142 research outputs found

    A study of the adaptive immune system in coronary thromboaspirate during human acute myocardial infarction

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    Introduction: This thesis aims to characterize the biology of solid and liquid phase coronary thromboaspirate obtained during therapeutic aspiration at primary angioplasty for ST elevation myocardial infarction (STEMI). Methods: We studied coronary thromboaspirate obtained from the coronary artery (CA) in STEMI and focussed on three lines of investigation: • Intracoronary solid phase thrombus was subjected to immunohistochemistry for characterization and quantification of the different leukocyte types and proteins involved in the thrombus. • Resident cell populations in the liquid phase filtrate from the aspirate including platelets and leukocytes along with their subpopulations were analysed by flow cytometry for phenotypic and activation markers. Comparison was made with cells in the peripheral femoral artery (FA) blood. • Paired plasma/serum from the CA filtrate and FA blood were analysed for the presence of autoreactive antibodies and cytotoxic potential. Results: • Leukocytes were heterogeneously distributed in the ex-vivo thrombus. The granulocyte population was predominant and strongly expressed CD11b and vimentin. • The CA aspirate filtrate when compared to the paired FA blood contained significantly more leukocyte-platelet conjugates, more activated platelets, and more Vimentin. • More of the CD4+ T cells in the CA than FA had lost the co-stimulatory molecule CD28 (p<0.00001) and they often expressed effector phenotype marker. • Conversely, the immune-regulatory T cells expressing the FoxP3 were more attenuated in the CA than FA (p<0.00001). • Whilst IgG and IgM antivimentin antibody titres in the CA sera were consistently lower than the titres in FA sera (p<0.001), auto-reactive non-HLA IgM were more prevalent in CA sera. The CA sera had increased potential to induce apoptosis than FA sera when incubated with endothelial cells (p<0.001). Conclusions: • Aspirated intracoronary clot contained granulocytes as the predominant leukocyte component. This investigation of the immune system in the CA during AMI therefore moved on to the adaptive system in the coronary filtrate. • Increased concentrations of pro-inflammatory immune cells and reduced concentrations of immune-modulating cells were observed in the aspirate from the culprit site of CA occlusion when compared with the FA. The presence of T memory cells implies that this subset may have been released from the ruptured coronary plaque and this phenotypic analysis may help clarify the role of the immune system in the pathogenesis of coronary plaque instability. • The higher titres of auto-reactive IGM in the CA than FA sera have the potential to activate the complement system and may contribute to myocardial injury following therapeutic restoration of coronary flow in STEMI

    Effects of Storage Structures and Moisture Contents on Seed Quality Attributes of Quality Protein Maize

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    The study was aimed to examine the effects of various storage structures and moisture contents on seed quality attributes of quality protein maize seed. The quality protein maize (QPM-1) seed was tested in conventional seed storage containers (Fertilizer sack and earthen pot) and the improved hermetic ones (Metal bin, Super grain bag, and Purdue Improved Crop Storage (PICS) bag) at Seed Science and Technology Division, Khumaltar, Nepal during February, 2015 to January 2016. Ten treatments comprising 5 storage devices in two moisture regimes (11% and 9%) replicated thrice and laid out in Completely Randomized Design (CRD). Data on temperature, relative humidity (RH), germination, electrical conductivity (EC), seed moisture content (MC) were collected bimonthly. The conventional containers were found liable to the external environmental condition whereas the hermetic structures observed with controlled RH level below 40% in all combinations. Electrical conductivity (EC) for seed vigor showed that hermetic containers provide higher seed vigor than the conventional ones. Up to 4 months all treatments were found statistically at par for germination. A significant difference was observed in each treatment after 4 months where PICS bag &amp; Super grain bag showed best germination followed by metal bin while fertilizer bag &amp; earthen-pot showed poorer and poorest germination respectively till one year. Almost all treatments with lower MC showed better results than the treatments with higher MC. A negative correlation (R2=69.7%) was found between EC and Germination. All six figures from 2 to 12 months on MC showed statistically different where hermetic plastic bags were found maintaining MC as initial whereas MC of fertilizer bags and earthen pot was spiked than the basal figure. The finding evidenced that the hermetic containers and low MC are the seed storage approaches for retaining the quality of seed even in an ambient environmental condition for more than a year

    Incidence and predation rate of hornet (Vespa spp.) on European honeybee (Apis mellifera L.) apiary at mid-hill areas of Lalitpur district, Nepal

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    Predatory hornets are considered as one of the major constraints to beekeeping industry. Therefore, its incidence and predation rate was studied throughout the year at two locations- rural and forest areas of mid-hill in Laliptur district during 2016/017 to 2017/018. Observation was made on the number of hornet and honey bee captured by hornet in three different times of the day for three continuous minutes every fortnightly on five honeybee colonies. During the study period, major hornet species captured around the honeybee apiary at both locations were, Vespa velutina Lepeletier, Vespa basalis Smith, Vespa tropica (Linnaeus) and Vespa mandarina Smith. The hornet incidence varied significantly between the years and locations along with different observation dates. Their incidence and predation rates were low in early spring and summer that gradually increased with the highest peak in October and November in both locations. The maximum predation was on mid-November (62.07%) and early-November (53.49%) at rural and forest locations, respectively during 2016/017. In 2017/018, the highest predation was on early-November (70.27%) at rural area while it was in mid-November (58.62%) in the apiaries near the forest area. The population of hornet was considerably higher at forest areas and their incidence around the honeybee apiaries were negatively correlated with rainfall. Hence, assessment of the temporal and spatial population variations and predation rates along with weather parameters is helpful in to develop sustainable management plans of the hornet in apiary

    Evaluating the Effectiveness of Interventions to Improve the Follow-up Rate for Children With Visual Disabilities in an Eye Hospital in Nepal: Nonrandomized Study

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    Background: Monitoring ocular morbidity among pediatric patients requires regular follow-up visits. We found that the follow-up rate was poor among children in our setting. Therefore, we intended to assess the effectiveness of 2 interventions—(1) counseling and (2) SMS text messaging and phone calls—to improve the follow-up rates. Objective: This study aimed to evaluate the effectiveness of 2 interventions, counseling and SMS and phone calls group, as well as a routine standard care for improving the follow-up rate of pediatric patients. Methods: A Nonrandomized, quasiexperimental design was used. Children (aged 0-16 years) with ocular conditions requiring at least 3 follow-up visits during the study period were included. A total of 264 participants were equally allocated to the 3 intervention groups of (1) counseling, (2) SMS and phone calls, and (3) routine standard care group. A 20-minute counseling session by a trained counselor with the provision of disease-specific leaflets were given to those in the counseling group. For the second intervention group, parents of children received an SMS text 3 days before and a phone call 1 day before their scheduled follow-up visits. Participants allocated for the routine standard care group were provided with the existing services with no additional counseling and reminders. Participants attending 3 follow-ups within 2 days of the scheduled visit date were considered compliant. The difference in and among the proportion of participants completing all 3 follow-up visits in each group was assessed. Results: The demographic characteristics of the participants were similar across the study groups. Only 3% (8/264) of participants completed all 3 follow-up visits, but overall compliance with the follow-up, as defined by the investigators, was found to be only 0.76% (2/264). There was no statistically significant difference in the proportion of follow-up between the intervention groups. However, the proportion of participants attending the first and second follow-ups, as well as the overall total number of follow-ups, was more in the SMS and phone-call group followed by the counseling group. Conclusions: We did not find any evidence on the effectiveness of our interventions to improve the follow-up rate. The primary reason could be that this study was conducted during the COVID-19 pandemic. It could also be possible that the intensity of the interventions may have influenced the outcomes. A rigorously designed study during the absence of any lockdown restrictions is warranted to evaluate intervention effectiveness. The study also provides useful insights and highlights the importance of designing and systematically developing interventions for improving the follow-up rate and ensuring a continuum of care to children with visual disabilities in Nepal and similar contexts. Trial Registration: ClinicalTrials.gov NCT04837534; https://clinicaltrials.gov/ct2/show/NCT04837534 International Registered Report Identifier (IRRID): RR2-10.2196/3157

    Search for the Chiral Magnetic Effect in Au+Au collisions at sNN=27\sqrt{s_{_{\rm{NN}}}}=27 GeV with the STAR forward Event Plane Detectors

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    A decisive experimental test of the Chiral Magnetic Effect (CME) is considered one of the major scientific goals at the Relativistic Heavy-Ion Collider (RHIC) towards understanding the nontrivial topological fluctuations of the Quantum Chromodynamics vacuum. In heavy-ion collisions, the CME is expected to result in a charge separation phenomenon across the reaction plane, whose strength could be strongly energy dependent. The previous CME searches have been focused on top RHIC energy collisions. In this Letter, we present a low energy search for the CME in Au+Au collisions at sNN=27\sqrt{s_{_{\rm{NN}}}}=27 GeV. We measure elliptic flow scaled charge-dependent correlators relative to the event planes that are defined at both mid-rapidity η<1.0|\eta|<1.0 and at forward rapidity 2.1<η<5.12.1 < |\eta|<5.1. We compare the results based on the directed flow plane (Ψ1\Psi_1) at forward rapidity and the elliptic flow plane (Ψ2\Psi_2) at both central and forward rapidity. The CME scenario is expected to result in a larger correlation relative to Ψ1\Psi_1 than to Ψ2\Psi_2, while a flow driven background scenario would lead to a consistent result for both event planes[1,2]. In 10-50\% centrality, results using three different event planes are found to be consistent within experimental uncertainties, suggesting a flow driven background scenario dominating the measurement. We obtain an upper limit on the deviation from a flow driven background scenario at the 95\% confidence level. This work opens up a possible road map towards future CME search with the high statistics data from the RHIC Beam Energy Scan Phase-II.Comment: main: 8 pages, 5 figures; supplementary material: 2 pages, 1 figur

    Event-by-event correlations between Λ\Lambda (Λˉ\bar{\Lambda}) hyperon global polarization and handedness with charged hadron azimuthal separation in Au+Au collisions at sNN=27 GeV\sqrt{s_{\text{NN}}} = 27 \text{ GeV} from STAR

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    Global polarizations (PP) of Λ\Lambda (Λˉ\bar{\Lambda}) hyperons have been observed in non-central heavy-ion collisions. The strong magnetic field primarily created by the spectator protons in such collisions would split the Λ\Lambda and Λˉ\bar{\Lambda} global polarizations (ΔP=PΛPΛˉ<0\Delta P = P_{\Lambda} - P_{\bar{\Lambda}} < 0). Additionally, quantum chromodynamics (QCD) predicts topological charge fluctuations in vacuum, resulting in a chirality imbalance or parity violation in a local domain. This would give rise to an imbalance (Δn=NLNRNL+NR0\Delta n = \frac{N_{\text{L}} - N_{\text{R}}}{\langle N_{\text{L}} + N_{\text{R}} \rangle} \neq 0) between left- and right-handed Λ\Lambda (Λˉ\bar{\Lambda}) as well as a charge separation along the magnetic field, referred to as the chiral magnetic effect (CME). This charge separation can be characterized by the parity-even azimuthal correlator (Δγ\Delta\gamma) and parity-odd azimuthal harmonic observable (Δa1\Delta a_{1}). Measurements of ΔP\Delta P, Δγ\Delta\gamma, and Δa1\Delta a_{1} have not led to definitive conclusions concerning the CME or the magnetic field, and Δn\Delta n has not been measured previously. Correlations among these observables may reveal new insights. This paper reports measurements of correlation between Δn\Delta n and Δa1\Delta a_{1}, which is sensitive to chirality fluctuations, and correlation between ΔP\Delta P and Δγ\Delta\gamma sensitive to magnetic field in Au+Au collisions at 27 GeV. For both measurements, no correlations have been observed beyond statistical fluctuations.Comment: 10 pages, 10 figures; paper from the STAR Collaboratio

    Measurement of Λ4H\rm ^4_{\Lambda}H and Λ4He\rm ^4_{\Lambda}He binding energy in Au+Au collisions at sNN\sqrt{s_\mathrm{NN}} = 3 GeV

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    Measurements of mass and Λ\Lambda binding energy of Λ4H\rm ^4_{\Lambda}H and Λ4He\rm ^4_{\Lambda}He in Au+Au collisions at sNN=3\sqrt{s_{_{\rm NN}}}=3 GeV are presented, with an aim to address the charge symmetry breaking (CSB) problem in hypernuclei systems with atomic number A = 4. The Λ\Lambda binding energies are measured to be 2.22±0.06(stat.)±0.14(syst.)\rm 2.22\pm0.06(stat.) \pm0.14(syst.) MeV and 2.38±0.13(stat.)±0.12(syst.)\rm 2.38\pm0.13(stat.) \pm0.12(syst.) MeV for Λ4H\rm ^4_{\Lambda}H and Λ4He\rm ^4_{\Lambda}He, respectively. The measured Λ\Lambda binding-energy difference is 0.16±0.14(stat.)±0.10(syst.)\rm 0.16\pm0.14(stat.)\pm0.10(syst.) MeV for ground states. Combined with the γ\gamma-ray transition energies, the binding-energy difference for excited states is 0.16±0.14(stat.)±0.10(syst.)\rm -0.16\pm0.14(stat.)\pm0.10(syst.) MeV, which is negative and comparable to the value of the ground states within uncertainties. These new measurements on the Λ\Lambda binding-energy difference in A = 4 hypernuclei systems are consistent with the theoretical calculations that result in ΔBΛ4(1exc+)ΔBΛ4(0g.s.+)<0\rm \Delta B_{\Lambda}^4(1_{exc}^{+})\approx -\Delta B_{\Lambda}^4(0_{g.s.}^{+})<0 and present a new method for the study of CSB effect using relativistic heavy-ion collisions.Comment: 8 pages, 5 figure
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