Investigations of flocculation possibilities of the water alumina suspension in the presence of nonionic polymer

The effect of solution pH and molecular weight of polyethylene glycol (PEG) and polyethylene oxide (PEO) on their adsorption as well as stability of the colloidal Al₂O₃ water suspension was studied. The following methods were applied: turbidimetry, spectrophotometry, viscosimetry, potentiometric titration and microelectrophoresis.It was shown that the increasing solution pH affects conformation of the adsorbed macromolecules which affects the stability properties of such systems. The polymer adsorption causes deterioration of the stability conditions of the investigated alumina systems in comparison to those without polymer at all investigated pH values. At pH 3 and 6 the effect of the suspension destabilization is significantly smaller than at pH 9. The most effective flocculent of Al₂O₃ water suspension is PEO of the molecular weight 218,000 at pH 9.     

Influence of nanoparticles of platinum on chicken embryo development and brain morphology

Platinum nanoparticles (NP-Pt) are noble metal nanoparticles with unique physiochemical properties that have recently elicited much interest in medical research. However, we still know little about their toxicity and influence on general health. We investigated effects of NP-Pt on the growth and development of the chicken embryo model with emphasis on brain tissue micro- and ultrastructure. The embryos were administered solutions of NP-Pt injected in ovo at concentrations from 1 to 20 μg/ml. The results demonstrate that NP-Pt did not affect the growth and development of the embryos; however, they induced apoptosis and decreased the number of proliferating cells in the brain tissue. These preliminary results indicate that properties of NP-Pt might be utilized in brain cancer therapy, but potential toxic side effects must be elucidated in extensive follow-up research.     

Effect of LBM and large-area EBM finishing on micro-injection moulding surfaces

Micro-injection moulding is an efficient process for large series production of thermoplastic polymer micro-parts. The moulding surface quality in the moulds is important and determines the manufacturing specifications for a given micro-engineering component. In this study, melting and vaporisation removal technologies were analysed: laser beam machining (LBM) as the material removal technique and electron beam machining (EBM) as the finishing process. Stainless steel DIN X42Cr13 was used for machining 10?×?10?mm² flat surfaces. LBM parameters, namely intensity, frequency, cutting depth, scanning speed and hatching, and EBM conditions, as energy density, number of irradiation and frequency, were varied. The surface topography and integrity and the micro-structure were characterised by optical and electronic microscopy, roughness profilometry, X-ray spectroscopy and micro- and ultrahardness tests. It was shown that the combination of LBM and large-area EBM is an interesting alternative to polishing by hand lapping of moulding surfaces for micro-moulding, improving surface roughness and surface integrity without cracks and smaller HAZ. The morphology analysis demonstrated that EBM finishing improves corrosion and oxidation resistance compared with conventional heat-treated surfaces.     

Biphenyl sulfonylamino methyl bisphosphonic acids as inhibitors of matrix metalloproteinases and bone resorption

A number of matrix metalloproteinases (MMPs), proteins important in the balance of bone remodeling, play a critical role both in cancer metastasis and in bone matrix turnover associated with the presence of cancer cells in bone. Here, we report the synthesis and biological evaluation of a new class of MMP inhibitors characterized by a bisphosphonate function as the zinc binding group. Since the bisphosphonate group is also implicated in osteoclast inhibition and provides a preferential affinity to biological apatite, the new molecules can be regarded as bone-seeking medicinal agents. Docking experiments were performed to clarify the mode of binding of bisphosphonate inhibitors in the active site of MMP-2. The most promising of the studied bisphosphonates showed nanomolar inhibition against MMP-2 and resulted in potent inhibition of osteoclastic bone resorption in vitro.     

利用绿道规划和设计提升小城市竞争力——以葡萄牙里斯本大都市区维拉弗莱克德希亚市为例

以葡萄牙里斯本大都市区维拉弗莱克德希亚市为例,旨在研究和探讨绿道在帮助葡萄牙中型和小型城市提升城市竞争力方面扮演的角色.以维拉弗莱克德希哑市的7个样地为例,着重分析绿道理念在设计和应用层面的表现,主要包括绿道规划设计的方法以及取得的成效,如提升城市公共空间的品质.本文采用的策略和执行过程可供其他小城市借鉴.     

Usher Syndrome: Genetics of a Human Ciliopathy

Usher syndrome (USH) is an autosomal recessive syndromic ciliopathy characterized by sensorineural hearing loss, retinitis pigmentosa and, sometimes, vestibular dysfunction. There are three clinical types depending on the severity and age of onset of the symptoms; in addition, ten genes are reported to be causative of USH, and six more related to the disease. These genes encode proteins of a diverse nature, which interact and form a dynamic protein network called the “Usher interactome”. In the organ of Corti, the USH proteins are essential for the correct development and maintenance of the structure and cohesion of the stereocilia. In the retina, the USH protein network is principally located in the periciliary region of the photoreceptors, and plays an important role in the maintenance of the periciliary structure and the trafficking of molecules between the inner and the outer segments of photoreceptors. Even though some genes are clearly involved in the syndrome, others are controversial. Moreover, expression of some USH genes has been detected in other tissues, which could explain their involvement in additional mild comorbidities. In this paper, we review the genetics of Usher syndrome and the spectrum of mutations in USH genes. The aim is to identify possible mutation associations with the disease and provide an updated genotype–phenotype correlation.     

Photocatalytic properties of PMMA‐TiO2 class I and class II hybrid nanofibers obtained by electrospinning

The preparation, characterization, and photocatalytic activity evaluation of three hybrid fibrous materials composed mainly by poly(methyl methacrylate) (PMMA), methyl methacrylate (MMA): 3‐(trimethoxysilyl) propyl methacrylate (TMSPM): titanium butoxide (TBT), TiO₂ nanoparticles (NPTiO₂), and TiO₂ nanowires (NWTiO₂) is studied. Two types of fibe?s structures were prepared, single and core‐shell structures. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed both structures, single and core‐shell, as well as the inorganic phase were dispersed in the hybrid fibers. Infrared spectroscopic analysis (FT‐IR) and thermal analysis showed the organic and inorganic components, as well as the weight percentage of the inorganic phase present in hybrid fibers. The photocatalytic activity of the hybrid fibers class I and II showed that the best photodegradative efficiency for methylene blue in aqueous solution (2.9 × 10^?5 M) was 95%, provided by PMMA—10 wt % NPTiO₂. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44334.     

CO2 sorption performance by aminosilane functionalized spheres prepared via co‐condensation and post‐synthesis methods

Amine functionalized silica microspheres were synthesised via a modified Stöber reaction for carbon dioxide (CO₂) adsorption. A number of adsorbents were synthesized by co‐condensation and post synthesis immobilization of amines on porous silica spheres. CO₂ adsorption studies were carried out on a fixed bed gas adsorption rig with online mass spectrometry. Amine co‐condensed silica spheres were found to adsorb up to 66 mg CO₂ g^?1 solid in a 0.15 atm CO₂ stream at 35°C. Simple post‐synthesis addition of aminopropyltriethoxysilane to amine co‐condensed silica was found to significantly increase the uptake of CO₂ to 211 mg CO₂ g^?1 under similar conditions, with CO₂ desorption commencing at temperatures as low as 60°C. The optimum temperature for adsorption was found to be 35°C. This work presents a CO₂ adsorbent prepared via a simple synthesis method, with a high CO₂ adsorption capacity and favorable CO₂ adsorption/desorption performance under simulated flue gas conditions. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2825–2832, 2016     

Cesium Carbonate‐Promoted Hydroamidation of Alkynes: Enamides,Indoles and the Effect of Iron(III) Chloride

A series of enamide derivatives was prepared by a simple procedure for the hydroamidation of alkynes with amides and sulfonamides. The use of such a mild base as cesium carbonate promotes the latter transformation, and the addition of catalytic amounts of iron(III) chloride has a beneficial effect in the outcome of some of the presented hydroamidation reactions. A range of indoles was also synthesized from ortho‐alkynylanilides by both complementary procedures, which proved to be useful for the construction of the indolo[1,2‐c]quinazoline tetracyclic system from an ortho‐(2‐aminophenylalkynyl)anilide.     

Antioxidant activity of phenolic compounds identified in sunflower seeds

The antioxidant activity and phenolic compound profiles of six fractions (I–VI) obtained from sunflower seed extract were studied. HPLC–MS(ESI) analysis was applied for quantitative and qualitative determination of phenolic compounds of the fractions. The antioxidant activity of the fractions was studied in terms of their ability to scavenge DPPH^· and ABTS^·+ and to reduce Fe³⁺/ferricyanide complex to the ferrous form and was expressed as EC₅₀, TEAC and reducing power values, respectively. The results of all antioxidant activity tests showed good correlations among each other and with the phenolic contents for the individual fractions. The fractions IV–VI were characterized by high antioxidant activity. 5-O-Caffeoylquinic acid was a predominant compound of fractions IV and V, while dicaffeoylquinic acid isomers and caffeoyl-dimethoxycinnamoylquinic acid isomers accounted for 76.6 % of phenolic compounds of fraction VI. Ferulic acid, p-coumaroylquinic acid isomers, ferulic acid dehydrotrimer isomers and some quercetin derivatives were also identified. The highest content of those compounds was noted in fraction III.