67 research outputs found
Multiplicity distributions inside parton cascades developing in a medium
The explanation of the suppression of high-pT hadron yields at RHIC in terms
of jet-quenching implies that the multiplicity distributions of particles
inside a jet and jet-like particle correlations differ strongly in
nucleus-nucleus collisions at RHIC or at the LHC from those observed at e+e- or
hadron colliders. We present a framework for describing the medium-induced
modification, which has a direct interpretation in terms of a probabilistic
medium-modified parton cascade, and which treats leading and subleading partons
on an equal footing. We show that our approach can account for the strong
suppression of single inclusive hadron spectra measured in Au-Au collisions at
RHIC, and that this implies a characteristic distortion of the single inclusive
distribution of soft partons inside the jet. We determine, as a function of the
jet energy, to what extent the soft fragments within a jet can be measured
above some momentum cut.Comment: 5 pages, 4 eps-figures; talk given at Hot Quarks 2006, Villasimius
(Sardinia, Italy), May 15-20, 200
Plasmodium knowlesi reinfection in human
To the Editor: In 2004, a large number of patients infected with Plasmodium knowlesi (simian malarial species) were reported in Sarawak, Malaysia (1). P. knowlesi infection was also reported in Peninsular Malaysia (2). Here we report a case of human P. knowlesi reinfection. Phylogenetic sequence analysis shows that the first and second infections were caused by different strains of P. knowlesi
Jet hadrochemistry as a characteristics of jet quenching
Jets produced in nucleus-nucleus collisions at the LHC are expected to be
strongly modified due to the interaction of the parton shower with the dense
QCD matter. Here, we point out that jet quenching can leave signatures not only
in the longitudinal and transverse jet energy and multiplicity distributions,
but also in the hadrochemical composition of the jet fragments. In particular,
we show that even in the absence of medium effects at or after hadronization,
the medium-modification of the parton shower can result in significant changes
in jet hadrochemistry. We discuss how jet hadrochemistry can be studied within
the high-multiplicity environment of nucleus-nucleus collisions at the LHC.Comment: 15 pages, 7 figures, LaTe
Comparison of Resting PD/PA with Fractional Flow Reserve Using a Monorail Pressure Catheter
Background: The RXi™ system (ACIST Medical Systems, MN, USA) is a new Fractional Flow Reserve (FFR) technology utilising an ultrathinmonorail microcatheter (Navvus®; ACIST Medical Systems) with an optical pressure sensor located close to the distal catheter tip. FFR measurement using monorail microcatheter is comparable to the
conventional pressure wires. However, the predictive value of resting distal coronary artery pressure/aortic pressure (Pd/Pa) on hyperemic FFR value in the real world practice is unknown.
Objective: To explore the diagnostic accuracy of resting Pd/Pa in relation to hyperemic FFR using the monorail pressure catheter.
Methods: Resting Pd/Pa and FFR were measured using monorail pressure catheter in 67 consecutive patients with intermediate coronary artery lesions (30% to 80% diameter stenoses) between 01-03-2016 to 17-01-2017. Of 121 studied lesions, 29 (23.97%) were excluded because of no hyperemic FFR due to postive resting Pd/Pa (n=17), severe or non-critical stenosis (n=11) and suboptimal
acquisition (n=1), leaving 92 lesions for final analysis. Hyperemic FFR was induced with intracoronary adenosine. The selection of coronary wire and the dose of intracoronary nitroglycerine were at the operators’ discretions.
Results: Bland-Altman plots showed a moderate degree of scatter between Pd/Pa and FFR value. On average, Pd/Pa exceeded FFR by 0.066 (-0.09 to +0.22). Receiver-operating characteristic curves of the resting Pd/Pa with FFR≤0.80 as the reference variable showed an area under the curve of 0.78 (95% confidence intervals 0.680 to
0.881, pb0.001), with a diagnostic accuracy of 79.3% when the resting Pd/Pa was ≤0.86. Certain cutoff values of Pd/Pa can reliably predict whether hyperemic FFR was positive or negative (FFR cutoff≤0.80). Resting Pd/Pa value of N0.96 had a negative predictive value (NPV) of 100% and sensitivity of 100%; the resting Pd/Pa value
of ≤0.82 had a positive predictive value (PPV) of 100% and specificity of 98.3%. These were consistent regardless of coronary vessel, location of lesion or degree of diameter stenosis.
Conclusions: Certain range of resting Pd/Pa measured by monorail pressure catheter had excellent NPV and sensitivity or excellent PPV and specificity to predict hyperemic FFR. Clinical outcome studies are required to determine whether the results might obviate the need for
hyperemia in selected patients
Prognostic Value of N-terminal B-type Natriuretic Peptide in Patients with Acute Myocardial Infarction: A Multicenter Study
Background: Several models have been developed to help the clinician in risk stratification for Acute Coronary Syndrome (ACS),such as the TIMI and GRACE risk scores. However, there is conflicting evidence for the prognostic value of NT-ProBNP in acute myocardial infarction (AMI).
Objective: (1) To explore the association of NT-proBNP with 30-day clinical outcome in AMI patients. (2) To compare the prognostic value of NT-proBNP with TIMI and GRACE risk scores in AMI patients.
Methods: We conducted a multicenter, prospective observational study recruiting patients presented with AMI between 29-October-2015 and 14-January-2017, involving 1 cardiology referral centre and 4 non-cardiology hospitals. NT-proBNP level (Alere Triage®, US)was measured within 24 hours fromthe diagnosis of AMI. Patientswere followed-up for 1 month.
Results: A total of 186 patients were recruited, 143 from tertiary cardiology centre and 43 from non-cardiology hospitals. Mean age was 54.7±10.0 years, 87.6% male and 64% were STEMI. The NT-proBNP level ranged from 60 to 16700pg/ml, with a median of 714pg/ml. Using the 75th centile as the cutoff, Kaplan-Meier survival analysis for the 30-day cardiac related mortality was significantly higher for patient with NT-proBNP level of ≥1600pg/ml (6.4% vs. 0.7%, p=0.02). Cox-regression analysis showed that NT-proBNP level of ≥1600pg/ml was an independent
predictor of 30-day cardiac related mortality, regardless of TIMI risk score, GRACE score, LV ejection fraction and study hospitals (HR 9.274, p=0.054, 95%CI 0.965, 89.161). Readmission for heart failure at 30-day was also higher for patient with NT-proBNP level of ≥1600pg/ml (HR 9.308, p=0.053, 95%CI 0.969, 89.492). NT-proBNP level was not
associated with all-cause mortality, risk of readmission for ACS, arrhythmia and stroke (pN0.05). By adding 50 score to GRACE risk score for NT-proBNP level of ≥1600pg/ml, combination of GraceNT-proBNP scores of more than 200 appeared to be a better independent predictor for 30-day cardiac related mortality (HR:28.28, p=0.004, 95%CI 2.94, 272.1). ROC analysis showed that this new score had 75% sensitivity and 91.2% specificity in predicting 30-day cardiac related mortality (AUC
0.791, p=0.046).
Conclusions: NT-proBNP is a useful point-of-care risk stratification biomarker in AMI. It can be combined to the current risk score model for better risk stratification in AMI patients
Reversal of cardiac damage in patients with symptomatic severe aortic stenosis following transcatheter aortic valve implantation: An echocardiographic study
Background: Severe aortic stenosis (AS) results in cardiac damages, such as left ventricular hypertrophy, left atrial enlargement, pulmonary pressure elevation and in advanced stage, right ventricular damage. Généreux and colleagues proposed a staging classification based on these extra-valvular damages in 2017, with increasing stage representing more cardiac damage. While regression of these cardiac damages is expected following aortic valve replacement, the reversal of cardiac damage based on this staging system has not been described.
Purpose: This study aimed to describe and stage the changes in cardiac structure and function at 6 months and 1 year after transcatheter aortic valve implantation (TAVI) in patients with symptomatic severe AS.
Methods: This was a retrospective, single center, longitudinal observational study. Echocardiographic data of patients who underwent TAVI were retrieved and analysed.
Results: From May 2018 to Feb 2021, 31 patients underwent TAVI. 5 patients were excluded due to death <6 months post-procedure (n=2) and incomplete echocardiographic data (n=3). The mean age of the remaining 26 patients was 70.9±9.4 years, 57.7% were male, and 34.6% bicuspid aortic valve. After TAVI, transvalvular aortic mean pressure gradient reduced from 45.2±14.5 mmHg to 8.0±5.4 mmHg (p<0.001), and aortic valve area increased from 0.57±0.21 cm2 to 1.75±0.68 cm2 (p<0.001). At baseline, 6-month and 1-year, the left ventricular mass index (LVMi) were 183.4±60.7g/m2, 150.8±55.3 g/m2 and 126.8±42.1 g/m2 (p<0.001) respectively; left-atrial volume index (LAVI) were 60.4±22.8 ml/m2 , 51.7±23.8ml/m2, and 48.1±23.6ml/m2 (p=0.009) respectively; left ventricular ejection fraction (LVEF) were 52.3±25.4%, 64.2±29.3%, and 62.4±12.1% (p=0.005) respectively. Based on the proposed cardiac damage staging for AS, at baseline 38% of patients were stage 1, 65.4% stage 2, 7.7% stage 3 and 23.1% stage 4. At 1 year, 8.3% were stage 0, 29.2% stage 1, 58.3% stage 2, and 4.2% stage 4. 12 patients (46%) showed improvement in cardiac damage staging, and the other 14 (54%) remained in the same stage.
Conclusion: In patients with symptomatic severe AS, there were overall significant regression in LVMi and LAVI, and improvement in LVEF at 1 year after TAVI. However, improvement in cardiac damage staging was observed in only 46% of patients
Toxoplasma gondii: Serological characterization and immunogenicity of recombinant surface antigen 2 (SAG2) expressed in the yeast Pichia pastoris
The full length surface antigen 2 (SAG2) gene of the protozoan parasite Toxoplasma gondii was cloned and intracellularly expressed in the Pichia pastoris expression system. The molecular weight of the expressed recombinant SAG2 (36 kDa) was much larger than the native SAG2 (22 kDa). This discrepancy in size was due to hyperglycosylation, as deglycosylation assay reduced the size of the recombinant SAG2 to 22 kDa. Despite being hyperglycosylated, the recombinant SAG2 reacted strongly with pooled anti-Toxoplasma human serum, pooled anti-Toxoplasma mouse serum and a SAG2-specific monoclonal antibody. The glycosylated recombinant SAG2 was further evaluated in Western blot and in-house enzyme-linked immunosorbent assay (ELISA) using 80 human serum samples, including confirmed early acute (IgM positive, IgG negative; n = 20), acute (IgM positive, IgG positive; n = 20) and chronic (IgM negative, IgG positive; n = 20) toxoplasmosis patients, and toxoplasmosis negative control patients (n = 20). Results of the Western blot showed that the recombinant SAG2 reacted with all 60 samples of the toxoplasmosis cases but not with the Toxoplasma-negative samples. The sensitivity of in-house ELISA was 80, 95 and 100 for early acute, acute and chronic patients' serum samples, respectively. Vaccination study showed that serum from mice immunised with the glycosylated recombinant SAG2 reacted specifically with the native SAG2 of T. gondii. The mice were significantly protected against lethal challenge with live T. gondii RH strain tachyzoites (P < 0.01) and their survival time was increased compared to controls. Therefore, the present study shows that the A pastoris-derived recombinant SAG2 was specific and suitable for use as antigen for detecting anti-Toxoplasma IgG and IgM antibodies. The vaccination study showed that recombinant SAG2 protein was immunoprotective in mice against lethal challenge. (c) 2008 Elsevier Inc. All rights reserved
Localized surface plasmon resonance: A unique property of plasmonic nanoparticles for nucleic acid detection
10.1039/c3nr02257aNanoscale52412043-1207
Evolution from Goods Products to Services Products in T-commerce: A Case Study of Eastern Home opping Network in Taiwan
Head-to-tail: Hybridization and single-mismatch discrimination in metallic nanoparticle-DNA assembly
10.1039/c3ra23162cRSC Advances3176076-608
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