PO4 Groups Research Articles

Formulasi dan Karakterisasi Nanopartikel Ekstrak Biji Carica (Carica pubescens) dengan Variasi Konsentrasi Kitosan menggunakan Metode Gelasi Ionik

Carica seeds (Carica pubescens) contain alkaloid, saponin, and flavonoid compounds, which have pharmacological activities such as antibacterial, anti-inflammatory, immunomodulatory, and antihyperlipidemic properties, but their bioavailability is low. Nanotechnology has significantly advanced in drug delivery systems because it can enhance absorption in the gastrointestinal tract, allowing entry into the bloodstream. This study aims to create and evaluate the characteristics of carica seed extract nanoparticles with varying concentrations of chitosan. The carica seed extract was obtained using the maceration method with 70% ethanol as the solvent. The Carica seed extract was then formulated into nanoparticles using the ionic gelation method with varying concentrations of chitosan: NaTPP, specifically formulas FA (0.3:1), FB (0.2:1), and FC (0.1:1). The resulting nanoparticle colloids were characterized for particle size, polydispersity index (PDI), percent transmittance (%T), and specific functional groups. The results showed that the particle sizes for formulas FA, FB, and FC were 243.7 nm, 47.96 nm, and 116.6 nm, respectively. The PDI values for formulas FA, FB, and FC were 0.378, 0.357, and 0.52, respectively. The percent transmittance for all three formulas ranged from 99.5% to 99.6%. The characterization of functional groups indicated interactions between the carica seed extract, chitosan, and NaTPP, with the presence of OH, N-H, aliphatic CH, P=O, and PO3 groups. These interactions were observed based on the shift in wavenumbers in the FTIR results for each sample. All carica seed nanoparticle formulas showed particle sizes within the nanometer range (<1000 nm), polydispersity indices less than 1, percent transmittance close to 100%, and specific functional groups indicating interactions between the extract and the coating polymer. Formula FB was the optimal formula, with the smallest nanoparticle size (<100 nm), a PDI value of <0.5, and a percent transmittance of >99%.

Impact of ion exchange on vibrational modes in Rb-doped KTiOPO4 : A Raman spectroscopy study on the interplay between ion exchange and polarization switching

Recently, ion exchange (IE) has been used to periodically modify the coercive field (Ec) of the crystal prior to periodic poling, to fabricate fine-pitch domain structures in Rb-doped KTiOPO4 (RKTP). Here, we use micro-Raman spectroscopy to understand the impact of IE on the vibrational modes related to the Rb/K lattice sites, TiO6 octahedra, and PO4 tetrahedra, which all form the basis of the RKTP crystal structure. We analyze the Raman spectra of three different RKTP samples: (1) a RKTP sample that shows a poled domain grating only, (2) a RKTP sample that has an Ec grating only, and (3) a RKTP sample that has both an Ec and a domain grating of the nominally same spacing. This allows us to determine the impact of IE on the vibrational modes of RKTP. We characterize the changes in the lower Raman peaks related to the alkali-metal ions, as well as observe lattice modifications induced by the incorporation of Rb+ that extend further into the crystal bulk than the expected IE depth. Moreover, the influence of IE on the domain walls is also manifested in their Raman peak shift. We discuss our results in terms of the deformation of the PO4 and TiO6 groups. Our results highlight the intricate impact of IE on the crystal structure and how it facilitates periodic poling, paving the way for further development of the Ec-engineering technique. Published by the American Physical Society 2024

Role of BPO4 flux in BaBPO5 crystal growth characterized through high-temperature Raman spectroscopy

In this study, we explored the growth of incongruently melting crystals in a starting solution with flux to better understand the role of flux in crystal growth mechanisms. We recorded the spectrum of BaBPO5 crystals across a 200-1400 cm−1 range for detailed Raman spectroscopic analysis. The observed Raman bands corresponded to the vibrations of PO4 and BO4 units. These units link with B-O-P bonds via common corners to form PBO7 groups that serve as basic structural units of the crystal. Notably, these PBO7 structures remain stable at high temperatures up to the crystal melting point, at which the isolated PO4 groups predominantly exist in the melt, as revealed by high-temperature Raman spectroscopy. Further investigations into the Raman spectra of the starting solution enriched with BPO4 self-flux indicate that PBO7 groups are crucial for crystal growth. The addition of PBO4 flux aids in the formation of these PBO7 units. This research paves the way for expanding our understanding to other systems, which will help elucidate the mechanisms behind crystal growth.

Exploring the influence of yttrium on the structural, physical, and optical properties of sol-gel synthesized silicophosphate glasses for photonics applications

Yttrium-incorporated silicophosphate glasses hold significant appeal in key sectors such as photonics, optoelectronics, lasers, biomedical applications, and light-emitting diodes (LEDs). In this study, the sol-gel method has been used to prepare the pure and yttrium-doped silicophosphate glasses. The aim of this study is to discover the effect of yttrium doping on the structural, physical, and optical properties of silicophosphate glasses. Various techniques such as X-ray diffraction (XRD), FTIR spectroscopy, and UV–visible analysis have been employed to examine the structural and optical properties of the prepared samples. The XRD analysis confirmed that all the prepared samples exhibited an amorphous nature. Optical measurements conducted indicated that the incorporation of trivalent yttrium ions led to an increase in the refractive index of the prepared samples. Furthermore, a decrease in the energy band-gap values of the samples was observed. The FTIR spectral analysis unveiled the presence of diverse vibration modes in the synthesized samples. These encompassed symmetrical and asymmetrical stretching vibrations of P-O-P linkages, bending vibrations of P-O in PO4 groups, elongation and flexure vibrations of OH groups, and water absorption vibrations of P-O-H in the glasses. The acquired spectra robustly substantiate the function of yttrium oxide as a network modifier within the silicophosphate glass system. The theoretical values of optical basicity (Λth) demonstrated an increase from 0.465 to 0.472, while the values of the interaction parameter (A) exhibited a decrease from 0.218 Å−3 to 0.215 Å−3. Silicophosphate glasses doped with trivalent yttrium ions exhibit significant potential as materials for optoelectronic devices and optical filter systems.

Thermal characteristics of LiMnxFe1-xPO4 (x = 0, 0.6) cathode materials for safe lithium-ion batteries

Lithium-ion batteries have recently gained attention as energy storage devices due to their high energy densities and various applications. Layered Ni-Mn-Co-based cathode materials are widely used for their high energy density; however, their high cost necessitates the exploration of alternatives. Consequently, olivine-type LiMnxFe1-xPO4 materials are gaining popularity and are being increasingly adopted. While the synthesis methods and electrochemical properties of these materials have been extensively studied, thermal analyses remain limited. In this study, we investigated the thermal properties of olivine-type LiMnxFe1-xPO4 by combining thermal analysis, structural analysis, and computational calculations to evaluate the safety of lithium-ion batteries. Our results show that the formation energy of LiMn0.6Fe0.4PO4 is more stable than that of LiFePO4. As temperature increases, LiFePO4 decomposes at 350 °C, whereas LiMn0.6Fe0.4PO4 begins to decompose at 450 °C. The P-O bond plays a crucial role in the thermal stability of these materials; as the temperature rises, the thermal stability of the PO4 group diminishes, leading to structural decomposition. To enhance thermal stability, it is recommended to experiment with doping small amounts of various elements at the P site. This paper provides valuable insights for the design and development of thermally stable olivine-structured cathodes for lithium-ion batteries.

Direct writing of calcium phosphate/graphite nanocomposite film using laser-induced graphitization of polyimides

We report the direct writing of calcium phosphate/graphite nanocomposite using laser-induced graphitization of suspension-covered polyimide (PI) films. Calcium phosphate/graphite nanocomposites are desirable for the osteoconductive, osteoconductive, and resorptive properties of calcium phosphate and the electrical conductivity of graphitic carbon. Two forms of calcium phosphate, namely, EggCaP and CaOP, were synthesized by chemomechanical alloying of diammonium hydrogen phosphate (DHP) with eggshells – a waste material – and reagent-grade calcium oxide (CaO) powders, respectively. Fourier transform infrared (FTIR) spectroscopy of the synthesized powders revealed the phase change of starting materials to calcium phosphates (CaP), and powders were suspended in methanol to form printing suspension. Laser irradiation of synthesized CaP powder suspension-covered polyimide (PI) surfaces resulted in the formation of electrically conductive films due to laser-induced graphitization of PI. Laser-induced graphited films based on EggCaP suspension (ELIG) and CaOP (CLIG) had a sheet resistance of 25 Ω/∎ and 30 Ω/∎, respectively, and had lower resistance than the LIG films formed from bare PI (60 Ω/∎). Raman spectroscopy revealed that repeated laser irradiation of ELIG and CLIG film led to decreased defects and higher graphitization. ELIG had an ID/IG ratio of 0.65 after the first irradiation, but repeated irradiation reduced the ratio to 0.38. Similarly, CLIG had a higher ID/IG ratio of 0.55 during the first irradiation, and repeated irradiation reduced it to 0.42. Furthermore, CO, CO stretch modes, and various PO4 groups were also found in the Raman spectrum, indicating the formation of CaP/graphite nanocomposites in the graphitized films. SEM results showed that both graphitized films had closed foam-like microstructure with CaP particles deposited on the pore walls. Films formed after single irradiation had discrete CaP particle deposits on the surface, but repeated laser irradiation led to the integration of CaP particles into the pore walls. The ELIG films showed higher incorporation of the CaP particles and the highest electrical conductivity. The laser-induced graphitic transformation leads to incorporating the CaP particles into a conductive substrate, resulting in a CaP/graphite nanocomposite. The high electrical conductivity, closed-foam-like microstructure, porosity, biocompatibility, and hierarchical surface roughness of the ELIG and CLIG films make them attractive for biosensors, bioelectronics, and implant applications.

Lithium ionic conductivity and structural studies of NASICON structured Li0.4Sr0.3Zr0.5Ti1.5(PO4)3

Stable solid electrolytes have been the subject of intense research due to the growing demand for energy storage and portable energy sources in rechargeable Li-ion batteries. Sodium (NA) super (S) ionic (I) conductor (CON) abbreviated as NASICON are suitable for use as solid electrolytes due to their excellent ionic conductivity and chemical stability. We have reported the effect of partial doping of Sr at Li and Zr4+ at Ti4+ position on the structure and ionic conductivity of composition Li0.4Sr0.3Ti2(PO4)3 (LSTP). The composition with formula Li0.4Sr0.3Ti2−xZrx(PO4)3 (x = 0.0, 0.5, 2.0) were prepared by solid state reaction method. The phase and crystal structure were examined using X-ray diffraction (XRD) patterns. The compositions were in rhombohedral phase with the space group R 3¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline{3}$$\\end{document} c. The doping of Zr4+ in LSTP causes the peaks in the XRD spectra for doped composition (x = 0.5, 2.0) to move towards lower angle. The displacement of the XRD peaks towards lower angle side show the expansion in the lattice of the Zr doped compositions Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 and Li0.4Sr0.3Zr2(PO4)3. The presence of stretching and bending modes of PO4 groups in the prepared compositions was identified by FTIR spectra. The enhanced bulk conductivity of 4.32 × 10–5 S/cm for Zr doped composition Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 and 3.20 × 10–5 S/cm for composition Li0.4Sr0.3Zr2(PO4)3 is observed at 25 °C. The modulus peaks in the Zr doped composition Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 is displaced towards higher frequencies at 450 °C, indicating the presence of the thermally produced dielectric relaxation phenomenon and charge carrier hopping. The cole cole plot consisting of one semicircle in case of Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 discusses the contribution of bulk and grain boundary resistances and is fitted by equivalent circuit consisting of CPE and R element joined in parallel.

Preparation of Nb5+ Doped Na3V2(PO4)3 Cathode Material for Sodium Ion Batteries.

Sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries (LIBs) due to the abundance and low cost of sodium resources. Cathode material plays a crucial role in the performance of sodium ion batteries determining the capacity, cycling stability, and rate capability. Na3V2(PO4)3 (NVP) is a promising cathode material due to its stable three-dimensional NASICON structure, but its discharge capacity is low and its decay is serious with the increase of cycle period. We focused on modifying NVP cathode material by coating carbon and doping Nb5+ ions for synergistic electrochemical properties of carbon-coated NVP@C as a cathode material. X-ray diffraction analysis was performed to confirm the phase purity and crystal structure of the Nb5+ doped NVP material, which exhibited characteristic diffraction peaks that matched well with the NASICON structure. Nb5+-doped NVP@C@Nbx materials were prepared using the sol-gel method and characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Raman and Brunauer -Emmett-Teller (BET) analysis. First-principles calculations were performed based on density functional theory. VASP and PAW methods were chosen for these calculations. GGA in the PBE framework served as the exchange-correlation functional. The results showed the NVP unit cell consisted of six NVP structural motifs, each containing octahedral VO6 and tetrahedral PO4 groups to form a polyanionomer [V2(PO4)3] along with the c-axis direction by PO4 groups, which had Na1(6b) and Na2(18e) sites. And PDOS revealed that after Nb doping, the d orbitals of the Nb atoms also contributed electrons that were concentrated near the Fermi surface. Additionally, the decrease in the effective mass after Nb doping indicated that the electrons could move more freely through the material, implying an enhancement of the electron mobility. The electrochemical properties of the Nb5+ doped NVP@C@Nb cathode material were evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge tests, electrochemical impedance spectroscopy (EIS), and X-ray photoelectric spectroscopy (XPS). The results showed that NVP@C@Nb0.15 achieved an initial discharge capacity as high as 114.27 mAhg-1, with a discharge capacity of 106.38 mAhg-1 maintained after 500 cycles at 0.5C, and the retention rate of the NVP@C@Nb0.15 composite reached an impressive 90.22%. NVP@C@Nb0.15 exhibited low resistance and high capacity, enabling it to create more vacancies and modulate crystal structure, ultimately enhancing the electrochemical properties of NVP. The outstanding performance can be attributed to the Nb5+-doped carbon layer, which not only improves electronic conductivity but also shortens the diffusion length of Na+ ions and electrons, as well as reduces volume changes in electrode materials. These preliminary results suggested that the as-obtained NVP@C@Nb0.15 composite was a promising novel cathode electrode material for efficient sodium energy storage.

Hybrid Density Functional Theory Calculations for the Crystal Structure and Electronic Properties of Al3+ Doped KDP Crystals

Intentionally adding select ions such as Al3+ could be helpful in controlling the crystal habit of KDP crystal for high yield of optics. The study of how Al3+ ions affect crystal quality can provide a basis for selecting an appropriate doping level without negatively affecting the optical properties of crystals. Here, the influence of Al3+ ions on the crystal structure and properties of KDP crystals have been investigated by using first-principles calculations. Theoretical calculations show that Al3+ ions mainly replace K sites in KDP crystals and could complex with intrinsic VH− point defects to form AlK2+ + 2VH− cluster defects. The linear absorption spectra indicate that the presence of Al3+ ions has minimal impact on the linear absorption of KDP crystals, aligning well with the experimental findings. And Al3+ ions could cause a slight shortening of the band gap of KDP crystals. However, these ions could bring significant deformations of O-H bonds. As the concentration of Al3+ ions increase, more O-H bonds linking to PO4 groups are distorted in KDP crystals. As a result, the structural instability could be fast enhanced with increasing the defect concentration. Therefore, high concentrations of Al3+ ions could cause the instability of the crystal structure, which finally affects the laser-induced damage resistance of the KDP crystals. This manuscript contributes to a more comprehensive understanding of the physical mechanisms by which different impurity ions affect the optical properties of KDP crystals.

How a Single 5 eV Electron Can Induce Double-Strand Breaks in DNA: A Time-Dependent Density Functional Theory Study.

Low-energy (<20 eV) electrons (LEEs) can resonantly interact with DNA to form transient anions (TAs) of fundamental units, inducing single-strand breaks (SSBs), and cluster damage, such as double-strand breaks (DSBs). Shape resonances, which arise from electron capture in a previously unfilled orbital, can induce only a SSB, whereas a single core-excited resonance (i.e., two electrons in excited orbitals of the field of a hole) has been shown experimentally to cause cluster lesions. Herein, we show from time-dependent density functional theory (TDDFT) that a core-excited resonance can produce a DSB, i.e., a single 5 eV electron can induce two close lesions in DNA. We considered the nucleotide with the G-C base pair (ds[5'-G-3']) as a model for electron localization in the DNA double helix and calculated the potential energy surfaces (PESs) of excited states of the ground-state TA of ds[5'-G-3'], which correspond to shape and core-excited resonances. The calculations show that shape TAs start at ca. 1 eV, while core-excited TAs occur only above 4 eV. The energy profile of each excited state and the corresponding PES are obtained by simultaneously stretching both C5'-O5' bonds of ds[5'-G-3']. From the nature of the PES, we find two dissociative (σ*) states localized on the PO4 groups at the C5' sites of ds[5'-G-3']. The first σ* state at 1 eV is due to a shape resonance, while the second σ* state is induced by a core-excited resonance at 5.4 eV. As the bond of the latter state stretches and arrives close to the dissociation limit, the added electron on C transfers to C5' phosphate, thus demonstrating the possibility of producing a DSB with only one electron of ca. 5 eV.

A Noncentrosymmetric Metal-Free Borophosphate: Achieving a Large Birefringence and Excellent Stability by Covalent-Linkage.

Organic-inorganic hybrid linear and nonlinear optical (NLO) materials have received increasingly wide spread attention in recent years. Herein, the first hybrid noncentrosymmetric (NCS) borophosphate, (C5H6N)2B2O(HPO4)2 (4PBP), is rationally designed and synthesized by a covalent-linkage strategy. 4-pyridyl-boronic acid (4PB) is considered as a bifunctional unit, which may effectively improve the optical properties and stability of the resultant material. On the one hand, 4PB units are covalently linked with PO3(OH) groups via strong B-O-P connections, which significantly enhances the thermal stability of 4PBP (decomposition at 321, vs lower 200°C of most of hybrid materials). On the other hand, the planar π-conjugated C5H6N units and their uniform layered arrangements represent large structural anisotropy and hyperpolarizability, achieving the largest birefringence (0.156 @ 546nm) in the reported borophosphates and a second-harmonic generation response (0.7 × KDP). 4PBP also exhibits a wide transparency range (0.27-1.50µm). This work not only provides a promising birefringent material, but also offers a practical covalent-attachment strategy for the rational design of new high-performance optical materials.

Phosphate uptake is an essential process for rapid bone mineralization during early diagenesis – evidence from bone alteration experiments

Bones and teeth are often the only fossil remains of vertebrates that are preserved over geological time in sedimentary rocks. They render valuable archives for geochemical proxies which are commonly used for paleo-reconstructions. However, the fossilization mechanisms of bone are not yet well understood. Crucial processes are the transformation of bioapatite into and the replacement of collagen by thermodynamically more stable apatite phases, such as fluorapatite. In the present study, aqueous alteration experiments on cortical bone samples were performed under simulated early diagenetic conditions in order to investigate whether and how an external phosphate (PO4) source affects post mortem bone mineralization. Additionally, abiotic oxygen isotope exchange mechanisms between bioapatite and aqueous solutions were assessed by using either 18O-enriched water or PO4 as a tracer. The presence of an external sedimentary 18O-labeled PO4 source led to a rapid formation of new fluorapatite crystallites at the sample’s margin that was highly enriched in 18O. Meanwhile, in the interior of the samples carbonate-poor hydroxylapatite formed through a dissolution-precipitation process without incorporating significant amounts of the 18O tracer. These two processes appear to act independently from each other. In samples exposed to 18O-labeled aqueous solutions lacking a PO4 source, no newly grown apatite crystallites were found, however in the interior of these samples, nano-crystalline carbonate-poor or -free hydroxylapatite precipitated. A comparatively low but uniform 18O-enrichment was measured from the sample’s margin towards its interior, which is assumed to have resulted from the adsorption of H218O onto crystallite surface sites and collagen. Overall, our results suggest that a fast incorporation of 18O-doped PO4 from the sediment source accelerated bone mineralization and consequently changed the oxygen isotope composition of the PO4 group in the bone mineral phase more rapidly and to a greater extent than in a diagenetic setting lacking additional external PO4. Dissolved PO4 from the taphonomic setting thus seems to be an important factor fostering bone fossilization and preservation as well as oxygen isotope alteration.

Heart rate characteristics predict risk of mortality in preterm infants in low and high target oxygen saturation ranges.

The Neonatal Oxygenation Prospective Meta-analysis found that in infants <28 weeks gestational age, targeting an oxygen saturation (S pO2 ) range of 85-89% versus 91-95% resulted in lower rates of retinopathy of prematurity but increased mortality. We aimed to evaluate the accuracy of the heart rate characteristics index (HRCi) in assessing the dynamic risk of mortality among infants managed with low and high target S pO2 ranges. We linked the SUPPORT and HRCi datasets from one centre in which the randomised controlled trials overlapped. We examined the maximum daily HRCi (MaxHRCi24) to predict mortality among patients randomised to the lower and higher target S pO2 groups by generating predictiveness curves and calculating model performance metrics, including area under the receiver operating characteristics curve (AUROC) at prediction windows from 1-60 days. Cox proportional hazards models tested whether MaxHRCi24 was an independent predictor of mortality. We also conducted a moderation analysis. There were 84 infants in the merged dataset. MaxHRCi24 predicted mortality in infants randomised to the lower target S pO2 (AUROC of 0.79-0.89 depending upon the prediction window) and higher target S pO2 (AUROC 0.82-0.91). MaxHRCi24 was an important additional predictor of mortality in multivariable modelling. In moderation analysis, in a model that also included demographic predictor variables, the individual terms and the interaction term between MaxHRCi24 and target S pO2 range all predicted mortality. Associations between HRCi and mortality, at low and high S pO2 target ranges, suggest that future research may find HRCi metrics helpful to individually optimise target oxygen saturation ranges for hospitalised preterm infants.

Boosting sodium-ion battery performance by anion doping in NASICON Na4MnCr(PO4)3 cathode

Na superionic conductor (NASICON)-structured Na4MnCr(PO4)3 (NMCP) possessing unique three-electron transfer process renders admirable energy density for sodium ion batteries (SIBs). However, the current issues like its sluggish Na+ diffusion kinetics, deficient intrinsic conductivity, and unsatisfactory structural stability, hinder its practical application. Herein, a selective replacement of O elements in PO4 group by Cl anions in the NMCP system was developed to significantly enhance its electrochemical performance. The results affirm that the enhanced performance of Cl doped samples can be attributed to the enlargement of cell size, the creation of Na vacancies and the weakness of Na2O bond after Cl doping. The as-prepared Na3.85□0.15MnCr(PO3.95Cl0.05)3/C (NMCPC − 15/C) cathode delivers a high capacity (128.0 mAh/g at 50 mA g−1) and excellent rate performance (73.0 mAh/g at 1000 mA g−1) in contrast to NMCP/C that merely provides 105.2 mAh/g at 50 mA g−1 and reduces to 47.4 mAh/g at 1000 mA g−1. Meanwhile, NMCPC − 15/C shows a capacity retention of 60.7 % at 1000 mA g−1 after 500 cycles, while only 37.1 % for NMCP/C in the same test conditions. Moreover, the satisfactory performance and energy density of NMCPC − 15/C||hard carbon (HC) full cell confirm the potential practicality of NMCPC − 15. Therefore, chloride ions doping into NMCP has practical application prospects in the preparation of high-performance cathode materials and our work also offers new inspiration to apply anion doping strategies in promoting the performance of the other NASICON-structured cathodes for SIBs.

Na12(NbO)3(PO4)7: A Congruent Melting Nonlinear Optical Crystal with Large NbO6 Distortion and High Laser-Induced Damage Threshold.

A new noncentrosymmetric crystal Na12(NbO)3(PO4)7 was successfully synthesized in the niobium phosphate system. Its structure characterizes isolated and highly distorted NbO6 octahedra joining with isolated PO4 groups to form a unit of a (Nb6P6O12) hexagonal star by sharing O atoms. In (Nb6P6O12) hexagonal stars, all Nb and P atoms are in a hexagonal star-like arrangement and all Na atoms are also in a hexagonal star-like arrangement, except for Na(3) and Na(10) atoms. Notably, it exhibits a strong phase-matched second harmonic response: 3 × KDP, which is rare in known niobium phosphate systems. Meanwhile, it also has a wide optically transparent window (0.29-4.44 μm) and a high laser-induced damage threshold (3.5 GW/cm2). More importantly, Na12(NbO)3(PO4)7 is a congruent melting compound that has the potential to be grown into large-sized single crystals by the Czochralski method. These excellent properties make it a promising candidate as a mid-infrared nonlinear optical crystal.

Enhanced Adsorption Stability and Biofunction Durability with Phosphonate-Grafted, PEGylated Copolymer on Hydroxyapatite Surface.

Nonfouling surfaces are crucial in applications such as biosensors, medical implants, marine coatings, and drug delivery vehicles. However, their long-term coating stability and robust surface binding strength in physiological media remain challenging. Herein, a phosphonate-grafted, PEGylated copolymer on the hydroxyapatite (HA) surface is proposed to significantly improve the adsorption stability and thus enhance the biofunction durability accordingly. The phosphoryl (-PO3) grafted branch is employed in the functional polymer to facilitate attaching to the HA substrate. In addition, the polymer integrates the nonfouling polymer brushes of poly(ethylene glycol) (PEG) with the cell-adhesive moiety of cyclic Arg-Gly-Asp-d-Phe-Cys peptides (cRGD). A systematic study on the as-synthesized PEGylated graft copolymer indicates a synergistic binding mechanism of the NH2 and PO3 groups to HA, achieving a high surface coverage with desirable adsorption stability. The cRGD/PEGylated copolymers of optimized grafting architecture are proven to effectively adsorb to HA surfaces as a self-assembled copolymer monolayer, showing stability with minimal desorption even in a complex, physiological medium and effectively preventing nonspecific protein adsorption as examined with X-ray photoelectron spectroscopy (XPS) and a quartz crystal microbalance with dissipation (QCM-D). Direct adhesion assays further confirm that the enhanced coating stability and biofunction durability of the phosphonate-grafted, cRGD-PEGylated copolymer can considerably promote osteoblast attachment on HA surfaces, meanwhile preventing microbial adhesion. This research has resulted in a solution of self-assembly polymer structure optimization that exhibits stable nonfouling characteristics.

Structural and compositional data for childrenite from the Homolka granite, Czech Republic

Abstract. Members of the childrenite–eosphorite series, ideally (Fe1−xMnx)AlPO4(OH)2⋅H2O, from the highly evolved Homolka granite, in the southern Czech Republic, were characterized using a multi-analytical approach. They occur as anhedral grains, up to ∼0.2 mm in size, associated with quartz, muscovite, albite, and K-feldspar. Tiny inclusions of probable uraninite have been observed. Backscattered electron images reveal a patchy zoning of these members of the childrenite–eosphorite series, related to an uneven distribution of Fe and Mn. On the basis of electron microprobe analysis, the average composition of the studied material is (Fe0.68Mn0.28Ca0.03)Σ0.99Al0.96(P1.04Si0.01)Σ1.05O4.00(OH)2.09⋅0.91H2O, thus corresponding to childrenite. Unit-cell parameters of this species are a=6.9226(9), b=10.4081(13), c=13.3957(17) Å. Its crystal structure was refined in the space group Cmca down to R1=0.0295 on the basis of 602 unique reflections with Fo&gt;4σ(Fo) and 66 refined parameters. The crystal structure analysis agrees with the results of electron microprobe analysis and suggests that, in the studied material, Fe occurs in the divalent oxidation state only. Crystal structure data are also consistent with the Raman spectrum collected on the same grain that was structurally characterized, confirming the occurrence of PO4 groups only in childrenite.

Performance evaluation of wastewater treatment plants in Taman’s public health center in Sidoarjo District

Introduction: In general, wastewater produced by Public health centers contains many microorganisms, pathogenic compounds, and hazardous and toxic chemicals that can cause environmental pollution and transmit various diseases.1 The danger posed by the liquid waste produced is quite large, so it is necessary to have a wastewater treatment process before it is disposed of. Wastewater treatment is carried out using a wastewater treatment plant (WWTP). Thus, this study aims to evaluate the performance, environment and economy of WWTPs in Public health centers. Methods: This research uses descriptive quantitative research methods. The inclusion criteria were the laboratory data results in 2018 and 2019. The exclusion criteria were the data needed to be completed. The research variable was the performance of the WWTP on wastewater quality. The data analysis of the laboratory test results is analyzed and compared with the East Java Governor Regulation Number 72 of 2013 concerning Wastewater Quality Standards for Business and Hospital Activities. Results: The results of laboratory tests in 2018 showed the parameters by the requirements according to regulations, such as temperature, pH, BOD5, COD and TSS. At the same time, the parameters were not following requirements according to rules such as free NH3-N, PO4 and MPN-coliform bacteria. Data from laboratory test results in 2019 showed requirements according to regulations: temperature, pH, BOD5, and TSS. The effects on the COD parameter were seen only in July that they did not follow the requirements, while most of the results for the NH3-N, PO4 and MPN-free coli groups did not meet the criteria. Conclusion: Based on the research done in this study, the following conclusions can be drawn: The results of the performance evaluation of the WWTP at the Taman Public health center are included in the category that meets the stipulated regulatory requirements.

The Crystal Structure of Pb10(PO4)6O Revisited: The Evidence of Superstructure

The crystal structure of Pb10(PO4)6O, the proposed matrix for the potential room-temperature superconductor LK-99, Pb10−xCux(PO4)6O (x = 0.9–1.0), has been reinvestigated via single-crystal X-ray diffraction using crystals prepared by Merker and Wondratschek (Z. Anorg. Allg. Chem. 1960, 306, 25–29). The crystal structure is trigonal, P3¯, a = 9.8109(6), c = 14.8403(12) Å, V = 1237.06(15), R1 = 0.0413 using 3456 unique observed reflections. The crystal structure of Pb10(PO4)6O is a superstructure with regard to the ‘standard’ P63/m apatite structure type. The doubling of the c parameter is induced through the ordering of the split sites of ‘additional’ O’ atoms within the structure channels running parallel to the c axis and centered at (00z). The O’ atoms form short bonds to the Pb1 atoms, resulting in splitting the Pb1 site into two, Pb1A and Pb1B. The structural distortions are further transmitted to the Pb phosphate framework formed by four Pb2 sites and PO4 groups. The structure data previously reported by Krivovichev and Burns (Z. Kristallogr. 2003, 218, 357–365) may either correspond to the Pb10(PO4)6Ox(OH)2−2x (x ~ 0.4) member of the Pb10(PO4)6O—Pb10(PO4)6(OH)2 solid solution series, or to the high-temperature polymorph of Pb10(PO4)6O (with the phase with doubled c parameter being the low-temperature polymorph).

Na2Mg2P2O7F2: A new diphosphate of the cuspidine family without disorder designed by targeted structural modulation

A new alkali/alkali-earth metal pyrophosphate fluoride Na2Mg2P2O7F2 without the structural disorder in the cuspidine family has been successfully prepared in the sealed system. Na2Mg2P2O7F2 crystallizes in the space group P21/c (No. 14) of the monoclinic crystal system. The structure of Na2Mg2P2O7F2 is shown to be an intricate three-dimensional (3D) framework that consists of the 2D layers [Mg4O12F2]∞ and the 1D chain [Na2O8F3]∞ interlinked by isolated P2O7 groups, which demonstrates the precise coordination environment of cations and the framework in inorganic alkali/alkaline earth metal pyrophosphate fluoride. By comparing with other phosphate structures, we found that the introduction of F is conducive to the consistent arrangement of anionic group P2O7 and enriches the diversity of cationic polyhedra. In addition, first-principle theoretical studies were also carried out to aid the understanding of microstructures, and Na2Mg2P2O7F2 possesses a large band gap (7.1 eV) and has potential applications in the deep ultraviolet region.