Design,Synthesis, and Biomedical Applications of Glycotripods for Targeting Trimeric Lectins

In the last decades, various efforts have been made to synthesize optimal glycotripods for targeting trimeric glycoproteins like asialoglycoprotein receptor, hemagglutinin, and langerin. All these trimeric glycoproteins have sugar binding pockets which are highly selective for a particular carbohydrate ligand. Optimized glycotripods are high affinity binders and have been used for delivering drugs or even applied as drug candidates. The selection of the tripodal base scaffold together with the length and flexibility of the linker between the scaffold and sugar residue, as important design parameters are discussed in this review.     

A highly thermal stable solid phase microextraction fiber prepared by an inorganic binder

An easy method to prepare solid phase microextraction fibers by introducing an inorganic binder was demonstrated in this study, where MoS₂ was selected as the extraction phase material because of its graphite-like layered structure with large specific adsorption area and good stability, and was then adhered to a stainless steel wire by acid aluminum phosphate binder with the spraying method. The as-prepared solid phase microextraction fiber coupled with gas chromatography was then used to extract some polycyclic aromatic hydrocarbons target analytes including the low-volatile benzo(a)pyrene etc. from a standard sample. Comparing with the MoS₂-epoxy resin and commercial polyacrylate fibers, the MoS₂-acid aluminum phosphate fiber has a higher thermal stability because of highly thermal stable acid aluminum phosphate, which is durable for a long service life at a high temperature (320 °C), and has the advantage in the extraction of low-volatility analytes. After the optimization of adsorption and desorption factors (ionic strength, adsorption time and temperature, and desorption temperature), method detection limits of <0.1 μg L⁻¹ were achieved, and the calibration curves were all linear (R² ≥ 0.9981) within the range of 0.1–100 μg L⁻¹. The satisfying repeatability was also achieved, the RSD values of single-fiber were 3.49–5.81%, and the ones of fiber-to-fiber were 5.32–7.22%. As a result, the present fiber with good thermal stability can work at high temperature for a long service life, which is useful for the detection of low-volatility target analytes in practical applications.     

Fatty Acids and Their Metal Salts: A Review of Their Infrared Spectra in Light of Their Presence in Cultural Heritage

In a cultural heritage context, fatty acids are usually found as breakdown products of lipid-containing organic remains in archaeological findings, binders in aged oil paintings, and additives in modern art-related materials. They may further interact with the ionic environment transforming into metal soaps, a process that has been recognized as a threat in aged paintings but has received less attention in archaeological objects. The investigation of the above related categories of materials with infrared spectroscopy can provide an overall picture of the organic components’ identity and demonstrate their condition and prehistory. The capability of investigating and distinguishing fatty acids and their metal soaps through their rich infrared features, such as the acidic carbonyl, the carboxylate shifts, the variable splits of alkyl chain stretching, bending, twisting, wagging, and rocking vibrations, as well as the hydroxyl peak envelopes and acid dimer bands, allows for their direct detailed characterization. This paper reviews the infrared spectra of selected saturated fatty monoacids and diacids, and their corresponding sodium, calcium, and zinc salts and, supported by newly recorded data, highlights the significance of their spectroscopic features.     

Binding of permanganate anion to pentaammineazidocobalt(III) cation in solution and solid phases: synthesis,characterization, X-ray structure,and genotoxic effects of [Co(NH3)5N3](MnO4)2⋅H2O

A pentaammineazidocobalt(III) complex, [Co(NH₃)₅N₃](MnO₄)₂XH₂O has been synthesized by an one-pot synthesis method. It was characterized by studies such as infrared (IR) and UV-visible spectroscopy. The single crystal X-ray structure analysis revealed that the title complex crystallizes in space group Cc. The cobalt center is six coordinated with slightly octahedral geometry. The supramolecular architecture is also formed by intermolecular N-H…O (anion and H₂O) and Mn-O…O-H hydrogen bonds. The binding property of the cation, [Co(NH₃)₅N₃]²⁺ with the anion, MnO₄^– has also been determined (in solution phase) with the help of UV-visible spectroscopic titrations. Further, the genotoxic effects of KMnO₄, [Co(NH₃)₅N₃]Cl₂ and [Co(NH₃)₅N₃](MnO₄)₂XH₂O were studied using Allium cepa root chromosomal aberration assay and it revealed that the genotoxicity of the newly synthesized complex is 1.97–1.76 fold, which is less compared to KMnO₄. The order of genotoxic potential has been observed to be KMnO₄ > [Co(NH₃)₅N₃](MnO₄)₂XH₂O > [Co(NH₃)₅N₃]Cl₂.     

The development of a gas chromatographic–mass spectrometric analytical procedure for the determination of lipids,proteins and resins in the same paint micro-sample avoiding interferences from inorganic media

This paper presents a GC–MS analytical procedure for determining proteinaceous materials, glycerolipids, natural waxes and terpenoid resins in the same paint micro-sample. The procedure is also reliable when high amounts of interfering inorganic pigments, dryers and charges are present. The characterisation of proteinaceous binders in a paint sample can be subject to analytical interferences by inorganic materials. Such materials may form complexes with functional groups of proteins, thus preventing their efficient derivatisation, which is necessary prior to GC analysis. For this reason an analytical procedure has been developed based on two extractions and a clean-up step, in order to obtain two fractions: a lipid-resinous fraction and a proteinaceous fraction. The lipid-resinous fraction is subjected to salification/saponification assisted by microwaves, followed by acidification, extraction, derivatisation and GC–MS analysis. The proteinaceous fraction is analysed by GC–MS after hydrolysis and derivatisation of the freed amino acids. The desalting step is applied before the hydrolysis, and is based on the use of the monolithic sorbent tip technology with a C4 stationary phase. Reference paint replicas of egg, casein and animal glue were prepared with and without several metals containing pigments, and used to develop and validate the analytical procedure. The procedure proved to be efficient in desalting the proteinaceous materials both from cations and anions. Although non quantitative, it is reliable in the analysis of samples whose content of extractable proteins is <1 μg, thus showing it to be suitable for the characterisation of paint samples. An example of how the analytical procedure was used to characterise a sample from a 15th century panel painting is also discussed.     

A technique for evaluating the oil/heavy-oil viscosity changes under ultrasound in a simulated porous medium

Theoretically, Ultrasound method is an economical and environmentally friendly or “green” technology, which has been of interest for more than six decades for the purpose of enhancement of oil/heavy-oil production. However, in spite of many studies, questions about the effective mechanisms causing increase in oil recovery still existed. In addition, the majority of the mechanisms mentioned in the previous studies are theoretical or speculative. One of the changes that could be recognized in the fluid properties is viscosity reduction due to radiation of ultrasound waves. In this study, a technique was developed to investigate directly the effect of ultrasonic waves (different frequencies of 25, 40, 68 kHz and powers of 100, 250, 500 W) on viscosity changes of three types of oil (Paraffin oil, Synthetic oil, and Kerosene) and a Brine sample. The viscosity calculations in the smooth capillary tube were based on the mathematical models developed from the Poiseuille’s equation. The experiments were carried out for uncontrolled and controlled temperature conditions. It was observed that the viscosity of all the liquids was decreased under ultrasound in all the experiments. This reduction was more significant for uncontrolled temperature condition cases. However, the reduction in viscosity under ultrasound was higher for lighter liquids compare to heavier ones. Pressure difference was diminished by decreasing in the fluid viscosity in all the cases which increases fluid flow ability, which in turn aids to higher oil recovery in enhanced oil recovery (EOR) operations. Higher ultrasound power showed higher liquid viscosity reduction in all the cases. Higher ultrasound frequency revealed higher and lower viscosity reduction for uncontrolled and controlled temperature condition experiments, respectively. In other words, the reduction in viscosity was inversely proportional to increasing the frequency in temperature controlled experiments. It was concluded that cavitation, heat generation, and viscosity reduction are three of the promising mechanisms causing increase in oil recovery under ultrasound.     

A simple protocol for Matrix Assisted Laser Desorption Ionization- time of flight-mass spectrometry (MALDI-TOF-MS) analysis of lipids and proteins in single microsamples of paintings

A simple protocol, based on Bligh–Dyer (BD) extraction followed by MALDI-TOF-MS analysis, for fast identification of paint binders in single microsamples is proposed. For the first time it is demonstrated that the BD method is effective for the simultaneous extraction of lipids and proteins from complex, and atypical matrices, such as pigmented paint layers. The protocol makes use of an alternative denaturing anionic detergent (RapiGest™) in order to improve efficiency of protein digestion and purification step. Detection of various lipid classes, such as triacylglycerols (TAGs) and phospholipids (PLs), and their oxidation by-products was accomplished, whereas proteins could be identified by peptide mass fingerprinting. The effect of pigments on ageing of lipids and proteins was also investigated.     

Olefin/paraffin gas separations with 6FDA-based polyimide membranes

Pure gas permeation and sorption experiments were carried out for the gases ethylene, ethane, propylene and propane using polyimides based on 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA). Composite membranes and free films were used. Experiments were performed at 308 K and feed pressures up to 17 atm for ethylene and ethane and 9 atm for propylene and propane. Mixed gas permeation experiments were carried out with 50 : 50 olefin/paraffin feed mixtures. For all investigated polyimides, the ideal ethylene/ethane separation factor ranged between 3.3 and 4.4 and the ideal propylene/propane separation factor ranged between 10 and 16 at a feed pressure of 3.8 atm and 308 K. In mixed gas permeation experiments, up to 20% lower selectivity was found for the ethylene/ethane separation and up to 50% reduced selectivity for the propylene/propane separation compared to the ideal selectivity. The influence of feed temperature on separation and permeation properties will be discussed based on pure gas permeability data at 298 and 308 K.     

煤沥青筑路油受氢改质

研究了煤沥青在供氢剂（再生橡胶）的上,族组成随反应时间的变化规律及其受氢改质机理。利用核磁共振、元素分析、分子量测定等手段,计算得到了煤沥青、溶剂油以及改质筑路油等的平均结构参数。结果表明,与空白样对比,加入再生橡胶使得筑路油中沥青质含量由４５．０％增加到６１．５％,软沥青由２７．０％降低到１４．４％,不溶物由２８．０％降低至２４．１％,对比橡胶和筑路油族组成的＾１Ｈ～ＮＭＲ谱图可发现,在化学位移     

Ionic/electronic conductivity regulation of n-type polyoxadiazole lithium sulfonate conductive polymer binders for high-performance silicon microparticle anodes

Low-cost silicon microparticles(SiMP),as a substitute for nanostructured silicon,easily suffer from cracks and fractured during the electrochemical cycle.A novel n-type conductive polymer binder with excellent electronic and ionic conductivities as well as good adhesion,has been successfully designed and applied for high-performance SiMP anodes in lithium-ion batteries to address this problem.Its unique features are attributed to the stro ng electron-withdrawing oxadiazole ring structure with sulfonate polar groups.The combination of rigid and flexible components in the polymer ensures its good mechanical strength and ductility,which is beneficial to suppress the expansion and contraction of SiMP s during the charge/discharge process.By fine-tuning the monomer ratio,the conjugation and sulfonation degrees of the polymer can be precisely controlled to regulate its ionic and electronic conductivities,which has been systematically analyzed with the help of an electrochemical test method,filling in the gap on the conductivity measurement of the polymer in the doping state.The experimental results indicate that the cell with the developed n-type polymer binder and SiMP(~0.5 μm) anodes achieves much better cycling performance than traditional non-conductive binders.It has been considered that the initial capacity of the SiMP anode is controlled by the synergetic effect of ionic and electronic conductivity of the binder,and the capacity retention mainly depends on its electronic conductivity when the ionic conductivity is sufficient.It is worth noting that the fundamental research of this wo rk is also applicable to other battery systems using conductive polymers in order to achieve high energy density,broadening their practical applications.