Direct electrochemistry of an [FeFe]-hydrogenase on a TiO2 electrode.

[FeFe]-hydrogenases are efficient natural catalysts that can be exploited for hydrogen production. Immobilization of the recombinant [FeFe]-hydrogenase CaHydA was achieved for the first time on an anatase TiO(2) electrode. The enzyme is able to interact and exchange electrons with the electrode and to catalyze hydrogen production with an efficiency of 70%.

P450-based porous silicon biosensor for arachidonic acid detection.

A porous silicon biosensor based on P450 enzyme for arachidonic acid detection was developed. A new transduction method is presented with a simultaneous measurement of refractive index and fluorescence intensity changes when the analyte is binding to an enzyme on the porous silicon surface. A fluorophore bound to a cysteine residue in an allosteric position of the haem domain (BMP) of cytochrome P450 BM3 enhances its fluorescence intensity upon interaction with its substrate arachidonic acid, involved in diseases such as Alzheimer's, liver cancer and cellular inflammation processes.

Comparison of standard and nonstandard helmets and variants influencing the choice of helmets: A preliminary report of cross-sectional prospective analysis of 100 cases.

Background: The literature does not offer the rate of protection provided by different types of helmets used, especially as it applies to developing countries. We hypothesize that standard versus nonstandard types of helmets might differ in the rate of complications of head and neck trauma occurring in victims of motorcycle accidents. Here we report the rate of occurrence, the type of injuries and differences thereof in standard and nonstandard helmet bearers, and its relevance to protection from serious injury.

Spontaneous conversion of fibrous dysplasia into osteosarcoma.

Spontaneous degeneration of sarcomatosis of fibrous dysplasia is a rare phenomenon in adolescence. Fibrous dysplasia is often a deforming and devastating condition that begins in childhood and accounts for approximately 7.5% of the benign bone neoplasms.

Altitude distribution of the auroral acceleration potential determined from cluster satellite data at different heights.

Aurora, commonly seen in the polar sky, is a ubiquitous phenomenon occurring on Earth and other solar system planets. The colorful emissions are caused by electron beams hitting the upper atmosphere, after being accelerated by quasistatic electric fields at 1-2 R(E) altitudes, or by wave electric fields. Although aurora was studied by many past satellite missions, Cluster is the first to explore the auroral acceleration region with multiprobes.

Influence of poplar clones on fertility life-table parameters of Chaitophorus leucomelas (Hemiptera: Aphididae).

The aphid Chaitophorus leucomelas Koch (Hemiptera: Aphididae) is one of the most important pests of poplar (Populus spp.) plantations in Iran. In this study, development, reproduction, and life history of the aphid were assessed on 11 poplar clones; belong to three species, Populus nigra L.

Primary immunodeficiency in children: report of seven years study.

Background: Primary immunodeficiency diseases (PIDs) are a genetically heterogeneous group of disorders that affect distinct components of the innate and adaptive immune system, such as neutrophils, macrophages, dendritic cells, complement proteins, natural killer cells, T and B lymphocytes. These disorders are rare, with an estimated prevalence of 1:10,000 live births.

Objectives: This study aimed at describing the clinical features, disease complications, treatment modalities and overall outcome of patients with Primary Immunodeficiency Diseases (PID) in Masih Daneshvari hospital during a 7-year period (2001-2008).

Multimodal integration after unilateral labyrinthine lesion: single vestibular nuclei neuron responses and implications for postural compensation.

Plasticity in neuronal responses is necessary for compensation following brain lesions and adaptation to new conditions and motor learning. In a previous study, we showed that compensatory changes in the vestibuloocular reflex (VOR) following unilateral vestibular loss were characterized by dynamic reweighting of inputs from vestibular and extravestibular modalities at the level of single neurons that constitute the first central stage of VOR signal processing. Here, we studied another class of neurons, i.

Esophageal adenocarcinoma incidence in individuals with gastroesophageal reflux: synthesis and estimates from population studies.

Objectives: Recent advances in the management of Barrett's esophagus may kindle enthusiasm for screening for esophageal adenocarcinoma (EAC). Symptoms of gastroesophageal reflux disease (GERD) are recognized as relative risks for EAC. However, the absolute incidence of EAC in specific populations with GERD is unknown.

Prevalence of human Metapneumovirus (hMPV) in children with wheezing in Shiraz-Iran.

Human metapneumovirus (hMPV) infection plays an important role in the pediatric respiratory infections. The aim of this study was to determine the relationship between asthma and wheezing with hMPV in hospitalized children. Nasal pharyngeal swabs obtained from 120 children aged 1-60 months, hospitalized during a one year period, were tested for the hMPV by RT-PCR.

An electrochemical microfluidic platform for human P450 drug metabolism profiling.

This paper is the first report of a P450-electrode in a microfluidic format. A 30 μL microfluidic cell was made in poly(methyl methacrylate) containing the inlet, outlet, and reaction chamber with two electrode strips, one of which contains the human cytochrome P450 3A4 covalently bound to gold via a 6-hexanethiol and 7-mercaptoheptanoic acid (1:1) self-assembled monolayer. The electrochemical response of the P450-electrode in the microfluidic cell was tested using four drugs that are known substrates of P450 3A4: quinidine, nifedipine, alosetron and ondansetron.

Gain without inversion in hybrid quantum dot-metallic nanoparticle systems.

We study the generation of tunable gain without inversion in semiconductor quantum dots using plasmonic effects. For this we investigate the impact of localized surface plasmons on coherent nonlinear exciton effects in a quantum dot when it is located in the vicinity of a metallic nanoparticle. It is shown that when such a system is exposed to a laser field and the distance between the quantum dot and the metallic nanoparticle is reduced the initial impact of plasmons is enhancement of the ac-Stark shift in the quantum dot.

Effects of 5-year interventions on cardiovascular risk factors of factories and offies employees of isfahan and najafabad: worksite intervention project-isfahan healthy heart program.

Background: Effects of 5-year interventions of Worksite Intervention Project from Isfahan Healthy Heart Program on cardiovascular risk factors of factories and offices employees were studied in Isfahan and Najafabad (intervention area) compared to Arak (control area).

Methods: We had especial interventions for nutrition, physical activity and smoking as well as hypertension and obesity screening systems in all offices and factories, and other risk factors screening systems whenever possible. Before and after the interventions, questionnaires containing demographic and other required data were completed for the two populations; height, weight and blood pressure (BP) were measured and a fasting and 2h blood sample was taken for the measurement of blood sugar (BS) and lipid levels.

Understanding uncoupling in the multiredox centre P450 3A4-BMR model system.

Understanding the uncoupling at the haem active site and/or at the level of multidomain electron transfer is an important element in cytochrome P450 chemistry. Here a chimeric model system consisting of human cytochrome P450 3A4 and the soluble reductase domain of CYP102A1 from Bacillus megaterium (BMR) is used to study the relationship between electron transfer and the coupling efficiency in substrate monoxygenation. Several regulatory features were considered.

Early experiences of abuse and current depressive disorders in Iranian women.

Early experience of abuse may be viewed as a risk factor for mental disorders in women later in life. This case-control study in Isfahan screened 709 women aged 20-45 years using the Beck Depression Inventory and structured clinical interviews for Diagnostic Statistical Manual-IV criteria. Lifetime history of abuse was determined using a standard questionnaire.

Shaping ability of NiTi rotary versus stainless steel hand instruments in simulated curved canals.

Objectives: The purpose of this in-vitro study was to compare shaping ability of NiTi rotary Mtwo and FlexMaster with stainless steel hand K-Flexofile in simulated curved root canals.

Study Design: Forty-five simulated canals in resin blocks were prepared with Mtwo, FlexMaster and stainless steel hand K-Flexofile (15 blocks in each group). Using pre- and post- instrumentation images, straightening of the canal curvature was determined with a computer image analysis program.

Prevalence of odontogenic sinus tracts in 728 endodontically treated teeth.

Objectives: The primary aim of this study was to assess the prevalence of sinus tracts in endodontically treated teeth in an Iranian population. The second aim was to seek and analyze the relationship between the clinically detected sinus tracts and factors such as sex, age, tooth type and location.

Study Design: A total of 728 patients' records and radiographs were reviewed of 427 females and 301 males for demographic data, preoperative pulpoperiapical status of treated teeth and the presence of sinus tract.

Towards information processing from nonlinear physical chemistry: a synthetic electrochemical cognitive system.

It is evident that complex animate materials, which operate far from equilibrium, exhibit sensory responses to the environment through emergent patterns. Formation of such patterns is often the underlying mechanism of an active response to environmental changes and can be interpreted as a result of the distributed parallel information processing taking place within the material. Such emergent patterns are not limited to biological entities; indeed there is a wide range of complex nonlinear dissipative systems which exhibit interesting emergent patterns within a range of parameters.

Tunable nanoswitches based on nanoparticle meta-molecules.

We introduce ultra-fast tunable nanoswitches based on the transition between states of nanoparticle meta-molecules. These molecules are formed (activated) when hybrid systems consisting of metallic nanoparticles and semiconductor quantum dots interact with coherent light sources (laser fields). The switching process occurs via minuscule changes of the refractive index of the environment or the distance between the quantum dots and metallic nanoparticles.

Neural correlates of motor learning in the vestibulo-ocular reflex: dynamic regulation of multimodal integration in the macaque vestibular system.

Motor learning is required for the reacquisition of skills that have been compromised as a result of brain lesion or disease, as well as for the acquisition of new skills. Behaviors with well characterized anatomy and physiology are required to yield significant insight into changes that occur in the brain during motor learning. The vestibulo-ocular reflex (VOR) is well suited to establish connections between neurons, neural circuits, and motor performance during learning.

Electro-catalysis by immobilised human flavin-containing monooxygenase isoform 3 (hFMO3).

Human flavin-containing monooxygenases are the second most important class of drug-metabolizing enzymes after cytochromes P450. Here we report a simple but functional and stable enzyme-electrode system based on a glassy carbon (GC) electrode with human flavin-containing monooxygenase isoform 3 (hFMO3) entrapped in a gel cross-linked with bovine serum albumin (BSA) by glutaraldehyde. The enzymatic electrochemical responsiveness is characterised by using well-known substrates: trimethylamine (TMA), ammonia (NH(3)), triethylamine (TEA), and benzydamine (BZD).

Breakthrough in P450 bioelectrochemistry and future perspectives.

Improving the electrochemical performance of cytochrome P450 enzymes is highly desirable due to their versatility in the recognition of different biological and xenobiotic compounds. The task poses an exciting challenge because it leads not only to the acquisition of fundamental knowledge on the redox properties of these enzymes, but it also opens opportunities for technological and commercial applications. Interfacing these enzymes to electrode surfaces and electrochemically driving their catalytic cycle has proven to be very difficult.

Assessment of the potential role of muscle spindle mechanoreceptor afferents in chronic muscle pain in the rat masseter muscle.

Background: The phenotype of large diameter sensory afferent neurons changes in several models of neuropathic pain. We asked if similar changes also occur in "functional" pain syndromes.

Methodology/principal Findings: Acidic saline (AS, pH 4.

Control of human cytochrome P450 2E1 electrocatalytic response as a result of unique orientation on gold electrodes.

Oriented immobilization of human cytochrome P450 2E1 and its catalytic activity by direct electrochemistry was achieved by engineering two multisite mutants of P450 2E1: MUT261 (C268S-C480S-C488S) and MUT268 (C261S-C480S-C488S). Here, all the exposed cysteines are mutated into serines, with the exception of one (C261 for MUT261 and C268 for MUT268) that is able to link covalently to a modified gold electrode. The P450 2E1 wild type, as well as the two mutants, were immobilized onto gold electrodes using dithio-bismaleimidoethane as a self-assembled monolayer.