Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 308
Filtrar
1.
Mov Disord ; 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696306

RESUMO

BACKGROUND: Calcitriol, the active form of vitamin D (also known as 1,25-dihydroxycholecalciferol), improves the phenotype and increases frataxin levels in cell models of Friedreich ataxia (FRDA). OBJECTIVES: Based on these results, we aimed measuring the effects of a calcitriol dose of 0.25 mcg/24h in the neurological function and frataxin levels when administered to FRDA patients for a year. METHODS: 20 FRDA patients where recluted and 15 patients completed the treatment for a year. Evaluations of neurological function changes (SARA scale, 9-HPT, 8-MWT, PATA test) and quality of life (Barthel Scale and Short Form (36) Health Survey [SF-36] quality of life questionnaire) were performed. Frataxin amounts were measured in isolated platelets obtained from these FRDA patients, from heterozygous FRDA carriers (relatives of the FA patients) and from non-heterozygous sex and age matched controls. RESULTS: Although the patients did not experience any observable neurological improvement, there was a statistically significant increase in frataxin levels from initial values, 5.5 to 7.0 pg/µg after 12 months. Differences in frataxin levels referred to total protein levels were observed among sex- and age-matched controls (18.1 pg/µg), relative controls (10.1 pg/µg), and FRDA patients (5.7 pg/µg). The treatment was well tolerated by most patients, and only some of them experienced minor adverse effects at the beginning of the trial. CONCLUSIONS: Calcitriol dosage used (0.25 mcg/24 h) is safe for FRDA patients, and it increases frataxin levels. We cannot rule out that higher doses administered longer could yield neurological benefits. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

2.
Blood Adv ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38739715

RESUMO

Little is known about risk factors for central nervous system (CNS) relapse in mature T- and NK-cell neoplasms (MTNKN). We aimed to describe the clinical epidemiology of CNS relapse in patients with MTNKN and developed the CNS relapse In T-cell lymphoma Index (CITI) to predict patients at highest risk of CNS relapse. We reviewed data from 135 patients with MTNKN and CNS relapse from 19 North American institutions. After exclusion of leukemic and most cutaneous forms of MTNKN, patients were pooled with non-CNS relapse control patients from a single institution to create a CNS relapse-enriched training set. Using a complete case analysis (N=182), of whom 91 had CNS relapse, we applied a LASSO Cox regression model to select weighted clinicopathologic variables for the CITI score, which we validated in an external cohort from the Swedish Lymphoma Registry (N=566). CNS relapse was most frequently observed in patients with PTCL, NOS (25%). Median time to CNS relapse and median overall survival after CNS relapse was 8.0 months and 4.7 months, respectively. We calculated unique CITI risk scores for individual training set patients and stratified them into risk terciles. Validation set patients with low-risk (N=158) and high-risk (N=188) CITI scores had a 10-year cumulative risk of CNS relapse of 2.2% and 13.4%, respectively (HR 5.24, 95%CI 1.50-18.26, P=0.018). We developed an open-access web-based CITI calculator (https://redcap.link/citicalc) to provide an easy tool for clinical practice. The CITI score is a validated model to predict patients with MTNKN at highest risk of developing CNS relapse.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38698161

RESUMO

PURPOSE: Most of Superior Semicircular Canal Dehiscence (SSCD) are located in the apical region of the SSC. However, in a small number of cases, it may be situated in the medial wall, causing the SSC to contact with the superior petrosal sinus (SPS). The aim of this study is to describe four patients with SSCD involving the superior petrosal sinus (SSCD-SPS) and to perform a review of the literature. METHODS: Observational retrospective study of patients diagnosed of SSCD-SPS in a tertiary referral center. A systematic review was made, identifying 7 articles in the literature. Clinical presentation, complementary test (pure-tone audiometry, PTA; vestibular evoked myogenic potential, VEMP; computed tomography, CT), therapeutic management and outcomes were reported. RESULTS: Four new cases of SSCD-SPS are reported, in three of them a transmastoid plugging was performed. 54 patients with SSCD-SPS (57 dehiscences) were reported in the literature. The most frequent symptoms were aural pressure (57.41%) and vertigo provoked by pressure/Valsalva (55.55%). Conductive hearing loss was the most common finding in PTA (47.37%). Abnormally low thresholds were observed in 59.46% of reported VEMP. Transmastoid approach was used in ten cases, middle fossa approach in four, round window reinforcement in one, and occlusion of the SPS using coils in two. CONCLUSIONS: Within SSCD, we have encountered a rare subtype characterized by its medial wall location in close proximity to the SPS. This subgroup needs special consideration as it has shown its own distinct characteristics. Regarding therapeutic management, we advocate a transmastoid approach.

4.
J Microsc ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594963

RESUMO

We present a comparison of common electron microscopy sample preparation methods for studying crystallisation processes from solution using both scanning and transmission electron microscopy (SEM and TEM). We focus on two widely studied inorganic systems: calcium sulphate, gypsum (CaSO4·2H2O) and calcium carbonate (CaCO3). We find significant differences in crystallisation kinetics and polymorph selection between the different sample preparation methods, which indicate that drying and chemical quenching can induce severe artefacts that are capable of masking the true native state of the crystallising solution. Overall, these results highlight the importance of cryogenic (cryo)-quenching crystallising solutions and the use of full cryo-TEM as the most reliable method for studying the early stages of crystallisation.

5.
Int J Sports Med ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38626907

RESUMO

Mixed-gender studies predominate the current literature exploring the interaction between physical activity and dementia risk. Considering that menopause appears to contribute to females' increased risk of cognitive decline when compared to males, further clarity is required on the impact of physical activity in reducing late-life dementia risk specifically in perimenopausal females. A literature search of MEDLINE, EMBASE, Web of Science, SCOPUS and CINAHL databases yielded fourteen studies for review. A significant inverse relationship between perimenopausal leisure time physical activity, or physical fitness, and future all-cause dementia risk was found in most studies exploring this interaction. Higher levels of perimenopausal household physical activity and combined non-leisure time physical activity also displayed a favourable impact in lowering dementia risk. A dose-response effect was demonstrated, with approximately 10 MET-hour/week of leisure time physical activity required for significant dementia risk reduction. Three of four papers exploring causality provided analyses that are proposed to counter the 'reverse causation' argument, suggesting that physical activity may indeed have a protective role in reducing dementia risk post-menopause. The current systematic review provides promising results regarding the impact of pre- and perimenopausal physical activity on reducing late-life dementia risk, suggesting that promoting perimenopausal physical activity may serve as a crucial tool in mitigating the risk of post-menopausal cognitive decline.

6.
bioRxiv ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38585729

RESUMO

In the early secretory pathway, endoplasmic reticulum (ER) and Golgi membranes form a nearly spherical interface. In this ribosome-excluding zone, bidirectional transport of cargo coincides with a spatial segregation of anterograde and retrograde carriers by an unknown mechanism. We show that at physiological conditions, Trk-fused gene (TFG) self-organizes to form a hollow, anisotropic condensate that matches the dimensions of the ER-Golgi interface. Regularly spaced hydrophobic residues in TFG control the condensation mechanism and result in a porous condensate surface. We find that TFG condensates act as a molecular sieve, enabling molecules corresponding to the size of anterograde coats (COPII) to access the condensate interior while restricting retrograde coats (COPI). We propose that a hollow TFG condensate structures the ER-Golgi interface to create a diffusion-limited space for bidirectional transport. We further propose that TFG condensates optimize membrane flux by insulating secretory carriers in their lumen from retrograde carriers outside TFG cages.

8.
J Med Virol ; 96(3): e29511, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38469884

RESUMO

To date, former research about the impact of HIV infection on mpox poor outcomes is still limited and controversial. Therefore, the aim of this study was to assess the impact of HIV on the clinical course of mpox, in a large population of patients from Spain. Nationwide case-series study. Patients from 18 Spanish hospitals, with PCR-confirmed mpox from April 27, 2022 to June 30, 2023 were included in this study. The main outcome was the development of long or complicated (LC) mpox, defined as: (i) duration of the clinical course ≥ 28 days, or; (ii) disseminated disease, or: (iii) emergence of severe complications. One thousand eight hundred twenty-three individuals were included. Seven hundred eighty-six (43%) were people living with HIV (PLWH), of whom 11 (1%) had a CD4 cell count < 200 cells/mm3 and 33 (3%) <350 cells/mm3 . HIV viral load ≥ 1000 cp/mL was found in 27 (3%) PLWH, none of them were on effective ART. Fifteen (60%) PLWH with HIV-RNA ≥ 1000 cp/mL showed LC versus 182 (29%) PLWH with plasma HIV-RNA load < 1000 copies/mL and 192 (24%) individuals without HIV infection (p < 0.001). In multivariate analysis, adjusted by age, sex, CD4 cell counts and HIV viral load at the time of mpox, only plasma HIV-RNA ≥ 1000 cp/mL was associated with a greater risk of developing LC mpox [adjusted OR = 4.06 (95% confidence interval 1.57-10.51), p = 0.004]. PLWH with uncontrolled HIV infection, due to lack of ART, are at a greater risk of developing LC mpox. Efforts should be made to ensure HIV testing is carried out in patients with mpox and to start ART without delay in those tested positive.


Assuntos
Infecções por HIV , Mpox , Humanos , Contagem de Linfócito CD4 , Progressão da Doença , RNA
9.
Artigo em Inglês | MEDLINE | ID: mdl-38346489

RESUMO

INTRODUCTION: Vestibular schwannoma (VS) is the most common tumour of the cerebellopontine angle. The greater accessibility to radiological tests has increased its diagnosis. Taking into account the characteristics of the tumour, the symptoms and the age of the patient, three therapeutic strategies have been proposed: observation, surgery or radiotherapy. Choosing the most appropriate for each patient is a frequent source of controversy. MATERIAL AND METHODS: This paper includes an exhaustive literature review of issues related to VS that can serve as a clinical guide in the management of patients with these lesions. The presentation has been oriented in the form of questions that the clinician usually asks himself and the answers have been written and/or reviewed by a panel of national and international experts consulted by the Otology Commission of the SEORL-CCC. RESULTS: A list has been compiled containing the 13 most controversial thematic blocks on the management of VS in the form of 50 questions, and answers to all of them have been sought through a systematic literature review (articles published on PubMed and Cochrane Library between 1992 and 2023 related to each thematic area). Thirty-three experts, led by the Otology Committee of SEORL-CCC, have analyzed and discussed all the answers. In Annex 1, 14 additional questions divided into 4 thematic areas can be found. CONCLUSIONS: This clinical practice guideline on the management of VS offers agreed answers to the most common questions that are asked about this tumour. The absence of sufficient prospective studies means that the levels of evidence on the subject are generally medium or low. This fact increases the interest of this type of clinical practice guidelines prepared by experts.


Assuntos
Neuroma Acústico , Radiocirurgia , Humanos , Neuroma Acústico/diagnóstico , Neuroma Acústico/terapia , Estudos Prospectivos , Imageamento por Ressonância Magnética , Microcirurgia
10.
Inorg Chem ; 63(7): 3207-3211, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38306699

RESUMO

Extended reduction of [Mo2Cp2(µ-Cl)(µ-PtBu2)(NO)2] (1) with Na(Hg) in acetonitrile (MeCN) at room temperature resulted in an unprecedented full cleavage of the C≡N bond of a coordinated MeCN molecule to yield the vinylidene derivative Na[Mo2Cp2(µ-PtBu2)(µ-CCH2)(NO)2], which upon protonation with (NH4)PF6 gave the ethylidyne complex [Mo2Cp2(µ-PtBu2)(µ-CMe)(NO)2] [Mo1-Mo2 = 2.9218(2) Å] in a selective and reversible way. Controlled reduction of 1 at 273 K yielded instead, after protonation, the 30-electron acetamidinate complex [Mo2Cp2(µ-PtBu2)(µ-κN:κN'-HNCMeNH)(µ-NO)]PF6 [Mo1-Mo2 = 2.603(2) Å], in a process thought to stem from the paramagnetic MeCN-bridged intermediate [Mo2Cp2(µ-PtBu2)(µ-NCMe)(NO)2], followed by a complex sequence of elementary steps including cleavage of the N≡O bond of a nitrosyl ligand.

11.
Eur J Case Rep Intern Med ; 11(2): 004246, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38352815

RESUMO

We report the case of a 24-year-old male presenting with obstructive renal failure, characterised by imaging evidence of a cystic lesion contingent upon the seminal vesicle and concurrent renal agenesis. Initial management involved urinary diversion, followed by outpatient monitoring and subsequent recurrence. Subsequent diagnostic assessments led to the identification of Zinner's syndrome, accompanied by retroperitoneal fibrosis. We present the clinical course, diagnostic methodology and the efficacious implementation of medical-surgical therapeutic interventions, yielding favourable outcomes. LEARNING POINTS: The value of the Internal Medicine team in the assessment of low prevalence diseases.The importance of multidisciplinary teams.Integration of the internists in the surgical teams.

13.
Phys Ther ; 104(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37831899

RESUMO

OBJECTIVE: Chronic postsurgical pain (CPSP) is a significant adverse effect shown in around 20% of people who had undergone a knee arthroplasty (KA). Psychological risk factors have emerged as significant and potentially modifiable risk factors for its development. However, there is still little evidence when assessing these factors during the acute postoperative period. This study aimed to assess the predictive value of postoperative pain catastrophizing, pain-related fear of movement, anxiety, depression, and pain attitudes in developing CPSP after KA. METHODS: A 6-month follow-up prospective observational study design was used. The study sample comprised 115 people who underwent a KA due to painful primary osteoarthritis. Measures of pain catastrophizing, pain-related fear of movement, anxiety, depression, and pain attitudes were obtained 1 week after surgery. CPSP was set at an intensity of ≥30 using a 100-mm visual analog scale at 3 and 6 months after surgery. RESULTS: Analysis revealed that baseline pain intensity, pain catastrophizing, pain-related fear of movement, anxiety, depression, and maladaptive pain attitudes were significant predictors of chronic pain at 3 and 6 months after surgery in a univariate analysis. However, at 3 months after surgery, only pain intensity and pain catastrophizing were predictors in the final multivariate model forecasting disturbing pain. Moreover, 6 months after surgery, pain intensity and distrust in medical procedures remained independent predictors. Most of the psychological factors can be grouped into a single dimension defined as pain-related psychological distress. CONCLUSION: The results suggest that postoperative pain intensity, pain catastrophizing, and pain attitudes are independent predictors for CPSP after KA. IMPACT: Postoperative cognitive and emotional factors should be considered alongside pain intensity during postoperative rehabilitation after KA because they could influence the development of CPSP.


Assuntos
Artroplastia do Joelho , Dor Crônica , Transtornos Fóbicos , Humanos , Estudos Prospectivos , Ansiedade/psicologia , Catastrofização/psicologia , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/psicologia , Dor Crônica/complicações
14.
Epileptic Disord ; 26(1): 60-68, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38116687

RESUMO

Infantile Epileptic Spasms Syndrome (IESS) is an epileptic encephalopathy in childhood that affects infants under the age of two years. When spasm series occur, prognosis for cognitive outcome is poor in the majority of cases. The encephalopathy in IESS includes delayed maturation of normal sleep phenomena in the EEG, such as sleep spindles. Children with intellectual disabilities often have abnormal sleep, and children with sleep problems have difficulties learning at school. We examined whether there is evidence of prognostic value of detection of sleep spindles in the EEG of children with IESS on their future cognitive development. A systematic literature search yielded five studies touching this question. They were evaluated by two scorers independently. The lack of normal sleep patterns including lack of sleep spindles was used as a biomarker of poor cognitive outcome. Positive (PPV) and Negative (NPV) prognostic values were calculated. A summary of all five studies indicates a PPV of 82% and an NPV of 45%. Given the small amount of data, the retrospective quality of most studies, and the differences in the outcome parameters reported, it is prudent to say that currently available data do not allow us to conclude whether spindles have a specific and independent role in the cognitive prognosis of affected children. Since sleep spindles are needed for memory consolidation and demonstrate the active role of sleep for learning and memory, the hypothesis remains that their absence in the EEG may indicate an increased risk of cognitive delay, but more supporting data are needed to reach such a firm conclusion.


Assuntos
Espasmos Infantis , Lactente , Criança , Humanos , Pré-Escolar , Prognóstico , Espasmos Infantis/diagnóstico , Estudos Retrospectivos , Eletroencefalografia , Sono , Síndrome , Espasmo
15.
Organometallics ; 42(19): 2826-2838, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37842181

RESUMO

Reactions of complexes [MoMCp(µ-PMes*)(CO)6] with H2 and several p-block element (E) hydrides mostly resulted in the cleavage of E-H bonds under mild conditions [M = Re (1a) and Mn (1b); Mes* = 2,4,6-C6H2tBu3]. The reaction with H2 (ca. 4 atm) proceeded even at 295 K to give the hydrides [MoMCp(µ-H)(µ-PHMes*)(CO)6]. The same result was obtained in the reactions with H3SiPh and, for 1a, upon reduction with Na(Hg) followed by protonation of the resulting anion [MoReCp(µ-PHMes*)(CO)6]-. The latter reacted with [AuCl{P(p-tol)3}] to yield the related heterotrimetallic cluster [MoReAuCp(µ-PHMes*)(CO)6{P(p-tol)3}]. The reaction of 1a with thiophenol gave the thiolate-bridged complex [MoReCp(µ-PHMes*)(µ-SPh)(CO)6], which evolved readily to the pentacarbonyl derivative [MoReCp(µ-PHMes*)(µ-SPh)(CO)5]. In contrast, no P-H bond cleavage was observed in reactions of complexes 1a,b with PHCy2, which just yielded the substituted derivatives [MoMCp(µ-PMes*)(CO)5(PHCy2)]. Reactions with HSnPh3 again resulted in E-H bond cleavage, but now with the stannyl group terminally bound to M, while 1a reacted with BH3·PPh3 to give the hydride-bridged derivatives [MoReCp(µ-H)(µ-PHMes*)(CO)5(PPh3)] and [MoReCp(µ-H){µ-P(CH2CMe2)C6H2tBu2}(CO)5(PPh3)], which follow from hydrogenation, C-H cleavage, and CO/PPh3 substitution steps. Density functional theory calculations on the PPh-bridged analogue of 1a revealed that hydrogenation likely proceeds through the addition of H2 to the Mo=P double bond of the complex, followed by rearrangement of the Mo fragment to drive the resulting terminal hydride into a bridging position.

16.
Acta Crystallogr C Struct Chem ; 79(Pt 10): 395-398, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37725081

RESUMO

Some of us reported previously the structure of di-µ-carbonyl-bis[tricarbonyl(pyridine)technetium], [Tc2(µ-CO)2(C5H5N)2(CO)6], as the main product of the reaction of [Tc2(CO)10] with pyridine at room temperature, using the reagent itself as solvent [Zuhayra et al. (2008). Inorg. Chem. 47, 10177-10182]. On the basis of an X-ray analysis of the product, a molecular structure was proposed with two bridging carbonyls displaying very unusual geometrical features, not explained at the time. Subsequent chemical considerations, coupled with density functional theory (DFT) calculations, prompted us to revise the original structure determination. Using the original raw diffraction data, we have now performed new refinements to show that the previously proposed `bridging carbonyls' actually correspond to bridging methoxide groups, and that the crystals analyzed at the time therefore would correspond to the complex di-µ-methoxido-bis[tricarbonyl(pyridine)technetium], syn-[Tc2(µ-OMe)2(NC5H5)2(CO)6]. This methoxide-bridged complex likely was a minor side product formed along with the main product in the above reaction, perhaps due to the presence of trace amounts of methanol and air in the reaction mixture.

17.
Arch. cardiol. Méx ; 93(3): 348-354, jul.-sep. 2023. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1513589

RESUMO

Resumen El soporte nutricional (SN) en pacientes adultos que reciben terapia de oxigenación por membrana extracorpórea (ECMO, extracorporeal membrane oxygenation) es controvertido. Si bien existen guías para el SN en pacientes pediátricos con ECMO, en adultos no se cuenta con estos lineamientos para el uso, tipo, ruta y momento de la terapia nutricional. En pacientes críticamente enfermos es bien sabido que la nutrición enteral (NE) temprana es beneficiosa, no obstante existe la posibilidad de que en pacientes con ECMO la NE temprana condicione complicaciones gastrointestinales. Asimismo, no se han establecido metas calóricas, proteicas y dosis o tipos de micronutrimentos que usar para esta población en específico, siendo un reto para el clínico encargado de brindar el SN. Aunado a esto los pacientes con ECMO son algunos de los más gravemente enfermos en las unidades de cuidados intensivos, donde la desnutrición se asocia con una mayor morbilidad y mortalidad. En cuanto al uso de nutrición parenteral (NP), no se tiene descrito si implica riesgo de falla en el circuito al momento de introducir lípidos al oxigenador. Por lo anterior es imperativa una correcta evaluación e intervención nutricional específica, realizada por expertos en el tema para mejorar el pronóstico y la calidad de vida en esta población, siendo un objetivo primordial en los cuidados de los pacientes adultos que reciben terapia de ECMO.


Abstract Nutritional support in adult patients receiving extracorporeal membrane oxygenation (ECMO) therapy is controversial. Although there are guidelines for the NS (Nutritional support) in pediatric patients with ECMO, in adults these guidelines are not available for the use, type, route and timing of nutritional therapy. In critically ill patients it is well known that early enteral nutrition is beneficial, however there is the possibility that in patients with ECMO early enteral nutrition leads to gastrointestinal complications. Likewise, there have not been established caloric targets, proteins and doses or types of micronutrients to use for this specific population being a challenge for the clinician. In addition, patients with ECMO are some of the most seriously ill in intensive care units, where malnutrition is associated with increased morbidity and mortality. Regarding the use of parenteral nutrition (NP) it has not been described if it implies a risk of circuit failure at the time of introducing lipids to the oxygenator. Therefore, a correct evaluation and specific nutritional intervention by experts in the field is imperative to improve the prognosis and quality of life in this population, which is a primary goal in the care of adult patients receiving extracorporeal membrane oxygen.

18.
Organometallics ; 42(15): 2052-2064, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37592950

RESUMO

Reactions of [MoReCp(µ-PMes*)(CO)6] with internal alkynes RC≡CR yielded the phosphapropenylidene-bridged complexes [MoReCp(µ-κ2P,C:η3-PMes*CRCR)(CO)5] (Mes* = 2,4,6-C6H2tBu3; R = CO2Me, Ph). Terminal alkynes HC≡CR1 gave mixtures of isomers [MoReCp(µ-κ2P,C:η3-PMes*CHCR1)(CO)5] and [MoReCp(µ-κ2P,C:η3-PMes*CR1CH)(CO)5], with the first isomer being major (R1 = CO2Me) or unique (R1 = tBu), indicating the relevance of steric repulsions during the [2 + 2] cycloaddition step between Mo=P and C≡C bonds in these reactions. Similar reactions were observed for [MoMnCp(µ-PMes*)(CO)6]. Addition of ligands to these complexes promoted rearrangement of the phosphapropenylidene ligand into the allyl-like µ-η3:κ1C mode, as shown by the reaction of [MoReCp(µ-κ2P,C:η3-PMes*CHC(CO2Me)}(CO)5] with CN(p-C6H4OMe) to give [MoReCp{µ-η3:κ1C-PMes*CHC(CO2Me)}(CO)5{CN(p-CH4OMe)}2]. The MoRe phosphinidene complex reacted with S=C=NPh to give as major products the phosphametallacyclic complex [MoReCp{µ-κ2P,S:κ2P,S-PMes*C(NPh)S}(CO)5] and its thiophosphinidene-bridged isomer [MoReCp(µ-η2:κ1S-SPMes*)(CO)5(CNPh)]. The first product follows from a [2 + 2] cycloaddition between Mo=P and C=S bonds, with specific formation of P-C bonds, whereas the second one would arise from the alternative cycloaddition involving the formation of P-S bonds, more favored on steric grounds. The prevalence of the µ-η2:κ1S coordination mode of the SPMes* ligand over the µ-η2:κ1p mode was investigated theoretically to conclude that steric congestion favors the first mode, while the kinetic barrier for interconversion between isomers is low in any case.

19.
J Phys Chem Lett ; 14(32): 7256-7263, 2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37555761

RESUMO

Calculating observable properties of chemical systems is often classically intractable and widely viewed as a promising application of quantum information processing. Here, we introduce a new framework for solving generic quantum chemical dynamics problems using quantum logic. We experimentally demonstrate a proof-of-principle instance of our method using the QSCOUT ion-trap quantum computer, where we experimentally drive the ion-trap system to emulate the quantum wavepacket dynamics corresponding to the shared-proton within an anharmonic hydrogen bonded system. Following the experimental creation and propagation of the shared-proton wavepacket on the ion-trap, we extract measurement observables such as its time-dependent spatial projection and its characteristic vibrational frequencies to spectroscopic accuracy (3.3 cm-1 wavenumbers, corresponding to >99.9% fidelity). Our approach introduces a new paradigm for studying the chemical dynamics and vibrational spectra of molecules and opens the possibility to describe the behavior of complex molecular processes with unprecedented accuracy.

20.
Arch Cardiol Mex ; 93(3): 348-354, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37562137

RESUMO

Nutritional support in adult patients receiving extracorporeal membrane oxygenation (ECMO) therapy is controversial. Although there are guidelines for the NS (Nutritional support) in pediatric patients with ECMO, in adults these guidelines are not available for the use, type, route and timing of nutritional therapy. In critically ill patients it is well known that early enteral nutrition is beneficial, however there is the possibility that in patients with ECMO early enteral nutrition leads to gastrointestinal complications. Likewise, there have not been established caloric targets, proteins and doses or types of micronutrients to use for this specific population being a challenge for the clinician. In addition, patients with ECMO are some of the most seriously ill in intensive care units, where malnutrition is associated with increased morbidity and mortality. Regarding the use of parenteral nutrition (NP) it has not been described if it implies a risk of circuit failure at the time of introducing lipids to the oxygenator. Therefore, a correct evaluation and specific nutritional intervention by experts in the field is imperative to improve the prognosis and quality of life in this population, which is a primary goal in the care of adult patients receiving extracorporeal membrane oxygen.


El soporte nutricional (SN) en pacientes adultos que reciben terapia de oxigenación por membrana extracorpórea (ECMO, extracorporeal membrane oxygenation) es controvertido. Si bien existen guías para el SN en pacientes pediátricos con ECMO, en adultos no se cuenta con estos lineamientos para el uso, tipo, ruta y momento de la terapia nutricional. En pacientes críticamente enfermos es bien sabido que la nutrición enteral (NE) temprana es beneficiosa, no obstante existe la posibilidad de que en pacientes con ECMO la NE temprana condicione complicaciones gastrointestinales. Asimismo, no se han establecido metas calóricas, proteicas y dosis o tipos de micronutrimentos que usar para esta población en específico, siendo un reto para el clínico encargado de brindar el SN. Aunado a esto los pacientes con ECMO son algunos de los más gravemente enfermos en las unidades de cuidados intensivos, donde la desnutrición se asocia con una mayor morbilidad y mortalidad. En cuanto al uso de nutrición parenteral (NP), no se tiene descrito si implica riesgo de falla en el circuito al momento de introducir lípidos al oxigenador. Por lo anterior es imperativa una correcta evaluación e intervención nutricional específica, realizada por expertos en el tema para mejorar el pronóstico y la calidad de vida en esta población, siendo un objetivo primordial en los cuidados de los pacientes adultos que reciben terapia de ECMO.


Assuntos
Oxigenação por Membrana Extracorpórea , Desnutrição , Adulto , Humanos , Criança , Qualidade de Vida , Nutrição Parenteral , Unidades de Terapia Intensiva
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA