bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical investigation into coordination and selectivity of uranyl‐unilateral benzotriazole salophens (X = O/S) for R/S‐triadimefons
Authors: Sun Wei‐Zhen , Dai Lin‐Lin , Kong Xiang‐He , Mao Yu , Wu Zhi‐Lin , Liao Li‐Fu , Xiao Xi‐Lin , Nie Chang‐Ming
Published: January 2020

The design of new uranyl‐ligands (uranyl‐Ls) is of great significance for the separation and utilization of uranium. In this paper, the triazole group was introduced into uranyl‐salophen (uranyl‐S) to form new asymmetric uranyl‐unilateral benzotriazole salophen (uranyl‐UBS); we further replaced two oxygen atoms of uranyl‐UBS with two sulfur atoms to generate uranyl‐unilateral benzotriazole thio‐salophen (uranyl‐UBTS) as a new receptor. Then, we comprehensively explored coordination models of uranyl‐UBS and uranyl‐UBTS with R/S‐triadimefons (R/S‐TDFs) enantiomers as the guests using density functional theory calculations at the B3LYP//RECP/6‐311G** level; we then investigated enantioselectivity recognition of the new receptors to the guests R/S‐TDFs. The results indicated that the uranium atoms of the receptors uranyl‐S, uranyl‐UBS and uranyl‐UBTS could coordinate with the carbonyl oxygens in guests R/S‐TDFs to form complexes of guest‐receptors R/S‐TDFs‐uranyl‐Ls that exhibited two stable V‐shaped structures with quite different properties. It was found that the coordination ability to the guests R/S‐TDFs is uranyl‐UBTS > uranyl‐UBS > uranyl‐S, while the enantioselectivity for the guests is uranyl‐UBTS > uranyl‐S > uranyl‐UBS and, when the receptor is the same, R‐TDF has stronger coordination ability than S‐TDF. These results provide information and theoretical supports for the experiments of asymmetric uranyl‐UBS with R/S‐TDFs, and produce a reference for further exploring the coordination characteristics of asymmetric uranyl‐salophen with the triazole derivatives.
X‐ray structure of host‐guest nanosized organotin supramolecular coordination polymer based on cobalt cyanide and quinoxaline as an efficient catalyst for treatment of waste water
Authors: Etaiw Safaa Eldin H. , Abd El‐Aziz Dina M. , Shalaby Elsayed M. , Elzeny Islam
Published: January 2020

New host‐guest supramolecular coordination polymer catalyst 3∞[Co(μ2CN)5(CN)(μ2‐Me3Sn)2(Me3Sn)(H2O)(qox)], SCP1 (qox = quinoxaline) has been synthesized and characterized by single crystal X‐ray diffraction, FT‐IR, UV/Visible and fluorescence spectra, thermal and elemental analyses. The tin atoms act as bridges connecting the Co (CN)6 building blocks. The structure of SCP1 exhibits an unusual self‐coordinated host‐guest 3D network with qox as guest molecule. Also, the nanosized1\ was prepared under ultrasonic irradiation while the morphological features of both were examined by TEM and SEM. SCP1 and nanosized1\ are used as heterogeneous catalysts for removal of toxic dyes under UV and ultrasonic irradiation. The results show high effectively decolorized of indigo carmine dye (IC) without generation of any hazardous wastes or byproducts. The reaction is first order with respect to IC, while the factors affecting the rate constant of the degradation reaction are investigated. Mineralization of IC was investigated by IR and UV spectra. The trapping experiments were carried out to determine the role of active species used for degradation of the dye. The activation parameters of the reaction have been estimated and a possible mechanism of degradation was proposed and discussed in detail.
Regulation of natural convection heat transfer for SiO2–solar salt nanofluids by optimizing rectangular vessels design
Authors: Hu Yanwei , Zhang Borui , Tan Kaiyu , He Yurong , Zhu Jiaqi
Published: January 2020

Natural convection heat transfer of molten salt is widely used in concentrated solar plants, such as the solar receiver, the single‐tank thermal energy storage system, and so forth. Meanwhile, adding nanoparticles into molten salts to form nanofluids can obviously improve the thermal properties of the working medium. However, the heat transfer performance of the molten salt‐based nanofluids has not been investigated extensively, and the action mechanism between base fluids and nanoparticles is still unclear. In the present work, a lattice Boltzmann model considering fluid and nanoparticles as two different phases was developed, and various interactions were taken into consideration. Meanwhile, the effects of nanoparticle concentrations, aspect ratios of the rectangular vessel, and Ra on natural convection heat transfer of solar salt‐based SiO2 nanofluids were analysed. The results show that specific heat capacity contributes substantially to heat transfer for all aspect ratios, and the maximum enhancement of natural convection heat transfer is obtained with a mass fraction of 1.0%. However, increase in Ra intensifies the effect of viscosity and weakens the heat transfer enhancement. Through interaction analysis, it indicated that nanoparticles tend to be driven to the top area of the rectangular vessel by temperature difference, driving force, and drag force. Meanwhile, a Nu enhancement contour was provided to optimize the design of a single energy storage tank.
Photodegradation of low‐density polyethylene with prooxidant and photocatalyst
Authors: Gharehdashli Abdolnaser , Mortazavi Saeed , Rashidi Hamed
Published: January 2020

Low‐density polyethylene (LDPE) composite films with trisilver phosphate (Ag3PO4) and cadmium selenide (CdSe) particles as photocatalysts and manganese stearate as prooxidant were prepared. The film samples were irradiated under UV and visible light and their photodegradation were evaluated using Fourier‐transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. The carbonyl index of the photocatalyst containing samples was very higher than the pure irradiated LDPE and even prooxidant containing film. The morphologies of the irradiated composite films were completely changed and had many cavities and cracks. The thermal stability of the composites was very lower than the pure polyethylene. However the crystallinity of the LDPE films with photocatalysts was enhanced contrarily the LDPE film with manganese stearate. Generally the results showed that the combination of the prooxidant with photocatalyst have synergistic effect on the photodegradation of the LDPE and can be used to accelerate the degradation of the polyethylene films.
Preparation and characterization of cyclodextrin microencapsulated ammonium polyphosphate and its application in flame retardant polypropylene
Authors: Ding Siyin , Liu Peng , Zhang Shimin , Ding Yanfen , Wang Feng , Gao Chong , Yang Mingshu
Published: January 2020

A novel microencapsulated ammonium polyphosphate (MAPP) with shell of crosslinked β‐cyclodextrin (HDI‐CD) was prepared. The HDI‐CD shell had a fibrous structure and covered with good completeness on the APP core, and a solid chemical bonding was found between the APP core and HDI‐CD shell. The microcapsules were more hydrophobic than the pristine APP. When compounded within polypropylene (PP), the MAPP exhibited good compatibility and dispersibility. The combustion testing results showed that the novel all‐in‐one intumescent flame retardant had efficient flame retardancy for PP materials.
Seasonal phenotype‐specific expression of microRNAs during metamorphosis in the European map butterfly Araschnia levana
Authors: Mukherjee Krishnendu , Baudach Arne , Vogel Heiko , Vilcinskas Andreas
Published: January 2020

The European map butterfly (Araschnia levana) is a well‐known example of seasonal polyphenism because the spring and summer imagoes exhibit distinct morphological phenotypes. The day length and temperature during larval and prepupal development determine whether spring or summer imagoes emerge after metamorphosis. Inspired by the fundamentally different transcriptomic profiles in prepupae developing from larvae exposed to long days or short days, we postulate that posttranscriptional epigenetic regulators such as microRNAs (miRNAs) may contribute to the epigenetic control of seasonal polyphenism in A. levana. To test this hypothesis, we used microarrays containing over 2,000 insect miRNAs to identify candidate regulators that are differentially expressed in last‐instar larvae or pupae developing under long‐day or short‐day conditions. We used our transcriptomic database to identify potential 3′‐untranslated regions of messenger RNAs to predict miRNA targets by considering both base pair complementarity and minimum free energy hybridization. This approach resulted in the identification of multiple targets of miRNAs that were differentially regulated in polyphenic morphs of A. levana including a candidate (miR‐2856‐3p) regulating the previously identified diapause bioclock protein gene. In conclusion, the expression profiling of miRNAs provided insights into their possible involvement in seasonal polyphenism of A. levana and offer an important resource for further studies.
Coronary total occlusion and minimalist approach: When less is more
Authors: Musumeci Giuseppe , Baralis Giorgio
Published: January 2020

Key Points

The minimalistic hybrid algorithm is a possible alternative sequence of steps in the setting of coronary total occlusion (CTO) recanalization.

A fully transradial approach in CTO is a valid alternative to transfemoral approach with a high rate of success.

A minimalistic hybrid algorithm maintains all the available possible options for crossing the CTO lesions.
Mid‐term results of in situ fenestration stented with balloon‐expandable bare metal stents during thoracic endovascular aortic repair
Authors: Bai Jun , Liu Yandong , Jin Jie , Wu Jianjin , Qu Lefeng
Published: January 2020

Purpose

To assess the safety, feasibility and effectiveness of balloon‐expandable bare metal stents (BMS) as bridge stents during thoracic endovascular aortic repair (TEVAR).

Materials and Methods

Retrospective analysis was conducted on 103 consecutive patients who underwent TEVAR procedures from December 2015 to March 2018. Thirty‐one patients fulfilled requirements for inclusion and exclusion in the analysis. Thirty‐three in situ fenestration (ISF) procedures (single fenestration [n = 29]; dual fenestration [n = 2]) were performed in the 31 patients (67.7% men; median age, 61.5 year) who underwent TEVAR for thoracic lesions (aortic dissection [n = 23], aortic aneurysm [n = 3], aortic ulcer [n = 5]) with 34 stents (33 balloon‐expandable BMS, 1 covered stents) implanted in supraaortic arteries. The success rate of overall intervention, fenestration, and implantation of BMS was recorded. The therapeutic effects and complications during admission and follow‐up (median 29.7 months, range 18–45 months) were the primary outcomes.

Results

The technical success rate was 90.3% (28/31). All thoracic lesions were totally excluded. Major complications (6.5%) were one dissection in the left subclavian artery (n = 1) and thrombus formation (n = 1). Minor complications (12.9%) were hematoma (n = 1), and type III endoleak (n = 3). During follow‐up, no endoleak developed and all fenestrated branch arteries were patent, except for one left subclavian artery dissection and occlusion.

Conclusions

Use of balloon‐expandable BMS in ISF is safe and effective in reconstruction of supraarotic arteries during TEVAR.
Epitaxial Cubic Silicon Carbide Photocathodes for Visible‐Light‐Driven Water Splitting
Authors: Han Xiuxiu , Heuser Steffen , Tong Xili , Yang Nianjun , Guo Xiang‐Yun , Jiang Xin
Published: January 2020

Cubic silicon carbide (3C‐SiC) material feature a suitable bandgap and high resistance to photocorrosion. Thus, it has been emerged as a promising semiconductor for hydrogen evolution. Here, the relationship between the photoelectrochemical properties and the microstructures of different SiC materials is demonstrated. For visible‐light‐derived water splitting to hydrogen production, nanocrystalline, microcrystalline and epitaxial (001) 3C‐SiC films are applied as the photocathodes. The epitaxial 3C‐SiC film presents the highest photoelectrochemical activity for hydrogen evolution, because of its perfect (001) orientation, high phase purity, low resistance, and negative conduction band energy level. This finding offers a strategy to design SiC‐based photocathodes with superior photoelectrochemical performances.
Zeit und Budget einhalten
Authors: Dörges Barbara
Published: January 2020

Aveva optimiert Investitionsprojekte durch die Integration von Engineering, Projektabwicklung und Auslieferung in das operative Geschäft
Sicherheitslücke geschlossen
Authors: Schäfer Bernd , Terentiev Alexandre
Published: January 2020

Die Digitalisierung von Feldgeräten bietet Anlagenbetreibern riesiges Potential, um die Betriebskosten zu senken und die Produktivität zu steigern. Highway Addressable Remote Transducer (HART) basierte Feldgeräte bergen jedoch nicht unerhebliche Risiken d
Wie schütze ich was?
Authors: Frigger Anja
Published: January 2020

Explosionsfähige Atmosphären treten meist in verfahrenstechnischen Anlagen auf. Wie welche Anlagenteile optimal geschützt werden, wird in diesem Beitrag erläutert.
An erster Stelle steht die Sicherheit im Prozess
Authors: Sienk Thorsten
Published: January 2020

Für die Förderung von Staub und Gas gehört der Ex‐Schutz innerhalb der unterschiedlichen Atex‐Zonen bei der Aerzener Maschinenfabrik, einem Spezialisten in der Gebläse‐ und Verdichtertechnik, zur täglichen Praxis. Welche Einzelmaßnahmen zu einem Rundumschutz führen, fasst dieser Beitrag zusammen.
Frequent KRAS and HRAS mutations in squamous cell papillomas of the head and neck
Authors: Sasaki Eiichi , Masago Katsuhiro , Fujita Shiro , Hanai Nobuhiro , Yatabe Yasushi
Published: January 2020

Squamous cell papilloma (SCP) is a benign neoplasm of the head and neck. Human papillomavirus (HPV) has been reported to be a tumourigenic factor for SCP. However, not all SCPs are positive for HPV, suggesting that other possible mechanisms are involved in their development. In this study, we examined the mutational status of 51 SCPs using targeted panel sequencing in addition to HPV status using GP5+/GP6+ PCR. HPV DNA was detected in 6 (12%) SCPs, while KRAS and HRAS mutations were detected in 18 (35%) and 17 (33%) SCPs, respectively. Notably, KRAS mutations, HRAS mutations and HPV infection were mutually exclusive. The larynx and trachea (4/7, 57%) were more preferentially infected by HPV than the other sites (2/44, 5%, p = 0.0019) and HPV was associated with multifocal development (4/5, 80%). In contrast, KRAS and HRAS mutations in SCPs were evenly distributed across the anatomical sites and found only in single SCPs. In conclusion, this study demonstrated that HPV was not frequently involved in SCPs and that RAS mutations were more common alterations. In contrast to inverted sinonasal papillomas and oncocytic sinonasal papillomas, SCP may not be a precursor lesion of carcinoma, because these aetiological events in SCP are distinct from squamous cell carcinoma in the same sites.
Color measurement of single yarn based on hyperspectral imaging system
Authors: Zhang Jianxin , Wu Junkai , Zhang Xinen , Hu Xudong
Published: January 2020

This article proposed a novel approach to color measurement of a single yarn using hyperspectral imaging system (HIS). Due to the size of a single yarn, it is impossible for spectrophotometers to measure its color directly. The HIS can acquire the spectral reflectance of continuous bands within a region of interest on a yarn sample, which can achieve color measurement of a single yarn compared with traditional spectrophotometers. A single yarn is segmented from the background by a spectral matching method through adaptively setting threshold of Fréchet distance values. The spectral reflectance of single yarn is specified by a method that lightness of pixels used as weight. The experiment based on Pantone Cotton Chip Set shows that the interinstrument agreement between the HIS and a standard spectrophotometer Datacolor SF650 has a significant improvement after using the R‐Model, and the average percentage improvement of the color difference is up to 54.99%. The yarn segmentation comparative experimental results show that the proposed method to segment single yarn from background is better in retaining the edge information of the yarn than the modified K‐means clustering method, and the color of the yarn segmented by the proposed method is more similar to the actual color of single yarn.
Rapid recovery of ecosystem function following extreme drought in a South African savanna grassland
Authors: Wilcox Kevin R. , Koerner Sally E. , Hoover David L. , Borkenhagen Andrea K. , Burkepile Deron E. , Collins Scott L. , Hoffman Ava M. , Kirkman Kevin P. , Knapp Alan K. , Strydom Tercia , Thompson Dave I. , Smith Melinda D.
Published: January 2020

Climatic extremes, such as severe drought, are expected to increase in frequency and magnitude with climate change. Thus, identifying mechanisms of resilience is critical to predicting the vulnerability of ecosystems. An exceptional drought (<first percentile) impacted much of southern Africa during the 2015 and 2016 growing seasons, including the site of a long‐term fire experiment in Kruger National Park, South Africa. Prior to the drought, experimental fire frequencies (annual, triennial, and unburned) created savanna grassland plant communities that differed in composition and function, providing a unique opportunity to assess ecosystem resilience mechanisms under different fire regimes. Surprisingly, aboveground net primary productivity (ANPP) recovered fully in all fire frequencies the year after this exceptional drought. In burned sites, resilience was due mostly to annual forb ANPP compensating for reduced grass ANPP. In unburned sites, resilience of total and grass ANPP was due to subdominant annual and perennial grass species facilitating recovery in ANPP after mortality of other common grasses. This was possible because of high evenness among grass species in unburned sites predrought. These findings highlight the importance of both functional diversity and within‐functional group evenness as mechanisms of ecosystem resilience to extreme drought.
Joining High Coloration and Fast Color Fading with Photochromic Fused‐Naphthopyrans
Authors: Sousa Céu M. , Coelho Paulo J.
Published: January 2020

An easy synthesis of photochromic naphthopyrans with a lactone ring linking the naphthalene core to the pyran double bond is described. UV irradiation (or exposure to sunlight) of these uncolored compounds provide a single photoisomer with an intense orange coloration that returns completely to the initial uncolored state much faster than common naphthopyrans used in commercial photochromic ophthalmic lenses. A polymeric uncolored material doped with one of these lactone‐fused naphthopyrans develops an intense orange coloration (ΔAbs = 0.73) when exposed to the UV light for 30 s, at room temperature, and returns to the uncolored state in just 1 min. The use of these photochromic compounds allows a faster adaptation of the material's coloration to the surrounding UV‐light intensity, without compromising the color intensity, an important feature to create high performance photochromic ophthalmic lenses.
Evaluating functional connectivity in a small agricultural catchment under contrasting flood events by using UAV
Authors: Calsamiglia Aleix , Gago Jorge , Garcia‐Comendador Julián , Bernat Josep Fortesa , Calvo‐Cases Adolfo , Estrany Joan
Published: January 2020

Concentrated erosion, a major feature of land degradation, represents a serious problem for soil and water resources management and a threat to ecosystems. Understanding the internal mechanisms (de‐)coupling sediment pathways can improve the management and resilience of catchments. In this study, concentrated erosion and deposition forms were mapped accurately through field and aerial unmanned aerial vehicle (UAV) campaigns, in order to assess the evolution of connectivity pathways over a series of three contrasted and consecutive flood events occurring between October 2016 and January 2017 (return period ranging from 0.5 to 25 years) in a small Mediterranean agricultural catchment (Can Revull, Mallorca, Spain; 1.4 km2). In addition, a morphometric index of connectivity (IC) was used to identify the potential trajectories of different concentrated erosion forms and deposition areas. IC predictions were calibrated by identifying the optimal critical thresholds, i.e. those most consistent with field observations after each of the events studied. The results found that the index performed well in predicting the occurrence and the length/area of the different type of landforms, giving kappa (κ) coefficients of variation ranging between 0.21 and 0.92 and linear correlations R2 between 0.33 and 0.72. The type of landform affected the correspondence of IC predictions and field observations, with lower thresholds the greater the magnitude of their associated geomorphic processes. Rainfall magnitude proved to be a very important factor controlling the development of erosion and deposition landforms, with large differences in length/area between the contrasted events. The evolution of the observed trajectories revealed feedback dynamics between the structural and functional connectivity of the catchment, in which morphological changes determined the spatial distribution of the processes’ activity in the successive events and vice versa. © 2020 John Wiley & Sons, Ltd.
The predictability of stock market volatility in emerging economies: Relative roles of local, regional, and global business cycles
Authors: Bouri Elie , Demirer Riza , Gupta Rangan , Sun Xiaojin
Published: January 2020

This paper explores the role of business cycle proxies, measured by the output gap at the global, regional, and local levels, as potential predictors of stock market volatility in the emerging BRICS nations. We observe that the emerging BRICS nations display a rather heterogeneous pattern when it comes to the relative role of idiosyncratic factors as a predictor of stock market volatility. While domestic output gap is found to capture significant predictive information for India and China particularly, the business cycles associated with emerging economies and the world in general are strongly important for the BRIC countries and weakly for South Africa, especially in the postglobal financial crisis era. The findings suggest that despite the increase in the financial integration of world capital markets, emerging economies can still bear significant exposures to idiosyncratic risk factors, an issue of high importance for the profitability of global diversification strategies.
Experimental investigation of smart carbonated water injection method in carbonates
Authors: Soleimani Payam , Shadizadeh Seyed Reza , Kharrat Riyaz
Published: January 2020

Enhanced oil recovery (EOR) has been noticed during recent years from reservoirs that are at the end of their life plateau or in which production has been declined. Two of these EOR methods are as follows: carbonated water and smart water injection. In carbonated water injection method, CO2‐contained water is injected in reservoirs in order to decrease free CO2 injection mobility, increase water viscosity, and store/remove produced greenhouse CO2 gas safely, and in smart water injection method, the ions in brine are modified in order to make controlled reactions with distributed ions on the surface of rock to cause more hydrocarbon recovery. In this paper, the combination of these two methods is investigated as hybrid smart carbonated water injection to find out the recovery factor change and effective mechanisms. Experimental core flooding setup is used for investigation of hybrid EOR injection applicability and mechanisms. Probable mechanisms are measured using different cores and five water samples are used for preparing carbonated water (at pressure of 2500 psi) including sea water (34 261 ppm), river water (1329 ppm), one of Iranian reservoir formation water (FW) (163 711 ppm), 10 times diluted FW (0.1 FW), and 100 times diluted FW (0.01 FW). The effect of both brine content and volume of CO2 is determined during hybrid EOR assessment. The main mechanisms activated including pH variation, oil swelling, oil viscosity reduction, ion concentration variation in brine and porous media, and wettability alteration have been investigated. Hybrid method resulted in highest recovery (70%) mainly due to ion exchange, wettability alteration, oil swelling, and permeability enhancement. In addition, type of salt concentration will affect recovery as 0.01 FW results in 8% and 16% additional oil recovery compared to sea and river waters, respectively. Coupling of CO2 and salts will increase recovery factor due to mechanisms activated by each of these factors as 0.01 FW results in 10% more oil recovery compared to FW. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.
Developmental trajectory of oligodendrocyte progenitor cells in the human brain revealed by single cell RNA sequencing
Authors: Perlman Kelly , Couturier Charles P. , Yaqubi Moein , Tanti Arnaud , Cui Qiao‐Ling , Pernin Florian , Stratton Jo Anne , Ragoussis Jiannis , Healy Luke , Petrecca Kevin , Dudley Roy , Srour Myriam , Hall Jeffrey A. , Kennedy Timothy E. , Mechawar Naguib , Antel Jack P.
Published: January 2020

Characterizing the developmental trajectory of oligodendrocyte progenitor cells (OPC) is of great interest given the importance of these cells in the remyelination process. However, studies of human OPC development remain limited by the availability of whole cell samples and material that encompasses a wide age range, including time of peak myelination. In this study, we apply single cell RNA sequencing to viable whole cells across the age span and link transcriptomic signatures of oligodendrocyte‐lineage cells with stage‐specific functional properties. Cells were isolated from surgical tissue samples of second‐trimester fetal, 2‐year‐old pediatric, 13‐year‐old adolescent, and adult donors by mechanical and enzymatic digestion, followed by percoll gradient centrifugation. Gene expression was analyzed using droplet‐based RNA sequencing (10X Chromium). Louvain clustering analysis identified three distinct cellular subpopulations based on 5,613 genes, comprised of an early OPC (e‐OPC) group, a late OPC group (l‐OPC), and a mature OL (MOL) group. Gene ontology terms enriched for e‐OPCs included cell cycle and development, for l‐OPCs included extracellular matrix and cell adhesion, and for MOLs included myelination and cytoskeleton. The e‐OPCs were mostly confined to the premyelinating fetal group, and the l‐OPCs were most highly represented in the pediatric age group, corresponding to the peak age of myelination. Cells expressing a signature characteristic of l‐OPCs were identified in the adult brain in situ using RNAScope. These findings highlight the transcriptomic variability in OL‐lineage cells before, during, and after peak myelination and contribute to identifying novel pathways required to achieve remyelination.
SPATIO‐TEMPORAL VARIATIONS OF SEVEN WEATHER VARIABLES IN IRAN: APPLICATION OF CRU TS AND GPCC DATA SETS†
Authors: Ababaei Behnam
Published: January 2020

Iran's climate‐sensitive agriculture and water resources are vulnerable to climate change and investigation of climatic trends helps in preparing adaptation strategies. Weather stations are sparsely distributed and access to complete weather data is limited. In such situations, gridded global/regional data sets are promising alternatives. Here, monthly time series of seven weather variables (i.e. monthly averages or monthly totals of daily values) were obtained from the Climatic Research Unit TS V4.01 and Global Precipitation Climatology Centre V7 gridded data sets in 675 grid cells covering the country and analysed over the periods 1957–1986 and 1987–2016 at annual, seasonal and monthly scales. Over the two periods and at a national scale, mean temperature has increased by 0.004 (P = 0.717) and 0.04 °C yr−1 (P = 0.000), while the diurnal temperature range has not significantly changed (P > 0.6). Annual total precipitation experienced an insignificant increase (0.81 mm yr−1; P = 0.666) over the first period but declined by 2.12 mm yr−1 (P = 0.041) over the second. Potential evapotranspiration (PET) has increased by 0.32 (P = 0.398) and 1.43 mm yr−1 (P = 0.015), respectively. Since 1987, significant increasing trends in temperature were detected all over the country. While significant increasing trends in annual precipitation were detected in the central regions and south‐west over the first period, decreasing trends prevailed during 1987–2016 in the south, southwest and east with winter being the largest contributor to annual trends. Over the last three decades, annual PET has increased mostly in the north‐west and south‐east while significant increasing trends were detected in 89% of grid cells, except in a few cells in the north‐east. Cloud cover, vapour pressure and frequency of frost days were also analysed. These results are crucial for policy‐makers, researchers and engineers in the country and internationally who usually base their decisions and designs on outdated data sparsely distributed in space. © 2020 John Wiley & Sons, Ltd.
Retracted: The promoting effect of MMP13 on mediating the development of HFLS‐RA by the target of miR‐19a through IL‐17 signaling pathway
Authors: Su Jiang , Zhang Jing , Zhu Jing , Liu Yi
Published: January 2020

By investigating the expression profiles of miR‐19a and metalloproteinases (MMP13) in human fibroblast‐like synoviocytes‐rheumatoid arthritis (HFLS‐RA) and HFL cells lines, this study intends to confirm the directly target connection between them and reveal the effect of suppressing MMP13 on HLFS‐RA migration, invasion and apoptosis. After screening the abnormal expressed messenger RNAs and microRNAs in synovial tissues of patients with RA, the underlying pathway was determined by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The HFLS‐RA cell line was transfected for the following experiments with pcDNA3.1(+) served as vector. The directly target association between miR‐19a and MMP13 was confirmed by Luciferase reporter assay. Microarray analysis suggested that MMP13 was upregulated while miR‐19a was downregulated in HFLS of RA tissues compared with the healthy control group. MMP13 was related to many proteins in protein‐protein interaction network, which might be the main influencing factor of RA. KEGG pathway analysis identified that interleukin (IL)‐17 pathway was activated in the regulation of MMP13 in the development of RA. Through observing the alteration of luciferase activity, miR‐19a could indeed bind to the 3′UTR of the downstream of MMP13, the target association was then confirmed. The proliferation and invasion of HFLS‐RA were promoted by overexpressing MMP13 protein. miR‐19a could function as a suppressor of MMP13 and thereby retard the severity of RA. The results showed that miR‐19a could regulate the expression of MMP13 in HFLS‐RA by mediating the proliferation and invasion of HFLS‐RA through IL‐17 signaling pathway, thereby participating in the degradation of chondrocytes in the progression of RA.
Circular RNA circABCC4 regulates lung adenocarcinoma progression via miR‐3186‐3p/TNRC6B axis
Authors: Liu Meijuan , Wang Pengwei , Sui Xiaomei , Ding Fang , Liu Li , Gao Zengyan , Cheng Zhaozhong
Published: January 2020

Lung adenocarcinoma (LUAD), a general kind of bronchogenic malignancy globally, is depicted as one of the most critical factors affecting human health severely. Featured with loop structure, circular RNA (circRNA) has been described as an essential regulator of multiple human malignancies. Nevertheless, knowledge concerning the regulatory function of circRNA in LUAD progression remains limited. Identified as a novel circRNA, circABCC4 has not been studied in LUAD as yet. This is the first time to probe into the underlying role of circABCC4 in LUAD. In this study, a notably elevated expression of circABCC4 was found in LUAD tissues and cells. Besides, circABCC4 is verified to be characterized with a circular structure in LUAD. Functional assays elucidated that knockdown of circABCC4 significantly impaired LUAD cell proliferation, migration as well as accelerated cell apoptosis. Molecular mechanism experiments later revealed that circABCC4 could bind with miR‐3186‐3p and miR‐3186‐3p was a tumor suppressor in LUAD. Moreover, TNRC6B was validated to combine with miR‐3186‐3p, and its expression was respectively negatively and positively regulated by miR‐3186‐3p and circABCC4 in LUAD. Final rescue experiments further delineated that TNRC6B upregulation partially restored circABCC4 downregulation‐mediated effect on LUAD progression. In sum, circABCC4 regulates LUAD progression via miR‐3186‐3p/TNRC6B axis.
Exosomes from mesenchymal stem cells overexpressing MIF enhance myocardial repair
Authors: Liu Xiaolin , Li Xin , Zhu Wenwu , Zhang Yuelin , Hong Yimei , Liang Xiaoting , Fan Baohan , Zhao Hongyan , He Haiwei , Zhang Fengxiang
Published: January 2020

Accumulating evidence has shown that mesenchymal stem cell (MSC)‐derived exosomes (exo) mediate cardiac repair following myocardial infarction (MI). Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, plays a critical role in regulating cell homeostasis. This study aimed to investigate the cardioprotective effects of exo secreted from bone marrow‐MSCs (BM‐MSCs) overexpressing MIF in a rat model of MI. MIF plasmid was transducted in BM‐MSCs. Exo were isolated from the supernatants of BM‐MSCs and MIF‐BM‐MSCs, respectively. The morphology of mitochondria in neonatal mice cardiomyocytes (NRCMs) was determined by MitoTracker staining. The apoptosis of NRCMs was examined by deoxynucleotidyl transferase‐mediated dUTP nick end‐labeling. BM‐MSC‐exo and MIF‐BM‐MSC‐exo were intramuscularly injected into the peri‐infarct region in a rat model of MI. The heart function of rats was assessed by echocardiography. The expression of MIF was greatly enhanced in MIF‐BM‐MSCs compared with BM‐MSCs. Both BM‐MSC‐exo and MIF‐BM‐MSC‐exo expressed CD63 and CD81. NRCMs treated with MIF‐BM‐MSC‐exo exhibited less mitochondrial fragmentation and cell apoptosis under hypoxia/serum deprivation (H/SD) challenge than those treated with BM‐MSC‐exo via activating adenosine 5′‐monophosphate‐activated protein kinase signaling. Moreover, these effects were partially abrogated by Compound C. Injection of BM‐MSC‐exo or MIF‐BM‐MSC‐exo greatly restored heart function in a rat model of MI. Compared with BM‐MSC‐exo, injection of MIF‐BM‐MSC‐exo was associated with enhanced heart function, reduced heart remodeling, less cardiomyocyte mitochondrial fragmentation, reactive oxygen species generation, and apoptosis. Our study reveals a new mechanism of MIF‐BM‐MSC‐exo‐based therapy for MI and provides a novel strategy for cardiovascular disease treatment.
miR‐885 mediated cardioprotection against hypoxia/reoxygenation‐induced apoptosis in human cardiomyocytes via inhibition of PTEN and BCL2L11 and modulation of AKT/mTOR signaling
Authors: Meng Xin , Mei Lijun , Zhao Chedong , Chen Wei , Zhang Ning
Published: January 2020

Ischemia/reperfusion (I/R) injury could cause the enhanced cell apoptosis of cardiomyocytes, which is one of key contributors for the development of ischemic heart disease. Recent studies emphasized the role of microRNAs (miRNAs) in regulating cardiomyocyte apoptosis. The study planned to elucidate the molecular actions of miR‐885 on mediating human cardiomyocytes (HCMs) apoptosis induced by hypoxia/reoxygenation (H/R) and to explore the potential molecular mechanisms. The present data revealed that H/R stimulation inhibited HCM viability and potentiated HCM apoptosis, and more importantly, the expression of miR‐885 in HCMs was markedly repressed after H/R stimulation. Further experimental examinations demonstrated that overexpression of miR‐885 attenuated H/R‐induced increased in HCM apoptotic rates, while miR‐885 knockdown impaired HCM viability and increased HCM apoptotic rates. Moreover, the mechanistic studies showed that miR‐885 inversely regulated the expression of phosphatase and tensin homolog (PTEN) and BCL2 like 11 (BCL2L11) in HCMs, and enforced expression of PTEN and BCL2L11 partially antagonized the protective actions of miR‐885 overexpression on H/R‐induced HCM injury. Moreover, H/R suppressed AKT/mTOR signaling, which was attenuated by miR‐885 overexpression in HCMs. In conclusion, the present study for the first time showed the downregulation of miR‐885 induced by H/R in HCMs, and provided the evidence that miR‐885 attenuated H/R‐induced cell apoptosis via inhibiting PTEN and BLC2L11 and modulation of AKT/mTOR signaling in HCMs.
Circular RNA hsa_circ_0004277 contributes to malignant phenotype of colorectal cancer by sponging miR‐512‐5p to upregulate the expression of PTMA
Authors: Yang Lu , Sun Hongwei , Liu Xing , Chen Jinxin , Tian Zhimin , Xu Jia , Xiang Bowen , Qin Baoli
Published: January 2020

In recent years, extensive reports have been published concerning the molecular mechanism underlying the occurrence and progression of colorectal cancer. Circular RNAs (circRNAs) have been identified as important modulators in the biological processes of colorectal cancer. Microarray analysis unveiled that differential circ‐0004277 expression was identified in tissue samples of colorectal cancer. High circ‐0004277 expression was then verified in tissue samples and cell lines of colorectal cancer via qRT‐PCR. Kaplan–Meier analysis was used for identifying the association between circ‐0004277 expression and the overall survival rate of colorectal cancer patients. A relationship existed between higher circ‐0004277 expression and decreased overall survival rate of colorectal cancer patients. From a functional perspective, circ‐0004277 knockdown accelerated cell apoptosis and restrained cell proliferation of colorectal cancer. From mechanistic perspective, circ‐0004277 upregulated PTMA by sponging miR‐512‐5p. Rescue assay was used for verifying the roles of the circ‐0004277‐miR‐512‐5p‐PTMA axis. Both miR‐512‐5p and PTMA participated in circ‐0004277‐mediated colorectal cancer cell proliferation based on experiments. In summary, our study showed that circ‐0004277 promoted the proliferation of colorectal cancer cells as a miR‐512‐5p sponge to upregulate the PTMA expression.
Wnt/β‐catenin‐mediated heat exposure inhibits intestinal epithelial cell proliferation and stem cell expansion through endoplasmic reticulum stress
Authors: Zhou Jia‐yi , Huang Deng‐gui , Zhu Min , Gao Chun‐qi , Yan Hui‐chao , Li Xiang‐guang , Wang Xiu‐qi
Published: January 2020

Heat stress induced by continuous high ambient temperatures or strenuous exercise in humans and animals leads to intestinal epithelial damage through the induction of intracellular stress response. However, the precise mechanisms involved in the regulation of intestinal epithelial cell injury, especially intestinal stem cells (ISCs), remain unclear. Thereby, in vitro a confluent monolayer of IPEC‐J2 cells was exposed to the high temperatures (39, 40, and 41°C), the IPEC‐J2 cell proliferation, apoptosis, differentiation, and barrier were determined, as well as the expression of GRP78, which is a marker protein of endoplasmic reticulum stress (ERS). The Wnt/β‐catenin pathway‐mediated regenerative response was validated using R‐spondin 1 (Rspo1). And ex‐vivo, three‐dimensional cultured enteroids were developed from piglet jejunal crypt and employed to assess the ISC activity under heat exposure. The results showed that exposure to 41°C for 72 hr, rather than 39°C and 40°C, decreased IPEC‐J2 cell viability, inhibited cell proliferation and differentiation, induced ERS and cell apoptosis, damaged barrier function and restricted the Wnt/β‐catenin pathway. Nevertheless, Wnt/β‐catenin reactivation via Rspo1 protects the intestinal epithelium from heat exposure‐induced injury. Furthermore, exposure to 41°C for 24 hr reduced ISC activity, stimulated crypt‐cell apoptosis, upregulated the expression of GRP78 and caspase‐3, and downregulated the expression of β‐catenin, Lgr5, Bmi1, Ki67, KRT20, ZO‐1, occludin, and claudin‐1. Taken together, we conclude that heat exposure induces ERS and downregulates the Wnt/β‐catenin signaling pathway to disrupt epithelial integrity by inhibiting the intestinal epithelial cell proliferation and stem cell expansion.
MicroRNA‐214‐3p enhances erastin‐induced ferroptosis by targeting ATF4 in hepatoma cells
Authors: Bai Tao , Liang Ruopeng , Zhu Rongtao , Wang Weijie , Zhou Lin , Sun Yuling
Published: January 2020

Primary liver cancer is the second most frequent cause of cancer‐related deaths. Ferroptosis, a recognized form of regulated cell death, recently gains attention. MicroRNA‐214‐3p (miR‐214) plays a regulatory role in hepatocarcinogenesis. However, the role of miR‐214 in cellular ferroptosis is unclear. This study aimed at elucidating whether miR‐214 could regulate ferroptosis of liver cancer. In vitro, HepG2 and Hep3B cancer cells were treated with erastin, a ferroptosis inducer, and then erastin was demonstrated to suppress the cell viability. Moreover, pre‐miR‐214 overexpression caused that HepG2 and Hep3B cells were more susceptible to erastin, whereas anti‐miR‐214 sponge showed the opposite effect. Additionally, pre‐miR‐214 overexpression increased the malondialdehyde and reactive oxygen species levels, upregulated Fe2+ concentration, and decreased glutathione levels in cancer cells exposed to erastin. Further, erastin enhanced the activation of transcription factor 4 (ATF4) in HepG2 and Hep3B cells, and pre‐miR‐214 overexpression inhibited ATF4 expression. The luciferase reporter data validated ATF4 as a direct target of miR‐214. Cancer cells transfected with ATF4 overexpression plasmid rendered lower susceptible to miR‐214‐induced ferroptotic death. In vivo, erastin significantly reduced the size and weight of xenografted tumors, and miR‐214 elevated the ferroptosis‐promoting effects of erastin and decreased ATF4 expression. In summary, our study demonstrates that the ferroptosis‐promoting effects of miR‐214 in hepatoma cells are attributed at least to its inhibitory effects on ATF4, which may provide a new target for therapy of hepatoma regarding ferroptosis.
Design, synthesis, and antimicrobial evaluation of some nifuroxazide analogs against nosocomial infection
Authors: Dwivedi Deepak K. , Sahu Adarsh , Dighade Sachin J. , Agrawal Ram Kishore
Published: January 2020

A series of 10 p‐substitutedbenzoylmethylene hydrazide derivatives 4a‐j were synthesized by protecting carboxylic group of 4‐hydroxybenzoic acid using methanol and sulfuric acid than reacting it with hydrazide to form 4‐hydroxybenzohydrazide followed by reacting with a variety of aldehydes and evaluated for their activity against nosocomial infection. All the synthesized compounds were characterized by Fourier‐transform infrared (FT‐IR), 1H nuclear magnetic resonance (NMR), and mass spectral data. The in vitro antimicrobial potential of synthesized compounds was estimated against prominent strains of nosocomial pathogens (Staphylococcus aureus, Escherichia coli, and Aspergillus niger). The antimicrobial evaluation revealed compounds 4b, 4c, 4d, 4e, 4f, and 4j to be the most active compounds of the series with IC50 value for antibacterial in the range 0.39 to 0.75 μM/mL. Furthermore, the in vitro cytotoxic potential of the compounds was appraised by hemolytic assay. The results showed that some of the synthesized compounds exhibited marked activity.
Sensory and nutritional properties of peanut‐based beverages: a promising solution for undernutrition in Malawi and possibly beyond
Authors: Gama Aggrey P , Mwangwela Agnes M , Gichohi‐Wainaina Wanjiku N , Adhikari Koushik
Published: January 2020

BACKGROUND

Undernutrition remains a challenge in countries like Malawi. The search for effective nutrition interventions to address this challenge is ongoing. In this study, the sensory profiles of six peanut‐based beverage prototypes were determined. Three of the prototypes had barley malt in their formulations, and the other three had sorghum malt in their formulations. Nutrient profiles were determined using official standard analytical methods, and the results were compared with daily nutrient requirements to estimate their nutritional value.

RESULTS

All the six prototypes were acceptable, with mean overall liking scores ranging from 7.0 to 7.6. Prototypes containing sorghum malt were perceived as tasty, creamy, thick, and whitish, whereas those containing barley malt were perceived as sweet, watery, and brown. These terms, except whitish, had a significant impact (P < 0.05) on the overall liking mean score. The formulation incorporating sorghum malt (F‐B) had a better nutrient profile than that containing barley malt (F‐A) in terms of protein, total dietary fiber, potassium, phosphorus, calcium, magnesium, iron, and zinc. A 237 mL (8 oz.) serving of F‐B was an excellent source (% DV ≥20) of high‐quality protein, total dietary fiber, phosphorus, calcium, molybdenum, and manganese, and a good source (10 ≤ % DV < 20) of potassium and magnesium.

CONCLUSION

Based on consumer acceptability, both formulations can potentially increase peanut consumption in Malawi. Given its nutritional quality, F‐B may help in the management of undernutrition. The peanut‐based beverage may also be valuable in other countries, besides Malawi, where undernutrition is also a challenge. © 2020 Society of Chemical Industry
Theoretical Aspects of Iterative Coupling for Linear Oligomers and Polymers
Authors: Saker Neto Nicolau , Jones David John , Wong Wallace Wing Ho
Published: January 2020

A conceptual study of iterative coupling (IC) is performed, providing a unified description and new research directions. IC chain growth rates and functional group choice are analyzed, guiding construction of efficient schemes. The concept of cycle efficiency is defined as a more complete metric of experimental implementations of IC, and then applied to the main linear and exponential IC processes. The mathematical relations between individual reactions, cycles, and the iterative process as a whole are studied. Finally, macromolecule IC is proposed as a strikingly complementary process to standard IC, with potential to reduce the dispersity of non‐uniform samples. Due to its connection with the central limit theorem of statistics, it provides an unusually robust, powerful, and general method for scalable production of polymer samples with narrow distribution. In all, this contribution assists development of improved IC processes targeting low dispersity linear oligomers and polymers.
Compact dual‐band bandpass filter using a modified hexagonal split ring resonator
Authors: Troudi Zied , Macháč Jan , Osman Lotfi
Published: January 2020

In this article, a compact dual‐band bandpass filter (BPF) is studied and designed by utilizing a modified hexagonal split ring resonator (H‐SRR). The modified H‐SRR consists of a classical H‐SRR loaded by an open‐stepped impedance stub and a grounding via located at the symmetrical plane of the resonator. The proposed BPF operates at 2.5 and 4.83 GHz. Its advantages include simplicity of design, high rejection level due to transmission zeros, and low insertion loss. In addition, the size of the circuit occupies only 142.6 mm2. A good agreement is obtained between measurement and simulation results.