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Porcine circoviruses (PCVs) are a significant cause of concern for swine health, with four genotypes currently recognized. Two of these, PCV3 and PCV4, have been detected in pigs across all age groups, in both healthy and diseased animals. These viruses have been associated with various clinical manifestations, including porcine dermatitis and nephropathy syndrome (PDNS) and respiratory and enteric signs. In this study, we detected PCV3 and PCV4 in central China between January 2022 and February 2023. We tested fecal swabs and tissue samples from growing-finishing and suckling pigs with or without respiratory and systemic manifestations and found the prevalence of PCV3 to be 15.15% (15/99) and that of PCV3/PCV4 coinfection to be 4.04% (4/99). This relatively low prevalence might be attributed to the fact that most of the clinical samples were collected from pigs exhibiting respiratory signs, with only a few samples having been obtained from pigs with diarrhea. In some cases, PCV2 was also detected, and the coinfection rates of PCV2/3, PCV2/4, and PCV2/3/4 were 6.06% (6/99), 5.05% (5/99), and 3.03% (3/99), respectively. The complete genomic sequences of four PCV3 and two PCV4 isolates were determined. All four of the PCV3 isolates were of subtype PCV3b, and the two PCV4 isolates were of subtype PCV4b. Two mutations (A24V and R27K) were found in antibody recognition domains of PCV3, suggesting that they might be associated with immune escape. This study provides valuable insights into the molecular epidemiology and evolution of PCV3 and PCV4 that will be useful in future investigations of genotyping, immunogenicity, and immune evasion strategies. [ABSTRACT FROM AUTHOR]

Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties, and great efforts have been made in the past decades to find more effective synthetic methods. However, the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B–H bond condensation reaction, critical for the synthesis of the polyhedral boranes, is not well understood. Here we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate (1–) (B11H14−) and dodecahydrido-dodecaborates (2–) (B12H122−) anions by employing commercially available and inexpensive starting materials. Both theoretical and experimental investigations are carried out to elucidate the reaction mechanisms. We have found that the nature of the B–H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens (bridged hydrogens) play a crucial role. The current study has not only led to more effective and selective synthetic methods for B11H14− and B12H122− but also unveiled the nature of the B–H bond condensation and the general formation mechanisms of polyhedral boranes. This finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of M2B10H14 (M = Na and K) has been developed. The two possible formation mechanisms of the B10H142− anion are proposed, in which the NH2BH3− anion acts as a proton abstractor and a hydride donor. Furthermore, the B10H13− and B10H15− intermediates were detected. [ABSTRACT FROM AUTHOR]

Porcine circovirus-like virus (PCLV) is a recently discovered virus that may be associated with diarrhea in pigs. To investigate the epidemic profile and genetic characteristics of this virus, 175 clinical samples (141 intestinal samples, 17 blood samples, and 17 fecal samples) were collected from diseased piglets during outbreaks of diarrhea from 33 pig farms in 19 cities of Henan and Shanxi provinces of China between 2016 and 2021 and were screened by PCR for the presence of PCLV. The results showed that the positive rate for PCLV was 32% (56/175) at the sample level, 60.6% (20/33) at the farm level, and 57.9% (11/19) at the city level, which varied from 5.88% to 44.12% between 2016 and 2021. It was also found that PCLV occurred in coinfections with porcine circovirus type 2 (PCV2), PCV3, PCV4, porcine epidemic diarrhea virus, and porcine reproductive and respiratory syndrome virus, but no nucleic acids were detected for transmissible gastroenteritis virus, porcine deltacoronavirus, or porcine rotavirus in piglets with diarrhea. Notably, PCLV was detected in 13 diarrheal piglets from four different farms that were negative for the other porcine viruses. These findings suggest that PCLV may be associated with porcine diarrhea and that it has been circulating in piglets in Henan and Shanxi provinces of China. In addition, the complete genomes of 13 PCLV strains were sequenced and found to share 35.4%–91.0% nucleotide sequence identity with sequences available in the GenBank database. Phylogenetic analysis based on Rep amino acid sequences revealed that the 13 PCLV strains from this study clustered in group 1 and were closely related to eight Chinese PCLV strains, Bo-Circo-like virus CH, American strains 21 and 22, and Hungarian strains 288_4 and 302_4, but they differed genetically from seven other foreign PCLV strains. The whole genome and rep gene of 13 PCLV strains in this study were 72.2%-82% and 83.8%-89.7% identical, respectively, to those of Bo-Circo-like virus strain CH, indicating that PCLV is a novel virus in pigs that may be involved in cross-species transmission. Evidence of a recombination event was found in the rep region of the 13 PCLV strains sequenced. This study enriches the epidemiological data on PCLV infection in pigs in China and lays a foundation for further study on the pathogenesis of PCLV. [ABSTRACT FROM AUTHOR]

All-solid-state K batteries are ideal energy storage devices for grid-scale applications of renewable energies. A novel electrolyte K[B3H7NH2BH2NH2B3H7] with weakly coordinating anions was synthesized. It has a high K+ conductivity of 1.01 × 10−4 S cm−1 at 75 °C, which is probably due to the increased electrostatic potential and size of the anions. [ABSTRACT FROM AUTHOR]

Porcine epidemic diarrhea virus (PEDV) is the major pathogen that causes diarrhea and high mortality in newborn piglets, with devastating impact on the pig industry. To further understand the molecular epidemiology and genetic diversity of PEDV field strains, in this study the complete genomes of four PEDV variants (HN2021, CH-HNYY-2018, CH-SXWS-2018, and CH-HNKF-2016) obtained from immunized pig farms in central China between 2016 to 2021 were characterized and analyzed. Phylogenetic analysis of the genome and S gene showed that the four strains identified in the present study had evolved into the subgroup G2a, but were distant from the vaccine strain CV777. Additionally, it was noteworthy that a new PEDV strain (named HN2021) belonging to the G2a PEDV subgroup was successfully isolated in vitro and it was further confirmed by RT-PCR that this isolate had a large natural deletion at 207–373 nt of the ORF3 gene, which has never been reported before. Particularly, in terms of pathogenicity evaluation, colostrum deprivation piglets challenged with PEDV HN2021 showed severe diarrhea and high mortality, confirming that PEDV HN2021 was a virulent strain. Hence, PEDV strain HN2021 of subgroup G2a presents a promising vaccine candidate for the control of recurring porcine epidemic diarrhea (PED) in China. This study lays the foundation for better understanding of the genetic evolution and molecular pathogenesis of PEDV. [ABSTRACT FROM AUTHOR]

The high heterogeneity of oral squamous cell carcinoma (OSCC) is the main obstacle for individualized treatment. Recognizing the characteristics of different subtypes and investigating the promising strategies for each subclass are of great significance in precise treatment. In this study, we systematically evaluated hypoxia-mediated patterns together with immune characteristics of 309 OSCC patients in the TCGA training set and 97 patients in the GSE41613 testing set. We further identified two different hypoxia subtypes with distinct immune microenvironment traits and provided treatment programs for the two subclasses. In order to assess hypoxia level individually, we finally constructed a hypoxia-related risk score, which could predict the clinical outcome and immunotherapy response of OSCC patients. In summary, the recognition of different hypoxia patterns and the establishment of hypoxia-related risk score might enhance our understanding of the tumor microenvironment of OSCC and provide more personalized treatment strategies in the future. [ABSTRACT FROM AUTHOR]

A safe and efficient synthetic method for MB3H8 (M = Na, K, Rb and Cs) has been developed with excellent yields by directly reacting the corresponding MBH4 with the dimethyl sulfide borane complex (DMS·BH3). A general mechanism for constructing B3H8−, a basic unit for building polyhedral boranes, has been unravelled. [ABSTRACT FROM AUTHOR]

We have synthesized the tetrabutylammonium ([Bu4N]+), tetraethylammonium ([Et4N]+), guanidinium ([C(NH2)3]+), and methylguanidinium ([C(N3H5CH3)]+) salts of the [BH3(NH2BH2)2H]− anion, a five‐membered B/N anionic chain, in high yields by the metathesis reactions of Na[BH3(NH2BH2)2H] with the corresponding halides and characterized them by NMR (11B, 11B{1H}, 1H, 1H{11B}, 13C), IR, elemental analysis, TGA‐DSC, and TGA‐MS. These complexes behave like ionic liquids (ILs), in which the melting point of the [Bu4N][BH3(NH2BH2)2H] is the lowest (−51 °C). The dehydrogenation of these ILs have been studied through the thermal decomposition and catalytic hydrolysis in aqueous solution using the noble or non‐noble metals or their salts as catalysts, and the results indicate that these ILs of five‐membered B/N anionic chain are promising hydrogen storage materials. [ABSTRACT FROM AUTHOR]

Herein, a highly regioselective propargylic benzylation with propargylic carbonates and benzyl 1,4-dihydropyridine derivatives was developed via a photoredox/palladium dual-catalyzed process, which represents a novel catalytic model for non-terminal propargylic functionalization. The reaction showed excellent regioselectivity and functional group compatibility. A radical coupling mechanism between the propargylic radical and benzyl radical was proposed. [ABSTRACT FROM AUTHOR]

B/N anionic aminoborane linear or branched chain complexes, [BH3(NH2BH2)nH]− (n = 1, 2, and 3) and [BH(NH2BH3)3]−, have been synthesized through the controlled reactions of ammonia borane (NH3BH3) with NaH by adjusting the reactant ratios and reaction temperatures. The possible reaction mechanisms were elucidated based on experimental and theoretical studies. [ABSTRACT FROM AUTHOR]

Long-sought mechanisms for the conversion of diammoniate of diborane ([NH3BH2NH3]+[BH4]−) into NH3BH3 and [NH2BH2]n as well as ammonium aminodiborane ([NH4]+[BH3NH2BH3]−) into a butane analogue, NH3BH2NH2BH3, have been elucidated on the basis of extensive experimental and theoretical studies. The [NH4]+ ammonium cation and the (η2-H2)BH2R moiety are found to be critical in B/N chain expansion. [ABSTRACT FROM AUTHOR]

Octahydridoborate, i.e. [B3H8]− containing compounds, have recently attracted interest for hydrogen storage. In the present study, the structural, hydrogen storage, and ion conductivity properties of KB3H8 have been systematically investigated. Two distinct polymorphic transitions are identified for KB3H8 from a monoclinic (α) to an orthorhombic (α′) structure at 15 °C via a second-order transition and eventually to a cubic (β) structure at 30 °C by a first-order transition. The β-polymorph of KB3H8 displays a high degree of disorder of the [B3H8]− anion, which facilitates increased cation mobility, reaching a K+ conductivity of ∼10−7 S cm−1 above 100 °C. β-KB3H8 starts to release hydrogen at ∼160 °C, simultaneously with the release of B5H9 and trace amounts of B2H6. KBH4 and K3(BH4)(B12H12) are identified as crystalline decomposition products above 200 °C, and the formation of a KBH4 deficient structure of K3−x(BH4)1−x(B12H12) is observed at elevated temperature. The hydrogen-uptake properties of a KB3H8–2KH composite have been examined under 380 bar H2, resulting in the formation of KBH4 at T≥ 150 °C along with higher metal hydridoborates, i.e. K2B9H9, K2B10H10, and K2B12H12. [ABSTRACT FROM AUTHOR]

An efficient synthetic method for MB3H8 (M = Li and Na) has been developed with improved yields on the basis of the investigation of the interconversion between THF·B3H7 and corresponding MB3H8. The mechanism was tentatively proposed based on the understanding of the nucleophilicity of the B–H bonding pair electrons. [ABSTRACT FROM AUTHOR]

A facile synthesis of heavy alkali metal octahydrotriborates (MB3H8; M=K, Rb, and Cs) has been developed. It is simply based on reactions of the pure alkali metals with THF⋅BH3, does not require the use of electron carriers or the addition of other reaction media such as mercury, silica gel, or inert salts as for previous procedures, and delivers the desired products at room temperature in very high yields. However, no reactions were observed when pure Li or Na was used. The reaction mechanisms for the heavy alkali metals were investigated both experimentally and computationally. The low sublimation energies of K, Rb, and Cs were found to be key for initiation of the reactions. The syntheses can be carried out at room temperature because all of the elementary reaction steps have low energy barriers, whereas reactions of LiBH4/NaBH4 with THF⋅BH3 have to be carried out under reflux. The high stability and solubility of KB3H8 were examined, and a crystal structure thereof was obtained for the first time. Sublime reactivity: Unsolvated MB3H8 (M=K, Rb, and Cs) salts were prepared by reactions of the respective pure alkali metals with THF⋅BH3 in high yield at room temperature, and the structure of unsolvated KB3H8 was elucidated. The proposed reaction mechanisms are based on experimental and theoretical results. It was found that the physical properties of the alkali metals play a crucial role. [ABSTRACT FROM AUTHOR]

A facile synthesis of heavy alkali metal octahydrotriborates (MB3H8; M=K, Rb, and Cs) has been developed. It is simply based on reactions of the pure alkali metals with THF⋅BH3, does not require the use of electron carriers or the addition of other reaction media such as mercury, silica gel, or inert salts as for previous procedures, and delivers the desired products at room temperature in very high yields. However, no reactions were observed when pure Li or Na was used. The reaction mechanisms for the heavy alkali metals were investigated both experimentally and computationally. The low sublimation energies of K, Rb, and Cs were found to be key for initiation of the reactions. The syntheses can be carried out at room temperature because all of the elementary reaction steps have low energy barriers, whereas reactions of LiBH4/NaBH4 with THF⋅BH3 have to be carried out under reflux. The high stability and solubility of KB3H8 were examined, and a crystal structure thereof was obtained for the first time. [ABSTRACT FROM AUTHOR]

A facile synthesis of heavy alkali metal octahydrotriborates (MB3H8; M=K, Rb, and Cs) has been developed. It is simply based on reactions of the pure alkali metals with THF⋅BH3, does not require the use of electron carriers or the addition of other reaction media such as mercury, silica gel, or inert salts as for previous procedures, and delivers the desired products at room temperature in very high yields. However, no reactions were observed when pure Li or Na was used. The reaction mechanisms for the heavy alkali metals were investigated both experimentally and computationally. The low sublimation energies of K, Rb, and Cs were found to be key for initiation of the reactions. The syntheses can be carried out at room temperature because all of the elementary reaction steps have low energy barriers, whereas reactions of LiBH4/NaBH4 with THF⋅BH3 have to be carried out under reflux. The high stability and solubility of KB3H8 were examined, and a crystal structure thereof was obtained for the first time. Sublime reactivity: Unsolvated MB3H8 (M=K, Rb, and Cs) salts were prepared by reactions of the respective pure alkali metals with THF⋅BH3 in high yield at room temperature, and the structure of unsolvated KB3H8 was elucidated. The proposed reaction mechanisms are based on experimental and theoretical results. It was found that the physical properties of the alkali metals play a crucial role. [ABSTRACT FROM AUTHOR]

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Abstract In this paper, CuO hollow microspheres with different shell thickness and porosity have been synthesized using carbonaceous saccharide microspheres as templates according to a modified literature method. These CuO hollow microspheres were characterized and their catalytic properties in the hydrolytic dehydrogenation of ammonia borane (NH 3 BH 3 , AB) were examined. A kinetic study indicated that a maximum hydrogen generation rate of 294 mL H 2 min−1 (g catalyst)−1 can be achieved at 45 ± 0.2 °C in the present system, which is comparable with that for other reported Cu based catalysts. Graphical abstract Image 1 Highlights • CuO hollow microspheres with different features have been synthesized. • They were used to catalyze the hydrolytic dehydrogenation of ammonia borane. • A maximum H 2 release rate of 294 mL H 2 min−1 (g catalyst)−1 was achieved. • This method is simple, green and cost effective. [ABSTRACT FROM AUTHOR]

Boron compounds are well-known electrophiles. Much less known are their nucleophilic properties. By recognition of the nucleophilicity of the B-H bond, the formation mechanism of octahydrotriborate (B3H8-) was elucidated on the bases of both experimental and computational investigations. Two possible routes from the reaction of BH4- and THF-BH3 to B3H8- were proposed, both involving the B2H6 and BH4- intermediates. The two pathways consist of a set of complicated intermediates, which can convert to each other reversibly at room temperature and can be represented by a reaction circle. Only under reflux can the B2H6 and BH4-intermediates be converted to B2H5- and BH3(H2) via a high energy barrier, from which H2 elimination occurs to yield the B3H8- final product. The formation of B2H6from THF-BH3 by nucleophilic substitution of the B-H bond was captured and identified, and the reaction of B2H6 with BH4- to produce B3H8- was confirmed experimentally. On the bases of the formation mechanisms of B3H8-, we have developed a facile synthetic method for MB3H8 (M = Li and Na) in high yields by directly reacting the corresponding MBH4salts with THF-BH3. In the new synthetic method for MB3H8, no electron carriers are needed, allowing convenient preparation of MB3H8 in large scales and paving the way for their wide applications. [ABSTRACT FROM AUTHOR]

The reactivity of sodium amidoborane (NaNH2BH3) as a Brønsted and Lewis base was studied systematically. The [NH2BH3]- anion can act as a proton acceptor or a hydride donor in different types of reactions. In reactions with very weak Brønsted acids such as cyclopentadiene, ammonia, and pyrazole, the [NH2BH3]- anion acts as a proton acceptor through the lone pair on N. The reactions of [NH2BH3]- with stronger Brønsted acids are complicated. In the reaction with ammonium chloride or acetic acid, [NH2BH3]- accepts a proton, reforming NH3BH3. However, in the reaction with HCl or methanol, N-B bond cleavage occurs. [NH2BH3]- can also donate hydride in some reactions. The possible mechanisms of these reactions are discussed. [ABSTRACT FROM AUTHOR]

The reactivity of sodium amidoborane (NaNH2BH3) as a Brønsted and Lewis base was studied systematically. The [NH2BH3]- anion can act as a proton acceptor or a hydride donor in different types of reactions. In reactions with very weak Brønsted acids such as cyclopentadiene, ammonia, and pyrazole, the [NH2BH3]- anion acts as a proton acceptor through the lone pair on N. The reactions of [NH2BH3]- with stronger Brønsted acids are complicated. In the reaction with ammonium chloride or acetic acid, [NH2BH3]- accepts a proton, reforming NH3BH3. However, in the reaction with HCl or methanol, N-B bond cleavage occurs. [NH2BH3]- can also donate hydride in some reactions. The possible mechanisms of these reactions are discussed. [ABSTRACT FROM AUTHOR]

Our previous work on the classical over-barrier ionization model for helium double ionization is extended to the complex multi-electron system of Ne. The total and q-fold ionization cross sections are calculated at energies ranging from a few tens to several hundred keV/u. The calculation results are in good agreement with the experimental data, and the energy dependence of the cross sections suggests that the multi-ionization of a strong perturbated complex atom is probably the sequential over-barrier ionization process. [ABSTRACT FROM AUTHOR]

In this paper a projectile ion-recoil ion coincidence technique is used to investigate the transfer ionization processes in collisions of 0.22-6.30 MeV Cq+ ions and 0.25-6.35 MeV Oq+ ions (q = 1, 2, 3, 4) with the He atom separately. The cross section ratio f of transfer ionization to single electron transfer is measured, and the dependence of f on both charge state q and energy E of the projectiles is investigated. The electron-structure and the mechanisms leading to transfer ionization affect the dependence of f on q and E. Our measurements, along with other data published previously, suggest a similar dependence of f on charge state and energy of projectile for partially stripped ions over a large energy range. The maximum value of f is approximately 0.17q0.60; the energy corresponding to maximum f is about 160q0.60 keV/u. [ABSTRACT FROM AUTHOR]

We measure the multiple ionization cross-section ratios Rk1 of Ar impacted by Cq+ (q = 1−3) ions in the energy range of 20–500 keV/u. The measured ratios Rk1 increase with the projectile energy at lower energies, and reach the maximum at energies of 50–150 keV/u, then decrease for higher energies. We also use the classical over barrier ionization model to calculate the ratios Rk1, and the calculation results are in good agreement with the data, which suggest that the multiple ionization process is described by the sequential over-barrier ionization process. [ABSTRACT FROM AUTHOR]

The values of cross-section ratio Rk1 of direct k-fold ionization cross section (σk) to direct single ionization cross section (σ1) of Ne impacted by Cq+ (q = 1–3) ions in an energy range of 10 keV/u–500 keV/u are measured in this work. The experimental data are compared with the results from our multi-electron classical over-barrier ionization (ME-COBI) model, showing that the model can give a good estimate to the experimental data. [ABSTRACT FROM AUTHOR]

We extend our previous work of a classical over-barrier ionization (COBI) model to calculate the single ionization cross sections of noble gases ranging from He to Xe at strong perturbative energies. The calculation results are in good agreement with extensive experimental data. The scaling law of single ion–atom impact ionization cross sections of noble gases on projectile charge q and energy E, also on target ionization energy I is drawn from the model. [ABSTRACT FROM AUTHOR]