Cycles Of Deflation Research Articles

Characterization of fatigue behavior of 3D printed pneumatic fluidic elastomer actuators

Soft robots have gained significant interest due to their high flexibility and adaptability to various working conditions. Recent advancements in engineering and innovative materials have enabled the design and production of sophisticated soft robotic systems with enhanced capabilities. This study aims to evaluate the fatigue behavior of bellow-type pneumatic soft actuators fabricated through fused filament fabrication (FFF) using thermoplastic polyurethane (TPU), compared to silicone rubber cast actuators. The actuators were equipped with resistive flex sensors to monitor bending motion, and fatigue tests were performed with cycles of inflation and deflation until failure. Results showed that 3D printed TPU actuators could withstand a significant number of cycles before failure, with an average of 6410 cycles at 3 bar pressure, compared to 3439 cycles at 1 bar pressure for the silicone actuators. The study identified a set of fabrication parameters that positively affect the durability of TPU actuators, providing valuable insights for replicating these results. Additionally, the study established a plausible range of utilization for 3D-printed FFF actuators in terms of the number of cycles they can endure, offering critical data for engineers and designers to make informed decisions about the design and application of these actuators in various practical scenarios. The findings demonstrate the potential of FFF for producing durable, long-lasting pneumatic soft actuators.

Stacking of Distributed Dynamic Strain Reveals Link Between Seismic Velocity Changes and the 2020 Unrest in Reykjanes

AbstractIn this study, we measure seismic velocity variations during two cycles of crustal inflation and deflation in 2020 on the Reykjanes peninsula (SW Iceland) by applying coda wave interferometry to ambient noise recorded by distributed dynamic strain sensing (also called DAS). We present a new workflow based on spatial stacking of raw data prior to cross‐correlation which substantially improves the spatial coherency and the time resolution of measurements. Using this approach, a strong correlation between velocity changes and ground deformation (in the vertical and horizontal direction) is revealed. Our findings may be related to the infiltration of volcanic fluids at shallow depths, even though the concurrent presence of various processes complicates the reliable attribution of observations to specific geological phenomena. Our work demonstrates how the spatial resolution of DAS can be exploited to enhance existing methodologies and overcome limitations inherent in conventional seismological data sets.

Potential Effects of Ischemic Postconditioning and Changes in Heat Shock Protein 72 in Patients with Acute Myocardial Infarction without Prodromal Angina.

The effectiveness of ischemic postconditioning (iPoC) in patients with ST-elevation myocardial infarction (STEMI) without ischemic preconditioning has not been determined. Therefore, we investigated the impact of iPoC and its potential mechanism related to heat shock protein 72 (HSP72) induction on myocardial salvage in patients with STEMI without prodromal angina (PA).We retrospectively analyzed data from 102 patients with STEMI with successful reperfusion among 323 consecutive patients with acute coronary syndrome. Among these, 55 patients with iPoC (iPoC (+) ) underwent 4 cycles of 60-second inflation and 30-second deflation of the angioplasty balloon. Both the iPoC (+) and iPoC (-) groups were divided into 2 further subgroups: patients with PA (PA (+) ) and those without (PA (-) ). We analyzed HSP72 levels in neutrophils, which were measured until 48 hours after reperfusion. I-123 β-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) scintigraphy was performed within a week of reperfusion therapy. In 64% of patients, thallium-201 (TL) scintigraphy was performed 6-8 months after STEMI onset.Using BMIPP and TL, in the PA (-) subgroups, the iPoC (+) group had a significantly greater myocardial salvage ratio than the iPoC (-) group. iPoC was identified as an independent predictor of the myocardial salvage ratio. The HSP72 increase ratio was significantly elevated in the iPoC (+) PA (-) group. Importantly, the myocardial salvage effect in patients without PA was significantly correlated with the HSP72 increase ratio, which was greater in patients with iPoC.These results suggest the potential impact of iPoC via HSP72 induction on myocardial salvage; however, the effects may be limited to patients with STEMI without PA.

Adjunct remote ischemic conditioning to PCI in ST-segment elevation myocardial infraction patients: Systematic review and meta-analysis

Abstract Introduction ST-segment elevation myocardial infarction (STEMI) is the most dangerous presentation of the acute coronary syndrome (ACS). Throughout the last three decades, clinicians have been attempting to reduce the short and long-term major adverse cardiac events (MACE) associated with STEMI. Remote ischemic conditioning (RIC) is one of the new adjunctive modalities to PCI in treating STEMI patients whereby brief reversible episodes of ischemia and reperfusion are applied to the tissue (by alternative cycles of inflation and deflation of a blood pressure cuff on the upper or lower limb) confers global protection and renders remote tissues resistant to ischemia/reperfusion injury. This review aims to provide reliable evidence from published randomized controlled trials (RCTs) regarding whether RIC is beneficial for STEMI patients or not. Methods We followed the PRISMA guidelines during the preparation of this systematic review and meta-analysis. A computer literature search for (PubMed, Web of Science, Scopes, and Google Scholar) was carried out. We included RCT, comparing the remote ischemic conditioning, regardless of its timing of application to PCI, with either placebo or sham procedure, in terms of both short-term and long-term cardio protection. Outcomes of myocardial salvage index, myocardial infarction size, and left ventricular ejection fraction were pooled as the standardized mean difference between the two groups from baseline to endpoint. Results 11 RCTs (7151 patients), were included in this analysis. The overall effect on short-term outcomes, was in favor of PCI only in terms of myocardial salvage index(P value=0.04, 95% CI [0.00-0.08]), and left ventricular ejection fraction(P value=0.05, 95% CI [0.02,2.16]), while the adjunctive application of remote ischemic conditioning was beneficial in terms of: myocardial infarct size ( P value=0.004, 95% CI [-3.22,-0.62]). Regarding the long-term outcomes, the overall effect did not show any benefit in either of the two groups in terms of: major adverse cardiac and cerebrovascular events (MACCE) (P value=0.13, 95% CI [0.48,1.10]), hospitalization for heart failure (P value=1.00, 95% CI [0.83,1.20]), and cardiac death (P value=0.91, 95% CI [0.73,1.32]). Conclusion The adjunctive application of RIC to PCI during treatment of STEMI patients showed a beneficial effect only on short-term reduction of myocardial infarct size, nevertheless, it was not of benefit regarding the other short and long-term metrics of myocardial salvage and left ventricular function.

Numerical models of restless caldera volcanoes

Caldera volcanoes undergo cycles of inflation and deflation on both long and short timescales. This study uses the Distinct Element Method to model numerically a pressurized magma reservoir within a brittle host rock in order to investigate the effects on these cycles of: (i) host rock strength, (ii) strain localization, (iii) fault reactivation and (iv) surface deformation. Additionally, the critical over- or under-pressure within the magma reservoir - i.e. the pressure prior to reservoir roof failure leading to eruption or collapse - is determined. The model results indicate that with increasing number of inflation/deflation cycles, the host rock weakens and strain is increasingly localized onto faults that are reactivated during both inflation and deflation. Consequently, both the critical over- and under-pressure magnitudes for eruption or collapse decrease from cycle to cycle. The relationships of surface uplift and subsidence with magma reservoir over- and under-pressure, respectively, display hysteresis behavior. This means that the magnitude of elevation change as a function of the change of magma pressure differs for inflating and deflating magma reservoirs. These results provide new insight into the relationships between structural development, elevation change, pressure change, and the generation of potential eruptive pathways at caldera volcanoes.

Coated microbubbles swim via shell buckling

Engineered microswimmers show great promise in various biomedical applications. However, their application is hindered by the slow mobility, limited maneuverability and poor biocompatibility. Lipid coated microbubbles have high compressibility and are already approved for clinical use as diagnostic ultrasound contrast agents. Here we experimentally investigate the swimming motion of these microbubbles under external cyclic overpressure. A net displacement was generated via reproducible and non-destructive cycles of deflation and re-inflation of the microbubble. We also propose a numerical model which allows a maximum swimming speed on the order of meters per second, which falls in the range of blood flow velocity in large vessels. Unlike the acoustic radiation force technique, where the displacement is always directed along the axis of ultrasound propagation, here, the direction of propulsion is controlled in the shell reference frame. This provides a solution toward controlled steering for ultrasound molecular imaging and drug delivery.

Remote ischaemic conditioning combined with bimanual task training to enhance bimanual skill learning and corticospinal excitability in children with unilateral cerebral palsy: a study protocol of a single centre, phase II randomised controlled trial

IntroductionChildren with unilateral cerebral palsy (UCP) have difficulty in bimanual coordination that restricts the child’s independence in daily activities. Although several efficacious interventions to improve bimanual coordination exist, these interventions...

Drift Corrected Seafloor Pressure Observations of Vertical Deformation at Axial Seamount 2018–2021

AbstractAxial Seamount is a seafloor volcano with frequent eruptions and periodic cycles of inflation and deflation. Seafloor pressure gauges monitor vertical deformation with time, but inherent instrumental drift complicates and biases geodetic interpretation. A drift corrected pressure recorder was deployed on Axial Seamount on 6 July 2018, at coordinates 45° 57.29′ North latitude, −130° 0.56′ East longitude, depth 1,535 m. This system includes two independent quartz‐resonant pressure gauges, which nearly continuously observe the seafloor pressure. At regular intervals, the gauges are calibrated in situ with a modified deadweight tester at a pressure within 98% of the nominal seafloor pressure. Using the calibration data, the drift of each gauge has been modeled as a simple linear plus decaying exponential function of time. The two estimated linear sensor drift rates are 0.45 ± 0.12 and 0.36 ± 0.08 kPa/year; the modeled sensor drift represents a significant error if uncorrected. The standard deviations of the drift model residuals are of order 0.06 kPa or 6 mm depth equivalent. Once calibrated, the difference between the two seafloor pressure timeseries exhibits a RMS deviation of ±6 mm at the 90% confidence limit and a linear trend less than 1 mm/year. A time series from July 2018 to December 2021 tracks the inflation of Axial Seamount with differing inflation rates over different time intervals.

Deformation at the open-vent Erebus volcano, Antarctica, from more than 20 years of GNSS observations

Erebus volcano on Ross Island in Antarctica is an iconic open-vent volcano that has hosted a convecting anorthoclase-rich phonolite lava lake for at least 50 years. Recent magnetotelluric observations have imaged a conduit system originating at least 60km below Erebus. This terminates in a seismically-imaged shallow magma reservoir about 500m NW of the crater with an upper surface at about 500m depth. A narrow and inclined terminal conduit system connects the shallow reservoir to the lava lake. Bomb-ejecting Strombolian eruptions from the lava lake and sporadically active adjacent vents are common. Larger eruptive activity with locally substantially elevated hazard has also been observed, including exceptionally energetic Strombolian activity in 1984 and an Inner Crater phreatic explosion in 1993. Despite sustained degassing and frequent eruptions, geochemical data show the composition of the lava has remained stable for the last 17ka, consistent with the long-lived transcrustal magmatic system underlying the lake.Global Navigation Satellite System (GNSS) data collection on Ross Island began in the late 1990s with campaign observations. In the early 2000s, additional benchmarks were added closer to the summit of Erebus and continuous GNSS (cGNSS) sites were co-located with a seismic network. Today, seven cGNSS sites operate on the summit plateau and flanks of the volcano, and a network of eight campaign benchmarks has been surveyed episodically.We present the first comprehensive geodetic data analysis and modeling results integrating these more than two decades of data collected at Erebus. We resolve long-term subsidence of Ross Island, which a simple viscoelastic model links to the long-term growth of Erebus over the last 20ka. The data also show multi-year cycles of inflation and deflation in the summit area, consistent with activity in the shallow summit magmatic system. These small amplitude (several mm/yr) transient dynamics suggest multi-year pulses of pressurization and depressurization, or geometric changes within the shallow magmatic system that we can reproduce with analytical source models. The most recent inflation pulse lasted from November 2020 until March 2022 when several stations moved radially away from the shallow magmatic system and upwards at 10–15mm/yr. Based on prior cycles, this deformation may result in increased eruptive activity suggesting that continued and enhanced surveillance of Erebus is warranted. These observations contrast with the long-term general stability of the lava lake, but reflect Inner Crater dynamics, which can include changes in lava lake elevation and associated topographic changes of over 20m on multi-year time scales. Our results emphasize the value of long-term and campaign-aided high-accuracy GNSS observations at open-vent volcanoes. This is especially true for volcanoes like Erebus which are remote and may only be accessible for a few months a year, and that deform at amplitudes and periods that may be difficult to resolve with satellite-based radar.

Neuroprotective effect of remote ischemic preconditioning in patients undergoing cardiac surgery: A randomized controlled trial.

BackgroundThe neuroprotective effect of remote ischemic preconditioning (RIPC) in patients undergoing elective cardiopulmonary bypass (CPB)-assisted coronary artery bypass graft (CABG) or valvular cardiac surgery remains unclear.MethodsA randomized, double-blind, placebo-controlled superior clinical trial was conducted in patients undergoing elective on-pump coronary artery bypass surgery or valve surgery. Before anesthesia induction, patients were randomly assigned to RIPC (three 5-min cycles of inflation and deflation of blood pressure cuff on the upper limb) or the control group. The primary endpoint was the changes in S-100 calcium-binding protein β (S100-β) levels at 6 h postoperatively. Secondary endpoints included changes in Neuron-specific enolase (NSE), Mini-mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA) levels.ResultsA total of 120 patients [mean age, 48.7 years; 36 women (34.3%)] were randomized at three cardiac surgery centers in China. One hundred and five patients were included in the modified intent-to-treat analysis (52 in the RIPC group and 53 in the control group). The primary result demonstrated that at 6 h after surgery, S100-β levels were lower in the RIPC group than in the control group (50.75; 95% confidence interval, 67.08 to 64.40 pg/ml vs. 70.48; 95% CI, 56.84 to 84.10 pg/ml, P = 0.036). Compared to the control group, the concentrations of S100-β at 24 h and 72 h and the concentration of NSE at 6 h, 24 h, and 72 h postoperatively were significantly lower in the RIPC group. However, neither the MMSE nor the MoCA revealed significant between-group differences in postoperative cognitive performance at 7 days, 3 months, and 6 months after surgery.ConclusionIn patients undergoing CPB-assisted cardiac surgery, RIPC attenuated brain damage as indicated with the decreased release of brain damage biomarker S100-β and NSE.Clinical trial registration[ClinicalTrials.gov], identifier [NCT01231789].

The Aeolian Environment in Glen Torridon, Gale Crater, Mars

AbstractThe Mars Science Laboratory (MSL) rover spent a full martian year exploring the phyllosilicate‐bearing Glen Torridon trough on the flank of Aeolis Mons in Gale crater, enabling in‐depth assessment of aeolian processes. MSL encountered erosional and depositional features recording a long aeolian history. The trough has served as a long‐term conduit for sand transport, probably involving many cycles of sand accumulation and deflation. Rock abrasion textures indicate sand‐driving winds blowing W‐SW (opposite of abrasion textures on the Greenheugh Pediment above the trough floor). Indurated megaripple surfaces with 2–5 mm grains contrast with seasonally active ripples having finer maximum grain sizes, indicating more vigorous saltation in the past. Active ripples display a broad continuum of wavelengths, as well as coarser grains at crests than troughs, consistent with origins as impact ripples. Orientations of a wind streak extending from a large ripple field, and sandy wind tails behind obstacles, indicate sand is driven W‐SW in the current era, approximately along the trough axis. Erosion of drill tailings piles was strongly seasonal, enhanced during late spring and early summer (perihelion). Climate modeling suggests W‐SW sand transport can be attributed to seasonal enhancement of nighttime regional winds entering Gale crater from the N, combined with local katabatic winds flowing down the slopes of Aeolis Mons. However, it is unclear whether sand transport at Glen Torridon is primarily from these wind components combining and acting simultaneously, or occurring in serial at different times of night; field evidence supports both possibilities.

Preventing Ischemic Cerebrovascular Events in High-Risk Patients With Non-disabling Ischemic Cerebrovascular Events Using Remote Ischemic Conditioning: A Single-Arm Study

Background: Secondary stroke prevention after a high-risk, non-disabling ischemic cerebrovascular event needs to be enhanced. The study was conducted to investigate whether remote ischemic conditioning (RIC) is effective in preventing recurrent ischemic events within 3 months.Methods: This was a four-center, single-arm, open-label Phase IIa futility trial (PICNIC-One Study). Adult patients (≥18 years of age) who had an acute minor ischemic stroke (AMIS) with a National Institutes of Health Stroke Scale score ≤ 3 or a transient ischemic attack (TIA) with moderate-to-high risk of stroke recurrence (ABCD score ≥ 4) within 14 days of symptom onset were recruited. Patients received RIC as adjunctive therapy to routine secondary stroke prevention regimen. RIC consisted of five cycles of 5-min inflation (200 mmHg) and 5-min deflation of cuffs (45 min) on bilateral upper limbs twice a day for 90 days.Results: A total of 285 patients met the study criteria, of which 167 provided signed informed consent and were enrolled. Data from 162 were analyzed with five subjects excluded. Recurrent AIS/TIA occurred in 6/162 (3.7%) patients within 3 months, with no occurrence of hemorrhagic stroke. The top three adverse events were upper limb pain (44/162, 27.2%), petechia (26/162, 16.0%), and heart palpitation (5/162, 3.1%). About 68 (42.0%) subjects completed ≥ 50% of 45-min RIC sessions.Conclusions: RIC is a safe add-on procedure and it has a potential benefit in reducing recurrent cerebrovascular events in patients with high-risk, non-disabling ischemic cerebrovascular events as the risk of stroke/TIA events is lower than expected; however, its compliance needs to be improved. Our study provides critical preliminary data to plan a large sample size, randomized controlled clinical study to systematically investigate the safety and efficacy of RIC in this population.

Caldera Collapse as the Trigger of Chaos and Fractured Craters on the Moon and Mars

AbstractChaotic terrains are broad regions on Mars characterized by the disruption of the basaltic bedrock into polygonal blocks separated by deep fractures. To date, the proposed genetic scenarios often involve the occurrence of subsurface ice or liquid H2O. Nevertheless, similar features also occur within some craters on the Moon, namely floor‐fractured craters (FFCs), where water ice reservoirs are not present. We propose a new formation mechanism for Martian chaotic terrains as well as for lunar and Martian FFCs. The proposed mechanism does not require a major role of water but multiple cycles of inflation and deflation of a buried magma chamber. This process results in a particular type of caldera collapse, called the piecemeal (or chaotic) caldera collapse. A series of analog experiments show both geometrical and quantitative correspondence with natural case studies: Arsinoes Chaos (Mars), an unnamed FFC (Mars), and Komarov crater (FFC on the Moon).

Effect of remote ischemic post conditioning on incidence of contrast induce acute kidney injury in STEMI patients undergoing primary percutaneous coronary intervention

Abstract Funding Acknowledgements Type of funding sources: None. Background Primary percutaneous coronary intervention (PPCI) is a treatment of choice in ST elevation myocardial infarction patients (STEMI). However, this approach could increase the risk of contrast induce acute kidney injury (CI-AKI) due to iodinated contrast exposure to the patient. Remote ischemic post conditioning (RIPostC) is a non-invasive and simple method that not only has cardioprotective but also renoprotective effect that could prevent the incidence of CI-AKI. Purpose The aim of this study was to investigate the effect of RIPostC to CI-AKI incident in STEMI patients undergoing PPCI. Methods This study uses pre and post-test only with control group design with experimental research designs. Data was taken at the Instalasi Pelayanan Jantung Terpadu (IPJT) RSUP Dr. M. Djamil Padang from June 2019 until March 2020, there were 66 patients with ST-segment elevation myocardial infarction (STEMI) being performed RIPostC procedure. with intermittent ischaemia and reperfusion applied to the arm through five cycles of 5-min inflation and 5-min deflation of an automated cuff device after crossing wire. Creatinine and eGFR were measured pre and 48 hours post PPCI. CI-AKI diagnosis based on increase of creatinine level >0,5 mg/dL or 25% from baseline value on 48 hours after PPCI. Bivariate analysis was performed to determine the effect RIPostC to incidence of CI-AKI using the Chi-square test. Result A total of 66 patients who underwent the PPCI procedure were divided into two groups RIPostC (n = 33) and without RIPostC (n = 33). The baseline characteristic in both of group was similar. The RIPostC group had a lower CI-AKI incident if we compare with the non RIPostC (15,2% vs 42,4%, p < 0,05). Conclusion RIPostC effectively reduced incidence of CI-AKI in STEMI patient who underwent the PPCI with statistically significant result. Effect of RIPostC in CI-AKI post PPCIPPCICI-AKI (+)(f/%)CI-AKI (-)(f/%)Total(f/%)OR (95% CI)p valueRIPostC (+)5 (15,2)28 (84,8)33 (100)0,024 (0,07-0,76)0,03*bRIPostC (-)14 (42,4)19 (57,6)33 (100)Total19 (28,8)47 (71,2)66 (100)* significant p if < 0,05b, chi square testAbstract Figure. Effect of RIPostC in CI-AKI post PPCI

Effect of remote ischemic post conditioning on kidney function in STEMI patients undergoing primary percutaneous coronary intervention

Abstract Funding Acknowledgements Type of funding sources: None. Background Primary percutaneous coronary intervention (PPCI) is a treatment of choice in ST elevation myocardial infarction patients (STEMI). However, this approach could affect the kidney function due to iodinated contrast exposure to the patient. Remote ischemic post conditioning (RIPostC) is a non-invasive and simple method that not only has cardioprotective but also renoprotective effect for kidney function. Purpose The aim of this study was to investigate the effect of RIPostC to kidney function in STEMI patients undergoing PPCI. Methods This study uses pre and post-test only with control group design with experimental research designs. Data was taken at an Indonesian Heart Center from June 2019 until March 2020, there were 66 patients with ST-segment elevation myocardial infarction (STEMI) being performed RIPostC procedure with intermittent ischaemia and reperfusion applied to the arm through five cycles of 5-min inflation and 5-min deflation of an automated cuff device after crossing wire. Creatinine and eGFR were measured pre and 48 hours post PPCI. Kidney function were determined by eGFR post PPCI, ΔeGFR (pre and 48 hours post PPCI), creatinine post PPCI and Δcreatinine (pre and 48 hours post PPCI). Bivariate analysis was performed to determine the effect RIPostC to kidney function using the Chi-square test. Result A total of 66 patients who underwent the PPCI procedure were divided into two groups RIPostC (n = 33) and without RIPostC (n = 33). The baseline characteristic in both of group was similar. We found that there were no differences of eGFR (70,46 ± 23,06 vs 65,88 ± 23,36, p = 0,424), ΔeGFR (0 [-34,68 - 37,32] vs 0 [-121,53 - 29,70], p value= 0,406), creatinine (1,00 [0,70 - 4,60] vs 1,20 [0,60-4,10], p value= 0,633) and Δcreatinine (0 [-1,20-1,10] vs 0 [-0,50-0,90], p value= 0,390) RIPostC group had a lower CI-AKI incident if we compare with the non RIPostC (15,2% vs 42,4%, p < 0,05). Conclusion Remote ischaemic conditioning does not significantly improve kidney function (eGFR, ΔeGFR, creatinine and Δcreatinine) in patients with STEMI undergoing PPCI The differences of kidney functionVariableRIPostCControlp valueeGFR post PPCI (ml/min/1,73 m2), mean70,46 ± 23,0665,88 ± 23,360,424aΔeGFR(ml/min/1,73 m2), median0 [-34,68 - 37,32]0 [-121,53 - 29,70]0,406bCreatinine post PPCI (mg/dL), median1,00 [0,70 - 4,60]1,20 [0,60-4,10]0,633bΔcreatinine (mg/dL), median0 [-1,20-1,10]0 [-0,50-0,90]0,390ba = Independent sample T testb = mann whitney testAbstract Figure. ΔeGFR and Δcreatinine pre and post PPCI

The Effect of Remote Ischemic Preconditioning on Serum Creatinine in Patients Undergoing Partial Nephrectomy: A Randomized Controlled Trial.

Renal function declines after partial nephrectomy due to ischemic reperfusion injury induced by surgical insult or renal artery clamping. The effect of remote ischemic preconditioning (RIPC) on reducing renal injury after partial nephrectomy has not been studied regarding urinary biomarkers. Eighty-one patients undergoing partial nephrectomy were randomly assigned to either RIPC or the control group. RIPC protocol consisted of four cycles of five-min inflation and deflation of a blood pressure cuff to 250 mmHg. Serum creatinine levels were compared at the following time points: preoperative baseline, immediate postoperative, on the first and third days after surgery, and two weeks after surgery. The incidence of acute kidney injury, other surgical complication rates, and urinary biomarkers, including urine creatinine, β-2 microglobulin, microalbumin, and N-acetyl-beta-D-glucosaminidase were compared. Split renal functions measured by renal scan were compared up to 18 months after surgery. There was no significant difference in the serum creatinine level on the first postoperative day (median (interquartile range) 0.87 mg/dL (0.72–1.03) in the RIPC group vs. 0.92 mg/dL (0.71–1.12) in the control group, p = 0.728), nor at any other time point. There was no significant difference in the incidence of acute kidney injury. Secondary outcomes, including urinary biomarkers, were not significantly different between the groups. RIPC showed no significant effect on the postoperative serum creatinine level of the first postoperative day. We could not reveal any significant difference in the urinary biomarkers and clinical outcomes. However, further larger randomized trials are required, because our study was not sufficiently powered for the secondary outcomes.

Remote Ischemic Preconditioning for Prevention of Contrast-Induced Acute Kidney Injury in Patients of CKD Stage III and IV Undergoing Elective Coronary Angiography: A Randomized Controlled Trial.

Introduction:Contrast-induced acute kidney injury (CI-AKI) is a serious complication of coronary angiography (CA). The aim of this randomized, parallel group, single blind, sham-controlled trial was to assess the safety and efficacy of the remote ischemic preconditioning on the prevention of CI-AKI.Methods:Patients of 18–80 years of age with CKD 3 and 4, who were admitted for elective coronary angiography in a tertiary care hospital in eastern India were randomized in a 1:1 ratio to standard care with ischemic preconditioning (n = 45; intermittent arm ischemia through 4 cycles of 5-min inflation and 5-min deflation of a blood pressure cuff) or with standard care and sham ischemic preconditioning (n = 42). Overall, both study groups were at moderate risk of developing CI-AKI according to the Mehran risk score. The primary endpoint was the incidence of CI-AKI, defined as an increase in serum creatinine ≥25% or ≥0.5 mg/dL above baseline at 48 h after contrast medium exposure.Results:CI-AKI occurred in 8 patients (19.04%) in the control group and 2 (4.4%) in the remote ischemic preconditioning group (odds ratio, 0.198, 95% confidence interval, 0.087 to 0.452; P = 0.04). No major adverse events were related to remote ischemic preconditioning.Conclusions:This study indicates that remote ischemic preconditioning is a simple and well-tolerated procedure, which reduces the incidence of CI-AKI in CKD 3 and 4 patients undergoing coronary angiography.

REMOTE Ischemic Perconditioning Among Acute Ischemic Stroke Patients in Catalonia: REMOTE-CAT PROJECT.

Rationale: Remote ischemic perconditioning during cerebral ischemia (RIPerC) refers to the application of brief episodes of transient limb ischemia commonly to a limb, it represents a new safe, simple and low-cost paradigm in neuroprotection.Aim and/or Hypothesis: To evaluate the effects of RIPerC on acute ischemic stroke (AIS) patients, applied in the ambulance, to improve functional outcomes compared with standard of care.Sample Size Estimates: A sample size of 286 patients in each arm achieves 80% power to detect treatment differences of 14% in the outcome, using a two-sided binomial test at significance level of 0.05, assuming that 40% of the control patients will experience good outcome and an initial misdiagnosis rate of 29%.Methods and Design: We aim to conduct a multicentre study of pre-hospital RIPerC application in AIS patients. A total of 572 adult patients diagnosed of suspected clinical stroke within 8 h of symptom onset and clinical deficit >0 according to prehospital rapid arterial occlusion evaluation (RACE) scale score will be randomized, in blocks of size 4, to RIPerC or sham. Patients will be stratified by RACE score scale. RIPerC will be started in the ambulance before hospital admission and continued in the hospital if necessary. It will consist of five cycles of electronic tourniquet inflation and deflation (5 min each). The cuff pressure for RIPerC will be 200 mmHg during inflation. Sham will only simulate vibration of the device.Study Outcome(s): The primary outcome will be the difference in the proportion of patients with good outcomes as defined by a mRS score of 2 or less at 90 days. Secondary outcomes to be monitored will include early neurological improvement rate, treatment related serious adverse event rates, size of the infarct volume, symptomatic intracranial hemorrhage, metabolomic and lipidomic response to RIPerC and Neuropsychological evaluation at 90 days.Discussion: Neuroprotective therapies could not only increase the benefits of available reperfusion therapies among AIS patients but also provide an option for patients who are not candidates for these treatments. REMOTE-CAT will investigate the clinical benefit of RIC as a new neuroprotective strategy in AIS.Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03375762.

Remote ischemic conditioning in active ulcerative colitis: An explorative randomized clinical trial

Remote ischemic conditioning (RIC) by repetitive brief periods of limb ischemia and reperfusion renders organs more resistant to ischemic injury. The protection is partly through down-regulation of the inflammatory response. Our aim was to investigate the clinical and anti-inflammatory effects of RIC in patients with active ulcerative colitis (UC). We included 22 patients with active UC in this explorative, randomized, sham-controlled clinical trial. The patients were randomly assigned 1:1 to RIC (induced in the arm through four cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff) or sham (incomplete inflation of the blood-pressure cuff) once daily for 10 days. Outcome variables were measured at baseline and on day 11. When compared with sham, RIC did not affect inflammation in the UC patients measured by fecal calprotectin, plasma C-reactive protein, Mayo Score, Mayo Endoscopic Subscore, Nancy Histological Index or inflammatory cytokines involved in UC and RIC. The mRNA and miRNA expression profiles in the UC patients were measured by RNA sequencing and multiplexed hybridization, respectively, but were not significantly affected by RIC. We used the Langendorff heart model to assess activation of the organ protective mechanism induced by RIC, but could not confirm activation of the organ protective mechanism in the UC patients.

Evidence for Active Rhyolitic dike Intrusion in the Northern Main Ethiopian Rift from the 2015 Fentale Seismic Swarm

AbstractMagmatic intrusions play a vital role not only in accommodating extensional stresses in continental rifts but also in feeding volcanic systems. The location, orientation, and timescale of dike intrusions are dictated by the interaction of regional and local stresses, the effect of pre‐existing weaknesses, and the composition of magma. Observing active intrusions can provide important information regarding the interaction between magmatic processes and the tectonic stress field during continental rifting. We focus on a seismic swarm that occurred in 2015 to the northeast of Fentale volcano, in the Main Ethiopian Rift (MER), and use radar interferometry to study surface deformation associated with the seismic swarm. Interferograms show a pattern of dike‐induced deformation, with a model estimate of volume change of 33×106±0.6×106m3 at a depth range of 5.4 to 8 km. We use a small baseline subset algorithm to calculate line of sight time series and find that the displacements decay exponentially with a decay constant of ∼83 days. Coupled source‐sink models suggest that such slow dike intrusions require a high viscosity rhyolitic magma. The difference in behavior between Fentale and other caldera systems in the MER, which show multi‐year cycles of inflation and deflation, suggests fundamental differences in magma composition and architecture of the plumbing system. This is the first direct observation of a dike intrusion in the MER and provides new constraints on the temporal‐spatial patterns of stress and strain that occur during continental rifting. Whether this activity is transient or a long‐term feature associated with rift evolution is an open question.