BACKGROUND: Although smoking rates have been declining worldwide, new types of tobacco products have been gradually spreading in recent years, especially in Japan, where heated tobacco products (HTPs) users are rapidly increasing. Oxidative stress caused by reactive oxygen species (ROS) is one of the causes of smoking-induced carcinogenesis, respiratory diseases, and cardiovascular diseases. However, information on the amount of ROS contained in mainstream smoke from HTPs is limited. In this study, we measured the amount of ROS generated from HTPs to evaluate the oxidative stress-related toxicity of HTPs. METHODS: IQOS ILUMA, glo hyper+, and Ploom X ADVANCED were used as the HTP devices. Mainstream smoke was collected from each HTP according to Health Canada Intense regime (smoke volume, 55 mL; smoke duration, 2 s). The collected ROS were reacted with 2,7'-dichlorodihydrofluorescein reagents, and the amount of ROS was calculated as H₂O₂ equivalent from the fluorescence intensity obtained. RESULTS: The ROS in the mainstream smoke from IQOS ILUMA, glo hyper+ (high-temperature mode), and Ploom X ADVANCED was found to be 48.8 ± 8.6, 86.6 ± 12.6, and 40.8 ± 5.7 nmol H₂O₂/stick, respectively (n = 6, mean ± standard deviation), with the highest being from glo hyper+ (high-temperature mode). The amount of ROS was significantly higher in the high-temperature mode of glo hyper+ than in the standard mode of glo hyper+. Additionally, the estimated amount of ROS from smoking 20 heated sticks per day (674-2160 nmol H₂O₂/day) was equivalent to 2.2-96 times the amount of daily exposure to ROS in the urban atmosphere (approximately 22-300 nmol H₂O₂/day). CONCLUSIONS We found that ROS is generated from HTPs of different devices. This study suggests that HTPs users may be exposed to much more ROS than they are exposed to in normal life.
Reactive Oxygen Species/analysis* ; Tobacco Products/analysis* ; Smoke/analysis* ; Hot Temperature ; Japan ; Oxidative Stress

A method for determining volatile organic compounds (VOCs) emitted from medical molecular sieve oxygen concentrators was developed using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The oxygen concentrator gas was sampled at a flow rate of 0.5 L/min through a branched sampling system onto Tenax GR/carbopack B adsorption tubes. The adsorbed compounds were desorbed and introduced using a programmed temperature vaporization inlet system, followed by chromatographic separation on an SH-I-624Sil MS column. Four VOCs (BHT-Q, PTBP, BHT-quinol, and EHB) were detected in the medical oxygen concentrator using this method. Calibration curves for these compounds exhibited excellent linearity ( R ²>0.99) within the range of 3~100 ng. With a sampling volume of 20 L, the detection limit of the four VOCs ranged from 0.003 9 to 0.022 2 μg/m ³. Spike recovery rates for the four VOCs were between 95% and 115%, with relative standard deviations (RSDs) below 5% ( n=6). The method is simple, rapid, highly sensitive, and accurate, making it suitable for VOCs detection in medical molecular sieve oxygen concentrators.
Volatile Organic Compounds/analysis* ; Gas Chromatography-Mass Spectrometry/methods* ; Oxygen

OBJECTIVES: To study the clinical value of intestinal regional oxygen saturation (rSO₂) and C-reactive protein (CRP) in the diagnosis of necrotizing enterocolitis (NEC) in preterm infants. METHODS: A prospective observational study was conducted among the preterm infants who were hospitalized in Children's Hospital Affiliated to Anhui Medical University, from October 2020 to December 2021, with 22 infants in the NEC group and 35 infants in the non-NEC group. Intestinal rSO₂ was monitored 24 hours after a confirmed diagnosis of NEC in the NEC group, and serum CRP levels were measured before anti-infection therapy. In the non-NEC group, intestinal rSO₂ monitoring and serum CRP level measurement were performed at the corrospording time points. The two groups were compared in terms of intestinal rSO₂ and serum CRP level. The receiver operating characteristic (ROC) curve was used to analyze the value of intestinal rSO₂ alone, serum CRP alone, and intestinal rSO₂ combined with CRP in the diagnosis of NEC in preterm infants. RESULTS: Compared with the non-NEC group, the NEC group had a significantly lower level of intestinal rSO₂ (P<0.05) and a higher serum CRP level (P<0.05). The ROC curve analysis showed that intestinal rSO₂ had an optimal cut-off value of 50.75% in the diagnosis of NEC in preterm infants, with a sensitivity of 81.8%, a specificity of 85.7%, and an area under the ROC curve (AUC) of 89.4%; CRP had an optimal cut-off value of 12.05 mg/L in the diagnosis of NEC in preterm infant, with a sensitivity of 72.7%, a specificity of 74.3%, and an AUC of 74.8%; intestinal rSO₂ combined with CRP had a sensitivity of 90.9%, a specificity of 77.1%, and an AUC of 91.9% in the diagnosis of NEC. The AUC of intestinal rSO₂ alone in the diagnosis NEC was higher than that of CRP (P<0.05). There was no significant difference in the AUC between intestinal rSO₂ alone and intestinal rSO₂ combined with CRP (P>0.05). CONCLUSIONS The value of intestinal rSO₂ in the diagnosis NEC is higher than that of CRP, and is equivalent to that of the combination of intestinal rSO₂ and CRP in preterm infants.
Infant ; Child ; Infant, Newborn ; Humans ; Enterocolitis, Necrotizing/diagnosis* ; Infant, Premature ; C-Reactive Protein/analysis* ; Oxygen Saturation ; Infant, Newborn, Diseases

Oxygen reserve index (ORI) is a novel dimensionless index used for noninvasive, real-time, and continuous monitoring of oxygenation, and ORI value ranges from 0 to 1, which reflects the range of 100-200 mmHg for arterial partial pressure of oxygen. ORI combined with pulse oximetry may help to accurately adjust the concentration of inspired oxygen and prevent hyperoxemia and hypoxemia. ORI is suitable for various clinical situations, and the medical staff should master this novel parameter and use it properly to assess the oxygenation of patients. In addition, several limitations of ORI should be noticed during clinical application.
Humans ; Oxygen ; Blood Gas Analysis ; Oxygen Inhalation Therapy ; Oximetry ; Hypoxia/therapy*

BACKGROUND: The 2019 novel coronavirus has caused the outbreak of the acute respiratory disease in Wuhan, Hubei Province of China since December 2019. This study was performed to analyze the clinical characteristics of patients who succumbed to and who recovered from 2019 novel coronavirus disease (COVID-19). METHODS: Clinical data were collected from two tertiary hospitals in Wuhan. A retrospective investigation was conducted to analyze the clinical characteristics of fatal cases of COVID-19 (death group) and we compare them with recovered patients (recovered group). Continuous variables were analyzed using the Mann-Whitney U test. Categorical variables were analyzed by χ test or Fisher exact test as appropriate. RESULTS: Our study enrolled 109 COVID-19 patients who died during hospitalization and 116 recovered patients. The median age of the death group was older than the recovered group (69 [62, 74] vs. 40 [33, 57] years, Z = 9.738, P < 0.001). More patients in the death group had underlying diseases (72.5% vs. 41.4%, χ = 22.105, P < 0.001). Patients in the death group had a significantly longer time of illness onset to hospitalization (10.0 [6.5, 12.0] vs. 7.0 [5.0, 10.0] days, Z = 3.216, P = 0.001). On admission, the proportions of patients with symptoms of dyspnea (70.6% vs. 19.0%, χ = 60.905, P < 0.001) and expectoration (32.1% vs. 12.1%, χ = 13.250, P < 0.001) were significantly higher in the death group. The blood oxygen saturation was significantly lower in the death group (85 [77, 91]% vs. 97 [95, 98]%, Z = 10.625, P < 0.001). The white blood cell (WBC) in death group was significantly higher on admission (7.23 [4.87, 11.17] vs. 4.52 [3.62, 5.88] ×10/L, Z = 7.618, P < 0.001). Patients in the death group exhibited significantly lower lymphocyte count (0.63 [0.40, 0.79] vs. 1.00 [0.72, 1.27] ×10/L, Z = 8.037, P < 0.001) and lymphocyte percentage (7.10 [4.45, 12.73]% vs. 23.50 [15.27, 31.25]%, Z = 10.315, P < 0.001) on admission, and the lymphocyte percentage continued to decrease during hospitalization (7.10 [4.45, 12.73]% vs. 2.91 [1.79, 6.13]%, Z = 5.242, P < 0.001). Alanine transaminase (22.00 [15.00, 34.00] vs. 18.70 [13.00, 30.38] U/L, Z = 2.592, P = 0.010), aspartate transaminase (34.00 [27.00, 47.00] vs. 22.00 [17.65, 31.75] U/L, Z = 7.308, P < 0.001), and creatinine levels (89.00 [72.00, 133.50] vs. 65.00 [54.60, 78.75] μmol/L, Z = 6.478, P < 0.001) were significantly higher in the death group than those in the recovered group. C-reactive protein (CRP) levels were also significantly higher in the death group on admission (109.25 [35.00, 170.28] vs. 3.22 [1.04, 21.80] mg/L, Z = 10.206, P < 0.001) and showed no significant improvement after treatment (109.25 [35.00, 170.28] vs. 81.60 [27.23, 179.08] mg/L, Z = 1.219, P = 0.233). The patients in the death group had more complications such as acute respiratory distress syndrome (ARDS) (89.9% vs. 8.6%, χ = 148.105, P < 0.001), acute cardiac injury (59.6% vs. 0.9%, χ = 93.222, P < 0.001), acute kidney injury (18.3% vs. 0%, χ = 23.257, P < 0.001), shock (11.9% vs. 0%, χ = 14.618, P < 0.001), and disseminated intravascular coagulation (DIC) (6.4% vs. 0%, χ = 7.655, P = 0.006). CONCLUSIONS Compared to the recovered group, more patients in the death group exhibited characteristics of advanced age, pre-existing comorbidities, dyspnea, oxygen saturation decrease, increased WBC count, decreased lymphocytes, and elevated CRP levels. More patients in the death group had complications such as ARDS, acute cardiac injury, acute kidney injury, shock, and DIC.
Adult ; Aged ; Aged, 80 and over ; Betacoronavirus ; C-Reactive Protein ; analysis ; Coronavirus Infections ; complications ; mortality ; Female ; Humans ; Male ; Middle Aged ; Oxygen ; blood ; Pandemics ; Pneumonia, Viral ; complications ; mortality ; Retrospective Studies

Monitoring cerebral oxygenation using a near infrared spectroscopy (NIRS) device is useful for estimating cerebral hypoperfusion and is available during liver transplantation (LT). However, high serum bilirubin concentration can interfere with NIRS because bilirubin absorbs near infrared light. We report a patient who underwent LT with a diagnosis of vanishing bile duct syndrome, whose regional cerebral oxygen saturation (rSO₂) remained below 15% even with alert mental status and SpO2₂ value of 99%. The rSO₂ values were almost fixed at the lowest measurable level throughout the intra- and postoperative period. We report a case of erroneously low rSO₂ values during the perioperative period in a liver transplant recipient which might be attributable to skin pigmentation rather than higher serum bilirubin concentration.
Bile Ducts* ; Bile* ; Bilirubin ; Diagnosis ; Humans ; Hyperbilirubinemia ; Hypoxia, Brain ; Liver Transplantation* ; Liver* ; Oxygen* ; Perioperative Period ; Postoperative Period ; Skin Pigmentation ; Spectrum Analysis ; Transplant Recipients

The denitrifier method is widely used as a novel pretreatment method for the determination of nitrogen and oxygen isotope ratios as it can provide quantitative and high-sensitivity measurements. Nevertheless, the method is limited by relatively low measurement accuracy for δ18O. In this study, we analyzed the factors influencing the accuracy of δ18O determination, and then systematically investigated the effects of dissolved oxygen concentrations and nitrate sample sizes on estimates of the δ15N and δ18O of nitrate reference materials. The δ18O contraction ratio was used to represent the relationship between the measured difference and true difference between two reference materials. We obtained the following main results: (1) a gas-liquid ratio of 3:10 (v/v) in ordinary triangular flasks and a shaking speed of 120 r/min produced an optimal range (1.9 to 2.6 mg/L) in the concentration of dissolved oxygen for accurately determining δ18O, and (2) the δ18O contraction ratio decreased as nitrate sample size decreased within a certain range (1.0 to 0.1 μmol). Our results suggested that δ18O contraction is influenced mainly by dissolved oxygen concentrations in pure culture, and provided a model for improving the accuracy of oxygen isotope analysis.
Denitrification ; Nitrates/analysis* ; Oxygen Isotopes/analysis*

simultaneous monitoring of blood flow and changes of concentration of oxyhemoglobin (ΔHbO) in brain is a key important method for the research of cerebrovascular disease. In this study, a new monitoring system, combining laser speckle contrast imaging method and spectral analysis method, was proposed, which could be utilized to measure the cerebral blood flow and ΔHbO on mice during traumatic brain injury. The principle of the present system was studied and the hardware platform of the detection system was built. Then, user interface software and algorithms were implemented based on Labview and Matlab software. Finally, the performance of the present system was verified by the experiments.
Algorithms ; Animals ; Blood Gas Analysis ; instrumentation ; Brain ; Cerebrovascular Circulation ; Lasers ; Mice ; Oxygen ; analysis

The aim of this study was to determine the effects of extremely low frequency electromagnetic field (ELF-EMF) on energy metabolism and oxidative stress in Caenorhabditis elegans (C. elegans). Worms in three adult stages (young adult stage, egg-laying stage and peak egg-laying stage) were investigated under 50 Hz, 3 mT ELF-EMF exposure. ATP levels, ATP synthase activity in vivo, reactive oxygen species (ROS) content, and changes of total antioxidant capacity (TAC) were detected, and worms' oxidative stress responses were also evaluated under ELF-EMF exposure. The results showed that ATP levels were significantly increased under this ELF-EMF exposure, and mitochondrial ATP synthase activity was upregulated simultaneously. In young adult stage, worms' ROS level was significantly elevated, together with upregulated TAC but with a decreased ROS-TAC score indicated by principal component analysis. ROS level and TAC of worms had no significant changes in egg-laying and peak egg-laying stages. Based on these results, we concluded that ELF-EMF can enhance worm energy metabolism and elicit oxidative stress, mainly manifesting as ATP and ROS level elevation together with ATP synthase upregulation and ROS-TAC score decrease in young adult C. elegans.
Adenosine Triphosphate ; metabolism ; Animals ; Caenorhabditis elegans ; radiation effects ; Electromagnetic Radiation ; Energy Metabolism ; Mitochondrial Proton-Translocating ATPases ; metabolism ; Oxidative Stress ; Reactive Oxygen Species ; analysis

This article describes the design of a portable blood oxygen simulation system that can be used to simulate various blood gas saturation states of the human body. The system can be used to simulate various states of blood gas saturation, and can also simulate large blood oxygen saturation dynamic range, pulse rate range and perfusion index range. It can be used for testing, but not for clinical examination instruments. Moreover, the system has the characteristics of small size and low cost compared with the commercial blood oxygen simulator. Although the simulation system is not directly used for the detection of blood gas saturation of patients, it is also an essential equipment in the production and testing process, so it has certain practical value.
Heart Rate ; Humans ; Oximetry ; instrumentation ; Oxygen ; analysis