bluuebunny/crossref_metadata_2025 huggingface dataset:
Colonization of Dental Unit Waterlines by Helicobacter pylori: Risk of Exposure in Dental Practices
Authors: Giacomuzzi Monica , Zotti Carla M. , Ditommaso Savina
Published: August 2019

Dental unit waterlines (DUWLs) can be considered one of the possible routes of H. pylori transmission, although its presence in DUWLs has not yet been investigated thoroughly. The present study aimed to discover the prevalence of H. pylori and oral streptococci (S. oralis and S. mutans) in DUWLs to evaluate the risk of exposure to human pathogens in dental practices. We collected the output water from 60 dental chair units (DCUs) in 26 private dentistry settings in Turin, searching for H. pylori and oral streptococci (OS) DNA, with a polymerase chain reaction (PCR) technique. At the same time, dentists completed a questionnaire about their DCUs, their main activities, the presence of anti-retraction devices, their attitudes about disinfection, etc. No dental chair unit tested was contaminated with H. pylori or S. mutans; only one dental chair was contaminated with S. oralis (1.7%). Considering the results, we can state that: (i) the lack of H. pylori DNA in water samples analyzed, suggests that municipal water is presumably treated with a sufficient chlorine level to inactivate DNA over time; (ii) the aspiration of oral fluids is limited by anti-retraction valves fitted distally to hand pieces; (iii) propidium monoazide qPCR (PMA-qPCR) could be a good technique to investigate and monitor potential environmental sources of infections such as DUWLs.
How Plants Handle Trivalent (+3) Elements
Authors: Poschenrieder Charlotte , Busoms Silvia , Barceló Juan
Published: August 2019

Plant development and fitness largely depend on the adequate availability of mineral elements in the soil. Most essential nutrients are available and can be membrane transported either as mono or divalent cations or as mono- or divalent anions. Trivalent cations are highly toxic to membranes, and plants have evolved different mechanisms to handle +3 elements in a safe way. The essential functional role of a few metal ions, with the possibility to gain a trivalent state, mainly resides in the ion’s redox activity; examples are iron (Fe) and manganese. Among the required nutrients, the only element with +3 as a unique oxidation state is the non-metal, boron. However, plants also can take up non-essential trivalent elements that occur in biologically relevant concentrations in soils. Examples are, among others, aluminum (Al), chromium (Cr), arsenic (As), and antimony (Sb). Plants have evolved different mechanisms to take up and tolerate these potentially toxic elements. This review considers recent studies describing the transporters, and specific and unspecific channels in different cell compartments and tissues, thereby providing a global vision of trivalent element homeostasis in plants.
Natriuretic Peptides in the Cardiovascular System: Multifaceted Roles in Physiology, Pathology and Therapeutics
Authors: Rubattu Speranza , Volpe Massimo
Published: August 2019

The natriuretic peptides (NPs) family includes a class of hormones and their receptors needed for the physiological control of cardiovascular functions. The discovery of NPs provided a fundamental contribution into our understanding of the physiological regulation of blood pressure, and of heart and kidney functions. NPs have also been implicated in the pathogenesis of several cardiovascular diseases (CVDs), including hypertension, atherosclerosis, heart failure, and stroke. A fine comprehension of the molecular mechanisms dependent from NPs and underlying the promotion of cardiovascular damage has contributed to improve our understanding of the molecular basis of all major CVDs. Finally, the opportunity to target NPs in order to develop new therapeutic tools for a better treatment of CVDs has been developed over the years. The current Special Issue of the Journal covers all major aspects of the molecular implications of NPs in physiology and pathology of the cardiovascular system, including NP-based therapeutic approaches.
Antioxidant and Cytoprotective Effects of (−)-Epigallocatechin-3-(3″-O-methyl) Gallate
Authors: Kim Eunji , Han Sang Yun , Hwang Kyeonghwan , Kim Donghyun , Kim Eun-Mi , Hossain Mohammad Amjad , Kim Jong-Hoon , Cho Jae Youl
Published: August 2019

Reactive oxygen species (ROS) are generated from diverse cellular processes or external sources such as chemicals, pollutants, or ultraviolet (UV) irradiation. Accumulation of radicals causes cell damage that can result in degenerative diseases. Antioxidants remove radicals by eliminating unpaired electrons from other molecules. In skin health, antioxidants are essential to protect cells from the environment and prevent skin aging. (−)-Epigallocatechin-3-(3″-O-methyl) gallate (3″Me-EGCG) has been found in limited oolong teas or green teas with distinctive methylated form, but its precise activities have not been fully elucidated. In this study, we examined the antioxidant roles of 3″Me-EGCG in keratinocytes (HaCaT cells). 3″Me-EGCG showed scavenging effects in cell and cell-free systems. Under H2O2 exposure, 3″Me-EGCG recovered cell viability and increased the expression of heme oxygenase 1 (HO-1). Under ultraviolet B (UVB) and sodium nitroprusside (SNP) exposure, 3″Me-EGCG protected keratinocytes and regulated the survival protein AKT1. By regulating the AKT1/NF-κB pathway, 3″Me-EGCG augmented cell survival and proliferation in HaCaT cells. These results indicate that 3″Me-EGCG exhibits antioxidant properties, resulting in cytoprotection against various external stimuli. In conclusion, our findings suggest that 3″Me-EGCG can be used as an ingredient of cosmetic products or health supplements.
Reaction of Electrons with DNA: Radiation Damage to Radiosensitization
Authors: Kumar Anil , Becker David , Adhikary Amitava , Sevilla Michael D.
Published: August 2019

This review article provides a concise overview of electron involvement in DNA radiation damage. The review begins with the various states of radiation-produced electrons: Secondary electrons (SE), low energy electrons (LEE), electrons at near zero kinetic energy in water (quasi-free electrons, (e−qf)) electrons in the process of solvation in water (presolvated electrons, e−pre), and fully solvated electrons (e−aq). A current summary of the structure of e−aq, and its reactions with DNA-model systems is presented. Theoretical works on reduction potentials of DNA-bases were found to be in agreement with experiments. This review points out the proposed role of LEE-induced frank DNA-strand breaks in ion-beam irradiated DNA. The final section presents radiation-produced electron-mediated site-specific formation of oxidative neutral aminyl radicals from azidonucleosides and the evidence of radiosensitization provided by these aminyl radicals in azidonucleoside-incorporated breast cancer cells.
Genomics and the Acute Respiratory Distress Syndrome: Current and Future Directions
Authors: Hernández-Beeftink Tamara , Guillen-Guio Beatriz , Villar Jesús , Flores Carlos
Published: August 2019

The excessive hospital mortality associated with acute respiratory distress syndrome (ARDS) in adults mandates an urgent need for developing new therapies and tools for the early risk assessment of these patients. ARDS is a heterogeneous syndrome with multiple different pathogenetic processes contributing differently in different patients depending on clinical as well as genetic factors. Identifying genetic-based biomarkers holds the promise for establishing effective predictive and prognostic stratification methods and for targeting new therapies to improve ARDS outcomes. Here we provide an updated review of the available evidence supporting the presence of genetic factors that are predictive of ARDS development and of fatal outcomes in adult critically ill patients and that have been identified by applying different genomic and genetic approaches. We also introduce other incipient genomics approximations, such as admixture mapping, metagenomics and genome sequencing, among others, that will allow to boost this knowledge and likely reveal new genetic predictors of ARDS susceptibility and prognosis among critically ill patients.
The Role of Nrf2 in the Antioxidant Cellular Response to Medical Ozone Exposure
Authors: Galiè Mirco , Covi Viviana , Tabaracci Gabriele , Malatesta Manuela
Published: August 2019

Ozone (O3) is a natural, highly unstable atmospheric gas that rapidly decomposes to oxygen. Although not being a radical molecule, O3 is a very strong oxidant and therefore it is potentially toxic for living organisms. However, scientific evidence proved that the effects of O3 exposure are dose-dependent: high dosages stimulate severe oxidative stress resulting in inflammatory response and tissue injury, whereas low O3 concentrations induce a moderate oxidative eustress activating antioxidant pathways. These properties make O3 a powerful medical tool, which can be used as either a disinfectant or an adjuvant agent in the therapy of numerous diseases. In this paper, the cellular mechanisms involved in the antioxidant response to O3 exposure will be reviewed with special reference to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its role in the efficacy of ozone therapy.
Roles of Direct Photoreception and the Internal Circadian Oscillator in the Regulation of Melatonin Secretion in the Pineal Organ of the Domestic Turkey: A Novel In Vitro Clock and Calendar Model
Authors: Prusik Magdalena , Lewczuk Bogdan
Published: August 2019

The regulation of melatonin secretion in the avian pineal organ is highly complex and shows prominent interspecies differences. The aim of this study was to determine the roles of direct photoreception and the internal oscillator in the regulation of melatonin secretion in the pineal organ of the domestic turkey. The pineal organs were collected from 12-, 13- and 14-week-old female turkeys reared under a 12 L:12 D cycle with the photophase from 07.00 to 19.00, and were incubated in superfusion culture for 3–6 days. The cultures were subjected to different light conditions including 12 L:12 D cycles with photophases between 07.00 and 19.00, 13.00 and 01.00 or 01.00 and 13.00, a reversed cycle 12 D:12 L, cycles with long (16 L:8 D) and short (8 L:16 D) photophases, and continuous darkness or illumination. The pineal organs were also exposed to light pulses of variable duration during incubation in darkness or to periods of darkness during the photophase. The secretion of melatonin was determined by direct radioimmunoassay. The turkey pineal organs secreted melatonin in a well-entrained diurnal rhythm with a very high amplitude. Direct photoreception as an independently acting mechanism was able to ensure quick and precise adaptation of the melatonin secretion rhythm to changes in light-dark conditions. The pineal organs secreted melatonin in circadian rhythms during incubation in continuous darkness or illumination. The endogenous oscillator of turkey pinealocytes was able to acquire and store information about the light-dark cycle and then to generate the circadian rhythm of melatonin secretion in continuous darkness according to the stored data. The obtained data suggest that the turkey pineal gland is highly autonomous in the generation and regulation of the melatonin secretion rhythm. They also demonstrate that the turkey pineal organ in superfusion culture is a valuable model for chronobiological studies, providing a highly precise clock and calendar. This system has several features which make it an attractive alternative to other avian pineal glands for circadian studies.
Peroxisome Maintenance Depends on De Novo Peroxisome Formation in Yeast Mutants Defective in Peroxisome Fission and Inheritance
Authors: Wróblewska Justyna P. , van der Klei Ida J.
Published: August 2019

There is an ongoing debate on how peroxisomes form: by growth and fission of pre-existing peroxisomes or de novo from another membrane. It has been proposed that, in wild type yeast cells, peroxisome fission and careful segregation of the organelles over mother cells and buds is essential for organelle maintenance. Using live cell imaging we observed that cells of the yeast Hansenula polymorpha, lacking the peroxisome fission protein Pex11, still show peroxisome fission and inheritance. Also, in cells of mutants without the peroxisome inheritance protein Inp2 peroxisome segregation can still occur. In contrast, peroxisome fission and inheritance were not observed in cells of a pex11 inp2 double deletion strain. In buds of cells of this double mutant, new organelles likely appear de novo. Growth of pex11 inp2 cells on methanol, a growth substrate that requires functional peroxisomes, is retarded relative to the wild type control. Based on these observations we conclude that in H. polymorpha de novo peroxisome formation is a rescue mechanism, which is less efficient than organelle fission and inheritance to maintain functional peroxisomes.
Electrical Stimulation of the Mesencephalic Locomotor Region Has No Impact on Blood–Brain Barrier Alterations after Cerebral Photothrombosis in Rats
Authors: Schuhmann Michael K. , Stoll Guido , Papp Lena , Bohr Arne , Volkmann Jens , Fluri Felix
Published: August 2019

Blood–brain barrier (BBB) disruption is a critical event after ischemic stroke, which results in edema formation and hemorrhagic transformation of infarcted tissue. BBB dysfunction following stroke is partly mediated by proinflammatory agents. We recently have shown that high frequency stimulation of the mesencephalic locomotor region (MLR-HFS) exerts an antiapoptotic and anti-inflammatory effect in the border zone of cerebral photothrombotic stroke in rats. Whether MLR-HFS also has an impact on BBB dysfunction in the early stage of stroke is unknown. In this study, rats were subjected to photothrombotic stroke of the sensorimotor cortex and implantation of a stimulating microelectrode into the ipsilesional MLR. Thereafter, either HFS or sham stimulation of the MLR was applied for 24 h. After scarifying the rats, BBB disruption was assessed by determining albumin extravasation and tight junction integrity (claudin 3, claudin 5, and occludin) using Western blot analyses and immunohistochemistry. In addition, by applying zymography, expression of pro-metalloproteinase-9 (pro-MMP-9) was analyzed. No differences were found regarding infarct size and BBB dysfunction between stimulated and unstimulated animals 24 h after induction of stroke. Our results indicate that MLR-HFS neither improves nor worsens the damaged BBB after stroke. Attenuating cytokines/chemokines in the perilesional area, as mediated by MLR-HFS, tend to play a less significant role in preventing the BBB integrity.
Deciphering the Molecular Recognition Mechanism of Multidrug Resistance Staphylococcus aureus NorA Efflux Pump Using a Supervised Molecular Dynamics Approach
Authors: Palazzotti Deborah , Bissaro Maicol , Bolcato Giovanni , Astolfi Andrea , Felicetti Tommaso , Sabatini Stefano , Sturlese Mattia , Cecchetti Violetta , Barreca Maria Letizia , Moro Stefano
Published: August 2019

The use and misuse of antibiotics has resulted in critical conditions for drug-resistant bacteria emergency, accelerating the development of antimicrobial resistance (AMR). In this context, the co-administration of an antibiotic with a compound able to restore sufficient antibacterial activity may be a successful strategy. In particular, the identification of efflux pump inhibitors (EPIs) holds promise for new antibiotic resistance breakers (ARBs). Indeed, bacterial efflux pumps have a key role in AMR development; for instance, NorA efflux pump contributes to Staphylococcus aureus (S. aureus) resistance against fluoroquinolone antibiotics (e.g., ciprofloxacin) by promoting their active extrusion from the cells. Even though NorA efflux pump is known to be a potential target for EPIs development, the absence of structural information about this protein and the little knowledge available on its mechanism of action have strongly hampered rational drug discovery efforts in this area. In the present work, we investigated at the molecular level the substrate recognition pathway of NorA through a Supervised Molecular Dynamics (SuMD) approach, using a NorA homology model. Specific amino acids were identified as playing a key role in the efflux pump-mediated extrusion of its substrate, paving the way for a deeper understanding of both the mechanisms of action and the inhibition of such efflux pumps.
Toothpaste Composition Effect on Enamel Chromatic and Morphological Characteristics: In Vitro Analysis
Authors: Muntean Alexandrina , Sava Sorina , Delean Ada Gabriela , Mihailescu Ana Maria , Dumitrescu Laura Silaghi , Moldovan Marioara , Festila Dana Gabriela
Published: August 2019

The aim of this in vitro study was to assess the effect of toothpastes, with different compositions, on optical and morphological features of sound and demineralized enamel. We selected twenty-five teeth, recently extracted for orthodontic purposes, for this in vitro study. The teeth were caries free, without stains, fissures, filling or hypoplasia observed at inspection under standard conditions. Teeth were brushed (for 2–3 min, twice a day, for 21 days), with five different toothpastes (four commercially available and an experimental one) containing fluoride and hydroxyapatite. After that, teeth were demineralized with 37% orthophosforic acid (Ultra Etch®, Ultradent Products Inc., South Jordan, UT, USA) for 60 s. We repeated the brushing protocol for another 21 days on demineralized enamel. Enamel vestibular surfaces were examined using a spectrophotometer (Vita EasyShade -Vita Zahnfabrik, Bad Sackingen, Germany) and a Scanning Electron Microscope (Inspect S®, FEI Company, Hillsboro, OR, USA). Differences were statistically significant for colour parameters L* and ΔE*. SEM evaluation reveals demineralized enamel mineral gain after brushing with selected toothpastes. Toothpastes with specific ingredients can represent a balance between aesthetic and mineralization, and an oral hygiene correct algorithm is able to preserve enamel characteristics during ortodontic treatement with fixed appliances.
Effect of Microstructure on the Corrosion Resistance of TIG Welded 1579 Alloy
Authors: Gnedenkov Andrey S. , Sinebryukhov Sergey L. , Mashtalyar Dmitry V. , Imshinetskiy Igor M. , Vyaliy Igor E. , Gnedenkov Sergey V.
Published: August 2019

The paper studies microstructure, chemical composition and corrosion activity of the tungsten inert gas welded joint of the Al-Mg-Sc alloy. An intensive corrosion attack of the heat affected zone (HAZ) was found due to precipitation of secondary phases at recrystallized grain boundaries. The ccorrosion process initiated along the boundary of α-Al grains, where a high concentration of anodic (Mg2Si and Mg2Al3) and cathodic phases ((MnFe)Al6) was observed. Increased temperatures during welding led to coalescence of the anodic phases in HAZ. Additionally, HAZ was found to be enriched with hard intermetallic compounds (Mg2Si and (MnFe)Al6). This area had a higher microhardness (930 MPa) compared to base metal (BM, 895 MPa) and fusion zone (FZ, 810 MPa). The volume fraction of secondary phases was 26% in BM, 28% in FZ and 38% in HAZ. The average grain size increased in the following order: (9 ± 3) µm (BM) < (16 ± 3) µm (HAZ) < (21 ± 5) µm (FZ). A plasma electrolytic oxidation (PEO) coating of aluminum-based material was applied to protect the weld from oxidation. The PEO-coating provided a high corrosion protection in the aggressive Cl−-containing environment.
Design and Development of Ti–Ni, Ni–Mn–Ga and Cu–Al–Ni-based Alloys with High and Low Temperature Shape Memory Effects
Authors: Pushin Vladimir , Kuranova Nataliya , Marchenkova Elena , Pushin Artemy
Published: August 2019

In recent years, multicomponent alloys with shape memory effects (SMEs), based on the ordered intermetallic compounds B2–TiNi, L21–Ni2MnGa, B2– and D03–Cu–Me (Me = Al, Ni, Zn), which represent a special important class of intelligent materials, have been of great interest. However, only a small number of known alloys with SMEs were found to have thermoelastic martensitic transformations (TMTs) at high temperatures. It is also found that most of the materials with TMTs and related SMEs do not have the necessary ductility and this is currently one of the main restrictions of their wide practical application. The aim of the present work is to design and develop multicomponent alloys with TMTs together with ways to improve their strength and ductile properties, using doping and advanced methods of thermal and thermomechanical treatments. The structure, phase composition, and TMTs were investigated by transmission- and scanning electron microscopy, as well as by neutron-, electron- and X-ray diffraction. Temperature measurements of the electrical resistance, magnetic susceptibility, as well as tests of the tensile mechanical properties and special characteristics of SMEs were also used. Temperature–concentration dependences for TMTs in the binary and ternary alloys of a number of quasi-binary systems were determined and discussed. It is shown that the ductility and strength of alloys required for the realization of SMEs can be achieved through optimal alloying, which excludes decomposition in the temperature range of SMEs’ usage, as well as via various treatments that ensure the formation of their fine- (FG) and ultra-fine-grained (UFG) structure.
Investigating Helium Bubble Nucleation and Growth through Simultaneous In-Situ Cryogenic, Ion Implantation, and Environmental Transmission Electron Microscopy
Authors: Taylor Caitlin A. , Briggs Samuel , Greaves Graeme , Monterrosa Anthony , Aradi Emily , Sugar Joshua D. , Robinson David B. , Hattar Khalid , Hinks Jonathan A.
Published: August 2019

Palladium can readily dissociate molecular hydrogen at its surface, and rapidly accept it onto the octahedral sites of its face-centered cubic crystal structure. This can include radioactive tritium. As tritium β-decays with a half-life of 12.3 years, He-3 is generated in the metal lattice, causing significant degradation of the material. Helium bubble evolution at high concentrations can result in blister formation or exfoliation and must therefore be well understood to predict the longevity of materials that absorb tritium. A hydrogen over-pressure must be applied to palladium hydride to prevent hydrogen from desorbing from the metal, making it difficult to study tritium in palladium by methods that involve vacuum, such as electron microscopy. Recent improvements in in-situ ion implantation Transmission Electron Microscopy (TEM) allow for the direct observation of He bubble nucleation and growth in materials. In this work, we present results from preliminary experiments using the new ion implantation Environmental TEM (ETEM) at the University of Huddersfield to observe He bubble nucleation and growth, in-situ, in palladium at cryogenic temperatures in a hydrogen environment. After the initial nucleation phase, bubble diameter remained constant throughout the implantation, but bubble density increased with implantation time. β-phase palladium hydride was not observed to form during the experiments, likely indicating that the cryogenic implantation temperature played a dominating role in the bubble nucleation and growth behavior.
Development of Nano-SiO2 and Bentonite-Based Mortars for Corrosion Protection of Reinforcing Steel
Authors: Karunarathne Venura Kiloshana , Paul Suvash Chandra , Šavija Branko
Published: August 2019

In this study, the use of nano-silica (nano-SiO2) and bentonite as mortar additives for combating reinforcement corrosion is reported. More specifically, these materials were used as additives in ordinary Portland cement (OPC)/fly ash blended mortars in different amounts. The effects of nano-silica and bentonite addition on compressive strength of mortars at different ages was tested. Accelerated corrosion testing was used to assess the corrosion resistance of reinforced mortar specimens containing different amounts of nano-silica and bentonite. It was found that the specimens containing nano-SiO2 not only had higher compressive strength, but also showed lower steel mass loss due to corrosion compared to reference specimens. However, this was accompanied by a small reduction in workability (for a constant water to binder ratio). Mortar mixtures with 4% of nano-silica were found to have optimal performance in terms of compressive strength and corrosion resistance. Control specimens (OPC/fly ash mortars without any additives) showed low early age strength and low corrosion resistance compared to specimens containing nano-SiO2 and bentonite. In addition, samples from selected mixtures were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Finally, the influence of Ca/Si ratio of the calcium silicate hydrate (C-S-H) in different specimens on the compressive strength is discussed. In general, the study showed that the addition of nano-silica (and to a lesser extent bentonite) can result in higher strength and corrosion resistance compared to control specimens. Furthermore, the addition of nano-SiO2 can be used to offset the negative effect of fly ash on early age strength development.
Investigation of the Microcharacteristics of Asphalt Mastics under Dry–Wet and Freeze–Thaw Cycles in a Coastal Salt Environment
Authors: Zhang Qinling , Huang Zhiyi
Published: August 2019

In the coastal areas of southeastern China, high temperatures and humidity in the summer and microfreezing in the winter, as well as a high concentration of salt spray in the environment, seriously deteriorate the durability of asphalt mixtures. Therefore, the microcharacteristics of asphalt mastics (asphalt mixed with mineral filler) under the effect of chlorine salt and “dry–wet and freeze–thaw” (DW-FT) cycles were investigated by Fourier-transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), and atomic force microscopy (AFM) techniques. Two factors, including asphalt mastic types (base and styrene-butadiene-styrene (SBS)-modified mastics) and numbers of DW-FT cycles, were considered based on the natural environment. Regression functions were established to explore the relationship between the FTIR, GPC, and AFM indexes. The results indicate that there were no chemical reactions between the asphalt and filler because the infrared spectrum of the base and SBS-modified mastics were similar. With the increase of the salt “DW-FT” cycle numbers, the sulfoxide index and large molecular size ratios ( L M S % ) increased, and the surface roughness ( R q and R a ) of the morphology decreased, as illustrated by a flatting mastics surface phenomenon in the AFM test. Regression analysis confirmed that there was a high correlation between the FTIR, GPC, and AFM indexes, and formation of the bee structures was closely related to the long chain index. The SBS-modified mastics had a better antiaging performance with a lower increase in the sulfoxide index after the salt “DW-FT” cycles in the coastal environment.
Biomedical Application of Electroactive Polymers in Electrochemical Sensors: A Review
Authors: Runsewe Damilola , Betancourt Tania , Irvin Jennifer A.
Published: August 2019

Conducting polymers are of interest due to their unique behavior on exposure to electric fields, which has led to their use in flexible electronics, sensors, and biomaterials. The unique electroactive properties of conducting polymers allow them to be used to prepare biosensors that enable real time, point of care (POC) testing. Potential advantages of these devices include their low cost and low detection limit, ultimately resulting in increased access to treatment. This article presents a review of the characteristics of conducting polymer-based biosensors and the recent advances in their application in the recognition of disease biomarkers.
Synthesis of One-Dimensional Mesoporous Ag Nanoparticles-Modified TiO2 Nanofibers by Electrospinning for Lithium Ion Batteries
Authors: Zhang Yuyao , Li Jun , Li Wenyao , Kang Danning
Published: August 2019

TiO2 is regarded as a prospective electrode material owing to its excellent electrochemical properties such as the excellent cycling stability and the high safety. However, its low capacity and low electronic conductivity greatly restrict the further improvement in electrochemical performance. A new strategy was put forward to solve the above defects involved in TiO2 in which the low capacity was enhanced by nanomerization and porosity of TiO2, and the low electronic conductivity was improved by introducing Ag with a high conductivity. One-dimensional mesoporous Ag nanoparticles-embedded TiO2 nanofibers (Ag@TiO2 nanofibers) were successfully synthesized via a one-step electrospinning process combined with subsequent annealing treatment in this study. The microstructure and morphology of mesoporous TiO2@Ag nanofibers were confirmed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption. TiO2 nanofibers mainly consisted of a large amount of anatase TiO2, accompanied with traces of rutile TiO2. Ag nanoparticles were uniformly distributed throughout TiO2 nanofibers and promoted the transformation of TiO2 from the anatase to the rutile. The corresponding electrochemical performances are measured by galvanostatic charge-discharge, cycle stability, rate performance, cycle voltammetry, and electrochemical impedance spectroscopy measurements in this research, with pristine TiO2 nanofibers as the reference. The results indicated that the introduction of Ag nanoparticles into TiO2 nanofibers significantly improved the diffusion coefficient of Li ions (5.42 × 10−9 cm2⋅s−1 for pristine TiO2, 1.96 × 10−8 cm2⋅s−1 for Ag@TiO2), and the electronic conductivity of TiO2 (1.69 × 10−5 S⋅cm−1 for pristine TiO2, and 1.99 × 10−5 S⋅cm−1 for Ag@TiO2), based on which the comprehensive electrochemical performance were greatly enhanced. The coulombic efficiency of the Ag@TiO2 nanofibers electrode at the first three cycles was about 56%, 93%, and 96%, which was higher than that without Ag (48%, 66%, and 79%). The Ag@TiO2 nanofibers electrode exhibited a higher specific discharge capacity of about 128.23 mAh⋅g−1 when compared with that without Ag (72.76 mAh·g−1) after 100 cycles at 100 mA·g−1. With the current density sharply increased from 40 mA·g−1 to 1000 mA·g−1, the higher average discharge capacity of 56.35 mAh·g−1 was remained in the electrode with Ag, when compared with the electrode without Ag (average discharge capacity of about 12.14 mAh·g−1). When the current density was returned to 40 mA·g−1, 80.36% of the initial value was returned (about 162.25 mAh·g−1) in the electrode with Ag, which was evidently superior to that without Ag (about 86.50 mAh·g−1, only 55.42% of the initial value). One-dimensional mesoporous Ag@TiO2 nanofibers can be regarded as a potential and promising candidate as anode materials for lithium ion batteries.
Interface Effects on He Ion Irradiation in Nanostructured Materials
Authors: Yang Wenfan , Pang Jingyu , Zheng Shijian , Wang Jian , Zhang Xinghang , Ma Xiuliang
Published: August 2019

In advanced fission and fusion reactors, structural materials suffer from high dose irradiation by energetic particles and are subject to severe microstructure damage. He atoms, as a byproduct of the (n, α) transmutation reaction, could accumulate to form deleterious cavities, which accelerate radiation-induced embrittlement, swelling and surface deterioration, ultimately degrade the service lifetime of reactor materials. Extensive studies have been performed to explore the strategies that can mitigate He ion irradiation damage. Recently, nanostructured materials have received broad attention because they contain abundant interfaces that are efficient sinks for radiation-induced defects. In this review, we summarize and analyze the current understandings on interface effects on He ion irradiation in nanostructured materials. Some key challenges and research directions are highlighted for studying the interface effects on radiation damage in nanostructured materials.
Comparison among Different Scoring Systems in Predicting Procedural Success and Long-Term Outcomes after Percutaneous Coronary Intervention in Patients with Chronic Total Coronary Artery Occlusions
Authors: Kalnins Artis , Strele Ieva , Lejnieks Aivars
Published: August 2019

Background and objectives: Different scoring systems are used to stratify patients with chronic total coronary artery occlusions (CTO) according to disease complexity to predict the success of the percutaneous coronary intervention (PCI). Comparison among different CTO scoring systems and long-term outcome for patients with CTO after PCI has not been well established. The objectives of the study were to assess the ability of different disease severity scoring systems to predict, first, procedural success and, second, overall survival in patients with a successful procedure. Materials and Methods: A total of 551 patients who underwent elective CTO PCI in Riga East University hospital from January 2007 to December 2016 were included in the study. Four scoring systems (J CTO, PROGRESS CTO, CL, and CASTLE) were calculated. ROC curves were used to assess the association between scores and procedural success, and the Kaplan–Meier method and Cox regression were used to estimate the association with death from any cause after a successful procedure, Results: 454 of 551 cases were successful. With increasing disease complexity, the procedural success rate was significantly reduced in all scoring systems (p < 0.001): Area under the curve was 0.714 for J CTO score, 0.605 for PROGRESS CTO, 0.624 for CL and 0.641 for CASTLE scores. During the median 6.8 years of follow-up time, survival was better in the successful procedure group (p = 0.041). Among patients with procedural success, only PROGRESS and CASTLE scores showed an association with all-cause risk of death. After adjustment for baseline characteristics, patients having high PROGRESS score had almost twice higher risk of death (HR 1.81(95% CI 1.19–2.75)), and those with high and intermediate CASTLE score experienced almost four (HR 3.68(95% CI 1.50–9.05)) and two (HR 2.15, (95% CI 1.42–3.23)) times higher risk of death than the low score patients, respectively. Conclusions: All four CTO scoring systems had moderate ability to predict procedural success. More complex CTO PCI patients, assessed by PROGRESS and CASTLE scores, has worse all-cause survival in six to seven years after a successful procedure; whereas J CTO and CL scores had no association with survival.
A Toolbox for Organelle Mechanobiology Research—Current Needs and Challenges
Authors: Feng Qian , Lee Sung , Kornmann Benoît
Published: August 2019

Mechanobiology studies from the last decades have brought significant insights into many domains of biological research, from development to cellular signaling. However, mechano-regulation of subcellular components, especially membranous organelles, are only beginning to be unraveled. In this paper, we take mitochondrial mechanobiology as an example to discuss recent advances and current technical challenges in this field. In addition, we discuss the needs for future toolbox development for mechanobiological research of intracellular organelles.
Towards a Miniaturized 3D Receiver WPT System for Capsule Endoscopy
Authors: Khan Sadeque Reza , Desmulliez Marc P.Y.
Published: August 2019

The optimization, manufacturing, and performance characterization of a miniaturized 3D receiver (RX)-based wireless power transfer (WPT) system fed by a multi-transmitter (multi-TX) array is presented in this study for applications in capsule endoscopy (CE). The 200 mm outer diameter, 35 μm thick printed spiral TX coils of 2.8 g weight, is manufactured on a flexible substrate to enable bendability and portability of the transmitters by the patients. The 8.9 mm diameter—4.8 mm long, miniaturized 3D RX—includes a 4 mm diameter ferrite road to increase power transfer efficiency (PTE) and is dimensionally compatible for insertion into current endoscopic capsules. The multi-TX is activated using a custom-made high-efficiency dual class-E power amplifier operated in subnominal condition. A resulting link and system PTE of 1% and 0.7%, respectively, inside a phantom tissue is demonstrated for the proposed 3D WPT system. The specific absorption rate (SAR) is simulated using the HFSSTM software (15.0) at 0.66 W/kg at 1 MHz operation frequency, which is below the IEEE guidelines for tissue safety. The maximum variation in temperature was also measured as 1.9 °C for the typical duration of the capsule’s travel in the gastrointestinal tract to demonstrate the patients’ tissues safety.
Contact Photolithography at Sub-Micrometer Scale Using a Soft Photomask
Authors: Wu Chun-Ying , Hsieh Heng , Lee Yung-Chun
Published: August 2019

This paper proposes a method for improving the patterning resolution of conventional contact photolithography from the micrometer, down to the sub-micrometer scale. The key element is a soft polydimethylsiloxane (PDMS) photomask, which is first replicated from a silicon mold and then patterned with a black photoresist (PR) layer to selectively block ultraviolet (UV) light. This soft PDMS photomask can easily form an intimate and conformable contact with a PR-coated substrate and hence can perform contact photolithography with high pattern resolution. The fabrication processes of this black-PR/PDMS soft photomask are experimentally carried out. Using the fabricated soft photomask, UV patterning by contact photolithography with the smallest line-width of 170 nm over a 4” wafer area was successfully achieved. The advantages and potentials of this new type of contact photolithography will be addressed.
Sabotage at the Powerhouse? Unraveling the Molecular Target of 2-Isopropylbenzaldehyde Thiosemicarbazone, a Specific Inhibitor of Aflatoxin Biosynthesis and Sclerotia Development in Aspergillus flavus, Using Yeast as a Model System
Authors: Dallabona Cristina , Pioli Marianna , Spadola Giorgio , Orsoni Nicolò , Bisceglie Franco , Lodi Tiziana , Pelosi Giorgio , Restivo Francesco Maria , Degola Francesca
Published: August 2019

Amongst the various approaches to contain aflatoxin contamination of feed and food commodities, the use of inhibitors of fungal growth and/or toxin biosynthesis is showing great promise for the implementation or the replacement of conventional pesticide-based strategies. Several inhibition mechanisms were found taking place at different levels in the biology of the aflatoxin-producing fungal species such as Aspergillus flavus: compounds that influence aflatoxin production may block the biosynthetic pathway through the direct control of genes belonging to the aflatoxin gene cluster, or interfere with one or more of the several steps involved in the aflatoxin metabolism upstream. Recent findings pointed to mitochondrial functionality as one of the potential targets of some aflatoxin inhibitors. Additionally, we have recently reported that the effect of a compound belonging to the class of thiosemicarbazones might be related to the energy generation/carbon flow and redox homeostasis control by the fungal cell. Here, we report our investigation about a putative molecular target of the 3-isopropylbenzaldehyde thiosemicarbazone (mHtcum), using the yeast Saccharomyces cerevisiae as model system, to demonstrate how the compound can actually interfere with the mitochondrial respiratory chain.
Synthesis of Daidzein Glycosides, α-Tocopherol Glycosides, Hesperetin Glycosides by Bioconversion and Their Potential for Anti-Allergic Functional-Foods and Cosmetics
Authors: Fujitaka Yuya , Hamada Hiroki , Uesugi Daisuke , Kuboki Atsuhito , Shimoda Kei , Iwaki Takafumi , Kiriake Yuya , Saikawa Tomohiro
Published: August 2019

Daidzein is a common isoflavone, having multiple biological effects such as anti-inflammation, anti-allergy, and anti-aging. α-Tocopherol is the tocopherol isoform with the highest vitamin E activity including anti-allergic activity and anti-cancer activity. Hesperetin is a flavone, which shows potent anti-inflammatory effects. These compounds have shortcomings, i.e., water-insolubility and poor absorption after oral administration. The glycosylation of bioactive compounds can enhance their water-solubility, physicochemical stability, intestinal absorption, and biological half-life, and improve their bio- and pharmacological properties. They were transformed by cultured Nicotiana tabacum cells to 7-β-glucoside and 7-β-gentiobioside of daidzein, and 3′- and 7-β-glucosides, 3′,7-β-diglucoside, and 7-β-gentiobioside of hesperetin. Daidzein and α-tocopherol were glycosylated by galactosylation with β-glucosidase to give 4′- and 7-β-galactosides of daidzein, which were new compounds, and α-tocopherol 6-β-galactoside. These nine glycosides showed higher anti-allergic activity, i.e., inhibitory activity toward histamine release from rat peritoneal mast cells, than their respective aglycones. In addition, these glycosides showed higher tyrosinase inhibitory activity than the corresponding aglycones. Glycosylation of daidzein, α-tocopherol, and hesperetin greatly improved their biological activities.
VOC Profiles of Saliva in Assessment of Halitosis and Submandibular Abscesses Using HS-SPME-GC/MS Technique
Authors: Monedeiro Fernanda , Milanowski Maciej , Ratiu Ileana-Andreea , Zmysłowski Hubert , Ligor Tomasz , Buszewski Bogusław
Published: August 2019

Halitosis and submandibular abscesses are examples of mouth-related diseases with the possible bacterial origin. Salivary volatile organic compounds (VOCs) are potential biomarkers of them, once they can be addressed as metabolites of bacterial activity. Healthy patients (n = 15), subjects with submandibular abscesses located in fascial deep space (n = 10), and subjects with halitosis (n = 5) were enrolled in the study. Saliva samples were subjected to headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to mass spectrometry (GC/MS) analysis. A total number of 164 VOCs was detected by the developed methodology, 23 specific for halitosis and 41 for abscess. Halitosis’ profiles were characterized by a larger number of sulfur compounds, while for abscess they had a higher variety of alcohols, aldehydes, and hydrocarbons—biomarkers of inflammatory processes. Principal components analysis allowed visualization of clusters formed according to the evaluated conditions. Kruskal-Wallis test indicated that 39 VOCs presented differentiated responses between the studied groups, with statistical relevance (p < 0.05). Random forest was applied, and a prediction model based on eight VOCs (2-butanone, methyl thioacetate, 2-methylbutanoic acid, S-methyl pentanethioate, dimethyl tetrasulfide, indolizine, pentadecane, and octadecanal) provided 100% of sensitivity, 82% of specificity, and 91% of balanced accuracy, indicating the specific presence of submandibular abscess.
Efficient Chemo-Enzymatic Transformation of Animal Biomass Waste for Eco-Friendly Leather Production
Authors: Sole Roberto , Taddei Lorenzo , Franceschi Clizia , Beghetto Valentina
Published: August 2019

Enzymatically processed animal biomass derived from treated bovine hides (wet blue scraps) is herein used as building block for the synthesis of a novel biopolymer. An enzymatic hydrolysis process allows to produce water-soluble lower molecular weight proteins (Bio-A), which are then reacted with glycerol and maleic anhydride (MA) in order to obtain a new intermediate (Bio-IA). With Bio-IA in hand, co-polymerization in the presence of acrylic acid is then carried out. Hydrolysed biomass, intermediates and the final biopolymer (Bio-Ac) have been characterized by means of NMR, FTIR and GPC analysis. Bio-Ac shows good performance when used as retanning agent to produce leather. Physical and mechanical properties of the leather treated with Bio-Ac have been compared with acrylic resin retanned leather, showing similar performance. The reported protocol represents an environmental-friendly interesting alternative to traditional petrochemical based retanning agents, commonly used by the leather industry.
Discovery of Lipid Peroxidation Inhibitors from Bacopa Species Prioritized through Multivariate Data Analysis and Multi-Informative Molecular Networking
Authors: Saesong Tongchai , Allard Pierre-Marie , Ferreira Queiroz Emerson , Marcourt Laurence , Nuengchamnong Nitra , Temkitthawon Prapapan , Khorana Nantaka , Wolfender Jean-Luc , Ingkaninan Kornkanok
Published: August 2019

A major goal in the discovery of bioactive natural products is to rapidly identify active compound(s) and dereplicate known molecules from complex biological extracts. The conventional bioassay-guided fractionation process can be time consuming and often requires multi-step procedures. Herein, we apply a metabolomic strategy merging multivariate data analysis and multi-informative molecular maps to rapidly prioritize bioactive molecules directly from crude plant extracts. The strategy was applied to 59 extracts of three Bacopa species (B. monnieri, B. caroliniana and B. floribunda), which were profiled by UHPLC-HRMS2 and screened for anti-lipid peroxidation activity. Using this approach, six lipid peroxidation inhibitors 1–6 of three Bacopa spp. were discovered, three of them being new compounds: monnieraside IV (4), monnieraside V (5) and monnieraside VI (6). The results demonstrate that this combined approach could efficiently guide the discovery of new bioactive natural products. Furthermore, the approach allowed to evidence that main semi-quantitative changes in composition linked to the anti-lipid peroxidation activity were also correlated to seasonal effects notably for B. monnieri.
Bioactivity of Methoxylated and Methylated 1-Hydroxynaphthalene-2-Carboxanilides: Comparative Molecular Surface Analysis
Authors: Michnová Hana , Pospíšilová Šárka , Goněc Tomáš , Kapustíková Iva , Kollár Peter , Kozik Violetta , Musioł Robert , Jendrzejewska Izabela , Vančo Ján , Trávníček Zdeněk , Čížek Alois , Bąk Andrzej , Jampílek Josef
Published: August 2019

A series of twenty-six methoxylated and methylated N-aryl-1-hydroxynaphthalene- 2-carboxanilides was prepared and characterized as potential anti-invasive agents. The molecular structure of N-(2,5-dimethylphenyl)-1-hydroxynaphthalene-2-carboxamide as a model compound was determined by single-crystal X-ray diffraction. All the analysed compounds were tested against the reference strain Staphylococcus aureus and three clinical isolates of methicillin-resistant S. aureus as well as against Mycobacterium tuberculosis and M. kansasii. In addition, the inhibitory profile of photosynthetic electron transport in spinach (Spinacia oleracea L.) chloroplasts was specified. In vitro cytotoxicity of the most effective compounds was tested on the human monocytic leukaemia THP-1 cell line. The activities of N-(3,5-dimethylphenyl)-, N-(3-fluoro-5-methoxy-phenyl)- and N-(3,5-dimethoxyphenyl)-1-hydroxynaphthalene-2-carbox- amide were comparable with or even better than the commonly used standards ampicillin and isoniazid. All promising compounds did not show any cytotoxic effect at the concentration >30 µM. Moreover, an in silico evaluation of clogP features was performed for the entire set of the carboxamides using a range of software lipophilicity predictors, and cross-comparison with the experimentally determined lipophilicity (log k), in consensus lipophilicity estimation, was conducted as well. Principal component analysis was employed to illustrate noticeable variations with respect to the molecular lipophilicity (theoretical/experimental) and rule-of-five violations. Additionally, ligand-oriented studies for the assessment of the three-dimensional quantitative structure–activity relationship profile were carried out with the comparative molecular surface analysis to determine electron and/or steric factors that potentially contribute to the biological activities of the investigated compounds.