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2.
Molecules ; 26(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34500645

RESUMO

Anharmonic quantum chemical calculations were employed to simulate and interpret a near-infrared (NIR) spectrum of caffeine. First and second overtones, as well as binary and ternary combination bands, were obtained, accurately reproducing the lineshape of the experimental spectrum in the region of 10,000-4000 cm-1 (1000-2500 nm). The calculations enabled performing a detailed analysis of NIR spectra of caffeine, including weak bands due to the second overtones and ternary combinations. A highly convoluted nature of NIR spectrum of caffeine was unveiled, with numerous overlapping bands found beneath the observed spectral lineshape. To properly reflect that intrinsic complexity, the band assignments were provided in the form of heat maps presenting the contributions to the NIR spectrum from various kinds of vibrational transitions. These contributions were also quantitatively assessed in terms of the integral intensities. It was found that the combination bands provide the decisively dominant contributions to the NIR spectrum of caffeine. The first overtones gain significant importance between 6500-5500 cm-1, while the second overtones are meaningful in the higher wavenumber regions, particularly in the 10,000-7000 cm-1 region. The obtained detailed band assignments enabled deep interpretation of the absorption regions of caffeine identified in the literature as meaningful for analytical applications of NIR spectroscopy focused on quantitative analysis of caffeine content in drugs and natural products.


Assuntos
Cafeína/química , Luz , Oxigênio/química , Espectrofotometria Infravermelho/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Vibração
3.
Nanoscale ; 13(32): 13681-13692, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34477643

RESUMO

A hypoxic environment in tumors hampers the therapeutic efficacy of radiotherapy. Moreover, radiotherapy, a localized treatment technique, can barely control tumor metastases. Herein, poly(lactic-co-glycolic acid) was used to encapsulate perfluorocarbon (PFC) for increasing the oxygen level and a lignan-derived compound (Q1) for enhancing IL-25 secretion from fibroblasts, thereby boosting the radiotherapeutic effect on local and distant tumors. The prepared co-delivery nanoplatform, PFC-Q1@PLGA, has a nano-scale size of around 160 nm and a negative zeta potential (about -13 mV). PFC-Q1@PLGA treatment leads to an arrest of the G2 phase (4n) in the cell cycle and reduces the mitochondria membrane potential. A high expression level of IL-25 in fibroblasts is detected after the cells are treated with PFC-Q1@PLGA, which increases the late apoptosis percentage of 4T1 cells after treatment with IL-25-containing conditional medium from fibroblasts. The oxygen level in tumors is significantly promoted to about 52.3% after injection of oxygen-saturated PFC-Q1@PLGA (O2), which is confirmed from the functional magnetic resonance images of the tumor site in mice. The in vivo study demonstrates that the injection of PFC-Q1@PLGA (O2) into local tumors significantly enhances the radiotherapeutic effect on local tumors and also inhibits the growth of remote tumors by an enhanced abscopal effect. This study presents a novel radiotherapy strategy to enable synergistic whole-body therapeutic responses after localized treatment with PFC-Q1@PLGA (O2).


Assuntos
Fluorcarbonetos , Lignanas , Nanopartículas , Neoplasias , Animais , Camundongos , Oxigênio , Microambiente Tumoral
4.
Nanoscale ; 13(31): 13506-13518, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34477755

RESUMO

Photodynamic therapy (PDT) has evolved as an essential method for infection control, but is confronted with challenges in terms of low oxygen supply, possible toxicity during light irradiation, and nonpersistent action. Herein, to address these limitations, black phosphorus (BP) is used as a photosensitizer and decorated with Pt nanoparticles and aminobenzyl-2-pyridone (APy) moieties to obtain BP@APy-Pt. The stability of BP is improved through the capture and occupation of lone-pair electrons after reductive deposition of Pt nanoparticles and covalent conjugation of APy. Pt nanoparticles on BP@APy-Pt catalyze the decomposition of endogenous H2O2 to produce oxygen for consecutive cycles with a stable production capacity. The light exposure to BP@APy-Pt generates significantly higher 1O2 levels than those of BP/light, and the generated 1O2 is partially captured by APy moieties. The captured 1O2 during 20 min of illumination shows a constant release for 24 h in the dark. The cycled storage and release feature eliminates the toxicity of 1O2 at high levels during illumination and leads to efficient destruction of S. aureus and P. aeruginosa. Compared to the healing rates after treatment with BP/light (57.6%), BP@Pt/light (64.8%), BP@APy/light (77.8%), and BP@APy-Pt (48.5%), the skin wounds with infected S. aureus are fully healed after BP@APy-Pt/light treatment. Blood vessels and hair follicles are regenerated to resemble those of normal skin. Thus, this study expands the PDT strategy through integration with oxygen generation, 1O2 storage, and persistent release to promote bactericidal efficacy and eliminate side effects.


Assuntos
Oxigênio , Fotoquimioterapia , Homicídio , Peróxido de Hidrogênio , Fósforo , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Staphylococcus aureus
5.
J Hazard Mater ; 416: 125964, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492876

RESUMO

An ideal way to boost the selectivity of sensing materials is that improving the sensitivity of the target gas while suppressing that of other interfering ones. Here, the "screening behavior" of the Li doped WO3 nanofibers (Li/WO3 NFs) have been discovered in suppressing the response from interfering gases, while elevating the H2S sensing response. Beneficially, the H2S response of Li/WO3 NFs sensor prototype is three times (Ra / Rg = 64@10 ppm) as high as that of the pristine WO3 ones (Ra / Rg = 21@10 ppm) at ~75% relative humidity and 260 °C. Moreover, Li/WO3 NFs sensor prototype presents the detection limit as low as 100 ppb. Particularly, the Li/WO3 NFs sensors detect simulated halitosis breath, of which the accuracy is comparable with gas chromatography. Theoretically, the decrease of the responses of Li/WO3 NFs to interfering gases is ascribed to the enhancement of the adsorption of water molecules by Li dopant. While the improved response to H2S is attributed to stronger adsorption of H2S and WO3 and to the increased defect oxygen. The "screening behavior" of Li doped into WO3 NFs provides a new strategy that might improve the selectivity of other gas sensing.


Assuntos
Nanofibras , Gases , Lítio , Óxidos , Oxigênio
6.
Medicine (Baltimore) ; 100(36): e27020, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34516492

RESUMO

INTRODUCTION: The study aimed to reveal how the fraction of inspired oxygen (FIO2) affected the value of mixed venous oxygen saturation (SvO2) and the accuracy of Fick-equation-based cardiac output (Fick-CO). METHODS: Forty two adult patients who underwent elective cardiac surgery were enrolled and randomly divided into 2 groups: FIO2 < 0.7 or >0.85. Under stable general anesthesia, thermodilution-derived cardiac output (TD-CO), SvO2, venous partial pressure of oxygen, hemoglobin, arterial oxygen saturation, arterial partial pressure of oxygen, and blood pH levels were recorded before surgical incision. RESULTS: Significant differences in FIO2 values were observed between the 2 groups (0.56 ±â€Š0.08 in the <70% group and 0.92 ±â€Š0.03 in the >0.85 group; P < .001). The increasing FIO2 values lead to increases in SvO2, venous partial pressure of oxygen, and arterial partial pressure of oxygen, with little effects on cardiac output and hemoglobin levels. When comparing to TD-CO, the calculated Fick-CO in both groups had moderate Pearson correlations and similar linear regression results. Although the FIO2 <0.7 group presented a less mean bias and a smaller limits of agreement, neither group met the percentage error criteria of <30% in Bland-Altman analysis. CONCLUSION: Increased FIO2 may influence the interpretation of SvO2 and the exacerbation of Fick-CO estimation, which could affect clinical management. TRIAL REGISTRATION: ClinicalTrials.gov ID number: NCT04265924, retrospectively registered (Date of registration: February 9, 2020).


Assuntos
Débito Cardíaco , Procedimentos Cirúrgicos Cardíacos , Oxigênio/sangue , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Período Pós-Operatório , Estudos Prospectivos , Troca Gasosa Pulmonar , Adulto Jovem
7.
Mater Sci Eng C Mater Biol Appl ; 128: 112341, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474891

RESUMO

In order to maximize the retention of the photodynamic therapy (PDT) efficacy, while avoiding the dilemma of hypoxia and high reducing substances in tumor tissue, fluoropolymers were synthesized in a simple and effective methods. Fluorous effect with good oxygen carrying capacity was endowed by the fluorine-containing section in fluoropolymers and the perfluorodecalin (PFD) together, the reaction site with GSH was provided by the disulfide bond, which enhanced PDT efficiency through the sequential "AND" logic gate design. Two kind of fluorine-containing nanocarriers (M-Ce6 and E-Ce6) were obtained by solvent evaporation or ultrasound emulsification with PFD, respectively. In vitro, both of them showed promising high ROS generation under photoirradiation. Benefiting by cavitation effects, E-Ce6 had a more significant statistical difference in cellular uptake. Furthermore, the cells incubating with E-Ce6 hardly were noticed that the hypoxia signal appeared under hypoxia, while reducing the intracellular GSH content by more than 15%. Through the sequential "AND" logic gate design, ROS production even under hypoxia and GSH conditions of E-Ce6 was also almost 1.5 times that of Ce6 under normoxia. Enhancing effect of E-Ce6 was 13.47 times and 6.85 times, while selectivity ratio reached 5.13 times and 4.81 times compared with Ce6 and M-Ce6. The two-pronged strategy showed a high potential for delivering the Ce6 to deep inside of cancer cells and killing it in the simulated tumor by PDT. These above results demonstrated the potential of E-Ce6, as oxygen self-sufficiency and GSH depletion nanocarriers for combined enhancement of photodynamic therapy.


Assuntos
Fotoquimioterapia , Porfirinas , Linhagem Celular Tumoral , Flúor , Oxigênio , Fármacos Fotossensibilizantes/farmacologia
9.
Sci Rep ; 11(1): 17787, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493774

RESUMO

Despite COVID-19's significant morbidity and mortality, considering cost-effectiveness of pharmacologic treatment strategies for hospitalized patients remains critical to support healthcare resource decisions within budgetary constraints. As such, we calculated the cost-effectiveness of using remdesivir and dexamethasone for moderate to severe COVID-19 respiratory infections using the United States health care system as a representative model. A decision analytic model modelled a base case scenario of a 60-year-old patient admitted to hospital with COVID-19. Patients requiring oxygen were considered moderate severity, and patients with severe COVID-19 required intubation with intensive care. Strategies modelled included giving remdesivir to all patients, remdesivir in only moderate and only severe infections, dexamethasone to all patients, dexamethasone in severe infections, remdesivir in moderate/dexamethasone in severe infections, and best supportive care. Data for the model came from the published literature. The time horizon was 1 year; no discounting was performed due to the short duration. The perspective was of the payer in the United States health care system. Supportive care for moderate/severe COVID-19 cost $11,112.98 with 0.7155 quality adjusted life-year (QALY) obtained. Using dexamethasone for all patients was the most-cost effective with an incremental cost-effectiveness ratio of $980.84/QALY; all remdesivir strategies were more costly and less effective. Probabilistic sensitivity analyses showed dexamethasone for all patients was most cost-effective in 98.3% of scenarios. Dexamethasone for moderate-severe COVID-19 infections was the most cost-effective strategy and would have minimal budget impact. Based on current data, remdesivir is unlikely to be a cost-effective treatment for COVID-19.


Assuntos
COVID-19/tratamento farmacológico , COVID-19/terapia , Custos de Cuidados de Saúde/estatística & dados numéricos , Alocação de Recursos para a Atenção à Saúde/economia , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/economia , Monofosfato de Adenosina/uso terapêutico , Alanina/análogos & derivados , Alanina/economia , Alanina/uso terapêutico , COVID-19/diagnóstico , COVID-19/economia , COVID-19/mortalidade , COVID-19/virologia , Tomada de Decisão Clínica/métodos , Simulação por Computador , Análise Custo-Benefício , Dexametasona/economia , Dexametasona/uso terapêutico , Alocação de Recursos para a Atenção à Saúde/organização & administração , Humanos , Unidades de Terapia Intensiva/economia , Unidades de Terapia Intensiva/estatística & dados numéricos , Pessoa de Meia-Idade , Oxigênio/administração & dosagem , Oxigênio/economia , Anos de Vida Ajustados por Qualidade de Vida , Respiração Artificial/economia , SARS-CoV-2 , Índice de Gravidade de Doença , Resultado do Tratamento , Estados Unidos/epidemiologia
10.
JNMA J Nepal Med Assoc ; 59(236): 429-431, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-34508518

RESUMO

During the episodes of large case surge of COVID-19, the health care system of many nations have struggled, more so in nations with resource limitations. Recently, Nepal and the neighboring nation India are being hit hard by the pandemic. Management of patients with moderate and severe COVID-19 remains largely supportive, with oxygen therapy being the cornerstone of the management. Procurement, maintenance of oxygen supply system, coupled with avoiding misuse and wastage of oxygen is of paramount importance to better utilize the scarce resources amidst the peaks of a pandemic. Nepal needs to adopt policies to make best use of its stores and supplies with a collective effort from all stakeholders to save additional lives.


Assuntos
COVID-19 , Pandemias , Humanos , Nepal/epidemiologia , Oxigênio , Pandemias/prevenção & controle , SARS-CoV-2
11.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(8): 809-813, 2021 Aug 15.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34511170

RESUMO

OBJECTIVES: To evaluate the accuracy and safety of measurements of transcutaneous carbon dioxide partial pressure (TcPCO2) and transcutaneous oxygen partial pressure (TcPO2) at electrode temperatures lower than the value used in clinical practice in very low birth weight infants. METHODS: A total of 45 very low birth weight infants were enrolled. TcPCO2 and TcPO2 measurements were performed in these infants. Two transcutaneous monitors were placed simultaneously for each subject. One electrode was set and maintained at 42℃ used in clinical practice for neonates (control group), and the other was successively set at 38℃, 39℃, 40°C, and 41℃ (experimental group). The paired t-test was used to compare the measurement results between the groups. A Pearson correlation analysis was used to analyze the correlation between the measurement results of the experimental group and control group, and between the measurement results of experimental group and arterial blood gas parameters. RESULTS: There was no significant difference in TcPCO2 between each experimental subgroup (38-41℃) and the control group. TcPCO2 in each experimental subgroup (38-41℃) was strongly positively correlated with TcPCO2 in the control group (r>0.9, P<0.05) and arterial carbon dioxide partial pressure (r>0.8, P<0.05). There were significant differences in TcPO2 between each experimental subgroup (38-41℃) and the control group (P<0.05), but TcPO2 in each experimental subgroup (38-41℃) was positively correlated with TcPO2 in the control group (r=0.493-0.574, P<0.05) and arterial oxygen partial pressure (r=0.324-0.399, P<0.05). No skin injury occurred during transcutaneous measurements at all electrode temperatures. CONCLUSIONS: Lower electrode temperatures (38-41℃) can accurately measure blood carbon dioxide partial pressure in very low birth weight infants, and thus can be used to replace the electrode temperature of 42°C. Transcutaneous measurements at the lower electrode temperatures may be helpful for understanding the changing trend of blood oxygen partial pressure.


Assuntos
Monitorização Transcutânea dos Gases Sanguíneos , Dióxido de Carbono , Eletrodos , Humanos , Lactente , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Oxigênio , Pressão Parcial , Temperatura
12.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(8): 821-827, 2021 Aug 15.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34511172

RESUMO

OBJECTIVES: To study the change in regional oxygen saturation (rSO2) of intestinal tissue in preterm infants with hemodynamically significant patent ductus arteriosus (hsPDA) by near-infrared spectroscopy, and the clinical significance of the change in intestinal oxygen level in preterm infants with hsPDA. METHODS: The preterm infants with patent ductus arteriosus (PDA) who had gestational age <32 weeks and/or birth weight <1 500 g were prospectively enrolled, who were admitted to the Department of Neonatology, Shenzhen Longgang Central Hospital from October 2017 to October 2020.According to the diagnostic criteria for hsPDA, the preterm infants with patent ductus arteriosus (PDA) were divided into two groups: hsPDA and non-hsPDA. According to closure of the ductus arteriosus after oral administration of ibuprofen, the preterm infants in the hsPDA group were subdivided into two groups: hsPDA closure and hsPDA non-closure. Hemodynamic parameters were measured at diagnosis of PDA and after treatment, and the level of intestinal tissue rSO2 was monitored continuously to analyze its change. RESULTS: A total of 241 preterm infants with PDA were enrolled, with 55 infants (22.8%) in the hsPDA group and 186 infants (77.2%) in the non-hsPDA group. There were 36 infants (65%) in the hsPDA closure group and 19 infants (35%) in the hsPDA non-closure group. Compared with the non-hsPDA group, the hsPDA group had a significantly higher left atrial diameter/aortic root diameter ratio and significantly lower left ventricular ejection fraction and fractional shortening (P<0.05). At each time point within 6 hours after diagnosis (1, 2, 4, and 6 hours), the hsPDA group had significantly lower intestinal tissue rSO2 than the non-hsPDA group (P<0.05), and intestinal tissue rSO2 gradually decreased over time in the hsPDA group (P<0.05), with the lowest level of 0.448±0.014 at 6 hours. Compared with the hsPDA non-closure group, the hsPDA closure group had a significantly lower left atrial diameter/aortic root diameter ratio and significantly higher left ventricular ejection fraction and fractional shortening (P<0.05). At each time point within 48-96 hours after treatment (48, 72, and 96 hours), the hsPDA closure group had significantly higher intestinal tissue rSO2 than the hsPDA non-closure group (P<0.05), and intestinal tissue rSO2 gradually increased since 24 hours after treatment in the hsPDA closure group (P<0.05), with the highest level of 0.578±0.031 at 96 hours. CONCLUSIONS: hsPDA has an impact on intestinal tissue oxygenation in preterm infants, and continuous monitoring of intestinal tissue rSO2 by near-infrared spectroscopy can help to guide the clinical management of hsPDA in preterm infants.


Assuntos
Permeabilidade do Canal Arterial , Permeabilidade do Canal Arterial/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Oxigênio , Estudos Prospectivos , Espectroscopia de Luz Próxima ao Infravermelho , Volume Sistólico , Função Ventricular Esquerda
13.
Georgian Med News ; (316-317): 22-26, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34511438

RESUMO

The aim of our study was to compare the levels of myocardial damage markers and the state of the oxygen budget in patients with mitral valve insufficiency during its surgical correction, depending on the method of cardioprotection. We examined 85 patients with mitral valve insufficiency who underwent mitral valve replacement (MVR) surgery and anesthetic management according to the traditional method, the difference was only in the method of cardioprotection. In the I group (n=40) crystalloid cardioplegia (Bernsteinder's solution) was used, in the II group (n=45) - electrical fibrillation of the heart and intermittent clamping of the aorta. The level of markers of myocardial damage (MMD), indicators of the oxygen budget, and lactate were recorded in the patients. The method of cardioprotection of the heart did not affect the state of the myocardium, although such an indicator as the ratio of CPK MB/CPK was still lower in II group. In addition, in patients of this group, the state of the myocardium had a lesser effect on hemodynamic parameters. The oxygen budget was most influenced by the need for hemodilution, but indicators such as ΔSO2, ΔpO2, ΔCO2, EO2 and lactate levels indicate a more adequate supply of oxygen to tissues against the background of myocardial protection using electrical fibrillation of the heart and intermittent clamping of the aorta. Both methods of cardioprotection approximately equally affect the circulatory system, however, cardioprotection using electrical fibrillation of the heart and intermittent clamping of the aorta is more preferable.


Assuntos
Insuficiência da Valva Mitral , Creatina Quinase Forma MB , Coração , Humanos , Miocárdio , Oxigênio
14.
Nat Commun ; 12(1): 5243, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475406

RESUMO

Peroxisome, a special cytoplasmic organelle, possesses one or more kinds of oxidases for hydrogen peroxide (H2O2) production and catalase for H2O2 degradation, which serves as an intracellular H2O2 regulator to degrade toxic peroxides to water. Inspired by this biochemical pathway, we demonstrate the reactive oxygen species (ROS) induced tumor therapy by integrating lactate oxidase (LOx) and catalase (CAT) into Fe3O4 nanoparticle/indocyanine green (ICG) co-loaded hybrid nanogels (designated as FIGs-LC). Based on the O2 redistribution and H2O2 activation by cascading LOx and CAT catalytic metabolic regulation, hydroxyl radical (·OH) and singlet oxygen (1O2) production can be modulated for glutathione (GSH)-activated chemodynamic therapy (CDT) and NIR-triggered photodynamic therapy (PDT), by manipulating the ratio of LOx and CAT to catalyze endogenous lactate to produce H2O2 and further cascade decomposing H2O2 into O2. The regulation reactions of FIGs-LC significantly elevate the intracellular ROS level and cause fatal damage to cancer cells inducing the effective inhibition of tumor growth. Such enzyme complex loaded hybrid nanogel present potential for biomedical ROS regulation, especially for the tumors with different redox state, size, and subcutaneous depth.


Assuntos
Antineoplásicos/farmacologia , Nanogéis/química , Peroxissomos/enzimologia , Fotoquimioterapia/métodos , Animais , Antineoplásicos/química , Catalase/química , Catalase/metabolismo , Catálise , Linhagem Celular Tumoral , Óxido Ferroso-Férrico/química , Glutationa/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Verde de Indocianina/química , Camundongos , Oxigenases de Função Mista/química , Oxigenases de Função Mista/metabolismo , Nanopartículas/química , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Oxigênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Microambiente Tumoral/efeitos dos fármacos
15.
BMJ Open ; 11(9): e050995, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493522

RESUMO

OBJECTIVES: To characterise adoption and explore specific clinical and patient factors that might influence pulse oximetry and oxygen use in low-income and middle-income countries (LMICs) over time; to highlight useful considerations for entities working on programmes to improve access to pulse oximetry and oxygen. DESIGN: A multihospital retrospective cohort study. SETTINGS: All admissions (n=132 737) to paediatric wards of 18 purposely selected public hospitals in Kenya that joined a Clinical Information Network (CIN) between March 2014 and December 2020. OUTCOMES: Pulse oximetry use and oxygen prescription on admission; we performed growth-curve modelling to investigate the association of patient factors with study outcomes over time while adjusting for hospital factors. RESULTS: Overall, pulse oximetry was used in 48.8% (64 722/132 737) of all admission cases. Use rose on average with each month of participation in the CIN (OR: 1.11, 95% CI 1.05 to 1.18) but patterns of adoption were highly variable across hospitals suggesting important factors at hospital level influence use of pulse oximetry. Of those with pulse oximetry measurement, 7% (4510/64 722) had hypoxaemia (SpO2 <90%). Across the same period, 8.6% (11 428/132 737) had oxygen prescribed but in 87%, pulse oximetry was either not done or the hypoxaemia threshold (SpO2 <90%) was not met. Lower chest-wall indrawing and other respiratory symptoms were associated with pulse oximetry use at admission and were also associated with oxygen prescription in the absence of pulse oximetry or hypoxaemia. CONCLUSION: The adoption of pulse oximetry recommended in international guidelines for assessing children with severe illness has been slow and erratic, reflecting system and organisational weaknesses. Most oxygen orders at admission seem driven by clinical and situational factors other than the presence of hypoxaemia. Programmes aiming to implement pulse oximetry and oxygen systems will likely need a long-term vision to promote adoption, guideline development and adherence and continuously examine impact.


Assuntos
Oximetria , Oxigênio , Criança , Humanos , Hipóxia/diagnóstico , Quênia , Estudos Prospectivos , Estudos Retrospectivos
16.
Food Res Int ; 147: 110535, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399512

RESUMO

The great heterogeneity currently present when characterizing wine consumption kinetics means that a saturation method, as well as different parameters that allow comparison between wines, need to be established. The aim of this work was to establish a robust method for a wine saturation protocol and compare different fitting models to approximate the oxygen consumption kinetics. To differentiate wines, parameters extracted from the oxygen consumption curves were studied and proposed. 72 young commercial wines (red, white and rosé) from different Spanish appellations of origin, varieties and vintages were used. The results revealed that 5 min was enough to saturate wines up to the maximum level for each one at 35 °C. The inverse curve fitting model showed the best results for all wines. Oxygen at half consumption time (Omid) and time required to consume from 90% to 10% of the oxygen initially available (ΔtO_90_10) were the parameters that differentiated wines the most.


Assuntos
Vinho , Cinética , Oxigênio , Consumo de Oxigênio , Vinho/análise
17.
Food Res Int ; 147: 110555, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399532

RESUMO

Lipid oxidation compromises the shelf-life of lipid-containing foods, leading to the generation of unpleasant off-flavours. Monitoring lipid oxidation under normal shelf-life conditions can be time-consuming (i.e. weeks or months) and therefore accelerated shelf-life conditions are often applied. However, little is known on their impact on the lipid oxidation mechanisms. In this study, different oxygen partial pressures (PO2; 10 and 21%), temperatures (20, 30 and 40 °C), and the removal of antioxidants through stripping of the oil were tested to accelerate lipid oxidation. Increasing the incubation temperature of stripped oil blends from 30 to 40 °C reduced the onset of lipid oxidation from 4 to 2 weeks, whereas the PO2 had no impact. Surprisingly, at room temperature, an increase in PO2 resulted in a longer onset time (10 weeks under 10% oxygen, 15 weeks under 21% oxygen). We hypothesize that this is due to a shift in (initiation) mechanism. In non-stripped oil, an increase in PO2 from 10 to 21% decreased the onset time from 16 to 10 weeks (40 °C). Temperature elevations and stripping led to a shift towards more trans-trans diene hydroperoxides, as compared to the cis-trans conformation. Additionally, oil stripping led to an increase in oxidized PUFAs with three or more double bonds in which the hydroperoxide group is located between the double bond pattern, instead of on the edge of it. Lastly, it was shown that small additions of LC-PUFAs (0, 0.3, 0.6, 1.2 and 2.3%, w/w) accelerate lipid oxidation, even in relatively stable stripped oils. In conclusion, increased PO2 and slightly elevated temperatures hold fair potential for accelerated shelf-life testing of non-stripped oils with a limited impact on the lipid oxidation mechanisms, whereas stripping significantly changes propagation mechanisms.


Assuntos
Antioxidantes , Óleos Vegetais , Oxigênio , Pressão Parcial , Espectroscopia de Prótons por Ressonância Magnética , Temperatura
18.
Int J Mol Sci ; 22(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34445159

RESUMO

Polyetheretherketone (PEEK), due to its excellent mechanical and physico-chemical parameters, is an attractive substitute for hard tissues in orthopedic applications. However, PEEK is hydrophobic and lacks surface-active functional groups promoting cell adhesion. Therefore, the PEEK surface must be modified in order to improve its cytocompatibility. In this work, extreme ultraviolet (EUV) radiation and two low-temperature, EUV induced, oxygen and nitrogen plasmas were used for surface modification of polyetheretherketone. Polymer samples were irradiated with 100, 150, and 200 pulses at a 10 Hz repetition rate. The physical and chemical properties of EUV and plasma modified PEEK surfaces, such as changes of the surface topography, chemical composition, and wettability, were examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and goniometry. The human osteoblast-like MG63 cells were used for the analysis of cell viability and cell adhesion on all modified PEEK surfaces. EUV radiation and two types of plasma treatment led to significant changes in surface topography of PEEK, increasing surface roughness and formation of conical structures. Additionally, significant changes in the chemical composition were found and were manifested with the appearance of new functional groups, incorporation of nitrogen atoms up to ~12.3 at.% (when modified in the presence of nitrogen), and doubling the oxygen content up to ~25.7 at.% (when modified in the presence of oxygen), compared to non-modified PEEK. All chemically and physically changed surfaces demonstrated cyto-compatible and non-cytotoxic properties, an enhancement of MG63 cell adhesion was also observed.


Assuntos
Benzofenonas/química , Materiais Biocompatíveis/química , Nitrogênio/química , Osteoblastos/citologia , Oxigênio/química , Gases em Plasma/química , Polímeros/química , Adesão Celular , Linhagem Celular , Humanos , Propriedades de Superfície , Raios Ultravioleta
19.
Science ; 373(6553)2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34437092

RESUMO

Systematic and extensive investigation of enzymes is needed to understand their extraordinary efficiency and meet current challenges in medicine and engineering. We present HT-MEK (High-Throughput Microfluidic Enzyme Kinetics), a microfluidic platform for high-throughput expression, purification, and characterization of more than 1500 enzyme variants per experiment. For 1036 mutants of the alkaline phosphatase PafA (phosphate-irrepressible alkaline phosphatase of Flavobacterium), we performed more than 670,000 reactions and determined more than 5000 kinetic and physical constants for multiple substrates and inhibitors. We uncovered extensive kinetic partitioning to a misfolded state and isolated catalytic effects, revealing spatially contiguous regions of residues linked to particular aspects of function. Regions included active-site proximal residues but extended to the enzyme surface, providing a map of underlying architecture not possible to derive from existing approaches. HT-MEK has applications that range from understanding molecular mechanisms to medicine, engineering, and design.


Assuntos
Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Fosfatase Alcalina/antagonistas & inibidores , Fosfatase Alcalina/química , Biocatálise , Domínio Catalítico , Flavobacterium/enzimologia , Hidrólise , Cinética , Microfluídica , Modelos Moleculares , Mutação , Oxigênio/metabolismo , Fosfatos/metabolismo , Conformação Proteica , Dobramento de Proteína , Termodinâmica
20.
Sci Rep ; 11(1): 15619, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34341411

RESUMO

Triage is crucial for patient's management and estimation of the required intensive care unit (ICU) beds is fundamental for health systems during the COVID-19 pandemic. We assessed whether chest computed tomography (CT) of COVID-19 pneumonia has an incremental role in predicting patient's admission to ICU. We performed volumetric and texture analysis of the areas of the affected lung in CT of 115 outpatients with COVID-19 infection presenting to the emergency room with dyspnea and unresponsive hypoxyemia. Admission blood laboratory including lymphocyte count, serum lactate dehydrogenase, D-dimer and C-reactive protein and the ratio between the arterial partial pressure of oxygen and inspired oxygen were collected. By calculating the areas under the receiver-operating characteristic curves (AUC), we compared the performance of blood laboratory-arterial gas analyses features alone and combined with the CT features in two hybrid models (Hybrid radiological and Hybrid radiomics)for predicting ICU admission. Following a machine learning approach, 63 patients were allocated to the training and 52 to the validation set. Twenty-nine (25%) of patients were admitted to ICU. The Hybrid radiological model comprising the lung %consolidation performed significantly (p = 0.04) better in predicting ICU admission in the validation (AUC = 0.82; 95% confidence interval 0.73-0.97) set than the blood laboratory-arterial gas analyses features alone (AUC = 0.71; 95% confidence interval 0.56-0.86). A risk calculator for ICU admission was derived and is available at: https://github.com/cgplab/covidapp . The volume of the consolidated lung in CT of patients with COVID-19 pneumonia has a mild but significant incremental value in predicting ICU admission.


Assuntos
COVID-19 , Unidades de Terapia Intensiva , Modelos Biológicos , Pandemias , Admissão do Paciente , SARS-CoV-2/metabolismo , Tomografia Computadorizada por Raios X , COVID-19/sangue , COVID-19/diagnóstico por imagem , COVID-19/epidemiologia , COVID-19/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Valor Preditivo dos Testes
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