Synthesis of methanediol [CH2(OH)2]: The simplest geminal diol.

Geminal diols-organic molecules carrying two hydroxyl groups at the same carbon atom-have been recognized as key reactive intermediates by the physical (organic) chemistry and atmospheric science communities as fundamental transients in the aerosol cycle and in the atmospheric ozonolysis reaction sequence. Anticipating short lifetimes and their tendency to fragment to water plus the aldehyde or ketone, free geminal diols represent one of the most elusive classes of organic reactive intermediates. Here, we afford an exceptional glance into the preparation of the previously elusive methanediol [CH2(OH)2] transient-the simplest geminal diol-via energetic processing of low-temperature methanol-oxygen ices. Methanediol was identified in the gas phase upon sublimation via isomer-selective photoionization reflectron time-of-flight mass spectrometry combined with isotopic substitution studies. Electronic structure calculations reveal that methanediol is formed via excited state dynamics through insertion of electronically excited atomic oxygen into a carbon-hydrogen bond of the methyl group of methanol followed by stabilization in the icy matrix. The first preparation and detection of methanediol demonstrates its gas-phase stability as supported by a significant barrier hindering unimolecular decomposition to formaldehyde and water. These findings advance our perception of the fundamental chemistry and chemical bonding of geminal diols and signify their role as an efficient sink of aldehydes and ketones in atmospheric environments eventually coupling the atmospheric chemistry of geminal diols and Criegee intermediates.

Methanetriol─Formation of an Impossible Molecule.

Orthocarboxylic acids─organic molecules carrying three hydroxyl groups at the same carbon atom─have been distinguished as vital reactive intermediates by the atmospheric science and physical (organic) chemistry communities as transients in the atmospheric aerosol cycle. Predicted short lifetimes and their tendency to dehydrate to a carboxylic acid, free orthocarboxylic acids, signify one of the most elusive classes of organic reactive intermediates, with even the simplest representative methanetriol (CH(OH)3)─historically known as orthoformic acid─not previously been detected experimentally. Here, we report the first synthesis of the previously elusive methanetriol molecule in low-temperature mixed methanol (CH3OH) and molecular oxygen (O2) ices subjected to energetic irradiation. Supported by electronic structure calculations, methanetriol was identified in the gas phase upon sublimation via isomer-selective photoionization reflectron time-of-flight mass spectrometry combined with isotopic substitution studies and the detection of photoionization fragments. The first synthesis and detection of methanetriol (CH(OH)3) reveals its gas-phase stability as supported by a significant barrier hindering unimolecular decomposition. These findings progress our fundamental understanding of the chemistry and chemical bonding of methanetriol, hydroxyperoxymethane (CH3OOOH), and hydroxyperoxymethanol (CH2(OH)OOH), which are all prototype molecules in the oxidation chemistry of the atmosphere.

Climate change adaptation: Challenges for agricultural sustainability.

Climate change poses a substantial threat to agricultural sustainability globally. Agriculture is a vital component of the gross domestic production of developing countries. The multifaceted impacts of climate change on agriculture, highlighting how extreme weather events such as water stress, heatwaves, erratic rainfall, storms, floods, and emerging pest infestations are disrupting agricultural productivity. The socioeconomic status of farmers is particularly vulnerable to climatic extremes with future projections indicating significant increment in ambient air temperatures and unpredictable, intense rainfall patterns. Agriculture has historically relied on the extensive use of synthetic fertilizers, herbicides, and insecticides, combined with advancements in irrigation and biotechnological approaches to boost productivity. It encompasses a range of practices designed to enhance the resilience of agricultural systems, improve productivity, and reduce greenhouse gas emissions. By adopting climate-smart practices, farmers can better adapt to changing climatic conditions, thereby ensuring more sustainable and secure food production. Furthermore, it identifies key areas for future research, focusing on the development of innovative adaptation and mitigation strategies. These strategies are essential for minimizing the detrimental impacts of climate change on agriculture and for promoting the long-term sustainability of food systems. This article underscores the importance of interdisciplinary approaches and the integration of advanced technologies to address the challenges posed by climate change. By fostering a deeper understanding of these issues to inform policymakers, researchers, and practitioners about effective strategies to safeguard agricultural productivity and food security in the face of changing climate.

Exploration of Potential Anti-inflammatory cum Anti-Rheumatoid-arthritis Phyto-molecule through Integrated Green Approach: Network Pharmacology, Molecular Docking, Molecular dynamics, In-vitro and Ex-vivo study.

Rheumatoid arthritis (RA) and associated inflammatory complications are the most prevalent illnesses and can turn into fatal conditions if left untreated. Allopathic medicine is not satisfactory for curing RA. Scientific literature reports reveal that several phyto-compounds viz. flavonoids, saponins, and terpenoids, can heal joints and organs from auto-inflammatory rheumatoid arthritis and pain. Gene ontology, gene network analysis, molecular clustering, and literature review were used to optimise RA-specific highly expressed genes. In-silico molecular docking was performed to short-out potential phytomolecules (Neohesperidin dihydrochalcone (NHDC)) from 1000 datasets-library against RA and validate using MD simulation running at 100 ns. In-vitro anti-inflammatory assays of NHDC inhibited egg-albumin denaturation, IC50 of 47.739 ± 0.51 µg/ml. The ex-vivo MTT assay with NHDC rendered 67.209% inhibition at 100 µM against fd-FLS-cells. NHDC downregulated pro-inflammatory cytokine IL-17A production by 61.11% and 50% at 300 and 200 µM, respectively. Thus, this Studies recommend that NHDC may be highlighted as a novel multi-target PADI4 and JAK3 inhibitor with better efficacy and minimal toxicity in RA warranted to In-Vivo and clinical investigation. The current findings have uncovered remarkable genes and signalling pathways linked to RA, which could enhance our existing comprehension of the molecular mechanisms that drive its development and progression.

Diabetic Encephalopathy: Role of Oxidative and Nitrosative Factors in Type 2 Diabetes.

Diabetes mellitus is a set of complex metabolic disorders characterized by chronic hyperglycaemic condition due to defective insulin secretion (Type 1) and action (Type 2), which leads to serious micro and macro-vascular damage, inflammation, oxidative and nitrosative stress and a deranged energy homeostasis due to imbalance in the glucose and lipid metabolism. Moreover, patient with diabetes mellitus often showed the nervous system disorders known as diabetic encephalopathy. The precise pathological mechanism of diabetic encephalopathy by which it effects the central nervous system directly or indirectly causing the cognitive and motor impairment, is not completely understood. However, it has been speculated that like other extracerebellar tissues, oxidative and nitrosative stress may play significant role in the pathogenesis of diabetic encephalopathy. Therefore, the present review aimed to explain the possible association of the oxidative and nitrosative stress caused by the chronic hyperglycaemic condition with the central nervous system complications of the type 2 diabetes mellitus induced diabetic encephalopathy.

Enhancing drug bioavailability for Parkinson's disease: The promise of chitosan delivery mechanisms.

Parkinson's disease (PD) is a widely seen neurodegenerative condition recognized by misfolded α-synuclein (αSyn) protein, a prominent indicator for PD and other synucleinopathies. Motor symptoms like stiffness, akinesia, rest tremor, and postural instability coexist with nonmotor symptoms that differ from person to person in the development of PD. These symptoms arise from a progressive loss of synapses and neurons, leading to a widespread degenerative process in multiple organs. Implementing medical and surgical interventions, such as deep brain stimulation, has enhanced individuals' overall well-being and long-term survival with PD. It should be mentioned that these treatments cannot stop the condition from getting worse. The complicated structure of the brain and the existence of a semi-permeable barrier, commonly known as the BBB, have traditionally made medication delivery for the treatment of PD a challenging endeavor. The drug's low lipophilic nature, enormous size, and peculiarity for various ATP-dependent transport mechanisms hinder its ability to enter brain cells. This article delves at the potential of drug delivery systems based on chitosan (CS) to treat PD.

Clinical Pattern of Pediatric Hydatid Disease.

Context: Literature regarding hydatid disease in children is sparse. Aims: To highlight the peculiarities in the clinical pattern of pediatric hydatid disease (PHD). Settings and Design/Materials and Methods: Data were collected retrospectively from all children aged <18 years who presented to our tertiary care institute from July 2021 to June 2023 with hydatid disease involving any organ. Statistical Analysis Used: Simple statistical analysis involving sums, means, averages, and percentages. Results: Four of the 10 cases (40%) involved the lung, while only 2 (20%) involved the liver. There were five females and four males with an age range of 2-17 years. Four of the cases had primary extrahepatic extrapulmonary hydatid disease (40%), two involving the pancreas, one in the rectouterine pouch, and one intracranial. Conclusions: The clinical pattern of PHD is different from that of adults. Pulmonary echinococcosis is more common than hepatic involvement. Primary extrahepatic extrapulmonary hydatid disease is also more common in children than previously thought. A cystic lesion anywhere in a child warrants a differential of hydatid disease.

Formation of Graphene on Gold-Nickel Surface Alloys.

Nickel (Ni)-catalyzed growth of a single- or rotated-graphene layer is a well-established process above 800 K. In this report, a Au-catalyzed, low-temperature, and facile route at 500 K for graphene formation is described. The substantially lower temperature is enabled by the presence of a surface alloy of Au atoms embedded within Ni(111), which catalyzes the outward segregation of carbon atoms buried in the Ni bulk at temperatures as low as 400-450 K. The resulting surface-bound carbon in turn coalesces into graphene above 450-500 K. Control experiments on a Ni(111) surface show no evidence of carbon segregation or graphene formation at these temperatures. Graphene is identified by its out-of-plane optical phonon mode at 750 cm-1 and its longitudinal/transverse optical phonon modes at 1470 cm-1 while surface carbon is identified by its C-Ni stretch mode at 540 cm-1, as probed by high-resolution electron energy-loss spectroscopy. Dispersion measurements of the phonon modes confirm the presence of graphene. Graphene formation is observed to be maximum at 0.4 ML Au coverage. The results of these systematic molecular-level investigations open the door to graphene synthesis at the low temperatures required for integration with complementary metal-oxide-semiconductor processes.

Uric acid and diabetes mellitus: an update.

The relationship between diabetes mellitus (DM) and high serum uric acid is complex and controversial. Many epidemiological studies have reported a positive association, whereas others have reported an inverse association or none. In the pathogenesis of DM it is the intracellular urate that is more important than the extracellular and dissociation between the two is possible. Evidence suggests that high serum uric acid induces insulin resistance and beta cell failure in animal models. Reduction of intracellular uric acid can be achieved by dietary measures such as reducing fructose and salt intake, and uric acid-lowering drugs. We suggest that in the Western diet, these elements play a crucial role in pathogenesis of DM. To determine the precise and exact interrelationship between intracellular and extracellular uric acid, well-designed studies are required. Besides this, clinical trials are needed to determine whether intracellular and extracellular urate reduction will provide benefit in prevention and treatment of DM and complications associated with it.

Fabrication of polyaniline/graphene oxide composites for implementation in humidity sensing.

This work reports the measurement of impedance variations under various humidity conditions at frequency ranges between 100 Hz and 5 MHz. An electrochemical polymerization process has been used in the synthesis including varying the mass ratios of graphene oxide (GO) in polyaniline. An electrochemical deposition method has been used to produce a sample film on an indium tin oxide glass slide. The percentage relative humidity (RH%) of the samples has been estimated to be 20-90%. Impedance and humidity had an inverse relationship, i.e. the impedance value decreased with an increase in humidity. In contrast with platinum capacitive humidity sensors (HS), the GO-based HS had a sensitivity of 75-99%, which was ~10-fold more than that of traditional sensors. With three different parameter weight % of GO, the frequency range have been 100 Hz to 5 MHz and RH% has been found to 20-90%. The HS showed a fast response and recovery time. Therefore, GO appears to be a useful material for building HS with high sensitivity for a comprehensive approach.

Friedelin: Structure, Biosynthesis, Extraction, and Its Potential Health Impact.

Pharmaceutical companies are investigating more source matrices for natural bioactive chemicals. Friedelin (friedelan-3-one) is a pentacyclic triterpene isolated from various plant species from different families as well as mosses and lichen. The fundamental compounds of these friedelane triterpenoids are abundantly found in cork tissues and leaf materials of diverse plant genera such as Celastraceae, Asteraceae, Fabaceae, and Myrtaceae. They possess many pharmacological effects, including anti-inflammatory, antioxidant, anticancer, and antimicrobial activities. Friedelin also has an anti-insect effect and the ability to alter the soil microbial ecology, making it vital to agriculture. Ultrasound, microwave, supercritical fluid, ionic liquid, and acid hydrolysis extract friedelin with reduced environmental impact. Recently, the high demand for friedelin has led to the development of CRISPR/Cas9 technology and gene overexpression plasmids to produce friedelin using genetically engineered yeast. Friedelin with low cytotoxicity to normal cells can be the best phytochemical for the drug of choice. The review summarizes the structural interpretation, biosynthesis, physicochemical properties, quantification, and various forms of pharmacological significance.

Prevalence of Hypouricemia and Hyperuricemia and Looking Beyond Serum Uric Acid in Patients with Newly Onset Type 2 Diabetes Mellitus in Eastern Part of Uttar Pradesh: A Cross-sectional Study.

INTRODUCTION: The prevalence of hyperuricemia (HU) and hypouricemia (Hypo-U) is highly variable in different parts of India and there is a lack of data from the Eastern part of Uttar Pradesh. We designed this study in order to know the exact prevalence of HU and Hypo-U. MATERIALS AND METHODS: This is a cross-sectional study conducted in Varanasi. Data were collected from newly onset diabetic patients over a period of 1 year. RESULTS: Among the 312 diabetic patients, 12.5 and 19.23% were found to have HU and Hypo-U, respectively. Hypouricemic diabetic patients are phenotypically different. They are characterized by the female sex, higher glycated hemoglobin A1c (GlyHbA1c), higher estimated glomerular filtration rate (eGFR), lower body mass index (BMI), and less insulin resistance. CONCLUSION: The prevalence of HU and Hypo-U is high in newly-onset diabetic patients. Hypouricemic diabetic patients are phenotypically different. Hence routine screening of uric acid is essential for proper diagnosis and appropriate treatment of hypouricemic diabetic patients.

Soil microbes: a natural solution for mitigating the impact of climate change.

Soil microbes are microscopic organisms that inhabit the soil and play a significant role in various ecological processes. They are essential for nutrient cycling, carbon sequestration, and maintaining soil health. Importantly, soil microbes have the potential to sequester carbon dioxide (CO2) from the atmosphere through processes like carbon fixation and storage in organic matter. Unlocking the potential of microbial-driven carbon storage holds the key to revolutionizing climate-smart agricultural practices, paving the way for sustainable productivity and environmental conservation. A fascinating tale of nature's unsung heroes is revealed by delving into the realm of soil microbes. The guardians of the Earth are these tiny creatures that live beneath our feet and discreetly work their magic to fend off the effects of climate change. These microbes are also essential for plant growth enhancement through their roles in nutrient uptake, nitrogen fixation, and synthesis of growth-promoting chemicals. By understanding and managing soil microbial communities, it is possible to improve soil health, soil water-holding capacity, and promote plant growth in agricultural and natural ecosystems. Added to it, these microbes play an important role in biodegradation, bioremediation of heavy metals, and phytoremediation, which in turn helps in treating the contaminated soils. Unfortunately, climate change events affect the diversity, composition, and metabolism of these microbes. Unlocking the microbial potential demands an interdisciplinary endeavor spanning microbiology, ecology, agronomy, and climate science. It is a call to arms for the scientific community to recognize soil microbes as invaluable partners in the fight against climate change. By implementing data-driven land management strategies and pioneering interventions, we possess the means to harness their capabilities, paving the way for climate mitigation, sustainable agriculture, and promote ecosystem resilience in the imminent future.

Adverse reaction profile of sulfasalazine and its persistence in chronic therapy of rheumatoid arthritis and spondyloarthritis: A multicentric observational study.

OBJECTIVES: Sulfasalazine has been widely used in treatment of rheumatoid arthritis and spondyloarthritis. This study aims to assess persistence with sulfasalazine and also frequency and severity of adverse drug reactions (ADRs) encountered with this very well-established disease-modifying anti-rheumatoid drug. MATERIALS AND METHODS: This retrospective study was done in 1,114 patients from medicine and rheumatology outpatient departments of six centers across India. The inclusion criteria was patients taking sulfasalazine. Patients receiving sulfasalazine for rheumatoid arthritis or spondyloarthritis were selected and details on drugs used, duration of taking sulfasalazine, ADRs to sulfasalazine and whether sulfasalazine had to be stopped due to ADRs were analyzed. RESULTS: Of the total of patients included in the study, 10.1% had ADRs with sulfasalazine, and stopped the drug. Gastritis, deranged liver enzymes, hepatitis, skin rashes were the most commonly encountered ADRs. Of the total number of patients recruited for the study, 11% were lost to follow-up, as most of the centers were army hospitals and the officers and staff were posted to other places. Sulfasalazine was taken for less than 1 month by 3.8% patients while 12.5% had taken the drug for less than 6 months. Of the study patients, 28.6% had taken the drug for 24 - 60 months and 4.6% (51 patients) had taken it for more than 5 years. It was found that ADRs were most commonly encountered within the first year of using the drug, and persistence was seen in patients on long-term therapy. CONCLUSION: Sulfasalazine is a safe option in chronic therapy of rheumatoid arthritis and spondyloarthritis. Although frequency of ADRs with patients taking sulfasalazine is minimal, it did necessitate the stoppage of drug. If not well tolerated, sulfasalazine would not have been continued for more than 12 months as evidenced from this study.

Versatile nanoarchitectonics of Pt with morphology control of oxygen reduction reaction catalysts.

Electro-catalytic activity of Pt in the oxygen reduction reaction (ORR) depends strongly on its morphology. For an understanding of how morphology affects the catalytic properties of Pt, the investigation of Pt materials having well-defined morphologies is required. However, the challenges remain in rational and facile synthesis of Pt particles with tuneable well-defined morphology. A promising approach for the controlled synthesis of Pt particles is 'self-assembly of building blocks'. Here, we report a unique synthesis method to control Pt morphology by using a self-assembly route, where nanoflower, nanowire, nanosheet and nanotube morphologies of Pt particles have been produced in a controlled manner. In the growth mechanism, Pt nanoparticles (5-11 nm) are rapidly prepared by using NaBH4 as a reductant, followed by their agglomeration promoted by adding 1,2-ethylenediamine. The morphology of the resulting Pt particles can be easily controlled by tuning hydrophobic/hydrophilic interactions by the addition of isopropanol and H2O. Of the Pt particles prepared using this method, Pt nanotubes show the highest ORR catalytic activity in an acid electrolyte with an onset potential of 1.02 V vs. RHE.

Bacterial degradation of mixed-PAHs and expression of PAH-catabolic genes.

Polyaromatic hydrocarbons (PAHs) are hazardous organic compounds with established toxicity, carcinogenicity, and mutagenicity, ubiquitous distribution, and persistence in different environmental matrices. In the present study, degradation of the mixture of PAHs (phenanthrene, anthracene, fluorene, and pyrene) by Kocuria flava and Rhodococcus pyridinivorans was investigated. The individual strains and consortium of both degraded 55.6%, 59.5%, and 59.1% of 10 mg L-1 of mixed PAHs, respectively, within 15 days. The participation of catabolic enzymes [catechol 2,3-dioxygenase (C23O), dehydrogenase (DH), and peroxidase (POD)] was confirmed during catalytic oxidation through meta-cleavage of mixed PAHs in this study. The catabolic gene expression of naphthalene dioxygenase (NAH) and catechol 2,3-dioxygenase (C23O) during degradation was confirmed using RT-qPCR in the present study. This is the first study that shows significant gene expression of the catabolic genes during degradation of mixed PAHs by selected bacterial strains. The C23O gene showed a 6.02 log fold higher expression in Kocuria flava in comparison to Rhodococcus pyridinivorans whereas NAH gene exhibited a 7.9 log fold higher expression in Rhodococcus pyridinivorans in comparison to Kocuria flava. Hence it is likely to conclude that combination of Kocuria flava and Rhodococcus pyridinivorans can effectively remove hazardous mixture of PAHs from the contaminated environmental matrix.

Activating Nitrogen-doped Graphene Oxygen Reduction Electrocatalysts in Acidic Electrolytes using Hydrophobic Cavities and Proton-conductive Particles.

Although pyridinic-nitrogen (pyri-N) doped graphene is highly active for the oxygen reduction reaction (ORR) of fuel cells in alkaline media, the activity critically decreases under acidic conditions. We report on how to prevent the deactivation based on the mechanistic understanding that O 2 + p y r i - N H + + e - → O 2 , a + p y r i - N H ${{{\rm O}}_{2}+{\rm p}{\rm y}{\rm r}{\rm i}{\rm { -}}{\rm N}{{\rm H}}^{+}+{{\rm e}}^{-}{\to }_{\ }^{{\rm \ }}{{\rm O}}_{2,{\rm a}}+{\rm p}{\rm y}{\rm r}{\rm i}{\rm { -}}{\rm N}{\rm H}}$ governs the ORR kinetics. First, we considered that the deactivation is due to the hydration of pyri-NH+ , leading to a lower shift of the redox potential. Introducing the hydrophobic cavity prevented the hydration of pyri-NH+ but inhibited the proton transport. We then increased proton conductivity in the hydrophobic cavity by introducing SiO2 particles coated with ionic liquid polymer/Nafion® which kept the high onset potentials with an increased current density even in acidic media.

ICU Memories and Patient Outcomes in a Low Middle-Income Country: A Longitudinal Cohort Study.

OBJECTIVES: To study memories of ICU following discharge, their associations, and impact on mental health and quality of life in a low- and middle-income country. DESIGN: Prospective observational cohort; data on memories (pain, fear, nightmare, factual), clinical and demographic variables, anxiety-depression, posttraumatic stress symptoms, and quality of life were collected 0, 7, 14, 30, 90, and 180 days post discharge. Home visits for assessment minimized loss to follow-up. Linear mixed-models and regression analyses were used to estimate adjusted effects of memories controlling for age, sex, time, and severity of illness. SETTING: Twenty-five bedded ICU of a tertiary care center in East India. PATIENTS: Adult ICU survivors between January 2017 and July 2018 able to communicate their memories. INTERVENTIONS: Not applicable. MEASUREMENTS AND MAIN RESULTS: Final sample consisted of 322 patients who completed 180 days follow-up. Pain, fear, factual, and nightmare memories dropped from 85%, 56%, 55%, and 45% at discharge to less than or equal to 5% at 180 days. Patients with gaps in ICU memory had worse anxiety-depression, posttraumatic stress symptoms, and quality of life at all follow-up points. Sedation (odds ratio, 0.54; CI, 0.4-0.7), steroids (odds ratio, 0.47; CI, 0.3-0.8), benzodiazepines (odds ratio, 1.74; CI, 1-3.04), and mechanical ventilation (odds ratio, 0.43; CI, 0.2-0.8) were independently associated with gaps in memory. Non-ICU factor such as substance addiction (odds ratio, 5.38; CI, 2-14) was associated with memories affecting mental health and quality of life. CONCLUSIONS: Gaps in memory and various memory types were common after ICU admission, whose prevalence waned over time. Compared with nightmares and fearful memories, gaps in memories were most strongly associated with poor mental health and quality of life. Identifying patients with gaps in memories might be an objective way of planning interventions to improve their long-term outcomes.

Role of Pyridinic Nitrogen in the Mechanism of the Oxygen Reduction Reaction on Carbon Electrocatalysts.

The introduction of pyridinic nitrogen (pyri-N) into carbon-based electrocatalysts for the oxygen reduction reaction is considered to create new active sites. Herein, the role of pyri-N in such catalysts was investigated from a mechanistic viewpoint using carbon black (CB)-supported pyri-N-containing molecules as model catalysts; the highest activity was observed for 1,10-phenanthroline/CB. X-ray photoemission spectroscopy showed that in acidic electrolytes, both pyri-N atoms of 1,10-phenanthroline could be protonated to form pyridinium ions (pyri-NH+ ). In O2 -saturated electrolytes, one of the pyri-NH+ species was reduced to pyri-NH upon the application of a potential; no such reduction was observed in N2 -saturated electrolytes. This behavior was ascribed to electrochemical reduction of pyri-NH+ occurring simultaneously with the thermal adsorption of O2 , as supported by DFT calculations. According to these calculations, the coupled reduction was promoted by hydrophobic environments.

The Elusive Ketene (H2 CCO) Channel in the Infrared Multiphoton Dissociation of Solid 1,3,5-Trinitro-1,3,5-Triazinane (RDX).

Understanding of the fundamental mechanisms involved in the decomposition of 1,3,5-trinitro-1,3,5-triazinane (RDX) still represents a major challenge for the energetic materials and physical (organic) chemistry communities mainly because multiple competing dissociation channels are likely involved and previous detection methods of the products are not isomer selective. In this study we exploited a microsecond pulsed infrared laser to decompose thin RDX films at 5 K under mild conditions to limit the fragmentation channels. The subliming decomposition products during the temperature programed desorption phase are detected using isomer selective single photoionization time-of-flight mass spectrometry (PI-ReTOF-MS). This technique enables us to assign a product signal at m/z=42 to ketene (H2 CCO), but not to diazomethane (H2 CNN; 42 amu) as speculated previously. Electronic structure calculations support our experimental observations and unravel the decomposition mechanisms of RDX leading eventually to the elusive ketene (H2 CCO) via an exotic, four-membered ring intermediate. This study highlights the necessity to exploit isomer-selective detection schemes to probe the true decomposition products of nitramine-based energetic materials.