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1.
J Clin Monit Comput ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38451341

RESUMO

Elderly and multimorbid patients are at high risk for developing unfavorable postoperative neurocognitive outcomes; however, well-adjusted and EEG-guided anesthesia may help titrate anesthesia and improve postoperative outcomes. Over the last decade, dexmedetomidine has been increasingly used as an adjunct in the perioperative setting. Its synergistic effect with propofol decreases the dose of propofol needed to induce and maintain general anesthesia. In this pilot study, we evaluate two highly standardized anesthetic regimens for their potential to prevent burst suppression and postoperative neurocognitive dysfunction in a high-risk population. Prospective, randomized clinical trial with non-blinded intervention. Operating room and post anesthesia care unit at Hospital Base San José, Osorno/Universidad Austral, Valdivia, Chile. 23 patients with scheduled non-neurologic, non-cardiac surgeries with age > 69 years and a planned intervention time > 60 min. Patients were randomly assigned to receive either a propofol-remifentanil based anesthesia or an anesthetic regimen with dexmedetomidine-propofol-remifentanil. All patients underwent a slow titrated induction, followed by a target controlled infusion (TCI) of propofol and remifentanil (n = 10) or propofol, remifentanil and continuous dexmedetomidine infusion (n = 13). We compared the perioperative EEG signatures, drug-induced changes, and neurocognitive outcomes between two anesthetic regimens in geriatric patients. We conducted a pre- and postoperative Montreal Cognitive Assessment (MoCa) test and measured the level of alertness postoperatively using a sedation agitation scale to assess neurocognitive status. During slow induction, maintenance, and emergence, burst suppression was not observed in either group; however, EEG signatures differed significantly between the two groups. In general, EEG activity in the propofol group was dominated by faster rhythms than in the dexmedetomidine group. Time to responsiveness was not significantly different between the two groups (p = 0.352). Finally, no significant differences were found in postoperative cognitive outcomes evaluated by the MoCa test nor sedation agitation scale up to one hour after extubation. This pilot study demonstrates that the two proposed anesthetic regimens can be safely used to slowly induce anesthesia and avoid EEG burst suppression patterns. Despite the patients being elderly and at high risk, we did not observe postoperative neurocognitive deficits. The reduced alpha power in the dexmedetomidine-treated group was not associated with adverse neurocognitive outcomes.

2.
Int J Mol Sci ; 25(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38203762

RESUMO

Botrytis cinerea is a necrotrophic fungus that can cause gray mold in over 1400 plant species. Once it is detected by Arabidopsis thaliana, several defense responses are activated against this fungus. The proper activation of these defenses determines plant susceptibility or resistance. It has been proposed that the RAC/ROP small GTPases might serve as a molecular link in this process. In this study, we investigate the potential role of the Arabidopsis RAC7 gene during infection with B. cinerea. For that, we evaluated A. thaliana RAC7-OX lines, characterized by the overexpression of the RAC7 gene. Our results reveal that these RAC7-OX lines displayed increased susceptibility to B. cinerea infection, with enhanced fungal colonization and earlier lesion development. Additionally, they exhibited heightened sensitivity to bacterial infections caused by Pseudomonas syringae and Pectobacterium brasiliense. By characterizing plant canonical defense mechanisms and performing transcriptomic profiling, we determined that RAC7-OX lines impaired the plant transcriptomic response before and during B. cinerea infection. Global pathway analysis of differentially expressed genes suggested that RAC7 influences pathogen perception, cell wall homeostasis, signal transduction, and biosynthesis and response to hormones and antimicrobial compounds through actin filament modulation. Herein, we pointed out, for first time, the negative role of RAC7 small GTPase during A. thaliana-B. cinerea interaction.


Assuntos
Arabidopsis , Proteínas Monoméricas de Ligação ao GTP , Citoesqueleto de Actina , Arabidopsis/genética , Sistema Imunitário , Proteínas Monoméricas de Ligação ao GTP/genética , Transdução de Sinais
3.
PLoS One ; 18(12): e0294334, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38060483

RESUMO

Reactive oxygen species (ROS), produced by NADPH oxidases known as RBOHs in plants, play a key role in plant development, biotic and abiotic stress responses, hormone signaling, and reproduction. Among the subfamily of receptor-like kinases referred to as CrRLK, there is FERONIA (FER), a regulator of RBOHs, and FER requires a GPI-modified membrane protein produced by LORELEI (LRE) or LORELEI-like proteins (LLG) to reach the plasma membrane and generate ROS. In Arabidopsis, AtLLG1 is involved in interactions with microbes as AtLLG1 interacts with the flagellin receptor (FLS2) to trigger the innate immune response, but the role of LLGs in mutualistic interactions has not been examined. In this study, two Phaseolus vulgaris LLG genes were identified, PvLLG2 that was expressed in floral tissue and PvLLG1 that was expressed in vegetative tissue. Transcripts of PvLLG1 increased during rhizobial nodule formation peaking during the early period of well-developed nodules. Also, P. vulgaris roots expressing pPvLLG1:GFP-GUS showed that this promoter was highly active during rhizobium infections, and very similar to the subcellular localization using a construct pLLG1::PvLLG1-Neon. Compared to control plants, PvLLG1 silenced plants had less superoxide (O2-) at the root tip and elongation zone, spotty hydrogen peroxide (H2O2) in the elongation root zone, and significantly reduced root hair length, nodule number and nitrogen fixation. Unlike control plants, PvLLG1 overexpressing plants showed superoxide beyond the nodule meristem, and significantly increased nodule number and nodule diameter. PvLLG1 appears to play a key role during this mutualistic interaction, possibly due to the regulation of the production and distribution of ROS in roots.


Assuntos
Phaseolus , Rhizobium tropici , Rhizobium , Rhizobium tropici/genética , Rhizobium tropici/metabolismo , Nódulos Radiculares de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo , Peróxido de Hidrogênio/metabolismo , Simbiose/genética , Rhizobium/genética , Raízes de Plantas/metabolismo
4.
Appl Environ Microbiol ; 89(12): e0149123, 2023 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-37966212

RESUMO

IMPORTANCE: Many parameters affect phage-bacteria interaction. Some of these parameters depend on the environment in which the bacteria are present. Anaerobiosis effect on phage infection in facultative anaerobic bacteria has not yet been studied. The absence of oxygen triggers metabolic changes in facultative bacteria and this affects phage infection and viral life cycle. Understanding how an anaerobic environment can alter the behavior of phages during infection is relevant for the phage therapy success.


Assuntos
Bacteriófagos , Anaerobiose , Bactérias
5.
Nanoscale ; 15(42): 17113-17123, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37850381

RESUMO

Self-assembled monolayers composed of various long-chain aliphatic molecules and different tail functional groups have been synthesized on the Au(111) surface and characterized by Kelvin probe force microscopy and ultraviolet photoelectron spectroscopy. Carboxy, amino, thio and methyl terminal groups have been considered in the design of self-assembled monolayers with different aliphatic chain lengths (from C6 to C16). Work function measurements by Kelvin probe force microscopy have been carried out under a controlled and room atmosphere. Remarkably, a reduction of the relative humidity from 40% to 3% has induced a work function shift of up to 0.3 eV. As expected, the changes of the chain length of the aliphatic moiety and of the tail group have a significant impact on the tuning of the measured work function (3.90 eV for dodecanethiol versus 4.57 eV for mercaptohexadecylamine). Surprisingly, the change of the net dipole moment of the tail group (sign and amplitude) does not dominate the work function variations. In contrast, the change of the chain length and the possibility of the tail group to form a complex hydrogen bond network between molecules lead to significant modulations of the work function. In order to interpret these original findings, density functional theory models of equivalent self-assembled monolayers adsorbed on the Au(111) surface have been developed at an unprecedented level of description with large supercells including simultaneously 27 co-adsorbed molecules and weak van der Waals interactions between them. Such large systems have allowed the theoretical modeling of complex hydrogen bond networks between molecules when possible (carboxy tail group). The comparison between computed and measured work functions shows a striking agreement, thus allowing the disentanglement of the previously mentioned competing effects. This consistency between experiment and theory will help in designing the electronic properties of self-assembled monolayers in the context of molecular electronics and organic transistors.

6.
JAMA ; 330(20): 1982-1990, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37877609

RESUMO

Importance: Among patients receiving mechanical ventilation, tidal volumes with each breath are often constant or similar. This may lead to ventilator-induced lung injury by altering or depleting surfactant. The role of sigh breaths in reducing ventilator-induced lung injury among trauma patients at risk of poor outcomes is unknown. Objective: To determine whether adding sigh breaths improves clinical outcomes. Design, Setting, and Participants: A pragmatic, randomized trial of sigh breaths plus usual care conducted from 2016 to 2022 with 28-day follow-up in 15 academic trauma centers in the US. Inclusion criteria were age older than 18 years, mechanical ventilation because of trauma for less than 24 hours, 1 or more of 5 risk factors for developing acute respiratory distress syndrome, expected duration of ventilation longer than 24 hours, and predicted survival longer than 48 hours. Interventions: Sigh volumes producing plateau pressures of 35 cm H2O (or 40 cm H2O for inpatients with body mass indexes >35) delivered once every 6 minutes. Usual care was defined as the patient's physician(s) treating the patient as they wished. Main Outcomes and Measures: The primary outcome was ventilator-free days. Prespecified secondary outcomes included all-cause 28-day mortality. Results: Of 5753 patients screened, 524 were enrolled (mean [SD] age, 43.9 [19.2] years; 394 [75.2%] were male). The median ventilator-free days was 18.4 (IQR, 7.0-25.2) in patients randomized to sighs and 16.1 (IQR, 1.1-24.4) in those receiving usual care alone (P = .08). The unadjusted mean difference in ventilator-free days between groups was 1.9 days (95% CI, 0.1 to 3.6) and the prespecified adjusted mean difference was 1.4 days (95% CI, -0.2 to 3.0). For the prespecified secondary outcome, patients randomized to sighs had 28-day mortality of 11.6% (30/259) vs 17.6% (46/261) in those receiving usual care (P = .05). No differences were observed in nonfatal adverse events comparing patients with sighs (80/259 [30.9%]) vs those without (80/261 [30.7%]). Conclusions and Relevance: In a pragmatic, randomized trial among trauma patients receiving mechanical ventilation with risk factors for developing acute respiratory distress syndrome, the addition of sigh breaths did not significantly increase ventilator-free days. Prespecified secondary outcome data suggest that sighs are well-tolerated and may improve clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02582957.


Assuntos
Síndrome do Desconforto Respiratório , Lesão Pulmonar Induzida por Ventilação Mecânica , Humanos , Masculino , Adulto , Adolescente , Feminino , Respiração , Ventiladores Mecânicos , Pacientes Internados , Síndrome do Desconforto Respiratório/terapia
7.
Front Plant Sci ; 14: 1152493, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37465390

RESUMO

Arbuscular mycorrhizal (AM) fungi and rhizobia form two of the most important plant-microbe associations for the assimilation of phosphorus (P) and nitrogen (N). Symbiont-derived signals are able to coordinate the infection process by triggering multiple responses in the plant root, such as calcium influxes and oscillations, increased reactive oxygen species (ROS), cytoskeletal rearrangements and altered gene expression. An examination was made of the role of tetraspanins, which are transmembrane proteins that self-organize into tetraspanin web regions, where they recruit specific proteins into platforms required for signal transduction, membrane fusion, cell trafficking, and ROS generation. In plant cells, tetraspanins are scaffolding proteins associated with root radial patterning, biotic and abiotic stress responses, cell fate determination, plasmodesmata and hormonal regulation. Some plant tetraspanins, such as Arabidopsis thaliana TETRASPANIN 8 and TETRASPANIN 9 (AtTET8 and AtTET9) are associated with exosomes during inter-kingdom communication. In this study, a homolog of AtTET8, PvTET8-1, in common bean (Phaseolus vulgaris L. var. Negro Jamapa) was examined in roots during interactions with Rhizobium tropici and Rhizophagus irregularis. The promoter of PvTET8-1 contained several cis-acting regulatory DNA elements potentially related to mutualistic interactions, and PvTET8-1 was transcriptionally activated during AM fungal and rhizobial associations. Silencing it decreased the size and number of nodules, nitrogen fixation, and mycorrhizal arbuscule formation, whereas overexpressing it increased the size and number of nodules, and mycorrhizal arbuscule formation but decreased nitrogen fixation. PvTET8-1 appears to be an important element in both of these mutualistic interactions, perhaps through its interaction with NADPH oxidase and the generation of ROS during the infection processes.

8.
Plant Physiol ; 193(2): 1508-1526, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37427869

RESUMO

Legume roots can be symbiotically colonized by arbuscular mycorrhizal (AM) fungi and nitrogen-fixing bacteria. In Lotus japonicus, the latter occurs intracellularly by the cognate rhizobial partner Mesorhizobium loti or intercellularly with the Agrobacterium pusense strain IRBG74. Although these symbiotic programs show distinctive cellular and transcriptome signatures, some molecular components are shared. In this study, we demonstrate that 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase 1 (DAHPS1), the first enzyme in the biosynthetic pathway of aromatic amino acids (AAAs), plays a critical role in root hair development and for AM and rhizobial symbioses in Lotus. Two homozygous DAHPS1 mutants (dahps1-1 and dahps1-2) showed drastic alterations in root hair morphology, associated with alterations in cell wall dynamics and a progressive disruption of the actin cytoskeleton. The altered root hair structure was prevented by pharmacological and genetic complementation. dahps1-1 and dahps1-2 showed significant reductions in rhizobial infection (intracellular and intercellular) and nodule organogenesis and a delay in AM colonization. RNAseq analysis of dahps1-2 roots suggested that these phenotypes are associated with downregulation of several cell wall-related genes, and with an attenuated signaling response. Interestingly, the dahps1 mutants showed no detectable pleiotropic effects, suggesting a more selective recruitment of this gene in certain biological processes. This work provides robust evidence linking AAA metabolism to root hair development and successful symbiotic associations.


Assuntos
Lotus , Micorrizas , Lotus/microbiologia , Raízes de Plantas/metabolismo , Simbiose/genética , Micorrizas/fisiologia , Fenótipo , Nódulos Radiculares de Plantas/metabolismo
9.
Phytopathology ; 113(8): 1387-1393, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37081724

RESUMO

Strains of Xanthomonas citri pv. malvacearum cause bacterial blight of cotton, a potentially serious threat to cotton production worldwide, including in sub-Saharan countries. Development of disease symptoms, such as water soaking, has been linked to the activity of a class of type 3 effectors, called transcription activator-like (TAL) effectors, which induce susceptibility genes in the host's cells. To gain further insight into the global diversity of the pathogen, to elucidate their repertoires of TAL effector genes, and to better understand the evolution of these genes in the cotton-pathogenic xanthomonads, we sequenced the genomes of three African strains of X. citri pv. malvacearum using nanopore technology. We show that the cotton-pathogenic pathovar of X. citri is a monophyletic lineage containing at least three distinct genetic subclades, which appear to be mirrored by their repertoires of TAL effectors. We observed an atypical level of TAL effector gene pseudogenization, which might be related to resistance genes that are deployed to control the disease. Our work thus contributes to a better understanding of the conservation and importance of TAL effectors in the interaction with the host plant, which can inform strategies for improving resistance against bacterial blight in cotton.

10.
Methods Enzymol ; 683: 265-289, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37087192

RESUMO

Reactive oxygen species (ROS) are highly reactive reduced oxygen molecules that play a myriad of roles in animal and plant cells. In plant cells the production of ROS results from aerobic metabolism during respiration and photosynthesis. Therefore mitochondria, chloroplasts, and peroxisomes constitute an important source of ROS. However, ROS can also be produced in response to many physiological stimuli such as pathogen attack, hormone signaling, abiotic stresses or during cell wall organization and plant morphogenesis. The study of ROS in plant cells has been limited to biochemical assays and use of fluorescent probes, however, the irreversible oxidation of the fluorescent dyes prevents the visualization of dynamic changes. We have previously reported that Hyper 1 is a biosensor for H2O2 and consists of a circularly permutated YFP (cpYFP) inserted into the regulatory domain of the Escherichia coli hydrogen peroxide (H2O2) sensor protein OxyR rendering it an H2O2-specific quantitative probe (Bilan & Belousov, 2018; Hernandez-Barrera et al., 2015). Herein we describe an updated protocol for using the improved new version of Hyper 2 and Hyper 3 as a dynamic biosensor for H2O2 in Arabidopsis with virtually unlimited potential to detect H2O2 throughout the plant and under a broad range of developmental and environmental conditions (Bilan et al., 2013).


Assuntos
Peróxido de Hidrogênio , Sondas Moleculares , Animais , Peróxido de Hidrogênio/metabolismo , Espécies Reativas de Oxigênio , Células Vegetais/metabolismo , Fotossíntese
11.
Methods Enzymol ; 683: 291-308, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37087193

RESUMO

Among the biologically relevant reactive oxygen species (ROS), hydrogen peroxide (H2O2) has special properties. H2O2 can diffuse across membranes, has a low reactivity, and is very stable. Deprotonated cysteine residues in proteins can be oxidized by H2O2 into a highly reactive sulfenic acid derivative (-SOH), which can react with another cysteine to form a disulfide. Under higher oxidative stress the sulfenic acid undergo further oxidation to sulfinic acid (Cys-SO2H), which can subsequently be reduced. The sulfinic acid can be hyperoxidized to sulfonic acid (Cys-SO3H), whose reduction is irreversible. Formation of sulfenic acids can have a role in sensing oxidative stress, signal transduction, modulating localization and activity to regulate protein functions. Therefore, there is an emerging interest in trying to understand the pool of proteins that result in these sorts of modification in response to oxidative stress. This is known as the sulfenome and several approaches have been developed in animal and plant cells to analyze the sulfenome under different stress responses. These approaches can be proteomic, molecular, immunological (i.e., antibodies), or expressing genetically encoded probes that specifically react to sulfenic modifications. In this chapter, we describe an additional approach that allows visualization of sulfenic modification in vivo. This is newly developed fluorescent probe DCP-Rho1 can be implemented in any plant cell to analyze the sulfenic modification.


Assuntos
Cisteína , Ácidos Sulfênicos , Animais , Ácidos Sulfênicos/química , Cisteína/química , Corantes Fluorescentes , Células Vegetais/metabolismo , Peróxido de Hidrogênio/química , Proteômica , Ácidos Sulfínicos , Proteínas/química , Oxirredução
12.
Rev. medica electron ; 45(2)abr. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1442027

RESUMO

Introducción: el 1 de enero de 1899 inició la ocupación militar de Cuba por Estados Unidos, cuyo objetivo fundamental fue sentar las bases de la futura República neocolonial. Objetivo: describir el comportamiento de la salud pública matancera durante el período de ocupación militar norteamericana 1899-1902. Materiales y métodos: se utilizó el método histórico descriptivo para estudiar el comportamiento de la salud pública matancera en el período de ocupación militar, y se realizó la revisión bibliográfica y documental. Resultados: no obstante los logros sociales -en especial en el ámbito de la salud pública-, las medidas y posiciones antinacionales que adoptó el gobierno interventor encontraron el rechazo de las clases y sectores interesados en lograr la absoluta soberanía de Cuba. Conclusiones: los matanceros realizaron notables esfuerzos para enfrentar la difícil situación sanitaria a través de la apertura de hospitales e instituciones, que brindaban servicios, sobre todo, a los sectores pobres de la población, y de la campaña de higienización para evitar la propagación de enfermedades y epidemias.


Introduction: the period of U.S. military occupation in Cuba officially began on January 1, 1899. Its main objective was to lay the foundation of the future neocolonial republic. Objective: to describe the behavior of Matanzas public health during the period of the US military occupation 1899-1902. Materials and methods: the historical descriptive method was used to study the behavior of Matanzas public health in the period of military occupation, and a bibliographic and documental review was conducted. Results: despite the social achievements- especially in the field of public health-, antinational measures and positions adopted by the intervening government found the rejection of the classes and sectors interested in achieving the absolute sovereignty of Cuba. Conclusions: the people of Matanzas made notable efforts to face the difficult sanitary situation opening hospitals and institutions which provided services, above all, to the poor sectors of the population, and to carry out a sanitation campaign to prevent the spread of diseases and epidemics.

13.
Int J Mol Sci ; 24(6)2023 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-36982308

RESUMO

Legumes associate with Gram-negative soil bacteria called rhizobia, resulting in the formation of a nitrogen-fixing organ, the nodule. Nodules are an important sink for photosynthates for legumes, so these plants have developed a systemic regulation mechanism that controls their optimal number of nodules, the so-called autoregulation of nodulation (AON) pathway, to balance energy costs with the benefits of nitrogen fixation. In addition, soil nitrate inhibits nodulation in a dose-dependent manner, through systemic and local mechanisms. The CLE family of peptides and their receptors are key to tightly controlling these inhibitory responses. In the present study, a functional analysis revealed that PvFER1, PvRALF1, and PvRALF6 act as positive regulators of the nodule number in growth medium containing 0 mM of nitrate but as negative regulators in medium with 2 and 5 mM of nitrate. Furthermore, the effect on nodule number was found to be consistent with changes in the expression levels of genes associated with the AON pathway and with the nitrate-mediated regulation of nodulation (NRN). Collectively, these data suggest that PvFER1, PvRALF1, and PvRALF6 regulate the optimal number of nodules as a function of nitrate availability.


Assuntos
Phaseolus , Nodulação , Nodulação/genética , Nódulos Radiculares de Plantas/metabolismo , Phaseolus/genética , Phaseolus/metabolismo , Nitratos/farmacologia , Nitratos/metabolismo , Peptídeos/metabolismo , Simbiose , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
14.
Wound Manag Prev ; 68(12): 20-24, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36493363

RESUMO

BACKGROUND: Standardized treatment of split-thickness skin graft (STSG) donor sites is not established. Bleeding can necessitate premature dressing changes, interrupting the healing process and increasing pain. PURPOSE: A collagen/oxidized regenerated cellulose (C/ORC) dressing was used on the donor site. The authors hypothesized that the collagen matrix could decrease bleeding-related complications, reduce pain, and foster epithelialization. METHODS: The C/ORC matrix was applied to the donor site after hemostasis was achieved. Dressings were removed between postoperative days 4 and 7, and the patients' pain levels, bleeding complications, and percentage healed were recorded. RESULTS: Thirty-nine patients were treated with the C/ORC donor site dressing. Of these, 35 patients (89.7%) were receiving at least prophylactic anticoagulation, and no bleeding complications were recorded. The average area of donor sites was 123.8 cm2 (range, 20-528 cm2). Utilizing the Numerical Rating Scale, 25 patients (64.1%) reported no pain with dressing removal while 5 (12.8%) reported a decrease in pain. The percentage of epithelialization as assessed by treating clinician was at least equivalent to other modalities. CONCLUSIONS: The application of a C/ORC matrix to STSG donor wound sites resulted in no bleeding complications and excellent pain control while promoting epithelialization in the patients studied. Following this study, the C/ORC dressing has been incorporated into the authors' standard protocol.


Assuntos
Celulose Oxidada , Transplante de Pele , Humanos , Transplante de Pele/efeitos adversos , Transplante de Pele/métodos , Celulose Oxidada/farmacologia , Celulose Oxidada/uso terapêutico , Projetos Piloto , Manejo da Dor , Colágeno/uso terapêutico
15.
RSC Adv ; 12(44): 28712-28719, 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36320491

RESUMO

Copolymerizations of ethylene and alfa-olefins, using Ziegler-Natta or metallocene catalysts, testing two methods of co-monomer addition, through batch or dossing mode during the reactions, are reported in this work. Copolymerizations are monitored by in line Raman spectroscopy, comparing the effect of the kind of catalyst and the co-monomer addition modes on the chemical composition of the copolymers produced. The global co-monomer composition is determined by 13C NMR spectroscopy, compared with the monitoring by Raman spectroscopy along the reactions, where it is possible to define homogeneous or heterogeneous co-monomer distributions. Batch addition achieves higher incorporations of co-monomers, compared to dosed addition, where it is possible to determine the maximal co-monomer addition without affecting activities by transfer reactions. The incorporation mode of alfa-olefins in this type of reaction has been little reported, and until it is known, there is no rapid technique available to determine the uniformity of the co-monomer incorporations in real time. Copolymerization kinetics are also reported here and correlated to the addition method of the comonomers in both kinds of reactions. Homogeneous and heterogeneous co-monomer incorporations promoted by a single site catalyst (metallocene) or multisite system (Ziegler-Natta) is related to the homogeneous or heterogeneous co-monomer distributions detected by Raman spectroscopy, using each kind of catalytic system.

17.
Phys Chem Chem Phys ; 24(37): 22815-22822, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36112061

RESUMO

A sequential analysis using Ultra-violet Photoelectron Spectroscopy (UPS) and X-ray Photoelectron Spectroscopy (XPS) on ceria nanopowders has been implemented to identify the influence of the X-ray beam on the surface of this oxide. For the first time, UPS analysis evidenced the photoreductive effect of XPS analysis on ceria after an oxidative in situ pretreatment, leading to an overestimation of the Ce3+/Ce4+ ratio obtained by XPS. Based on this spectroscopy methodology, UPS imposes itself as a leading technique for analyzing powders with minimal impact on the authentic chemical state, thus paving the way for identifying the real ratio of Ce4+ and Ce3+ of ceria after oxidative and reductive in situ treatments.

18.
Rev. Fac. Med. Hum ; 22(3): 489-496, julio-Septiembre 2022.
Artigo em Inglês, Espanhol | LILACS-Express | LILACS | ID: biblio-1381848

RESUMO

Introducción: La macrosomía fetal es una condición del embarazo que genera complicaciones a corto, mediano y largo plazo para el feto, en recién nacido y la madre. Objetivos: Determinar los factores maternos asociados a macrosomía fetal según la encuesta nacional de demografía y salud familiar de 2020 Métodos: Estudio observacional, retrospectivo, analítico, transversal que se realizó basado en la encuesta ENDES en el período 2020, utilizando los datos de 5096 mujeres de 12-49 años que cumplieron con los criterios establecidos. Para el análisis estadístico se empleó el SPSS versión 25, la prueba F corregida para muestras complejas y un nivel de significancia menor de 0,05. Resultados: La prevalencia de macrosomía fetal es de 7.5%. El análisis multivariado encontró que, dentro de los factores personales, la edad materna tiene asociación significativa con la macrosomía fetal (RPa 1.04, IC 95% 1.008 ­ 1.078). De los factores patológicos, la obesidad materna tiene asociación significativa con la macrosomía fetal (RPa 1.05, IC 95% 1.027 ­ 1.080). De los factores sociales y demográficos asociados a macrosomía fetal, ninguna variable descrita muestra asociación significativa. Conclusión: Se determinó que la edad materna mayor de 34 años y la obesidad materna son factores asociados a presentar mayor prevalencia de macrosomía fetal.


Introduction: Fetal macrosomia is an embarrassing condition that causes complications in short, medium and wide placenta for the fetus, both pregnant and pregnant. Objectives: To determine the maternal factors associated with fetal macrosomia following the national demographic and health survey 2020. Materials and methods: Observational, retrospective, analytical, cross-sectional study carried out in the ENDES survey in the period 2020 to 5096 women aged 12 to 49 years who they meet the established criteria. For the statistical analysis, SPSS version 25 is used, the F sample corrected for complete samples and a significance level of 0.05. Results: The prevalence of fetal macrosomia is 7.5%. Multivariate analysis found that, among personal factors, maternal edema has a significant association with fetal macrosomia (RPa 1.04, 95% IC 1.008 - 1.078). Of the pathological factors, maternal obesity has a significant association with fetal macrosomia (RPa 1.05, 95% CI 1.027 - 1.080). Of the social and demographic factors associated with fetal macrosomia, no variable describes a significant association. Conclusion: It was determined that maternal age over 34 years and maternal obesity are factors associated with a higher prevalence of fetal macrosomia.

19.
Crit Care Explor ; 4(5): e0690, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35510150

RESUMO

OBJECTIVES: Acute respiratory distress syndrome is treated by utilizing a lung protective ventilation strategy. Obesity presents with additional physiologic considerations, and optimizing ventilator settings may be limited with traditional means. Transpulmonary pressure (PL) obtained via esophageal manometry may be more beneficial to titrating positive end-expiratory pressure (PEEP) in this population. We sought to determine the feasibility and impact of implementation of a protocol for use of esophageal balloon to set PEEP in obese patients in a community ICU. DESIGN: Retrospective cohort study of obese (body mass index [BMI] ≥ 35 kg/m2) patients undergoing individualized PEEP titration with esophageal manometry. Data were extracted from electronic health record, and Wilcoxon signed rank test was performed to determine whether there were differences in the ventilatory parameters over time. SETTING: Intensive care unit in a community based hospital system in Newark, Delaware. PATIENTS: Twenty-nine mechanically ventilated adult patients with a median BMI of 45.8 kg/m2 with acute respiratory distress syndrome (ARDS). INTERVENTION: Individualized titration of PEEP via esophageal catheter obtained transpulmonary pressures. MEASUREMENTS AND MAIN RESULTS: Outcomes measured include PEEP, oxygenation, and driving pressure (DP) before and after esophageal manometry at 4 and 24 hr. Clinical outcomes including adverse events (pneumothorax and pneumomediastinum), increased vasopressor use, rescue therapies (inhaled pulmonary vasodilators, extracorporeal membrane oxygenation, and new prone position), continuous renal replacement therapy, and tracheostomy were also analyzed. Four hours after PEEP titration, median PEEP increased from 12 to 20 cm H2O (p < 0.0001) with a corresponding decrease in median DP from 15 to 13 cm H2O (p = 0.002). Subsequently, oxygenation improved as median Fio2 decreased from 0.8 to 0.6 (p < 0.0001), and median oxygen saturation/Fio2 (S/F) ratio improved from 120 to 165 (p < 0.0001). One patient developed pneumomediastinum. No pneumothoraces were identified. Improvements in oxygenation continued to be seen at 24 hr, compared with the prior 4 hr mark, Fio2 (0.6-0.45; p < 0.004), and S/F ratio (165-211.11; p < 0.001). Seven patients required an increase in vasopressor support after 4 hours. Norepinephrine and epinephrine were increased by 0.05 (± 0.04) µg/kg/min and 0.02 (± 0.01) µg/kg/min on average, respectively. CONCLUSIONS: PL-guided PEEP titration in obese patients can be used to safely titrate PEEP and decrease DP, resulting in improved oxygenation.

20.
Cureus ; 14(4): e24321, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35607546

RESUMO

Introduction Negative-pressure wound therapy (NPWT) with instillation and dwell time is an accepted adjunct therapy for infected wounds. A study was conducted to assess whether the use of hypochlorous acid preserved wound cleanser (HAPWOC) (Vashe, Urgo Medical North America, Fort Worth, TX, USA) as the irrigant would reduce the cost of care in comparison to 0.9% saline (NaCl). Method A comparative, observational, retrospective analysis assessed 27 serious and infected wounds in 24 patients. The lesions were of different and complex etiologies, including necrotizing fasciitis and stage IV diabetic foot ulcers. NPWT was used as part of the overall multimodal treatment regimen. The only variance in the treatment protocol was the use of saline (N=8) or HAPWOC (N=19) as the irrigant. Results When compared to NaCl, wounds treated with HAPWOC trended toward fewer operating room (OR) visits versus NaCl (3.3 versus 4.1) and a shorter length of hospital stay (LOS) (24.3 days versus 37.9 days). The Orlando Health Transparency guide shows the cost of OR debridement as $2,525. Thus, debridement for HAPWOC-treated wounds ($8,332) costs $2,020 (24%) less than for NaCl-treated wounds ($10,352). Using the 2016 Kaiser Health data (average daily hospital cost, excludingall interventions: $2,052), the cost of HAPWOC and NaCl instill translates to $49,864 and $77,771, respectively, a difference of $27,906 (56%) more for NaCl treatment. The Agency for Healthcare Research and Quality (AHRQ) 2012 data indicate an average daily cost of hospital stay, including all interventions, of $10,400. Thus, HAPWOC treatment cost translates to $252,720 versus NaCl-related costs of $394,160; in these calculations, using NaCl costs $141.440 (+56%) more per patient than HAPWOC. Conclusion The use of NPWT with HAPWOC versus NaCl as instillation in NPWT reduces the number of visits to the operating room and LOS. This has a significant impact on lowering the cost of care when HAPWOC is used.

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