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A paper-based electrochemical dual-function biosensor capable of determining pH and TCO 2 was synthesized for the first time using an iridium oxide pH electrode and an all-solid-state ion electrode (ASIE). In the study, to obtain highly reliable results, the biosensor was equipped with a real-time pH correction function before TCO 2 measurements. Compared to traditional liquid-filling carbon dioxide detection sensors, the utilization of ferrocene endows our novel sensor with abundant positive sites, and thus greatly improves its performance. Conversely, the introduction of MXene with conductivity close to that of metals reduces electrode resistance, which is beneficial for accelerating the electrochemical reaction of the sensor and reducing LOD. After optimization, the detection range of TCO 2 is 0.095 nM-0.66 M, with a detection limit of as low as 0.023 nM. In addition, the sensor was used in real serum sample-spiked recovery experiments and comparison experiments with existing clinical blood gas analyzers, which confirmed the effectiveness of its clinical application. This study provides a method for the rational design of paper-based electrochemical biosensors and a new approach for the clinical detection of blood carbon dioxide., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

The rapid acceleration in emissions of inevitably generated CO 2 due to numerous activities mainly anthropogenic have devastating environmental effects leading to climatic concerns. Hence, significant, sustainable approaches should be developed for reduction of CO 2 emission targets, balancing the existing needs of the current population. Biological carbon acquisition, storage and usage are considered crucial alternative strategies in assimilating inorganic carbon, manifested by diverse variety of microorganisms. Furthermore, central biochemical routes along with associated enzymes serve as considerable factors for understanding molecular microbial CO 2 assimilation. Microorganisms exhibit an impeccable capability to facilitate evolved mechanisms in sequestering inorganic carbon at higher pace to produce biomaterials like biofuels, bioplastics etc. This review endorses the importance of microorganisms in reducing the concomitant release of CO 2 by providing supervision in biotechnological applications (such as genetic engineering, microbial electrosynthesis, gas fermentation and protein engineering) to mitigate CO 2 at an industrial scale., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Saccharomyces cerevisiae is one of the common spoilage microorganisms in fruit juices. This paper investigated the influences of carvacrol on S. cerevisiae inactivation by mild pressure carbon dioxide (MPCO 2 ). The results demonstrated that carvacrol synergistically enhanced the antifungal activity against S. cerevisiae of MPCO 2 . With the increase of carvacrol concentration (20-160 µg/mL), CO 2 pressure (1.5-3.5 MPa), process temperature (20-40 °C), and treatment time (15-60 min), the inactivation effect of carvacrol combined with MPCO 2 on S. cerevisiae was gradually increased and significantly stronger than either single treatment. In the presence of carvacrol, MPCO 2 severely disordered the plasma membrane of S. cerevisiae, including the increase of membrane permeability, and the loss of membrane potential and integrity. MPCO 2 and carvacrol in combination also aggravated the mitochondrial depolarization of S. cerevisiae and reduced intracellular ATP and protein content. This study suggests the potential of carvacrol and pressurized CO 2 as an alternative technology for food pasteurization., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The decrease in ocean pH that results from the increased concentration of dissolved carbon dioxide (CO 2 ) is likely to influence many physiological functions in organisms. It has been shown in different fish species that ocean acidification (OA) mainly affects sensory systems, including olfaction. Impairment of olfactory function may be due to a dysfunction of the GABAergic system and to an alteration of neuronal plasticity in the whole brain and particularly in olfactory bulbs. Recent studies revealed that OA-driven effects on sensory systems are partly mediated by the regulation of the expression of genes involved in neurotransmission and neuronal development. However, these studies were performed in fish exposed to acidified waters for short periods, of only a few days. In the present paper, we investigated whether such effects could be observed in adult (4-years old) European sea bass (Dicentrarchus labrax) exposed to two hypercapnic and acidified conditions (PCO 2 ≈ 980 µatm; pH total = 7.7 and PCO 2 ≈ 1520 µatm; pH total = 7.5) from the larval stage. In a first approach, we analyzed by qPCR the expression of five genes involved in neurogenesis (DCX) or expressed in GABAergic (Gabra3), glutamatergic (Gria1) or dopaminergic (TH and DDC) neurons in the olfactory bulbs. The tested experimental conditions did not change the expression of any of the five genes. This result would indicate that a potential disruption of the olfactory function of sea bass exposed for a long term to near-future OA, either occurs at a level other than the transcriptional one or involves other actors of the sensory function.

The increasing need for rapid, in situ, and robust tissue profiling approaches in the context of intraoperative diagnostics has led to the development of a large number of ambient ionization-based surface sampling strategies. This paper compares the performances of a diathermic knife and a CO 2 laser handpiece, both clinically approved, coupled to a rapid evaporative ionization mass spectrometry (REIMS) source for quasi-instantaneous tissue classification. Several fresh meat samples (muscle, liver, bone, bone marrow, cartilage, skin, fat) were obtained from different animals. Overall, the laser produced cleaner cuts and more reproducible and higher spectral quality signals when compared with the diathermic knife (CV laser = 9-12%, CV diathermic = 14-23%). The molecular profiles were subsequently entered into a database and PCA/LDA classification/prediction models were built to assess if the data generated with one sampling modality can be employed to classify the data generated with the other handpiece. We demonstrate that the correct classification rate of the models increases (+ 25%) with the introduction of a model based on peak lists that are tissue-specific and common to the two handpieces, compared with considering solely the whole molecular profile. This renders it possible to use a unique and universal database for quasi-instantaneous tissue recognition which would provide similar classification results independent of the handpiece used. Furthermore, the laser was able to generate aerosols rich in lipids from hard tissues such as bone, bone marrow, and cartilage. Combined, these results demonstrate that REIMS is a valuable and versatile tool for instantaneous identification/classification of hard tissue and coupling to different aerosol-generating handpieces expands its field of application. Graphical abstract.

Purpose: While CO2 capture and storage (CCS) technology has been well studied in terms of its efficacy and cost of implementation, there is limited available data concerning the potential for occupational exposure to amines, mixtures of amines, or degradation of by-products from the CCS process. This paper is a critical review of the available data concerning the potential effects of amines and CCS-degradation by-products., Methods: A comprehensive review of the occupational health and safety issues associated with exposure to amines and amine by-products at CCS facilities was performed, along with a review of the regulatory status and guidelines of amines, by-products, and CCS process vapor mixtures., Results: There are no specific guidelines or regulations regarding permissible levels of exposure via air for amines and degradation products that could form atmospheric oxidation of amines released from post-combustion CO2 capture plants. While there has been a worldwide effort to develop legal and regulatory frameworks for CCS, none are directly related to occupational exposures., Conclusions: By-products of alkanolamine degradation may pose the most significant health hazard to workers in CCS facilities, with several aldehydes, amides, nitramines, and nitrosamines classified as either known or potential/possible human carcinogens. The absence of large-scale CCS facilities; absence and unreliability of reported data in the literature from pilot facilities; and proprietary amine blends make it difficult to estimate potential amine exposures and predict formation and exposure to degradation products.

This work proposes a committee of Cascade Correlation neural networks as an online smoother for random measurement noise. The goals of this paper are twofold: first it intends to explore the possibilities of using a constructive neural network algorithm to learn how to filter typical noisy data from a bioreactor, CO(2) mol fractions of the effluent gas during the aerobic cultivation of Bacillus megaterium to produce the enzyme penicillin G acylase. Second, to propose a committee of such networks for achieving more realistic results, capturing the inherent trend of the process. In order to do that this paper discusses the advantages of using a constructive neural network algorithm, describes how the committee of NNs operates and evaluates its performance using real CO(2) online data obtained in laboratorial experiments. The paper also presents results obtained with classical filtering algorithms, for comparison.

Partitioning of CO(2) incorporation into oxygenic phototrophic, anoxygenic phototrophic, and chemolithoautotrophic guilds was determined in a freshwater lake (Lake Cisó, Banyoles, Spain). CO(2) incorporation into the different types of microorganisms was studied at different depths, during diel cycles, and throughout the year. During winter holomixis, the whole lake became anoxic and both the anoxygenic and chemolithoautotrophic guilds were more active at the surface of the lake, whereas the activity of the oxygenic guild was negligible. During stratification, the latter guild was more active in the upper metalimnion, whereas the anoxygenic guild was more active in the lower metalimnion. Specific growth rates and doubling times were estimated for the most conspicuous phototrophic microorganisms. Doubling times for Cryptomonas phaseolus ranged between 0.5 and 192 days, whereas purple sulfur bacteria (Chromatiaceae-like) ranged between 1.5 and 238 days. These growth rates were similar to those calculated with a different approach in previous papers and indicate slow-growing populations with very large biomass. Overall, the annual total CO(2) incorporation in Lake Cisó was 220 g C m(-2). Most of the CO(2) incorporation, however, was due to the chemolithoautotrophic guild (61% during holomixis and 56% during stratification), followed by the anoxygenic phototrophic guild (35 and 19%, respectively) and the oxygenic phototrophs (4 and 25%, respectively), making dark carbon fixation the key process in the autotrophic metabolism of the lake.

This paper analyses the presence of and changes in free amino acids and biogenic amines in red and white muscle of bigeye tuna during storage in controlled atmospheres with 2 gas mixes containing different concentrations of CO(2) and O(2). Levels of amines were generally higher in white than in red muscle, with the exception of putrescine and spermidine. Levels of biogenic amines increased (p<0.05) throughout storage, commencing later in red than in white muscle. A correlation between the amino acid histidine and the biogenic amine histamine was observed, but only in white muscle. Only in the case of tryptophan did white and red muscle differ (p<0.05) in terms of essential free amino acid content. They also differed in anserine content. Concentrations of the non-essential FAAs glutamic acid, glycine and alanine were higher in red than in white muscle. The effectiveness of the atmospheres was reflected in the evolution of both biogenic amines and FAAs. Gas mix 1, containing a higher concentration of CO(2), was the more effective.

The aim of this paper was to analyse the difference between end-tidal carbon dioxide tension (PETCO2) and arterial carbon dioxide tension (PaCO2) at rest and during exercise using a homogeneous lung model that simulates the cyclic feature of breathing. The model was a catenary two-compartment model that generated five non-linear first-order differential equations and two equations for gas exchange. The implemented mathematical modelling described variations in CO2 and O2 compartmental fractions and alveolar volume. The model also included pulmonary capillary gas exchange. Ventilatory experimental data were obtained from measurements performed on a subject at rest and during four 5-min bouts of exercise on a cycle ergometer at 50, 100, 150 and 200 W, respectively. Analysis of the PETCO2-PaCO2 difference between experimental and sinusoidally adjusted ventilatory flow profiles at rest and during exercise showed that the model produced similar values in PETCO2-PaCO2 for different respiratory flow dynamics (P approximately equal to 0.75). The model simulations allowed us to study the effects of metabolic, circulatory and respiratory parameters on PETCO2-PaCO2 at rest and during exercise. During exercise, metabolic CO2 production, O2 uptake and cardiac output affected significantly the PETCO2-PaCO2 difference from the 150-W workload (P < 0.001). The pattern of breathing had a significant effect on the PETCO2-PaCO2 difference. The mean (SD) PETCO2-PaCO2 differences simulated using experimental profiles were 0.80 (0.95), 1.65 (0.40), 2.40 (0.20), 3.30 (0.30) and 4.90 (0.20) mmHg, at rest and during exercise at 50, 100, 150 and 200 W, respectively. The relationship between PETCO2-PaCO2 and tidal volume was similar to data published by Jones et al. (J Appl Physiol 47: 954-960, 1979).

A modified facelifting technique with simultaneous carbon dioxide laser resurfacing makes for improved quality of the overlying skin, which enhances the effect of repositioning of the deep facial structures. Concerns have been expressed with regard to complications which may occur when this approach to facelifting is used. This paper presents guidelines which, if observed, allow this procedure to be performed safely in terms of laser skin injury. Over 100 patients have been treated using this combined technique, frequently with the addition of further ancillary procedures. Patient follow-up ranged from 1 to 36 months and showed none of the feared complications to have occurred. This combined approach has improved the results achieved previously by either technique used on its own. In addition, it saves time for both patient and surgeon, and apart from redness, the postoperative recovery period is similar. This technique requires patient education and a postoperative team effort by surgeon, nurse, and aesthetician. Experience has shown that this is a safe procedure which can produce good results with the proper pre- and postoperative management.

In this paper the rationale behind utilizing the brain tissue measurements of oxygen, carbon dioxide, pH and temperature is evaluated in the context of ischemia. These parameters were measured using an intraparenchymal multi-parametric brain tissue monitor (Paratrend 7). The need to establish the relevance of this type of monitoring becomes acute as further experience is gained using this kind of technology. Our experience with such a device is presented and is illustrated with two clinical cases. The potential caveats and areas of possible future work are also delineated.

Unlabelled: Currently, even in prehospital emergency medicine (PEM), continuous end-tidal CO2 monitoring is frequently used as a sensitive and non-invasive technique in ventilated patients. Due to its central role, the continuous measurement of exhaled CO2 provides immediate information about the status of three essential functions of the organism: ventilation, circulation, and metabolism., Methods: Recent literature, obtained by a computer-guided search (Winspirs), and product information of all currently available capnometry devices were reviewed in detail. Firstly, the theoretical background of different CO2-measurement methods and techniques is described. Secondly, indications and specific implications for the out-of-hospital use of capnometry are discussed. Thirdly, different monitoring systems suitable for pre-hospital care are evaluated., Results: There are two basic principles to reliably determine end-tidal CO2 (EtpCO2) that can be realised in portable monitors: qualitative measurements with a paper indicator and quantitative measurements using non-dispersive infrared spectroscopy. Capnography is a feature of more advanced units to provide the emergency physician with additional information by displaying EtpCO2 values versus time. Multiple indications for capnometry in emergency situations are listed, all related to the evaluation of patient's ventilation, circulation, and metabolism. Specific implications regarding mobility, ease of use, patient hygiene and accuracy of measurements are mentioned. Five units, each representing a different type of CO2 monitor, are described and evaluated for their use in PEM., Conclusions: Some current portable CO2 monitors allow fast and reliable measurement of EtpCO2 even in the out-of-hospital care of critically ill patients. However, the development of a new portable monitoring system comprising the three most important ventilation parameters (ventilation rate, EtpCO2 and peripheral O2 saturation) seems to be a promising step for the improvement of monitoring in out-of-hospital emergencies.

Today it is widely known and accepted that indoor air pollution can affect health. To ensure a healthy indoor climate through source control it is necessary to be able to predict how much of a source can be introduced into a building without unacceptable health and comfort effects. This paper describes a study of human eye irritation, which is part of a research program aimed at developing the use of sensory reference scaling in source characterization. In reference scaling the sensory eye irritation caused by exposure to polluted air is measured in terms of a concentration of a reference gas causing equivalent eye irritation intensity. The purpose of this study, therefore, was to estimate a possible difference in the magnitude of perceived sensory irritation between unilateral and bilateral exposure of human eyes. In each of four runs ten subjects were exposed to five progressive concentrations of CO2. In two of the runs the subjects were exposed unilaterally and in the other two runs the subjects were exposed bilaterally. In an analysis of variance no significant difference was found between unilateral and bilateral exposures. As expected, the intensity of the perceived irritation increased significantly with increasing exposure level. The sensitivity decreased slightly but significantly following previous exposures. These results enable us to develop a model for source characterization in which sensory eye irritation is measured by reference scaling. The use of reference scaling has the advantage that an otherwise subjective response (perceived irritation intensity) becomes less biased.