BACKGROUND

Determination of serum bicarbonate (HCO3 - ) using arterial blood gas analysis in patients with diabetic ketoacidosis allows for the evaluation of the severity of the condition, determines whether HCO3 - therapy is required, and tracks the progression and resolution of the disease. Serum carbon dioxide combining power (CO2CP) from venous chemistry analysis has often been used as an indicator of metabolic acidosis. This study investigated the relationship between HCO3 - and CO2CP and developed an approximation formula for serum bicarbonate concentration using its predictor variables, as this may lessen the need to repeat arterial blood gas analysis or be used in settings in which blood gas analyzers are unavailable.

METHODOLOGY

This single-center, retrospective, cross-sectional study investigated a total of 77 patients diagnosed with diabetic ketoacidosis. Assessment of the bivariate correlations between serum HCO3 - and serum CO2CP as well as other potential predictor variables was done via Pearson’s correlation coefficient. Predictor variables that were significantly correlated with serum HCO3 - were identified and an approximation formula was developed by regression analysis. Evaluation of the correlation between the approximated HCO3 - value and the actual serum HCO3 - concentration was performed using correlation coefficient and residual statistics to assess agreement.

RESULTS

Serum CO2CP had significant correlation with serum HCO3 - (r = 0.768, p < 0.05). By multiple regression analysis, the following approximation formula was therefore expressed: HCO3 - = 12.682 + (0.612 x CO2CP) – [ketones] + (0.085 x BUN) - (0.026 x SGPT) – (1.23 x Creatinine) - (0.067 x Chloride). Examination of residuals revealed a mean of zero (0), indicating no significant difference between the actual and approximated levels of serum HCO3 -

CONCLUSION

The predictor variables included in the formula collectively contribute significantly to the approximation of serum HCO3 - . The approximated serum HCO3 - values also showed significant correlation with actual serum HCO3 - concentration; thus, the formula may be utilized to derive an approximation of serum bicarbonate concentration in patients with diabetic ketoacidosis.

Human ; Male ; Female ; Adolescent: 13-18 Yrs Old ; Young Adult: 19-24 Yrs Old ; Adult: 25-44 Yrs Old ; Attention ; Bicarbonates ; Carbon Dioxide ; Diabetic Ketoacidosis ; Ketosis ; Patients ; Carbon ; Power (psychology) ; Power, Psychological ; Serum

In this study, high-throughput promoter screening was employed to optimize the heterologous expression of Mesorhizobium loti carbonic anhydrase (MlCA) in order to reduce the costs associated with carbon capture and storage (CCS). To simplify the complexity of traditional vectors, a fusion protein expression system was constructed using superfolder green fluorescent protein (sfGFP) and MlCA. The synthetic promoter library in Escherichia coli was utilized for efficient one-step screening. Based on fluorescence intensity on agar plates, a total of 143 monoclonal colonies were identified, forming a library with varying expression levels. The top four recombinants with the highest fluorescence intensity were selected, among which MlCA driven by the promoter 342042/+ exhibited the highest enzymatic activity, with a specific activity of the 34.6 Wilbur-Anderson units (WAU)/mg. Optimization experiments revealed that MlCA exhibited the best performance when cultured for 4 days under pH 7.0 and 40 ℃ conditions. The Michaelis constant (K_m·hdy) and maximum reaction rate (V_max·hdy) for CO₂ hydration were determined to be 62.46 mmol/L and 0.164 mmol/(s·L), respectively. For esterase hydrolysis, MlCA showed the K_m and V_max of 639.8 mmol/L and 0.035 mmol/(s·L), respectively. MlCA accelerated the CO₂ hydration process, promoting CO₂ mineralized into CaCO₃ within 9 min at low pH and room temperature conditions. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses confirmed that the precipitated product was calcite. This study provides a low-cost and environmentally friendly alternative for future CCS applications.
Carbonic Anhydrases/biosynthesis* ; Promoter Regions, Genetic/genetics* ; Escherichia coli/metabolism* ; Carbon Sequestration ; Carbon Dioxide/metabolism* ; Green Fluorescent Proteins/metabolism*

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*

OBJECTIVES: To evaluate the immunogenicity and osteogenic ability of animal-derived bone graft material decellularized with supercritical carbon dioxide. METHODS: Porcine femurs were randomly divided into two groups after preliminary treatment, and decellularized with conventional method (control group) or supercritical carbon dioxide (experimental group). Allogenic demineralized bone matrix was used as positive control. Clearance rate of galactose-α-1, 3-galactose (α-Gal) antigen was determined by enzyme-linked immunosorbent assay and residual DNA was detected by a fluorescence method. Nine SPF-grade male athymic nude mice of 6 weeks old were randomly divided into experimental, control and positive control groups. Samples were implanted over biceps femoris muscle of athymic nude mice. The explants were collected 4 weeks post implantation. Hematoxylin and eosin (HE) staining and immunohistochemistry were applied to determine the osteogenic ability and bone tissue-associated protein expressions of the implants. RESULTS: The clearance rates of α-Gal antigen in the experimental group and the control group were (99.09±0.26)% and (30.18±2.02)%, respectively (t=58.67, P<0.01). The residual DNA of the experimental, control and positive control groups were (13.49±0.07), (15.20±0.21) and (14.70±0.17) ng/mg. The residual DNA in the experimental group was significantly lower than that in the control group (t=－13.41, P<0.01) and positive control group (t=－11.30, P<0.01). HE staining results showed that multiple bone formation centers with active osteogenesis and rich bone marrow were observed in experimental group 4 weeks after implantation, but only a small number of bone formation centers were observed in the control and positive control groups, with no obvious osteoblasts present. Immunohistochemistry results indicated that the expressions of alkaline phosphatase, Runt-related transcription factor 2, collagen typeⅠand osteocalcin in the experimental group showed an increasing trend compared with those in the control and positive control groups. CONCLUSIONS Compared with clinically used allogenic demineralized bone matrix and bone graft material decellularized with conventional method, bone graft material decellularized with supercritical carbon dioxide exhibits lower immunogenicity and better osteogenic ability.
Animals ; Mice ; Swine ; Male ; Bone Transplantation/methods* ; Mice, Nude ; Carbon Dioxide ; Osteogenesis/drug effects* ; Femur ; Bone Substitutes ; Tissue Engineering/methods*

OBJECTIVE: To evaluate the effect of transcutaneous acupoint electrical stimulation (TEAS) at Neiguan (PC 6) on general anesthesia under preserving spontaneous breathing in thoracoscopic lobectomy. METHODS: A total of 66 patients of primary lung cancer undergoing thoracoscopic lobectomy were divided to an observation group (33 cases, 1 case discontinued) and a control group (33 cases). In the observation group, TEAS at Neiguan (PC 6) was used 30 min before anesthesia induction till the end of surgery. The surgery time, maximum value of partial pressure of end-tidal carbon dioxide (P_ETCO₂) and minimum value of oxygen saturation (SpO₂) of the two groups were recorded. The dosage of propofol, sufentanil, remifentanil and dexmedetomidine were analyzed. Separately, before induction (T₀), at the start of surgery (T₁), thoracic exploration (T₂) and lobectomy (T₃), as well as 30 min (T₄) and 60 min (T₅) after lobectomy, the mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), serum cortisol (Cor) and norepinephrine (NE) were measured. The time of post anesthesia care unit (PACU) stay, ambulation, flatus, chest drainage and the incidence of nausea and vomiting were compared between the two groups. RESULTS: The maximum value of P_ETCO₂, the dosage of propofol and remifentanil in the observation group were lower than those in the control group (P < 0.05, P < 0.01), the minimum value of SpO₂ in the observation group was higher than that of the control group (P < 0.01). At T₁-T₅, the MAP, HR, serum Cor and NE levels in the observation group were all lower than those in the control group (P < 0.05). The ambulation time, the time for the flatus, chest drainage time, and the incidence of nausea and vomiting in the observation group were all lower than those in the control group (P<0.001, P < 0.01). CONCLUSION For the general anesthesia under preserving spontaneous breathing in thoracoscopic surgery, TEAS at Neiguan (PC 6) relieves stress response, reduces opioids dosage and promotes postoperative recovery.
Humans ; Acupuncture Points ; Carbon Dioxide ; Flatulence ; Propofol ; Remifentanil ; Anesthesia, General ; Nausea ; Norepinephrine ; Electric Stimulation

Extracorporeal carbon dioxide removal is an artificial lung auxiliary technique based on extrapulmonary gas exchange and can effectively remove carbon dioxide and provide oxygenation to a certain extent, and it is one of the effective treatment techniques for hypercapnia developed after mechanical ventilation and extracorporeal membrane oxygenation in recent years and has wide application prospect. This article elaborates on the development, working principle, advantages, classification, complications, and clinical application of extracorporeal carbon dioxide removal, so as to provide a new choice for extracorporeal carbon dioxide removal in clinical practice.
Humans ; Carbon Dioxide ; Extracorporeal Membrane Oxygenation ; Renal Dialysis ; Respiration, Artificial

Objective: To explore the clinical effects of fractional carbon dioxide laser combined with minimally invasive scar release in the treatment of post-acne atrophic scars. Methods: A retrospectively observational study was conducted. From January to June 2021, 60 patients with grade 3 and 4 post-acne atrophic scars who met the inclusion criteria were admitted to the First Affiliated Hospital of Henan University of Traditional Chinese Medicine. According to the adopted treatment methods, 30 patients treated with fractional carbon dioxide laser combined with minimally invasive scar release were included in combined treatment group (19 males and 11 females, aged (26±4) years), and 30 patients treated with fractional carbon dioxide laser alone were included in laser alone group (18 males and 12 females, aged (25±6) years). All the patients received the treatment once every two months, totally 3 times. Before the first treatment and 2 months after the last treatment, the scars were assessed by échelle d'évaluation clinique des cicatrices d'acné (ECCA). In 2 months after the last treatment, the curative effect was evaluated and the total effective rate was calculated according to the ECCA score. The adverse reactions of patients during the treatment were recorded. Data were statistically analyzed with independent sample t test, Wilcoxon rank-sum test, Mann-Whitney U test, chi-square test, and Fisher's exact probability test. Results: Before the first treatment, the ECCA scores of patients in the two groups were similar (P>0.05). In 2 months after the last treatment, the ECCA scores of patients in combined treatment group were significantly lower than those of laser alone group (Z=-2.89, P<0.05). The ECCA scores of patients in combined treatment group and laser alone group in 2 months after the last treatment were both significantly lower than those before the first treatment (with Z values of -4.81 and -4.79, respectively, P<0.05). In 2 months after the last treatment, the treatment in laser alone group cured the scars in 2 patients, and were markedly effective in 13 patients, effective in 7 patients, and ineffective in 8 patients; the treatment in combined treatment group cured the scars in 4 patients, and were markedly effective in 22 patients, effective in 3 patients, and ineffective in one patients. The total effective rate of scar treatment in combined treatment group (96.67%, 29/30) was significantly higher than 73.33% (22/30) in laser alone group (P<0.05). During treatment, in combined treatment group, 3 patients had pain, one patient had redness and swelling, and one patient had pigmentation. In laser alone group, one patient had pain, and 2 patients had pigmentation. No infection occurred in the wounds of all the patients in the two groups. Conclusions: Compared with fractional carbon dioxide laser alone, fractional carbon dioxide laser combined with minimally invasive scar release for post-acne atrophic scars can result in a higher total effective rate, with simple operation and good effect, so it is worthy of clinical application.
Male ; Female ; Humans ; Cicatrix/therapy* ; Retrospective Studies ; Treatment Outcome ; Lasers, Gas/therapeutic use* ; Acne Vulgaris ; Atrophy ; Pain ; Carbon Dioxide