Individual Bi Research Articles

Cathepsin C (dipeptidyl peptidase 1) inhibition in adults with bronchiectasis: AIRLEAF®, a Phase II randomised, double-blind, placebo-controlled, dose-finding study.

Bronchiectasis is characterised by uncontrolled neutrophil serine protease (NSP) activity. Cathepsin C (CatC; dipeptidyl peptidase 1) activates NSPs during neutrophil maturation. CatC inhibitors can potentially reduce neutrophil-mediated lung damage. This Phase II, randomised, double-blind, placebo-controlled trial (AIRLEAF®; NCT05238675) evaluated efficacy, safety and optimal dosing of BI 1291583, a novel, reversible CatC inhibitor, in adults with bronchiectasis.In total, 322 participants were randomised (2:1:1:2) to receive one of three oral doses of BI 1291583 (1 mg/2.5 mg/5 mg) or placebo for 24 to 48 weeks. A multiple comparison procedure and modelling approach was used to demonstrate a non-flat dose-response curve based on the time to first pulmonary exacerbation up to Week 48. In addition, efficacy of individual BI 1291583 doses was evaluated based on the frequency of exacerbations, severe exacerbations (fatal or leading to hospitalisation and/or intravenous antibiotic administration), lung function and quality of life.A significant dose-dependent benefit of BI 1291583 over placebo was established based on time to first exacerbation (shape: Emax; adjusted p-value: 0.0448). Treatment with BI 1291583 5 mg and 2.5 mg numerically reduced the risk of an exacerbation compared with placebo (hazard ratios: 0.71 and 0.66, 95% CIs 0.48-1.05 and 0.40-1.08; both p>0.05). BI 1291583 2.5 mg showed numerically better efficacy compared with 5 mg across several endpoints; 1 mg was similar to placebo. The safety profile of BI 1291583 was similar to placebo.Treatment with BI 1291583 resulted in a reduction in the risk of experiencing an exacerbation in adults with bronchiectasis.

The C-BixSnSb composite toward fast-charging and long-life sodium-ion batteries

Sodium ion batteries (SIBs) fitted with high-rate and high-capacity anodes are attractive for their higher energy density and faster charging capability. However, it is still a challenge to develop high-energy SIBs with high power and long life, due to the sluggish kinetic and limited Na+ insertion in electrode materials. The inherent crystal structure and constituent element are two important factors to resolve the critical issues faced above. Taking the merits of layer-structure and middle-entropy, herein, we proposed and designed a high ion-conductive composite combing with ternary alloy and layered BixSnSb@C nanofibers, which eliminate ion migration barriers while maintaining the structural framework for superior rate property and cycle stability. Used as anode for SIBs, the multiphase BixSnSb@C with adjustable Bi content exhibits excellent Na storage capability as compared to their single phase counterpart. Specially, up to a rate of 132C (50 A g−1), the capacity is still as high as 400 mAh g−1, meanwhile, after 5000 charge and discharge cycles at a current density of 12C, the capacity still maintains 85 % of its initial capacity, which outperform the individual Bi- or SnSb-based materials. The superior electrochemical performances originate from the middle-entropy nature and layer structure of BiSnSb alloy, which can provide more channels for fast Na+ transport, and accommodate large volume changes. Besides, the activity energy and ions transport resistance of Na+ in different composites were evaluated. Furthermore, the full-cell coupled with NaNi1/3Fe1/3Mn1/3O2 as cathode was formed and a capacity retention of ∼80 % is realized in 100 cycles. The results show that the BixSnSb@C is a potential anode for fast-charging Na-ion batteries and could be used to guide the design of multi-component alloy-base anodes.

THE BIOGRAPHICAL APPROACH IN THE STUDY OF VASYL LOBURETS’ PEDAGOGICAL PERSONALITY (1930–2006)

The article substantiates the expediency of using the biographical approach to study the pedagogical personality of the out- standing historian, local historian, teacher, leader of education and science Vasyl Loburets (1930-2006). Based on the analysis of the works of foreign (Erik Erikson, C. Wright Mills, Carlo Ginzburg, Ronald A. Giere, William H. McNeill, Antonina Kloskowska) and Ukrainian (H. Belan, N. Dichek, M. Leshchenko, N. Lisovska-Muskieieva, M. Sydorov, O. Sukhomlynska) researchers, the article reveals the peculiarities of using the biographical approach, the sources and methods of studying the creative biography of the scientist.It is proved that at the end of the twentieth century, the biographical approach became widespread not only in psychology and sociology, but also in the literary, historical, historical and pedagogical fields. As a result of these transformations, a sepa- rate scientific field emerged – biography – the object of study of which was a prominent personality in the context of his or her various connections with society. The article substantiates the idea that biography as a separate scientific field has acquired an interdisciplinary status and is based on the methodology of the humanities (sociology, philosophy, psychology, history, literary studies, history of pedagogy, etc.).The use of a biographical approach allows for a greater contextual understanding of the issue. By studying individual bi- ographies, historians of education can gain a deeper understanding of the social, political and cultural contexts of a particular historical era. The formation of scholarly ideas and personal experiences is largely influenced by significant historical forces, so the study of biographies can help to reveal the cultural and social connections between educational definitions.The use of the biographical approach creates a holistic view of science that combines the intellectual, professional and personal aspects of scientific achievements, and provides a fundamental and critical analysis of the educational sphere. The biographical approach is a universal tool for studying Vasyl Loburets’ pedagogical personality. On the basis of biographical research, socio-pedagogical reality is studied in chronological and cultural aspects.

Porously Reduced 2‐Dimensional Bi2O2CO3 Petals for Strain‐Mediated Electrochemical CO2 Reduction to HCOOH

Here we introduce bismuth‐based catalysts for the efficient electrochemical reduction of CO2 to formic acid (HCOOH), which are composed of petal‐shaped Bi2O2CO3 (BOC) that spontaneously formed from Bi thin film in aqueous carbonate solution at room temperature. During the electrochemical reduction process, the BOC petals transform to reduced BOC (R‐BOC) consisting of individual BOC and Bi domains. Lattice mismatch between both domains induces biaxial strain at the interfaces. Density functional theory calculations suggest that the tensile strain on the Bi domain stabilizes the *OCHO intermediate, reducing the thermodynamic barrier toward CO2 conversion to HCOOH. Together with the thermodynamic benefit and the unique nanoporous petal‐shaped morphology, R‐BOC petals have a superior Faradaic efficiency of 95.9% at −0.8 VRHE for the electrochemical conversion of CO2 to HCOOH. This work demonstrates that the spontaneously formed binary phases with desirable lattice strain can increase the activity of bismuth catalysts to the CO2 reduction reaction; such a strategy can be applicable in design of various electrocatalysts.

Bi2Te3 Thin Films Deposited by the Combination of Bi and Te Plasmas in a PLD Process

Bismuth telluride thin films were grown by pulsed laser deposition by implementing a novel method that combines both Te and Bi plasmas resulting from the laser ablation of individual Bi and Te targets. Furthermore, the mean kinetic ion energy and density of the plasmas, as estimated by TOF curves obtained from Langmuir probe measurements, were used as control parameters for the deposition process. The obtained thin films exhibit a metallic mirror-like appearance and present good adhesion to the substrate. Morphology of the thin films was observed by SEM, yielding smooth surfaces where particulates were also observed (splashing). Chemical composition analysis obtained by EDS showed that apparently the films have a Te-rich composition (ratio of Te/Bi of 3); however, Te excess arises from the splashing as revealed by the structural characterization (XRD and Raman spectroscopy). The XRD pattern indicated that depositions have the rhombohedral (D3d5 (R3¯m)) structure of Bi2Te3. Likewise, Raman spectra exhibited the presence of signals that correspond to Eg2, A1u2 and A1g2(LO) vibrational modes of the same rhombohedral phase of Bi2Te3. Additionally, oxidation states, analyzed by XPS, resulted in signals associated to Bi3+ and Te2- that correspond to the Bi2Te3 compound. Finally, surface topology and thickness profiles were obtained from AFM measurements, confirming a combination of a smooth surface with particulates on top of it and a film thickness of 400 nm.

Recent Development Strategies for Bismuth-Driven Materials in Sustainable Energy Systems and Environmental Restoration.

Bismuth(Bi)-based materials have gained considerable attention in recent decades for use in a diverse range of sustainable energy and environmental applications due to their low toxicity and eco-friendliness. Bi materials are widely employed in electrochemical energy storage and conversion devices, exhibiting excellent catalytic and non-catalytic performance, as well as CO2 /N2 reduction and water treatment systems. A variety of Bi materials, including its oxides, chalcogenides, oxyhalides, bismuthates, and other composites, have been developed for understanding their physicochemical properties. In this review, a comprehensive overview of the properties of individual Bi material systems and their use in a range of applications is provided. This review highlights the implementation of novel strategies to modify Bi materials based on morphological and facet control, doping/defect inclusion, and composite/heterojunction formation. The factors affecting the development of different classes of Bi materials and how their control differs between individual Bi compounds are also described. In particular, the development process for these material systems, their mass production, and related challenges are considered. Thus, the key components in Bi compounds are compared in terms of their properties, design, and applications. Finally, the future potential and challenges associated with Bi complexes are presented as a pathway for new innovations.

Orbital contributions in the element-resolved valence electronic structure of Bi2Se3

In this work, we studied the bulk band structure of a topological insulator (TI) Bi2Se3 and determined the contributions of the Bi and Se orbital states to the valence bands using standing wave-excited hard x-ray photoemission spectroscopy (SW-HAXPES). This SW technique can provide the element-resolved information and extract individual Bi and Se contributions to the Bi2Se3 valence band. Comparisons with density functional theory (DFT) calculations (LDA and GW) reveal that the Bi 6s, Bi 6p, and Se 4p states are dominant in the Bi2Se3 HAXPES valence band. These findings pave a way for studying the element-resolved band structure and orbital contributions of this class of TIs.

Bi-accentism, translanguaging, or just a costume? Margaret Thatcher’s pronunciation and its portrayal in films as a case of sociolinguistic boundaries and ideologies

This paper discusses the extent to which some well-known traditional notions of English language studies, above all Received Pronunciation (RP), can be considered valid in light of present-day sociolinguistics. Language and superdiversity, translanguaging and related concepts are recent approaches to the variations that can be found in speech communities. Arguably, most speakers are not static but dynamic in that their linguistic repertoires consist of many styles and registers, as well as dialects, accents and/or separate languages. Terms such as monolingual speakers, homogeneous speech communities, separate named languages and dialects, even the names of accents, can only be considered as convenient approximations. Some of the most rigidly defined concepts seem to be those related to codified or standard dialects and accents. In this article, the example analyzed to illustrate the point is a comparison of the way in which the British Prime Minister, Margaret Thatcher, pronounced English in a Thames TV interview of 1987 and how her pronunciation was represented by two American actors: Meryl Streep in The Iron Lady (2011) and Gillian Anderson in Season 4 of The Crown (2020). The material aims to demonstrate the transcending of borders: those of RP and of individual bi- or multiaccentism.

Bi/BiPO4 nanocubes supported BiOI-BiOCl nanoplate as a heterostructured blue-light-driven photocatalyst for degradation of Auramine O

Bi surface plasmon resonance (SPR)-promoted BiPO4/BiOI-BiOCl (Bi/BPCI) ternary heterostructure as plasmonic blue-light-driven photocatalyst was prepared by one-pot UV-photoreduction process assisted hydrothermal method with to require any additives. As-prepared photocatalyst was characterized by PL, DRS, FESEM, XRD, EDS and EIS methods and its hierarchical heterostructured exhibits excellent photocatalytic activity toward Auramine O (AO) as typical cationic organic dyes under blue light irradiation. The band structures of the Bi/BiPO4, BiOI and BiOCl are determined combined with the flat potential (Vfb) and bandgap energy (Eg) evaluated by UV–Vis diffuse reflectance spectra. The founding illustrate that the as-synthesized composite of the three Bi-based semiconductors facilitates the photosensitized degradation of AO under blue light as well as we described the optical absorption originated from the SPR influence and direct band gap transition in an individual Bi and transportation of photogenerated carriers at the interface of Bi/BPCI. The photocatalytic mechanism is further proposed by identifying the photogenerated reactive species and intermediates by scavenger test. The OH radical generation confirmed that the OH and h+ were the key species in the present system, which lead to the elimination and part mineralization of the AO.

Cross-Linking Effects Dictate the Preference of Galectins to Bind LacNAc-Decorated HPMA Copolymers.

The interaction of multi-LacNAc (Galβ1-4GlcNAc)-containing N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers with human galectin-1 (Gal-1) and the carbohydrate recognition domain (CRD) of human galectin-3 (Gal-3) was analyzed using NMR methods in addition to cryo-electron-microscopy and dynamic light scattering (DLS) experiments. The interaction with individual LacNAc-containing components of the polymer was studied for comparison purposes. For Gal-3 CRD, the NMR data suggest a canonical interaction of the individual small-molecule bi- and trivalent ligands with the lectin binding site and better affinity for the trivalent arrangement due to statistical effects. For the glycopolymers, the interaction was stronger, although no evidence for forming a large supramolecule was obtained. In contrast, for Gal-1, the results indicate the formation of large cross-linked supramolecules in the presence of multivalent LacNAc entities for both the individual building blocks and the polymers. Interestingly, the bivalent and trivalent presentation of LacNAc in the polymer did not produce such an increase, indicating that the multivalency provided by the polymer is sufficient for triggering an efficient binding between the glycopolymer and Gal-1. This hypothesis was further demonstrated by electron microscopy and DLS methods.

Electrolytic separation of Dy from Sm in molten LiCl-KCl using Pb-Bi eutectic alloy cathode

To study the application prospect of binary Pb-Bi eutectic (LBE) alloy electrode in pyroprocessing, the reduction mechanisms of Sm(III) and Dy(III) on W, liquid Bi, liquid Pb, and LBE alloy electrodes were explored. The reduction of Dy(III) and Sm(III) on LBE alloy electrode were found to proceed in one-step and two-step reactions, respectively. The reduction peaks of Dy(III)/Dy(0) and Sm(II)/Sm(0) on LBE alloy electrodes were −1.31 V and −1.56 V (vs. Ag/AgCl), respectively, which were located between the individual liquid Pb and liquid Bi electrodes. Then, the reduction process of Ln (Sm and Dy) in LiCl-KCl-BiCl3-PbCl2 melt on the W electrode were also investigated to get more information on intermetallic compounds. The electrochemical separation of Dy from Sm was performed on the LBE alloy electrode by pulse potential electrolysis (PPE). X-ray diffraction analysis indicated the predominant separation products to be Pb3Dy and BiDy. The concentrations of Sm(III) and Dy(III) were monitored by differential pulse voltammetry and analyzed by ICP-MS. The average relative measurement errors obtained were 6.2% and 7.7% for SmCl3 and DyCl3, respectively. The highest extraction efficiency of Dy could reach 98.9%, and the separation factors (SFDy/Sm) of Dy and Sm are reached up to 786.

Improved corrosion response of squeeze-cast AZ91 magnesium alloy with calcium and bismuth additions

The corrosion responses of the individual and combined Ca and Bi incorporated AZ91 alloy are investigated through the immersion, hydrogen evolution, and electrochemical tests. All the modified alloys exhibit better corrosion resistance than the base AZ91 alloy. The AZ91 + 1.0Ca (wt%) alloy unveils better corrosion resistance than the AZ91 + 0.5Bi (wt%) alloy owing to the Al2Ca phase formation. The combined Ca and Bi added AZ91 alloys acquire better corrosion resistance than the individual Ca or Bi added AZ91 alloys. The AZ91 + 2.0Ca + 0.5Bi (wt%) and AZ91 + 1.0Ca + 1.0Bi (wt%) alloys exhibit the lowest and the highest corrosion rates among the combined additions.

Cu nanowire bridged Bi nanosheet arrays for efficient electrochemical CO2 reduction toward formate

Abstract Electrocatalytic reduction of CO2 can not only reduce its concentration in atmosphere but also produces useful fuels and value-added chemicals like CO, CH4, and HCOOH, which has been considered as a promising means to resolve both environmental and energy problems. Recent studies showed that bismuth (Bi) in aqueous solution can electrocatalytically reduce CO2 to formic acid. However, individual Bi when used as electrocatalyst still suffers from low efficiency of electrocatalytic CO2 reduction reaction (CO2RR) to formate. Considering that copper (Cu) has good conductivity and feature of empty half 4s level that can behave as an electron donor or acceptor, here we synthesized Cu nanowires (NWs) bridged Bi nanosheets (Cu NWs-Bi NSs) arrays grown on carbon cloth through facile electrochemical routes. The as-obtained electrocatalysts showed larger partial current density and better selectivity for CO2RR to fomate than pristine Bi NSs. The enhanced electrocatalytic activity and improved selectivity could be attributed to improved charge transfer and electronic effect incurred by Cu NWs. The present work provides a new strategy for designing nanostructured electrocatalysts for highly efficient CO2RR.

High efficiency and selectivity from synergy: Bi nanoparticles embedded in nitrogen doped porous carbon for electrochemical reduction of CO2 to formate

Electrochemical reduction of CO2 (ECR) into formate is an efficient and environmentally friendly approach contributing to carbon-neutral cycle. However, conventional catalysts for ECR usually suffer from low product selectivity, inferior activity and poor durability. Herein, we highlight Bi nanoparticles embedded in nitrogen doped porous carbon (Bi@NPC) as a promising integrated catalyst for ECR. This catalyst demonstrates a remarkable formate faradaic efficiency of 92.0%, and more encouragingly, a high formate current density of 14.4 mA cm−2 at a low potential of −1.5 V (vs SCE) in 0.1 M KHCO3 solution, which is significantly superior to the individual Bi nanoparticles (Bi-NP). Besides, the Bi@NPC catalyst exhibits a robust durability for 20 h operation. The advanced electrocatalytic performance of the Bi@NPC catalyst is likely attributed to the ensemble effect of Bi nanoparticles and NPC matrix. This attractive route discloses a broad prospect for the development of a promising integrated catalyst for ECR.

Control of SEI Formation for Stable Potassium-Ion Battery Anodes by Bi-MOF-Derived Nanocomposites.

Bismuth (Bi)-based electrodes are highly attractive for potassium-ion batteries (PIBs) while suffering from a short cycle life due to the larger diameter of K ion, leading to unstable solid electrolyte interface (SEI) films during continuous potassiation/depotassiation. Herein, we developed novel ultrathin carbon film@carbon nanorods@Bi nanoparticle (UCF@CNs@BiN) materials for the long cycle life anode of PIBs. Bi nanoparticles are uniformly distributed in carbon nanorods, which not only provides a high-speed channel for ion transport but also accommodates the volume change of Bi nanoparticles during continuous potassiation/depotassiation processes. The UCF@CN matrix can direct most SEI film formation on the surface of the carbon film, not on the surface of individual Bi nanoparticles, avoiding the fracture of the matrix. Benefiting from their unique structure, the UCF@CNs@BiN anodes exhibit an outstanding capacity of ∼425 mAh g-1 at 100 mA g-1 and a capacity decay of 0.038% per cycle over 600 cycles. Even at a higher current density of 1000 mA g-1, there is a capacity decay as low as 0.036% per cycle during 700 cycles. Meanwhile, this work provides a new way of utilizing the metal-organic framework structure and reveals a highly promising PIB anode.

In Situ Attachment of Acrylamido Sulfonic Acid-Based Monomer in Terpolymer Hydrogel Optimized by Response Surface Methodology for Individual and/or Simultaneous Removal(s) of M(III) and Cationic Dyes.

Herein, grafting of starch (STR) and in situ strategic inclusion of 2-(3-(acrylamido)propylamido)-2-methylpropane sulfonic acid (APMPS) via solution polymerization of 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS) and acrylamide (AM) have resulted in the synthesis of smart STR-grafted-AMPS-co-APMPS-co-AM (i.e., STR-g-TerPol) interpenetrating terpolymer (TerPol) network hydrogels. For fabricating the optimum hydrogel showing excellent physicochemical properties and recyclability, amounts of ingredients and temperature of synthesis have been optimized using multistage response surface methodology. STR-g-TerPol bearing the maximum swelling ability, along with the retention of network integrity, has been employed for individual and/or simultaneous removal(s) of metal ions (i.e., M(III)), such as Bi(III) and Sb(III), and dyes, such as tris(4-(dimethylamino)phenyl)methylium chloride (i.e., crystal violet) and (7-amino-8-phenoxazin-3-ylidene)-diethylazanium dichlorozinc dichloride (i.e., brilliant cresyl blue). The in situ strategic protrusion of APMPS, grafting of STR into the TerPol matrix, variation of crystallinity, thermal stabilities, surface properties, mechanical properties, swellability, adsorption capacities (ACs), and ligand-selective superadsorption have been inferred via analyses of unadsorbed and/or adsorbed STR-g-TerPol using Fourier transform infrared (FTIR), 1H/13C NMR, UV–vis, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray, dynamic light scattering, and rheological analyses and measuring the lower critical solution temperature, % gel content, pH at point of zero charge (pHPZC), and network parameters, such as ρc and Mc. The prevalence of covalent, ionic (I), and variegated interactions between STR-g-TerPol and M(III) has been understood through FTIR analyses, fitting of kinetics data to the pseudosecond-order model, and by the measurement of activation energies of adsorption. The formation of H-aggregate type dimers and hypochromic and hypsochromic shifts has been explained via UV–vis analyses during individual and/or simultaneous removal(s) of cationic dyes. Several isotherm models were fitted to the equilibrium experimental data, of which Langmuir and combined Langmuir–Freundlich models have been best fitted for individual Bi(III)/Sb(III) and simultaneous Sb(III) + Bi(III) removals, respectively. Thermodynamically spontaneous chemisorption processes have shown the maximum ACs of 1047.39/282.39 and 932.08/137.85 mg g–1 for Bi(III) and Sb(III), respectively, at 303 K, adsorbent dose = 0.01 g, and initial concentration of M(III) = 1000/30 ppm. The maximum ACs have been changed to 173.09 and 136.02 mg g–1 for Bi(III) and Sb(III), respectively, for binary Sb(III) + Bi(III) removals at 303 K, adsorbent dose = 0.01 g, and initial concentration of Bi(III)/Sb(III) at 30/5 and 5/30 ppm.

Improvement in the mechanical properties of eutectic Sn58Bi alloy by 0.5 and 1 wt% Zn addition before and after thermal aging

A comparative analysis of the microstructure and the mechanical properties of the eutectic Sn58Bi, 0.5 wt% and 1 wt% zinc (Zn)-functionalized Sn58Bi alloys was conducted before and after solid-state thermal aging. Cross-sectional microstructure observation and tensile tests were performed on bulk solder alloys. The fracture surfaces were observed after the tensile tests. In addition, the mechanical properties of individual Sn and Bi phases were obtained using nanoindentation tests. The results indicated that finer microstructures were obtained in the Zn-added samples compared to the eutectic Sn58Bi before and after aging since the Sn–Bi phase boundary segregation of Zn occurred during aging, and the movement of the diffusion entities (Sn and Bi atoms) through the boundaries was obstructed. The fine microstructure was responsible for the ultimate tensile strength improvement obtained in the Zn-added samples. Meanwhile, a significant hardness decrease of the Sn phase in the Sn58Bi1Zn alloy was believed to be a possible reason for the superior elongation of the Zn-added samples.

Re-assess Vector Indices Threshold as an Early Warning Tool for Predicting Dengue Epidemic in a Dengue Non-endemic Country.

BackgroundDespite dengue dynamics being driven by complex interactions between human hosts, mosquito vectors and viruses that are influenced by climate factors, an operational model that will enable health authorities to anticipate the outbreak risk in a dengue non-endemic area has not been developed. The objectives of this study were to evaluate the temporal relationship between meteorological variables, entomological surveillance indices and confirmed dengue cases; and to establish the threshold for entomological surveillance indices including three mosquito larval indices [Breteau (BI), Container (CI) and House indices (HI)] and one adult index (AI) as an early warning tool for dengue epidemic.Methodology/Principal FindingsEpidemiological, entomological and meteorological data were analyzed from 2005 to 2012 in Kaohsiung City, Taiwan. The successive waves of dengue outbreaks with different magnitudes were recorded in Kaohsiung City, and involved a dominant serotype during each epidemic. The annual indigenous dengue cases usually started from May to June and reached a peak in October to November. Vector data from 2005–2012 showed that the peak of the adult mosquito population was followed by a peak in the corresponding dengue activity with a lag period of 1–2 months. Therefore, we focused the analysis on the data from May to December and the high risk district, where the inspection of the immature and mature mosquitoes was carried out on a weekly basis and about 97.9% dengue cases occurred. The two-stage model was utilized here to estimate the risk and time-lag effect of annual dengue outbreaks in Taiwan. First, Poisson regression was used to select the optimal subset of variables and time-lags for predicting the number of dengue cases, and the final results of the multivariate analysis were selected based on the smallest AIC value. Next, each vector index models with selected variables were subjected to multiple logistic regression models to examine the accuracy of predicting the occurrence of dengue cases. The results suggested that Model-AI, BI, CI and HI predicted the occurrence of dengue cases with 83.8, 87.8, 88.3 and 88.4% accuracy, respectively. The predicting threshold based on individual Model-AI, BI, CI and HI was 0.97, 1.16, 1.79 and 0.997, respectively.Conclusion/SignificanceThere was little evidence of quantifiable association among vector indices, meteorological factors and dengue transmission that could reliably be used for outbreak prediction. Our study here provided the proof-of-concept of how to search for the optimal model and determine the threshold for dengue epidemics. Since those factors used for prediction varied, depending on the ecology and herd immunity level under different geological areas, different thresholds may be developed for different countries using a similar structure of the two-stage model.

Ammoxidation of propane to acrylonitrile over silica-supported Fe-Bi nanocatalysts

Ammoxidation of propane to acrylonitrile was examined over a Fe3BiOx/SiO2 sample prepared by thermal decarbonylation of [Et4N][Fe3(CO)10(μ3-Bi)] on the surface of mesoporous silica. Catalytic measurements performed at 500°C showed that this sample yields 49% acrylonitrile selectivity at 36% propane conversion when a 5.5%C3H8/30%O2/11%NH3/He balance reaction mixture was used at a GHSV of 1360h−1. HRSTEM, EDS, and XPS measurements indicate that mixed Fe3BiO6 oxide particles less than 2nm in size were formed on the surface of this material under reaction conditions. A Fe/Bi atomic ratio in these particles is approximately 3:1 and the Fe and Bi ions both are in the +3 oxidation state. A Fe-Bi/SiO2 sample prepared by co-impregnation of individual Fe and Bi salts had very low activity and low selectivity for acrylonitrile formation from propane under similar experimental conditions due to larger sizes of particles formed under reaction conditions and enrichment of their surface with Fe.

Controllable phase evolution of bismuth ferrite oxides by an organic additive modified hydrothermal method

Bismuth ferrite crystallites were synthesized by an organic additive modified hydrothermal method using Fe(NO3)3·9H2O and Bi(NO3)3·5H2O as starting materials with NaOH as the mineralizer. The phase evolution of bismuth ferrites in the process of hydrothermal reactions was controlled by adjusting the process parameters, such as NaOH concentration, reaction temperature and duration time. X-ray diffraction (XRD) analysis indicated that the pure phase of Bi25FeO40, BiFeO3 and Bi2Fe4O9 were synthesized at the temperature of 200°C for 24h with NaOH concentration of 2, 5 and 10M, respectively, with the addition of polyvinyl alcohol (PVA). It was found that the addition of PVA postponed the evolution progress between different phases of bismuth ferrites and widened the individual Bi–Fe oxides existence range of processing parameters. Moreover, the mechanism of forming different bismuth ferrites in the hydrothermal process was investigated and discussed.