstractFine‐tuning of G protein‐coupled receptor (GPCR) signaling is important to maintain cellular homeostasis. Recent studies demonstrated that lateral GPCR interactions in the cell membrane can impact signaling profiles. Here, we report on a one‐step labeling method of multiple membrane‐embedded GPCRs. Based on short peptide tags, complementary probes transfer the cargo (e. g. a fluorescent dye) by an acyl transfer reaction with high spatial and temporal resolution within 5 min. We applied this approach to four receptors of the cardiovascular system: the endothelin receptor A and B (ETAR and ETBR), angiotensin II receptor type 1, and apelin. Wild type‐like G protein activation after N‐terminal modification was demonstrated for all receptor species. Using FRET‐competent dyes, a constitutive proximity between hetero‐receptors was limited to ETAR/ETBR. Further, we demonstrate, that ETAR expression regulates the signaling of co‐expressed ETBR. Our orthogonal peptide‐templated labeling of different GPCRs provides novel insight into the regulation of GPCR signaling.
Creation of an Engineered Amide Synthetase Biocatalyst by the Rational Separation of a Two‐Step Nitrile Synthetase
Authors: Hennessy Alexis J. A. , Huang Wenli , Savary Chloé , Campopiano Dominic J. 
Published: October 2021

AbstractThe synthesis of amides through acid and amine coupling is one of the most commonly used reactions in medicinal chemistry, yet still requires atom‐inefficient coupling reagents. There is a current demand to develop greener, biocatalytic approaches to amide bond formation. The nitrile synthetase (NS) enzymes are a small family of ATP‐dependent enzymes which catalyse the transformation of a carboxylic acid into the corresponding nitrile via an amide intermediate. The Bacillus subtilis QueC (BsQueC) is an NS involved in the synthesis of 7‐cyano‐7‐deazaguanine (CDG) natural products. Through sequence homology and structural analysis of BsQueC we identified three highly conserved residues, which could potentially play important roles in NS substrate binding and catalysis. Rational engineering led to the creation of a NS K163A/R204A biocatalyst that converts the CDG acid into the primary amide, but does not proceed to the nitrile. This study suggests that NSs could be further developed for coupling agent‐free, amide‐forming biocatalysts.
Scalable and Selective β‐Hydroxy‐α‐Amino Acid Synthesis Catalyzed by Promiscuous l‐Threonine Transaldolase ObiH
Authors: Doyon Tyler J. , Kumar Prasanth , Thein Sierra , Kim Maeve , Stitgen Abigail , Grieger Abbigail M. , Madigan Cormac , Willoughby Patrick H. , Buller Andrew R. 
Published: October 2021

AbstractEnzymes from secondary metabolic pathways possess broad potential for the selective synthesis of complex bioactive molecules. However, the practical application of these enzymes for organic synthesis is dependent on the development of efficient, economical, operationally simple, and well‐characterized systems for preparative scale reactions. We sought to bridge this knowledge gap for the selective biocatalytic synthesis of β‐hydroxy‐α‐amino acids, which are important synthetic building blocks. To achieve this goal, we demonstrated the ability of ObiH, an l‐threonine transaldolase, to achieve selective milligram‐scale synthesis of a diverse array of non‐standard amino acids (nsAAs) using a scalable whole cell platform. We show how the initial selectivity of the catalyst is high and how the diastereomeric ratio of products decreases at high conversion due to product re‐entry into the catalytic cycle. ObiH‐catalyzed reactions with a variety of aromatic, aliphatic and heterocyclic aldehydes selectively generated a panel of β‐hydroxy‐α‐amino acids possessing broad functional‐group diversity. Furthermore, we demonstrated that ObiH‐generated β‐hydroxy‐α‐amino acids could be modified through additional transformations to access important motifs, such as β‐chloro‐α‐amino acids and substituted α‐keto acids.
Application of Nanotechnology in the Production of Biohydrogen: A Review
Authors: Biswal Trinath , Shadangi Krushna Prasad , Sarangi Prakash Kumar 
Published: October 2021

AbstractHydrogen is an outstanding source of energy that does not create any hostile carbon footprint as it produces only water during combustion. The application of nanotechnology is one of the recent advanced technologies used to enhance the rate of hydrogen production from biomass. The use of nanoparticles (NPs) in the conversion process enhances this rate. Biological methods such as dark fermentation and photobiological route of conversion of biomass to hydrogen are the most suitable and cost‐effective paths. Hydrogen production with nanotechnology in dark fermentation utilizes organic or inorganic NPs in the bioreactor membrane. The efficiency of biohydrogen production depends on the concentration and nature of the NPs used, and the kind of biowastes or biomass feed. The effectiveness of both processes is discussed.
Effect of MG‐132 on myofibrillogenesis and the ubiquitination of GAPDH in quail myotubes
Authors: Dube Dipak K. , Wang Jushuo , Fan Yingli , Dube Syamalima , Abbott Lynn , Sanger Jean M. , Channaveerappa Devika , Darie Costel C. , Poiesz Bernard J. , Sanger Joseph W. 
Published: October 2021

AbstractIn the three‐step myofibrillogenesis model, mature myofibrils are formed through two intermediate structures: premyofibrils and nascent myofibrils. We have recently reported that several inhibitors of the Ubiquitin Proteosome System, for example, MG‐132, and DBeQ, reversibly block progression of nascent myofibrils to mature myofibrils. In this investigation, we studied the effects of MG132 and DBeQ on the expression of various myofibrillar proteins including actin, myosin light and heavy chains, tropomyosin, myomesin, and myosin binding protein‐C in cultured embryonic quail myotubes by western blotting using two loading controls—α‐tubulin and glyceraldehyde 3‐phosphate dehydrogenase (GAPDH). Surprisingly, we found that MG‐132 affected the level of expression of GAPDH but DBeQ did not. Reverse transcription polymerase chain reaction (RT‐PCR) and quantitative reverse transcription‐PCR (qRT‐PCR) showed no significant effect of MG‐132 on GAPDH transcription. Two‐dimensional (2D) western blot analyses with extracts of control and MG‐132‐treated cells using anti‐ubiquitin antibody indicated that MG132‐treated myotubes show a stronger emitter‐coupled logic signal. However, Spot% and Spot volume calculations for all spots from both western blot film signals and matched Coomassie‐stained 2D polyacrylamide gel electrophoresis showed that the intensity of staining in a spot of ~39 kDa protein is 3.5‐fold lower in the gel of MG‐132‐treated extracts. Mass spectrometry analyses identified the ~39 kDa protein as quail GAPDH. Immunohistochemical analysis of fixed MG‐132‐treated myotubes with anti‐GAPDH antibody showed extensive clump formation, which may be analogous to granule formation by stress response factors in MG132‐treated cells. This is the first report on in vivo ubiquitination of GAPDH. This may be essential for the moonlighting (Jeffery, 1999) activity of GAPDH for tailoring stress in myotubes.
A finite element model to predict the consequences of endolymphatic hydrops in the basilar membrane
Authors: Areias Bruno , Parente Marco P. L. , Gentil Fernanda , Caroça Cristina , Paço João , Natal Jorge Renato M. 
Published: October 2021

AbstractMénière's disease is an inner ear disorder, associated with episodes of vertigo, fluctuant hearing loss, tinnitus, and aural fullness. Ménière's disease is associated with endolymphatic hydrops. Clinical evidences show that this disease is often incapacitating, negatively affecting the patients' everyday life. The pathogenesis of Ménière's disease is still not fully understood and remains unclear. Previous numerical studies available in the literature related with endolymphatic hydrops, are very scarce. The present work applies the finite element method to investigate the consequences of endolymphatic hydrops in the normal hearing, associated with the Ménière's disease. The obtained results for the steady state dynamics analysis are in accordance with clinical evidences. The results show that the basilar membrane is not affected in the same intensity along its length and that the lower frequencies are more affected by the endolymphatic hydrops. From a clinical point of view, this work shows the relationship between the increasing of the endolymphatic pressure and the development of hearing loss.
Extended boost active switch‐controlled switched inductor‐based Z‐source inverter
Authors: Das Sudhansu Sekhar , Panda Aurobinda 
Published: October 2021

AbstractThe presented topology in this paper represents a boosting topology known as extended boost active switch‐controlled switched inductor Z‐source inverter (EBASCSI‐ZSI). The presented topology has the ability to provide high boost output voltage with lower shoot‐through duty cycle. Three existing topologies in the field of Z‐source inverter, namely, qZSI, DA‐qZSI, and CA‐qZSI, have been compared with the presented topology. It has been found that the boosting factor of the presented topology is higher compared to the three topologies. The presented topology has used the same number of inductors and a less capacitor compared to CA‐qZSI topology, the same number of inductors and capacitors as compared to DA‐qZSI topology, a more capacitor, and an inductor compared to qZSI topology. The voltage stress across the capacitors of the presented topology is approximately the same compared to CA‐qZSI topology at higher shoot‐through state, and the voltage stress is more compared to DA‐qZSI and qZSI topologies at the same shoot‐through state. The current stress across the inductors of the presented topology is similar across some inductors of the DA‐qZSI and CA‐qZSI topologies while in some other inductors, it is lower than that of CA‐qZSI topology. The presented topology has been designed with a common ground between the source and inverter bridge while drawing continuous current from the source. The simulation model and its hardware prototype have been developed in the laboratory. The theoretical formulae obtained from the proposed model are matching with outcome of the simulation and hardware model.
Fuzzy adaptive singular value decomposition cubature Kalman filtering algorithm for lithium‐ion battery state‐of‐charge estimation
Authors: Yang Xiao , Wang Shunli , Xu Wenhua , Qiao Jialu , Yu Chunmei , Fernandez Carlos 
Published: October 2021

AbstractTo solve the problem of the slow convergence speed for the battery state‐of‐charge estimation of cubature Kalman filter algorithm, the ternary lithium‐ion battery is taken as the research object, and an algorithm combining the fuzzy self‐adaptation and singular value decomposition cubature Kalman filtering is proposed. The algorithm takes the system innovation and its change rate as the fuzzy input and the output as the adjustment factor, which is used to adjust the process noise covariance matrixR. The Kalman gain is adjusted through the fuzzy control ofR. To ensure the stability of the algorithm in the calculation process, the singular value decomposition is applied to cubature Kalman algorithm. Then, a second‐order RC equivalent circuit model with double internal resistance is built and tested under different conditions to verify the rationality of the improved algorithm. The verification results show that under the simple condition, the convergence speed of the proposed algorithm in the different initial state‐of‐charge values increased by 40.00% and 25.00%, the maximum estimation error of the state‐of‐charge is 2.52% and 2.51%, the Mean Absolute Error is 0.816% and 0.880%, and the Root Mean Square Error is 1.276% and 1.380%. When the initial state‐of‐charge value is 0.8, the convergence speed in the complex condition is increased by about 30.00%; the maximum estimation result error, Mean Absolute Error, and Root Mean Square Error are 2.21%, 0.222%, and 1.327%, respectively. When the initial state‐of‐charge value is 0.6, the convergence speed in the complex condition is increased by about 10.00%; the maximum estimation result error, Mean Absolute Error, and Root Mean Square Error are 2.72%, 0.941%, and 1.327%, respectively. Without reducing the estimation accuracy, the improved algorithm can significantly increase the convergence speed of predictive value tracking, which provides a theoretical basis for the wide application of lithium‐ion batteries.
Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea
Authors: Pagano Anthony M. , Durner George M. , Atwood Todd C. , Douglas David C. 
Published: October 2021

AbstractAnimals responding to habitat loss and fragmentation may increase their home ranges to offset declines in localized resources or they may decrease their home ranges and switch to alternative resources. In many regions of the Arctic, polar bears (Ursus maritimus) exhibit some of the largest home ranges of any quadrupedal mammal. Polar bears are presently experiencing a rapid decline in Arctic sea ice extent and a change in sea ice composition. For the Southern Beaufort Sea subpopulation of polar bears, this has resulted in a divergent movement pattern where most of the subpopulation remains on the sea ice in the summer melt season while the remainder move to land. We evaluated the effects of summer land use and maternal denning on the annual and seasonal utilization distribution size (i.e., home range) of adult female polar bears in the Southern Beaufort Sea subpopulation over 30 yr (1986–2016) during a period of rapid sea ice decline. For bears that remained on the summer sea ice, model‐derived mean annual utilization distributions were 64% larger in 1999–2016 ( = 176,000 km2) relative to 1986–1998 ( = 107,000 km2). This increase was primarily driven by increases in summer utilization distributions that encompassed increased amounts of open water and decreased amounts of preferred sea ice. The mean centroid of summer utilization distributions for bears that remained on the sea ice was 193 km further north‐northeast in 1999–2016. In contrast, bears that summered on land during 1999–2016 exhibited 88% smaller mean annual utilization distribution sizes ( = 22,000 km2) relative to bears that remained on the summer sea ice during the same period. Our findings highlight the impacts of sea ice declines on polar bear space use and the increasing importance of land as an alternative summer refuge.
The therapeutic dilemma of immunosuppressive drugs for refractory cardiac sarcoidosis in COVID‐19 infection
Authors: Goto Kohsaku , Uehara Masae , Okamoto Koh , Takeda Norifumi , Morita Hiroyuki , Hatano Masaru , Komuro Issei 
Published: October 2021

AbstractPatients with refractory cardiac sarcoidosis (CS) take a high dose of corticosteroid and immunosuppressive agents. During the pandemic outbreak of severe acute respiratory syndrome coronavirus 2, appropriate treatment of corticosteroids or immunosuppressive agents in CS patients with coronavirus disease 2019 (COVID‐19) is unknown. Here, the woman with refractory CS receiving maintenance therapy with 15 mg of prednisolone daily and 10 mg of methotrexate weekly was emergently admitted to our hospital because of COVID‐19. This case was successfully treated by the intravenous administration of dexamethasone 6 mg/day instead of prednisolone and interruption of methotrexate without resulting in recurrent life‐threatening ventricular lethal arrhythmias or obvious sarcoidosis flare‐ups. She started taking prednisolone and methotrexate at the maintenance dose immediately and at 2 weeks after discharge, respectively. Although the optimal regimen of immunosuppressive agents during COVID‐19 is under intense debate, this report might provide an effective treatment strategy for CS patients with COVID‐19.
Analytical solution to dielectric droplet diffusiophoresis under Debye–Hückel approximation
Authors: Tsai Meng‐Yu , Wu Yvonne , Fan Leia , Jian Elaine , Lin Jason , Tseng Jessica , Tseng Andy , Wan Renee , Lee Eric 
Published: October 2021

AbstractA simple analytical formula is obtained for the diffusiophoresis of a dielectric fluid droplet in symmetric binary electrolyte solutions under Debye–Hückel approximation valid for weakly charged droplets. The chemiphoresis is found to yield negative mobilities most of the time for droplets of constant surface charge density, which implies that the droplets tend to move away from the source releasing ionic chemicals. This is undesirable in some practical applications like drug delivery with liposomes in terms of conveying the drug‐carrying liposomes to the desired area in the human body releasing specific ionic chemicals utilizing the self‐guiding nature of diffusiophoresis. The further involvement of the electrophoresis component, however, may change the scenario via the oriented electric field generated by the induced diffusion potential. The lesson here is that while the impact of the chemiphoresis component is determined by nature and uncontrollable, the electrophoresis component serves as an artificially adjustable factor via choosing droplets with the surface charge of appropriate sign in practical applications. The results here have potential use in practical applications such as drug delivery. The portable simple analytical formula is a powerful asset to experimental researchers and design engineers in colloid science and technology to facilitate their works.
US‐China cooperation on low carbon development planning and analysis in China's provinces and cities
Authors: Peterson Thomas D. , Roe Stephen M. , Ugliano Arianna , Yu Qingchan , Liao Cuiping 
Published: October 2021

AbstractFrom 2009 to 18, the US based Center for Climate Strategies and Beijing based Global Environmental Institute led a cooperative US‐China relations program on low carbon development (LCD). The template for bilateral cooperation leveraged traditional policy innovation and mainstreaming procedures in China through early stage training and counterpart exchange, co‐development and piloting of tools, national endorsement for official use, training and capacity building, and cooperative planning actions. The experience suggests that the bilateral cooperation model through high level technical and institutional cooperation between governmental and nongovernmental experts worked well and can be replicated with customization to new bilateral relationships at different jurisdictional levels and for different issue areas. However, to succeed it requires years of stable investment and continuous counterpart engagement, and its application to new bilateral cooperation must address a variety of barriers. The China subnational LCD co‐development process was enabled by an existing US template for state level comprehensive climate action planning applied in over 20 US states. Its domestication in China resulted in creation of the China Subnational LCD Planning and Analysis Toolkit, a pilot in Chongqing, official endorsement by China's National Development and Reform Commission (NDRC), and further recognition through a US State Department – China NDRC EcoPartnership. Ultimately, it involved many partners, including the Chinese Academy of Sciences Institute for Policy and Management, the Guangzhou Institute of Energy Conversion, and over 30 provinces and cities. It led to new China efforts addressing renewable energy implementation in South China, and for LCD and renewable energy cooperation in Southeast Asia.
Seismic vulnerability modelling of building portfolios using artificial neural networks
Authors: Kalakonas Petros , Silva Vitor 
Published: October 2021

ABSTRACTThe incorporation of machine learning (ML) algorithms in earthquake engineering can improve existing methodologies and enable new frameworks to solve complex problems. In the present study, the use of artificial neural networks (ANNs) for the derivation of seismic vulnerability models for building portfolios is explored. Large sets of ground motion records (GMRs) and structural models representing the building stock in the Balkan region were used to train ANNs for the prediction of structural response, damage and economic loss conditioned on a vector of ground shaking intensity measures. The structural responses and loss ratios (LRs) generated using the neural networks were compared with results based on traditional regression models using scalar intensity measures in terms of efficiency, sufficiency, bias and variability. The results indicate a superior performance of the ANN models over traditional approaches, potentially allowing a greater reliability and accuracy in scenario and probabilistic seismic risk assessment.