Molecularly Imprinted Supermacroporous Cryogels for Myoglobin Recognition

Myoglobin is a primary iron, and oxygen-binding protein of muscle tissues and levels can be an important diagnostic biomarker for acute myocardial infarction, myocardial necrosis, or other cardiac diseases. The establishment of myoglobin recognition systems is important because of its protein’s structural and functional values in physiology, biochemistry, and diagnostic value in some damaged muscle tissue and cardiac diseases. For this purpose, we used molecular imprinting technique for myoglobin recognition from aqueous solutions and human plasma. In the first step, myoglobin-imprinted poly(hydroxyethyl methacrylate) (PHEMA) cryogels (MGb-MIP) were prepared, and optimum myoglobin adsorption conditions were determined. Selectivity experiments have been done with the competitive proteins, and myoglobin adsorption from IgG and albumin-free human plasma was studied. The purity of the desorbed samples was determined with SDS-PAGE. The desorption efficiency and reusability of the MGb-MIP cryogels were tested, and it was shown that without any significant loss in the adsorption capacity, MGb-MIP cryogels can be used a number of times for myoglobin recognition and separation.     

Multiresidue analysis of multiclass plant growth regulators in grapes by liquid chromatography/tandem mass spectrometry

A selective and rapid multiresidue analysis method is presented for simultaneous estimation of 12 plant growth regulators (PGRs), namely, auxins (indol-3-acetic acid, indol-3-butyric acid, and naphthyl acetic acid), cytokinins (kinetin, zeatin, and 6-benzyladenine), gibberellic acid (GA3), abscisic acid, and synthetic compounds, namely, forchlorfenuron, paclobutrazole, isoprothiolane, and 2,4-dichlorophenoxy acetic acid (2,4-D) in bud sprouts and grape berries at the development stages of 2-3 and 6-8 mm diameters, which are the critical phases when exogenous application of PGRs may be necessary to achieve desired grape quality and yield. The sample preparation method involved extraction of plant material with acidified methanol (50%) by homogenization for 2 min at 15000 rpm. The pH of the extract was enhanced up to 6 by adding ammonium acetate, followed by homogenization and centrifugation. The supernatant extract was cleaned by SPE on an Oasis HLB cartridge (200 mg, 6 cc). The final extract was measured directly by LC/MS/MS with electrospray ionization in positive mode, except for 2,4-D, GA3, and abscisic acid extracts, which required analysis in negative mode. Quantification by multiple reaction monitoring (MRM) was supported with full-scan mass spectrometric confirmation using "information-dependent acquisition" triggered with MRM to "enhanced product ionization" mode of the hybrid quadrupole-ion trap mass analyzer. The LOQ of the test analytes varied between 1 and 10 ng/g with associated recoveries of 80-120% and precision RSD <25% (n = 8). Significant matrix-induced signal suppression was recorded when the responses for pre- and postextraction spikes of analytes were compared; this could be resolved by using matrix-matched calibration standards. The method could successfully be applied in analyzing incurred residue samples and would, therefore, be useful in precisely deciding the necessity and dose of exogenous applications of PGRs on the basis of measured endogenous levels.     

Mass Spectral Studies Reveal the Structure of Aβ1-16-Cu(2+) Complex Resembling ATCUN Motif

In Alzheimer's disease, copper binds to amyloid beta (Aβ) peptide and generates oxidative stress. The coordination of histidine (His) residues to Cu(2+) is still uncertain. We studied Cu(2+) binding to Aβ1-16 peptide using the diethyl pyrocarbonate (DEPC) assay and mass spectrometry. Our results show that only one His is involved in Cu(2+) coordination, which is identified as His6 using mass spectral studies. Novel nickel displacement studies have further supported the proposal that the Cu(2+) binding site of Aβ1-16 peptide resembles the ATCUN motif of human serum albumin.     

Overlapping B3Π0u ← X1Σ g/+ and 1Π1u ← X1Σ g/+ non-radiative characteristic of Br2 vapour in the wavelength region 505–541 nm

The vibronic vapour phase photoacoustic spectrum of Br₂ in the wavelength region 505–541 nm (19796–18480 cm⁻¹) has been recorded using microphone as well as pump-probe method. Discrete vibronic bands superimposed on a monotonically increasing continuum background towards the dissociation limit results from the overlapping B ³Π _0u ^/+ ← X ¹Σ _g ^/+ and ¹Π_1u ← X ¹Σ _g ^/+ electronic transitions. Vibronic bands originating from υ″=0 have been used to estimate the relative rate of non-radiative relaxation as a function of the excited state B ³Π_0u vibrational quantum number υ′. A comparison with the optical absorption spectroscopy of Br₂ leads to the identification of three broad spectral regions between 505 and 541 nm (19796 and 18480 cm⁻¹) on the basis of different non-radiative relaxation processes.     

关于Hirota-Satsuma系统初值问题的局部和整体适定性

本文利用ＫＤＶ方程所对应的线性方程解所具有的光滑效应及压缩映像原理,得到了Ｈｉｒｏｔａ－Ｓａｔｓｕｍａ系统初值问题的局部和整体适定性结果．     

Effect of ecological factors on conjugal transfer of chromium-resistant plasmid in Escherichia coli isolated from tannery effluent

The influence of total organic carbon (TOC), pH, and mating temperature on transfer of chromium-resistant plasmid between Escherichia coli strains in terms of variation in the number of transconjugants formed and variation in transfer frequency was investigated. In vitro transfer was studied in five chromate-tolerant E. coli strains isolated from tannery effluent using E. coli K12 J62 (Nal^r Lac⁻) as a recipient. Conjugal transfer of different selection markers was observed in three strains. The study was carried out in sterile wastewater. A gradual decrease was observed both in the number of transconjugants and in transfer frequencies as the concentration of TOC in the mating medium descended from 10,095 to 1.2 mg of C/L, obtaining the maximum values with a TOC concentration of 10,095 mg of C/L. The number of transconjugants and the transfer frequency were maximum at 30°C. However, neither the transfer frequency nor the transconjugant number varied significantly in the range of pHs assayed. The strains were also found resistant to different heavy metals and antibiotics. Curing of these strains resulted in loss of one or more resistance markers indicating the plasmid-borne resistance. It is inferred that plasmid transfer by conjugation occurs in wastewater bodies within a wide range of conditions.     

Carboxymethyl chitosan‐montmorillonite nanoparticles for controlled delivery of isoniazid: evaluation of the effect of the glutaraldehyde and montmorillonite

Chitosan, a natural biopolymer, is used for drug delivery application. But its potential application is limited by its low solubility in aqueous media. The present study was designed to prepare carboxymethyl chitosan (CMC), a water soluble derivative of chitosan, and evaluate the prospective of crosslinked CMC‐Montmorillonite (MMT) nanoparticles for controlled delivery of isoniazid. The nanoparticles were characterized by Fourier Transmission Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and Transmission emission microscopy (TEM). The effects of MMT and glutaraldehyde on nanoparticles were assessed with regard to encapsulation efficiency, percentage swelling degree, and cumulative release. Percentage swelling degree and cumulative release were studied in pH medium 1.2 and 7.4 for 6 h. The cumulative release was studied by UV‐visible spectrophotometer. Cell viability study was performed by MTT assay analysis. FTIR and NMR study indicated the successful preparation of CMC. FTIR study confirmed the interaction of MMT with CMC. The exfoliation of MMT layers and molecular level dispersion of isoniazid in CMC was examined by XRD and TEM. SEM study showed that the surface of the CMC‐MMT nanoparticles was smooth compared with those of CMC nanoparticles. Swelling and release of isoniazid from the nanoparticles increased with the decrease in the MMT and glutaraldehyde content. The percentage swelling degree and cumulative release was more in pH 1.2. Cell viability study revealed that CMC was not cytotoxic, and the nanoparticles containing MMT was less cytotoxic than those of MMT free nanoparticles. CMC‐MMT nanoparticles can be exploited as potential drug carrier for controlled release applications. Copyright © 2014 John Wiley & Sons, Ltd.     

In vitro DNA damage characterisation studies on plasmid pBR322 after exposure to γ radiation by <Superscript>60</Superscript>Co

When a biological system is either accidentally or intentionally exposed to radiation, the energy absorbed triggers a number of successive events including damage to living tissues. Major radiation damage is due to the aqueous free radicals generated by the radiolysis of water. These free radicals act as molecular marauders and in turn damage DNA, mitochondrial membrane, lipid, cellular protein, resulting in cellular dysfunction and mortality. In view of the above mentioned facts an experiment was conducted to study the genotoxic effects of γ radiation and its dose effectiveness. The present experiment was conducted on samples of plasmid pBR322 DNA as the in vitro experimental model devoid of any DNA repair and replication machinery. The samples were exposed to different doses of gamma radiations from 1 to 200 Gy. Exposure of plasmid pBR322 DNA to γ radiation resulted in production of single strand breaks as a result of which, the supercoiled (SC) form was converted to relaxed form (RL). Exposure of radiation, even at very low dose of 1 Gy, exhibited a significant damage to DNA resulting in about 70% SC form and 30% RL form of DNA. At a dose of 10 Gy the SC form was reduced to about 37% and further 5% at a dose of 50 Gy with about 88.5 and 6.5% RL and linear (L) forms of DNA respectively. Thus, the disappearance of supercoiled form of plasmid pBR322 DNA was found to be directly related to radiation dose and exhibited a radiation dose dependent pattern.     

Spectroscopic Properties of Dysprosium Oxide Containing Lithium Borate Glasses

In this paper, we discussed the optical and luminescence properties of dysprosium oxide containing lithium borate glasses along with the structural properties. Absorption spectra of these glasses show strong absorption bands in ultraviolet and visible regions. Increase in dysprosium oxide content decreases in optical energy band gap, which is explained on the basis of glass structure. These glasses show bright blue emission at 482 nm and yellow emission at 573.5 nm due to ⁴ F _9/2  →  ⁶ H _15/2 and ⁴ F _9/2  →  ⁶ H _13/2 transitions of dysprosium ions.     

A new salicin derivative from the stem bark of Populus davidiana

Phytochemical study on the BuOH-soluble fraction of the stem bark of Populus davidiana resulted in the isolation of a new salicin derivative(1),named davidianoside.The structure was elucidated on the basis of extensive physicochemical and spectroscopic analyses.