The Excited State Dynamics of a Mutagenic Guanosine Etheno Adduct Investigated by Femtosecond Fluorescence Spectroscopy and Quantum Mechanical Calculations.

Femtosecond fluorescence upconversion experiments were combined with CASPT2 and time dependent DFT calculations to characterize the excited state dynamics of the mutagenic etheno adduct 1,N2-etheno-2'-deoxyguanosine (εdG). This endogenously formed lesion is attracting great interest because of its ubiquity in human tissues and its highly mutagenic properties. The εdG fluorescence is strongly modified with respect to that of the canonical nucleoside dG, notably by an about 6-fold increase in fluorescence lifetime and quantum yield at neutral pH. In addition, femtosecond fluorescence upconversion experiments reveal the presence of two emission bands with maxima at 335 nm for the shorter-lived and 425 nm for the longer-lived. Quantum mechanical calculations rationalize these findings and provide absorption and fluorescence spectral shapes similar to the experimental ones. Two different bright minima are located on the potential energy surface of the lowest energy singlet excited state. One planar, slightly less stable, is associated with the emission at 335 nm, whereas the other, with a bent etheno ring, is associated with the red-shifted emission.

The photoactivated dynamics of dGpdC and dCpdG sequences in DNA: a comprehensive quantum mechanical study.

Study of alternating DNA GC sequences by different time-resolved spectroscopies has provided fundamental information on the interaction between UV light and DNA, a process of great biological importance. Multiple decay paths have been identified, but their interplay is still poorly understood. Here, we characterize the photophysics of GC-DNA by integrating different computational approaches, to study molecular models including up to 6 bases described at a full quantum mechanical level. Quantum dynamical simulations, exploiting a nonadiabatic linear vibronic coupling (LVC) model, coupled with molecular dynamics sampling of the initial structures of a (GC)5 DNA duplex, provide new insights into the photophysics in the sub-picosecond time-regime. They indicate a substantial population transfer, within 50 fs, from the spectroscopic states towards G → C charge transfer states involving two stacked bases (CTintra), thus explaining the ultrafast disappearance of fluorescence. This picture is consistent with that provided by quantum mechanical geometry optimizations, using time dependent-density functional theory and a polarizable continuum model, which we use to parametrize the LVC model and to map the main excited state deactivation pathways. For the first time, the infrared and excited state absorption signatures of the various states along these pathways are comprehensively mapped. The computational models suggest that the main deactivation pathways, which, according to experiment, lead to ground state recovery on the 10-50 ps time scale, involve CTintra followed by interstrand proton transfer from the neutral G to C-. Our calculations indicate that CTintra is populated to a larger extent and more rapidly in GC than in CG steps and suggest the likely involvement of monomer-like and interstrand charge transfer decay routes for isolated and less stacked CG steps. These findings underscore the importance of the DNA sequence and thermal fluctuations for the dynamics. They will also aid the interpretation of experimental results on other sequences.

Proton-Coupled Electron Transfer Ring Opening of Cycloalkanols Followed by a Giese Radical Addition Enabled by an Electron Donor-Acceptor Complex.

Herein, we describe the formation of an electron donor-acceptor (EDA) complex between electron-rich cycloalkanols and electron-deficient alkenes that triggers the proton-coupled electron transfer ring opening of strained and unstrained cycloalkanols without the need for an external photocatalyst. This activation generates a remote alkyl radical that undergoes a Giese reaction with the Michael acceptor in an efficient manner. Mechanistic investigations corroborate both the formation of the EDA complex and the consecutive Giese reaction.

Valorization applications of pineapple and papaya byproducts in food industry.

The recent increase in the harvesting and industrial processing of tropical fruits such as pineapple and papaya is leading to unavoidable amounts of byproducts rich in valuable compounds. Given the significance of the chemical composition of these byproducts, new research avenues are opening up to exploit them in the food industry. In this sense, the revalorization of pineapple and papaya byproducts is an emerging trend that is encouraging the full harnessing of these tropical fruits, offering the opportunity for developing innovative value-added products. Therefore, the main aim of this review is to provide an overview of the state of the art of the current valorization applications of pineapple and papaya byproducts in the field of food industry. For that proposal, comprehensive research of valorization applications developed in the last years has been conducted using scientific databases, databases, digital libraries, and scientific search engines. The latest valorization applications of pineapple and papaya byproducts in the food industry have been systematically revised and gathered with the objective of synthesizing and critically analyzing existing scientific literature in order to contribute to the advancement of knowledge in the field of tropical byproduct revalorization providing a solid foundation for further research and highlighting scientific gaps and new challenges that should be addressed in the future.

Photodissociation of leucine-enkephalin protonated peptide: an experimental and theoretical perspective.

Understanding the competing processes that govern far ultraviolet photodissociation (FUV-PD) of biopolymers such as proteins is a challenge. Here, we report a combined experimental and theoretical investigation of FUV-PD of protonated leucine-enkephalin pentapeptide ([YGGFL + H]+) in the gas-phase. Time-dependent density functional theory (TD-DFT) calculations in combination with experiments and previous results for amino acids and shorter peptides help in rationalizing the evolution of the excited states. The results confirm that fragmentation of [YGGFL + H]+ results mainly from vibrationally excited species in the ground electronic state, populated after internal conversion. We also propose fragmentation mechanisms for specific photo-fragments such as tyrosine side chain loss (with an extra hydrogen) or hydrogen loss. In general, we observe the same mechanisms as for smaller peptides or protonated Tyr and Phe, that are not quenched by the presence of other amino acids. Nevertheless, we also found some differences, as for H loss, in part due to the fact that the charge is solvated by the peptide chain and not only by the COOH terminal group.

Ultrafast Formation of a Delocalized Triplet-Excited State in an Epigenetically Modified DNA Duplex under Direct UV Excitation.

Epigenetic modifications impart important functionality to nucleic acids during gene expression but may increase the risk of photoinduced gene mutations. Thus, it is crucial to understand how these modifications affect the photostability of duplex DNA. In this work, the ultrafast formation (<20 ps) of a delocalized triplet charge transfer (CT) state spreading over two stacked neighboring nucleobases after direct UV excitation is demonstrated in a DNA duplex, d(G5fC)9•d(G5fC)9, made of alternating guanine (G) and 5-formylcytosine (5fC) nucleobases. The triplet yield is estimated to be 8 ± 3%, and the lifetime of the triplet CT state is 256 ± 22 ns, indicating that epigenetic modifications dramatically alter the excited state dynamics of duplex DNA and may enhance triplet state-induced photochemistry.

Triplet Excimer Formation in a DNA Duplex with Silver Ion-Mediated Base Pairs.

The dynamics of excited electronic states in self-assembled structures formed between silver(I) ions and cytosine-containing DNA strands or monomeric cytosine derivatives were investigated by time-resolved infrared (TRIR) spectroscopy and quantum mechanical calculations. The steady-state and time-resolved spectra depend sensitively on the underlying structures, which change with pH and the nucleobase and silver ion concentrations. At pH ∼ 4 and low dC20 strand concentration, an intramolecularly folded i-motif is observed, in which protons, and not silver ions, mediate C-C base pairing. However, at the higher strand concentrations used in the TRIR measurements, dC20 strands associate pairwise to yield duplex structures containing C-Ag+-C base pairs with a high degree of propeller twisting. UV excitation of the silver ion-mediated duplex produces a long-lived excited state, which we assign to a triplet excimer state localized on a pair of stacked cytosines. The computational results indicate that the propeller-twisted motifs induced by metal-ion binding are responsible for the enhanced intersystem crossing that populates the triplet state and not a generic heavy atom effect. Although triplet excimer states have been discussed frequently as intermediates in the formation of cyclobutane pyrimidine dimers, we find neither computational nor experimental evidence for cytosine-cytosine photoproduct formation in the systems studied. These findings provide a rare demonstration of a long-lived triplet excited state that is formed in a significant yield in a DNA duplex, demonstrating that supramolecular structural changes induced by metal ion binding profoundly affect DNA photophysics.

The photophysics of protonated cytidine and hemiprotonated cytidine base pair: A computational study.

We here study the effect that a lowering of the pH has on the excited state processes of cytidine and a cytidine/cytidine pair in solution, by integrating time-dependent density functional theory and CASSCF/CASPT2 calculations, and including solvent by a mixed discrete/continuum model. Our calculations reproduce the effect of protonation at N3 on the steady-state infrared and absorption spectra of a protonated cytidine (CH+ ), and predict that an easily accessible non-radiative deactivation route exists for the spectroscopic state, explaining its sub-ps lifetime. Indeed, an extremely small energy barrier separates the minimum of the lowest energy bright state from a crossing region with the ground electronic state, reached by out-of-plane motion of the hydrogen substituents of the CC double bond, the so-called ethylenic conical intersection typical of cytidine and other pyrimidine bases. This deactivation route is operative for the two bases forming an hemiprotonated cytidine base pair, [CH·C]+ , the building blocks of I-motif secondary structures, whereas interbase processes play a minor role. N3 protonation disfavors instead the nπ* transitions, associated with the long-living components of cytidine photoactivated dynamics.

Free-Water Imaging in Friedreich Ataxia Using Multi-Compartment Models.

BACKGROUND: The neurological phenotype of Friedreich ataxia (FRDA) is characterized by neurodegeneration and neuroinflammation in the cerebellum and brainstem. Novel neuroimaging approaches quantifying brain free-water using diffusion magnetic resonance imaging (dMRI) are potentially more sensitive to these processes than standard imaging markers. OBJECTIVES: To quantify the extent of free-water and microstructural change in FRDA-relevant brain regions using neurite orientation dispersion and density imaging (NODDI), and bitensor diffusion tensor imaging (btDTI). METHOD: Multi-shell dMRI was acquired from 14 individuals with FRDA and 14 controls. Free-water measures from NODDI (FISO) and btDTI (FW) were compared between groups in the cerebellar cortex, dentate nuclei, cerebellar peduncles, and brainstem. The relative sensitivity of the free-water measures to group differences was compared to microstructural measures of NODDI intracellular volume, free-water corrected fractional anisotropy, and conventional uncorrected fractional anisotropy. RESULTS: In individuals with FRDA, FW was elevated in the cerebellar cortex, peduncles (excluding middle), dentate, and brainstem (P < 0.005). FISO was elevated primarily in the cerebellar lobules (P < 0.001). On average, FW effect sizes were larger than all other markers (mean ηρ 2 = 0.43), although microstructural measures also had very large effects in the superior and inferior cerebellar peduncles and brainstem (ηρ 2 > 0.37). Across all regions and metrics, effect sizes were largest in the superior cerebellar peduncles (ηρ 2 > 0.46). CONCLUSIONS: Multi-compartment diffusion measures of free-water and neurite integrity distinguish FRDA from controls with large effects. Free-water magnitude in the brainstem and cerebellum provided the greatest distinction between groups. This study supports further applications of multi-compartment diffusion modeling, and investigations of free-water as a measure of disease expression and progression in FRDA. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Uso de modelos de impresión 3D en Ortopedia y Traumatología: Serie de casos / Use of 3D printing models in orthopedics and traumatology. Case series

Introducción: Comprender y tratar deformidades, defectos y fracturas complejas sigue siendo un desafío en el área de la Ortopedia y Traumatología. La aplicación de modelos de impresión 3D incluye el diagnóstico, la planificación quirúrgica, la creación de guías intraoperatorias e implantes y el entrenamiento quirúrgico. Las deformidades y fracturas articulares complejas representan un reto en el tratamiento quirúrgico debido a la complejidad tridimensional. La tecnología de impresión 3D permite simular la anatomía, la reducción de trazos fracturarios, osteotomías, y la dirección y longitud de los tornillos. El objetivo de este artículo es comunicar una serie de casos en los que se implementó la impresión 3D y presentar una revisión narrativa. Se describen dos casos de fractura de acetábulo, dos de escoliosis idiopática, una fractura del pilón tibial compleja y una fractura de astrágalo en los que se crearon modelos de impresión 3D para la planificación quirúrgica que resultaron beneficiosos tanto para el paciente como para el equipo quirúrgico. Conclusiones: Con el auge de la impresión 3D en el área de la Ortopedia y Traumatología, podremos facilitar el entendimiento de fracturas y deformidades complejas y mejorar las planificaciones prequirúrgicas. El tiempo de producción del modelo puede demorarse y ser una limitación para su uso en urgencias. Aún faltan estudios para evaluar los beneficios significativos para el paciente y el equipo médico, como la reducción del tiempo operatorio, la pérdida de sangre intraoperatoria y la exposición a la radiación. Nivel de Evidencia: IV

Introduction: Understanding and treating deformities, defects and complex fractures remains a challenge in the area of orthopedics and traumatology. 3D printing models are used for diagnostics, surgical planning, the manufacturing of intraoperative guides and implants, and surgical training. The objective of our work was to report on a series of cases where 3D printing was implemented in our service and to carry out a narrative review. The case series includes two acetabular fractures, two idiopathic scoliosis, a complex tibial pilon fracture, and a talar fracture. 3D printing models were used for surgery planning, which benefited both the patient and the surgical team. Conclusions: With the rise of 3D printing in orthopedics and traumatology, we are able to better understand fractures and complex deformities, as well as improve preoperative planning. The model's production timelines may be delayed, limiting its usefulness in an emergency. There are yet insufficient studies that report substantial benefits to the patient and medical team, such as reduced surgical time, intraoperative blood loss, and radiation exposure. Level of Evidence: IV

Effect of the DNA Polarity on the Relaxation of Its Electronic Excited States.

The DNA polarity, i.e., the order in which nucleobases are connected together via the phosphodiester backbone, is crucial for several biological processes. But, so far, there has not been experimental evidence regarding its effect on the relaxation of DNA electronic excited states. Here we examine this aspect for two dinucleotides containing adenine and guanine: 5'-dApdG-3' and 5'-dGpdA-3' in water. We used two different femtosecond transient absorption setups: one providing high temporal resolution and broad spectral coverage (330-650 nm) between 30 fs and 50 ps, and the other recording decays at selected wavelengths until 1.2 ns. The transient absorption spectra corresponding to the minima in the potential energy surface of the first excited state were computed by quantum chemistry methods. Our results show that the excited charge transfer state in 5'-dGpdA-3' is formed with a ∼75% higher quantum yield and exhibits slower decay (170 ± 10 ps vs 112 ± 12 ps) compared to 5'-dApdG-3'.

Impaired lung function in multiple sclerosis: a single-center observational study in 371 persons.

INTRODUCTION: Abnormal lung function in people with multiple sclerosis (PwMS) could be considered as the result of muscle weakness or MS-specific structural central nervous system (CNS) abnormalities as a precipitant factor for the worsening of motor impairment or cognitive symptoms. METHODS: This is a cross-sectional observational study in PwMS. Forced spirometry was conducted, and normative metrics of forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the relation FEV1/FVC were calculated. Qualitative and quantitative brain magnetic resonance imaging (MRI) examinations were carried out. RESULTS: A total of 371 PwMS were included in the study. Of those, 196 (53%) had RRMS, 92 (25%) SPMS, and 83 (22%) PPMS. Low FVC and FEV1 was present in 16 (8%), 16 (19%), and 23 (25%) of the patients in the RRMS, PPMS, and SPMS, respectively. PwMS with T2-FLAIR lesions involving the corpus callosum (CC) had a significantly higher frequency of abnormally low FVC and FEV1 (OR 3.62; 95% CI 1.33-9.83; p = 0.012) than patients without lesions in that region. This association remained significant in the RRMS group (OR 10.1; 95% CI 1.3-67.8; p 0.031) when the model excluded PPMS and SPMS. According to our study, for every increase of 1 z score of FVC, we observed an increase of 0.25 cm3 of hippocampal volume (ß 0.25; 95% CI 0.03-0.47; p 0.023) and 0.43 cm3 of left hippocampus volume (ß 0.43; 95% CI 0.16-0.71; p 0.002). CONCLUSIONS: We observed an incremental prevalence of abnormally low pulmonary function tests that parallels a sequence from more early relapsing courses to long-standing progressive courses (RRMS to PPMS or SPMS).

The technology of high-power ultrasound and its effect on the color and aroma of rosé wines.

BACKGROUND: The application of high-power ultrasound (US) has been studied extensively to obtain value-added red wines using short maceration times. It is a technique of wide interest for the extraction of aromatic compounds and compounds responsible for color, so it could also be an important tool to use in the elaboration process of rosé wines. Thus, this study focused on the effect of the application of US on the phenolic, aromatic, and sensorial profile of rosé wines. For this, three different types of rosé wine were produced: a control with direct pressing after crushing, another wine obtained from a 4 h macerated must, and a wine whose crushed and destemmed grape was sonicated and subsequently pressed. RESULTS: The results showed a higher color intensity and a higher total polyphenol and anthocyanin content in the wine obtained from sonicated grape compared to both control wine and that obtained from grape macerated for 4 h. Ultrasound treatment enhanced the extraction of varietal volatile compounds in must, especially the free faction of terpenes and norisoprenoids. It also gave rise to wines with a higher concentration of C6 alcohols and other compounds such as guaiacol and 4-vinylguaiacol, but led to fewer fatty acids, especially C6, C4 and C8 acids. Sensorially these wines showed intense aromas of red fruits and flowers, while no defects in aroma or astringency were found. CONCLUSIONS: The color and sensory profile of the resulting wines indicate that the US may be an interesting tool for obtaining quality rosé wines, replacing the maceration stage and reducing potential oxidation problems. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Curved Nanographenes: Multiple Emission, Thermally Activated Delayed Fluorescence, and Non-Radiative Decay.

The intriguing and rich photophysical properties of three curved nanographenes (CNG 6, 7, and 8) are investigated by time-resolved and temperature-dependent photoluminescence (PL) spectroscopy. CNG 7 and 8 exhibit dual fluorescence, as well as dual phosphorescence at low temperature in the main PL bands. In addition, hot bands are detected in fluorescence as well as phosphorescence, and, in the narrow temperature range of 100-140 K, thermally activated delayed fluorescence (TADF) with lifetimes on the millisecond time-scale is observed. These findings are rationalized by quantum-chemical simulations, which predict a single minimum of the S1 potential of CNG 6, but two S1 minima for CNG 7 and CNG 8, with considerable geometric reorganization between them, in agreement with the experimental findings. Additionally, a higher-lying S2 minimum close to S1 is optimized for the three CNG, from where emission is also possible due to thermal activation and, hence, non-Kasha behavior. The presence of higher-lying dark triplet states close to the S1 minima provides mechanistic evidence for the TADF phenomena observed. Non-radiative decay of the T1 state appears to be thermally activated with activation energies of roughly 100 meV and leads to disappearance of phosphorescence and TADF at T > 140 K.

Peptide Bond Formation in the Protonated Serine Dimer Following Vacuum UV Photon-Induced Excitation.

Possible routes for intra-cluster bond formation (ICBF) in protonated serine dimers have been studied. We found no evidence of ICBF following low energy collision-induced dissociation (in correspondence with previous works), however, we do observe clear evidence for ICBF following photon absorption in the 4.6-14 eV range. Moreover, the comparison of photon-induced dissociation measurements of the protonated serine dimer to those of a protonated serine dipeptide provides evidence that ICBF, in this case, involves peptide bond formation (PBF). The experimental results are supported by ab initio molecular dynamics and exploration of several excited state potential energy surfaces, unraveling a pathway for PBF following photon absorption. The combination of experiments and theory provides insight into the PBF mechanisms in clusters of amino acids, and reveals the importance of electronic excited states reached upon UV/VUV light excitation.

How is fish market waste managed in the Philippines?

Improper management of fish waste is one of the factors that makes Philippine fisheries unsustainable. A considerable portion of fish waste is produced in wet markets where bulk of fish products are sold. A comparison of existing practices in different municipalities can indicate the best points of intervention and identify existing traditional practices that can be promoted. This study interviewed stakeholders of the fisheries industry and collected information at the market level to determine existing fish waste management systems. From the responses gathered, the average daily production of fish waste in Philippine wet markets was 70.3 + 0.93 kg, with no significant differences across locations (p = 0.2501). Of the fish waste produced, 32.3 + 1.33 kg per wet market were disposed of, 18.9 + 0.81 kg were sold, and 19.1 + 1.15 kg were given away to stakeholders who re-use the fish waste. A significantly greater proportion of fish waste in rural areas were re-used compared to Metro Manila (p = 0.0311). Incentivizing innovations that maximize the use of derived fish waste at the municipal level, and promoting existing traditional practices, can prove effective in contributing to the Philippine circular economy while providing alternative sources of income for the stakeholders of the fisheries industry.

Clinical features and lipid metabolism genes as potential biomarkers in advanced lung cancer.

BACKGROUND: Lung cancer is one of the most lethal tumors with a poor survival rate even in those patients receiving new therapies. Metabolism is considered one of the hallmarks in carcinogenesis and lipid metabolism is emerging as a significant contributor to tumor metabolic reprogramming. We previously described a profile of some lipid metabolism related genes with potential prognostic value in advanced lung cancer. AIM: To analyze clinical and pathological characteristics related to a specific metabolic lipid genomic signature from patients with advanced lung cancer and to define differential outcome. METHODS: Ninety samples from NSCLC (non-small cell lung cancer) and 61 from SCLC (small cell lung cancer) patients were obtained. We performed a survival analysis based on lipid metabolic genes expression and clinical characteristics. The primary end point of the study was the correlation between gene expression, clinical characteristics and survival. RESULTS: Clinical variables associated with overall survival (OS) in NSCLC patients were clinical stage, adenocarcinoma histology, Eastern Cooperative Oncology Group (ECOG), number and site of metastasis, plasma albumin levels and first-line treatment with platinum. As for SCLC patients, clinical variables that impacted OS were ECOG, number of metastasis locations, second-line treatment administration and Diabetes Mellitus (DM). None of them was associated with gene expression, indicating that alterations in lipid metabolism are independent molecular variables providing complementary information of lung cancer patient outcome. CONCLUSIONS: Specific clinical features as well as the expression of lipid metabolism-related genes might be potential biomarkers with differential outcomes.

Photophysical Characterization of Isoguanine in a Prebiotic-Like Environment.

It is intriguing how a mixture of organic molecules survived the prebiotic UV fluxes and evolved into the actual genetic building blocks. Scientists are trying to shed light on this issue by synthesizing nucleic acid monomers and their analogues under prebiotic Era-like conditions and by exploring their excited state dynamics. To further add to this important body of knowledge, this study discloses new insights into the photophysical properties of protonated isoguanine, an isomorph of guanine, using steady-state and femtosecond broadband transient absorption spectroscopies, and quantum mechanical calculations. Protonated isoguanine decays in ultrafast time scales following 292 nm excitation, consistently with the barrierless paths connecting the bright S1 (ππ*) state with different internal conversion funnels. Complementary calculations for neutral isoguanine predict similar photophysical properties. These results demonstrate that protonated isoguanine can be considered photostable in contrast to protonated guanine, which exhibits 40-fold longer excited state lifetimes.

Examination of Cerebellar Grey-Matter Volume in Children with Neurodevelopmental Disorders: a Coordinated Analysis Using the ACAPULCO Algorithm.

Alterations in cerebellar morphology relative to controls have been identified in children with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and developmental coordination disorder (DCD). However, it is not clear if common cerebellar regions are affected in each neurodevelopmental disorder and whether cerebellar morphological changes reflect a generic developmental vulnerability, or disorder-specific characteristic. The present study concatenated anatomical MRI scans from five existing cohorts, resulting in data from 252 children between the age of 7 and 12 years (ASD = 58, ADHD = 86, DCD = 22, Controls = 86). The ACAPULCO processing pipeline for cerebellar segmentation was conducted on T1-weighted images. A voxel-wise approach with general linear model was used to compare grey-matter volume of the 27 cerebellar lobules between each clinical group and controls. Our findings revealed that the ADHD group showed lower grey-matter volume in the left Crus I - part of the executive/non-motor portion of the cerebellum, relative to controls (p = 0.02). This no longer remained significant after controlling for medication status. There were no regions of significant differences in volume of the cerebellar lobules in ASD or DCD compared to controls. Future work will conduct harmonisation of behavioural data (cognitive and motor outcomes) across cohorts, enabling more advanced analyses to identify symptom cluster across neurodevelopmental disorders.