bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Donepezil and Vitamin B12 Supplement on Serum Thyroid Profile in Alzheimer’s Disease
Authors: Yeram Neelam , M. Dalvi Shubhangi , Patil Vinayak W. , Kale Vinayak P. , Jagiasi Kamlesh , Abichandani Leela G.
Published: January 2020

Aims: The aim of this study was to investigate thyroid status in Alzheimer’s Disease (AD) patients and its response to donepezil and vitamin B12 supplement therapy for 6 months.

Design: Case-Control Observational study.

Place and Duration: Department of Biochemistry, GGMC & Sir J. J. Group of Hospitals, Mumbai, India between March 2017 and July 2019.

Methodology: Case-Control study comprised of 71 AD patients and 70 healthy controls above 60 years of age.  Blood serum samples were analyzed for thyroid hormones levels by the chemiluminescence method. AD patients were treated with donepezil (5 mg/day) and vitamin B12 supplement (1.5 mg/day) and thyroid profile was observed at intervals of 3 and 6 months. Statistical evaluation was done by using IMB SPSS statistics version 25.

Results: Serum levels of thyroid hormones were low in euthyroid AD patients when compared with controls at the baseline level [T3 (120.64 ± 20.64 vs 127.8 ± 17.29), T4 (7.71 ± 2.34 vs 7.54 ± 1.85), FT3 (1.2 ± 0.13 vs 2.26 ± 0.63) and FT4 (0.79 ± 0.08 vs 1.29 ± 0.27)] except TSH which was increased in AD [TSH (2.71 ± 1.19 vs 2.34 ± 0.65)]. During follow-ups at 3 and 6 months, there was a slight decrease in TSH levels in response to the therapy.

Conclusion: The AD patients were euthyroid with low T3, FT3 and FT4 serum levels and high TSH serum levels. Thyroid hormones might play a role as markers for disease progression. Donepezil and vitamin B12 therapy could not benefit restore the normal thyroid functioning in a period of 6 months. Further longitudinal research with larger cohort might help in elucidating thyroid dysfunction in AD and develop novel therapeutic strategies.
Systemic Disease Comorbidities among Ophthalmic Patients in Nigeria: Implications for Preventive Ophthalmology
Authors: Ireju Onyinye Chukwuka , Chinyere Nnenne Pedro-Egbe
Published: January 2020

Background/Aim: Quite often patients who are refracted in our clinics have other ocular or systemic conditions that may affect the result or delay the issuance of spectacle corrections – for instance poorly controlled diabetic patients may have to wait for months to achieve better control of their condition. These associated comorbidities may require medical or surgical intervention before spectacles are ordered. The aim of this study is to determine the systemic comorbidities that exist in ophthalmic patients attending the Nigerian National Petroleum Corporation (NNPC) Eye Clinic in Port Harcourt, Nigeria.

Methodology: This was a descriptive cross-sectional study in which adult patients who presented in the clinic for change of glasses within the stipulated period of the study were included. They were interviewed to get the relevant information and the data retrieved for each patient included baseline information such as age, gender, unaided visual acuity, visual acuity with their last correction if any as well as co-existing ocular or systemic pathology. The collected data was subsequently analysed using Predictive Analysis Software version 20.

Results: Sixty patients participated in study; both males and females were equally represented. Of this this number, thirty-three patients (55%) had systemic comorbidities .Hypertension was present in 43.3% (n=26) while both hypertension and diabetes mellitus occurred in 10% (n=6) of the participants. Forty percent of those with refractive error had hypertension while about 30% of those with glaucoma were both hypertensive and diabetic.

Conclusion: There is a very high level of systemic comorbidities in adult patients attending this peripheral clinic, and this is a pointer to the high prevalence of these conditions in the larger population.
1D Triboelectric Nanogenerator Operating by Repeatedly Stretching and as a Self‐Powered Electronic Fence and Geological Monitor
Authors: Yang Jing , Yang Shuai , Guo Rui , Li Yanping , Sang Shengbo , Zhang Hulin
Published: January 2020

The micromechanical energy caused by a repeating tension is abundant and widely existed in human life, which is usually related to dynamic monitoring in a low‐dimensional system. Here, a 1D tensile triboelectric nanogenerator (TENG) that is consisted of a copper and a latex tube is reported. The subtle TENG can not only serve as a sustainable power source by harvesting tensile mechanical energy, but also operate actively to detect some surrounding mechanical stimulations. Due to the high sensitivity to stretching, the TENG unit shows a self‐powered counting function. Furthermore, a sensor square frame, composed of four TENG units, is demonstrated as a feasible self‐powered electronic fence by effectively monitoring ambient collisions from different directions. In addition, the simulated landslide experiment indicates that the tensile TENG can detect different geological activities and has a directional selectivity that facilitates geological hazard monitoring. This work further expands TENG‐based applications, especially in safety engineering and geological monitoring.
Charge‐Transport Processes in Host–Dopant Organic Semiconductors
Authors: Li Peicheng , Lu Zheng‐Hong
Published: January 2020

Host–dopant systems are the foundation for designing the light‐emission zones of organic light‐emitting diodes (OLEDs). An efficient OLED design has to consider the detailed charge transport processes in a host–dopant system in order to regulate charges for optimal distribution of excitons. It is reported that two charge transport pathways, Frenkel–Poole type transport via either host sites or dopant sites and charge hopping between host and dopant sites, are at play. The activation energy barrier in the hopping transport is identified as the energy level offset at the host–dopant interface, and is found consistent with the energy offset in the highest occupied molecular orbitals directly measured by ultraviolet photoemission spectroscopy. Dopant concentration and the host–dopant energy offset are identified as the key parameters dictating charge conduction path in the system. Practical equations are derived to calculate carrier mobility as a function of dopant concentration and dopant–host molecular energy offset.
In Situ Formation of Co9S8 Quantum Dots in MOF‐Derived Ternary Metal Layered Double Hydroxide Nanoarrays for High‐Performance Hybrid Supercapacitors
Authors: Yang Qingjun , Wang Qishun , Long Yan , Wang Fan , Wu Lanlan , Pan Jing , Han Jie , Lei Yong , Shi Weidong , Song Shuyan
Published: January 2020

Layered double hydroxides (LDHs) are promising cathode materials for supercapacitors because of the enhanced flow efficiency of ions in the interlayers. However, the limited active sites and monotonous metal species further hinder the improvement of the capacity performance. Herein, cobalt sulfide quantum dots (Co9S8‐QDs) are effectively created and embedded within the interlayer of metal‐organic‐frameworks‐derived ternary metal LDH nanosheets based on in situ selective vulcanization of Co on carbon fibers. The hybrid CF@NiCoZn‐LDH/Co9S8‐QD retains the lamellar structure of the ternary metal LDH very well, inheriting low transfer impedance of interlayer ions. Significantly, the selectively generated Co9S8‐QDs expose more abundant active sites, effectively improving the electrochemical properties, such as capacitive performance, electronic conductivity, and cycling stability. Due to the synergistic relationship, the hybrid material delivers an ultrahigh electrochemical capacity of 350.6 mAh g−1 (2504 F g−1) at 1 A g−1. Furthermore, hybrid supercapacitors fabricated with CF@NiCoZn‐LDH/Co9S8‐QD and carbon nanosheets modified by single‐walled carbon nanotubes display an outstanding energy density of 56.4 Wh kg−1 at a power density of 875 W kg−1, with an excellent capacity retention of 95.3% after 8000 charge–discharge cycles. Therefore, constructing hybrid electrode materials by in situ‐created QDs in multimetallic LDHs is promising.
Pore‐scale modeling of competition and cooperation of multispecies biofilms for nutrients in changing environments
Authors: Aghajani Delavar Mojtaba , Wang Junye
Published: January 2020

In this article, we developed a pore‐scale model of integrated lattice Boltzmann method and cellular automata to investigate competitive growth of aerobic nitrite and ammonium oxidizers in a bioreactor. The results showed that inlet nutrient concentrations have significant effects on maximum biofilm concentration, ratio of microorganisms' concentrations, growth pattern, and time. The local availability of oxygen could control the competition, resulting in different growth patterns. The coexistence of ammonium and nitrite in same inlet zone increased not only the biofilm concentration (7%) but also the ratio of microorganisms' concentrations (36%). Although this coexistence decreased the total biofilm concentration in some cases, it increased the growth rate about 25%. Changes of the maximum biomass concentration could change biofilm concentration of about 40% and microorganisms' concentrations ratio of about 30%. This framework provides a powerful tool to improve our understanding of dynamic interdependency of many complex microbial consortia systems with environments.
Streamlining care in cystic fibrosis: survey of otolaryngologist, pulmonologist, and patient experiences
Authors: Farzal Zainab , Dean Kelly M. , Sreenath Satyan B. , Hodge Sarah E. , Thorp Brian D. , Ebert Jr Charles S. , Zanation Adam M. , Senior Brent A. , Kimple Adam J.
Published: January 2020

Background

Care coordination for cystic fibrosis (CF) is essential. The objectives of this study were to: (1) compare otolaryngologists’ and pulmonlogists’ understanding of long‐term chronic rhinosinusitis (CRS) management; and (2) query patient perceptions of otolaryngologic care and CRS.

Methods

A cross‐sectional survey was administered by the Cystic Fibrosis Foundation in 2018 to patients with CF or their caregivers, otolaryngologists, and pulmonologists. Statistical analysis was performed comparing specialists. Descriptive statistics were computed for patient/caregiver‐reported data.

Results

Respondents included 126 otolaryngologists, 115 pulmonologists, and 186 patients with CF or their caregivers. Pulmonologists had greater experience caring for CF patients compared with otolaryngologists (66.7% vs 43.2% with 13+ years of experience, respectively), but more otolaryngologists cared for both adult and pediatric CF patients (39.2% vs 10.4%, respectively). Significantly more otolaryngologists advocated for establishing otolaryngologic care at time of CF diagnosis (64.8%) compared with pulmonologists (14.4%, p < 0.001), of whom 60.4% recommended otolaryngologist referral when sinonasal symptoms affect quality of life. More otolaryngologists perceived sinus surgery as beneficial for pulmonary function (74.5% vs 57.7%, p = 0.009); 60.8% of patients first sought otolaryngologic care in infancy or childhood (<13 years). Median number of sinus surgeries was 3 (interquartile range, 2‐5). The most common perceived benefits of surgery according to patients/caregivers included improved breathing (31.2%) and improved sinonasal symptoms (23.7%). Top patients/caregiver otolaryngologic priorities included symptom/infection control (49.0%) and care coordination (15.0%).

Conclusion

Our results highlight variable patient/caregiver experiences, and suggest that otolaryngologist and pulmonologist perceptions of CF otolaryngologic care also differ in some respects requiring improved interspecialty coordination/education.
Comparative study among TMTD, TBzTD, and ZBEC accelerators in isobutylene‐isoprene elastomer vulcanization
Authors: Gobbi Vinícius Guedes , da Silva Talita Goulart , Cunha Matheus Santos , Mendonça Tiago dos Santos , Gobbi Vitor Guedes , da Silva Moreira Thiré Rossana Mara , Mendonça Roberta Helena
Published: January 2020

Accelerators such as tetramethylthiuram disulfide (TMTD) are responsible for releasing nitrosamines, considered carcinogenic by international organizations. Tetrabenzylthiuram disulfide (TBzTD) and zinc dibenzyldithiocarbamate (ZBEC) are indicated as substituents of TMTD for not releasing noxious nitrosamines. Thus, the objective of this work was to compare the use of TMTD, TBzTD, and ZBEC accelerators in the production of isobutylene‐isoprene rubber compounds. It was evaluated the effect of TBzTD/mercaptobenzothiazole and ZBEC/N‐cyclohexyl‐2‐benzothiazolesulfenamide pairs in the rheological properties and the first pair achieved better results. Subsequently, it was evaluated compounds containing TBzTD and ZBEC accelerators separately. The experimental design data of the obtained maximum torque were correlated by an interpolation method (thin‐plate spline interpolation method). Physical–mechanical and thermodynamic measurements showed a decrease in the mechanical properties of TBzTD and ZBEC compounds. Thermogravimetric analysis did not indicate thermal differences between the compounds, Fourier transform infrared and swelling degree analyses corroborated the difference found in the crosslink densities of the compounds. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48965.
Nondestructive rapid and quantitative analysis for the curing process of silicone resin by near‐infrared spectra
Authors: Yang Jian , Zhang Tong , Yin Yue , Jiang Wenhong , Du Yunzhe , Zhu Xiaofei , Jiang Bo , Huang Yudong
Published: January 2020

Reactive group content was a key parameter in polymer curing process. However, the conventional methods to measure the curing were destructive and time consuming. In this article, near‐infrared spectra technology had been applied for reactive group analysis of the photothermal curing silicone to achieve rapid nondestructive and quantitative detection. The calibration model was developed about epoxy value and CC double bond value, with determination coefficient (R2) of 0.9631 and 0.9689. Root mean square error of prediction were 0.0179 and 0.0143 by partial least square regression. The optimized calibration model was used to predict the content of epoxy value and CC double bond value in the photothermal curing process, it proved that the silicone resin cured under UV‐radiation and heat. This novel method provided a promising approach to analysis the curing mechanism and quality parameters of resin.
Mechanical behavior of cold‐water fish gelatin gels crosslinked with 1,4‐butanediol diglycidyl ether
Authors: Czerner Marina , Prudente Mariano , Martucci Josefa Fabiana , Rueda Federico , Fasce Laura Alejandra
Published: January 2020

In this work, chemical crosslinking with 1,4‐butanediol diglycidyl ether (BDDGE) is used as strategy to enhance mechanical performance of fish gelatin (FG) gels in order to meet the properties' range of mammalian gelatin physical gels. Joint analysis of free amino groups, swelling ratio, and total soluble material indicates that crosslinking degree increases with increasing FG concentration and it is favored by a 0.2 BDDGE/FG ratio. Increasing crosslinking degree enhances gel indentation strength and shear modulus (μ) while decreases fracture toughness (GIC). Measured μ and GIC values lies within the range exhibited by mammalian gelatin physical gels, but the relationship between these parameters is opposite. This is due to the different fracture mechanisms occurring in chemically crosslinked and physical gels.
Silica/poly(styrene‐alt‐maleic anhydride) hybrid particles as a reactive toughener for epoxy resin
Authors: Wei Wei , Zhao Yingying , Zhang Bowen , Cui Yuqing , Li Xiaojie , Fei Xiaoma , Liu Xiaoya
Published: January 2020

Amino‐modified silica nanoparticles (SiO2─NH2) were first prepared by hydrolytic condensation of tetraethyl orthosilicate and 3‐aminopropylmethyldiethoxysilane. Then, organic–inorganic hybrid particles (SiO2─SMA) were prepared by the amidation reaction between SiO2─NH2 and poly(styrene‐alt‐maleic anhydride) (SMA). Subsequently, SiO2─SMA particles were employed for modifying bisphenol‐A epoxy/anhydride thermoset. Compared with pure cured epoxy, the modified epoxy thermosets with only 1 wt % of SiO2─SMA particles could achieve a simultaneous toughening and reinforcing performance. The tensile strength, impact strength, and fracture toughness of epoxy thermoset were increased by 14.1, 44.3, and 114.4%, respectively. Moreover, the modification also improved the thermal stability of epoxy thermosets, and the modulus and glass transition temperature of cured resin were not sacrificed. It can be attributed to the rigid structure of SiO2, as well as the anhydride and carboxyl groups onto the surface of SiO2─SMA particles participating in the epoxy curing reaction and effectively enhancing the crosslinking density of epoxy thermoset.
About the influence of temperature and environmental relative humidity on the longitudinal and transverse mechanical properties of elementary alfa fibers
Authors: Khaldi Mokhtar , Bouziane Mohamed Mokhtar , Vivet Alexandre , Bougherara Habiba
Published: January 2020

Composites reinforced with plant‐based fibers present a high potential for valorization in new industrial applications due to their good specific mechanical characteristics, renewability, and recyclability. In order to accelerate their wide industry adoption, it is critical to assess their behavior and durability in heat and humid environments. This article aims at investigating the effects of temperature and relative humidity (RH) on the longitudinal and transverse mechanical properties of the lignocellulosic fibers extracted from alfa plant (Stipa tenacissima L). For this purpose, tensile and nanoindentation tests were performed on elementary alfa fibers subjected to a thermal cycle of 200°C. The fibers were held at various periods of 15, 30, 60 and 120 min. The test results showed that the longitudinal and transverse Young's moduli are moderately affected by short thermal cycles having duration of 15–30 min. However, for longer thermal cycle (i.e., 2 hr), a degradation of 21% for the transverse modulus was recorded. This degradation doubled for the longitudinal modulus (43 vs. 21%). A similar trend was observed for the breaking strength. This study also showed that the RH strongly affects the mechanical performances of alfa fibers.
Verkehrsschwingungen bei Betonierarbeiten auf bestehenden Straßenbrücken
Authors: Ralbovsky Marian , Vorwagner Alois , Kleiser Michael , Kozakow Thomas , Geier Roman
Published: January 2020

Bauarbeiten an bestehenden Brücken müssen oft bei aufrechterhaltenem Verkehr stattfinden. Bei Brückenverbreiterungen oder dem Schließen von Arbeitsfugen ist der erhärtende Beton verkehrsinduzierten Schwingungen ausgesetzt, welche das Gefüge nachhaltig schädigen können. Dabei ist die Amplitude der auftretenden Schwingschnelle ein maßgeblicher Parameter. Im konkreten Fall werden Einflüsse auf die Größe der verkehrsinduzierten Schwingungen eines Plattentragwerks im Zuge von Bauarbeiten an der Autobahn A 23 der Hochstraße Inzersdorf in Wien untersucht, welches unter Verkehr in mehreren Bauphasen neu errichtet wurde. Mittels dynamischer Zeitverlaufsüberfahrtsberechnungen wurden durch Variation der Fahrgeschwindigkeit, der Fahrzeugmasse und des Straßenprofils jene Parameter identifiziert, die den größten Einfluss auf die Brückenschwingungen ausüben. Dabei wurden für FEM‐Simulationen reale gemessene Straßenprofildaten verwendet, die durch ein hochauflösendes Laserscanning der maßgebenden Fahrspuren erhoben wurden. Die dynamischen Tragwerkseigenschaften wurden durch Schwingungsmessung verifiziert. Während die Durchbiegungen und Dehnungen des Tragwerks vor allem durch die Fahrzeugmasse beeinflusst werden, sind die Schwinggeschwindigkeiten in erster Linie durch das Straßenprofil bestimmt. Die prognostizierten Schwinggeschwindigkeiten wurden mit einem der Literatur entnommenen Grenzwert verglichen, bei dessen Einhaltung es zu keiner Beeinträchtigung des jungen Betons kommen sollte. Die Ergebnisse dienten als Entscheidungsbasis für die Wahl der geeigneten Maßnahmen während der kritischen Erhärtungsphase des Betons in der Anschlussfuge.
Luminescence properties of the Ln–EDTA complexes covalently linked to the chitosan biopolymers containing β‐diketonate as antenna ligands
Authors: Costa Israel F. , Pires Gilvan P. , Espínola José Geraldo P. , Brito Hermi F. , Felinto Maria Claudia F.C. , Faustino Wagner M. , Teotonio Ercules E.S.
Published: January 2020

This paper reports on the preparation, characterization, and photoluminescence properties of novel hybrid materials, in which the EDTA–Ln–L complexes (where L: H2O, acac, bzac, dbm, and tta ligands, and Ln: Eu, Gd, and Tb) were covalently linked to the precursor medium molecular weight chitosan surface (CS) matrices or on the chitosan surfaces previously crosslinked with epichlorohydrin (CSech). The emission spectra of these materials were characterized by intraconfigurational‐4fN transitions centred on the Eu3+ and Tb3+ ions. Some broad bands from the polymeric matrix were also observed in the emission spectra, however the relative intensities of the intraconfigurational bands increased significantly for systems containing diketonate ligands when the antenna effect became more efficient. The values of the radiative rates (Arad) were higher for crosslinked hybrid systems with epichlorohydrin, while nonradiative rates (Anrad) presented the opposite behaviour. These data contributed to an increase in the values of emission quantum efficiency (η) for crosslinked materials. The effect of the modification process and antenna ligand on the values of intensities, intensity parameters Ω2 e Ω4 of the Eu3+ complexes were also investigated. The results showed that the crosslinked biopolymer surfaces have great potential for applications in molecular devices light converters.
Establishing Suspension Cell Cultures for Improved Manufacturing of Oncolytic Adenovirus
Authors: Moreira Ana Sofia , Silva Ana Carina , Sousa Marcos F. Q. , Hagner‐McWhirterc Åsa , Ahlénc Gustaf , Lundgren Mats , Coroadinha Ana S. , Alves Paula M. , Peixoto Cristina , Carrondo Manuel J. T.
Published: January 2020

Recent clinical trials have shown the potential of oncolytic adenoviruses as a cancer immunotherapy. A successful transition of oncolytic adenovirus to clinical applications requires efficient and good manufacturing practice compatible production and purification bioprocesses. Suspension cultures are preferable for virus production as they can reduce process costs and increase product quality and consistency. This work describes the adaptation of the A549 cell line to suspension culture in serum‐reduced medium validated by oncolytic adenovirus production in stirred tank bioreactor. Cell concentrations up to 3 × 106 cells mL−1 are obtained during the production process. At harvest 1.4 × 1010 infectious particles mL−1 and 6.9 ± 1.1 × 1010 viral genome mL−1 are obtained corresponding to a viral genome: infectious particles ratio of 5.2 (± 1.9): 1 confirming the virus quality. Overall, the suspension characteristics of these A549 cells support an easily scalable, less time‐consuming, and more cost‐effective process for expanded success in the use of oncolytic viruses for cancer therapy.
Effect of intraperitoneal chemotherapy concentration on morbidity and survival
Authors: Elekonawo F M K , Eden W J , Plas W Y , Ewalds R S G , Jong L A W , Bremers A J A , Hemmer P H J , Kok N F M , Kruijff S , Aalbers A G J , Reuver P R
Published: January 2020

Background

Selected patients with colorectal peritoneal metastases are treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The concentration of intraperitoneal chemotherapy reflects the administered dose and perfusate volume. The aim of this study was to calculate intraperitoneal chemotherapy concentration during HIPEC and see whether this was related to clinical outcomes.

Methods

An observational multicentre study included consecutive patients with colorectal peritoneal metastases who were treated with CRS–HIPEC between 2010 and 2018 at three Dutch centres. Data were retrieved from prospectively developed databases. Chemotherapy dose and total circulating volumes of carrier solution were used to calculate chemotherapy concentrations. Postoperative complications, disease-free and overall survival were correlated with intraoperative chemotherapy concentrations. Univariable and multivariable logistic regression, Cox regression and survival analyses were performed.

Results

Of 320 patients, 220 received intraperitoneal mitomycin C (MMC) and 100 received oxaliplatin. Median perfusate volume for HIPEC was 5·0 (range 0·7–10·0) litres. Median intraperitoneal chemotherapy concentration was 13·3 (range 7·0–76·0) mg/l for MMC and 156·0 (91·9–377·6) mg/l in patients treated with oxaliplatin. Grade III or higher complications occurred in 75 patients (23·4 per cent). Median overall survival was 36·9 (i.q.r. 19·5–62·9) months. Intraperitoneal chemotherapy concentrations were not associated with postoperative complications or survival.

Conclusion

CRS–HIPEC was performed with a wide variation in intraperitoneal chemotherapy concentrations that were not associated with complications or survival.
Incurred sample reanalysis of cefuroxime in rabbit ocular tissues—A case study
Authors: Gabani Bhavesh Babulal , Kiran Vinay , Praharaj Shuvranshu , Srinivas Nuggehally R. , Mullangi Ramesh
Published: January 2020

In this paper, we present the incurred sample reanalysis (ISR) data for cefuroxime in various ocular tissues of rabbits. Based on the cefuroxime concentration vs. time profile in various ocular tissues, three chosen time points enabled ISR assessment. Cefuroxime was quantitated in the ocular tissues using a published liquid chromatography–electrospray ionization/tandem mass spectrometry method operated under the multiple reaction‐monitoring mode in positive ion mode. Regardless of the ocular tissue, the linearity range was 12.7–2760 ng/ml with a correlation coefficient (r2) of ≥0.996. All of the ISR samples representing various ocular tissues met the acceptance criteria. To the best of our knowledge, this is the first report showing the ISR of ocular tissues in any species.
Biochemical characterization and structural insights into the high substrate affinity of a dimeric and Ca2+ independent Bacillus subtilis α‐amylase
Authors: Salem Karima , Elgharbi Fatma , Ben Hlima Hajer , Perduca Massimiliano , Sayari Adel , Hmida‐Sayari Aïda
Published: January 2020

An extracellular amylase (AmyKS) produced by a newly isolated Bacillus subtilis strain US572 was purified and characterized. AmyKS showed maximal activity at pH 6 and 60°C with a half‐life of 10 min at 70°C. It is a Ca2+ independent enzyme and able to hydrolyze soluble starch into oligosaccharides consisting mainly of maltose and maltotriose. When compared to the studied α‐amylases, AmyKS presents a high affinity toward soluble starch with a Km value of 0.252 mg ml−1. Coupled with the size‐exclusion chromatography data, MALDI–TOF/MS analysis indicated that the purified amylase is a dimer with a molecular mass of 136,938.18 Da. It is an unusual feature of a non‐maltogenic α‐amylase. A 3D model and a dimeric model of AmyKS were generated showing the presence of an additional domain suspected to be involved in the dimerization process. This dimer arrangement could explain the high substrate affinity and catalytic efficiency of this enzyme.
Whole‐Cell Biocatalysis in Seawater: New Halotolerant Yeast Strains for the Regio‐ and Stereoselectivity Reduction of 1‐Phenylpropane‐1,2‐Dione in Saline‐Rich Media
Authors: Andreu Cecilia , del Olmo Marcellí
Published: January 2020

The application of green chemistry concepts in catalysis has considerably increased in recent years, and the interest in using sustainable solvents in the chemical industry is growing. One of the recent proposals to fall in line with this is to employ seawater as a solvent in biocatalytic processes. This involves selecting halotolerant strains capable of carrying out chemical conversions in the presence of the salt concentrations found in this solution. Recent studies by our group have revealed the interest in using strains belonging to Debaryomyces and Schwanniomyces for catalytic processes run in this medium. In the present work, we select other yeasts based on their halotolerance to widen the scope of this strategy. We consider them for the monoreduction of 1‐phenylpropane‐1,2‐dione, a well‐characterized reaction that produces acyloin intermediates of pharmaceutical interest. The results obtained herein indicate that using seawater as a solvent for this reaction is possible. The best ones were obtained for Saccharomyces cerevisiae FY86 and Kluyveromyces marxianus, for which acyloins with different stereochemistry were obtained with good to excellent enantiomeric excess.
Nutritional properties of pea protein‐enriched flour treated with different proteases to varying degrees of hydrolysis
Authors: Konieczny Dellaney , Stone Andrea K. , Nosworthy Matthew G. , House James D. , Korber Darren R. , Nickerson Michael T. , Tanaka Takuji
Published: January 2020

Background and objectives

Pulses are a good source of protein; however, they contain phytochemicals that can negatively affect the protein quality. Enzymatic hydrolysis could be a means to enhance the nutritional value of pea by improving the digestibility of the protein. To this aim, a commercial air‐classified pea protein‐enriched flour (PPEF) was hydrolyzed by different proteases (trypsin, Savinase, papain, and pepsin) to different degrees of hydrolysis (DH 2%–4% and 10%–12%) and levels of phytochemicals and in vitro protein digestibility corrected amino acid score were examined.

Findings

Protease treatments reduced the contents of condensed tannins and total phenolics, as well as trypsin inhibitor and chymotrypsin inhibitor activities. Hydrolysis at 10%–12% DH (degrees of hydrolysis) improved the amino acid score of the PPEF, but it was still limiting sulfur amino acids, whereas low levels of hydrolysis (DH 2%–4%) decreased the amino acid score. The in vitro protein digestibility score increased slightly following hydrolysis, with the greatest improvement in digestibility occurring with the papain treatment (DH 10%–12%). The in vitro protein digestibility corrected amino acid score with trypsin hydrolysis at DH 2%–4% was the lowest at 59.17%, whereas pepsin hydrolysis (10%–12% DH) gave the highest score (72.89%).

Conclusions

Specific hydrolysis treatments could be used to improve the overall nutrition of PPEF, enhancing the potential utilization of modified pea protein ingredients.

Significance and novelty

This study utilized four enzymes with different specificities resulting in PPEF hydrolysates with different protein quality even when the DH was the same. Increasing the nutritional quality of a PPEF may give it a competitive advantage over other pea ingredients.
Metal Ionic Liquids for the Rapid Chemical Fixation of CO2 under Ambient Conditions
Authors: Chen Gang , Zhang Jianling , Cheng Xiuyan , Tan Xiuniang , Shi Jinbiao , Tan Dongxing , Zhang Bingxing , Wan Qiang , Zhang Fanyu , Liu Lifei , Han Buxing , Yang Guanying
Published: January 2020

CO2 cycloaddition is an important reaction for chemical fixation of CO2. It is desirable to design facile and green route for the efficient CO2 cycloaddition reaction, especially at ambient conditions. Here we propose a novel route for CO2 cycloaddition by utilizing metal ionic liquid (MIL) as both reaction media and catalyst. Outstandingly, propylene oxide can be completely converted to propylene carbonate with more than 99.0 % yield and more than 99 % selectivity at room temperature and atmospheric pressure. This strategy is efficient, facile, environmentally benign, which involves no additional catalyst and can easily recycle the MIL after reaction. It has potential for the practical procedure of gas separation and CO2 utilization in industrial waste gas.
Biological Water Treatment by a Hybrid Fluidized‐Bed Bioreactor: Theoretical Study
Authors: Tabiś Bolesław , Boroń Dominika , Bizon Katarzyna
Published: January 2020

A hybrid fluidized‐bed bioreactor for water purification was proposed and analyzed. It is a novel type of bioreactor characterized by hitherto unknown stationary and dynamic features. Steady‐state characteristics of this hybrid bioreactor with external liquid circulation are presented. A quantitative analysis of steady‐state properties of the bioreactor was performed with the aid of an original mathematical model developed for a double‐substrate aerobic microbiological process. A steady‐state analysis of aerobic processes characterized by different oxygen demand was performed. The effect of essential parameters was evaluated, including carbonaceous substrate concentration in the feed stream to the apparatus, aeration intensity, total residence time of a liquid in the bioreactor, and height of the bed of fine carrier particles.
Triple Frustrated Lewis Pair‐Type Reactivity on a Single Rare‐Earth Metal Center
Authors: Sun Xiong , Su Wei , Shi Kaiying , Xie Zhuoyi , Zhu Congqing
Published: January 2020

Rare‐earth metal cations have been used rarely as Lewis‐acidic components in the chemistry of frustrated Lewis pairs (FLPs). Herein, we report the first cerium/phosphorus system (2) employing a heptadentate N4P3 ligand, which exhibits triple FLP‐type reactivity towards a series of organic substrates, including isocyanates, isothiocyanates, diazomethane, and azides on a single rare‐earth Lewis acidic Ce center. This result shows that the Ce center and three P atoms in 2 could simultaneously activate three equivalents of small molecules under mild conditions. This study broadens the diversity of FLPs and demonstrates that rare earth based FLP exhibit unique properties compared with other FLP systems.
Synthesis of Benzodiazepines Through Ring Opening/Ring Closure of Benzimidazole Salts
Authors: Tao Sheng , Bu Qingqing , Shi Qianqian , Wei Donghui , Dai Bin , Liu Ning
Published: January 2020

Pyrido‐benzodiazepine derivatives are undoubtedly one of the most important structural motifs in the marketed drugs and the drug candidates. Commonly synthetic methods for construction of the benzodiazepine ring derivatives are based on the condensation reactions of two highly functionalized synthons. The development of synthesis for these compounds, however, is hampered by the regioselectivity and atom economy. In this work, a one‐step synthesis of pyrido‐benzodiazepine backbones and its analogues is achieved through continuous ring‐opening hydrolysis of benzimidazole salts and intramolecular C−H bond activation. The reaction mechanism is explored by control experiments and density functional theory (DFT) calculations.
Understanding the behaviour of dodecylamine as a model cationic collector in oil sands tailings dewatering applications using a novel FTIR based method
Authors: Ripmeester Matthew , Duford David A. , Yuan Simon
Published: January 2020

Tailings treatment technology is currently being developed at Syncrude Canada Ltd. (SCL) that involves adding a cationic surfactant (collector) to fluid fine tailings (FFT) in order to alter clay surfaces from hydrophilic to hydrophobic and promote faster dewatering. To understand the behaviour and effects of cationic collectors, a robust analytical method for measuring concentrations of aliphatic amine collectors in aqueous samples was developed. Dodecylamine (DDA) was used as the model collector molecule for this study. The method involves a liquid‐liquid extraction with dichloromethane (DCM) at basic pH followed by Fourier transform infrared (FTIR) detection of the primary amine N─H stretch of DDA at ~3382 cm−1. This method was successfully used to measure DDA in the matrices of recycled oil sands process affected water (RCW) and FFT. The optimized method was then used to understand the behaviour of DDA in a number of geochemical environments that could occur during tailings treatment. Analysis of the solubility of DDA in RCW found that the solubility of DDA increases with decreasing pH, while increasing temperature increased the solubility of DDA to a lesser degree. The solubility of DDA in RCW at its natural pH of 9.16 was found to be 4.22 mg · kg−1. Lastly, preliminary tests verified that FFT solids have a high relative DDA adsorption capacity and that the current standard DDA dosage used at SCL of 650 g/t, is effective as all the DDA was found tightly bound to clay surfaces with no excess DDA left in the water, even under acidic conditions.
Iron‐Catalyzed Aminomethyloxygenative Cyclization of Hydroxy‐α‐diazoesters with N,O‐Aminals
Authors: Zou Suchen , Zhang Tianze , Wang Siyuan , Huang Hanmin
Published: January 2020

Summary of main observation and conclusion

A new and efficient cyclization reaction has been developed to synthesize cyclic α,α‐disubstituted β‐amino esters via iron‐catalyzed intramolecular aminomethyloxygenative cyclization of diazo compounds with N,O‐aminal under mild reaction conditions. A broad range of hydroxy‐α‐diazoesters with different substituents and various N,O‐aminals were compatible with this protocol, affording the corresponding α,α‐disubstituted β‐amino esters bearing a five‐ to eight‐membered oxacycle in good yields.
Mild and Efficient Synthesis of Diverse Organo‐AuI‐L Complexes in Green Solvents
Authors: Ingner Fredric J. L. , Schmitt Ann‐Cathrin , Orthaber Andreas , Gates Paul J. , Pilarski Lukasz T.
Published: January 2020

An exceptionally mild and efficient method was developed for the preparation of (hetero)aryl‐AuI‐L complexes using ethanol or water as the reaction medium at room temperature and Ar‐B(triol)K boronates as the transmetalation partner. The reaction does not need an exogeneous base or other additives, and quantitative yields can be achieved through a simple filtration as the only required purification method, which obviates considerable waste associated with alternative workup methods. A broad reaction scope was demonstrated with respect to both the L and (hetero)aryl ligands on product Au complexes. Despite the polar reaction medium, large polycyclic aromatic hydrocarbon units can be incorporated on the Au complexes in very good to excellent yields. The approach was demonstrated for the chemoselective manipulation of orthogonally protected aryl boronates to afford a new class of N‐heterocyclic carbene‐Au‐aryl complexes. A mechanistic rationale was proposed.
Synthesis of NH‐Sulfoximines by Using Recyclable Hypervalent Iodine(III) Reagents under Aqueous Micellar Conditions
Authors: Zhang Guocai , Tan Hongsheng , Chen Weichun , Shen Hong C. , Lu Yue , Zheng Changwu , Xu Hongxi
Published: January 2020

The synthesis of NH‐sulfoximines from sulfides has been first developed under mild conditions in an aqueous solution with surfactant TPGS‐750‐M as the catalyst at room temperature. In this newly developed process, a simple and convenient recycling strategy to regenerate the indispensable hypervalent iodine(III) is used. The resulting 1,2,3‐trifluoro‐5‐iodobezene can be recovered almost quantitively from the mixture by liquid–liquid extraction and then oxidized to give the corresponding iodine(III) species. This optimized procedure is compatible with a broad range of functional groups and can be easily performed on a gram scale, providing a green protocol for the synthesis of sulfoximines.
Target‐dependent retrograde signaling mediates synaptic plasticity at theDrosophilaneuromuscular junction
Authors: Berke Brett , Le Linh , Keshishian Haig
Published: January 2020

Neurons that innervate multiple targets often establish synapses with target‐specific strengths, and local forms of synaptic plasticity. We have examined the molecular‐genetic mechanisms that allow a singleDrosophilamotoneuron, the ventral Common Exciter (vCE), to establish connections with target‐specific properties at its various synaptic partners. By driving transgenes in a subset of vCE’s targets, we found that individual target cells are able to independently control the properties of vCE's innervating branch and synapses. This is achieved by means of a trans‐synaptic growth factor secreted by the target cell. At the larval neuromuscular junction, postsynaptic glutamate receptor activity stimulates the release of the BMP4/5/6 homolog Glass bottom boat (Gbb). As larvae mature and motoneuron terminals grow, Gbb activates the R‐Smad transcriptional regulator phosphorylated Mad (pMad) to facilitate presynaptic development. We found that manipulations affecting glutamate receptors or Gbb within subsets of target muscles led to local effects either specific to the manipulated muscle or by a limited gradient within the presynaptic branches. While presynaptic development depends on pMad transcriptional activity within the motoneuron nucleus, we find that the Gbb growth factor may also act locally within presynaptic terminals. Local Gbb signaling and presynaptic pMad accumulation within boutons may therefore participate in a “synaptic tagging” mechanism, to influence synaptic growth and plasticity inDrosophila.
Fog and fauna of the Namib Desert: past and future
Authors: Mitchell Duncan , Henschel Joh R. , Hetem Robyn S. , Wassenaar Theo D. , Strauss W. Maartin , Hanrahan Shirley A. , Seely Mary K.
Published: January 2020

The future of fog‐dependent habitats under climate change is unknown but likely precarious; many have experienced recent declines in fog. Fog‐dependent deserts particularly will be threatened, because, there, fog can be the main water source for biota. We review the interactions between fog and fauna of the Namib Desert, about which there is 50 yr of research. We resynthesize the data, seeking patterns and mechanisms that could provide a framework for predicting outcomes of changes in fog regime in other fog‐dependent deserts. In the Namib, fog constitutes the most‐predictable form of free water. At least 48 Namib animal species consume free water from fog, or are likely to do so, employing both liquid and vapor phase. Fog also sustains plants that form the base for metabolic water production and wets the diet to provide pre‐formed water. So fog provides or underpins all the water intake of Namib fauna. Only a few species are active fog‐harvesters, though. Among Namib beetles, two species are unique in that they fog‐bask; they assume stereotyped postures in wind‐driven fog and droplets deposit on their carapaces. Some Namib beetle species construct surface ridges that trap fog water, which they consume. Some arthropods emerge from their subsurface habitats, or occupy its wet top layers, to access fog water, at times and in conditions outside their usual surface activity. Many more taxa, including vertebrates, use fog water opportunistically. They do not actively seek it out but use it when available. Acquiring fog water from droplets requires overcoming spherical surface tension so is possible only for animals heavier than ~100 mg. Smaller animals extract water from films or acquire it in the vapor phase. Some Namib animals use hygroscopic surfaces to extract vapor from unsaturated air, at ambient humidities attained in fog or sometimes between fogs. Rapid acquisition of water during episodic fog events creates problems for storage and osmoregulation, which some Namib animals have solved in enterprising ways, including long‐term internal storage of water and sequestering of osmolytes. Although not yet comprehensive, the body of research reviewed, and the principles that we have elucidated underlying fog usage, should inform future research on fauna throughout fog‐dependent deserts.
Methamphetamine‐related cardiovascular diseases
Authors: Schwarzbach Valentin , Lenk Karsten , Laufs Ulrich
Published: January 2020

Aims

Abuse of crystal methamphetamine (MA) poses a growing problem for health services worldwide. This review summarizes the current literature on the effects of MA on the cardiovascular system.

Methods and results

This article is a presentation of a case report and review of the current literature. In Europe, especially the eastern countries and the eastern states of Germany are affected. MA increases the concentration of catecholamines in the synaptic gap leading to euphoria, alertness, and hunger suppression as well as psychiatric and gastrointestinal complications. MA consumption is associated with hypertension, acute and chronic myocardial toxicity, stroke, coronary artery disease, and sudden cardiac death. Although many aspects of the underlying pathophysiology remain unknown, catecholamine‐mediated pathologies appear to play an important role. The duration of MA consumption is the most important determinant for the prognosis.

Conclusions

Awareness is needed as cardiac complications are important causes of morbidity and mortality in patients with MA consumption. Drug abstinence is the mainstay of therapy, cardiac and other complications should be treated according to the respective guidelines. Incompliance to therapy and frequent relapses are the main challenges for successful treatment. Further research is required to improve the understanding of this rapidly increasing cardiomyopathy.
Preparation and Mechanistic Studies of 2‐Substituted Bisthiazolidines by Imine Exchange
Authors: Martínez Verónica , Villamil Valentina , Duarte Diego , Saiz Cecilia , Davyt Danilo , Fontana Carolina , Veiga Nicolás , Mahler Graciela
Published: January 2020

Bisthiazolidines (BTZ) are bicyclic compounds considered as penicillin analogs that inhibit the full range of Metallo‐β‐Lactamases (MBLs) and potentiate β‐lactam activity against resistant bacteria. Herein, we present a new methodology to prepare 2‐substituted bisthiazolidines by aldehyde exchange. Thirteen new bisthiazolidines were prepared using this methodology, with yields ranging from 31 to 75 %. The reaction is based on in situ imines formation, which are able to exchange side chains. The reaction intermediates were studied based on NMR experiments, and a key imine 1b‐II could be detected in the reaction mixture. Furthermore, a DFT computational analysis was performed to gain insights into the reaction mechanism, allowing us to unveil the different pathways and their activation barriers within the synthetic route. The results suggest that the most favorable route involve the formation of the thiazolidine 1b‐III by i) a N‐assisted N–C bond cleavage, and ii) a thiol‐mediated 5 endo‐trig cyclization followed by a C–N bond cleavage. In contrast with previously reported evidence, the imine metathesis was discarded as a plausible pathway. Finally, the reaction of 1b‐III with aldehyde 2a leads to bicycle 4a via the iminium ion 1b‐V.
Nanocarbon Materials Modified with the Zinc Complex of Protoporphyrin IX, Recognized Antibiotics in Water Samples
Authors: Stefan‐van Staden Raluca‐Ioana , Mincu Mariana
Published: January 2020

The complex between protoporphyrin IX and zinc was immobilized on nanocarbon paste and on nanodiamond paste to design two stochastic microsensors. The microsensors were used for the recognition and analysis of antibiotics: amoxicillin, ampicillin, and biotin in water samples. Stochastic sensors provided different signatures for the three antibiotics making possible their simultaneous recognition and assay in water samples. Low limits of determination 0.3 pg/mL for amoxicillin and ampicillin, and 0.21 pg/mL for biotin were obtained when nanocarbon paste was used, and 0.03 pg/mL for amoxicillin, 0.30 pg/mL for ampicillin, and 2.14 fg/mL for biotin were obtained when nanodiamond paste was used. Recoveries higher than 99.32 % with RSD lower than 1.00 % were obtained for the assay of the antibiotics in water samples.