Optimization temperature sensitivity using the optically detected magnetic resonance spectrum of a nitrogen-vacancy center ensemble

Temperature sensing with nitrogen vacancy (NV) centers using quantum techniques is very promising and further development is expected. Recently, the optically detected magnetic resonance (ODMR) spectrum of a high-density ensemble of the NV centers was reproduced with noise parameters [inhomogeneous magnetic field, inhomogeneous strain (electric field) distribution, and homogeneous broadening] of the NV center ensemble. In this study, we use ODMR to estimate the noise parameters of the NV centers in several diamonds. These parameters strongly depend on the spin concentration. This knowledge is then applied to theoretically predict the temperature sensitivity. Using the diffraction-limited volume of 0.1 micron^3, which is the typical limit in confocal microscopy, the optimal sensitivity is estimated to be around 0.76 mK/Hz^(1/2) with an NV center concentration of 5.0e10^17/cm^3. This sensitivity is much higher than previously reported sensitivities, demonstrating the excellent potential of temperature sensing with NV centers.Comment: 17 pages, 4 figures, 1 tabl

Field-induced water electrolysis switches an oxide semiconductor from an insulator to a metal

Here we demonstrate that water-infiltrated nanoporous glass electrically switches an oxide semiconductor from an insulator to metal. We fabricated the field effect transistor structure on an oxide semiconductor, SrTiO3, using 100%-water-infiltrated nanoporous glass - amorphous 12CaO*7Al2O3 - as the gate insulator. For positive gate voltage, electron accumulation, water electrolysis and electrochemical reduction occur successively on the SrTiO3 surface at room temperature, leading to the formation of a thin (~3 nm) metal layer with an extremely high electron concentration of 10^15-10^16 cm^-2, which exhibits exotic thermoelectric behaviour.Comment: 21 pages, 12 figure

Role of the employment status and education of mothers in the prevalence of intestinal parasitic infections in Mexican rural schoolchildren

<p><b>Background:</b> Intestinal parasitic infections are a public health problem in developing countries such as Mexico. As a result, two governmental programmes have been implemented: a) "National Deworming Campaign" and b) "Opportunities" aimed at maternal care. However, both programmes are developed separately and their impact is still unknown. We independently investigated whether a variety of socio-economic factors, including maternal education and employment levels, were associated with intestinal parasite infection in rural school children.</p> <p><b>Methods:</b> This cross-sectional study was conducted in 12 rural communities in two Mexican states. The study sites and populations were selected on the basis of the following traits: a) presence of activities by the national administration of albendazole, b) high rates of intestinal parasitism, c) little access to medical examination, and d) a population having less than 2,500 inhabitants. A total of 507 schoolchildren (mean age 8.2 years) were recruited and 1,521 stool samples collected (3 per child). Socio-economic information was obtained by an oral questionnaire. Regression modelling was used to determine the association of socio-economic indicators and intestinal parasitism.</p> <p><b>Results:</b> More than half of the schoolchildren showed poliparasitism (52%) and protozoan infections (65%). The prevalence of helminth infections was higher in children from Oaxaca (53%) than in those from Sinaloa (33%) (p < 0.0001). Giardia duodenalis and Hymenolepis nana showed a high prevalence in both states. Ascaris lumbricoides, Trichuris trichiura and Entamoeba hystolitica/dispar showed low prevalence. Children from lower-income families and with unemployed and less educated mothers showed higher risk of intestinal parasitism (odds ratio (OR) 6.0, 95% confidence interval (CI) 1.6–22.6; OR 4.5, 95% CI 2.5–8.2; OR 3.3, 95% CI 1.5–7.4 respectively). Defecation in open areas was also a high risk factor for infection (OR 2.4, 95% CI 2.0–3.0).</p> <p><b>Conclusion:</b> Intestinal parasitism remains an important public health problem in Sinaloa (north-western Mexico) and Oaxaca (south-eastern Mexico). Lower income, defecation in open areas, employment status and a lower education level of mothers were the significant factors related to these infections. We conclude that mothers should be involved in health initiatives to control intestinal parasitism in Mexico.</p&gt

An Artificial Heme Enzyme for Cyclopropanation Reactions

An artificial heme enzyme was created through self-assembly from hemin and the lactococcal multidrug resistance regulator (LmrR). The crystal structure shows the heme bound inside the hydrophobic pore of the protein, where it appears inaccessible for substrates. However, good catalytic activity and moderate enantioselectivity was observed in an abiological cyclopropanation reaction. We propose that the dynamic nature of the structure of the LmrR protein is key to the observed activity. This was supported by molecular dynamics simulations, which showed transient formation of opened conformations that allow the binding of substrates and the formation of pre-catalytic structures

Seroprevalence of Antibody to Hepatitis E Virus in Voluntary Blood Donors in Northern Thailand

We report the results of seroepidemiological study of hepatitis E virus (HEV) infection in 636 voluntary blood donors in four Provinces of Northern Thailand. The average seroprevalence of anti-HEV was 8.7%, which is lower than previous reports from HEV endemic areas and even in the central Thailand. No significant differences of the prevalence were found geographically and also by age and sex. Our findings suggest that Northern Thailand belongs to an intermediate prevalence group of HEV infection between non-endemic and endemic regions and the improvement of socioeconomic and hygienic status might control the spreading of HEV infection in this area

Bornavirus closely associates and segregates with host chromosomes to ensure persistent intranuclear infection.

Bornaviruses are nonsegmented negative-strand RNA viruses that establish a persistent infection in the nucleus and occasionally integrate a DNA genome copy into the host chromosomal DNA. However, how these viruses achieve intranuclear infection remains unclear. We show that Borna disease virus (BDV), a mammalian bornavirus, closely associates with the cellular chromosome to ensure intranuclear infection. BDV generates viral factories within the nucleus using host chromatin as a scaffold. In addition, the viral ribonucleoprotein (RNP) interacts directly with the host chromosome throughout the cell cycle, using core histones as a docking platform. HMGB1, a host chromatin-remodeling DNA architectural protein, is required to stabilize RNP on chromosomes and for efficient BDV RNA transcription in the nucleus. During metaphase, the association of RNP with mitotic chromosomes allows the viral RNA to segregate into daughter cells and ensure persistent infection. Thus, bornaviruses likely evolved a chromosome-dependent life cycle to achieve stable intranuclear infection

Autofluorescence-based high-throughput isolation of nonbleaching Cyanidioschyzon merolae strains under nitrogen-depletion

Photosynthetic organisms maintain optimum levels of photosynthetic pigments in response to environmental changes to adapt to the conditions. The identification of cyanobacteria strains that alleviate bleaching has revealed genes that regulate levels of phycobilisome, the main light-harvesting complex. In contrast, the mechanisms of pigment degradation in algae remain unclear, as no nonbleaching strains have previously been isolated. To address this issue, this study attempted to isolate nonbleaching strains of the unicellular red alga Cyanidioschyzon merolae after exposure to nitrogen (N)-depletion based on autofluorescence information. After four weeks under N-depletion, 13 cells from 500,000 cells with almost identical pre- and post-depletion chlorophyll a (Chl a) and/or phycocyanin autofluorescence intensities were identified. These nonbleaching candidate strains were sorted via a cell sorter, isolated on solid medium, and their post-N-depletion Chl a and phycocyanin levels were analyzed. Chl a levels of these nonbleaching candidate strains were lower at 1–4 weeks of N-depletion similar to the control strains, however, their phycocyanin levels were unchanged. Thus, we successfully isolated nonbleaching C. merolae strains in which phycocyanin was not degraded under N-depletion, via autofluorescence spectroscopy and cell sorting. This versatile method will help to elucidate the mechanisms regulating pigments in microalgae

Inhibition of Extracellular Signal-Regulated Kinases Ameliorates Hypertension-Induced Renal Vascular Remodeling in Rat Models

The aim of this study is to investigate the effect of the extracellular signal-regulated kinases 1/2 (ERK1/2) inhibitor, PD98059, on high blood pressure and related vascular changes. Blood pressure was recorded, thicknesses of renal small artery walls were measured and ERK1/2 immunoreactivity and erk2 mRNA in renal vascular smooth muscle cells (VSMCs) and endothelial cells were detected by immunohistochemistry and in situ hybridization in normotensive wistar kyoto (WKY) rats, spontaneously hypertensive rats (SHR) and PD98059-treated SHR. Compared with normo-tensive WKY rats, SHR developed hypertension at 8 weeks of age, thickened renal small artery wall and asymmetric arrangement of VSMCs at 16 and 24 weeks of age. Phospho-ERK1/2 immunoreactivity and erk2 mRNA expression levels were increased in VSMCs and endothelial cells of the renal small arteries in the SHR. Treating SHR with PD98059 reduced the spontaneous hypertension-induced vascular wall thickening. This effect was associated with suppressions of erk2 mRNA expression and ERK1/2 phosphorylation in VSMCs and endothelial cells of the renal small arteries. It is concluded that inhibition of ERK1/2 ameliorates hypertension induced vascular remodeling in renal small arteries

Idiopathic Normal-Pressure Hydrocephalus: Temporal Changes in ADC during Cardiac Cycle

Normal-pressure hydrocephalus (NPH) is characterized by a clinical triad of ataxia, incontinence, and dementia, as well as dilated ventricles but normal cerebrospinal fluid (CSF) pressures. In patients with NPH, CSF shunt placement is effective for improving these symptoms (1). NPH has attracted attention as one of the few treatable causes of dementia. Diagnosis of idiopathic NPH (INPH) without a known cause of communicating hydrocephalus, including subarachnoid hemorrhage or meningitis, is particularly difficult (2). Moreover, to clarify the cause of NPH, accurately diagnose NPH, and identify appropriate patients for shunt surgery, several tests have been proposed, including cisternography, the CSF tap test, resistance measures, external lumbar drainage, and intracranial pressure recording, in addition to clinical findings and conventional imaging diagnosis with x-ray computed tomography or magnetic resonance (MR) imaging (3–6). It has also been reported (7) that a single standard for the prognostic evaluation of patients with INPH was lacking and that supplemental tests could increase the predictive accuracy of the prognosis. The CSF tap test is a particularly reliable examination, but it is invasive and has low sensitivity. It has been proposed that MR imaging CSF flow studies can be used to noninvasively obtain information about intracranial mechanical properties in INPH (eg, intracranial compliance) (2,8–12). However, the diagnostic utility of this latter method is still not established.Arterial inflow into the cranium induces venous and CSF outflow and displacement of the intracranial spinal cord during the cardiac cycle, resulting in pulsatile brain motion (12–14). Brain pulsation (ie, bulk motion) reportedly can give rise to artifactual phase dispersion and may lead to overestimation of the apparent diffusion coefficient (ADC) (15,16). Brockstedt et al (17) reported that ADC was not changed significantly during the cardiac cycle with the single-shot echo-planar imaging (EPI) sequence widely used in diffusion MR imaging. However, they analyzed only two delay times (100 and 400 msec) between the R peaks in the cardiac cycle. To more completely analyze ADC changes during the cardiac cycle, our own group has previously evaluated the temporal change in ADC during the entire cardiac cycle by using an electrocardiographically (ECG)-triggered single-shot diffusion EPI sequence to minimize bulk motion effect. As a result, we revealed in a previous study that white matter ADC changed significantly over the cardiac cycle and that such changes were synchronized with the arterial inflow (volume loading) at systole (18). We further hypothesize that changes in ADC during the cardiac cycle are related to the biomechanical properties of intracranial tissues; hence, observed temporal changes in ADC in diseases such as INPH that are characterized by low intracranial compliance (12) may well be different than those in other diseases. Therefore, the purpose of our study was to determine whether temporal changes in ADC over the cardiac cycle were different in patients with INPH as compared with patients with ex vacuo ventricular dilatation and healthy control subjects