Magnetic and dielectric properties of BiFeO3 nanoparticles

Single crystalline nano-sized multiferroic BiFeO3 (BFO) powders were synthesized through simple chemical co-precipitation method using polyethylene glycol (PEG) as capping agent. We obtained pure phase BiFeO3 powder by controlling pHand calcination temperature. From X-ray diffraction studies the nanoparticles were unambiguously identified to have a rhombohedrally distorted perovskite structure belonging to the space group of R3c. No secondary phases were detected. It indicates single phase structure. EDX spectra indicated the appearance of three elements Bi, Fe, O in 1:1:3. From the UV-Vis diffuse reflectance spectrum, the absorption cut-off wavelength of the BFO sample is around 558nm corresponding to the energy band gap of 2.2 eV. The size (60-70 nm) and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM).   Linear M−H behaviour and slight hysteresis at lower magnetic field is observed for BiFeO3 nanoparticles from Vibrating sample magnetometer studies. It indicates weak ferromagnetic behaviour at room temperature. From dielectric studies, the conductivity value is calculated from the relation s = L/RbA Sm-1 and it is around 7.2 x 10-9 S/m

A retrospective validation of CanAssist Breast in European early-stage breast cancer patient cohort

Hormone-receptor positive; Chemotherapy; Early-stage breast cancerReceptor de hormonas positivo; Quimioterapia; Cáncer de mama en fase inicialReceptor d'hormones positiu; Quimioteràpia; Càncer de mama en fase inicialCanAssist Breast (CAB), a prognostic test uses immunohistochemistry (IHC) approach coupled with artificial intelligence-based machine learning algorithm for prognosis of early-stage hormone-receptor positive, HER2/neu negative breast cancer patients. It was developed and validated in an Indian cohort. Here we report the first blinded validation of CAB in a multi-country European patient cohort. FFPE tumor samples from 864 patients were obtained from-Spain, Italy, Austria, and Germany. IHC was performed on these samples, followed by recurrence risk score prediction. The outcomes were obtained from medical records. The performance of CAB was analyzed by hazard ratios (HR) and Kaplan Meier curves. CAB stratified European cohort (n = 864) into distinct low- and high-risk groups for recurrence (P 50 years (HR: 2.93 (1.44–5.96), P = 0.0002). CAB had an HR of 2.57 (1.26–5.26), P = 0.01) in women with N1 disease. CAB stratified significantly higher proportions (77%) as low-risk over IHC4 (55%) (P < 0.0001). Additionally, 82% of IHC4 intermediate-risk patients were stratified as low-risk by CAB. Accurate risk stratification of European patients by CAB coupled with its similar performance inIndian patients shows that CAB is robust and functions independent of ethnic differences. CAB can potentially prevent overtreatment in a greater number of patients compared to IHC4 demonstrating its usefulness for adjuvant systemic therapy planning in European breast cancer patients

A compendium of molecules involved in vector-pathogen interactions pertaining to malaria

Malaria is a vector-borne disease causing extensive morbidity, debility and mortality. Development of resistance to drugs among parasites and to conventional insecticides among vector-mosquitoes necessitates innovative measures to combat this disease. Identification of molecules involved in the maintenance of complex developmental cycles of the parasites within the vector and the host can provide attractive targets to intervene in the disease transmission. In the last decade, several efforts have been made in identifying such molecules involved in mosquito-parasite interactions and, subsequently, validating their role in the development of parasites within the vector. In this study, a list of mosquito proteins, which facilitate or inhibit the development of malaria parasites in the midgut, haemolymph and salivary glands of mosquitoes, is compiled. A total of 94 molecules have been reported and validated for their role in the development of malaria parasites inside the vector. This compendium of molecules will serve as a centralized resource to biomedical researchers investigating vector-pathogen interactions and malaria transmission. © 2013 Sreenivasamurthy et al.; licensee BioMed Central Ltd

Rational discovery of a SOD1 tryptophan oxidation inhibitor with therapeutic potential for amyotrophic lateral sclerosis.

Formation of Cu, Zn superoxide dismutase 1 (SOD1) protein inclusions within motor neurons is one of the principal characteristics of SOD1-related amyotrophic lateral sclerosis (ALS). A hypothesis as to the nature of SOD1 aggregation implicates oxidative damage to a solvent-exposed tryptophan as causative. Here, we chart the discovery of a phenanthridinone based compound (Lig9) from the NCI Diversity Set III by rational methods by in silico screening and crystallographic validation. The crystal structure of the complex with SOD1, refined to 2.5 Å, revealed that Lig9 binds the SOD1 β-barrel in the β-strand 2 and 3 region which is known to scaffold SOD1 fibrillation. The phenanthridinone moiety makes a substantial π-π interaction with Trp32 of SOD1. The compound possesses a significant binding affinity for SOD1 and inhibits oxidation of Trp32; a critical residue for SOD1 aggregation. Thus, Lig9 is a good candidate from which to develop a new library of SOD1 aggregation inhibitors through protection of Trp32 oxidation. Communicated by Ramaswamy H. Sarma

A Novel Phenanthridionone Based Scaffold As a Potential Inhibitor of the BRD2 Bromodomain: Crystal Structure of the Complex

<div><p>Bromodomain containing proteins recognize the level of histone acetylation and regulate epigenetically controlled processes like gene transcription and chromatin modification. The BET (<u>b</u>romodomain and <u>e</u>xtra-<u>t</u>erminal) family proteins, which are transcriptional co-regulators, have been implicated in the pathogenesis of cancer, neurodegenerative disorders, and defects in embryonic stem cell differentiation. Inhibitors selectively targeting the BET bromodomains can pave the path for new drug discovery against several forms of major diseases. By a rational structure-based approach, we have identified a new inhibitor (NSC127133) of the second bromodomain (BD2) of the BET family protein BRD2 using the NCI Diversity Set III library. A high-resolution crystal structure of the BRD2-BD2 in complex with this compound and in <i>apo</i>- form is refined to 0.91 and 0.94 Å, respectively. The compound, which is a phenanthridinone derivative, binds well to the acetyl-lysine binding pocket of BD2 and displays significant hydrophobic and hydrophilic interactions. Moreover, the atomic resolution data obtained in this study allowed us to visualize certain structural features of BD2 which remained unobserved so far. We propose that the discovered compound may be a potential molecule to develop a new library for inhibiting the BRD2-BD2 function.</p></div

Superposition of <i>BD2-H4K5ac</i> (PDB Id: 2E3K) and <i>BD2-L10</i> complex.

<p>The H4K5ac and L10 are represented in grey and yellow, respectively. The binding site residues corresponding to <i>BD2-L10</i> (purple), the ligand L10 (yellow), H433 of <i>BD2-H4K5ac</i> (grey) and the <i>H4K5ac</i> side-chain (grey) are shown as sticks. H433 is swung in towards the binding pocket in the <i>BD2-L10</i> complex.</p

Superposition of BC and ZA loop regions of <i>BD2-H4K5ac</i> complex (PDB Id: 2E3K) and <i>apo-</i>form.

<p>Binding site residues (purple) in the <i>apo-</i>form demonstrating conformations different to that observed in the <i>BD2-H4K5ac</i> complex structure (grey). The side chain of C425 and M438 are flipped in the <i>apo-</i>form compared to the <i>H4K5ac</i> structure. The residues near the binding site region, which possess alternate conformations, are shown as sticks. |2Fo|-|Fc| map of the residues contoured at 1.0σ. The hydrogen bonds are shown as broken lines.</p

Binding analysis of L10 towards BRD2-BD2.

<p>SPR sensorgrams obtained by running different concentrations of L10 over immobilized BRD2-BD2. The figure in the inset shows fitting of data points at equilibrium (Req) for the interaction of different concentrations of L10 to immobilized BD2.</p

Data reduction and refinement statistics of the <i>apo-</i>form of BRD2-BD2 and <i>BD2-L10</i> structures.

<p>Data reduction and refinement statistics of the <i>apo-</i>form of BRD2-BD2 and <i>BD2-L10</i> structures.</p