bluuebunny/crossref_metadata_2025_split huggingface dataset:
Doping Effect on Piezoelectric, Magnetic and Magnetoelectric Properties of Perovskite—Ferromagnetic Magnetoelectric Composites
Authors: A. Islam Rashed 
Published: February 2021

This chapter explains the effect of compositional modification on the magnetoelectric coefficient in sintered piezoelectric – magnetostrictive composites. It was found that 15 at% doping of Pb(Zn1/3Nb2/3)O3 [PZN] in Pb(Zr0.52Ti0.48)O3 [PZT] enhances the piezoelectric and magnetoelectric properties of a PZT – 20 at% Ni0.8Zn0.2Fe2O4 [NZF] composite. The effect of doping on the ferromagnetic phase was also investigated. With increases in Zn concentration, it was found that the coercive field and Curie temperature of Ni(1-x)ZnxFe2O4 [NZF] decreases, while its saturation magnetization has a maxima at 30 mole% Zn. X-ray diffraction revealed that the lattice constant of NZF increases from 8.32 Å for 0 at% Zn to 8.39 Å for 50 at% Zn. The magnetoelectric coefficient was found to have a maxima of 144 mV/cm.Oe at 30 at% Zn. To understand better, the effect of 40% (by mole) Zn substitution on structural, piezoelectric, ferromagnetic and magnetoelectric properties of Pb(Zr0.52Ti0.48)O3 - CoFe2O4 (PZT - CFO) sintered composite is also explained. X-ray diffraction of Co0.6Zn0.4Fe2O4 (CZF) showed the shift in almost all diffraction peaks to lower diffraction angle confirming the increase in lattice parameter in all three direction from 8.378 (for CFO) to 8.395 Å for (Co,Zn)Fe2O4 (CZF). SEM and TEM results showed defect structure (cleavage, twins, strain fields) in the CZF particle, which is a clear indication of misfit strain developed due to lattice expansion. Magnetic properties measured over temperature (5 K – 1000 K) showed increased magnetization but lower magnetic Curie temperature in PZT - CZF particle. Magnetoelectric coefficient measured as function of ferrite concentration showed an increase of more than 100% after doping the CFO phase with 40% Zn. This enhancement can be attributed to increase in the lattice strain, magnetic permeability and decrease in coercivity.
Rhodium Catalyzed Regioselective C−H Allylation of Simple Arenes via C−C Bond Activation of Gem‐difluorinated Cyclopropanes
Authors: Jiang Zhong‐Tao , Huang Jiangkun , Zeng Yaxin , Hu Fangdong , Xia Ying 
Published: February 2021

AbstractHerein, we report a rhodium catalyzed directing‐group free regioselective C−H allylation of simple arenes. Readily available gem‐difluorinated cyclopropanes can be employed as highly reactive allyl surrogates via a sequence of C−C and C−F bond activation, providing allyl arene derivatives in good yields with high regioselectivity under mild conditions. The robust methodology enables facile late‐stage functionalization of complex bioactive molecules. The high efficiency of this reaction is also demonstrated by the high turnover number (TON, up to 1700) of the rhodium catalyst on gram‐scale experiments. Preliminary success on kinetic resolution of this transformation is achieved, providing a promising access to enantio‐enriched gem‐difluorinated cyclopropanes.
Tracking Reactions of Asymmetric Organo‐Osmium Transfer Hydrogenation Catalysts in Cancer Cells
Authors: Bolitho Elizabeth M. , Coverdale James P. C. , Bridgewater Hannah E. , Clarkson Guy J. , Quinn Paul D. , Sanchez‐Cano Carlos , Sadler Peter J. 
Published: February 2021

AbstractMost metallodrugs are prodrugs that can undergo ligand exchange and redox reactions in biological media. Here we have investigated the cellular stability of the anticancer complex [OsII[(η6‐p‐cymene)(RR/SS‐MePh‐DPEN)] [1] (MePh‐DPEN=tosyl‐diphenylethylenediamine) which catalyses the enantioselective reduction of pyruvate to lactate in cells. The introduction of a bromide tag at an unreactive site on a phenyl substituent of Ph‐DPEN allowed us to probe the fate of this ligand and Os in human cancer cells by a combination of X‐ray fluorescence (XRF) elemental mapping and inductively coupled plasma‐mass spectrometry (ICP‐MS). The BrPh‐DPEN ligand is readily displaced by reaction with endogenous thiols and translocated to the nucleus, whereas the Os fragment is exported from the cells. These data explain why the efficiency of catalysis is low, and suggests that it could be optimised by developing thiol resistant analogues. Moreover, this work also provides a new way for the delivery of ligands which are inactive when administered on their own.
Host–Guest Interaction Modulation in Porous Coordination Polymers for Inverse Selective CO2/C2H2Separation
Authors: Gu Yifan , Zheng Jia‐Jia , Otake Ken‐ichi , Shivanna Mohana , Sakaki Shigeyoshi , Yoshino Haruka , Ohba Masaaki , Kawaguchi Shogo , Wang Ying , Li Fengting , Kitagawa Susumu 
Published: February 2021

AbstractControlling gas sorption by simple pore modification is important in molecular recognition and industrial separation processes. In particular, it is challenging to realize the inverse selectivity, which reduces the adsorption of a high‐affinity gas and increases the adsorption of a low‐affinity gas. Herein, an “opposite action” strategy is demonstrated for boosting CO2/C2H2selectivity in porous coordination polymers (PCPs). A precise steric design of channel pores using an amino group as an additional interacting site enabled the synergetic increase in CO2adsorption while suppressing the C2H2adsorption. Based on this strategy, two new ultramicroporous PCP physisorbents that are isostructural were synthesised. They exhibited the highest CO2uptake and CO2/C2H2volume uptake ratio at 298 K. Origin of this specific selectivity was verified by detailed density functional theory calculations. The breakthrough separation performances with remarkable stability and recyclability of both the PCPs render them relevant materials for C2H2purification from CO2/C2H2mixtures.
p‐Type Charge Transfer Doping of Graphene Oxide with (NiCo)1−yFeyOx for Air‐Stable, All‐Inorganic CsPbIBr2 Perovskite Solar Cells
Authors: Du Jian , Duan Jialong , Yang Xiya , Duan Yanyan , Zhou Quanzhu , Tang Qunwei 
Published: February 2021

AbstractThe precise regulation of interfacial charge distribution highly determines the power conversion efficiency of perovskite solar cells (PSCs). Herein, inorganic (NiCo)1−yFeyOx nanoparticle decorated graphene oxide (GO) is successfully demonstrated as a hole booster for all‐inorganic CsPbIBr2 PSC free of precious metal electrode. Arising from the spontaneous electron transfer induced p‐type doping of GO from edged oxygen‐containing functional groups to (NiCo)1−yFeyOx, the best all‐inorganic CsPbIBr2 PSC achieves an efficiency of 10.95 % under one standard sun owing to the eliminated paradox between charge extraction and charge localization in GO surface. Furthermore, the champion device exhibits an excellent long‐term stability at 10 % relative humidity without encapsulation over 70 days because of the suppressed ions migration.
Pressure‐Responsive Two‐Dimensional Metal–Organic Framework Composite Membranes for CO2 Separation
Authors: Ying Yunpan , Zhang Zhengqing , Peh Shing Bo , Karmakar Avishek , Cheng Youdong , Zhang Jian , Xi Lifei , Boothroyd Chris , Lam Yeng Ming , Zhong Chongli , Zhao Dan 
Published: February 2021

AbstractThe regulation of permeance and selectivity in membrane systems may allow effective relief of conventional energy‐intensive separations. Here, pressure‐responsive ultrathin membranes (≈100 nm) fabricated by compositing flexible two‐dimensional metal–organic framework nanosheets (MONs) with graphene oxide nanosheets for CO2 separation are reported. By controlling the gas permeation direction to leverage the pressure‐responsive phase transition of the MONs, CO2‐induced gate opening and closing behaviors are observed in the resultant membranes, which are accompanied with the sharp increase of CO2 permeance (from 173.8 to 1144 gas permeation units) as well as CO2/N2 and CO2/CH4 selectivities (from 4.1 to 22.8 and from 4 to 19.6, respectively). The flexible behaviors and separation mechanism are further elucidated by molecular dynamics simulations. This work establishes the relevance of structural transformation‐based framework dynamics chemistry in smart membrane systems.
Isotopic Labelling of Confined Carbyne
Authors: Cui Weili , Shi Lei , Cao Kecheng , Kaiser Ute , Saito Takeshi , Ayala Paola , Pichler Thomas 
Published: February 2021

AbstractCarbyne is a one‐dimensional allotrope of carbon consisting of a linear chain of carbon atoms bonded to each other with exceptional strength. Its outstanding mechanical, optical, and electronic properties have been theoretically predicted, but its stability has only been achieved when grown encapsulated in the hollow core of carbon nanotubes. One of the advantages of this confinement is that its properties can be controlled by the chain's length and surrounding environment. We investigated an alternative way of gaining control of its properties is using isotope labelling as tuning mechanism. The optimized liquid precursor was first chosen among several options, which can greatly enhance the yield of the confined carbyne. Then isotopic labelled liquid precursor was encapsulated for further synthesis of isotopic labelled confined carbyne. This allowed us to obtain pioneering results on isotope engineered carbyne with around 11.9 % of 13C‐labelling using 13C‐methanol as precursor.
Proton Capture Strategy for Enhancing Electrochemical CO2 Reduction on Atomically Dispersed Metal–Nitrogen Active Sites**
Authors: Wang Xinyue , Sang Xiahan , Dong Chung‐Li , Yao Siyu , Shuai Ling , Lu Jianguo , Yang Bin , Li Zhongjian , Lei Lecheng , Qiu Ming , Dai Liming , Hou Yang 
Published: February 2021

AbstractElectrocatalysts play a key role in accelerating the sluggish electrochemical CO2 reduction (ECR) involving multi‐electron and proton transfer. We now develop a proton capture strategy by accelerating the water dissociation reaction catalyzed by transition‐metal nanoparticles (NPs) adjacent to atomically dispersed and nitrogen‐coordinated single nickel (Ni−Nx) active sites to accelerate proton transfer to the latter for boosting the intermediate protonation step, and thus the whole ECR process. Aberration‐corrected scanning transmission electron microscopy, X‐ray absorption spectroscopy, and calculations reveal that the Ni NPs accelerate the adsorbed H (Had) generation and transfer to the adjacent Ni−Nx sites for boosting the intermediate protonation and the overall ECR processes. This proton capture strategy is universal to design and prepare for various high‐performance catalysts for diverse electrochemical reactions even beyond ECR.
Development of Generic G Protein Peptidomimetics Able to Stabilize Active State Gs Protein‐Coupled Receptors for Application in Drug Discovery
Authors: Mannes Morgane , Martin Charlotte , Triest Sarah , Pia Dimmito Marilisa , Mollica Adriano , Laeremans Toon , Menet Christel J. , Ballet Steven 
Published: February 2021

AbstractG protein‐coupled receptors (GPCRs) represent an important group of membrane proteins that play a central role in modern medicine. Unfortunately, conformational promiscuity hampers full therapeutic exploitation of GPCRs, since the largest population of the receptor will adopt a basal conformation, which subsequently challenges screens for agonist drug discovery programs. Herein, we describe a set of peptidomimetics able to mimic the ability of G proteins in stabilizing the active state of the β2 adrenergic receptor (β2AR) and the dopamine 1 receptor (D1R). During fragment‐based screening efforts, these (un)constrained peptide analogues of the α5 helix in Gs proteins, were able to identify agonism pre‐imprinted fragments for the examined GPCRs, and as such, they behave as a generic tool, enabling an engagement in agonist earmarked discovery programs.
A High‐Resolution View of the Coordination Environment in a Paramagnetic Metalloprotein from its Magnetic Properties
Authors: Ravera Enrico , Gigli Lucia , Suturina Elizaveta A. , Calderone Vito , Fragai Marco , Parigi Giacomo , Luchinat Claudio 
Published: February 2021

AbstractMetalloproteins constitute a significant fraction of the proteome of all organisms and their characterization is critical for both basic sciences and biomedical applications. A large portion of metalloproteins bind paramagnetic metal ions, and paramagnetic NMR spectroscopy has been widely used in their structural characterization. However, the signals of nuclei in the immediate vicinity of the metal center are often broadened beyond detection. In this work, we show that it is possible to determine the coordination environment of the paramagnetic metal in the protein at a resolution inaccessible to other techniques. Taking the structure of a diamagnetic analogue as a starting point, a geometry optimization is carried out by fitting the pseudocontact shifts obtained from first principles quantum chemical calculations to the experimental ones.
Construction of Covalent Organic Frameworks with Crown Ether Struts
Authors: An Shuhao , Xu Qing , Ni Zhihui , Hu Jun , Peng Changjun , Zhai Lipeng , Guo Yu , Liu Honglai 
Published: February 2021

AbstractCrown ethers are a class of macrocyclic molecules with unique flexible structures but they are rarely integrated in covalent organic frameworks (COFs). To date, employing flexible organic units such as crown ethers to construct COFs with high crystallinity and surface area are still a challenge. In this work, two new COFs with different flexible crown ethers as backbone rather than side chains are synthesized and further employed for alkali metal ions separation. Both of COFs possess high surface areas, good crystallinity, and excellent chemical stability. Interestingly, these two new COFs with 18‐crown‐6 or 24‐crown‐8 units showed remarkable binding ability of K+ or Cs+ owing to the size‐fit effect. This work demonstrated that the unique structural features of crown ethers will lead to increase interest in fabricating COFs with crown ethers.
A Balance Between Capture and Release: How Nanochaperones Regulate Refolding of Thermally Denatured Proteins
Authors: Ma Feihe , Wu Xiaohui , Li Ang , Xu Linlin , An Yingli , Shi Linqi 
Published: February 2021

AbstractNanochaperones have been designed and used for regulating the (re)folding of proteins, treating protein misfolding‐related diseases, and, more recently, in drug delivery. Despite various successes, a complete understanding of the working mechanisms remains elusive, which represents a challenge for the realization of their full potential. Here, we thoroughly investigated the functioning of differently charged nanochaperones that regulate the refolding of thermally denatured lysozyme. We found that the balance between the capture and release of lysozyme clients that are controlled by nanochaperones plays a key role in regulating refolding. More importantly, the findings could be applied to other enzymes with various physicochemical properties. On the basis of these results, we could recover the activity of enzymes with high efficiency either after 20 days of storage at 40 °C or heating at high temperatures for 30–60 min. Our results provide important new design strategies for nanochaperone systems to improve their properties and expand their applications.
A Self‐Catabolic Multifunctional DNAzyme Nanosponge for Programmable Drug Delivery and Efficient Gene Silencing
Authors: Wang Jing , Yu Shanshan , Wu Qiong , Gong Xue , He Shizhen , Shang Jinhua , Liu Xiaoqing , Wang Fuan 
Published: February 2021

AbstractDNAzyme‐based gene therapy holds immense prospects for effectively treating severe diseases, yet is constrained with inefficient delivery and unconditional activation. Herein, we designed a bioinspired self‐catabolic DNA nanocapsule for sustaining tumor‐specific cascade activation of therapeutic DNAzyme. The exquisite DNAzyme was temporarily masked by the self‐excising DNAzyme in the hierarchical rolling circle replication (RCR) nanostructures, thus stayed in an inactive state in physiological fluids. Through the multivalent tumor‐anchoring aptamer strands, the RCR nanocapsule was specifically accumulated in cancer cells and was sequentially activated for motivating the ultimate DNAzyme‐mediated gene silencing via the intelligent stimuli‐responsive cascade DNAzyme activation. By virtue of the programmable RCR assembly strategy, our compact DNAzyme nanoplatform shows great promise for developing versatile smart gene therapeutics and personalized nanomedicines.
Towards High‐Performance Zinc‐Based Hybrid Supercapacitors via Macropores‐Based Charge Storage in Organic Electrolytes
Authors: Qiu Xuan , Wang Nan , Wang Zhuo , Wang Fei , Wang Yonggang 
Published: February 2021

AbstractZn‐based aqueous supercapacitors are attracting extensive attention. However, most of the reported long‐life and high‐power performances are achieved with low Zn‐utilization (<0.6 %) and low mass loading in cathode (<2 mg cm−2). And, many obtained high energy densities are generally evaluated without considering the mass of Zn‐anode. Herein, we propose a Zn‐based hybrid supercapacitor, involving a metal organic framework derived porous carbon cathode, a Zn‐anode and an N, N‐dimethylformamide (DMF)‐based electrolyte containing Zn2+. We demonstrate that the charge storage of cathode mainly occurs in macropores, showing high rate performance at high mass loading (40 mg cm−2). Furthermore, the aprotic nature of electrolyte and formation of Zn2+‐DMF complex avoid the Zn‐corrosion and dendrite formation. Therefore, the supercapacitor shows a long‐life (9,000 cycles) with a high Zn‐utilization (2.2 %). When calculated with the total mass of cathode (40 mg cm−2) and Zn‐anode, the energy density reaches 25.9 Wh kg−1.
A Cysteine‐Mediated Synthesis of Red Phosphorus Nanosheets
Authors: Mo Jianbin , Xu Yun , Zhu Longqian , Wei Wei , Zhao Jing 
Published: February 2021

AbstractAmong phosphorus‐based nanomaterials, layered black phosphorus and violet phosphorus have been actively explored in the past decade. However, methods for the synthesis of red phosphorus nanosheets (RPNSs) is lacking, even though red phosphorus (RP) is commercially available at low cost and has excellent chemical stability at room temperature. We report an efficient strategy for fabrication of RPNSs and doped RPNSs using cysteine as a reducing reagent. Data from in vitro and in vivo studies suggested that RPNSs can trigger production of reactive oxygen species, DNA damage, and subsequent autophagy‐mediated cell death in a shape‐dependent manner. Our findings provide a method for construction of layered RP nanomaterials and they present a unique mechanism for the application of phosphorus‐based materials in nanomedicines.
Influence of grape marc extract on tuning the intermolecular interactions in the high‐density polyethylene
Authors: Zujovic Zoran , Ray Sudip , Vandermeer Charlotte , Bowmaker Graham A. , Kilmartin Paul A. 
Published: February 2021

AbstractIntermolecular interactions and molecular dynamics in thin films of high‐density polyethylene (HDPE) containing a high loading of Grape Marc Extract (GME) were analyzed by solid‐state NMR. Optical microscopy (OM), Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) studies were used to corroborate the findings. The OM and SEM images and 1H‐13C RAMP CP/MAS (ramped amplitude cross‐polarization/magic‐angle spinning) spectra of HDPE, HDPE‐GME, and GME confirmed the incorporation of the GME into the HDPE structure. The results were compared to those for an unfilled HDPE film. The influence of GME on enhancing the amorphous nature of HDPE, altering the crystalline melting behavior and possible intermolecular interactions were evident from the DSC and FTIR. The NMR spin‐diffusion and T1(1H), T2(1H), T1ρ*(13C), T1ρ(1H) relaxation and variable contact time experiments revealed the interactions and dynamics at the sub‐micron level.
Three endogenous cellulases from termite, Reticulitermes speratus KMT001
Authors: Ahn Hee‐Hoon , Kim Tae‐Jong 
Published: February 2021

AbstractAmong termites, lower termites need symbiotic microorganisms in the digestive tract for digestion and cellulose metabolism. In this symbiotic relationship, the decomposition of cellulose is initiated by endoglucanase in termite salivary glands and completed by β‐glycosidase of symbiotic microorganisms in the hindgut. The expression of β‐glycosidase in lower termites has been reported in recent studies. The expression of two endoglucanases and one β‐glycosidase gene related to cellulose degradation was identified in Reticulitermes speratus, a lower termite, through transcriptomic analysis. The proposed enzyme activities of three identified cellulose degradation genes were confirmed by heterologous expression in Escherichia coli. In addition to the endoglucanase expressed in the salivary gland, additional endoglucanase and β‐glycosidase genes suggest that R. speratus performs the overall cellulose digestion using its own enzymes at all stages.
F‐wave parameters and body mass index in carpal tunnel syndrome
Authors: Adebayo Philip B. , Mwakabatika Rose E. 
Published: February 2021

AbstractBackgroundSevere carpal tunnel syndrome (CTS) readily lends itself to both clinical and electrophysiological recognition. The uncertainty sometimes is in identifying and quantifying motor involvement in mild and, perhaps, in moderate CTS. Our study aimed to evaluate F responses in mild and moderate CTS and determine the contribution of BMI to the F‐wave parameters.MethodsA retrospective review of the clinical and electrophysiological data of patients with CTS seen at the clinical neurophysiology laboratory of Aga Khan Hospital, Dar es Salaam, between 1 August 2017 and 31 July 2019 was retrieved. Carpal tunnel syndrome was graded according to the electrophysiological criteria of Padua. The F‐wave parameters of patients with mild‐to‐moderate CTS were analyzed and compared with asymptomatic controls.ResultWe studied 91 hands. Twenty‐two hands were asymptomatic controls, 30 hands had mild CTS, and 39 hands had moderate CTS. Patients with moderate CTS were more obese (p =.011), had more females (p =.044), and were older (p= <0.001). F‐wave parameters were not convincingly different between mild and moderate CTS. F‐wave chronodispersion (p =.035) and F‐wave persistence (0.019) were significantly different between nonobese control and mild and moderate CTS. Median–ulnar F‐wave latency difference (FWLD) was significant between obese patients with mild CTS and moderate CTS scores (p =.017).ConclusionAlthough a clear difference exists between F‐wave parameters in asymptomatic controls and those with CTS, the F‐wave study is inadequate in distinguishing mild and moderate CTS even in the context of BMI. Median–ulnar F‐wave latency difference (FWLD) appeared to be a promising discriminant parameter between obese patients with mild CTS and those with moderate CTS.