bluuebunny/crossref_metadata_2025 huggingface dataset:
‘Remote’ behavioural ecology: do megaherbivores consume vegetation in proportion to its presence in the landscape?
Authors: Marston Christopher G. , Wilkinson David M. , Sponheimer Matt , Codron Daryl , Codron Jacqui , O’Regan Hannah J.
Published: February 2020

Examination of the feeding habits of mammalian species such as the African elephant (Loxodonta africana) that range over large seasonally dynamic areas is exceptionally challenging using field-based methods alone. Although much is known of their feeding preferences from field studies, conclusions, especially in relation to differing habits in wet and dry seasons, are often contradictory. Here, two remote approaches, stable carbon isotope analysis and remote sensing, were combined to investigate dietary changes in relation to tree and grass abundances to better understand elephant dietary choice in the Kruger National Park, South Africa. A composited pair of Landsat Enhanced Thematic Mapper satellite images characterising flushed and senescent vegetation states, typical of wet and dry seasons respectively, were used to generate land-cover maps focusing on the forest to grassland gradient. Stable carbon isotope analysis of elephant faecal samples identified the proportion of C3(typically browse)/C4(typically grass) in elephant diets in the 1–2 days prior to faecal deposition. The proportion of surrounding C4land-cover was extracted using concentric buffers centred on faecal sample locations, and related to the faecal %C4content. Results indicate that elephants consume C4vegetation in proportion to its availability in the surrounding area during the dry season, but during the rainy season there was less of a relationship between C4intake and availability, as elephants targeted grasses in these periods. This study illustrates the utility of coupling isotope and cost-free remote sensing data to conduct complementary landscape analysis at highly-detailed, biologically meaningful resolutions, offering an improved ability to monitor animal behavioural patterns at broad geographical scales. This is increasingly important due to potential impacts of climate change and woody encroachment on broad-scale landscape habitat composition, allowing the tracking of shifts in species utilisation of these changing landscapes in a way impractical using field based methods alone.
Size Frequency Distribution, Length-length and Weight-length Relationships and Condition Factor of Eight Fish Species of Nkam River, Coastal Cameroon
Authors: Tiogué Claudine Tekounegning , Medjo Evrard Kouopestchop , Makongo Franklin David Ndilock
Published: February 2020

Aims: To assess the aquaculture potential of endogenous species in their habitat for domestication and preservation.

Study Design: Growth performances of fish caught was analyzed by family, species, sex and month.

Place and Duration: This study was conducted from April 12 to June 28, 2016 at CREVS (Cameroon Reptiles and Ecosystems Valorization Society) located in the District of Yabassi, Department of Nkam, Coastal Region of Cameroon.

Methodology: A total of 160 fishes were collected by quantitative sampling for 3 months in the Nkam River.

Results: It appears that two families of fish were recorded: the Cyprinidae (Labeo sanagaensis) and the Cichlidae (Tilapia cameronensis, Sarotherodon galilaeus sanagaensis, Sarotherodon nigripinnis dolloi, Tylochromis sudanensis, Hemichromis elongatus, Tylochromis trewavasae and Chromidotilapia gutheri gutheri). L. sanagaensis recorded the highest relative abundance (30%) against 3.13% (C. gutheri gutheri). Large fish were recorded in the majority of species in males, except in T. trewavasae and H. elongatus. The average total length was 23.71 ± 8.31 cm and the average total weight was 266.11 ± 200.96 g. Size frequency distribution of fish was bimodal with a large mode at size 20 cm and a small at size 36 cm. Small fish were abundant in catches especially in S. nigripinnis dolloi and C. gutheri gutheri. The allometric coefficient b of the weight-length relationship averaged 3.01 ± 0.87. The fish presented three types of growth: isometric, positive and negative allometric, and the condition factor K was greater than 1.

Conclusion: It was concluded that these fish species could in general be potential candidates for domestication.
A Micro Level Investigation of Costs & Returns of Different Agro-ecosystems in Kashmir Region of Jammu and Kashmir: India
Authors: Ganaie Shabeer A. , Bhat Arshad , Qadir Abid , Qureshi Iqra
Published: February 2020

The basic objectives of the study were to enquire in to the involvement of various types of costs, the returns per rupee invested and the benefit thereof in different agro-ecosystems in the state of Jammu and Kashmir in general and valley of Kashmir in particular, especially the sampled districts.  This study was based upon primary and secondary data. A multi-stage random sampling was utilised for collection of date from 432 respondents of four different agro-ecological zones. For major crops, the cost of cultivation were estimated by concept utilised by Commission on Agricultural Costs and Prices (CACP), Government of India. The results revealed that fruit crop agro-ecosystem is highly remunerative than field crop and crop agro-ecosystems, though the fruit crop involve huge of investment in terms of different costs. The livestock based agro-ecosystem is also dominant in some parts of the Kashmir region with declining trend. The results revealed that the gross returns of paddy and apple, livestock and cash crop were Rs. 23250, Rs. 321000, Rs. 108920 and 106915 respectively. This study had its applicability in the daily routine life of any household dwelling in the sampled agro-ecosystems. The study could be of utmost importance in selecting the crop in which the region/agro-ecosystem had specialisation or absolute advantage.
A Cost‐Performance Analysis of a Sodium Heat Engine for Distributed Concentrating Solar Power
Authors: Gunawan Andrey , Singh Abhishek K. , Simmons Richard A. , Haynes Megan W. , Limia Alexander , Ha Jong Min , Kottke Peter A. , Fedorov Andrei G. , Lee Seung Woo , Yee Shannon K.
Published: February 2020

A sodium thermal electrochemical converter (Na‐TEC) generates electricity directly from heat through isothermal expansion of sodium ions across a beta″‐alumina solid‐electrolyte. This heat engine has been considered for use with conventional concentrating solar power (CSP) systems before. However, unlike previous single‐stage devices, the improved design uses two stages with an interstage reheat, allowing more economical and efficient conversion up to 29% at a hot side temperature of 850 °C. Herein, a cost‐performance analysis for this improved design assesses opportunities for distributed‐CSP in the context of micro‐combined heat and power systems. A high‐level techno‐economic analysis (TEA) is presented that explores four scenarios where a Na‐TEC is used as the heat engine for a distributed‐CSP system. Overnight capital cost and levelized cost of electricity (LCOE) are estimated for a system lifetime of 30 years, revealing that overnight capital costs in a range from $3.57 to $17.71 per We are feasible, which equate to LCOEs from 6.9 to 17.2 cents kWhe−1. This analysis makes a significant contribution by concurrently quantifying the efficiency and unit costs for a range of multistage configurations, and demonstrating that a Na‐TEC may be a promising alternative to Stirling engines for distributed‐CSP systems at residential scale of 1–5 kWe.
Evaluation of edamame genotypes suitable for growing in Florida
Authors: Guo Jia , Rahman Atikur , Mulvaney Michael J. , Hossain Mohammad Maksud , Basso Kari , Fethiere Richard , Babar Md Ali
Published: February 2020

Edamame, or vegetable soybean, has gained popularity in the United States, likely due to its nutritional quality, purported human health benefits, and flavor. Little information is available about the performance of current edamame cultivars in Florida areas. The objective of this study was to evaluate yield and production potential of edamame genotypes in northern Florida. Nineteen genotypes (based on preliminary study) were selected and planted at two locations (Jay and Citra) to evaluate phenotypic performance, including emergence, plant height, nodes per plant, 100‐green seed weight, fresh pod yield, percentage of 1‐, 2‐, and 3‐seeded pods, total lipid concentration, and total protein content. Genotypes and locations showed a significant effect on most of the traits studied. Edamame grown at Jay produced significantly higher yield and 100‐green seed weight than the plants grown at Citra. Two early maturing genotypes (PI614832 and PI584470) and one late maturing genotype (PI633424) showed high yield potential, >30 g of 100‐green seed weight, and high protein content at Jay. In addition, PI417206 showed the highest 100‐green seed weight across locations (50.81 g) and demonstrated moderate yield potential with high protein content and low lipid concentration and may be a suitable candidate for cultivation in different areas in Florida after further evaluation. Number of pods per plant and 100‐green seed weight significantly correlated with pod yield, could be considered as selection tool for edamame yield under Florida growing conditions. This study has established a basic knowledge on edamame production for Florida growers and selected lines suitable for the region.
Essential Updates 2018/2019: Essential Updates for esophageal cancer surgery
Authors: Seto Yasuyuki
Published: February 2020

Key papers to treatment of esophageal cancer surgery and reduction of postoperative complications after esophagectomy published between 2018 and 2019 were reviewed. Within this review there was a focus on minimally invasive esophagectomy (MIE), robot‐assisted MIE (RAMIE), and centralization to high‐volume center. Advantages of MIE, irrespectively of hybrid or total MIE, to prevent postoperative complications, especially pneumonia, were shown in comparison to open procedure. However, whether total MIE has evident effects or not, as compared to hybrid MIEs, still remains unclear. Differences between RAMIE and MIE were reported to be marginal, though the advantage of lymphadenectomy, especially along recurrent laryngeal nerve, has been suggested. Centralization to high‐volume center evidently benefits esophageal cancer patients by improving short‐term outcomes. The definition of high‐volume center has not been established yet, though institutional structure and quality are thought to be important. Transmediastinal esophagectomy, currently developed, has a potential to be one radical option of MIE for esophageal cancer.
The presentation of Crohn's disease with acute massive gastrointestinal hemorrhage
Authors: Lee Kuan‐Chieh , Kuo Chia‐Jung , Tseng Jeng‐Hwei , Su Ming‐Yao , Chiu Cheng‐Tang , Huang Shih‐Chiang , Kang Shih‐Ching
Published: February 2020

Severe gastrointestinal (GI) hemorrhage is a rare initial presentation in Crohn's disease (CD) and poses a therapeutic challenge for clinical care. Currently, there is no conclusive consensus or guideline on the treatment modalities for CD‐related GI bleeding. We present the case of a 21‐year‐old man with acute lower GI bleeding who accepted transcatheter arterial embolization to attain hemostasis. After 1 day of embolization, intractable abdominal pain happened and emergent laparoscopic exploration was arranged. Operation finding reported stenosis and chronic inflammation changes near ileal‐cecal valve. Besides, several bleeding sites and perforation are detected, which is different from splanchnic branch of embolization. Pathology of resected bowel reported transmural acute and chronic inflammation with fibrin and purulent exudates is shown on the serosa. CD is favored. In CD, the most common bleeding site in the literature is located at descending and sigmoid colon. To attain hemostasis, some literature studies raise concerns about embolic‐related complication of intestinal infarction. We would like to share a case of unusual bleeding site and provide consideration of embolization as an option for the treatment of CD.
Patterns of heritability across the human diphyodont dental complex: Crown morphology of Australian twins and families
Authors: Paul Kathleen S. , Stojanowski Christopher M. , Hughes Toby E. , Brook Alan H. , Townsend Grant C.
Published: February 2020

Objectives

This study generates a series of narrow‐sense heritability estimates for crown morphology of the deciduous and permanent dentition with two overarching aims. The first is to test the hypothesis that deciduous teeth provide a more faithful reflection of genetic information than their permanent successors. The second is to use quantitative genetic methods to evaluate assumptions underlying common data collection and analysis practices in biodistance research.

Materials and Methods

Dental morphology data were collected from longitudinal dental casts representing Australian twins and families using Arizona State Dental Anthropology System standards. Polygenic models and estimates of narrow‐sense heritability were generated using SOLAR v.8.1.1. Each model considered age, sex, and age/sex interaction as covariates.

Results

Heritability estimates significantly differed from zero for the majority of morphological crown characters. Most estimates fell within the 0.4–0.8 range typically observed for crown morphology. Mean heritability was stable across the dental complex, but for paired homologues, permanent traits often yielded higher estimates than their deciduous counterparts. Results indicate directional asymmetry in environmental influence for crown morphology and inform biodistance “best practices” related to data collection and treatment.

Conclusions

Overall, results for this sample support the use of crown morphology as a proxy for genetic variation in evolutionary research. This includes the deciduous dentition, which justifies the expansion of efforts to incorporate subadults into reconstructions of past microevolutionary processes. Results do not indicate that deciduous phenotypes more closely approximate underlying genotype, at least for deciduous/permanent homologues.
Pathway from N‐Alkylglycine to Alkylisonitrile Catalyzed by Iron(II) and 2‐Oxoglutarate‐Dependent Oxygenases
Authors: Chen Tzu‐Yu , Chen Jinfeng , Tang Yijie , Zhou Jiahai , Guo Yisong , Chang Wei‐chen
Published: February 2020

N‐alkylisonitrile, a precursor to isonitrile‐containing lipopeptides, is biosynthesized by decarboxylation‐assisted ‐N≡C group (isonitrile) formation by using N‐alkylglycine as the substrate. This reaction is catalyzed by iron(II) and 2‐oxoglutarate (Fe/2OG) dependent enzymes. Distinct from typical oxygenation or halogenation reactions catalyzed by this class of enzymes, installation of the isonitrile group represents a novel reaction type for Fe/2OG enzymes that involves a four‐electron oxidative process. Reported here is a plausible mechanism of three Fe/2OG enzymes, Sav607, ScoE and SfaA, which catalyze isonitrile formation. The X‐ray structures of iron‐loaded ScoE in complex with its substrate and the intermediate, along with biochemical and biophysical data reveal that ‐N≡C bond formation involves two cycles of Fe/2OG enzyme catalysis. The reaction starts with an FeIV‐oxo‐catalyzed hydroxylation. It is likely followed by decarboxylation‐assisted desaturation to complete isonitrile installation.
Electrooxidation Enables Selective Dehydrogenative [4+2] Annulation between Indole Derivatives
Authors: Song Chunlan , Liu Kun , Jiang Xu , Dong Xin , Weng Yue , Chiang Chien‐Wei , Lei Aiwen
Published: February 2020

Dearomative annulation of indoles has emerged as a powerful tool for the preparation of polycyclic indoline‐based alkaloids. Compared with well‐established methods towards five‐membered‐ring‐fused indolines, the six‐membered‐ring‐fused indolines are rarely accessed under thermal conditions. Herein, a dearomative [4+2] annulation between different indoles is developed through an electrochemical pathway. This transformation offers a remarkably regio‐ and stereoselective route to highly functionalized pyrimido[5,4‐b]indoles under oxidant‐ and metal‐free conditions. Notably, this electrochemical approach maintains excellent functional‐group tolerance and can be extended as a modification tactic for pharmaceutical research. Preliminary mechanism studies indicate that the electrooxidation annulation proceeds through radical–radical cross‐coupling between an indole radical cation and an N‐centered radical generated in situ.
Flash‐photoreduction method to enhance hydrogen photogeneration on Pd@TiO2
Authors: Dadsetan Samira , Farshidfar Farshad , Baghshahi Saeid , Rezaei Mehran
Published: February 2020

A novel method for the preparation of highly dispersed Pd nanoparticles on TiO2 (P25) was proposed based on ultraviolet irradiation over a converging strip of the solution passing through a quartz reactor, which leads to a flash photoreduction. The high‐resolution transmission electron microscopy (HRTEM) results clearly indicated that the flash type irradiation reduced the Pd particle size to less than 9 nm and shifted the absorption edge of bare TiO2 from 3.25 to below 3.0 eV after Pd loading without any change in structural and lattice parameters of the support. The narrow size distribution of Pd particles and their single crystalline feature are endorsed by X‐ray powder diffraction, CO chemisorption, HRTEM, and CO‐Fourier‐transform infrared spectroscopy methods. Increasing the rate of H2 photogeneration to 868 μmol·g−1·hr−1 is the result of the developed method for the Pd loading on TiO2.
Curcumin stimulates angiogenesis through VEGF and expression of HLA‐G in first‐trimester human placental trophoblasts
Authors: Basak Sanjay , Srinivas Vilasagaram , Mallepogu Aswani , Duttaroy Asim K.
Published: February 2020

Curcumin has a protective role in placental diseases like preeclampsia and preterm birth. Very little is known about its functional effects on growth, angiogenesis, and epigenetic activities of human first trimester placenta. HTR8/SVneo trophoblasts cells were used as model for human first trimester placenta. Effects of curcumin (≥80%) in these cells were investigated using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT), radioactive thymidine uptake, quantitative real‐time polymerase chain reaction (qRT‐PCR), promoter DNA methylation, qRT‐PCR array, tube formation, wound healing, and immunoblot assays. PC3 (prostate cancer), JEG‐3 (trophoblast), and HMEC‐1 (endothelial) cells were used as control in various experiments. Unlike in PC3 cells, curcumin stimulated growth, proliferation, and viability in HTR8/SVneo cells. Curcumin increased tube formation, and messenger RNA (mRNA) expression of angiogenic factors such as vascular endothelial growth factor A (VEGFA) and protein expression of proangiogenic factor VEGF receptor‐2 and fatty acid‐binding protein‐4 (FABP4) in these cells. Curcumin‐stimulated tube formation was associated with an increased expression of VEGFR2 and FABP4. The stimulatory effects of curcumin were inhibited by VEGFR2 (SU5416) and FABP4 (BMS309403) inhibitors. Curcumin also significantly increased both mRNA and protein expression of HLA‐G in HTR8/SVneo cells. Curcumin increased mRNA expression of DNMT3A and NOTCH signaling system whereas down‐regulated mRNA expression of HSD11β2. Curcumin enhanced hypomethylation of gene promoters against oxidative stress and DNA damage pathway mediators. Curcumin promotes cell growth, migration, and thus angiogenic potential of these cells. Increased expression of HLA‐G by curcumin, hitherto unknown, is a novel finding since HLA‐G not only favors the immune environment for invasive trophoblasts but also positively modulates angiogenesis.
Electrostatic Self‐Assembled Bracelet‐Like Au@Pt Nanoparticles: An Efficient Electrocatalyst for Highly Sensitive Non‐Enzymatic Hydrogen Peroxide Sensing
Authors: Li Zhi , Qian Weina , Guo Hui , Long Xu , Tang Yuping , Zheng Jianbin
Published: February 2020

In this study, a non‐enzymatic electrochemical sensor was developed based on bracelet‐like Au@Pt nanoparticles (B−Au@Pt NPs) and used for extremely sensitive detection of hydrogen peroxide (H2O2). The uniquely shaped B−Au@Pt NPs with a well‐defined core–shell structure were synthesized by a combination of seed‐mediated growth and electrostatic self‐assembly, especially using both sodium citrate (SC) and cetyltrimethylammonium chloride (CTAC). Through characterization by dynamic light scattering (DLS), high‐resolution transmission electron microscopy (HRTEM) and UV/Vis absorption spectra, it was evident that each Au NP was surrounded by several ultrasmall Pt NPs, all of which were detached from and lose contact with Au cores. Compared with sea urchin‐like Au@Pt NPs (S−Au@Pt NPs) synthesized only by a seed‐mediated growth, B−Au@Pt NPs presented obvious electrochemical response and exhibited substantially enhanced electrocatalytic activity towards H2O2 reduction. This H2O2 sensor, denoted as B−Au@Pt NPs/GCE (GCE=glassy carbon electrode), with enhanced sensitivity, has shown much better sensing performance than other sensors based on Pt reported earlier, particularly the high sensitivity of 882.2 μA mM−1 cm−2. Moreover, this non‐enzymatic electrochemical sensor based on B−Au@Pt NPs may offer the potential for sensitive detection of H2O2 in aquatic environmental monitoring.
Metal‐Modulated Nitrogen‐Doped Carbon Electrocatalyst for Efficient Carbon Dioxide Reduction
Authors: Peng Zhen , Huang Yiyin , Wang Jian , Yang Rui , Xie Jiafang , Wang Yaobing
Published: February 2020

Carbon‐based catalysts have been increasingly studied for electrochemical CO2 reduction, and their design is mainly focused on modulation of heteroatom dopants, of which chemical states rely highly on the synthesis approach and precursor used. In this work, we present a nitrogen‐doped carbon (NC) catalyst with modulation of N assembled states by Fe particles. The synthetic NC@Fe electrocatalyst enabled efficient and durable CO2 reduction at the maximum CO Faradaic efficiency of 90.6 % and 93 % reservation of its initial activity after long‐term electrolysis. Studies from experiments and DFT calculations indicated that Fe particles induced formation of N‐doped carbon layers in NC@Fe electrocatalyst. These N‐doped carbon layers provide more N‐assembled domains on the surface, in which the triple graphitic N, triple pyridinic N and graphitic‐pyrrolic N configurations were revealed to reduce the formation energy of key intermediates *COOH and *CO for efficient CO2‐to‐CO conversion. These results are hoped to motivate more research on modulation over chemical states of heteroatoms toward synthesis of efficient carbon‐based catalysts for electrocatalytic applications.
Rhodium‐Catalyzed ortho‐Olefination of Sterically Demanding Benzamides: Application to the Asymmetric Synthesis of Axially Chiral Benzamides
Authors: Yoshimura Ryo , Tanaka Ken
Published: February 2020

It has been established that an unsubstituted cyclopentadienyl rhodium(III) (CpRhIII) complex is a highly active catalyst for the aerobic oxidative ortho C−H bond olefination of sterically demanding ortho‐substituted benzamides with alkenes. This catalysis was successfully applied to the diastereoselective synthesis of axially chiral N,N‐dialkylbenzamides. The combination of the ruthenium(II)‐catalyzed enantioselective hydrogenation and the CpRhIII‐catalyzed diastereoselective ortho C−H bond olefination enabled the asymmetric synthesis of axially chiral N,N‐dialkylbenzamide derivatives with high ee values.
Recent Trends in Chiroptical Spectroscopy: Theory and Applications of Vibrational Circular Dichroism and Raman Optical Activity
Authors: Krupová Monika , Kessler Jiří , Bouř Petr
Published: February 2020

Chiroptical spectroscopy exploring the interaction of matter with polarized light provides many tools for molecular structure and interaction studies. Here, some recent discoveries are reviewed, primarily in the field of vibrational optical activity. Technological advances results in the development of more sensitive vibrational circular dichroism (VCD), Raman optical activity (ROA) or circular polarized luminescence (CPL) spectrometers. Significant contributions to the field also come from the light scattering and electronic structure theories, and their implementation in computer systems. Finally, new chiroptical phenomena have been observed, such as enhanced circular dichroism of biopolymers (protein fibrils, nucleic acids), plasmonic and resonance chirality‐transfer ROA experiments. Some of them are not yet understood or attributed to instrumental artifacts so far. Nevertheless, these unknown territories also indicate the vast potential of the chiroptical spectroscopy, and their investigation is even more challenging.
Comparative analysis of seed proteome of Glycine max and Glycine soja
Authors: Hashiguchi Takuyu , Hashiguchi Masatsugu , Tanaka Hidenori , Gondo Takahiro , Akashi Ryo
Published: February 2020

Soybean, a globally important grain legume, contains large amounts of proteins, lipids, and secondary metabolites and, when ingested, has a wide array of physiological functions that may improve human health. In the development of cultivated soybean [Glycine max (L.) Merr.] with improved abiotic and biotic stress resistance, high yield, and seed quality, wild soybean (Glycine soja Siebold & Zucc.) has been an excellent source of germplasm, owing to its genetic diversity. Although genomic differences between the two species have been intensively studied, the differences in seed protein expression remain poorly understood. In the present study, we used a shotgun proteomic comparative analysis approach to further characterize the seed proteome in cultivated and wild soybean. Protamine sulfate‐mediated precipitation successfully decreased the levels of two major proteins that had previously masked the detection of low‐abundant proteins. We identified 65 differentially expressed proteins between the two species, with 39 proteins expressed more highly in G. soja and 26 proteins expressed more highly in G. max. Among these proteins, various stress tolerance‐related proteins were found in wild soybean, perhaps reflecting its adaptation to diverse ecological conditions. Cultivated soybean expressed high levels of sucrose and lipid biosynthesis proteins, and this was also confirmed at the transcriptional level. Bioinformatic analyses revealed that cellular and metabolic process was the functional category most frequently linked to the differentially expressed proteins. These data provide valuable information that will contribute to a better understanding of soybean seed biology and help to promote G. max breeding for improved agronomic traits using wild relatives.
Blue Chemistry. Marine Polysaccharide Biopolymers in Asymmetric Catalysis: Challenges and Opportunities
Authors: Aguilera Daniel Antonio , Tanchoux Nathalie , Fochi Mariafrancesca , Bernardi Luca
Published: February 2020

Alginate, chitin (precursor of chitosan), and carrageenan are natural polysaccharides derived from marine sources and available in nearly unlimited amounts. In contrast with other natural polysaccharides (i.e. cellulose), their monomers bear functional groups (amine, carboxylate, sulfate). These functional groups can be used to anchor catalytic species, or even as catalytically active units. In this mini‐review, the utilization of marine polysaccharides in asymmetric catalysis is discussed. Examples include: i) combinations with chiral catalysts, resulting in heterogeneous catalytic systems, and ii) utilization of the biopolymers as chirality inducing elements – serving as chiral ligands or organocatalysts. The reviewed works propose innovative and unconventional utilizations of these renewable materials, providing not only a useful alternative to oil‐based polymers, but also unforeseen and fascinating opportunities in the field of asymmetric catalysis.
Recent Advances in the Catalytic Dearomatization of Naphthols
Authors: An Juzeng , Bandini Marco
Published: February 2020

The catalytic dearomatization of naphthols offers a unique platform to rapidly access structurally complex and densely functionalized molecular architectures. Thermodynamically more favorable, with respect to the analogous phenol‐variant, the transformation of the phenolic ring into the corresponding naphthalenone (cited here as naphthyl dearomatization) has faced a considerable amount of attention over the past decade with constant improvements towards stereocontrol. A collection of the most representative and recent catalytic variants involving carbon–carbon as well as carbon–heteroatom bond forming events are presented in thisMinireviewarticle.
High‐throughput microscale extraction using ionic liquids and derivatives: A review
Authors: Trujillo‐Rodríguez María J. , Pino Verónica , Miró Manuel
Published: February 2020

Ionic liquids and derivatives—mainly polymeric ionic liquids and magnetic ionic liquids—have been extensively used in microscale extraction over the past few years. Current trends in analytical sample preparation gear toward linking microextraction approaches with high‐throughput sample processing to comply with green analytical chemistry requirements. A variety of high sample throughput strategies that are coupled to both ionic‐liquid‐based solid‐phase microextraction and ionic liquid‐based liquid‐phase microextraction are herein reported. The review is focused on microscale extraction methods that use (i) custom‐made and dedicated extraction devices, (ii) parallel extraction, (iii) magnetic‐based separation, and (iv) miniaturized systems employing semi‐automatic or fully automatic flow injection methods, related micro/millifluidic devices, and robotic equipment.
Improvement of microstructure and properties of air‐cooled 46MnVS5 forging steel rod for fracture splitting connecting by thermomechanical control process (TMCP) and by niobium micro alloying
Authors: Zhang W. , Fang W. , Zhang C. , Ma X. , Li J.
Published: February 2020

Microstructure control and properties of air‐cooled high‐strength 46MnVS5 forging steel rod for fracture splitting connecting were systematically investigated by quantitative metallographic analysis, thermomechanical simulation and industrial trials etc. The results indicate that the critical cooling rate for bainite transformation in the steel is about 1.5 °C/s–2 °C/s during continuous cooling. Cooling parameters are optimized in two sections. That is, the specimen is firstly cooled to 750 °C at a rate of 4 °C/s, then continuously cooled to 570 °C at 1 °C/s, 1.5 °C/s. Addition of 0.024 wt.% niobium improves the fracture splitting performance by 10 %–20 % reduction of decarburization sensitivity. Finally, the optimized parameters for the niobium micro alloyed steel in the laboratory were successfully applied to produce the connecting rod with excellent fracture splitting performance on the traditional production line.
Prediction of hardness of stir cast LM13 aluminum alloy ‐ copper coated short steel fiber reinforced composites using response surface methodology
Authors: Chelladurai S.J.S. , Arthanari R.
Published: February 2020

Copper coated steel fibers reinforced LM13 aluminum alloy composites have been prepared using stir casting process. Experiments have been designed using response surface methodology (RSM) by varying wt % of reinforcement (0–10), stirrer speed (350 min−1–800 min−1) and pouring temperature (700 °C–800 °C). Microstructure and hardness of composites have been investigated. Analysis of variance, significance test and confirmation tests have been performed and regressions model has been developed to predict the hardness of composites. Response surface plots reveal that hardness of composites increases with increasing wt % of reinforcement and stirrer speed. The optimum stir cast process parameters for obtaining higher hardness are found to be the wt % of reinforcement of 8.2, pouring temperature of 748 °C and stirrer speed of 708 min−1.
VHF band spaceborne element rotation angle controlled phased antenna array for SAT‐AIS application
Authors: Xue Kai , Liao Shaowei , Xue Quan , Ding Liqin , Wang Yang , Guo Qing
Published: February 2020

A novel very‐high frequency (VHF) band spaceborne phased antenna array for satellite‐automatic identification system/VHF data exchange (SAT‐AIS/VDE) applications operating at 159 MHz is proposed in this letter. Element phase shifting is achieved by controlling each element mechanical rotation angle rather than the phase shifter behind each element. Thanks to the new working scheme, the proposed array shows several advantages over its former counterpart, including low cost, high power capacity, and broad phase‐shifting bandwidth. This letter explains the basic principle, and presents a preliminary study on element rotation angle controlled phased antenna array technology, and an eight‐element‐array which is implemented on solar panel supporting plate is designed to validate the concept.
A locally segmented reconstruction method for parallel imaging
Authors: So Seohee , Seo Hyunseok , Park HyunWook
Published: February 2020

Purpose

A locally segmented parallel imaging reconstruction method is proposed that efficiently utilizes sensitivity distribution of multichannel receiver coil.

Theory and Methods

A method of locally segmenting a MR signal is introduced to maximize the differences in sensitivity between receiver channels. A 1D Fourier transformation of the undersampled k‐space data is performed along the readout direction, which generates a hybrid 2D space. The hybrid space is partitioned into localized segments along the readout direction. In every localized segment, kernels representing relation between adjacent signals are estimated from autocalibration signals, and data at unsampled points are estimated using the kernels. Then, the images are reconstructed from full k‐space data that consists of the sampled data and the estimated data at unsampled points.

Results

In a computer simulation and in vivo experiments, the locally segmented reconstruction method produced fewer residual artifacts compared to the conventional parallel imaging reconstruction methods with the same kernel geometry. The performance gain of the proposed method comes from maximizing encoding capability of receiver channels, thus resulting in the accurately estimated kernel weights that reflect the relation between adjacent signals.

Conclusion

The proposed spatial segmentation method maximally utilizes differences in the sensitivity of receiver channels to reconstruct images with reduced artifacts.
Translating Cancer Molecular Variability into Personalized Information Using Bulk and Single Cell Approaches
Authors: Kravchenko‐Balasha Nataly
Published: February 2020

Cancer research is striving toward new frontiers of assigning the correct personalized drug(s) to a given patient. However, extensive tumor heterogeneity poses a major obstacle. Tumors of the same type often respond differently to therapy, due to patient‐specific molecular aberrations and/or untargeted tumor subpopulations. It is frequently not possible to determine a priori which patients will respond to a certain therapy or how an efficient patient‐specific combined therapy should be designed. Large‐scale datasets have been growing at an accelerated pace and various technologies and analytical tools for single cell and bulk level analyses are being developed to extract significant individualized signals from such heterogeneous data. However, personalized therapies that dramatically alter the course of the disease remain scarce, and most tumors still respond poorly to medical care. In this review, the basic concepts of bulk and single cell approaches are discussed, as well as their emerging role in individualized designs of drug therapies, including the advantages and limitations of their applications in personalized medicine.
Tumor Microenvironment Adaptable Nanoplatform for O2 Self‐Sufficient Chemo/Photodynamic Combination Therapy
Authors: Li Shi‐Ying , Zhao Lin‐Ping , Zheng Rong‐Rong , Fan Gui‐Ling , Liu Ling‐Shan , Zhou Xiang , Chen Xian‐Tong , Qiu Xiao‐Zhong , Yu Xi‐Yong , Cheng Hong
Published: February 2020

Malignant proliferation of tumor cells induces abnormal tissue microenvironments, leading to therapeutic resistance and poor therapeutic outcome. In this paper, manganese dioxide (MnO2) nanoshells are coated on a porphyrinic metal–organic framework of porous coordination network (PCN)‐224 for doxorubicin (DOX) loading and hyaluronic acid (HA) modification to obtain an intelligent nanoplatform of PCN@MnO2@DOX@HA (PMDH). Benefiting from the HA functionalization, PMDH prefers to accumulate in tumor sites and enhance the cellular uptake by CD44‐overexpressed tumor cells. Subsequently, the internalized PMDH could catalyze the abundant H2O2 in cells into O2 to relieve tumor hypoxia. Further, the MnO2 nanoshells of PMDH could be degraded into Mn2+ for magnetic resonance imaging with glutathione reduction and the release of DOX. By integrating the O2 self‐sufficiency with glutathione reduction abilities, PMDH possesses highly potent chemo/photodynamic combination therapeutic effects against hypoxic tumors. Significantly, PMDH exhibits a good biocompatibility with a low cardiotoxicity and negligible systemic side effects, which provides a new insight in developing tumor microenvironment adaptable nanoplatforms for synergistic tumor theranostics.
Electrical Properties of La2−xCexTi2O7 (x = 0–0.1) Ceramics
Authors: Li Yueyi , Jiang Laiming , Jiao Zhifeng , Liang Dayun , Chen Qiang , Zhu Jianguo
Published: February 2020

As an important functional material, the applications of piezoelectric materials have shifted from convenient use to service in extreme environments. Herein, a new layered high‐temperature ceramic La2Ti2O7 (LTO) with the substitution of La3+ ions by Ce3+ ions at A sites is designed and synthesized using the conventional solid‐state sintering technology. The effects of dopant Ce3+ ions on the microstructure, phase structure, and electrical properties of LTO are investigated methodically. Moderate dopant Ce3+ ions decrease the concentration of thermions in LTO ceramics, but excess dopant Ce3+ ions can lead to cell distortions, which have some relationships with defects. Through analysis, the La1.95Ce0.05Ti2O7 (LCTO‐0.05) ceramics with a pure monoclinic phase possess optimal electrical properties. At 650 °C, the enhanced fitted direct current (DC) resistivity of the LCTO‐0.05 ceramics is 1.5 × 106 Ω cm. The activation energy of conductivity and relaxation activation energy of imaginary impedance Z″ for LCTO‐0.05 ceramics are 1.12 and 1.16 eV, respectively, in the high‐temperature regime. The piezoelectric coefficient d33 of LCTO‐0.05 ceramics is up to 3.6 pCN−1. It is believed that this ceramic system promotes the development of LTO‐based high‐temperature piezoelectric ceramics.
Improving the Luminescent Properties of Atomic Layer Deposition Eu:Y2O3 Thin Films through Optimized Thermal Annealing
Authors: Scarafagio Marion , Tallaire Alexandre , Chavanne Marie-Hélène , Cassir Michel , Ringuedé Armelle , Serrano Diana , Goldner Philippe , Ferrier Alban
Published: February 2020

Crystalline rare‐earth (RE)‐doped Y2O3 films are an attractive system for a wide range of photonics applications including quantum technologies which aim at harnessing optical or spin transitions with long coherence times to achieve new functionalities such as quantum storage or information processing. Herein, atomic layer deposition (ALD) of Eu‐doped Y2O3 thin films with improved optical properties is presented. A crucial post‐treatment step to obtain high‐quality films is annealing at elevated temperatures (>900 °C). However, the main drawback of this approach is the formation of unwanted parasitic phases due to reaction at the interface with the substrate, especially with silicon. In this article, this issue is discussed for different kinds of substrates and buffer layers. The use of such modified substrates allows advantageously extending the maximum thermal treatment up to 1150 °C without being limited by interface reactions. It is demonstrated that the emission of the 5D0 → 7F2 transition for Eu3+ in Y2O3 film can be as narrow as that of bulk materials when optimized thermal treatments and a thin undoped Y2O3 buffer layer are used. Thus, a versatile method to reduce the impact of the substrate–film interface on the optical properties is proposed.
Matrine triggers colon cancer cell apoptosis and G0/G1 cell cycle arrest via mediation of microRNA‐22
Authors: Liu Jiao , Guo Yazhuo , Cao Jing
Published: February 2020

Matrine (MAT) is an alkaloid in the dried roots of Sophora flavescens. The antitumor activity has been testified in colon cancer. Howbeit, the latent mechanism is still indistinct. The research probed the antitumor mechanism of MAT in colon cancer cells. MAT (0.25, 0.5, 0.75, 1, and 1.25 mM) was utilized to stimulate SW480 and SW620 cells for 24, 48, and 72 hr. Cell viability, apoptosis, cell cycle, and the correlative proteins were assessed via Cell Counting Kit‐8, flow cytometry, and Western blot. microRNA‐22 (miR‐22) in MAT‐treated or miR‐22‐silenced cells was estimated via real‐time quantitative polymerase chain reaction. The functions of miR‐22 inhibition were reassessed. Western blot was conducted for quantifying β‐catenin, MEK, and ERK. Luciferase reporter assay was done for confirming the targeting relationship between miR‐22 and ERBB3 or MECOM. MAT prohibited cell viability, accelerated apoptosis, and triggered cells cycle stagnation at G0/G1 phase. Additionally, miR‐22 was elevated by MAT; meanwhile, the influences of MAT were all inverted by miR‐22 inhibitor. MAT enhanced the expression of miR‐22, thereby obstructing Wnt/β‐catenin and MEK/ERK pathways. miR‐22 had a potential to target mRNA 3'UTR of ERBB3 and MECOM. These discoveries manifested that MAT could evoke colon cancer cell apoptosis and G0/G1 cell cycle arrest via elevating miR‐22.
Silicone pneumonitis after gluteal filler: a case report and literature review
Authors: Ng Boon Hau , Mat Wan Rahiza Wan , Abeed Nik Nuratiqah Nik , Hamid Mohamed Faisal Abdul , Yu‐Lin Andrea Ban , Soo Chun Ian
Published: February 2020

Liquid silicone (polydimethylsiloxane) is an inert material that is commonly used for cosmetic purpose. Silicone embolization syndrome (SES) can rapidly progress to pneumonitis as a consequence of the injection of nonmedical‐grade liquid silicone. We describe a case of severe silicone pneumonitis complicated with acute respiratory distress syndrome and bilateral pneumothorax secondary to silicone gluteal augmentation. In this case report, we aim to discuss our experience and approach in managing an uncommon case of SES.
From emotional exhaustion to cynicism in academic burnout among Korean high school students: Focusing on the mediation effects of hatred of academic work
Authors: Lee Minyoung , Lee Kyeong‐Joo , Lee Sang M. , Cho Soohyun
Published: February 2020

This study aimed to investigate the effect of academic hatred, referring to the hatred of academic work, on the developmental process of the core dimensions of academic burnout, namely, emotional exhaustion and cynicism. Data were collected from 1015 (57.3% female) senior high school students in South Korea. The results showed that emotional exhaustion, cynicism and academic hatred were stable across three waves. An autoregressive cross‐lagged model showed that emotional exhaustion was predictive of future academic hatred, which in turn was associated with future cynicism. Significant mediation pathways were also identified, with academic hatred mediating the longitudinal link between emotional exhaustion and cynicism. This longitudinal study can strengthen the understanding of academic hatred within the developmental process of academic burnout. The theoretical and practical implications of these findings are discussed.
Just urban transitions: Toward a research agenda
Authors: Hughes Sara , Hoffmann Matthew
Published: February 2020

While there are excellent policy and academic foundations for thinking about and making sense of urban climate action and questions of justice and climate change independently, there is less work that considers their intersection. The nature and dynamics of, and requirements for, a just urban transition (JUT)—the fusion of climate action and justice concerns at the urban scale—are not well understood. In this review article we seek to rectify this by first examining the different strains of justice scholarship (environmental, energy, climate, urban) that are informing and should inform JUT. We then turn to a discussion of just transitions in general, tracing the history of the term and current understandings in the literature. These two explorations provide a foundation for considering both scholarly and policy‐relevant JUT agendas. We identify what is still needed to know in order to recognize, study, and foster JUT.

This article is categorized under:

The Carbon Economy and Climate Mitigation > Benefits of Mitigation

Climate, Nature, and Ethics > Climate Change and Global Justice
Modular orbits at higher genus
Authors: Robbins Daniel , Vandermeulen Thomas
Published: February 2020

Abstract

We extend the modular orbits method of constructing a two-dimensional orbifold conformal field theory to higher genus Riemann surfaces. We find that partition functions on surfaces of arbitrary genus can be constructed by a straightforward generalization of the rules that one would apply to the torus. We demonstrate how one can use these higher genus objects to compute correlation functions and OPE coefficients in the underlying theory. In the case of orbifolds of free bosonic theories by subgroups of continuous symmetries, we can give the explicit results of our procedure for symmetric and asymmetric orbifolds by cyclic groups.
First attempt success of video versus direct laryngoscopy for endotracheal intubation by ambulance nurses: a prospective observational study
Authors: Breeman Wim , Van Vledder Mark G. , Verhofstad Michael H. J. , Visser Albert , Van Lieshout Esther M. M.
Published: February 2020

Purpose

The aim of this study was to compare the rate of first attempt success of endotracheal intubation performed by ambulance nurses in patients with a Glasgow Coma Scale (GCS)  of 3 using video laryngoscopy versus direct laryngoscopy.

Methods

A prospective cohort study was conducted in a single, independent ambulance service. Twenty of a total of 65 nurse-staffed ambulances were equipped with a video laryngoscope; a classic direct laryngoscope (Macintosh) was available on all 65 ambulances. The primary outcome was first attempt success of the intubation. Secondary outcomes were overall success, time needed for intubation, adverse events, technical or environmental issues encountered, and return of spontaneous circulation (ROSC). Ambulance nurses were asked if the intubation device had affected the outcome of the intubation.

Results

The first attempt success rate in the video laryngoscopy group [53 of 93 attempts (57%)] did not differ from that in the direct laryngoscopy group [61 of 126 (48%); p = 0.221]. However, the second attempt success rate was higher in the video laryngoscopy group [77/93 (83%) versus 80/126 (63%), p = 0.002]. The median time needed for the intubation (53 versus 56 s) was similar in both groups. Ambulance nurses more often expected a positive effect when performing endotracheal intubation with a video laryngoscope (n = 72, 81%) compared with a direct laryngoscope (n = 49, 52%; p < 0.001).

Conclusion

Although no significant effect on the first attempt success was found, video laryngoscopy did increase the overall success rate. Ambulance nurses had a more positive valuation of the video laryngoscope with respect to success chances.