Enhanced photodegradation of diphenhydramine in aqueous solution containing natural sand particles

Understanding the effects of natural solid particles on the phototransformation of pharmaceuticals in aqueous environments is very important, but studies on this are still limited. In this study, natural sands were selected as a solid particle model due to their wide distribution in surface waters during the rainy season, and the phototransformation of diphenhydramine (DP) in the presence of the sands was investigated. The kinetic studies showed that the natural sands exhibited significant photocatalytic activity for the DP photodegradation, and the activity varied depending on their sources. Scavenging experiments and electron paramagnetic resonance analysis demonstrated that O₂⁻˙ and ˙OH were produced in the irradiated natural sand systems, and O₂⁻˙ played a more important role than ˙OH in the photodegradation of DP. The results obtained from H₂O₂ treatment and deoxygenation experiments verified that the generation of radicals was mainly attributed to the low content of natural organic matter (NOM) in the sands. The possible reaction mechanism was that the NOM in the sands was excited and became triplet-state NOM after irradiation, and then induced the generation of free radicals through an electron transfer mechanism, resulting in DP oxidation. This work indicated that natural sand particles were a key factor affecting the phototransformation of drugs, and should be considered in evaluating their fate in natural waters.

Natural sand particles induced the generation of free radicals under simulated solar irradiation, resulting in the enhanced photodegradation of diphenhydramine.     

Synthesis,crystal structures,HF-EPR,and magnetic properties of six-coordinate transition metal (Co,Ni, and Cu) compounds with a 4-amino-1,2,4-triazole Schiff-base ligand

We have synthesized a series of transition metal compounds [M(L)₂(H₂O)₂] (M = Co (1), Ni (2), and Cu (3)) by using the 4-amino-1,2,4-triazole Schiff-base ligand via the hydrothermal methods. They are all mononuclear compounds with the octahedral geometry. Direct-current magnetic and HF-EPR measurements were combined to reveal the negative D values (–28.78 cm⁻¹, –10.79 cm⁻¹) of complexes 1 and 2, showing the easy-axis magnetic anisotropies of compounds 1 and 2. Applying a dc field of 800 Oe at 2.0 K, the slow magnetic relaxation effects were observed in compound 1, which is a remarkable feature of single-ion magnets.

We have synthesized a series of transition metal compounds [M(L)₂(H₂O)₂] (M = Co (1), Ni (2), and Cu (3)) by using the 4-amino-1,2,4-triazole Schiff-base ligand via the hydrothermal methods.     

Switching porosity of stable triptycene-based cage via solution-state assembly processes

It is a great challenge to tune the porosity of porous materials. As most porous organic cages are soluble, solution processability can be a possible way to regulate the porosity of such materials. Herein, a triptycene-based cage (TC) is demonstrated to be stable in acid, base or boiling water. Meanwhile, its porosity can be tuned by adjusting the solution-state assembly processes. TC molecules crystallized slowly from solution exhibit nearly no porosity to nitrogen (off-state). While, after rapid precipitating from methanol/dichloromethane solution, the obtained TC (TC-rp) is in a porous state and exhibit a high BET surface area of 653 m² g⁻¹ (on-state).

Here, a kind of triptycene-based cage is demonstrated to have good chemical stability in acid, base and boiling water. Moreover, its porosity can be tuned by varying the solution-state assembly processes.     

Analysis of rice and wheat flour by particle nebulization ICP-MS

Analysis of toxic elements in food samples (e.g., rice and wheat) is very important for human health. A direct nebulization of solid particles for inductively coupled plasma (ICP) ionization and subsequent analysis of toxic elements (i.e., As, Cd, Hg, and Pb) by mass spectrometry (MS) was developed. Dried and well-ground food particles (mean size of 0.9–1.0 μm) were stably dispersed in 0.5% polyethylene-imine (PEI) and the particle slurries were analyzed by ICP-MS using aqueous standard calibration. The transportation and ionization behaviors of particles with different particle sizes in ICP-MS were compared with those of aqueous standards containing equivalent concentrations of the analyte. The results indicated that the upper limits of particle sizes for the efficient transportation and complete ionization were 7.5–8.0 μm and 3.3–3.5 μm, respectively. Satisfactory recovery (94–107%), and precision (0.4–6.5%, RSD, n = 3) were verified by analyzing a series of rice and wheat standard reference materials (SRMs). The limits of quantitation (LOQs, 1.1 ng g⁻¹ (Hg) to 3.5 ng g⁻¹ (As)) are compared with the traditional microwave-assisted acid digestion ICP-MS method, however, the analysis throughput of the proposed method is improved by more than 10 times.

A simple and green particle nebulization ICP-MS method for the direct measurement of trace toxic elements in rice and wheat samples was developed.     

Micron-sized SiOx/N-doped carbon composite spheres fabricated with biomass chitosan for high-performance lithium-ion battery anodes

To achieve superior lithium storage performance, SiO_x is usually designed into nanostructured SiO_x/C composites by complex or expensive methods. Here, micron-sized interconnected SiO_x/N-doped carbon (NC) microspheres composed of evenly dispersed SiO_x nano-domains and NC have been fabricated by a scalable microemulsion method and following pyrolysis, using vinyltriethoxysilane and chitosan as precursors. The unique structure of the micron-sized SiO_x/NC spheres leads to enhanced structural integrity and enables stable long-term cycling (800 cycles at 2 A g⁻¹). Benefiting from the enhanced electron/Li⁺ diffusion kinetics originated from the unique structure and N-doping, SiO_x/NC-2 presents considerable capacitive-controlled Li storage capacity, which leads to outstanding rate capability. Consequently, the assembled SiO_x/NC-2//LiFePO₄ full cell exhibits superior rate capability (106 mA h g⁻¹ at 4C) and stable long-term cycling at 2C (102 mA h g⁻¹ after 350 cycles). This work opens a new door for the application of chitosan in building micron-sized high-performance SiO_x/C anode materials, and to some extent facilitates the recycling of waste seafood shells.

Chitosan is employed as a carbon precursor to fabricate micron-scale interconnected SiO_x/NC spheres that exhibit excellent lithium storage performance.     

Photocatalytic degradation of diphenhydramine in aqueous solution by natural dolomite

Natural dolomite, an inexpensive and vastly available natural material, was demonstrated as a potential heterogeneous photocatalyst for the efficient removal of diphenhydramine (DP) from aqueous solution under simulated solar light in this study. About 65% DP removal and 14% mineralization were achieved with dolomite as a catalyst after 75 min irradiation. The electron spin resonance analysis and scavenger experiments verified that ¹O₂, ˙OH, and O₂⁻˙ produced in the dolomite system were the main reactive species responsible for DP degradation. Furthermore, first-principle calculations combined with deoxygenation experiments were employed to elucidate the photocatalytic mechanism. The results revealed that the dolomite changed from an insulator to a semiconductor after partial substitution of Mg²⁺ by Fe²⁺, suggesting that natural dolomite could act as a semiconductor photocatalyst in photoreactions. Under irradiation, photo-excited electrons and holes separate and migrate to the surface of dolomite, and subsequently react to form reactive species resulting in the DP degradation. Product studies demonstrated that the main degradation pathways of DP included hydroxylation of the aromatic ring as well as hydroxyl radical mediated oxidation of the alkylamine side chain. This work indicated that natural dolomite could be applied in water and wastewater treatment as a promising photocatalyst.

Natural dolomite, an inexpensive and vastly available natural material, was demonstrated as a potential heterogeneous photocatalyst for the efficient removal of diphenhydramine (DP) from aqueous solution under simulated solar light in this study.     

植骨对移位性关节内跟骨骨折手术效果的影响

目的比较手术治疗移位性关节内跟骨骨折植骨与否的临床疗效。方法 2014年5月—2015年5月湖北省中医院骨科采用切开复位内固定治疗移位性关节内跟骨骨折40例,根据植骨与否分为植骨组和非植骨组,每组各20例。其中男性29例,女性11例;年龄18～60岁,平均40. 1岁。高处坠落伤27例,道路交通伤13例。观察两组患者手术时间、住院天数、切口并发症、临床功能[美国足踝外科协会(AOFAS)评分]、骨折愈合时间、B?hler角、跟骨高度、B?hler角丢失度、跟骨高度丢失度。结果两组患者手术时间、住院天数、切口并发症、末次随访时AOFAS评分、骨折愈合时间、B?hler角和跟骨高度比较差异无统计学意义(P> 0. 05),但植骨组B?hler角丢失度和跟骨高度丢失度显著低于非植骨组(P <0. 05)。结论尽管采用切开复位内固定治疗移位性关节内跟骨骨折,是否植骨不影响患者临床功能,但是植骨可减少术后B?hler角和跟骨高度的丢失,不增加并发症,因此建议使用。     

Synthesis of glutathione C60 derivative and its protective effect on hydrogen peroxide-induced apoptosis in rat pheochromocytoma cells

Oxidized glutathione C(60) derivative has been synthesized and characterized in our research. As a novel derivative of C(60), the glutathione C(60) derivative is soluble in dimethylsulfoxide, dimethylformamide and dimethylacetamide. Rat pheochromocytoma (PC12) cells are treated with hydrogen peroxide and underwent cytotoxicity; apoptotic death is determined by MTT assay, flow cytometry analysis, PI/Hoechst 33342 staining and glutathione assay. The results suggest that glutathione C(60) derivative has the potential to prevent oxidative stress-induced cell death without evident toxicity.     

Monte Carlo simulations for external neutron dosimetry based on the visible Chinese human phantom

A group of Monte Carlo simulations has been performed for external neutron dosimetry calculation based on a whole-body anatomical model, the visible Chinese human (VCH) phantom, which was newly developed from high-resolution cryosectional color photographic images of a healthy Chinese adult male cadaver. Physical characteristics of the VCH computational phantom that consists of 230 x 120 x 892 voxels corresponding to an element volume of 2 x 2 x 2 mm(3) are evaluated through comparison against a variety of other anthropomorphic models. Organ-absorbed doses and the effective doses for monoenergic neutron beams ranging from 10(-9) MeV to 10 GeV under six idealized irradiation geometries (AP, PA, LLAT, RLAT, ROT and ISO) were calculated using the Monte Carlo code MCNPX2.5. Absorbed dose results for selected organs and the effective doses are presented in the form of tables. Dose results are also compared with currently available neutron data form ICRP Publication 74 and those of VIP-Man. Anatomical variations between different models, as well as their influence on dose distributions, are explored. Detailed information derived from the VCH phantom is able to lend quantitative references to the widespread application of human computational models in radiology.     

A novel method for analysis of single ion channel signal based on wavelet transform

A single ion channel signal was analysed by the power distribution fraction constructed by a discrete wavelet transform. Average opening time and energy distribution of the signal can be obtained directly by this method. The method can also be used when the signal is corrupted by noise. By contrast, the conventional frequency domain analysis method--power spectral density--is less effective. Power distribution fraction will therefore give more useful information in analysis of experimental ion channel signals, principally by giving values of the mean channel opening time. The method may be applied to distinguish different ion channels more efficiently and to find their reactions to drugs.