bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermoelectric Generating Properties of Perovskite Like Materials
Authors: Kohri Hitoshi , Kato Masahiko , Ohsugi Isao J. , Shiota Ichiro
Published: October 2010

Research and development of thermoelectric generators have been actively carried out to use waste heat. It is well known some p-type oxides show high thermoelectric performance. However, an n-type oxide with high performance has not been found. An n-type CaMnO3 is a promising material because of its high Seebeck coefficient. The electrical resistivity of this oxide is, however, too high to use it practically. Not only high Seebeck coefficient but also low electrical resistivity is required for practical use. At first, we investigated the effects of element substitution in order to decrease the resistivity. N-type CaMn0.9M0.1O3 (M=Cu, In) compounds were prepared by solid-state reaction and hot pressing. The maximum value of power factor for CaMn0.9In0.1O3 was 0.204 mWm-1K-2, which was the largest of all specimens at 673 K. This value was, however, not enough to use it practically. Secondly, we focus attention on Aurivillius compounds. The Aurivillius compounds consist of Perovskite layers and Bi-O layers. We expect that this crystal structure shows large Seebeck coefficient due to the quantum confinement of electron in Perovskite layer. Bi2VO5.5 with Aurivillius structure was prepared by solid-state reaction and hot pressing. The Seebeck coefficient of Bi2VO5.5 decreased with increasing temperature and was positive value below 600 K and was negative value above 600 K. The power factor of annealed Bi2VO5.5 showed the highest value of all specimens at the temperature range above 800 K.
Synthesis of Fluorinated Organic and Organometallic Electroluminescent Materials: Tuning Emission in the Blue
Authors: Farinola Gianluca M. , Babudri Francesco , Cardone Antonio , Hassan Omar Omar , Martinelli Carmela , Naso Francesco , Pinto Vita , Ragni Roberta
Published: October 2010

Functionalization with fluorine atoms represents a versatile structural modification to finely tune both the emission colour and the electronic properties of organic and organometallic electroluminescent compounds. This paper reports an overview of our systematic investigation on the design and synthesis of the fluorinated version of two important classes of materials for organic light emitting diodes (OLEDs), namely poly(arylenevinylene)s and phosphorescent phenylpyridine Iridium complexes. Synthetic pathways based on organometallic methodologies affording selectively fluorinated molecular structures will be discussed together with a summary of the effect of fluorination on the optical properties of the resulting materials. In particular we will highlight the possibilities offered by the organometallic methodologies as straightforward and resourceful tools to provide a wide series of fluorinated molecular architectures with high regio- and stereoselectivity, mild experimental conditions and good yields.
Development of Low-Loss (Bi,Pb)-2223 Tapes with Interfilamentary Resistive Barriers
Authors: Inada Ryoji , Oota Akio , Li Cheng Shan , Zhang Ping Xiang
Published: October 2010

This paper presents our recent activities for the development of low-loss (Bi,Pb)-2223 tapes with interfilamentary resistive barriers. To suppress the side effect on the phase formation in the filaments during sintering, SrZrO3 were selected as barrier materials. Moreover, small amount of Bi-2212 was mixed with SrZrO3 to improve their ductility for cold working. For non-twisted barrier tapes, transport critical current densities Jc at 77 K and self-field were ranged between 18 and 21 kA/cm2 and its uniformity within 4% along a 1 m length. By combining the barrier introduction, reducing the tape width (< 3 mm) and twisting the filaments tightly, coupling frequency fc exceeded 250 Hz even in an AC perpendicular field at 77 K. Transport Jc of the barrier tapes with tightly twisted filaments were in the range of 1214 kA/cm2 at 77 K and self-field. In our knowledge, this is the first result to achieve both Jc > 12 kA/cm2 and fc > 250 Hz simultaneously in an isolated (Bi,Pb)-2223 tape. At 50 mT and 50 Hz, our twisted barrier tapes showed 60-70% lower perpendicular field losses than a conventional 4 mm-width tape with fully coupled filaments.
Radar Absorbing Materials Based on Metamaterials
Authors: Lagarkov Andrey Nikolayevich , Kisel Vladimir Nikolayevich , Semenenko Vladimir Nikolayevich
Published: October 2010

The use of metamaterial for design of radar absorbing material (RAM) is discussed. The typical features of the frequency dependencies of , , ,  of composites manufactured of different types of resonant inclusions are given as an example. The RAM characteristics obtained by the use of the composites are given. It is shown that it is possible to use for RAM design the metamaterials with both the positive values of ,  and negative ones. Making use of the frequency band with negative  and  it is possible to create a RAM with low reflection coefficient in a wide range of the angles of electromagnetic wave incidence.
Trapped Rainbow Storage of Light in Metamaterials
Authors: Hess Ortwin , Tsakmakidis Kosmas L.
Published: October 2010

We review recent theoretical and experimental breakthroughs in the realm of slow and stopped light in structured photonic media featuring negative electromagnetic parameters (permittivity/permeability and/or refractive index). We explain how and why these structures can enable complete stopping of light even in the presence of disorder and, simultaneously, dissipative losses. Using full-wave numerical simulations we show that the incorporation of thin layers made of an active medium adjacently to the core layer of a negative-refractive-index waveguide can completely remove dissipative losses – in a slow-light regime where the effective index of the guided wave is negative.
Specific Cell Cultivation on Nanofibrous Layer
Authors: Michálek Jiří , Mareková Dana , Martinová Lenka , Hobzová Radka , Kostecká Petra , Lubasová Daniela , Lesný Petr , Přádný Martin , Jendelová Pavla , Syková Eva
Published: October 2010

Recent advances in the preparation of nanofibre layers, especially using the Nanospider™ technology, allow prepare a sufficiently large area of nanofibrous layer of reproducible thickness and structure. Subsequently, it is possible to employ these layers as cell carriers and evaluate their efficiency in laboratory bioreactors. The construction of the functional hepatal bioreactor is particularly given by the positive response of hepatocyte cells to the used carrier layer as well as by the cell morphology, their viability and biological activity in certain period of time. We compared cell growth on collagen with nanofibres electrospun from selected copolymers of methacrylic esters (HEMA/EOEMA) and from differently prepared polycaprolactone (PCL) layers. The morphology was evaluated using Phaloidin/DAPI staining. On the nanofibres based on methacrylates, the cells survived and showed a common morphology comparing with cells grown on collagen (controls). On the PCL nanofibres, the cells attached well and showed a better growth than cells grown on collagen (controls). The results obtained in laboratory bioreactor proved the biochemical functionality of the studied system.
Novel Silicon Based Gene Carrier Systems
Authors: Sommerwerk Anett , Struckmeyer Guido , Tillmann Janine , Uhr Michael , Schäfer J. , Richter Heinrich , Bakowsky Udo
Published: October 2010

The preparation and charactersiation of novel gene vehicles based on synthetic organic silicon derivatives are which are formulated as solid lipid nanoparticles (SLN) and liposomes are investigated in the presented study. Physicochemical parameters and morphology were studied by photon correlation spectroscopy, zeta potential measurements (NanoZ Malvern) and Atomic Force Microscopy (Digital Nanoscope IV Bioscope), while the biological activity was determined using a standard in vitro transfection assay and corelated with established gene transfection systems.
Nanotechonology for Drug Targeting
Authors: Ruozi Barbara , Tosi Giovanni , Forni Flavio , Vandelli Maria Angela
Published: October 2010

Nanoparticles (Np) and liposomes (L) were engineered obtaining selective drug delivery systems able to cross BBB and to treat cancer diseases, respectively. The first goal was achieved conjugating a specific epta-glucopeptide (g7) to polymeric nanoparticles (Np). The data related the nociceptive activity showed the ability of g7-Np to cross the BBB and to release loperamide in the brain. To reach the second goal we have recently proposed the immunoliposomes (ILp) for tumor-targeted delivery of gene material (particularly SiRNAs), which are selected in vitro for the specific antineoplastic activity against herpesvirus-associated B-cell lymphomas, particularly HHV8+ Primary Effusion Lymphoma (PEL). In the preliminary study we have prepared and characterized the ILp direct to PEL cells (BCBL-1 cell line). The cellular trafficking of the encapsulated model FITC-ODN obtained by flow cytometry and confocal microscopy was evaluated by the ability of the new carriers to selectively interact with cells. The data were compared with the different behaviour of these liposomes respect to the un-targeted cationic and pegylated liposomes.
A Critical Assessment of the Clinical Efficacy and Cellular Response to Low Intensity Pulsed Ultrasound for Fracture Repair
Authors: Laurencin Cato T. , Khan Yusuf
Published: October 2010

Fracture repair continues to be widely investigated, both within the clinical realm and at the fundamental research level. Clinical application of low intensity pulsed ultrasound (LIPUS) has shown great promise as an effective, minimally invasive treatment for accelerating fracture repair and has warranted further investigation into the cellular manifestation of applied ultrasound. Toward this end much has been learned about the response of osteoblasts to LIPUS stimulation. In vitro and in vivo evaluation of cellular response to LIPUS have revealed an increase in proliferation, protein synthesis, collagen synthesis, membrane permeability, integrin expression, and increased cytosolic calcium, to name a few, further clarifying its utility and overall impact on cellular behavior. Considerable effects of LIPUS on the cells of musculoskeletal soft tissue have been reported as well. The growing body of research in this area suggests that LIPUS may be a powerful tool in the development of novel approaches to musculoskeletal repair and regeneration. Regenerative engineering-based approaches to musculoskeletal healing and regeneration that incorporate polymeric scaffolds and stem cells may be combined with LIPUS to move beyond bone repair to large scale multicomponent tissue repair.
Carbon Nanotubes In Vitro and In Vivo Biological Effects
Authors: Bellucci Stefano
Published: October 2010

I review some recent results obtained by my group at INFN, in collaboration with Collegues at CNR-IREA, Napoli, Italy about the cytotoxicity of buckypaper in human lymphocytes, as well as with Collegues at “La Sapienza” Rome University about the effect of buckypaper on cancer and primary cell lines in vitro and in vivo on laboratory rats
Role of Grain Size Fluctuations on the Environmental Resistance of Alumina-Zirconia Composite in Comparison with Commercially Available Monolithic Zirconia Femoral Head
Authors: Sugano Nobuhiko , Pezzotti Giuseppe
Published: October 2010

Raman microprobe spectroscopy and atomic force microscopy (AFM) were systematically used to characterize the surface of an advanced alumina/zirconia composite (henceforth also referred to as zirconia toughened alumina, ZTA), in comparison with a commercially available femoral head made of monolithic zirconia. Experiments were conducted before and after in vitro exposure in water moist environment up to 100 h. Both materials contained zirconia partly stabilized with yttria. Tetragonal-to-monoclinic phase transformation, which was quantitatively characterized by confocal Raman spectroscopy as a function of grain size, showed significant difference between the investigated samples. Such difference was similarly found with respect to both roughness level and time needed for such topologic changes to occur. Variation of phase fractions and of topologic surface parameters were plotted as a function of in vitro exposure time and compared.
Stoichiometry and Surface Stress Analyses in Advanced Alumina/Zirconia Composites for Hip Arthroplasty Applications
Authors: Porporati Alessandro Alan , Munisso Maria Chiara , Lessnau Kristina , Pezzotti Giuseppe
Published: October 2010

A spatially resolved cathodoluminescence (CL) analysis is used as a means for chemical and mechanical analyses of the composite surface after environmental exposure. CL emission proves extremely efficient in concurrently monitoring the concentration of point defects (e.g., oxygen vacancies) on the material surface. Using CL, averaging effects from sub-surface parts of the material can be minimized, and the actual chemical state of the material surface is revealed. As a result, information about the stoichiometry of the material surface can be obtained directly from the lattices of the constituent phases, this enabling one to pattern relevant connections to the environmental resistance of oxide-based bioceramics. A highly fracture resistant alumina/zirconia composite represents the latest trend in ceramics for arthroplastic applications in alternative to monolithic alumina or zirconia ceramics. This composite material is designed from both chemical and microstructural viewpoints in order to prevent environmental degradation and fracture events in vivo, an important step forward in the full exploitation of ceramic materials in the field of arthroplasty. Systematically monitoring the optical activity of oxygen vacancies in both alumina and zirconia phase reveals the distinct role on the kinetics of polymorphic transformation. From the presented data an explicit role is evinced for oxygen vacancy formation in the alumina matrix in the complex cascade of mechanochemical events determining the environmental resistance of the composite.
Biodegradable Polymers Derived from Amino Acids for Biological Applications
Authors: Cohen-Arazi Naomi , Hagag Ilanit , Kolitz Michal , Domb Abraham J. , Katzhendler Jeoshua
Published: October 2010

Optically active α-hydroxy acids derived from amino acids have been synthesized and polymerized into new biodegradable polyesters. The variety of functional side chains enables the design of positively charged, negatively charged, hydrophobic and hydrophilic chiral building blocks or any combination of these constituents. Hydroxy acids of 15 natural amino acids were prepared with retention of configuration using a straightforward and reliable method of diazotization of α-amino acids. Polyesters were synthesized from these hydroxy acids by a number of methods: direct condensation in bulk, microwave assisted synthesis and ring opening polymerization. The molecular weight of the prepared polymers ranges between 2000 to 5000Da for the direct condensation and the microwave methods, whereas the ring opening polymerization results in high molecular weight polymers (20000 to 30000Da). The polymers were analyzed for their optical activity (Circular Dichroism Spectroscopy), thermal properties (DSC), solubility, molecular weight and polydispersity (GPC), and aqueous degradation. These polymers were tested for their compatibility to neuronal cells growth and differentiation.
Osseointegration and Biocompatibility Study of Macroporous Biphasic Calcium Phosphate (BCP) Ceramics Obtained by Consolidation Using Albumin
Authors: Ribeiro Christiane , Goia Tamiye S. , Violin Kalan B. , Bressiani José Carlos , Bressiani Ana Helena Almeida
Published: October 2010

The potential of porous materials for applications in the medical, engineering and pharmaceutical areas has been widely reported. Several processing techniques have contributed to the progress in research involving porous biomaterials. To this purpose, a globular protein based (i.e. ovalbumin) consolidation approach has been proposed. In the present study, a porous hydroxyapatite: -tricalcium phosphate - biphasic ceramics (BCP), was processed by direct consolidation using the protein-action technique. The processed porous ceramic exhibited appropriate pore configuration in terms of size, morphology and distribution. BCP cylindrical samples were implanted in male rabbits tibia to the evaluation of the initial biocompatibility and osseointegration for a 30 days period. The morphological analyses, optical microscopy and scanning electron microscopy evaluated the osseointegration. A rough surface pattern displayed by the ceramics seemed to have improved cell adhesion and proliferation processes. Furthermore, the open porosity of samples was an essential requirement for a suitable bone-implant osseointegration. In conclusion, this study revealed that the porous matrices obtained, promoted suitable development for bone tissue growth and also properties for osseoconduction and osseointegration.
Effects of a solar wind dynamic pressure increase in the magnetosphere and in the ionosphere
Authors: Juusola L. , Andréeová K. , Amm O. , Kauristie K. , Milan S. E. , Palmroth M. , Partamies N.
Published: October 2010

Abstract. On 17 July 2005, an earthward bound north-south oriented magnetic cloud and its sheath were observed by the ACE, SoHO, and Wind solar wind monitors. A steplike increase of the solar wind dynamic pressure during northward interplanetary magnetic field conditions was related to the leading edge of the sheath. A timing analysis between the three spacecraft revealed that this front was not aligned with the GSE y-axis, but had a normal (−0.58,0.82,0). Hence, the first contact with the magnetosphere occurred on the dawnside rather than at the subsolar point. Fortunately, Cluster, Double Star 1, and Geotail happened to be distributed close to the magnetopause in this region, which made it possible to closely monitor the motion of the magnetopause. After the pressure front had impacted the magnetosphere, the magnetopause was perceived first to move inward and then immediately to correct the overshoot by slightly expanding again such that it ended up between the Cluster constellation with Double Star 1 inside the magnetosphere and Geotail in the magnetosheath. Coinciding with the inward and subsequent outward motion, the ground-based magnetic field at low latitudes was observed to first strengthen and then weaken. As the magnetopause position stabilised, so did the ground-based magnetic field intensity, settling at a level slightly higher than before the pressure increase. Altogether the magnetopause was moving for about 15 min after its first contact with the front. The high latitude ionospheric signature consisted of two parts: a shorter (few minutes) and less intense preliminary part comprised a decrease of AL and a negative variation of PC. A longer (about ten minutes) and more intense main part of the signature comprised an increase of AU and a positive variation of PC. Measurements from several ground-based magnetometer networks (210 MM CPMN, CANMOS, CARISMA, GIMA, IMAGE, MACCS, SuperMAG, THEMIS, TGO) were used to obtain information on the ionospheric E×B drift. Before the pressure increase, a configuration typical for the prevailing northward IMF conditions was observed at high latitudes. The preliminary signature coincided with a pair of reverse convection vortices, whereas during the main signature, mainly westward convection was observed at all local time sectors. Afterwards, the configuration preceding the pressure increase was recovered, but with slightly enhanced convection. Based on the timing analysis, the existence of the preliminary signature coincided with the passage of the oblique pressure front, whereas during the main signature the front was already well past Earth. The main signature existed during the time the magnetopause was observed to move. As the position stabilised, also the signature disappeared.
Email Intervention Following Traumatic Brain Injury: Two Case Reports
Authors: Kim Min Jung , Stierwalt Julie A.G. , LaPointe Leonard L.
Published: October 2010

An email intervention for two individuals with TBI was conducted to investigate if this electronic medium would show potential as a therapeutic delivery method. Specifically, this study measured participants’ compliance to a plan that incorporated email and a reading assignment. Prior to the email intervention, a clinician and participants designed an intervention plan, which included specific guidelines for scheduled email correspondence regarding a daily reading task. After reviewing the daily emails the clinician provided therapeutic feedback. The participants’ compliance to the plan was measured by punctuality of email correspondence and completion of tasks as detailed in the plan. Over a 4-week intervention period, both participants demonstrated improvement in task completion and time adherence. With these individuals, email proved to be a feasible option as a therapeutic delivery method.      Keywords: email intervention, individuals with TBI, task completion, time adherence
VOIP for Telerehabilitation: A Risk Analysis for Privacy, Security, and HIPAA Compliance
Authors: Watzlaf Valerie J.M. , Moeini Sohrab , Firouzan Patti
Published: October 2010

Voice over the Internet Protocol (VoIP) systems such as Adobe ConnectNow, Skype, ooVoo, etc. may include the use of software applications for telerehabilitation (TR) therapy that can provide voice and video teleconferencing between patients and therapists.  Privacy and security applications as well as HIPAA compliance within these protocols have been questioned by information technologists, providers of care, and other health care entities. This paper develops a privacy and security checklist that can be used within a VoIP system to determine if it meets privacy and security procedures and whether it is HIPAA compliant. Based on this analysis, specific HIPAA criteria that therapists and health care facilities should follow are outlined and discussed, and therapists must weigh the risks and benefits when deciding to use VoIP software for TR.
Weed Harrowing and Inter-Row Hoeing in Organic Grown Quinoa (Chenopodium Quinoa Willd.)
Authors: Jacobsen Sven-Erik , Christiansen Jørgen L. , Rasmussen Jesper
Published: October 2010

Weeds, with their negative influence on both yield and quality, constitute a major problem in the organic production of quinoa, a potential new seed crop for protein feed and human consumption in Europe. To attain effective weed control, mechanical weeding strategies, such as weed harrowing and inter-row hoeing, were studied. Weed harrowing operates over the entire plot with flexible tines, affecting both crop and weeds, whereas inter-row hoeing is performed between the rows, aiming only at the weeds. The study showed that both hoeing and harrowing reduced the quinoa density in one out of two years, whereas there was no effect on quinoa density in the other year. Yield was increased by both methods, but hoeing increased yield more than harrowing due to better weed control. Regression analysis showed that crop yield was related to weed dry matter and showed no indications of higher crop damage associated with weed harrowing. Protein content was low when weeds were not treated, and increased significantly when weeds were controlled. As a conclusion, inter-row hoeing was more efficient than weed harrowing with respect to weed control; however, weed harrowing should be optimized in future trials in narrow row spacing systems, and the results indicate that weed harrowing can be used as a supplement to inter-row hoeing.
Functioning of the Public Distribution System in India
Authors: Kumar Parmod
Published: October 2010

The Public Distribution System (PDS) continues to be a major instrument of food security for the poor in the Indian subcontinent. This paper examines how efficiently food is being delivered under this food subsidy scheme and measures the extent of diversion of food meant for the poor. The study is based on a large primary survey of 12 states surveying 1,000 households from each state over six consecutive months. The findings indicate huge identification errors and incidences of diversion of food, especially in the case of households below the poverty line. The gross failure of identification of the correct beneficiaries in almost all the selected states raises a major question about the very genesis of this subsidy scheme.
Sino–US Agricultural Trade Potential: A Gravity Model Approach
Authors: Shuai Chuanmin
Published: October 2010

Agricultural trade is an important component of the economic and trading relations between China and the USA. Given the world financial crisis, the economic downturn and the potential rise of trade protectionism, it is important to analyse and estimate the mutual benefits and potential of Sino–US agricultural trade before and after China's accession to the World Trade Organization (WTO) in an attempt to re-examine and reconsider the benefits of trade liberalization. Adopting the gravity model approach with a fixed-effect hypothesis and using SPSS software 17.0, the author undertakes an empirical analysis of the agri-trade potential between China and the USA and between the two countries and their major trade partners. The results indicate that (a) China's WTO accession has brought about opportunities for agricultural trade for both countries, but the USA has gained more benefits from the bilateral trade than China; (b) the major factors influencing Chinese and US agri-exports are different, reflecting the features of the economic growth and industrial structures of the two countries; and (c) China and the USA have different potentials for agri-exports with different regional characteristics. Based on these findings, policy recommendations are proposed for both China and the USA to strengthen their agri-trade ties.
Research and Development on Cotton during and after the Indian-Supported Agricultural Development Project in Senegal
Authors: Ahuja S.L.
Published: October 2010

An analysis was carried out of the contributions of research and development on cotton to increases in production and productivity during and after the Government of India's Agricultural Development Project (ADP) in Senegal. It is suggested that cotton research programmes need to focus on the breeding of region-specific varieties with resistance to bollworms and exploiting the available world genetic stocks to achieve the desirable characteristics. The primary need is for the introduction of Indian varieties of Gossypium arboreum and G. herbaceum, an emphasis on the implementation of integrated pest management (IPM) technology and a strengthening of seed production programmes. The possible roles of Bt and organic cottons are also discussed.
Factors Contributing to Sustainable Livelihoods in Different Farming Systems in the Coastal Areas of Tamil Nadu, India
Authors: Ponnusamy K. , Gupta Jancy
Published: October 2010

Coastal farmers follow different enterprise combinations according to the resources available to them. A study conducted in the coastal districts of Tamil Nadu revealed that the major farming systems practised by the farmers were: crop + dairy, crop + dairy + poultry, crop + dairy + poultry + fisheries, crop + dairy + poultry + sheep/goats, crop + dairy + poultry + horticulture, and crop + dairy + poultry + sheep/goats + horticulture. Livestock holdings, landholding, marketing behaviour, the perception of integrated farming systems and communication behaviour were the important contributing factors to sustainable livelihoods in the farming systems found. Broad-based extension systems would be the ideal extension approach to promote integrated farming systems for developing sustainable livelihoods. Appropriate institutional and infrastructure support could also facilitate the adoption of profitable and sustainable farming systems in the coastal region.
Freeze‐Casting of Arbitrary‐Shaped Porous Ceramics
Authors: Zhang Feng , Jia Man , Wang Jiahang , Xu Mengjia , Wei Chenxu , Li Weidong , Li Zongan
Published: May 2024

Porous ceramics hold the great potential in the field such as bone tissue engineering, superinsulation material, and energy storage. However, it is quite challenging to fabricate them with arbitrary shape using conventional processes. Herein, a method to fabricate arbitrary‐shaped porous ceramic structure is presented by combining traditional freeze‐casting process and indirect three‐dimensional printing technology. Various polydimethylsiloxane (PDMS) soft molds are prepared for freeze‐casting, and diverse‐shaped porous ceramics are fabricated. It proves that PDMS molds are ideal choices for freeze‐casting of porous ceramics with complex geometries. The freeze‐casting process of a complex‐shaped model with PDMS is simulated by finite element analysis. The effect of the solid loading of the alumina suspension on the microstructure and compressive strength of the as‐fabricated porous ceramics are investigated. The present study provides a strategy to fabricate complex‐shaped porous ceramic structure that can be used in a wide variety of applications.
Synergistic Effect of ZnO Thin Films with Gold as Antifungal Coatings
Authors: Pereira‐Silva Patrícia , Pacheco Maria Inês , Borges Joel , Vaz Filipe , Sampaio Paula
Published: May 2024

Microbial contamination on surfaces is a problem worldwide, affecting public health and industry. The increasing prevalence and severity of microbial infection outbreaks across various environments have highlighted the urgent need to develop antimicrobial coatings/surfaces to mitigate the risk of disease transmission through high‐touched surfaces. This work focuses on assessing the antifungal activity of thin films based on zinc oxide (ZnO), produced by reactive magnetron sputtering with varying thicknesses, and evaluating the impact of varying gold concentrations within the ZnO matrix on both microstructure and antifungal activity. The developed thin films exhibit noteworthy antifungal activity against the fungus Candida albicans, achieving 80% reduction in cell viability, regardless of thickness and gold concentration (up to 15.4 at%). Annealing treatment at 600 °C induces the formation of large and irregular gold nanostructures (sizes from 39 to 260 nm), enhancing the antifungal activity compared to the as‐deposited samples. This highlights the surface‐dependent antifungal efficacy of ZnO‐based thin films and a synergistic effect when combined with gold. Additionally, the thin films not only exhibit antifungal activity but also demonstrate potential for localized surface plasmon resonance applications. Overall, ZnO‐based thin films hold promise as antifungal coatings for diverse surfaces, offering a preventive measure against microbial contamination.
Enhancement of Flow Boiling Heat Transfer Characteristics on Diamond/Cu Heterogeneous Surface
Authors: Wu Nan , Sun Mingmei , Guo Hong , Xie Zhongnan , Du Shijie
Published: May 2024

Surface treatment is an effective method of enhancing the heat transfer performance of flow boiling. Diamond/Cu, as a particle‐reinforced composite, exhibits heterogeneous surface properties and surface microstructures that play distinct roles in heat transfer. To elucidate the synergistic effect of heterogeneous material surfaces and microstructures, pure copper surface (PC), untreated diamond/Cu surface (DC), and surface‐treated diamond/Cu surface (SDC) are prepared for this experiment. These surfaces demonstrate various combinations of diamond, copper, and their corresponding surface microstructures. DC, characterized by heterogeneous wetting properties, demonstrates a heat transfer coefficient (HTC) that is 9%–24% higher than that of PC. The surface treatment of SDC results in the formation of a superhydrophilic CuO nanosheet structure, significantly enhancing both surface roughness and energy. SDC develops microcracks on the surface of diamond. The increased roughness provides numerous nucleation areas for the hydrophobic diamond, enhancing the overall wettability of the surface when combined with the superhydrophilic CuO region. SDC demonstrates the advantage of enhanced flow boiling on the surface of heterogeneous materials. At the identical heat flux, SDC exhibits a reduction of 5–10 °C in wall superheat and an increase of 38%–47% in HTC.
Semiconducting Polymer Dots for Dual‐Wavelength Differential Background‐Suppressed Photoacoustic Imaging
Authors: Wang Bo , Li Lingfeng , Liu Ye , Xie Zhuojun , Deng Sile , Men Xiaoju , Wu Changfeng , Chen Haobin , Xiao Jiaying
Published: May 2024

Photoacoustic imaging (PAI) can sensitively detect regions and substances with strong optical absorption, which means that diseased tissue can be imaged with high contrast in the presence of surrounding healthy tissue through the photoacoustic effect. However, its signal intensity and resolution may be limited by background signals generated by endogenous chromophores such as melanin and hemoglobin. A feasible method for practical application of this so‐called background‐suppressed PAI is still lacking. In this work, a dual‐wavelength differential background noise‐suppressed photoacoustic tomography is developed based on organic semiconducting polymer dots (Pdots). The Pdots have a strong absorption peak at 945 nm, and then the absorption decreases sharply with the increase of wavelength, and the absorption intensity drops to only about a quarter of the original value at 1050 nm. The present system significantly suppresses the strong background noise of blood through dual‐wavelength differential PAI, enabling precise monitoring of the distribution information of theranostic agents in diseased tissues. The signal‐to‐noise ratio of the theranostic agent distribution map is increased by about 20 dB. This work provides a platform for real‐time and accurate monitoring of tumors and drugs, which helps avoid damage to healthy tissue during treatment and has clinical significance in cancer treatment.
Solid Decolorization: Dismantling of an Orange‐Red Zwitterionic Cocrystal by Multicomponent Milling
Authors: Ezekiel Charles Izuchukwu , Ortiz‐de León Celymar , Reinheimer Eric , MacGillivray Leonard R.
Published: May 2024

An application of multi‐component milling is described to achieve a decolorization by dismantling the orange‐red zwitterionic cocrystal (PDA)∙(APAP) (where PDA = 2,4‐pyridinedicarboxylic acid, APAP = acetaminophen) using n,n′‐BPE (BPE = trans‐1,2‐bis(n‐pyridylethylene and for n = n′ = 3 or 4). Each of n,n′‐BPE forms a colorless hydrogen‐bonded cocrystal with PDA.
Hydrophilic Photocrosslinkers as a Universal Solution to Endow Water Affinity to a Polymer Photocatalyst for an Enhanced Hydrogen Evolution Rate
Authors: An Sanghyeok , Jeong Kyeong‐Jun , Hassan Syed Zahid , Ham Gayoung , Kang Seonghyeon , Lee Juhyeok , Ma Hyeonjong , Kwon Jieun , Jeong Sang Young , Yang Jiwoong , Woo Han Young , Cho Han‐Hee , Cha Hyojung , Son Chang Yun , Chung Dae Sung
Published: May 2024

A universal approach for enhancing water affinity in polymer photocatalysts by covalently attaching hydrophilic photocrosslinkers to polymer chains is presented. A series of bisdiazirine photocrosslinkers, each comprising bisdiazirine photophores linked by various aliphatic (CL‐R) or ethylene glycol‐based bridge chains (CL‐TEG), is designed to prevent crosslinked polymer photocatalysts from degradation through a safe and efficient photocrosslinking reaction at a wavelength of 365 nm. When employing the hydrophilic CL‐TEG as a photocrosslinker with polymer photocatalysts (F8BT), the hydrogen evolution reaction (HER) rate is considerably enhanced by 2.5‐fold compared to that obtained using non‐crosslinked F8BT photocatalysts, whereas CL‐R‐based photocatalysts yield HER rates comparable to those of non‐crosslinked counterparts. Photophysical analyses including time‐resolved photoluminescence and transient absorption measurements reveal that adding CL‐TEG accelerates exciton separation, forming long‐lived charge carriers. Additionally, the in‐depth study using molecular dynamics simulations elucidates the dual role of CL‐TEG: it enhances water penetration into the polymer matrix and stabilizes charge carriers after exciton generation against undesirable recombination. Therefore, the strategy highlights endowing a high‐permittivity environment within polymer photocatalyst in a controlled manner is crucial for enhancing photocatalytic redox reactivity. Furthermore, this study shows that this hydrophilic crosslinker approach has a broad applicability in general polymer semiconductors and their nanoparticulate photocatalysts.
Unlocking the Potential of Bi2S3‐Derived Bi Nanoplates: Enhanced Catalytic Activity and Selectivity in Electrochemical and Photoelectrochemical CO2 Reduction to Formate
Authors: Ma Ahyeon , Lee Yongsoon , Seo Dongho , Kim Jiyoon , Park Soohyeok , Son Jihoon , Kwon Woosuck , Nam Dae‐Hyun , Lee Hyosung , Kim Yong‐Il , Um Han‐Don , Shin Hyeyoung , Nam Ki Min
Published: May 2024

Various electrocatalysts are extensively examined for their ability to selectively produce desired products by electrochemical CO2 reduction reaction (CO2RR). However, an efficient CO2RR electrocatalyst doesn't ensure an effective co‐catalyst on the semiconductor surface for photoelectrochemical CO2RR. Herein, Bi2S3 nanorods are synthesized and electrochemically reduced to Bi nanoplates that adhere to the substrates for application in the electrochemical and photoelectrochemical CO2RR. Compared with commercial‐Bi, the Bi2S3‐derived Bi (S‐Bi) nanoplates on carbon paper exhibit superior electrocatalytic activity and selectivity for formate (HCOO−) in the electrochemical CO2RR, achieving a Faradaic efficiency exceeding 93%, with minimal H2 production over a wide potential range. This highly selective S‐Bi catalyst is being employed on the Si photocathode to investigate the behavior of electrocatalysts during photoelectrochemical CO2RR. The strong adhesion of the S‐Bi nanoplates to the Si nanowire substrate and their unique catalytic properties afford exceptional activity and selectivity for HCOO− under simulated solar irradiation. The selectivity observed in electrochemical CO2RR using the S‐Bi catalyst correlates with that seen in the photoelectrochemical CO2RR system. Combined pulsed potential methods and theoretical analyses reveal stabilization of the OCHO* intermediate on the S‐Bi catalyst under specific conditions, which is critical for developing efficient catalysts for CO2‐to‐HCOO− conversion.
Community‐engaged pedagogy in an emergency medicine clerkship: Teaching trauma‐informed addiction care and harm reduction through a peer‐assisted learning case
Authors: Fockele Callan , Lindgren Elsa , Ferreira Jordan , Salehipour Dena , Shandro Jamie , Jauregui Joshua
Published: May 2024

Background

The impact of opioid use disorder (OUD) in the United States continues to rise, yet this topic has limited coverage in most medical school curricula. The study partnered with academic and community harm reductionists to design a peer‐assisted learning case of opioid withdrawal to teach fourth‐year medical students about trauma‐informed OUD care and harm reduction services during their emergency medicine clerkship.

Methods

Academic and community harm reductionists iteratively codesigned this case in partnership with the research team. Community‐engaged pedagogy informed this process to promote social action and power sharing through education. This case was integrated into the existing weekly peer‐assisted learning curriculum (i.e., medical students teaching medical students through a structured case) for all fourth‐year medical students during their required emergency medicine clinical rotation. Participants completed a postcase evaluation survey.

Results

Sixty‐four medical students completed the survey between June and November 2022. A total of 98.5% of participants found the educational session quite or extremely relevant to their medical education, and 87.5% believed the case to be quite or extremely effective in achieving the learning objectives. A total of 45.3% initially felt quite or extremely competent in talking with patients about their drug use, whereas 53.2% felt quite or extremely more competent after participating in the case. Finally, 21.9% initially felt quite or extremely competent in proposing a treatment plan for a patient who uses drugs, whereas 62.5% felt quite or extremely more competent after participating in the case.

Conclusions

This study supports the feasibility and importance of incorporating the voices of people with lived and living experience into medical school curricular development. This peer‐assisted learning case focused on the treatment of OUD in the emergency department was seamlessly integrated into the existing curriculum and well received by medical students. By engaging local experts, it could easily be adapted and expanded to other sites.
Comparison of the pathogenicity and neutrophil and monocyte response between SARS‐CoV‐2 prototype and Omicron BA.1 in a lethal mouse model
Authors: Rong Na , Wu Jing , Zhao Binbin , Peng Wanjun , Yang Hekai , Zhang Gengxin , Ruan Dangting , Wei Xiaohui , Liu Jiangning
Published: May 2024

Background

SARS‐CoV‐2, first identified in late 2019, has given rise to numerous variants of concern (VOCs), posing a significant threat to human health. The emergence of Omicron BA.1.1 towards the end of 2021 led to a pandemic in early 2022. At present, the lethal mouse model for the study of SARS‐CoV‐2 needs supplementation, and the alterations in neutrophils and monocytes caused by different strains remain to be elucidated.

Methods

Human ACE2 transgenic mice were inoculated with the SARS‐CoV‐2 prototype and Omicron BA.1, respectively. The pathogenicity of the two strains was evaluated by observing clinical symptoms, viral load and pathology. Complete blood count, immunohistochemistry and flow cytometry were performed to detect the alterations of neutrophils and monocytes caused by the two strains.

Results

Our findings revealed that Omicron BA.1 exhibited significantly lower virulence compared to the SARS‐CoV‐2 prototype in the mouse model. Additionally, we observed a significant increase in the proportion of neutrophils late in infection with the SARS‐CoV‐2 prototype and Omicron BA.1. We found that the proportion of monocytes increased at first and then decreased. The trends in the changes in the proportions of neutrophils and monocytes induced by the two strains were similar.

Conclusion

Our study provides valuable insights into the utility of mouse models for simulating the severe disease of SARS‐CoV‐2 prototype infection and the milder manifestation associated with Omicron BA.1. SARS‐CoV‐2 prototype and Omicron BA.1 resulted in similar trends in the changes in neutrophils and monocytes.
Orthogonal Radical and Cationic Single‐Unit Monomer Insertions for Engineering Polymer Architectures
Authors: Wei Ze , He Wei , Liu Zhihua , Lin Yating , Wang Maolin , Li Liang , Wu Chunxiao , Yang Sheng , Liu Guhuan , Yang Ronghua
Published: May 2024

The single‐unit monomer insertion (SUMI), derived from living/controlled polymerization, can be directly functionalized at the end or within the chain of polymers prepared by living/controlled polymerization, offering potential applications in the preparation of polymers with complex architectures. Many scenarios demand the simultaneous incorporation of monomers suitable for different polymerization methods into complex polymers. Therefore, it becomes imperative to utilize SUMI technologies with diverse mechanisms, especially those that are compatible with each other. Here, we reported the orthogonal SUMI technique, seamlessly combining radical and cationic SUMI approaches. Through the careful optimization of monomer and chain transfer agent pairs and adjustments to reaction conditions, we can efficiently execute both radical and cationic SUMI processes in one pot without mutual interference. The utilization of orthogonal SUMI pairs facilitates the integration of radical and cationic reversible addition‐fragmentation chain transfer (RAFT) polymerization in various configurations. This flexibility enables the synthesis of diblock, triblock, and star polymers that incorporate both cationically and radically polymerizable monomers. Moreover, we have successfully implemented a mixing mechanism of free radicals and cations in RAFT step‐growth polymerization, resulting in the creation of a side‐chain sequence‐controlled polymer brushes.
Opening and Constructing Stable Lithium‐ion Channels within Polymer Electrolytes
Authors: Zhao Yangmingyue , Li Libo , Zhou Da , Ma Yue , Zhang Yonghong , Yang Hang , Fan Shubo , Tong Hao , Li Suo , Qu Wenhua
Published: May 2024

Lithium‐ion batteries play an integral role in various aspects of daily life, yet there is a pressing need to enhance their safety and cycling stability. In this study, we have successfully developed a highly secure and flexible solid‐state polymer electrolyte (SPE) through the in situ polymerization of allyl acetoacetate (AAA) monomers. This SPE constructed an efficient Li+ transport channel inside and effectively improved the solid‐solid interface contact of solid‐state batteries to reduce interfacial impedance. Furthermore, it exhibited excellent thermal stability, an ionic conductivity of 3.82×10−4 S cm−1 at room temperature (RT), and a Li+ transport number (tLi+) of 0.66. The numerous oxygen vacancies on layered inorganic SiO2 created an excellent environment for TFSI− immobilization. Free Li+ migrated rapidly at the C=O equivalence site with the poly(allyl acetoacetate) (PAAA) matrix. Consequently, when cycled at 0.5C and RT, it displayed an initial discharge specific capacity of 140.6 mAh g−1 with a discharge specific capacity retention rate of 70 % even after 500 cycles. Similarly, when cycled at a higher rate of 5C, it demonstrated an initial discharge specific capacity of 132.3 mAh g−1 while maintaining excellent cycling stability.
Boosting Solar‐Driven CO2 Conversion to Ethanol via Single‐Atom Catalyst with Defected Low‐Coordination Cu‐N2 Motif
Authors: Shi Hainan , Liang Yan , Hou Jungang , Wang Haozhi , Jia Zhenghao , Wu Jiaming , Song Fei , Yang Hong , Guo Xinwen
Published: May 2024

Cu‐based catalysts have been shown to selectively catalyze CO2 photoreduction to C2+ solar fuels. However, they still suffer from poor activity and low selectivity. Herein, we report a high‐performance carbon nitride supported Cu single‐atom catalyst featuring defected low‐coordination Cu‐N2 motif (Cu‐N2‐V). Lead many recently reported photocatalysts and its Cu‐N3 and Cu‐N4 counterparts, Cu‐N2‐V exhibits superior photocatalytic activity for CO2 reduction to ethanol and delivers 69.8 μmol g−1 h−1 ethanol production rate, 97.8 % electron‐based ethanol selectivity, and a yield of ~10 times higher than Cu‐N3 and Cu‐N4. Revealed by the extensive experimental investigation combined with DFT calculations, the superior photoactivity of Cu‐N2‐V stems from its defected Cu‐N2 configuration, in which the Cu sites are electron enriched and enhance electron delocalization. Importantly, Cu in Cu‐N2‐V exist in both Cu+ and Cu2+ valence states, although predominantly as Cu+. The Cu+ sites support the CO2 activation, while the co‐existence of Cu+/Cu2+ sites are highly conducive for strong *CO adsorption and subsequent *CO‐*CO dimerization enabling C−C coupling. Furthermore, the hollow microstructure of the catalyst also promotes light adsorption and charge separation efficiency. Collectively, these make Cu‐N2‐V an effective and high‐performance catalyst for the solar‐driven CO2 conversion to ethanol. This study also elucidates the C‐C coupling reaction path via *CO‐*CO to *COCOH and rate‐determining step, and reveals the valence state change of partial Cu species from Cu+ to Cu2+ in Cu‐N2‐V during CO2 photoreduction reaction.