bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic Resonance Imaging in the Preoperative T Staging of Gastric Cancer (A Critical Appraisal)
Authors: Ahmad Syed Sajad , Robbani Irfan , Rasool Sheikh Riaz , Yaseen Syed Besina , Wani Rouf Ahmad , Mir Abdul Wahid , Mushtaq Tabasum
Published: June 2020

Background: Gastric cancer accounts for many cancer-related deaths, is one of the top leading cause of cancer-associated mortality. Tumor staging and classification depends upon histological, immune histochemical tests along with the radiological imaging. In the preoperative T staging of gastric cancer, Magnetic Resonance Imaging (MRI) has become principal attention in recent years.

Aim: Evaluating the accuracy of MRI in the preoperative T staging of gastric cancer vis-a-vis post-operative pathological staging.

Methods: A total of 37 patients were initially taken in our study, out of which 13 patients were excluded as they underwent neo adjuvant chemoradiotherapy for the down staging of the tumor. The 24 patients became the sample size of our study and their magnetic resonance imaging (MRI) T stage was correlated with pathological T-stage.

Results: The diagnostic accuracy of T1 stage by MRI was 87.5%, with 94.7% specificity and 60% sensitivity (n=24, κ -value = 0.58; P-value<0.05). The diagnostic accuracy of T2 stage by MRI was 87.5%, with 88.2% specificity and 85.7% sensitivity (n=24, κ- value= 0.69; P-value<0.05). The diagnostic accuracy of T3 stage by MRI was 91.7% with 93.3% specificity and 88.9% sensitivity (n=24, κ -value= 0.82; P-value<0.05). The diagnostic accuracy of T4 stage by MRI was 95.8%, with 100% specificity and 75% sensitivity (n=24, κ- value= 0.80; P-value<0.05).

Conclusion: Because of high accuracy and specificity in determining the depth of invasion of gastric cancer, MRI proves to be an invaluable diagnostic tool in the preoperative T staging of gastric cancer and therefore is very useful in sidestepping unnecessary surgery by supervising the selection of treatment decisions.
Prevalence of Carbapenem-Resistance among Enterobacteriaceae Isolated from Patients Attending Uduth Sokoto, North West Nigeria
Authors: Iduh M. U. , Mohammed K. , Garba M. K. , Nataala S. U. , Ashcroft O. F. , Abdulkadir A.
Published: June 2020

The major problem threatening the continued success of antimicrobial drugs is the development of resistant organisms. This study was designed to determine the occurrence and prevalence of carbapenem resistance among enterobacteriaceae isolated from in-patients attending Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto, and also to determine the antimicrobial susceptibility patterns of the organisms isolated. The Methodology involves the use of trypticase soy broth containing 10 μg of carbapenem (imipenem) for primary isolation. The secondary isolation involves the use of MacConkey agar and biochemical (Simmon citrate Agar) for identification, and then antimicrobial susceptibility testing by the disk diffusion method. A total of 191 stool samples from male and female in-patients within the range of 2-60 years were screened for the gastrointestinal colonization of Carbapenem Resistance Enterobacteriacea (CRE). Data were analysed using Statistical Package for Social Sciences (SPSS) windows version 21. The overall prevalence was 15.7% The prevalence rate was found exclusively in males. The highest prevalence was found within the age group of 30-40 years. Escherichia coli, Klebsiella species, Pseudomonas species and salmonella species were the bacteria isolated. The most predominant bacteria isolated were Escherichia coli, accounting for 85 (9.4%) resistant strains, Klebsiella species accounting for 50 (8%) resistant strain, Pseudomonas aeruginosa 21% and Salmonella species accounting for 42 (0%) no resistant strain isolated. The misuse of antibiotics is a major factor responsible for the high rate of bacterial resistance. Improvement on the management and personal hygiene, as well as the appropriate use of antibiotics would reduce the prevalence of Nosocomial Carbapenem Resistance (NCR) especially among prolonged hospitalized patients.
Sensory and Nutritional Properties of Protein Enriched Biscuits
Authors: Narmada M. , Lakshmi V. Vijaya , Hymavathi T. V. , Kameswari S. Lakshmi
Published: June 2020

Malnutrition remains a major nutritional problem nowadays. So there is a need to develop protein-rich products. Biscuits are extensively used for protein fortification vehicles due to their long shelf life and high acceptability. In the present study, biscuits were produced by substituting the refined wheat flour (RWF) with the foxtail millet flour (FMF), pearl millet flour (PMF), defatted soy flour (DFS) and whey protein isolate (WPI) at different levels. The formulations developed were FMWIB (Foxtail millet whey isolate biscuit), PMWIB (Pearl millet whey isolate biscuit) and MMWIB (Mixed millet whey isolate biscuit) and control (RWB-Refined wheat flour biscuit) contained 100% RWF. There was a significant difference (p<0.05) found among the formulations for all sensory parameters. Proximate analysis of the experimental (MMWIB) and RWB biscuit revealed that addition of millet flours, DFS and WPI significantly (p<0.01) improved the moisture (2.47%), protein (16.6%), ash (1.39%), crude fiber (1.9%) and fat (24.74%) content of the biscuits compared to RWB which were 2.36%, 5.56%, 0.63%, 0.21% and 23.11% respectively. The highest protein value was observed for MMWIB (16.6%) followed by PMWIB (15.81%), FMWIB (15.18%) and RWB (5.56%). MMWIB could contribute 38% of the recommended daily protein intake of 3 to 10 years old and 18% of RDA for adolescents group. Nutritional composition revealed that MMWIB had high TDF (15.49%) and IVPD (62.65%) values than RWB. Therefore, millet flours, DFS and WPI has a good potential for use in biscuit formulation to enhance its nutritional quality and also sensory properties.
Grain Zinc Phytic Acid and Nutrient Uptake in Common Bean is Influenced by Sources and Concentrations of Zinc Fertilization
Authors: Baligah Hujjat Ul , Mir Shakeel Ahmad , Sofi Parvaze , Mir Aamir Hassan
Published: June 2020

Aim: To study the effect of different sources and levels of zinc fertilization on phytic acid content and nutrient uptake in common beans.

Design: Randomized complete block design.

Place and Duration of study: Division of soil science and agricultural chemistry, Faculty of Agriculture, Sheri Kashmir University of agricultural science and technology, Kashmir, between 2017-2018.

Methodology: A field experiment was conducted to verify the response of common bean (Phaseolus vulgaris L.) to the different sources zinc fertilizer. Three different sources of Zinc Viz:- Zinc Sulphate, Zinc Gluconate and Zinc EDTA were used. Each fertilizer was used in three different amounts. Concentration of Zinc, overall zinc uptake, phytic acid, phytic acid Zinc molar ratio and overall nutrient uptake was estimated.

Results: The data was analyzed using OPSTAT software at P= 0.05. The application of zinc had a positive impact on increase of zinc concentration from 36.6 to 58.2 mg kg-1 in common bean and overall zinc uptake from 0.43 to 1.02 kg ha-1. It was observed that with the increase in levels of zinc there was a decrease in the concentration of phytic acid from 11.92 to 7.8 mg g-1 hence, phytic acid: Zinc molar ratio also decreased from 31.2 to 13.2. There was a positive correlation between nutrient uptake and zinc concentration in beans.

Conclusion: Application of Zinc significantly increased the overall nutrient uptake of plants except phosphorus. Among all the sources, Zinc EDTA proved to be most efficient fertilizer followed by zinc Gluconate for enhancing the concentration of zinc and decreasing the concentration of anti- nutritional factor (phytic acid) in beans. Therefore zinc fertilization can be used as an effective method to improve zinc concentration in beans and hence combat zinc deficiency.
In vitro Assessment of Antiplasmodial Activity and Acute Oral Toxicity of Dissotis rotundifolia Extracts and Fractions on Plasmodium falciparum Strains
Authors: Djehoue Rock , Adamou Rafiou , Amoussa Abdou Madjid O. , Medjigbodo Adande A. , Laleye Anatole , Sanni Ambaliou , Djogbenou Luc S. , Lagnika Latifou
Published: June 2020

Aim: Dissotis rotundifolia were selected after an ethnopharmacological survey conducted on plants used traditionally for malaria treatment in South Benin, with the aim of discovering new natural active extracts against malaria parasites.

Place and Duration of Study: Laboratory of Biochemistry and Bioactive Natural Substances, University of Abomey-Calavi (Benin)/ Laboratory of Infectious Vector Borne Diseases, Regional Institute of Public Health (Benin)/ Laboratoire d’Histologie, de Cytogénétique et d’Embryologie, Faculté des Sciences de la Santé (Benin). The study was conduct from October 2018 to June 2019 in Benin.

Methodology: The antiplasmodial activity of the plant extracts was evaluated using the parasite lactate dehydrogenase (pLDH) immunodetection assay. The extract with the best antiplasmodial activity were used on Wistar rats for acute toxicity.

Results: Ethanolic extract of Dissotis rotundifolia showed promising activity (Isolate: IC50 = 22.58 ± 1.12 µg/mL; 3D7: IC50 = 6.81 ± 0.85 µg/mL) on Plasmodium falciparum compared to the aqueous extract (Isolate: IC50 > 100 µg/mL; 3D7: IC50> 100 µg/mL). The aqueous fraction of D. rotundifolia exhibit highly potent activity against P. falciparum strain (Isolate: IC50 > 100 µg/mL μg/mL; 3D7: IC50 = 4.05 ± 0.72 μg/mL). Haemolytic effect of actives extracts and fractions is less than 5%. Ethanolic extract of D. rotundifolia revealed no obvious acute toxicity in rat up to the highest dose administered (2000 mg/kg).

Conclusion: This study justifies traditional uses of D. rotundifolia against malaria. A bioguided fractionation of these extracts would identify molecules responsible for their antiplasmodial activity. Moreover, these results could lead to the design of improved traditional medicines in the basis of this plant.
Fast and Effective Region-based Depth Map Upsampling with Application to Location Map-Free Reversible Data Hiding
Authors: Chung Kuo-Liang , Tseng Yu-Ling , Chan Tzu-Hsien , Wang Ching-Sheng
Published: June 2020

In this paper, we rst propose a fast and eective region-based depth map upsampling method, and then propose a joint upsampling and location map-free reversible data hiding method, simpled called the JUR method. In the proposed upsampling method, all the missing depth pixels are partitioned into three disjoint regions: the homogeneous, semi-homogeneous, and non- homogeneous regions. Then, we propose the depth copying, mean value, and bicubic interpolation approaches to reconstruct the three kinds of missing depth pixels quickly, respectively. In the proposed JUR method, without any location map overhead, using the neighboring ground truth depth pixels of each missing depth pixel, achieving substantial quality, and embedding capacity merits. The comprehensive experiments have been carried out to not only justify the execution-time and quality merits of the upsampled depth maps by our upsampling method relative to the state-of-the-art methods, but also justify the embedding capacity and quality merits of our JUR method when compared with the state-of-the-art methods.
Mathematical Modeling and Analysis of Mathematics Anxiety Behavior on Mathematics Performance in Kenya
Authors: Nathan O. M. , Jackob K. O.
Published: June 2020

We propose a deterministic model that describes the dynamics of students who have the capabilityWe propose a deterministic model that describes the dynamics of students who have the capabilityto perform well in mathematics examinations and engage in careers that demand its applicationand the negative inuence of individuals with mathematics anxiety on the potential students.Our model is based on SIR classical infectious model classes with Susceptible (S) and Infected (I)taken as Math anxious students (Ax) and Removed (R) adopted as achievers students (Aa) . Themodel is shown to be both epidemiologically and mathematically well posed. In particular, weprove that all solutions of the model are positive and bounded; and that every solution with initialconditions in remains in the set for all time. The existence of unique math anxious-freeand endemic equilibrium points is proved and the basic reproduction number R0 computed usingnext generation matrix approach. A global stability of anxious-free and the endemic equilibria areperformed using Lasselles invariance principle of Lyapunov functions. Sensitivity analysis showsthat achievement rate of potential achievers and achievement rate of math anxious students are the most sensitive parameters. This indicates that effort should be directed towards theseparameters, by having well trained mathematics staff and the best printed and technological resources so as to control the spread of mathematics anxiety. Furthermore, scaling up the understanding level of mathematics algorithms, lowers the mathematics anxiety level and consequently, the spread of mathematics anxiety amongst students reduces. Lastly, some numerical simulations are performed to verify the theoretical analysis result using Matlab software.
Modelling the Mining Equipment Market Trend by Field Theory
Authors: Sorin Pricope , Doina Muntean Luminița
Published: June 2020

Using the Beckman’s field theory of spatial economics, the flows of main products are analyzed between demand and offer, in the mining equipment market, and the segmentation of the world market is put to evidence. The data regarding the market suppliers, customers, trade intensity and average flows from published reports are used for extracting usefull conclusions.
Study on the Association of Casualties and Classification of Heat Wave Weather Patterns in South Korea Using K-Means Clustering Analysis
Authors: Lee Hyeon-Cheol , Cho Young-Jun , Lim Byunghwan , Kim Seung-Bum
Published: June 2020

In this study, weather patterns (WPs) associated with the heat wave in South Korea are objectively classified by applying K-means clustering analysis. The representative weather patterns that caused the heat wave were divided into three WPs, namely WP 1, WP 2, and WP 3. The heat wave over the Korean Peninsula was mainly related to the expansion of the North Pacific High (NPH). Moreover, we analyzed the relationship between casualties and WPs of the heat wave. In WP 1, the isobar of NPH was located in the southern part of South Korea. Most casualties (18 people) occurred in this region. In WP 2, NPH was distributed throughout South Korea, with nationwide casualties of 44 people. Moreover, the duration of the heat wave for WP 2 was the longest, at 4.5 days. WP 3 occurred mainly in June, when the NPH was not yet developed, presenting the smallest number of casualties.
Analysis of the Power Cable Fire Case in Busan-JungKwan Energy
Authors: Ji Hongkeun , Cho Youngjin
Published: June 2020

In this paper, the fire cause of blackout occurred in the Busan-JungKwan Energy as a Community Energy System (CES) was analyzed. Through analysis of the data such as burn patterns at the site, melted shape of cable head by the fire, overcurrent relay (OCR) of the control system, and event log, it was confirmed that first ground fault occurred at the termination connection of secondary cable of transformer. It was concluded because the void space of insulation and electrical melting trace conductor were investigated in the cable stress cone by detailed investigation and X-ray inspection for cable termination. In addition, as the damage by the tool on the vertical direction to the conductor was identified, it was presumed that the accident occurred by deterioration progress of insulation which was accelerated than that of the other parts.
Study on Improved Measures for Fire Safety Management in Sports Facilities
Authors: Hwang Woongi , Shin Hoisik , Yang Junseo
Published: June 2020

Recently, there have been many fires in the facilities where the safety of the people should be prioritized, such as the Jecheon Sports Center, Ansan Far East Sports Center, and Futsal Stadium in Suwon. The fire incidents in sports facilities, such as in the Jecheon Sports Center, have affected a lot of lives due to various factors such as the closing of evacuation routes. This study investigated the management status of firefighting and safety measures through analysis of the fire cases in sports facilities used by unspecified number of people. We propose checklists and inspection manuals for common firefighting and safety measures in sports facilities, and post checklists in a location that can be easily seen by both people and users. We intend to contribute to the improvement of inspection management of sports facilities in terms of fire reduction and firefighting, and safety measures through inspection and posting.
Analysis of Material Performance According to the Cooling Method of Fire Damaged Concrete
Authors: Kang Hyun , Kweon Oh Sang
Published: June 2020

In this study, material performance was analyzed depending on the cooling method of concrete damaged by fire. Various non-destructive and destructive tests were conducted for material performance analysis. Further, the influence of cooling methods was assessed according to each test. As a result of the evaluation, it was confirmed that the residual performance of the concrete was significantly different according to the cooling method (air cooling and water cooling), and the performance difference according to the cooling method was also observed depending on the exposure temperature. Through this study, it was possible to understand the impact of water used in firefighting on fire-damaged RC structures, and it is deemed necessary to further study various concrete mixing models.
Behavioral Evaluation of Modular ICH RC Columns through Quasi-Static Cyclic Tests
Authors: Kim Sungwon , Hong Hyemin , Han Taek Hee
Published: June 2020

Owing to the recent expansion in sizes of wind turbines, the required height for the wind turbine tower is increasing. Therefore, new types of structures are needed to fulfill this requirement. In this study, a modular Internally Confined Hollow Reinforced Concrete (ICH RC) column was suggested for a wind power tower, and quasi-static test was performed to evaluate its bending performance. One single body specimen (SP-S) and two modular specimens (SP-MP, SP-MF) applying different connection methods were fabricated. The specimens were designed and manufactured while considering the numerical analysis and conditions of the testing laboratory. The test was conducted by controlling the displacement according to the drift ratio. The experimental results of moments, lateral loads, displacements, dissipation energy, ductility, etc. for each specimen were compared with those of numerical modeling. Consequently, plastic hinges were found at the bottom of the column and connection part for SP-S and modular specimens, respectively, which is due to the rigidity change at the connection of the modular specimens. Therefore, the result of energy dissipation was 40% higher in the case of the modular specimens than that of SP-S whereas the lateral force and moment in the case of the modular specimens were smaller than those of SP-S. In terms of displacement and energy ductility, modular specimens exhibited 50% higher results than those of SP-S. For the future work, it is necessary to enhance the performance of the connection part to apply the modular ICH RC structure to a wind turbine tower.
Study for Analyzing Travel Time and Runout Distance of the Debris Flow
Authors: Jun Sanghyun , Choi Joonsik , Kwon Hyukjae , Park Byungsoo
Published: June 2020

In this study, model experiments in laboratory were performed to analyze the behavior of debris flow that included the travel time and deposit area according to the change in topographic conditions and rainfall intensity. According to the experimental results, the travel time at failure initiation was shortened owing to the increased channel slope and rainfall intensity. Similarly, runout distance of the debris flow increased when the length of slope and thickness of the soil increased. Further, deposit area of the debris flow was increased as the channel slope, length of slope, and thickness of soil increased, and the analysis on deposit area was related to the increase in the amount of debris flow. According to the experimental result of the various topographical conditions, the deposit area was increased linearly as the travel time increased. Moreover, increase in the rainfall intensity resulted in decreased travel time and increased debris amount.
A Study on the Interworking Method of BIM Technology and Fire Simulation
Authors: Lee Byeong-Heun , Jin Seung-Hyun , Kim Dong-Eun , Kwon Young-Jin
Published: June 2020

In Korea, the use of BIM in designing is consistently increasing, and in line with current situation, it is necessary to find a method that can interconnect the existing fire simulation and BIM. In this study, we suggested an interworking method of Add-on Program that is possible link with BIM, and conducted a case study with existing programs. Further, it was tested by comparing the temperature at any point. Comparing the result of maximum temperature, a difference of approximately 0.3 ℃, 2.4 ℃, and 17 ℃ was observed in case of T-1, T-2, and T-3. The reason of difference was that a human user cannot create the coordinates like a computer when developing the fire model. In the future, there will be consideration to conduct more case studies.
A Study on Development of the Guideline (Draft) for Performance-based Structural Fire Engineering Design in Building Structures
Authors: Kwon Inkyu
Published: June 2020

A building fire can cause severe loss of life and damage to the property and is regarded as a social disaster. Therefore, employing the fire resistant structures appears to be a potential solution of the stated problem. In this study, the guideline (draft) of the structural fire engineering design, using scientific and engineering methods for evaluation of the structural stabilities in a fire, was developed. Further, by application of the guideline when the desired building is under construction, the rational solution for the improved fire safety and cost competitiveness is expected.
Relation of plasma β‐amyloid, clusterin, and tau with cerebral microbleeds: Framingham Heart Study
Authors: Romero José Rafael , Demissie Serkalem , Beiser Alexa , Himali Jayandra J. , DeCarli Charles , Levy Daniel , Seshadri Sudha
Published: June 2020

Objective

Cerebral microbleeds (CMBs) are associated with higher risk of stroke and dementia, predating clinical diagnosis by several years. CMB are considered markers of cerebral small vessel disease (CSVD): hypertensive (deep CMB) and cerebral amyloid angiopathy (lobar CMB). We related plasma β‐Amyloid (40, 42 and their ratio), clusterin, and tau levels to CMB to elucidate their role as biomarkers for the angiopathies represented by CMB.

Methods

Dementia, stroke, and other neurological disease‐free Framingham Heart Study participants with available CMB and biomarker measurements were included. We related biomarker levels (standardized for analyses) to CMB presence overall and stratified by brain topography (any, lobar, deep), using multivariable logistic regression analyses.

Results

CMB were observed in 208 (5.7%) participants (mean age 57 years, 54% women). After multivariable adjustment, Aβ1‐40 was associated with any CMB (OR (95%CI) 1.20 (0.99, 1.45) P = 0.062)) and lobar CMB (OR (95%CI) 1.33 (1.05, 1.68) P = 0.019), but not with deep CMB. Log‐Aβ1‐42 levels were not associated with CMB overall. Clusterin was related to mixed CMB (1.70 [1.05, 2.74], P = 0.031). Tau levels were associated with any CMB (OR (95%CI) 1.26 (1.07, 1.49) P = 0.006), lobar CMB (OR (95%CI) 1.26 (1.05, 1.52) P = 0.013), and with deep CMB (OR (95% CI) 1.46 (1.13, 1.89) P = 0.004).

Interpretation

We found that plasma Aβ1‐40 and Tau are associated with CMB but further studies are needed to confirm their role in hemorrhage prone CSVD represented by CMB and as indicators of ongoing subclinical neuronal injury.
A Standardized, Pragmatic Approach to Knee Ultrasound for Clinical Research in Osteoarthritis: The Johnston County Osteoarthritis Project
Authors: Yerich Nadiya V. , Alvarez Carolina , Schwartz Todd A. , Savage‐Guin Serena , Renner Jordan B. , Bakewell Catherine J. , Kohler Minna J. , Lin Janice , Samuels Jonathan , Nelson Amanda E.
Published: June 2020

Objective

This study sought to develop and employ a comprehensive and standardized ultrasound (US) protocol and scoring atlas for the evaluation of features relevant to knee osteoarthritis (KOA) in a community‐based cohort in the United States, with the goals of demonstrating feasibility, reliability, and validity.

Methods

We utilized data from the fourth follow‐up (2016‐2018) of the Johnston County OA Project, which includes individuals with (~50%) and without radiographic KOA. All participants underwent standardized knee radiography and completed standard questionnaires including the Knee Injury and Osteoarthritis Outcome Score (KOOS). Bilateral knee US images were obtained by a trained sonographer using a standardized protocol and scored by trained rheumatologists using an atlas developed for this study. A total of 396 knees were each scored by two readers according to the atlas. Associations between US features, radiographic findings (graded by an expert radiologist), and KOOS scores were assessed.

Results

Overall interreader reliability for US scoring was fair to moderate. The strongest correlations between US and radiographic features were seen for osteophytes, and similarly strong correlations were seen between US osteophytes and overall radiographic Kellgren‐Lawrence Grade, demonstrating criterion validity. Features of effusion/synovitis and osteophytes were most associated with KOOS pain and impaired function.

Conclusion

US is a feasible, reliable, and valid method to assess features relevant to KOA in clinical and research settings. The protocol and atlas developed in this study can be utilized to evaluate KOA in a standardized fashion in future clinical studies, enabling greater utilization of this valuable modality in osteoarthritis.
Bioresorbable, Wireless, Passive Sensors as Temporary Implants for Monitoring Regional Body Temperature
Authors: Lu Di , Yan Ying , Avila Raudel , Kandela Irawati , Stepien Iwona , Seo Min‐Ho , Bai Wubin , Yang Quansan , Li Chenhang , Haney Chad R. , Waters Emily A. , MacEwan Matthew R. , Huang Yonggang , Ray Wilson Z. , Rogers John A.
Published: June 2020

Measurements of regional internal body temperatures can yield important information in the diagnosis of immune response‐related anomalies, for precisely managing the effects of hyperthermia and hypothermia therapies and monitoring other transient body processes such as those associated with wound healing. Current approaches rely on permanent implants that require extraction surgeries after the measurements are no longer needed. Emerging classes of bioresorbable sensors eliminate the requirements for extraction, but their use of percutaneous wires for data acquisition leads to risks for infection at the suture site. As an alternative, a battery‐free, wireless implantable device is reported here, which is constructed entirely with bioresorbable materials for monitoring regional internal body temperatures over clinically relevant timeframes. Ultimately, these devices disappear completely in the body through natural processes. In vivo demonstrations indicate stable operation as subcutaneous and intracranial implants in rat models for up to 4 days. Potential applications include monitoring of healing cascades associated with surgical wounds, recovery processes following internal injuries, and the progression of thermal therapies for various conditions.
A High‐Efficiency CoSe Electrocatalyst with Hierarchical Porous Polyhedron Nanoarchitecture for Accelerating Polysulfides Conversion in Li–S Batteries
Authors: Ye Zhengqing , Jiang Ying , Li Li , Wu Feng , Chen Renjie
Published: June 2020

Lithium–sulfur (Li–S) batteries are recognized as promising candidates for next‐generation electrochemical energy storage systems owing to their high energy density and cost‐effective raw materials. However, the sluggish multielectron sulfur redox reactions are the root cause of most of the issues for Li–S batteries. Herein, a high‐efficiency CoSe electrocatalyst with hierarchical porous nanopolyhedron architecture (CS@HPP) derived from a metal–organic framework is presented as the sulfur host for Li–S batteries. The CS@HPP with high crystal quality and abundant reaction active sites can catalytically accelerate capture/diffusion of polysulfides and precipitation/decomposition of Li2S. Thus, the CS@HPP sulfur cathode exhibits an excellent capacity of 1634.9 mAh g−1, high rate performance, and a long cycle life with a low capacity decay of 0.04% per cycle over 1200 cycles. CoSe nanopolyhedrons are further fabricated on a carbon cloth framework (CC@CS@HPP) to unfold the electrocatalytic activity by its high electrical conductivity and large surface area. A freestanding CC@CS@HPP sulfur cathode with sulfur loading of 8.1 mg cm−2 delivers a high areal capacity of 8.1 mAh cm−2 under a lean electrolyte. This work will enlighten the rational design of structure–catalysis engineering of transition‐metal‐based nanomaterials for diverse applications.
Bulk Spin Torque‐Driven Perpendicular Magnetization Switching in L10 FePt Single Layer
Authors: Tang Meng , Shen Ka , Xu Shijie , Yang Huanglin , Hu Shuai , Lü Weiming , Li Changjian , Li Mengsha , Yuan Zhe , Pennycook Stephen J. , Xia Ke , Manchon Aurelien , Zhou Shiming , Qiu Xuepeng
Published: June 2020

Due to its inherent superior perpendicular magnetocrystalline anisotropy, the FePt in L10 phase enables magnetic storage and memory devices with ultrahigh capacity. However, reversing the FePt magnetic state, and therefore encoding information, has proven to be extremely difficult. Here, it is demonstrated that an electric current can exert a large spin torque on an L10 FePt magnet, ultimately leading to reversible magnetization switching. The spin torque monotonically increases with increasing FePt thickness, exhibiting a bulk characteristic. Meanwhile, the spin torque effective fields and switching efficiency increase as the FePt approaches higher chemical ordering with stronger spin–orbit coupling. The symmetry breaking that generates spin torque within L10 FePt is shown to arise from an inherent structural gradient along the film normal direction. By artificially reversing the structural gradient, an opposite spin torque effect in L10 FePt is demonstrated. At last, the role of the disorder gradient in generating a substantial torque in a single ferromagnet is supported by theoretical calculations. These results will push forward the frontier of material systems for generating spin torques and will have a transformative impact on magnetic storage and spin memory devices with simple architecture, ultrahigh density, and readily application.
Boosting Visible‐Light Photocatalytic Performance for CO2 Reduction via Hydroxylated Graphene Quantum Dots Sensitized MIL‐101(Fe)
Authors: Liu Ning , Tang Mengqi , Wu Jinxing , Tang Liang , Huang Wenyuan , Li Qiutao , Lei Jianqiu , Zhang Xiaodong , Wang Liang
Published: June 2020

Herein, a one‐step solvothermal method that shows incorporation of the graphene quantum dots (GQDs) on Fe‐based metal organic frameworks (MOFs) [MIL‐101(Fe)] to form GQD/MIL‐101(Fe) (G/M101) composites is reported. MIL‐101(Fe) with the sensitization of GQDs could significantly improve the photocatalytic reduction efficiency of CO2 to generate CO. The prepared composites exhibit excellent optical properties and the photocatalytic activity of G/M101 composites is relevant to GQDs ratio. The CO production rate over G/M101‐5% (224.71 µmol h−1 g−1) is 5 times higher than that of MIL‐101(Fe) (46.20 µmol h−1 g−1). The promising photocatalytic activity of G/M101‐5% strongly depends on the beneficial separation and transfer of photoinduced carriers via a charge migration between GQDs and MIL‐101(Fe). The microstructures and interfacial structures of the G/M101‐5% composite demonstrate that GQDs are closely loaded on the surface of MIL‐101 (Fe), and thus favors to the photoreduction according to their sp2 bonding. This work may figure a new way for the synthesis of photocatalysts for the application on carbon stabilization.
Angular Scattering Pattern of Femtosecond Laser‐Induced Refractive Index Modifications in Optical Fibers
Authors: Reupert Aaron , Heck Maximilian , Nolte Stefan , Wondraczek Lothar
Published: June 2020

Focused femtosecond laser irradiation is used to induce light scattering modifications in the core of an optical fiber. This turns the fiber into a diffuse, line‐shaped light source. The scattering is investigated by imaging almost the full solid angle far‐field pattern for the first time. Additionally, an electromagnetic scattering model is developed to explain the observations. The findings herein change how the relationship between light scattering and the refractive index fluctuations is perceived by showing that the far‐field scattering pattern is the power spectral density of the polarization current inside the scattering center. Further, the authors contribute to a better estimation of the scattering process by showing that the total scattering power scales quadratically with the laser‐induced refractive index change and its volume.
Cinchona Squaramide‐Catalyzed Intermolecular Desymmetrization of 1,3‐Diketones Leading to Chiral 1,4‐Dihydropyridines
Authors: Dajek Maciej , Pruszczyńska Agnieszka , Konieczny Krzysztof A. , Kowalczyk Rafał
Published: June 2020

Addition of prochiral cyclic 1,3‐diketones to Michael acceptors applying bifunctional Cinchona‐derived squaramides resulted in chiral adducts with stereoselectivities of up to 99% ee and allowed for desymmetrization of the nucleophile. These labile hemiacetal intermediates were transformed to new 1,4‐dihydropyridines with high diastereoselectivities and no erosion of optical purity. Their further oxidation to pyridine followed by Fisher indolization provided chiral pyridine‐indoles.

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Anionic Redox Activity Regulated by Transition Metal in Lithium‐Rich Layered Oxides
Authors: Song Jun‐Hyuk , Yoon Gabin , Kim Byunghoon , Eum Donggun , Park Hyeokjun , Kim Do‐Hoon , Kang Kisuk
Published: June 2020

The anionic redox activity in lithium‐rich layered oxides has the potential to boost the energy density of lithium‐ion batteries. Although it is widely accepted that the anionic redox activity stems from the orphaned oxygen energy level, its regulation and structural stabilization, which are essential for practical employment, remain still elusive, requiring an improved fundamental understanding. Herein, the oxygen redox activity for a wide range of 3d transition‐metal‐based Li2TMO3 compounds is investigated and the intrinsic competition between the cationic and anionic redox reaction is unveiled. It is demonstrated that the energy level of the orphaned oxygen state (and, correspondingly, the activity) is delicately governed by the type and number of neighboring transition metals owing to the π‐type interactions between LiOLi and M t2g states. Based on these findings, a simple model that can be used to estimate the anionic redox activity of various lithium‐rich layered oxides is proposed. The model explains the recently reported significantly different oxygen redox voltages or inactivity in lithium‐rich materials despite the commonly observed LiOLi states with presumably unhybridized character. The discovery of hidden factors that rule the anionic redox in lithium‐rich cathode materials will aid in enabling controlled cumulative cationic and anionic redox reactions.
Reinterpretation ofPaleoazolla: a heterosporous water fern from the Late Cretaceous of Patagonia, Argentina
Authors: De Benedetti Facundo , Zamaloa María del C. , Gandolfo María A. , Cúneo Néstor R.
Published: June 2020

Premise

Undoubtedly, fossils are critical for understanding evolutionary transformations in deep time. Here, we reinvestigate the microspores and megaspores ofPaleoazolla patagonica, a water fern found in Late Cretaceous sediments of the Chubut Province, Patagonia, Argentina, which provides novel evidence on the past history of the water fern clade. The study was based on recently collected specimens and additional observations of the original material.

Methods

Most specimens analyzed herein were obtained from new palynological samples collected at the Cerro Bosta and Cañadón del Irupé localities, La Colonia Formation. Samples were mechanically disaggregated and treated with hydrofluoric and hydrochloric acid. Spores were studied using standard light microscopy and scanning electron microscopy. We also reexamined the original materials.

Results

The newly described characters ofPaleoazollainclude the presence of heterosporangiate sori composed of one ellipsoidal megasporangium surrounded by three to four oval microsporangia, megasporangium containing one hairy massula that encloses two trilete megaspores (rarely one or three), and microsporangia containing numerous microspore massulae with non‐septate multibarbed glochidia and one trilete microspore per massula.

Conclusions

The reinterpretation has revealed a novel set of characters for understanding the evolution of heterosporous water ferns. The presence of two megaspores in the megasporangium ofPaleoazollaexposes serious gaps in the current knowledge on the evolution of monomegaspory in heterosporous water ferns, a fact that emphasizes the need of including fossils within phylogenies to elucidate patterns of character acquisition among water ferns.
Evodiamine derivatives improve cognitive abilities in APPswe/PS1ΔE9 transgenic mouse models of Alzheimer's disease
Authors: Pang Shuo , Sun Caixian , Gao Shan , Yang Yajun , Pan Xiandao , Zhang Lianfeng
Published: June 2020

Background

Alzheimer's disease (AD) is a complex neurodegenerative disease. Due to the complexity of its molecular pathogenesis and the interaction of the numerous factors involved, the etiology and pathogenesis of AD have not been fully elucidated. Therefore, effective treatment for AD remains to be developed. Evodiamine, a quinolone alkaloid, has been found to improve learning and memory ability to in the APPswe/PS1△E9 mouse model of dementia. However, the cytotoxicity and physicochemical properties of evodiamine have limited its use in the treatment of AD.

Methods

Evodiamine and its derivatives were effectively synthesized by EDCI‐mediated condensation at room temperature. These target compounds contained 1 thio‐ and 21 oxo‐evodiamine derivatives with different substituted groups. The cytotoxicity of evodiamine and its derivatives and the neuroprotective effects of the evodiamine derivatives against H2O2‐induced cell loss in SH‐SY5Y cells were investigated using the WST‐8 assay. The Morris water‐maze test was used to detect the effect of evodiamine and its derivatives on improving learning and memory in APPswe/PS1△E9 mice.

Results

In this study, a series of oxo‐ and thio‐evodiamine derivatives was synthesized. Several derivatives showed lower cytotoxicity and stronger neuroprotective effects than evodiamine and elicited enhanced cognitive improvement, especially in the test of spatial memory in APPswe/PS1△E9 mice.

Conclusion

Our study provides insights for developing novel evodiamine derivatives for chemical intervention and treatment of AD.
Rapid development and deployment of high‐volume vaccines for pandemic response
Authors: Kis Zoltán , Kontoravdi Cleo , Dey Antu K. , Shattock Robin , Shah Nilay
Published: June 2020

Overcoming pandemics, such as the current Covid‐19 outbreak, requires the manufacture of several billion doses of vaccines within months. This is an extremely challenging task given the constraints in small‐scale manufacturing for clinical trials, clinical testing timelines involving multiple phases and large‐scale drug substance and drug product manufacturing. To tackle these challenges, regulatory processes are fast‐tracked, and rapid‐response manufacturing platform technologies are used. Here, we evaluate the current progress, challenges ahead and potential solutions for providing vaccines for pandemic response at an unprecedented scale and rate. Emerging rapid‐response vaccine platform technologies, especially RNA platforms, offer a high productivity estimated at over 1 billion doses per year with a small manufacturing footprint and low capital cost facilities. The self‐amplifying RNA (saRNA) drug product cost is estimated at below 1 USD/dose. These manufacturing processes and facilities can be decentralized to facilitate production, distribution, but also raw material supply. The RNA platform technology can be complemented by an a priori Quality by Design analysis aided by computational modeling in order to assure product quality and further speed up the regulatory approval processes when these platforms are used for epidemic or pandemic response in the future.
Hollow Carbon Sphere Nanoreactors Loaded with PdCu Nanoparticles: Void‐Confinement Effects in Liquid‐Phase Hydrogenations
Authors: Dong Chao , Yu Qun , Ye Run‐Ping , Su Panpan , Liu Jian , Wang Guang‐Hui
Published: June 2020

Nanoreactors with hollow structures have attracted great interest in catalysis research due to their void‐confinement effects. However, the challenge in unambiguously unraveling these confinement effects is to decouple them from other factors affecting catalysis. Here, we synthesize a pair of hollow carbon sphere (HCS) nanoreactors with presynthesized PdCu nanoparticles encapsulated inside of HCS (PdCu@HCS) and supported outside of HCS (PdCu/HCS), respectively, while keeping other structural features the same. Based on the two comparative nanoreactors, void‐confinement effects in liquid‐phase hydrogenation are investigated in a two‐chamber reactor. It is found that hydrogenations over PdCu@HCS are shape‐selective catalysis, can be accelerated (accumulation of reactants), decelerated (mass transfer limitation), and even inhibited (molecular‐sieving effect); conversion of the intermediate in the void space can be further promoted. Using this principle, a specific imine is selectively produced. This work provides a proof of concept for fundamental catalytic action of the hollow nanoreactors.
Chemo‐ and Enantioselective Oxidative α‐Azidation of Carbonyl Compounds
Authors: Uyanik Muhammet , Sahara Naoto , Tsukahara Mayuko , Hattori Yuhei , Ishihara Kazuaki
Published: June 2020

We report high‐performance I+/H2O2 catalysis for the oxidative or decarboxylative oxidative α‐azidation of carbonyl compounds by using sodium azide under biphasic neutral phase‐transfer conditions. To induce higher reactivity especially for the α‐azidation of 1,3‐dicarbonyl compounds, we designed a structurally compact isoindoline‐derived quaternary ammonium iodide catalyst bearing electron‐withdrawing groups. The nonproductive decomposition pathways of I+/H2O2 catalysis could be suppressed by the use of a catalytic amount of a radical‐trapping agent. This oxidative coupling tolerates a variety of functional groups and could be readily applied to the late‐stage α‐azidation of structurally diverse complex molecules. Moreover, we achieved the enantioselective α‐azidation of 1,3‐dicarbonyl compounds as the first successful example of enantioselective intermolecular oxidative coupling with a chiral hypoiodite catalyst.
Swelling behavior of expandable poly(methyl methacrylate‐acrylic acid)/polymethyl methacrylate bio‐composites with different crosslinking densities
Authors: Chen Lei , Tang Yufei , Zhao Kang , Jiang Xiashu , Zhou Xuerui , Wu Zixiang
Published: June 2020

The volume shrinkage of poly(methyl methacrylate‐acrylic acid) (PMMA) bone cement was mainly tackled by the different types and contents of the hydrophilic additives. While the crosslinking density was assumed to regulate the hydrophilic group amounts and 3D network structures in the additives, which influenced the absorption and swelling capacity of the PMMA‐based bone cement. In this study, the expandable PMMA/polymethyl methacrylate bio‐composites (EBC) with different N, N‐methylenebisacrylamide (MBA) contents were synthesized to investigate the relationship between the crosslinking density and swelling performance, and also promoted the absorption and swelling properties before the solidification of EBC. The results demonstrated that the equilibrium absorption ratio and the equilibrium swelling ratio both exhibited a normal distribution with the various MBA content. In addition, the controlled absorption ratio (7.3–60.2%) and swelling ratio (8.5–61.8%) of EBC could be obtained by altering crosslinking density in the system. Furthermore, EBC could obtain a similar equilibrium absorption ratio and equilibrium swelling ratio with different mechanical properties, which provided more options for meeting the requirements of EBC in different clinical settings.
Cultural factors and the role of privacy concerns in acceptance of government surveillance
Authors: Thompson Nik , McGill Tanya , Bunn Anna , Alexander Rukshan
Published: June 2020

Though there is a tension between citizens' privacy concerns and their acceptance of government surveillance, there is little systematic research in this space and less still in a cross‐cultural context. We address the research gap by modeling the factors that drive public acceptance of government surveillance, and by exploring the influence of national culture. The research involved an online survey of 242 Australian and Sri Lankan residents. Data were analyzed using partial least squares, revealing that privacy concerns around initial collection of citizens' data influenced levels of acceptance of surveillance in Australia but not Sri Lanka, whereas concerns about secondary use of data did not influence levels of acceptance in either country. These findings suggest that respondents conflate surveillance with the collection of data and may not consider subsequent secondary use. We also investigate cultural differences, finding that societal collectivism and power distance significantly affect the strength of the relationships between privacy concerns and acceptance of surveillance, on the one hand, and adoption of privacy protections, on the other. Our research also considers the role of trust in government, and perceived need for surveillance. Findings are discussed with their implications for theory and practice.
Quantitative analysis of amino acids by HPLC in dried blood and urine in the neonatal period: Establishment of reference values
Authors: Nolasco Daniela M. , Fortes Isabel C. P. , Valadares Eugênia R.
Published: June 2020

Quantitative analysis of amino acids in blood and urine is primarily indicated for the diagnosis of amino acid disorders. The high‐performance liquid chromatography (HPLC) technique is frequently used for this detection. The frequency of sample collection on filter paper has been increasing exponentially, and there are many advantages attributed to processing biological samples in this way. The aim of this study was to validate a quantitative analysis of amino acids by HPLC in blood and urine collected on filter paper and to establish reference values in the neonatal period. Dried blood and dried urine samples of respectively 58 and 45 healthy newborns (2–9 days) were collected. Pre‐treatment and extraction of samples were done according to the literature. Separation and analysis of amino acids were carried out by HPLC with fluorescence detection. The developed method demonstrated excellent separation, linearity, limits of detection and quantification, repeatability and recovery. The reference values for 17 amino acids were defined in dried blood and urine samples of newborns. This work presents a simple, fast and effective method for the simultaneous analysis of 17 amino acids in blood and urine collected on filter paper in a single run. The reference values were established and validated.