Material-enhanced laser desorption/ionization (MELDI)—A new protein profiling tool utilizing specific carrier materials for time of flight mass spectrometric analysis

Over the past couple of years, proteomics pattern analysis has emerged as an effective method for the early diagnosis of diseases such as ovarian, breast, or prostate cancer, without identification of single biomarkers. MALDI-TOF MS, for example, offers a simple approach for fast and reliable protein profiling, especially by using carrier materials with various physical and chemical properties, in combination with a MALDI matrix. This approach is referred to as material-enhanced laser desorption/ionization (MELDI). In this paper, we report the development and application of derivatized carrier materials [cellulose, silica, poly(glycidyl methacrylate/divinylbenzene) (GMA/DVB) particles, and diamond powder] for fast and direct MALDI-TOF MS protein profiling. The applicability of MELDI for rapid protein profiling was evaluated with human serum samples. These carriers, having various hydrophobicities, resulted in characteristic mass fingerprints, even if all materials were derivatized with iminodiacetic acid (IDA) to yield an immobilized metal affinity chromatography (IMAC) functionality. Our study demonstrates that analyzing complex biological samples, such as human serum, by employing different MELDI carrier materials yielded type- and size-dependent performance variation.     

铋和镍对钒磷氧化物催化剂性能的影响YunHinTaufiq-Yap,ChoonSeonYuen,Nawi简

Vanadium phosphorus oxide (VPO) catalysts were synthesized by the dihydrate method which involved the two steps for the preparation of the dihydrate (VOPO₄×2H₂O) and the precursor hemihydrate (VOHPO₄×0.5H₂O). Bi and Ni salt were added into the mixture of VOPO₄×2H₂O and isobutanol, and the obtained precursors were calcined in a flow of a n-butane/air mixture to produce the promoted VPO catalysts. The catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption-desorption, inductively coupled plasma-atomic emission spectroscopy, scanning electron microscopy (SEM), and H₂ temperature-programmed reduction (H₂-TPR). Their catalytic properties were tested using a fixed-bed microreactor. All the catalysts gave main XRD peaks at 2θ = 22.9°, 28.5°, and 30.0°, attributing to the (020), (204), and (221) planes of the pyrophosphate phase (VO)₂P₂O₇, respectively. The promoted catalysts have smaller crystallite size and higher specific surface areas. SEM micrographs revealed the formation of more prominent plate-like crystallites that were arranged as rosette clusters. H₂-TPR results showed that the promoted catalysts had lower reduction peak temperatures and possessed higher amounts of V⁵⁺-O^2- and V⁴⁺-O^- pairs, which gave higher selectivity and activity in the selective oxidation of n-butane to maleic anhydride.     

铋和镍对钒磷氧化物催化剂性能的影响(英文)

Vanadium phosphorus oxide (VPO) catalysts were synthesized by the dihydrate method which involved the two steps for the preparation of the dihydrate (VOPO4 2H2 O) and the precursor hemi-hydrate (VOHPO4 0.5H2 O). Bi and Ni salt were added into the mixture of VOPO4 2H2 O and isobu-tanol, and the obtained precursors were calcined in a flow of a n-butane/air mixture to produce the promoted VPO catalysts. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorp-tion- desorption, inductively coupled plasma-atomic emission spectroscopy, scanning electron mi-croscopy (SEM), and H2 temperature-programmed reduction (H2 -TPR). Their catalytic properties were tested using a fixed-bed microreactor. All the catalysts gave main XRD peaks at 2θ = 22.9°, 28.5°, and 30.0°, attributing to the (020), (204), and (221) planes of the pyrophosphate phase (VO)2 P2 O7, respectively. The promoted catalysts have smaller crystallite size and higher specific surface areas. SEM micrographs revealed the formation of more prominent plate-like crystallites that were arranged as rosette clusters. H2 -TPR results showed that the promoted catalysts had lower reduction peak temperatures and possessed higher amounts of V5+-O2– and V4+-O– pairs, which gave higher selectivity and activity in the selective oxidation of n-butane to maleic anhydride.     

Electrochemical determination of zearalenone using a label-free competitive aptasensor

An in situ preparation of metal-organic framework (HKUST-1) on the surface of an organic polymer is reported. The hybrid material was evaluated as sorbent for solid-phase extraction (SPE) of oxygenated and nitrated polycyclic aromatic hydrocarbons (PAHs). The growth of HKUST-1 on MAA-based polymer was accomplished using a layer-by-layer assembly strategy. The HKUST-1-polymer was characterized using powder X-ray diffraction and scanning electron microscopy to demonstrate the incorporation of MOF crystals onto the polymer surface. The MOF (nano)crystals were characterized using high-resolution transmission electron microscopy and high-angle annular-dark-field scanning transmission electron microscopy. The water-stable MOF-polymer was evaluated as SPE sorbent, and several variables that can influence the extraction recoveries of PAH derivatives were investigated. Under the selected conditions, the detection limits varied between 4 and 21 ng·L−1, and the precision (relative standard deviation) was below 12%. The recovery values for spiked solutions ranged from 95 to 104%, and the enrichment factor achieved was close to 1000-fold using a high sample volume (100 mL) and very low desorption volume (100 μL). The SPE enrichment combined with HPLC and DAD detector was successfully applied to the extraction and determination of polycyclic hydrocarbons in environmental water samples.     

A Validated LC Method for Simultaneous Determination of Phenolic, Coumarin and Phthalide Compounds in the Ethanolic Extract of Angelica tenuissima

In this study, an LC method for the simultaneous determination of six bioactive compounds from Angelica tenuissima, namely chlorogenic acid, ferulic acid, Z-ligustilide, nodakenin, decursin and decursinol angelate was developed and validated. Chromatographic analysis was carried out on a C₁₈ column with a mobile phase consisting of 0.1% formic acid, methanol and acetonitrile at a flow rate of 0.8 mL min^?1 and the effluent from the column was monitored by UV detector at 325 nm. The excellent linear behavior was observed over the investigated concentration range for reported compounds. The intra- and inter-day precision over the concentration range of compounds were lower than 1.7% (as relative standard deviation), and accuracy was between 97.2 and 106.0%. These results showed that the developed method is accurate, reproducible, and consequently applicable for the quantitation of bioactive components from the ethanolic extract of Angelica tenuissima Nakai.     

Low temperature capture of pseudorotaxanes

Yields of a rotaxane can be improved by employing a two-step capture protocol. Cooling a solution of the linear and macrocyclic components required for the rotaxane increases the population of the target pseudorotaxane, which is then captured by a rapid capping reaction between an azide and PPh(3). The resulting iminophosphorane rotaxane can then be manipulated synthetically at elevated temperatures.     

Zinc oxide films prepared by sol–gel spin coating technique

Zinc oxide (ZnO) thin films and micro- and nanostructures are very promising candidates for novel applications in emerging thin-film transistors, solar cells, sensors and optoelectronic devices. In this paper, a low-cost sol–gel spin coating technique was used to fabricate ZnO films on glass substrates. The sol–gel fabrication process of the ZnO films is described. The influence of precursor concentration on the material properties of the ZnO films was investigated. Atomic force microscopy and X-ray diffractometry were employed to examine the structural properties of the ZnO films. The optical properties of the ZnO films were characterized with ultraviolet–visible spectroscopy. The experimental results reveal that the precursor concentration in the sol–gel spin coating process exerts a strong influence on the properties of the ZnO films. The effects of the precursor concentration are discussed.     

Zerumbone Ameliorates Neuropathic Pain Symptoms via Cannabinoid and PPAR Receptors Using In Vivo and In Silico Models

Neuropathic pain is a chronic pain condition persisting past the presence of any noxious stimulus or inflammation. Zerumbone, of the Zingiber zerumbet ginger plant, has exhibited anti-allodynic and antihyperalgesic effects in a neuropathic pain animal model, amongst other pharmacological properties. This study was conducted to further elucidate the mechanisms underlying zerumbone’s antineuropathic actions. Research on therapeutic agents involving cannabinoid (CB) and peroxisome proliferator-activated receptors (PPARs) is rising. These receptor systems have shown importance in causing a synergistic effect in suppressing nociceptive processing. Behavioural responses were assessed using the von Frey filament test (mechanical allodynia) and Hargreaves plantar test (thermal hyperalgesia), in chronic constriction injury (CCI) neuropathic pain mice. Antagonists SR141716 (CB₁ receptor), SR144528 (CB₂ receptor), GW6471 (PPARα receptor) and GW9662 (PPARγ receptor) were pre-administered before the zerumbone treatment. Our findings indicated the involvement of CB₁, PPARα and PPARγ in zerumbone’s action against mechanical allodynia, whereas only CB₁ and PPARα were involved against thermal hyperalgesia. Molecular docking studies also suggest that zerumbone has a comparable and favourable binding affinity against the respective agonist on the CB and PPAR receptors studied. This finding will contribute to advance our knowledge on zerumbone and its significance in treating neuropathic pain.     

Synthesis and characterization of epoxy composites filled with Pb, Bi or W compound for shielding of diagnostic x-rays

Lead chloride, bismuth oxide and tungsten oxide filled epoxy composites with different weight fractions were fabricated to investigate their x-ray transmission characteristics in the x-ray diagnostic imaging energy range (40–127 kV) by using a conventional laboratory x-ray machine. Characterizations of the microstructure properties of the synthesized composites were performed using synchrotron radiation diffraction, backscattered electron imaging microscopy, three-point bend test and Rockwell hardness test. As expected, the x-ray transmission was decreased by the increment of the filler loading. Meanwhile, the flexural modulus and hardness of the composites were increased through an increase in filler loading. However, the flexural strength showed a marked decrease with the increment of filler loading (≥30 wt%). Some agglomerations were observed for the composites having ≥50 wt% of filler.     

Constant heat flux solution for mixed convection boundary layer viscoelastic fluid

The mixed convection boundary layer of a viscoelastic fluid past a circular cylinder with constant heat flux is discussed. The boundary layer equations are an order higher than those for the Newtonian (viscous) fluid and the adherence boundary conditions are insufficient to determine the solution of these equations completely. The governing non-similar partial differential equations are transformed into dimensionless forms and then solved numerically using the Keller-box method by augmenting an extra boundary condition at infinity. Numerical results obtained in the form of velocity distributions and temperature profiles are presented for a range of values of the dimensionless viscoelastic fluid parameter. It is found that for some values of the viscoelastic parameter and some negative values of the mixed convection parameter (opposing flow) the momentum boundary layer separates from the cylinder. Heating the cylinder delays separation and can, if the cylinder is warm enough, suppress the separation completely. Similar to the case of a Newtonian fluid, cooling the cylinder brings the separation point nearer to the lower stagnation point.