bluuebunny/crossref_metadata_2025 huggingface dataset:
Nudging in perspectief
Authors: Raymaekers Pieter , Brans Marleen
Published: June 2020

Nudging in perspectief: De verbreding van gedragsinzichten in beleid

Theorieën en methoden uit de gedragswetenschappen betreden steeds nadrukkelijker de beleidsscene. Gedragsinzichten en nudging beloven beleid te verrijken en te versterken. Het begin van deze gedragswetenschappelijke omslag of behavioural turn laat men doorgaans samenvallen met de publicatie van het boek Nudge van Richard Thaler en Cass Sunstein in 2008. In dit artikel plaatsen we nudging in perspectief en argumenteren we dat het concept zowel een zegen als een vloek betekent, en zowel een katalysator als een rem is voor de bredere toepassing en verankering van gedragsinzichten in beleid. Ondanks het aantrekkelijke narratief botst nudging op functionele limieten en ethische bezwaren. Om de gedragswetenschappelijke, experimentele en evidence-based beleidsbeloften alsnog in te lossen, zien we een strategie van steeds verdere verbreding. Het programma van de Behavioural Insights-beweging op basis van vijf pijlers leek in eerste instantie een oplossing te bieden, maar kampt door een eendimensionale interpretatie met interne spanningen. De nog bredere en ambitieuzere Behavioural Public Policy-agenda biedt nieuwe perspectieven, maar moet op functioneel en ethisch vlak nog verder onderbouwd worden.
Glycemic Index (GI) Values for Major Sources of Dietary Carbohydrates in Iran
Authors: Kazemi Fatemeh , Danaei Goodarz , Farzadfar Farshad , Malik Vasanti , Parsaeian Mahboubeh , Pouraram Hamed , Zamaninour Negar , Rahmani Jamal , Dorosty Motlagh Ahmad Reza
Published: June 2020

Background: The glycemic index (GI) values of staple foods are not available in a standardized method in Iran. Objectives: The aim of this study was to measure the GI values of the major carbohydrate sources in a typical Iranian diet. Methods: Using the international standard method, the GI values were determined for four wheat flatbreads, barley and rye bread, white and brown rice, as well as white and brown rice mixed with lentils. Twelve healthy adults were given 50 g anhydrous glucose three times (as the reference carbohydrate) and the test foods once each throughout the study. Using finger-prick blood samples, capillary blood glucose was measured using a reliable glucometer. The GI was calculated using the trapezoidal method. Results: The GI values of the following types of bread were: Barley 66, Lavash 72, Taftoon 79, Sangak 82, rye 84, and Barbari 99. The GI values for brown and white rice were 65 and 71, respectively. The mixture of brown rice with lentils had a GI value of 55, and the mixture of white rice with lentils had a GI of 79. Conclusions: The most common types of bread and white rice consumed in Iran have high GI values. There is potential to reduce the overall GI values in the Iranian diet by encouraging the consumption of barley bread and brown rice.
Inquiry and Gender Inequity in the Undergraduate Mathematics Classroom
Authors: Johnson Estrella , Andrews-Larson Christine , Keene Karen , Melhuish Kathleen , Keller Rachel , Fortune Nicholas
Published: June 2020

Our field has generally reached a consensus that active-learning approaches improve student success; however, there is a need to explore the ways that particular instructional approaches affect various student groups. We examined the relationship between gender and student learning outcomes in one context: inquiry-oriented abstract algebra. Using hierarchical linear modeling, we analyzed content assessment data from 522 students. We detected a gender performance difference (with men outperforming women) in the inquiry-oriented classes that was not present in other classes. We take the differential result between men and women to be evidence of gender inequity in our context. In response to these findings, we present avenues for future research on the gendered experiences of students in such classes.
One Pot Synthesis of Cu(II) and Ni(II) Peroxo Complexes Containing Schiff Base: Physicochemical, Spectral and Antibacterial Investigations
Authors: Ali Md. Mahasin , Bitu Md. Nur Amin , Hossain Md. Saddam , Hossen Md. Faruk , Asraf Md. Ali , Farooque Md. Akhter , Zahan Md. Kudrat-E-
Published: June 2020

Two new peroxo complexes of Cu(II) and Ni(II) ion containing Schiff base (SB) were synthesized and characterized by TLC, Elemental analyses, conductivity, magnetic moment measurements, UV-Vis. and IR and ESI-MS spectral studies. The Schiff base ligand derived from cinnamaldehyde and o-aminophenol participated in complexation through a single pot reaction. IR spectra showed that the Schiff base ligand coordinated to the metal ion through nitrogen of azomethine group and oxygen of hydroxyl group & peroxo group (O-O). Magnetic moment value coupled with electronic spectral data suggested a square planar geometry for both the complexes. The molar conductance values indicated the non-electrolytic nature of the complexes. Antibacterial activity of the complexes was tested against four pathogenic bacteria, two Gram-positive Staphylococcus aureus & Bacillus cereus and two Gram-negative Escherichia coli & Shigella dysenteriae with Kanamycin (K-30) standard. The result shows that Cu(II) complex exhibited more potential antibacterial activity than the Ni(II) complex against all the tested organisms.
Quantitative Analysis by Gas Chromatography / Mass Spectrometry of Heroin Traded in Kuwait during 2016 – 2017, and Its Comparison with Results of Analyzing Heroin Traded during 2012 and Addicts Death Rate Statistics during 2011 – 2018
Authors: Al-Abkal N. A. , Metwally E. Kh. , Alezzbawy S. R. , Orabi Kh. Y. , Alshammari Sh. H.
Published: June 2020

Aim: To compare the main and additive components of heroin trafficked in the Stateof Kuwait during 2012 with those components of heroin traded recently in the country during 2016 and 2017, and to provide a satisfactory explanation for the increase in deaths among heroin addicts during the period2011 -2018.

Study Design: Selected samples of non-pure powder heroin seized in Kuwait during 2016 and 2017, with pure heroin and a set of10 pure different heroin component standards, all have been quantitatively analyzed in the Forensic Laboratories.

Place and Duration of Study: All qualitative and quantitative analyses for 2016 and 2017 samples were conducted in the Forensic Laboratories of the General Department of Criminal Evidences – Ministry of Interior – State of Kuwait.

Methodology: By using Gas Chromatography/Mass Spectrometry (GC/MS) to qualitative and quantitative analysis have been made on a total of hundred samples of non-pure powder heroin seized in Kuwait during the years 2016 and 2017, in addition to ten pure standards.

Results: The concentration of the diacetylmorphine (active substance of heroin) in Kuwait during the year 2017 are much higher than the concentration during the year 2016. The additive substances (adulterants) for the years 2016 and 2017, are shared with the year 2012 by the component's paracetamol, caffeine and diazepam with different concentrations. But new adulterants in recent years are recorded in samples 2016 and 2017, including methamphetamine, dextromethorphan, and methylphenidate which is absent in 2016 samples.

Conclusion: The concentration % of illicit heroin traded in Kuwait as diacetylmorphine has increase from 10% to 50% for year 2016, and further from 30% - 70% for year 2017, which marks identified a substantial rising in the purity of heroin. In addition, additive substances in the two years include paracetamol (acetaminophen), caffeine and diazepam, previously recorded in 2012. However, totally different new adulterates are recorded in 2016 and 2017 samples, including methamphetamine, dextromethorphan, and methylphenidate. All new three adulterates are detected in quite a few numbers of samples with methylphenidate recorded in a very low concentration of 0. 01 mg. Both new adulterates and higher purity of heroin constitute the main reasons for rising the rate of deaths between heroin addicts in recent years. Also, recent UN reports (12,18) provide evidence that the GC countries Afghanistan, Iran and Pakistan are still manufacturing and trading the above mentioned new adulterates.
Biocontrol of Fungi Associated with Onion (Allium cepa) Bulb Rot during Post Harvest
Authors: Achong Theresa E. Omara- , Okey Peggy A. , Okey Edward N. , Ukpong Patience M.
Published: June 2020

Post-harvest deterioration is a major problem of onions (Allium cepa) in Nigeria. The use of chemicals has been the main control measure. Chemicals are hazardous and environmentally unfriendly. There is therefore, a need for search for effective bio-pesticides as alternatives. A survey of fungal onions diseases was conducted in two markets in Mkpat Enin Local Government Area, Akwa Ibom State, Nigeria. Two hundred onions bulbs (100 from each market) were collected separately from the two markets. The collected bulbs were put into separate polythene bags before taken to the laboratory for macroscopic and microscopic examinations. Fungal isolates were obtained from naturally infected bulbs and their pathogenicity confirmed using Kochs’ postulate. In vivo and in vitro testing based on growth inhibition were also carried out to determine the efficacy of the aqueous plant extracts. Phytochemical analysis of alcohol extracts was conducted following standard procedures. Results of market surveys indicated disease incidences of 26% and 23% from Akpaden and Ukam markets, respectively. Three fungal species were isolated and identified as Botrytis allii, Fusarium oxysporum and Alternaria porri. Pathogenicity tests confirmed these isolates to be common agents of onion bulb rot. In vitro testing of Chromolaena odorata and Mangiferia indica leaf extracts at 10, 20 and 30% concentrations showed inhibitory effects of both extracts with increasing concentrations on the pathogens. C. odorata extracts indicated significantly higher inhibition, compared to M. indica. In vivo tests of the extracts also showed a significant growth inhibition of the pathogens on onion bulb rot, compared to the control. Phytochemical screening of the extracts indicated the presence of tannins, saponins, polyphenols and flavonoids. The antifungal activities of these extracts and their availability makes them potential control agents of fungal onion rot. C. odorata and M. indica plant extracts should therefore, be further explored as alternatives bio-control agents or onions fungal rot.
Anxiolytic Mechanism(S) and Corticosterone-Attenuating Effect of Hydroalcoholic Leaf Extract of Tapinanthus globiferus Mistletoe Growing on Azadirachta indica Tree
Authors: Umarudeen A. M. , Magaji M. G.
Published: June 2020

Similar pharmacodynamic mechanism(s) often underlie drug actions and toxicities of anxiolytic agents and medicinal extracts. Extracts of Tapinanthus globiferus and related plant species have been reported with anxiolytic activities. But mechanistic evaluations on these plant extracts are few. This study investigated the anxiolytic mechanism(s), including the corticosterone-attenuating effect, of hydroalcoholic Tapinanthus globiferus (HATG) leaf extract harvested from Azadirachta indica host tree in the mouse elevated zero-maze and restraint-induced acute stress paradigms using per cent open segment time (%OST) and brain/plasma corticosterone levels as endpoints, respectively. The results show that anxiolytic activity (%OST) of 150 mg/kg HATG leaf extract was reversed by pretreatment with 5 mg/kg caffeine (HATG alone, 10.90±1.73;HATG+Caffeine, 8.66±1.74), 2 mg/kg methysergide (MTD) (HATG alone, 98.70±14.98; HATG+MTD, 74.20±10.82) and 5 mg yohimbine (HATG alone, 120.10±10.72; HATG+Yohimine, 78.44±13.92) but not by 0.5 m/kg atropine (HATG alone, 104.60±25.31; HATG+Atropine, 105.40±11.85), 0.5 mg/kg flumazenil (HATG alone,80.27±9.69; HATG+Flumazenil, 80.75±10.19), 2 mg/kg cyproheptadine (HATG alone, 88.67±16.44; HATG+Cyproheptadine, 92.11±12.58), 0.2 mg/kg haloperidol (HATG alone, 74.11±17.33; HATG+Haloperidol, 94.00±32.54) and 5 mg/kg naloxone (HATG alone, 94.30±10.84; HATG+Naloxone, 95.30±6.86). The results also indicate HATG leaf extract (at 50, 150, 500 and 1500 mg/kg) caused largely dose-dependent and significant (p<0.05) attenuations in brain/plasma corticosterone levels (5.64±0.66/3.91±0.44,3.78±0.39/3.39±0.38, 4.26±0.34/3.22±0.18 and 2.74±0.51/2.74±0.22), respectively, in extract- compared to distilled water- (5.93±0.60/4.56±0.37) and diazepam-treated (2.34±0.19/2.44±0.29) mice subjected to restraint-induced acute stress. These findings suggest anxiolytic mechanism(s) of the extract may involve its interactions with the adenosine, non-5HT2 serotonin, alpha (α)2 receptors and the hypothalamus-pituitary-adrenal (HPA) axis. This study may constitute the first mechanistic and corticosterone modulation report on the extracts of this parasitic medicinal plant and may benefit from confirmatory radio-labelled binding assays in subsequent studies.
Formulation and in vitro Characterization of Donepezil-loaded Chitosan Nanoparticles
Authors: Amjad Muhammad Wahab , Alotaibi Nawaf Mohamed
Published: June 2020

Millions of people are affected globally by alzheimer’s disease and it is regarded as a dangerous progressive medical and socio-economic burden. The drug delivery to brain is hindered due to the presence of blood brain barrier. Nanoparticle mediated drug delivery is a promising approach in this regard. Chitosan is a hydrophilic polysaccharide polymer of N-acetylglycosamine and glucosamine. Owing to its biodegradability, nontoxicity and biocompatibility it is regarded as a safe excipient. The aim of the study was to fabricate donepezil-loaded sustained release chitosan nanoparticles as a simple way to deliver nano-drugs to the brain. The nanoparticles were fabricated using ionic gelation method using different concentrations of Sodium tripolyphosphate (TPP) and chitosan. The fabricated nanoparticles were assessed for particle size, zeta potential, encapsulation efficiency and in vitro drug release. The effect of sonication time on the particle size of nanoparticles was also studied. The nanoparticles exhibited mean particle size (between 135-1487 nm) and zeta potential (between +3.9-+38mV) depending on chitosan and TPP concentration used. The rise in the sonication time from 25 to 125 sec exhibited a decrease in particle size. The encapsulation efficiency was found to be in the range of 39.1-74.4%. Sustained and slow release of donepezil at a constant rate was exhibited from nanoparticles. The nanoparticles show potential to deliver donepezil to brain with enhanced encapsulation efficiency.
Assessment of the Dermal Acute Irritation Potential of Natural Veterinary Medicine Minyak Rajas in Albino Rabbits
Authors: Merdana I Made , Arjana Anak Agung Gde , Widyastuti Sri Kayati , Tetrania Tisa , Budiasa Ketut , Sudimartini Luh Made , Sudira I Wayan
Published: June 2020

Aims: This study was designed to assess the potential for acute dermal irritation of natural veterinary medicine Minyak Rajas (produce by Songgolangit Persada Limited Company, Bali, Indonesia) in albino rabbits. It is a rather thick liquid which contains various medicinal herbal extracts, formulated with effective microorganism technology. This medicine is effective in the treatment of skin infections and inflammation, wounds, intestinal worms and digestive disorder. Additionally, it works for game fowl muscle strengthening.

Place and Duration of Study: This study was conducted at the Veterinary Pharmacy and Pharmacology Laboratory, Faculty of Veterinary Medicine, Udayana University, between April 2020 and May 2020.

Methodology: Experimental animals used were three male albino rabbits (Oryctolagus cuniculus) in healthy conditions and weighing of >2 Kg. Test procedures followed the guidelines of Organisation for Economic Cooperation and Development, and chemicals used were applied in a single dose of 0.5 ml on animal skins, with untreated skin as a control.

Results: Very slight erythema was found after the Minyak Rajas application and the lesion was about 48 hours. Overall, no severe erythema, edema or other skin lesions were observed. According to the Amanded Draize system, the Primary Irritation Indexes of 0.16 is categorized as non-irritating.

Conclusion: We conclude that the natural veterinary medicine of Minyak Rajasis safe to be used.
Phenolic Content and Enzyme Inhibition Activities Barbarea auriculata var. paludosa, B. integrifolia and B. plantaginea (Brassicaceae)'s
Authors: Badem Merve , Sener Sıla Ozlem , Korkmaz Nuriye , Kanbolat Seyda , Yildirmiş Sermet , Ozgen Ufuk , Aliyazicioglu Rezzan , Kandemir Ali
Published: June 2020

Barbarea genus has been presented about 12 species, 9 taxon are endemic, in Turkey. In this sudy, enzyme inhibition was carried out on methanolic extract, chloroform extract, ethyl acetate extract, and the remaining aqueous phases from the aerial parts of B. auriculata var paludosa, B. integrifolia, and B. plantaginea species and HPLC studies were carried on their methanolic extract in the present study for the first time. Phenolic compounds were determined using reverse phase-high performance liquid chromatography (RP-HPLC). p-OH benzoic acid, vanilic acid, syringaldehyde, coumaric acid, synapic acid and benzoic acid were detected as major phenolic compounds in the species. Assay of enzyme inhibition activities were done using spectrophotometric methods. Results of these studies reveal that the extracts from these species have moderate tyrosinase, AChE and BuChE inhibitory activity. In the biological activity studies, it was observed that B. integrifolia was the highest activity.
Surface‐guided tomotherapy improves positioning and reduces treatment time: A retrospective analysis of 16 835 treatment fractions
Authors: Haraldsson André , Ceberg Sofie , Ceberg Crister , Bäck Sven , Engelholm Silke , Engström Per E.
Published: June 2020

Purpose

In this study, we have quantified the setup deviation and time gain when using fast surface scanning for daily setup/positioning with weekly megavoltage computed tomography (MVCT) and compared it to daily MVCT.

Methods

A total of 16 835 treatment fractions were analyzed, treated, and positioned using our TomoTherapy HD (Accuray Inc., Madison, USA) installed with a Sentinel optical surface scanning system (C‐RAD Positioning AB, Uppsala, Sweden).

Patients were positioned using in‐room lasers, surface scanning and MVCT for the first three fractions. For the remaining fractions, in‐room laser was used for setup followed by daily surface scanning with MVCT once weekly. The three‐dimensional (3D) setup correction for surface scanning was evaluated from the registration between MVCT and the planning CT. The setup correction vector for the in‐room lasers was assessed from the surface scanning and the MVCT to planning CT registration. The imaging time was evaluated as the time from imaging start to beam‐on.

Results

We analyzed 894 TomoTherapy treatment plans from 2012 to 2018. Of all the treatment fractions performed with surface scanning, 90 % of the residual errors were within 2.3 mm for CNS (N = 284), 2.9 mm for H&N (N = 254), 8.7 mm for thorax (N = 144) and 10.9 for abdomen (N = 134) patients. The difference in residual error between surface scanning and positioning with in‐room lasers was significant (P < 0.005) for all sites. The imaging time was assessed as total imaging time per treatment plan, modality, and treatment site and found that surface scanning significantly reduced patient on‐couch time compared to MVCT for all treatment sites (P < 0.005).

Conclusions

The results indicate that daily surface scanning with weekly MVCT can be used with the current target margins for H&N, CNS, and thorax, with reduced imaging time.
Study finds ‘low‐risk’ alcohol relapsers have same brain volume as abstainers
Authors: Knopf Alison
Published: June 2020

While abstinence is an option for many, requiring it also can deter patients from seeking treatment, or doom them to failure if they relapse, according to some researchers. A study published June 17 in Alcoholism: Clinical and Experimental Research has found that gray matter brain volume is the same for people who relapse to low risk levels as it is for people who stay abstinent. Furthermore, the study, “Not All Is Lost for Relapsers: Relapsers With Low WHO Risk Drinking Levels and Complete Abstainers Have Comparable Regional Gray Matter Volumes,” found that low‐risk relapsers have better cognitive performance than high‐risk relapsers.
Commercial marijuana could learn from tobacco: California
Authors: Knopf Alison
Published: June 2020

California legalized marijuana but didn't adopt the lessons already known from tobacco control to prevent youth use and reduce demand, according to a study published last week in JAMA Network Open. The harm caused by tobacco is well known; the risk of harm from marijuana is less well known, as is the best regulatory practice for the new drug. All this means that the population is exposed to “significant potential harm,” the researchers wrote.
Associated anomalies in cases with congenital clubfoot
Authors: Stoll Claude , Alembick Yves , Dott Beatrice , Roth Marie‐Paule
Published: June 2020

Congenital clubfoot CTEV is a common congenital anomaly, its etiology is unclear and its pathogenesis is controversial. Cases with CTEV often have other non‐CTEV associated congenital anomalies. The purpose of this study was to assess the prevalence and the types of these associated anomalies in a defined population. The associated anomalies in cases with CTEV were collected in all livebirths, stillbirths, and terminations of pregnancy during 29 years in 387,067 consecutive births in the area covered by our population‐based registry of congenital malformations. Of the 504 cases with CTEV, representing a prevalence of 13.02 per 10,000, 107 (21.2%) had associated anomalies. There were 31 (6.1%) cases with chromosomal abnormalities, and 21 (4.2%) non‐chromosomal recognized dysmorphic conditions including syndromes: 6 arthrogryposis multiplex congenita, 2 22q11.2 microdeletion, and one fetal alcohol syndrome. Fifty‐five (10.9%) of the cases had nonsyndromic multiple congenital anomalies (MCA). Anomalies in the cardiovascular, the central nervous, the urinary, the orofacial, and the musculoskeletal systems were the most common other anomalies in the cases with MCA. The anomalies associated with CTEV could be classified into a recognizable malformation syndrome in 52 of the 107 cases (48.6%) with associated anomalies. This study included special strengths: it is population‐based, each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for anomalies was continued until 2 years of age. In conclusion the overall prevalence of associated anomalies, one of five cases, emphasizes the need for a screening for other anomalies in cases with CTEV.
Shared genetic etiology underlying late‐onset Alzheimer's disease and posttraumatic stress syndrome
Authors: Lutz Michael W. , Luo Sheng , Williamson Douglas E. , Chiba‐Falek Ornit
Published: June 2020

Introduction

Late‐onset Alzheimer's disease (LOAD) manifests comorbid neuropsychiatric symptoms and posttraumatic stress disorder (PTSD) is associated with an increased risk for dementia in late life, suggesting the two disorders may share genetic etiologies.

Methods

We performed genetic pleiotropy analysis using LOAD and PTSD genome‐wide association study (GWAS) datasets from white and African‐American populations, followed by functional‐genomic analyses.

Results

We found an enrichment for LOAD across increasingly stringent levels of significance with the PTSD GWAS association (LOAD|PTSD) in the discovery and replication cohorts and a modest enrichment for the reverse conditional association (PTSD|LOAD). LOAD|PTSD association analysis identified and replicated theMS4Agenes region. These genes showed similar expression pattern in brain regions affected in LOAD, and across‐brain‐tissue analysis identified a significant association forMS4A6A. The African‐American samples showed moderate enrichment; however, no false discovery rate–significant associations.

Discussion

We demonstrated common genetic signatures for LOAD and PTSD and suggested immune response as a common pathway for these diseases.
Extracellular vesicle biomarkers of Alzheimer's disease associated with sub‐clinical cognitive decline in late middle age
Authors: Eren Erden , Hunt Jack F. V. , Shardell Michelle , Chawla Sahil , Tran Joyce , Gu Jeffrey , Vogt Nick M. , Johnson Sterling C. , Bendlin Barbara B. , Kapogiannis Dimitrios
Published: June 2020

Introduction

Neuronal extracellular vesicle (nEV) tau and insulin signaling biomarkers may detect preclinical Alzheimer's disease and age‐associated cognitive decline.

Methods

This case‐control study used repeated serum samples from 73 cognitively declining and 73 stable Wisconsin Registry for Alzheimer's Prevention participants (62.4 ± 6.3 years old). We immunocaptured nEVs; measured tau and insulin signaling biomarkers; and examined biomarker differences by group, their performance in group classification in training and test datasets (97, 49 individuals, respectively), and whether they predict cognitive performance change.

Results

Declining compared to stable individuals showed higher baseline total, p231‐, and p181‐tau with older age and higher annualized change for p‐IR and p‐IGF‐1R. Combining biomarkers classified decliners with 94% area under the curve (AUC), 86.0% sensitivity and 86.7% specificity, in training data, and 75% AUC, 71.4% sensitivity, and 77.3% specificity, in test data. Insulin biomarkers predicted cognitive performance change prospectively.

Discussion

Combining nEV biomarkers can identify individuals with age‐associated cognitive decline.
Single‐Molecule Observation of Intermediates in Bioorthogonal 2‐Cyanobenzothiazole Chemistry
Authors: Qing Yujia , Liu Mira D. , Hartmann Denis , Zhou Linna , Ramsay William J. , Bayley Hagan
Published: June 2020

We report a single‐molecule mechanistic investigation into 2‐cyanobenzothiazole (CBT) chemistry within a protein nanoreactor. When simple thiols reacted reversibly with CBT, the thioimidate monoadduct was approximately 80‐fold longer‐lived than the tetrahedral bisadduct, with important implications for the design of molecular walkers. Irreversible condensation between CBT derivatives and N‐terminal cysteine residues has been established as a biocompatible reaction for site‐selective biomolecular labeling and imaging. During the reaction between CBT and aminothiols, we resolved two transient intermediates, the thioimidate and the cyclic precursor of the thiazoline product, and determined the rate constants associated with the stepwise condensation, thereby providing critical information for a variety of applications, including the covalent inhibition of protein targets and dynamic combinatorial chemistry.
Wechselwirkung von Polyelektrolyt‐Architekturen mit Proteinen und Biosystemen
Authors: Achazi Katharina , Haag Rainer , Ballauff Matthias , Dernedde Jens , Kizhakkedathu Jayachandran N. , Maysinger Dusica , Multhaup Gerd
Published: June 2020

Gegenionen, die die Ladungen von Polyelektrolyten wie DNA oder Heparin neutralisieren, können im Wasser dissoziieren und beeinflussen stark deren Wechselwirkung mit Biomolekülen, insbesondere mit Proteinen. In diesem Artikel geben wir einen Überblick über Studien zur Wechselwirkung von Proteinen mit Polyelektrolyten und den Nutzen dieses Wissens für die medizinische Forschung. Hauptantriebskraft für die Bindung von Proteinen an Polyelektrolyte ist die Freisetzung von Gegenionen: Positiv geladene Bereiche des Proteins werden hierbei zu mehrwertigen Gegenionen des Polyelektrolyten, sodass zuvor gebundene Gegenionen des Polyelektrolyten freigesetzt werden und sich zugleich die Entropie erhöht, wie wir anhand von Studien zu Wechselwirkung von Proteinen mit natürlichen und synthetischen Polyelektrolyten zeigen. Ein Schwerpunkt liegt dabei auf sulfatierten dendritischen Polyglycerinen (dPGS). Die Literatur zeigt, dass wir Fortschritte beim Verständnis der Ladungs‐Ladungs‐Wechselwirkung in biologisch relevanten Systemen machen. Die Forschung auf diesem Gebiet wird die Entwicklung synthetischer Polyelektrolyte für die Medizin voranbringen.
Fluorogenic Probes/Inhibitors of β‐Lactamase and their Applications in Drug‐Resistant Bacteria
Authors: Ding Yang , Li Zheng , Xu Chenchen , Qin Wenjing , Wu Qiong , Wang Xuchun , Cheng Xiamin , Li Lin , Huang Wei
Published: June 2020

β‐Lactam antibiotics are generally perceived as one of the greatest inventions of the 20th century, and these small molecular compounds have saved millions of lives. However, upon clinical application of antibiotics, the β‐lactamase secreted by pathogenic bacteria can lead to the gradual development of drug resistance. β‐Lactamase is a hydrolase that can efficiently hydrolyze and destroy β‐lactam antibiotics. It develops and spreads rapidly in pathogens, and the drug‐resistant bacteria pose a severe threat to human health and development. As a result, detecting and inhibiting the activities of β‐lactamase are of great value for the rational use of antibiotics and the treatment of infectious diseases. At present, many specific detection methods and inhibitors of β‐lactamase have been developed and applied in clinical practice. In this Minireview, we describe the resistance mechanism of bacteria producing β‐lactamase and further summarize the fluorogenic probes, inhibitors of β‐lactamase, and their applications in the treatment of infectious diseases. It may be valuable to design fluorogenic probes with improved selectivity, sensitivity, and effectiveness to further identify the inhibitors for β‐lactamases and eventually overcome bacterial resistance.
Stereospecific 1,2‐Migrations of Boronate Complexes Induced by Electrophiles
Authors: Wang Hui , Jing Changcheng , Noble Adam , Aggarwal Varinder Kumar
Published: June 2020

The stereospecific 1,2‐migration of boronate complexes is one of the most representative reactions in boron chemistry. This process has been used extensively to develop powerful methods for asymmetric synthesis, with applications spanning from pharmaceuticals to natural products. Typically, 1,2‐migration of boronate complexes is driven by displacement of an α‐leaving group, oxidation of an α‐boryl radical, or electrophilic activation of an alkenyl boronate complex. The aim of this article is to summarize the recent advances in the rapidly expanding field of electrophile‐induced stereospecific 1,2‐migration of groups from boron to sp2 and sp3 carbon centers. It will be shown that three different conceptual approaches can be utilized to enable the 1,2‐migration of boronate complexes: stereospecific Zweifel‐type reactions, catalytic conjunctive coupling reactions, and transition metal‐free sp2–sp3 couplings. A discussion of the reaction scope, mechanistic insights, and synthetic applications of the work described is also presented.
Understanding the Interaction of Polyelectrolyte Architectures with Proteins and Biosystems
Authors: Achazi Katharina , Haag Rainer , Ballauff Matthias , Dernedde Jens , Kizhakkedathu Jayachandran N. , Maysinger Dusica , Multhaup Gerd
Published: June 2020

The counterions neutralizing the charges on polyelectrolytes such as DNA or heparin may dissociate in water and greatly influence the interaction of such polyelectrolytes with biomolecules, particularly proteins. In this Review we give an overview of studies on the interaction of proteins with polyelectrolytes and how this knowledge can be used for medical applications. Counterion release was identified as the main driving force for the binding of proteins to polyelectrolytes: Patches of positive charge become multivalent counterions of the polyelectrolyte and lead to the release of counterions from the polyelectrolyte and a concomitant increase in entropy. This is shown from investigations on the interaction of proteins with natural and synthetic polyelectrolytes. Special emphasis is paid to sulfated dendritic polyglycerols (dPGS). The Review demonstrates that we are moving to a better understanding of charge–charge interactions in systems of biological relevance. Research along these lines will aid and promote the design of synthetic polyelectrolytes for medical applications.
Synthesis of 2‐aminobenzophenone‐based Schiff base Pd(II) complexes: Investigation on crystal structure, biological behavior of DNA/protein‐binding, molecular docking, and in vitro anticancer activities
Authors: Satheeshkumar Rajendran , Wu Jing , Chandrasekaran Rajamanickam , Revathi Kannan , Sparkes Hazel A. , Wang Wen‐Long
Published: June 2020

Two new monobasic bidentate ligands and their Pd(II) complexes have been synthesized and characterized by analytical and spectroscopic methods. The structures of the complexes were confirmed by single‐crystal X‐ray diffraction. The bimolecular binding of the ligands and complexes has been carried out and described. Interestingly, both the bidentate chelating ligands replaced all the triphenyl arsine and chloride ions from the metal precursor in the formation of new complexes and were found to be approximately square planar. The interaction of the ligands and the complexes with calf thymus DNA and bovine serum albumin was studied by electronic and emission spectroscopy techniques, which suggested an intercalation mode of binding. It is well‐known that the viscosity of a DNA solution increases if any compound added binds to it through intercalation because this process lengthens the DNA helix due to the increased separation of the DNA base pairs when the compound slides in between, whereas a partial, nonclassical intercalation could bend (or kink) the DNA helix, which leads to a reduction in length and thereby reducing its viscosity. By contrast, there will be no change in the viscosity when the compounds bind with DNA grooves or by partial intercalation, which was further confirmed by viscosity measurements and molecular docking studies. It has been found that the compounds cleaved supercoiled DNA into nicked DNA without any external agent. The in vitro cytotoxicity studies of the ligands and complexes against human lung (A549) and breast (MCF7) cancer cell lines showed significant activity for both species.
MgO nanopowders catalyzed synthesis of pyrano[4,3‐d]thiazolo[3,2‐a]pyrimidine derivatives
Authors: Khalaj Mehdi , Mousavi‐Safavi Seyed Mahmoud , Farahani Nasrin , Lipkowski Janusz
Published: June 2020

A cubic phase of pure MgO nanopowders was prepared in an aqueous solution containing freshly squeezed orange juice with pulp and characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDS), and Fourier transform infrared (FT‐IR) spectroscopic techniques. The catalytic potential of MgO nanopowders was evaluated in preparation of pyrano[4,3‐d]thiazolo[3,2‐a]pyrimidine and chromeno[4,3‐d]thiazolo[3,2‐a]pyrimidines derivatives using the three simple methods including thermal, ultrasonic irradiation, and high‐speed ball milling (HSBM) technique under solvent‐free conditions. All products were successfully formed in high yields.
CO2‐fixation into carbonate anions for the construction of 3d‐4f cluster complexes with salen‐type Schiff base ligands: from molecular magnetic refrigerants to luminescent single‐molecule magnets
Authors: Liu Cai‐Ming , Hao Xiang , Zhang De‐Qing
Published: June 2020

Six new carbonate‐bridged Zn2Ln2 cluster complexes derived from salen‐type Schiff base ligands [H2La = N, N′‐bis(3‐methoxysalicylidene)‐1,3‐diaminopropane and H2Lb = N, N′‐bis(3‐methoxysalicylidene)‐ 1,2‐diaminoethane] have been synthesized. The bis‐imine chain in Schiff base ligands have an obvious influence on the cluster complexes' structures, magnetic and luminescence properties. The carbonate bridging ligand exactly comes from autoimmobilization of carbon dioxide, which may mediate ferromagnetic coupling between Ln3+ ions, favoring magnetocaloric effects and single molecule magnet (SMM) properties. Complexes Zn2Dy2(μ3‐CO3)2(La)2(NO3)2(MeOH)2 (1) and [Zn2Dy2(μ3‐CO3)2(Lb)2(NO3)2]·2MeOH (2) show field‐induced SMM properties; complexes Zn2Tb2(μ3‐CO3)2(La)2(NO3)2(MeOH)2 (3) and [Zn2Tb2(μ3‐CO3)2(Lb)2(NO3)2]·2MeOH (4) display both luminescence and field‐induced SMM behaviors; while complexes [Zn2Gd2(μ3‐CO3)2(La)2(NO3)2]·2MeOH (5) and [Zn2Gd2(μ3‐CO3)2(Lb)2(NO3)2]·2MeOH (6) exhibit medium magnetic entropy changes, which are candidates for cryogenic molecular magnetic refrigerants.
High‐performance epoxy nanocomposites via constructing rigid structured interphase with epoxy‐rich graphene oxide
Authors: Zhang Xueqin , Heng Zhengguang , Shen Lu , Liang Mei , Zeng Zhong , Chen Yang , Zou Huawei
Published: June 2020

Epoxy resins, as the most important thermosetting matrix of carbon fiber reinforced polymer (CFRP) composites, are widely used in the structural field, but the highly intrinsic brittleness of epoxy resins greatly limits their application. Therefore, it is urgent to develop new method to prepare high‐performance epoxy composites. In this research, GO riched with rigid short‐chain structure epoxy group on its surface was synthesized by chemically grafting dopamine, hexachlorocyclotriphosphazene and glycidol successively. Then the modified nanofillers were incorporated into the epoxy matrix to prepare high‐performance nanocomposites. The effect of epoxy‐rich GO nanosheets as fillers on mechanical properties of aerospace grade epoxy was studied. The results revealed that the epoxy‐rich GO could effectively optimize the performance of epoxy resins owing to forming the rigid structured interphase. The tensile strength and elongation at break of the nanocomposites were up to 113 MPa and 7.6% with 0.075 wt% additives, respectively, which greatly surpassed the value reported by the limited researches on strengthening epoxy with GO and its derivate nanofillers. Therefore, instructive idea and effective method were provided to obtain high‐performance polymer nanocomposite matrix in this study.
Quantitative prediction of elastomer degradation and mechanical behavior based on diffusion–reaction process
Authors: Lu Min , Zhang Haowei , Sun Li
Published: June 2020

Thermal oxidative aging and other chemical‐induced degradation greatly affect the service life of elastomer components. In this article, we presented a strategy to predict the long‐term mechanical behavior of elastomeric components, to foresee the failure of elastomer components in design stage. The accumulation and consumption of small molecule reactants in elastomers are described using a diffusion–reaction process. Free‐volume theory is applied to consider the diffusivity change during this process. Degradation of elastomers under elevated temperature up to 500 K, environmental pressure up to 4 atm, and different cross‐link densities are studied in this simulation. Methodology of prediction of mechanical behavior is proposed based on the affined network model.
Ammonium nitrogen adsorption from aqueous solution by poly(sodium acrylate)s: Effect on the amount of crosslinker and initiator
Authors: Li I‐Chi , Huang Guan‐Wei , Tsai Cheng‐Hsien , Chen Yung‐Chung , Hong Ming‐Chang , Tsai Tsung‐Yueh
Published: June 2020

In this work, we discuss the ammonium nitrogen adsorption and reusability from aqueous solution by using poly(sodium acrylate) (PANa) hydrogels (Polymers 1–6) under different amount of crosslinker and initiator. The PANa hydrogels were synthesized from the neutralized acrylic acid (AA) monomer via free radical thermal polymerization by using ammonium persulfate (APS) as an initiator and N,N′‐methylene‐bisacrylamide (MBA) as a crosslinker. These polymers exhibited glass transition temperatures (Tg) of 68–88°C and Td values (5% weight loss temperature) in the range of 190–221°C under nitrogen atmosphere. The PANa hydrogels had swollen ratios ranging from 387 to 4,063%, related to the crosslinking density. The final equilibrium adsorption capacity of the polymers was in the range of 20–39 ppm with an initial ammonium nitrogen concentration of 100 ppm. Among them, Polymer 3 without MBA crosslinker displayed the highest swollen characteristic along with the most efficient adsorption capacity. In comparison, the as‐prepared high crosslinking density hydrogels showed relative lower adsorption capability but higher reusability. The polymer composition in this work determines the ability to absorb and desorb ammonium nitrogen compound.
Poly(lactic acid)/pulp fiber composites: The effect of fiber surface modification and hydrothermal aging on viscoelastic and strength properties
Authors: Paunonen Sara , Berthold Fredrik , Immonen Kirsi
Published: June 2020

Poly(lactic acid) (PLA)/kraft pulp fiber (30 wt%) composites were prepared with and without a coupling agent (epoxidized linseed oil, ELO, 1.5 wt%) by injection molding. The non‐annealed composite samples, along with lean PLA, were exposed to two hydro‐thermal conditions: cyclic 50% RH/90% RH at 23 and 50°C, both up to 42 days. The aging effects were observed by size exclusion chromatography, differential scanning calorimetry, dynamic and tensile mechanical analysis, and fracture surface imaging. ELO temporarily accelerated the material's internal transition from viscous to an increasingly elastic response during the aging at 50°C. ELO also slowed down the tensile strength reduction of the composites at 50°C. These observations were explained with the hydrophobic ELO molecules' coupling and plasticizing effects at fiber/matrix interfaces. No effects were observed at 23°C.
Xanthoangelol alleviates cerebral ischemia reperfusion injury in rats
Authors: Chao Meng , Gao Chao , Huang Yaping
Published: June 2020

Ischemia/reperfusion (I/R) injury accounts to be a prime cause of neurological deficit following stroke. This study aimed to explore the neuro‐protective effects of Xanthoangelol (XAG) on I/R‐induced injury in both in vivo and in vitro models. Our data demonstrated that XAG can shrink infarct size and brain edema in middle cerebral artery occlusion (MCAO) model. In addition, XAG was capable of alleviating the neurological deficit in rats that have undergone MCAO procedure. Meanwhile, antiapoptotic activities of XAG against I/R‐induced neuronal injury were evidenced and further illustrated that XAG elicits antiapoptotic activities by suppressing excessive oxidative stress via nuclear factor erythroid‐2‐related factor 2 activation. Overall, our study revealed that XAG displayed the potential to be utilized as a neuroprotective agent against I/R‐induced neurological injury.
Birnbaum‐Saunders quantile regression and its diagnostics with application to economic data
Authors: Sánchez Luis , Leiva Víctor , Galea Manuel , Saulo Helton
Published: June 2020

The Birnbaum‐Saunders (BS) distribution is a model that frequently appears in the statistical literature and has proved to be very versatile and efficient across a wide range of applications. However, despite the growing interest in the study of the BS distribution, quantile regression modeling has not been considered for this distribution. To fill this gap, we introduce a class of quantile regression models based on the BS distribution, which allows us to describe positive and asymmetric data when a quantile must be predicted using covariates. We use an approach based on a quantile parameterization to generate the model, permitting us to consider a similar framework to generalized linear models, providing wide flexibility. The methodology proposed includes a thorough study of theoretical properties and practical issues, such as maximum likelihood parameter estimation and diagnostic analytics based on local influence and residuals. The performance of the residuals is evaluated by simulations, whereas an illustrative example of income data is conducted using the methodology to show its potential for applications. The numerical results report an adequate performance of the approach to quantile regression, indicating that the BS distribution is a good modeling choice when dealing with data that have both positive support and asymmetry. The economic implications of our investigation are discussed in the final section. Hence, it can be a valuable addition to the tool kit of applied statisticians and econometricians.
A novel approach to production of Chlorella protothecoides oil‐loaded nanoparticles via electrospraying method: Modeling of critical parameters for particle sizing
Authors: Karakaş Canan Yağmur , Özçimen Didem
Published: June 2020

Bioactive compounds in algae have chain rings that protect the tissue from chemical damage and disease symptoms. In addition, algal bioactive agents have the ability to stimulate the immune system, protective and therapeutic effects against many diseases, including various types of cancers, coronary heart disease, premature aging, and arthritis. These bioactive compounds also have antioxidant, anticoagulant, antiviral, and anti‐inflammatory properties. It is very important to encapsulate these algal compounds for preserving bioactive properties. Two of the most efficient methods used for encapsulation are electrospraying and microemulsion techniques. Although electrospraying is a novel technique to produce nanoparticles in recent years, microemulsion is more conventional method compared with electrospraying. In this study, Chlorella protothecoides oil was encapsulated by using sodium alginate and chitosan biopolymers, and the effects of production parameters of electrospraying and microemulsion methods on the particle size and loading efficiency were investigated. Statistical modeling of critical parameters for particle sizing in microemulsion method and electrospraying technique, which is a novel approach to obtain microalgal oil‐loaded nanoparticles, was also presented. It was seen that electrospraying is suitable for obtaining smaller nanoparticles (123.9–610 nm), homogeneous distribution, and higher oil loading efficiency (60%–77%) compared with microemulsion method (756.9–1128.2 nm and 57%–73%).
Fatty alcohol production: an opportunity of bioprocess
Authors: Munkajohnpong Pobthum , Kesornpun Chatchai , Buttranon Supacha , Jaroensuk Juthamas , Weeranoppanant Nopphon , Chaiyen Pimchai
Published: June 2020

Fatty alcohols are widely used for various applications and are found in products ranging from detergents to cosmetics and cleaning agents. Currently, over 3 million tonnes of fatty alcohols are produced per year from bio‐based and petroleum‐based feedstocks through chemical conversion and synthetic processes. However, the environmental impact of current fatty alcohol production processes has become a major concern, and several bioprocesses have emerged as alternative methods for synthesis. These biological processes are environmentally friendly due to their metal‐free nature, low consumption of energy, and mild reaction conditions. This review overviews the current status of fatty alcohol production – both chemical and biological approaches. Our focus is on biological synthesis approaches using biocatalysis and metabolic engineering due to their proven efficacy. Potential downstream processing for these bioprocesses is also presented. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd