5 research outputs found
Comparison between regional lung CT values and lung densities estimated using EIT
In this paper we report the results of our study in which we compared lung density values obtained from EIT and CT values (HU) within a region of interest. The purpose was to verify clinical use of lung density estimation using EIT data. Image resolution of CT images, which was originally 512*512 pixels, was changed to 16*16 pixels, to match that of the EIT images. The CT and EIT images were recorded from eight patients in an intensive care unit and the results showed a correlation coefficient of 0.66 (p<0.05) between the CT values (HU) and the lung density values (kg/m3) obtained from EIT
Three Dimensional Monitoring of Thawing of Biological Tissue using Electrical Impedance Tomography
1,3-Diiodocalix[4]arene: Synthesis by Ullmann-Type Iodination of 1,3-Bistriflate Ester of Calix[4]arene, Conformational Analysis, and Transformation into 1,3-Dicarboxy‑, Diformyl‑, and Dialkylcalix[4]arenes
A facile synthesis
of 1,3-diiodocalix[4]arene <b>6</b> has
been achieved by copper-catalyzed iodination of the 1,3-bistriflate
ester <b>2a</b> of <i>p</i>-<i>tert</i>-butylcalix[4]arene.
After protection of the hydroxy groups with iodomethane, diiodide <b>6</b> is subjected to halogen–lithium exchange with butyllithium,
followed by carbonation with CO<sub>2</sub> or formylation with <i>N</i>-formylpiperidine and subsequent deprotection of the hydroxy
groups to give novel dicarboxylic acid <b>11</b> or dialdehyde <b>16</b> in practical yields. The iodo groups of diiodide <b>6</b> pass through the calixarene macrocycle; the activation free
energy for the conversion of the more stable syn conformer <b>6</b><sub>syn</sub> to the less stable anti conformer <b>6</b><sub>anti</sub> is Δ<i>G</i><sup>⧧</sup> = 104
kJ mol<sup>–1</sup> at 298 K. Dialdehyde <b>16</b> shows
fast self-exchange between two equivalent species with a cone
conformation, Δ<i>G</i><sup>⧧</sup>, being
63.2 kJ mol<sup>–1</sup>. Dicarboxylic acid <b>11</b> adopts a cone conformation and forms a dimer in solution as suggested
by <sup>1</sup>H NMR and X-ray crystallographic analyses. The arrangement
of the iodide groups of compound <b>6</b> can be fixed predominantly
to anti (<b>17a</b> and <b>17b</b>) by introducing bulky
alkyl groups (e.g., propyl groups) onto the hydroxy groups. The stereospecific
alkylation of the iodo groups of the resulting di-O<i>-</i>alkylated <i>anti-</i>1,3-diiodides provides access to
the <i>anti</i>-1,3-dialkylcalixarenes <b>19</b>,
which is otherwise difficult
to obtain
Validation of the severe COVID-19 prognostic value of serum IL-6, IFN-λ3, CCL17, and calprotectin considering the timing of clinical need for prediction.
Although biomarkers to predict coronavirus disease 2019 (COVID-19) severity have been studied since the early pandemic, no clear guidelines on using them in clinical practice are available. Here, we examined the ability of four biomarkers to predict disease severity using conserved sera from COVID-19 patients who received inpatient care between January 1, 2020 and September 21, 2021 at the National Center for Global Health and Medicine, collected at the appropriate time for prediction. We predicted illness severity in two situations: 1) prediction of future oxygen administration for patients without oxygen support within 8 days of onset (Study 1) and 2) prediction of future mechanical ventilation support (excluding non-invasive positive pressure ventilation) or death of patients within 4 days of the start of oxygen administration (Study 2). Interleukin-6, IFN-λ3, thymus and activation-regulated chemokine, and calprotectin were measured retrospectively. Other laboratory and clinical information were collected from medical records. AUCs were calculated from ROC curves and compared for the predictive ability of the four biomarkers. Study 1 included 18 patients, five of whom had developed oxygen needs. Study 2 included 45 patients, 13 of whom required ventilator management or died. In Study 1, IFN-λ3 showed a good predictive ability with an AUC of 0.92 (95% CI 0.76-1.00). In Study 2, the AUC of each biomarker was 0.70-0.74. The number of biomarkers above the cutoff showed the possibility of good prediction with an AUC of 0.86 (95% CI 0.75-0.97). When two or more biomarkers were positive, sensitivity and specificity were 0.92 and 0.63, respectively. In terms of biomarker testing at times when prognostication may be clinically useful, IFN-λ3 was predictive of oxygenation demand and a combination of the four biomarkers was predictive of mechanical ventilator requirement