bluuebunny/crossref_metadata_2025_split huggingface dataset:
α‐Iminophosphonates: Useful Intermediates for Enantioselective Synthesis of α‐Aminophosphonates
Authors: Maestro Aitor , de Marigorta Edorta Martinez , Palacios Francisco , Vicario Javier 
Published: February 2020

AbstractA wide range of methods for the enantioselective synthesis of α‐aminophosphonic acid derivatives have been developed over the years. Although the most used methodology is the Pudovik reaction, the use of α‐iminophosphonates for the synthesis of optically active α‐aminophosphonates has emerged during the last years. The existing methods for the synthesis of α‐phosphorylated imines and their enantioselective reactions for the synthesis of enantio‐enriched α‐aminophosphonates are summarized in this review.
An iterative design method for regeneration reuse water network with internal water mains
Authors: Wang Honghai , Wang Zhao , Wei Xiaoxiao , Zhou Qi , Su Weiyi 
Published: February 2020

AbstractCompared with the conventional water network, the water network with internal water mains has the advantages of simple structure, easy design and control. Regeneration reuse can avoid accumulation of contaminants compared with regeneration recycling. There are few studies on regeneration reuse water network with internal water mains. This paper analyzes the water‐using relationship between the water‐using unit and the internal water main and then provides an iterative design method for the regeneration reuse water network with internal water mains. Reasonably determining the flowrate of the internal water mains is the key to the design. The presented method is applicable to two types of regeneration units. Two cases are studied to demonstrate the applicability of the presented method.
6‐Phosphogluconate dehydrogenase fuels multiple aspects of cancer cells: From cancer initiation to metastasis and chemoresistance
Authors: Sarfraz Iqra , Rasul Azhar , Hussain Ghulam , Shah Muhammad Ajmal , Zahoor Ameer Fawad , Asrar Muhammad , Selamoglu Zeliha , Ji Xin‐Ying , Adem Şevki , Sarker Satyajit D. 
Published: February 2020

AbstractReprogrammed metabolism is key biochemical characteristic of malignant cells, which represents one of the emerging hallmarks of cancer. Currently, there is rising contemplation on oxidative pentose phosphate pathway (PPP) enzymes as potential therapeutic hits due to their affiliation with tumor metabolism. 6‐Phosphogluconate dehydrogenase (6PGD), third oxidative decarboxylase of PPP, has received a great deal of attention during recent years due to its critical role in tumorigenesis and redox homeostasis. 6PGD has been reported to overexpress in number of cancer types and its hyperactivation is mediated through post‐transcriptional and post‐translational modifications by YTH domain family 2 (YTHDF2), Nrf2 (nuclear factor erythroid 2‐related factor 2), EGFR (epidermal growth factor receptor) and via direct structural interactions with ME1 (malic enzyme 1). Upregulated expression of 6PGD provides metabolic as well as defensive advantage to cancer cells, thus, promoting their proliferative and metastatic potential. Moreover, enhanced 6PGD expression also performs key role in development of chemoresistance as well as radiation resistance in cancer. This review aims to discuss the historical timeline and cancer‐specific role of 6PGD, pharmacological and genetic inhibitors of 6PGD and 6PGD as prognostic biomarker in order to explore its potential for therapeutic interventions. We anticipate that targeting this imperative supplier of NADPH might serve as tempting avenue to combat the deadly disease like cancer.
From pKa to the pH of weak base solutions
Authors: McEvoy James P. 
Published: February 2020

AbstractUndergraduate biochemistry students frequently find the quantitative treatment of weak acids and bases troublesome. Given the pKa of a weak acid HA, for instance, many students struggle to calculate the pH of a solution of the conjugate base A− at concentration C, pH(A−, C). The traditional method involves calculating the base dissociation constant Kb and the artificial quantity pOH before reaching pH, but these steps increase the risk of mistakes and provide little insight into acid–base equilibria. The alternative method presented here allows students to calculate the pH of a weak base solution from the pKa of its conjugate acid without calculating Kb and pOH, using a memorable relationship: pH(HA, C) + pH(A−, C) = pKa + 7.
SiGOAM: Web system for developing quality mobile learning objects
Authors: Huerta Guerrero Miguel A. , Cueto García Arturo , López Domínguez Eduardo , Hernández Velázquez Yesenia , Medina Nieto María A. , De la Calleja Jorge , Domínguez Isidro Saúl 
Published: February 2020

AbstractMobile learning (m‐learning) refers to knowledge and abilities acquisition through the use of mobile technology anywhere at any time. Mobile learning objects (MLOs) are key elements for this teaching paradigm; several software tools have been proposed to support the construction of MLOs; however, they do not take into account pedagogical and technological aspects simultaneously during the construction cycle of MLOs. This paper presents the analysis, design, and development of a web system called SiGOAM, which supports specialized services to professors to generate quality MLOs. These services follow a formal MLO's construction cycle integrated into four phases: analysis, design, development, and product‐oriented assessment. As a result of this formal approach, the proposed system generates quality MLOs that are embedded in mobile devices and accessed through web browsers. We performed a usability assessment of our system SiGOAM based on a field study. The results show that professors assigned acceptable values for effectiveness, efficiency, and satisfaction.
Neuregulin‐1 promotes mitochondrial biogenesis, attenuates mitochondrial dysfunction, and prevents hypoxia/reoxygenation injury in neonatal cardiomyocytes
Authors: Zhang Xiao‐Xia , Wu Xue‐Si , Mi Shu‐Hua , Fang Shan‐Juan , Liu Sa , Xin Yi , Zhao Quan‐Ming 
Published: February 2020

Neuregulin‐1 (NRG‐1)/erythroblastic leukaemia viral oncogene homologues (ErbB) pathway activation plays a crucial role in regulating the adaptation of the adult heart to physiological and pathological stress. In the present study, we investigate the effect of recombined human NRG‐1 (rhNRG‐1) on mitochondrial biogenesis, mitochondrial function, and cell survival in neonatal rat cardiac myocytes (NRCMs) exposed to hypoxia/reoxygenation (H/R). The results of this study showed that, in the H/R‐exposed NRCMs, mitochondrial biogenesis was impaired, as manifested by the decrease of the expression of peroxisome proliferator‐activated receptor gamma coactivator‐1 alpha (PGC‐1α) and mitochondrial membrane proteins, the inner membrane (Tim23), mitofusin 1 (Mfn1), and mitofusin 2 (Mfn2). RhNRG‐1 pretreatment effectively restored the expression of PGC‐1α and these membrane proteins, upregulated the expression of the anti‐apoptosis proteins Bcl‐2 and Bcl‐xL, preserved the mitochondrial membrane potential, and attenuated H/R‐induced cell apoptosis. Blocking PGC‐1 expression with siRNA abolished the beneficial role of rhNRG‐1 on mitochondrial function and cell survival. The results of the present study strongly suggest that NRG‐1/ErbB activation enhances the adaption of cardiomyocytes to H/R injury via promoted mitochondrial biogenesis and improved mitochondrial homeostasis.Significance of the StudyThe results of this research revealed for the first time the relationship between neuregulin‐1 (NRG‐1)/erythroblastic leukaemia viral oncogene homologues (ErbB) activation and mitochondrial biogenesis in neonatal cardiomyocytes and verified the significance of this promoted mitochondrial biogenesis in attenuating hypoxia/reoxygenation injury. This finding may open a new field to further understand the biological role of NRG‐1/ErbB signalling pathway in cardiomyocyte.
Overexpression and one‐step renaturation‐purification of the tagged creatinine deiminase of Corynebacterium glutamicum in Escherichia coli cells
Authors: Zakalskiy Andriy E. , Stasyuk Nataliya Ye. , Zakalska Oksana M. , Boretsky Yuriy R. , Gonchar Mykhailo V. 
Published: February 2020

AbstractThe codA gene of Corynebacterium glutamicum PCM 1945 coding for a creatinine deiminase (CDI) (EC 3.5.4.21) has been amplified and cloned. The recombinant strain of Escherichia coli that overproduces the (His)6‐tagged inactive CDI of C. glutamicum as inclusion bodies has been constructed. After solubilization of inclusion bodies in the presence of 0.3% N‐lauroylsarcosine, the enzyme was renaturated and purified by a single‐step procedure using metal‐affinity chromatography. The yield of the (His)6‐tagged CDI is ~30 mg from 1 L culture. The purified enzyme is sufficiently stable under the conditions designed and possesses an activity of 10–20 U/mg. The main characteristics of the tagged enzyme remained similar to that of the natural enzyme.
PrFeO3 Photocathodes Prepared Through Spray Pyrolysis
Authors: Freeman Emma , Kumar Santosh , Thomas Sophie R. , Pickering Hayley , Fermin David J. , Eslava Salvador 
Published: February 2020

AbstractPerovskite oxides are receiving wide interest for photocatalytic and photoelectrochemical devices, owing to their suitable band gaps for solar light absorption and stability in aqueous applications. Herein, we assess the activity of PrFeO3 photocathodes prepared by using spray pyrolysis and calcination temperatures between 500 and 700 °C. Scanning electron microscopy shows corrugated films of high surface coverage on the conductive glass substrate. The electrochemically active surface area shows slight decreases with temperature increases from 500 to 600 and 700 °C. However, transient photocurrent responses and impedance spectroscopy data showed that films calcined at higher temperatures reduced the probabilities of recombination due to trap states, resulting in faster rates of charge extraction. In this trade‐off, a calcination temperature of 600 °C provided a maximum photocurrent of ‐130±4 μA cm−2 at +0.43 VRHE under simulated sunlight, with an incident photon‐to‐current conversion efficiency of 6.6 % at +0.61 VRHE and 350 nm and an onset potential of +1.4 VRHE for cathodic photocurrent.
Multicomponent Self‐Assembly of PdII/PtII Interlocked Molecular Cages: Cage‐to‐Cage Conversion and Self‐Sorting in Aqueous Medium
Authors: Kumar Atul , Mukherjee Partha Sarathi 
Published: February 2020

AbstractCoordination‐driven self‐assembly is an efficient approach for constructing complicated molecules with the aid of reversible bond formation. However, constructing topologically complicated interlocked systems and their formation studies remain challenging tasks. The formation of two water‐soluble hexanuclear interlocked cages by multicomponent self‐assembly of a flexible triimidazole donor (L1) and a rigid tripyridyl donor (L2) based on a triazine core in combination with 90° cis‐blocked PdII and PtII acceptors is reported here. Formation of interlocked systems having a composition of M6(L1)2(L2)2 (M=Pd or Pt) becomes feasible through cavity‐induced self‐recognition of two similar units having a composition of M3(L1)(L2). Self‐sorting of two independently prepared cages of [M3(L1)2] and [M6(L2)4] in aqueous medium leads to the formation of interlocked systems, and their formation was monitored by time‐dependent 1H NMR spectroscopy. Self‐recognition of L1 by [M6(L2)4] or L2 by [M3(L1)2] leads to the formation of interlocked systems, as confirmed from 1H NMR spectroscopic titrations of L1 with cages {M6(L2)4} and L2 with {M3(L1)2}, respectively. Both the interlocked cages of Pd and Pt are highly stable, and formation of either system is equally probable as observed from the treatments of Pd3(L1)2 with Pt6(L2)4 or Pt3(L1)2 with Pd6(L2)4, which lead to the formation of two different self‐assembled homometallic interlocked cages [Pt6(L1)2(L2)2+Pd6(L1)2(L2)2] instead of forming any other heterometallic assemblies. Formation of interlocked cages is dependent on the steric bulk of the diamine ligand bound to the metal acceptors. A N‐alkyl‐substituted blocking amine prefers the non‐interlocked cage instead of the interlocked analogue.
Defluoroalkylation of sp3 C−F Bonds of Industrially Relevant Hydrofluoroolefins
Authors: Phillips Nicholas A. , Coates Gregory J. , White Andrew J. P. , Crimmin Mark R. 
Published: February 2020

AbstractA simple, one‐pot procedure is reported for the selective defluoroalkylation of trifluoromethyl alkene derivatives with aldehydes and ketones. The reaction sequence allows construction of a new C−C bond in a highly selective manner from a single sp3 C−F bond of a CF3 group in the presence of sp2 C−F bonds. The scope incorporates industrially relevant fluorocarbons including HFO‐1234yf and HFO‐1234ze. No catalyst, additives or transition metals are required, rather the methodology relies on a recently developed boron reagent. Remarkably, the boron site of this reagent plays a dual role in the reaction sequence, being nucleophilic at boron in the C−F cleavage step (SN2’) but electrophilic at boron en route to the carbon–carbon bond‐forming step (SE2’). The duplicitous behaviour is underpinned by a hydrogen atom migration from boron to the carbon atom of a carbene ligand.
Residual Dipolar‐Coupling‐Based Conformational Comparison of Noncovalent Ubiquitin Homodimer with Covalently Linked Diubiquitin
Authors: Shine A. , Shenoy J. , Jayan Parvathy , Jiji A. C. , Vijayan Vinesh 
Published: February 2020

AbstractAlthough the conformation of the polymer chain of Ubiquitin (Ub) mainly depends on the type of isopeptide linkage connecting two Ub molecules, the non‐covalent (noncovalent) interaction between two Ub molecules within the chain could also tune their conformational preference. Here, we studied the conformation of noncovalently formed Ub dimers in solution using residual dipolar couplings (RDCs). Comparing the RDC derived alignment tensor of the noncovalently formed dimer with the two most abundant (K11 and K48) covalent linked Ub dimers revealed that the conformation of K11 linked and noncovalent Ub dimers were similar. Between the various NMR and crystal structures of K11 linked Ub dimers, RDC tensor analysis showed that the structure of K11 linked dimer crystalized at neutral pH is similar to noncovalent dimer. Analogous to the experimental study, the comparison of predicted order matrix of various covalent Ub dimers with that of the experimentally determined order matrix of noncovalent Ub dimer also suggests that the conformation of K11 linked dimers crystalized at neutral pH is similar to the noncovalent dimer.
Viologen Derivatives Extended with Aromatic Rings Acting as Negative Electrode Materials for Use in Rechargeable Molecular Ion Batteries
Authors: Kato Minami , Sano Hikaru , Kiyobayashi Tetsu , Yao Masaru 
Published: February 2020

AbstractMany types of batteries have been proposed as next‐generation energy‐storage systems. One candidate is a rocking‐chair‐type “molecular ion battery” in which a molecular ion, instead of Li+, works as a charge carrier. Previously, we reported a viologen‐type derivative as a negative electrode material that releases and receives PF6− anions during the charge–discharge process; however, its redox potential was not satisfactorily low. Further, the two potential plateaus of this material (difference=0.5 V) should be reduced. In this study, PF6− salts of viologen (bipyridinium) derivatives extended by aromatic rings were synthesized to obtain a negative electrode material with a lower redox potential and small potential change during the charge and discharge processes. Some of the synthesized viologen derivatives were fluorescent even in solid‐state electrodes. In the half‐cell configuration, the prepared negative electrode materials showed average voltages of approximately 2 V (vs. Li+/Li), which is lower than that of conventional viologen derivatives.
Redox‐Active Functional Electrolyte for High‐Performance Seawater Batteries
Authors: Lee Seyoung , Cho Il Young , Kim Dowan , Park Nam Kyu , Park Jaehyun , Kim Yongil , Kang Seok Ju , Kim Youngsik , Hong Sung You 
Published: February 2020

AbstractRechargeable seawater batteries have gained recognition as key sustainable electrochemical systems by employing the near‐infinite and eco‐friendly catholyte seawater. However, their practical applications have been limited owing to the low chemical and electrochemical stability of the anode component. Herein, a stability‐secured approach was developed by using sodium‐biphenyl‐dimethoxyethane solution as a redox‐active functional anolyte for high‐performance seawater batteries. This anolyte system shows high electrochemical stability, superior cycle performance, and cost‐effectiveness over conventional electrolyte systems.
A novel antenna for sub‐atmospheric radio‐frequency discharge
Authors: Hu Xinyue , Chang Lei , Yuan Xiaogang , Yang Xin , Chang Yunju , Zhang Lupeng , Zhou Haishan , Luo Guangnan , Dai Jia , Liu Jia , Hang Guanrong 
Published: February 2020

AbstractA novel antenna that can generate plasma efficiently for pressure up to thousands of Pascal with 1 kW–13.56 MHz radio‐frequency power supply is reported. It consists of two isolated solenoids so that involves both capacitively coupling and inductively coupling effects, together with magnetic mirror effect which confines the formed plasma axially to a certain extent. Experiments show that the novel discharge has directional preference depending on the applied voltage, a character of dielectric barrier discharge, and can run steadily for tens of hours without severe thermal load. Simulations using COMSOL Multiphysics reveal consistent variations of electron temperature and electron density with base pressure, input power, separation distance of isolated solenoids, and the number of turns of each solenoid. This ionization method is of great interest for plasma processing and propulsion in sub‐atmospheric environment.
Spatiotemporal organization of myoclonic twitching in sleeping human infants
Authors: Sokoloff Greta , Hickerson Meredith M. , Wen Rebecca Y. , Tobias Megan E. , McMurray Bob , Blumberg Mark S. 
Published: February 2020

AbstractDuring the perinatal period in mammals when active sleep predominates, skeletal muscles twitch throughout the body. We have hypothesized that myoclonic twitches provide unique insight into the functional status of the human infant's nervous system. However, assessments of the rate and patterning of twitching have largely been restricted to infant rodents. Thus, here we analyze twitching in human infants over the first seven postnatal months. Using videography and behavioral measures of twitching during bouts of daytime sleep, we find at all ages that twitching across the body occurs predominantly in bursts at intervals of 10 s or less. We also find that twitching is expressed differentially across the body and with age. For example, twitching of the face and head is most prevalent shortly after birth and decreases over the first several months. In addition, twitching of the hands and feet occurs at a consistently higher rate than does twitching elsewhere in the body. Finally, the patterning of twitching becomes more structured with age, with twitches of the left and right hands and feet exhibiting the strongest coupling. Altogether, these findings support the notion that twitches can provide a unique source of information about typical and atypical sensorimotor development.
An intelligent linear time trajectory data compression framework for smart planning of sustainable metropolitan cities
Authors: Bashir Maryam , Ashraf Jawad , Habib Asad , Muzammil Muhammad 
Published: February 2020

AbstractThe urban road networks and vehicles generate exponential amount of spatio‐temporal big‐data, which invites researchers from diverse fields of interest. Global positioning system devices may transceive data every second thus producing huge amount of trajectory data. Subsequently, it requires optimized computing for various operations such as visualization and mining hidden patterns. This sporadically stored big‐data contains invaluable information, which is useful for a number of real‐time applications. Compression is a highly important, but knotty task. Optimized compression enables us achieve the desired results in efficient and effective manner by using minimum energy and computational resources without compromising on important information. We present two versions of a compression technique based on the points of intersections (PoI) of urban roads networks. Based on intelligent mining paradigm, we created a compressed lookup lexicon to store the PoIs of dynamically selected region of interests (ROI). An important feature of our lexicon is the key pattern, which is intelligently computed based on the relative geographic position of a spatial geodetic vertex with respect to Euclidean space origin in a given ROI. This compresses trajectories in linear time, making it feasible for mission critical real world applications. Our experimental dataset contained 959 547, 517 436, and 231 740 trajectories for Bikes, Cars, and Taxis, respectively. The Compr10 reduced these trajectories to 17 428, 11 084, and 6565, respectively. Results of Compr15 and Compr20 show promising results. We define the quality of the compression in context of the considered problem. The results show that the proposed technique achieved satisfactory quality of the compression.
Adaptive NOMA towards 5G green wireless network
Authors: Jain Preksha , Gupta Akhil 
Published: February 2020

AbstractA nonorthogonal multiple access (NOMA) enabled downlink single‐cell communication network with cooperating relay nodes, is considered in this article. NOMA simultaneously transmits signals to a group of users. The formation of the group users, in NOMA, depends on their spatial restrictions. These spatial restrictions are defined by the transmission range of the relay equipment. Therefore, it is important to find the transmission range of the relay. This article presents a novel angle selection scheme for finding the transmission range of the relay. Ever‐increasing cellular traffic needs improvement in data rates and power saving. So, an adaptive NOMA scheme in which the system adaptively chooses its working model is proposed in this article. The adaptive NOMA scheme maximizes the sum rate and optimizes the energy efficiency of the fifth‐generation communication network. It also reduces the power consumption at the circuit of the end‐user equipment, hence, achieving power saving. Comprehensive numerical results emphasize that the proposed scheme achieves higher system energy efficient as compared to the conventional NOMA scheme. Such an adaptive framework also improves the average signal‐to‐interference noise ratio and the fairness factor, as shall be examined. The implications of proposing an adaptive NOMA network are evaluated through simulation results.