RESUMO
The microalgae Chlorella vulgaris and Tetraselmis chui are valued for their nutrient-rich content, including lipids and polyunsaturated fatty acids (PUFA). However, little is known about how storage and processing affect their lipid quality. This study aimed to assess the impact of domestic storage and cooking practices in dried biomass of C. vulgaris and T. chui. Four conditions were tested: control (newly opened package), light (storage at room temperature and daily light regimen for three weeks), frozen (storage in the freezer at -20 °C for three weeks), and heated (three cycles of 90 min at 100 °C). Lipid extracts were analyzed by GC-MS and LC-MS, and antioxidant activity through DPPH and ABTS radical scavenging assays. Tested storage conditions promoted a decrease in fatty acid content and in diacyl/lyso lipid species ratios of phospholipid (PC/LPC, PE/LPE) and betaine lipids (DGTS/MGTS). Lipid extracts from light treatment showed the lowest antioxidant activity in C. vulgaris (ABTS, IC40: 104.9; DPPH, IC20: 187.9 ± 15.0), while heat affected the antioxidant activity of T. chui (ABTS, IC40: 88.5 ± 2.8; DPPH, IC20 209.4 ± 10.9). These findings underscore the impact of managing storage and processing conditions to optimize the nutritional and functional benefits of C. vulgaris and T. chui in food and feed applications.
Assuntos
Antioxidantes , Chlorella vulgaris , Microalgas , Antioxidantes/farmacologia , Chlorella vulgaris/química , Microalgas/química , Lipídeos , Armazenamento de Alimentos , Ácidos Graxos/análise , CulináriaRESUMO
Facial aesthetic procedures have become increasingly popular and complex, making knowledge of facial anatomy crucial for achieving desired outcomes without complications. Some of the most common procedures include blepharoplasty, bichectomy, face-lifts, facial implants, thread lifting, and fillers. Blepharoplasty and bichectomy are surgical procedures that respectively aim to restore youthful contours to the periorbita and create a slimmer lower face by removing Bichat fat from the maxillofacial region. Facial implants are used for aesthetic augmentation of the skeletal structure and restoration of facial contour by using biomaterials or autogenous bone grafts. Face-lift surgeries involve incisions and removal of excess skin, and thread lifts involve less invasive procedures performed by inserting threads beneath the skin, with the aim to lift the skin and thus reduce wrinkles and sagging. Fillers improve wrinkles and loss of facial volume, with biologic types made from animal, human, or bacterial sources (such as hyaluronic acid), while synthetic fillers include substances such as paraffin, silicone, calcium hydroxyapatite, polymethylmethacrylate microspheres, polyacrylamide hydrogel, hydroxyethyl-ethyl methacrylate, and poly-l-lactic acid. Synthetic fillers can be classified as rapidly resorbable (<12 months), slowly resorbable (<24 months), or permanent. Imaging modalities such as US, CT, and MRI can help identify and analyze each type of facial aesthetic procedure or filler, as well as their possible complications such as foreign-body granuloma, noninflammatory nodule, late intermittent persistent edema, filler migration, infection, or complications after removal of the buccal fat pad. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center The online slide presentation from the RSNA Annual Meeting is available for this article.
Assuntos
Técnicas Cosméticas , Animais , Humanos , Técnicas Cosméticas/efeitos adversos , Materiais Biocompatíveis , Silicones , Polimetil MetacrilatoRESUMO
In this study, we present the synthesis of benzimidazo[1,2-a] quinoline-based heterocycles bearing organosulfur and organoselenium moieties through transition-metal-free cascade reactions involving a sequential intermolecular aromatic nucleophilic substitution (SNAr). Both sulfur and selenium derivatives presented absorption maxima located around 355 nm related to spin and symmetry allowing electronic 1π-π* transitions, and fluorescence emission at the violet-blue region (~440 nm) with relatively large Stokes shift. The fluorescence quantum yields were slightly influenced by the chalcogen, with the sulfur derivatives presenting higher values than the selenium analogs. In this sense, the quantum yields for selenium derivatives can probably be affected by the intersystem crossing or even the photoinduced electron transfer process (PET). The compounds were successfully applied in all-solution-processed organic light-emitting diodes (OLEDs), where poly(9-vinylcarbazole) was employed as a dispersive matrix generating single-layer device cells. The obtained electroluminescence spectra are a sum of benzimidazo[1,2-a]quinolines and PVK singlet and/or triplet emissive states, according to their respective energy band gaps. The best diode rendered a luminance of 25.4 cdâ m-2 with CIE (0.17, 0.14) and current efficiency of 20.2 mcdâ A-1, a fivefold improvement in comparison to the PVK device that was explained by a 50-fold increase of charge-carriers electrical mobility.
RESUMO
We evaluated the environmental quality in mangrove areas of the Western Atlantic with different levels and history of contamination, considering biomarkers for the crab Ucides cordatus. For this purpose, specimens were collected in two climatic seasons (rainy and dry seasons) and assays of genotoxicity (MN, micronucleus), cytotoxicity (NRRT, neutral red retention time) and biochemical (MT, metallothionein; and LPO, lipoperoxidation) were conducted. In the most impacted mangroves, there was an increase in the mean of micronucleus (frequency of MN/1000), which was associated with a shorter retention time (minutes of NRRT). In contrast, the most pristine areas showed MN < 3 and NRRT < 100 min, with no seasonal effect, indicating a lower effect of degenerative processes by xenobiotics. The rainy season was more harmful, especially regarding cytogenotoxicity. The use of bioindicator species for environmental monitoring should be guided by an analysis of biomarkers considering the season, because during the period of highest rainfall, biomarkers values can change.
Assuntos
Braquiúros , Poluentes Químicos da Água , Animais , Biomarcadores/análise , Braquiúros/fisiologia , Monitoramento Ambiental , Estações do Ano , Espécies Sentinelas , Poluentes Químicos da Água/análiseRESUMO
Alzheimer's disease (AD) is a worldwide problem, and there are currently no treatments that can stop this disease. To investigate the binding affinity of 6-((4-fluorophenyl) selanyl)-9H-purine (FSP) with acetylcholinesterase (AChE), to verify the effects of FSP in an AD model in mice and to evaluate the toxicological potential of this compound in mice. The binding affinity of FSP with AChE was investigated by molecular docking analyses. The AD model was induced by streptozotocin (STZ) in Swiss mice after FSP treatment (1 mg/kg, intragastrically (i.g.)), 1st-10th day of the experimental protocol. Anxiety was evaluated in an elevated plus maze test, and memory impairment was evaluated in the Y-maze, object recognition and step-down inhibitory avoidance tasks. The cholinergic system was investigated based on by looking at expression and activity of AChE and expression of choline acetyltransferase (ChAT). We evaluated expression and activity of Na+/K+-ATPase. For toxicological analysis, animals received FSP (300 mg/kg, i.g.) and aspartate aminotransferase, alanine aminotransferase activities were determined in plasma and δ-aminolevulinate dehydratase activity in brain and liver. FSP interacts with residues of the AChE active site. FSP mitigated the induction of anxiety and memory impairment caused by STZ. FSP protected cholinergic system dysfunction and reduction of activity and expression of Na+/K+-ATPase. FSP did not modify toxicological parameters evaluated and did not cause the death of mice. FSP protected against anxiety, learning and memory impairment with involvement of the cholinergic system and Na+/K+-ATPase in these actions.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Ansiedade/tratamento farmacológico , Comportamento Animal/efeitos dos fármacos , Memória/efeitos dos fármacos , Selênio/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Animais , Ansiedade/metabolismo , Aprendizagem da Esquiva/efeitos dos fármacos , Colina O-Acetiltransferase/metabolismo , Modelos Animais de Doenças , Masculino , Camundongos , Simulação de Acoplamento Molecular , Selênio/uso terapêuticoRESUMO
A low-cost signal processing circuit developed to measure and drive a heat dissipation soil matric potential sensor based on a single thermosensitive resistor is demonstrated. The SnSe2 has a high thermal coefficient, from -2.4Ω/°C in the 20 to 25 °C to -1.07Ω/°C in the 20 to 25 °C. The SnSe2 thermosensitive resistor is encapsulated with a porous gypsum block and is used as both the heating and temperature sensing element. To control the power dissipated on the thermosensitive resistor and keep it constant during the heat pulse, a mixed analogue/digital circuit is used. The developed control circuit is able to maintain the dissipated power at 327.98±0.3% mW when the resistor changes from 94.96Ω to 86.23Ω. When the gravimetric water content of the porous block changes from dry to saturated (θw=36.7%), we measured a variation of 4.77Ω in the thermosensitive resistor, which results in an end-point sensitivity of 130 mΩ/%. The developed system can easily meet the standard requirement of measuring the gravimetric soil water content with a resolution of approximately Δθw=1%, since the resistance is measured with a resolution of approximately µ31µΩ, three orders of magnitude smaller than the sensitivity.
RESUMO
The changes in the ability of three fluorescent derivatives of 2-(2'-hydroxyphenyl)benzothiazole to undergo excited-state intramolecular proton transfer (ESIPT) processes have been correlated with the rheological properties of four amino-polydimethylsiloxanes with different molar masses and containing different amounts of monomer units with amino pendant groups, in the presence and absence of a cross-linking molecule, CO2. The changes lead to a variety of species (keto, enol, and enolate forms) in both the ground and excited states. Calculations using the density-functional theory/time-dependent density-functional theory method at the CAM-B3LYP/6-311++G(d,p) level helped to identify how ESIPT is involved in the formation of the intermediates. The results demonstrate that proton transfer in 2-(2'-hydroxyphenyl)benzothiazoles is a powerful tool to identify local changes in the viscosity and micropolarity of the environment that are attributed to the structural differences of the amino-polydimethylsiloxanes and their cross-linking.
RESUMO
Globally, there is limited knowledge about management and conservation of Callianassidae family. Their catches seem to be recently increasing in several parts of the world and evidences raise concern on the need of specialized literature focused on populations monitoring. At Southeast of Brazil, the species Callichirus major (Say 1818), known as the ghost shrimp, is frequently captured for use as bait in sport fishing and, according to previous studies, the overexploitation could threaten the population. The aim of this study was evaluated over a year this harmful human pressure on the species C. major in two beaches contiguous but susceptible to different anthropogenic impacts due to the existence of legislation on one beach that prohibits the capture of this crustacean. The population of C. major presented where the prohibition regulation does not exist a density almost three times lower when compared to the beach that prohibits the capture, with individuals with smaller carapace oval area and a shorter reproductive period. This paper alert to some evidence of C. major structure population disturbance resulting from its exploitation at Southeast of Brazil. Recommendations were also addressed to conservation management considering the species' ecological importance.
Assuntos
Crustáceos/classificação , Pesqueiros/legislação & jurisprudência , Animais , Brasil , Conservação dos Recursos Naturais/métodos , Feminino , Humanos , Masculino , Densidade Demográfica , Estações do AnoRESUMO
The histone variant macroH2A generally associates with transcriptionally inert chromatin; however, the factors that regulate its chromatin incorporation remain elusive. Here, we identify the SWI/SNF helicase ATRX (α-thalassemia/MR, X-linked) as a novel macroH2A-interacting protein. Unlike its role in assisting H3.3 chromatin deposition, ATRX acts as a negative regulator of macroH2A's chromatin association. In human erythroleukemic cells deficient for ATRX, macroH2A accumulates at the HBA gene cluster on the subtelomere of chromosome 16, coinciding with the loss of α-globin expression. Collectively, our results implicate deregulation of macroH2A's distribution as a contributing factor to the α-thalassemia phenotype of ATRX syndrome.
Assuntos
Cromatina/metabolismo , DNA Helicases/metabolismo , Regulação da Expressão Gênica , Histonas/metabolismo , Proteínas Nucleares/metabolismo , alfa-Globinas/genética , alfa-Globinas/metabolismo , DNA Helicases/genética , Células Eritroides/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Humanos , Células K562 , Deficiência Intelectual Ligada ao Cromossomo X/patologia , Proteínas Nucleares/genética , Telômero/metabolismo , Proteína Nuclear Ligada ao X , Talassemia alfa/patologiaRESUMO
Patients undergoing angioplasty and stent insertion require double prophylactic anti-aggregation or monotherapy. This is a challenging procedure with a high risk of morbidity and coronary mortality. The aim of this protocol is to provide guidelines for a presurgical approach to patients with a coronary stent who will be undergoing non-coronary surgery. This protocol highlights potential complications that may occur, namely those related with the cardiac stent and the evaluation of cardiac risk, and notes the thrombotic and hemorrhagic risks associated with the surgical procedure and the decision algorithms for both elective surgery and urgent surgery involving the suspension and re-introduction of antiplatelet therapy. Our main goal is to outline an optimized approach to these cases in order to improve cardiac outcomes and to minimize the risk of complications.
Assuntos
Oclusão Coronária , Stents , Oclusão Coronária/cirurgia , Procedimentos Cirúrgicos Eletivos , Humanos , Inibidores da Agregação Plaquetária , Fatores de RiscoRESUMO
A simple method for the direct mono- and bis-organylselenylation of N-substituted pyrroles through a multicomponent reaction promoted by ultrasonic radiation was described. These sonochemical promoted reactions were performed between different primary amines, 2,5-hexanedione and dialkyl, diheteroaryl, or diaryl diselenides, using catalytic amounts of copper iodide. Depending on the amount of copper iodide and diorganyl diselenide used in the reactions, mono- or bis-organylselenylation products were efficiently synthesized in high yields.
RESUMO
A salicylidene derivative, N,N'-bis(salicylidene)-(2-(3',4'-diaminophenyl)benzothiazole) (BTS), reactive in the Excited State Intramolecular Proton Transfer (ESIPT) process, was synthesized and its photophysical properties were evaluated, presenting an emission covering the entire range of the visible spectrum. Due to its broad emission band, BTS was successfully tested as an active layer in solution-processed organic light-emitting diodes with white-light emission. These diodes were prepared using solution-based protocols with the dye solubilized in a poly(9-vinylcarbazole) matrix. Different guest : host (polymer : BTS) molar ratios were used to optimize the diode performance. The optimized architecture rendered the best so far all-solution-processed ESIPT OLED with a luminance of 34 cd m-2 at 13.5 V with CIE coordinates 0.31, 0.40.
RESUMO
This work presents the determination of acidic strengths at the electronic ground and excited states (pKa and ) of three flavonol derivatives using electronic absorption and fluorescence emission spectroscopy. The differences of the pKa and values were successfully correlated with the molecular structures according to the substitution pattern at the flavonol structure (hydrogen, diethylamino or fluoro moieties). In order to obtain more information about the observed photoacidity of these superacids, geometry optimizations and excitation energy calculations were performed at the CAM-B3LYP/6-311++G(d,p) level for their neutral, protonated and deprotonated species.
RESUMO
The Southeast region of Portugal, particularly the Guadiana valley, is currently the reintroduction territory of Lynx pardinus (Iberian lynx), one of the most endangered felids in the world that is only found in the Iberian Peninsula. Over the last century, populations have declined, placing L. pardinus at extremely high risk of extinction in the wild and relying on reintroduction projects. Among the aspects taken into account in the establishment of new populations is the sanitary status of the selected habitats, especially concerning infectious diseases, including tick-borne pathogens (TBPs). This study presents the results of TBPs survey on ticks collected at sensitive conservation areas of Southeast Portugal. From 2012 to 2014, 231 ticks obtained from vegetation, sympatric domestic and wild animals were submitted for analysis. The presence of Babesia spp., Cytauxzoon spp., Theileria spp., Hepatozoon spp., Anaplasma spp., Ehrlichia spp., Candidatus Neoehrlichia mikurensis, among other Anaplasmataceae, and Coxiella burnetii were investigated by PCR. Six tick species were recorded, Dermacentor marginatus (n = 13/5.6%), Hyalomma lusitanicum (n = 175/75.8%), Ixodes ricinus (n = 4/1.7%), Rhipicephalus bursa (n = 7/3.0%), R. pusillus (n = 21/9.1%) and R. sanguineus sensu lato (n = 11/4.8%). The molecular screening confirmed the presence of two tick-borne pathogens, C. burnetii (N = 34) and Anaplasma platys (N = 1), and one tick-endosymbiont, Candidatus Midichloria mitochondrii (N = 45). The results obtained provide new information on the circulation of ticks and TBPs with potential veterinary importance in Iberian lynx habitat.
Assuntos
Reação em Cadeia da Polimerase/métodos , Carrapatos/genética , Animais , Geografia , Lynx/parasitologia , PortugalRESUMO
We describe here a simple method for the synthesis of 6-arylselanylpurines with antioxidant and anticholinesterase activities, and memory improvement effect. This class of compounds was synthesized in good yields by a reaction of 6-chloropurine with diaryl diselenides using NaBH4 as reducing agent and PEG-400 as solvent. Furthermore, the synthesized compounds were evaluated for their in vitro antioxidant and acetylcholinesterase (AChE) inhibitor activities. The best AChE inhibitor was assessed on the in vivo memory improvement. Our results demonstrated that the 6-((4-chlorophenyl)selanyl)-9H-purine and 6-(p-tolylselanyl)-9H-purine presented in vitro antioxidant effect. In addition, 6-((4-fluorophenyl)selanyl)-9H-purine inhibited the AChE activity and improved memory, being a promising therapeutic agent for the treatment of Alzheimer's disease.
Assuntos
Acetilcolinesterase/metabolismo , Antioxidantes/farmacologia , Inibidores da Colinesterase/farmacologia , Memória/efeitos dos fármacos , Compostos Organosselênicos/farmacologia , Purinas/farmacologia , Doença de Alzheimer/tratamento farmacológico , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/síntese química , Relação Dose-Resposta a Droga , Masculino , Camundongos , Estrutura Molecular , Compostos Organosselênicos/administração & dosagem , Compostos Organosselênicos/síntese química , Purinas/administração & dosagem , Purinas/química , Relação Estrutura-AtividadeRESUMO
The complex of formic acid (FA, HCOOH) with nitrous oxide (N2O) was studied experimentally and computationally. Eight structures of the trans-FA···N2O complex and nine structures of the cis-FA···N2O complex were found at the density functional theory (M06-2X and wB97XD), MP2(full), and CCSD(T)-F12a levels. Two structures of the trans-FA···N2O complex (1t and 3t) and two structures of the cis-FA···N2O complex (1c and 3c) were identified by infrared spectroscopy in an argon matrix. Structure 1t with the bonded OH group appears in the matrices after deposition. Structures 3t and 3c with the free OH groups were prepared by vibrational excitation of the trans-FA conformer in structures 1t and 3t, respectively. Structure 3t is thermally unstable and relaxes to structure 1t at â¼15 K. Structure 1c with the bonded OH group is made by vibrational excitation of trans-FA monomer combined with thermal annealing. The lifetimes of the cis-FA···N2O complex structures 1c (81.5 min) and 3c (18.7 min) in an argon matrix at 4.3 K are longer than that of cis-FA monomer (6.3 min). This difference agrees with the calculated stabilization barriers of these species.
RESUMO
Globally, there is a lack of knowledge about tropical ecotoxicology dealing with the potential impact of metal contamination in mangrove ecosystem. This habitat is considered a nursery for several animal species, among them the "uçá"-crab (Ucides cordatus), known as a key species due to its biological and economical importance. This study evaluated the association involving metal contamination (Cd, Cu, Pb, Cr, Mn and Hg) in water, sediment, red-mangrove vegetation (Rhizophora mangle) and tissues of uçá crab, together with its geno-cytotoxic responses, based on micronucleated hemocytes frequency and the retention time of neutral red in lysosomes. We assessed six mangrove areas with distinct pollution levels in São Paulo State, Brazil, where the water and sediment contamination by metals were associated with accumulation of these pollutants in biotic compartments (mangrove leaves and crab). In U. cordatus, metal accumulation was best explained by metal concentration found in leaves of R. mangle than in the water or sediment, indicating that feeding drives metal exposure in this organism. Mercury (Hg) concentration in sediment, copper (Cu) concentration in hepatopancreas of U. cordatus and lead (Pb) in water and green leaves of R. mangle showed a significant correlation with genotoxic impact in U. cordatus. However, copper concentration (in green/senescent leaves and hepatopancreas) and lead (in sediment), were the major metals affecting lysosomal membrane integrity. Therefore, representatives of all compartments were associated with cyto and genotoxicity in this species, thus requiring a holistic approach to issues related to sublethal damage. Probability estimates of cytogenetic impacts related to metal concentration in abiotic compartments (significantly correlated with known biomarkers: Hg in sediment; and Pb in water and sediment) are also presented. Our results highlight the need for environmental restoration of mangroves areas contaminated with metals, responsible for cytogenetic injuries and revealing a pre-pathological condition in this sentinel species, in addition to ecological disturbances.
Assuntos
Braquiúros/efeitos dos fármacos , Monitoramento Ambiental/métodos , Metais Pesados/análise , Rhizophoraceae/efeitos dos fármacos , Espécies Sentinelas/crescimento & desenvolvimento , Poluentes Químicos da Água/análise , Animais , Biomarcadores/análise , Braquiúros/química , Brasil , Metais Pesados/toxicidade , Rhizophoraceae/química , Poluentes Químicos da Água/toxicidade , Áreas AlagadasRESUMO
We present here the design and fabrication of a self-powered and autonomous fringing field capacitive sensor to measure soil water content. The sensor is manufactured using a conventional printed circuit board and includes a porous ceramic. To read the sensor, we use a circuit that includes a 10 kHz triangle wave generator, an AC amplifier, a precision rectifier and a microcontroller. In terms of performance, the sensor's capacitance (measured in a laboratory prototype) increases up to 5% when the volumetric water content of the porous ceramic changed from 3% to 36%, resulting in a sensitivity of S = 15.5 pF per unity change. Repeatability tests for capacitance measurement showed that the θ v sensor's root mean square error is 0.13%. The average current consumption of the system (sensor and signal conditioning circuit) is less than 1.5 µ A, which demonstrates its suitability for being powered by energy harvesting systems. We developed a complete irrigation control system that integrates the sensor, an energy harvesting module composed of a microgenerator installed on the top of a micro sprinkler spinner, and a DC/DC converter circuit that charges a 1 F supercapacitor. The energy harvesting module operates only when the micro sprinkler spinner is irrigating the soil, and the supercapacitor is fully charged to 5 V in about 3 h during the first irrigation. After the first irrigation, with the supercap fully charged, the system can operate powered only by the supercapacitor for approximately 23 days, without any energy being harvested.
RESUMO
A technique to eliminate the offset drift in the demodulator circuitry of open-loop interferometric fiber optic gyroscopes is presented. This technique employs a demodulation scheme that uses the area of the negative half-cycles of the output signal of a sinusoidally modulated gyroscope to obtain the angular velocity. We propose an electronic circuitry that periodically reverses the demodulator input, allowing for the acquisition of two samples of the gyroscope signal with the same magnitude and opposite polarities. The angular velocity is obtained from the subtraction of these two samples, suppressing the electronic offset. Experiments showed that the proposed method reduces the demodulator offset drift from 4.4 µV/°C to about 14 nV/°C, which is equivalent to a reduction, from 0.2 deg/h/°C to about 0.0006 deg/h/°C in the tested gyroscope. The proposed technique improved the bias stability of the tested gyroscope from 0.0162 to 0.0071 deg/h.
RESUMO
Vacuum ultraviolet (VUV, 130-170 nm) photochemistry of the H2OCO complex is studied by matrix-isolation infrared spectroscopy. The H2OCO complexes in Ne, Ar, Kr, and Xe matrices are generated by ultraviolet (UV, 193 and 250 nm) photolysis of formic acid (HCOOH). VUV photolysis of the H2OCO complexes is found to lead to the formation of the OHCO radical-molecule complexes and trans-HOCO radicals. It is shown that the matrix material, local matrix morphology, and possibly the H2OCO complex geometry strongly affect the VUV photolysis pathways. The intrinsic reactivity of the matrix-isolated OHCO complex resulting in the formation of trans-HOCO is directly demonstrated for the first time. This reaction occurs in Ar, Kr, and Xe matrices upon annealing above 25 K and may proceed over the barrier. The case of a Ne matrix is very special because the formation of trans-HOCO from the OHCO complex is observed even at the lowest experimental temperature (4.5 K), which is in sharp contrast to the other matrices. It follows that quantum tunneling is probably involved in this process in the Ne matrix at such a low temperature. Infrared light also promotes this reaction in the Ne matrix at 4.5 K, which is not the case in the other matrices. The last findings show the effect of the environment on the tunneling and infrared-induced rates of this fundamental chemical reaction.