bluuebunny/crossref_metadata_2025 huggingface dataset:
Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion
Authors: Neatu Stefan , Trandafir Mihaela M. , Stănoiu Adelina , Florea Ovidiu G. , Simion Cristian E. , Leonat Lucia N. , Cobianu Cornel , Gheorghe Marin , Florea Mihaela , Neatu Florentina
Published: May 2019

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.
Optimization on Reducing Slag Entrapment in 150 × 1270 mm Slab Continuous Casting Mold
Authors: Wang Yang , Yang Shufeng , Wang Feng , Li Jingshe
Published: May 2019

To reduce slag entrapment in 150 × 1270 mm slab continuous casting molds at the Tang Steel Company, the effect of submerged entrance nozzle (SEN) depth and casting speed on the phenomenon was studied by computational fluid dynamics simulations. Then, the slag entrapment behavior in continuous casting molds, utilizing Large Eddy Simulation (LES) by coupling the volume of fluid (VOF) method, was also used. Finally, the effect of several common oils usually used to simulate slag in water modelling on slag entrapment was discussed and the water modelling results were used to validate the numerical simulation findings. The results showed that the optimum scheme is a submerged depth of SEN 90 mm and a casting speed of 1.6 m/min. Under optimal conditions, the maximum surface velocity is smallest (0.335 m/s) and the maximum slag entrapment ratio (0.44%) appears in the position of 0.1 m below the meniscus after 15 s. The water modelling results were in good agreement with the numerical simulation results.
Data-Driven Microstructure Property Relations
Authors: Lißner Julian , Fritzen Felix
Published: May 2019

An image based prediction of the effective heat conductivity for highly heterogeneous microstructured materials is presented. The synthetic materials under consideration show different inclusion morphology, orientation, volume fraction and topology. The prediction of the effective property is made exclusively based on image data with the main emphasis being put on the 2-point spatial correlation function. This task is implemented using both unsupervised and supervised machine learning methods. First, a snapshot proper orthogonal decomposition (POD) is used to analyze big sets of random microstructures and, thereafter, to compress significant characteristics of the microstructure into a low-dimensional feature vector. In order to manage the related amount of data and computations, three different incremental snapshot POD methods are proposed. In the second step, the obtained feature vector is used to predict the effective material property by using feed forward neural networks. Numerical examples regarding the incremental basis identification and the prediction accuracy of the approach are presented. A Python code illustrating the application of the surrogate is freely available.
Biochemical Characterization and Elucidation of Action Pattern of a Novel Polysaccharide Lyase 6 Family Alginate Lyase from Marine Bacterium Flammeovirga sp. NJ-04
Authors: Li Qian , Hu Fu , Zhu Benwei , Sun Yun , Yao Zhong
Published: May 2019

Alginate lyases have been widely used to prepare alginate oligosaccharides in food, agricultural, and medical industries. Therefore, discovering and characterizing novel alginate lyases with excellent properties has drawn increasing attention. Herein, a novel alginate lyase FsAlyPL6 of Polysaccharide Lyase (PL) 6 family is identified and biochemically characterized from Flammeovirga sp. NJ-04. It shows highest activity at 45 °C and could retain 50% of activity after being incubated at 45 °C for 1 h. The Thin-Layer Chromatography (TLC) and Electrospray Ionization Mass Spectrometry (ESI-MS) analysis indicates that FsAlyPL6 endolytically degrades alginate polysaccharide into oligosaccharides ranging from monosaccharides to pentasaccharides. In addition, the action pattern of the enzyme is also elucidated and the result suggests that FsAlyPL6 could recognize tetrasaccharide as the minimal substrate and cleave the glycosidic bonds between the subsites of −1 and +3. The research provides extended insights into the substrate recognition and degradation pattern of PL6 alginate lyases, which may further expand the application of alginate lyases.
Imbalance of Controlled Death in Peripheral Blood Lymphocytes in Crohn’s Disease and Ulcerative Colitis
Authors: Dudzińska Ewa , Szymona Kinga , Gil-Kulik Paulina , Chomik Piotr , Świstowska Małgorzata , Gryzińska Magdalena , Kocki Janusz
Published: May 2019

Background and objectives: Inflammatory bowel disease (IBD) mainly includes Crohn’s disease (CD) and ulcerative colitis (UC). Both conditions are associated with an exacerbated intestinal immune response to harmless stimuli, leading to upregulation of pro-inflammatory mediators. Materials and Methods: The subjects of the study were 55 patients with IBD. The control group consisted of 35 healthy subjects. The researched material consisted of peripheral blood lymphocytes collected from the subjects. Expression of the genes BAX, BCL2, CASP3 and CASP9 was assessed at the mRNA level in the peripheral blood lymphocytes of patients with ulcerative colitis and Crohn’s disease relative to the healthy subjects. The expression of the genes was determined by rtPCR using TaqMan probes specific for these genes. Results: The group of patients diagnosed with CD had statistically significantly higher expression of the genes BAX (p = 0.012), BCL2 (p = 0.022), CASP3 (p = 0.003) and CASP9 (p = 0.029) than healthy subjects. Expression of BAX, BCL2, CASP3 and CASP9 in UC patients in the active phase of the disease was significantly lower than in patients in remission: BAX (p = 0.001), BCL2 (p = 0.038) and CASP9 (p = 0.007). In patients with UC, the BAX/BCL2 ratio was significantly correlated (r = 0.473) with the duration of the disease. In the group of CD patients treated biologically, a significantly lower BAX/BCL2 ratio was demonstrated than in patients that were not biologically treated. Conclusions: Our research has shown a simultaneous increase in the expression of the anti-apoptotic BCL2 gene and the proapoptotic BAX gene, which suggests the dysregulation of apoptosis mechanisms in IBD. Significantly higher expression of BAX and BCL2 in UC patients in remission as compared to CD may suggest differences in these diseases in terms of prognosis and treatment. Our results may suggest that an underlying imbalance in factors controlling apoptosis in peripheral blood lymphocytes may be the response of the immune system to inflammation of the intestinal mucosa. Modulation of apoptosis may become an important therapeutic mechanism in IBD.
Early Clinical Features, Time to Secondary Progression, and Disability Milestones in Polish Multiple Sclerosis Patients
Authors: Rzepiński Łukasz , Zawadka-Kunikowska Monika , Maciejek Zdzisław , Newton Julia L. , Zalewski Paweł
Published: May 2019

Background and Objectives: Determining the clinical course of multiple sclerosis (MS) and prediction of long-term disability can be a big challenge. To determine early clinical features of MS, their influence on long-term disability progression, and time to transition from relapsing-remitting MS (RRMS) to secondary progressive MS (SPMS), a cohort of Polish patients was studied. Materials and Methods: We retrospectively evaluated 375 Polish MS patients based on data from available medical records. We assessed early clinical MS features and the relationship between demographics and time from disease onset to attainment of 4 and 6 points on the Expanded Disability Status Scale (EDSS), as well as time to conversion from RRMS to SPMS. Results: The differences between initial MS variants were significantly associated with gender, age at disease onset, number and type of the first symptoms, and rate of the disability accrual. Mean times from disease onset to attainment of EDSS 4 and 6 were significantly influenced by the disease variant, age at onset, gender, degree of recovery from the initial symptoms, and first inter-bouts interval. The mean time to secondary progression was significantly influenced by the number and type of the first symptoms of RRMS. Conclusions: Early clinical features of MS are important in determining the disease variant, the time to transition from RRMS to SPMS, as well as predicting the disability accumulation of patients. Despite the small differences regarding the first MS symptoms, the disability outcomes in the cohort of Polish patients are similar to other regions of the world.
GLP-1 Receptor Agonists and Kidney Protection
Authors: Greco Eulalia , Russo Giuseppina , Giandalia Annalisa , Viazzi Francesca , Pontremoli Roberto , De Cosmo Salvatore
Published: May 2019

Type 2 diabetes mellitus (T2DM) is the leading cause of chronic kidney disease (CKD). Diabetic nephropathy (DN) is determined by specific pathological structural and functional alterations of the kidneys in patients with diabetes, and its clinical manifestations are albuminuria and decline of glomerular filtration rate (GFR). Apart from renin–angiotensin–aldosterone system (RAAS) inhibitors, no other drugs are currently available as therapy for diabetic kidney disease (DKD). Glucagon-like peptide-1 receptor (GLP-1R) agonists are a new class of anti-hyperglycemic drugs which have been demonstrated to prevent the onset of macroalbuminuria and reduce the decline of GFR in diabetic patients. These drugs may exert their beneficial actions on the kidneys through blood glucose- and blood pressure (BP)-lowering effects, reduction of insulin levels and weight loss. Clinical benefits of GLP-1R agonists were acknowledged due to data from large randomized phase III clinical trials conducted to assess their cardiovascular(CV) safety. These drugs improved renal biomarkers in placebo-controlled clinical studies, with effects supposed to be independent of the actions on glycemic control. In this review, we will focus on the actions of GLP-1R agonists on glucose metabolism and kidney physiology, and evaluate direct and indirect mechanisms through which these drugs may confer renal protection.
Migration of Ethylene Vinyl Alcohol Co-Polymer in the Urinary Tract Successfully Managed
Authors: Ierardi Anna Maria , Pesapane Filippo , Arrichiello Antonio , Fontana Federico , Piacentino Filippo , Carrafiello Gianpaolo
Published: May 2019

Selective embolization is the treatment of choice for traumatic renal pseudoaneurysm. The use of ethylene vinyl alcohol copolymer (EVOH) was recently described as an embolic agent in peripheral lesions. The aim of a good embolic agent is to: achieve rapid and effective embolization; reach and fill distal vasculature targeted for embolization; be easy to prepare and use. Moreover, it should be highly radiopaque, controllable during administration, biocompatible and cost-effective. EVOH is a non-adhesive embolic agent and its efficacy is independent from the coagulant status. The risk of non-targeted embolization should be reduced by the good radio-opacity of the embolic material that is injected under continuous fluoroscopy. Nevertheless, symptomatic EVOH migration was described. We report a unique case of embolization of a renal pseudoaneurysm and migration of EVOH in the urinary tract. Retrograde trans-urethral removal of the migrated embolic agent was successfully performed. Our case report indicates that EVOH may not be appropriate when a fistula with renal calyx is suspected, even if its migration in the urinary tract may be managed.
Severe Abnormalities of Lens Epithelial Cells in Exfoliation Syndrome: A Transmission Electron Microscopy Study of Patients with Age-Related Cataract
Authors: Sorkou Konstantina Ν. , Manthou Maria Eleni , Meditskou Soultana , Ziakas Nikolaos , Tsaousis Konstantinos T. , Tsinopoulos Ioannis T.
Published: May 2019

Background and objectives: The aim of this study was to examine via electron microscopy the lens epithelial cells in age-related cataracts and compare the findings between patients with and without exfoliation syndrome, in the Greek population. Materials and Methods: Twenty-one patients with age-related cataracts, older than 60 years, were included in the study. Eleven of them also suffered from exfoliation syndrome. Anterior lens capsules, obtained during phacoemulsification, were examined with a transmission electron microscope. Results: In all cases, ultrastructural features of diffuse intracellular and extracellular oedema were noticed to a varying degree and transparent vacuoles were detected. Often, there was more than one layer of cells, giving the impression that healthier cells tried to cover neighboring cells presenting extensive damage. Commonly, cells lost their regular shape and appeared with expanded nuclei carrying dense granules. Apoptotic cells were also detected. The epithelial cells frequently were completely destroyed or absent, exhibiting loose connections amongst them or with the basement membrane. In exfoliation syndrome (XFS) patients the alterations were more severe. Additionally, the lens epithelial cells (LECs) apical cell membrane appeared with varying distances from the basement membrane, due to different cell “heights”, creating an irregular margin of the epithelium (p < 0.05). Conclusion: Transmission electron microscope (TEM) examination revealed ultrastructural abnormalities in all patients’ lens epithelia, more extended and more frequently observed in XFS group. In all cases, the lesions were comparable to those described in severe pathologies, all of which were excluded from the study. Environmental factors such as increased ultraviolet B (UVB) radiation exposure in Mediterranean countries, genetic factors, epigenetic factors, or all of them, could contribute to these alterations. Further epidemiological and molecular biology research is needed, so as to justify these results.
Gallic Acid-Chitosan Conjugate Inhibits the Formation of Calcium Oxalate Crystals
Authors: Queiroz Moacir Fernandes , Melo Karoline Rachel Teodosio , Sabry Diego Araujo , Sassaki Guilherme Lanzi , Rocha Hugo Alexandre Oliveira , Costa Leandro Silva
Published: May 2019

It has recently been shown that chitosan (Chit) induces the formation of calcium oxalate (CaOx) crystals, which are mainly responsible for the appearance of kidney stones, and this might limit the use of Chit in vivo. Here, Chit was conjugated with gallic acid (Chit-Gal) to decrease the formation of CaOx crystal. This conjugation was confirmed by FTIR and NMR analyses. Chit-Gal contains 10.2 ± 1.5 mg GA per g of Chit. Compared to the control group, Chit increased the number of crystals by six-fold, mainly in the number of monohydrated CaOx crystals, which are the most harmful CaOx crystals. In addition, Chit increased the zeta potential (ζ) of CaOx crystals by three-fold, indicating that Chit was associated with the crystals. These alterations were abolished when Chit-gal was used in these tests. As oxidative stress is related to renal calculus formation, Chit and Chit-Gal were also evaluated as antioxidants using total antioxidant Capacity (TAC), reducing power, ferrous chelation, and copper chelation tests. Chit-gal was more efficient antioxidant agent in TAC (2 times), in ferrous chelation (90 times), and in reducing Power (5 times) than Chit. Overall, Chit-gal has higher antioxidant activity than Chit, does not induce the formation of CaOx crystals. Thus, Chit-Gal has potential to be used as a chit substitute.
A New Approach for the Prevention and Treatment of Cardiovascular Disorders. Molecular Hydrogen Significantly Reduces the Effects of Oxidative Stress
Authors: LeBaron Tyler W. , Kura Branislav , Kalocayova Barbora , Tribulova Narcis , Slezak Jan
Published: May 2019

Cardiovascular diseases are the most common causes of morbidity and mortality worldwide. Redox dysregulation and a dyshomeostasis of inflammation arise from, and result in, cellular aberrations and pathological conditions, which lead to cardiovascular diseases. Despite years of intensive research, there is still no safe and effective method for their prevention and treatment. Recently, molecular hydrogen has been investigated in preclinical and clinical studies on various diseases associated with oxidative and inflammatory stress such as radiation-induced heart disease, ischemia-reperfusion injury, myocardial and brain infarction, storage of the heart, heart transplantation, etc. Hydrogen is primarily administered via inhalation, drinking hydrogen-rich water, or injection of hydrogen-rich saline. It favorably modulates signal transduction and gene expression resulting in suppression of proinflammatory cytokines, excess ROS production, and in the activation of the Nrf2 antioxidant transcription factor. Although H2 appears to be an important biological molecule with anti-oxidant, anti-inflammatory, and anti-apoptotic effects, the exact mechanisms of action remain elusive. There is no reported clinical toxicity; however, some data suggests that H2 has a mild hormetic-like effect, which likely mediate some of its benefits. The mechanistic data, coupled with the pre-clinical and clinical studies, suggest that H2 may be useful for ROS/inflammation-induced cardiotoxicity and other conditions.
p53 Binds Preferentially to Non-B DNA Structures Formed by the Pyrimidine-Rich Strands of GAA·TTC Trinucleotide Repeats Associated with Friedreich’s Ataxia
Authors: Helma Robert , Bažantová Pavla , Petr Marek , Adámik Matej , Renčiuk Daniel , Tichý Vlastimil , Pastuchová Alena , Soldánová Zuzana , Pečinka Petr , Bowater Richard P. , Fojta Miroslav , Brázdová Marie
Published: May 2019

Expansions of trinucleotide repeats (TNRs) are associated with genetic disorders such as Friedreich’s ataxia. The tumor suppressor p53 is a central regulator of cell fate in response to different types of insults. Sequence and structure-selective modes of DNA recognition are among the main attributes of p53 protein. The focus of this work was analysis of the p53 structure-selective recognition of TNRs associated with human neurodegenerative diseases. Here, we studied binding of full length p53 and several deletion variants to TNRs folded into DNA hairpins or loops. We demonstrate that p53 binds to all studied non-B DNA structures, with a preference for non-B DNA structures formed by pyrimidine (Py) rich strands. Using deletion mutants, we determined the C-terminal DNA binding domain of p53 to be crucial for recognition of such non-B DNA structures. We also observed that p53 in vitro prefers binding to the Py-rich strand over the purine (Pu) rich strand in non-B DNA substrates formed by sequence derived from the first intron of the frataxin gene. The binding of p53 to this region was confirmed using chromatin immunoprecipitation in human Friedreich’s ataxia fibroblast and adenocarcinoma cells. Altogether these observations provide further evidence that p53 binds to TNRs’ non-B DNA structures.
Novel pH Selective, Highly Lytic Peptides Based on a Chimeric Influenza Hemagglutinin Peptide/Cell Penetrating Peptide Motif
Authors: Algayer Bethany , O’Brien Ann , Momose Aaron , Murphy Dennis J. , Procopio William , Tellers David M. , Tucker Thomas J.
Published: May 2019

Delivery of macromolecular cargos such as siRNA to the cytosol after endocytosis remains a critical challenge. Numerous approaches including viruses, lipid nanoparticles, polymeric constructs, and various peptide-based approaches have yet to yield a general solution to this delivery issue. In this manuscript, we describe our efforts to design novel endosomolytic peptides that could be used to facilitate the release of cargos from a late endosomal compartment. These amphiphilic peptides, based on a chimeric influenza hemagglutinin peptide/cell-penetrating peptide (CPP) template, utilize a pH-triggering mechanism in which the peptides are protonated after acidification of the endosome, and thereby adopt an alpha-helical conformation. The helical forms of the peptides are lytically active, while the non-protonated forms are much less or non-lytically active at physiological pH. Starting from an initial lead peptide (INF7-Tat), we systematically modified the sequence of the chimeric peptides to obtain peptides with greatly enhanced lytic activity that maintain good pH selectivity in a red blood cell hemolysis assay.
Pharmacokinetics and Tissue Distribution of a Novel Bis-Chelated Gold(I) Diphosphine Compound, Bis(2,3-bis(tert-butylmethylphosphino)Quinoxaline)Aurate(I), in Rats
Authors: Peng Ying , Qi Huanhuan , Chang Qingqing , Zhang Yu , Liu Weiyi , Liu Minyu , Liu Quanhai , Wang Guangji , Sun Jianguo
Published: May 2019

GC20, a novel soluble bis-chelated gold(I)−diphosphine compound, has been reported as a promising anticancer candidate. Assessing the pharmacokinetic properties of GC20 is critical for its medicinal evaluation. First, a sensitive and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and well validated to determine GC20 in rat plasma and rat tissue homogenate after one step protein precipitation. Chromatographic separation was achieved on an Angilent ZORBAX-C18 column (3.5 μm, 2.1 × 50 mm) with gradient elution and mass spectrometry was performed on a triple quadrupole in positive ion mode using an electrospray ionization source. This method was then applied to investigate the pharmacokinetics and tissue distribution of GC20 in rats after intravenous administration. The results showed that the plasma exposure of GC20 in vivo increased with increasing doses after a single dose. However, after multiple doses, a significant accumulation and a saturation at elimination were observed for GC20 in rats. Moreover, after intravenous administration, GC20 was widely distributed in various tissues, with the highest levels in the lung, spleen, liver, and pancreas, followed by the kidney and heart, while the lowest level was found in the brain. This is the first report on the pharmacokinetic properties of GC20.
Time-Gated Luminescent In Situ Hybridization (LISH): Highly Sensitive Detection of Pathogenic Staphylococcus aureus
Authors: Sayyadi Nima , Connally Russell E. , Lawson Thomas S. , Yuan Jingli , Packer Nicolle H. , Piper James A.
Published: May 2019

We describe simple direct conjugation of a single TEGylated Europium chelate to DNA that binds to intracellular rRNA and is then detected using a homogeneous luminescent in situ hybridisation (LISH) technique. As a proof-of-principle, Staphylococcus aureus (S. aureus) was selected as a model for our study to show the ability of this probe to bind to intracellular 16S ribosomal rRNA. A highly purified Europium chelate conjugated oligonucleotide probe complementary to an rRNA sequence-specific S. aureus was prepared and found to be soluble and stable in aqueous solution. The probe was able to bind specifically to S. aureus via in situ hybridisation to differentiate S. aureus from a closely related but less pathogenic Staphylococcus species (S. epidermidis). A time-gated luminescent (TGL) microscope system was used to generate the high signal-to-noise ratio (SNR) images of the S. aureus. After excitation (365 nm, Chelate λmax = 335 nm), the long-lived (Eu3+) luminescent emission from the probe was detected without interference from natural background autofluorescence typically seen in biological samples. The luminescent images were found to have 6 times higher SNR or sensitivity compared to the fluorescent images using conventional fluorophore Alexa Fluor 488. The TEGylated Europium chelate -oligo probe stained S. aureus with mean signal intensity 3.5 times higher than the threshold level of signal from S. epidermidis (with SNR 8 times higher). A positive control probe (EUB338–BHHTEGST–Eu3+) has mean signal intensity for S. aureus and S. epidermidis equally 3.2 times higher than the threshold of signal for a negative NON-EUB338 control probe. The direct conjugation of a single Europium chelate to DNA provides simplicity and improvement over existing bovine serum albumin (BSA)/streptavidin/biotinylated DNA platforms for multi-attachment of Europium chelate per DNA and more importantly makes it feasible for hybridisation to intracellular RNA targets. This probe has great potential for highly sensitive homogeneous in situ hybridisation detection of the vast range of intracellular DNA targets.
Synthesis of Graphene Oxide Based Sponges and Their Study as Sorbents for Sample Preparation of Cow Milk Prior to HPLC Determination of Sulfonamides
Authors: Maggira Martha , Deliyanni Eleni A. , Samanidou Victoria F.
Published: May 2019

In the present study, a novel, simple, and fast sample preparation technique is described for the determination of four sulfonamides (SAs), namely Sulfathiazole (STZ), sulfamethizole (SMT), sulfadiazine (SDZ), and sulfanilamide (SN) in cow milk prior to HPLC. This method takes advantage of a novel material that combines the extractive properties of graphene oxide (GO) and the known properties of common polyurethane sponge (PU) and that makes sample preparation easy, fast, cheap and efficient. The PU-GO sponge was prepared by an easy and fast procedure and was characterized with FTIR spectroscopy. After the preparation of the sorbent material, a specific extraction protocol was optimized and combined with HPLC-UV determination could be applied for the sensitive analysis of trace SAs in milk. The proposed method showed good linearity while the coefficients of determination (R2) were found to be high (0.991–0.998). Accuracy observed was within the range 90.2–112.1% and precision was less than 12.5%. Limit of quantification for all analytes in milk was 50 μg kg−1. Furthermore, the PU-GO sponge as sorbent material offered a very clean extract, since no matrix effect was observed.
Homo- and Copolymerization of Ethylene with Norbornene Catalyzed by Vanadium(III) Phosphine Complexes
Authors: Zanchin Giorgia , Gavezzoli Alessia , Bertini Fabio , Ricci Giovanni , Leone Giuseppe
Published: May 2019

Herein, we report the homo- and co-polymerization of ethylene (E) with norbornene (NB) catalyzed by vanadium(III) phosphine complexes of the type VCl3(PMenPh3-n)2 [n = 2 (1a), 1 (1b)] and VCl3(PR3)2 [R = phenyl (Ph, 1c), cyclohexyl (Cy, 1d), tert-butyl (tBu, 1e)]. In the presence of Et2AlCl and Cl3CCOOEt (ETA), 1a–1e exhibit good activities for the polymerization of ethylene, affording linear, semicrystalline PEs with a melting temperature of approximately 130 °C. Mainly alternating copolymers with high comonomer incorporation were obtained in the E/NB copolymerization. A relationship was found between the electronic and steric properties of the phosphine ligands and the catalytic performance. Overall, the presence of electron-withdrawing ligand substituents increases the productivity, complexes with aryl phosphine (weaker σ–donor character) exhibiting a higher (co)polymerization initiation rate than those with alkyl phosphines (stronger σ–donor character). Steric effects also seem to play a key role since 1d and 1e, having large size phosphines (PCy3 θ = 170° and PtBu3 θ = 182°, respectively) are more active than 1a (PMe2Ph θ = 122°). In this case, the larger size of PtBu3 and PCy3 likely compensates for their higher donor strength compared to PMe2Ph.
What Is the Nature of Supramolecular Bonding? Comprehensive NBO/NRT Picture of Halogen and Pnicogen Bonding in RPH2···IF/FI Complexes (R = CH3, OH, CF3, CN, NO2)
Authors: Jiao Yinchun , Weinhold Frank
Published: May 2019

We employ a variety of natural bond orbital (NBO) and natural resonance theory (NRT) tools to comprehensively investigate the nature of halogen and pnicogen bonding interactions in RPH2···IF/FI binary complexes (R = CH3, OH, CF3, CN, and NO2) and the tuning effects of R-substituents. Though such interactions are commonly attributed to “sigma-hole”-type electrostatic effects, we show that they exhibit profound similarities and analogies to the resonance-type 3-center, 4-electron (3c/4e) donor-acceptor interactions of hydrogen bonding, where classical-type “electrostatics” are known to play only a secondary modulating role. The general 3c/4e resonance perspective corresponds to a continuous range of interatomic A···B bond orders (bAB), spanning both the stronger “covalent” interactions of the molecular domain (say, bAB ≥ ½) and the weaker interactions (bAB ˂ ½, often misleadingly termed “noncovalent”) that underlie supramolecular complexation phenomena. We show how a unified NBO/NRT-based description of hydrogen, halogen, pnicogen, and related bonding yields an improved predictive utility and intuitive understanding of empirical trends in binding energies, structural geometry, and other measurable properties that are expected to be manifested in all such supramolecular interaction phenomena.
Stacked-Cup Carbon Nanotube Flexible Paper Based on Soy Lecithin and Natural Rubber
Authors: Shayganpour Amirreza , Naderizadeh Sara , Grasselli Silvia , Malchiodi Annalisa , Bayer Ilker S.
Published: May 2019

Stacked-cup carbon nanotubes (SCCNTs) are generally referred to as carbon nanofibers (CNFs). SCCNTs are much less expensive to fabricate and are regarded as good polymer modifiers suitable for large-scale production. Flexible, SCCNT-based soy lecithin biocomposites were fabricated using liquid natural rubber latex as binder. Natural polymers and the SCCNTs were dispersed in a green solvent using a benchtop high-pressure homogenizer. The inks were simply brush-on painted onto cellulose fiber networks and compacted by a hydraulic press so as to transform into conductive paper-like form. The resulting flexible SCCNT papers demonstrated excellent resistance against severe folding and bending tests, with volume resistivity of about 85 Ω·cm at 20 wt % SCCNT loading. The solvent enabled formation of hydrogen bonding between natural rubber and soy lecithin. Thermomechanical measurements indicated that the biocomposites have good stability below and above glass transition points. Moreover, the SCCNT biocomposites had high through-plane thermal conductivity of 5 W/mK and 2000 kJ/m3K volumetric heat capacity, ideal for thermal interface heat transfer applications.
Extreme and Topological Dissipative Solitons with Structured Matter and Structured Light
Authors: Rosanov Nikolay N. , Fedorov Sergey V. , Nesterov Leonid A. , Veretenov Nikolay A.
Published: May 2019

Structuring of matter with nanoobjects allows one to generate soliton-like light bundles with extreme characteristics—temporal duration and spatial dimensions. On the other hand, structuring of light gives the possibility to form light bundles with complicated internal structure; their topology could be used for information coding similar to that in self-replicating RNA molecules carrying genetic code. Here we review the both variants of structuring. In the first variant, we consider a linear molecular chain and organic film interacting resonantly with laser radiation. Demonstrated are optical bistability, switching waves, and dissipative solitons, whose sizes for molecular J-aggregates can reach the nanometer range. We also discuss some theoretical approaches to take into account multi-particle interaction and correlations between molecules. In the second variant, light structuring in large-size laser medium with saturable amplification and absorption is achieved by preparation of the initial field distribution with a number of closed and unclosed vortex lines where the field vanishes. Various types of topological solitons, parameter domains of their stability, and transformation of the solitons with slow variation of the scheme parameters are presented.
Microfiltration of Submicron-Sized and Nano-Sized Suspensions for Particle Size Determination by Dynamic Light Scattering
Authors: Ullmann Christian , Babick Frank , Stintz Michael
Published: May 2019

Dynamic light scattering (DLS) is commonly used for the determination of average particle diameters and suspension stability and popular in academics and industry. However, DLS is not considered suitable for polydisperse samples. The presence of little quantities of micrometre particles in nano and submicrometre suspensions especially affect the reliability of DLS results. Microfiltration might be a suitable method for the removal of unwanted large particles. This study investigates the effect of microfiltration on the diameter distributions as measured by DLS. Polystyrene standards (40–900 nm diameter), and monomodal silica suspensions were filtered with polytetrafluoroethylene (PTFE) membranes (0.1–1.0 µm pore size) to investigate retention properties and grade efficiency. Non-ideal materials were used to prove the results. Experiments showed that a mono-exponential decay can be achieved by filtration. A size safety factor of at least three between labeled pore size and average diameter was found to keep separation as low as possible. Filtration in order to enhance DLS for particulate submicrometre materials was considered suitable for narrowly distributed coated titania and kaolin powder. In a regulatory context, this might have an impact on considering a substance false positive or false negative according to the European Commission (EC) recommendation of a definition of the term nanomaterial.
Towards a Food Pharmacy: Immunologic Modulation through Diet
Authors: Molendijk Ilse , van der Marel Sander , Maljaars P.W. Jeroen
Published: May 2019

Patients frequently wonder whether their dietary pattern influences the course of inflammatory bowel disease (IBD). Many patients even avoid certain foods that aggravate their symptoms. Although interest in nutritional interventions is rising among physicians, the current application of nutritional interventions in the IBD population is limited due to the lack of scientific evidence from clinical trials. Several studies, however, have identified associations between diet, gut microbiota, intestinal epithelial integrity, and mucosal immune responses. In patients consuming predominantly a Western diet high in n-6 poly-unsaturated fatty acids (PUFAs), sugars, and meat, and low in fruits and vegetables, an impaired gut epithelial barrier and disturbances in the intestinal microbiota have been observed, resulting in a chronic mucosal inflammation. An anti-inflammatory diet may restore this disbalance. In this review, we discuss the effects of diet on the composition of the microbiota, the gut epithelial barrier function, and the mucosal immune system.
The Chemical Composition and Nutritional Value of Chia Seeds—Current State of Knowledge
Authors: Kulczyński Bartosz , Kobus-Cisowska Joanna , Taczanowski Maciej , Kmiecik Dominik , Gramza-Michałowska Anna
Published: May 2019

Chia (Salvia hispanica) is an annual herbaceous plant, the seeds of which were consumed already thousands of years ago. Current research results indicate a high nutritive value for chia seeds and confirm their extensive health-promoting properties. Research indicates that components of chia seeds are ascribed a beneficial effect on the improvement of the blood lipid profile, through their hypotensive, hypoglycaemic, antimicrobial and immunostimulatory effects. This article provides a review of the most important information concerning the potential application of chia seeds in food production. The chemical composition of chia seeds is presented and the effect of their consumption on human health is discussed. Technological properties of chia seeds are shown and current legal regulations concerning their potential use in the food industry are presented.
High-Dose Astaxanthin Supplementation Suppresses Antioxidant Enzyme Activity during Moderate-Intensity Swimming Training in Mice
Authors: Zhou Yingsong , Baker Julien S , Chen Xiaoping , Wang Yajun , Chen Haimin , Davison Gareth W , Yan Xiaojun
Published: May 2019

Exercise-induced reactive oxygen and nitrogen species are increasingly considered as beneficial health promotion. Astaxanthin (ASX) has been recognized as a potent antioxidant suitable for human ingestion. We investigated whether ASX administration suppressed antioxidant enzyme activity in moderate-intensity exercise. Seven-week-old male C57BL/6 mice (n = 8/group) were treated with ASX (5, 15, and 30 mg/kg BW) combined with 45 min/day moderate-intensity swimming training for four weeks. Results showed that the mice administrated with 15 and 30 mg/kg of ASX decreased glutathione peroxidase, catalase, malondialdehyde, and creatine kinase levels in plasma or muscle, compared with the swimming control group. Beyond that, these two (15 and 30 mg/kg BW) dosages of ASX downregulated gastrocnemius muscle erythroid 2p45 (NF-E2)-related factor 2 (Nrf2). Meanwhile, mRNA of Nrf2 and Nrf2-dependent enzymes in mice heart were also downregulated in the ASX-treated groups. However, the mice treated with 15 or 30 mg/kg ASX had increased constitutive nitric oxidase synthase and superoxide dismutase activity, compared with the swimming and sedentary control groups. Our findings indicate that high-dose administration of astaxanthin can blunt antioxidant enzyme activity and downregulate transcription of Nrf2 and Nrf2-dependent enzymes along with attenuating plasma and muscle MDA.
Low-Dose Stevia (Rebaudioside A) Consumption Perturbs Gut Microbiota and the Mesolimbic Dopamine Reward System
Authors: Nettleton Jodi E. , Klancic Teja , Schick Alana , Choo Ashley C. , Shearer Jane , Borgland Stephanie L. , Chleilat Faye , Mayengbam Shyamchand , Reimer Raylene A.
Published: May 2019

Stevia is a natural low-calorie sweetener that is growing in popularity in food and beverage products. Despite its widespread use, little is understood of its impact on the gut microbiota, an important environmental factor that can mediate metabolism and subsequent obesity and disease risk. Furthermore, given previous reports of dysbiosis with some artificial low-calorie sweeteners, we wanted to understand whether prebiotic consumption could rescue potential stevia-mediated changes in gut microbiota. Three-week old male Sprague–Dawley rats were randomized to consume: (1) Water (CTR); (2) Rebaudioside A (STV); (3) prebiotic (PRE); (4) Rebaudioside A + prebiotic (SP) (n = 8/group) for 9 weeks. Rebaudioside was added to drinking water and prebiotic oligofructose-enriched inulin added to control diet (10%). Body weight and feces were collected weekly and food and fluid intake biweekly. Oral glucose and insulin tolerance tests, gut permeability tests, dual X-ray absorptiometry, and tissue harvest were performed at age 12 weeks. Rebaudioside A consumption alone did not alter weight gain or glucose tolerance compared to CTR. Rebaudioside A did, however, alter gut microbiota composition and reduce nucleus accumbens tyrosine hydroxylase and dopamine transporter mRNA levels compared to CTR. Prebiotic animals, alone or with Rebaudioside A, had reduced fat mass, food intake, and gut permeability and cecal SCFA concentration. Adding Rebaudioside A did not interfere with the benefits of the prebiotic except for a significant reduction in cecal weight. Long-term low-dose Rebaudioside A consumption had little effect on glucose metabolism and weight gain; however, its impact on gut microbial taxa should be further examined in populations exhibiting dysbiosis such as obesity.
Human Enriched Serum Following Hydrolysed Collagen Absorption Modulates Bone Cell Activity: from Bedside to Bench and Vice Versa
Authors: Wauquier Fabien , Daneault Audrey , Granel Henri , Prawitt Janne , Fabien Soulé Véronique , Berger Juliette , Pereira Bruno , Guicheux Jérôme , Rochefort Gael Y. , Meunier Nathalie , Blot Adeline , Wittrant Yohann
Published: May 2019

Collagen proteins are crucial components of the bone matrix. Since collagen-derived products are widely used in the food and supplement industry, one may raise the question whether collagen-enriched diets can provide benefits for the skeleton. In this study, we designed an innovative approach to investigate this question taking into account the metabolites that are formed by the digestive tract and appear in the circulation after ingestion of hydrolysed collagen. Blood samples collected in clinical and pre-clinical trials following ingestion and absorption of hydrolysed collagen were processed and applied on bone-related primary cell cultures. This original ex vivo methodology revealed that hydrolysed collagen-enriched serum had a direct impact on the behaviour of cells from both human and mouse origin that was not observed with controls (bovine serum albumin or hydrolysed casein-enriched serum). These ex vivo findings were fully in line with in vivo results obtained from a mouse model of post-menopausal osteoporosis. A significant reduction of bone loss was observed in mice supplemented with hydrolysed collagen compared to a control protein. Both the modulation of osteoblast and osteoclast activity observed upon incubation with human or mouse serum ex vivo and the attenuation of bone loss in vivo, clearly indicates that the benefits of hydrolysed collagen for osteoporosis prevention go beyond the effect of a simple protein supplementation.
Perceptions of UK Community Pharmacists on Current Consultation Skills and Motivational Interviewing as a Consultation Approach: A Qualitative Study
Authors: Jalal Zahraa , Akhtar Sania , Finlay Katherine , King Kathryn , Goel Neera , Ward Jonathan
Published: May 2019

Objectives: Community pharmacists’ roles in the UK are evolving; pharmacists currently deliver a wider range of clinical services with more patient-focused care. The objectives of this study were (i) to investigate UK community pharmacists’ views on their current communication skills in pharmacist-patient facing consultations, and (ii) to explore the perceptions of UK community pharmacists towards the application of motivational interviewing (MI) in a pharmacy consultation. In-depth qualitative face-to-face, semi-structured interviews with ten practicing community pharmacists were carried out, ranging from 30–60 min in length. The interviews were audio recorded, transcribed verbatim and thematic analysis was employed. Four themes emerged from the data: (1) the fight for time; (2) wrestling with consultation styles; (3) a personal communication evolution; and (4) unfamiliar but engaging motivational interviewing. These themes demonstrated the juxtaposition between the desire for patient-centred care and the pressures of managing broader dispensing work. Participants were critical of academic and continuous professional learning (CPD) training in communication skills and there was a strong recognition of the potential role of MI in promoting patient autonomy and outcomes. Participants recognized a few elements of MI techniques in their current consultations, but welcomed further training on behavioral change for effective consultations, expressing a desire for practical MI-specific training. Face-to-face CPD of consultation skills is needed to avoid the feeling of isolation among UK practicing pharmacists and rigidity in consultation delivery. Support for community pharmacists from other pharmacy staff could relieve current pressures and allow pharmacists time to develop and acquire effective skills for patient facing roles. Behavioural change consultation skills training for pharmacists could be an effective strategy to address these current challenges.
Role of Silicon in Mediating Salt Tolerance in Plants: A Review
Authors: Zhu Yong-Xing , Gong Hai-Jun , Yin Jun-Liang
Published: May 2019

Salt stress is a major threat for plant growth worldwide. The regulatory mechanisms of silicon in alleviating salt stress have been widely studied using physiological, molecular genetics, and genomic approaches. Recently, progresses have been made in elucidating the alleviative effects of silicon in salt-induced osmotic stress, Na toxicity, and oxidative stress. In this review, we highlight recent development on the impact of silicon application on salt stress responses. Emphasis will be given to the following aspects. (1) Silicon transporters have been experimentally identified in different plant species and their structure feature could be an important molecular basis for silicon permeability. (2) Silicon could mediate salt-induced ion imbalance by (i) regulating Na+ uptake, transport, and distribution and (ii) regulating polyamine levels. (3) Si-mediated upregulation of aquaporin gene expression and osmotic adjustment play important roles in alleviating salinity-induced osmotic stress. (4) Silicon application direct/indirectly mitigates oxidative stress via regulating the antioxidant defense and polyamine metabolism. (5) Omics studies reveal that silicon could regulate plants’ response to salt stress by modulating the expression of various genes including transcription factors and hormone-related genes. Finally, research areas that require further investigation to provide a deeper understanding of the role of silicon in plants are highlighted.
Myrica esculenta Buch.-Ham. ex D. Don: A Natural Source for Health Promotion and Disease Prevention
Authors: Kabra Atul , Martins Natália , Sharma Rohit , Kabra Ruchika , Baghel Uttam Singh
Published: May 2019

Myrica esculenta (Myricaceae) is a popular medicinal plant most commonly found in the sub-tropical Himalayas. It is widely used in folk medicine to treat several ailments such as asthma, cough, chronic bronchitis, ulcers, inflammation, anemia, fever, diarrhea, and ear, nose, and throat disorders. Due to its multidimensional pharmacological and therapeutic effects, it is well recognized in the ayurvedic pharmacopeia. However, the recent upsurge in M. esculenta use and demand has led to illicit harvesting by the horticultural trade and habitat loss, pushing the plant to the brink of extinction. Thus, the present review aims to provide updated information on M. esculenta botany, ethnomedicinal uses, phytochemistry, pharmacological effects, toxicity, and conservation methods, as well as also highlight prospective for future research. Particular emphasis is also given to its antioxidant potential in health promotion. In-depth literature was probed by searching several sources via online databases, texts, websites, and thesis. About 57 compounds were isolated and identified from M. esculenta, and the available reports on physicochemical parameters, nutritional and high-performance thin-layer chromatography analysis of bioactive plant parts are portrayed in a comparative manner. Friendly holistic conservation approaches offered by plant biotechnology applications, such as micropropagation, germplasm preservation, synthetic seed production, and hairy root technologies are also discussed. Nonetheless, further studies are needed to propose the mechanistic role of crude extracts and other bioactives, and even to explore the structure–function relationship of active components.