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The perfluorocarbons tetrafluoromethane (CF4, PFC-14) and hexafluoroethane (C2F6, PFC-116) are potent greenhouse gases with near-permanent atmospheric lifetimes relative to human timescales and global warming potentials thousands of times that of CO2. Using long-term atmospheric observations from a Chinese network and an inverse modeling approach (top--down method), we determined that CF4 emissions in China increased from 4.7 (4.2-5.0, 68% uncertainty interval) Gg y-1 in 2012 to 8.3 (7.7-8.9) Gg y-1 in 2021, and C2F6 emissions in China increased from 0.74 (0.66-0.80) Gg y-1 in 2011 to 1.32 (1.24-1.40) Gg y-1 in 2021, both increasing by approximately 78%. Combined emissions of CF4 and C2F6 in China reached 78 Mt CO2-eq in 2021. The absolute increase in emissions of each substance in China between 2011-2012 and 2017-2020 was similar to (for CF4), or greater than (for C2F6), the respective absolute increase in global emissions over the same period. Substantial CF4 and C2F6 emissions were identified in the less-populated western regions of China, probably due to emissions from the expanding aluminum industry in these resource-intensive regions. It is likely that the aluminum industry dominates CF4 emissions in China, while the aluminum and semiconductor industries both contribute to C2F6 emissions. Based on atmospheric observations, this study validates the emission magnitudes reported in national bottom--up inventories and provides insights into detailed spatial distributions and emission sources beyond what is reported in national bottom--up inventories. [ABSTRACT FROM AUTHOR]

Atmospheric transport and dispersion models (ATDMs) are widely used to study and forecast pollution events. In the frame of the "Effect of Megacities on the transport and transformation of pollutants on the regional to global scales" (EMeRGe) project, ATDM forecasts were carried out to identify potential airborne sampling areas of perfluorocarbons (PFCs) emanating from controlled PFC releases. The forecasts involved short-distance transport over small-scale topographic maxima (Manilla; Philippines), short-distance transport over large-scale topographic maxima (Taipei, Taiwan) and long-distance transport over mixed topography (Nanjing, China, sampled over Taiwan). In situ aircraft measurements of PFC mixing ratios down to a few parts per quadrillion (ppqv) provide us with a unique dataset to explore the added benefits of dynamical downscaling. Transport simulations were repeated using FLEXPART driven by ERA5 and IFS meteorological data and FLEXPART-WRF with dynamically downscaled IFS data down to 1.1 km and four PBL parametrisations. Of the three cases studied, dynamical downscaling led to significant differences for the Manilla and Taipei releases that can be interpreted through changes in the modelled orographic flow regimes. The choice of PBL scheme also significantly impacted accuracy, but there was no systematically better-performing option, highlighting the benefits of ensemble forecasting. Results show how convergence and divergence between ensemble members can be utilised to help decision-making during field campaigns. This study highlights the role that dynamical downscaling can play as an important component in campaign planning when dealing with observations over orographically complex areas. [ABSTRACT FROM AUTHOR]

Hydrogels have emerged as a focal point of research in the biomedical field due to their applications in tissue repair. However, the majority of hydrogels lack the capability to release oxygen, constraining their therapeutic outcomes in environments with hypoxic tissues. In recent years, oxygen‐releasing hydrogels have garnered extensive attention in the field of tissue engineering, owing to their ability to modulate oxygen release and meet the diverse oxygenation requirements of various tissues. These hydrogels can enhance repair efficiency and promote tissue regeneration in hypoxic tissue environments. The design of oxygen‐releasing hydrogels primarily involves the utilization of diverse oxygen sources, such as algae, perfluorocarbons, and peroxides, to achieve optimal tissue oxygenation. This review provides a comprehensive summary of the design and fabrication strategies of oxygen‐releasing hydrogels, discusses deeply into their underlying oxygen‐releasing mechanisms, and their myriad applications in tissue repair along with the prospective challenges. [ABSTRACT FROM AUTHOR]

Gas-filled microbubbles are well-established contrast agents for ultrasound imaging and widely studied as delivery systems for theranostics. Herein, we have demonstrated the promising potential of the hydrophobin HFBII—a fungal amphiphilic protein—in stabilizing microbubbles with various fluorinated core gases. A thorough screening of several experimental parameters was performed to find the optimized conditions regarding the preparation technique, type of core gas, HFBII initial concentration, and protein dissolution procedure. The best results were obtained by combining perfluorobutane (C4F10) gas with 1 mg/mL of aqueous HFBII, which afforded a total bubble concentration higher than 109 bubbles/mL, with long-term stability in solution (at least 3 h). Acoustic characterization of such microbubbles in the typical ultrasound frequency range used for diagnostic imaging showed the lower pressure resistance of HFBII microbubbles, if compared to conventional ones stabilized by phospholipid shells, but, at the same time, revealed strong non-linear behavior, with a significant harmonic response already at low acoustic pressures. These findings suggest the possibility of further improving the performance of HFBII-coated perfluorinated gas microbubbles, for instance by mixing the protein with other stabilizing agents, e.g., phospholipids, in order to tune the viscoelastic properties of the outer shell. [ABSTRACT FROM AUTHOR]

Gas-filled microbubbles are well-established contrast agents for ultrasound imaging and widely studied as delivery systems for theranostics. Herein, we have demonstrated the promising potential of the hydrophobin HFBII—a fungal amphiphilic protein—in stabilizing microbubbles with various fluorinated core gases. A thorough screening of several experimental parameters was performed to find the optimized conditions regarding the preparation technique, type of core gas, HFBII initial concentration, and protein dissolution procedure. The best results were obtained by combining perfluorobutane (C4F10) gas with 1 mg/mL of aqueous HFBII, which afforded a total bubble concentration higher than 109 bubbles/mL, with long-term stability in solution (at least 3 h). Acoustic characterization of such microbubbles in the typical ultrasound frequency range used for diagnostic imaging showed the lower pressure resistance of HFBII microbubbles, if compared to conventional ones stabilized by phospholipid shells, but, at the same time, revealed strong non-linear behavior, with a significant harmonic response already at low acoustic pressures. These findings suggest the possibility of further improving the performance of HFBII-coated perfluorinated gas microbubbles, for instance by mixing the protein with other stabilizing agents, e.g., phospholipids, in order to tune the viscoelastic properties of the outer shell.

Supplementing sufficient oxygen to cells is always challenging in biomedical engineering fields such as tissue engineering. Originating from the concept of a 'blood substitute', nano-sized artificial oxygen carriers (AOCs) have been studied for a long time for the optimization of the oxygen supplementation and improvement of hypoxia environments in vitro and in vivo. When circulating in our bodies, micro-sized human red blood cells (hRBCs) feature a high oxygen capacity, a unique biconcave shape, biomechanical and rheological properties, and low frictional surfaces, making them efficient natural oxygen carriers. Inspired by hRBCs, recent studies have focused on evolving different AOCs into microparticles more feasibly able to achieve desired architectures and morphologies and to obtain the corresponding advantages. Recent micro-sized AOCs have been developed into additional categories based on their principal oxygen-carrying or oxygen-releasing materials. Various biomaterials such as lipids, proteins, and polymers have also been used to prepare oxygen carriers owing to their rapid oxygen transfer, high oxygen capacity, excellent colloidal stability, biocompatibility, suitable biodegradability, and long storage. In this review, we concentrated on the fabrication techniques, applied biomaterials, and design considerations of micro-sized AOCs to illustrate the advances in their performances. We also compared certain recent micro-sized AOCs with hRBCs where applicable and appropriate. Furthermore, we discussed existing and potential applications of different types of micro-sized AOCs. [ABSTRACT FROM AUTHOR]

Tetrafluoromethane (CF4), the simplest perfluorocarbon (PFC), has the potential to exacerbate global warming. Catalytic hydrolysis is a viable method to degrade CF4, but fluorine poisoning severely restricts both the catalytic performance and catalyst lifetime. In this study, Ga is introduced to effectively assists the defluorination of poisoned Al active sites, leading to highly efficient CF4 decomposition at 600 °C with a catalytic lifetime exceeding 1,000 hours. 27Al and 71Ga magic‐angle spinning nuclear magnetic resonance spectroscopy (MAS NMR) showed that the introduced Ga exists as tetracoordinated Ga sites (GaIV), which readily dissociate water to form Ga−OH. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density function theory (DFT) calculations confirmed that Ga−OH assists the defluorination of poisoned Al active sites via a dehydration‐like process. As a result, the Ga/Al2O3 catalyst achieved 100 % CF4 decomposition keeping an ultra‐long catalytic lifetime and outperforming reported results. This work proposes a new approach for efficient and long‐term CF4 decomposition by promoting the regeneration of active sites. [ABSTRACT FROM AUTHOR]

Hydrogen gas is recently proven to have anti-oxidative and anti-inflammation effects on ischemia-reperfusion injury. However, the efficacy of hydrogen therapy is limited by the efficiency of hydrogen storage, targeted delivery, and controlled release. In this study, H2-PFOB nanoemulsions (NEs) is developed with high hydrogen loading capacity for targeted ischemic myocardium precision therapy. The hydrogen-carrying capacity of H2-PFOB NEs is determined by gas chromatography and microelectrode methods. Positive uptake of H2-PFOB NEs in ischemia-reperfusion myocardium and the influence of hydrogen on 19F-MR signal are quantitatively visualized using a 9.4T MR imaging system. The biological therapeutic effects of H2-PFOB NEs are examined on a myocardial ischemia-reperfusion injury mouse model. The results illustrated that the developed H2-PFOB NEs can efficaciously achieve specific infiltration into ischemic myocardium and exhibit excellent antioxidant and anti-inflammatory properties on myocardial ischemia-reperfusion injury, which can be dynamically visualized by 19F-MR imaging system. Moreover, hydrogen burst release induced by low-intensity focused ultrasound (LIFU) irradiation further promotes the therapeutic effect of H2-PFOB NEs with a favorable biosafety profile. In this study, the potential therapeutic effects of H2-PFOB NEs is fully unfolded, which may hold great potential for future hydrogen-based precision therapeutic applications tailored to ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

At present, most of the research on lithium–air batteries (LABs) is carried out in a dry pure oxygen environment, and their working stability still needs to be further explored in the air environment. In this paper, the synergistic effect of perfluoronaphthane (PFDL) was added to the organic electrolyte (LiTFSI-TEGDME) of LABs. An oxygenating additive was systematically studied to improve the working stability of the battery in the air environment. The electrochemistry of LABs doped with PFDL electrolyte was studied by cyclic voltammetry, electrochemical impedance spectroscopy, a constant current and constant volume charge–discharge test, and deep charge–discharge test. At the same time, scanning electron microscopy and x-ray diffraction analysis were used to characterize the air cathode before and after the operation. The results showed that the best volume ratio of electrolyte to PFDL is 7:3. Under the condition of the charge–discharge current density of 100 mA cm−2, 136 cycles (1360 h) of lithium–air battery using PFDL mixed electrolyte in the air environment were achieved, which was about 5.5 times that of LABs with basic electrolyte, which is close to the cycle times of a battery in pure oxygen under the same conditions. At the same time, the specific capacity of the battery at first discharge reached 4730 mAh g−1. In addition, based on experiments, combined with simulation software, we established a mesoscopic mass transfer model to further verify the influence of adding PFDL into electrolytes on oxygen mass transfer and diffusion. Experimental and simulation results show that PFDL has excellent oxygen solubility and good hydrophobicity. It optimizes the oxygen transmission in the battery, makes the LABs more stable in air, and provides a wider space for the application of PFCs in LABs. [ABSTRACT FROM AUTHOR]

Heptafluoropropyl methyl ether (HFE-347mcc3), as a lower-GWP (global warming potential) alternative to PFCs (perfluorocarbons), was used to etch SiO2 contact holes. The etch profiles of the SiO2 contact holes in HFE-347mcc3/O2/Ar plasmas showed more bowing at lower flow rate ratios of HFE-347mcc3 to Ar, whereas more narrowing occurred at higher ratios. The measurements of the angular dependences of the deposition rates of fluorocarbon films on the surface of SiO2 and the etch rates of SiO2 showed that the shape evolution of contact-hole etch profiles at different HFE-347mcc3/Ar ratios was attributed to an increase in etch resistance and a decrease in etch ability of the sidewalls of the contact hole with the increasing HFE-347mcc3/Ar ratio. This resulted in determining the optimum ratio of HFE-347mcc3 to Ar to achieve the maximum anisotropy of the contact hole etched in HFE-347mcc3/O2/Ar plasmas. By carefully selecting the specific flow rates of HFE-347mcc3/O2/Ar (9/2/19 sccm), a highly anisotropic and bowing-free SiO2 contact hole, with a 100 nm diameter and an aspect ratio of 24, was successfully achieved. [ABSTRACT FROM AUTHOR]

Sonosensitive high-boiling point perfluorocarbon F 8 TAC 18 -PFOB emulsions previously exhibited thermal enhancement during focused ultrasound heating in ex vivo pig livers, kidneys and a laminar flow phantom. The main objectives of this study were to evaluate heating under turbulent conditions, observe perfusion effects, quantify heating in terms of acoustic absorption and model the experimental data. In this study, similar perfluorocarbon emulsions were circulated at incremental concentrations of 0.07, 0.13, 0.19 and 0.25% v:v through a percolated turbulent flow phantom, more representative of the biological tissue than a laminar flow phantom. The concentrations represent the droplet content in only the perfused fluid, rather than the droplet concentration throughout the entire cross-section. The temperature was measured with magnetic resonance thermometry, during focused ultrasound sonications of 67 W, 95% duty cycle and 33 s duration. These were used in Bioheat equation simulations to investigate in silico the thermal phenomena. The temperature change was compared with the control condition by circulating de-gassed and de-ionized water through the flow phantom without droplets. With these 1.24 µm diameter droplets at 0.25% v:v, the acoustic absorption coefficient increased from 0.93 ± 0.05 at 0.0% v:v to 1.82 ± 0.22 m–1 at 0.25% v:v using a 0.1 mL s–1 flow rate. Without perfusion at 0.25% v:v, an increase was observed from 1.23 ± 0.07 m–1 at 0.0% v:v to 1.65 ± 0.17 m–1. The results further support previously reported thermal enhancement with F 8 TAC 18 -PFOB emulsion, quantified the increased absorption at small concentration intervals, illustrated that the effects can be observed in a variety of visceral tissue models and provided a method to simulate untested scenarios. [ABSTRACT FROM AUTHOR]

Despite the long-standing use of per- and polyfluorinated carbons (FCs) as pore size–reducing agents for polyurethane rigid (PUR) foams, their mechanisms of action remain poorly understood. To shed light on these mechanisms, we provide a quantitative analysis of the influence of the FC concentration on the pore size of PUR cup foams of two different model PUR foam systems: an industrially-relevant "technical system" and a simplified "scientific system." Combining scanning electron microscopy (SEM) and the PORE!SCAN method, we provide a detailed analysis of the pore size distributions of the obtained foams. We confirm that the characteristic pore size of both systems is indeed significantly reduced by adding small quantities of FC. However, we show that there seems to exist a critical FC concentration (about 3 wt.% with respect to the A-component) beyond which adding more FC has a negligible effect. More interestingly, the relative extent of the pore size reduction is almost identical for both PUR foam systems and the normalized pore size distributions remain largely unchanged over the whole range of FC concentrations. Our findings suggest that the FC-driven pore size reduction is a general effect caused by distinct mechanisms that are independent of the choice of the PUR foam system. Moreover, we hypothesize that this effect is not to be searched for during foam aging, as often reported, but during the pre-mixing step. [ABSTRACT FROM AUTHOR]

Perfluorocarbons, saturated carbon chains in which all the hydrogen atoms are replaced with fluorine, form a separate phase from both organic and aqueous solutions. Though perfluorinated compounds are not found in living systems, they can be used to modify biomolecules to confer orthogonal behavior within natural systems, such as improved stability, engineered assembly, and cell-permeability. Perfluorinated groups also provide handles for purification, mass spectrometry, and 19 F NMR studies in complex environments. Herein, we describe how the unique properties of perfluorocarbons have been employed to understand and manipulate biological systems.

BackgroundPer- and polyfluoroalkyl substances (PFASs) have been detected in drinking water supplies around the world and are the subject of intense regulatory debate. While they have been associated with several illnesses, their effects on reproductive outcomes remains uncertain.MethodsWe analyzed birth outcomes in the east Minneapolis-St. Paul metropolitan area from 2002 to 2011, where a portion of the population faced elevated exposure to PFASs due to long-term contamination of drinking water supplies from industrial waste disposal. Installation of a water filtration facility in the highly contaminated city of Oakdale, MN at the end of 2006 resulted in a sharp decrease in exposure to PFASs, creating a "natural experiment". Using a difference-in-differences approach, we compare the changes in birth outcomes before and after water filtration in Oakdale to the changes over the same period in neighboring communities where the treatment of municipal water remained constant.ResultsAverage birth weight and average gestational age were statistically significantly lower in the highly exposed population than in the control area prior to filtration of municipal water supply. The highly exposed population faced increased odds of low birth weight (adjusted odds ratio 1.36, 95% CI 1.25-1.48) and pre-term birth (adjusted odds ratio 1.14, 95% CI 1.09-1.19) relative to the control before filtration, and these differences moderated after filtration. The general fertility rate was also significantly lower in the exposed population (incidence rate ratio 0.73, 95% CI 0.69-0.77) prior to filtration and appeared to be rebounding post-2006.ConclusionsOur findings provide evidence of a causal relationship between filtration of drinking water containing high levels of exposure to PFASs and improved reproductive outcomes.

Photodynamic therapy (PDT) has shown promising development due to its low toxicity, high selectivity and low side effects. However, the effectiveness of PDT is dependent on the concentration of oxygen and tumor cells have a hypoxia microenvironment that reduces the therapeutic effect of PDT. Therefore, near-infrared absorbing conjugated copolymers with perfluorocarbon side chains, 2,5-bis(2- octyldodecyl)-3,6-di(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione-co-2,5-thiophene-co-9,9-bis(N-methylperfluorohexylsulfonamidoethyl propionate)- fluorene copolymers, with the ability to generate singlet oxygen under hypoxia conditions were designed and synthesized. The structures of the copolymers were characterized by Fourier transform infrared spectrometer (FTIR) and proton nuclear magnetic resonance spectrum (1HNMR). The singlet oxygen generation ability of the copolymers and corresponding nanoparticles under organic solvents and aqueous conditions was investigated. The results show that the absorption wavelengths of the fluorine-containing conjugated copolymers are greater than 650 nm and they show strong absorption in near-infrared region. The perfluorocarbon (PFC) side chain endows the copolymers with high singlet oxygen generation capability. As the content of fluorine-containing structural units increases, the generation capability of singlet oxygen increases. When the proportion of fluorine-containing structural units is 35%mol (P3-F35%), the copolymer has the singlet oxygen quantum yield of 36.29%. And the singlet oxygen generation capability of the fluorine-containing copolymers is significantly enhanced even under hypoxia conditions. The nanoparticle of fluorine-containing conjugated polymer shows good singlet oxygen generation ability in aqueous suspension. The results of this study indicate that introducing fluorine-containing structure unit into near-infrared absorbing conjugated copolymers is an effective way to enhance the singlet oxygen generation capability of copolymers, which may have broad application prospects in the field of photodynamic therapy. [ABSTRACT FROM AUTHOR]

The efficacy of photodynamic therapy (PDT) strictly depends on the availability of molecular oxygen to trigger the light-induced generation of reactive species. Fluorocarbons have an increased ability to dissolve oxygen and are attractive tools for gas delivery. We synthesized three fluorous derivatives of chlorin with peripheral polyfluoroalkyl substituents. These compounds were used as precursors for preparing nanoemulsions with perfluorodecalin as an oxygen depot. Therefore, our formulations contained hydrophobic photosensitizers capable of absorbing monochromatic light in the long wavelength region and the oxygen carrier. These modifications did not alter the photosensitizing characteristics of chlorin such as the generation of singlet oxygen, the major cytocidal species in PDT. Emulsions readily entered HCT116 colon carcinoma cells and accumulated largely in mitochondria. Illumination of cells loaded with emulsions rapidly caused peroxidation of lipids and the loss of the plasma membrane integrity (photonecrosis). Most importantly, in PDT settings, emulsions potently sensitized cells cultured under prolonged (8 weeks) hypoxia as well as cells after oxygen depletion with sodium sulfite (acute hypoxia). The photodamaging potency of emulsions in hypoxia was significantly more pronounced compared to emulsion-free counterparts. Considering a negligible dark cytotoxicity, our materials emerge as efficient and biocompatible instruments for PDT-assisted eradication of hypoxic cells. [ABSTRACT FROM AUTHOR]

The effect of perfluorocarbon (PFC) nanoparticles on the functioning of blood cells is considered. Evidence is presented indicating that emulsified PFC nanoparticles in small volumes affect gas transport function of blood, increasing the rate of oxygen diffusion from erythrocytes to tissues. It was found that PFC nanoparticles also affect the state of blood cells (erythrocytes, leukocytes, and platelets) in a dose-dependent manner. It was assumed that depending on the emulsion dose, that is, the density of nanoparticles in the surrounding space of cells, the reaction of receptor apparatus can cause activation or deterioration of their functioning. [ABSTRACT FROM AUTHOR]

Developing chemical tools to detect and influence biological processes is a cornerstone of chemical biology. Here we combine two tools which rely on orthogonality– perfluorocarbons and multiplexed shortwave infrared (SWIR) fluorescence imaging– to visualize nanoemulsions in real time in living mice. Drawing inspiration from fluorous and SWIR fluorophore development, we prepared two SWIR‐emissive, fluorous‐soluble chromenylium polymethine dyes. These are the most red‐shifted fluorous fluorophores– "fluorofluorophores"—to date. After characterizing the dyes, their utility was demonstrated by tracking perfluorocarbon nanoemulsion biodistribution in vivo. Using an excitation‐multiplexed approach to image two variables simultaneously, we gained insight into the importance of size and surfactant identity on biodistribution. [ABSTRACT FROM AUTHOR]

Featured Application: The results obtained in this work may be of scientific and practical significance for the development of new biocatalytic approaches to the treatment of wastewater of complex composition, contaminated by perfluorocarbons and organophosphorus compounds, with simultaneous production of biomass of phototrophic microorganisms as renewable raw materials with a wide range of possibilities for conversion into valuable products. The results can also be taken into account for predicting changes in aquatic ecosystems when the mentioned pollutants enter them. The effects of the presence of perfluorocarbons (PFC) with a gas transport function in media with different phototrophic microorganisms on their growth rates and the accumulation of their biomass when using free and immobilized cells as inoculums were investigated. The significant increase in the average rate of biomass accumulation as well as levels of biomass accumulation in the presence of various PFCs were established for Chlorella vulgaris cells. When 1 g/L glycerol was introduced into the growth medium with PFCs and C. vulgaris cells, the increase in the rate of biomass accumulation was 9–32%. The maximum intracellular ATP concentrations corresponded to the combination of microalgae (Chlorella vulgaris) with bacterial cells (Pseudomonas esterophilus and Rhodoccus ruber) obtained with a mass ratio of 25:1. It provided for the formation of a consortium, which was able to accumulate the maximum amount of microalgae biomass for 3 days in the medium with PFCs and organophosphorus pesticide. The obtained data allow, on the one hand, predicting the growth of microalgae under environmental conditions in media with PFC pollution and, on the other hand, developing approaches to regulation of phototrophic microorganisms' growth in order to obtain and use their high biomass yields for various purposes. [ABSTRACT FROM AUTHOR]

As a typical hallmark of solid tumors, hypoxia affects the effects of tumor radiotherapy, chemotherapy, and photodynamic therapy. Therefore, targeting the hypoxic tumor microenvironment (TME) is a promising treatment strategy for cancer therapy. Here, we prepared an Albumin Human Serum (HSA)-coated perfluorocarbon (PFC) carrying oxygen (PFC@O2) to minimize OSCC hypoxia. The results showed that PFC@O2 significantly downregulated the expression of HIF-1α and the number of M2-like macrophages in vitro. Furthermore, PFC@O2 effectively inhibited the growth of oral squamous cell carcinoma (OSCC) and reduced the proportion of negative immunoregulatory cells, including myeloid-derived suppressor cells (MDSCs) and M2-like macrophages of TME in a 4-nitroquinoline N-oxide (4NQO)-induced mouse model. Conversely, the infiltration of CD4+ and CD8+ T cells was significantly increased in TME, suggesting that the anti-tumor immune response was enhanced. However, we also found that hypoxia-relative genes expression was positively correlated with CD68+/CD163+ TAMs in human tissue specimens. In summary, PFC@O2 could effectively inhibit the progression of OSCC by alleviating hypoxia, which provides a practical basis for gas therapy and gas synergistic therapy for OSCC. [ABSTRACT FROM AUTHOR]

Electrolysis of a cryolite-alumina melt is accompanied by emission of harmful pollutants into the atmosphere: hydrogen fluorides, perfluorocarbons, fluorine (gaseous and solid), tarry matters, benzopyrene. Workers of the potroom receive the highest dose of harmful emissions, which leads to a multiple risk of developing serious occupational diseases, including lung cancer. For these reasons, ensuring the environmental safety of production is an important and relevant task, which also corresponds to the goals of sustainable development of the aluminium production industry. The appearance of smoke in the potroom signals a malfunction of the gas treatment system, depressurization of aluminum reduction cell, disruptions of the anode carbon or occurrence of the anode effect. Such situations require immediate actions of the staff. The objective of the research is to improve the monitoring quality and reduce the emissions of pollutants into the environment, which are generated as a result of the cryolite-alumina melt electrolysis. To improve the emissions detection rate, an automatic system for monitoring the visible emissions of pollutants in the atmosphere of the potroom has been developed. The development is a vision system based on a convolutional neural network. The neural network was trained using the TensorFlow machine learning software and a dataset of labeled photographs of the model of the aluminum reduction cell with different smoke variations. The results of neural network testing show that the overall accuracy of the trained model was 94.75%. It proves that the model can be used to detect smoke and visible emissions of pollutants. The developed automatic monitoring system allows increasing the detection rate of an emergency situation by 2 times compared to traditional systems based on gas sensors, reducing the time for aluminium reduction cells depressurization and, consequently, reducing emissions of pollutants into the environment. [ABSTRACT FROM AUTHOR]

Hydrofluorocarbons and perfluorocarbons (F-gases) play a substantial role in global warming via the greenhouse effect and thus have been under increased investigation recently. EU member states, including the Czech Republic, already have measures limiting F-gas use based on their GWP such as EU regulation No. 517/2014. This manuscript explains the current status of F-gas emissions and describes a methodology of their estimation for the years 2010 to 2050. The computational method is based on the IPCC 2006 Guidelines. Currently available data, distribution of F-gases and active policies are crucial parameters for standard greenhouse gas emission estimates as well as for long-term projections. The outcomes demonstrate the effectiveness of the regulations implemented and provides a prediction scenario for how F-gas emissions will develop. According to these projections, a total F-gas emission decline is expected in the Czech Republic. For F-gas applications in refrigeration and air-conditioning, the predicted downward trend is more significant compared to the other F-gas application sectors, as they are currently some of the biggest contributors in the actual state of emissions. [ABSTRACT FROM AUTHOR]

A perfluorocarbon (PFC) investigated for treatment of traumatic brain injury (TBI) delivers oxygen to support brain function, but causes transient thrombocytopenia. TBI can cause acute inflammation with resulting thrombocytopenia; an interaction between the PFC effects and TBI inflammation might exacerbate thrombocytopenia. Therefore, PFC effects on platelet (PLT) function and hemostasis in a lipopolysaccharide (LPS) model of inflammation in the baboon were studied. Animals were randomized to receive saline ±LPS, and ± one of two doses of PFC. PLT count, transmission electron microscopy, and microparticle populations were quantified at baseline (BL) and at 2, 24, 48, 72, and 96 hours; hemostatic parameters for aggregometry and for blood clotting were measured at baseline (BL) and days 3 and 4. Injection of vehicle and LPS caused thrombocytopenia within hours; PFCs caused delayed thrombocytopenia beginning 48 hours post-infusion. LPS+PFC produced a more prolonged PLT decline and decreased clot strength. LPS+PFC increased ADP-stimulated aggregation, but PFC alone did not. Microparticle abundance was greatest in the LPS+PFC groups. LPS+PFC caused diffuse microvascular hemorrhage and death in 2 of 5 baboons in the low dose LPS-PFC group and 2 of 2 in the high dose LPS-PFC group. Necropsy and histology suggested death was caused by shock associated with hemorrhage in multiple organs. Abnormal morphology of platelets and red blood cells were notable for PFC inclusions. In summary, PFC infusion caused clinically significant thrombocytopenia and exacerbated LPS-induced platelet activation. The interaction between these effects resulted in decreased hemostatic capacity, diffuse bleeding, shock and death. [ABSTRACT FROM AUTHOR]

Perfluorinated compounds (PFCs) are a kind of refractory organic compounds, which cause serious damage to human health and environmental quality. Firstly, the ecological risks and biological toxicity of perfluorocarbons were introduced. The four removal technologies of adsorption, electrochemical oxidation, membrane separation and photochemical oxidation were reviewed. The removal effects of different removal technologies and the effects of materials on the removal rate were compared. Secondly, the treatment effect and influence factors of different methods on actual wastewater were discussed. Finally, based on the advantages and disadvantages of the treatment methods of perfluorinated compounds, the improvement of the removal effect and stability of perfluorinated compounds by different combinations of technologies was emphatically discussed, in order to provide useful reference for the research and development of high-efficiency removal technology of perfluorinated compounds. [ABSTRACT FROM AUTHOR]

Fluorination represents one of the most powerful modern design strategies to impart biomacromolecules with unique functionality, empowering them for widespread application in the biomedical realm. However, the properties of fluorinated protein materials remain unpredictable due to the heavy context-dependency of the surrounding atoms influenced by fluorine's strong electron-withdrawing tendencies. This review aims to discern patterns and elucidate design principles governing the biochemical synthesis and rational installation of fluorine into protein and peptide sequences for diverse biomedical applications. Several case studies are presented to deconvolute the overgeneralized fluorous stabilization effect and critically examine the duplicitous nature of the resultant enhanced chemical and thermostability as it applies to use as biomimetic therapeutics, drug delivery vehicles, and bioimaging modalities. [ABSTRACT FROM AUTHOR]

• Transformation of PFAS before, during and after thermal treatment of biosolids were reviewed. • Primary and secondary thermal units are the critical stage for PFAS destruction. • PFAS are volatilised and potentially destroyed during inert and oxidative thermal treatments. • Alkaline earth minerals can facilitate PFAS mineralisation during biosolids thermal treatment. • The fate of fluorine post-thermal destruction of PFAS was critically discussed. Biosolids (stabilised sewage sludge) are the final solid residues of the wastewater treatment process and are generally applied on agricultural land in many countries, including Australia. Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic fluorinated chemicals with ubiquitous applications in consumer products and persist in the environment. Globally, PFAS have been detected in biosolids and are considered a source of PFAS discharge to the environment. The thermal treatment of biosolids is gaining increasing interest in the water sector. Therefore, the viability of thermal techniques for the safe destruction of PFAS has received substantial research attention in the last few years. Recent studies suggest that PFAS in biosolids can be removed and potentially destroyed during combustive (such as incineration) and non-combustive thermal treatment, such as pyrolysis, gasification, and hydrothermal carbonisation/liquefaction. However, there is limited understanding on the fate and transformation of PFAS degradation products across the overall thermal treatment process from biosolids feed pre-treatment to the gas cleaning (post-thermal treatment) stage. This review consolidates the current knowledge on PFAS transformation, destruction, and final fate before, during, and after thermal treatment of biosolids, covering lab, pilot scale, and industrial studies. It is suggested that PFAS degradation mechanisms during thermal treatment of biosolids may differ from the established pathways for pure PFAS salts, given that biosolids have a complex organic and inorganic matrix and typically have low PFAS concentrations. Among all thermal treatment techniques, pyrolysis has received extensive investigations at different scales of operation. However, for all techniques, treatment temperatures and residence time need to be sufficiently optimised for designing realistic large-scale thermal systems relevant to biosolids' compositional peculiarities for PFAS destruction. [ABSTRACT FROM AUTHOR]

This paper describes the development of a new adaptation of the traditional tracer gas test (TGT) used for total air change rates (ACH) measurement. This adapted TGT, based on constant tracer injection, is intended for use in large-scale IAQ assessments and employs an alternative tracer gas that is more adequate than the currently employed SF6 and perfluorocarbons, and that can be co-captured and co-analyzed with commonly assessed VOCs by commercial passive IAQ-sampling. As it is based on passive sampling, the proposed TGT yields long-term integrated ACH values, and is thus indicated only for studies focused on characterizations based on average estimations rather than on analyses requiring fine temporal resolution. By means of literature study and lab experiments, decane-D22 was selected as a suitable tracer substance. The selected tracer was shown not to adhere/absorb significantly to surfaces. A passive source of decane-D22 was selected and optimized in lab, providing stable and repeatable emission rates unaffected by varying RH and ACH. An exponential prediction curve was derived for determining the source emission rate from the average room temperature. Moreover, a range of adequate levels of liquid tracer inside the source is suggested. A successful field test application for validation of the new TGT is also described. [ABSTRACT FROM AUTHOR]

The perfluorocarbons tetrafluoromethane (CF 4 , PFC-14) and hexafluoroethane (C 2 F 6 , PFC-116) are potent greenhouse gases with near-permanent atmospheric lifetimes relative to human timescales and global warming potentials thousands of times that of CO 2 . Using long-term atmospheric observations from a Chinese network and an inverse modeling approach (top-down method), we determined that CF 4 emissions in China increased from 4.7 (4.2-5.0, 68% uncertainty interval) Gg y -1 in 2012 to 8.3 (7.7-8.9) Gg y -1 in 2021, and C 2 F 6 emissions in China increased from 0.74 (0.66-0.80) Gg y -1 in 2011 to 1.32 (1.24-1.40) Gg y -1 in 2021, both increasing by approximately 78%. Combined emissions of CF 4 and C 2 F 6 in China reached 78 Mt CO 2 -eq in 2021. The absolute increase in emissions of each substance in China between 2011-2012 and 2017-2020 was similar to (for CF 4 ), or greater than (for C 2 F 6 ), the respective absolute increase in global emissions over the same period. Substantial CF 4 and C 2 F 6 emissions were identified in the less-populated western regions of China, probably due to emissions from the expanding aluminum industry in these resource-intensive regions. It is likely that the aluminum industry dominates CF 4 emissions in China, while the aluminum and semiconductor industries both contribute to C 2 F 6 emissions. Based on atmospheric observations, this study validates the emission magnitudes reported in national bottom-up inventories and provides insights into detailed spatial distributions and emission sources beyond what is reported in national bottom-up inventories., Competing Interests: Competing interests statement:The authors declare no competing interest.