Pressure Increment Research Articles

Comparative study on heat extraction performance of three enhanced geothermal systems

Enhanced geothermal systems (EGSs) in this study are classified as fracturing-EGS (F-EGS), pipe-EGS (P-EGS) and excavation-EGS (E-EGS) according to reservoir stimulation strategies. However, the heat extraction performances of three EGSs employing different stimulation strategies are not fully understood. Here, we define the region where the pore pressure increment calculated by a hydraulic fracturing process is higher than rock tensile strength as the stimulation region for establishing a more accurate F-EGS model, and then compare three geothermal systems to select a appropriate reservoir stimulation strategy. We find that the F-EGS model assuming an entire stimulated region significantly exaggerates the heat extraction results. The optimal conditions for P-EGS are low injection rates and short operation times, which is suiTablefor seasonal heating or multi-energy co-generation projects including a thermal recovery phase. Theoretically, E-EGS has better geothermal extraction performance than F-EGS based on existing model assumptions, but its construction feasibility and economics need further exploration. H2O is more suiTableas a heat exchange fluid in E-EGS than supercritical CO2. This study provides a reference for geothermal mining simulation and reservoir stimulation strategy selection.

Brachial-ankle pulse wave velocity trajectories in a middle-aged population.

The "trajectory" phenotype was observed in several cardiovascular risk factors with aging. We aim to identify multiple brachial-ankle Pulse Wave Velocity (baPWV) trajectory phenotypes and assess their determinants. Among 5,182 participants with baPWV measurements (2010-2016) at no less than three time points in Kailuan Study, we derived baPWV trajectory pattern using SAS Proc Traj program. We applied the lowest Bayesian information criterion to identify the best typing model, related the identified trajectory pattern to baseline and changes in characteristics. Among 5.3 ± 1.7 years follow-up, four distinct baPWV trajectories were identified as low (1,961,37.8%), medium-low (1,846,35.6%), medium-high (1,024,19.8%), and high (351,6.8%) groups. In the stepwise models, mean arterial pressure and age were the main determinators of the trajectory patterns, with a Δpseudo-R2 of 0.335 and 0.164, respectively. With the low trajectory group as reference and multivariable adjustment, odd ratios of medium low, medium high and high associated with 1 mmHg increment of mean arterial pressure were 1.08(95%CI: 1.07-1.09), 1.13(1.12-1.14), and 1.16(1.15-1.18). The estimates for age were 1.08(1.07-1.10), 1.20(1.18-1.21) and 1.28(1.26-1.31). Additionally, baseline resting heart rate, low-density lipoprotein cholesterol, fasting blood glucose, hypersensitive C-reaction protein and uric acid, and changes in mean arterial pressure, resting heart rate, fasting blood glucose, and uric acid were positively associated with the trajectory, while BMI was negatively associated. The changes in baPWV overtime followed a "trajectory" pattern, mainly determined by mean arterial pressure and age.

Coupled thermal-hemodynamics computational modeling of cryoballoon ablation for pulmonary vein isolation

Cryoballoon ablation (CBA) is a cryo-energy based minimally invasive treatment procedure for patients suffering from left atrial (LA) fibrillation. Although this technique has proved to be effective, it is prone to reoccurrences and some serious thermal complications. Also, the factors affecting thermal distribution at the pulmonary vein-antrum junction that are critical to the treatment success is poorly understood. Computer modeling of CBA can resolve this issue and help understand the factors affecting this treatment. To do so, however, numerical challenges associated with the simulation of advection-dominant transport process must be resolved. Here, we describe the development of a thermal-hemodynamics computational framework to simulate incomplete occlusion in a patient-specific LA geometry during CBA. The modeling framework uses the finite element method to predict hemodynamics, thermal distribution, and lesion formation during CBA. An incremental pressure correction scheme is used to decouple velocity and pressure in the Navier-Stokes equation, whereas several stabilization techniques are also applied to overcome numerical instabilities. The framework was implemented using an open-source FE library (FEniCS). We show that model predictions of the hemodynamics in a realistic human LA geometry match well with measurements. The effects of cryoballoon position, pulmonary vein blood velocity and mitral regurgitation on lesion formation during CBA was investigated. For a −700C cryoballoon temperature, the model predicts lesion formation for gaps less than 2.5 mm and increasing efficiency of CBA for higher balloon tissue contact areas. The simulations also predict that lesion formation is not sensitive to variation in pulmonary vein blood velocity and mitral regurgitation. The framework can be applied to optimize CBA in patients for future clinical studies.

Thermal Behaviors and Interaction Mechanism of Ammonium Dinitramide with Nitrocellulose.

The initial interaction mechanism is very important for the design and safety of nano-scale composite energetic materials composed of ammonium dinitramide (ADN) and nitrocellulose (NC). The thermal behaviors of ADN, NC and an NC/ADN mixture under different conditions were studied by using differential scanning calorimetry (DSC) with sealed crucibles, an accelerating rate calorimeter (ARC), a self-developed gas pressure measurement instrument and a DSC-thermogravimetry (TG)-quadrupole mass spectroscopy (MS)-Fourier transform infrared spectroscopy (FTIR) combined technique. The results show that the exothermic peak temperature of the NC/ADN mixture shifted forward greatly in both open and closed circumstances compared to those of NC or ADN. After 585.5 min under quasi-adiabatic conditions, the NC/ADN mixture stepped into the self-heating stage at 106.4 °C, which was much less than the initial temperatures of NC or ADN. The significant reduction in net pressure increment of NC, ADN and the NC/ADN mixture under vacuum indicates that ADN initiated the interaction of NC with ADN. Compared to gas products of NC or ADN, two new kinds of oxidative gases O2 and HNO2 appeared for the NC/ADN mixture, while NH3 and aldehyde disappeared. The mixing of NC with ADN did not change the initial decomposition pathway of either, but NC made ADN more inclined to decompose into N2O, which resulted in the formation of oxidative gases O2 and HNO2. The thermal decomposition of ADN dominated the initial thermal decomposition stage of the NC/ADN mixture, followed by the oxidation of NC and the cation of ADN.

High pressure hydrogen compression exploiting Ti1.1(Cr,Mn,V)2 and Ti1.1(Cr,Mn,V,Fe)2 alloys

For metal hydride compressors to be used in substitution to the mechanical ones in the hydrogen infrastructures, it is mandatory to develop new compositions that can satisfy the desired goal of a pressure of 700 bar. To achieve the goal, Laves (C14) intermetallic compounds Ti(Cr,Mn)2-based are very promising. New Ti1.1(Cr,Mn,V)2 and Ti1.1(Cr,Mn,V,Fe)2 compositions were synthetized and characterized in this work. The influence of the substitution of Cr with Mn and Fe on the crystal structure, and its correlation with the hydrogen sorption properties, was investigated, detecting an increment in the plateau pressure and the hysteresis gap. Thanks to suitable thermodynamics, developed alloys are good candidates for the high-pressure hydrogen compression. Moreover, they present an easy activation, that can be performed at room temperature, and a fast reaction rate, with few seconds required to absorb about 90% of the hydrogen content in the alloy. The most promising composition is the Ti1.1Cr0.9Mn0.8V0.1Fe0.2, that is estimated to release hydrogen at about 700 bar at 150 °C. A possible integration of developed alloy in a metal hydride compressor is evaluated.

Effect of chemical corrosion on propagation of complex fracture networks under different hydraulic pressures in enhanced geothermal systems

Chemical corrosion and hydraulic fracturing are important ways to improve the permeability of the enhanced geothermal systems. In this work, we developed a discrete element code for simulating the hydraulic fracturing of three different fracture network models after chemical corrosion. Mechanisms of the crack extension and coalescence in the field-scale models with fracture network were systematically revealed, in which the effects of corrosion time, inclination of the fracture (γ), pH value and hydraulic pressure were considered. The results show that the simulated cracking behaviors of granites agree well with those obtained through Brazilian tests and triaxial compression tests, verifying the validity of the developed discrete element code. During hydraulic fracturing, the impact of γ on the fracture network connectivity increases with the increment of hydraulic pressure (Pin). With the increase in hydraulic pressure, crack propagation accelerates whereas the connectivity of fracture network models decreases. The reasons are that the excessive hydraulic pressure causes the crack to spread in an unfavorable direction and increases the effect of γ on the connectivity of models of fracture networks. As the pH value increases from 2 to 12, the crack growth rate first decreases and subsequently raises. The numbers of cracks per time step of sparse mixed fracture networks with artificial fractures (SM), dense mixed fracture networks with artificial fractures (DM) and dense mixed fracture networks without artificial fractures (NDM) are in the ranges of 0.06601–0.1259, 0.05176–0.2072 and 0.1727–0.6846, respectively. The connectivity of SM is better than that of NDM under the same hydraulic fracturing conditions, indicating that artificial fractures can greatly improve the fracture network connectivity and the utilization efficiency of EGS.

Mantle transition zone-derived eclogite xenolith entrained in a diamondiferous Mesoproterozoic (∼1.1 Ga) kimberlite from the Eastern Dharwar Craton, India: evidence from a coesite, K-omphacite, and majoritic garnet assemblage

AbstractSubduction-related kimberlite-borne eclogite xenoliths of the Precambrian age may provide significant information about the evolution and recycling of a subducting crust as exhumed/orogenic eclogites of the pre-Mesoproterozoic time-frame are globally rare. In this paper, we report a kimberlite-borne eclogite xenolith from the diamondiferous Kalyandurg kimberlite cluster of the Eastern Dharwar Craton, India, which contains a plethora of ultra-high-pressure minerals such as coesite, majoritic garnet, and supersilicic K-rich omphacite. The presence of these ultra-high-pressure minerals is confirmed byin situX-ray diffractometry, laser Raman spectra and electron probe microanalysis. The presence of coesite undisputedly pinpoints a subduction origin for the eclogite at ∼2.8 GPa pressure, which corresponds to ∼100 km depth. The geothermobarometric estimations involving garnet–omphacite–kyanite–coesite reveal that such an eclogitic assemblage equilibrated at ∼5–8 GPa (∼175–280 km) pressure during ultra-deep subduction. The textural relationship between omphacite, coarse-grained garnet and majoritic garnet coupled with the laser Raman spectra and geobarometric estimations obtained from the majoritic garnet demonstrate that the majoritic garnet formed at ∼8–19 GPa (∼280–660 km) owing to disassociation of omphacite and coarse-grained garnet to majoritic garnet during increment of pressure up to the mantle transition zone. Thus, the mineralogical and geothermobarometric data suggest that the studied eclogite possibly travelled down to the mantle transition zone before it was rapidly carried up by a pre-Mesoproterozoic mantle plume, and subsequently entrained as a xenolith by the Mesoproterozoic (∼1.1 Ga) kimberlite.

Spark plasma sintering of translucent polycrystalline α/β‐silicon nitride ceramics with Y2O3 additive

Translucent polycrystalline α/β‐silicon nitride ceramics had been fabricated for the first time by spark plasma sintering from α-Si3N4 starting powder with 2 wt% Y2O3. It aimed to investigate the influence of process parameters on the phase evolution, microstructural development, and mechanical properties of sintered ceramics. The increase in sintering temperature from 1750 °C to 1800 °C under 25 MPa considerably raised relative density, promoted α-β phase transformation, increased hardness and fracture toughness values, and exhibited translucency in the visible region. Furthermore, the highest relative density (98%), hardness (∼HV: 14.9 GPa), fracture toughness (∼9.8 MPa m1/2) values, and a higher degree of translucency were achieved with the increment of uniaxial pressure from 25 to 50 MPa at 1750 °C. These results indicated that translucent polycrystalline α/β‐silicon nitride ceramics, produced by liquid phase assisted spark plasma sintering at 1750 °C under 50 MPa, can be used as transparent armors and visible windows under harsh conditions.

Analysis of unsteady flow field and near-field aerodynamic noise of scale high-speed trains in long tunnel

The hybrid LES/APE method is used to simulate the unsteady flow field and the near-field aerodynamic noise of a 1/25 scale eight-coach high-speed train in long tunnel, validated by time-averaged pressure coefficients and Power Spectral Density of surface pressure from the aerodynamic wind tunnel test of a same scale two-coach train model. Train induced wind with the maximum velocity of 28 m/s in the opposite direction of train operating is formed in tunnel. Blocking effect leads to larger turbulent pressure and streamwise increment of turbulent power level from 133.7 dB to 138.2 dB, which is from130.3 dB to 133.4 dB in open air. With APE solver, three cases including tunnel with fully reflective walls, tunnel with fully absorptive walls and open air, are conducted to compare the influence of blocking effect and acoustic reflection on sound pressure. Total sound pressure level on the train body in tunnel is overall stronger than that in open air. The difference of sound power level between tunnel and open air is mostly contributed by acoustic reflection: 84.7 % at Coach 1, 84.3 % at Coach 8 and 66.0 ∼ 77.5 % from Coach 2 to Coach 7. Five peak frequencies: 520 Hz, 800 Hz, 1440 Hz, 2600 Hz and 3880 Hz are found from the frequency spectra of sound pressure of the probes in bogie cavities and pantograph grooves, in tunnel with fully reflective walls. Sound pressure modes help to clarify the generation mechanisms of peak frequencies: 520 Hz and 800 Hz are caused by the tunnel cavity resonance; 1440 Hz is caused by the first-order vertical mode from the bottom of the pantograph groove to the top of tunnel walls; 2600 Hz is caused by the first-order vertical mode from the ground to the top of bogie cavity, but 3880 Hz is not generated by simple in-phase cavity resonance.

Association of Blood Pressure With Rates of Macular Ganglion Cell Complex Thinning in Patients With Glaucoma

There are scarce data on the association of blood pressure measures with subsequent macular structural rates of change in patients with glaucoma. To investigate the association of baseline blood pressure measures with rates of change of the macular ganglion cell complex in patients with central or moderate to advanced glaucoma damage at baseline. This prospective cohort study, conducted from August 2021 to August 2022, used data from patients in the Advanced Glaucoma Progression Study at the University of California, Los Angeles. Participants were between 39 and 80 years of age and had more than 4 macular imaging tests and 2 or more years of follow-up. A diagnosis of glaucoma with either central damage or a visual field mean deviation worse than -6 dB. The main outcome was the association of blood pressure measures with ganglion cell complex rates of change. Macular ganglion cell complex thickness rates of change were estimated with a bayesian hierarchical model. This model included relevant demographic and clinical factors. Blood pressure measures, intraocular pressure, and their interactions were added to the model to assess the association of baseline blood pressure measures with global ganglion cell complex rates of change. The cohort included 105 eyes from 105 participants. The mean (SD) age, 10-2 visual field mean deviation, and follow-up time were 66.9 (8.5) years, -8.3 (5.3) dB, and 3.6 (0.4) years, respectively, and 67 patients (63.8%) were female. The racial and ethnic makeup of the cohort was 15 African American (14.3%), 23 Asian (21.9%), 12 Hispanic (11.4%), and 55 White (52.4%) individuals based on patient self-report. In multivariable analyses, female sex, history of taking blood pressure medications, higher intraocular pressure, thicker central corneal thickness, shorter axial length, higher contrast sensitivity at 12 cycles per degree, and higher baseline 10-2 visual field mean deviation were associated with faster ganglion cell complex thinning. Lower diastolic blood pressure was associated with faster rates of ganglion cell complex thinning at higher intraocular pressures. For intraocular pressures of 8 and of 16 mm Hg (10% and 90% quantiles, respectively), every 10 mm Hg-lower increment of diastolic blood pressure was associated with 0.011 μm/y slower and -0.130 μm/y faster rates of ganglion cell complex thinning, respectively. In this cohort study, a combination of lower diastolic blood pressure and higher intraocular pressure at baseline was associated with faster rates of ganglion cell complex thinning. These findings support consideration of evaluating and addressing diastolic blood pressure as a therapeutic measure in patients with glaucoma if supported by appropriate clinical trials.

Effect of Three-Month Weight Training Program on Resting Heart Rate and Blood Pressure in Healthy Young Adult Males.

Background A planned and structured physical activity is the cornerstone of improving and sustaining body fitness. The underlying reason for exercise is personal interest, maintaining good health, or improving endurance for sports. Furthermore, exercise may be either isotonic or isometric. In weight training, different types of weight are being used and are lifted against gravity, and this type of exercise is of isotonic type. Objective The objective of this study was to observe the changes in heart rate (HR) and blood pressure (BP) after a three-month weight training intervention in healthy young adult males and to compare them with age-matched healthy control. Materials and methods We initially recruited a total of 25 healthy male volunteers for the study and 25 age-matched participants in the control group. Research participants were screened for any existing diseases and suitability for participation by the Physical Activity Readiness Questionnaire. We lost one participant from the study group and three participants from the control group in the follow-up. A structured weight training program (five days a week for three months) was applied for the study group with direct instruction and supervision in a controlled environment. A single expert clinician measured baseline and post-program (after three months) HR and BP (measured after 15 minutes, 30 minutes, and 24 hours of rest after exercise) to reduce any possible inter-observer variation. For comparing the pre-exercise and post-exercise parameters, we considered the post-exercise measurement, which was done after 24 hours of exercise. Mann-Whitney Utest, Wilcoxon signed-rank test, and Friedman test compared the parameters. Result A total of 24 males with a median age of 19 years (Q1-Q3: 18-20) participated as the study group and 22 males with the same median age were the control group. At the end of the three-month weight training exercise program, there was no significant change in the HR (median 82 versus 81 bpm, p = 0.27) in the study group. The systolic BP was increased (median 116 versus 126 mmHg, p <0.0001) after three months of the weight training program. In addition, pulse pressure and mean arterial BP was also increased. However, diastolic (median 76 versus 80 mmHg, p = 0.11) BP was not significantly increased. There was no change in HR, systolic and diastolic BP in the control group. Conclusion A structured weight training program (used in this study) for three months may sustain an increase in systolic BP at rest in young adult males while diastolic BP remains the same. The HR remains unchanged before and after the exercise program. Hence, those enrolling in such an exercise program should be monitored frequently for changes in BP over time for any timely intervention appropriate for the candidate. However, being a small-scale study, the result of this study would be validated by further observing the underlying causes of the increment of systolic blood pressure.

Cross-mode stabilized stochastic shallow water systems using stochastic finite element methods

The development of surrogate models to study uncertainties in hydrologic systems requires significant effort in the development of sampling strategies and forward model simulations. Furthermore, in applications where prediction time is critical, such as prediction of hurricane storm surge, the predictions of system response and uncertainties can be required within short time frames. Here, we develop an efficient stochastic shallow water model to address these issues. To discretize the physical and probability spaces we use a Stochastic Galerkin method and an Incremental Pressure Correction Scheme to advance the solution in time. To overcome discrete stability issues, we propose cross-mode stabilization methods which employs existing stabilization methods in the probability space by adding stabilization terms to every stochastic mode in a modes-coupled way. We extensively verify the developed method for both idealized shallow water test cases and hindcasting of past hurricanes. We subsequently use the developed and verified method to perform a comprehensive statistical analysis of the established shallow water surrogate models. Finally, we propose a predictor for hurricane storm surge under uncertain wind drag coefficients and demonstrate its effectivity for Hurricanes Ike and Harvey.

Experimental Assessment of Aero-Propulsive Effects on a Large Turboprop Aircraft with Rear-Engine Installation

This paper deals with the estimation of propulsive effects for a three-lifting surface turboprop aircraft concept, with rear engine installation at the horizontal tail tips, conceived to carry up to 130 passengers. This work is focused on how the propulsive system affects the horizontal tailplane aerodynamics and, consequently, the aircraft’s static stability characteristics using wind tunnel tests. Both direct and indirect propulsive effects have been estimated. The former produces moments whose values depend on the distance from the aircraft’s centre of gravity to the thrust lines and propeller disks. The latter entails a change in the angle of attack and an increment of dynamic pressure on the tailplane. Several tests were also performed on the body-empennage configuration to investigate the propulsive effects on the aircraft’s static stability without the appearance of any aerodynamic interference phenomena, especially from the canard. The output of the experimental campaign reveals a beneficial effect of the propulsive effects on the aircraft’s longitudinal stability, with an increase in the stability margin of about 2.5% and a reduction in the directional stability derivative of about 4%, attributed to the different induced drag contributions of the two horizontal tail semi-planes. Moreover, the rolling moment coefficient experiences a greater variation due to the propulsion depending on the propeller rotation direction. The outcomes of this paper allow the enhancement of the technical readiness level for the considered aircraft, giving clear indications about the feasibility of the aircraft configuration.

Effect of fracture distribution on the triaxial shear behavior of loess

Fractures are widespread phenomena on loess slopes in northwestern China. Fractures are of various types and have different distribution patterns, and they are important factors affecting the mechanical properties of loess. In this paper, the effect of different fracture distribution modes (fracture angle, fracture position and fracture combination) on the shear strength of loess is investigated by carrying out consolidated undrained triaxial shear tests. The results show that the existence of fractures in loess can significantly weaken the strength of the soil under consolidated undrained conditions. Compared with unfractured loess, fractures weaken the shear strength of loess mainly by weakening the cohesion. The internal friction angles of fractured loess, however, are hardly affected by the existence of fractures and the fracture distribution mode. Furthermore, a comparison of three fracture distribution modes, namely, the fracture angle, position and combination, reveals that the fracture angle is the most significant factor weakening the loess strength, followed by fracture combination, and the least is fracture position. In addition, confining pressure increments can greatly improve the shear strength of both unfractured and fractured loess, and confining pressure increments can inhibit the weakening effect of fractures on loess strength.

Factors Associating with Non-Dipping Pattern of Nocturnal Blood Pressure in Patients with Essential Hypertension.

Background: In patients with essential hypertension, a non-dipping blood pressure pattern is a strong risk factor for cardiovascular diseases. However, background factors associating with such a blood pressure pattern remain unknown. Methods: Untreated essential hypertensive patients without chronic kidney diseases who were admitted to our outpatient clinic were included. Blood sampling and 24 h ambulatory blood pressure monitoring were mandatorily performed. Non-dipper status was defined as a maximum decrease in nocturnal systolic blood pressure within 10%. Clinical factors associating with non-dipper status were investigated. Results: A total of 154 patients (56 ± 12 years old, 86 men) were included. Among baseline characteristics, a higher serum uric acid level was independently associated with non-dipper status (odds ratio 1.03, 95% confidence interval 1.00−1.05, p < 0.05). Among those with non-dipper status, a higher high-sensitivity C-reactive protein level tended to be associated with incremental nighttime systolic blood pressure levels (p = 0.065). Conclusions: Hyperuricemia and micro-inflammation might be associated with attenuated nocturnal blood pressure dipping and incremental nighttime systolic blood pressure levels.

Epidemiological characteristics and climatic variability of viral meningitis in Kazakhstan, 2014-2019.

The comprehensive epidemiology and impact of climate on viral meningitis (VM) in Kazakhstan are unknown. We aimed to study the incidence, in-hospital mortality and influence of climatic indicators on VM from 2014 to 2019. Nationwide electronic healthcare records were used to explore this study. ICD-10 codes of VM, demographics, and hospital outcomes were evaluated using descriptive statistics and survival analysis. During the 2014-2019 period, 10,251 patients with VM were admitted to the hospital. 51.35% of them were children, 57.85% were males, and 85.9% were from the urban population. Enteroviral meningitis was the main cause of VM in children. The incidence rate was 13 and 18 cases per 100,000 population in 2014 and 2019, respectively. Case fatality rate was higher in 2015 (2.3%) and 2017 (2.0%). The regression model showed 1°C increment in the daily average temperature might be associated with a 1.05-fold (95% CI 1.047-1.051) increase in the daily rate of VM cases, 1hPa increment in the average air pressure and 1% increment in the daily average humidity might contribute to a decrease in the daily rate of VM cases with IRRs of 0.997 (95% CI 0.995-0.998) and 0.982 (95% CI 0.981-0.983), respectively. In-hospital mortality was 35% higher in males compared to females. Patients residing in rural locations had a 2-fold higher risk of in-hospital death, compared to city residents. Elderly patients had a 14-fold higher risk of in-hospital mortality, compared to younger patients. This is the first study in Kazakhstan investigating the epidemiology and impact of climate on VM using nationwide healthcare data. There was a tendency to decrease the incidence with outbreaks every 5 years, and mortality rates were higher for Russians and other ethnicities compared to Kazakhs, for males compared to females, for elder patients compared to younger patients, and for patients living in rural areas compared to city residents. The climatic parameters and the days of delay indicated a moderate interaction with the VM cases.

Longitudinal Trends in Blood Pressure Associated with The Changes in Living Environment Caused by the Great East Japan Earthquake: The Fukushima Health Management Survey.

The Great East Japan Earthquake occurred on 11 March 2011, forcing Fukushima Prefecture residents to change their living environment. Such sudden changes possibly have long-term effects on cardiovascular-related diseases. We therefore sought to identify temporal relationships between living environment changes and blood pressure levels over three years following the earthquake. Participants included 14,941 men and 21,533 women aged 16 years or older who answered self-administered questionnaires, including questions on living environment changes at baseline (2012). Blood pressure levels were measured each year from 2012 to 2015. Linear mixed-effects models were used to analyze associations between living environment changes and blood pressure levels. Men with changes in living environment (i.e., those living in shelters or in temporary housing, rental apartments, relatives' houses, or others) showed significantly higher diastolic blood pressure levels than those who lived in their home at baseline (77.3 mmHg vs. 77.8 mmHg; p < 0.001). The time-dependent effect of diastolic blood pressure levels associated with living environment was not statistically significant, indicating a sustained difference in diastolic blood pressure associated with living environment changes at baseline after three years. The effect of living environment changes on diastolic blood pressure increment was also evident in men without antihypertensive medication use during the study period and in men who were current drinkers at baseline. There were no associations between living environment changes and diastolic blood pressure levels among women. Sudden changes in living environment due to the disaster had an impact on the long-term effects of higher diastolic blood pressure among middle-aged men.

Proposed cardio-pulmonary model to investigate the effects of COVID-19 on the cardiovascular system

In this paper, we propose a new mathematical model of cardiovascular system coupled with a respiratory system to study the effects of COVID-19 on global blood circulation parameters using the lumped parameters model. We use the fourth-order Runge-Kutta method for solving the sets of equations of motion. We validate our model by showing that the simulated flows in pulmonary and aortic valves corroborate, respectively, the results established by Smith et al. [IFAC Proceedings Volumes, 39 (2006) 453–458]. Then we examine the effects of the new coronavirus (covid-19) on the cardiopulmonary system through the impact of the high respiratory frequency and the variation of the alveoli volume. To achieve this aim, we propose a new exponential law for the time varying of the pulmonary resistance. It appears that when the respiratory frequency grows, the delay between the systemic artery flow and the flow in the pulmonary artery diminishes. Therefore, the efficiency of the cardiac pump is reduced. Moreover, our results also show that variations of the alveoli volume cause the increment of the pleural pressure in the vascular cavities that induces an exponential growth of the pulmonary resistance. Furthermore, this growth of the pulmonary resistance provokes the augmentation of pressure in some organs and its reduction in others. We found that patient with covid-19 having a prior history of cardiovascular diseases is exposed to a severe case of inflammation/damage of certain organs than those with no history of cardiovascular disease.

Synthesis of 2,5-dimethylhexene by isobutene dimerization with H2S co-feeding.

This study investigates the effect of hydrogen sulfide (H2S) co-feeding on the synthesis of 2,5-dimethyl-1-hexene, 2,5-dimethyl-2-hexene, and 2,5-dimethylhexane (2,5-DMHs), useful compounds, using the dimerization of isobutene under mild pressure conditions. The dimerization of isobutene did not proceed in the absence of H2S, whereas the desired products of 2,5-DMHs were produced under H2S co-feeding conditions. The effect of reactor size on the dimerization reaction was then examined, and the optimal reactor was discussed. To enhance the yield of 2,5-DMHs, we changed the reaction conditions of the temperature, molar ratio of isobutene to H2S (iso-C4[double bond, length as m-dash]/H2S) in the feed gas, and the total feed pressure. The optimum reaction condition was at 375 °C and 2/1 of iso-C4[double bond, length as m-dash]/H2S. The product of 2,5-DMHs monotonously increased by an increment of total pressure from 1.0 to 3.0 atm with a fixed iso-C4[double bond, length as m-dash]/H2S ratio at 2/1.

Is hypertonic saline an effective alternative to mannitol in the treatment of TBI in adult and pediatric patients? A systematic review and meta-analysis

Aim: This meta-analysis and systematic review aims to investigate and compare the efficacy of mannitol and hypertonic saline in treating patients who have suffered from traumatic brain injury (TBI). Methods: We reviewed publications from the Medline database, Web of Science, and Google Scholar from inception to 13 October 2022 with only English-based literature. The risk of bias from included Randomized controlled trial (RCT) s was assessed using the Cochrane Collaboration&amp;apos;s Tool. Newcastle-Ottawa Scale was employed to assess the included cohort\&amp;apos;s quality. The main outcomes of this review were treatment failure, mortality, intracranial pressure (ICP) reduction, and Cerebral Perfusion Pressure (CPP) increment. All the statistical analyses were performed using the Review Manager 5.4.1. A random-effects model was used to pool the studies when heterogeneity was seen, and the results were reported in the odds ratios (OR) and mean differences (MD) and the corresponding 95% confidence intervals. Results: The results of the statistical study found that there was a significantly lower treatment failure rate [OR = 1.80 (1.26, 2.57); p = 0.001; I 2 = 74%], the lower mortality rate [OR = 2.17 (1.26, 3.73); p = 0.005; I 2 = 0%], a greater increase in CPP [MD = -1.28 (-2.50, -0.05); p = 0.04; I 2 = 0%] associated with hypertonic saline treatment as compared to mannitol treatment. However, concerning ICP decrease, there was no significant difference between the two treatment options [MD = 1.86 (-0.64, 4.36); p = 0.14; I 2 = 70%]. Conclusions: Quantitative and qualitative analysis of trials and observational studies comparing the efficacy of hypertonic saline and mannitol demonstrates that hypertonic saline is a preferable treatment option with greater effectiveness and safety than mannitol in managing patients with TBI.