bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Mirror and Weibel modes: peculiarities of quasi-linear dynamics
Authors: Pokhotelov O. A. , Sagdeev R. Z. , Balikhin M. A. , Fedun V. N. , Dudnikova G. I.
Published: December 2010

Abstract. A theory for nonlinear evolution of the mirror modes near the instability threshold is developed. It is shown that during initial stage the major instability saturation is provided by the flattening of the velocity distribution function in the vicinity of small parallel ion velocities. The relaxation scenario in this case is accompanied by rapid attenuation of resonant particle interaction which is replaced by a weaker adiabatic interaction with mirror modes. The saturated plasma state can be considered as a magnetic counterpart to electrostatic BGK modes. After quasi-linear saturation a further nonlinear scenario is controlled by the mode coupling effects and nonlinear variation of the ion Larmor radius. Our analytical model is verified by relevant numerical simulations. Test particle and PIC simulations indeed show that it is a modification of distribution function at small parallel velocities that results in fading away of free energy driving the mirror mode. The similarity with resonant Weibel instability is discussed.
Effect of ocean acidification on marine fish sperm (Baltic cod: Gadus morhua)
Authors: Frommel A. Y. , Stiebens V. , Clemmesen C. , Havenhand J.
Published: December 2010

Abstract. Ocean acidification, as a consequence of increasing marine pCO2, may have severe effects on the physiology of marine organisms. However, experimental studies remain scarce, in particular concerning fish. While adults will most likely remain relatively unaffected by changes in seawater pH, early life-history stages are potentially more sensitive – particularly the critical stage of fertilization, in which sperm motility plays a central role. In this study, the effects of ocean acidification (decrease of pHT to 7.55) on sperm motility of Baltic cod, Gadus morhua, were assessed. We found no significant effect of decreased pH on sperm speed, rate of change of direction or percent motility for the population of cod analyzed. We predict that future ocean acidification will probably not pose a problem for sperm behavior, and hence fertilization success, of Baltic cod.
Deciphering the spatio-temporal complexity of climate change of the last deglaciation: a model analysis
Authors: Roche D. M. , Renssen H. , Paillard D.
Published: December 2010

Abstract. Understanding the sequence of events occuring during the last major glacial to interglacial transition (21 ka BP to 9 ka BP) is a challenging task that has the potential to unveil the mechanisms behind large scale climate changes. Though many studies have focused at a complex understanding of the sequence of rapid climatic change that accompanied or interrupted the deglaciation, few have analysed it in a more theoretical framework with simple forcings. In the following, we address when and where the first significant temperature anomalies appear when using slow varying forcing of the last deglaciation. We use here coupled transient simulations of the last deglaciation, including ocean, atmosphere and vegetation components to analyse the spatial timing of the deglaciation. To keep the analysis in a simple framework, we do not include rapid freshwater forcings that have led to rapid climate shifts during that time period. We aim to disentangle the direct and subsequent response of the climate system to slow forcing and moreover the location where those changes are more clearly expressed. In a data-modelling comparison perspective this could help understanding the physically plausible phasing between known forcings and recorded climatic changes. Our analysis of climate variability could also help to distinguish deglacial warming signals from internal climate variability. We thus are able to better pinpoint the onset of local deglaciation, as defined by the first significant local warming, and further show that there is a large regional variability associated with it, even with the set of slow forcings used here.
A viscoelastic Rivlin-Ericksen material model applicable to glacier ice
Authors: Riesen P. , Hutter K. , Funk M.
Published: December 2010

Abstract. We present a viscoelastic constitutive relation which describes transient creep of a modified second grade fluid enhanced with elastic properties of a solid. The material law describes a Rivlin-Ericksen material and is a generalization of existing material laws applied to study the viscoelastic properties of ice. The intention is to provide a formulation tailored to reproduce the viscoelastic behaviour of ice ranging from the instantaneous elastic response, to recoverable deformation, to viscous, stationary flow at the characteristic minimum creep rate associated with the deformation of polycrystalline ice. We numerically solve the problem of a slab of material shearing down a uniformly inclined plate. The equations are made dimensionless in a form in which elastic effects and/or the influence of higher order terms (i.e., strain accelerations) can be compared with viscous creep at the minimum creep rate by means of two dimensionless parameters. We discuss the resulting material behaviour and the features exhibited at different parameter combinations. Also, a viable range of the non-dimensional parameters is estimated in the scale analysis.
Climate of the Greenland ice sheet using a high-resolution climate model – Part 2: Near-surface climate and energy balance
Authors: Ettema J. , van den Broeke M. R. , van Meijgaard E. , van de Berg W. J.
Published: December 2010

Abstract. The spatial variability of near-surface variables and surface energy balance components over the Greenland ice sheet are presented, using the output of a regional atmospheric climate model for the period 1958–2008. The model was evaluated in Part 1 of this paper. The near-surface temperature over the ice sheet is affected by surface elevation, latitude, longitude, large-scale and small-scale advection, occurrence of summer melt and mesoscale topographical features. The atmospheric boundary layer is characterised by a strong temperature inversion, due to continuous longwave cooling of the surface. In combination with a gently sloping surface the radiative loss maintains a persistent katabatic wind. This radiative heat loss is mainly balanced by turbulent sensible heat transport towards the surface. In summer, the surface is near radiative balance, resulting in lower wind speeds. Absorption of shortwave radiation and a positive subsurface heat flux due to refreezing melt water are heat sources for surface sublimation and melt. The strongest temperature deficits (>13 °C) are found on the northeastern slopes, where the strongest katabatic winds (>9 m s−1) and lowest relative humidity (<65%) occur. Due to strong large scale winds, clear sky (cloud cover <0.5) and a concave surface, a continuous supply of cold dry air is generated, which enhances the katabatic forcing and suppresses subsidence of potentially warmer free atmosphere air.
Quality of broiler´s production on the farm in the application of welfare
Authors: Medveď Ján , Angelovičová Mária
Published: December 2010

Two experiments were carried out in practical conditions on the farm for fattening of chickens. In the hall with deep litter, which were carried out experiments, was installations with breeding technology of Big Dutchman with automatic feeding, watering, automatically set to light and temperature regimes. During both experiments were observed recommended microclimate conditions and the length of light and ventilation in the hall. The concentration of broilers per one square meter was 27.22, respectively. 29.34 kg. Their vitality was 94.2 and 95.6%. The average body weight of chickens at the end of the experiment (day 42) were 1986.65 and 2074.29 g, with a statistically proved differences between experiments (P < 0.01). The average carcass weight of broilers in the live weight 1800.0 g were 1384.67 and 1407.0 g, while the difference was not statistically proved (P > 0.05).
Cereals as basis of preventing nutrition against obesity
Authors: Duchoňová Lenka , Šturdí­k Ernest
Published: December 2010

Still more alarming obesity studies show in fact that it is largely due to incorrect diet and lifestyle. For suitable alternative for prevention of this disease are now considered cereal foods, mainly based on increased fiber content. The importance of dietary fiber for human organism consist primarily in its protective function before civilization diseases. It has beneficial effects on digestive physiology and it is therefore an important factor in the prevention of obesity, but also other diseases. Fiber consumption in developed countries is low and it is below the lower limit of the recommended dose. Slovaks per day take only 10-12 g of fiber, which represents only 47% of the recommended dose. Recent large-scale epidemiological studies have shown that regular consumption of wholegrain cereals can reduce the risk of heart disease and certain cancers by 30 percent. One of the factors that increase the functionality of foods is the so-called indigestible resistant starch. For its the positive impact on the physiology of digestion is referred to as prebiotics new generation of dietary fiber. The increasing availability of tasty, whole grain products rich in fiber could be health benefits.
Evaluation of elisa method to detection of cow β-lactoglobulin in sheep milk and sheep milk products
Authors: Zeleňáková Lucia , Židek Radoslav , Čanigová Margita , Paulov Juraj , Gallisová Tatiana
Published: December 2010

The aim of work was to optimalize the ELISA method to detect the adulteration of sheep milk and sheep milk products by cow milk in the laboratory. We have focused on laboratory testing of ELISA kit (β-Lactoglobulin ELISA Set, SEDIUM R&D) for detection of cow β-Lg in sheep milk order to obtain high-quality, reliable and economically advantageous method suitable for routine use in practice. The results shown that for the quality of adulteration determination  it is necessary to verify the sensitivity of applied kit by the samples dilution in accordance with the producer declared quantification range contained in the manual ELISA kit. The starting point for obtaining of relevant data was to create separate regression curves with high deter­mination coefficient, which allowed to quickly and easily detect the cow milk additions in sheep milk, cloddish sheep and Slovak sheep cheese.
Effect of moderate red wine consumption on the development and progression of metabolic syndrome as a complex risk factor for cardiovascular disease and diabetes mellitus II.
Authors: Gažarová Martina , Habánová Marta , Chlebo Peter , Kopčeková Jana
Published: December 2010

Metabolic syndrome is characterized by a set of clinical symptoms that are related to the development of cardiovascular disease. These abdominal obesity, which is the strongest associate with the metabolic syndrome and clinically manifested increasing waist circumference and ratio of waist to hip, atherogenic dyslipidaemia, which is reflected in the routine diagnosis of increased levels of triglycerides and reduced levels of HDL-cholesterol, high blood pressure, insulin resistance and/or various forms of glucose intolerance, proinflammatory and prothrombotic state. Epidemiological, experimental and clinical investigations have shown that diets supplemented with moderate quantities of alcoholic beverages lead to biochemical changes, that are widely regarded to prevent cardiovascular diseases. Red wine contains a naturally rich sources of antioxidants which may protect the body from oxidative stress. We investigated the relationship between red wine intake and lipide profile, glucose, blood pressure and WHR index changes. Participants consumed 200 ml of red wine Frankovka modra (VÍNO-MASARYK, s.r.o., Skalica) each day during supper for six weeks and were encouraged to maintain their usual diet and exercise habits. Daily intake of Frankovka modra during six weeks was associated with lower plasma levels of total cholesterol (5.66±1.12 vs 5.36±1.04), triglycerides (1.68±0.23 vs 1.47±0.66), LDL-cholesterol (3.46±0.81 vs 3.26±0.76) and glucose (5.35±0.82 vs 5.26±0.78). On the contrary we recorded higher level of „good“ HDL cholesterol (1.42±0.63 vs 1.80±0.58). Systolic and diastolic blood pressure was also decreased and diastolic blood pressure after six weeks of consumption of red wine decreased statistically significantly. Research results have shown that moderate consumption of red wine have a positive impact on changes waist and ultimately to the Waist to Hip Ratio. Our study demonstrates a positive association between moderate wine consumption and risk of cardiovascular disease and metabolic syndrome.
Federal Reserve Monetary Policy and US Hospitality Stock Returns
Authors: Chen Ming-Hsiang
Published: November 2010

This study examines the impact of the Federal Reserve (Fed) monetary policy on US hospitality stock returns. Specifically, this research paper investigates the stock performance of US hospitality firms under different Fed monetary policy regimes. Hospitality companies include gambling firms, lodging companies and restaurants. Changes in the discount rate and federal funds rate are used to measure shifts in the Fed monetary policy and to classify the full monetary policy period as either a restrictive or an expansive monetary policy environment. An expansive monetary condition is a period with a decrease in the discount or federal funds rate; a restrictive monetary environment experiences an increase in the discount or federal funds rate. Empirical test results reveal that the influence of the two monetary policy indicators on hospitality stock returns varies to a great extent. The stock returns of US restaurants are related significantly to changes in the federal funds rate. However, changes in the discount rate generally have no strong impact on US hospitality stock returns.
Exploring Relationships between Mongolian Destination Brand Equity, Satisfaction and Destination Loyalty
Authors: Chen Ching-Fu , Myagmarsuren Odonchimeg
Published: November 2010

There has been growing interest among researchers in the concept of the customer-based brand equity (CBBE) model that is widely applied in marketing research. Viewing a tourist destination as a brand, the CBBE model has been applied recently to tourism studies and incorporates the notions of perceptual brand equity and behavioural brand equity from the marketing literature. This study proposes the destination brand equity model by incorporating various antecedents, including perceived service quality, destination awareness and destination image as the perceptual brand equity, and destination loyalty as the behavioural brand equity. A relationship model between perceptual brand equity components, tourist satisfaction and destination loyalty is constructed and applied to Mongolia as a tourist destination. The study's results in general confirm the causal relationship between perceptual brand equity and behavioural brand equity. More specifically, a relationship path is identified: destination awareness → destination image → perceived quality → satisfaction → destination loyalty. The empirical implications are discussed, as is the value of the approach for destination marketers.
Live-Aboard Dive Boats in the Great Barrier Reef: Regional Economic Impact and the Relative Values of Their Target Marine Species
Authors: Stoeckl Natalie , Birtles Alastair , Farr Marina , Mangott Arnold , Curnock Matthew , Valentine Peter
Published: November 2010

Using data collected from more than 1,000 tourists on live-aboard dive boats operating in the Cairns/Cooktown management area of the Great Barrier Reef, this paper estimates the regional economic impact of that live-aboard industry. It also uses a subset of these data (247 respondents) to investigate some of the relative ‘values’ of key marine species seen on the trips that included the Coral Sea location of Osprey Reef and which targeted multiple species of wildlife. The authors find that (i) each year, the live-aboard dive boats are directly responsible for generating at least AU$16 million worth of income in the Cairns/Port Douglas region; (ii) visitors participating in different types of trips gain their highest levels of ‘satisfaction’ from interacting with different types of species; and (iii) visitors to Osprey Reef would be willing to pay more for a ‘guaranteed’ sighting of sharks than they would for a ‘guaranteed’ sighting of large fish, marine turtles or a ‘wide variety of species’.
Regional Development and National Parks in South Africa: Lessons Learned
Authors: Saayman M. , Saayman A.
Published: November 2010

National parks are playing an important role in the South African tourism landscape – especially in their respective regional economies – since most foreign and many domestic tourists visit one or more of the 21 national parks annually. For the purpose of this article, socio-economic impact analyses were conducted at four national parks using similar methodology. These parks differ considerably and the results confirm that a variety of variables play a role in contributing to the magnitude of the socio-economic impact. From these case studies, a number of interesting lessons have been learned, which have implications for managing national parks. In terms of regional development, it is also shown that different parks play different roles in their regional economies.
Internal and Locational Factors Affecting Hotel Industry Efficiency: Evidence from Italian Business Corporations
Authors: Bernini Cristina , Guizzardi Andrea
Published: November 2010

This paper investigates whether and how the competitive delay of the Italian hotel industry is influenced by the level of business corporation efficiency. A stochastic frontier production approach is proposed in which technical inefficiency is specified as a function of the internal and locational factors in a firm. The model is estimated on a balanced panel of tourism business corporations observed during 1998–2005. Estimates show that the competitive gap in the Italian accommodation system is not a result of poor business corporation performance, and the importance of location, human and immaterial capital is assessed as (in)efficiency determinants. The authors then suggest policies to improve the Italian tourist industry's competitiveness.
Research Note: International Travel: The Relationship between Exchange Rate, World GDP, Revenues and the Number of Travellers to Brazil
Authors: Meurer Roberto
Published: November 2010

This paper analyses the behaviour of foreign travellers to Brazil and the revenues thus generated in the balance of payments, using annual data from 1970 to 2007 and quarterly data from 1989 to 2007. The author concludes that the number of travellers is quite sensitive to world income and less sensitive to the exchange rate. Revenues do not react to the exchange rate. Exchange rate has an influence on revenues with a lag of four quarters. These results may mean that the expenditures of foreign travellers are not influenced by their costs measured in the currency of the country of origin.
Statistical Properties and Survey Design of Visitor Spending Using Segmentation
Authors: Sun Ya-Yen , Wong Kam-Fai , Lai Hsien-Chung
Published: November 2010

Estimating visitor spending through the segmentation approach has several advantages in terms of policy evaluation, user management and sampling design. This approach generally relies on visitor surveys to estimate two parameters, average spending per segment and segment share, so that total visitation can be apportioned to each subgroup. Equivalently, this approach is to estimate the weighted average spending by taking into consideration the relative shares of each user segment. This paper first provides a statistical formula to compute the variance of weighted average spending by taking into account the stochastic nature of spending and segment shares. Second, simulation analysis is adopted to compare the accuracy and precision of the spending estimator based on different study designs. The results show that conducting additional short surveys to obtain information on user segments provides two advantages. First, it helps to reduce non-response bias since certain visitor groups have higher ratios of unreturned questionnaires, incomplete data or non-participation. Second, it helps to decrease the variance of the estimator so that the upper and lower bound of the confidence interval can be narrowed. The level of variance reduction will depend on the relative segment shares, the average spending, cases that are obtained, spending variation and the probability of giving full spending information across segments. The implications for survey design are offered in light of the results.
The Contribution of Tourism to Micro and Small Enterprise Growth
Authors: Mshenga Patience M. , Richardson Robert B. , Njehia Bernard K. , Birachi Eliud A.
Published: November 2010

Tourism is an increasingly important economic sector in many developing countries. In Kenya, it represents the second greatest contribution to gross domestic product (GDP) after agriculture. Data from a survey of 449 micro and small enterprises (MSEs) in coastal Kenya were used in a modified Evans growth model to examine the contribution of tourism to the growth of farm and non-farm MSEs. The authors also examined the influence of entrepreneur and business characteristics on the growth of farm and non-farm MSEs along the Kenyan Coast. The age of the business, business income, marital status, number of employees and form of business organization were found to influence MSE growth significantly. Tourist spending and activities were also found to have a significant effect on MSE growth. The results have implications for the role of tourism in economic development, small business growth and poverty alleviation.
Research Note: Hail to the Chief: Assessing the Economic Impact of Presidential Inaugurations on the Washington, DC, Local Economy
Authors: Baumann Robert , Engelhardt Bryan , Matheson Victor A.
Published: November 2010

While presidential inaugurations routinely attract hundreds of thousands or more visitors to Washington, DC, for the quadrennial celebration, the authors' examination of employment from the Current Employment Statistics survey from 1939 to the present, and both employment and unemployment from the Current Population Survey from 1977 to the present, finds no noticeable effect from the event on either variable. The residents of DC should not expect an inauguration to make them any richer and the city should not count on any economic benefits generated by the event to cover the significant costs of hosting it.
Thoracopagus Conjoined Twins: A Case Report
Authors: Osmanağaoğlu Mehmet A. , Aran Turhan , Güven Süleyman , Kart Cavit , Özdemir Özgür , Bozkaya Hasan
Published: November 2010

Objective. Conjoined twin is a rarely seen congenital anomaly together with severe mortality and morbidity. The more common types of conjoined twins include the thoracopagus type, where the fusion is anterior, at the chest, and involves the heart. We are reporting one case of conjoined thoracopagus twins diagnosed by ultrasonography at 11 weeks. Case Report. In a multigravid pregnant woman who has been admitted to our clinic with a diagnosis of conjoined twins, thoracopagus, by ultrasonography at an 11-week gestation, termination of the pregnancy was performed. Conclusion. Making an early diagnosis with ultrasonographic examination gives the parents a chance to elect pregnancy termination.
Feasibility of Repurposing the Polyanionic Microbicide, PPCM, for Prophylaxis against HIV Transmission during ART
Authors: Anderson Robert A. , Brown David , Jackson Erin M. , Feathergill Kenneth A. , Bremer James W. , Morack Ralph , Rawlins Richard G.
Published: November 2010

HIV-serodiscordant couples wishing to conceive often seek assisted reproduction, during which spermatozoa from infected men are washed to minimize the risk of HIV transmission to partner and fetus. We sought to improve this method by adding a microbicide, PPCM, as an HIV prophylactic. HIV-1 (BaL) inhibition by PPCM appears irreversible and independent of added Ca2+. Without added Ca2+, PPCM (≤10 mg/mL, ≤90 min), a stimulus of Ca2+-dependent acrosomal loss, has no effect on sperm motility, forward progression, or acrosomal status. PPCM-treated (10 mg/mL) sperm retain their ability to acrosome react when Ca2+is added. Sperm DNA integrity/function is unaffected by PPCM (≤10 mg/mL). Adding PPCM (5 mg/mL, 30 min) to washing media reduces infectivity (viral antigen p24 and RNA) ofex-vivoHIV-infected semen by 3-4 Logs compared with washing alone. Sperm washing with appropriate extracellular Ca2+levels and PPCM is significantly more effective than washing alone at reducing HIV infectivity.
Hospitalizations for Chronic Obstructive Pulmonary Disease Exacerbation During COVID-19
Authors: Bourdin Arnaud , Ahmed Engi , Vachier Isabelle , Roche Nicolas , Pissarra Joana , Malafaye Nicolas , Molinari Nicolas
Published: May 2024

This cross-sectional study investigates changes in the number of chronic obstructive pulmonary disease (COPD)–related admissions before, during, and after the COVID-19 pandemic in France.
Acrylonitrile–Butadiene–Styrene (ABS) Polymers
Authors: Li Dejin , Wang Shi , Mahmoodi Mehdi
Published: May 2024

Acrylonitrile–butadiene–styrene (ABS) polymers are composed of elastomer dispersed as a grafted particulate phase in a thermoplastic matrix of styrene and acrylonitrile copolymer (SAN). The presence of SAN grafted onto the elastomeric component, usually polybutadiene or a butadiene copolymer, compatabilizes the rubber with the SAN component. Property advantages provided by this graft terpolymer include excellent toughness, good dimensional stability, good processibility, and chemical resistance. The system is structurally complex. This allows considerable versatility in the tailoring of properties to meet specific product requirements. Consequently, research and development in ABS systems is active. Numerous grades of ABS are available, including new alloys and specialty grades for high heat, flaming‐retardant, or static dissipative product requirements. Good chemical resistance combined with the relatively low water absorptivity (<1%) results in high resistance to staining agents. Antioxidants substantially improve oxidative stability. Applications involving extended outdoor exposure require the use of stabilizing additives, pigments, and protective coatings. In manufacturing, grafting is achieved by the free‐radical copolymerization of styrene and acrylonitrile monomers. The commercial processes for manufacturing ABS are discussed. ABS can be processed by compression and injection molding, extrusion, calendering, and blow molding. Postprocessing operations include cold forming, painting, and adhesive bonding. ABS is one of the two major plastic materials used in 3D printing, an emerging additive manufacturing technology that is developing rapidly in the last couple of decades. As a ‘bridge’ polymer between commodity plastics and higher performance engineering thermoplastics, ABS has become the largest selling engineering thermoplastic.
Hybrid optimized deep quantum neural network in Internet of Things platform using routing algorithm for detecting smart maize leaf disease
Authors: Gunisetti Loshma , Koduri Shirin Bhanu , Jagannathan Veeraraghavan , Chundru Raja Ramesh
Published: May 2024

The productivity in the agricultural sector is minimized due to the disease in plants. In general, the ailments that affect plants are identified by the farmers and the losses are minimized, when the diseases are identified early. The early identification of leaf diseases is difficult in the traditional approaches. Hence, in this article, for detecting maize leaf disease, an adaptive competitive shuffled shepherd optimization‐driven deep quantum neural network (adaptive CSSO‐based deep QNN) is implemented. Here, the initial process is the simulation of the IoT nodes and the leaf data are collected. This data are transferred to base station (BS) via the best routes. The optimal routes are identified using the adaptive CCSO algorithm. The adaptive concept, shuffled shepherd optimization algorithm (SSOA) and competitive swarm optimizer (CSO) are merged for forming the adaptive‐CSSO algorithm. The leaf detection is done in the BS and initially, the data is preprocessed using region of interest (ROI). Then, the relevant features are extracted. Finally, the disease in the maize leaf is detected using Deep QNN and the training is done by adaptive CSSO. The devised approach has maximum accuracy of 96.04%, sensitivity of 97.41%, specificity of 94.35%, energy of 0.01 J, and minimum delay of 0.9596 s.
Epoxy Fiber Derived All‐Polymer Films for High Performance Electrostatic Energy Storage Dielectrics
Authors: Xu Pengpeng , Ma Peilin , Yu Junyi , Jiang Kelun , Ke Shanming , Huang Haitao , Yu Shuhui , Zhou Yangbo , Luo Suibin
Published: May 2024

Dielectric films with high discharged energy density are highly desired in electrical and electronic systems. Adding inorganic nanoparticles, especially for 1D inorganic fillers, in polymer films is recognized as one of the most effective methods to improve the electric breakdown strength, which is a key parameter of energy storage. However, 1D inorganic fillers added into thin films will undoubtedly introduce many defects and reduce the electric insulation performance. Herein, homogeneous epoxy fiber derived all‐polymer films are fabricated by electrospinning, laminating, and curing in sequence. The existing 1D structure of the epoxy films significantly enhance the dielectric constant and electric breakdown strength, resulting in a very high enhancement of 2.7 times the discharged energy storage density at 25 °C, up to 9.6 J cm−3. Assisted by the simulation analysis, the enhanced dipole polarization and reduced current density are found to be the main reasons for the improved energy storage performances. Preparing all‐polymer films with fiber structure has proved to be an effective way to find advanced energy storage dielectric films.
MXene‐Cobalt Hybrid Electrodes for Electroactive Artificial Muscle
Authors: Ali Syed Sheraz , Mahato Manmatha , Lam Do Van , Sambyal Pradeep , Valurouthu Geetha , Garai Mousumi , Dewan Anweshi , Nguyen Van Hiep , Khan Mannan , Taseer Ashhad Kamal , Ahn Chi Won , Oh Il‐Kwon
Published: May 2024

The synthesis of MXene‐cobalt hybrid (MX‐Co) is presented utilizing a molten salt approach, targeting the application in artificial muscle technology. Mxenes possess exceptional electronic conductivity and surface chemistry, making them ideal candidates for electrochemical applications. Cobalt, known for its ferromagnetic qualities, is a good match for MXenes and enhances artificial muscles’ mechanical performance. By circumventing hazardous hydrofluoric (HF) acid, a facile and scalable synthesis process for MX‐Co hybrids is demonstrated. Their structural and electrochemical characteristics are revealed through characterization using cutting‐edge spectroscopic and microscopic techniques. When compared to typical PEDOT: PSS electrodes, electrochemical experiments show that MX‐Co electrodes have higher electroactive performance, with enhanced bending deformation under various input conditions. MX‐Co hybrids exhibit a specific capacitance of 77.34 F g−1, 1.6 times higher than PEDOT: PSS, and achieve a substantial enhancement of electrochemical bending displacement, up to 11.72 mm under a low input voltage of 1 V, showcasing their potential for soft actuator applications.
In Situ Reconstructed Ru Clusters on LaRuSi3 with Enhanced Electrocatalytic Activity for Alkaline Hydrogen Evolution
Authors: Zhang Huanhuan , Song Kai , Lin Zhiping , Wang Zongpeng , Zhang Lili , Shen Shijie , Gu Lin , Zhong Wenwu
Published: May 2024

The surface reconstruction of electrochemically activated catalysts is an effective way to improve performance. However, there is currently a dearth of study on the surface reconstruction of silicide catalysts for hydrogen evolution reactions (HER). Here, a new HER electrocatalyst, LaRuSi3, is synthesized and electrochemically triggered it to produce Ru clusters on its surface. Experimental data and theoretical simulations reveal that Ru clusters optimize the charge distribution of LaRuSi3, which promotes the adsorption of water by Ru sites and improves the adsorption of hydrogen by Si sites. The conductivity and electrochemical active sites of the catalysts are also enhanced. The catalyst has an overpotential of 45 mV to attain a current density of 10 mA cm−2 in alkaline media, which exceeds the majority of other Ru‐based compounds. This work contributes to the exploration of more efficient novel silicides HER electrocatalysts and broadens the application of surface reconstruction techniques.
Biomaterials‐Boosted Immunotherapy for Osteosarcoma
Authors: Sun Chao , Li Shuqiang , Ding Jianxun
Published: May 2024

Osteosarcoma (OS) is a primary malignant bone tumor that emanates from mesenchymal cells, commonly found in the epiphyseal end of long bones. The highly recurrent and metastatic nature of OS poses significant challenges to the efficacy of treatment and negatively affects patient prognosis. Currently, available clinical treatment strategies primarily focus on maximizing tumor resection and reducing localized symptoms rather than the complete eradication of malignant tumor cells to achieve ideal outcomes. The biomaterials‐boosted immunotherapy for OS is characterized by high effectiveness and a favorable safety profile. This therapeutic approach manipulates the tumor microenvironments at the cellular and molecular levels to impede tumor progression. This review delves into the mechanisms underlying the treatment of OS, emphasizing biomaterials‐enhanced tumor immunity. Moreover, it summarizes the immune cell phenotype and tumor microenvironment regulation, along with the ability of immune checkpoint blockade to activate the autoimmune system. Gaining a profound comprehension of biomaterials‐boosted OS immunotherapy is imperative to explore more efficacious immunotherapy protocols and treatment options in this setting.
Metal–Organic Framework‐Based Antimicrobial Touch Surfaces to Prevent Cross‐Contamination
Authors: Fonseca Javier , Cano‐Sarabia Mary , Cortés Pilar , Saldo Jordi , Montpeyó David , Lorenzo Julia , Llagostera Montserrat , Imaz Inhar , Maspoch Daniel
Published: May 2024

Infection diseases are a major threat to global public health, with nosocomial infections being of particular concern. In this context, antimicrobial coatings emerge as a promising prophylactic strategy to reduce the transmission of pathogens and control infections. Here, antimicrobial door handle covers to prevent cross‐contamination are prepared by incorporating iodine‐loaded UiO‐66 microparticles into a potentially biodegradable polyurethane polymer (Baycusan eco E 1000). These covers incorporate MOF particles that serve as both storage reservoirs and delivery systems for the biocidal iodine. Under realistic touching conditions, the door handle covers completely inhibit the transmission of Gram‐positive bacterial species (Staphylococcus aureus, and Enterococcus faecalis), Gram‐negative bacterial species (Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii), and fungi (Candida albicans). The covers remain effective even after undergoing multiple contamination cycles, after being cleaned, and when tinted to improve discretion and usability. Furthermore, as the release of iodine from the door handle covers follow hindered Fickian diffusion, their antimicrobial lifetime is calculated to be as long as approximately two years. Together, these results demonstrate the potential of these antimicrobial door handle covers to prevent cross‐contamination, and underline the efficacy of integrating MOFs into innovative technologies.
A Hot Exciton Luminogen Constructed by an o‐Carborane Scaffold
Authors: Yu Xiao , Xu Jingkai , Wang Mengmeng , Miao Xiaofei , Fan Quli , Tu Deshuang , Wang Zhaojin , Duan Chunbo , Lu Changsheng , Xu Hui , Yan Hong
Published: May 2024

Emitters with the combination of an electron donor (D) and an acceptor (A) have been widely studied and usually exhibited interesting photophysical properties. Hot exciton materials involving an ordinary D‐A structure typically undergo a hybridized local charge transfer (HLCT) process. However, the hot exciton molecules containing more D/A fragments are much less explored. In this study, a new hot exciton material based on an inorganic boron cluster is designed and synthesized, which possesses a V‐type D–A–A′–D′ molecular architecture. The emitter shows an impressive photoluminescence quantum yield (PLQY) of up to 90% and demonstrates multiple emissions, excitation‐wavelength‐, solvent‐, and temperature‐dependent emissions. These characteristics are attributed to the coexistence of HLCT and the through‐space charge transfer process (TSTC) triggered by an o‐carborane scaffold in the excited state. Besides, the interchangeable HLCT/TSCT/hRISC processes are demonstrated by temperature‐dependent spectra and femtosecond time‐resolved transient absorption spectra. These findings confirm a novel hot exciton mechanism, simultaneously induced by HLCT and TSCT. This is also the first example of a carborane‐based hot exciton molecule. The current study not only reports a new molecular architecture for a hot exciton material but also gives rise to a new insight into the hot exciton mechanism.
All‐Inorganic Cs2YbCl5·H2O Perovskite with Luminescence Response to Methanol for Anti‐Counterfeiting
Authors: Guo Xiu‐Xian , Chen Jing‐Hua , Luo Jian‐Bin , Wei Jun‐Hua , Zhang Zhi‐Zhong , He Zi‐Lin , Peng Qing‐Peng , Kuang Dai‐Bin
Published: May 2024

Stimuli‐responsive luminescent materials have attracted much research attention due to their wide application potential in various fields. Typically, the family of hydrated double perovskite A2MIIIX5·H2O shows unique emission color transformation between hydrated and dehydrated complexes, highlighting the application potential in advanced anti‐counterfeiting. Herein, two zero‐dimensional perovskites of Cs2YbCl5·H2O and Cs3YbCl6, are reported and broad‐band self‐trapped exciton recombination emission can be realized via external Sb3+ doping. Intriguingly, the Cs2YbCl5·H2O can be transformed to the dehydrated counterpart of Cs3YbCl6 through a facile methanol treatment at room temperature, leading to the emission color transformation from yellow to green. Notably, the green‐emissive Cs3YbCl6:Sb3+ delivers a high photoluminescence quantum yield of 67.3%. Leveraging the advantages of obvious methanol‐induced emission color transformation between Cs2YbCl5·H2O and Cs3YbCl6 at room temperature, Cs2YbCl5·H2O can be used in the field of high‐security‐level anti‐counterfeiting.
Valproate Mediated Proteasome Dysfunctions Induce Apoptosis
Authors: Kinger Sumit , Jagtap Yuvraj Anandrao , Dubey Ankur Rakesh , Kumar Prashant , Choudhary Akash , Karmakar Surojit , Lal Girdhari , Prajapti Vijay Kumar , Jha Hem Chandra , Gutti Ravi Kumar , Mishra Amit
Published: May 2024

Several studies suggest Valproate's (VPA) therapeutic use in treating seizures, epilepsy, and bipolar disorder. Valproate is a class I histone deacetylases (HDACs) inhibitor and an attractive chemotherapeutic agent for targeting cancer. Few reports suggest that Valproate can suppress cell growth and cell differentiation and is linked with anti‐tumor activity. However, Valproate‐associated anti‐tumoral function and intracellular signaling cascade‐mediated anti‐cellular proliferation activities still need to be better understood. This current study suggests that Valproate can elevate proteasomal dysfunctions, resulting in misfolded protein accumulation and abnormal mitochondrial functions that successively induce apoptosis. Present findings indicate that treatment of Valproate inhibits Proteasome activities and also aggravates accumulation of expanded polyglutamine proteins and other proteasomal substrates. Overall, the aggregation of aberrant proteins and mitochondrial dysfunctions are observed, such as cytochrome c release, and disturbed mitochondrial membrane potential. Treatment of Valproate induces apoptotic morphological changes and cell death. These observations suggest that Valproate can cause mitochondrial abnormalities associated with apoptosis. These findings can provide new possible insights and suggest molecular approaches for developing better and specific Proteasome inhibitors that can be better useful with other anti‐tumor drugs for treatment of cancer and other complex diseases.
Halogenated Hole Selective Contact Enhances Interfacial Weak Bonding of Perovskite Solar Cells
Authors: Wang Aili , Zhai Mengde , Du Kaihuai , Yang Jinman , Zhang Luozheng , Li Bairu , Luo Long , Dong Xu , Li Lvzhou , Li Guixiang , Li Meng , Abate Antonio , Cheng Ming , Ding Jianning
Published: May 2024

Weak bonding between the perovskite and charge transport layers can lead to interfacial defects, hindering charge transfer and limiting the efficiency and stability of perovskite solar cells (PSCs). To address this issue, two halogenated spiro[fluorene‐9,9′‐xanthene]‐based molecules (SFX‐DM‐F and SFX‐DM‐Cl) are designed as an interfacial layer between perovskite and hole transport materials (HTMs). Both first‐principles simulations and experimental results are used to demonstrate that these halogenated interfacial layers improve the contact stability between perovskite's Pb(II) and HTMs, increasing the efficiency of charge transfer. The similar structure of interlayer to HTM also enhances the interfacial hole transfer integral, favoring effective hole transport. The PSCs based on SFX‐DM‐Cl achieve power conversion efficiencies of 24.8% (0.0625 cm2) and 23.1% (1 cm2). Even after 2000 h at a relative humidity of 15–20%, the unencapsulated PSC retains 94% of its initial efficiency. This work proposes the halogenated homologous HTMs as interfacial molecular bridges to optimize weak chemical bonds and hole transfer, thereby enabling efficient and stable PSCs.
Highly Oriented FAPbI3 via 2D Ruddlesden Popper Perovskite Template Growth
Authors: Wang Yaxin , Shi Zejiao , Wang Yanyan , Zhang Juan , Zhang Xin , Li Xiaoguo , Wang Haoliang , Li Chongyuan , Wang Jiao , Zhang Hao , Yang Yingguo , Zhang Jia , Yu Anran , Zhan Yiqiang
Published: May 2024

2D perovskites are demonstrated as the growth template for the modulation of phase transition and crystallization of formamidinium lead triiodide (FAPbI3). However, it is challenging to obtain highly oriented α‐FAPbI3 and regulate crystallization at the bottom of the FAPbI3 film. Here, a 2D (BA)2PbI4 layer with preferred orientation is introduced to perform as the bottom template for the quasi‐epitaxial growth of FAPbI3, which triggers the α‐FAPbI3 perovskite formation. Owing to the assembly of [PbI6]4− octahedral on the 2D template, the highly (100) oriented FAPbI3 perovskites from the bottom to the top are attained. At the optimum concentration, 2D perovskites gradually vanish due to the extrusion of BA+ cation from the template, which guarantees the charge transport at the bottom. Consequently, the strategy effectively promotes film quality and suppresses non‐radiative recombination. The efficiency of perovskite solar cells (PSCs) is promoted from 23.06% to 24.78%.
A cross‐sectional study of α‐synuclein seed amplification assay in Alzheimer's disease neuroimaging initiative: Prevalence and associations with Alzheimer's disease biomarkers and cognitive function
Authors: Tosun Duygu , Hausle Zachary , Iwaki Hirotaka , Thropp Pamela , Lamoureux Jennifer , Lee Edward B. , MacLeod Karen , McEvoy Sean , Nalls Michael , Perrin Richard J. , Saykin Andrew J. , Shaw Leslie M. , Singleton Andrew B. , Lebovitz Russ , Weiner Michael W. , Blauwendraat Cornelis ,   for the Alzheimer's Disease Neuroimaging Initiative
Published: May 2024

INTRODUCTION

Alzheimer's disease (AD) pathology is defined by β‐amyloid (Aβ) plaques and neurofibrillary tau, but Lewy bodies (LBs; 𝛼‐synuclein aggregates) are a common co‐pathology for which effective biomarkers are needed.

METHODS

A validated α‐synuclein Seed Amplification Assay (SAA) was used on recent cerebrospinal fluid (CSF) samples from 1638 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants, 78 with LB‐pathology confirmation at autopsy. We compared SAA outcomes with neuropathology, Aβ and tau biomarkers, risk‐factors, genetics, and cognitive trajectories.

RESULTS

SAA showed 79% sensitivity and 97% specificity for LB pathology, with superior performance in identifying neocortical (100%) compared to limbic (57%) and amygdala‐predominant (60%) LB‐pathology. SAA+ rate was 22%, increasing with disease stage and age. Higher Aβ burden but lower CSF p‐tau181 associated with higher SAA+ rates, especially in dementia. SAA+ affected cognitive impairment in MCI and Early‐AD who were already AD biomarker positive.

DISCUSSION

SAA is a sensitive, specific marker for LB‐pathology. Its increase in prevalence with age and AD stages, and its association with AD biomarkers, highlights the clinical importance of α‐synuclein co‐pathology in understanding AD's nature and progression.

Highlights

SAA shows 79% sensitivity, 97% specificity for LB‐pathology detection in AD.

SAA positivity prevalence increases with disease stage and age.

Higher Aβ burden, lower CSF p‐tau181 linked with higher SAA+ rates in dementia.

SAA+ impacts cognitive impairment in early disease stages.

Study underpins need for wider LB‐pathology screening in AD treatment.
A Systematic Study of Methyl Carbodithioate Esters as Effective Gold Contact Groups for Single‐Molecule Electronics
Authors: Ward Jonathan S. , Vezzoli Andrea , Wells Charlie , Bailey Steven , Jarvis Samuel P. , Lambert Colin J. , Robertson Craig , Nichols Richard J. , Higgins Simon J.
Published: May 2024

There are several binding groups used within molecular electronics for anchoring molecules to metal electrodes (e.g., R−SMe, R−NH2, R−CS2−, R−S−). However, some anchoring groups that bind strongly to electrodes have poor/unknown stability, some have weak electrode coupling, while for some their binding motifs are not well defined. Further binding groups are required to aid molecular design and to achieve a suitable balance in performance across a range of properties. We present an in‐depth investigation into the use of carbodithioate esters as contact groups for single‐molecule conductance measurements, using scanning tunnelling microscopy break junction measurements (STM‐BJ) and detailed surface spectroscopic analysis. We demonstrate that the methyl carbodithioate ester acts as an effective contact for gold electrodes in STM‐BJ measurements. Surface enhanced Raman measurements demonstrate that the C=S functionality remains intact when adsorbed on to gold nanoparticles. A gold(I) complex was also synthesised showing a stable C=S→AuI interaction from the ester. Comparison with a benzyl thiomethyl ether demonstrates that the C=S moiety significantly contributes to charge transport in single‐molecule junctions. The overall performance of the CS2Me group demonstrates it should be used more extensively and has strong potential for the fabrication of larger area devices with long‐term stability.