237 research outputs found
Reactive oxygen species-driven transcription in Arabidopsis under oxygen deprivation
Reactive oxygen species (ROS) play an important role as triggers of gene expression during biotic and abiotic stresses, among which is low oxygen (O2). Previous studies have shown that ROS regulation under low O2 is driven by a RHO-like GTPase that allows tight control of hydrogen peroxide (H2O2) production. H2O2 is thought to regulate the expression of heat shock proteins, in a mechanism that is common to both O2 deprivation and to heat stress. In this work, we used publicly available Arabidopsis (Arabidopsis thaliana) microarray datasets related to ROS and O2 deprivation to define transcriptome convergence pattern. Our results show that although Arabidopsis response to anoxic and hypoxic treatments share a common core of genes related to the anaerobic metabolism, they differ in terms of ROS-related gene response. We propose that H2O2 production under O2 deprivation is a trait present in a very early phase of anoxia, and that ROS are needed for the regulation of a set of genes belonging to the heat shock protein and ROS-mediated groups. This mechanism, likely not regulated via the N-end rule pathway for O2 sensing, is probably mediated by a NADPH oxidase and it is involved in plant tolerance to the stress
Heavy Metal Ion Sensing By Surface Plasmon Resonance on Gold Nanoparticles
Surface Plasmon resonance (SPR) based heavy metal ions sensor is one of the most sensitive sensor for detecting toxic metal ions. It is an inexpensive, portable and also feasible for real time detection. SPR sensor is a type of optical sensor in which toxic metal ions get adsorbed on the functionalized metal (mostly Au) film causes the change in refractive index of the metal (Au)-dielectric (sensing) medium. The change of the refractive index leads to a shift in the angular spectrum of the reflected light and can be accurately monitored by optical methods. In this paper,we are trying to optimize the detection level of heavy metal ions by surface plasmon resonance on gold nanoparticles using UV-VIS spectroscopy. Polymer like chitosan is being used with gold nanoparticles to detect copper and zinc ions and detection till very low concentrations of the toxic metal ions is obtained.Keywords: Surface Plasmon Resonance, Optical sensor, metal nanoparticles, reducing agent,chelating agent, polymer capping.*Cite as: Sandhya Banti Dutta Borah, Sunandan Baruah, Waleed Soliman Joydeep Dutta “Heavy Metal Ion Sensing By Surface Plasmon Resonance On Gold Nanoparticles†ADBU-J.Engg Tech, 1(2014) 0011404(5pp
Hafnium Oxidation at High Temperature in Steam
To assess the potential impact of using hafnium as absorber material in LWRs in high temperature accidental situations, the oxidation behavior of hafnium was studied up to 1400 °C, i.e. at temperature conditions relevant to severe accidents. Different sample geometries were tested and oxidized in steam/argon mixtures, either in a furnace or in a thermogravimetric analyzer. Metallographic examinations, hydrogen measurements and EPMA oxygen profiles were then performed. For hafnium rods/discs, metallographic examinations showed the presence of a dense and protective oxide film after steam oxidation. No or little hydrogen was detected in the metallic part of the rod/disc specimens. The reaction rate can be described by a parabolic law in the tested temperature range in the mid-to-long term, and the value of the effective activation energy determined from the experimental data in steam is in good agreement with the ones published in the literature. The diffusion coefficient of oxygen in hafnium was estimated at each temperature by fitting the experimental oxygen profile obtained on hafnium rods and its temperature dependence is derived in the temperature range 700-1400 °C. The hafnium claddings produced for the application in integral bundle tests exhibited a lower resistance to steam oxidation than hafnium rods/discs. Metallographic examinations showed a non-protective layer and a significant hydrogen amount was picked up by hafnium claddings. Above 800 °C, the oxidation rate for hafnium claddings follows a cubic to quartic law and the effective activation energy was determined in the temperature range 800-1100 °C. These tests highlighted the influence of the surface conditions on the oxidation rate of hafnium in steam. However, hafnium oxidation rate remains well below the oxidation rate of zirconium alloys in the same temperature range
Maternal-foetal attachment independently predicts the quality of maternal-infant bonding and post-partum psychopathology
Purpose: The aim of this study was to evaluate the association of maternal antenatal attachment and post-partum psychopathology, maternal–infant bonding, while checking for antenatal psychopathology, for lifetime psychiatric diagnosis and for the known risk factors for peripartum depression. Methods: One hundred and six women recruited at the first month of pregnancy (T0) were evaluated with the structured interview for DSM-IV TR (SCID-I) to assess the presence of lifetime psychiatric diagnosis and with the Perinatal Depression Predictor Inventory-Revised (PDPI-R), the Edinburgh Postnatal Depression Scale (EPDS), and the State–Trait Anxiety Inventory (STAI). At the sixth month of pregnancy (T1) and at the first month post-partum (T2), all patients were evaluated with the PDPI-R, the EPDS, the STAI, at T1, with the Maternal Antenatal Attachment Scale (MAAS), and at T2 with the Maternal Postnatal Attachment Scale (MPAS). Results: Multivariate regression analyses showed that maternal–foetal attachment was the variable most significantly associated with postnatal symptoms of depression and anxiety and with quality of maternal-infant attachment. The logistic regression analyses showed that antenatal attachment may predict postnatal depressive and anxiety symptoms (respectively, OR: 0.83–IC [0.74 − 0.95], p =.005, OR: 0.88–IC [0.79 − 0.98], p =.02), and the quality of maternal postnatal attachment (OR: 1.17–IC [1.08 − 1.27], p <.001), also after taking into account the known risk factors for perinatal depression, the sociodemographic variables and lifetime psychiatric diagnosis. Conclusion: The quality of maternal–foetal bonding may independently predict the quality of maternal–infant attachment and post-partum depressive and anxiety symptoms. A comprehensive assessment of maternal risk factors for perinatal psychopathology during pregnancy should include the evaluation of antenatal attachment that could be modifiable by specific interventions promoting the quality of maternal bonding
PW06-05 The predictive role of anxiety disorders on depressive phenomenology during post-partum period
Aims:To investigate the predictive role of any specific (DSM-IV) Anxiety Disorders (AD) on depressive symptoms and Major or Minor Depressive Disorder (MDD, mDD) during early postpartum period.Method:Women (at the 12th-15th gestational week, N=1066) were recruited in the framework of the Program 'Perinatal Depression - Research & Screening Unit (PND-ReScU)". Depressive symptoms were assessed by the Edinburgh Postnatal Depression Scale (EPDS), and Axis-I disorders (AD, MDD, mDD) were diagnosed with the Structured Clinical Interview for Axis-I Disorders (SCID-I).Results:Any current AD at baseline (3rd month of pregnancy) was detected in 231 (21.7%). Having at least one current AD, was associated with a greater likelihood of having MDD or mDD during the early postpartum period, even after the adjustment for the confounding factor of having a lifetime history of MDD (RR=3.86 95%CI 1.58-9.42).In particular, women affected by Obsessive Compulsive Disorder (N=17; 1.6%) or Panic Disorder (N=43; 4%) had at higher risk to develop depressive symptoms (EPDS≥13) during the postpartum period than women without these AD (RR=6.9 and 6.7 respectively). As for the risk of developing PPD, the strongest association was found for women with Panic Disorder (RR=7.6 95% CI 2.62-22.0).Conclusions:AD are associated with a greater likelihood to develop depressive symptoms and MDD or mDD during the early postpartum period. Women with current PD have the strongest risk to develop both MDD or mDD and depressive symptoms during early postpartum period compared to other anxiety disorders
Internal consistency and discriminant validity of the Structured Clinical Interview for Panic Agoraphobic Spectrum (SCI-PAS)
This paper reports on the feasibility, acceptability and psychometric properties of the Structured Clinical Interview for Panic-Agoraphobic Spectrum (SCI-PAS). This interview was designed to assess the lifetime presence of symptoms and other clinical features considered to comprise the panic-agoraphobic spectrum. The interview has 114 items grouped into nine domains. A total of 422 subjects, from 11 centres located throughout Italy, participated in this study. Data were collected from three groups of subjects: psychiatric patients meeting DSM-IV criteria for panic disorder (n = 141), cardiovascular patients (n = 140), including 29 with post-myocardial infarction, and university students (n = 141). The inter-rater reliability and the internal consistency of the SCI-PAS measures were assessed using the intra-class correlation coefficient and the Kuder-Richardson coefficient, respectively. Discriminant validity was assessed by comparing results in patients with panic disorder to those in the other groups. The interview required an average of 25 (±5) minutes to administer. Patients and clinicians found the scale to be highly useful, providing information not previously obtained. Internal consistency was good (>0.70) for six out of nine SCI-PAS domains. The inter-rater reliability was excellent (>0.70) for all the domains except for 'other phobias' (0.467). Patients with panic disorder scored significantly higher on each domain, and on the overall panic spectrum, than did the control subjects. In conclusion, the SCI-PAS is a useful clinical interview, which can be administered in a reasonable period of time. This assessment further demonstrates good internal consistency, discriminant validity, and inter-rater reliability. Copyright © 1999 Whurr Publishers Ltd
Identification of histone deacetylase inhibitors with (arylidene)aminoxy scaffold active in uveal melanoma cell lines
Uveal melanoma (UM) represents an aggressive type of cancer and currently, there is no effective treatment for this metastatic disease. In the last years, histone deacetylase inhibitors (HDACIs) have been studied as a possible therapeutic treatment for UM, alone or in association with other chemotherapeutic agents. Here we synthesised a series of new HDACIs based on the SAHA scaffold bearing an (arylidene)aminoxy moiety. Their HDAC inhibitory activity was evaluated on isolated human HDAC1, 3, 6, and 8 by fluorometric assay and their binding mode in the catalytic site of HDACs was studied by molecular docking. The most promising hit was the quinoline derivative VS13, a nanomolar inhibitor of HDAC6, which exhibited a good antiproliferative effect on UM cell lines at micromolar concentration and a capability to modify the mRNA levels of HDAC target genes similar to that of SAHA
Silver nanoparticles from oregano leaves’ extracts as antimicrobial components for non-infected hydrogel contact lenses
The oregano leaves’ extract (ORLE) was used for the formation of silver nanoparticles
(AgNPs(ORLE)). ORLE and AgNPs(ORLE) (2 mg/mL) were dispersed in polymer hydrogels to give
the pHEMA@ORLE_2 and pHEMA@AgNPs(ORLE)_2 using hydroxyethyl–methacrylate (HEMA).
The materials were characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction
analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), derivative thermogravimetry/differential scanning calorimetry (DTG/DSC), ultraviolet (UV-Vis), and attenuated total
reflection mode (ATR-FTIR) spectroscopies in solid state and UV–Vis in solution. The crystallite size
value, analyzed with XRPD, was determined at 20 nm. The antimicrobial activity of the materials
was investigated against Gram-negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and
Escherichia coli (E. coli). The Gram-positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) are known to be involved in microbial keratitis by the
means of inhibitory zone (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal
concentration (MBC). The IZs, which developed upon incubation of P. aeruginosa, E. coli, S. epidermidis,
and S. aureus with paper discs soaked in 2 mg/mL of AgNPs(ORLE), were 11.7 ± 0.7, 13.5 ± 1.9,
12.7 ± 1.7, and 14.3 ± 1.7 mm. When the same dose of ORLE was administrated, the IZs were
10.2 ± 0.7, 9.2 ± 0.5, 9.0 ± 0.0, and 9.0 ± 0.0 mm. The percent of bacterial viability when they were
incubated over the polymeric hydrogel discs of pHEMA@AgNPs(ORLE)_2 was interestingly low
(66.5, 88.3, 77.7, and 59.6%, respectively, against of P. aeruginosa, E. coli, S. epidermidis, and S. aureus) and those of pHEMA@ORLE_2 were 89.3, 88.1, 92.8, and 84.6%, respectively. Consequently,
pHEMA@AgNPs(ORLE)_2 could be an efficient candidate toward the development of non-infectious
contact lenses
Two-step analytical procedure for the characterization and quantification of metal soaps and resinates in paint samples
Metal soaps and resinates are known to be spontaneously formed in artistic paintings, as a product of the reaction between aliphatic and terpenoid acids released by hydrolysis and oxidation of the organic media and certain cations contained in some inorganic pigments. In this paper we present an optimization and the validation of a GC/MS method for the qualitative and quantitative analysis of mixtures of terpenoid acids and aliphatic mono and dicarboxylic acids and metal carboxylates of terpenoid and aliphatic mono and dicarboxylic acids in the same paint microsample. This is based on a two-step analytical approach entailing the subsequent use of two silylating agents, N,O-bis(trimethylsilyl)trifluoroacetamide for the analysis of free acids and metal carboxylates, and 1,1,1,3,3,3-hexamethyldisilazane for the analysis of free acids. The application of this approach is possible because of the good stability at room temperature of the TMS derivatives of aliphatic and terpenoid species, characterized by high boiling points and relatively low vapour pressures. The method was then applied to the characterization of samples collected from two reference paint layers aged for 20 years, a paint sample taken from a pulpit, and sample of the varnish coating of a wooden writing desk, both from the second half of the seventeenth century
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