Magnetic structure and charge ordering in Fe3BO5 ludwigite

The crystal and magnetic structures of the three-leg ladder compound Fe3BO5 have been investigated by single crystal x-ray diffraction and neutron powder diffraction. Fe3BO5 contains two types of three-leg spin ladders. It shows a charge ordering transition at 283 K, an antiferromagnetic transition at 112 K, ferromagnetism below 70 K and a weak ferromagnetic behavior below 40K. The x-ray data reveal a smooth charge ordering and an incomplete charge localization down to 110K. Below the first magnetic transition, the first type of ladders orders as ferromagnetically coupled antiferromagnetic chains, while below 70K the second type of ladders orders as antiferromagnetically coupled ferromagnetic chains

Wnt signaling: Moving in a new direction

Evidence supporting the postulated role of a Wnt ligand in the establishment of planar cell polarity has been elusive, but recent studies show that the movement of epithelial cells during vertebrate gastrulation or Drosophila dorsal closure depends on both a Wnt ligand and the planar cell polarity pathway

Wnt signaling: Moving in a new direction

Evidence supporting the postulated role of a Wnt ligand in the establishment of planar cell polarity has been elusive, but recent studies show that the movement of epithelial cells during vertebrate gastrulation or Drosophila dorsal closure depends on both a Wnt ligand and the planar cell polarity pathway

NoSQL: Latar Belakang, Konsep, dan Kritik

Berkembangnya aplikasi berbasis web yang memerlukan pengolahan data dalam skala besar melahirkan paradigma baru dalam teknologi basis data. Beberapa website seperti Facebook, Twitter, Digg, Google, Amazon, dan SourceForge menyimpan dan mengolah data puluhan giga setiap harinya, dan total keseluruhan data yang disimpan oleh applikasi tersebut sudah mencapai ukuran petabyte. Ukuran data yang sangat besar menimbulkan permasalahan dari segi skalabilitas, karena pertambahan data yang terjadi setiap saat. Peningkatan kemampuan server secara vertikal yang dimiliki Relational Database Management System (RDBMS) terbatas pada penambahan prosesor, memori, dan media penyimpanan dalam satu node server yang terbatas. Sedangkan peningkatan kemampuan server secara horizontal yang meliputi penambahan perangkat server baru dalam suatu jaringan memerlukan biaya yang mahal dan sulit dalam pengelolaannya. Salah satu cara yang diterapkan oleh website berskala besar untuk mengatasi permasalahan tersebut adalah dengan menggunakan NoSQL, sebuah paradigma basis data yang merelaksasikan aturan-aturan konsistensi yang terdapat pada basis data relasional. Jika RDBMS menggunakan aturan Atomicity, Consistency, Isolation, dan Durability (ACID) untuk penyimpanan dan pengolahan data, maka NoSQL menggunakan paradigma Basically Available, Soft State, and Eventually consistent (BASE) untuk merelaksasikan aturan tersebut. Hasilnya, NoSQL dapat mengolah data dalam jumlah besar dengan memartisi data ke dalam beberapa server secara lebih mudah. Makalah ini membahas dan menjelaskan latar belakang kemunculan, konsep dasar, dan penggunaan NoSQL. Kata kunci : Basis data, RDBMS, Skalabilitas, NoSQ

Differential Disruption of EWS-FLI1 Binding by DNA-Binding Agents

Fusion of the EWS gene to FLI1 produces a fusion oncoprotein that drives an aberrant gene expression program responsible for the development of Ewing sarcoma. We used a homogenous proximity assay to screen for compounds that disrupt the binding of EWS-FLI1 to its cognate DNA targets. A number of DNA-binding chemotherapeutic agents were found to non-specifically disrupt protein binding to DNA. In contrast, actinomycin D was found to preferentially disrupt EWS-FLI1 binding by comparison to p53 binding to their respective cognate DNA targets in vitro. In cell-based assays, low concentrations of actinomycin D preferentially blocked EWS-FLI1 binding to chromatin, and disrupted EWS-FLI1-mediated gene expression. Higher concentrations of actinomycin D globally repressed transcription. These results demonstrate that actinomycin D preferentially disrupts EWS-FLI1 binding to DNA at selected concentrations. Although the window between this preferential effect and global suppression is too narrow to exploit in a therapeutic manner, these results suggest that base-preferences may be exploited to find DNA-binding compounds that preferentially disrupt subclasses of transcription factors

Approaches to Pharmaceutical Analysis of Modern Peptide and Oligonucleotide Products as Illustrated by a Small Interfering RNA-Based Novel Therapeutic for the Treatment of Bronchial Asthma

Methods used to control the quality of peptide products depend on the level of development of analytical and bioorganic chemistry, and the level of instrumentation. Peptide identification is a difficult task and largely depends on the complexity of its structure. There does not exist a comprehensive and simple test, except for NMR, which, however, is rather expensive and time-consuming and involves complex data interpretations. Moreover, it does not allow for unambiguous determination of the peptide purity and formula (amino acid composition, sequence, chirality of amino acid residues). For this reason, a combination of methods is often used, including amino acid analysis, TLC/HPLC and mass spectrometry, and, less frequently, sequencing. Current international practice of peptide analysis is to use HPLC in combination with mass spectrometric, mainly tandem (HPLC-MS/MS), detection. According to literature sources the amino acid sequence of linear peptides can be analysed using various enzymes and subsequent identification of proteolysis products by mass spectrometry. This article presents approaches to the development of test methods for analysis of purity and identification testing of a small interfering RNA-based novel medicinal product, which will help standardise and control the quality of the production process