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

OBJECTIVES: To prepare a stable mouse model of chronic liver fibrosis induced by dietary vitamin A (VA) deficiency combined with CCl₄ injections. METHODS: A total of 126 Balb/c mice were randomized into 3 groups for feeding with a normal VA diet or a VA-deficient diet containing 500 or 200 IU/kg VA. After 4 weeks of feeding, half of the mice in each group were given intraperitoneal injections of 5% CCl₄ (10 mL/kg, twice a week) for 8 weeks. Serum retinol, ALT/AST and liver index of the mice were examined, liver tissue pathologies were observed with HE and Masson staining, and liver fibrosis score and oxidative stress level were evaluated. RESULTS: Four weeks of VA-deficient feeding, especially at 200 IU/kg, significantly lowered serum retinol level of the mice. CCl₄ injections for 8 weeks obviously increased liver index and ALT/AST and caused obvious liver fibrosis in all the mice, but liver pathologies were more severe in the 2 VA-deficient groups; severe liver necrosis with inflammatory cell infiltration was observed in 200 IU/kg VA group, where 2 mice died. After discontinuation of CCl₄, the mice with normal dietary VA showed gradual recovery of the liver index, ALT/AST, liver cord structure and liver fibrosis; the mice with VA deficiency, however, showed no significant improvements in these parameters, and the mice with 200 IU/kg VA still had serious abdominal adhesion, false lobules and massive inflammatory cell infiltration with a fibrosis stage score of 3. The oxidative damage index 8-OHdG was significantly higher in 500 IU/kg VA group than in normal VA group after CCl₄ modeling. CONCLUSIONS Feeding with diet containing 500 IU/kg VA for 4 weeks and 10 mL/kg CCl₄ injections for 8 weeks can result in stable moderate to severe liver fibrosis in mice without spontaneous reversal at 8 weeks of drug withdrawal.
Animals ; Mice ; Mice, Inbred BALB C ; Disease Models, Animal ; Carbon Tetrachloride ; Vitamin A Deficiency/complications* ; Male ; Liver Cirrhosis/etiology* ; Oxidative Stress ; Vitamin A/blood*

Acute carbon monoxide poisoning (ACMP) is one of the most common gas poisonings in the emergency department, with tens of thousands of people seeking medical attention for carbon monoxide (CO) poisoning each year. The severity of poisoning is dependent upon environmental and human factors, with hypoxia and oxidative stress being important mechanisms of cardiac toxicity induced by CO. Myocardial involvement is common in moderate to severe ACMP, including myocardial injury, myocardial infarction, arrhythmia, and sudden death, which are associated with a high risk of death. Ferroptosis is a cell death mechanism caused by iron-dependent lipid peroxidation (LPO), although ferroptosis has been shown to play a critical role in various cardiovascular diseases, the potential mechanism by which it contributes to ACMP-induced myocardial injury is unclear. This review discusses the established link between ferroptosis and cardiovascular disease and summarizes the potential role of ferroptosis in ACMP-induced myocardial injury and the detrimental effects of ACMP on the heart. Elucidating these mechanisms could guide the development of novel therapeutic strategies that target ferroptosis to mitigate ACMP-induced myocardial injury. This review aims to provide a theoretical foundation for future research on the potential use of ferroptosis as a therapeutic target for ACMP-induced myocardial injury.
Humans ; Carbon Monoxide Poisoning/complications* ; Ferroptosis ; Lipid Peroxidation ; Myocardium/pathology* ; Oxidative Stress

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*

Small urban wetlands are widely distributed and susceptible to human activities, serving as important sources and sinks of carbon. Microorganisms play a crucial role in carbon cycle, while limited studies have been conducted on the microbial diversity in small urban wetlands and the functions of microbiome in carbon fixation and metabolism. To probe into the microbiome-driven carbon cycling in small urban wetlands and dissect the composition and functional groups of microbiome, we analyzed the relationships between the microbiome structure, element metabolism pathways, and habitat physicochemical properties in sediment samples across three small wetlands in Huzhou City, and compared them with natural wetlands in the Zoige wetland. High-throughput sequencing of 16S rRNA gene amplicons and metagenomics was employed to determine the species and functional groups. Sixty medium to high-quality metagenome-assembled genomes (MAGs) were constructed, including 55 bacterial and 5 archaeal taxa, and their potential in driving elemental cycles were analyzed, with a focus on carbon fixation. Several bacterial species were found to encode a nearly complete carbon fixation pathway, including the Calvin cycle, the reductive tricarboxylic acid cycle, the Wood-Ljungdahl pathway, and the reductive glycine pathway. There were several potential novel carbon-fixing bacterial members, such as those belonging to Syntrophorhabdus (Desulfobacterota) and UBA4417 (Bacteroidetes), which had high relative abundance in the wetland microbiome. Unveiling the genetic potential of these functional groups to facilitate element cycling is of great scientific importance for enhancing the carbon sequestration capacity of small urban wetlands.
Wetlands ; Microbiota/genetics* ; Carbon Cycle/genetics* ; Bacteria/classification* ; RNA, Ribosomal, 16S/genetics* ; China ; Cities ; Geologic Sediments/microbiology* ; Archaea/classification* ; Metagenomics ; Metagenome

Microalgae possess high photosynthetic efficiency, robust adaptability, and substantial biomass, serving as excellent biological resources for large-scale cultivation. Malic enzyme (ME), a ubiquitous metabolic enzyme in living organisms, catalyzes the decarboxylation of malate to produce pyruvate, CO₂, and NAD(P)H, playing a role in multiple metabolic pathways including energy metabolism, photosynthesis, respiration, and biosynthesis. In this study, we identified the Scenedesmus quadricauda malic enzyme gene (SqME) and its biological functions, aiming to provide excellent target genes for the genetic improvement of higher plants. Based on the RNA-seq data from S. quadricauda under the biofilm cultivation mode with high CO₂ and light energy transfer efficiency and small water use, a highly expressed gene (SqME) functionally annotated as ME was cloned. The physicochemical properties of the SqME-encoded protein were systematically analyzed by bioinformatics tools. The subcellular localization of SqME was determined via transient transformation in Nicotiana benthamiana leaves. The biological functions of SqME were identified via genetic transformation in Nicotiana tabacum, and the potential of SqME in the genetic improvement of higher plants was evaluated. The ORF of SqME was 1 770 bp, encoding 590 amino acid residues, and the encoded protein was located in chloroplasts. SqME was a NADP-ME, with the typical structural characteristics of ME. The ME activity in the transgenic N. tabacum plant was 1.8 folds of that in the wild-type control. Heterologous expression of SqME increased the content of chlorophyll a, chlorophyll b, and total chlorophyll by 20.9%, 26.9%, and 25.2%, respectively, compared with the control. The transgenic tobacco leaves showed an increase of 54.0% in the fluorescence parameter NPQ and a decrease of 30.1% in Fo compared with the control. Moreover, the biomass, total lipids, and soluble sugars in the transgenic tobacco leaves enhanced by 20.5%, 25.7%, and 9.5%, respectively. On the contrary, the starch and protein content in the transgenic tobacco leaves decreased by 22.4% and 12.2%, respectively. Collectively, the SqME-encoded protein exhibited a strong enzymatic activity. Heterologous expressing of SqME could significantly enhance photosynthetic protection, photosynthesis, and biomass accumulation in the host. Additionally, SqME can facilitate carbon metabolism remodeling in the host, driving more carbon flux towards lipid synthesis. Therefore, SqME can be applied in the genetic improvement of higher plants for enhancing photosynthetic carbon fixation and lipid accumulation. These findings provide scientific references for mining of functional genes from S. quadricauda and application of these genes in the genetic engineering of higher plants.
Nicotiana/genetics* ; Photosynthesis/physiology* ; Malate Dehydrogenase/biosynthesis* ; Plant Leaves/genetics* ; Scenedesmus/enzymology* ; Carbon Cycle/genetics* ; Lipid Metabolism/genetics* ; Plants, Genetically Modified/metabolism*

The escalating pressure from global population growth, climate change, and resource consumption is intensifying the burden on traditional agricultural production. Against this backdrop, soil degradation and pollution present increasingly severe challenges, creating a vicious cycle with rising food demands. Maintaining soil health and its ecosystem services has thus become a critical prerequisite for achieving sustainable agriculture in the future. This review explores the impacts of soil carbon (C) and nitrogen (N) dynamics on soil microbial communities and their interactions. Soil C and N are key determinants of microbial diversity and community structure, intrinsically linked to soil C/N cycling, crop productivity, and ecological balance. Environmental factors such as nitrogen fertilizer application, organic matter amendment application, litter decomposition, elevated CO₂ concentrations, and nitrogen deposition significantly influence soil C and N dynamics. Changes in soil C and N content regulate microbial community dynamics and the synergistic, competitive, and antagonistic interactions among microorganisms. Meanwhile, microbial communities actively respond to alterations in soil C and N availability. The resulting shifts in microbial communities and their interactions subsequently regulate soil C/N cycling and ecosystem stability, ultimately influencing ecosystem functions. By elucidating the mechanisms underlying soil carbon-nitrogen-microbial interactions, this review significantly advances our understanding of soil ecosystem responses and feedback mechanisms in the context of global change, while also providing crucial practical guidance for enhancing soil fertility and promoting sustainable agricultural development through microbial regulation.
Soil Microbiology ; Nitrogen/metabolism* ; Carbon/metabolism* ; Soil/chemistry* ; Bacteria/growth & development* ; Fungi/metabolism* ; Ecosystem ; Fertilizers ; Agriculture

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

Under the background of carbon peaking and carbon neutrality goals, the Ministry of Ecology and Environment, together with 15 national ministries and commissions, has formulated the Implementation Plan on Establishing a Carbon Footprint Management System, and it is urgent for traditional Chinese medicine(TCM) pharmaceutical enterprises to carry out research on carbon footprint accounting methods of related products. Based on the life cycle assessment(LCA) theory, taking mulberry leaf extract produced by a certain enterprise as an example, this study analyzed the carbon footprint of TCM extracts during the life cycle. The results show that for every 1 kg of product produced, the carbon emissions from the stages of raw material acquisition, transportation, and extract production are-20.569, 1.205, and 173.577 kgCO_2eq(CO_2 equivalent), respectively. The carbon footprint of the product is 154.213 kgCO_2eq·kg~(-1). In addition, the carbon emission is the highest in the production stage, in which the consumption of ethanol solvents makes the greatest contribution to the carbon footprint, accounting for 25.71%, more than one-fourth of the total carbon footprint. The second contribution was from the treatment process of TCM residues, accounting for 19.67%, closely followed by wastewater treatment(17.71%), the consumption of hot steam(17.43%), and drinking water(16.90%). The consumption of electric power and packaging materials has a smaller carbon emission of 2.58%. In particular, the carbon emission caused by the consumption of packaging materials is only 0.04%, which is negligible. The results of the study are expected to provide a reference for TCM enterprises to carry out research on the carbon footprint of products, offer ideas for collaborative innovation in reducing pollution and carbon emissions throughout the entire industry chain of TCM, and develop new quality productivity of modern TCM industry based on green and low-carbon manufacturing.
Morus/chemistry* ; Plant Leaves/chemistry* ; Carbon Footprint ; Drugs, Chinese Herbal/chemistry* ; Plant Extracts/analysis* ; Medicine, Chinese Traditional

Traditional Chinese medicine(TCM) solid waste is characterized by widespread availability, renewability, and substantial production volume. In the context of the "dual carbon" goals, the pyrolysis of TCM solid waste for producing fuel gas for recycling in pharmaceutical production has emerged as a crucial strategy for optimizing the energy structure in the TCM industry and developing renewable energy. This paper comprehensively reviews both internal and external factors that influence the pyrolysis of TCM solid waste. Internal factors encompass moisture content, particle size, ash content, and the morphology of the raw materials, while external factors include pyrolysis conditions, equivalence ratios, types of gasifiers, and gasifying agents. Furthermore, this paper details the challenges associated with the pyrolysis of TCM solid waste, such as the dispersion of feedstocks, the diversity of resources, the complexity of the pyrolysis process, and the variations in gasifier performance. Finally, this paper proposes measures to address these challenges. This paper aims to provide insights into the development of a circular economy for TCM resources and the advancement of low-carbon energy utilization in the TCM industry.
Pyrolysis ; Carbon/chemistry* ; Medicine, Chinese Traditional ; Solid Waste/analysis* ; Drugs, Chinese Herbal/chemistry* ; Gases/chemistry*