Ecological cultivation is an important way for the sustainable production of traditional Chinese medicine in the context of the carbon peaking and carbon neutrality goals. Facility cultivation and simulative habitat cultivation modes have been developed and applied to develop the endangered Dendrobium huoshanense on the basis of protection. However, the differences in the greenhouse gas emissions and global warming potential of these cultivation modes remain unexplored, which limits the accurate assessment of carbon-friendly ecological cultivation modes of D. huoshanense. Greenhouse gas emission flux monitoring based on the static chamber method provides an effective way to solve this problem. Therefore, this study conducted a field experiment in the facility cultivation and simulative habitat cultivation modes at a D. huoshanense cultivation base in Dabie Mountains, Anhui Province. From April 2023 to March 2024, samples of greenhouse gases were collected every month, and the concentrations of CO_2, CH_4, and N_2O of the samples were then detected by gas chromatography. The greenhouse gas emission fluxes, cumulative emissions, and global warming potential were further calculated, and the following results were obtained.(1)The two cultivation modes of D. huoshanense showed significant differences in greenhouse gas emission fluxes, especially the CO_2 emission flux, with a pattern of facility cultivation>simulative habitat cultivation [(35.60±11.70)mg·m~(-2)·h~(-1) vs(2.10±4.59)mg·m~(-2)·h~(-1)].(2) The annual cumulative CO_2 emission flux in the case of facility cultivation was significantly higher than that of simulative habitat cultivation[(3 077.00±842.00)kg·hm~(-2) vs(221.00±332.00)kg·hm~(-2)], while no significant difference was found in annual cumulative CH_4 and N_2O emission fluxes.(3) The facility cultivation mode had a significantly higher global warming potential than the simulative habitat cultivation mode [(3 053.00±847.00)kg·hm~(-2) vs(196.00±362.00)kg·hm~(-2)]. Overall, the simulative habitat cultivation of D. huoshanense has obvious carbon-friendly characteristics compared with facility cultivation, which is in line with the concept of ecological cultivation of medicinal plants. This study is of great reference significance for the implementation and promotion of the ecological cultivation mode of D. huoshanense under carbon peaking and carbon neutrality goals.
Dendrobium/chemistry* ; Greenhouse Gases/metabolism* ; Carbon/analysis* ; Ecosystem ; Carbon Dioxide/metabolism* ; China ; Global Warming

End-tidal carbon dioxide monitoring is an important means of evaluating human lung function and is widely used in fields such as clinical emergency treatment and cardiopulmonary resuscitation. This paper develops a microstream end-tidal carbon dioxide monitoring system. It adopts an integrated gas circuit design to further reduce the size of the equipment. The system uses the method of calculating the root mean square (RMS) of differential pressure signals to regulate the gas circuit flow, enabling the system to stably operate at a flow state of 30 mL/min. In addition, by simultaneously detecting multiple environmental parameters such as temperature and pressure, the system realizes system state monitoring and gas parameter compensation. The test results show that various indicators of the system meet the requirements of relevant standards, laying a good foundation for subsequent engineering applications.
Carbon Dioxide/analysis* ; Equipment Design ; Monitoring, Physiologic/methods* ; Humans

OBJECTIVE: To explore the effects of veno-venous extra corporeal carbon dioxide removal (V-V ECCO₂R) on local mechanical power and gas distribution in the lungs of patients with mild to moderate acute respiratory distress syndrome (ARDS) receiving non-invasive ventilation. METHODS: Retrospective research methods were conducted. Sixty patients with mild to moderate ARDS complicated with renal insufficiency who were transferred to the respiratory intensive care unit (RICU) through the 96195 platform critical care transport green channel from January 2018 to January 2020 at the collaborative hospitals of Henan Provincial People's Hospital were enrolled. According to different treatment methods, they were divided into a conventional treatment group and an ECCO₂R group, with 30 patients in each group. Both groups received standard treatments including primary disease treatment, airway management, and non-invasive ventilation. The conventional treatment group received bedside continuous renal replacement therapy (CRRT), and the ECCO₂R group received V-V ECCO₂R treatment. General information of patient such as gender, age, cause of disease, and acute physiology and chronic health evaluation II (APACHE II) were recorded; arterial blood gas analysis was performed before treatment and at 12 hours and 24 hours during treatment, recording arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), and oxygenation index (PaO₂/FiO₂). Respiratory mechanics parameters [tidal volume, respiratory rate, maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP)] were recorded, and the rapid shallow breathing index (RSBI) was calculated; electrical impedance tomography (EIT) was used to measure regional of interest (ROI) values in different lung areas at 12 hours and 24 hours of treatment, and the pulmonary mechanical energy was calculated. RESULTS: The arterial blood gas analysis indicators, respiratory mechanics parameters, and pulmonary mechanical energy of patients in the conventional treatment group and ECCO₂R group improved significantly after 24 hours of treatment compared to 12 hours of treatment (all P < 0.05). The levels of PaCO₂, RSBI, total mechanical power, and non-dependent zone mechanical power in the ECCO₂R group were significantly lower than those in the conventional treatment group at both 12 hours and 24 hours during the treatment [PaCO₂ (mmHg, 1 mmHg ≈ 0.133 kPa): 44.03±2.96 vs. 49.96±2.50 at 12 hours, 41.65±3.21 vs. 48.53±2.33 at 24 hours; RSBI (times×min^-1×L^-1): 88.67±4.05 vs. 92.35±4.03 at 12 hours, 77.66±4.64 vs. 90.98±4.21 at 24 hours; total mechanical power (mJ): 10.40±1.15 vs. 12.93±1.68 at 12 hours, 11.13±1.18 vs. 14.05±1.69 at 24 hours; non-dependent zone mechanical power (mJ): 7.15±0.84 vs. 7.98±0.75 at 12 hours, 7.77±0.93 vs. 9.13±1.10 at 24 hours], and MEP and MIP in the ECCO₂R group were significantly higher than those in the conventional treatment group at both 12 hours and 24 hours during the treatment [MEP (cmH₂O, 1 cmH₂O ≈ 0.098 kPa): 89.88±5.04 vs. 86.09±5.57 at 12 hours, 96.57±2.59 vs. 88.66±2.98 at 24 hours; MIP (cmH₂O): 47.64±2.82 vs. 41.93±2.44 at 12 hours, 60.11±6.53 vs. 43.63±2.80 at 24 hours], the differences were statistically significant (all P < 0.05). CONCLUSIONS V-V ECCO₂R combined with non-invasive ventilation can effectively reduce the regional tidal volume, mechanical power, and respiratory rate in the non-gravitational dependent zones of patients with mild to moderate ARDS, and improve respiratory distress and oxygenation status.
Humans ; Respiratory Distress Syndrome/physiopathology* ; Retrospective Studies ; Carbon Dioxide ; Blood Gas Analysis ; Lung/physiopathology* ; Intensive Care Units ; Male ; Female ; Noninvasive Ventilation/methods* ; Continuous Renal Replacement Therapy/methods* ; APACHE ; Middle Aged

Prehospital emergency care is the primary stage in the treatment of critically ill patients, where efficient and accurate monitoring methods are crucial for patient survival and prognosis. End-tidal carbon dioxide (EtCO₂) monitoring is a real-time, non-invasive method that can sensitively capture the status of respiratory, circulatory, and metabolic functions, particularly in the urgent and complex pre-hospital environment, a immediate detection and non-invasive method, can sensitively capture the respiratory, circulatory, and metabolic status of patients. It provides valuable guidance for rapid decision-making and precise interventions. This is particularly valuable in the complex and urgent prehospital environment, providing critical data for rapid decision-making and precise intervention. This paper systematically reviews the advancements in the application of EtCO₂ monitoring across various fields, including sepsis identification, trauma assessment, cardiac arrest, respiratory critical care, endotracheal intubation confirmation, and management of metabolic diseases, aiming to explore its application value and prospects in pre-hospital emergency care.
Humans ; Emergency Medical Services/methods* ; Carbon Dioxide/analysis* ; Monitoring, Physiologic/methods* ; Critical Illness ; Capnography/methods*

OBJECTIVE: To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults. METHODS: This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results. RESULTS: The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m². During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m³, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m³, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m³ increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m³. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter. CONCLUSION Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.
Humans ; Female ; Adult ; Young Adult ; Air Pollutants/analysis* ; Heart Rate/physiology* ; Volatile Organic Compounds/analysis* ; Carbon Dioxide ; Particulate Matter/adverse effects* ; Environmental Pollutants

Objective: To explore the occupational hazards caused by three kinds of welding operations, and to provide data support for individual protection. Methods: In October 2020, the welding fumes, metal elements and welding arc generated by three welding operations of argon gas shielded welding (JS80 welding wire) , manual welding (ZS60A welding rod) and carbon dioxide shielded welding (907A flux cored wire) were collected and measured in the welding laboratory. The samples were analyze and compare in the laboratory, and the differences of the occupational hazard factors of the three welding operations were judged. Results: The concentration of welding fume produced by carbon dioxide shielded welding, manual welding (ZS60A electrode) , and argon gas shielded welding (JS80 welding wires) were 6.80 mg/m(3), 6.17 mg/m(3), and 3.13 mg/m(3), respectively. The effective irradiance of the welding arc outside the welding mask from high to low is manual welding (ZS60A electrode) , carbon dioxide shielded welding (907A flux-cored welding wire) , and argon shielded welding (JS80 welding wire) , respectively 1 010.7, 740.9, 589.5 μW/cm(2). The long-wave ultraviolet UVA intensity generated by argon shielded welding (JS80 welding wire) is the largest, which is 1 500 μW/cm(2). The content of Mn in the three welding operations is the highest, and JS80 welding wire has the highest Mn content of 128493.2 mg/kg. 907A flux cored wire has the highest Ti content, which is 24355.5mg/kg. The electrode ZS60A has the highest Cu content, which is 24422.12 mg/kg. Conclusion: The intensity of occupational hazards is different in the three kinds of welding operations, so the methods of personal protective equipment, field exposure assessment and health monitoring should be more targeted.
Air Pollutants, Occupational/analysis* ; Argon/analysis* ; Carbon Dioxide/analysis* ; Gases/analysis* ; Occupational Exposure/analysis* ; Welding/methods*

At present, the death cases of simple asphyxiant gas acute poisoning are increasing sharply. Common asphyxiant gases in death cases include nitrogen, helium, carbon dioxide, methane, propane, laughing gas, etc. Simple asphyxiant gas has no affinity for biological matrices and escapes quickly, which puts forward new requirements for autopsy procedures, selection and collection of samples, laboratory analysis and identification. This paper reviews the research and development process of death cases caused by simple asphyxiant gas acute poisoning and put forwards the collection and analysis strategy of the samples in such cases. The most valuable biological samples in such cases should be lung tissues associated with the airways, followed by brain tissue and cardiac blood. Gaseous samples from the esophageal cavity, tracheal cavity, pulmonary bronchi, gastric and cardiac areas are also recommended as valuable samples. In the case of postmortem examination, the gas should be injected into gas sample bag directly. Biological materials such as tissue and blood should be directly sealed in head-space vials and analyzed by using the headspace gas chromatography-mass spectrometry.
Carbon Dioxide/analysis* ; Autopsy ; Gas Chromatography-Mass Spectrometry ; Methane/analysis* ; Nitrogen

OBJECTIVES: The association between concentrations of sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), ozone (O), and emergency ambulance dispatches (EADs) for asthma was explored in the central Sichuan Basin of southwestern China for the first time. METHODS: EADs for asthma were collected from the Chengdu First-Aid Command Center. Pollutant concentrations were collected from 24 municipal environmental monitoring centers and including SO, NO, CO, daily 8-h mean concentrations of O (O-8 h), and particulate matter less than 2.5 μm in aerodynamic diameter (PM). The climatic data were collected from the Chengdu Municipal Meteorological Bureau. All data were collected from years spanning 2013-2017. A time-stratified case-crossover design was used to analyze the data. RESULTS: After controlling for temperature, relative humidity, and atmospheric pressure, IQR increases in SO (13 μg/m), NO (17 μg/m), and CO (498 μg/m) were associated with 18.8%, 11.5%, and 3.1% increases in EADs for asthma, respectively. The associations were strongest for EADs and SO, NO, and CO levels with 3-, 5-, and 1-day lags, respectively. CONCLUSIONS This study provides additional data to the limited body of literature for potential health risks arising from ambient gaseous pollutants. The results of the study suggest that increased concentrations of SO, NO, and CO were positively associated with emergency ambulance dispatches for asthma in Chengdu, China. Further studies are needed to investigate the effects of individual air pollutants on asthma.
Air Pollutants ; analysis ; toxicity ; Asthma ; chemically induced ; epidemiology ; Carbon Monoxide ; analysis ; toxicity ; China ; epidemiology ; Cities ; Cross-Over Studies ; Emergency Medical Dispatch ; statistics & numerical data ; Environmental Monitoring ; statistics & numerical data ; Humans ; Nitrogen Dioxide ; analysis ; toxicity ; Ozone ; analysis ; toxicity ; Particle Size ; Particulate Matter ; analysis ; toxicity ; Risk ; Sulfur Dioxide ; analysis ; toxicity

BACKGROUND: Beyond its current function as a rescue therapy in acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) may be applied in ARDS patients with less severe hypoxemia to facilitate lung protective ventilation. The purpose of this study was to evaluate the efficacy of extended ECMO use in ARDS patients. METHODS: This study reviewed 223 adult patients who had been admitted to the intensive care units of 11 hospitals in Korea and subsequently treated using ECMO. Among them, the 62 who required ECMO for ARDS were analyzed. The patients were divided into two groups according to pre-ECMO arterial blood gas: an extended group (n=14) and a conventional group (n=48). RESULTS: Baseline characteristics were not different between the groups. The median arterial carbon dioxide tension/fraction of inspired oxygen (FiO2) ratio was higher (97 vs. 61, p<0.001) while the median FiO2 was lower (0.8 vs. 1.0, p<0.001) in the extended compared to the conventional group. The 60-day mortality was 21% in the extended group and 54% in the conventional group (p=0.03). Multivariate analysis indicated that the extended use of ECMO was independently associated with reduced 60-day mortality (odds ratio, 0.10; 95% confidence interval, 0.02–0.64; p=0.02). Lower median peak inspiratory pressure and median dynamic driving pressure were observed in the extended group 24 hours after ECMO support. CONCLUSION: Extended indications of ECMO implementation coupled with protective ventilator settings may improve the clinical outcome of patients with ARDS.
Adult ; Anoxia ; Carbon Dioxide ; Extracorporeal Membrane Oxygenation ; Humans ; Intensive Care Units ; Korea ; Lung ; Mortality ; Multicenter Studies as Topic ; Multivariate Analysis ; Oxygen ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult ; Retrospective Studies ; Ventilation ; Ventilators, Mechanical

PURPOSE: Removal of CO₂ is much efficient during high-frequency oscillatory ventilation (HFOV) for preterm infants. However, an optimal carbon dioxide diffusion coefficient (DCO₂) and tidal volume (VT) have not yet been established due to much individual variance. This study aimed to analyze DCO₂ values, VT, and minute volume in very-low-birth-weight (VLBW) infants using HFOV and correlates with plasma CO₂ (pCO₂). MATERIALS AND METHODS: Daily respiratory mechanics and ventilator settings from twenty VLBW infants and their two hundred seventeen results of blood gas analysis were collected. Patients were treated with the Dräger Babylog VN500 ventilator (Drägerwerk Ag & Co.) in HFOV mode. The normocapnia was indicated as pCO₂ ranging from 45 mm Hg to 55 mm Hg. RESULTS: The measured VT was 1.7 mL/kg, minute volume was 0.7 mL/kg, and DCO₂ was 43.5 mL²/s. Mean results of the blood gas test were as follows: pH, 7.31; pCO₂, 52.6 mm Hg; and SpO₂, 90.5%. In normocapnic state, the mean VT was significantly higher than in hypercapnic state (2.1±0.5 mL/kg vs. 1.6±0.3 mL/kg), and the mean DCO₂ showed significant difference (68.4±32.7 mL²/s vs. 32.4±15.7 mL²/s). The DCO₂ was significantly correlated with the pCO₂ (p=0.024). In the receiver operating curve analysis, the estimated optimal cut-off point to predict the remaining normocapnic status was a VT of 1.75 mL/kg (sensitivity 73%, specificity 80%). CONCLUSION: In VLBW infants treated with HFOV, VT of 1.75 mL/kg is recommended for maintaining proper ventilation.
Blood Gas Analysis ; Carbon Dioxide/analysis ; Female ; High-Frequency Ventilation ; Humans ; Hypercapnia/physiopathology ; Incidence ; Infant ; Infant, Newborn ; Infant, Very Low Birth Weight/physiology ; Male ; ROC Curve ; Tidal Volume