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2021 ◽  
Vol 2119 (1) ◽  
pp. 012059
Author(s):  
G V Bartkus ◽  
V V Kuznetsov

Abstract The aim of this work is an experimental study of a gas-liquid flow in a rectangular slit microchannel with a cross-section of 200 × 2045 μm. Ethanol/water (95/5) mixture and nitrogen are used as working liquid and gas, accordingly. The external T-mixer is used for obtaining of wavy-annular flow pattern. The experimental data on interfacial waves and their characteristics in the meniscus area on the short side of the microchannel are obtained using high-speed visualization for a wide range of gas and liquid superficial velocities. Images are processed using the Python libraries to define the average liquid layer thickness and maximum amplitude of waves. An increase of gas superficial velocity causes decreasing in the average liquid layer thickness and maximal amplitude of the liquid layer thickness. The waves on the liquid layer surface (maximal amplitude) can be three times larger than the average liquid layer thickness for presented liquid and gas velocities. With increasing gas superficial velocities more liquid displace from the meniscus area to the liquid film on the wide side of the microchannel.


Author(s):  
Dmitrii Kulbatskii ◽  
Zakhar Shenkarev ◽  
Maxim Bychkov ◽  
Eugene Loktyushov ◽  
Mikhail Shulepko ◽  
...  

Lypd6 is a GPI-tethered protein from the Ly-6/uPAR family expressed in the brain. Lypd6 enhances the Wnt/β-catenin signaling, although its action on nicotinic acetylcholine receptors (nAChRs) have been also proposed. To investigate a cholinergic activity of Lypd6, we studied a recombinant water-soluble variant of the human protein (ws-Lypd6) containing isolated “three-finger” LU-domain. Experiments at different nAChR subtypes expressed in Xenopus oocytes revealed the negative allosteric modulatory activity of ws-Lypd6. Ws-Lypd6 inhibited ACh-evoked currents at α3β4- and α7-nAChRs with IC50 of ∼35 and 10 μM, respectively, and the maximal amplitude of inhibition of 30–50%. EC50 of ACh at α3β4-nAChRs (∼30 μM) was not changed in the presence of 35 μM ws-Lypd6, while the maximal amplitude of ACh-evoked current was reduced by ∼20%. Ws-Lypd6 did not elicit currents through nAChRs in the absence of ACh. Application of 1 μM ws-Lypd6 significantly inhibited (up to ∼28%) choline-evoked current at α7-nAChRs in rat hippocampal slices. Similar to snake neurotoxin α-bungarotoxin, ws-Lypd6 suppressed the long-term potentiation (LTP) in mouse hippocampal slices. Colocalization of endogenous GPI-tethered Lypd6 with α3β4- and α7-nAChRs was detected in primary cortical and hippocampal neurons. Ws-Lypd6 interaction with the extracellular domain of α7-nAChR was modeled using the ensemble protein-protein docking protocol. The interaction of all three Lypd6 loops (“fingers”) with the entrance to the orthosteric ligand-binding site and the loop C of the primary receptor subunit was predicted. The results obtained allow us to consider Lypd6 as the endogenous negative modulator involved in the regulation of the cholinergic system in the brain.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manon Robbe-Saule ◽  
Cyprien Morize ◽  
Yann Bertho ◽  
Alban Sauret ◽  
Anthony Hildenbrand ◽  
...  

AbstractModeling of tsunami waves generated by subaerial landslides is important to provide accurate hazard and risk assessments in coastal areas. We perform small-scale laboratory experiments where a tsunami-like wave is generated by the gravity-driven collapse of a subaerial granular column into water. We show that the maximal amplitude reached near-shore by the generated wave in our experiments is linked to the instantaneous immersed volume of grains and to the ultimate immersed deposit. Despite the differences in scale and geometry between our small-scale experiments and the larger-scale geophysical events, a rather good agreement is found between the experimental law and the field data. This approach offers an easy way to estimate the amplitude of paleo-tsunamis.


2021 ◽  
Vol 64 (3) ◽  
pp. E324-E329
Author(s):  
Daniel You ◽  
Leslie Skeith ◽  
Robert Korley ◽  
Paul Cantle ◽  
Adrienne Lee ◽  
...  

Background: Venous thromboembolism (VTE) is the second most common complication after hip fracture surgery. We used thrombelastography (TEG), a whole-blood, point-of-care test that can provide an overview of the clotting process, to determine the duration of hypercoagulability after hip fracture surgery. Methods: In this prospective study, consecutive patients aged 51 years or more with hip fractures (trochanteric region or neck) amenable to surgical treatment who presented to the emergency department were eligible for enrolment. Thrombelastography, including calculation of the coagulation index (CI) (combination of 4 TEG parameters for an overall assessment of coagulation) was performed daily from admission until 5 days postoperatively, and at 2 and 6 weeks postoperatively. All patients received 28 days of thromboprophylaxis. We used single-sample t tests to compare mean maximal amplitude (MA) values (a measure of clot strength) to the hypercoagulable threshold of greater than 65 mm, a predictor of in-hospital VTE. Results: Of the 35 patients enrolled, 11 (31%) were hypercoagulable on admission based on an MA value greater than 65 mm, and 29 (83%) were hypercoagulable based on a CI value greater than 3.0; the corresponding values at 6 weeks were 23 (66%) and 34 (97%). All patients had an MA value greater than 65 mm at 2 weeks. Patients demonstrated normal coagulation on admission (mean MA value 62.2 mm [standard deviation (SD) 6.3 mm], p = 0.01) but became significantly hypercoagulable at 2 weeks (mean 71.6 mm [SD 2.6 mm], p < 0.001). There was a trend toward persistent hypercoagulability at 6 weeks (mean MA value 66.2 mm [SD 3.8 mm], p = 0.06). Conclusion: More than 50% of patients remained hypercoagulable 6 weeks after fracture despite thromboprophylaxis. Thrombelastography MA thresholds or a change in MA over time may help predict VTE risk; however, further study is needed.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1378
Author(s):  
Ildar Daminov ◽  
Rémy Rigo-Mariani ◽  
Raphael Caire ◽  
Anton Prokhorov ◽  
Marie-Cécile Alvarez-Hérault

(1) Background: This paper proposes a strategy coupling Demand Response Program with Dynamic Thermal Rating to ensure a transformer reserve for the load connection. This solution is an alternative to expensive grid reinforcements. (2) Methods: The proposed methodology firstly considers the N-1 mode under strict assumptions on load and ambient temperature and then identifies critical periods of the year when transformer constraints are violated. For each critical period, the integrated management/sizing problem is solved in YALMIP to find the minimal Demand Response needed to ensure a load connection. However, due to the nonlinear thermal model of transformers, the optimization problem becomes intractable at long periods. To overcome this problem, a validated piece-wise linearization is applied here. (3) Results: It is possible to increase reserve margins significantly compared to conventional approaches. These high reserve margins could be achieved for relatively small Demand Response volumes. For instance, a reserve margin of 75% (of transformer nominal rating) can be ensured if only 1% of the annual energy is curtailed. Moreover, the maximal amplitude of Demand Response (in kW) should be activated only 2–3 h during a year. (4) Conclusions: Improvements for combining Demand Response with Dynamic Thermal Rating are suggested. Results could be used to develop consumer connection agreements with variable network access.


Author(s):  
Linda Sandström ◽  
Ellika Schalling ◽  
Fredrik Karlsson ◽  
Patric Blomstedt ◽  
Lena Hartelius

Purpose Deep brain stimulation (DBS) is often successful in alleviating motor symptoms of essential tremor (ET); however, DBS may also induce adverse speech effects. The caudal zona incerta (cZi) is a promising DBS target for tremor, but less is known about the consequences of cZi DBS for speech. This preliminary study examined how habitual cZi DBS and cZi stimulation at high amplitudes may affect speech function in persons with ET. Method Fourteen participants with ET were evaluated: off stimulation, on habitual cZi DBS, and with unilateral cZi stimulation at increasing stimulation amplitudes. At each stimulation condition, the participants read three 16-word sentences. Two speech-language pathologists made audio-perceptual consensus ratings of overall speech function, articulation, and voice using a visual sort and rate method. Rated functions when off stimulation, on habitual cZi DBS, and at maximal-amplitude stimulation were compared using Friedman nonparametric tests. For participants with bilateral habitual DBS ( n = 5), the effects of bilateral and unilateral stimulation were described in qualitative terms. Results Habitual cZi DBS had no significant group-level effect on any of the investigated speech parameters. Maximal-amplitude stimulation had a small but significant negative effect on articulation. Participants with reduced articulatory precision ( n = 9) had more medially placed electrodes than the nonaffected group ( n = 5). Bilateral and unilateral left stimulation had comparable effects on speech. Conclusions Findings from this preliminary study of cZi DBS indicate that speech is generally not affected by stimulation at habitual levels. High-amplitude cZi stimulation may, however, induce adverse effects, particularly on articulation. Instances of decreased articulatory function were associated with stimulation of more medial electrode contacts, which could suggest cerebello-rubrospinal involvement.


2021 ◽  
pp. 6-16
Author(s):  
V. N. Danilov

On the basis of computer modelling spectra and pulses of signals of the combined angle beam probe with composite piezoplate with piezoelectric ceramics several types it is shown, that short pulses with the greatest amplitudes are provided with use in piezoplate segnetosoft ceramics (for example, types PZT-5H, APC-850). At use piezoelectric ceramics intermediate type (CTS-19) the maximal amplitude of a pulse of the angle beam probe with such piezoplate appears much less, than for segnetosoft ceramics. Application in composite piezoplate piezoelectric ceramics such as TKS-21 (with the increased anisotropy of factors of electromechanical coupling coefficients) is inexpedient because of small amplitude of a pulse.Use of polymeric matrixes with small wave resistance provides additional increase of amplitude and reduction of length of pulses of angle beam probes.


2020 ◽  
Vol 9 (12) ◽  
pp. 3883
Author(s):  
Sang Min Kim ◽  
Sang-Il Kim ◽  
Gina Yu ◽  
June-Sung Kim ◽  
Seok In Hong ◽  
...  

(1) Background: The currently proposed criteria for diagnosing overt disseminated intravascular coagulation (DIC) are not suitable for early detection of DIC. Thromboelastography (TEG) rapidly provides a comprehensive assessment of the entire coagulation process and is helpful as a guide for correcting consumptive coagulopathy in sepsis-induced DIC. This study aimed to investigate the role of TEG in the prediction of DIC in patients with septic shock. (2) Methods: TEG was conducted prospectively in 1294 patients with septic shock at the emergency department (ED) between January 2016 and December 2019. After exclusion of 405 patients with “do not attempt resuscitation” orders, those refusing enrollment, and those developing septic shock after ED presentation, 889 patients were included. DIC was defined as an International Society on Thrombosis and Hemostasis score ≥ 5 points within 24 h. (3) Results: Of the 889 patients with septic shock (mean age 65.6 ± 12.7 years, 58.6% male), 158 (17.8%) developed DIC. TEG values, except lysis after 30 min, were significantly different between the DIC and non-DIC groups. Among the TEG values, the maximal amplitude (MA) had the highest discriminating power for DIC, with an area under the curve of 0.814. An MA < 60 indicated DIC with 79% sensitivity, 73% specificity, and 94% negative predictive value. Based on multivariable analysis, MA < 60 was an independent predictor of DIC (odds ratio 5.616 (95% confidence interval: 3.213–9.818)). (4) Conclusions: In patients with septic shock, the MA value in TEG could be a valuable tool for early prediction of DIC.


2020 ◽  
Author(s):  
Yirao Tao ◽  
Jing Xu ◽  
Samira Yerima Bako ◽  
Xiaobo Yao ◽  
Donghui Yang

Abstract Objective: Apical hypertrophic cardiomyopathy (ApHCM) is a phenotypic variant of nonobstructive HCM. ApHCM is characterized by left ventricular hypertrophy involve the distal apex. The electrocardiographic character of ApHCM can mimic non-ST elevation acute coronary syndrome (NSTEACS) which triggers a series of studies and treatments that may be unnecessary. This study aimed to clarify the ECG differences between the two diseases.Methods: Initial electrocardiogram (ECG) recordings of 41 patients with ApHCM and 72 patients with NSTEACS were analyzed retrospectively. We analyzed the voltage of negative T (neg T) wave, R wave and the change of ST-segment in the 12-lead ECGs as well as the number of leads with neg T waves.Results: Across the 12-lead ECGs, the magnitude of R wave significantly differed between ApHCM and NSTEACS in 10 leads excluding leads aVR and V1. ApHCM was associated with a greater maximal amplitude of R wave in lead V5 (3.13±1.08 vs. 1.38±0.73, P=0.000). The magnitude of T wave significantly differed between ApHCM and NSTEACS in 10 leads excluding leads II and V1. ApHCM was associated with a greater maximal amplitude of neg T wave in lead V4 (0.85±0.69 vs. 0.35±0.23, P=0.000). The frequency of giant neg T (1mv or more) wave was higher in ApHCM (36.5% vs. 0%, P=0.000). The magnitude of ST-segment deviation significantly differed between ApHCM and NSTEACS in 10 leads excluding leads aVF and V2. ApHCM was associated with a greater maximal amplitude of ST-segment depression in lead V5 (0.19±0.07 vs. 0.03±0.06, P=0.000). The number of leads with neg T waves also differed between ApHCM and NSTEACS (6.75±1.42 vs. 6.08±1.51, P=0.046). The sum of R wave in lead V5, neg T wave in lead V6 and ST-segment depression in lead V4>2.585 mV identified ApHCM with 90.2% sensibility and 87.5% specificity, representing the highest diagnostic accuracy.Conclusions: Compared with NSTEACS patients, ApHCM patients presented higher R waves and neg T wave voltage as well as a greater ST-segment depression in the 12-lead ECGs.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2424-2424
Author(s):  
Marisol Betensky ◽  
Ernest Amankwah ◽  
Stephanie Brandal ◽  
Allen Everett ◽  
Neil A Goldenberg

Background:Knowledge of prognostic factors for the development of post-thrombotic syndrome (PTS) is limited, particularly in the pediatric population. Elevated plasma levels of D-dimer and FVIII, both markers of coagulation activation and inflammation, are associated with an increased risk of adverse thrombosis outcomes, including PTS, in children. Similarly, increased levels of inflammatory cytokines, such as interleukin-6 (IL-6), have been associated with venous endothelial dysfunction and fibrosis, suggesting a potential role in the development of PTS. Given the strong interplay between inflammation and coagulation, the aims of this study were to: (1)Investigate a hypothesized association between increased levels of plasma cytokines during the first 3 months post-diagnosis of deep venous thrombosis (DVT) with the development of PTS in patients <21 years old; and (2) to investigate an association between increased plasma coagulability during the first 3 months post-DVT diagnosis with the development of PTS. Methods:We used banked plasma biospecimens and masked clinical data from an ongoing NHLBI-sponsored multinational multicenter trial of VTE treatment in patients <21 years old (the Kids-DOTT trial, NCT00687882). All patients with an extremity DVT who underwent PTS assessment at 1 year were included in this analysis. The Clot Formation and Lysis (CloFAL) spectrophotometric assay was performed, as previously described, on banked plasma samples obtained at 6 weeks and 3 months post-VTE diagnosis. All samples were pre-treated with heparinase prior to assay. Assay measurements included maximal amplitude of the CloFAL waveform (MA), time to maximal amplitude (T1), and area under the curve at 60 minutes, indexed to that of the pooled normal plasma standard (AUC60). Levels of IL-6, IL-8, IL-12/IL-23p40, IL-17, vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, interferon (IFN)-γ and C-reactive protein (CRP) were measured via V-Plex kit (Meso Scale Discovery, Rockville, MD). For each patient, the change in each laboratory parameter between the 3 months and 6 weeks post-VTE time points was calculated. The diagnosis of PTS was made at the one year follow-up assessment using the Manco-Johnson Instrument. Descriptive statistics were used to summarize data on patient and VTE characteristics as well as PTS outcome. Putative prognostic factors for PTS (age group, complete thrombus occlusion, CloFAL parameters, and inflammatory cytokines) were evaluated via univariate logistic regression, using odds ratios (OR) and 95% confidence intervals (CI). Variables with P-values <0.1 in univariate analyses were pre-specified for inclusion in an adjusted (multivariate) regression analysis. The blind was maintained in the Kids-DOTT trial throughout data transfer and analysis. Results: A total of 80 patients were included in the present analysis. Median age was 12.7 years (range 0.04 - 20.8 years). Patient and VTE characteristics at baseline, as well as PTS outcomes, are summarized in Table 1. PTS developed in 34% of patients by the 1 year post-VTE follow up visit. Univariate logistic regression analysis identified change in CloFAL AUC60 (OR=1.46, 95%CI=1.02-2.09; P=0.036) and complete thrombus occlusion at 6 weeks post-VTE (OR=3.29, 95%CI=0.93-11.6; P=0.064) as putative prognostic factors for PTS (Table 2). After adjustment in multivariate regression, change in CloFAL AUC60 remained the only possibly-significant (P=0.06) independent prognostic factor for PTS. Specifically, for each 1 A.U. increase in CloFAL AUC from the 6 weeks to 3 months post-VTE diagnosis, the odds of PTS increased by more than 40% (OR=1.43, 95%CI=0.99-2.08; Table 3). Changes in none of the measured inflammatory cytokines were prognostic of PTS. Conclusions: PTS developed in 34% of patients <21 years old enrolled in enrolled in an ongoing multicenter trial of provoked DVT treatment. A rise in plasma coagulability during the first 3 months post-DVT diagnosis, as measured by increase in AUC60 in the CloFAL assay is a candidate prognostic factor for PTS in patients <21 years old with provoked DVT. Future work should seek to investigate the mechanisms of increased plasma coagulability following a course of anticoagulation therapy in young VTE patients, and to substantiate findings of its potential prognostic significance for the development of PTS. Disclosures Everett: ImmunArray: Consultancy, Patents & Royalties. Goldenberg:NIH: Other: research support and salary support.


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