nuclear spin circular dichroism in fullerenes a computational study

Chemically different carbons in C70 give distinct signals in nuclear spin circular dichroism spectroscopy, a novel candidate for high-resolution identification of chemical compounds

TD-DFT Investigation of the Magnetic Circular Dichroism Spectra of Some Purine and Pyrimidine Bases of Nucleic Acids

We present a computational study of the magnetic circular dichroism (MCD) spectra in the 200-300 nm wavelength region of purine and its derivative hypoxanthine, as well as of the pyrimidine bases of nucleic acids uracil, thymine, and cytosine, using the B3LYP and CAM-B3LYP functionals. Solvent effects are investigated within the polarizable continuum model and by inclusion of explicit water molecules. In general, the computed spectra are found to be in good agreement with the experimental ones, apart from some overall blue shifts. Both the pseudo-A term shape of the MCD spectra of the purines and the B term shape of the spectra of pyrimidine bases are reproduced. Our calculations also correctly reproduce the reversed phase of the MCD bands in purine compared to that of its derivatives present in nucleic acids. Solvent effects are sizable and system specific, but they do not in general alter the qualitative shape of the spectra. The bands are dominated by the bright \u3c0 \u2192 \u3c0* transitions, and our calculations in solution nicely reproduce their energy differences, improving the estimates obtained in the gas phase. Shoulders are predicted for purine and uracil due to n \u2192 \u3c0* excitations, but they are too weak to be observed in the experiment

Functional Lung MRI in Chronic Obstructive Pulmonary Disease: Comparison of T1 Mapping, Oxygen-Enhanced T1 Mapping and Dynamic Contrast Enhanced Perfusion

Purpose Monitoring of regional lung function in interventional COPD trials requires alternative end-points beyond global parameters such as FEV1. T1 relaxation times of the lung might allow to draw conclusions on tissue composition, blood volume and oxygen fraction. The aim of this study was to evaluate the potential value of lung Magnetic resonance imaging (MRI) with native and oxygen-enhanced T1 mapping for the assessment of COPD patients in comparison with contrast enhanced perfusion MRI. Materials and Methods 20 COPD patients (GOLD I-IV) underwent a coronal 2-dimensional inversion recovery snapshot flash sequence (8 slices/lung) at room air and during inhalation of pure oxygen, as well as dynamic contrast-enhanced first-pass perfusion imaging. Regional distribution of T1 at room air (T1), oxygen-induced T1 shortening (Delta T1) and peak enhancement were rated by 2 chest radiologists in consensus using a semi-quantitative 3-point scale in a zone-based approach. Results Abnormal T1 and Delta T1 were highly prevalent in the patient cohort. T1 and Delta T1 correlated positively with perfusion abnormalities (r = 0.81 and r = 0.80;p&0.001), and with each other (r = 0.80;p< 0.001). In GOLD stages I and II Delta T1 was normal in 16/29 lung zones with mildly abnormal perfusion (15/16 with abnormal T1). The extent of T1 (r = 0.45;p< 0.05), T1 (r = 0.52;p< 0.05) and perfusion abnormalities (r = 0.52;p< 0.05) showed a moderate correlation with GOLD stage. Conclusion Native and oxygen-enhanced T1 mapping correlated with lung perfusion deficits and severity of COPD. Under the assumption that T1 at room air correlates with the regional pulmonary blood pool and that oxygen-enhanced T1 reflects lung ventilation, both techniques in combination are principally suitable to characterize ventilation-perfusion imbalance. This appears valuable for the assessment of regional lung characteristics in COPD trials without administration of i. v. contrast

Intra-breath arterial oxygen oscillations detected by a fast oxygen sensor in an animal model of acute respiratory distress syndrome

Background There is considerable interest in oxygen partial pressure (Po2) monitoring in physiology, and in tracking PO2 changes dynamically when it varies rapidly. For example, arterial PO2 (PaO2) can vary within the respiratory cycle in cyclical atelectasis (CA), where PaO2 is thought to increase and decrease during inspiration and expiration, respectively. A sensor that detects these PaO2 oscillations could become a useful diagnostic tool of CA during acute respiratory distress syndrome (ARDS). Methods We developed a fibreoptic PO2 sensor (<200 µm diameter), suitable for human use, that has a fast response time, and can measure PO2 continuously in blood. By altering the inspired fraction of oxygen (FIO2) from 21 to 100% in four healthy animal models, we determined the linearity of the sensor's signal over a wide range of PaO2 values in vivo. We also hypothesized that the sensor could measure rapid intra-breath PaO2 oscillations in a large animal model of ARDS. Results In the healthy animal models, PaO2 responses to changes in FIO2 were in agreement with conventional intermittent blood-gas analysis (n=39) for a wide range of PaO2 values, from 10 to 73 kPa. In the animal lavage model of CA, the sensor detected PaO2 oscillations, also at clinically relevant PaO2 levels close to 9 kPa. Conclusions We conclude that these fibreoptic PaO2 sensors have the potential to become a diagnostic tool for CA in ARDS

Dynamic contrast-enhanced magnetic resonance imaging in patients with pulmonary arterial hypertension.

Dynamic contrast-enhanced (DCE) time-resolved magnetic resonance (MR) imaging is a technique whereby the passage of an intravenous contrast bolus can be tracked through the pulmonary vascular system. The aim of this study was to investigate the prognostic significance of DCE-MR pulmonary blood transit times in patients with pulmonary arterial hypertension (PAH). Seventy-nine patients diagnosed with PAH underwent pulmonary DCE imaging at 1.5 T using a time-resolved three-dimensional spoiled gradient echo sequence. The prognostic significance of two DCE parameters, full width at half maximum (FWHM) of the first-pass clearance curve and pulmonary transit time (PTT), along with demographic and invasive catheter measurements, was evaluated by univariate and bivariate Cox proportional hazards regression and Kaplan-Meier analysis. DCE-MR transit times were most closely correlated with cardiac index (CI) and pulmonary vascular resistance index (PVRI) and were both found to be accurate for detecting reduced CI (FWHM area under the curve [AUC] at receiver operating characteristic analysis = 0.91 and PTT AUC = 0.92, respectively) and for detecting elevated PVRI (FWHM AUC = 0.88 and PTT AUC = 0.84, respectively). During the follow-up period, 25 patients died. Patients with longer measurements of FWHM (P = 0.0014) and PTT (P = 0.004) were associated with poor outcome at Kaplan-Meier analysis, and both parameters were strong predictors of adverse outcome from Cox proportional hazards analysis (P = 0.013 and 0.010, respectively). At bivariate analysis, DCE measurements predicted mortality independent of age, gender, and World Health Organization functional class; however, invasive hemodynamic indexes CI, PVRI, and DCE measurements were not independent of one another. In conclusion, DCE-MR transit times predict mortality in patients with PAH and are closely associated with clinical gold standards CI and PVRI

Post-activation Performance Enhancement after a Bout of Accentuated Eccentric Loading in Collegiate Male Volleyball Players

The purpose of this study was to investigate the benefit of post-activation performance enhancement (PAPE) after accentuated eccentric loading (AEL) compared to traditional resistance loading (TR). Sixteen male volleyball athletes were divided in AEL and TR group. AEL group performed 3 sets of 4 repetitions (eccentric: 105% of concentric 1RM, concentric: 80% of concentric 1RM) of half squat, and TR group performed 3 sets of 5 repetitions (eccentric & concentric: 85% of 1RM). Countermovement jump (CMJ), spike jump (SPJ), isometric mid-thigh pull (IMTP), and muscle soreness test were administered before (Pre) exercise, and 10 min (10-min), 24 h (24-h), and 48 h (48-h) after exercise. A two-way repeated measures analysis of variance was used to analyze the data. Peak force and rate of development (RFD) of IMTP in AEL group were significantly greater (p 0.05) groups x time. AEL seemed capable to maintain force production in IMTP, but not in CMJ and SPJ. It is recommended the use of accentuated eccentric loading protocols to overcome the fatigue

How will lung cancer screening and lung nodule management change the diagnostic and surgical lung cancer landscape?

INTRODUCTION: Implementation of lung cancer screening, with its subsequent findings, is anticipated to change the current diagnostic and surgical lung cancer landscape. This review aimed to identify and present the most updated expert opinion and discuss relevant evidence regarding the impact of lung cancer screening and lung nodule management on the diagnostic and surgical landscape of lung cancer, as well as summarise points for clinical practice. METHODS: This article is based on relevant lectures and talks delivered during the European Society of Thoracic Surgeons-European Respiratory Society Collaborative Course on Thoracic Oncology (February 2023). Original lectures and talks and their relevant references were included. An additional literature search was conducted and peer-reviewed studies in English (December 2022 to June 2023) from the PubMed/Medline databases were evaluated with regards to immediate affinity of the published papers to the original talks presented at the course. An updated literature search was conducted (June 2023 to December 2023) to ensure that updated literature is included within this article. RESULTS: Lung cancer screening suspicious findings are expected to increase the number of diagnostic investigations required therefore impacting on current capacity and resources. Healthcare systems already face a shortage of imaging and diagnostic slots and they are also challenged by the shortage of interventional radiologists. Thoracic surgery will be impacted by the wider lung cancer screening implementation with increased volume and earlier stages of lung cancer. Nonsuspicious findings reported at lung cancer screening will need attention and subsequent referrals where required to ensure participants are appropriately diagnosed and managed and that they are not lost within healthcare systems. CONCLUSIONS: Implementation of lung cancer screening requires appropriate mapping of existing resources and infrastructure to ensure a tailored restructuring strategy to ensure that healthcare systems can meet the new needs.</p

Mapping and quantifying hyperpolarized 3He magnetic resonance imaging apparent diffusion coefficient gradients

We measured hyperpolarized 3He magnetic resonance imaging (MRI) apparent diffusion coefficients (ADC) and quantified ADC gradients in each three-by-three voxel region of interest (ROI). Such local ADC gradients can be represented in vector maps showing the magnitude (|G3x3|) and direction of ADC gradients, providing a qualitative visualization tool and quantitative measurement of airway and air space heterogeneity. Twenty-four subjects (15 male, mean age=67+/-7 yr) with global initiative for chronic obstructive lung disease (GOLD) stage II (n=9, mean age 68+/-6 yr), GOLD stage III chronic obstructive pulmonary disease (COPD; n=7, mean age 67+/-8 yr), and age-matched healthy volunteers (n=8, mean age 67+/-6 yr) were enrolled based on their age and spirometry results. Hyperpolarized 3He MRI was performed on a whole body 3.0 Tesla system. Mean 3He ADC and ADC standard deviation were calculated for the center coronal slice, and the mean magnitude and direction of the ADC gradient vectors were calculated for each three-by-three voxel matrix (|G3x3|). While the 3He ADC standard deviation was not significantly different, mean |G3x3| was significantly different between subjects with stage II (0.14+/-0.03 cm/s) and stage III COPD (0.19+/-0.03 cm/s;