Metallic Transition Metal Selenide Holey Nanosheets for Efficient Oxygen Evolution Electrocatalysis

Catalysts for oxygen evolution reaction (OER) are pivotal to the scalable storage of sustainable energy by means of converting water to oxygen and hydrogen fuel. Designing efficient electrocatalysis combining the features of excellent electrical conductivity, abundant active surface, and structural stability remains a critical challenge. Here, we report the rational design and controlled synthesis of metallic transition metal selenide NiCo₂Se₄-based holey nanosheets as a highly efficient and robust OER electrocatalyst. Benefiting from synergistic effects of metallic nature, heteroatom doping, and holey nanoarchitecture, NiCo₂Se₄ holey nanosheets exhibit greatly enhanced kinetics and improved cycling stability for OER. When further employed as an alkaline electrolyzer, the NiCo₂Se₄ holey nanosheet electrocatalyst enables a high-performing overall water splitting with a low applied external potential of 1.68 V at 10 mA cm^-2. This work not only represents a promising strategy to design the efficient and robust OER catalysts but also provides fundamental insights into the structure-property-performance relationship of transition metal selenide-based electrocatalytic materials.

Toxicological Profiling of Highly Purified Metallic and Semiconducting Single-Walled Carbon Nanotubes in the Rodent Lung and E. coli

The electronic properties of single-walled carbon nanotubes (SWCNTs) are potentially useful for electronics, optics, and sensing applications. Depending on the chirality and diameter, individual SWCNTs can be classified as semiconducting (S-SWCNT) or metallic (M-SWCNT). From a biological perspective, the hazard profiling of purified metallic versus semiconducting SWCNTs has been pursued only in bacteria, with the conclusion that aggregated M-SWCNTs are more damaging to bacterial membranes than S-SWCNTs. However, no comparative studies have been performed in a mammalian system, where most toxicity studies have been undertaken using relatively crude SWCNTs that include a M:S mix at 1:2 ratio. In order to compare the toxicological impact of SWCNTs sorted to enrich them for each of the chirality on pulmonary cells and the intact lung, we used density gradient ultracentrifugation and extensive rinsing to prepare S- and M-SWCNTs that are >98% purified. In vitro screening showed that both tube variants trigger similar amounts of interleukin 1β (IL-1β) and transforming growth factor (TGF-β1) production in THP-1 and BEAS-2B cells, without cytotoxicity. Oropharyngeal aspiration confirmed that both SWCNT variants induce comparable fibrotic effects in the lung and abundance of IL-1β and TGF-β1 release in the bronchoalveolar lavage fluid. There was also no change in the morphology, membrane integrity, and viability of E. coli, in contradistinction to the previously published effects of aggregated tubes on the bacterial membrane. Collectively, these data indicate that the electronic properties and chirality do not independently impact SWCNT toxicological impact in the lung, which is of significance to the safety assessment and incremental use of purified tubes by industry.

Hybrid Sol-gel Coatings for Corrosion Mitigation: A Critical Review

The corrosion process is a major source of metallic material degradation, particularly in aggressive environments, such as marine ones. Corrosion progression affects the service life of a given metallic structure, which may end in structural failure, leakage, product loss and environmental pollution linked to large financial costs. According to NACE, the annual cost of corrosion worldwide was estimated, in 2016, to be around 3%-4% of the world's gross domestic product. Therefore, the use of methodologies for corrosion mitigation are extremely important. The approaches used can be passive or active. A passive approach is preventive and may be achieved by emplacing a barrier layer, such as a coating that hinders the contact of the metallic substrate with the aggressive environment. An active approach is generally employed when the corrosion is set in. That seeks to reduce the corrosion rate when the protective barrier is already damaged and the aggressive species (i.e., corrosive agents) are in contact with the metallic substrate. In this case, this is more a remediation methodology than a preventive action, such as the use of coatings. The sol-gel synthesis process, over the past few decades, gained remarkable importance in diverse areas of application. Sol-gel allows the combination of inorganic and organic materials in a single-phase and has led to the development of organic-inorganic hybrid (OIH) coatings for several applications, including for corrosion mitigation. This manuscript succinctly reviews the fundamentals of sol-gel concepts and the parameters that influence the processing techniques. The state-of-the-art of the OIH sol-gel coatings reported in the last few years for corrosion protection, are also assessed. Lastly, a brief perspective on the limitations, standing challenges and future perspectives of the field are critically discussed.

A novel route for processing cobalt-chromium-molybdenum orthopaedic alloys

Spark plasma sintering has been used for the first time to prepare the ASTM F75 cobalt-chromium-molybdenum (Co-Cr-Mo) orthopaedic alloy composition using nanopowders. In the preliminary work presented in this report, the effect of processing variables on the structural features of the alloy (phases present, grain size and microstructure) has been investigated. Specimens of greater than 99.5 per cent theoretical density were obtained. Carbide phases were not detected in the microstructure but oxides were present. However, harder materials with finer grains were produced, compared with the commonly used cast/wrought processing methods, probably because of the presence of oxides in the microstructure.

Contact and Support Considerations in the Hydrogen Evolution Reaction Activity of Petaled MoS2 Electrodes

Petaled MoS2 electrodes grown hydrothermally from Mo foils are found to have an 800 nm, intermediate, MoSxOy layer. Similar petaled MoS2 films without this intermediate layer are grown on Au. X-ray photoelectron and Raman spectroscopies and transmission electron microscopy indicate the resulting petaled multilayer MoS2 films are frayed and exhibit single-layer, 1T-MoS2 behavior at the edges. We compare the electrocatalytic hydrogen evolution reaction activity via linear sweep voltammetry with Tafel analysis as well as the impedance properties of the electrodes. We find that petaled MoS2/Au and petaled MoS2/Mo exhibit comparable overpotential to 10 mA cm(-2) at -279 vs -242 mV, respectively, and similar Tafel slopes of ∼68 mV/decade indicating a similar rate-determining step. The exchange current normalized to the geometric area of petaled MoS2/Au (0.000921 mA cm(-2)) is 3 times smaller than that of petaled MoS2/Mo (0.00290 mA cm(-2)), and is attributed to the lower petal density on the Au support. However, Au supports increase the turnover frequency per active site of petaled MoS2 to 0.48 H2 Mo(-1) s(-1) from 0.25 H2 Mo(-1) s(-1) on Mo supports. Both petaled MoS2 films have nearly ohmic contacts to their supports with uncompensated resistivity Ru of <2.5 Ω·cm(2).

The Mystery of "Metal Mouth" in Chemotherapy

Of all the oral sensations that are experienced, "metallic" is one that is rarely reported in healthy participants. So why, then, do chemotherapy patients so frequently report that "metallic" sensations overpower and interfere with their enjoyment of food and drink? This side-effect of chemotherapy-often referred to (e.g., by patients) as "metal mouth"-can adversely affect their appetite, resulting in weight loss, which potentially endangers (or at the very least slows) their recovery. The etiology of "metal mouth" is poorly understood, and current management strategies are largely unevidenced. As a result, patients continue to suffer as a result of this poorly understood phenomenon. Here, we provide our perspective on the issue, outlining the evidence for a range of possible etiologies, and highlighting key research questions. We explore the evidence for "metallic" as a putative taste, and whether "metal mouth" might therefore be a form of phantageusia, perhaps similar to already-described "release-of-inhibition" phenomena. We comment on the possibility that "metal mouth" may simply be a direct effect of chemotherapy drugs. We present the novel theory that "metal mouth" may be linked to chemotherapy-induced sensitization of TRPV1. Finally, we discuss the evidence for retronasal olfaction of lipid oxidation products in the etiology of "metal mouth." This article seeks principally to guide much-needed future research which will hopefully one day provide a basis for the development of novel supportive therapies for future generations of patients undergoing chemotherapy.

A Review on Current Designation of Metallic Nanocomposite Hydrogel in Biomedical Applications

In the past few decades, nanotechnology has been receiving significant attention globally and is being continuously developed in various innovations for diverse applications, such as tissue engineering, biotechnology, biomedicine, textile, and food technology. Nanotechnological materials reportedly lack cell-interactive properties and are easily degraded into unfavourable products due to the presence of synthetic polymers in their structures. This is a major drawback of nanomaterials and is a cause of concern in the biomedicine field. Meanwhile, particulate systems, such as metallic nanoparticles (NPs), have captured the interest of the medical field due to their potential to inhibit the growth of microorganisms (bacteria, fungi, and viruses). Lately, researchers have shown a great interest in hydrogels in the biomedicine field due to their ability to retain and release drugs as well as to offer a moist environment. Hence, the development and innovation of hydrogel-incorporated metallic NPs from natural sources has become one of the alternative pathways for elevating the efficiency of therapeutic systems to make them highly effective and with fewer undesirable side effects. The objective of this review article is to provide insights into the latest fabricated metallic nanocomposite hydrogels and their current applications in the biomedicine field using nanotechnology and to discuss the limitations of this technology for future exploration. This article gives an overview of recent metallic nanocomposite hydrogels fabricated from bioresources, and it reviews their antimicrobial activities in facilitating the demands for their application in biomedicine. The work underlines the fabrication of various metallic nanocomposite hydrogels through the utilization of natural sources in the production of biomedical innovations, including wound healing treatment, drug delivery, scaffolds, etc. The potential of these nanocomposites in relation to their mechanical strength, antimicrobial activities, cytotoxicity, and optical properties has brought this technology into a new dimension in the biomedicine field. Finally, the limitations of metallic nanocomposite hydrogels in terms of their methods of synthesis, properties, and outlook for biomedical applications are further discussed.

Composition, Electronic and Magnetic Investigation of the Encapsulated ZnFe2O 4 Nanoparticles in Multiwall Carbon Nanotubes Containing Ni Residuals

We report investigation on properties of multiwall carbon nanotubes (mCNTs) containing Ni residuals before and after encapsulation of zinc ferrite nanoparticles. The pristine tubes exhibit metallic character with a 0.3 eV reduction in the work function along with ferromagnetic behavior which is attributed to the Ni residuals incorporated during the preparation of tubes. Upon encapsulation of zinc ferrite nanoparticles, 0.5 eV shift in Fermi level position and a reduction in both the π band density of state along with a change in the hybridized sp(2)/sp(3) ratio of the tubes from 2.04 to 1.39 are observed. As a result of the encapsulation, enhancement in the σ bands density of state and coating of the zinc ferrite nanoparticles by the internal layers of the CNTs in the direction along the tube axis is observed. Furthermore, Ni impurities inside the tubes are attracted to the encapsulated zinc ferrite nanoparticles, suggesting the possibility of using these particles as purifying agents for CNTs upon being synthesized using magnetic catalyst particles. Charge transfer from Ni/mCNTs to the ZnFe2O4 nanoparticles is evident via reduction of the density of states near the Fermi level and a 0.3 eV shift in the binding energy of C 1 s core level ionization. Furthermore, it is demonstrated that encapsulated zinc ferrite nanoparticles in mCNTs resulted in two interacting sub-systems featured by distinct blocking temperatures and enhanced magnetic properties; i.e., large coercivity of 501 Oe and saturation magnetization of 2.5 emu/g at 4 K.

Bent Ferroelectric Domain Walls as Reconfigurable Metallic-Like Channels

Use of ferroelectric domain-walls in future electronics requires that they are stable, rewritable conducting channels. Here we demonstrate nonthermally activated metallic-like conduction in nominally uncharged, bent, rewritable ferroelectric-ferroelastic domain-walls of the ubiquitous ferroelectric Pb(Zr,Ti)O3 using scanning force microscopy down to a temperature of 4 K. New walls created at 4 K by pressure exhibit similar robust and intrinsic conductivity. Atomic resolution electron energy-loss spectroscopy confirms the conductivity confinement at the wall. This work provides a new concept in "domain-wall nanoelectronics".

Severe Flexible Pes Planovalgus Deformity Correction Using Trabecular Metallic Wedges

BACKGROUND:

Lateral column lengthening and plantarflexion dorsal opening wedge osteotomy of the medial cuneiform are 2 commonly used procedures to address the deformity seen in severe flexible pes planovalgus deformity. Traditionally, iliac crest allograft or autograft has been used to fill the osteotomy sites. Porous metallic wedges can be used as an alternative to avoid the concerns associated with both autograft and allograft.

METHODS:

We performed a retrospective review of patients who had corrective osteotomies utilizing metallic wedges to address flexible pes planovalgus with at least 2 years of follow-up data. Preoperative radiographic measurements (anteroposterior [AP] and talo-first metatarsal angle, calcaneal pitch, talocalcaneal angle, and talonavicular uncoverage angle) and functional scores (visual analog scale [VAS] pain, Foot and Ankle Ability Measure [FAAM] Activities of Daily Living [ADL], FAAM Sports) were compared to postoperative radiographic measurements and functional scores.

RESULTS:

There were statistically significant improvements in all radiographic parameters and functional scores. Two nonunions were seen, one of which healed with revision surgery while the other was asymptomatic. At the time of last radiographic follow-up, there were no recurrences of deformity or collapse.

CONCLUSION:

Porous metallic wedges offer an attractive alternative to autograft and/or allograft in the setting of corrective osteotomies for severe flexible pes planovalgus. Patients who underwent corrective osteotomies using these wedges demonstrated reliable, effective, and stable radiographic correction as well as significant improvements in function and pain.

LEVEL OF EVIDENCE:

Level IV, case series.

Nanotechnological Advances in the Treatment of Epilepsy

Epilepsy is known as one of the major challenges for medical science. The sudden appearance of a seizure has been a significant health emergency as it may lead to further complications. Although key advancement have been achieved in terms of pharmacological approaches for epilepsy, many issues remain uncertain. Lipid carriers have been at the forefront, especially in neurodegenerative diseases such as epilepsy, Alzheimer's, dementia, etc. The blood-brain barrier still appears to be a major impediment in the successful treatment of epileptic seizures. This is mainly due to the limited bioavailability of most anti-convulsant drugs. The present review encompasses the issues underlying the current approach for epilepsy drug treatment and highlights the newer, novel, and more precise drug delivery system to manage seizures. The advantage of using a lipid-based delivery system is its superior absorption in the brain cells. Ample evidence shows that reducing the particle size also infuses the drug easily through the blood-brain barrier. The application of liposomes, polymeric nanoparticles, metallic nanoparticles, and solid lipid nanoparticles for the treatment and management of epilepsy has been highlighted in the present review. This review will provide an overview of the current status of the treatment and recent advances in the treatment of epilepsy.

Metal-to-Semiconductor Transition in Two-Dimensional Metal-Organic Frameworks: An Ab Initio Dynamics Perspective

Two-dimensional (2D) π-stacked layered metal-organic frameworks (MOFs) are permanently porous and electrically conductive materials with easily tunable crystal structures. Here, we provide an accurate examination of the correlation between structural features and electronic properties of Ni₃(HITP)₂, HITP = 2,3,6,7,10,11-hexaiminotriphenylene, as an archetypical 2D MOF. The main objective of this work is to unravel the responsive nature of the layered architecture to external stimuli such as temperature and show how the layer flexibility translates to different conductive behaviors. To this end, we employ a combination of quantum mechanical tools, ab initio molecular dynamics (AIMD) simulations, and electronic band structure calculations. We compare the band structure and projected density of states of equilibrated system at 293 K to that of the 0 K optimized structure. Effect of interlayer π-π and intralayer d-π interactions on charge mobility is disentangled and studied by increasing the distance between layers of Ni₃(HITP)₂ and comparison to an exemplary case of Zn₃(HITP)₂ 2D MOF. Our findings show how a structural change, which can be deformations along the layers, slipping of layers, or change of the interlayer distance, can induce metal-to-semiconductor or indirect-to-direct semiconductor transition, suggesting a way to adjust or even switch between the intralayer vs interlayer conductive anisotropy in Ni₃(HITP)₂, in particular, and 2D MOFs in general.

Direct-Contact Cytotoxicity Evaluation of CoCrFeNi-Based Multi-Principal Element Alloys

Transition metal multi-principal element alloys (MPEAs) are novel alloys that may offer enhanced surface and mechanical properties compared with commercial metallic alloys. However, their biocompatibility has not been investigated. In this study, three CoCrFeNi-based MPEAs were fabricated, and the in vitro cytotoxicity was evaluated in direct contact with fibroblasts for 168 h. The cell viability and cell number were assessed at 24, 96, and 168 h using LIVE/DEAD assay and alamarBlue assay, respectively. All MPEA sample wells had a high percentage of viable cells at each time point. The two quaternary MPEAs demonstrated a similar cell response to stainless steel control with the alamarBlue assay, while the quinary MPEA with Mn had a lower cell number after 168 h. Fibroblasts cultured with the MPEA samples demonstrated a consistent elongated morphology, while those cultured with the Ni control samples demonstrated changes in cell morphology after 24 h. No significant surface corrosion was observed on the MPEAs or stainless steel samples following the cell culture, while the Ni control samples had extensive corrosion. The cell growth and viability results demonstrate the cytocompatibility of the MPEAs. The biocompatibility of MPEAs should be investigated further to determine if MPEAs may be utilized in orthopedic implants and other biomedical applications.

Updates on the use of ureteral stents: focus on the Resonance(®) stent

The Resonance(®) metallic ureteral stent is one of the latest additions to the urologist's armamentarium in managing ureteral obstruction. One advantage of this stent over traditional polymer-based stents is resistance to encrustation with stone material, which allows longer dwell times and less frequent exchange procedures. Although exchanging a metallic stent is slightly more complicated than exchanging a polymer stent, the fluoroscopic techniques required are familiar to most urologists. The Resonance stent is also more resistant to compression by external forces, potentially allowing greater applicability in patients with metastatic cancer. Furthermore, the use of this stent in patients with benign ureteral obstruction is shown to be associated with significant cost reduction. Clinical studies on the use of this stent are accumulating and the results are mixed, although Level 1 evidence is lacking. In this article we present a comprehensive review of the available literature on the Resonance metallic ureteral stent.

Theoretical Investigation of Optical Detection and Recognition of Single Biological Molecules Using Coherent Dynamics of Exciton-Plasmon Coupling

We use quantum coherence in a system consisting of one metallic nanorod and one semi-conductor quantum dot to investigate a plasmonic nanosensor capable of digital optical detection and recognition of single biological molecules. In such a sensor the adsorption of a specific molecule to the nanorod turns off the emission of the system when it interacts with an optical pulse having a certain intensity and temporal width. The proposed quantum sensors can count the number of molecules of the same type or differentiate between molecule types with digital optical signals that can be measured with high certainty. We show that these sensors are based on the ultrafast upheaval of coherent dynamics of the system and the removal of coherent blockage of energy transfer from the quantum dot to the nanorod once the adsorption process has occurred.

Defect-Rich Monolayer MoS2 as a Universally Enhanced Substrate for Surface-Enhanced Raman Scattering

Monolayer 2H-MoS₂ has been widely noticed as a typical transition metal dichalcogenides (TMDC) for surface-enhanced Raman scattering (SERS). However, monolayer MoS₂ is limited to a narrow range of applications due to poor detection sensitivity caused by the combination of a lower density of states (DOS) near the Fermi energy level as well as a rich fluorescence background. Here, surfaced S and Mo atomic defects are fabricated on a monolayer MoS₂ with a perfect lattice. Defects exhibit metallic properties. The presence of defects enhances the interaction between MoS₂ and the detection molecule, and it increases the probability of photoinduced charge transfer (PICT), resulting in a significant improvement of Raman enhancement. Defect-containing monolayer MoS₂ enables the fluorescence signal of many dyes to be effectively burst, making the SERS spectrum clearer and making the limits of detection (LODs) below 10⁻⁸ M. In conclusion, metallic defect-containing monolayer MoS₂ becomes a promising and versatile substrate capable of detecting a wide range of dye molecules due to its abundant DOS and effective PICT resonance. In addition, the synergistic effect of surface defects and of the MoS₂ main body presents a new perspective for plasma-free SERS based on the chemical mechanism (CM), which provides promising theoretical support for other TMDC studies.

Macroscale Robust Superlubricity on Metallic NbB2

Robust superlubricity (RSL), defined by concurrent superlow friction and wear, holds great promise for reducing material and energy loss in vast industrial and technological operations. Despite recent advances, challenges remain in finding materials that exhibit RSL on macrolength and time scales and possess vigorous electrical conduction ability. Here, the discovery of RSL is reported on hydrated NbB₂ films that exhibit vanishingly small coefficient of friction (0.001-0.006) and superlow wear rate (≈10^-17 m³ N^-1 m^-1 ) on large length scales reaching millimeter range and prolonged time scales lasting through extensive loading durations. Moreover, the measured low resistivity (≈10^-6 Ω m) of the synthesized NbB₂ film indicates ample capability for electrical conduction, extending macroscale RSL to hitherto largely untapped metallic materials. Pertinent microscopic mechanisms are elucidated by deciphering the intricate load-driven chemical reactions that generate and sustain the observed superlubricating state and assessing the strong stress responses under diverse strains that produce the superior durability.

Mechanisms and Assessment of Genotoxicity of Metallic Engineered Nanomaterials in the Human Environment

Engineered nanomaterials (ENMs) have a broad array of applications in agriculture, engineering, manufacturing, and medicine. Decades of toxicology research have demonstrated that ENMs can cause genotoxic effects on bacteria, mammalian cells, and animals. Some metallic ENMs (MENMs), e.g., metal or metal oxide nanoparticles TiO2 and CuO, induce genotoxicity via direct DNA damage and/or reactive oxygen species-mediated indirect DNA damage. There are various physical features of MENMs that may play an important role in promoting their genotoxicity, for example, size and chemical composition. For a valid genotoxicity assessment of MENMs, general considerations should be given to various factors, including, but not limited to, NM characterization, sample preparation, dosing selection, NM cellular uptake, and metabolic activation. The recommended in vitro genotoxicity assays of MENMs include hprt gene mutation assay, chromosomal aberration assay, and micronucleus assay. However, there are still knowledge gaps in understanding the mechanisms underlying the genotoxicity of MENMs. There are also a variety of challenges in the utilization and interpretation of the genotoxicity assessment assays of MENMs. In this review article, we provide mechanistic insights into the genotoxicity of MENMs in the human environment. We review advances in applying new endpoints, biomarkers, and methods to the genotoxicity assessments of MENMs. The guidance of the United States, the United Kingdom, and the European Union on the genotoxicity assessments of MENMs is also discussed.

Direct Writing of Microfluidic Three-Dimensional Photonic Crystal Structures for Terahertz Technology Applications

The direct writing technology was used to create microfluidic three-dimensional terahertz photonic crystal structures (3D-TPCSs) with a glass cement ink, which demonstrated potentials for various terahertz technology applications. By a simple injection of liquid alloy into them, metallic 3D-TPCSs could be created easily at a low cost to solve the challenges of their creation by current approaches. These microfluidic 3D-TPCSs also possessed a specific capability of changing their terahertz properties in real time without structural changes by injecting fluidic media with different dielectric properties into their microfluidic channels, which endowed them the easy integration into various terahertz devices that require terahertz modulation for a wide range of applications. Due to their microsized channel structure and subsequent reduction of terahertz irradiation absorption by water in them, they demonstrated the potential as real time, nondestructive biological and chemical sensors to detect changes occurring in them in the fluidic media with the terahertz time-domain spectroscopy (THz-TDS).

The Science of Developing Appealing Flavors to Drive Compliance

OBJECTIVES

To develop flavors for oral care formulations containing zinc oxide, zinc citrate and L-arginine that are stable for the toothpaste shelf life, mask the unpleasant astringency and metallic off notes of the base, have an appealing taste which pleases global consumers, stimulate regimen compliance, and therefore help deliver whole mouth health benefits to people throughout the world.

METHODS

For stability evaluation, flavor materials were formulated in Dual Zinc plus Arginine base and these samples were subjected to accelerated aging which consists of exposure to a temperature of 49°C for 6 weeks. The samples were analyzed by gas chromatography with flame ionization detector (GC FID) and gas chromatography mass spectrometry (GC MS) to confirm stability or establish changes in the chemical profile - loss of material and generation of degradation compounds. These samples were evaluated organoleptically by a flavor expert for taste acceptability and changes due to instability. Using state-of-the-art flavor expertise, tailor-made flavors were created. Their consumer appeal and acceptance were validated with monadic identified product tests. Their cooling attributes were evaluated by a panel of creative flavorists.

RESULTS

Certain classes of flavor molecules were not stable in the zinc and arginine-containing dentifrice. This significantly limited the choice of flavor materials that could be used to mitigate the undesirable taste of the dentifrice excipients and provide consumer acceptable taste. Through understanding of consumer expectations and needs, creative formulation using stable raw materials, and various novel cooling technologies, we were able to prepare flavors that successfully masked the unpleasant mouth sensation of the zinc and arginine-containing base. These specially designed flavors also provided impactful long-lasting cooling and freshness, thus complementing the toothpaste's therapeutic benefits. Consumer tests validated that these flavors had strong performance and acceptability among users of the original Colgate® Total® triclosan-containing dentifrice.

CONCLUSIONS

Combining in-depth flavor scientific research and formulation creativity, we were able to deliver flavors that are stable and appealing to the global consumer for Colgate's new therapeutic segment.

Metallic: A Bivalent Ambimodal Material Property?

Many metallic visual stimuli, especially the so-called precious metals, have long had a rich symbolic meaning for humans. Intriguingly, however, while metallic is used to describe sensations associated with pretty much every sensory modality, the descriptor is normally positively valenced in the case of vision while typically being negatively valenced in the case of those metallic sensations that are elicited by the stimulation of the chemical senses. In fact, outside the visual modality, metallic would often appear to be used to describe those sensations that are unfamiliar and unpleasant as much as to refer to any identifiable perceptual quality (or attribute). In this review, we assess those sensory stimuli that people choose to refer to as metallic, summarising the multiple, often symbolic, meanings of (especially precious) metals. The evidence of positively valenced sensation transference from metallic serviceware (e.g., plates, cups, and cutlery) to the food and drink with which it comes into contact is also reviewed.

A Low-Symmetry Copper Benzenehexathiol Coordination Polymer with In-Plane Electrical Anisotropy

Electrically conductive coordination polymers (ECCPs), particularly those incorporating benzenehexathiol (BHT) ligands, are emerging as a distinctive class of electronic materials with tunable semiconducting and metallic properties. However, the exploration of novel ECCPs with low-symmetry structures and electrical anisotropy remains under development. Here, we report the on-water surface synthesis of a novel ECCP, namely Cu5BHT, which exhibits a low-symmetry structure and unique in-plane electrical anisotropy that differs from the well-known Cu3BHT phase. Utilizing imaging and diffraction techniques, we elucidate the unit cell and crystal structure of Cu5BHT, revealing an asymmetric arrangement of the kagome resembling lattice connected by two different secondary building units: square planar CuS4 and non-planar Cu2S4. Theoretical studies indicate that Cu5BHT is metallic and exhibits in-plane electrical anisotropy due to the structure arranged in interconnected well-conducting CuS4 chains and less-conducting Cu2S4 slabs oriented along single crystal direction. Single-crystal electrical measurements confirm a metallic character characterized by the increase of conductance upon cooling. Notably, the measured conductance along different crystal directions within the ab plane unambiguously reveals a significant anisotropy, with an anisotropic factor reaching ~8. This work demonstrates a novel low-symmetry ECCP and highlights its potential for achieving in-plane electrical anisotropy.

A Novel Approach of Optimum Time Interval Estimation for Al-7.5Si/Al-18Si Liquid-Liquid Bimetal Casting in Sand and Metallic Moulds

This work describes a novel approach for Al-7.5Si/Al-18Si liquid-liquid bimetal casting in sand and metallic moulds. The aim of the work is to facilitate and develop a simple procedure to produce an Al-7.5Si/Al-18Si bimetallic material with a smooth gradient interface structure. The procedure involves the theoretical calculation of total solidification time (TST) of the first liquid metal (M1), pouring the liquid metal (M1), and allowing it to solidify; then, before complete solidification, the second liquid metal (M2) is introduced into the mould. This novel approach has been proven to produce Al-7.5Si/Al-18Si bimetal materials using liquid-liquid casting. The optimum time interval of Al-7.5Si/Al-18Si bimetal casting with modulus of cast M_c ≤ 1 was estimated based on subtracting 5-15 s or 1-5 s from TST of M1 for sand and metallic moulds, respectively. Future work will involve determining the appropriate time interval range for castings having modulus ≥ 1 using the current approach.

Resorbable Patient-Specific Implants of Molybdenum for Pediatric Craniofacial Surgery-Proof of Concept in an In Vivo Pilot Study

Titanium continues to be the gold standard in the field of osteosynthesis materials. This also applies to pediatric craniofacial surgery. Various resorbable materials have already been developed in order to avoid costly and risky second operations to remove metal in children. However, none of these resorbable materials have been able to completely replace the previous gold standard, titanium, in a satisfactory manner. This has led to the need for a new resorbable osteosynthesis material that fulfills the requirements for biocompatibility, stability, and uniform resorption. In our previous in vitro and in vivo work, we were able to show that molybdenum fulfills these requirements. To further confirm these results, we conducted a proof of concept in four domestic pigs, each of which was implanted with a resorbable molybdenum implant. The animals were then examined daily for local inflammatory parameters. After 54 days, the animals were euthanized with subsequent computer tomography imaging. We also removed the implants together with the surrounding tissue and parts of the spleen, liver, and kidney for histopathological evaluation. The molybdenum implants were also analyzed metallographically and using scanning electron microscopy. A blood sample was taken pre- and post-operatively. None of the animals showed clinical signs of inflammation over the entire test period. Histopathologically, good tissue compatibility was found. Early signs of degradation were observed after 54 days, which were not sufficient for major resorption. Resorption is expected with longer in situ residence times based on results of similar earlier investigations.

The Influence of Titanium Oxide Nanoparticles and UV Radiation on the Electrical Properties of PEDOT:PSS-Coated Cotton Fabrics

With the rapid growth of electronic textiles, there is a need for highly conductive fabrics containing fewer conductive materials, allowing them to maintain flexibility, low cost and light weight. Poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS), is one of the most promising conductive materials for the production of conductive fabrics due to its excellent properties such as solubility, relatively high conductivity, and market availability. Moreover, its electrical conductivity can be enhanced by polar solvents or acid treatment. The aim of this work was to fabricate conductive cotton fabrics with a small fixed amount of PEDOT:PSS and to investigate how titanium dioxide (TiO2) nanoparticles affect the electrical, thermal and structural properties of PEDOT:PSS-coated cotton fabrics. The change in electrical conductivity of the nanocomposite fabric was then related to morphological analysis by scanning electron microscopy and X-ray diffraction. We found that the sheet resistance of the nanocomposite cotton fabric depends on the TiO2 concentration, with a minimum value of 2.68 Ω/□ at 2.92 wt% TiO2. The effect of UV light on the sheet resistance of the nanocomposite cotton fabric was also investigated; we found that UV irradiation leads to an increase in conductivity at an irradiation time of 10 min, after which the conductivity decreases with increasing irradiation time. In addition, the electrical behavior of the nanocomposite cotton fabric as a function of temperature was investigated. The nanocomposite fabrics exhibited metallic behavior at high-TiO2 concentrations of 40.20 wt% and metallic semiconducting behavior at low and medium concentrations of 11.33 and 28.50 wt%, respectively. Interestingly, cotton fabrics coated with nanocomposite possessed excellent washing durability even after seven steam washes.