Clinical and epidemiological characteristics of 96 pediatric human metapneumovirus infections in Henan, China after COVID-19 pandemic: a retrospective analysis.

BACKGROUND: In the aftermath of the COVID-19 pandemic, there has been a surge in human metapneumovirus (HMPV) transmission, surpassing pre-epidemic levels. We aim to elucidate the clinical and epidemiological characteristics of HMPV infections in the post-COVID-19 pandemic era. METHODS: In this retrospective single-center study, participants diagnosed with laboratory confirmed HMPV infection through Targeted Next Generation Sequencing were included. The study encompassed individuals admitted to Henan Children's Hospital between April 29 and June 5, 2023. Demographic information, clinical records, and laboratory indicators were analyzed. RESULTS: Between April 29 and June 5, 2023, 96 pediatric patients were identified as infected with HMPV with a median age of 33.5 months (interquartile range, 12 ~ 48 months). The majority (87.5%) of infected children were under 5 years old. Notably, severe cases were statistically younger. Predominant symptoms included fever (81.3%) and cough (92.7%), with wheezing more prevalent in the severe group (56% vs 21.1%). Coinfection with other viruses was observed in 43 patients, with Epstein-Barr virus (EBV) (15.6%) or human rhinovirus A (HRV type A) (12.5%) being the most common. Human respiratory syncytial virus (HRSV) coinfection rate was significantly higher in the severe group (20% vs 1.4%). Bacterial coinfection occurred in 74 patients, with Haemophilus influenzae (Hin) and Streptococcus pneumoniae (SNP) being the most prevalent (52.1% and 41.7%, respectively). Severe patients demonstrated evidence of multi-organ damage. Noteworthy alterations included lower concentration of IL-12p70, decreased lymphocytes percentages, and elevated B lymphocyte percentages in severe cases, with statistical significance. Moreover, most laboratory indicators exhibited significant changes approximately 4 to 5 days after onset. CONCLUSIONS: Our data systemically elucidated the clinical and epidemiological characteristics of pediatric patients with HMPV infection, which might be instructive to policy development for the prevention and control of HMPV infection and might provide important clues for future HMPV research endeavors.

Mycoplasma pneumonia in a patient with X-linked agammaglobulinemia.

BACKGROUND: X-linked agammaglobulinemia (XLA), also referred to as Bruton's tyrosine kinase deficiency, is a rare genetic disorder that affects the immune system. We conducted genetic analysis on patients suffering from immunodeficiency by utilizing Next-Generation Sequencing techniques, as well as their closest relatives, to facilitate accurate diagnosis, offer genetic counseling services, and enhance our comprehension of XLA.

Preformation of Insoluble Solid-Electrolyte Interphase for Highly Reversible Na-Ion Batteries.

Stable solid-electrolyte interphase (SEI) is crucial for cycling reversibility of Na-ion batteries by mitigating continuous side reactions. So far, the severe SEI dissolution leads to low Coulombic efficiency (CE) and short cycle life. Meanwhile, the quantified relationship between SEI components and their solubility remains unclear. In this work, we establish the direct correlation between SEI components and SEI solubility, and quantify that the solubility of organic-rich SEI is 3.26 times of inorganic-rich SEI. We further propose a feasible strategy to preform inorganic-rich insoluble SEI and demonstrate a practical hard carbon (HC)||NaMn0.33Fe0.33Ni0.33O2 full cell in commercial electrolyte of 1 M NaPF6 in propylene carbonate (PC) with 80.0% capacity retention for 900 cycles, and achieve a record-high average CE of 99.95% for a practical Na-ion full cell. This study provides an effective strategy of preforming insoluble SEI to suppress its dissolution towards highly reversible Na-ion batteries.

Stereochemically Active Tin(II)-Induced Enhancement of Birefringence in SnII SnIV (PO4 )2 and SrSn(PO4 )PO2 (OH)2.

Two new tin(II) phosphates, SnII SnIV (PO4 )2 and SrSn(PO4 )PO2 (OH)2 , were synthesized by the high-temperature solution method and hydrothermal method, respectively. Theoretical study indicates that by introducing tin(II) with stereochemical activity lone pairs (SCALP) in metal phosphates, the birefringence was enhanced, 0.048@1064 nm for SnII SnIV (PO4 )2 and 0.080@1064 nm for SrSn(PO4 )PO2 (OH)2 .

Noncentrosymmetric versus Centrosymmetric: Halogen Induced Variable Coordination Modes of Sn2+ and Structural Transition in Sn3B3O7X (X = Cl and Br).

Two new borate halides, Sn3B3O7X (X = Cl and Br), were successfully synthesized via introducing Sn2+ with lone-pair and halogen into borate. Interestingly, halogen-induced variable coordination modes of Sn2+ and anion frameworks make them crystallize in different space groups, from noncentrosymmetric (Pna21) to centrosymmetric (Pbca). Sn3B3O7Cl possesses an SHG response of about 0.5 times that of KDP, while Sn3B3O7Br exhibits a large birefringence (0.123@1064 nm). The theoretical calculations were performed to elucidate the structure-property relationships.

Hydroxyl-Driven Enhanced Birefringence in Borophosphates.

Borophosphates have become promising candidates for ultraviolet or deep-ultraviolet functional crystals. Through high-temperature solution method, four new borophosphates, K2B2P2O9, (NH4)2BP2O7(OH), K2BP2O7(OH), and P21/c-(NH4)2B2P3O11(OH), were acquired successfully. Single crystal X-ray diffraction suggests that K2B2P2O9, (NH4)2BP2O7(OH), and K2BP2O7(OH) belong to the noncentrosymmetric space group, while P21/c-(NH4)2B2P3O11(OH) belongs to the centrosymmetric compound. It is worth mentioning that K2B2P2O9, (NH4)2BP2O7(OH), and K2BP2O7(OH) present the new fundamental building blocks [B2P2O11], [BP2O10H], and [BP2O9(OH)], respectively, as far as we know. Compared with K2B2P2O9, (NH4)2BP2O7(OH), K2BP2O7(OH), and P21/c-(NH4)2B2P3O11(OH) exhibit a larger optical anisotropy, further confirming the positive effect of hydroxyl groups on birefringence. UV-vis-NIR diffuse reflectance spectra display that K2B2P2O9 and (NH4)2BP2O7(OH) have short UV cutoff edges. Meanwhile, theoretical calculations were conducted to comprehend their optical properties and electronic structures.

Na2BaB12O18F4: A Mixed Alkali/Alkaline-Earth Metal Fluorooxoborate with Two Unprecedented Interpenetrating Three-Dimensional B-O/F Anionic Networks and a Short Ultraviolet Cutoff Edge.

Fluorooxoborates are promising yet largely untapped crystal materials for linear and nonlinear optical applications. The introduction of a strong electronegative F atom into an oxyboron anionic group offers a virtually unlimited chance for structural engineering and ultimately purposeful tuning of the macroscopic optical properties of the crystal. Herein, a new mixed alkali/alkaline-earth fluorooxoborate, Na2BaB12O18F4, was synthesized in a closed system. Na2BaB12O18F4 features a [B6O11F2] fundamental building unit (FBB), which polymerizes into two new (first example) independent interpenetrating three-dimensional (3D) B-O/F anionic networks constructed entirely from BO3 and BO3F units. Based on optical characterizations and the first-principles calculations, Na2BaB12O18F4 exhibits a moderate birefringence (0.054 @ 1064 nm) and a short ultraviolet (UV) cutoff edge (below 190 nm). The successful synthesis and characterization of Na2BaB12O18F4 may speed up the subsequent discovery of other mixed alkali/alkaline-earth metal fluorooxoborates.

Recent Development of SnII , SbIII -based Birefringent Material: Crystal Chemistry and Investigation of Birefringence.

The combination of SnII or SbIII with π, non-π-conjugated units has produced birefringent crystals with birefringence ranging from 0.005 to 0.468@1064 nm. It is proven that introducing SnII or SbIII into crystals is a feasible strategy to enlarge the birefringence, which not only promotes the miniaturization of fabricated devices, but also effectively modulates polarized light. Herein, recently discovered SnII , SbIII -based birefringent crystals with birefringence investigated are summarized, including their crystal structure and optical properties, especially birefringence. This review also presents the influence of SnII , SbIII with stereochemically active lone pair on the optical anisotropy. We hope that this work provides a clear perspective on the crystal chemistry of SnII , SbIII -based optical functional crystals and promotes the development of new birefringent crystals with large optical anisotropy.

Birefringence Regulation by Clarifying the Relationship Between Stereochemically Active Lone Pairs and Optical Anisotropy in Tin-based Ternary Halides.

It is important to establish and clarify the relationship between stereochemically active lone pairs and birefringence, since it is one of the significantly effective routes to explore birefringent crystals by introducing Sn-centered polyhedra with stereochemically active lone pairs. Herein, four tin(II)-based ternary halides A3 SnCl5 and ASn2 Cl5 (A=NH4 and Rb) have been synthesized successfully. The experimental birefringence of Rb3 SnCl5 and RbSn2 Cl5 is larger than or equal to 0.046 and 0.123@546 nm, respectively. Through investigating the alkali or alkaline-earth metal tin(II)-based ternary halides, the structure-performance relationship has been concluded between stereochemically active lone pairs and optical anisotropy. It is beneficial to the analysis and prediction of birefringence in tin-based halides and provides a guide for exploring tin(II)-based optoelectronic functional materials.

Enhancement of Birefringence in Borophosphate Pushing Phase-Matching into the Short-Wavelength Region.

Borophosphates are very known for the short ultraviolet (UV) cutoff edge and have become the promising UV and deep-UV functional crystals candidates; however, tetrahedral [PO4] and [BO4] groups own weak anisotropy of polarizability and are not conducive to large birefringence, which hinders their application in the short-wavelength region. Improving their birefringence without compromising the band gap is the main research objective. By introducing the excellent birefringent functional groups, such as [B2O5], [BO2]∞ chain, [B2Ox(OH)5-x], and so forth into borophosphates, seven borophosphates with improved birefringence were successfully synthesized (Δn > 0.05@532 nm). Remarkably, among them, the centimeter-sized crystal of Rb3B8PO16 with a short deep-UV cutoff edge (175 nm) and large birefringence (Δn(exp.) ∼ 0.072@589.3 nm) exhibits the shortest phase-matching wavelength (222 nm), which makes Rb3B8PO16 a promising UV NLO crystal, while KB6PO10(OH)4 with deep-UV cutoff edge features the largest birefringence (Δn(exp.) ∼ 0.103@546 nm) in the reported borophosphate system, making KB6PO10(OH)4 a promising deep-UV birefringent crystal. This study not only provides feasible strategies for increasing the birefringence of borophosphates but also pushes phase-matching into the short-wavelength region.

Sn3B10O17Cl2 Achieving Birefringence Enhancement by Stereochemical Activity Lone Pair.

Sn3B10O17Cl2 was successfully obtained for the first time under the sealed environment and crystallized in the space group Pbcn belonging to the orthorhombic system, which is featured by the fundamental building blocks [B5O11] that are linked to construct a three-dimensional framework with Cl and Sn atoms located inside and at the edge of the channel to balance the charge. Moreover, the optical performance measurement shows that Sn3B10O17Cl2 owns a cutoff edge of about 280 nm. Theoretical study indicates its large optical anisotropy with the birefringence 0.125@546 nm; meanwhile, the structure-performance relationships were analyzed by the first-principle calculation.

The First Mixed Calcium Zinc Borate with a Flexible [B8 O17 ] Fundamental Building Block and Short UV Cutoff Edge.

The first mixed calcium zinc borate with a new fundamental building block (FBB) [B8 O17 ], Ca1.13 Zn0.87 B8 O14 has been successfully synthesized. It exhibits two independent interpenetrating three-dimensional B-O anion networks constructed by [B8 O17 ] groups, enriching the structural diversity of B-O configurations. In particular, the UV-Vis-NIR diffuse-reflectance spectrum shows that it has a short UV cutoff edge (<195 nm).

Cation Substitution of Hexagonal Triple Perovskites: A Case in Trimetallic Tellurates A2A'BTe2O9.

Three new tellurates, namely, K2BaPb0.62Ba0.38Te2O9 (1), Rb2BaPb0.7Ba0.3Te2O9 (2), and Ba2KLiTe2O9 (3), with hexagonal triple-perovskite structures have been designed via a cation substitution strategy. All three centrosymmetric compounds crystallize in the same hexagonal space group P63/mmc. In their structures, the [BTe2O9] (B = Pb/Ba for 1 and 2 and Li for 3) groups construct the final three-dimensional framework using face-sharing [Te2O9] dimmers and vertex-linked [BO6] linkages. Meanwhile, the theoretical calculations demonstrate the numerical differences of their birefringence. Thermal stability analysis and differential scanning calorimetry were performed, and UV-vis-NIR diffuse reflectance spectra and infrared spectra of the three title compounds were also characterized and analyzed.

Li3La2(BO3)3 and Li1.75Na1.25La2(BO3)3: A Great Enhancement in Birefringence Induced by Optimal Arrangement of π-Conjugated [BO3] Units.

In virtue of the essential role in controlling polarized light, outstanding ultraviolet (UV) and deep-ultraviolet (DUV) birefringent crystals are imperative in many advanced optical instruments. To design the UV and DUV crystals with large birefringence, we paid more attention to combining the excellent gene, π-conjugated [BO3] unit and metal cations beneficial to blue-shift the cutoff edge; finally, two rare-earth borates Li3La2(BO3)3 and Li1.75Na1.25La2(BO3)3 have been synthesized using the high-temperature solution method. Compared with Na3La2(BO3)3, Li3La2(BO3)3 and Li1.75Na1.25La2(BO3)3 are isostructural, and the isolated [BO3] units are arranged nearly parallel to each other in the structure, which is conducive to generating a larger birefringence. The structural comparison between the two crystals and Na3La2(BO3)3 indicates that the various coordination environments of alkali metal cations play an important role in the evolution of the crystal structure from Li3La2(BO3)3 and Li1.75Na1.25La2(BO3)3 to Na3La2(BO3)3. This work can contribute to a better understanding of the enhancement in birefringence from Na3La2(BO3)3 (0.023 @ 1064 nm) to Li3La2(BO3)3 (0.078 @ 1064 nm) with the perspective of structure-property relationships. Meanwhile, the two title crystals possess the DUV cutoff edge (<190 nm), suggesting that they can be applied as the DUV birefringent crystals.

α-SnF2 : A UV Birefringent Material with Large Birefringence and Easy Crystal Growth.

The simple binary fluoride α-SnF2 is shown to be an excellent birefringent material with outstanding birefringence, about 14 times that of MgF2 . Furthermore, it exhibits a shorter UV cutoff edge and easy crystal growth at ambient temperature compared to YVO4 and TiO2 . A novel theoretical calculation mode was established to analyze the stereochemical-activity lone-pair (SCALP) contribution to the birefringence (SCB) based on the SCALP's strength and arrangement, and it was found that the large birefringence of α-SnF2 mainly benefits from well-aligned [SnF5 ] polyhedra with a strong SCALP. The exploration of the α-SnF2 birefringent crystal points out the direction of the future search for excellent birefringent materials.

Discovery of First Magnesium Fluorooxoborate with Stable Fluorine Terminated Framework for Deep-UV Nonlinear Optical Application.

The generated light can be tuned to cover almost the entire spectral range from deep-ultraviolet to terahertz wavelengths by utilizing the nonlinear optical crystals with a simple frequency doubling process. Among them, the discovery of novel candidates for the production of deep-ultraviolet light is by extension a great challenge toward realizing the vast potential. Actually, the availability for this process mainly depends on whether the critical performance can be well coexisted in one practical crystal. Herein, the first magnesium fluorooxoborate MgB5 O7 F3 was synthesized as a new competitive candidate for deep-ultraviolet nonlinear optical application. It has a sufficiently large nonlinearity and a deep-ultraviolet phase matching wavelength, indicating that it holds great potential for the production of coherent light below 200 nm. The critical performance enhancement of MgB5 O7 F3 when compared with its isomorphic phases was demonstrated and discussed. More importantly, we proposed that fluorooxoborate system with the general formula of MB5 O7 F3 (M=divalent metal) possesses stable fluorine terminated framework, which makes them tend to retain their crystallized space groups unchanged.

Sn2 PO4 I: An Excellent Birefringent Material with Giant Optical Anisotropy in Non π-Conjugated Phosphate.

Exploring non π-conjugated phosphate birefringent crystal with a large birefringence has been a great challenge. Herein, based on the unique two-dimensional layered structure in KBe2 BO3 F2 (KBBF), two new compounds, Sn2 PO4 I and Sn2 BO3 I, were designed and synthesized successfully, maintaining the layer structural feature and enhancing the optical anisotropy of crystals. In particular, the birefringence of Sn2 PO4 I is larger than or equal to 0.664 @546 nm, which is largest among the reported borates and phosphates, even surpassing commercial birefringent crystals YVO4 and TiO2 . This work indicates that a breakthrough in birefringence of inorganic compound was achieved. Also, it provides a guiding idea for exploring large birefringence materials in the future.

Hydroxyfluorooxoborate Na[B3 O3 F2 (OH)2 ]⋠[B(OH)3 ]: Optimizing the Optical Anisotropy with Heteroanionic Units for Deep Ultraviolet Birefringent Crystals.

Maximizing the optical anisotropy in birefringent materials has emerged as an efficient route for modulating the polarization-dependent light propagation. Currently, the generation of deep-ultraviolet (deep-UV) polarized light below 200 nm is essential but challenging due to the interdisciplinary significance and insufficiency of high-performing birefringent crystals. Herein, by introducing multiple heteroanionic units, the first sodium difluorodihydroxytriborate-boric acid Na[B3 O3 F2 (OH)2 ]⋅[B(OH)3 ] has been characterized as a novel deep-UV birefringent crystal. Two rare heteroanionic units, [B3 O3 F2 (OH)2 ] and [B(OH)3 ], optimally align to induce large optical anisotropy and also the dangling bonds are eliminated with hydrogens, which results in an extremely large birefringence and band gap. The well-ordered OH/F anions in [B3 O3 F2 (OH)2 ] and [B(OH)3 ] were identified and confirmed by various approaches, and also the origin of large birefringence was theoretically discussed. These results confirm the feasibility of utilizing hydrogen involved heteroanionic units to design crystals with large birefringence, and also expand the alternative system of deep-UV birefringent crystals with new hydroxyfluorooxoborates.

Band-Gap Modulation of Nonlinear-Optical Fluorooxoborates by Controlling the F/B Ratios.

A large band gap is an important prerequisite for deep-ultraviolet materials. Here we provide a strategy to adjust the band gaps by tuning the F/B ratios. By analyzing the molecular orbitals of fluorooxo-functional groups and the electronic structures of fluorooxoborates, we find that the fluorooxo-functional groups with high F/B ratio change the composition of the highest occupied and lowest unoccupied molecular orbitals and the corresponding valence-band maximum/conduction-band minimum.

Gold nanorods-based multicolor immunosensor for visual detection of enterovirus 71 infection.

Based on the etching of gold nanorods (GNRs) and enzyme-linked immunosorbent assay (ELISA), a multicolor immunosensor for visual detection of enterovirus 71 infection is proposed. Once the immunocomplex is formed, the horseradish peroxidase bound to the ELISA plate oxidizes 3,3',5,5'-tetramethylbenzidine (TMB) into TMB2+ in the presence of hydrogen peroxide. Subsequently, TMB2+ quantitatively etches GNRs to the short GNRs, leading to a blue shift of longitudinal localized surface plasmon resonance and corresponding color responses. This change is used to develop two types of cut-off standards, which respond to the human anti-enterovirus at a concentration of 71 IgM antibody. The method has been validated with clinical serum samples and showed high sensitivity and specificity . This visual immunosensor has an important application value for point-of-care detection of EV71, especially in areas lacking detection equipment. Graphical abstract.