ICE Trial Research Articles

Ледовые натурные испытания ледокола «Новороссийск» в Карском море

Ледовые натурные испытания ледокола «Новороссийск» в Карском море

Functional Changes in Motor Cortical Brain Regions following Passive and Exertional Heat Stress

Endurance performance is impaired when exercising in the heat. Hyperthermia-induced fatigue cannot be entirely explained by alterations in peripheral mechanisms. The central nervous system may have key roles in hyperthermia-induced fatigue and thus warrant further investigations. PURPOSE: To evaluate functional changes in the brain following passive or exertional heat stress. METHODS: Five moderately-trained athletes (mean ± SD: age 23.6 ± 1.7 years; body fat 9.3±2.0%; VO2max 58±6 ml kg-1 min-1) underwent a motor task-based blood-oxygen-level dependent (BOLD) fMRI scan while donning a water-perfused thermal suit in a familiarization and four randomized, counterbalanced trials. fMRI scans were conducted after (a) running on a motorized treadmill at 70% VO2max with ingestion of ambient water (EX) or (b) ice slurry (ICE), (c) passive heating via warm water immersion at 41°C (PAH), or (d) rest (CON). Serum osmolality was evaluated from blood samples collected at the start and end of each trial. Rectal temperature (Tre) and heart rate (HR) were assessed using two-way ANOVA with p < 0.05 considered as significant. RESULTS: Participants started all trials euhydrated (mean serum osmolality: 292 ± 1 mOsmol/kg; p= 0.719), with similar baseline HR (66 ± 2 beats/min; p=0.908) and Tre (36.9 ± 0.1°C; p=0.431). Post-intervention percent body mass change were similar across trials (-0.7 ± 0.2%; p= 0.110). Post-intervention Tre for EX (39.4 ± 0.2°C) was similar to PAH trial (39.3 ± 0.2°C; p = 0.59) but higher than ICE (39.0 ± 0.2°C; p = 0.01) and CON trials (36.5 ± 0.2°C; p < 0.01). Mean Tre achieved during post-intervention fMRI scan were 38.5 ± 0.1°C for both EX and PAH trials, 37.7 ± 0.1°C for ICE trial and 36.3 ± 0.1°C for CON trial. Task-based fMRI detected lower BOLD signals from primary motor cortex in PAH (fold changes from baseline: 0.46 ± 0.35) compared to EX trials (1.03 ± 0.21, p = 0.01). BOLD signals were also lower in primary somatosensory cortex for PAH (0.39 ± 0.23) compared to EX (1.04 ± 0.18, p < 0.01) and CON trials (0.98 ± 0.10, p = 0.02). CONCLUSION: Preliminary results from task-based BOLD analysis showed that passive heating led to functional suppression in the sensorimotor areas in the brain. Supported by DIRP Grant, PA No. 9015102335.

Measuring disease activity and clinical response during maintenance therapy in CIDP: from ICE trial outcome measures to future clinical biomarkers.

Some patients with chronic inflammatory demyelinating polyradiculoneuropathy who respond to initial intravenous immunoglobulin require repeated courses over prolonged periods of time; however, evidence to guide dosage and interval of intravenous immunoglobulin during maintenance therapy is limited. Optimizing treatment requires assessment of underlying disease activity and clinical outcome. Electrophysiological measures of demyelination, and clinical measures using handgrip strength and walking velocity promise to be particularly informative. Major advances in resolution and image processing have expanded clinical applications for ultrasound to include the study of peripheral nerves. Ultrasonography shows promise in diagnosing chronic inflammatory demyelinating polyradiculoneuropathy and distinguishing it from other conditions, providing first ever insight into gross pathology of peripheral nerves. Ultrasonography may also have a role in monitoring disease activity and treatment response.

FIRE AND ICE: The quest for the perfect modality in atrial fibrillation ablation.

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. Catheter ablation of atrial fibrillation plays an important role in the management of AF. Radiofrequency ablation is widely used in practice all over the world. Cryoablation has emerged as an alternative method for AF ablation. The FIRE and ICE trial was a non inferiority, multicentre, randomized trial that compared between the two modalities and proved cryoablation to be non inferior to radiofrequency in terms of efficacy and safety. However, the rate of AF recurrence was markedly high in both arms of the study.

Cryoballoon or radiofrequency ablation for symptomatic paroxysmal atrial fibrillation: reintervention, rehospitalization, and quality-of-life outcomes in the FIRE AND ICE trial.

AimsThe primary safety and efficacy endpoints of the randomized FIRE AND ICE trial have recently demonstrated non-inferiority of cryoballoon vs. radiofrequency current (RFC) catheter ablation in patients with drug-refractory symptomatic paroxysmal atrial fibrillation (AF). The aim of the current study was to assess outcome parameters that are important for the daily clinical management of patients using key secondary analyses. Specifically, reinterventions, rehospitalizations, and quality-of-life were examined in this randomized trial of cryoballoon vs. RFC catheter ablation.Methods and resultsPatients (374 subjects in the cryoballoon group and 376 subjects in the RFC group) were evaluated in the modified intention-to-treat cohort. After the index ablation, log-rank testing over 1000 days of follow-up demonstrated that there were statistically significant differences in favour of cryoballoon ablation with respect to repeat ablations (11.8% cryoballoon vs. 17.6% RFC; P = 0.03), direct-current cardioversions (3.2% cryoballoon vs. 6.4% RFC; P = 0.04), all-cause rehospitalizations (32.6% cryoballoon vs. 41.5% RFC; P = 0.01), and cardiovascular rehospitalizations (23.8% cryoballoon vs. 35.9% RFC; P < 0.01). There were no statistical differences between groups in the quality-of-life surveys (both mental and physical) as measured by the Short Form-12 health survey and the EuroQol five-dimension questionnaire. There was an improvement in both mental and physical quality-of-life in all patients that began at 6 months after the index ablation and was maintained throughout the 30 months of follow-up.ConclusionPatients treated with cryoballoon as opposed to RFC ablation had significantly fewer repeat ablations, direct-current cardioversions, all-cause rehospitalizations, and cardiovascular rehospitalizations during follow-up. Both patient groups improved in quality-of-life scores after AF ablation.Clinical trial registrationClinicalTrials.gov identifier: NCT01490814.

Results and Implications of the FIRE AND ICE Trial

Whilst radiofrequency ablation is widely considered the “gold standard” for pulmonary-vein isolation, cryoballoon ablation is considered easier to perform. The aim of the randomised, multicentre FIRE AND ICE trial was to demonstrate, in patients with paroxysmal atrial fibrillation, the non-inferiority of cryoballoon ablation with respect to the time to a first documented clinical failure within 1 year outside a 90-day “blanking period” after the index ablation. This editorial gives an overview of the trial and its findings.

Ice Slurry Ingestion Leads to a Lower Net Heat Loss during Exercise in the Heat.

To compare the reductions in evaporative heat loss from the skin (Esk) to internal heat loss (Hfluid) induced by ice slurry (ICE) ingestion relative to 37 °C fluid and the accompanying body temperature and local thermoeffector responses during exercise in warm, dry conditions (33.5 °C ± 1.4 °C; 23.7% ± 2.6% relative humidity [RH]). Nine men cycled at approximately 55% VO2peak for 75 min and ingested 3.2 mL · kg(-1) aliquots of 37 °C fluid or ICE after 15, 30, and 45 min of exercise. Metabolic heat production (M-W), rectal temperature (Tre), mean skin temperature (Tsk), whole-body sweat loss (WBSL), local sweat rate (LSR), and skin blood flow (SkBF) were measured throughout. Net heat loss (HLnet) and heat storage (S) were estimated using partitional calorimetry. Relative to the 37 °C trial, M-W was similar (P = 0.81) with ICE ingestion; however, the 200 ± 20 kJ greater Hfluid (P < 0.001) with ICE ingestion was overcompensated by a 381 ± 199-kJ lower Esk (P < 0.001). Net heat loss (HLnet) was consequently 131 ± 120 kJ lower (P = 0.01) and S was greater (P = 0.05) with ICE ingestion compared with 37 °C fluid ingestion. Concurrently, LSR and WBSL were lower by 0.16 ± 0.14 mg · min(-1) · cm(-2) (P < 0.01) and 191 ± 122 g (P < 0.001), respectively, and SkBF tended to be lower (P = 0.06) by 5.4%maxAU ± 13.4%maxAU in the ICE trial. Changes in Tre and Tsk were similar throughout exercise with ICE compared to 37 °C fluid ingestion. Relative to 37 °C, ICE ingestion caused disproportionately greater reductions in Esk relative to Hfluid, resulting in a lower HLnet and greater S. Mechanistically, LSR and possibly SkBF were suppressed independently of Tre or Tsk, reaffirming the concept of human abdominal thermoreception. From a heat balance perspective, recommendations for ICE ingestion during exercise in warm, dry conditions should be reconsidered.

Comparison of the effects of cold water and ice ingestion on endurance cycling capacity in the heat

PurposeThe purpose of this study was to examine the effects of pre-cooling and fluid replacement with either crushed ice or cold water. MethodsOn 2 separate occasions, in a counterbalanced order, 9 recreationally-trained males ingested 1.25 g/kg (80–100 g) of either crushed ice (0.5°C) or cold water (4°C) every 5 min for 30 min before exercise. They also ingested 2.0 g/kg (130–160 g) of the same treatment drink at 15 min, 30 min, and 45 min after the commencement of cycling to exhaustion at 60%VO2max until voluntary exhaustion in a hot environment (35°C and 30% relative humidity). ResultsThe cycling time to exhaustion in the crushed ice trial (50.0 ± 12.2 min) was longer than the cold water trial (42.2 ± 10.1 min; p = 0.02). Although the rectal temperature fell by 0.37°C ± 0.03°C (p = 0.01) at the end of the resting period after the crushed ice ingestion, the rates of rise in rectal temperature during the exercise period were not significantly different between these 2 conditions (crushed ice: 0.23°C ± 0.07°C, 5 min; cold water: 0.22°C ± 0.07°C, 5 min; p = 0.94). ConclusionCrushed ice ingestion before and during exercise in a hot environment may be a preferred and effective approach for minimizing thermal strain, and for improving endurance performance as compared with cold water ingestion.

Detrimental Reductions In Evaporative Heat Loss During Cycling Following Ice Slurry Ingestion In The Heat

PURPOSE: To compare the magnitude of reduction in evaporative heat loss from the skin (Esk) with different levels of internal heat loss (Hint) induced by ice slurry and 1.5°C fluid ingestion relative to 37°C fluid ingestion during cycling in a hot environment. METHODS: Nine men RESULTS: All data are expressed relative to the NEU trial. Hprod was similar to NEU in both trials (COL: +34±154 kJ; P=0.52, ICE +17±210 kJ; P=0.81). Hint was progressively lower in the COL (-105±18 kJ) and ICE (-200±20 kJ) trials relative to NEU. In parallel, Esk was also progressively lower in the COL (-137±165 kJ; P=0.037) and ICE (-381±199 kJ; P<0.001) trials. However while evaporative reductions were equal to Hint in the COL trial (P=0.64), they were greater than Hint in the ICE trial (P=0.05), leading to a greater heat storage with ICE ingestion. Mean local sweat rates (COL: -0.06 ±0.09 mg•min-1•cm-2; P=0.09, ICE: -0.16±0.14 mg•min-1•cm-2; P=0.009) and whole-body sweat losses (COL: -56±69 g; P=0.04, ICE: -191±122 g; P<0.001) were lower compared to NEU. Conversely, changes in Tre (COL: +0.04±0.24°C; P=0.63, ICE: +0.07±0.12°C; P=0.11), Tsk (COL: -0.07±0.35°C; P=0.55, ICE: -0.04±0.38°C; P=0.74) and local skin blood flow (COL: -2.9±10.9%max, P=0.45; ICE: -6.8±13.7%max, P=0.18) were similar to the NEU trial. CONCLUSIONS: The greater internal loss with 1.5°C fluid, relative to 37°C fluid, was balanced by an equal reduction in Esk. However the internal heat loss with ice slurry ingestion, relative to 37°C fluid, was paralleled by a disproportionately greater reduction in Esk. These results indicate that the temperature of an ingested fluid has no net influence on human heat balance, but ice slurries should potentially be avoided.

Study on Influence of Ship Speed on Local Ice Loads on Bow of the IBRV ARAON

This study presents the analysis of relationship between ship speed and local ice load on the Korean Icebreaker ARAON. The relationship curves were made from the data obtained at two areas: the Arctic and the Antarctic; and for two operation condition: the icebreaking condition in sea ice trial and general operation in ice covered sea. The strain data were converted to the equivalent stress value, and the influence of ship speed on the local ice load was analyzed and compared each other. These analysis results are useful in working on a statistically valid hull design approach.

빙해지역 일반 운항 및 쇄빙 운항 시의 빙하중 특성 비교 연구

The icebreaking research vessel ARAON had her second ice trial in the Arctic Ocean from July 16 to August 12, 2010. In this study, the ice loads measured during the “general” operation and “ice breaking” operation in ice-covered waters were analyzed and compared. Whereas the “general” operation stands for the voyage in the water partially covered by ice, the “ice breaking” operation involved substantial ice floes for the ice breaking performance test. Based on the measured data, comparisons of the relationship between the ship speed and ice load, and between the locations of strain gauges and ice loads were investigated. Peak stresses higher than 20 MPa were found. The longitudinal and vertical correlations between the measurement location and ice load were analyzed, and the probability of peak stress was calculated. As a result, the probability function for higher ice loads during both operation modes was expressed in an exponential and power forms.

쇄빙연구선 ARAON호의 남극해 쇄빙운항 중 계측된 스트레인게이지 데이터 분석

Estimation of correct ice load under various operating conditions is important during the design and the operation stages of an icebreaker. Normal operating conditions are expected from the official field ice trials and also from general ice transit action. In this paper ice load for the Korean icebreaking research vessel, ARAON, under normal operating condition, is discussed. Published ice load data from full-scale sea trials of six icebreakers were analysed to derive an empirical ice load prediction formula. The IBRV ARAON had sea ice trials during 2010 and 2012 summer season. Strain gauge signal were recorded during her icebreaking voyage and the measured strain data were converted to the equivalent hull stress values. The effect of ARAON's speed in ice and the hull stresses are investigated. By comparing the empirical formula and ice load calculation based von measured data, it is recommended to use the empirical ice load estimation formula for the initial design stage.

Rationale and Design of FIRE AND ICE: A multicenter randomized trial comparing efficacy and safety of pulmonary vein isolation using a cryoballoon versus radiofrequency ablation with 3D-reconstruction.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia imposing substantial morbidity and mortality. Catheter-based pulmonary vein isolation (PVI) using radiofrequency current (RFC) has become a standard treatment for drug-resistant and symptomatic paroxysmal AF (PAF). In recent years, the cryoballoon-based technique is increasingly used as a promising alternative with a short learning curve. The FIRE AND ICE trial is a prospective, randomized, controlled, open, blinded outcome assessment, noninferiority trial comparing cryoballoon-, and RFC-based PVI. Patients with drug-resistant PAF will be randomized in a 1:1 matrix in multiple European centers. The primary hypothesis is that cryoballoon ablation is not inferior to RFC ablation using 3-dimensional mapping with respect to clinical efficacy. The primary endpoint is defined as the time to first documented clinical failure, including: (1) recurrence of AF; (2) atrial flutter or atrial tachycardia; (3) prescription of class I or III antiarrhythmic drugs; or (4) re-ablation, whichever comes first, following a blanking period of 3 months after the index ablation procedure. The primary safety endpoint is a composite of death, stroke/transient ischemic attack, cardiac arrhythmias (apart from AF recurrence) causally related to the therapeutic intervention, and procedure-related serious adverse events. The FIRE AND ICE trial compares 2 different technologies to perform catheter ablation of PAF with respect to efficacy and safety. It aims at providing objective data to guide selection and usage of ablation catheters in the treatment of AF.

Effect of dynamic bending of level ice on ship's continuous-mode icebreaking

This paper focuses on the influences of the dynamic effects of ship–ice–water interaction on ship performance, ship motions, and ice resistance. The effects of the dynamic bending of ice wedges and ship speeds are especially investigated. The study is carried out using a numerical procedure simulating ship operations in level ice with ship motions in six degrees of freedom (DOFs). A case study is conducted with the Swedish icebreaker Tor Viking II. The 3-D hull geometry of the ship is modeled based on the lines drawing. The predicted performance of the ship is compared with data from full-scale ice trials.

북극해 운항 중 계측된 빙하중에 대한 분석 연구

The icebreaking research vessel, ARAON had her second ice trial in the Arctic Sea from 16th July to 12th August 2010. During the voyage, the local ice loads acting on the bow of port side were measured from 14 strain gauges. The measurements were also carried out in ice waters with various ice concentration ratio as well as the icebreaking performance tests. In this study, the ice loads measured during the 'general' operation in ice waters were analyzed. As a first step, the relationship between the location of strain gauges and the ice loads were investigated, and then the possibility for observation of higher ice loads was estimated based on the probability density function. The relationship between the ship speed and the ice load was also investigated. 718 peak stresses data higher than 20 MPa obtained from strain gauges array attached in longitudinally and vertically was analyzed. In general, the ice load increases as the ship speed increases in the low ship speed range, and ice load decreases as the ship speed is greater than a certain speed.

북극해 계측자료에 기초한 아라온호의 국부 빙압력 계산 연구

The icebreaking research vessel (IBRV) ARAON had her second ice trial in the Arctic Ocean in the summer season of 2010. During the voyage, the local ice loads acting on the bow of the port side were measured using 14 strain gauges. These measurements were carried out in three icebreaking performance tests. To convert the measured strains into the local ice pressures, a finite element model of the instrumented area was developed. The influence coefficient method (ICM), which uses the influence coefficient from the finite element model, and the direct method, which uses the measured strain, were selected as the conversion methods. As a result, the maximum measured pressure was 1.236MPa, and the average difference between ICM and the direct method was about 5% for an area of <TEX>$0.2m^2$</TEX>. The pressure-area relationship of the measurement falls below the range of the existing pressure-area curve, which is due to the low ice strength of melted ice in the summer.

북극해에서 계측된 국부 빙하중에 대한 선속 및 빙두께 영향

The icebreaking research vessel ARAON conducted her second ice trial in the Arctic Ocean during the summer season of 2010. During this voyage, the local ice loads acting on the bow of the port side were measured using 14 strain gauges. The measurement was carried out during icebreaking while measuring the thickness of the ice every 10 m. The obtained strain data were converted to the equivalent stress values, and the effects of the ship speed and ice thickness on the ice load were investigated. As a result, it was found that a faster speed produced a larger stress, according to the variation in the peak values below an ice thickness condition of 1.5 m. Meanwhile, the effect of the ice thickness on the ice load was not clear.

Full scale ice sea trials of Korean ice breaking research vessel ‘Araon’ on the big floes near Antarctica

A speed sea trial was performed in the Amundsen Sea in February and March of 2012. The Korean ice breaking research vessel “Araon” was used to check speed performance on the big floes. Two of ice trial cases were carried out. We describe the time history of location, the engine power, and the revolutions per minute during the ice trial, and the trajectory of the ship. Additionally, the measured ice properties are considered and discussed. The ice trial results were analyzed according to variation in ice thicknesses, ice strength, propulsion power, and the speed level of the ship. Our analysis results are compared to model test results and ice trial results. A correction to the target ice thickness was used to compare the power and speed relation in the same ice thickness because it is easy to know the relative speed performance of the ship. The Hamburgische Schiffbau-Versuchs Anstalt method was applied for the correction. The speed of Araon in big floes was higher than the speed in level ice. The speed after the correction at 10 MW of power and 103 cm of ice thickness was 5.4 knots based on analysis results.

Ice slurry ingestion during cycling improves Olympic distance triathlon performance in the heat

This study investigated the effect of ice slurry ingestion during a triathlon on intragastric temperature and 10 km running performance in the heat. Nine well-trained male triathletes performed two randomised trials of a simulated Olympic distance triathlon in hot conditions (32–34°C). Exercise intensity during the swim (1500 m) and cycle (1 hr) legs was standardised, and the 10 km run leg was a self-paced time trial. During the cycle leg, either 10 g · kgBM−1 of ice slurry (< 1°C) or room temperature fluid (32–34°C) was ingested. In the run leg of the ice slurry trial, performance time (43.4 ± 3.7 vs. 44.6 ± 4.0 min; P = 0.03), intragastric temperature (at 1.5 km; 35.5 ± 1.2 vs. 37.5 ± 0.4°C; P = 0.002) and perceived thermal stress (at 5 km; 73 ± 9 vs. 80 ± 7 mm; P = 0.04) were significantly lower. Oxygen consumption was significantly higher in the ice trial between 9.5–10 km (52.4 ± 3.4 vs. 47.8 ± 5.4 mL · kg−1 · min−1; P = 0.04). The results suggest ice slurry ingestion was an effective ergogenic aid for triathlon running performance in the heat. The attenuation of intragastric temperature and perceived thermal stress were likely contributors to the self-selection of a higher running intensity and improved performance time.

큰 빙판에서 아라온 호 쇄빙 속도 성능 해석

The speed performances of ice sea trial on the Arctic(2010 & 2011) area were shown different results depend on the ice floe size. Penetration phenomena of level ice was not happened on medium ice floe and tore up by the impact force because the mass of medium ice floe is similar to the mass of Araon which is Korean ice breaking research vessel and did not shut up by the ice ridge or iceberg. The sea trial on the Amundsen sea was performed at the big floe which is classified by WMO(World Meteorological Organization). Three measurements of ice properties and five results of speed trial were obtained with different ice thicknesses and engine powers. To evaluate speed of level ice trial and model test results at the same ice thickness and engine power, the correction method of HSVA(Hamburg Ship Model Basin) was used. The thickness, snow effect, flexural strength and friction coefficient were corrected to compare the speed of sea trial. The analyzed speed at 1.03m thickness of big floe was 5.85 knots at 10MW power and it's 6.10 knots at 1.0m ice thickness and the same power. It's bigger than the results of level ice because big floe was also slightly tore up by the impact force of vessel based on the observation of recorded video.