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According to the few researches on Nearly zero energy residential buildings (NZERB) in hot-summer and cold-winter zone, although it could reduce the cooling load of buildings due to its high thermal insulation and air tightness, it still needed for certain cooling in summer. This paper studied indoor environment of NZERB under three kinds of air-conditioners (split-type air-conditioner, multi-line air-conditioner and ceiling radiant air-conditioner). Firstly, a simulation model of NZERB was established based on Nanjing, a typical city in hot-summer and cold-winter zone. Secondly, variation of indoor air temperature and building load characteristics with outdoor air temperature were studied. Thirdly, indoor environment and energy consumption under three selected conventional air-conditioners in summer were simulated. Finally, the discussion was given, and an air-conditioner combining with convective and radiant cooling were proposed. The results indicated that the air-conditioner needed to be turned on in NZERB in hot-summer and cold-winter zone due to the room air temperature in off-air condition ranged from 32 °C to 36 °C, which was higher than designed indoor environment temperature in summer, but the indoor environment of NZERB under three selected conventional air-conditioners could not meet the requirements of energy saving and comfort at the same time, and a proposed convective-radiant air-conditioner could be fast, stable, and energy saving. The findings can provide a reference for conducting active technology in NZERB.

PURPOSE To investigate the effects in cataract surgery using local anesthesia along with a 30% low-concentration nitrous oxide (N2O) anesthesia compared with local anesthesia only. SETTING Saneikai Tsukazaki Hospital. DESIGN Retrospective, consecutive study. METHODS Patients who underwent bilateral cataracts surgeries were enrolled. 37 patients using room air inhalation (Air group) and 45 patients using 30% low-concentration N2O anesthesia (70% oxygen, total 6 L/min) at the surgery's beginning (N2O group) were retrospectively reviewed. Systolic blood pressure (BPs), diastolic blood pressure (BPd), and heart rate (HR) at the surgery's beginning and end, and mean intraoperative oxygen saturation (% SpO2) were examined. Immediately following surgery, a questionnaire using the Visual Analog Scale score was done to determine intraoperative pain, anxiety, memory, and nausea. RESULTS No systemic symptoms and ocular complications requiring treatment were observed. For the N2O and Air groups, changes in BPs were -5.38 ± 11.07(P = 0.01) and 1.27 ± 13.61 mmHg, and HR were -2.24 ± 6.76 and 0.89 ± 5.18 bpm (P = 0.001), respectively; intraoperative SpO2 was 99.05 ± 0.74% and 97.44 ± 1.31% (P < 0.001), intraoperative anxiety was 21.76 ± 23.2 and 37.17 ± 32.79(P = 0.002), and intraoperative memory was 55.24 ± 36.8 and 68.91 ± 33.81(P = 0.01), respectively. No patients experienced intraoperative nausea. There was no statistically difference in BPd and intraoperative pain. CONCLUSIONS Low-concentration N2O anesthesia may not cause respiratory depression, abnormal vital signs, or nausea in cataract surgery. It can suppress intraoperative anxiety and memory and decrease and stabilize vital signs.

Objective The dental treatment such as local anesthetic injections are a common source of anxiety and fear during dental procedures. One of the causes of these anxiety and fear are regarded as taste and tactile sensory input. The purpose of this study was to investigate the effects of inhalation sedation with nitrous oxide (IS–N2O) on intraoral taste and tactile sensory input in human. Materials and methods We performed taste testing using electrogustometry and the filter paper disc test in the proglossis region, and precise tactile function testing using the Semmes-Weinstein monofilaments (SWM) test was performed on the mandibular incisor interdental gingival papilla of healthy male and female volunteers. Results On electrogustometry, the 50% IS-N2O threshold was significantly higher than those of other conditions (vs. room air [RA], 100% O2, Recovery, vs. 30% IS-N2O). In the filter paper disc test, the 30%/50% IS-N2O thresholds were significantly higher than those of other conditions (vs. RA, 100% O2, Recovery) for all tastes. However, no significant difference in the recognition threshold was noted between 30% IS-N2O and 50% IS-N2O. In the SWM test, the 30%/50% IS-N2O thresholds were significantly higher than those of other conditions (vs. RA, 100% O2, Recovery), but the 50% IS-N2O threshold was higher than the 30% IS-N2O threshold. Conclusion IS-N2O inhibit the input of taste and tactile sensations and may be an effective tool for patients undergoing dental procedures.

In plant factories, the plant microclimate is affected by the control system, plant physiological activities and aerodynamic characteristics of leaves, which often leads to poor ventilation uniformity, suboptimal environmental conditions and inefficient air conditioning. In this study, interlayer cool airflow (ILCA) was used to introduce room air into plants’ internal canopy through vent holes in cultivation boards and air layer between cultivation boards and nutrient solution surface (interlayer). By using optimal operating parameters at a room temperature of 28°C, the ILCA system achieved similar cooling effects in the absence of a conventional air conditioning system and achieved an energy saving of 50.8% while bringing about positive microclimate change in the interlayer and nutrient solution. This resulted in significantly reduced root growth by 41.7% without a negative influence on lettuce crop yield. Future development in this precise microclimate control method is predicted to replace the conventional cooling (air conditioning) systems for crop production in plant factories.

Excessive dynamic airway collapse (EDAC) contributes to breathlessness and reduced quality of life in individuals with emphysema. We tested a novel, portable, oral positive expiratory pressure (o-PEP) device in a patient with emphysema and EDAC. MRI revealed expiratory tracheal narrowing to 80 mm2 that increased to 170 mm2 with the o-PEP device. After 2-weeks use of the o-PEP device for 33% to 66% of activities, breathlessness, quality of life, and exertional dyspnea improved compared with minimal clinically important differences (MCID): University of California-San Diego Shortness of Breath questionnaire score declined 69 to 42 (MCID, ≥5), St. George's Respiratory Questionnaire score decreased 71 to 27 (MCID, ≥4), and before and after the 6-minute walk test Borg score difference improved from Δ3 to Δ2 (MCID, ≥1). During the 6-minute walk test on room air without the use of the o-PEP device, oxyhemoglobin saturation declined 91% to 83%; whereas, with the o-PEP device, the nadir was 90%. Use of the o-PEP device reduced expiratory central airway collapse and improved dyspnea, quality of life, and exertional desaturation in a patient with EDAC and emphysema.

Improving air quality in occupied area has always been the core focus of ventilation design in cleanrooms. A 10,000 class pharmaceutical cleanroom, with secondary return system, was firstly introduced. Full computational fluid dynamics procedure validated by on-site measurements was then applied to model such cleanroom airflow and particle transport. Energy balance of this ventilation system was also analyzed. Details of room airflow and contaminant fields for the specific zone (above the device and around the human body) were subsequently analyzed concerning the effect of delivering ventilation flow rate and return air volume. Representative parameters, mean age of air, contaminant removal effectiveness, and air change efficiency at the occupied zone and the whole space were evaluated. Results demonstrate that promotion of the return air volume in the occupied area could appropriately reduce pollutant concentration level. Moreover, an increase in ACH (air change rate per hour) did not always shorten the local age of air near the equipment. For a large ACH, it not only will raise the dust around the machine again, it will also cause uncomfortable flow draft. Additionally, when ACH = 20 h−1 and 25 h−1 were achieved respectively, the age of air was reduced by 32% and 21.4% in the whole room and further done by 31.1% and 23.5% in the occupied zone; with identical changes, room air change efficiency (RACE) was achieved at 49.3 % and 50.4 %, respectively. It shows that the increase of ACH seems to have little effect on the air change efficiency. When ACH increases from 15 h−1 to 20 h−1, the efficiency of pollutant removal at the occupied zone will not be significantly improved ( e = 1.78).

In order to satisfy seasonal energy demand in both daytime and nighttime for the building, a hybrid PV/T solar wall system is proposed for area with four distinct seasons. Three different modes are introduced for summer, winter and transition season respectively. Not only are electricity and hot water (or air) generated to reduce building’s energy load in the daytime, cooling load in summer and heating load in other seasons are decreased during the nighttime. Continuous full-day experiments are conducted in three seasons. In transition season, electrical and thermal efficiencies are 11.6% and 55% respectively; temperature of experimental room is 0.6 °C lower and 0.8 °C higher than reference room in the daytime and nighttime respectively; cooling load in the daytime and heating load in the nighttime are both decreased. In winter, electrical efficiency is 12.3%; room air temperature is 10.8 °C and 1.4 °C higher than reference room in the daytime and nighttime respectively; full-day space heating is achieved. In summer, the electrical and thermal efficiencies are 10.2% and 57.3% respectively; room air temperature is 1.2 °C and 0.5 °C lower than reference room in the daytime and nighttime respectively, full-day cooling load is decreased.

On her presentation she was conscious pulse rate was 92 beats per minute and respiratory rate was 16/minute and decreased air entry bilateral lungs and coarse crepitations in both infrascapular and infraaxillary and mammary area- not maintaining saturation with spo2 69% at room air. She was put on nonbreathable mask @ 15 L/minute and she achieved spo2of 92%. Her fetal assessment was done using NST which was reactive. She was managed conservatively on antiviral, antibiotic, oxygen therapy by combination of high flow nasal cannula @60L/min at fio2 80% along with NRM @15 L/min. She was planned for induction once stable and once weaned from high flow nasal cannula. However she kept deteriorating and became tachypneic, dehydrated and delirious. Her repeated investigation revealed rise in TLC of 11800/ul and falling albumin level of 2.6 g/dl and rise in ferritin of 726ng/ml. Her subsequent ABG were suggestive of respiratory alkalosis. Subsequently she was not maintaining saturation and she was intubated and she collapsed. Keywords: Mortality, pregnant patient, COVID-19, respiratory alkalosis.

Hyperthermic (or Heated) Intraperitoneal Chemotherapy (HIPEC) is a surgical procedure that’s giving new hope to patients with abdominal cancers. Immediately after removing visible tumors through cytoreductive surgery, surgeons give a dose of heated chemotherapy inside a patient’s abdomen. The technique involves macroscopic resection of disease burden and metastases, followed by infusion of chemotherapy heated to 41°C–43°C into the peritoneal cavity through a special device. After 90 minutes of the infusion, the chemo is washed out and incisions are closed. Chemotherapy: -In HIPAC (Intraperitoneal) mitomycin-c is the most common drug administrated and platinum-based drugs, cisplatin, carboplatin, and oxaliplatin which have a synergistic effect with heat, and doxorubicin, paclitaxel, docetaxel, and 5-fluorouracil drugs are commonly less used. The technique of Hyperthermic intraperitoneal chemotherapy Administration: HIPEC is administrated by two classical methods, the open abdomen method, and the closed method. Skin preparation of patient: Skin preparation is from the mid-chest to midthigh with the preparation of the genitalia and catheterization.Safety guidelines for administration of HIPEC: A sign the HIPEC is in progress should be placed at the door and the entry of personnel not involved in the procedure should be restricted. N95 grade mask provides the best protection against surgical smoke produced during the use of electrocautery. Doors should be closed during the operation with pressurized closures. The temperature should be 18–26 degrees Celsius and air humidity 45–60 %. The Association for peri-Operative Registered Nurses (AORN) recommends that operating room air exchanges should be maintained at a minimum of 15 air exchanges per hour. Air inflow volume should be 15 % higher than the outflow, airspeed must be lesser than 0.3 m/s. Appropriate PPE (personal protective equipment) consists of an N95 face mask (a simple surgical mask does not provide adequate protection), gloves, protective gown, and overshoes or laggings to provide adequate protection to all involved team members.Handling of the chemotherapy during HIPEC: it should be prepared in the bio-safety cabinet not in the ward because of the danger from spillage and contamination, while preparing cytotoxic drugs to wear nitrile or neoprene powder-free long cuff gloves and wear a gown non-permeable long sleeve, cuffed and solid fronted and use an aerosol-free mask. Every effort should be taken to avoid any spill. Hospital policies to prevent spills should be adopted by the surgical and operation theatre team members and written procedures must specify the team responsible for spill management. Health care institutions should develop a plan and policy for handling hazardous medications. Collection, labeling, storage, transport, and disposal of contaminated waste should be done as per hospital policy.Cleaning the operating room after HIPEC: Soap water is adequate to clean the operating room after HIPEC three consecutive times. 70% of isopropyl alcohol is also safe and effective.Conclusions: All available studies point out that the correct use of specific protective measures is a key factor to minimize exposure. Emphasis has to be also placed on educating and instructing the involved personnel in the hazards and safe use of chemotherapy, the importance of adherence to safety protocols, and the correct use of the recommended personal protective equipment.

BACKGROUND: This study aimed to evaluate the accuracy of pulse oximetry-derived oxygen saturation (SpO2) on room air, determined at hospital admission, as a predictor for the need for mechanical ventilatory support in patients with Coronavirus Disease-2019 (COVID-19). METHODS: In this retrospective observational study, demographic and clinical details of the patients were obtained during ICU admission. SpO2 and respiratory rate (RR) on room air were determined within the first 6 h of hospital admission. As all measurements were obtained on room air, we calculated the simplified respiratory rate­oxygenation (ROX) index by dividing the SpO2 by the RR. Based on the use of any assistance of mechanical ventilator (invasive or noninvasive), patients were divided into mechanical ventilation (MV) group and oxygen therapy group. The accuracy of the SpO2, CT score, and ROX index to predict the need to MV were determined using the Area under receiver operating curve (AUC). RESULTS: We included 72 critically ill patients who tested COVID-19-positive. SpO2 on the room air could predict any MV requirement (AUC [95% confidence interval]: 0.9 [0.8-0.96], sensitivity: 70%, specificity 100%, cut-off value ≤78%, P < 0.001). Within the MV group, the use of noninvasive ventilation (NIV) was successful in 37 (74%) patients, whereas 13 patients (26%) required endotracheal intubation. The cut-off ROX value for predicting early NIV failure was ≤1.4, with a sensitivity of 85%, a specificity of 86%, and an AUC of 0.86 (95% confidence interval of 0.73-0.94, P < 0.0001). CONCLUSIONS: A baseline SpO2 ≤78% is an excellent predictor of MV requirement with a positive predictive value of 100%. Moreover, the ROX index measured within the first 6 h of hospital admission is a good indicator of early NIV failure.

Objective To determine the presence of genetic material from potentially infectious airborne respiratory virus pathogens in a pediatric emergency department (PED) waiting room. Methods A cross-sectional study in the waiting room area of PED at Santo Antonio Children's Hospital, Porto Alegre, in southern Brazil. The room air samples were collected with a portable cyclone sampler (Coriolis®), twice a day (8 a.m. and 8 p.m.), during 5 consecutive weekdays, during two seasons, fall and spring (20 samples), in 2016. Reverse transcription polymerase chain reaction was used to detect influenza A, influenza B, parainfluenza 2, parainfluenza 3, human metapneumovirus, respiratory syncytial virus, human adenovirus, human bocavirus, and Bordetella pertussis. The PED provides care to an average of 6000 patients per month and the age of patients ranges from 1 month to 17 years old. It is waiting area has 645 ft square. Results Genetic material from pathogens was detected in 12 out of 20 samples (60%). In 5 samples, more than one pathogen of respiratory virus was identified. Human adenovirus was the most frequent pathogen (n = 9/52%), followed by Bordetella pertussis (n = 4/24%), respiratory syncytial virus (n = 2/12%) and human bocavirus (n = 2/12%). Season and number of people in the waiting room were not associated with the presence of genetic material from pathogens. Conclusions Genetic material from pathogens potentially associated with severe respiratory diseases was found in the room air of a pediatric ED waiting room.

The inferior alveolar nerve block (IANB) does not always result in successful pulpal anesthesia. Nitrous oxide may increase the success of the IANB. The purpose of this investigation was to study the effect of nitrous oxide/oxygen (N(2)O/O(2)) on IANB injection pain and mandibular pulpal anesthesia in asymptomatic subjects. One hundred five asymptomatic subjects received an IANB after the administration of N(2)O/O(2) or room air/oxygen (air/O(2)) at 2 separate appointments. After the IANB, subjects rated their level of pain for each phase of the injection (needle insertion, needle placement, and solution deposition) using a Heft Parker visual analog scale. Pulpal anesthesia was evaluated with an electric pulp tester for 60 minutes. The mean pain rating for all 3 injection phases showed a statistically significant reduction in pain when N(2)O/O(2) was used compared with Air/O(2) (P < .05). Odds ratios demonstrated a statistically significant increase in IANB success for the N(2)O/O(2) group compared with the air/O(2) group. N(2)O/O(2) administration statistically decreased pain for all 3 injection phases of the IANB. In addition, nitrous oxide statistically increased the likelihood of pulpal anesthesia for posterior mandibular teeth. However, the incidence of pulpal anesthesia was not 100%.

In this research, Medwave air and surface disinfection system (model:Klin20)selected to investigation effect , towards aerosolised enveloped viruses in room air. Phi6Pseudomonas syringae phage, a surrogate for coronavirus and influenza, was used in the trials Viral suspensions of Phi6 were aerosolised within the ukas accreditation Campden BRI aerobiology laboratory to achieve initial levels of ~106PFU/m3, representing very heavily contaminated air . Air samples were taken at 15 minute intervals and analysed to determine levels of Phi6 in the room air over a total test period of 135 minutes. On 3 separate days, paired trials were carried out with the Medwave switched onand with the units witched off as a control to determine baseline levels of virus in the air overtime. Trials carried out on the first two test days showed no reduction in viral titre compared with the control. Further investigation revealed that a wiring loom within the test unit had become disconnected during transport and the instrument was therefore not functioning correctly. Results from the trial showed that the level of Phi6 in the room air decreased rapidly from an initial titre of 6.12 log PFU/m3to undetectable levels (

HC-290 is one of the alternatives to HCFC22 in room air-conditioners. With the phase-down schedules in Kigali Amendment, it is imperative to use HC-290. However, there are concerns about its flammability in the event of a leak from the AC indoor unit (IDU). IEC 60335-2-40 has been revised to extend the capacity ranges for A2L refrigerants and is being further revised with a focus on A2 and A3 refrigerants. In real-life situations, furniture and occupants are present inside the room and these may positively or negatively influence the dispersion of any leaked HC-290. CFD simulation of dispersion of leaked HC-290 has been carried out for a variety of scenarios. The variables include leakage rates, IDU installation heights, IDU blower ON or OFF and types of furniture. Furniture, in general, appears to promote mixing, thereby reducing HC-290 stratification. The maximum concentration occurs on the side where the leak is directed by the momentum of the jet from IDU. There is no significant effect on the concentration distribution by the type and size of furniture with legs, although solid furniture has some marginal effect due to reduction of room free volume. The average concentration of HC-290 in the room is slightly more when the solid furniture like cupboards are placed some distance away from the IDU. The highest concentration at 30 cm above floor level, is 44% of LFL when the blower is ON, while it is 62% when the blower is OFF.

Oxygen supplementation is rarely considered when anesthetizing laboratory mice, despite reports that mice become profoundly hypoxic under anesthesia. Little is known about the effects of hypoxia on anesthetic performance. This article focuses on the effects of oxygen supplementation on physiologic parameters and depth of anesthesia in male and female C57BL/6 mice. Anesthesia was performed via common injectable anesthetic protocols and with isoflurane. Mice anesthetized with injectable anesthesia received one of 3 drug protocols. Low-dose ketamine/xylazine (100/8 mg/kg) was chosen to provide immobilization of mice, suitable for imaging procedures. Medium-dose ketamine/xylazine/acepromazine (100/10/1 mg/kg) was chosen as a dose that has been recommended for surgical procedures. High-dose ketamine/xylazine/acepromazine (150/12/3 mg/kg) was chosen after pilot studies to provide a long duration of a deep plane of anesthesia. We also tested the effects of oxygen supplementation on the minimum alveolar concentration (MAC) of isoflurane in mice. Mice breathed supplemental 100% oxygen, room air, or medical air with 21% oxygen. Anesthetized mice that did not receive supplemental oxygen all became hypoxic, while hypoxia was prevented in mice that received oxygen. Oxygen supplementation did not affect the MAC of isoflurane. At the high injectable dose, all mice not receiving oxygen supplementation died while all mice receiving oxygen supplementation survived. At low and medium doses, supplemental oxygen reduced the duration of the surgical plane of anesthesia (low dose with oxygen: 22 ± 14 min; low dose without supplementation: 29 ± 18 min; medium dose with oxygen: 43 ± 18 min; medium dose without supplementation: 61 ± 27 min). These results suggest that mice anesthetized with injectable and inhalant anesthesia without supplemental oxygen are routinely hypoxic. This hypoxia prolongs the duration of anesthesia with injectable drug protocols and affects survival at high doses of injectable anesthetics. Because of variable responses to injectable anesthetics in mice, oxygen supplementation is recommended for all anesthetized mice.

To investigate the impact of oxygen delivery on the clinical outcomes of accelerated transepithelial corneal cross-linking (A-TE CXL). Fifty-seven eyes of 44 progressive keratoconus (KCN) patients were randomly separated into two age–sex-matched groups. Twenty-nine eyes of 23 KCN patients that underwent oxygen-supplemented A-TE CXL formed the study group and 28 eyes of 21 patients treated with the same procedure but under room air conditions formed the control group. All patients were examined preoperatively, one, six and twelve months after the procedure. The logMAR spectacle-corrected distance visual acuity (CDVA), maximum keratometry (Kmax), mean keratometry, apical posterior keratometry, cylindrical power, minimum central corneal thickness, keratoconus vertex front and back, ocular aberrations, endothelial cell density (ECD), demarcation line depth (DLD) and proportion measures were recorded for statistical analysis. The preoperative, 1st, 6th and 12th months mean Kmax values of the study group were 55.14 ± 3.99D, 54.85 ± 3.82D, 54.37 ± 3.84D and 54.40 ± 3.86, respectively, and 54.47 ± 3.17D, 54.52 ± 2.97D, 54.25 ± 2.95D and 54.20 ± 2.97 in the control group. The mean Kmax value was decreased significantly more in the oxygen-supplemented group after 12 months compared to the control group (p = 0.019). The mean DLD was also significantly deeper in the study group (320 ± 17 µm) compared to the control group (269 ± 19 µm). There was no significant difference between the two groups in terms of ECD alterations at any of the time intervals (p > 0.05). Keratoconus progression was significantly halted in both groups 12 months after the treatment. In addition, oxygen supplementation during A-TE CXL further significantly increased clinical outcomes compared to room air conditions without any significant change in ECD measures.

Background. Inhaled nitric oxide is a highly selective pulmonary vasodilator, the potential benefits of which include reduced resistance and pressure in the pulmonary artery without systemic arterial hypotension, vasodilation in well-ventilated areas of the lungs, rapid onset of action, and a fairly low incidence of side effects in the therapeutic dose range.Objective. Тс estimate the clinical efficacy and safety of the method for synthesizing nitric oxide from room air in the postoperative period of cardiac surgery.Design and methods. A total of 110 patients were enrolled in the study: 55 patients were included in the main group (nitric oxide was synthesized from room air by AIT-NO-01 device), 55 patients were enrolled in the retrospective control group (nitric oxide was inhaled from the balloon). Inclusion criteria were: undergone heart surgery, mean pulmonary artery pressure (PAPm) ≥ 25 mm Hg., pulmonary artery wedge pressure (PAWP) ≤ 15 mm Hg.Results. After one hour of nitric oxide inhalation in the main group, there were a 35 % decrease in PVR and a 16 % decrease in PAPm. In the control group, there were a decrease in PVR by 40 % and decrease in PAPm by 19 %. Inhalation of nitric oxide did not affect the systemic circulation hemodynamics both in the main and in the control groups. The median duration of the mechanical ventilation (MV) was 7.3 (4.5; 13.8) h and the median length of stay (LOS) in the ICU was 23.2 (21.3; 46) h in the main group. In the retrospective control group, the median duration of MV was 8.2 (5; 14.1) h, and the length of ICU stay was 24 (22; 45.3) h; found no differences between the groups.Conclusion. Nitric oxide synthesized from room air significantly reduces PVR and PAPm in patients with precapillary pulmonary hypertension after cardiac surgery. There were no significant differences in the effect on a pulmonary circulation, clinical data and side effects between the methods of synthesis of nitric oxide from room air and dosing from balloons.

Aerosol transmission is now widely accepted as the principal way that COVID‐19 is spread, as has the importance of ventilation—natural and mechanical. But in other than healthcare facilities, mechanical ventilation is designed for comfort, not airborne infection control, and cannot achieve the 6 to 12 room air changes per hour recommended for airborne infection control. More efficient air filters have been recommended in ventilation ducts despite a lack of convincing evidence that SARS‐CoV‐2 virus spreads through ventilation systems. Most transmission appears to occur in rooms where both an infectious source COVID‐19 case and other susceptible occupants share the same air. Only two established room‐based technologies are available to supplement mechanical ventilation: portable room air cleaners and upper room germicidal UV air disinfection. Portable room air cleaners can be effective, but performance is limited by their clean air delivery rate relative to room volume. SARS‐CoV‐2 is highly susceptible to GUV, an 80‐year‐old technology that has been shown to safely, quietly, effectively and economically produce the equivalent of 10 to 20 or more air changes per hour under real life conditions. For these reasons, upper room GUV is the essential engineering intervention for reducing COVID‐19 spread., Besides natural and mechanical ventilation, the two main approaches to increased air disinfection in rooms are upper room ultraviolet germicidal irradiation (UVGI) and room air cleaners—forcing room air through a HEPA filter, UV, plasma fields or filter enhanced by bipolar ionization. In an unpublished study in Russia, Drs Grigory Volchenkov and Paul Jensen (then US CDC) used a recently renovated hospital room to aerosolize test organisms and perform quantitative air sampling. They found upper room UVGI far less expensive per year per equivalent air changes per hour (ACH) compared to mechanical ventilation or 3 different commercial air cleaners.

Workplaces with elevated organic dust levels such as animal feed barns also commonly have elevated levels of gasses, such as CO2. Workers exposed to such complex environments often experience respiratory effects that may be due to a combination of respirable factors. We examined the effects of CO2 on lung innate immune responses in mice co-exposed to the inflammatory agents lipopolysaccharide (LPS) and organic dust. We evaluated CO2 levels at the building recommended limit (1000 ppm) as well as the exposure limit (5000 ppm). Mice were nasally instilled with dust extracts or LPS and immediately put into chambers with a constant flow of room air (avg. 430 ppm CO2), 1000 ppm, or 5000 ppm CO2 enriched air. Results reveal that organic dust exposures tended to show decreased inflammatory responses with 1000 ppm CO2 and increased responses at 5000 ppm CO2. Conversely, LPS with addition of CO2 as low as 1000 ppm tended to inhibit several inflammatory markers. In most cases saline treated animals showed few changes with CO2 exposure, though some changes in mRNA levels were present. This shows that CO2 as low as 1000 ppm CO2 was capable of altering innate immune responses to both LPS and organic dust extracts, but each response was altered in a different fashion.

In this project an air conditioner was fabricated using R-410a as refrigerant and its COP is calculated. CFCs have been phased out, except for essential users, and HCFCs are to be eliminated by 2020, because of their ozone depletion potential.This generates a need for the investigation of zero ozone depletion potential (ODP) refrigerants or refrigerant blends.R410A is among newer brand of refrigerant blend, with zero ODP. The biggest difference to R22 is the pressure levels generated which are more than50% higher. The refrigerant R410A operates at higher pressure at the same saturated temperatures than R22, therefore system should be re designed. The overall COP of the system is 5 to 6% more than the R22. We also calculated the relative humidity of room air after it gets cooled, heat removed from the air by considering the input data from weather online which provides us the day to day climatic conditions. Present work provides us regarding performance of an self fabricated zeotropic air conditioner.

A numerical simulation was carried out to investigate the cooling performance and thermal comfort of a 4-way cassette air conditioner when its vanes are positioned at constant angles of 30°, 40°, 50° and 60° and swinging with a constant angular velocity. The indoor airflow characteristics and thermal comfort were evaluated. The average room temperature variation with respect to time have a good agreement with the measured data with a maximum relative error of 2 %. The average room air temperature variation according to time shows that the case of swinging vane is increased by 5.9 %, compared to the case of fixed vane angle of 60°, due to the enhancement of heat transfer by the swinging motion of discharged airflow. Moreover, the flapping discharged airflow resulting from the swinging motion makes occupants feel thermally more comfortable, based on thermal comfort indices.

To investigate if the detergent sclerosant sodium tetradecyl sulfate (STS) is deactivated by the lipid-based contrast agent ethiodised oil. 3% STS was mixed with ethiodised oil and room air in a 2:1:4 ratio in two luer lock syringes and a three way connector and agitated to make foam (the Tessari technique) to replicate the clinical use of the products. The assay of STS in the mixture was assessed using the British Pharmacopoeia method. Briefly this is a manual titration method where the solution of STS is mixed with an indicator solution and titrated with hyamine solution of known concentration; the concentration of the STS can then be calculated with the titration results. To further mimic the clinical environment with the presence of blood, the effect of adding increasing amounts of albumin to the STS-ethiodised oil mixture was assessed. The assay of STS in the solution after mixing with ethiodised oil was 3% indicating that the ethiodised oil did not deactivate the STS. The addition of albumin to the STS-contrast mixture resulted in near linear neutralisation of the STS with increasing concentrations in the same quantities as with STS alone. The mixture of the lipid-based contrast agent ethiodised oil with the detergent sclerosant STS did not affect the availability of the sclerosant. The continued use of STS-ethiodised oil in the management of vascular malformations can be supported.

Due to the airborne transmission of the coronavirus disease 2019 (COVID 19) via aerosols or microdroplets, this study investigated the effect of a mobile air filter system in a surgical examination room. The use of the air filter system led to a significant reduction of aerosols in the room. Therefore the use of a high efficiency air filtration device, in examination rooms with poor ventilation, e.g. lack of windows or local exhaust, is mandatory.Vor dem Hintergrund des Übertragungsweges von SARS-CoV-2-Viren durch kontaminierte Luftschwebeteilchen (Aerosole) wurde in einem chirurgischen Untersuchungsraum ohne Lüftungsmöglichkeit die Belastung an Luftschwebeteilchen mit bzw. ohne Verwendung eines Luftfiltergerätes gemessen. Hierbei zeigte sich bei Verwendung des Filtergerätes eine deutliche Reduktion der entsprechenden Luftpartikel. In Untersuchungs- und Behandlungsräumen, die baubedingt keine Lüftungsmöglichkeiten bieten, sollten mobile Luftfiltergeräte daher zum Einsatz kommen.

Burn injury and operating room fires are significant risks for both surgical patients and staff. The purpose of this study was to examine the fire and burn risks associated with two types of fiberoptic light cables and evaluate the efficacy of a novel device in reducing the risk of these fire and burn injuries. A 300-W light source was connected sequentially to two standard fiberoptic cables (Storz and Olympus). The distal ends were buried in, or rested on, standard operating room materials including a cotton green towel and a blue propylene drape to assess the risk of fire formation or burn injury. The Gloshield device was then attached to the ends of the cables and the experiment was repeated. Trials simulating improper use of the device were then conducted with the Gloshield device placed either too deep or too shallow on the end of the light cable. All trials were conducted for a maximum of 10 min or until a positive result (burn or fire) was achieved. Trials were conducted in room air or with supplemental 100% oxygen and repeated for accuracy. Both the Storz and Olympus fiber optic cables were capable of producing burns in standard operating room towels and drapes in control trials. The Gloshield device prevented thermal injury when properly attached in all conditions. Improper use trials demonstrated that the device may be ineffective when not applied properly. The Gloshield device is effective in reducing the risk of thermal burn injury by protecting the distal ends of endoscopic light cables from operating room materials. However, the device needs to be attached appropriately in order to provide protective benefits.

To assess potential exposure of non-users to exhaled constituents from pod and cartridge electronic nicotine delivery systems (ENDS) products, an environmental clinical study was conducted with (n = 43) healthy adult smokers. Room air concentrations of 34 selected constituents (nicotine, propylene glycol, glycerin, 15 carbonyls, 12 volatile organic compounds, and 4 trace metals) and particle number concentration (0.3 to 25 µm) were compared from use of two ENDS products and conventional cigarettes using room ventilations representative of a residential, an office or a hospitality setting over a 4-h. exposure period. Products used were JUUL ENDS, Virginia Tobacco flavor (Group I), VUSE Solo, Original flavor (Group II) (5.0 and 4.8% nicotine by weight, respectively) and subjects’ own conventional cigarettes (Group III). Cumulative 4-h room air sampling and particle counting were performed during prescribed (Groups I and II) and ad libitum product use (all Groups). Conventional cigarette use resulted in significantly more constituents detected and higher 4-h cumulative constituent concentrations compared to use of the ENDS products tested, except for the predominant ENDS ingredients, propylene glycol and glycerin. Use of conventional cigarettes also resulted in greater total particle number concentration than either prescribed or ad libitum use of either of the ENDS used in this study.

Background Chronic lung disease remains a burden for extremely preterm infants. The changes in ventilation over time and optimal ventilatory management remains unknown. Newer, non-invasive technologies provide insight into these patterns. Methods This single-center prospective cohort study enrolled infants ≤32 0/7 weeks. We obtained epochs of transcutaneous carbon dioxide (TcCO2) measurements twice each week to describe the pattern of hypercarbia throughout their hospitalization. Results Patterns of hypercarbia varied based on birth gestational age and post-menstrual age (PMA) (p = 0.03), regardless of respiratory support. Infants receiving the most respiratory support had values 16–21 mmHg higher than those on room air (p

The most part of chemical substances applied in clean rooms are aggressive and toxic, which requires analysis of air removal system not only from functionally related standpoint but also with regard to energy and environment. This study investigates the possibility of applying the methodology of energy and environmental analysis to compare the environmental friendliness of various air removal systems of clean rooms. It was shown that direct air removal, although having a thermodynamic advantage over a system with purification, was less favorable for the environment due to the significant level of the environmental index, which reflected the considerable potential economic damage from emissions to the atmosphere. This investigation has revealed the pollutants dominating in the composition of emissions and determining the validity of the decision on the structure of the air removal system of the clean room, taking into account the environmental, economic and biomedical aspects of its operation.

Background , school education facilities, including higher education as a place and public facilities for formal education facilities in this country, should be a comfortable place to study. Besides functioning as a place of learning, schools can also be a threat of disease transmission . measurement number of bacteria in the air-conditioned classrooms Wulan R22 (2016) 12.167 CFU / m 3 , Nur Latifah (2018) an average of 217.92 colony / hr / ft 2 , hadita (2018) 331.6 colonies / hr / ft 2 . Research question is how is the effectiveness of UVAerator in reducing the number of air germs and dust levels in the lecture hall R22 building Campus 7 Poltekkes Kemenkes Semarang ? Research objectives is to find the effectiveness of UVAerator in reducing the number of air germs and dust levels in the lecture hall. Research method included a quasi-experimental design with a non-equivalent control group pre test - post test. Data collection by measuring, observational, interview. The variables were temperature, humidity, lighting, air germ count, dust content. Analysis using pairet-t test comparisons and unpaired t test data. Result, the average number of bacteria with no air space UVAerator in the morning is ( 668,00 g / m 3 ) and in the afternoon is ( 680.10 g / m 3 ) the difference was not significant (p = 0.873), whereas the existing space UVAerator in the morning ( 876.50 g / m 3 ) and in the afternoon ( 655.50 g / m 3 ) shows significant difference (p = 0.001). The number of room air germs that do not exist and have UVAerator is significantly different (p = 0.002), the number of room air germs that are not there and without any UVAerator is not significant (p = 0.763), while the change in the number of room air germs that does not exist and exist UVAerator has a significant difference (p = 0.015). On average PM10 space dust that has no UVAerator in the morning ( 12.38 ug / m 3 ) and in the afternoon ( 17.38 ug / m 3 ) shows significant difference (p = 0.008), whereas the existing space UVAerator in the morning ( 11.63 g / m 3 ) and day ( 14.50 µg / m 3 ) shows that the difference is not significant (p = 0.127). PM10 dust in the room that does not exist and there is no UVAerator ported, the difference is not significant (p = 0.821), the PM10 dust in the room noon and there is UVAerator, the difference shows that it is not significant (p = 0.432), while the change in room PM10 without dust and there is a difference in UVAerator significant (p = 0.004). In conclusion , the effectiveness of reducing the number of air germs without UVAerator on average (4.56%), with UVAerator (-24.52%), the difference was not significant (p = 0.057). The effectiveness of reducing PM10 without UVAerator, mean (60.50%), with UVAerator (38.30%), the difference was not significant (p = 0.369). Suggestion, , It is necessary to control the sound intensity caused by UVAerator by adding aeration bubble breakers. The pump suction power is enlarged to accelerate the circulation of room air.

Pneumonia associated with coronavirus disease 2019 (COVID-19) has been accounted for high mortality rate in severe COVID-19 worldwide, and additional serious scarcity of standard and effective anti-inflammatory drug in COVID-19 pneumonia management is a big challenge. Baricitinib, a Janus kinase (JAK) inhibitor, is a promising drug in COVID-19 pneumonia. This study aims to compare the clinical outcome of moderate-to-severe COVID-19 pneumonia treated with baricitinib with or without a loading dose. This prospective case-control study enrolled 37 adult patients where 17 patients (control) received baricitinib at 4 mg oral daily dose and 20 patients (case) received an additional single 8 mg oral loading dose. The median day to gain blood oxygen saturation level ≥95% (in room air) and return in normal breathing function were lower in case group than the control group. The requirement of intensive care unit and mechanical ventilation support was higher in the control group than in the case group [29.4% (N = 17)/10% (N = 20), P < 0.05; 11.8% (N = 17)/5% (N = 20), P > 0.05), respectively]. Thus, an additional loading dose of baricitinib revealed better clinical outcome of patients with COVID-19 pneumonia.

The multifactorial nature of the retinopathy of prematurity (ROP) pathogenesis, makes the thorough study of the mechanism of pathological retinal neovascularization actual. However recently the attention of scientists has been attracted by the participation of renin-angiotensin system (RAS) in the development of retinal vasoproliferative diseases. Purpose: to study the role of AT-II in the pathogenesis of experimental ROP (EROP) in the original model of the disease. Material and methods. To reproduce EROP Wistar rats (n = 15) were exposed to the oxygen concentration varying from 60 to 15% every 12 hours for 14 days from the first day after birth followed by room air for 7 days. Throughout the experiment, the room maintained a constant temperature (+26 °C) and light regime (12 hours a day, 12 hours a night) modes. Control rats (n = 12) were born and kept under normal oxygen content (21 %). Batches of EROP (n = 5) and control (n = 4) rats were sacrificed on 7, 14 and 21 days. All rats underwent binocular enucleation, after which every eyeball was opened on the limb, the cornea and lens were removed with the remains of a persistent vascular bag and a hyaloid artery. Retinas were isolated, homogenized and stored at -20 °C. Angiotensin-II (AT-II) in homogenates was measured using the IFA kit. Results. On the 7th day of the experiment, the level of AT-II in the retina of the experimental group rats was 0.19 ± 0.02 pg/mg protein that was significantly higher than in controls (0.12 ± 0.01 pg/mg protein). On the 14th and 21st days concentrations of AT-II in EROP and control groups had no significant difference. Conclusion. On the 7th day of the experiment, i.e. at the period corresponding to the existence of avascular retinal zones in both groups concentration of AT-II in the retinas of rats with EROP was significantly higher than in controls. This fact indicate the role of this proangiogenic factor in the induction of pathological neovascularization in ROP. Possible prognostic function of this parameter during the period before ROP manifestation has undoubted practical significance.

Interest for air-conditioning systems (ACs) has exponentially expanded worldwide throughout the most recent couple of decades. Countries with booming economies including Saudi Arabia report high growth of sales of room air conditioners. With the expanded (GDP) and warming climates, interest for room air-conditioning systems is required to additionally increment. Meeting the expanded need for electricity energy will be a challenge. Expanded utilization of energy-efficient air conditioners impactsly affects lowering the electricity demand. In an ordinary AC, the blower runs at a fixed speed and is either ON or OFF. In an inverter AC, the compressor is consistently on; however, power drawn relies upon the demand for cooling. The speed of the compressor is adjusted appropriately. In this paper, the energy consumption of non-inverter and an inverter AC of the same capacity was assessed in an average office room, under comparative operating conditions, to find the differences in the energy saving, Carbon Dioxide (CO2) emission, and power consumption of air conditioner. Energy consumption was measured for about 108 days, which is from July 16th to October 31st, 24/7, and compared. The experiment is conducted with the same conditions and same capacity air conditioners (18,000 BTU). Results show that the day-by-day normal vitality utilization, the inverter will save up to 44% of electrical consumption compared to a non-inverter of 3471 kWh/year and 6230 kWh/year respectively. Furthermore, the Total Equivalent Warming Impact (TEWI) analysis shows that inverters can save 49% of CO2 emissions.

To respond to new energy efficiency standards and environmentally friendly policies in hot climate regions, it is necessary to develop high-efficiency air conditioners. The environmentally friendly...

Aims The aim of the study was to explore the functional and structural changes of the diaphragm and underlying mechanisms in response to 12 or 24 weeks of cigarette smoke (CS) exposure in rats. Materials and methods Rats were exposed to CS to develop a COPD model and the rats exposed to room air served as a control group. Rats were randomly divided into four groups: CS12W, CON12W, CS24W, and CON24W. Pulmonary function, lung histopathology, and the contractile properties and ultrastructure of diaphragm muscle were examined in these rats. The changes of transcriptomic profiling of diaphragm muscle were further compared between CS and control rats by the RNA Seq. Results Both CS groups showed lower FEV0.3/FVC, elevated mean linear intercept (MLI), and reduced mean alveolar numbers (MAN) vs the control groups. The fatigue index (FI) of the diaphragm muscle from the CS12W group, but not CS24W, was significantly increased. Conversely, the force-frequency curves of the diaphragm muscle from the CS24W group, but not CS12W group, were significantly decreased. Consistently, mitochondrial number density (NA) and volume density (Vv) were increased in the CS12W diaphragm muscle, while being decreased in the CS24W group. Furthermore, the diaphragm transcriptomic profiling results showed that genes regulating cell proliferation and energy metabolic activity were un-regulated and genes regulating protein degradation were down-regulated in the CS12W diaphragm, while CS24W diaphragm showed opposite changes. Conclusion These observations suggested a transition of diaphragm muscle from initial compensatory to decompensatory changes in function, structure, and gene expression during the development of COPD.

Shifting of air conditioning and ventilation plants from conventional to renewable energy systems is one of the effective ways to save energy and attain sustainability. In this experimental study, an effort has been made to design, fabricate, and evaluate the cooling performance of a solar-powered domestic air cooler with Peltier plates to meet the comfort criteria as per ASHRAE standards. It also investigates the effect of Peltier modules on the performance of conventional room air cooler. The experiments were conducted in a 12×12 room with one, two, three, and four Peltier modules operating at various ambient temperatures. The experiments were repeated three times at specified conditions. Peltier effect was used to decrease water temperature, and subsequently cooled water was used to decrease the temperature of the air after coming in contact with this water. The cooled air was then used to create a comfort zone. The results indicated a decrease in temperature of the experimental zone by 5 %, 13 %, 19 %, and 23 % using one, two, three, and four Peltier modules respectively. The increase in relative humidity was recorded as 5 % at 27 °C temperature of the experimental zone. The results of energy analysis showed a substantial amount of energy savings in this study and suggest that more than 200 MW energy can be saved by replacing conventional electric air coolers all over the country with proposed Peltier based domestic solar powered air cooler.

BACKGROUND/AIMS: Room air (RA) and carbon dioxide (CO(2)) are widely used to insufflate the colon to examine the mucosa in colonoscopy. Pain, discomfort, and bloating can be seen during and after colonoscopy secondary to bowel distention. This study aimed to investigate the effect of CO(2) on post-procedure pain sensation (PPPS) in comparison with RA. MATERIALS AND METHODS: Patients were randomly assigned to the RA and CO(2) insufflation groups in a 1:1 ratio. The visual analog scale (VAS) was used to measure the pain before and after the colonoscopy. VAS score of 0 was accepted as the absence of pain and above 0 was accepted as the presence of pain. The primary outcome was to investigate the effect of CO(2) insufflation on PPPS. Secondary outcomes were to investigate the other contributing factors affecting PPPS and the effect of CO(2) on PPPS in patients with inflammatory bowel disease (IBD). RESULTS: A total of 204 patients were enrolled in the study. No significant difference in PPPS was seen between the 2 groups at any point in time after the colonoscopy. Furthermore, there was no significant difference in pain sensation between the CO(2) and RA groups in patients with IBD. When we investigated the other contributing factors to pain sensation, body-mass index (BMI) was found to be significant at 30 minutes and BMI and colonoscopy time were found to be significant at 6 hours afterwards. CONCLUSION: We found no favorable effect of CO(2) insufflation on PPPS in colonoscopy, including in patients with IBD.

Background Pulmonary gas exchange efficiency, determined by the alveolar-to-arterial P o 2 difference (A-aD o 2), progressively worsens during exercise at sea-level; this response is further elevated during exercise in hypoxia. Traditionally, pulmonary gas exchange efficiency is assessed through measurements of ventilation and end-tidal gases paired with direct arterial blood gas (ABG) sampling. Because these measures have a number of caveats, particularly invasive blood sampling, the development of new approaches for the noninvasive assessment of pulmonary gas exchange is needed. Research Question Is a noninvasive method of assessing pulmonary gas exchange valid during rest and exercise in acute hypoxia? Study Design and Methods Twenty-five healthy participants (10 female) completed a staged maximal exercise test on a cycle ergometer in a hypoxic chamber (F io 2 = 0.11). Simultaneous ABGs via a radial arterial catheter and noninvasive gas-exchange measurements (AGM100) were obtained in 2-minute intervals. Noninvasive gas exchange, termed the O2 deficit, was calculated from the difference between the end-tidal and the calculated Pa o 2 (via pulse oximetry and corrected for the Bohr effect by using the end-tidal P co 2). Noninvasive O2 deficit was compared with the traditional alveolar to arterial oxygen difference (A-aD o 2), using the traditional Riley analysis. Results Under conditions of rest at room air, hypoxic rest, and hypoxic exercise, strong correlations between the calculated gPa o 2 and directly measured Pa o 2 (R2 = 0.97; P o 2 (R2 = 0.68; P o 2 (R2 = 0.70; P Interpretations Our findings support the use of a noninvasive measure of gas exchange during acute hypoxic exercise in heathy humans. Further studies are required to determine whether this approach can be used clinically as a tool during normoxic exercise in patients with preexisting impairments in gas exchange efficiency.

Background Surgical procedures that use insufflation carry a risk of gas embolism, which is considered relatively harmless because of the high solubility of carbon dioxide. However, an in vitro study suggested that valveless insufflation devices may entrain non-medical room air into the surgical cavity. Our aim was to verify if this occurs in actual surgical procedures. Methods The oxygen percentage in the pneumoperitoneum or pneumorectum/pneumopelvis of eight patients operated with use of the AirSeal® was continuously measured, to determine the percentage of air in the total volume of the surgical cavity. Results Basal air percentage in the surgical cavity was 0–5%. During suctioning from the operative field air percentage increased to 45–65%. Conclusions The AirSeal® valveless insufflation device maintains optimal distension of the surgical cavity not only by insufflating carbon dioxide, but also by entraining room air, especially during suctioning from the operative field. This may theoretically lead to air embolism in patients operated on with this device.

As the World Health Organization is examining the airborne nature of COVID 19, there is past research on other airborne infections which set all encompassing guidelines. Even as more data begins to be available regarding COVID, there is proven spread of airborne disease like tuberculosis being transmitted by this route. As the summer months approach, there is an increased use of Air Conditioners in the tropical regions of the world. India, too being in this part of the world sees an active rise in the indoors which are being air conditioned to meet the thermal comfort requirements of the rising urban population which is spending a large chunk of time indoors. This is coupled with the enforced lockdown which encourages people to stay indoors to prevent the spread of infection. In such situations the use of Room air conditioner requires rethinking as they re-circulate the indoor air without any Fresh air supply into the room. To reduce heat gain and save the electric load of the room AC, people tend to seal the windows further. This paper looks at many possible ways of finding out infection spread in spaces and one of them is used to find out the probability of airborne infection spread in a typical public space. An experiment to validate the same has been conducted in a classroom setup with results analysed. Increased ventilation has been demonstrated to show a lesser probability of infection spread.

Negative ion air purifiers (NIAPs), as a less costly alternative to the HEPA filtration, have been increasingly deployed in China and potentially elsewhere. While reducing indoor concentrations of fine particulate matter (PM2.5 ), NIAPs generate massive amounts of negative ions that may be of health concern. We performed week-long interventions with NIAPs in the dormitories of 56 healthy college students living in Beijing. In a randomized order, each student underwent a true and a sham NIAP session. Cardiorespiratory outcomes were measured before and after each session. The use of true NIAPs reduced indoor PM2.5 concentrations significantly, while notably increased negative ion levels. Increases in PM2.5 and negative ion (NI) exposure were independently associated with increased urinary concentration of malondialdehyde, a biomarker of systemic oxidative stress, resulting in a null net effect of NIAP on malondialdehyde. Likewise, no significant net effects of NIAPs were observed for other outcomes indicative of lung function, vascular tone, arterial stiffness, and inflammation. Our findings suggest that negative ions, possibly along with their reaction products with the room air constituents, adversely affect health. The downsides do not support the use of NIAPs as a health-based mitigation strategy to reduce PM2.5 exposure, especially in residences with PM2.5 concentrations that are not extremely high.

Background: The transmission of respiratory viruses such as influenza and corona viruses from one person to another is still not fully understood. Methods: A literature search showed that there is a strong scientific rationale and evidence that viruses are very efficiently spread through aerosols by the patient's breathing only. It is not necessary for the patient to cough or sneeze. Results: The exhaled aerosol particles are generated by normal breathing in the deep lung through reopening of collapsed small airways during inspiration. These mucus/surfactant aerosols (size range between 0.2 and 0.6 μm) can transport viruses out of the lungs of patients and be present in the room air for hours. Conclusion: These aerosol particles are difficult to filter out of the air; because of their physical properties, new strategies must be developed to protect people from these virus aerosols.

INTRODUCTION: An adequate increase in minute ventilation to defend arterial oxyhemoglobin saturation (SpO(2)) during hypoxic exercise is commonly viewed as an important factor contributing to large inter-individual variations in the degree of exercise performance impairment in hypoxia. Although the hypoxic ventilatory response (HVR) could provide insight into the underpinnings of such impairments, it is typically measured at rest under isocapnic conditions. Thus, we aimed to determine whether 1) HVR at rest and during exercise are similar and 2) exercise HVR is related to the degree of impairment in cycling time trial (TT) performance from normoxia to acute hypoxia (ΔTT). METHODS: Sixteen endurance-trained men (V̇O(2peak), 62.5 ± 5.8 mL·kg(−1)·min(−1)) performed two poikilocapnic HVR tests: one during seated rest (HVR(REST)) and another during submaximal cycling (HVR(EX)). On two separate visits, subjects (n = 12) performed a 10-km cycling TT while breathing either room air (F(i)O(2) = 0.21) or hypoxic gas mixture (F(i)O(2) = 0.16) in a randomized order. RESULTS: HVR(EX) was significantly (P < 0.001) greater than HVR(REST) (1.52 ± 0.47 and 0.22 ± 0.13 L·min(−1)·%SpO(−1)(2), respectively), and these measures were not correlated (r = −0.16, P = 0.57). ΔTT was not correlated with HVR(REST) (P = 0.70) or HVR(EX) (P = 0.54), but differences in ventilation and end-tidal CO(2) between hypoxic and normoxic TT and the ventilatory equivalent for CO(2) during normoxic TT explained ~85% of the variance in performance impairment in acute hypoxia (P < 0.01). CONCLUSION: We conclude that 1) HVR is not an appropriate measure to predict the exercise ventilatory response or performance impairments in acute hypoxia and 2) an adequate and metabolically matched increase in exercise ventilation, but not the gain in the ventilatory response to hypoxia, is essential for mitigating hypoxia-induced impairments in endurance cycling performance.

This study aimed to understand the exposure levels of trihalomethanes (THMs) in an indoor swimming pool and calculate the risks of exposure to THMs, based on the presence of each THM species, of children swimmers aged 6–17, in Beijing, China. We obtained exposure factors for the children through questionnaires and measured THM concentrations through laboratory tests, and we combined the results with an exposure model to calculate the risks, with consideration of different exposure routes (oral ingestion, inhalation and dermal absorption). In terms of exposure factors for the swimmers aged 6–17, the average body weight, exposure duration, exposure frequency, swimming time, shower time, changing time, warm-up exercise and rest time, skin surface area and ingestion rate of pool water were 40.46 kg, 2.70 years, 96 events/year, 64.03 min/event, 17.04 min/event, 15.31 min/event, 12.71 min/event, 1.37 m2 and 48.93 ml/event, respectively. The THM concentrations in swimming pool water, shower water, swimming pool air and locker room air were 67.17 μg/L, 12.64 μg/L, 358.66 μg/m3 and 40.98 μg/m3, respectively. The average cancer risk of THMs was 5.44 × 10−6, which is an unacceptable risk according to the United State Environmental Protection Agency (USEPA) Guidelines. The average hazard index was 0.007, i.e., less than 1, indicating that the noncancer risk was acceptable. Chloroform (TCM) was the main substance in four species of THMs and inhalation exposure was the main exposure pathway. The risk of cancer and noncancer from inhalation exposure to THMs accounts for 97–99% of the total risk. As a result, the disease control authorities and administrative department should pay attention to the health and safety of swimming facilities and, at the same time, establish standards for THMs in the air through further research.

PURPOSE: This study was intended to determine the effect of skin cooling on breath-hold duration and predicted emergency air supply duration during immersion.METHODS: While wearing a helicopter transport suit with a dive mask, 12 subjects (29 ± 10 yr, 78 ± 14 kg, 177 ± 7 cm, 2 women) were studied in 8 and 20°C water. Subjects performed a maximum breath-hold, then breathed for 90 s (through a mouthpiece connected to room air) in five skin-exposure conditions. The first trial was out of water for Control (suit zipped, hood on, mask off). Four submersion conditions included exposure of the: Partial Face (hood and mask on); Face (hood on, mask off); Head (hood and mask off); and Whole Body (suit unzipped, hood and mask off).RESULTS: Decreasing temperature and increasing skin exposure reduced breath-hold time (to as low as 10 ± 4 s), generally increased minute ventilation (up to 40 ± 15 L · min−1), and decreased predicted endurance time (PET) of a 55-L helicopter underwater emergency breathing apparatus. In 8°C water, PET decreased from 2 min 39 s (Partial Face) to 1 min 11 s (Whole Body).CONCLUSION: The most significant factor increasing breath-hold and predicted survival time was zipping up the suit. Face masks and suit hoods increased thermal comfort. Therefore, wearing the suits zipped with hoods on and, if possible, donning the dive mask prior to crashing, may increase survivability. The results have important applications for the education and preparation of helicopter occupants. Thermal protective suits and dive masks should be provided.Madu VC, Carnahan H, Brown R, Ennis K-A, Tymko KS, Hurrie DMG, McDonald GK, Cornish SM, Giesbrecht GG. Skin cooling on breath-hold duration and predicted emergency air supply duration during immersion. Aerosp Med Hum Perform. 2020; 91(7):578–585.

Lower body positive pressure treadmills (LBPPT) are beneficial for rehabilitation and exercise training. Running on a LBPP treadmill (AlterGTM) involves sealing the lower half of the body in a high air pressure flexible sealed chamber to simulate exercise at lower body weight. The effects of the sealed chamber on treadmill and tympanic temperature during exercise have yet to be investigated. The purpose of the study was to measure treadmill and tympanic temperatures while participants were running on a normal treadmill and compare temperatures to running on a LBPP treadmill. Fifteen well-trained runners completed three running trials on a LBPP treadmill at 60, 75, and 85% of body weight (BW). A 100% BW trial was run on a normal treadmill. Participants ran at three steady state speeds (2.9, 3.4, and 3.8 m·s-1) for four minutes each. Room air, tympanic, and LBPPT chamber temperatures (°C) were recorded. The main finding was that treadmill temperature was significantly greater among the three BW conditions on the LBPPT compared to normal treadmill (average of all LBPPT, 30.7 ± 2.3°C, normal treadmill, 22.5 ± 2.1°C). Tympanic temperatures were not different between all BW conditions. Runners may use LBPPT for rehabilitation or low-impact training yet should be aware of the increase in LBPP chamber temperature.