Using Electron Induced Dissociation (EID) on an LC Time-Scale to Characterize a Mixture of Analogous Small Organic Molecules

LC ESI FTICR MS of a sample of cediranib identified this pharmaceutical target molecule plus an additional 10 compounds of interest, all of which were less than 10% total ion current (TIC) peak intensity relative to cediranib. LC FTICR tandem mass spectrometry using electron induced dissociation (EID) has been achieved and has proven to be the best way to generate useful product ion information for all of these singly protonated molecules. Cediranib [M + H]⁺ fragmented by EID to give 29 product ions whereas QTOF-CID generated only one very intense product ion, and linear ion trap-CID, which generated 10 product ions, but all with poor S/N. Twenty-six of the EID product ions were unique to this fragmentation technique alone. By considering the complementary LC-EID and LC-CID data together, all 10 unknown compounds were structurally characterized and proven to be analogous to cediranib. Of particular importance, EID produced unique product ion information for one of the low level cediranib analogues that enabled full characterization of the molecule such that the presence of an extra propylpyrrolidine group was discovered and proven to be located on the pyrrolidine ring of cediranib, solving an analytical problem that could not be solved by collision induced dissociation (CID). Thus, it has been demonstrated that EID is in harmony with the chromatography duty-cycle and the dynamic concentration range of synthetic compounds containing trace impurities, providing crucial analytical information that cannot be obtained by more traditional methodologies.     

A low-molecular-weight supramolecular hydrogel of riboflavin bolaamphiphile for VEGF-siRNA delivery

A low-molecular-weight hydrogel derived from riboflavin (vitamin B(2)) that self-assembles to provide supramolecular nanofibers, biocompatible material, can be used to deliver VEGF-siRNA efficiently into human cells by the endocytosis pathway, where the siRNA is functionalized.     

An experimental study and theoretical analysis of the mode characteristics of a narrow line-width,pulsed dye laser oscillator at different pump powers

This paper presents an experimental study and theoretical analysis on the effect of pump power on the divergence, pointing, line-width and wavelength stability of a narrow line-width, high repetition rate dye laser oscillator. The dye laser oscillator, based on the hybrid multiple-prism grazing-incidence grating cavity, was pumped by copper vapor laser (CVL). The dye laser mode characteristics were studied at CVL average pump powers of 2, 4 and 8 W. The single pulse dye laser divergence/pointing stability was studied by far-field intensity distributions. The line-width and wavelength stability were studied using a high resolution wave-meter. The experimental results were theoretically analyzed in terms of dye laser mode structure drift induced by beam pointing instability, beam divergence and thermally induced optical path length fluctuation. A comprehensive theoretical treatment on pointing stability of dye laser beam and its influence in the dye laser wavelength stability is presented. The theoretical and experimental trends were found to be in good agreement.     

Acute lung injury induced by Staphylococcal enterotoxin B: disruption of terminal vessels as a mechanism of induction of vascular leak

The current hypothesis of alveolar capillary membrane dysfunction fails to completely explain the severe and persistent leak of protein-rich fluid into the pulmonary interstitium, seen in the exudative phase of acute lung injury (ALI). The presence of intact red blood cells in the pulmonary interstitium may suggest mechanical failure of pulmonary arterioles and venules. These studies involved the pathological and ultrastructural evaluation of the pulmonary vasculature in Staphylococcal enterotoxin B (SEB)-induced ALI. Administration of SEB resulted in a significant increase in the protein concentration of bronchoalveolar lavage fluid and vascular leak in SEB-exposed mice compared to vehicle-treated mice. In vivo imaging of mice demonstrated the pulmonary edema and leakage in the lungs of SEB-administered mice. The histopathological studies showed intense clustering of inflammatory cells around the alveolar capillaries with subtle changes in architecture. Electron microscopy studies further confirmed the diffuse damage and disruption in the muscularis layer of the terminal vessels. Cell death in the endothelial cells of the terminal vessels was confirmed with TUNEL staining. In this study, we demonstrated that in addition to failure of the alveolar capillary membrane, disruption of the pulmonary arterioles and venules may explain the persistent and severe interstitial and alveolar edema.     

Hydrazine nitrosation of a metal-bound nitric oxide: structural evidence for the formation of an ammine complex

Hydrazine nitrosation of [Ru(NO)(py(si)S4)]Br.THF (1) (py(si)S4(2-) = 2,6-bis(3-triphenylsilyl-2-sulfanylphenylthiomethyl)pyridine2-) in methanol/DMF led to the formation of mononuclear ammine complex [Ru(NH3)(py(si)S4)] (2) and N2O, whereas the reaction performed in THF/CH2Cl2/toluene afforded thioether-bridged dinuclear ammine complex [(NH3)Ru(mu-py(si)S4)Ru(py(si)S4)] (3). Compound 2 dimerizes in solution at room temperature to form 3 and is regenerated upon treatment of 3 with NH3. A plausible mechanism for the hydrazine nitrosation of 1 has been proposed. The reaction of 1 with NH3 or N3- does not lead to a nucleophilic attack at the NO+ ligand but to a deprotonation that yields neutral nitrosyl complex [Ru(NO){py(si)S4(H+)}] (4), which is supported by density functional theory calculations.     

Cytotoxic diterpenoids from Podocarpus madagascariensis from the Madagascar rainforest

Bioassay-directed fractionation of an extract of the root and bark of Podocarpus madagascariensis resulted in the isolation of a new totarol diterpenoid (1) in addition to the three known cytotoxic diterpenoids 19-hydroxytotarol (2), totaradiol (3), and 4beta-carboxy-19-nor-totarol (4). The structure of the new compound 1 was established as methyl-13-hydroxy-14-isopropyl-9(11),12,14(8)-podocarpatriene-19-oate on the basis of 1D and 2D NMR spectroscopic interpretation and methylation of 4. All the compounds exhibited cytotoxic activity against the A2780 ovarian cancer cell line.     

Poly(ethylene glycol) (400) as superior solvent medium against ionic liquids for catalytic hydrogenations with PtO2

Adams' catalyst in poly(ethylene glycol) (PEG) (400) has been found to be a superior solvent over the ionic liquids by severalfold in promoting the hydrogenation of various functional groups. Both the catalyst and PEG were recycled efficiently over 10 runs without loss of activity, and substrate cross contamination was not observed despite a change in the substrate four times.     

Light meson spectrum and their leptonic decay widths in the frame work of constituent quark models

The phenomenological non-relativistic quark model has been employed to obtain the ground state masses of light vector mesons and their radially excited states and their decay widths.The full hamiltonian used in the investigation has kinetic energy,the confinement potential and the one-gluon-exchange potential.A good agreement is obtained with the experimental masses and their leptonic decay widths.     

Optics based biometric encryption using log polar transform

We propose an optics based biometric encryption technique using log polar transform. In this method, the key of the encryption process has been linked to the fingerprint of the enrolled person. The order of fractional Fourier transform and the seed values of the chaotic random phase masks in combination act as the key for the encryption process. In order to link the combined key to the fingerprint, a lookup table has been formed by the key and the log polar transform of the fingerprint. The linking algorithm not only encrypts the image of the enrolled person but also authenticates the input image. The main advantage of this method is its capability to retrieve the same key in the decryption process by using the live fingerprint. The key is not required to be communicated to the receiver side. The retrieval of the image is possible only when the live fingerprint of the enrolled person is presented at the decryption side. The real life fingerprints have been used to demonstrate the proposed technique. Simulations have been performed on the Matlab platform to validate the proposed technique. The signal to noise ratio and mean square error has been calculated in order to support the proposed technique. The effect of the rotation and the scaling of the fingerprints have been studied to check the key retrieval from the live fingerprint of the enrolled person. The study of the different whorl types of fingerprint of different persons has also been done to check the efficacy of the key retrieval from the whorl types of the live fingerprints of different person.     

Optics based biohashing using joint transform correlator

Most authentication process uses password and personal identification numbers (PIN) for security purposes. In order to remove the problem of hacking or stealing of the password and PIN numbers, there has been an increased interest in the utilization of specific biometric feature of the user. Recently, biohashing systems have been introduced for automatic biometric recognition. In a biohashing system, biohash codes are generated using the feature of the biometric. A basic biohashing system involves two steps. First is the extraction of the feature from the input biometric image and second is the discretisation of the obtained feature vector by using ortho-normalized random numbers. In this paper, a new biohashing system has been proposed in which joint transform correlator (JTC) has been used for extraction of the specific feature of the biometric. In the enrolment process, a biohash code has been generated by using a single face image and then stored. In the verification process, this biohash code is matched with the verification codes for recognition purpose. The main advantage of the proposed biohashing method is the possibility of the optical implementation of the feature extraction of the face image. Experimental as well as simulation results have been given to validate the proposed technique. Normalized Hamming distance has been calculated to discriminate the genuine and impostor face images. By varying the dimension of the feature matrix, the study of the variation of the normalized Hamming distance with the density of the population has been undertaken. For the performance evaluation of the proposed technique the false rejection ratio (FRR) and false acceptance ratio (FAR) have also been calculated.