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1.
Angew Chem Int Ed Engl ; : e202405818, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38665012

RESUMEN

Molecular solar thermal systems (MOST) represent an auspicious solution for the storage of solar energy. We report silver salts as a unique class of catalysts, capable of releasing the stored energy from the promising 1,2-dihydro-1,2-azaborinine based MOST system. Mechanistic investigations provided insights into the silver catalyzed thermal backreaction, concurrently unveiling the first crystal structure of a 2-aza-3-borabicyclo[2.2.0]hex-5-ene, the Dewar isomer of 1,2-dihydro-1,2-azaborinine. Quantification of activation energies by kinetic experiments has elucidated the advantageous energy outcomes associated with Lewis acid catalysts, a phenomenon corroborated through computational analysis. By means of low temperature NMR spectroscopy, mechanistic insights into the coordination of Ag+ to the 1,2-dihydro-1,2-azaborinine were gained.

2.
J Intensive Care Med ; 39(3): 277-287, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37670670

RESUMEN

BACKGROUND: Sepsis-associated destruction of the pulmonary microvascular endothelial glycocalyx (EGCX) creates a vulnerable endothelial surface, contributing to the development of acute respiratory distress syndrome (ARDS). Constituents of the EGCX shed into circulation, glycosaminoglycans and proteoglycans, may serve as biomarkers of endothelial dysfunction. We sought to define the patterns of plasma EGCX degradation products in children with sepsis-associated pediatric ARDS (PARDS), and test their association with clinical outcomes. METHODS: We retrospectively analyzed a prospective cohort (2018-2020) of children (≥1 month to <18 years of age) receiving invasive mechanical ventilation for acute respiratory failure for ≥72 h. Children with and without sepsis-associated PARDS were selected from the parent cohort and compared. Blood was collected at time of enrollment. Plasma glycosaminoglycan disaccharide class (heparan sulfate, chondroitin sulfate, and hyaluronan) and sulfation subtypes (heparan sulfate and chondroitin sulfate) were quantified using liquid chromatography tandem mass spectrometry. Plasma proteoglycans (syndecan-1) were measured through an immunoassay. RESULTS: Among the 39 mechanically ventilated children (29 with and 10 without sepsis-associated PARDS), sepsis-associated PARDS patients demonstrated higher levels of heparan sulfate (median 639 ng/mL [interquartile range, IQR 421-902] vs 311 [IQR 228-461]) and syndecan-1 (median 146 ng/mL [IQR 32-315] vs 8 [IQR 8-50]), both p = 0.01. Heparan sulfate subtype analysis demonstrated greater proportions of N-sulfated disaccharide levels among children with sepsis-associated PARDS (p = 0.01). Increasing N-sulfated disaccharide levels by quartile were associated with severe PARDS (n = 9/29) with the highest quartile including >60% of the severe PARDS patients (test for trend, p = 0.04). Higher total heparan sulfate and N-sulfated disaccharide levels were independently associated with fewer 28-day ventilator-free days in children with sepsis-associated PARDS (all p < 0.05). CONCLUSIONS: Children with sepsis-associated PARDS exhibited higher plasma levels of heparan sulfate disaccharides and syndecan-1, suggesting that EGCX degradation biomarkers may provide insights into endothelial dysfunction and PARDS pathobiology.


Asunto(s)
Síndrome de Dificultad Respiratoria , Sepsis , Humanos , Niño , Estudios Retrospectivos , Sindecano-1/metabolismo , Sulfatos de Condroitina/metabolismo , Estudios Prospectivos , Glicocálix/química , Glicocálix/metabolismo , Sepsis/complicaciones , Sepsis/metabolismo , Heparitina Sulfato/metabolismo , Biomarcadores , Proteoglicanos/metabolismo , Disacáridos/metabolismo
3.
J Surg Res ; 293: 709-716, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37844411

RESUMEN

INTRODUCTION: Plasma levels of syndecan-1 (Sdc-1), a biomarker of endothelial glycocalyx (EG) damage, correlate with worse outcomes in trauma patients. However, EG injury is not well characterized in injured older adults (OA). The aims of this study were to characterize Sdc-1 shedding in OA trauma patients relative to younger adults (YA) and determine associations with putative regulators of EG sheddases. METHODS: We performed a secondary analysis of data from the Pragmatic, Randomized Optimal Platelet, and Plasma Ratios (PROPPR) trial, stratifying bluntly injured subjects into OA and YA groups based on upper age quartile (57 y). Plasma Sdc-1 levels were compared in OA and YA at hospital arrival through postinjury day 3, and the independent association between age and Sdc-1 level at arrival was determined after adjusting for differences in gender, shock index (SI), and pre-existing comorbidities. In a follow-up analysis, case-control matching was used to create populations of OA and YA with equivalent SI and injury severity score. Levels of Sdc-1 were compared between these matched groups, and the relationships with candidate regulators of EG shedding were assessed. RESULTS: Of 680 subjects in the Pragmatic, Randomized Optimal Platelet, and Plasma Ratios trial, 350 (51%) had blunt injuries, and 92 (26.3%) of these were OA. Plasma Sdc-1 levels at arrival, 2 h, and 6 h were significantly lower in OA compared to YA (all P < 0.05). After adjusting for sex, pre-existing morbidities and SI, age was associated with decreased Sdc-1 levels at arrival. In the matched analyses, Sdc-1, high-mobility group box 1 and tissue inhibitor of metalloproteinase-2 levels were lower in OA compared to YA. Both high-mobility group box-1 and tissue inhibitor of metalloproteinase-2 significantly correlated with arrival Sdc-1 and were inversely associated with age. CONCLUSIONS: This study indicates that increased age is independently associated with decreased Sdc-1 levels among patients with blunt injuries. Suppressed plasma levels of sheddases in relation to diminished Sdc-1 shedding suggest that mechanisms regulating EG cleavage may be impaired in injured older adults. These findings provide novel insight into the age-dependent impact of injury on the vascular endothelium, which could have important implications for the clinical management of older adults following trauma.


Asunto(s)
Inhibidor Tisular de Metaloproteinasa-2 , Heridas no Penetrantes , Humanos , Anciano , Glicocálix , Hemorragia , Puntaje de Gravedad del Traumatismo , Heridas no Penetrantes/complicaciones , Heridas no Penetrantes/diagnóstico , Sindecano-1
4.
ACS Omega ; 8(48): 45970-45975, 2023 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-38075750

RESUMEN

The electronic structure of ammonia-borane (NH3BH3) has been investigated by using valence and core photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy at the nitrogen and boron K edges. The first two valence ionic states display vibronic structure, in agreement with the published results for the first ionic state. Analysis of the vibrational frequency of the second state yields an assignment which is consistent with the calculated molecular orbital character reported in the literature. The energies of the valence ionic states are in good agreement with recent calculations. More accurate experimental core-level binding energies, compared with older values, are provided and are in very good agreement with recent calculations. The near-edge X-ray absorption fine structure spectra display a vibronic structure, and the values of the vibrational energies are analyzed to assign the resonance structure.

5.
Phys Chem Chem Phys ; 25(46): 31655-31666, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37964643

RESUMEN

The dissociative double photoionization of isoxazole molecules has been investigated experimentally and theoretically. The experiment has been carried out in the 27.5-36 eV photon energy range using vacuum ultraviolet (VUV) synchrotron radiation excitation combined with ion time-of-flight (TOF) spectrometry and photoelectron-photoion-photoion coincidence (PEPIPICO) technique. Five well-resolved two-body dissociation channels have been identified in the isoxazole's coincidence maps, and their appearance energies have been determined. The coincidence yield curves of these dissociation channels have been obtained in the photon energy ranges from their appearance energies up to 36 eV. The double photoionization of isoxazole produces a C3H3NO2+ transient dication, which decomposes into fragments differing from previously reported photofragmentation products of isoxazole. We have found no evidence of pathways leading to the C3H2NO+, HCN+, C2H2O+, C3HN+, or C2H2+ fragments or their neutral counterparts that have been observed in previous neutral photodissociation and single photoionization studies. Instead, the dissociation of isoxazole after the ejection of two electrons is bond-selective and is governed by two reactions, HCO+ + H2CCN+ and H2CO+ + HCCN+, whose appearance energies are 28.6 (±0.3) and 29.4 (±0.3) eV, respectively. A third dissociation channel turns out to be a variant of the most intense channel (HCO+ + H2CCN+), where one of the fragment ions contains a heavy isotope. Two minor dissociation channels occurring at higher energies, CO+ + CH3CN+ and CN+ + H3CCO+, are also identified. The density functional and ab initio quantum chemical calculations have been performed to elucidate the dissociative charge-separating mechanisms and determine the energies of the observed photoproducts. The present work unravels hitherto unexplored photodissociation mechanisms of isoxazole and thus provides deeper insight into the photophysics of five-membered heterocyclic molecules containing two heteroatoms.

6.
ASAIO J ; 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37976539

RESUMEN

Refractory vasodilatory shock (RVS) following massive calcium channel blocker (CCB) overdose remains a challenging clinical entity. Peripheral venoarterial extracorporeal membrane oxygenation (ECMO) has proven useful in several cases of CCB intoxication, however, its use in the pediatric population poses unique challenges given the generally small size of pediatric peripheral vasculature in comparison to the high flow rates necessary for adequate mechanical circulatory support. As a result of these challenges, our group has adopted a "primary" central ECMO cannulation approach to the treatment of children and adolescents admitted to our center with profound RVS after CCB ingestion. We present four cases within the last year using this approach. All patients were successfully discharged from the hospital with no late morbidity at most recent follow-up. Central ECMO support in cases of massive vasodilatory shock following CCB overdose is safe and effective and should be considered early in the clinical course of these critically ill patients.

7.
J Chem Phys ; 159(10)2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37702355

RESUMEN

In search of the cause behind the similarities often seen in the fragmentation of PANHs, vacuum ultraviolet (VUV) photodissociation of two pairs of isomers quinoline-isoquinoline and 2-naphthylamine-3-methyl-quinoline are studied using the velocity map imaging technique. The internal energy dependence of all primary fragmentation channels is obtained for all four target molecules. The decay dynamics of the four molecules is studied by comparing their various experimental signatures. The dominant channel for the first pair of isomers is found to be hydrogen cyanide (HCN) neutral loss, while the second pair of isomers lose HCNH neutral as its dominant channel. Despite this difference in their primary decay products and the differences in the structures of the four targets, various similarities in their experimental signatures are found, which could be explained by isomerization mechanisms to common structures. The fundamental role of these isomerization in controlling different dissociative channels is explored via a detailed analysis of the experimental photoelectron-photoion coincidences and the investigation of the theoretical potential energy surface. These results add to the notion of a universal PANH fragmentation mechanism and suggests the seven member isomerization as a key candidate for this universal mechanism. The balance between isomerization, dissociation, and other key mechanistic processes in the reaction pathways, such as hydrogen migrations, is also highlighted for the four molecules.

8.
Front Med (Lausanne) ; 10: 1216538, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37654664

RESUMEN

Severe acute respiratory distress syndrome in children, or PARDS, carries a high risk of morbidity and mortality that is not fully explained by PARDS severity alone. Right ventricular (RV) dysfunction can be an insidious and often under-recognized complication of severe PARDS that may contribute to its untoward outcomes. Indeed, recent evidence suggest significantly worse outcomes in children who develop RV failure in their course of PARDS. However, in this narrative review, we highlight the dearth of evidence regarding the incidence of and risk factors for PARDS-associated RV dysfunction. While we wish to draw attention to the absence of available evidence that would inform recommendations around surveillance and treatment of RV dysfunction during severe PARDS, we leverage available evidence to glean insights into potentially helpful surveillance strategies and therapeutic approaches.

9.
Physiother Theory Pract ; : 1-13, 2023 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-37688439

RESUMEN

Critical physiotherapy has been a rapidly expanding field over the last decade and could now justifiably be called a professional sub-discipline. In this paper we define three different but somewhat interconnected critical positions that have emerged over the last decade that share a critique of physiotherapy's historical approach to health and illness, while also diverging in the possibilities for new forms of practice and thinking. These three positions broadly align with three distinctive philosophies: approaches that emphasize lived experience, social theory, and a range of philosophies increasingly referred to as the "posts". In this paper we discuss the origins of these approaches, exploring the ways they critique contemporary physiotherapy thinking and practice. We offer an overview of the key principles of each approach and, for each in turn, suggest readings from key authors. We conclude each section by discussing the limits of these various approaches, but also indicate ways in which they might inform future thinking and practice. We end the paper by arguing that the various approaches that now fall under the rubric of critical physiotherapy represent some of the most exciting and opportune ways we might (re)think the future for the physiotherapy profession and the physical therapies more generally.

10.
Nanoscale ; 15(34): 14025-14031, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37559557

RESUMEN

Helium nanodroplets are ideal model systems to unravel the complex interaction of condensed matter with ionizing radiation. Here we study the effect of purely elastic electron scattering on angular and energy distributions of photoelectrons emitted from He nanodroplets of variable size (10-109 atoms per droplets). For large droplets, photoelectrons develop a pronounced anisotropy along the incident light beam due to a shadowing effect within the droplets. In contrast, the detected photoelectron spectra are only weakly perturbed. This opens up possibilities for photoelectron spectroscopy of dopants embedded in droplets provided they are smaller than the penetration depth of the light and the trapping range of emitted electrons in liquid helium.

11.
Molecules ; 28(13)2023 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-37446880

RESUMEN

The behavior of nitrosyl chloride (ClNO) exposed to ionizing radiation was studied by direct probing valence-shell electrons in temporal coincidence with ions originating from the fragmentation process of the transient ClNO2+. Such a molecular dication was produced by double photoionization with synchrotron radiation in the 24-70 eV photon energy range. The experiment has been conducted at the Elettra Synchrotron Facility of Basovizza (Trieste, Italy) using a light beam linearly polarized with the direction of the polarization vector parallel to the ClNO molecular beam axis. ClNO molecules crossing the photon beam at right angles in the scattering region are generated by effusive expansion and randomly oriented. The threshold energy for the double ionization of ClNO (30.1 ± 0.1 eV) and six dissociation channels producing NO+/Cl+, N+/Cl+, N+/O+, O+/Cl+, ClN+/O+, NO+/Cl2+ ion pairs, with their relative abundance and threshold energies, have been measured.


Asunto(s)
Fotones , Sincrotrones , Fenómenos Físicos , Italia
12.
J Chem Phys ; 158(24)2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37347125

RESUMEN

Polycyclic aromatic hydrocarbons have widely been conjectured to be ubiquitous in space, as supported by the recent discovery of two isomers of cyanonaphthalene, indene, and 2-cyanoindene in the Taurus molecular cloud-1 using radioastronomy. Here, the photoionization dynamics of 1-cyanonaphthalene (1-CNN) are investigated using synchrotron radiation over the hν = 9.0-19.5 eV range, revealing that prompt autoionization from the plasmon resonance dominates the photophysics for hν = 11.5-16.0 eV. Minimal photo-induced dissociation, whether originating from an excited state impulsive bond rupture or through internal conversion followed by a statistical bond cleavage process, occurs over the microsecond timescale (as limited by the experimental setup). The direct photoionization cross section and photoelectron angular distributions are simulated using an ezDyson model combining Dyson orbitals with Coulomb wave photoejection. When considering these data in conjunction with recent radiative cooling measurements on 1-CNN+, which showed that cations formed with up to 5 eV of internal energy efficiently stabilize through recurrent fluorescence, we conclude that the organic backbone of 1-CNN is resilient to photodestruction by VUV and soft XUV radiation. These dynamics may prove to be a common feature for the survival of small polycyclic aromatic hydrocarbons in space, provided that the cations have a suitable electronic structure to support recurrent fluorescence.


Asunto(s)
Frío , Hidrocarburos Policíclicos Aromáticos , Fluorescencia , Isomerismo , Transición de Fase
13.
Phys Chem Chem Phys ; 25(23): 15635-15646, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37166113

RESUMEN

The photoionisation and photofragmentation of the two cyclic dipetides cyclo(alanyl-glycine) cGA and cyclo(glycyl-glycine) cGG, have been studied combining experiments and simulations. State selected fragments from the ionized molecules are detected using photo-electron photo-ion coincidence (PEPICO) measurements and specific fragmentation paths are identified and characterized via the use of ion-neutral coincidence maps. The simulations, performed using Quantum Chemistry methods, allow us to infer the fragmentation mechanisms of the ionized and excited molecules. We show that ring opening is followed by emission of the neutral fragments CO and HNCO. In the case of cGG the emission of neutral CO leads to a metastable structure that breaks producing small cationic fragments. The studied cyclic dipeptides evolve under ionizing radiation generating different small aziridin moieties and oxazolidinones. These two species are key reactants to elongate producing peptide chains. The corresponding mechanisms have been computed and show that the reaction requires very low energy and may occur in the presence of ionizing radiation.


Asunto(s)
Dicetopiperazinas , Péptidos , Dipéptidos/química , Glicilglicina , Aminoácidos Cíclicos
14.
Phys Chem Chem Phys ; 25(15): 10946-10955, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37016833

RESUMEN

We have investigated the electronic structure of isolated molecules of paracetamol, aspirin and ibuprofen using computational methods and benchmarked the results against valence and core photoelectron spectra. Paracetamol, aspirin and ibuprofen exist as multiple conformers, and we have calculated the free energies and populations of the lowest energy conformers. We find generally good agreement with previous experimental and theoretical structural results. The valence band spectrum of gas phase aspirin has not been reported previously, and we report it and assign the features based on calculations. The effect of acetylation on the frontier orbitals of the parent molecule, salicylic acid, is to increase the ionization potential of the highest occupied molecular orbital (HOMO), and to exchange the energetic ordering of the following two orbitals. The acetyl π bond contributes to the next orbital, which is hybridised with ring π orbitals. The core level spectra of all three molecules are reported and compared with calculations and with the spectra of parent molecules (salicylic acid for aspirin, 4-aminophenol for paracetamol). Observed core ionization energies are in agreement with theory. Although all compounds share a benzene ring, and they also have a number of other chromophores in common, the spectroscopic data indicate chemical diversity, suggesting that their modes of bonding under physiological conditions are likely to be diverse.


Asunto(s)
Acetaminofén , Ibuprofeno , Aspirina , Espectroscopía de Fotoelectrones , Ácido Salicílico , Gases
15.
Crit Care ; 27(1): 34, 2023 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-36691080

RESUMEN

BACKGROUND: Recent single-center reports have suggested that community-acquired bacteremic co-infection in the context of Coronavirus disease 2019 (COVID-19) may be an important driver of mortality; however, these reports have not been validated with a multicenter, demographically diverse, cohort study with data spanning the pandemic. METHODS: In this multicenter, retrospective cohort study, inpatient encounters were assessed for COVID-19 with community-acquired bacteremic co-infection using 48-h post-admission blood cultures and grouped by: (1) confirmed co-infection [recovery of bacterial pathogen], (2) suspected co-infection [negative culture with ≥ 2 antimicrobials administered], and (3) no evidence of co-infection [no culture]. The primary outcomes were in-hospital mortality, ICU admission, and mechanical ventilation. COVID-19 bacterial co-infection risk factors and impact on primary outcomes were determined using multivariate logistic regressions and expressed as adjusted odds ratios with 95% confidence intervals (Cohort, OR 95% CI, Wald test p value). RESULTS: The studied cohorts included 13,781 COVID-19 inpatient encounters from 2020 to 2022 in the University of Alabama at Birmingham (UAB, n = 4075) and Ochsner Louisiana State University Health-Shreveport (OLHS, n = 9706) cohorts with confirmed (2.5%), suspected (46%), or no community-acquired bacterial co-infection (51.5%) and a comparison cohort consisting of 99,170 inpatient encounters from 2010 to 2019 (UAB pre-COVID-19 pandemic cohort). Significantly increased likelihood of COVID-19 bacterial co-infection was observed in patients with elevated ≥ 15 neutrophil-to-lymphocyte ratio (UAB: 1.95 [1.21-3.07]; OLHS: 3.65 [2.66-5.05], p < 0.001 for both) within 48-h of hospital admission. Bacterial co-infection was found to confer the greatest increased risk for in-hospital mortality (UAB: 3.07 [2.42-5.46]; OLHS: 4.05 [2.29-6.97], p < 0.001 for both), ICU admission (UAB: 4.47 [2.87-7.09], OLHS: 2.65 [2.00-3.48], p < 0.001 for both), and mechanical ventilation (UAB: 3.84 [2.21-6.12]; OLHS: 2.75 [1.87-3.92], p < 0.001 for both) across both cohorts, as compared to other risk factors for severe disease. Observed mortality in COVID-19 bacterial co-infection (24%) dramatically exceeds the mortality rate associated with community-acquired bacteremia in pre-COVID-19 pandemic inpatients (5.9%) and was consistent across alpha, delta, and omicron SARS-CoV-2 variants. CONCLUSIONS: Elevated neutrophil-to-lymphocyte ratio is a prognostic indicator of COVID-19 bacterial co-infection within 48-h of admission. Community-acquired bacterial co-infection, as defined by blood culture-positive results, confers greater increased risk of in-hospital mortality, ICU admission, and mechanical ventilation than previously described risk factors (advanced age, select comorbidities, male sex) for COVID-19 mortality, and is independent of SARS-CoV-2 variant.


Asunto(s)
Bacteriemia , COVID-19 , Coinfección , Infecciones Comunitarias Adquiridas , Humanos , Masculino , SARS-CoV-2 , Estudios de Cohortes , Estudios Retrospectivos , Respiración Artificial , Pandemias , Mortalidad Hospitalaria , Bacterias , Factores de Riesgo , Unidades de Cuidados Intensivos
16.
Sportverletz Sportschaden ; 36(4): 188-199, 2022 12.
Artículo en Alemán | MEDLINE | ID: mdl-36446548

RESUMEN

BACKGROUND: Ankle sprains are among the most common injuries in sports and can result in chronic ankle instability. In therapy and prevention, a sensorimotor training approach on the structures surrounding the ankle joint has proven to be effective. There is evidence that training the intrinsic foot muscles can also improve balance, for example. OBJECTIVE/AIM: The aim of this narrative review is to present evidence regarding intrinsic foot muscles training in patients with ankle instability. METHODS: In January 2022, a systematic literature search was conducted in the databases PubMed, Cochrane Library, EBSCOhost, PEDro, SPONET and BISp-Surf and was complemented by a freehand search. We searched for meta-analyses, systematic reviews and intervention studies that examined the effects of a form of intrinsic foot muscle training on patients with ankle instability. The qualitative evaluation of the literature and evidence was based on the risk-of-bias tool (RoB tool) of the Cochrane Handbook and the GRADE system. MAIN RESULTS: Five randomised controlled trials involving 150 participants were included. Four trials used the Short-Foot Exercise (SFE), one trial used the Towel-Curl Exercise (TCE) and a toe-training program. The results of three studies showed a significant positive effect (p<0,05) on self-reported instability. Significant positive effects (p<0.05) on balance were shown for the SFE and the toe-training program, although the inclusion of the SFE in a training program did not result in any benefits. One study found significant positive effects (p<0.05) of the SFE on somatosensory function. All three forms of training led to significant (p<0.05) improvements in functional aspects. CONCLUSION: The results of this narrative review show positive effects of training the intrinsic foot muscles in patients with ankle instability on self-reported instability, balance, somatosensory function and on functional aspects. SFE and toe training seem to be effective forms of training and could be a useful addition to conventional therapy. However, the quality of evidence is too low and further research is needed to make a clear recommendation.


Asunto(s)
Tobillo , Inestabilidad de la Articulación , Humanos , Pie , Articulación del Tobillo , Músculos , Ensayos Clínicos Controlados Aleatorios como Asunto
17.
J Am Chem Soc ; 144(48): 21878-21886, 2022 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-36444673

RESUMEN

The photochemically induced ring-opening isomerization reaction of 1,3-cyclohexadiene to 1,3,5-hexatriene is a textbook example of a pericyclic reaction and has been amply investigated with advanced spectroscopic techniques. The main open question has been the identification of the single reactive state which drives the process. The generally accepted description of the isomerization pathway starts with a valence excitation to the lowest lying bright state, followed by a passage through a conical intersection to the lowest lying doubly excited state, and finally a branching between either the return to the ground state of the cyclic molecule or the actual ring-opening reaction leading to the open-chain isomer. Here, in a joint experimental and computational effort, we demonstrate that the evolution of the excitation-deexcitation process is much more complex than that usually described. In particular, we show that an initially high-lying electronic state smoothly decreasing in energy along the reaction path plays a key role in the ring-opening reaction.

18.
JMIR Res Protoc ; 11(10): e34564, 2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-36222801

RESUMEN

BACKGROUND: Despite the continued progress of medicine, dealing with breast cancer is becoming a major socioeconomic challenge, particularly due to its increasing incidence. The ability to better manage and adapt to the entire care process depends not only on the type of cancer but also on the patient's sociodemographic and psychological characteristics as well as on the social environment in which a person lives and interacts. Therefore, it is important to understand which factors may contribute to successful adaptation to breast cancer. To our knowledge, no studies have been performed on the combination effect of multiple psychological, biological, and functional variables in predicting the patient's ability to bounce back from a stressful life event, such as a breast cancer diagnosis. Here we describe the study protocol of a multicenter clinical study entitled "Predicting Effective Adaptation to Breast Cancer to Help Women to BOUNCE Back" or, in short, BOUNCE. OBJECTIVE: The aim of the study is to build a quantitative mathematical model of factors associated with the capacity for optimal adjustment to cancer and to study resilience through the cancer continuum in a population of patients with breast cancer. METHODS: A total of 660 women with breast cancer will be recruited from five European cancer centers in Italy, Finland, Israel, and Portugal. Biomedical and psychosocial variables will be collected using the Noona Healthcare platform. Psychosocial, sociodemographic, lifestyle, and clinical variables will be measured every 3 months, starting from presurgery assessment (ie, baseline) to 18 months after surgery. Temporal data mining, time-series prediction, sequence classification methods, clustering time-series data, and temporal association rules will be used to develop the predictive model. RESULTS: The recruitment process stared in January 2019 and ended in November 2021. Preliminary results have been published in a scientific journal and are available for consultation on the BOUNCE project website. Data analysis and dissemination of the study results will be performed in 2022. CONCLUSIONS: This study will develop a predictive model that is able to describe individual resilience and identify different resilience trajectories along the care process. The results will allow the implementation of tailored interventions according to patients' needs, supported by eHealth technologies. TRIAL REGISTRATION: ClinicalTrials.gov NCT05095675; https://clinicaltrials.gov/ct2/show/NCT05095675. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/34564.

19.
J Chem Inf Model ; 62(20): 5023-5033, 2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36214845

RESUMEN

Passive diffusion across biomembranes is an important mechanism of permeation for multiple drugs, including antibiotics. However, this process is frequently neglected while studying drug uptake and, in our view, warrants further investigation. Here, we apply molecular dynamics simulations to investigate the impact of changes in molecular hydrophobicity on the permeability of a series of inhibitors of the quorum sensing of Pseudomonas aeruginosa, previously discovered by us, across a membrane model. Overall, we show that permeation across this membrane model does not correlate with the molecule's hydrophobicity. We demonstrate that using a simple model for permeation, based on the difference between the maximum and minimum of the free energy profile, outperforms the inhomogeneous solubility-diffusion model, yielding a permeability ranking that better agrees with the experimental results, especially for hydrophobic permeants. The calculated differences in permeability could not explain differences in in bacterio activity. Nevertheless, substantial differences in molecular orientation along the permeation pathway correlate with the in bacterio activity, emphasizing the importance of analyzing, at an atomistic level, the permeation pathway of these solutes.


Asunto(s)
Antibacterianos , Simulación de Dinámica Molecular , Soluciones , Difusión , Interacciones Hidrofóbicas e Hidrofílicas
20.
J Chem Phys ; 157(12): 124306, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36182420

RESUMEN

The potential for selective bond breaking of a small molecule was investigated with electron spectroscopy and electron-ion coincidence experiments on ClNO. The electron spectra were measured upon direct valence photoionization and resonant core excitation at the N 1s- and O 1s-edges, followed by the emission of resonant-Auger (RA) electrons. The RA spectra were analyzed with particular emphasis on the assignment of the participator and spectator states. The states are of special relevance for investigating how distinct electronic configurations influence selective bond breaking. The electron-ion coincidence measurements provided branching fractions of the produced ion fragments as a function of electron binding energy. They explicitly demonstrate how the final electronic states created after photoionization and RA decay influence fragmentation. In particular, we observed a significantly different branching fraction for spectator states compared with participator states. In addition, it was also observed that the bonds broken for the spectator states correlate with the antibonding nature of the spectator-electron orbital.

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