bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation of Texaco and Barriers to Its Implementation
Authors: Al Dousari Shafi F.
Published: October 2019

Purpose: To evaluate the barriers for implementing learning policy to transform Texaco into a Learning Organization. Design/Methodology: The study has incorporated quantitative approach and distributed 200 questionnaires among the employees of Texaco, out of which 189 questionnaires were received with complete responses. The extent of paradigm shift to take place in Texaco was estimated by conducting personal interviews. Chi-Square and ANOVA test have been applied through SPSS on the dependent and independent variables. Findings: Non-Learning culture (p=0.000), Limited resources (p=0.001), Program Focus (p=0.00) and not discussing the un-discussible (p=0.00) have been found as the main barriers in the way of transformation of Texaco as a learning organization. Research Implications: The implication of this research can help to adopt the positive transformational changes of the company. Practical Implications: The findings can help Texaco to identify the potential barriers and mitigate their influence on their business operations. Social Implication: Positive societal influence can be significant in improving the competitive strategy of Texaco. Originality: The changes in the organizational process can be implemented to improve the learning policy of Texaco.
Corporate Reputation and Subsequent Financial Performance: A Theoretical Explanation of the Mediating Role of Trust
Authors: Gunawardena M. M. D. De S. , Senathiraja R. , Buvanendra S.
Published: October 2019

Amidst empirical evidence that claim corporate reputation affects subsequent financial performance of firms, the literature does not provide a comprehensive explanation for this relationship. The aim of this article therefore is to provide a theoretical explanation on how corporate reputation affects the subsequent financial performance. The available literature supports that corporate reputation signals trustworthiness of firms, based on which stakeholders make decisions such as to trust a firm and allocate valuable, scarce resources. The resources so allocated would help a firm to achieve its objectives, including targeted financial performance in subsequent years. In order to explain the role of trust in the relationship between corporate reputation and subsequent financial performance, the researchers combine two extensively referred models from the reputation and trust literature, the model of reputation-financial performance dynamics and the proposed model of organizational trust. The signaling theory and the stakeholder theory provide the theoretical explanation for the new model proposed.
Optimization of Ultrasound-Assisted Extraction of Phenolic Antioxidants from Lotus corniculatus
Authors: Fumić Barbara , Jug Mario , Zovko Končić Marijana
Published: October 2019

Ultrasound-assisted extraction of phenolic antioxidants from Lotus corniculatus was optimized using response surface methodology. The extraction was performed according to the Box–Behnken design with ethanol concentration, temperature, and pH, as independent variables. The responses were extraction yield, DPPH radical scavenging activity (RSA) IC50 and content of different phenolic compounds (total phenols, flavonoids and phenolic acids, as well as quercetin, kaempferol and genistein derivatives). The models were used to calculate best conditions for maximal extraction of phenolic compounds and antiradical activity. Use of the optimized extraction parameters increased the content of quercetin and kaempferol derivatives more than tenfold (from 6.07 to 65.10 mg mL–1 and 6.69 to 92.75 mg mL–1, respectively). The results of this work stress the importance of careful selection of conditions for flavonoids extraction. Abundance of bioactive phenolics in L. corniculatus extracts obtained under optimized extraction conditions opens the possibility for wider utilization of this plant.
Finansowanie terroryzmu
w państwach Unii Europejskiej
Authors: Żyła Edyta
Published: October 2019

Zagrożenie atakami terrorystycznymi w Europie Zachodniej skłoniło społeczność
międzynarodową do zintensyfikowania działań mających na celu walkę z terroryzmem.
Ich ważnym elementem stało się przeciwdziałanie finansowaniu terroryzmu
oraz jego zwalczanie. Główną rolę w tym procesie odgrywa Grupa Specjalna do
spraw Przeciwdziałania Praniu Pieniędzy (FATF), która przygotowuje i aktualizuje
stosowne rekomendacje dla poszczególnych państw oraz diagnozuje zagrożenia
i usiłuje im przeciwdziałać.
Autorka określa zakres i specyfikę zagrożeń związanych z finansowaniem terroryzmu
w państwach Unii Europejskiej oraz wskazuje działania podejmowane
przez FATF w celu określenia zagrożeń.
Social and geographical inequalities in the choice of foot therapy as preventive care: A nationwide registry study on Danish people with diabetes
Authors: Halling Christine Marie Bækø , Ladenburg Jacob
Published: October 2019

Diabetic foot ulcers are a serious complication of diabetes with high costs and adverse sequelae, such as lower-extremity amputations. International guidelines recommend that all people with diabetes should have their feet inspected at least once a year. This study is aimed at determining whether socioeconomic factors influence the probability of having the feet inspected by a chiropodist on a nationally representative sample of people with diabetes. We estimate a logit model for the choice determinants of foot inspections among people with diabetes. Of all people with diabetes, 73% have not had their feet inspected by a chiropodist. The results indicate social and geographical inequality with regard to diabetic foot care. Especially for ethnic minorities, people with low income and people living in rural and remote areas. The findings are robust to a series of sensitivity analyses.Published: Online October 2019.
Optimal Design of Narrow Line‐Width Front Contact Grid Pattern for Silicon Solar Cells and Low‐Cost Fabrication of Electroless Nickel Plated Imprint Lithography Hard Stamp
Authors: Aleem Mahaboobbatcha , Karuppanan Karthikeyan K. , Raghu Appu Vengattoor , Satheesan Nijil , Krishnan Balachander , Pullithadathil Biji
Published: October 2019

Herein, a systematic investigation on the design and development of a cost‐effective nickel hard stamp suitable for fabrication of a new front‐side metallization pattern to reduce the shadow losses in solar cells is demonstrated. Finite element analysis (FEA)–based simulations indicate an optimal finger width of ≈20 μm with interfinger spacing of 1000 μm which can effectively enhance solar cell efficiency by ≈1% due to reduced shadow loss. The optimal grid design is further patterned by means of nanoimprint lithography (NIL) followed by an electroless deposition method. A cost‐effective, electroless deposited nickel hard template is developed for NIL patterning using UV pattern transfer. To avoid the physical damages during the imprinting process and improve the durability of the NIL stamp, silane‐based antiadhesive coating is used which can withstand up to 18 cycles of imprinting process. The nickel hard stamp exhibits improved hardness of 5.63 GPa and roughness of 8 nm and is used to transfer the narrow‐line width patterns during the imprinting process. The proposed industry‐ready technology overcomes the limitations of the existing screen printing process pertaining to the formation of high‐aspect‐ratio narrow line‐width finger grid patterns.
3D Printed Cartilage‐Like Tissue Constructs with Spatially Controlled Mechanical Properties
Authors: de Melo Bruna A. G. , Jodat Yasamin A. , Mehrotra Shreya , Calabrese Michelle A. , Kamperman Tom , Mandal Biman B. , Santana Maria H. A. , Alsberg Eben , Leijten Jeroen , Shin Su Ryon
Published: October 2019

Developing biomimetic cartilaginous tissues that support locomotion while maintaining chondrogenic behavior is a major challenge in the tissue engineering field. Specifically, while locomotive forces demand tissues with strong mechanical properties, chondrogenesis requires a soft microenvironment. To address this challenge, 3D cartilage‐like tissue is fabricated using two biomaterials with different mechanical properties: a hard biomaterial to reflect the macromechanical properties of native cartilage, and a soft biomaterial to create a chondrogenic microenvironment. To this end, a bath composed of an interpenetrating polymer network (IPN) of polyethylene glycol (PEG) and alginate hydrogel (MPa order compressive modulus) is developed as an extracellular matrix (ECM) with self‐healing properties. Within this bath supplemented with thrombin, human mesenchymal stem cell (hMSC) spheroids embedded in fibrinogen are 3D bioprinted, creating a soft microenvironment composed of fibrin (kPa order compressive modulus) that simulate cartilage's pericellular matrix and allow a fast diffusion of nutrients. The bioprinted hMSC spheroids present high viability and chondrogenic‐like behavior without adversely affecting the macromechanical properties of the tissue. Therefore, the ability to locally bioprint a soft and cell stimulating biomaterial inside of a mechanically robust hydrogel is demonstrated, thereby uncoupling the micro‐ and macromechanical properties of the 3D printed tissues such as cartilage.
Synthesis and Enhancement of Electroactive Biomass/Polypyrrole Hydrogels for High Performance Flexible All‐Solid‐State Supercapacitors
Authors: Peng Zhiyuan , Wang Chuanzhi , Zhang Zhicheng , Zhong Wenbin
Published: October 2019

Recently, electroactive biomass‐based hydrogels have attracted great attention for flexible supercapacitor electrodes due to its porous, renewable, earth‐abundant, low‐cost, and environmentally friendly characters. However, it is challenging to facilely prepare biomass‐based hydrogels with simultaneously possesses high mechanical strength and excellent electrochemical performance. In this work, the lignosulfonate/polypyrrole (Lig/PPy) hydrogel (LP54) is obtained. In order to further improve the mechanical strength and electrochemical performance of LP54, functionalized porous carbon nanospheres/lignosulfonate/polypyrrole hydrogel (FPCSLP54) is prepared by introducing a trace of FPCS (≈4.5 wt%) fabricated by hydrothermal treatment the mixture of PCS and pyrrole into the prepared LP54 system. FPCS can be uniformly anchored into Lig/PPy framework. The LP54 and FPCSLP54 exhibit compressive strength of 6.0 and 9.3 kPa with the water content of 94.9% and 94.3%, respectively. Meanwhile, as‐prepared LP54 and FPCSLP54 are separately assembled into symmetric flexible supercapacitors with cellulose/H2SO4 hydrogel electrolytes, which exhibit superior areal capacitance (463 and 522 mF cm−2), good rate capability and outstanding energy density (41.2 and 72.5 µWh cm−2). Remarkably, flexible supercapacitors present outstanding electrochemical stability even suffering 1000 bending cycles. In this work, the strategy to construct electroactive biomass‐based hydrogels is contributed and a new method to enhance the properties of hydrogels is provided.
A Layered Inorganic–Organic Open Framework Material as a 4 V Positive Electrode with High‐Rate Performance for K‐Ion Batteries
Authors: Hameed Abdulrahman Shahul , Katogi Akihiro , Kubota Kei , Komaba Shinichi
Published: October 2019

K‐ion batteries (KIBs) are promising for large‐scale energy storage owing to various advantages like the high abundance of potassium resources in the Earth's crust, high operational potentials, and high power due to fast diffusion of K+ ions. However, to realize the practical application of KIBs, electrode materials are needed with high operational voltage, good capacity, long cycle life, and low‐cost. This work reports a layered open framework material, K2[(VOHPO4)2(C2O4)], composited with reduced graphene oxide (rGO) as a 4 V positive electrode material for KIBs. The material is prepared by a simple precipitation reaction at room temperature. The material demonstrates reversible K‐extraction/insertion with conventional carbonate ester KPF6 solutions; however, with low specific capacity and low Coulombic efficiency. A high discharge capacity of >100 mAh g−1 with good cycling stability and higher Coulombic efficiency is achieved in a highly concentrated electrolyte, 7 mol kg−1 of potassium bis(fluorosulfonyl)amide (KFSA) in dimethoxyethane (DME) at 0.1 C rate. Due to the facile migration of K+ ions in the framework, the material exhibits excellent rate capability with a discharge capacity of 80 mAh g−1 at 10 C rate, and a good capacity retention of 67% after 500 cycles at 2 C rate.
Asymmetric hybridization in Central European populations of theDryopteris carthusianagroup
Authors: Hornych Ondřej , Ekrt Libor , Riedel Felix , Koutecký Petr , Košnar Jiří
Published: October 2019

Premise

Hybridization is a key process in plant speciation. Despite its importance, there is no detailed study of hybridization rates in fern populations. A proper estimate of hybridization rates is needed to understand factors regulating hybridization.

Methods

We studied hybridization in the EuropeanDryopteris carthusianagroup, represented by one diploid and two tetraploid species and their hybrids. We sampled ~100 individuals per population in 40 mixed populations of theD. carthusianagroup across Europe. All plants were identified by measuring genome size (DAPIstaining) using flow cytometry. To determine the maternal parentage of hybrids, we sequenced the chloroplast regiontrnL–trnF of all taxa involved.

Results

We found hybrids in 85% of populations. TriploidD. ×ambroseaeoccurred in every population that included both parent species and is most abundant when the parent species are equally abundant. By contrast, tetraploidD. ×deweveriwas rare (15 individuals total) and triploidD. ×sarvelaewas absent. The parentage of hybrid taxa is asymmetric. Despite expectations from previous studies, tetraploidD. dilatatais the predominant male parent of its triploid hybrid.

Conclusions

This is a thorough investigation of hybridization rates in natural populations of ferns. Hybridization rates differ greatly even among closely related fern taxa. In contrast to angiosperms, our data suggest that hybridization rates are highest in balanced parent populations and support the notion that some ferns possess very weak barriers to hybridization. Our results from sequencing cpDNAchallenge established notions about the correlation of ploidy level and mating tendencies.
Grange syndrome due to homozygous YY1AP1 missense rare variants
Authors: Ciuffetelli Alamo Isabella V. , Kwartler Callie S. , Regalado Ellen R. , Afifi Rana O. , Parkash Sandhya , Rideout Andrea , Guo Dong‐chuan , Milewicz Dianna M.
Published: October 2019

Grange syndrome (OMIM 602531) is an autosomal recessive condition characterized by severe early onset vascular occlusive disease and variable penetrance of brachydactyly, syndactyly, bone fragility, and learning disabilities. Grange syndrome is caused by homozygous or compound heterozygous loss‐of‐function variants in the YYA1P1 gene. We report on the case of a 53‐year old female with novel homozygous missense variants in YYA1P1 (c.1079C>T, p.Pro360Leu), presenting with a history of brachysyndactyly, hypertension, and ischemic stroke. Imaging studies revealed stenosis of the bilateral internal carotid with extensive collateralization of cerebral vessels in a moyamoya‐like pattern, along with stenosis in the splenic, common hepatic, celiac, left renal, and superior mesenteric arteries. Functional studies conducted with the patient's dermal fibroblasts suggest that the p.Pro360Leu variant decreases the stability of the YY1AP1 protein. This is the first report of a missense variant associated with Grange syndrome characterized by later onset of vascular disease and a lack of developmental delay and bone fragility.
Coagulation/flocculation process for marble processing plant effluent: Modelling and optimization through response surface methodology
Authors: Çırak Mustafa , Atay Hüsnügül Yilmaz
Published: October 2019

In this study, the coagulation‐flocculation of a wastewater discharged from a marble processing plant was statistically analyzed and optimized. To make a systematic investigation on the coagulation‐flocculation of the highly turbid wastewater (>1000 NTU), the response surface methodology was used to estimate a capable quadratic model with R‐squared value of 98.84%. According to this model, the most critical parameter was the suspension pH with a p‐value < 0.0001. Furthermore, the PEO‐flocculant was proven as a substantial agglomerating reagent specifically at pH 12. On the other hand, no significant turbidity removal was observed upon the addition of the Fe‐coagulant. When the experimental parameters of the coagulation‐flocculation were optimized, it was found out that the minimum supernatant turbidity value of 3.81 NTU can be achieved by using the minimum amount of the Fe‐coagulant:50 mg/l, and the maximum amount of the PEO‐flocculant of 1.5 ppm at pH 11.5‐12.0. In conclusion, it was proved that the significance of the calcium dissolved from the marble particles was greater than the Fe‐coagulant in this process. The hydrolyzed calcium (CaOH+) species established a chemical bridge between the particle and the polymer and, as a result, enhanced the performance of the flocculation at the alkaline pH values.
High‐toughness, environment‐friendly solid epoxy resins: Preparation, mechanical performance, curing behavior, and thermal properties
Authors: Yang Jiayao , He Xingwei , Wang Hengxu , Liu Xiaohuan , Lin Peng , Yang Shengxiang , Fu Shenyuan
Published: October 2019

The development of a facile and efficient approach to prepare high‐toughness epoxy resin is vital but has remained an enormous challenge. Herein, we have developed a high‐performance environment‐friendly solid epoxy resin modified with epoxidized hydroxyl‐terminated polybutadiene (EHTPB)viaone‐step melt blending. The characterization, mechanical performance, curing behavior, and thermal properties of EHTPB‐modified epoxy resin were investigated. EHTPB‐modified epoxy resin exhibited excellent toughness with a 100% increase in elongation at break of tensile than that of neat epoxy resin. The transfer stress and dissipated energy in the rubber phase were predominant mechanisms of toughening. The toughening effect of EHTPB on solid epoxy resin was better than that of some of the previously reported liquid epoxy resins. Meanwhile, at 10 wt % of EHTPB loading, the EHTPB‐modified epoxy resin displayed high strength and 22 and 101% improvement of flexural strength and impact strength, respectively. Moreover, at 10 wt % of EHTPB loading, the activation energy of EHTPB‐modified epoxy resin for curing reaction decreased from 73.89 to 65.12 kJ·mol−1, which is beneficial for the curing reaction. Furthermore, EHTPB‐modified epoxy resin had a good thermal stability and the initial degradation temperature increased from 249 to 313 °C at 10 wt % of EHTPB loading. This work provides a simple‐preparation and highly efficient and large‐scale approach for the production of high‐toughness environment‐friendly solid epoxy resins. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2020,137, 48596.
Clavicle in Carnivorans: A Forgotten Bone
Authors: de Souza Junior Paulo , Viotto‐Souza Wilson , Mendes Vanessa Pereira , Bernardes Fernanda Coelho Simas , dos Anjos Bruno Leite , Abidu‐Figueiredo Marcelo , Santos André Luiz Quagliatto
Published: October 2019

The clavicle is a bone whose development is related to the versatility of the thoracic limbs in mammals. Studies with vestigial structures are scarce and controversial, especially in the order Carnivora. The objective of this study was to verify the presence and to investigate the shape and constitution of the clavicle in neotropical carnivores. In order to do this, 108 cadavers of 19 different species were collected dead on highways and were analyzed. The clavicles were submitted to dissections, longitudinal length measurements, radiographs, histological sections and, in some cases, diaphanization. Sixteen of the 19 species had clavicles in both sides, being significantly larger (P < 0.05) and distinctly more radiopaque in the felids than in the other families. There were no macro or microscopic evidence of clavicle in the specimens of Nasua nasua (n = 6), Conepatus semistriatus (n = 2), and Conepatus chinga (n = 1). The clavicle of the males of Lycalopex gymnocercus, Galictis cuja, and Leopardus geoffroyi was significantly larger (P < 0.05). The predominating contour of the clavicles was a thin stick with cranial convexity. The histological sections demonstrated compact bone consisting of trabecula and lamellae filled by bone marrow and different levels of occupation by chondroid matrix. It can be proposed the clavicles of the order Carnivora, although vestigial and rarely absent, have their presence, constitution and shape more associated with the phylogenetic proximity and evolutionary history of the species than to the variety of movements the thoracic limbs perform in free‐living conditions. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1831–1841, 2020. © 2019 American Association for Anatomy
How do students engage with visual sources in the teaching and learning of History?
Authors: Haward Tom
Published: October 2019

The idea that the emerging global society is also the age of the ‘pictorial turn’ is one in which the use of visual historical sources (VHS) in the teaching and learning of History in English secondary schools is situated. Yet there has been little research conducted into how such sources are experienced by teachers and students in the classroom, and the ways these are mediated by political, cultural and social forces. This article considers how students engage with VHS and some of the implications this has for teacher pedagogy. It is based on a qualitative study conducted with secondary (aged 11–18) school students, teachers and gallery educators that draws on a form of constructivist grounded theory. It uses thematic analysis, as well as a variety of theoretical positions, to help conceptualise the perceptions described and observed in the research. The findings illustrate how descriptions that emerge around how students engage with VHS can be seen to coalesce around a number of axes, based on binary positions such as immediate–distant and like text–not like text, which are used to describe experiences that may at times seem paradoxical, and which in turn have pedagogical implications for teachers.
Community through Culture: From Insects to Whales
Authors: Allen Jenny A.
Published: October 2019

It has become increasingly clear that social learning and culture occur much more broadly, and in a wider variety of animal communities, than initially believed. Recent research has expanded the list to include insects, fishes, elephants, and cetaceans. Such diversity allows scientists to expand the scope of potential research questions, which can help form a more complete understanding of animal culture than any single species can provide on its own. It is crucial to understand how culture and social learning present in different communities, as well as what influences community structure and culture may have on one another, so that the results across these different studies may most effectively inform one another. This review presents an overview of social learning in species across a spectrum of community structures, providing the necessary infrastructure to allow a comparison of studies that will help move the field of animal culture forward.
Fostering Systems Thinking in Biological Education Using the Example of Plant Hormones
Authors: Robischon Marcel
Published: October 2019

Systems thinking is an increasingly recognized paradigm in education in both natural and social sciences, a particular focus being, naturally, in biology. This article argues that plant biology, and in particular, plant hormonal signaling, provides highly illustrative models for learning and teaching in a systems paradigm, because it offers examples of highly complex networks, ranging from the molecular‐ to ecosystem‐scale, and in addition lends itself to the use of real‐life biological objects.
Fisetin, a phytopolyphenol, targets apoptotic and necroptotic cell death in HepG2 cells
Authors: Sundarraj Kiruthika , Raghunath Azhwar , Panneerselvam Lakshmikanthan , Perumal Ekambaram
Published: October 2019

Fisetin (3,7,3′,4′‐tetrahydroxyflavone), a bioactive dietary flavonoid, intrigued scientists for its anticancer potential against various cancer types. We investigated the fisetin‐induced inhibition of growth and survival of human hepatocellular carcinoma. Fisetin decreased cell viability and proliferation of HepG2 cells as revealed from MTT and clonogenicity assays. Cell cycle arrest in the G2/M phase was observed. Annexin V/propidium iodide (PI) staining followed by flow cytometry revealed that fisetin induced both apoptosis and necroptosis in HepG2 cells. Apoptotic cells were significantly increased on fisetin treatment as observed in morphological evaluations and 4′,6‐diamidino‐2‐phenylindole and Acridine orange staining. Flow cytometry, fluorescence imaging, and 2′, 7′‐dichlorofluorescein diacetate analyses showed an increase in reactive oxygen species (ROS) generation on fisetin treatment. Pretreatment with N‐acetyl cysteine inhibited ROS production and also rescued mitochondrial membrane potential in HepG2 cells. The underlying mechanisms of apoptosis and necroptosis were determined by analysis of their respective signaling molecules using qRT‐PCR and Western blotting. Fisetin showed a marked increase in the expression of TNFα and IKκB with a decrease in NF‐κB, pNF‐κB and pIKκB expression. Fisetin reduced the expression of Bcl2, and elevated levels of Bax, caspase‐3, and PARP and thus induced apoptosis in HepG2 cells. zVAD suppressed the fisetin‐induced expression of caspase‐8, RIPK1, RIPK3, and MLKL as opposed to fisetin treatment. Nec‐1 + fisetin could not completely block necroptosis, which warrants further investigation. Taken together, our findings demonstrate that the fisetin exhibited anti‐proliferative effects on HepG2 cells through apoptosis and necroptosis via multiple signaling pathways. Fiestin has potential as a therapeutic agent against hepatocellular carcinoma.
Simulation of pH level distribution inside a coiled flow inverter for continuous low pH viral inactivation
Authors: David Laura , Waldschmidt Lisa Marie , Lobedann Martin , Schembecker Gerhard
Published: October 2019

The continuous production of monoclonal antibodies (mAbs) with the help of disposable equipment poses one of the future major changes in the pharmaceutical industry. Consequently, continuous viral clearance needs to be developed as well. The coiled flow inverter (CFI) was successfully implemented in the continuous downstream as a residence time module for low pH viral inactivation. As the elution profile of the upstream continuously operated protein A chromatography results in fluctuating pH values, the pH level distribution inside the CFI is highly relevant.

This study presents a detailed investigation of pH level distribution inside the CFI at varying inlet conditions with the help of computational fluid dynamics simulation. The simulation model was validated first with the help of experimental data. Afterwards, the model was used for further investigations. It was determined that with a pH sine curve as input, the duration until steady state at the outlet requires two times the minimum residence time of the apparatus. Moreover, it could be observed that the CFI itself offers a progressive dampening effect on the pH level distribution. Afterwards, different forms of the sine curve representing different operation modes of the continuous protein A chromatograph were tested to evaluate this dampening capability. It became clear that the switch time has the highest influence on the resulting pH of the outlet stream and should be considered for process development. Finally, the radial pH profiles at different positions inside the CFI were determined. This once again revealed the high radial mixing capability of the CFI and its influence on the resulting product stream.
pH profiles of cellulases depend on the substrate and architecture of the binding region
Authors: Røjel Nanna , Kari Jeppe , Sørensen Trine H. , Borch Kim , Westh Peter
Published: October 2019

Understanding the pH effect of cellulolytic enzymes is of great technological importance. In this study, we have examined the influence of pH on activity and stability for central cellulases (Cel7A, Cel7B, Cel6A from Trichoderma reesei, and Cel7A from Rasamsonia emersonii). We systematically changed pH from 2 to 7, temperature from 20°C to 70°C, and used both soluble (4‐nitrophenyl β‐
d‐lactopyranoside [pNPL]) and insoluble (Avicel) substrates at different concentrations. Collective interpretation of these data provided new insights. An unusual tolerance to acidic conditions was observed for both investigated Cel7As, but only on real insoluble cellulose. In contrast, pH profiles on pNPL were bell‐shaped with a strong loss of activity both above and below the optimal pH for all four enzymes. On a practical level, these observations call for the caution of the common practice of using soluble substrates for the general characterization of pH effects on cellulase activity. Kinetic modeling of the experimental data suggested that the nucleophile of Cel7A experiences a strong downward shift in pKa upon complexation with an insoluble substrate. This shift was less pronounced for Cel7B, Cel6A, and for Cel7A acting on the soluble substrate, and we hypothesize that these differences are related to the accessibility of water to the binding region of the Michaelis complex.
Development of a gas chromatography–mass spectrometry method for breast cancer diagnosis based on nucleoside metabolomes 1‐methyl adenosine, 1‐methylguanosine and 8‐hydroxy‐2′‐deoxyguanosine
Authors: Omran Mohamed M. , Rashed Ramzy E. , Darwish Hossam , Belal Arafa A. , Mohamed Faten Z.
Published: October 2019

Metabolomes are small molecule metabolites (<1000 Da) produced by cellular processes. Metabolomes are close counterparts to the genome, transcriptome and proteome. The aim of this study was to develop a method to detect and quantify candidate nucleoside metabolomes 1‐methyl adenosine (1‐MA), 1‐methylguanosine (1‐MG) and 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) in the urine of patients with breast cancer using gas chromatography–mass spectrometry (GC–MS). The method was applied to urine specimens from patients with breast cancer (n = 56) and benign breast tumors (n = 22), as well as from healthy females (n = 20). The relative standard deviations of precision and repeatability analysis were <10%, and recoveries ranged from 88.5 to 105.6%. Limits of detection were 0.014, 0.012, and 0.018 mg/L for 1‐MA, 1‐MG and 8‐OHdG, respectively. The lower limits of quantitation were 0.056, 0.048 and 0.072 mg/L, respectively. There were significant differences in concentrations of candidate metabolomes between patients with cancer and the healthy individuals, especially for those in the early stages of the disease (p < 0.001). No significant differences were observed between the benign and healthy groups. In conclusion, a reliable GC–MS method for the detection and quantification of 1‐MA, 1‐MG, and 8‐OHdG metabolomes in urine has been developed.
Quantification and pharmacokinetic property of verubecestat an BACE1 inhibitor in rat plasma
Authors: Wang Qiong , Wang Haiyun , Zhong Youyan , Mei Yibin
Published: October 2019

In the present study, an ultra‐performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) approach was designed to measure the rat plasma levels of verubecestat with diazepam as the internal standard. Acetonitrile‐based protein precipitation was applied for sample preparation, then the analyte verubecestat was subjected to gradient elution chromatography with a mobile phase composed of acetonitrile (A) and 0.1% formic acid in water (B). Verubecestat was monitored by m/z 410.1 → 124.0 transition for quantification by multiple reaction monitoring (MRM) in positive ion electrospray ionization (ESI) source. When the concentration of verubecestat ranged from 1 to 2500 ng/mL, the method exhibited good linearity. For verubecestat, the intra‐ and inter‐day precision were determined with the values of 2.9–9.0% and 0.4–6.5%, respectively; and the accuracy ranged from −2.2% to 10.4%. Matrix effect, extraction recovery, and stability data were in line with the standard FDA guidelines for validating a bioanalytical method. The validity of the developed method was confirmed through the pharmacokinetic study.
Transcatheter aortic valve replacement versus surgical aortic valve replacement in low‐surgical‐risk patients: An updated meta‐analysis
Authors: Goel Sunny , Pasam Ravi T. , Wats Karan , Patel Jignesh , Chava Srilekha , Gotesman Joseph , Malik Bilal A. , Frankel Robert , Shani Jacob , Gidwani Umesh
Published: October 2019

Objective

The purpose of this meta‐analysis is to compare the safety and efficacy of transcatheter aortic‐valve replacement (TAVR) to surgical aortic valve replacement (SAVR) in low‐surgical‐risk patients.

Background

TAVR is proven to be safe and effective in patients with high‐ and intermediate‐risk aortic stenosis. However, there is limited data on the safety and efficacy of TAVR in patients with low surgical risk.

Methods

We conducted an electronic database search of all published data for studies that compared TAVR to SAVR in low‐surgical‐risk patients (mean society for thoracic surgery [STS] score <4% and/or logistic EuroScore <10%) and reported on subsequent all‐cause mortality, cardiac mortality, stroke rates, and other outcomes of interest. Event rates were compared with a forest plot of odds ratio using a random‐effects model assuming interstudy heterogeneity.

Results

A total of seven studies (n = 6,293 patients; TAVR = 2,912; and SAVR = 3,381) were included in the final analysis. There was no significant difference between TAVR and SAVR in terms of all‐cause mortality (OR 0.82; 95% CI 0.50–1.36, I2 = 51%), cardiac mortality (OR 0.57; 95% CI 0.32–1.02, I2 = 0%), new pacemaker implantation (OR = 3.11; 95% CI 0.58–16.60, I2 = 89%), moderate/severe paravalvular leak (PVL; OR 3.50; 95% CI 0.64–19.10, I2 = 54%) and rate of stroke (OR 0.63; 95% CI 0.34–1.15, I2 = 39%) at 1‐year follow‐up. TAVR was found to have a significantly lower incidence of atrial fibrillation (AF; OR 0.15, 95% CI 0.10–0.24, I2 = 38%) as compared to SAVR.

Conclusion

The results of our meta‐analysis demonstrate similar rates of all‐cause mortality, cardiac mortality, and stroke at 1‐year follow‐up in patients undergoing TAVR and SAVR. TAVR is associated with a lower incidence of AF relative to SAVR. However, there was a significantly higher incidence of PVL with TAVR compared to SAVR.
Real world validation of the nonhyperemic index of coronary artery stenosis severity—Resting full‐cycle ratio—RE‐VALIDATE
Authors: Kumar Gautam , Desai Rupak , Gore Ankita , Rahim Hussein , Maehara Akiko , Matsumura Mitsuaki , Kirtane Ajay , Jeremias Allen , Ali Ziad
Published: October 2019

Objective

The primary objective was to demonstrate diagnostic equivalence between RFR and iFR in clinical practice.

Background

The instantaneous wave‐free ratio (iFR), a nonhyperemic pressure ratio (NHPR), has been shown to be noninferior to fractional flow reserve (FFR) in determining coronary artery stenosis severity in intermediate lesions. However, iFR has a number of inherent limitations, including sensitive landmarking of the pressure waveform and the assumption that maximal flow and minimal microcirculatory resistance occur during a fixed period within diastole. The resting full‐cycle ratio (RFR) is a novel NHPR which evaluates the entire cardiac cycle independent of the ECG, landmark identification, and timing within the cardiac cycle.

Methods

RE‐VALIDATE RFR was designed to determine the diagnostic utility of RFR for the physiological assessment of coronary artery disease in clinical practice compared to iFR. RFR was also tested for equivalence (1% margin), diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), areas under the receiver operated characteristic curve (AUC), and correlations compared to calculated iFR (iFRcalc).

Results

From two centers, 501 blinded rest‐ and hyperemic pressure recordings from 431 patients were suitable for analysis according to a core laboratory. The mean FFR, RFR, and iFRcalc were 0.80 ± 0.09, 0.90 ± 0.08, and 0.90 ± 0.08, respectively. Based on a binary cut‐off approach (RFR/iFR ≤0.89), RFR demonstrated equivalence with iFRcalc (95% confidence interval: 0.025–0.019) with overall diagnostic accuracy 97.8%, sensitivity 97.8%, specificity 97.8%, PPV 96.2%, NPV 98.7%, and AUC 0.96 (0.94–0.97, p < .001). RFR had a mean bias 0.003 (95% limits of agreement: 0.019, −0.025).

Conclusions

RFR was equivalent to iFR in clinical practice. RFR is an alternative NHPR, avoiding the need for hyperemic agents, thus potentially reducing side effects, procedural time and cost compared to FFR.
Assessment of intermediate coronary lesions by fractional flow reserve and quantitative flow ratio in patients with small‐vessel disease
Authors: Erbay Aslihan , Steiner Julia , Lauten Alexander , Landmesser Ulf , Leistner David M. , Stähli Barbara E.
Published: October 2019

Background

Quantitative flow ratio (QFR) has recently been introduced as a novel, less‐invasive, adenosine‐free measure for functional coronary lesion assessment. Whether reference vessel dimensions affect functional lesion assessment is uncertain.

Methods

A total of 436 patients with 516 interrogated coronary vessels by means of FFR were included in the study. Patients were dichotomized according to the median reference vessel diameter (group 1: ≤2.8 mm and group 2: >2.8 mm). QFR analyses were performed offline at the institution's core laboratories.

Results

Reference vessel diameter was 2.5 [2.3–2.7] mm in group 1 and 3.3 [3.0–3.6] mm in group 2. Diameter stenosis (41.4 [36.4–47.6] % vs. 41.4 [36.4–45.7] %, p = .20) did not differ among groups. Median FFR values were lower in group 1 (0.87 [0.81–0.92]) as compared with group 2 (0.89 [0.84–0.93], p = .001). Consistently, QFR values were lower in group 1 (0.88 [0.82–0.92]) than in group 2 (0.91 [0.85–0.94], p = .001). The proportions of functionally significant coronary lesions as defined by FFR ≤0.80 were 24.1% and 14.2% in groups 1 and 2 (p = .005), and as defined by cQFR ≤0.80 20.4% and 11.8% (p = 0.009), respectively. In ROC analysis for an FFR ≤.80, the AUC was 0.89 (95% CI 0.85–0.93, p < .001) in group 1 and 0.81 (95% CI 0.76–0.86, p < .001) in group 2.

Conclusions

These results suggest that QFR measurements are accurate irrespective of the reference vessel diameter. Future studies are needed to elucidate the higher percentage of functionally significant lesions observed in small vessels despite a similar angiographic lesion severity.
Short‐term decrease of left atrial size predicts clinical outcome in patients with severe aortic stenosis undergoing TAVR
Authors: De Rosa Roberta , Murray Marie‐Isabel , Schranz Dietmar , Mas‐Peiro Silvia , Esmaeili Anoosh , Zeiher Andreas M. , Fichtlscherer Stephan , Vasa‐Nicotera Mariuca
Published: October 2019

Objectives

We investigated whether transcatheter aortic valve replacement (TAVR) results in a short‐term decrease in left atrium (LA) size and whether such decrease may predict patients' clinical outcome.

Background

Increased LA size is a hallmark of severe aortic stenosis (AS) and is associated with adverse patients' cardiovascular outcome. Whether TAVR may lead to a decrease in LA size is not known.

Methods and results

Hundred and four patients with severe symptomatic AS and dilated LA undergoing TAVR were enrolled. LA volume was assessed by echocardiography before and shortly after TAVR (median time: 7 days). Composite rate of death and hospitalization for acutely decompensated heart failure (HF) was recorded and clinical status was assessed through NYHA‐class evaluation at 12 months median follow‐up. After TAVR, 49 patients (47%) demonstrated a decrease in LA volume. Despite a similar baseline NYHA class, patients with decrease in LA size had significant better improvement in clinical status respect to patients with unvaried LA size (NYHA post: 1.2 ± 0.6 vs. 1.8 ± 1.1, p = .001; NYHA reduction: −1.6 ± 0.9 vs. −0.9 ± 1.0, p = .002, respectively). Moreover, these patients had a significantly reduced rate of death or HF‐hospitalization (4 vs. 29%, p = .001) and a significantly longer event‐free‐survival from Kaplan–Meier curves (p = .003). COX regression analysis showed that, among echocardiographic parameters, decrease in LA size was an independent predictor of clinical outcome (HR: 0.149, CI: 0.034–0.654, p = .012).

Conclusions

The lack of decrease in LA size shortly after TAVR is associated with significantly higher rates of death and HF‐hospitalization, as well as with impaired improvement in clinical status during long‐term follow‐up.
Facilitating right‐sided axillary artery access for transcatheter aortic valve replacement using the Edwards Sapien 3 and ultra valves: Technical considerations
Authors: Rajkumar Christopher A. , Cook Christopher , Shalhoub Joseph , Chukwuemeka Andrew , Jaffer Usman , Hadjiloizou Nearchos , Sen Sayan , Ruparelia Neil , Mikhail Ghada , Malik Iqbal S.
Published: October 2019

Trans‐Axillary Transcatheter Aortic Valve Replacement (TAVR) has become established as the safest arterial approach when femoral arterial anatomy is unfavorable. Although a left sided axillary approach is generally preferred, patient specific factors may require use of the right axillary artery. In this case series we describe procedural modifications that are required to overcome the challenge of restricted space in the ascending aorta for in situ valve preparation of balloon‐expandable valve systems when a right sided trans‐Axillary approach is taken. These steps permit implantation of both the Edwards LifeSciences Sapien 3 and Ultra prostheses via the right trans‐Axillary approach, allowing patients a greater range of valve options when this arterial route is required for TAVR.
Effect of roasting as a premilling treatment on the functional and bread baking properties of whole yellow pea flour
Authors: Young Gina , Bourré Lindsay , Frohlich Peter , Borsuk Yulia , Sarkar Ashok , Sopiwnyk Elaine , Jones Stuart , Dyck Adam , Malcolmson Linda
Published: October 2019

Background and objectives

There is a growing global interest in partially replacing wheat flour with pulse flours in foods, including bread. However, undesirable flavors associated with pulse flours, especially yellow pea flour, have limited their use in foods. Pretreating pulses prior to milling offers a possible solution for improving the flavor of pulse flours. The objective of this research was to examine the effect of oven roasting and Revtech roasting (with and without steam) on the compositional, functional, and bread baking properties of whole yellow peas.

Findings

Regardless of the roasting method used, a roasting temperature of 120°C resulted in flours that retained good functionality and bread baking properties with less detrimental changes in flour color. Bread made with peas roasted at 120°C also had reduced aroma and flavor properties compared to bread made with untreated peas.

Conclusions

The strong aroma and flavor properties of yellow peas can be reduced by pretreating the peas prior to milling using conventional oven roasting and Revtech roasting. By selecting the appropriate roasting temperature, flour functionality for bread baking can be maintained.

Significance and novelty

Roasting is a useful premilling treatment for yellow peas. Reducing the off‐flavors associated with pulses while maintaining flour functionality will allow for greater use of pulse flours in formulating foods.
Spontaneous Growth of 3D Silver Mesoflowers on Poly(4‐vinylpyridine) Brushes‐Grafted‐Graphene Oxide Films and Facile Creation of Nanoporosities over their Surface
Authors: Feng Lihua , Wang Wenqin , Li Xiyong , Chen Tao
Published: October 2019

Fabricating three‐dimensional (3D) hierarchical noble‐metal particles by spontaneous redox reactions between graphene and noble‐metal salts still remains a great challenge. Herein, the fact that graphene oxide (GO) itself acts as both a platform for grafting polymer brushes and a reducing agent to reduce [Ag(NH3)2]+ ions is taken advantages of. 3D flower‐like Ag mesoparticles (Ag mesoflowers, Ag MFs) with tunable size and shapes can spontaneous grow on poly(4‐vinylpyridine) brushes‐grafted‐graphene oxide (P4VP‐g‐GO) films in Ag(NH3)2OH solution without the use of any additional reducing agent. The residual Ag(NH3)2OH on 3D Ag MFs surface can be further reduced by NaBH4, causing abundant nanoporosities over the entire Ag MFs. The resulting Ag nanoporous MFs (Ag NMFs) with larger surface‐to‐volume ratio and higher nanoscale roughness exhibit ultrasensitivity in surface‐enhanced Raman spectroscopy (SERS) detection, and the detection limit for 4‐aminothiophenol is as low as 10−13 m.
The Effect of Lithium Doping in Solution‐Processed Nickel Oxide Films for Perovskite Solar Cells
Authors: Saki Zahra , Sveinbjörnsson Kári , Boschloo Gerrit , Taghavinia Nima
Published: October 2019

The effect of substitutional Li doping into NiOx hole transporting layer (HTL) for use in inverted perovskite solar cells was systematically studied. Li doped NiOx thin films with preferential crystal growth along the (111) plane were deposited using a simple solution‐based process. Mott‐Schottky analysis showed that hole carrier concentration (NA) is doubled by Li doping. Utilizing 4 % Li in NiOx improved the power conversion efficiency (PCE) of solar devices from 9.0 % to 12.6 %. Photoluminescence quenching investigations demonstrate better hole capturing properties of Li:NiOx compared to that of NiOx, leading to higher current densities by Li doping. The electrical conductivity of NiOx is improved by Li doping. Further improvements of the device were made by using an additional ZnO layer onto PCBM, to remove shunt paths, leading to a PCE of 14.2 % and a fill factor of 0.72.