Monitoring the hydrolyzation of aspirin during the dissolution testing for aspirin delayed-release tablets with a fiber-optic dissolution system

The purpose of this study was to investigate the hydrolyzation of aspirin during the process of dissolution testing for aspirin delayed-release tablets. Hydrolysis product of salicylic acid can result in adverse effects and affect the determination of dissolution rate assaying. In this study, the technique of differential spectra was employed, which made it possible to monitor the dissolution testing in situ. The results showed that the hydrolyzation of aspirin made the percentage of salicylic acid exceed the limit of free salicylic acid （4.0）, and the hydrolyzation may affect the quality detection of aspirin delayed-release tablets.

Effects of temperature and wavelength choice on in-situ dissolution test of Cimetidine tablets

The effects of temperature and wavelength choice on in-situ dissolution test instrument of Cimetidine were studied. Absorbance （A）〈 1.0 is required when using a fiber-optic dissolution test system. The detection wavelength of 2 （218 nm） was replaced by 244 nm to carry out this test. The absorbance of Cimetidine solution at different temperature showed an obvious change. Calibration of Cimetidine solution should be tested at the same temperature （37° C） with the test solution. A suitable wavelength with smaller tangent slope could be chosen for in-situ dissolution test of Cimetidine tablets.

Facile and effective synthesis strategy for terbium-doped hydroxyapatite toward photoelectric devices and flexible functional fibers

As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP.

A convenient method to prepare random LA/CL copolymers from poly(L-lactide) and ε-caprolactone

Sequential addition of L-lactide(LA) followed by ε-caprolactone(CL), and simultaneous addition of both monomers, afforded random LA/CL copolymers in the presence of lanthanide aryloxides under mild conditions. Transesterification was proved to play a predominant role in random copolymer formation. Moreover, treatment of poly(L-lactide) with ε-CL led to random copolymer formation, which provides a new strategy not only to prepare random LA/CL copolymers, but also to directly modify PLLA.

Structure and luminescence properties of color-tunable phosphor Sr_(2)La_(3)(SiO_(4))_(3)F:Tb^(3+),Sm^(3+)

A series of single-phase and color-tunable phosphors Sr_(2)La_(3)(SiO_(4))_(3)F:0.15Tb^(3+),xSm^(3+)(SLSOF:0.15Tb^(3+),xSm^(3+)) was prepared using solid-state route.The X-ray diffraction(XRD) was used to characterize the phase of the as-prepared samples.The synthesized phosphors have apatite-type structure without other impurities.Sm^(3+) and Tb^(3+) ions substitute La^(3+) into the lattice and form a single-phase solid solution.The elements are evenly distributed in the sample according to the scanning electron microscopy(SEM) results.The crystal structure of the host phosphor was refined by the Rietveld method.The optical properties were studied in detail by investigation of the luminescence and diffuse spectra,fluorescence decay curves and energy transfer efficiency.The phosphor color can be changed from green(0.29,0.48) to yellow/orange and red(0.57,0.42) via adjusting the doping ratio of Sm^(3+).The SLSOF:0.15Tb^(3+),xSm^(3+)phosphors can emit typical multicolor light such as green,yellow,orange and red with gradually increasing Sm^(3+)doping concentration.All results indicate the occurrence of the energy transfer which results in the color-tunable properties of the phosphors.

Metal halide perovskite nanocrystals with enhanced photoluminescence and stability toward anti-counterfeiting highperformance flexible fibers

As a new type of light-collecting and luminescent material,all-inorganic cesium lead halide CsPbX_(3)(X=Cl,Br,I)perovskite nanocrystals(NCs)are expected to have a wide range of applications in the fields of photovoltaics,optoelectronics,and fluorescence anti-counterfeiting,etc.Therefore,improving the fluorescence performance and stability of CsPbX_(3)perovskite NCs to prompt their applications would promise both fundamental and practical significance for in-depth research in the field of halide perovskites.In this paper,we developed a modification strategy to introduce a halogen source,zinc bromide(ZnBr_(2))in hexane,to CsPbX_(3)perovskite that can be conducted under atmospheric conditions with reduced reaction cost and easier operation.The first work in this paper was to apply the modification strategy to CsPbI_(3)nanowires(NWs).Compared with the untreated NWs,the ZnBr_(2)/hexane modified CsPbI_(3)NWs exhibited better fluorescence properties.Subsequently,based on the study of perovskite NWs,we investigated perovskite nanocrystal-CsPbI_(3)nanorods(NRs)with different morphologies and sizes.It was found that the luminescence properties of nanorods(NRs)were superior.Later,we infiltrated the modified NRs into the aramid/polyphenylene sulfide(ACFs/PPS)composite paper yielded from our previous work to study its fluorescence performance for anti-counterfeiting.Their luminescence properties under ultraviolet light irradiation enable better performance in fluorescence anti-counterfeiting.The ZnBr_(2)/hexane modification strategy and the applications studied in this work will expand the scope of perovskite research,laying the foundation for the applications of fluorescent anti-counterfeiting,nano-photoelectric devices,and fluorescent composite materials.

Synthesis and luminescence properties of apatite-type red-emitting Ba_(2)La_(8)(GeO_(4))_(6)O_(2):Eu^(3+)phosphors

A new kind of apatite-type red-emitting Ba_(2)La_(8)(GeO_(4))_(6)O_(2):Eu^(3+)phosphor was prepared by high temperature solid-state method.The Rietveld analysis based on the powder diffraction data shows that Ba_(2)La_(8)(GeO_(4))_(6)O_(2):Eu^(3+)phosphors possess a pure apatite phase without any impurity.The emission spectrum of Ba_(2)La_(8)(GeO_(4))_(6)O_(2):Eu^(3+)phosphor consists of two bands,an orange emission band from 500 to 600 nm and a red emission band from 600 to 680 nm.By varying the amount of the doped europium ions from 0.02 to 0.14 mol,it is found that the luminescent properties of this rare earth phosphor are the best when the concentration of europium ion is 0.08 mol.The optimum concentration is eventually proved to be 0.08 mol.The Eu^(3+)doping dependent luminescence quenching can be further ascribed to dipole-quadrupole interactions.The quantum yield of Ba_(2)La_(7.92)(GeO_(4))_(6)O_(2):0.08 Eu^(3+)is 37.23%.The CIE analysis confirms a reddish emission in the near ultraviolet(n-UV)excitation.All these above properties of the phosphor can help in contribution of promoting white light-emitting diode.

Cultivation of aerobic granular sludge in a conventional, continuous flow, completely mixed activated sludge system

Aerobic granules were formed in a conven- tional, continuous flow, completely mixed activated sludge system （CMAS）. The reactor was inoculated with seed sludge containing few filaments and fed with synthetic municipal wastewater. The settling time of the sludge and the average dissolved oxygen （DO） of the reactor were 2 h and 4.2 mg. L 1, respectively. The reactor was agitated by a stirrer, with a speed of 250r·min^-1, to ensure good mixing . The granular sludge had good settleability, and the sludge volume index （SVI） was between 50 and 90 mL ·g ^-1. The laser particle analyzer showed the diameter of the granules to be between 0.18 and 1.25 mm. A scanning electron microscope （SEM） investigation revealed the predominance of sphere-like and rod-like bacteria, and only few filaments grew in the granules. The microbial community structure of the granules was also analyzed by polymerase chain reaction-denaturing gradient gel electro- phoresis （PCR-DGGE）. Sequencing analysis indicated the dominant species were α, β, and γ-Proteobacteria, Bacteroidetes, and Firmicutes. The data from the study suggested that aerobic granules could form, if provided with sufficient number of filaments and high shear force. It was also observed that a high height-to-diameter ratio of the reactor and short settling time were not essential for the formation of aerobic granular sludge.

META-SYNTHESIS APPROACH TO EXPLORING CONSTRUCTING COMPREHENSIVE TRANSPORTATION SYSTEM IN CHINA

In this paper, meta-synthesis system approach （MSA） is applied to a consulting project on exploring constructing comprehensive transportation system in China. Firstly, brief introduction about the concept of comprehensive transportation is given to indicate that comprehensive transportation is an open complex giant system, which thus MSA is applied to exploring its constructing in China. A group argumentation environment （GAE） is applied to facilitate group divergent thinking process about what the concerned topics are in the project and acquire qualitative hypotheses for meta-synthetic system modeling. A multi-agent system model is constructed to analyze competitive relations of passenger transport between railway and highway as a demonstration of modeling by rule, one of 6 strategies of meta-synthetic system modeling. An evaluation support system is developed to integrate a variety of indicators and their related measure methods by a framework of input-output-outcome of comprehensive transportation to facilitate consultants to monitor current state of operation and management of transport system and generate alternatives of a set of indicators to evaluate efficiency or effectiveness of the whole system or its elements on demand.

Voxel-based analysis of brain microstructural diffusion indices changes in Parkinson disease with freezing of gait

To the Editor:Freezing of gait(FOG)is a common disabling movement disorder in Parkinson disease(PD),affecting approximately 50%to 80%of PD patients in their late state.FOG can cause the patients to fall easily,seriously affects their quality of life and exerts both economic and emotional burdens.Unlike the common motor symptoms of PD(such as bradykinesia,tremor,or rigidity),FOG is seldom improved by dopaminergic medication therapy or deep brain stimulation.Moreover,FOG may be resistant to(or even worsened by)levodopa.[1]However,cognitive training has showed it can reduce the severity of FOG.[2]These findings imply that FOG may be caused not only by motor impairment but also by cognitive impairment.It is reasonable to hypothesize that FOG+patients have impaired cognitive function and that the diffusion indices of the cerebral territories’microstructures associated with cognition are altered.To test this hypothesis,we applied whole-brain voxel-based analysis(VBA),a fully automated whole-brain analysis that uses voxel-wise statistics on diffusion metrics,to investigate the diffusion indices of brain microstructures changes in FOG+patients,PD patients without FOG(FOG-patients),and healthy controls(HCs).

CONNECTING INFORMAL NETWORKS TO MANAGEMENT OF TACIT KNOWLEDGE

The relationship between tacit knowledge and informal networks has not been fully explored. Tacit knowledge cannot be well managed directly, because it is deeply embedded in individual actions and experiences. This study proposes an approach to managing informal networks as a new middle way to facilitate the sharing and transferring of tacit knowledge, owing to the fact that tacit knowledge is mostly shared and transferred through informal networks. To support the idea of the approach, an empirical case study of applying the approach to management of a large scientific project is also included. Our findings suggest that informal networks play essential roles for management of tacit knowledge, and thus good management of informal networks can lead to efficient sharing and transferring of tacit knowledge.

Syntheses of bimetallic lanthanide bis(amido) complexes stabilized by bridged bis(guanidinate) ligands and their catalytic activity toward the hydrophosphonylation reaction of aldehydes and ketones

A series of bimetallic lanthanide bis(amido) complexes stabilized by bridged bis(guanidinate) ligands {[(Me3Si)2N]2Ln[(RN)2-CN(CH2)2]}2 [R=iPr, Ln=Sm(1), Yb(2), Y(3); R=cyclohexyl(Cy), Ln=Sm(4), and Yb(5)] were synthesized through the metathesis reactions of {Ln(μ-Cl)[N(Si Me3)2]2(THF)}2(Ln=Sm, Yb, Y) with lithium guanidinate {Li[(RN)2CN(CH2)2]}2(R=iPr, Cy), the latter of which was generated in situ by the reaction of carbodiimides with lithium amides. Complexes 1–5 were well characterized by elemental analyses, IR spectra, and(for Complex 3) NMR spectroscopy. The solid-state molecular structures of all of the complexes were determined by single-crystal X-ray analyses with the exception of Complex 3, which showed similar unsolvated centrosymmetric dinuclear structures. Each of the lanthanide centers is four-coordinated with two nitrogen atoms from a guanidinate ligand and two nitrogen atoms from two amido groups. The piperazidine rings adopt chair conformations in all cases. These organolanthanide complexes were found to be efficient catalysts for the hydrophosphonylation reaction of various aldehydes and unactivated ketones and to afford ?-hydroxyphosphonates in high yields under low catalyst loading(0.1 mol%) in a short reaction time.