bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence of Methicillin Resistant Staphylococcus aureus Isolated from Nostrils of Mouau Students
Authors: Okoh Miracle I. , Odoemena Philip C. , Amanze Emmanuel K. , Peter Jane K. , Azubuike Eberechukwu O. , Nwokafor Chibuzo V. , Omaba Justina O.
Published: July 2021

Aim: This study is carried out to determine the prevalence of nasal carriage of staphylococcus aureus among Michael Okpara University of Agriculture Umudike (MOUAU) students and determine the antibiotics susceptibility pattern.

Methods: Nasal swab specimens collected from the anterior nares were cultured on mannitol salt agar. S.aureus isolates were identified by mannitol fermentation, coagulase positivity and catalase positivity. Antimicrobial susceptibility test was performed on Meuller-Hinton Agar (MHA) by modified Kirby-Bauer disc diffusion method.

Result: Out of the 100 swabs collected, S.aureus was isolated from 60% of the samples. Among colonized students, 63.3% (n=38) were from male students whereas 36.7% (n=22) were from female. The antibiotic susceptibility pattern of the Staphylococcus aureus isolates indicates that Staphylococcus aureus isolates showed high rate of sensitivity towards antibiotics as follows; Gentamycin (81.67%), followed by Ciprofloxacin  (80%), Levofloxacin (76.67%), Ceftriaxone (58.33%), and resistance towards antibiotics Imipenem (100%) followed by Cefotaxime (90%), Cefexime (83.33%), Cefoxitin (65%), azithromycin (55%) and cefuroxime (50%).

Conclusion: This study showed a high rate of nasal carriage of Staphylococcus aureus among MOUAU students and a high incidence of antibiotics resistant Staphylococcus aureus carriage.
Bacteriological and Physicochemical Quality of Mono-pumps and Boreholes used as Sources of Domestic Water Supply in Abonnema Rivers State, Nigeria
Authors: Ibietela Douglas Salome , Alabo Alambo, Ayaba , Omokaro Obire,
Published: July 2021

Aim: This study was carried out to compare the bacteriological and physicochemical qualities of boreholes and mono-pumps water samples used as sources of domestic water supply, in Abonnema Community, Akuku-Toru Local Government Area, Rivers State.

Methodology: A total of forty-eight water samples were collected twice monthly for four months and evaluated. The bacteriological parameters such as total heterotrophic bacterial, total coliform, faecal coliform, Vibrio, Salmonella - Shigella and Pseudomonas were analyzed using standard microbiological methods.  The coliform was determined using the Most Probable number technique while, the physicochemical parameters were determined using Standard methods for the examination of water and wastewater.

Results: The total heterotrophic bacterial, coliform, faecal coliform, Vibrio, Salmonella-Shigella and Pseudomonas counts of the borehole samples ranged from 7.2×102 - 2.4×103, 2.3×102–4.0×102, 3.6×102-4.8×102, 7.3×102-1.4×103, 2.1×102-2.8×102 and 0.0×100Cfu/ml, respectively. The total heterotrophic bacterial counts, coliform counts, faecal coliform counts, Vibrio counts, Salmonella-Shigella counts and Pseudomonas counts for the mono-pump samples ranged from: 1.1×103- 1.8×103, 2.0×102– 9.1×102, 2.4×102- 3.8×102, 4.5×102-8.6×102, 1.4×102 - 4.2×102 and 0.0×100Cfu/ml, respectively. The bacterial genera identified were: Bacillus, Lynsinibacillus, Staphylococcus, Vibrio, Serratia, Enterobacter, Klebsiella, Shigella, Salmonella, Paenibacillus, Aeromonas and Geobacillus. The means of physicochemical parameters for borehole and mono-pump, respectively were: alkalinity: 41.72±0.01-60.85±0.20 and 29.14±0.01-214.87±1.36mg/l; BOD: 8.26±0.01-10.44±0.0 and 5.12±0.01-5.79±0.01; COD: 126.52±0.01-172.41±0.04 and 83.20±0.44-218.00±0.57; DO: 6.31±0.01 and 3.05±0.07-8.29±0.01; calcium: 5.10±0.28-; 4.83±0.00-10.15±0.00 and 2.71±0.00-14.04±0.00; iron: 2.01±0.00-3.37±0.00 and 1.90±0.00-4.73±0.00; lead: 0.38±0.00-1.07±0.00 and 1.24±0.00-1.63±0.00; nitrate: 0.42±0.00-1.08±0.00 and 1.14±0.00-1.75±0.00; zinc:1.10±0.00-3.18±0.00 and 0.39±0.00-1.82±0.00; phosphate: 0.03±0.00-0.13±0.00 and 0.15±0.00-0.87±0.00; pH: 6.54±0.00-7.05±0.07 and 6.29±0.00-6.93±0.01; salinity: 4.02±0.00-5.14±0.00 and 2.83±0.00-5.88±0.00; total organic carbon: 1.39±0.01-2.81±0.010 and 1.64±0.00-3.42±0.01; polycyclic aromatic hydrocarbon: 32.69±0.00-55.73±0.00 and 45.10±0.00-61.49±0.00mg/l; total petroleum hydrocarbon:58.90±0.00-66.15±0.00 and 60.31±0.00-92.11±0.00 mg/l.

Conclusion: The high counts of bacterial groups of public health importance identified from this study, including the presence of: COD, DO, Fe, Pb, Phosphate, Zinc, TPH and PAH in high concentrations reveals contamination of the water sources. Thus, treatment before drinking is recommended.
Implementation of a real‐time, ultrasound‐guided prostate HDR brachytherapy program
Authors: Smith Blake R. , Strand Sarah A. , Dunkerley David , Flynn Ryan T. , Besemer Abigail E. , Kos Jennifer D. , Caster Joseph M. , Wagner Bonnie S. , Kim Yusung
Published: July 2021

This work presents a comprehensive commissioning and workflow development process of a real‐time, ultrasound (US) image‐guided treatment planning system (TPS), a stepper and a US unit. To adequately benchmark the system, commissioning tasks were separated into (1) US imaging, (2) stepper mechanical, and (3) treatment planning aspects. Quality assurance US imaging measurements were performed following the AAPM TG‐128 and GEC‐ESTRO recommendations and consisted of benchmarking the spatial resolution, accuracy, and low‐contrast detectability. Mechanical tests were first used to benchmark the electronic encoders within the stepper and were later expanded to evaluate the needle free length calculation accuracy. Needle reconstruction accuracy was rigorously evaluated at the treatment planning level. The calibration length of each probe was redundantly checked between the calculated and measured needle free length, which was found to be within 1 mm for a variety of scenarios. Needle placement relative to a reference fiducial and coincidence of imaging coordinate origins were verified to within 1 mm in both sagittal and transverse imaging planes. The source strength was also calibrated within the interstitial needle and was found to be 1.14% lower than when measured in a plastic needle. Dose calculations in the TPS and secondary dose calculation software were benchmarked against manual TG‐43 calculations. Calculations among the three calculation methods agreed within 1% for all calculated points. Source positioning and dummy coincidence was tested following the recommendations of the TG‐40 report. Finally, the development of the clinical workflow, checklists, and planning objectives are discussed and included within this report. The commissioning of real‐time, US‐guided HDR prostate systems requires careful consideration among several facets including the image quality, dosimetric, and mechanical accuracy. The TPS relies on each of these components to develop and administer a treatment plan, and as such, should be carefully examined.
From Groundwork to Efficient Solar Cells: On the Importance of the Substrate Material in Co‐Evaporated Perovskite Solar Cells
Authors: Abzieher Tobias , Feeney Thomas , Schackmar Fabian , Donie Yidenekachew J. , Hossain Ihteaz M. , Schwenzer Jonas A. , Hellmann Tim , Mayer Thomas , Powalla Michael , Paetzold Ulrich W.
Published: July 2021

Vacuum‐based deposition of optoelectronic thin films has a long‐standing history. However, in the field of perovskite‐based photovoltaics, these techniques are still not as advanced as their solution‐based counterparts. Although high‐efficiency vacuum‐based perovskite solar cells reaching power conversion efficiencies (PCEs) above 20% are reported, the number of studies on the underlying physical and chemical mechanism of the co‐evaporation of lead iodide and methylammonium iodide is low. In this study, the impact of one of the most crucial process parameters in vacuum processes—the substrate material—is studied. It is shown that not only the morphology of the co‐evaporated perovskite thin films is significantly influenced by the surface polarity of the substrate material, but also the incorporation of the organic compound into the perovskite framework. Based on these studies, a selection guide for suitable substrate materials for efficient co‐evaporated perovskite thin films is derived. This selection guide points out that the organic vacuum‐processable hole transport material 2,2″,7,7″‐tetra(N,N‐di‐p‐tolyl)amino‐9,9‐spirobifluorene is an ideal candidate for the fabrication of efficient all‐evaporated perovskite solar cells, demonstrating PCEs above 19%. Furthermore, building on the insights into the formation of the perovskite thin films on different substrate materials, a basic crystallization model for co‐evaporated perovskite thin films is suggested.
Hierarchically Interconnected Piezoceramic Textile with a Balanced Performance in Piezoelectricity, Flexibility, Toughness, and Air Permeability
Authors: Hong Ying , Wang Biao , Long Zhihe , Zhang Zhuomin , Pan Qiqi , Liu Shiyuan , Luo Xiaowei , Yang Zhengbao
Published: July 2021

Softening of piezoelectric materials facilitates the development of flexible wearables and energy harvesting devices. However, as one of the most competitive candidates, piezoelectric ceramic‐polymer composites inevitably exhibit reduced power‐generation capability and weak mechanical strength due to the mismatch of strength and permittivity between the two phases inside. Herein a flexible, air‐permeable, and high‐performance piezoceramic textile composite with a mechanically reinforced hierarchical porous structure is introduced. Based on a template‐assisted sol‐gel method, a three‐order hierarchical ceramic textile is constructed by intertwining submillimeter‐scale multi‐ply ceramic fibers that are further formed by twisting micrometer‐scale one‐ply ceramic fibrils. Theoretical analysis indicates that large mechanical stress can be easily induced in the multi‐order hierarchical structure, which greatly benefits the electrical output. Fabricated samples generate an open‐circuit voltage of 128 V, a short‐circuit current of 120 µA, and an instantaneous power density of 0.75 mW cm−2, much higher than the previously reported works. The developed multi‐order and 3D‐interconnected piezoceramic textile shows satisfactory piezoelectricity (d33 of 190 pm V−1), air permeability (45.1 mm s−1), flexibility (Young's modulus of 0.35 GPa), and toughness (0.125 MJ m−3), collectively. The design strategy of obtaining balanced properties promotes the practicality of smart/functional materials in wearables and flexible electronics.
Electric Field Control of the Magnetic Weyl Fermion in an Epitaxial SrRuO3 (111) Thin Film
Authors: Lin Weinan , Liu Liang , Liu Qing , Li Lei , Shu Xinyu , Li Changjian , Xie Qidong , Jiang Peiheng , Zheng Xuan , Guo Rui , Lim Zhishiuh , Zeng Shengwei , Zhou Guowei , Wang Han , Zhou Jing , Yang Ping , Ariando  , Pennycook Stephen J. , Xu Xiaohong , Zhong Zhicheng , Wang Zhiming , Chen Jingsheng
Published: July 2021

The magnetic Weyl fermion originates from the time reversal symmetry (TRS)‐breaking in magnetic crystalline structures, where the topology and magnetism entangle with each other. Therefore, the magnetic Weyl fermion is expected to be effectively tuned by the magnetic field and electrical field, which holds promise for future topologically protected electronics. However, the electrical field control of the magnetic Weyl fermion has rarely been reported, which is prevented by the limited number of identified magnetic Weyl solids. Here, the electric field control of the magnetic Weyl fermion is demonstrated in an epitaxial SrRuO3 (111) thin film. The magnetic Weyl fermion in the SrRuO3 films is indicated by the chiral anomaly induced magnetotransport, and is verified by the observed Weyl nodes in the electronic structures characterized by the angle‐resolved photoemission spectroscopy (ARPES) and first‐principles calculations. Through the ionic‐liquid gating experiment, the effective manipulation of the Weyl fermion by electric field is demonstrated, in terms of the sign‐change of the ordinary Hall effect, the nonmonotonic tuning of the anomalous Hall effect, and the observation of the linear magnetoresistance under proper gating voltages. The work may stimulate the searching and tuning of Weyl fermions in other magnetic materials, which are promising in energy‐efficient electronics.
Hydrogel Ionic Diodes toward Harvesting Ultralow‐Frequency Mechanical Energy
Authors: Zhang Yong , Jeong Chang Kyu , Wang Jianjun , Chen Xin , Choi Kyoung Hwan , Chen Long‐Qing , Chen Wen , Zhang Q. M. , Wang Qing
Published: July 2021

Energy harvesting from human motion is regarded as a promising protocol for powering portable electronics, biomedical devices, and smart objects of the Internet of things. However, state‐of‐the‐art mechanical‐energy‐harvesting devices generally operate at frequencies (>10 Hz) well beyond human activity frequencies. Here, a hydrogel ionic diode formed by the layered structures of anionic and cationic ionomers in hydrogels is presented. As confirmed by finite element analysis, the underlying mechanism of the hydrogel ionic diode involves the formation of the depletion region by mobile cations and anions and the subsequent increase of the built‐in potential across the depletion region in response to mechanical pressure. Owing to the enhanced ionic rectification ratio by the embedded carbon nanotube and silver nanowire electrodes, the hydrogel ionic diode exhibits a power density of ≈5 mW cm−2 and a charge density of ≈4 mC cm−2 at 0.01 Hz, outperforming the current energy‐harvesting devices by several orders of magnitude. The applications of the self‐powered hydrogel ionic diode to tactile sensing, pressure imaging, and touchpads are demonstrated, with sensing limitation is as low as 0.01 kPa. This work is expected to open up new opportunities for ionic‐current‐based ionotronics in electronics and energy devices.
Multiple Response Colors of Invisible Hollow Silica Photonic Crystals Patterns for Information Encoding
Authors: Xiao Xin , Yang Zhaokun , Yu Qiuyan , Shi Dongjian , Dong Weifu , Zhang Hongji , Chen Mingqing
Published: July 2021

Combining responsive and invisible patterns into photonic crystals is an accepted encryption strategy for watermarking and information security. In order to fabricate an invisible pattern with excellent decrypted performance, environmental stability, full reversibility, and multiple responsive color, hollow silica photonic crystals (HSPCs) with selective wettability are fabricated by functional modification and photoinitiated Michael addition reaction. The patterned HSPCs show an identical purple color under a static environment, while they can reveal the hidden image with blue color and green color in response to water vapor flow and ethanol/water solutions, respectively. A large photonic bandgap shift (62 nm) is realized by glycerin wiping due to the large refractive index of glycerin. The prepared invisible PCs patterns show well reversibility in 100 cycles tests and maintain their excellent performances for more than 1 year. Such a multiple response invisible HSPCs patterns can play a crucial role in vapor sensing, information encoding, and anticounterfeiting application.
Visible Light Promoted Chan‐Lam Reaction and Cycloaddition to Prepare Chromeno[4,3‐c]isoxazolidines in One‐Pot Reaction
Authors: Zhao Jie , Huang Bing‐Qing , Zhu Bin‐Can , Ma Xiao‐Pan , Mo Dong‐Liang
Published: July 2021

A variety of chromeno[4,3‐c]isoxazolidines were prepared in good yields through visible light promoted Chan‐Lam reaction and [3+2] cycloaddition cascade reaction in one pot. Mechanistic studies showed that visible light promoted both Chan‐Lam reaction and cycloaddition. The obtained products were converted to various useful chromenone derivatives. Moreover, the reaction was easily performed at gram scales with the purification of products without column chromatography and used to efficiently synthesize estrone‐derived chromeno[4,3‐c]isoxazolidine.

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Multiple Longitudinal Polarization Vortices Generated via All‐Silicon Metasurface
Authors: Zheng Chenglong , Li Jie , Li Jitao , Yue Zhen , Zhao Hongliang , Hao Xuanruo , Zhang Yating , Yao Jianquan
Published: July 2021

Photons carry spin angular momentum and orbital angular momentum, vortex beams with helical phase fronts provide a new understanding of optical and physical phenomena. Here, the creation of four longitudinal polarized vortices with arbitrary topological charges is demonstrated using all‐silicon metasurfaces in terahertz band, integrating propagation phase and Pancharatnam–Berry phase. This efficient scheme allows the authors to flexibly control the longitudinal polarized electric field by designing the field distribution of the transverse polarization. As a proof of concept, two metasurfaces are designed to demonstrate the flexibility of such approach. One is used to generate dual longitudinal polarized superpositions of orbital angular momentum states with arbitrary topological charges, and the other is designed to generate four discrete longitudinal vortices. This method may find applications in manipulation of electron bunches and new imaging technology.
Photoresponsive Palladium and Nickel Catalysts for Ethylene Polymerization and Copolymerization
Authors: Peng Dan , Chen Changle
Published: July 2021

In this contribution, we install an azobenzene functionality in olefin polymerization catalysts and use light to modulate their properties via photoinduced trans–cis isomerization of the azobenzene moiety. The initially targeted azobenzene‐functionalized α‐diimine palladium and nickel catalysts are not photoresponsive. To address this issue, an imine–amine system bearing interrupted conjugation with the metal center, and a sandwich‐type α‐diimine system bearing an azobenzene unit at a position covalently far from the metal center were prepared and studied. We demonstrate that light can be used to tune their properties in ethylene polymerization and copolymerization with polar comonomers, enabling light‐induced control of the polymerization processes, polymer microstructures and polymer properties. More interestingly, the light‐mediated property changes were attributed to ligand electronic effects in one system and ligand steric effects in the other.
Carbene‐Stabilized Dithiolene (L0) Zwitterions
Authors: Wang Yuzhong , Tran Phuong M. , Xie Yaoming , Wei Pingrong , Glushka John N. , Schaefer Henry F. , Robinson Gregory H.
Published: July 2021

A series of reactions between Lewis bases and an imidazole‐based dithione dimer (1) has been investigated. Both cyclic(alkyl)(amino)carbene (CAAC) (2) and N‐heterocyclic carbene (NHC) (4), in addition to N‐heterocyclic silylene (NHSi) (6), demonstrate the capability to cleave the sulphur–sulphur bonds in 1, giving carbene‐stabilized dithiolene (L0) zwitterions (3 and 5) and a spirocyclic silicon–dithiolene compound (7), respectively. The bonding nature of 3, 5, and 7 are probed by both experimental and theoretical methods.
Facile synthesis of recoverable superparamagnetic AgFeO2@Polypyrrole/SiO2 nanocomposite as an excellent catalyst for reduction and oxidation of different dyes in wastewater
Authors: El‐Attar Heba G. , Salem Mohamed A. , Bakr Eman A.
Published: July 2021

Fabrication of a triple‐component nanocomposite system having a unique design and unusual property combinations offers a special chance to take advantage of all components and overcome the limitations of mono nanoparticles (NPs). Novel superparamagnetic AgFeO2@polypyrrole/SiO2 (AgFeO2@PPy/SiO2) triple‐component nanocomposite was synthesized in facile three‐step method using (i) coprecipitation, (ii) in situ chemical oxidative polymerization, and (iii) Stöber process. The structure and morphology of the nanocomposite were characterized by Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray powder diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The triple nanocomposite has a drastic catalytic effect as compared with AgFeO2@PPy core–shell NPs and AgFeO2 NPs. The rate constant of chromotrope 2R reduction followed the order: AgFeO2@PPy/SiO2 (0.9209 min−1) > AgFeO2@PPy (0.2274 min−1) > AgFeO2 (0.1365 min−1). AgFeO2@PPy/SiO2 exhibited high catalytic recyclable performance towards the degradation of different kinds of dyes either by reduction (chromotrope 2R, tartrazine, and methylene blue) or by oxidation (methylene blue, aniline blue, and methyl violet 2B) from aqueous solution. The degradation percentage for the reduced dyes was 99.38%, 98.64%, and 98.17% and for the oxidized dyes was 75.84%, 99.34%, and 91.79%, respectively. Batch mode catalytic study was conducted with the nanocomposite to determine the maximum removal of tartrazine and aniline blue under different operational parameters was 99.5% and 99.34%, respectively. The recovery and reusability of the AgFeO2@PPy/SiO2 nanocomposite were studied using the reduction of tartrazine and the oxidation of aniline blue. Thirteen consecutive recovery reaction cycles were performed for the reduction process and nine cycles for the oxidation reaction. All the reactions revealed high stability and constant efficiency of the catalyst. The maximum percentages were 99.5% for the reduction and 99.34% for the oxidation of dyes. These values decreased through the cycles to 76.35% and 79.70% for reduction and oxidation, respectively. Based on the experimental results obtained, the synthesized materials proved to have a high potential for the removal of all investigated dyes from an aqueous solution.
Magnetic porous nano‐carbon catalysts supported silver nanoparticles derived from chitin and their application in catalytic reduction reactions
Authors: Wang Guozhen , Wang Bowen , Chen Xi , Pei Ying , Zhou Shunchao , Ding Wenping
Published: July 2021

The exploitation of recycled carbonaceous catalysts from renewable biomass resources such as chitin is a crucial issue for the development of the sustainable society. In this article, the chitin‐based N and O doped carbon microspheres (ChC) were fabricated by a simple dissolution, sol–gel transformation, and the carbonization methods. Subsequently, the novel magnetic Ag‐Fe3O4@chitin‐based carbon microspheres catalyst (MChC) was successfully constructed through the in situ redox reaction. The as‐prepared MChC possessed rich micropores with high‐surface area, and a narrow size distribution (50–120 μm). The Ag‐Fe3O4 nanoparticles were immobilized through the interaction with C, N, and O atoms in the pores of MChC. The reduction of 4‐nitrophenol was applied to evaluate the catalytic activity of MChC. 4‐Nitrophenol (4‐NP) could be fully reduced to 4‐aminophenol (4‐AP) in 5 min with the catalyst MChC‐45. Moreover, MChC could be collected in solution with an external magnet in 8 s and remained relatively high‐catalytic activity after 10 cycle times. This work provided novel ideas for the fabrication of doped carbon material from biomass and promoted its utilization in nanocatalytic applications.
High‐temperature performance and cross‐linking mechanism of different types of gel systems in saline environment
Authors: Liu Jianbin , Zhong Liguo , Cao Zijuan , Hao Tongchun , Liu Yigang , Wu Wenwei
Published: July 2021

Profile modification of injection wells or water plugging of production wells are the most common ways to improve oil recovery with the continuous development of oil reservoirs. For high temperature and high‐salt oil and gas reservoirs, the plugging agent is required to have certain stability under high temperature and high‐salt conditions. Polymer gel is one of the commonly used plugging agents in oil fields. This article conducted detailed experimental research and mechanism analysis on six gel systems composed by two types of polymer (hydrolyzed polyacrylamide [HPAM] and terpolymer L‐1) and three types of cross‐linker systems (phenol/hexamethylenetetramine [HMTA], resorcinol/HMTA and bisphenol‐A/HMTA). The mechanisms of cross‐linker systems and polymer were studied, and the experimental researches were done on their gelation process, long‐term thermal stability, salt resistance, microstructure observation, rheological properties, and so on. The number of high‐temperature resistant cross‐linking points determines the performance of the gel system formed by cross‐linker systems with the polymer. The cross‐linker systems of bisphenol‐A/HMTA have four high‐temperature resistant cross‐linking points, and its performance was the best. Due to the introduction of ATBS and NVP groups on the polymer chain, the performance of gel system formed by the terpolymer L‐1 was significantly more stable than that of formed by HPAM. This study shows that the bisphenol‐A/HMTA‐L‐1 gel has excellent long‐term thermal stability and salt tolerance, and can be used in ultrahigh temperature (150°C) and high‐salt oil and gas reservoirs to improve oil recovery.
The C‐terminally shortened analogs of a hexapeptide derived from Lingzhi hydrolysate with enhanced tyrosinase‐inhibitory activity
Authors: Krobthong Sucheewin , Yingchutrakul Yodying , Samutrtai Pawitrabhorn , Choowongkomon Kiattawee
Published: July 2021

Ganoderma lucidum or Lingzhi (Chinese) is a medicinal fungus widely used in traditional medicine as a health supplement. This study was conducted to identify an approach to enhance the anti‐tyrosinase activity of a peptide from G. lucidum by chemical modification of its C‐terminus. The original peptide was obtained from protease‐digested Lingzhi proteins, followed by ultrafiltration (molecular weight cut‐off 3 kDa) and C18 solid‐phase extraction. The hexapeptide (NH2–VLTCGF–COOH) possessing the anti‐tyrosinase activity was identified by liquid chromatography–tandem mass spectrometry (LC‐MS/MS). This hexapeptide was subjected to shortening to enhance the anti‐tyrosinase activity. Both the original peptide and the shortened peptides were synthesized by solid‐phase peptide synthesis. The purity and mass of the synthetic peptide and the modified peptide were evaluated by high‐performance liquid chromatography and LC‐MS, respectively. Comparison of the tyrosinase activities showed that the modified peptide demonstrated more than 23.27 ± 1.07% activity, which was better than that of the hexapeptide. The structure‐related biological activity was explained by molecular docking, wherein the VLT–tyrosinase complex showed two interaction forces: Asn260 and Gly281 through H‐bonding and Glu256 through electrostatic interaction. This information could help toward gaining further understanding of the correlation between the anti‐tyrosinase activity and the molecular structure of the modified hexapeptide and support its potential use as a safe cosmetic ingredient with tyrosinase‐suppressing ability.
Global efficiency of the motor network is decreased in Parkinson's disease in comparison with essential tremor and healthy controls
Authors: Novaes Natalia Pelizari , Balardin Joana Bisol , Hirata Fabiana Campos , Melo Luciano , Amaro Edson , Barbosa Egberto Reis , Sato João Ricardo , Cardoso Ellison Fernando
Published: July 2021

Background

Graph theory (GT) is a mathematical field that analyses complex networks that can be applied to neuroimaging to quantify brain's functional systems in Parkinson's disease (PD) and essential tremor (ET).

Objectives

To evaluate the functional connectivity (FC) measured by the global efficiency (GE) of the motor network in PD and compare it to ET and healthy controls (HC), and correlate it to clinical parameters.

Methods

103 subjects (54PD, 18ET, 31HC) were submitted to structural and functional MRI. A network was designed with regions of interest (ROIs) involved in motor function, and GT was applied to determine its GE. Clinical parameters were analyzed as covariates to estimate the impact of disease severity and medication on GE.

Results

GE of the motor circuit was reduced in PD in comparison with HC (p .042). Areas that most contributed to it were left supplementary motor area (SMA) and bilateral postcentral gyrus. Tremor scores correlated positively with GE of the motor network in PD subgroups. For ET, there was an increase in the connectivity of the anterior cerebellar network to the other ROIs of the motor circuit in comparison with PD.

Conclusions

FC measured by the GE of the motor network is diminished in PD in comparison with HC, especially due to decreased connectivity of left SMA and bilateral postcentral gyrus. This finding supports the theory that there is a global impairment of the motor network in PD, and it does not affect just the basal ganglia, but also areas associated with movement modulation. The ET group presented an increased connectivity of the anterior cerebellar network to the other ROIs of the motor circuit when compared to PD, which reinforces what it is known about its role in this pathology.
Outcomes of axitinib versus sunitinib as first‐line therapy to patients with metastatic renal cell carcinoma in the immune‐oncology era
Authors: Numakura Kazuyuki , Muto Yumin , Naito Sei , Hatakeyama Shingo , Kato Renpei , Koguchi Tomoyuki , Kojima Takahiro , Kawasaki Yoshihide , Kandori Syuya , Kawamura Sadafumi , Arai Yoichi , Ito Akihiro , Nishiyama Hiroyuki , Kojima Yoshiyuki , Obara Wataru , Ohyama Chikara , Tsuchiya Norihiko , Habuchi Tomonori
Published: July 2021

Although combination immune checkpoint inhibitor (immuno‐oncology [IO]) therapy is the first‐line treatment for metastatic renal cell carcinoma (mRCC), it mostly causes resistance and tumor regrowth. Therefore, an optimal second‐line therapy is necessary. Such therapy typically comprises vascular endothelial growth factor receptor‐tyrosine kinase inhibitors (VEGFR‐TKIs). This study was aimed at comparing the efficacy of two TKIs—axitinib and sunitinib—in mRCC patients. From January 2008 to October 2018, we registered 703 mRCC patients from 8 Japanese institutes. Of these, 408 patients received axitinib or sunitinib as the first‐line treatment. Thereafter, efficacy and survival rate were compared between the axitinib and sunitinib groups. To reduce the effects of selection bias and potential confounders, propensity score matching analysis was performed. Axitinib and sunitinib were administered in 274 and 134 patients, respectively. More than 25% of the patients received nivolumab sequence therapy. To calculate the propensity scores for each patient, we performed multivariate logistic regression analysis. The objective response rate, progression‐free survival (PFS), cause‐specific survival, and overall survival (OS) were significantly better in the axitinib group than in the sunitinib group. Furthermore, the OS was better in the nivolumab‐treated patients in the axitinib group. Axitinib showed higher efficacy and afforded greater survival benefits than did sunitinib when administered as first‐line therapy in mRCC patients. Thus, from among VEGFR‐TKIs, axitinib might be a possible option for application in the middle of IO drug‐based treatment sequences.
NV14 from serine O‐acetyltransferase of cyanobacteria influences the antioxidant enzymes in vitro cells, gene expression against H2O2 and other responses in vivo zebrafish larval model
Authors: Velayutham Manikandan , Ojha Biswajeet , Issac Praveen Kumar , Lite Christy , Guru Ajay , Pasupuleti Mukesh , Arasu Mariadhas Valan , Al‐Dhabi Naif Abdullah , Arockiaraj Jesu
Published: July 2021

In this study, we have identified a novel peptide NV14 with antioxidative functions from serine O‐acetyltransferase (SAT) of Artrospira platensis (Ap). The full sequence of ApSAT and its derived NV14 peptide “NVRIGAGSVVLRDV” (141–154) was characterized using bioinformatics tools. To address the transcriptional activity of ApSAT in response to induce generic oxidative stress, the spirulina culture was exposed to H2O2 (10 mM). The ApSAT expression was studied using RT‐PCR across various time points and it was found that the expression of the ApSAT was significantly upregulated on Day 15. The in vitro cytotoxicity assay against NV14 was performed in human dermal fibroblast cells and human blood leukocytes. Results showed that NV14 treatment was non‐cytotoxic to the cells. Besides, in vivo treatment of NV14 in zebrafish larvae did not exhibit the signs of developmental toxicity. Further, the in vitro antioxidant assays enhanced the activity of the antioxidant enzymes, such as SOD and CAT, due to NV14 treatment; and also significantly reduced the MDA levels, while increasing the superoxide radical and H2O2 scavenging activity. The expression of antioxidant enzyme genes glutathione peroxidase, γ‐glutamyl cysteine synthase, and glutathione S‐transferase were found to be upregulated in the NV14 peptide pretreated zebrafish larvae when induced with generic oxidative stress, H2O2. Overall, the study showed that NV14 peptide possessed potent antioxidant properties, which were demonstrated over both in vitro and in vivo assays. NV14 enhanced the expression of antioxidant enzyme genes at the molecular level, thereby modulating and reversing the cellular antioxidant balance disrupted due to the H2O2‐induced oxidative stress.
Pincer‐Type Phosphorus Compounds With Boryl‐Pendant And Application In Catalytic H2 Generation From Ammonia‐Borane: A Theoretical Study
Authors: Yang Deshuai , Bao Panqing , Yang Zhen , Chen Zhaoxu , Sakaki Shigeyoshi , Maeda Satoshi , Zeng Guixiang
Published: July 2021

Metal‐free catalysts composed of heavy main group element(s) have been limited. Herein, a theoretical study unveils that pincer‐type phosphorus compound bearing a boryl‐pendant is good catalyst for H2 generation from ammonia borane through phosphorus‐boryl (P−B) cooperation function. Pincer‐type phosphorus compound without boryl‐pendant is not active for this reaction, indicating the important role of the P−B cooperation function.
Low‐Temperature Correlation of Property Data for Dilute Aqueous Lithium Bromide Solution
Authors: Fleßner Christian , Thraen Leonard , Ziegler Felix
Published: July 2021

A new correlation for some transport properties of aqueous solutions, based on the data published by Sawada et al. [1], is proposed. The main objective of the new fit is to give a smooth transition to the properties of pure water to allow the use of the fit in the region of very dilute solutions. Additionally, the quality of the fit to the experimental data is improved compared to the original correlation. An extrapolation of the new correlation in the other direction, i.e., to higher mass fractions and temperatures, is smooth but does not fully capture the trend described by other experimental datasets. To this end, the correlation has to be refined further.
Accelerated Electrochemical Investigation of Li Plating Efficiency as Key Parameter for Li Metal Batteries Utilizing a Scanning Droplet Cell
Authors: Dieckhöfer Stefan , Schuhmann Wolfgang , Ventosa Edgar
Published: July 2021

The scanning droplet cell (SDC) allows for automatized electrochemical experiments leading to time‐saving and reproducible experimental conditions. Its implementation for non‐aqueous battery research is discussed, and the necessary adaptations to be operated inside an Ar‐filled glovebox in complete absence of oxygen and moisture are described. Due to the importance of the use of Li metal electrodes for next‐generation high‐energy batteries, the complex multi‐parameter optimisation of the Li plating/stripping processes are investigated by means of the SDC. In particular, the influence of pulsed Li plating protocols on the coulombic efficiency is evaluated. The results clearly show that fine tuning of the parameters of pulsed Li plating protocols, i. e. the relaxation period and Li plating duration, is required to improve Li plating efficiencies at high current densities.
Forage production and steer performance in fertilized smooth bromegrass and smooth bromegrass–legume pastures
Authors: Hillhouse Heidi , Schacht Walter , Anderson Bruce , MacDonald James , Soper Jonathan M , Brink Kelly
Published: July 2021

Smooth bromegrass is a commonly used cool‐season pasture grass that responds favorably to annual spring fertilization, but annual fertilizer applications require annual inputs of both time and expense. This study was conducted to determine if interseeding legumes into established smooth bromegrass pasture is a viable alternative to spring fertilization. Steers (Bos taurus) were rotationally grazed in either fertilized smooth bromegrass pastures or smooth bromegrass pastures interseeded with legumes. Data were collected on forage production, forage available at the beginning of each grazing rotation, steer weight gain, and the number of grazing days. Total forage production for the growing season was not different between the pasture types, but fertilized pasture had greater available forage early in the growing season and interseeded pasture had greater forage production late in the growing season. Season‐long average daily gain of steers was not different between pasture types, but daily gains were greater in interseeded pasture late in the growing season and may be linked to proportionally greater abundance of legumes late in the season. Beef production ac–1 was higher in interseeded pastures, largely due to increased days of grazing. We found that interseeding legumes into established pasture can be a viable alternative to annual spring fertilization and may outperform fertilized pasture depending on the metric and growing conditions.
Diphenylalanine Motif Drives Self‐Assembling in Hybrid PNA‐Peptide Conjugates
Authors: Diaferia Carlo , Avitabile Concetta , Leone Marilisa , Gallo Enrico , Saviano Michele , Accardo Antonella , Romanelli Alessandra
Published: July 2021

Peptides and nucleic acids can self‐assemble to give supramolecular structures that find application in different fields, ranging from the delivery of drugs to the obtainment of materials endowed with optical properties. Forces that stabilize the “suprastructures” typically are hydrogen bonds or aromatic interactions; in case of nucleic acids, Watson‐Crick pairing drives self‐assembly while, in case of peptides, backbone hydrogen bonds and interactions between aromatic side chains trigger the formation of structures, such as nanotubes or ribbons. Molecules containing both aromatic peptides and nucleic acids could in principle exploit different forces to self‐assemble. In this work we meant to investigate the self‐assembly of mixed systems, with the aim to understand which forces play a major role and determine formation/structure of aggregates. We therefore synthesized conjugates of the peptide FF to the peptide nucleic acid dimer “gc” and characterized their aggregates by different spectroscopic techniques, including NMR, CD and fluorescence.
Enantiopure planar chiral [2.2]paracyclophanes: Synthesis and applications in asymmetric organocatalysis
Authors: Felder Simon , Wu Shiqi , Brom Jules , Micouin Laurent , Benedetti Erica
Published: July 2021

This short review focuses on enantiopure planar chiral [2.2]paracyclophanes (pCps), a fascinating class of molecules that possess an unusual three‐dimensional core and intriguing physicochemical properties. In the first part of the review, different synthetic strategies for preparing optically active pCps are described. Although classical resolution methods based on the synthesis and separation of diastereoisomeric products still dominate the field, recent advances involving the kinetic resolution of racemic compounds and the desymmetrization of meso derivatives open up new possibilities to access enantiopure key intermediates on synthetically useful scales. Due to their advantageous properties including high configurational and chemical stability, [2.2]paracyclophanes are increasingly employed in various research fields, ranging from stereoselective synthesis to material sciences. The applications of [2.2]paracyclophanes in asymmetric organocatalysis are described in the second part of the review. While historically enantiopure pCps have been mainly employed by organic chemists as chiral ligands in transition‐metal catalysis, these compounds can also be used as efficient catalysts in metal‐free reactions and may inspire the development of new transformations in the near future.
The role of transesophageal echocardiography in predicting technical problems and complications of transvenous lead extractions procedures
Authors: Nowosielecka Dorota , Jacheć Wojciech , Polewczyk Anna , Tułecki Łukasz , Kleinrok Andrzej , Kutarski Andrzej
Published: July 2021

Background

Transesophageal echocardiography (TEE) is a useful tool in preoperative evaluation of patients undergoing transvenous lead extraction (TLE).

Hypothesis

Echocardiographic phenomena may determine the difficulty and safety of the procedure.

Methods

Data from 936 transesophageal examinations (TEE) performed at a high volume center in patients awaiting TLE from 2015 to 2019 were assessed.

Results

TEE revealed a total of 1156 phenomena associated with the implanted leads in 697 (64.85%) patients, including: asymptomatic masses on endocardial leads (AMEL) (58.65%), vegetations (12,73%), fibrous tissue binding the lead to the vein or heart wall (33.76%), lead‐to‐lead binding sites (18.38%), excess lead loops (19.34%), intramural penetration of the lead tip (16.13%) and lead‐dependent tricuspid dysfunction (LDTD) (6.41%). Risk factors for technical difficulties during TLE in multivariate analysis were: fibrous tissue binding the lead to atrial wall (OR = 1.738; p < 0.05), to right ventricular wall (OR = 2.167; p < 0.001), lead‐to‐lead binding sites (OR = 1.628; p < 0.01) and excess lead loops (OR = 1.488; p < 0.05). Lead‐to‐lead binding sites increased probability of major complications (OR = 3.034; p < 0.05). Presence of fibrous tissue binding the lead to the superior vena cava (OR = 0.296; p < 0.05), right atrial wall (OR = 323; p < 0.05) and right ventricular wall (OR = 0.297; p < 0.05) reduced the probability of complete procedural success, whereas fibrous tissue binding the lead to the tricuspid apparatus decreased the probability of clinical success (OR = 0.307; p < 0.05).

Conclusions

Careful preoperative TEE evaluation of the consequences of extended lead implant duration (enhanced fibrotic response) increases the probability of predicting the level of difficulty of TLE procedures, their efficacy and risk of major complications.
Discovery of Antitumor Active Peptides Derived from Peroxiredoxin 5
Authors: Liu Juanjuan , Zou Sen , Zhang Yan , Lin Ru , Duan Yanbo , He Weiqing , Yang Zhaoyong
Published: July 2021

The peroxiredoxin 5 (PRDX5) is a member of peroxiredoxins with antitumor activity. However, as a recombinant protein, PRDX5 is restricted in clinic due to high cost and keeping high dose in medication. The alternative way is to explore the antitumor active fragments of PRDX5 for potential of peptide drugs. According to the sequence, crystal structure and enzyme function of PRDX5, seven peptides were designed and named as IMB‐P1∼7. The peptide IMB‐P1 (AFTPGCSKTHLPGFVEQAEAL) containing critical residue C47 exhibited antitumor activity similar to PRDX5 in vivo. Transcriptome analysis showed peptide IMB‐P1 could make influence on expression of multiple genes involved in tumorigenesis and deterioration. Besides, an important discovery is the down‐regulation of oxidation‐related genes. In CT26 cells, IMB‐P1 carried similar antitumor activity with increasing ROS level to intact PRDX5. The results demonstrated that peptide IMB‐P1 with easier synthesis from PRDX5 may serve as a promising antitumor candidate.
Sex‐specific and caste‐specific brain adaptations related to spatial orientation in Cataglyphis ants
Authors: Grob Robin , Heinig Niklas , Grübel Kornelia , Rössler Wolfgang , Fleischmann Pauline N.
Published: July 2021

Cataglyphis desert ants are charismatic central place foragers. After long‐ranging foraging trips, individual workers navigate back to their nest relying mostly on visual cues. The reproductive caste faces other orientation challenges, i.e. mate finding and colony foundation. Here we compare brain structures involved in spatial orientation of Cataglyphis nodus males, gynes, and foragers by quantifying relative neuropil volumes associated with two visual pathways, and numbers and volumes of antennal lobe (AL) olfactory glomeruli. Furthermore, we determined absolute numbers of synaptic complexes in visual and olfactory regions of the mushroom bodies (MB) and a major relay station of the sky‐compass pathway to the central complex (CX). Both female castes possess enlarged brain centers for sensory integration, learning, and memory, reflected in voluminous MBs containing about twice the numbers of synaptic complexes compared with males. Overall, male brains are smaller compared with both female castes, but the relative volumes of the optic lobes and CX are enlarged indicating the importance of visual guidance during innate behaviors. Male ALs contain greatly enlarged glomeruli, presumably involved in sex‐pheromone detection. Adaptations at both the neuropil and synaptic levels clearly reflect differences in sex‐specific and caste‐specific demands for sensory processing and behavioral plasticity underlying spatial orientation.
Repeated use of rich pictures to explore changes in subjective experiences over time of patients with advanced cancer
Authors: Bood Zarah M. , Scherer‐Rath Michael , Sprangers Mirjam A. G. , Timmermans Liesbeth , van Wolde Ellen , Cristancho Sayra M. , Heyning Fenna , Russel Silvia , van Laarhoven Hanneke W. M. , Helmich Esther
Published: July 2021

Background

The combination of verbal and visual tools may help unravel the experiences of advanced cancer patients. However, most previous studies have focused on a specific symptom, at only one moment in time. We recently found that a specific visual tool, originating from systems thinking, that is, rich pictures (RPs), could provide a more comprehensive view of the experiences of patients with advanced cancer.

Aims

To examine whether the repeated use of RPs can make changes in subjective experiences of patients living with advanced cancer visible over time.

Methods and results

We performed a prospective study with a generic qualitative approach that was mostly informed by the process of grounded theory. We invited patients to make an RP twice, at the start of the study, and again after 2 months. Both RP drawing sessions were directly followed by a semi‐structured interview. Patients with all types of solid tumors, above the age of 18, and with a diagnosis of advanced, incurable cancer, were eligible. Eighteen patients participated and 15 patients were able to draw an RP twice. In eight RP‐sets, considerable differences between the first and second RP were noticeable. Two patterns were distinguished: (1) a change (decline or improvement) in physical health (five patients), and/or (2) a change in the way patients related to cancer (three patients).

Conclusion

RPs are a valuable qualitative research method that can be used to explore the experiences of patients with advanced cancer, not only at a single point in time but also over time.
Cannabinoids, their cellular receptors, and effects on the invasive phenotype of carcinoma and metastasis
Authors: Glogauer Judah , Blay Jonathan
Published: July 2021

Background

The morbidity and mortality of cancer are significantly impacted by the invasive and metastatic potential of particular subgroups of malignant cells within a tumor. The particular pre‐metastatic properties of cancerous cells are thus a critical target for novel therapeutics in the oncology field. Cannabinoid molecules have been investigated in recent years in the context of invasion and metastasis of various malignancies, with varying effects reported in the literature.

Recent Findings

There was substantial variability in the findings reported by the literature of the effects of cannabinoid molecules on cancer cell invasion and metastasis. These effects varied depending on which ligand and which of the CB1, CB2, or GPR55 receptors were investigated. These findings suggest a role for the phenomenon of biased signaling in explaining the diversity of effects of cannabinoid molecules on cancer cell invasion.

Conclusion

While substantially more investigation is required into the effects of cannabinoid molecules on cancer cell invasion and metastasis, we describe in this review the significant diversity in the responses of cancer cells to cannabinoid molecules in terms of their invasive and metastatic capacities.