The societal economic impact of vision impairment in adults 40 years and above: findings from the National Eye Survey of Trinidad and Tobago.

BACKGROUND: Understanding and mitigating the societal economic impact of vision impairment (VI) is important for achieving the Sustainable Development Goals. AIM: To estimate the prevalent societal economic impact of presenting VI in Trinidad and Tobago using bottom-up cost and utilisation data from the 2014 National Eye Survey of Trinidad and Tobago. METHODS: We took a societal perspective to combine comprehensive, individual-level cost and utilisation data, with population-based prevalence estimates for VI, and additional data from a contemporaneous national eyecare system survey. We included direct (medical and non-medical) and indirect (productivity loss) costs, and intangible losses in total cost estimates, presented in 2014 Trinidad & Tobago (TT) dollars and UK sterling equivalent. We considered but excluded transfer payments and dead weight losses. Sensitivity analyses explored impact on total cost of parameter uncertainty and assumptions. RESULTS: Individual utilisation and cost data were available for 65.5% (n = 2792/4263) and 59.0% (n = 2516/4263) eligible participants aged ≥40 years, respectively. Participant mean age was 58.4(SD 11.8, range 40-103) years, 56.3% were female. We estimated total societal cost of VI in 2014 at UK£365,650,241 (TT$3,842,324,655), equivalent to £675 per capita (population ≥40 years). Loss of wellbeing accounted for 73.3%. Excluding this, the economic cost was UK£97,547,222 (TT$1,025,045,399), of which indirect costs accounted for 70.5%, followed by direct medical costs (17.9%), and direct non-medical costs (11.6%). CONCLUSION: This study provides a comprehensive estimate of the economic impact of vision loss in a Caribbean country, and highlights the extent to which affected individuals and their families bear the societal economic cost of vision impairment.

Signaling and crosstalk of rhizobacterial and plant hormones that mediate abiotic stress tolerance in plants.

Agricultural areas exhibiting numerous abiotic stressors, such as elevated water stress, temperatures, and salinity, have grown as a result of climate change. As such, abiotic stresses are some of the most pressing issues in contemporary agricultural production. Understanding plant responses to abiotic stressors is important for global food security, climate change adaptation, and improving crop resilience for sustainable agriculture, Over the decades, explorations have been made concerning plant tolerance to these environmental stresses. Plant growth-promoting rhizobacteria (PGPR) and their phytohormones are some of the players involved in developing resistance to abiotic stress in plants. Several studies have investigated the part of phytohormones in the ability of plants to withstand and adapt to non-living environmental factors, but very few have focused on rhizobacterial hormonal signaling and crosstalk that mediate abiotic stress tolerance in plants. The main objective of this review is to evaluate the functions of PGPR phytohormones in plant abiotic stress tolerance and outline the current research on rhizobacterial hormonal communication and crosstalk that govern plant abiotic stress responses. The review also includes the gene networks and regulation under diverse abiotic stressors. The review is important for understanding plant responses to abiotic stresses using PGPR phytohormones and hormonal signaling. It is envisaged that PGPR offer a useful approach to increasing plant tolerance to various abiotic stresses. However, further studies can reveal the unclear patterns of hormonal interactions between plants and rhizobacteria that mediate abiotic stress tolerance.

Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB.

Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-µs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coincidence with ^{32}Na nuclei. This is the only known microsecond isomer (1 µs≤T_{1/2}<1 ms) in the region. This nucleus is at the heart of the N=20 island of shape inversion and is at the crossroads of the spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to ^{32}Mg, ^{32}Mg+π^{-1}+ν^{+1}. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of ^{32}Mg, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed 2^{+} state at 885 keV and a low-lying shape-coexisting 0_{2}^{+} state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in ^{32}Na: a 6^{-} spherical shape isomer that decays by E2 or a 0^{+} deformed spin isomer that decays by M2. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.

Crossing N=28 Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB.

New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are compared to the latest quasiparticle random phase approximation and shell-model calculations. Overall, the measured half-lives are consistent with the available theoretical descriptions and suggest a well-developed region of deformation below ^{48}Ca in the N=28 isotones. The erosion of the Z=14 subshell closure in Si is experimentally confirmed at N=28, and a reduction in the ^{38}Mg half-life is observed as compared with its isotopic neighbors, which does not seem to be predicted well based on the decay energy and deformation trends. This highlights the need for both additional data in this very exotic region, and for more advanced theoretical efforts.

Lot-to-lot consistency of a hexavalent DTwP-IPV-HB-PRP∼T vaccine and non-inferiority to separate DTwP-HB-PRP∼T and IPV antigen-matching vaccines at 6-8, 10-12, and 14-16 weeks of age co-administered with oral rotavirus vaccine in healthy infants in India: A multi-center, randomized, controlled study.

Background: Combination vaccines reduce the number of pediatric injections but must be as safe, immunogenic, and effective as each of the individual vaccines given separately. Additionally, consistency in manufacturing lots is essential for WHO prequalification. This study aimed to establish the lot-to-lot consistency of a fully liquid, hexavalent diphtheria (D)-tetanus (T)-whole-cell pertussis (wP)-inactivated poliovirus (IPV)-hepatitis B (HB)-Haemophilus influenzae b (PRP-T) (DTwP-IPV-HB-PRP∼T) vaccine and to demonstrate non-inferiority to licensed DTwP-HB-PRP∼T and IPV vaccines. Methods: A Phase III, randomized, active-controlled, and open-label study was conducted at multiple centers across India. Healthy infants who had received a birth dose of oral poliovirus vaccine and hepatitis B vaccine received one of three lots of DTwP-IPV-HB-PRP∼T or separate DTwP-HB-PRP∼T and IPV vaccines at 6-8, 10-12, and 14-16 weeks of age. Oral rotavirus vaccine was co-administered at 6-8 weeks of age and 10-12/14-16 weeks of age. DTwP-IPV-HB-PRP∼T lot-to-lot consistency and non-inferiority (pooled DTwP-IPV-HB-PRP∼T) versus DTwP-HB-PRP∼T and IPV post-third dose were assessed using seroprotection rates (anti-D, anti-T, anti-HBs, anti-PRP, anti-polio 1, 2, 3) and adjusted geometric mean concentrations (anti-PT, anti-FIM). Safety was assessed by parental reports. Results: Lot-to-lot consistency was demonstrated for DTwP-IPV-HB-PRP∼T and non-inferiority versus DTwP-HB-PRP∼T and IPV was confirmed with 95% CIs for seroprotection rate differences and adjusted geometric mean concentration ratios within pre-defined clinical margins. Pooled seroprotection rate was ≥ 99.7% for anti-D ≥ 0.01 IU/mL, anti-T ≥ 0.01 IU/mL, anti-HBs ≥ 10 mIU/mL, anti-PRP ≥ 0.15 µg/mL, and anti-polio 1, 2, and 3 ≥ 8 (1/dil) and vaccine response rate was 83.9% for anti-PT and 97.7% for anti-FIM. There were no safety concerns. Conclusions: Immunogenicity of three lots of the fully liquid DTwP-IPV-HB-PRP∼T vaccine was consistent and non-inferior to licensed comparators following vaccination at 6-8, 10-12, and 14-16 weeks of age. There were no safety concerns and no evidence of any effect of co-administration with rotavirus vaccine.

Assessment of the Efficacy and Safety of Early Intracoronary Nicorandil Administration in Patients With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention.

Background No-reflow phenomenon (NRP) remains a challenge in ST-elevation myocardial infarction (STEMI) patients. We determined the efficacy and safety of early intracoronary administration of nicorandil as an adjunct to primary percutaneous coronary intervention (pPCI) in STEMI patients to reduce the risk of NRP. Materials and methods In this single-center case-control prospective study, 100 STEMI patients who underwent pPCI had thrombectomy performed using a suction catheter, and tirofiban (10 mg/kg) was injected distal to the vascular lesion. All patients were divided into two groups. Group A was a treatment group (nicorandil, n=50) and group B was a control group (placebo, n=50). The primary endpoint was the composite endpoint of in-hospital cardiovascular mortality or unscheduled re-hospitalization due to deterioration of congestive heart failure that was assessed with the help of brain natriuretic peptide (BNP), left ventricular end-diastolic diameter (LVEDD), and left ventricular ejection fraction at six months following pPCI. The secondary endpoints were thrombolysis in myocardial infarction (TIMI) flow grade, TIMI myocardial perfusion grade (TMPG), the incidence of reperfusion arrhythmias like ventricular tachycardia and ventricular fibrillation, and ST segment elevation resolution (STR) on ECG following pPCI. Results The in-hospital cardiovascular mortality and re-hospitalization rates were 2% and 6% in the nicorandil group, whereas it was 6% and 14% in the control group. On the 180th day of admission, the nicorandil group had significantly lower values of brain natriuretic peptide (348.45±112.32 pg/ml vs. 541.11±152.68 pg/ml, p=0.021) and left ventricular end-diastolic diameter (54.12±3.56 mm vs. 60.62±4.98 mm, p=0.011) than the control group. Nicorandil group had a significantly higher number of patients who attained TIMI 3 (p=0.022), TMPG 3 (p=0.034), and STR (p=0.008) than the control group. Ventricular arrhythmia was significantly lower in the nicorandil group than in the control group at 24 hours following pPCI (p=0.012). Conclusion Early intracoronary administration of nicorandil during pPCI may decrease the occurrence of NRP, in-hospital cardiovascular mortality, and re-hospitalization rates, as well as improve coronary blood flow and reduce reperfusion arrhythmia in STEMI patients.

Attitudes towards risk-reducing early salpingectomy with delayed oophorectomy for ovarian cancer prevention: a cohort study.

OBJECTIVE: To determine risk-reducing early salpingectomy and delayed oophorectomy (RRESDO) acceptability and effect of surgical prevention on menopausal sequelae/satisfaction/regret in women at increased ovarian cancer (OC) risk. DESIGN: Multicentre, cohort, questionnaire study (IRSCTN:12310993). SETTING: United Kingdom (UK). POPULATION: UK women without OC ≥18 years, at increased OC risk, with/without previous RRSO, ascertained through specialist familial cancer/genetic clinics and BRCA support groups. METHODS: Participants completed a 39-item questionnaire. Baseline characteristics were described using descriptive statistics. Logistic/linear regression models analysed the impact of variables on RRESDO acceptability and health outcomes. MAIN OUTCOMES: RRESDO acceptability, menopausal sequelae, satisfaction/regret. RESULTS: In all, 346 of 683 participants underwent risk-reducing salpingo-oophorectomy (RRSO). Of premenopausal women who had not undergone RRSO, 69.1% (181/262) found it acceptable to participate in a research study offering RRESDO. Premenopausal women concerned about sexual dysfunction were more likely to find RRESDO acceptable (odds ratio [OR] = 2.9, 95% CI 1.2-7.7, P = 0.025). Women experiencing sexual dysfunction after premenopausal RRSO were more likely to find RRESDO acceptable in retrospect (OR = 5.3, 95% CI 1.2-27.5, P < 0.031). In all, 88.8% (143/161) premenopausal and 95.2% (80/84) postmenopausal women who underwent RRSO, respectively, were satisfied with their decision, whereas 9.4% (15/160) premenopausal and 1.2% (1/81) postmenopausal women who underwent RRSO regretted their decision. HRT uptake in premenopausal individuals without breast cancer (BC) was 74.1% (80/108). HRT use did not significantly affect satisfaction/regret levels but did reduce symptoms of vaginal dryness (OR = 0.4, 95% CI 0.2-0.9, P = 0.025). CONCLUSION: Data show high RRESDO acceptability, particularly in women concerned about sexual dysfunction. Although RRSO satisfaction remains high, regret rates are much higher for premenopausal women than for postmenopausal women. HRT use following premenopausal RRSO does not increase satisfaction but does reduce vaginal dryness. TWEETABLE ABSTRACT: RRESDO has high acceptability among premenopausal women at increased ovarian cancer risk, particularly those concerned about sexual dysfunction.

Transcriptomic and epigenomic effects of insoluble particles on J774 macrophages.

Here we report epigenomic and transcriptomic changes in a prototypical J774 macrophage after engulfing talc or titanium dioxide particles in presence of estrogen. Macrophages are the first immune cells to engage and clear particles of various nature. A novel paradigm is emerging, that exposure to so-called 'inert' particulates that are considered innocuous is not really free of consequences. We hypothesized that especially the insoluble, non-digestible particles that do not release a known hazardous chemical can be underappreciated agents acting to affect the regulation inside macrophages upon phagocytosis. We performed gene chip microarray profiling and found that talc alone, and especially with oestrogen, has induced a substantially more prominent gene expression change than titanium dioxide; the affected genes were involved in pathways of cell proliferation, immune response and regulation, and, unexpectedly, enzymes and proteins of epigenetic regulation. We therefore tested the DNA methylation profiles of these cells via epigenome-wide bisulphite sequencing and found vast epigenetic changes in hundreds of loci, remarkably after a very short exposure to particles; ELISA assay for methylcytosine levels determined the particles induced an overall decrease in DNA methylation. We found a few loci where both the transcriptional changes and epigenetic changes occurred in the pathways involving immune and inflammatory signalling. Some transcriptomic and epigenomic changes were shared between talc and titanium dioxide, however, it is especially interesting that each of the two particles of similar size and insoluble nature has also induced a specific pattern of gene expression and DNA methylation changes which we report here.

[Formula: see text]-Symmetric Effective Model for Nonequilibrium Phase Transitions in a Dissipative Fermionic Mott Insulator Chain.

Nonequilibrium phase transitions in open dissipative systems can be described as instabilities in the spectra and wavefunctions of effective non-Hermitian Hamiltonians invariant under simultaneous parity ([Formula: see text]) and time-reversal ([Formula: see text]) transformations. The degree of non-Hermiticity reflects the strength of the external drive and dissipation, and the transition is described as a loss of the [Formula: see text] symmetry of the solutions corresponding to stationary low-drive dynamics. This approach has been successfully applied to spin, superconducting, and Mott insulator systems. However, the microscopic foundations for the employed phenomenological models are currently lacking. Here we propose a microscopic mechanism leading to the [Formula: see text]-symmetric effective model in the context of the nonequilibrium Mott transition in a dissipative Hubbard chain. Our model comprises a half-filled fermionic Hubbard chain subject to a constant electric field. The dissipation is introduced via the electron-phonon coupling. We obtain the explicit expressions for the non-Hermitian parameter in terms of the electron-phonon coupling strength and driving field. Analyzing the implications of microscopic model, we find a re-entrant Mott insulator with the increasing electric field for phonon density of states that increases slower than the square of the energy (such as in one or two dimensions), or varies non-monotonously with energy.

Sequence and Observer Variability in Gadoxectic Acid-Enhanced MRI Lesion Measurements in Hepatocellular Carcinoma.

RATIONALE AND OBJECTIVES: The purpose of the study was to investigate interobserver and intersequence variability in measuring hepatocellular carcinoma on magnetic resonance imaging (MRI). METHODS AND MATERIALS: Twenty treatment-naïve lesions on Gadoxetic Acid enhanced MRI scans from 20 patients were retrospectively measured by six reviewers with different levels of experience, twice, six weeks apart, on eight different MRI sequences, in randomized order. The sequences include arterial, hepatobiliary, transitional, portal venous, T2, and diffusion weighted images. The single longest diameter (SLD) and longest diameter perpendicular to the longest overall diameter were measured on axial images and products of diameters calculated in accordance to response evaluation criteria in solid tumors v1.1 and World Health Organization response criteria respectively. Lesion-wise intraclass correlation coefficients were used to estimate measurement agreement. RESULTS: All intraclass correlation coefficients were greater than 0.95. No substantive differences between SLD and products of diameters metrics. Means (∼2.8 mm, SLD) and standard deviations (∼2 mm, SLD) were similar across sequences and observers. Similarly, pairwise comparison between observers grouped by experience showed statistically significant differences, but the effect size was minor (∼2 mm). Arterial and HPB-weighted images had similar mean dimensions (2.76 cm) while the smallest mean was in the transitional phase (2.62 cm). A lesion was not measured on 140 occasions (7%), mostly in ADC. CONCLUSION: There is high interobserver and intersequence reliability despite small differences between observers based on experience level. Our results suggest that accurate measurements can be made on arterial phase despite the possibility of indistinct margins. Lesions, however, are more likely to be missed on diffusion-related sequences.

Dynamics of gene expression of hormones involved in the growth of broiler chickens in response to the dietary protein and energy changes.

The synergy between the genetic potential and the nutrient intake determines the growth performance of meat-type chicken and nutrigenomics approach helps us understand the response of candidate genes of growth in chicken to dietary manipulations. The current study aimed to assess the growth performance and expression of hepatic growth related genes in the naked neck broiler chicken in response to different dietary energy and protein levels with a hypothesis that high plane of nutrition enhances both of these positively. The results revealed that birds have shown significantly better growth performance under high protein (HP) and high energy (HE) dietary regime. The expression profiles of the genes studied revealed upregulation of IGF-1, IGF-2, and GH under dietary HP and HE regime relative to other protein and energy levels with greater upregulation at 3rd week than the 1st and 5th week of age of birds. The IGFR and GHR mRNA expression was significantly higher under HP and HE dietary regimen with an increasing and decreasing trend from 1st to 5th week of age, respectively. A consistent and significant downregulation of IGFBP-2 was observed under HP and HE regime throughout the feeding trial. The myostatin expression was higher at 3rd week of age followed by 1st week expression. The HP and HE as well as LP (Low protein) and HE diet resulted in significant upregulation of myostatin gene expression in liver. In support to the set hypothesis of this study the high protein and high energy diet resulted in better growth performance of broiler chickens with corresponding upregulation of IGF-1, IGF-2, IGFR, GH, GHR, and Myostatin gene expression and downregulation of IGFBP-2 in liver.

Socio-demographic and clinical determinants of dementia in the oldest old: National survey of ageing and cognition in Trinidad

Objective: To determine social and clinical factors associated with dementia in the oldest old (>85 years). Design and Methodology: A survey in a nationally representative sample of people aged 85 years and older using household enumeration was undertaken. Dementia status was ascertained using standardized interviews and algorithms from the 10/66 schedule. Information was also obtained on age, gender, level of education, ethnicity and previous occupation. Self-report on the presence of angina, heart disease, stroke, diabetes, high cholesterol, and hypertension was elicited and corroborated. Results: Of the participants 61.5% were females. The mean age was 89.0 years and dementia was present in 47.2 % persons. Dementia was significantly associated with age >95 (OR=2.02; 95%CI: 0.86- 4.69), female gender (OR=1.31; 95%CI: 0.85- 2.02), East Indian ethnicity (OR=1.45; 95%CI: 0.81-2.60), being widowed (OR=2.05; 95%CI: 0.59-7), Hindu religion (OR=2.10; 95%CI: 1.23- 3.58), history of working in the agricultural sector (OR=3.20; 95%CI: 1.59-6.48). Level of education (OR=0.14; 95%CI: 0.04-0.45), taking vitamins (OR=0.61; 95% CI: 0.37-0.97) and being of mixed ethnicity (African and East Indian) were protective factors. Of the self-reported disease conditions, those with greater than 3 medical co-morbidities were 2 times (OR=2.21; 95%CI: 0.48-9.94) more likely to have dementia than those with0-2 medical comorbidities. Dementia was not more likely to occur in diabetes (OR= 1.03; 95% CI: 0.65-1.64) and hypertension (OR= 0.67; 95% CI: 0.41-1.08). Conclusion: Our study, the first of its kind in Trinidad, supports more tailored policy and better planning of services for a rapidly expanding older population.

Comparing the peek retina to fundus camera, direct ophthalmoscope and Volk lens for the viewing of the optic disc

Objective: To compare the Peek Retina device with a fundus camera, direct ophthalmoscope and Volk lens. Design and Methodology: The comfort for the patient, efficiency when using the equipment, image quality, time taken, and usability of the equipment were analysed for the four different equipment when the optic disc was viewed. The direct ophthalmoscope, Volk lens and the slit lamp, and a fundus camera were used to view the optic disc in 50 patients at the UWI Optometry Clinic. This four equipment comparison study was done using questionnaires for both the patient and examiner. Results: It was found that peek retina was more comfortable than direct ophthalmoscope and the Volk lens, and it was similar to the fundus camera. Likert scale values showed that the fundus camera was the most efficient and the peek retina the least. The time frame using the fundus camera was the least which was 2.94 minutes compared with using the Volk lens which took the most time of 3.98 minutes. The usability values showed that it was easier to use the fundus camera 1.58 compared to peek retina 2.68, possibly because of the lack of experience with this new device. Conclusion: There was a significant difference among the different devices for the variables examined. The fundus camera was the best at most of the variables and the Peek Retina was the least, while the Volk lens was the most chosen to view the optic disc again due to the clear, stereoscopic and wide view of the back of the eye.

Trend analysis of the burden of cataract in Small Island Developing States (SIDS) in the Caribbean from 1990 to 2016

Objective: To study the trends in the burden of cataract in SIDS in the Caribbean using disability-adjusted life-years (DALYs). Design and Methodology: National and regional age and sex specific cataract DALY numbers, crude DALY rates, and agestandardised DALY rates from 1990 to 2016 for the SIDS in the Caribbean, were extracted from the Global Burden of Disease Study 2016. The human development index, healthcare access and quality (HAQ) index, and the World Bank's classification of economies were used as indicators of socioeconomic status. The Gini coefficient, Atkinson, Theil and concentration indices were used to measure health inequality. Paired Wilcoxon signed rank test, Pearson correlation, and linear regression analyses were performed to evaluate the sociodemographic and socioeconomic factors associated with differences in cataract burden. Results: Men had higher age-standardised DALY rates than women (P < 0.001) with median rates of 90.72 (Interquartile range [IQR], 87.8-94.2) and 83.94 (IQR, 80.9-86.5), respectively. The burden of cataract increased with age. Upper-middle income countries had higher age-standardised DALY rates than high income countries (P < 0.001), with median rates of 90.1 (IQR, 86.8 ­ 93.4) and 79.8 (IQR, 77.5 ­ 81.8), respectively. Age-standardised DALY rates were inversely correlated with both HDI (r = -0.61, ) and HAQ ( ). Between-country inequality was negligible and the burden of cataract is greater among the poor. Conclusions: This study confirmed the trends seen at the global level, except for the finding of men having a higher cataract burden than women in SIDS in the Caribbean. This is an area for further research.

Health status and risk factors for dementia in the middle old in Trinidad: Findings from a nationally representative survey

Objective: To investigate self-reported health status and risk factors for dementia in middle old (75-84 years) individuals. Design and Methodology: This study used the validated 10/66 door- to-door interview protocols. All individuals (836 persons) 75-84 years old were approached. The modified 10/66 dementia algorithm produced output in 811 (97%). Dementia diagnosis was made according to 10/66 criteria from: (1) cognitive tests, the Community Screening Instrument for Dementia (CSI'D), (2) EURO-D depression scale (3) informant interview. Demographic data included information on accommodation, social network, level of impairment and instrumental activities of daily living. Data were analyzed using multilevel logistic regression models. Results: Of the 811 participants, 55% were females. The mean age was 78.9±6.3 years and dementia was present in 198 (24.4%). High level of education, professional employment and having no comorbidities were significant protective factors. In multivariate analyses those with stroke were nearly 5 times more likely (OR=4.81, 95% CI: 2.72, 8.53) to have dementia, and those with diabetes were 2.5 times (OR=2.55; 95% CI: 1.71-3.78) more likely to have dementia than those without these comorbities. Impairment in climbing stairs walking and sight was more common in the dementia group than the non-demented. Individuals with dementia were more likely to be unable to perform all seven instrumental activities of daily living (IADL) and were less active compared with their non-demented counterparts. Conclusion: In the middle old population in Trinidad having diabetes and stroke with varying levels of impairment as well as a sedentary lifestyle puts an individual at increased risk of dementia.

Fluorescence "off" and "on" signalling of esculetin in the presence of copper and thiol: a possible implication in cellular thiol sensing.

The interaction of the cupric ion with esculetin, a dihydroxy coumarin derivative, was studied by absorption and fluorescence spectroscopic methods in aqueous medium. Esculetin formed a complex in the presence of the cupric ion which was characterised by the shift in its absorption band from 350 nm to 389 nm and the quenching of its fluorescence intensity at 466 nm. From Job's plot and fluorescence quenching studies, the stoichiometry of the copper ion and esculetin in the complex was estimated to be 1 : 2 respectively. Interestingly, the incubation of the Cu(ii)-esculetin complex with a thiol peptide, glutathione (GSH), showed restoration of the fluorescence intensity as well as absorption maxima to that of pure esculetin. Incubation with other common thiol and non-sulphur amino acids did not show a similar restoration of the photophysical properties of the complex except in the case of cysteine. Mechanistically, it was evident that two molecules of GSH were consumed in reducing the Cu(ii)-esculetin complex, which subsequently split into the copper ion and esculetin. In this process GSH was converted into oxidised GSH (GSSG) as evident from the mass spectroscopy and HPLC studies. The above florescence regeneration behaviour of the copper-esculetin system in the presence of GSH was also observed in the cellular system using Chinese hamster ovary (CHO) as model cells. In conclusion, these studies may find application in developing sensors for detecting the cellular thiol level.

Vibrational spectroscopic study of cationic phosphorus dendrimers with aminoethylpiperidine terminal groups.

Two generations of phosphoric dendrimers with piperidine functional groups were synthesized for use in biology and medicine. Neutral samples are soluble in organic solvents but after protonation these dendrimers become water soluble and can be used for biological experiments. The FTIR and FT Raman spectra of two generations of dendrimers Gi constructed from the cyclotriphosphazene core, repeating units OC6H4CHNN(CH3)P(S)< and aminoethylpiperidine end groups NH(CH2)2C5NH11 were recorded. The study of the IR spectra shows that the NH groups form hydrogen bonds. The calculation of the molecular structure and vibrational spectra of the first generation dendrimer was performed by the method of DFT. This molecule has flat, repeating units and a plane of symmetry passing through the core. The calculation of the distribution of potential energy made it possible to classify the bands in the experimental spectra of dendrimers. Amine groups are manifested in the form of a band of NH stretching vibrations at 3389 cm-1 in the IR spectrum of G1. NH+ stretching bands located at 2646 and 2540 cm-1 in the IR spectrum of G2. The stretching vibrations of NH+ groups are noticeably shifted to low frequencies due to the formation of a hydrogen bond with the chlorine atom. The line at 1575 cm-1 in the Raman spectrum of G1 is characteristic for repeating units.

Cardioprotective potential of curcumin against norepinephrine-induced cell death: a microscopic study.

Cardiomyopathy and associated heart failure continues to be one of the most severe complications that threaten a large population. Curcumin, one of the three curcuminoids of the spice turmeric, is very well known for a multitude of health benefits and functions. Norepinephrine (NE), a catecholamine and also a stress hormone may cause the cardiomyocytes to develop increased sensitivity to death with its increasing concentrations. In this study, we investigated the cardioprotective effect of curcumin in NE-induced cardiac apoptosis using several fluorescent and nonfluorescent microscopic techniques like DAPI, PI, Giemsa, PicroSirius and TUNEL. The aim of the study was to assess the effect of curcumin in preventing the occurrence of features underlying apoptosis such as nuclear disruption, chromatin condensation, DNA fragmentation and alterations in mitochondrial membrane permeability. Our results show that curcumin protects the cardiomyocytes against apoptosis significantly and also helps them to revert to their normal physiological state. Hence, we propose that curcumin has the potential to act as a therapeutic agent for the attenuation of NE-induced cardiac cell death and modulation of apoptosis in H9c2 cardiomyocytes.

Linear mode conversion of terahertz radiation into terahertz surface magnetoplasmons on a rippled surface of magnetized n-InSb.

A new mechanics of linear mode conversion of terahertz (THz) radiation into THz surface magnetoplasmons on a rippled surface of magnetized n-InSb is proposed. The normally incident THz radiation, polarized in the direction of a ripple wave vector, imparts oscillatory velocity to electrons in the ripple layer. This velocity beats with surface ripple to produce a nonlinear current that resonantly drives the THz surface magnetoplasmons. In the presence of an applied magnetic field, the surface plasmon (SP) mode splits into two modes-an upper mode and a lower mode. The amplitude of the SP for the upper branch mode is higher than that for the lower mode.

Temporal and spatial assessment of microbial communities in commercial silages from bunker silos.

Ensiling is a feed preservation method of moist forage crops that generally depends on naturally developing lactic acid bacteria to convert water-soluble carbohydrates into organic acids. While bacterial community dynamics have been previously assessed in bench-scale and pilot ensiling facilities, almost no studies have assessed the microbiomes of large-scale silage facilities. This study analyzed bacterial community composition in mature silage from bunker silos in three commercial production centers as related to pH, organic matter, volatile fatty acid composition, and spatial distribution within the ensiling bunker. It revealed significant physicochemical differences between "preserved" regions situated in the center and along the walls of the silage bunkers that were characterized by high concentrations of lactic acid and other volatiles and pH values below 5, and "spoiled" regions in the corners (shoulders) of the bunkers that had low lactic acid concentrations and high pH values. Preserved silage was dominated (>90 %) by lactic acid bacteria and characterized by high similarity and low taxonomic diversity, whereas spoiled silage had highly diverse microbiomes with low abundances of lactic acid bacteria (<5 %) that were sometimes characterized by high levels of Enterobacteriaceae. Spatial position had a much stronger impact on the microbial community composition than feedstock type, sampling date, or production center location supporting previous studies demonstrating that ecology and not geography is a major driver of environmental microbiomes.