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Due to the vital importance of early diagnosis and intervention of congenital hearing loss, the aim of this study was to compare the rate of newborn hearing screening before and after the COVID-19 pandemic quarantine. In this study, the data related to 6144 newborns during two 18-month time periods before and after the onset of the COVID-19 pandemic quarantine, was analyzed. From all visited newborns, 3770 and 2374 referred to the centre before and after the COVID-19 pandemic quarantine, respectively. There were statistically significant differences in the results of screening and the referral rate of neonates before and after the pandemic (p = 0.00). The results showed that both the residents of urban and rural regions visited for newborn hearing screening less frequently after the onset of the pandemic, but no statistically significant difference was shown between the number of boys and girls before and after the pandemic (p = 0.72). Our results help gain new insights regarding the impacts of disruptive events such as pandemics on the implementation of health screening programs. Boosting public knowledge by providing families with proper education appears to be helpful in preventing the negative effects of delayed implementation of health screening programs. [ABSTRACT FROM AUTHOR]

Polyoxometalates (POMs, metals=VV, NbV, TaV, MoVI, WVI) are molecular metal oxides that can be isolated without capping ligands. The high negative charge of polyoxoniobates (PONb) provides strong interactions with heterocations, advantageous for electrostatic assembly of modular materials. In four single‐crystal X‐ray structures, we demonstrate that carbonate combined with the very reactive decaniobate [Nb10O28]6− reassembles into a new decaniobate, [Nb10O25(CO3)6]12−, featuring three carbonate‐ligated Nb‐polyhedra. These Nb‐sites can be replaced by heterometals (lanthanides), and the tridentate carbonate can serve as an anchor point to build niobate‐frameworks. Small‐angle X‐ray scattering and two additional X‐ray structures reveal that the reaction pathway proceeds through a Nb24‐PONb intermediate, and the obtained PONb (with or without carbonate) is counterion, temperature, and solvent‐dependent (water or mixed water‐methanol). This provides an uncommon level of control for PONb chemistry. [ABSTRACT FROM AUTHOR]

The selective hydrolysis of proteins by non‐enzymatic catalysis is difficult to achieve, yet it is crucial for applications in biotechnology and proteomics. Herein, we report that discrete hafnium metal‐oxo cluster [Hf18O10(OH)26(SO4)13⋅(H2O)33] (Hf18), which is centred by the same hexamer motif found in many MOFs, acts as a heterogeneous catalyst for the efficient hydrolysis of horse heart myoglobin (HHM) in low buffer concentrations. Among 154 amino acids present in the sequence of HHM, strictly selective cleavage at only 6 solvent accessible aspartate residues was observed. Mechanistic experiments suggest that the hydrolytic activity is likely derived from the actuation of HfIV Lewis acidic sites and the Brønsted acidic surface of Hf18. X‐ray scattering and ESI‐MS revealed that Hf18 is completely insoluble in these conditions, confirming the HHM hydrolysis is caused by a heterogeneous reaction of the solid Hf18 cluster, and not from smaller, soluble Hf species that could leach into solution. [ABSTRACT FROM AUTHOR]

Atomically precise molecular metal‐oxo clusters provide ideal models to understand metal oxide surfaces, self‐assembly, and form‐function relationships. Devising strategies for synthesis and isolation of these molecular forms remains a challenge. Here, the synthesis of four Ln‐Fe oxo clusters that feature the ϵ‐{Fe13} Keggin cluster in their core is reported. The {Fe13} metal‐oxo cluster motif is the building block of two important iron oxyhydroxyide phases in nature and technology, ferrihydrite (as the δ‐isomer) and magnetite (the ϵ‐isomer). The reported ϵ‐{Fe13} Keggin isomer as an isolated molecule provides the opportunity to study the formation of ferrihydrite and magnetite from this building unit. The four currently reported isostructural lanthanide‐iron‐oxo clusters are fully formulated [Y12Fe33(TEOA)12(Hyp)6(μ3‐OH)20(μ4‐O)28(H2O)12](ClO4)23⋅50 H2O (1, Y12Fe33), [Gd12Fe33(TEOA)12(Hyp)6(μ3‐OH)20(μ4‐O)32(H2O)12](ClO4)15⋅50 H2O (2, Gd12Fe33) and [Ln16Fe29(TEOA)12(Hyp)6(μ3‐OH)24(μ4‐O)28(H2O)16](ClO4)16(NO3)3⋅n H2O (Ln=Y for 3, Y16Fe29, n=37 and Ln=Gd for 4, Gd16Fe29n=25; Hyp=trans‐4‐Hydroxyl‐l‐proline and TEOA=triethanolamine). The next metal layer surrounding the ϵ‐{Fe13} core within these clusters exhibits a similar arrangement as the magnetite lattice, and Fe and Ln can occupy the same positions. This provides the opportunity to construct a family of compounds and optimize magnetic exchange in these molecules through composition tuning. Small‐angle X‐ray scattering (SAXS) and high‐resolution electrospray ionization mass spectrometry (HRESI‐MS) show that these clusters are stable upon dissolution in both water and organic solvents, as a first step to performing further chemistry towards building magnetic arrays or investigating ferrihydrite and magnetite assembly from pre‐nucleation clusters. [ABSTRACT FROM AUTHOR]

Aqueous metal‐oxo clusters without organic ligands (including polyoxometalates and group 13 polycations) are useful for energy, environmental and biomolecular applications. While ligands stabilize clusters of different elements, such as open‐shell transition metals, they inhibit reactivity and solubility. Therefore a grand challenge is to conceive and execute synthetic strategies to isolate metal‐oxo clusters of any composition, without ligation. Here we crystallize and structurally characterize a Cr3+ dodecamer Keggin ion without organic ligation. Detailed characterization of its formation leads to understanding its reaction pathway, which may translate to isolation of other open‐shell transition metal‐oxo clusters. We employed electrospray ionization mass spectrometry, Raman spectroscopy and X‐ray scattering (small‐angle and total) to identify important reaction intermediates and processes. The aqueous synthesis presented here is simple to implement and scalable, producing pure phase materials in gram quantities. Discovering and isolating open‐shell, first‐row transition metal‐oxo clusters without organic ligands is desired for energy applications. The Cr3+ Keggin polycation reported here is the inaugural cluster of this type. The simple reaction pathway includes Zn‐promoted hydrolysis to dissociate the very stable chromium trimers, while nitrate evaporation forces condensation reactions. [ABSTRACT FROM AUTHOR]

Abstract: Metal oxo clusters and metal oxides assemble and precipitate from water in processes that depend on pH, temperature, and concentration. Other parameters that influence the structure, composition, and nuclearity of “molecular” and bulk metal oxides are poorly understood, and have thus not been exploited. Herein, we show that Bi3+ drives the formation of aqueous Fe3+ clusters, usurping the role of pH. We isolated and structurally characterized a Bi/Fe cluster, Fe3BiO2(CCl3COO)8(THF)(H2O)2, and demonstrated its conversion into an iron Keggin ion capped by six Bi3+ irons (Bi6Fe13). The reaction pathway was documented by X‐ray scattering and mass spectrometry. Opposing the expected trend, increased cluster nuclearity required a pH decrease instead of a pH increase. We attribute this anomalous behavior of Bi/Fe(aq) solutions to Bi3+, which drives hydrolysis and condensation. Likewise, Bi3+ stabilizes metal oxo clusters and metal oxides in strongly acidic conditions, which is important in applications such as water oxidation for energy storage. [ABSTRACT FROM AUTHOR]

This paper proposes an efficient approach for constraint handling in multi-objective particle swarm optimization. The particles population is divided into two non-overlapping populations, named infeasible population and feasible population. The evolution process in each population is done independent of the other one. The infeasible particles are evolved in the constraint space toward feasibility. During evolution process, if an infeasible particle becomes a feasible one, it migrates to feasible population. In a parallel process, the particles in feasible population are evolved in the objective space toward Pareto optimality. At each generation of multi-objective particle swarm optimization, a leader should be assigned to each particle to move toward it. In the proposed method, a different leader selection algorithm is proposed for each population. For feasible population, the leader is selected using a priority-based method in three levels and for infeasible population, a leader replacement method integrated by an elitism-based method is proposed. The proposed approach is tested on several constrained multi-objective optimization benchmark problems, and its results are compared with two popular state-of-the-art constraint handling multi-objective algorithms. The experimental results indicate that the proposed algorithm is highly competitive in solving the benchmark problems. [ABSTRACT FROM AUTHOR]

Missing values exist in many generated datasets in science. Therefore, utilizing missing data imputation methods is a common and important practice. These methods are a kind of treatment for uncertainty and vagueness existing in datasets. On the other hand, methods based on fuzzy-rough sets provide excellent tools for dealing with uncertainty, possessing highly desirable properties such as robustness and noise tolerance. Furthermore, they can find minimal representations of data and do not need potentially erroneous user inputs. As a result, utilizing fuzzy-rough sets for imputation should be an effective approach. In this paper, we propose three missing value imputation methods based on fuzzy-rough sets and its recent extensions; namely, implicator/t-norm based fuzzy-rough sets, vaguely quantified rough sets and also ordered weighted average based rough sets. These methods are compared against 11 state-of-the-art imputation methods implemented in the KEEL data mining software on 27 benchmark datasets. The results show, via non-parametric statistical analysis, that the proposed methods exhibit excellent performance in general. [ABSTRACT FROM AUTHOR]

Accidents involving falls and falling objects (group I) are highly frequent accidents in the construction industry. While being hit by a vehicle, electric shock, collapse in the excavation and fire or explosion accidents (group II) are much less frequent, they make up a considerable proportion of severe accidents. In this study, multiple-correspondence analysis, decision tree, ensembles of decision tree and association rules methods are employed to analyse a database of construction accidents throughout Iran between 2007 and 2011. The findings indicate that in group I, there is a significant correspondence among these variables: time of accident, place of accident, body part affected, final consequence of accident and lost workdays. Moreover, the frequency of accidents in the night shift is less than others, and the frequency of injury to the head, back, spine and limbs are more. In group II, the variables time of accident and body part affected are mostly related and the frequency of accidents among married and older workers is more than single and young workers. There was a higher frequency in the evening, night shifts and weekends. The results of this study are totally in line with the previous research. [ABSTRACT FROM PUBLISHER]

Two-dimensional hexagonal boron nitride (hBN) is an insulator with polar covalent B-N bonds. Monolayer and bilayer pentagonal BN emerge as an optoelectronic material, which can be used in photo-based devices such as photodetectors and photocatalysis. Herein, we implement spin polarized electron density calculations to extract electronic/optical properties of mono- and bilayer pentagonal BN structures, labeled as B 2 N 4 , B 3 N 3 , and B 4 N 2 . Unlike the insulating hBN, the pentagonal BN exhibits metallic or semiconducting behavior, depending on the detailed pentagonal structures. The origin of the metallicity is attributed to the delocalized boron (B) 2p electrons, which has been verified by electron localized function and electronic band structure as well as density of states. Interestingly, all 3D networks of different bilayer pentagonal BN are dynamically stable unlike 2D structures, whose monolayer B 4 N 2 is unstable. These 3D materials retain their metallic and semiconductor nature. Our findings of the optical properties indicate that pentagonal BN has a visible absorption peak that is suitable for photovoltaic application. Metallic behavior of pentagonal BN has a particular potential for thin-film based devices and nanomaterial engineering. [ABSTRACT FROM AUTHOR]