Influence and mechanism of solids on the air pressure fluctuations on the building drainage system.

The conventional building drainage system was constructed based on the theory of two-phase flow involving water and air. However, the drainage system contained a more intricate three-phase flow, encompassing water, air, and solids, which was relatively overlooked in research. This study addressed the impact of solids on pressure fluctuations, air flow rates, and hydraulic jump fullness within the drainage system, considering three factors: the mass factor, cross-section factor, and viscosity. The investigation was conducted within a single-stack system using both experimental methods and CFD simulations. The findings revealed a positive correlation between both positive and negative pressures and above three factors. The mass factor and the cross-section factor had a more significant impact on the negative pressure of the system. The maximum growth rates of negative pressure extremes under different mass and cross-section factors reached 7.72 and 16.52%, respectively. In contrast, the viscosity of fecal sludge had a slightly higher effect on the positive pressure fluctuation of the drainage system, with the maximum growth rate of positive pressure extremes at 3.41%.

An antagonistic variable-stiffness pneumatic flexible joint.

This paper develops an antagonistic variable-stiffness pneumatic flexible joint in which two groups of artificial muscles are symmetrically distributed on both sides of the elastic thin plate. The elastic thin plate restricts the axial movement of the joint. Therefore, the joint can achieve single-dimensional and bidirectional bending by controlling the air pressure value of the pneumatic artificial muscle. Two variable stiffness elastic dampers are also symmetrically installed on both sides of the elastic thin plate, using a positive-pressure driving method to achieve real-time posture maintenance function of the joint based on particle-blockage, wedge structure, and antagonistic effect. The mathematical models for the bending angle and stiffness of flexible joints were established, and relevant experiments were conducted. When the air pressure of the pneumatic artificial muscle is 0.32 MPa, the joint bending angle reaches 62.7°. When the bending angle is 60° and the air pressure of the variable-stiffness elastic damper is 0.5 MPa, the stiffness in the bending direction of the flexible joint with the variable-stiffness elastic damper is 6.9 times that of the flexible joint without the variable-stiffness elastic damper, and the stiffness in the reverse bending direction is 10.3 times that of the flexible joint without the variable-stiffness elastic damper under the same conditions.

Influence of altered torsional stiffness through sole modification of air pressure shoes on lower extremity biomechanical behaviour during side-step cutting maneuvers.

Directional changes in cutting maneuvers are critical in sports, where shoe torsional stiffness (STS) is an important factor. Shoes are designed based on different constructions and movement patterns. Hence, it is unclear how adjustable spacers into the sole constructions of air pressure chambers (APC) affect the STS in side-step cutting. Therefore, this study investigated the effects of altered STS through adjustable sole spacers on ground reaction force (GRF) and ankle and knee joint moments in side-step cutting. Seventeen healthy recreational athletes performed side-step cutting with experimental conditions including (i) barefoot (BF), (ii) unaltered shoes (UAS): soles consisting of APC, and (iii) altered shoes (AS): modified UAS by inserting elastomeric spacers into cavities formed by APC. Mechanical and biomechanical variables were measured. Significant differences were revealed across shoe conditions for impact peak (p = 0.009) and impulse (p = 0.018) in vertical GRF, time to achieve peak braking (p = 0.004), and peak propulsion (p = 0.025) for anterior-posterior GRF in ANOVA test. No significant differences were observed in GRF peaks and impulses between UAS and AS except for a trend of differences in impact peak (p = 0.087) for vertical GRF. At the ankle and knee joint, peak ankle power absorption (p = 0.019), peak knee internal rotation moment (p = 0.042), peak knee extension moment (p = 0.001), peak knee flexion moment (0.000), peak knee power absorption (p = 0.047) showed significant difference across three shoe conditions. However, no significant differences between the UAS and AS were noticed for peak joint moments and power. Altered shoe torsional stiffness did not significantly affect the peak forces and peak ankle and knee joint moments or powers; hence sole adjustment did not influence the cutting performance. This study might be insightful in sports footwear design, and adjusting shoe torsional stiffness by sole modification might be advantageous for athletes playing sports with cutting maneuvers to reduce the risk of injuries by controlling the twisting force at the ankle that frequently happens during cutting maneuvers.

Lumen air pressure regulated multifunctional microbiotas in membrane-aerated biofilm reactors for simultaneous nitrogen removal and antibiotic elimination from aquaculture wastewater.

In this study, two membrane-aerated biofilm reactors (MABRs) were constructed: one solely utilizing biofilm and another hybrid MABR (HMABR) incorporating both suspended-sludge and biofilm to treat low C/N aquaculture wastewater under varying lumen air pressure (LAP). Both HMABR and MABR demonstrated superior nitrogen removal than conventional aeration reactors. Reducing LAP from 10 kPa to 2 kPa could enhance denitrification processes without severely compromising nitrification, resulting in an increase in total inorganic nitrogen (TIN) removal from 50.2±3.1 % to 71.6±1.0 %. The HMABR exhibited better denitrification efficacy than MABR, underscoring its potential for advanced nitrogen removal applications. A decline in LAP led to decreased extracellular polymeric substance (EPS) production, which could potentially augment reactor performance by minimizing mass transfer resistance while maintaining microbial matrix stability and function. Gene-centric metagenomics analysis revealed decreasing LAP impacted nitrogen metabolic potentials and electron flow pathways. The enrichment of napAB at higher LAP and the presence of complete ammonia oxidation (Comammox) Nitrospira at lower LAP indicated aerobic denitrification and Comammox processes in nitrogen removal. Multifunctional microbial communities developed under LAP regulation, diversifying the mechanisms for simultaneous nitrification-denitrification. Increased denitrifying gene pool (narGHI, nirK, norB) and enzymatic activity at a low LAP can amplify denitrification by promoting denitrifying genes and electron flow towards denitrifying enzymes. Sulfamethoxazole (SMX) was simultaneously removed with efficiency up to 80.2 ± 3.7 %, mainly via biodegradation, while antibiotic resistome and mobilome were propagated. Collectively, these findings could improve our understanding of nitrogen and antibiotic removal mechanisms under LAP regulation, offering valuable insights for the effective design and operation of MABR systems in aquaculture wastewater treatment.

Effect of temperature and air pressure on the incidence of Bell's palsy in Hangzhou: a distributed lag non-linear analysis.

The etiology of Bell's palsy (BP) is currently unknown, and the findings from previous studies examining the association between seasonal or meteorological factors and BP have been inconsistent. This research aims to clarify this relationship by analyzing a larger dataset and employing appropriate statistical methods. Data from 5387 patients with BP treated at Zhejiang Provincial Hospital of Traditional Chinese Medicine in Hangzhou, Zhejiang Province, from May 1, 2018, to June 30, 2023, was gathered. We assessed the temporal distribution of meteorological factors and the incidence of BP across seasons and months. A distributed lag non-linear model was used to further investigate the lagged and overall effects of temperature and air pressure on the onset of BP. The temporal distribution of BP incidence revealed the highest average number of cases occurring in December and the lowest in June. A correlation existed between BP episodes and temperature or air pressure. The model revealed a higher relative risk during periods of low temperature and high air pressure, characterized by a time lag effect. This correlation was notably more pronounced in female patients and individuals in the young and middle-aged groups. Our findings suggest that exposure to low temperatures and high air pressure constitute risk factors for BP development.

Patterns of high-flying insect abundance are shaped by landscape type and abiotic conditions.

Insects are of increasing conservation concern as a severe decline of both biomass and biodiversity have been reported. At the same time, data on where and when they occur in the airspace is still sparse, and we currently do not know whether their density is linked to the type of landscape above which they occur. Here, we combined data of high-flying insect abundance from six locations across Switzerland representing rural, urban and mountainous landscapes, which was recorded using vertical-looking radar devices. We analysed the abundance of high-flying insects in relation to meteorological factors, daytime, and type of landscape. Air pressure was positively related to insect abundance, wind speed showed an optimum, and temperature and wind direction did not show a clear relationship. Mountainous landscapes showed a higher insect abundance than the other two landscape types. Insect abundance increased in the morning, decreased in the afternoon, had a peak after sunset, and then declined again, though the extent of this general pattern slightly differed between landscape types. We conclude that the abundance of high-flying insects is not only related to abiotic parameters, but also to the type of landscapes and its characteristics, which, on a long-term, should be taken into account for when designing conservation measures for insects.

Dry Powder Formulations for Inhalation Require a Smaller Aerodynamic Diameter for Usage at High Altitude.

BACKGROUND: High Altitude Pulmonary Edema (HAPE) seriously threatens the health of people at high altitudes. There are drug treatments for HAPE, and dry powder formulations (DPFs) represent a rapid and accessible delivery vehicle for these drugs. However, there are presently no reports on the inhalability of DPFs in low-pressure environments. Given the reduced atmospheric pressure typical at high altitudes, conventional DPFs might not be suitable for inhalation. Therefore, it is necessary to elucidate the deposition behaviors of dry powder in the respiratory tract at low pressure, as well as to improve their pulmonary deposition efficiency via adjustments to their formulation and design. METHODS: The effect of air pressure, inspiratory velocity, and particle properties (such as size, density, and aerodynamic diameter) on pulmonary deposition of DPFs was calculated by a computational fluid dynamics (CFD)-coupled discrete phase model. DPFs of various aerodynamic diameters were prepared by spray drying, and the inhalability of these DPFs in a low-pressure environment was evaluated in mice. Finally, a mouse model of HAPE was established, and the treatment of HAPE by nifedipine-loaded DPFs with small aerodynamic diameter was validated. RESULTS: CFD results showed that low pressure decreased the deposition of DPFs in the lungs. At 0.5 standard atmosphere, DPFs with aerodynamic diameter of ∼2.0 µm could not enter the lower respiratory tract; however, a decrease in the physical diameter, density, and, consequently, the aerodynamic diameter of the DPFs was able to enhance pulmonary deposition of these powders. To validate the CFD results, three kinds of dry powder with aerodynamic diameters of 0.66, 0.98, and 2.00 µm were prepared by spray drying. Powders with smaller aerodynamic diameter could be inhaled into the lungs of mice more effectively, and, consequently could ameliorate the progression of HAPE more effectively than conventional powders. These results were consistent with the CFD results. CONCLUSIONS: Low atmospheric pressure can prevent the pulmonary deposition of DPFs at high altitudes. Compared with conventional DPFs, powders with smaller aerodynamic diameter can be effectively inhaled at these pressures and thus might be more suitable for the treatment the HAPE.

Meteorological associations of Vibrio vulnificus clinical infections in tropical settings: Correlations with air pressure, wind speed, and temperature.

V. vulnificus is one of the deadliest waterborne pathogens, yet little is known of the ecological and environmental forces that drive outbreaks. As a nationally notifiable disease, all cases of V. vulnificus diagnosed in the United States are reported to the state in which they occurred, as well as to the Centers for Disease Control (CDC) in Atlanta, Georgia. Given that the state of Florida is a 'hotspot' for V. vulnificus in the United States, we examined the prevalence and incidence of cases reported to the Florida Department of Health (2008-2020). Using a dataset comprised of 448 cases of disease caused by V. vulnificus infection, we identified meteorological variables that were associated with clinical cases and deaths. Combined with data from the National Oceanic and Atmospheric Administration (NOAA), we first utilized correlation analysis to examine the linear relationships between satellite meteorological measurements such as wind speed, air temperature, water temperature, and sea-level pressure. We then measured the correlation of those meteorological variables with coastal cases of V. vulnificus, including the outcome, survival, or death. We also constructed a series of logistic regression models to analyze the relationship between temporal and meteorological variables during months that V. vulnificus cases were reported versus months when V. vulnificus cases were not reported. We report that between 2008 and 2020, V. vulnificus cases generally increased over time, peaking in 2017. As water temperature and air temperature increased, so too did the likelihood that infection with V. vulnificus would lead to patient death. We also found that as mean wind speed and sea-level pressure decreased, the probability that a V. vulnificus case would be reported increased. In summary, we discuss the potential factors that may contribute to the observed correlations and speculate that meteorological variables may increase in their public health relevance in light of rising global temperatures.

Effects of continuous positive air pressure on intraocular pressure in patients with obstructive sleep apnea during the split-night study: An open-label randomized controlled trial.

BACKGROUND: Intraocular pressure (IOP) is known to increase at midnight, when continuous positive airway pressure (CPAP) is initiated in split-night CPAP titration (SN-CPAP titration), in patients with obstructive sleep apnea (OSA); therefore, possible excessive increase in the IOP should be investigated. However, related studies on this topic are scarce. OSA causes increases and decreases in the IOP; however, its fluctuation during sleep remains unclear. Therefore, we determined the timing of these fluctuations in the IOP during sleep at night. METHODS: This study included 25 patients with OSA. A 7-hour period of night sleep was divided into first (Sleep-1) and second halves (Sleep-2). Patients were randomly divided into the SN (natural breathing during Sleep-1, CPAP applied during Sleep-2) and C (without CPAP) groups. IOP was measured using the iCare Pro before Sleep-1 and after Sleep-1 and Sleep-2. The main hypothesis was that IOP would be significantly higher in the SN group than in the C group. The sub-hypothesis was that the effects of OSA on IOP are manifested at different times. The correlation is shown as Pearson's r for normally distributed data or Spearman's rho for non-normally distributed data. The difference between the SN and C groups in the time course of IOP during the night's sleep was analyzed using repeated-measures analysis of variance. A P value of <.05 was considered significant. RESULTS: No significant difference was found in IOP between the groups, but the SN group showed a significantly increased IOP during Sleep-2 (post hoc Bonferroni test). The apnea-hypopnea index inversely correlated with IOP changes in Sleep-1 and positively correlated with those in Sleep-2. CONCLUSION: This study does not support our main hypothesis that SN-CPAP titration promotes the effect of CPAP in increasing IOP. However, an expected range of the effect of increased CPAP on IOP has also been suggested. IOP-lowering and IOP-raising effects were predominant in the first and second halves of sleep in OSA, thereby providing a new perspective on measured IOP and supporting the subhypothesis.

The effect of low molecular weight heparin combined with air pressure in the prevention of lower extremity venous thrombosis after cesarean section: A single-center retrospective study.

In this study, we investigated the effect of low-molecular-weight heparin combined with pneumatic pressure in preventing lower extremity deep vein thrombosis after cesarean section, as well as on the visual analog scale (VAS) score. 120 women who underwent cesarean sections at full term in our hospital from January 2019 to January 2022 were included and divided into a control group (55 cases) and an observation group (65 cases) based on the different treatment methods: the control group was treated with low-molecular-weight heparin and the observation group was treated with pneumatic compression therapy based on the control group. The 2 groups were analyzed for thrombosis, clinical efficacy of the treatment methods, and VAS scores. The incidence of deep vein thrombosis in the observation group were significantly lower than in the control group (4.62% vs 21.82%, P < .05). There were no statistically significant differences in activated partial thromboplastin time, prothrombin time, and thrombin time between the 2 groups (P > .05) before treatment; however, after treatment, activated partial thromboplastin time, prothrombin time, and thrombin time in the observation group were significantly higher than those in the control group (P < .05). The clinical efficacy was significantly higher in the observation group compared with the control group (95.38% vs 78.18%, respectively). The VAS scores in the observation group were significantly lower than those in the control group (P < .05). Hence, low-molecular-weight heparin combined with pneumatic pressure therapy significantly reduces the incidence of lower limb deep vein thrombosis after cesarean section. It also improves the coagulation index and reduces post-operative pain. Therefore, it should be considered for use in clinical practice.

Paediatric sleep apnea event prediction using nasal air pressure and machine learning.

Sleep-disordered breathing is an important health issue for children. The objective of this study was to develop a machine learning classifier model for the identification of sleep apnea events taken exclusively from nasal air pressure measurements acquired during overnight polysomnography for paediatric patients. A secondary objective of this study was to differentiate site of obstruction exclusively from hypopnea event data using the model. Computer vision classifiers were developed via transfer learning to either normal breathing while asleep, obstructive hypopnea, obstructive apnea or central apnea. A separate model was trained to identify site of obstruction as either adeno-tonsillar or tongue base. In addition, a survey of board-certified and board-eligible sleep physicians was completed to compare clinician versus model classification performance of sleep events, and indicated very good performance of our model relative to human raters. The nasal air pressure sample database available for modelling comprised 417 normal, 266 obstructive hypopnea, 122 obstructive apnea and 131 central apnea events derived from 28 paediatric patients. The four-way classifier achieved a mean prediction accuracy of 70.0% (95% confidence interval [67.1-72.9]). Clinician raters correctly identified sleep events from nasal air pressure tracings 53.8% of the time, whereas the local model was 77.5% accurate. The site of obstruction classifier achieved a mean prediction accuracy of 75.0% (95% confidence interval [68.7-81.3]). Machine learning applied to nasal air pressure tracings is feasible and may exceed the diagnostic performance of expert clinicians. Nasal air pressure tracings of obstructive hypopneas may "encode" information regarding the site of obstruction, which may only be discernable by machine learning.

A Single-Institution Experience About 10 Years With Children Undergoing Fractional Ablative Carbon Dioxide Laser Treatment After Burns: Measurement of Air Pressure-Induced Skin Elevation and Retraction Time (Dermalab) Including Standardized Subjective and Objective Scar Evaluation.

Laser treatment has gained more and more importance in the therapy of scars during the last years. Scientific work, especially in children, is scarce on this topic and mostly with an insufficient number of cases or only subjective descriptions. Our study included 77 children from 2012 to 2022 with scars after thermal injury. These were treated at least three times or more by CO2 laser or in combination with pulsed dyed laser (PDL). Beforehand, scar texture and elasticity were determined by a skin elasticity analysis system. Regarding the subjective evaluation, a questionnaire was given to the patients or their parents. Further criteria were the Patient and Observer Scar Assessment Scale (POSAS) and Vancouver Scar Scale (VSS). A statistically significant improvement in elasticity was demonstrated in all scars of any age after each laser treatment. In addition, a significant correlation was found between the number of laser treatments and an increase in elasticity. The assessments of scars after one or more laser sessions by the observer as well as the patient showed a decreasing score in all categories with an increase in the number of laser therapies. The VSS score also improved significantly after each laser session. The mean score before treatment was about 7, after the first laser session, the mean score was already below 6 with a statistical significance. Ninety-six percent of the patients or their parents were satisfied with the laser therapy, and 90% wished to repeat the procedure. This work confirms, by means of the objectification by the scar measurement, the previous scientific works concerning a scar therapy by laser and emphasizes particularly that this can also be used without problems with children with symptomatic scars, contractures, or with cosmetically relevant scars.

Superhydrophobic microstructures for better anti-icing performances: open-cell or closed-cell?

Based on geometrical characteristics, all surface microstructures are categorized into two types: closed-cell and open-cell structures. Closed-cell structures are well-known to have more stable and durable superhydrophobicity at room temperatures. However, in low-temperature environments where massive environmentally induced physical changes emerge, whether closed-cell surfaces can maintain good anti-icing performances has not yet been confirmed, and thus how to design optimal superhydrophobic anti-icing microstructures is rarely reported. Here, we apply an ultrafast laser to fabricate superhydrophobic surfaces with tunable patterned micro-nanostructures from a complete closed-cell to different ratios and to a complete open-cell. We discover that droplets on closed-cell structures completely degrade to the high-adhesion Wenzel state after icing and melting cycles while those on the open-cell structures well recover to the original Cassie-Baxter state. We propose an improved ideal gas model to clarify the mechanisms that the decreased air pocket pressure and the air dissolution on closed-cell structures induce easy impalement during icing and the difficult recovery during melting, paving the way for optimizing the anti-icing structure design. The optimized open-cell surfaces exhibit over 33 times lower ice adhesion strengths (1.4 kPa) and long-term icephobic durability (<20 kPa after 33 deicing cycles) owing to the increased air pocket pressure at low temperatures. Significant dewetting processes during condensation endow the open-cell structures with more remarkable high-humidity resistance and anti-frosting properties. Our study reveals the general design principle of superhydrophobic anti-icing structures, which might guide the design of superhydrophobic anti-icing surfaces in practical harsh environments.

Influences of Antithrombotic Elastic Socks Combined with Air Pressure in Reducing Lower Extremity Deep Venous Thrombosis for Patients Undergoing Cardiothoracic Surgery.

This study was designed to investigate the application and therapeutic effect of antithrombotic elastic socks combined with air pressure in the prevention of lower extremity deep venous thrombosis in patients undergoing cardiothoracic surgery. Sixty patients in cardiothoracic surgery of our hospital from January 2019 to December 2020 were randomly divided into a study group and control group. The control group was treated with routine treatment intervention. Based on routine treatment intervention, the study group was treated with antithrombotic elastic socks combined with pneumatic treatment intervention. The activated partial thromboplastin time (APTT), thrombin time (TT), femoral venous blood flow velocity of both lower limbs, and the incidence of lower extremity deep venous thrombosis (LEDVT), postoperative lower extremity swelling, inflammatory factors, and satisfaction were measured. After intervention, APTT (31.74 ± 1.15 s) and TT (14.58 ± 0.24 s) in the study group were higher than those in the control group APTT (25.13 ± 1.14 s) and TT (12.14 ± 0.23 s) (P < 0.05). The left lower limb femoral vein blood flow velocity and the right lower limb femoral vein blood flow velocity in the study group were better than those in the control group (P < 0.05). The incidence of postoperative lower limb swelling and deep vein in the study group was lower than that in the control group (P < 0.05). Serum tumor necrosis factor alpha and interleukin-6 concentrations in the study group were lower than those in the control group (P < 0.05). The satisfaction rate of patients in the study group (93.33%) was significantly higher than that in the control group (70.00%) (P < 0.05). In conclusion, after cardiothoracic surgery, antithrombotic elastic socks combined with air pressure can significantly reduce the incidence of LEDVT by improving patients' coagulation function, reducing inflammatory reaction. It is worthy of popularization and application in relevant surgery.

Prevention of Venous Thrombosis of Lower Limbs after Cesarean Section Based on Smart Medical Air Pressure Therapy Instrument.

Affected by the environment, the incidence of lower extremity venous thrombosis after cesarean section is gradually increasing, and postoperative nursing is becoming more and more important. The intelligent medical air pressure therapy instrument is a common and effective postpartum nursing method. This paper studies the role of pneumatic therapeutic apparatus in the prevention of lower extremity venous thrombosis after cesarean section in smart medicine, describes its importance in nursing, and analyzes the role of pneumatic therapeutic apparatus and smart medicine combined with the postoperative nursing situation of patients with cesarean section in our hospital. In this paper, we aggregate the description text of six levels of hospital intelligent service grading evaluation. In order to show the characteristics of each level and the requirements of each level of hospital intelligent service, we can roughly see the differences between different levels. Research shows that with the construction of medical information platform, more and more medical processes rely on hospital information system, which promotes the integration of medical platform and the interconnection of medical equipment, provides convenient services for patients, and provides patients with easier access to services. At the same time, the massive data generated by appointment, nursing, treatment, and other activities will be recorded, and the pneumatic therapeutic instrument can avoid the occurrence of 60% lower extremity venous thrombosis. The data of air pressure therapeutic instrument is dynamic, and its performance is mainly reflected in the recording of dynamic index data.

A Novel Low Air Pressure-Assisted Approach for the Construction of Cells-Decellularized Tendon Scaffold Complex.

OBJECTIVE: The goal of this study was to develop a decellularized tendon scaffold (DTS) and repopulate it with adipose-derived stem cells (ADSCs) assisted by low air pressure (LP). METHODS: The porcine superficial flexor tendons were processed into the DTSs using a combination of physical, chemical, and enzymatic treatments. The effectiveness of decellularization was verified by histological analysis and DNA quantification. The properties of the DTSs were evaluated by quantitative analysis of biochemical characterization, porosimetry, in vitro biocompatibility assessment, and biomechanical testing. Subsequently, the ADSCs-DTS complexes were constructed via cell injection assisted by LP or under atmospheric pressure. The differences in cell distribution, biomechanical properties, and the total DNA content were compared by histological analysis, biomechanical testing, and DNA quantification, respectively. RESULTS: Histological analysis confirmed that no cells or condensed nuclear materials were retained within the DTSs with widened interfibrillar space. The decellularization treatment resulted in a significant decrease in the content of DNA and glycosaminoglycans, and a significant increase in the porosity. The DTSs were cytocompatible in vitro and did not show reduced collagen content and inferior biomechanical properties compared with the fresh-frozen tendons. The assistance of LP promoted the broader distribution of cells into the adjacent interfibrillar space and cell proliferation in DTSs. The biomechanical properties of the scaffolds were not significantly affected by the recellularization treatments. CONCLUSION: A novel LP-assisted approach for the construction of cells-DTS complex was established, which could be a methodological foundation for further bioreactor and in vitro studies.

Influence of low air pressure on combined nitritation and anaerobic ammonium oxidation process.

At high altitude, wastewater aeration efficiency is low, which is detrimental to nitrification in conventional biological nitrogen removal. The combined partial nitritation and anaerobic ammonium oxidation (CPNA) process requires little oxygen and can be appropriate in low-pressure conditions. As such, in this study, we investigated the effect of air pressure on CPNA using a laboratory-scale reactor. We found that low air pressure promoted the removal of total inorganic nitrogen (TIN), achieving a TIN removal rate of 43,000 mg·N/(kg·VSS·d). The secretion of extracellular polymeric substances under low air pressure was not significantly different from that under ordinary air pressure, indicating no adverse effects on microbial aggregation ability, stability, or settleability. The abundance of aerobic ammonia-oxidizing bacteria (AeAOB) increased from 0.2% to 5.6%, and the activity of anaerobic ammonia-oxidizing bacteria (AnAOB) enhanced, giving AeAOB and AnAOB a competitive advantage over nitrite-oxidizing bacteria, thus forming a microbial community structure favorable to the CPNA process. Our further analysis of the results of batch tests in serum bottles confirmed the positive effect of low air pressure on the anaerobic ammonium oxidation (anammox) process, with a 28.5% ± 1.9% improvement in the specific anammox rate at 70 kPa compared with 100 kPa. AnAOB activity increased, which was reflected in the intracellular heme content increasing from 0.56 ± 0.18 µmol/(g·VSS) at 100 kPa to 2.56 ± 0.20 µmol/(g·VSS) at 70 kPa. We clarified the CPNA-process-promoting effect of low air pressure, which shows potential for nitrogen removal in high-altitude regions.

Long-distance air pressure differences correlate with European rain.

Precipitation in Europe shows natural fluctuations that differ considerably between seasons and geographical regions. A number of studies have linked local or seasonal rainfall variability to various long-distance air pressure differences in north-south or west-east direction. This paper presents the first continent-wide analysis of European rainfall variability on a month-by-month and country-by-country basis. We calculated Pearson r values for unsmoothed monthly rainfall data of 39 European countries over the period 1950-2019 with five potential climatic drivers, namely the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO), the North Sea Caspian Pattern (NCP), and two indices of Mediterranean Oscillation (MOI2, WeMOI). For a variety of countries and months we found substantial and statistically significant r values of up to r = 0.7 and more. The dynamic temporal-spatial evolution of the Pearson correlations was mapped out across the continent, tracking the gradual or abrupt expansion, displacement and subsequent waning of the various effects over the course of the year. The correlation analysis was complemented by best subset multiple regression, controlling for intercorrelation of the potential drivers. Our results may help to improve short- to midterm rainfall prognoses in Europe and provide important calibration data for the further refinement of climate models.

Extraction of cucumber phloem sap based on the capillary-air pressure principle.

Changes in the substances in phloem sap can effectively reflect the nutritional status of cucumber plants during their growth. Because of the limitations of the time-consuming and complex operations of existing phloem sap extraction methods, the authors proposed a new extraction method based on the capillary-air pressure principle and designed a new sap sampling device. To examine the feasibility of the new sampling device, sap sampled from the same plant with the new method and the common EDTA method was analyzed by gas-phase mass spectrometry. The data showed that the number of substances in the sap sampled using capillary-air pressure was higher than that observed using the EDTA method. The concentration of substances sampled using capillary-air pressure was much higher than that observed using EDTA.

What is the better choice for nurses? Alternating air pressure mattresses versus static air mattresses to prevent pressure ulcers in elderly hospitalized patients: A protocol for systematic review and meta-analysis.

BACKGROUND: Evidence on the comparative effectiveness between commercially available support surfaces in preventing pressure ulcer development is lacking. The purpose of this study was to compare the efficacy and safety of alternating air pressure mattresses (AAPMs) versus static air mattresses to prevent pressure ulcers in elderly hospitalized patients and to provide evidence for clinical practice. METHODS: The electronic databases of Cochrane Library, EMBASE, PubMed, and Web of Science will be searched in April 2022 using the following key terms: "pressure ulcers," "support surface," and "pressure mattresses," for all relevant studies. Only English publications are included. The primary outcome is the incidence of pressure ulcers; secondary outcomes include patient satisfaction, cost, and other bedridden complications. The Cochrane risk of bias tool will be independently used to evaluate the risk of bias of included randomized cohort studies by 2 reviewers. A modified version of the Downs and Black tool is adopted to evaluate the quality of nonrandomized cohort studies. All outcomes are pooled on random-effect model. RESULTS: We hypothesized that group with AAPMs will provide better therapeutic benefits compared with control group. CONCLUSIONS: It is worthy to critically review the evidence of the assessment of AAPMs and static air mattresses to inform clinical practice. OSF REGISTRATION NUMBER: 10.17605/OSF.IO/MYPZ2.