The development of miniature, sensitive, high throughput, and in-situ analytical instruments has been becoming developing field of modern analytical chemistry. Due to its unique advantages such as ...easy operation, simple configuration, ambient working temperature and pressure, low power consumption, and miniature dimension, dielectric barrier discharge (DBD) has always been a hot topic in analytical chemistry. This review gives an overview of miniature DBD application in analytical atomic spectrometry, starting with an introduction to its geometrical configuration and ionization mechanisms. Then, its applications such as excitation or atomization sources in atomic emission spectrometry (AES), atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS) are reviewed. Also, its application as vapor generation system in atomic spectrometry is discussed.
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•The application of miniature DBD in analytical atomic spectrometry is discussed.•The DBD configuration and plasma formation process are introduced.•The methodological development and analytical performance are reviewed.•The future development trend of miniature DBD in atomic spectrometry is presented.
Patient Health Questionnaire (PHQ-9) has nine questions and is used in diabetic or hypertensive patients to detect depressive symptoms. The PHQ-2 uses the first two questions of the PHQ-9 to rapidly ...detect those patients that should answer the whole questionnaire.
To validate the PHQ-2 to detect depressive symptoms in diabetic or hypertensive patients consulting at Primary Health Care (PHC).
Secondary analysis of data obtained during the baseline assessment of a clinical trial. Diabetic and hypertensive patients aged 18 years or more, attending a public health care clinic of Metropolitan Santiago, were invited to participate. Those accepting, answered the Patient Health Questionnaire (PHQ-9), consisting in nine questions about depressive symptoms. Demographics and health data were also collected. The PHQ-2 capacity to discriminate PHQ-9 scores equal or higher than 10 and 15 and the correlation between both versions, were assessed.
Ninety-four participants aged 64 ± years (73% women) answered the questionnaire. A cut-off score of 3 or more points in the PHQ-2 achieved the best tradeoff between sensitivity and specificity for discriminating PHQ-9 scores equal or higher than 10 (area under the receiver operating characteristic curve (ROC) = 0.92, 95% confidence interval 95% CI = 0.87 to 0.97) and 15 points (area under the ROC curve = 0.95, 95% CI = 0.92 to 0.99). Both versions had a high positive correlation (r = 0.87).
The PHQ-2 allows a stepped, simple and accurate screening for depressive symptoms. Diabetic or hypertensive patients with 3 or more points should be immediately assessed with the remaining questions of the PHQ-9.
Electrical isolation of the pulmonary veins (PVs) has been established in clinical routine as a curative treatment for atrial fibrillation (AF). While catheter ablation carries procedural risks, ...radiosurgery might be able to non-invasively induce lesions at the PV ostia to block veno-atrial electrical conduction. This porcine feasibility and dose escalation study determined the effect of radiosurgery on electrophysiologic properties of the left atrial-PV junction.
Eight adult Goettingen mini-pigs underwent electrophysiological voltage mapping in the left atrium and the upper right PV. Radiation was delivered with a conventional linear accelerator. A single homogeneous dose ranging from 22.5 to 40 Gy was applied circumferentially to the target vein antrum. Six months after radiosurgery, electrophysiological mapping was repeated and a histological examination performed. Voltage mapping consistently showed electrical potentials in the upper right PV at baseline. Pacing the target vein prompted atrial excitation, thus proving veno-atrial electrical conduction. After 6 months, radiation had reduced PV electrogram amplitudes. This was dose dependent with a mean interaction effect of -5.8%/Gy. Complete block of atrio-venous electrical conduction occurred after 40 Gy dose application. Histology revealed transmural scarring of the targeted PV musculature with doses >30 Gy. After 40 Gy, it spanned the entire circumference in accordance with pulmonary vein isolation.
Pulmonary vein isolation to treat AF can be achieved by radiosurgery with a conventional linear accelerator. Yet, it requires a high radiation dose which might limit clinical applicability.
To perform a proof-of-principle dose-escalation study to radiosurgically induce scarring in cardiac muscle tissue to block veno-atrial electrical connections at the pulmonary vein antrum, similar to ...catheter ablation.
Nine mini-pigs underwent pretreatment magnetic resonance imaging (MRI) evaluation of heart function and electrophysiology assessment by catheter measurements in the right superior pulmonary vein (RSPV). Immediately after examination, radiosurgery with randomized single-fraction doses of 0 and 17.5-35 Gy in 2.5-Gy steps were delivered to the RSPV antrum (target volume 5-8 cm(3)). MRI and electrophysiology were repeated 6 months after therapy, followed by histopathologic examination.
Transmural scarring of cardiac muscle tissue was noted with doses ≥32.5 Gy. However, complete circumferential scarring of the RSPV was not achieved. Logistic regressions showed that extent and intensity of fibrosis significantly increased with dose. The 50% effective dose for intense fibrosis was 31.3 Gy (odds ratio 2.47/Gy, P<.01). Heart function was not affected, as verified by MRI and electrocardiogram evaluation. Adjacent critical structures were not damaged, as verified by pathology, demonstrating the short-term safety of small-volume cardiac radiosurgery with doses up to 35 Gy.
Radiosurgery with doses >32.5 Gy in the healthy pig heart can induce circumscribed scars at the RSPV antrum noninvasively, mimicking the effect of catheter ablation. In our study we established a significant dose-response relationship for cardiac radiosurgery. The long-term effects and toxicity of such high radiation doses need further investigation in the pursuit of cardiac radiosurgery for noninvasive treatment of atrial fibrillation.
A decrease in blood lactate levels (Lac) >10% during the first hours of resuscitation in sepsis is associated with better outcomes, but the mechanisms are unclear. Our objective was to investigate ...the relationship between the time course of Lac, inflammatory response, and mitochondrial respiration during experimental sepsis.
Original data from two previously published studies were reanalyzed. In cohort 1, pigs were randomized to be resuscitated for 48 h starting at 6, 12, and 24 h, respectively, after fecal peritonitis induction (n = 8 each). Animals were categorized according to the decrease in Lac during the first 6 h of resuscitation (early if ≥10% Lac ≥10% or late if <10% or increased Lac <10%), and systemic hemodynamics, inflammatory parameters, and mitochondrial function were compared between groups. In a second group of animals with fecal peritonitis and 24 h of resuscitation (n = 16, cohort 2), abdominal regional Lac exchange was measured, and animals were categorized according to the decrease in Lac as in cohort 1.
Overall mortality was 20% (4 of 20) in the Lac ≥10% group and 60% (12 of 20) in the Lac <10% group (p = 0.022). In cohort 1, systemic hemodynamics were similar in the Lac ≥10% (n = 13) and Lac <10% (n = 11) groups. Plasma interleukin-6 levels increased during unresuscitated sepsis and decreased during resusciation in both groups, but they were lower at study end in the Lac ≥10% group (p = 0.047). Complexes I and II maximal (state 3) and resting (state 4) isolated brain mitochondrial respiration at study end was higher in the Lac ≥10% group than in the Lac <10% group, whereas hepatic, myocardial, and skeletal muscle mitochondrial respiration was similar in both groups. In cohort 2, mesenteric, total hepatic, and renal blood flow at study end was higher in the Lac ≥10% group (n = 7) than in the Lac <10% group (n = 9), despite similar cardiac output. Hepatic lactate influx and uptake in the Lac ≥10% group were approximately 1.5 and 3 times higher, respectively, than in the Lac <10% group (p = 0.066 for both).
A decrease in Lac >10% during early resuscitation (6 h) after abdominal sepsis is associated with lower levels of plasma interleukin-6 and improved brain but not hepatic or muscle mitochondrial respiration. Blood flow redistribution to abdominal organs in animals with early decrease in Lac concentrations increases the potential to both deliver and extract Lac.
The aim of this study was to compare the effects of goal-directed colloid fluid therapy with goal-directed crystalloid and restricted crystalloid fluid therapy on healthy and perianastomotic colon ...tissue in a pig model of colon anastomosis surgery.
Pigs (n = 27, 9 per group) were anesthetized and mechanically ventilated. A hand-sewn colon anastomosis was performed. The animals were subsequently randomized to one of the following treatments: R-RL group, 3 ml x kg(-1) x h(-1) Ringer lactate (RL); GD-RL group, 3 ml x kg(-1) x h(-1) RL + bolus 250 ml of RL; GD-C group, 3 ml x kg(-1) x h(-1) RL + bolus 250 ml of hydroxyethyl starch (HES 6%, 130/0.4). A fluid bolus was administered when mixed venous oxygen saturation dropped below 60%. Intestinal tissue oxygen tension and microcirculatory blood flow were measured continuously.
After 4 h of treatment, tissue oxygen tension in healthy colon increased to 150 +/- 31% in group GD-C versus 123 +/- 40% in group GD-RL versus 94 +/- 23% in group R-RL (percent of postoperative baseline values, mean +/- SD; P < 0.01). Similarly perianastomotic tissue oxygen tension increased to 245 +/- 93% in the GD-C group versus 147 +/- 58% in the GD-RL group and 116 +/- 22% in the R-RL group (P < 0.01). Microcirculatory flow was higher in group GD-C in healthy colon.
Goal-directed colloid fluid therapy significantly increased microcirculatory blood flow and tissue oxygen tension in healthy and injured colon compared to goal-directed or restricted crystalloid fluid therapy.
ON HOMOMORPHISM GRAPHS Brandt, Sebastian; Chang, Yi-Jun; Grebík, Jan ...
Forum of mathematics. Pi,
05/2024, Letnik:
12
Journal Article
Recenzirano
Odprti dostop
We introduce new types of examples of bounded degree acyclic Borel graphs and study their combinatorial properties in the context of descriptive combinatorics, using a generalization of the ...determinacy method of Marks Mar16. The motivation for the construction comes from the adaptation of this method to the
$\mathsf {LOCAL}$
model of distributed computing BCG+21. Our approach unifies the previous results in the area, as well as produces new ones. In particular, strengthening the main result of TV21, we show that for
$\Delta>2$
, it is impossible to give a simple characterization of acyclic
$\Delta $
-regular Borel graphs with Borel chromatic number at most
$\Delta $
: such graphs form a
$\mathbf {\Sigma }^1_2$
-complete set. This implies a strong failure of Brooks-like theorems in the Borel context.
Topographically organized neurons represent multiple stimuli within complex visual scenes and compete for subsequent processing in higher visual centers. The underlying neural mechanisms of this ...process have long been elusive. We investigate an experimentally constrained model of a midbrain structure: the optic tectum and the reciprocally connected nucleus isthmi. We show that a recurrent antitopographic inhibition mediates the competitive stimulus selection between distant sensory inputs in this visual pathway. This recurrent antitopographic inhibition is fundamentally different from surround inhibition in that it projects on all locations of its input layer, except to the locus from which it receives input. At a larger scale, the model shows how a focal top-down input from a forebrain region, the arcopallial gaze field, biases the competitive stimulus selection via the combined activation of a local excitation and the recurrent antitopographic inhibition. Our findings reveal circuit mechanisms of competitive stimulus selection and should motivate a search for anatomical implementations of these mechanisms in a range of vertebrate attentional systems.
Predictive analysis gradually gains importance in industry. For instance, service engineers at Siemens diagnostic centres unveil hidden knowledge in huge amounts of historical sensor data and use it ...to improve the predictive systems analysing live data. Currently, the analysis is usually done using data-dependent rules that are specific to individual sensors and equipment. This dependence poses significant challenges in rule authoring, reuse, and maintenance by engineers. One solution to this problem is to employ ontology-based data access (OBDA), which provides a conceptual view of data via an ontology. However, classical OBDA systems do not support access to temporal data and reasoning over it. To address this issue, we propose a framework for temporal OBDA. In this framework, we use extended mapping languages to extract information about temporal events in the RDF format, classical ontology and rule languages to reflect static information, as well as a temporal rule language to describe events. We also propose a
-based query language for retrieving temporal information and, finally, an architecture of system implementation extending the state-of-the-art OBDA platform Ontop.
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