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A so-called a??Triglycine phosphatea?? is a dubious crystal
摘要： It is shown that a so-called triglycine phosphate (TGP) crystal claimed as new crystal by Meera et al (J. Mol. Struct. 1144 (2017) 457-465) is not what the authors formulated. Based on reported unit cell parameters, powder X-ray diffraction pattern and infrared spectrum, it is proved that the so-called TGP, in fact, is glycine (alpha or gamma form). The determination of the crystal structure of the obtained crystal would allow the authors to avoid the error made.
关键词： glycine,dubious crystals,triglycine phosphate,improper characterization
更新于2025-09-23 15:19:57
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Bismuth-Doped Phosphate Glasses and H+-Implanted Waveguides
摘要： The work reports on the preparation and optical characterization of 75P2O5-15B2O3-9Al2O3-Bi2O3 glass by using the melt-quenching method and absorption spectroscopy, respectively. Further, 0.4-MeV proton implantation of a ?uence of 8.0 × 1016 ions/cm2 was carried out on this glassy sample and it was tested as a waveguide at a wavelength of 632.8 nm for the ?rst time to our knowledge. The m-line curves of the waveguide were measured before and after successive annealing treatments. The formation theory of the planar waveguides is discussed through simulations of the energy loss distribution and analysis of the reconstructed refractive index pro?le. The results should be useful in the design and fabrication of bismuth-doped phosphate glass and its use in integrated photonics devices.
关键词： Bismuth-doped phosphate glass,Optical waveguide,Ion implantation
更新于2025-09-23 15:19:57
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Indirect selective laser sintering printed microporous biphasic calcium phosphate scaffold promotes endogenous bone regeneration via activation of ERK1/2 signaling
摘要： Fabrication technique determines the physicochemical and biological properties of scaffold, including porosity, mechanical strength, osteoconductivity, and bone regenerative potential. Biphasic calcium phosphate (BCP)-based scaffolds are superior in bone tissue engineering due to their suitable physicochemical and biological properties. We developed an indirect selective laser sintering (SLS) printing strategy to fabricate 3D microporous BCP scaffolds for bone tissue engineering purposes. The green part of BCP scaffold was fabricated by SLS at relevantly low temperature in the presence of epoxy resin (EP) and the remaining EP was decomposed, and eliminated by a subsequent sintering process to obtain the microporous BCP scaffolds. Physicochemical properties, cell adhesion, biocompatibility, in vitro osteogenic potential and rabbit critical size cranial bone defect healing potential of the scaffolds were extensively evaluated. This indirect SLS printing eliminated the drawbacks of conventional direct SLS printing at high working temperatures, i.e., wavy deformation of the scaffold, hydroxyapatite decomposition, and conversion of β-TCP to α-TCP. Among the scaffolds printed with various binder ratios (by weight) of BCP and EP, the scaffold with 50/50 binder ratio (S4) showed the highest mechanical strength and porosity with the smallest pore size. Scaffold S4 showed the highest effect on osteogenic differentiation of precursor cells in vitro, and this effect was ERK1/2 signaling dependent. Scaffold S4 robustly promoted precursor cells homing, endogenous bone regeneration, and vascularization in rabbit critical-size cranial defect. In conclusion, BCP scaffold fabricated by indirect SLS printing maintains the physicochemical properties of BCP and possess the capacity to recruit host precursor cells to the defect site and promote the endogenous bone regeneration possibly via activation of ERK1/2 signaling.
关键词： endogenous bone regeneration,ERK1/2 signaling,biphasic calcium phosphate,selective laser sintering,bone tissue engineering
更新于2025-09-23 15:19:57
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A Report on Growth And Spectroscopic Studies on The L-Tartaric Acid Doped Potassium Dihydrogen Phosphate Non-Linear Optical Single Crystals
摘要： In recent years study of non-linear optical (NLO) materials is gaining rapid momentum due to their needs in several device applications. Potassium Dihydrogen Phosphate (KDP) is a well-known NLO material, whose non-linearity is enhanced by doping with amino acids. In this present study, single crystal of L-Tartaric acid doped potassium Dihydrogen phosphate (LTKDP) have been grown by slow evaporation method at room temperature. Good quality transparent crystals were obtained with 27-30 days. The crystallinity and cell parameters were characterized by X-ray diffraction analysis (XRD), the shifts in frequency assignments of various functional groups of KDP due to the addition of L-Tartaric acid was analysed by Fourier transform infrared (FTIR) and Fourier transform Raman spectroscopic studies. The dielectric constant and the dielectric loss of the single crystals were studied as a function of frequency. Kurtz- Perry power technique was employed to determine the Second Harmonic Generation (SHG) efficiency of LTKDP single crystal.
关键词： X-ray diffraction,SHG efficiency,L-Tartaric acid,slow evaporation method,FT-Raman,Potassium Dihydrogen Phosphate,FTIR,non-linear optical materials
更新于2025-09-23 15:19:57
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De-Ethylation and Cleavage of Rhodamine B by a Zirconium Phosphate/Silver Bromide Composite Photocatalyst
摘要： A composite heterogeneous photocatalyst based on silver bromide was prepared by a reaction of silver exchanged zirconium phosphate (ZrP) and HBr. The ZrP/AgBr composite containing 53 wt% AgBr was tested in the photocatalytic degradation of Rhodamine B (RhB) and exhibited higher catalytic activity with respect to pure AgBr. As a matter of fact, the time needed to achieve a percentage of chromophore cleavage of about 90% was 3 min for the composite versus the 30 min needed for pure AgBr. The ZrP/AgBr composite turned out to be stable for at least three consecutive cycles. The UV-Vis spectra of the RhB solution, recorded at different irradiation times, were also decomposed and the concentration of the species formed by de-ethylation and cleavage processes during photocatalysis were calculated; the data obtained for the AgBr-based catalysis were also compared with those for the AgCl-based catalysis, and the degradation mechanism was suggested for both catalytic systems.
关键词： photocatalysts,zirconium phosphate,Rhodamine B,silver halides
更新于2025-09-19 17:15:36
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Hydrophilic Truxene Derivative as a Fluorescent off-on Sensor for Copper (II) Ion and Phosphate Species
摘要： A new symmetrical truxene derivative (TP3) containing three dipicolylamino peripheral groups is successfully synthesized in four synthetic steps with an overall yield of 42%. This hydrophilic fluorescent compound exhibits a maximum absorption wavelength at 375 nm, an emission maximum at 474 nm with an outstanding 58% quantum efficiency in THF-HEPES buffer mixture. The compound shows a highly selective fluorescence quenching towards Cu(II) ion with a detection limit of 0.06 ppm. The results from mass spectrometry and Job plot indicate that a 1:1 complex between TP3 and Cu(II) ion is responsible for the signal quenching. Interestingly, this TP3-Cu complex can be used as a turn-on sensor for hydrogen phosphate and nucleoside phosphates. The limit of detection for hydrogen phosphate is estimated at 8.7 nM. The signal restoration involves a displacement of TP3 in the complex by the phosphates which have strong coordination abilities with Cu(II) ion.
关键词： Truxene,Fluorescence,Phosphate,Sensor,Picolylamine,Copper (II) ion
更新于2025-09-19 17:15:36
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A Strain Distribution Sensing System for Bone-Implant Interfaces Based on Digital Speckle Pattern Interferometry
摘要： This paper aims to provide an effective measurement method for the distribution of deformations and strains focusing on the response to external loading of bone-implant interfaces. To achieve this target, a novel speckle interference imaging method is proposed by introducing phosphate buffer saline medium, in which the samples were completely placed into a phosphate buffer saline solution medium to stable the water molecules. The stability of interferometry imaging is analyzed by using the concepts of co-occurrence matrix and moment of inertia. A series of experiments to measure load-driven deformation and strain in the bone-implant interface was carried out, and the experiments results were analyzed and discussed. It shows that the proposed method is feasible and effective for the no-contact strain measurements of biomaterials in a physiological condition. The proposed strain distribution sensing system will contribute to evaluating computational simulations and improving selection of implant designs and materials.
关键词： digital speckle pattern interferometry,speckle interference imaging,phosphate buffer saline solution,strain distribution detection,bone-implant interface
更新于2025-09-19 17:15:36
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Treatment of Vocal Fold Polyps with In-Office Potassium Titanyl Phosphate (KTP) Laser Ablation in Professional Singers
摘要： Vocal fold polyp (VFP) is an exophytic gelatinous lesion with an atrophic epithelium. After behavioral and conservative management, phonomicrosurgery is the treatment of choice for VFPs with excellent outcomes in terms of lesion resolution and postoperative vocal function. Office-based potassium titanyl phosphate (KTP) laser ablation is a new treatment modality for VFPs but its efficacy for professional singers has yet to be validated. Reported is a consecutive series of six professional singers (with seven episodes of VFP) who, based on patient and provider preference, underwent in-office KTP laser ablation of VFP. Two polyps required two ablation procedures; otherwise, a single treatment was successful in resolution of VFP at a mean resolution time of 44 days. Singing voice handicap index 10 improved from a mean of 30.8 (range 4?40) to 6.0 (range 0?22). All patients resumed their professional singing careers without vocal limitations. Posttreatment videos were reviewed by three blinded fellowship trained laryngologists, who were not able to accurately predict the laterality of the polyp (52% correct, p = 0.99).
关键词： Singer,Vocal fold polyp,Potassium titanyl phosphate laser,Laser ablation,Vocal fold lesion
更新于2025-09-19 17:13:59
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Visualizing different crystalline states during the infrared imaging of calcium phosphates
摘要： Methods utilizing relatively simple mathematical operations during physical analyses to enable the visualization of otherwise invisible correlations and effects are of particular appeal to researchers and students in pedagogical settings. At the same time, discerning the amorphous phase from its crystalline counterpart in materials is challenging with the use of vibrational spectroscopy and is nowhere as straightforward as in phase composition analytical methods such as X-ray diffraction. A method is demonstrated for the use of first- and second-order differentiation of Fourier transform infrared spectra of calcium phosphates to distinguish their amorphous states from the crystalline ones based on the exact line positioning rather than on comparatively vaguer band broadening and splitting effects. The study utilizes a kinetic approach, focusing on the comparison of spectral features of amorphous precursors annealed in air at different temperatures or aged for different periods of time in an aqueous solution until transforming to one or a mixture of crystalline phases, including hydroxyapatite and α- and β-tricalcium phosphate. One of the findings challenges the concept of the nucleation lag time preceding the crystallization from amorphous precursors as a “dead” period and derives a finite degree of constructive changes occurring at the atomic scale in its course. The differential method for highlighting spectral differences depending on the sample crystallinity allows for monitoring in situ the process of conversion of the amorphous calcium phosphate phase to its crystalline analogue(s). One such method can be of practical significance for synthetic solid state chemists testing for the chemical stability and/or concentration of the reactive amorphous phase in these materials, but also for biologists measuring the maturity of bone and medical researchers evaluating its phase composition and, thus, the state of metabolic and mechanical stability.
关键词： Hydroxyapatite,XRD,Derivative method,Crystallization,Amorphous,FTIR,Tricalcium phosphate
更新于2025-09-19 17:13:59
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Structural Analysis of Calcium Phosphate-Based Submicrospheres with Internally-Crystallized Iron Oxide Nanoparticles Fabricated by a Laser-Assisted Precipitation Process
摘要： Calcium phosphate (CaP)-based submicrospheres containing magnetic iron oxide (IO) nanoparticles (IO–CaP submicrospheres) have potential for various biomedical applications. We recently achieved facile one-pot fabrication of IO–CaP submicrospheres using a laser-assisted precipitation process in which weak pulsed laser irradiation was applied to a labile CaP reaction mixture supplemented with ferrous ions under adequate pH. In this study, we performed the resulting IO–CaP cross-sectional submicrospheres. The cross-sectional TEM analysis revealed that the IO–CaP submicrospheres were heterogeneous in their internal nanostructures and could be categorized into two types, namely types A and B. The type A submicrospheres contained single nano-sized IO nanoparticles homogeneously dispersed throughout the CaP-based matrix. The type B submicrospheres contained larger IO nanoparticles with an irregular or spherical shape, which were mostly a few tens of nanometers in size along with one or two submicron-sized domains. These findings provide new insight into the formation mechanism of IO–CaP submicrospheres in this fabrication technique as well as future applications of the resulting IO–CaP submicrospheres.
关键词： laser-assisted precipitation process,submicrospheres,calcium phosphate,cross-sectional analysis,iron oxide nanoparticles
更新于2025-09-19 17:13:59