bluuebunny/crossref_metadata_2025 huggingface dataset:
Cooperative effect through different bridges in nickel catalysts for polymerization of ethylene
Authors: Khoshsefat Mostafa , Dechal Abbas , Ahmadjo Saeid , Mortazavi S. Mohammad M. , Zohuri Gholamhossein , Soares Joao B.P.
Published: April 2019

A series of mononuclear (M1 and M2) and dinuclear (C1–C6) Ni α‐diimine catalysts activated by modified methylaluminoxane were used in polymerization of ethylene. Catalyst C2 bearing the optimum bulkiness showed the highest activity (1.6 × 106 g PE (mol Ni)−1 h−1) and the lowest short‐chain branching (32.5/1000 C) in comparison to the dinuclear and mononuclear analogues. Although the mononuclear catalysts M1 and M2 polymerized ethylene to a branched amorphous polymer, the dinuclear catalysts led to different branched semicrystalline polyethylenes. Homogeneity and heterogeneity in the microstructure of the polyethylene samples was observed. Different trends for each catalyst were assigned to syn and anti stereoisomers. In addition, thermal behavior of the samples in the successive self‐nucleation and annealing technique exhibited different orders and intensities from methylene sequences and lamellae thickness in respect of each stereoisomer behavior. Higher selectivity of hexyl branches obtained by catalyst C2 showed a cooperative effect between the centers. The results also revealed that for catalysts C5 and C6, selectivity of methyl branches led to very high endotherms and crystalline sequences with melting temperatures higher than that of 100% crystalline polyethylene indicating ethylene/propylene copolymer analogues. For catalysts C3 and C4, more vinyl end groups were a result of the long distance between the Ni centers. Kinetic profiles of polymerization along with a computational study of the precatalysts and catalysts demonstrated that there is a direct relation between rate constant, energy interval of catalyst and precatalyst, and interaction energy of Et···methyl cationic active center (Et···MCC or π–Comp.). Based on this, narrow energy interval (activation energy) of precatalyst and catalyst leads to fast and higher activation rate (catalyst M2), and strong interaction of ethylene and catalyst leads to high monomer uptake and productivity (catalyst C2). Moreover, theoretical parameters including electron affinity, Mulliken charge on Ni, chemical potential and hardness, and global electrophilicity showed optimum values for C2.
Fabrication of PEI‐grafted porous polymer foam for CO2 capture
Authors: Deng Jingqian , Liu Zuolong , Du Zhongjie , Zou Wei , Zhang Chen
Published: April 2019

A polymer foam material with both the open‐cell porous structure and the polyethylenemine (PEI)‐grafted inner face was constructed for CO2 capture. The porous poly(tert‐butyl acrylate) foam was first prepared via a concentrated emulsion polymerization, and then the carboxyl groups were introduced on the interface of porous polymer after the hydrolysis reaction. Subsequently, the surface of the foam was grafted with PEI, and finally the PEI‐grafted porous polymer foam designed as a CO2 capture material was obtained. The structures of the foams were characterized by infrared spectroscopy, EDS, and SEM. The CO2 adsorption properties were measured by adsorption/desorption cycles. As a result, the polymer foam contained a large number of amine groups (13.9 wt % N), and therefore possessed a high CO2 adsorption capacity (5.91 mmol g−1 at 40°C and 100 kPa). In addition, they also exhibited high CO2 adsorption rate, good selectivity for CO2‐N2 separation, and good stability according to CO2 cyclic adsorption/desorption test. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47844.
Microstructure of Vertebrae, Ribs, and Gastralia of Triassic Sauropterygians—New Insights into the Microanatomical Processes Involved in Aquatic Adaptations of Marine Reptiles
Authors: Klein Nicole , Canoville Aurore , Houssaye Alexandra
Published: April 2019

Isolated ribs and vertebrae of Middle Triassic sauropterygians are studied. The vertebrae have a well‐defined large cavity in their centra, which is a unique feature and is without any modern analogue. The articular facets of vertebrae are made of endochondral bone including calcified as well as uncalcified cartilage. Vertebrae are pachyosteosclerotic in the pachypleurosaurs Neusticosaurus and Serpianosaurus from the Alpine Triassic, and osteosclerotic in the placodont, in the medium‐sized Nothosaurus marchicus, and in the pachypleurosaur Anarosaurus. In large Nothosaurus specimens, the vertebrae are cavernous. The ribs of all sampled specimens are osteosclerotic, which resembles the microanatomy of long bones in all studied taxa. The proximal to medial part of ribs mainly consists of a compact periosteal cortex surrounding an inner endosteal territory. Toward the distal end of the ribs, the periosteal thickness decreases whereas the endosteal territory increases. Despite a shift from periosteal versus endosteal tissues, global rib compactness remains relatively constant. Osteosclerosis in ribs and vertebrae is reached by the same processes as in the long bones: by a relative increase in cortex thickness that is coupled by a reduction of the medullary cavity, by the persistence of calcified cartilage, and by an inhibition of remodeling although some resorption may occur but without complete redeposition of bone. Processes differ from those observed in Permian marine reptiles and some mosasaurines, where either extensive remodeling or inhibition of bone resorption leads to osteosclerosis. Besides differences regarding the microanatomy, all studied bones of a taxon are consistent in their bone tissue type. Anat Rec, 302:1770–1791, 2019. © 2019 American Association for Anatomy
Development of a simple method for simultaneous determination of tazarotene and betamethasone dipropionate and their metabolites using LC–MS method and its application to dermatopharmacokinetic study
Authors: Li Lingjun , Zhang Mengli , Ma Pengcheng , Qian Kun
Published: April 2019

In our study, a method for the determination for tazarotene and betamethasone dipropionate in human tissue‐engineered skin was established. Tazarotene gel, betamethasone dipropionate cream or a combination cream was administered to the skin. Then the skin was taken off at 0.25, 0.75, 1.75, 3, 5, 8, 12, 24, 36, 48 h time points after the residual drug was removed. The concentrations of tazarotene, betamethasone dipropionate and their major metabolites in skin were determined by LC–MS. Tazarotene and tazarotenic acid were detected in the concentration range of 2–200 μg/mL with an LLOQ of 2 μg/mL. Betamethasone dipropionate was detected in the concentration range 0.5–300 μg/mL with an LLOQ of 0.5 μg/mL, and betamethasone was detected at 2–200 μg/mL with an LLOQ of 2 μg/mL. The intra‐ and inter‐day precisions of the four analytes in the skin homogenate were all <15% (RSD, %). The results showed that tazarotene could be metabolized to tazarotenic acid and betamethasone dipropionate could be metabolized to betamethasone in tissue‐engineered skin. The results also revealed that this method was suitable for the simultaneous determination of tazarotene, betamethasone dipropionate and their metabolites in tissue‐engineered skin.
Effect of natural full weight‐bearing during standing on the rotation of the first metatarsal bone
Authors: Ota Tomohiko , Nagura Takeo , Yamada Yoshitake , Yamada Minoru , Yokoyama Yoichi , Ogihara Naomichi , Matsumoto Morio , Nakamura Masaya , Jinzaki Masahiro
Published: April 2019

To evaluate the rotational change in the first metatarsal bone (1MT) of the foot during natural standing using an upright computed tomography (CT) scanner with 320‐detector rows. A total of 52 feet of 28 asymptomatic subjects (aged 23–39 years) were evaluated in the natural standing position with or without weight‐bearing. A foot pressure plate was used to determine the non‐weight‐bearing (NWB) or single leg full‐weight‐bearing (s‐FWB) conditions. CT examinations were performed using a noise index of 15 for a slice thickness of 5 mm, rotation speed of 0.5 sec, and slice thickness of 0.5 mm. The rotation of the 1MT was measured on the coronal CT image, which cut the sesamoids' bellies in the frontal slide of the first metatarsal and sesamoids perpendicular to the longitudinal bisection of the third metatarsal, and compared between the weight‐bearing conditions. Intra‐ and inter‐observer reliabilities of the rotation angle were also evaluated. The intra‐ and inter‐observer correlation coefficients were 0.961 and 0.934, respectively. The 1MT pronation angle was significantly greater in the s‐FWB condition than in the NWB condition (15.2° ± 5.4° vs. 12.5° ± 5.3°, P < 0.01). No sex difference was found in the magnitude of the 1MT pronation angle as a result of weight‐bearing. This study first demonstrated that pronation of 1MT occurs due to natural full‐weight‐bearing in asymptomatic feet. The 1MT's rotational movement under weight‐bearing conditions may relate to the onset and pathogenesis of the hallux valgus. Clin. Anat. 32:715–721, 2019. © 2019 Wiley Periodicals, Inc.
Quantitative Isotopomer Rates in Real‐Time Metabolism of Cells Determined by NMR Methods
Authors: Reed Michelle A. C. , Roberts Jennie , Gierth Peter , Kupče Ēriks , Günther Ulrich L.
Published: April 2019

Tracer‐based metabolism is becoming increasingly important for studying metabolic mechanisms in cells. NMR spectroscopy offers several approaches to measure label incorporation in metabolites, including 13C‐ and 1H‐detected spectra. The latter are generally more sensitive, but quantification depends on the proton–carbon 1JCH coupling constant, which varies significantly between different metabolites. It is therefore not possible to have one experiment optimised for all metabolites, and quantification of 1H‐edited spectra such as HSQCs requires precise knowledge of coupling constants. Increasing interest in tracer‐based and metabolic flux analysis requires robust analyses with reasonably small acquisition times. Herein, we compare 13C‐filtered and 13C‐edited methods for quantification and show the applicability of the methods for real‐time NMR spectroscopy of cancer‐cell metabolism, in which label incorporations are subject to constant flux. We find an approach using a double filter to be most suitable and sufficiently robust to reliably obtain 13C incorporations from difference spectra. This is demonstrated for JJN3 multiple myeloma cells processing glucose over 24 h. The proposed method is equally well suited for calculating the level of label incorporation in labelled cell extracts in the context of metabolic flux analysis.
Two‐year safety evaluation of a biodegradable polymer sirolimus‐eluting stent with increased drug elution and polymer absorption kinetics in complex patient and lesion cohort
Authors: Jia Sida , Guan Changdong , Yuan Jinqing , Cao Xuebin , Qin Lei , Li Yi , Li Zhanquan , Nie Shaoping , Hou Shuang , Zhang Min , Brouwer Marc , Suryapranata Harry , Xu Bo , Gao Runlin
Published: April 2019

Objectives

The aim of the present report was to compare 2‐year safety outcomes of two biodegradable polymer (BP) sirolimus‐eluting stents (SESs) with different drug eluting and polymer absorption kinetics in a subgroup of complex patients and lesions.

Background

The previously published PANDA III study showed the BuMA BP SES, with faster drug elution and polymer absorption, was non‐inferior to the Excel SES in target lesion failure (TLF).

Methods

In PANDA III trial, patients who fulfilled one or more of the following criteria were included: Small vessel disease (reference vessel diameter ≤ 2.5 mm); long lesion (lesion length ≥ 20 mm); chronic total occlusion lesion; and diabetic patients.

Results

Among 2,348 patients randomly assigned to treatment with BuMA (n = 1,174) or Excel SES (n = 1,174) in the PANDA III study, 858 in the BuMA group and 855 in the Excel group satisfied the inclusion criteria. At 2‐year follow‐up, the incidence of definite/probable stent thrombosis (ST) was significantly lower with BuMA SES as compared with Excel SES (0.7% vs. 1.9%, p = 0.03). This difference was mainly caused by decreased subacute stent thrombosis rate (0% vs. 0.6%, p = 0.03). In patients who did not fulfill the complex patient and lesion criteria, there were no between‐group difference in ST (0.7% vs. 0%, p = 0.50). Myocardial infarction and TLF rates were similar (5.7% vs. 6.0%, p = 0.79 and 8.8% vs. 7.5%, p = 0.34, respectively), whereas patient‐oriented composite endpoint was higher with BuMA SES mainly due to high risk of revascularization (15.6% vs. 11.4%, p = 0.01; 8.4% vs. 4.6%, p < 0.01).

Conclusions

Two‐year subgroup analysis of the all‐comer PANDA III trial revealed the increased safety benefit of the BuMA SES is more prominently seen in complex patient and lesion population.

Clinical Trial

ClinicalTrial.gov, Identifier—NCT02017275.
Cyclometalated AuIII Complexes for Cysteine Arylation in Zinc Finger Protein Domains: towards Controlled Reductive Elimination
Authors: Wenzel Margot N. , Bonsignore Riccardo , Thomas Sophie R. , Bourissou Didier , Barone Giampaolo , Casini Angela
Published: April 2019

With the aim of exploiting the use of organometallic species for the efficient modification of proteins through C‐atom transfer, the gold‐mediated cysteine arylation through a reductive elimination process occurring from the reaction of cyclometalated AuIII C^N complexes with a zinc finger peptide (Cys2His2 type) is here reported. Among the four selected AuIII cyclometalated compounds, the [Au(CCON)Cl2] complex featuring the 2‐benzoylpyridine (CCON) scaffold was identified as the most prone to reductive elimination and Cys arylation in buffered aqueous solution (pH 7.4) at 37 °C by high‐resolution LC electrospray ionization mass spectrometry. DFT and quantum mechanics/molecular mechanics (QM/MM) studies permitted to propose a mechanism for the title reaction that is in line with the experimental results. Overall, the results provide new insights into the reactivity of cytotoxic organogold compounds with biologically important zinc finger domains and identify initial structure–activity relationships to enable AuIII‐catalyzed reductive elimination in aqueous media.
Long‐term outcomes in Japanese nonagenarians undergoing transcatheter aortic valve implantation: A multi‐center analysis
Authors: Yokoyama Hiroaki , Tobaru Tetsuya , Muto Yuki , Hagiya Kenichi , Higuchi Ryosuke , Saji Mike , Takamisawa Itaru , Shimizu Jun , Takanashi Shuichiro , Takayama Morimasa , Tomita Hirofumi , Tamura Harutoshi , Doi Shinichiro , Okazaki Shinya , Isobe Mitsuaki
Published: April 2019

Background and Hypothesis

Japan is an aging society, and the number of nonagenarians with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) is increasing, but their outcomes have not been determined fully.

Methods

We prospectively enrolled 767 consecutive patients who underwent TAVI in three Japanese institutions. Clinical characteristics and outcomes of nonagenarians (n = 94) were evaluated and compared with those of patients aged <90 years (n = 673).

Results

Prevalence of New York Heart Association (NYHA) class III/IV was not different between the two groups. Preoperative risk scores were significantly higher in nonagenarians compared with those in non‐nonagenarians, whereas the Clinical Frailty Scale was not different. Thirty‐day mortality tended to be higher (P = .06) and major vascular complication was significantly higher in nonagenarians than in non‐nonagenarians (P < .05), but 3‐year mortality was equivalent between the two groups. Even after adjustment for covariates, female sex (hazard ratio, 0.41; 95% confidence interval: 0.25‐0.67), body mass index (0.87, 0.80‐0.94), and NYHA class III/IV (1.84, 1.06‐3.29) were associated with all‐cause mortality. Age ≥ 90 years was not associated with all‐cause mortality.

Conclusions

TAVI could be undertaken safely and effectively in nonagenarians, who had acceptable long‐term results compared with those for younger patients, although careful attention should be paid to major vascular complication.
Static malware clustering using enhanced deep embedding method
Authors: Ng Chee Keong , Jiang Frank , Zhang Leo Yu , Zhou Wanlei
Published: April 2019

Malware refers to any software, programs, or files that are intentionally utilised to compromise the system and cause unexpected losses to end‐users such as economical losses or privacy breaches. The rapid growth of malware makes it impossible to keep up with its progress merely via human interventions or manual analysis. One of the challenges for the human‐oriented approaches is they will cause backlog and inability to keep up with the development traces of the malware. Hence, an efficient method is needed urgently to analyse effectively and identify accurately the malware in their domain. Malware clustering has been extensively studied in the machine learning area with regards to distance functions, grouping algorithm and cluster validation. A large number of research studies have been done via behavioral analysis for clustering to achieve high performance of malware detections. However, there is a trade‐off for better detection performance between behaviorial approaches and high computational forces. Up to date, little work focuses on the deep learning representations for malware clustering. Therefore, in this paper, we propose an enhanced deep embedded clustering method to facilitate an effective and efficient malware clustering process. The new method takes advantage of linear dimensionality reduction and a customised deep neural network to learn malware representations in an orthogonal space and performs cluster assignments. Our experimental results demonstrate that the proposed clustering model outperforms the traditional K‐means method with regards to the enhanced features using various auto‐encoder, pre‐trained weight and principle component analysis (PCA).
Fast and scalable algorithm for product large data on multicore system
Authors: Bahig Hazem M. , Bahig Hatem M. , Fathy Khaled A.
Published: April 2019

The problem of designing efficient parallel algorithms to calculate the product of n numbers when the multipliers are large is a fundamental problem in many applications of computer science such as cryptography. In this work, we present a new parallel algorithm on exclusive read shared memory model. The performance of the introduced algorithm is measured based on three factors, namely, (1) the number of cores, (2) the size of the array, and (3) the size of the multiplier. The experimental study on a multi core system reveals that the introduced algorithm is faster than the best‐known optimal parallel algorithm. The improvement of the proposed algorithm in processing time compared to the best known parallel algorithm is 80% when the size of the array was 220 and the sizes of the multiplier were 1024, 2048, and 4096 bits. Moreover, our algorithm is a highly scalable parallel algorithm compared with the best‐known optimal parallel algorithm.
Superhalogens as Building Blocks of Super Lewis Acids
Authors: Reddy G. Naaresh , Parida Rakesh , Jena Puru , Jana Madhurima , Giri Santanab
Published: April 2019

Lewis acids play an important role in synthetic chemistry. Using first‐principle calculations on some newly designed molecules containing boron and organic heterocyclic superhalogen ligands, we show that the acid strength depends on the charge of the central atom as well as on the ligands attached to it. In particular, the strength of the Lewis acid increases with increasing electron withdrawing power of the ligand. With this insight, we highlight the importance of superhalogen‐based ligands in the design of strong Lewis acids. Calculated fluoride ion affinity (FIA) values of B[C2BNO(CN)3]3 and B[C2BNS(CN)3]3 show that these are super Lewis acids.
Ecological insights from environmental disturbances in mesophotic coral ecosystems
Authors: Pinheiro Hudson T. , Eyal Gal , Shepherd Bart , Rocha Luiz A.
Published: April 2019

Mesophotic coral ecosystems (MCEs) have historically been considered more stable than shallow reefs and thus suggested to provide refuge to coral reef communities against natural and anthropogenic impacts. Despite this assumption, a growing body of literature has shown that deep reefs are not immune to natural disturbance. Here, based on our in situ observations, we propose that disturbance may actually represent an important mechanism for maintaining biodiversity in MCEs, as is the case for shallow reefs. Our observations suggest that disturbances can provide microhabitat and space necessary for the recruitment and occurrence of different species, increasing overall diversity. Since bioerosion rates are lower at depth, and most well‐developed coral reefs on MCEs are formed by dense aggregations of a single or a few species, intermediate levels of disturbance could represent a critical driver of community structure balancing. Therefore, instead of long‐term stability, intermediate disturbances should be expected on MCEs. However, high frequency and intensity of natural disturbances, or their association with anthropogenic stressors, might have stronger negative impacts on MCEs than on shallower reefs due to slower coral growth and calcification rates.
Explaining the birds and the bees: deriving habitat restoration targets from multi‐species occupancy models
Authors: Cole Jerry S. , Siegel Rodney B. , Loffland Helen L. , Tingley Morgan W. , Elsey Erin A. , Johnson Matthew
Published: April 2019

Riparian corridors can be highly biodiverse but are often degraded by human activities, and are therefore frequent targets of restoration actions. Yet managers often lack clear guidance on how to conserve or restore riparian vegetation structure and composition to promote wildlife biodiversity, due to the difficulty of balancing the needs of multiple species and taxonomic groups. We used independent multi‐species occupancy models to assess the response of riparian bird and bumble bee assemblages, respectively, to variation in vegetation structure and composition in montane riparian corridors. We sought to identify vegetation characteristics associated with relatively high richness across each taxonomic group to define target conditions for habitat restoration. Riparian bird occupancy increased with more willow (Salixspp.) cover and less overstory cover, while bumble bee occupancy increased with greater flowering plant richness, more forb cover, and less shrub cover. Relatively distinct habitat preferences of bumble bees and riparian birds emphasize the value of managing for habitat heterogeneity to promote biodiversity across multiple taxonomic groups. Multi‐species modeling distills the responses of numerous species down to a single estimate of a covariate effect for an assemblage of species and can provide land managers with empirically derived targets for habitat restoration that will benefit many species.
Migration of soil microbes may promote tree seedling tolerance to drying conditions
Authors: Allsup Cassandra , Lankau Richard
Published: April 2019

Soil–microbe interactions have the potential to mediate the ability of tree populations to persist in their current location or establish in new areas. Immigration of microbial taxa from drier conditions may promote seedling tolerance to drying climates. In a greenhouse experiment, we determined seedling performance of Ostrya virginiana and Betula nigra seedlings after experimentally swapping sterilized soils and local and foreign microbial inocula from nine sites over a gradient of precipitation and soil types, in well‐watered and water reduced conditions. Swapping microbial inocula relative to abiotic soils along latitudinal, but not longitudinal, gradients resulted in reduced seedling biomass. Additionally, growth in water reduced conditions was maximized when pots were inoculated with microbes from drier sites. These results suggest that extirpation of local microbial taxa, and/or immigration of novel microbial taxa to a site may be detrimental to plant growth due to mismatches between microbes and soil conditions. However, immigration of drought adapted microbial taxa may provide additional drought tolerance to plant populations facing drying conditions. This work contributes to the understanding of how microbial interactions may potentially exacerbate or mitigate challenges to plant populations caused by climate change.
An additive approximate Gaussian process model for large spatio‐temporal data
Authors: Ma Pulong , Konomi Bledar A. , Kang Emily L.
Published: April 2019

Motivated by a large ground‐level ozone data set, we propose a new computationally efficient additive approximate Gaussian process. The proposed method incorporates a computational‐complexity‐reduction method and a separable covariance function, which can flexibly capture various spatio‐temporal dependence structures. The first component is able to capture nonseparable spatio‐temporal variability, whereas the second component captures the separable variation. Based on a hierarchical formulation of the model, we are able to utilize the computational advantages of both components and perform efficient Bayesian inference. To demonstrate the inferential and computational benefits of the proposed method, we carry out extensive simulation studies assuming various scenarios of an underlying spatio‐temporal covariance structure. The proposed method is also applied to analyze large spatio‐temporal measurements of ground‐level ozone in the Eastern United States.
Temporal and spatial variation of soil erosion in wooded rangelands of southwest Spain
Authors: Rubio‐Delgado Judit , Schnabel Susanne , Gómez‐Gutiérrez Álvaro , Lavado‐Contador Joaquín Francisco
Published: April 2019

Changes in land use are common in Mediterranean areas and are reported as having produced changes in the intensity of soil erosion. Dehesas are rangelands with a disperse tree cover, widespread in the south‐western part of the Iberian Peninsula and similar ecosystems are also common in other areas with a Mediterranean climate. The aim of the present study is to analyse temporal and spatial variations of soil erosion rates estimated along three hillsides, located in two farms (Buitrera and Parapuños) in southwest Spain. To understand the temporal variation, soil erosion rates were studied in light of land use‐management changes that took place during the last few centuries. Results indicate very low erosion rates prior to the 18th century in both farms. In Buitrera, a first increase of soil loss rates was identified during the period 1831‐1897, amounting to 7.4 t ha‐1 y‐1. A further increase took place during the 20th century, reaching a mean erosion rate of 29.1 t ha‐1 y‐1. In Parapuños, data points to a significant increase from 1881 onwards, with an estimated mean erosion rate of 18.5 t ha‐1 y‐1. Those increases were presumably connected with an intensification of land use, such as cultivation and excessive livestock populations. Regarding spatial variation, the bare surface and the erosive power of run‐off along the hillsides accounts for 76% of the soil erosion rates dispersion. At a local scale, the variability of erosion rates could not be explained, because of (i) uncertainty related to the micromorphology of the past soil surface and (ii) the role of tillage erosion in the past. However, the results obtained offer valuable data on the temporal and spatial variation of erosion rates in dehesas at the hillslope scale and a similar approach could be used for other rangelands with a disperse tree cover. © 2019 John Wiley & Sons, Ltd.
Application of genetic modification and genome editing for developing climate‐smart banana
Authors: Tripathi Leena , Ntui Valentine Otang , Tripathi Jaindra Nath
Published: April 2019

Banana is a major staple food crop feeding more than 500 million people in tropical and subtropical countries. Its production is largely constrained by diseases and pests in addition to other factors such as declining soil fertility, narrow genetic diversity in germplasm, and inadequate availability of clean planting material. The impact of climate change, particularly a rise in temperature and drought, is predicted to affect production adversely due to direct effect on plant agronomy and also influence on pathogens, pests, and their interactions with host plants. There is need to develop climate‐smart varieties of banana with multiple and durable resistance to combat abiotic stresses such as extreme temperature and drought, and biotic stresses such as pathogens and pests. Modern breeding tools, including genetic modification and genome editing, can be applied for the improvement of banana bypassing the natural bottlenecks of traditional breeding. Intensive efforts using genetic modification have been made to develop improved banana varieties with resistance to biotic stresses; however, these need to be coupled with tolerance to abiotic stresses. Genome editing, an emerging powerful tool, can be applied for developing sustainable solutions to adapt to climate change by resisting biotic and abiotic stresses. CRISPR/Cas9‐based genome editing has been lately established for banana, paving the way for functional genomics allowing identification of genes associated with stress‐tolerant traits, which could be used for the improvement of banana for adaptation to a changing climate. This article presents an overview of recent advancements and prospective on the application of genetic modification and genome editing for developing climate‐smart banana.
Endoplasmic reticulum stress, a novel significant mechanism responsible for DEHP‐induced increased distance between seminiferous tubule of mouse testis
Authors: Pan Junlin , Yao YuanYuan , Guo Xiuxiu , Kong Fengyun , Zhou Jun , Meng Xiaoqian
Published: April 2019

Di(2‐ethylhexyl) phthalate (DEHP), a widely existed endocrine disruptor, has been concerned for many years owing to its toxicity in male reproductive development. In this study, we investigated the reproductive effects and the mechanism of mouse testis after in uterus exposure to the plasticizer DEHP. We found that the UPR signaling pathway could be fully activated after DEHP treatment. In uterus DEHP exposure significantly increased abnormal morphology seminiferous tubules, expanded the distance between the tubules as well as caused abnormal endoplasmic reticulum (ER) ultrastructure, which could be reversed by 4‐phenylbutyrate (4‐PBA), an ER stress inhibitor. In addition, DEHP‐induced ER stress pathway promoted a decline in protein expression, including cadherin protein N‐cadherin in testis, which could also be reversed by 4‐PBA. Taken together, our results provide compelling evidence that the ER stress would be a novel significant mechanism responsible for DEHP‐induced the increased the distance between seminiferous tubule by reducing the N‐cadherin expression.
Identification of the potential key genes for adipogenesis from human mesenchymal stem cells by RNA‐Seq
Authors: Yi Xia , Wu Ping , Liu Jianyun , Gong Ying , Xu Xiaoyuan , Li Weidong
Published: April 2019

Adipogenesis, a physiological process initiated with the committed preadipocytes expressing adipocyte‐specific genes and terminated in mature, differentiated and functional adipocytes, mainly involved with energy homeostasis. Abnormal distribution‐changes and dysfunctions in adipogenesis may lead to complex physiopathological disorders. However, it remains unclear for the key players working for the whole complex differentiating process of adipogenesis. Here, it investigated transcriptional profiling of adipogenesis from human mesenchymal stem cells (hMSCs) by RNA‐Seq transcriptome technique. Oil Red O staining assays were performed to assess adipogenic potential. Quantitative real‐time PCR (qRT‐PCR) and lentivirus transfection assays by small interference RNA (siRNA) were conducted to confirm the function of the candidate genes. A total of 1,078 differentially expressed genes shared at 7, 14, 21, and 28 days during adipogenesis from hMSCs, and 706 genes were significantly differentially expressed. It identified 20 potential key genes responsible for adipogenesis with four genes downregulating. The candidate gene, coagulation factor II thrombin receptor (F2R), encoding coagulation factor II thrombin receptor involving with a 7‐transmembrane receptor involved in the regulation of thrombotic response, also known as proteinase‐activated receptor‐1, contributed to adipogenesis, especially at Day 14, by Oil Red O staining, qRT‐PCR, and western blot after siRNA. A unique discovery shed new light to understand the key players of the whole processes of adipogenesis from hMSCs. The gene F2R might be used as an adipogenic marker to provide a potential target for understanding the metabolic syndromes like obesity, type‐2 diabetes, steatosis, atherosclerosis, and osteoporosis.
Exosome‐based intercellular communication in female reproductive microenvironments
Authors: Ranjbaran Ali , Latifi Zeinab , Nejabati Hamid Reza , Abroon Sina , Mihanfar Aynaz , Sadigh Aydin Raei , Fattahi Amir , Nouri Mohammad , Raffel Nathalie
Published: April 2019

Different strategies are applied for cellular cross‐talk and organization in multicellular organisms. Exosomes are a homogenous population of biological nanoparticles (30–100 nm), originated from multivesicular bodies. The exosomes (Exos) could regulate and affect both cellular physiology and pathophysiology in various organs, such as the female reproductive tract, by altering gene pathways and/or epigenetic programming. Besides, engineered Exos have the potential to be used as a novel drug and gene delivery tools. Here in this review, we discussed various aspects of exosome‐based intercellular communication in female reproductive microenvironments. Furthermore, we addressed the findings and issues related to Exos in reproductive biology to give a better view of the involved molecular mechanisms. Moreover, clinical applications of the Exos and their isolation source/methods have been considered to throw some light on the progression of new biological, diagnostic, and therapeutic approaches in clinical embryology.
An Integrated Population Pharmacokinetic Model Versus Individual Models of Depatuxizumab Mafodotin, an Anti‐EGFR Antibody Drug Conjugate, in Patients With Solid Tumors Likely to Overexpress EGFR
Authors: Mittapalli Rajendar K. , Stodtmann Sven , Friedel Anna , Menon Rajeev M. , Bain Earle , Mensing Sven , Xiong Hao
Published: April 2019

Depatuxizumab mafodotin (depatux‐m) is an antibody‐drug conjugate (ADC) designed for the treatment of tumors expressing epidermal growth factor receptor (EGFR), consisting of a veneered “humanized” recombinant IgG1κ antibody that has binding properties specific to a unique epitope of human EGFR with noncleavable maleimido‐caproyl linkers each attached to a potent antimitotic cytotoxin, monomethyl auristatin F. We aimed to describe the development and comparison of 2 population pharmacokinetic modeling approaches. Data from 2 phase 1 studies enrolling patients with glioblastoma multiforme or advanced solid tumors were included in the analysis. Patients in these studies received doses of depatux‐m ranging from 0.5 to 4.0 mg/kg as monotherapy, in combination with temozolomide, or radiation plus temozolomide depending on the study and/or arm. First, an integrated ADC model to simultaneously describe the concentration‐time data for ADC, total antibody, and cys‐mafodotin was built using a 2‐compartment model for ADC for each drug‐to‐antibody ratio. Then, 3 individual models were developed for ADC, total antibody, and cys‐mafodotin separately using 2‐compartment models for ADC and total antibody and a 1‐compartment model for cys‐mafodotin. Visual predictive checks suggested accurate model fitting across a range of concentrations. The analysis showed that both an integrated complex ADC model and the individual models that have shorter computational time would result in similar outcomes.
Highly Efficient One‐Pot Three‐Component Synthesis and Antimicrobial Activity of 2‐Amino‐4H‐chromene Derivatives
Authors: Aminkhani Ali , Talati Mina , Sharifi Roholah , Chalabian Firouzeh , Katouzian Fatemeh
Published: April 2019

A remarkably efficient three‐component reaction to synthesize 2‐amino‐4H‐chromenes derivatives from malononitrile, various aromatic aldehydes, and orcinol was described at room temperature in CH2Cl2 in the presence of catalytic amount of triethylamine. In a facile one‐pot procedure, excellent yields of products were achieved in less than 1 h. Some of the synthesized 2‐amino‐4H‐chromenes derivatives demonstrated potent antibacterial activities against Gram‐positive bacteria including Staphylococcus aureus and Bacillus anthracis, indicated by disk method, minimum inhibitory concentration, and minimum bactericidal concentration approaches. However, none of the tested compounds expressed any antibacterial activities against Enterococcus faecalis and Gram‐negative bacteria.
Cardiovascular risk factors among ART‐experienced people with HIV in South Africa
Authors: Hyle Emily P , Bekker Linda‐Gail , Martey Emily B , Huang Mingshu , Xu Ai , Parker Robert A , Walensky Rochelle P , Middelkoop Keren
Published: April 2019

Introduction

People with HIV (PWH) are at increased risk for atherosclerotic cardiovascular disease (CVD). Screening for CVD risk factors is recommended but not routine in South African HIV clinics. We sought to describe the prevalence of CVD risk factors among antiretroviral treatment (ART)‐experienced patients in South Africa.

Methods

We performed a prospective, observational cross‐sectional study of PWH (>21 years, excluding pregnant women) on ART in South Africa. We interviewed patients regarding CVD risk factors, and obtained two blood pressure (BP) measurements and random/fasting glucose via a point‐of‐care glucometer. Standardized chart reviews provided individuals' HIV‐specific data. We defined hypertension as: self‐reported use of antihypertensives or mean systolic BP (SBP) ≥140 mmHg or diastolic BP (DBP) ≥90 mmHg (Stage 1) or SBP ≥160 mmHg or DBP ≥100 mmHg (Stage 2). We defined diabetes as self‐reported use of insulin/oral hypoglycaemics or fasting (random) glucose ≥7.0 (≥11.1) mmol. We obtained risk ratios (RR) for hypertension from a multivariable log‐binomial regression model, adjusting for age, sex and diabetes.

Results

From March 2015 to February 2016, 458 participants enrolled with median age 38 years (interquartile range (IQR) 33 to 44 years) and median CD4 466/μL (IQR 317 to 638/μL); 78% were women. Participants were on ART for a median of four years, with 33% on ART ≥6 years. Almost a quarter (106/458) met the study definition for hypertension, of whom 45/106 (42%) were previously diagnosed, 23/45 (51%) were on medication and 4/23 (17%) were controlled. Eight participants had asymptomatic hypertensive urgency (BP≥180/110 mmHg). Of the 458 participants, 26 (6%) met the study definition for diabetes, half of whom (13/26) were already diagnosed; 11/13 (85%) were on treatment, of whom 4/11 (36%) had normal glucose. Age was the only significant predictor of hypertension (RR, 1.04; 95% CI, 1.03 to 1.06, p < 0.0001) in the multivariable model.

Conclusions

Hypertension and diabetes were prevalent among PWH prescribed ART in South Africa with less than half diagnosed, and still fewer treated and controlled. Hypertension was independently associated with age but not with HIV‐specific factors. Screening for and treatment of CVD risk factors could decrease future morbidity and mortality, especially as this population ages.
18F‐Labeled benzylpiperazine derivatives as highly selective ligands for imaging σ1 receptor with positron emission tomography
Authors: Ye Jiajun , Wang Liang , Deuther‐Conrad Winnie , Chen Yuanyuan , Zhang Xiaojun , Zhang Jinming , Huang Yiyun , Brust Peter , Jia Hongmei
Published: April 2019

We report the design, synthesis, and evaluation of a new series of benzylpiperazine derivatives as selective σ1 receptor ligands. All seven ligands possessed low nanomolar affinity for σ1 receptors (Ki(σ1) = 0.31‐4.19 nM) and high subtype selectivity (Ki(σ2)/Ki(σ1) = 50‐2448). The fluoroethoxy analogues also exhibited high selectivity toward the vesicular acetylcholine transporter (Ki(VAChT)/Ki(σ1) = 99‐18252). The corresponding radiotracers [18F]13, [18F]14, and [18F]16 with high selectivity (Ki(σ2)/Ki(σ1) > 100, Ki(VAChT)/Ki(σ1) > 1000) were prepared in 42% to 55% radiochemical yields (corrected for decay), greater than 99% radiochemical purity (RCP), and molar activity of about 120 GBq/μmol at the end of synthesis (EOS). All three radiotracers showed high initial brain uptake in mouse (8.37‐11.48% ID/g at 2 min), which was not affected by pretreatment with cyclosporine A, suggesting that they are not substrates for permeability‐glycoprotein (P‐gp). Pretreatment with SA4503 or haloperidol resulted in significantly reduced brain uptake (35%‐62% decrease at 30 min). In particular, [18F]16 displayed high brain‐to‐blood ratios and high in vivo metabolic stability. Although it may not be an optimal neuroimaging agent because of its slow kinetics in the mouse brain, [18F]16 can serve as a lead compound for further structural modifications to explore new potential radiotracers for σ1 receptors.
Effects of signal averaging, gradient encoding scheme, and spatial resolution on diffusion kurtosis imaging: An empirical study using 7T MRI
Authors: Chiang Chia‐Wen , Lin Shih‐Yen , Cho Kuan‐Hung , Wu Kuo‐Jen , Wang Yun , Kuo Li‐Wei
Published: April 2019

Background

Although diffusion gradient directions and b‐values have been optimized for diffusion kurtosis imaging (DKI), little is known about the effect of signal averaging on DKI reliability.

Purpose

To evaluate how signal averaging influences the reliability of DKI indices using two gradient encoding schemes with three spatial resolutions.

Study Type

Prospective.

Animal Model

Fifteen naïve Sprague–Dawley rats.

Field Strength/Sequence

DKI was performed at 7T using two schemes (30 directions with three b‐values [30d‐3b] and six directions with 15 b‐values [6d‐15b]), three resolutions, and eight repetitions.

Assessment

DKI reliability was assessed using voxelwise relative error (σ) and test–retest error of fractional anisotropy (FA), mean diffusivity (MD), and mean kurtosis (MK) within gray matter (GM) and white matter (WM). The number of excitations (NEX) was optimized by considering DKI reliability. The influence of the partial volume effect (PVE) was also assessed.

Statistical Test

One‐way analysis of variance.

Results

The 30d‐3b scheme, compared with the 6d‐15b scheme, exhibited apparently smaller σFA and σMK (eg, at NEX 1, in GM, for three resolutions, σFA: 19.9–38.2% vs. 34.2–61.4%, σMK: 6.9–11.4% vs. 14.1–15.4%) and similar σMD (all differences between two schemes <1.6%). The optimal NEX was determined as 2 for enabling a reliable measurement of DKI‐derived indices. The PVE at the lowest resolution apparently increased σFA for both schemes (19.9% for 30d‐3b and 34.2% for 6d‐15b) and σMK for the 6d‐15b scheme (14.7%) in GM, and exerted lower effects on MK values for the 30d‐3b scheme (P > 0.05).

Data Conclusion

A higher number of diffusion directions would benefit FA and MK estimation. A higher spatial resolution helps to reduce PVE. By using the 30d‐3b scheme, MK is considered a robust index to reflect microstructural changes in GM and WM. We propose a systematic approach to determine the optimal DKI protocols for appropriate preclinical settings.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2019;50:1593–1603.
Physico‐Mechanical and Antibacterial Properties of Pine Gum/Epoxy Composites with/without Silver Nanoparticles
Authors: Negi Ripudaman Singh , Bisht Rajendra Singh , Singh Raj K. , Prasad Lalta
Published: April 2019

Silver nanoparticles/polymer composite (Ag‐NPs/PC) may eventually be biodegradable, sustainable, or burned without production of lethal by‐products and can be utilized as packaging and biomedical device applications. Nanoparticles engaged in pine gum (resin and rosin) are preserved for months without any significant effect on particle size and distribution. This paper focuses on the pine gum/epoxy composites with and without silver nanoparticles fabricated by a hand lay‐up technique. Silver nanoparticles are fixed at 0.37% and pine gum varies from 2 to 24% by weight to acquire the best mechanical and wear properties. The result indicates that Ag‐NPs with pine gum (23.7 wt% resin &13.3 wt% rosin) has the best tensile and impact strength reaching a gain of 51.34% and 53.68% simultaneously. Hardness is noted most extreme 17.92% at Ag‐NPs sample (7.4 wt% resin and 3.7 wt% rosin) and wear resist behavior is best noted with neat pine gum/epoxy composite. The antibacterial assay of the Ag‐NPs is done against Escherichia coli and noted that the zone of inhibition is found to be 1.6 cm as compared to inhibition of 0.4 cm for pine gum reaching an advance of 75%. The various arrangements are enhanced and sited on the basis of TOPSIS technique.
Transparent Surfactant/Epoxy Composite Coatings with Self‐Healing and Superhydrophilic Properties
Authors: Li Wei , Wu Gang , Tan Jinhui , Yu Xufeng , Sun Gang , You Bo
Published: April 2019

In this paper, highly transparent, robust, and superhydrophilic polyethylene glycol tert‐octylphenyl ether nonionic surfactant/epoxy (Triton X‐100/epoxy, TXE) composite coatings are successfully prepared with a facile, one‐step drop‐casting method by mixing Triton X‐100 with an epoxy resin and an amine curing agent. The hydrogen bond reaction between the hydroxyl group of Triton X‐100 and the ether group of the epoxy resin improves the compatibility and reduces the glass transition temperature (Tg) of the TXE composite coatings. The free Triton X‐100 surfactant easily accumulates on the surface of the TXE composite coatings, which improves the hydrophilicity of the TXE composite coatings. The TXE composite coatings are self‐healable because of their low Tg and the migration of Triton X‐100 small molecule surfactant. Any damage arising from denting, cutting, or wiping by tetrahydrofuran can be healed, and the composite coating can regain its superhydrophilic properties through a heating process. The TXE composite coatings demonstrate excellent acid, alkali, salt, high temperature, and ultrasonic‐resistant properties. This facile preparation technique has the potential to be applied in the scalable fabrication of multifunctional coatings in anti‐fogging, oil–water separation, and optical–electric devices.
Controllable Aligned Nanofiber Hybrid Yarns with Enhanced Bioproperties for Tissue Engineering
Authors: Liu Chengkun , Li Boyu , Mao Xue , Zhang Qing , Sun Runjun , Gong R. Hugh , Zhou Fenglei
Published: April 2019

Electrospun nanofibers have large surface area, high porosity, and controllable orientation while conventional microfibers have appropriate mechanical properties such as stiffness, strength, and elasticity. Therefore, the combination of nanofibers and microfibers can provide building elements to engineer biomimetic scaffolds for tissue engineering. In this study, a core–shell structured fibrous structure with controllable surface topography is created by electrospinning polycaprolactone (PCL) nanofibers onto polyglycolic acid (PGA) microfibers. The surface morphology, surface wettability, and mechanical properties of the resultant core–shell structure are characterized. FE‐SEM images reveal that the orientation of PCL nanofibers on the yarn surface can be tuned by a fiber collector and rotating disks. Benefiting from the introduction of a shell of aligned PCL nanofibers on the core of PGA yarn, the uniaxially aligned PCL nanofiber–covered yarns (A‐PCLs) exhibit higher hydrophilicity, porosity, and mechanical properties than the core PGA yarns. Moreover, A‐PCLs promote the adhesion and proliferation of BALB/3T3 (mouse embryonic fibroblast cell line), and guide cell growth along the biotopographic cues of the PCL nanofibers with controllable alignment. The developed core–shell yarn having both the desired surface topography of PCL nanofibers and mechanical properties of PGA microfibers demonstrates great potential in constructing various tissue scaffolds.