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1.
Food Funct ; 15(10): 5613-5626, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38722062

RESUMO

Modification of dairy proteins during processing impacts structural assemblies, influencing textural and nutritional properties of dairy products, and release and availability of amino acids during digestion. By modifying only pH, acid heat-set bovine dairy gels with divergent textural properties were developed to alter protein digestion. In vitro assay confirmed faster digestion of protein from a firm gel (pH 5.65) versus a soft gel (pH 6.55). We hypothesised that firm gel (FIRM-G; pH 5.6) would result in greater indispensable amino acid (IAA) appearance in circulation over 5 h and corresponding differences in gastric myoelectrical activity relative to soft gel (SOFT-G; pH 6.2). In a randomised, single-blind cross-over trial, healthy females (n = 20) consumed 150 g of each gel; plasma amino acid appearance was assessed over 5 hours. Iso-nitrogenous, iso-caloric gels were prepared from identical mixtures of bovine milk and whey protein concentrates; providing 17.7 g (FIRM-G) and 18.9 g (SOFT-G) of protein per serving. Secondary outcomes included gastric myoelectrical activity measured by body surface gastric mapping, glycaemic, triglyceridaemic, and subjective appetite and digestive responses. Overall plasma IAA (area under the curve) did not differ between gels. However, plasma IAA concentrations were higher, and increased more rapidly over time after SOFT-G compared with FIRM-G (1455 ± 53 versus 1350 ± 62 µmol L-1 at 30 min, p = 0.024). Similarly, total, branched-chain and dispensable amino acids were higher at 30 min with SOFT-G than FIRM-G (total: 3939 ± 97 versus 3702 ± 127 µmol L-1, p = 0.014; branched-chain: 677 ± 30 versus 619 ± 34 µmol L-1, p = 0.047; dispensable: 2334 ± 53 versus 2210 ± 76 µmol L-1, p = 0.032). All other measured parameters were similar between gels. Peak postprandial aminoacidaemia was higher and faster following ingestion of SOFT-G. Customised plasma amino acid appearance from dairy is achievable by altering gel coagulum structure using pH during processing and may have minimal influence on related postprandial responses, with implications for targeting food design for optimal health. The Clinical Trial Registry number is ACTRN12622001418763 (https://www.anzctr.org.au) registered November 7, 2022.


Assuntos
Aminoácidos , Estudos Cross-Over , Géis , Feminino , Humanos , Adulto , Concentração de Íons de Hidrogênio , Aminoácidos/sangue , Aminoácidos/química , Géis/química , Animais , Adulto Jovem , Bovinos , Digestão , Temperatura Alta , Proteínas do Leite/química , Método Simples-Cego , Estômago/fisiologia , Estômago/química , Leite/química
2.
Am J Clin Nutr ; 119(5): 1200-1215, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38452857

RESUMO

BACKGROUND: Heat treatments of dairy, including pasteurization and ultra-high temperature (UHT) processing, alter milk macromolecular structures, and ultimately affect digestion. In vitro, animal, and human studies show faster nutrient release or circulating appearance after consuming UHT milk (UHT-M) compared with pasteurized milk (PAST-M), with a faster gastric emptying (GE) rate proposed as a possible mechanism. OBJECTIVES: To investigate the impact of milk heat treatment on GE as a mechanism of faster nutrient appearance in blood. We hypothesized that GE and circulating nutrient delivery following consumption would be faster for UHT-M than PAST-M. METHODS: In this double-blind randomized controlled cross-over trial, healthy female (n = 20; 27.3 ± 1.4 y, mean ± SD) habitual dairy consumers, consumed 500 mL of either homogenized bovine UHT-M or PAST-M (1340 compared with 1320 kJ). Gastric content volume (GCV) emptying half-time (T50) was assessed over 3 h by magnetic resonance imaging subjective digestive symptoms, plasma amino acid, lipid and B vitamin concentrations, and gastric myoelectrical activity were measured over 5 h. RESULTS: Although GCV T50 did not differ (102 ± 7 min compared with 89 ± 8 min, mean ± SEM, UHT-M and PAST-M, respectively; P = 0.051), GCV time to emptying 25% of the volume was 31% longer following UHT-M compared with PAST-M (42 ± 2 compared with 32 ± 4 min, P = 0.004). Although GCV remained larger for a longer duration following UHT-M (treatment × time interaction, P = 0.002), plasma essential amino acid AUC was greater following UHT-M than PAST-M (55,324 ± 3809 compared with 36,598 ± 5673 µmol·min·L-1, P = 0.006). Heat treatment did not impact gastric myoelectrical activity, plasma appetite hormone markers or subjective appetite scores. CONCLUSIONS: Contrary to expectations, GE was slower with UHT-M, yet, as anticipated, aminoacidemia was greater. The larger GCV following UHT-M suggests that gastric volume may poorly predict circulating nutrient appearance from complex food matrices. Dairy heat treatment may be an effective tool to modify nutrient release by impacting digestion kinetics. CLINICAL TRIAL REGISTRY: www.anzctr.org.au (ACTRN12620000172909).


Assuntos
Estudos Cross-Over , Esvaziamento Gástrico , Temperatura Alta , Leite , Pasteurização , Feminino , Animais , Humanos , Leite/química , Adulto , Bovinos , Método Duplo-Cego , Nutrientes , Adulto Jovem
3.
Eur J Appl Physiol ; 124(7): 2045-2056, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38386104

RESUMO

PURPOSE: Intestinal permeability is a critical component of gut barrier function. Barrier dysfunction can be triggered by certain stressors such as exercise, and if left unmanaged can lead to local and systemic disorders. The aim of this study was to investigate the effects of a specific whey protein fraction in alleviating exercise-induced gut permeability as assessed by recovery of lactulose/rhamnose (L/R) and lactulose/mannitol (L/M) urinary probes. METHODS: Eight males and eight females (aged 18-50) completed two arms of a double-blind, placebo-controlled, crossover study. For each arm participants performed two baseline intestinal permeability assessments, following which they consumed the treatment (2 g/day of milk powder containing 200 mg of whey protein) or placebo (2 g/day of milk powder) for 14 days, before performing a post-exercise permeability assessment. The exercise protocol involved a 20-min run at 80% of maximal oxygen uptake on a 1% incline. RESULTS: Mixed model analysis revealed an increase in L/R (23%; P < 0.001) and L/M (20%; P < 0.01) recovery following exercise. However, there was no treatment or treatment × exercise effect. CONCLUSION: The exercise protocol utilised in our study induces gut permeability. However, consuming whey protein, at the dose and timing prescribed, is not able to mitigate this effect.


Assuntos
Exercício Físico , Permeabilidade , Proteínas do Soro do Leite , Humanos , Proteínas do Soro do Leite/farmacologia , Proteínas do Soro do Leite/administração & dosagem , Masculino , Adulto , Feminino , Exercício Físico/fisiologia , Permeabilidade/efeitos dos fármacos , Animais , Método Duplo-Cego , Pessoa de Meia-Idade , Adulto Jovem , Lactulose/urina , Lactulose/farmacologia , Estudos Cross-Over , Adolescente , Bovinos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Ramnose/farmacologia , Manitol/farmacologia
4.
Lancet Public Health ; 8(9): e691-e700, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37633678

RESUMO

BACKGROUND: The association between duration of smoking abstinence before non-small-cell lung cancer (NSCLC) diagnosis and subsequent survival can influence public health messaging delivered in lung-cancer screening. We aimed to assess whether the duration of smoking abstinence before diagnosis of NSCLC is associated with improved survival. METHODS: In this retrospective, pooled analysis of cohort studies, we used 26 cohorts participating in Clinical Outcomes Studies of the International Lung Cancer Consortium (COS-ILCCO) at 23 hospitals. 16 (62%) were from North America, six (23%) were from Europe, three (12%) were from Asia, and one (4%) was from South America. Patients enrolled were diagnosed between June 1, 1983, and Dec 31, 2019. Eligible patients had smoking data before NSCLC diagnosis, epidemiological data at diagnosis (obtained largely from patient questionnaires), and clinical information (retrieved from medical records). Kaplan-Meier curves and multivariable Cox models (ie, adjusted hazard ratios [aHRs]) were generated with individual, harmonised patient data from the consortium database. We estimated overall survival for all causes, measured in years from diagnosis date until the date of the last follow-up or death due to any cause and NSCLC-specific survival. FINDINGS: Of 42 087 patients with NSCLC in the COS-ILCCO database, 21 893 (52·0%) of whom were male and 20 194 (48·0%) of whom were female, we excluded 4474 (10·6%) with missing data. Compared with current smokers (15 036 [40·0%] of 37 613), patients with 1-3 years of smoking abstinence before NSCLC diagnosis (2890 [7·7%]) had an overall survival aHR of 0·92 (95% CI 0·87-0·97), patients with 3-5 years of smoking abstinence (1114 [3·0%]) had an overall survival aHR of 0·90 (0·83-0·97), and patients with more than 5 years of smoking abstinence (10 841 [28·8%]) had an overall survival aHR of 0·90 (0·87-0·93). Improved NSCLC-specific survival was observed in 4301 (44%) of 9727 patients who had quit cigarette smoking and was significant at abstinence durations of more than 5 years (aHR 0·87, 95% CI 0·81-0·93). Results were consistent across age, sex, histology, and disease-stage distributions. INTERPRETATION: In this large, pooled analysis of cohort studies across Asia, Europe, North America, and South America, overall survival was improved in patients with NSCLC whose duration of smoking abstinence before diagnosis was as short as 1 year. These findings suggest that quitting smoking can improve overall survival, even if NSCLC is diagnosed at a later lung-cancer screening visit. These findings also support the implementation of public health smoking cessation strategies at any time. FUNDING: The Alan B Brown Chair, The Posluns Family Fund, The Lusi Wong Fund, and the Princess Margaret Cancer Foundation.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Feminino , Masculino , Estudos Retrospectivos , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Estudos de Coortes , Fumar/epidemiologia
5.
J Environ Manage ; 334: 117443, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36774897

RESUMO

We introduce the concept of relative water use perception bias to highlight the role of human relationships, social cues, and the built environment in household water consumption. Although previous studies have explored actual water use, it is also important to understand how people perceive their relative behaviors because humans are social animals and act in relation to each other. We combine household survey responses and water utility bills in a large sample of households to quantify the degree of over- and under-estimation bias in perceived relative household water use. We then use multi-level nested regression models to investigate four categories of potential influence: sociodemographic characteristics, perceived social norms, neighborhood characteristics, and water bill information. Results show that most households tended to view themselves as 'better than average' water users when they actually used more water compared to neighbors. Respondents in high-income households and those who are more concerned about water shortages were more likely to underestimate their relative water use (using comparatively more than they thought). However, in more suburbanized neighborhood environments, households were more likely to overestimate their relative water use (using comparatively less than they thought). We call the inaccuracy in assessing water usage compared to their neighbors' relative water use perception bias. We propose that a better understanding of this bias can aid the design of policy initiatives like neighborhood planning, better water bill design, targeted messaging, and social signaling. By bringing a relational lens to bear on water conservation studies, understanding relative water use perception bias sheds new light on the complex drivers of household water consumption.


Assuntos
Renda , Água , Animais , Humanos , Percepção
6.
Front Nutr ; 9: 835856, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35634409

RESUMO

There has been a growing interest in understanding how the relative levels of human milk fat globule (MFG) components change over the course of lactation, how they differ between populations, and implications of these changes for the health of the infant. In this article, we describe studies published over the last 30 years which have investigated components of the MFG in term milk, focusing on changes over the course of lactation and highlighting infant and maternal factors that may influence these changes. We then consider how the potential health benefits of some of the milk fat globule membrane (MFGM) components and derived ingredients relate to compositional and functional aspects and how these change throughout lactation. The results show that the concentrations of phospholipids, gangliosides, cholesterol, fatty acids and proteins vary throughout lactation, and such changes are likely to reflect the changing requirements of the growing infant. There is a lack of consistent trends for changes in phospholipids and gangliosides across lactation which may reflect different methodological approaches. Other factors such as maternal diet and geographical location have been shown to influence human MFGM composition. The majority of research on the health benefits of MFGM have been conducted using MFGM ingredients derived from bovine milk, and using animal models which have clearly demonstrated the role of the MFGM in supporting cognitive and immune health of infants at different stages of growth and development.

7.
Nutrients ; 14(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35565709

RESUMO

Nutrigenomics New Zealand (NuNZ) was a collaborative research programme built among three organisations-the University of Auckland, AgResearch Limited and Plant & Food Research. The programme ran for ten years, between 2004 and 2014, and was tasked with developing the then emerging field of nutrigenomics, investigating its applications to New Zealand, and potential benefits to the plant food and agricultural sectors. Since the beginning of the programme, nutrigenomics was divided into two fields-nutrigenetics and nutrigenomics. The first of these is now more commonly called personalised nutrition, and has recently been recognised and criticised by elements of the dietetics and management sector in New Zealand, who currently do not appear to fully appreciate the evolving nature of the field, and the differing validity of various companies offering the tests that form the basis of this personalisation. Various science laboratories are utilising "omics" sciences, including transcriptomics, metabolomics, proteomics and the comprehensive analysis of microbial communities such as the gut microbiota, in order to understand the mechanisms by which certain food products and/or diets relevant to New Zealand, confer a health benefit, and the nature of potential health claims that may be made on the basis of this information. In this article, we give a brief overview of the nutrigenomics landscape in New Zealand since the end of the NuNZ programme, with a particular focus on gastrointestinal health.


Assuntos
Dietética , Nutrigenômica , Metabolômica , Nova Zelândia , Estado Nutricional
8.
Eur J Clin Nutr ; 76(10): 1415-1422, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35459911

RESUMO

BACKGROUND/OBJECTIVES: Self-reported digestive intolerance to dairy foods is common. As dairy can be an important source of dietary protein, this study aimed to identify whether milk protein digestion is compromised in individuals with digestive intolerance. SUBJECTS/METHODS: Adult women (n = 40) were enroled in this double-blinded, randomised cross-over trial, with digestive symptoms characterised using a lactose challenge and self-reported digestive symptom questionnaire. Participants were classified as either lactose intolerant (LI, n = 10), non-lactose dairy intolerant (NLDI, n = 20) or dairy tolerant (DT, n = 10). In a randomised sequence, participants consumed three different kinds of milk (750 ml); conventional milk (CON), a2 Milk™ (A2M), and lactose-free conventional milk (LF-CON). Circulatory plasma amino acid (AA) concentrations were measured at baseline and every 30 min until 3 h post-ingestion. RESULTS: In all participants across all milk types, plasma AA concentrations (AUC0-180) increased after milk ingestion with no significant differences in responses observed between milk types or participants (P > 0.05), with the exception of the suppressed lysine response in the DT group following A2M ingestion, relative to the other two groups and milk types (P < 0.05). CONCLUSION: Milk protein digestion, as determined by circulatory AAs, is largely unaffected by dairy- and lactose- intolerances.


Assuntos
Aminoácidos , Intolerância à Lactose , Adulto , Aminoácidos/análise , Animais , Proteínas Alimentares/análise , Feminino , Humanos , Lisina/análise , Leite/química
9.
Cancer Epidemiol Biomarkers Prev ; 31(3): 679-687, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35027437

RESUMO

BACKGROUND: Somatic EGFR mutations define a subset of non-small cell lung cancers (NSCLC) that have clinical impact on NSCLC risk and outcome. However, EGFR-mutation-status is often missing in epidemiologic datasets. We developed and tested pragmatic approaches to account for EGFR-mutation-status based on variables commonly included in epidemiologic datasets and evaluated the clinical utility of these approaches. METHODS: Through analysis of the International Lung Cancer Consortium (ILCCO) epidemiologic datasets, we developed a regression model for EGFR-status; we then applied a clinical-restriction approach using the optimal cut-point, and a second epidemiologic, multiple imputation approach to ILCCO survival analyses that did and did not account for EGFR-status. RESULTS: Of 35,356 ILCCO patients with NSCLC, EGFR-mutation-status was available in 4,231 patients. A model regressing known EGFR-mutation-status on clinical and demographic variables achieved a concordance index of 0.75 (95% CI, 0.74-0.77) in the training and 0.77 (95% CI, 0.74-0.79) in the testing dataset. At an optimal cut-point of probability-score = 0.335, sensitivity = 69% and specificity = 72.5% for determining EGFR-wildtype status. In both restriction-based and imputation-based regression analyses of the individual roles of BMI on overall survival of patients with NSCLC, similar results were observed between overall and EGFR-mutation-negative cohort analyses of patients of all ancestries. However, our approach identified some differences: EGFR-mutated Asian patients did not incur a survival benefit from being obese, as observed in EGFR-wildtype Asian patients. CONCLUSIONS: We introduce a pragmatic method to evaluate the potential impact of EGFR-status on epidemiological analyses of NSCLC. IMPACT: The proposed method is generalizable in the common occurrence in which EGFR-status data are missing.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/epidemiologia , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/genética , Mutação , Análise de Sobrevida
10.
ACS Biomater Sci Eng ; 7(12): 5555-5572, 2021 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-34719916

RESUMO

A series of quaternary Zn-Al-Cu-Li alloys with different weight fractions of Cu, Al, and Li were developed and investigated for potential application in high load bearing bioresorbable implants. The developed alloys provided various fractions of binary and ternary intermetallic structures, which resulted in formation of multiphase microstructures containing a zinc-rich η-phase and LiZn4 and CuZn4 phases. The intermetallic phases promoted grain refinement and a good combination of mechanical properties. The developed Zn-2Al-4Cu-0.6Li alloy showed strength and ductility close to commercially pure Ti alloys with a UTS value of ∼535 MPa and elongation of 37%. The examination of in vitro corrosion behavior of the developed alloys in the modified Hanks' solution revealed suitable corrosion rates (∼38.5 µm/year). The moderate corrosion rate was controlled by the formation of a homogeneous layer of stable corrosion products that protected the alloys from the corrosive environment, particularly in the late stages of immersion. The developed alloys with the most promising mechanical and corrosion properties appeared to be biocompatible to mouse fibroblast cells and human umbilical mesenchymal stem cells, making them suitable candidates for implant applications.


Assuntos
Ligas , Zinco , Animais , Corrosão , Teste de Materiais , Camundongos , Resistência à Tração
11.
Front Nutr ; 8: 643350, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33996872

RESUMO

Background: Most milk consumed by humans undergoes heat treatment to ensure microbiological safety and extend shelf life. Although heat treatment impacts the structure and physiochemical properties of milk, effects on nutrient absorption in humans are unclear. Therefore, a rapid review was performed to identify studies conducted on healthy human adult subjects that have assessed the impacts of heat treatment of milk on protein and fat digestion and metabolism in the postprandial period (up to 24 h). Methods: Relevant databases (Medline, EMBASE, Cochrane, Scopus) were systematically screened for intervention studies on healthy adult men and women that assessed the impact of consuming heat-treated milk on the postprandial kinetics or appearance in peripheral circulation or urine of ingested proteins and/or lipids. The risk-of-bias assessment tool 2 was used for quality assessment. Results: Of 511 unique database records, 4 studies were included encompassing 6 study treatments (n = 57 participants, 20-68 years). Three studies evaluated pasteurization, two evaluated ultra-high temperature (UHT) treatment, and one evaluated oven-heated milk. Protein and lipid appearances in peripheral blood were reported in two sets of two studies. None of the studies used the same heat treatments and outcome measures, limiting generalization of effects. Protein appearance (ng/mL or area under the curve) (as plasma amino acids - lysine) was reduced when milk was oven-heated for 5 h in one study (n = 7 participants), while the other study reported a reduced retention of dietary N with UHT milk (n = 25 participants). Overall plasma triacylglycerol responses were unaffected by milk heat treatments reported, but plasma fatty acid composition differed. The studies observed higher plasma myristic and palmitic acid abundance with successive heat treatment at 2 h (n = 11 participants; pasteurized) and 4 h (n = 14 participants; UHT) after ingestion; other differences were inconsistent. All studies had moderate-high risk of bias, which should be taken into consideration when interpreting findings. Discussion: This review identified few studies reporting the effects of milk heat treatment on postprandial nutrient responses in adults. Although the findings suggest that milk heat treatment likely affects postprandial protein and lipid dynamics, generalization of the findings is limited as treatments, outcomes, and methods differed across studies. Because of the study variability, and the acute post-prandial nature of the studies, it is also difficult to draw conclusions regarding potential long-term health outcomes. However, the possibility that altered digestive kinetics may influence postprandial protein retention and anabolic use of dietary N suggests heat treatment of milk may impact outcomes such as long-term maintenance of muscle mass.

12.
Nutrients ; 13(4)2021 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-33801641

RESUMO

Polyphenols within fruits and vegetables may contribute to health benefits due to their consumption, with the anthocyanin sub-set also adding colour. The Lemonade™ apple variety has green skin and white flesh, with low anthocyanin content, while some apple varieties have high anthocyanin content in both the skin and flesh. Effects of red compared with white-fleshed apples were studied in healthy human subjects in a randomized, placebo-controlled, cross-over intervention trial. Twenty-five healthy subjects consumed dried daily portions of the red-fleshed or placebo (white-fleshed) apple for two weeks, followed by one-week washout and further two-week crossover period. During the study, volunteers provided faecal samples for microbiota composition analysis and blood samples for peripheral blood mononuclear cell (PBMC) gene expression analysis. Subtle differences were observed in the faecal microbiota of subjects that were fed the different apples, with significant (p < 0.05) reductions in relative abundances of Streptococcus, Ruminococcus, Blautia, and Roseburia, and increased relative abundances of Sutterella, Butyricicoccus, and Lactobacillus in subjects after consuming the red apple. Changes in PBMC gene expression showed 18 mRNA transcripts were differentially expressed between the two groups, of which 16 were immunoglobulin related genes. Pathway analysis showed that these genes had roles in pathways such as immunoglobulin production, B cell-mediated immunity, complement activation, and phagocytosis. In conclusion, this study shows that anthocyanin-rich apples may influence immune function compared to control apples, with changes potentially associated with differences in the faecal microbiota.


Assuntos
Fezes/microbiologia , Frutas/química , Regulação da Expressão Gênica/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Malus/química , Polifenóis/farmacologia , Adulto , Estudos Cross-Over , Feminino , Regulação da Expressão Gênica/imunologia , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Polifenóis/química , Adulto Jovem
13.
Nano Lett ; 21(8): 3379-3385, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33835813

RESUMO

The mechanical properties of magnetic materials are instrumental for the development of magnetoelastic theories and the optimization of strain-modulated magnetic devices. In particular, two-dimensional (2D) magnets hold promise to enlarge these concepts into the realm of low-dimensional physics and ultrathin devices. However, no experimental study on the intrinsic mechanical properties of the archetypal 2D magnet family of the chromium trihalides has thus far been performed. Here, we report the room temperature layer-dependent mechanical properties of atomically thin CrCl3 and CrI3, finding that the bilayers have Young's moduli of 62.1 and 43.4 GPa, highest sustained strains of 6.49% and 6.09% and breaking strengths of 3.6 and 2.2 GPa, respectively. This portrays the outstanding plasticity of these materials that is qualitatively demonstrated in the bulk crystals. The current study will contribute to the applications of the 2D magnets in magnetostrictive and flexible devices.

14.
Mater Sci Eng C Mater Biol Appl ; 122: 111897, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33641900

RESUMO

A series of Zn-Al-Li alloys with potential application in bioresorbable implants were cast, thermomechanically processed and tested. The formation of secondary phases, such as LiZn4, LiZn3Al and Al3Li, contributed to both dynamic recrystallization and grain refinement of the matrix (η-phase) during the hot-extrusion process, leading to grain sizes as small as 1.75 µm for Zn-4Al-0.6Li alloy (wt%). This alloy exhibited an ultimate tensile strength (UTS) of 451 MPa, a total elongation of 46% and a corrosion rate of 60 µm/year in simulated body fluid. The grain refinement played a major role in increasing the strength, but it also weakened the basal texture and promoted non-basal slip and grain boundary sliding, thus contributing to the increased plastic deformation of the alloy. The corrosion rate was affected by a layer of zinc oxide and phosphate formed in the early stages of the immersion tests. The corrosion products protected the substrate and tended to reduce the corrosion rate over time. The developed Zn-4Al-0.6Li and Zn-6Al-0.4Li alloys which showed promising mechanical and corrosion properties appeared to be cytocompatible in the mouse fibroblast cell line and human umbilical mesenchymal stem cells making them promising candidates for bioresorbable stent and implant applications.


Assuntos
Implantes Absorvíveis , Ligas , Animais , Corrosão , Teste de Materiais , Camundongos , Resistência à Tração , Zinco
15.
ACS Nano ; 15(2): 2600-2610, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33503379

RESUMO

Two-dimensional (2D) tungsten disulfide (WS2), tungsten diselenide (WSe2), and tungsten ditelluride (WTe2) draw increasing attention due to their attractive properties deriving from the heavy tungsten and chalcogenide atoms, but their mechanical properties are still mostly unknown. Here, we determine the intrinsic and air-aged mechanical properties of mono-, bi-, and trilayer (1-3L) WS2, WSe2, and WTe2 using a complementary suite of experiments and theoretical calculations. High-quality 1L WS2 has the highest Young's modulus (302.4 ± 24.1 GPa) and strength (47.0 ± 8.6 GPa) of the entire family, overpassing those of 1L WSe2 (258.6 ± 38.3 and 38.0 ± 6.0 GPa, respectively) and WTe2 (149.1 ± 9.4 and 6.4 ± 3.3 GPa, respectively). However, the elasticity and strength of WS2 decrease most dramatically with increased thickness among the three materials. We interpret the phenomenon by the different tendencies for interlayer sliding in an equilibrium state and under in-plane strain and out-of-plane compression conditions in the indentation process, revealed by the finite element method and density functional theory calculations including van der Waals interactions. We also demonstrate that the mechanical properties of the high-quality 1-3L WS2 and WSe2 are largely stable in air for up to 20 weeks. Intriguingly, the 1-3L WSe2 shows increased modulus and strength values with aging in the air. This is ascribed to oxygen doping, which reinforces the structure. The present study will facilitate the design and use of 2D tungsten dichalcogenides in applications such as strain engineering and flexible field-effect transistors.

16.
Transfus Med ; 31(1): 36-42, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33319442

RESUMO

OBJECTIVES: To evaluate the potential of the automated titre score (TS) as an alternative method to continuous flow analysis (CFA) for the prediction of the nature of anti-D in pregnancy. BACKGROUND: The 2016 revised British Society for Haematology (BSH) antenatal guidelines recommended a measurement of anti-D concentration by CFA to ensure the detection of potential immune anti-D. Due to high referral costs and resource pressures, uptake has been challenging for hospital laboratories. Serious Hazards of transfusion (SHOT) data have previously shown that this has contributed to missed antenatal follow ups for women with immune anti-D and neonates affected by haemolytic disease of the fetus/newborn. METHODS/MATERIALS: In this multicentre comparative study, samples referred for CFA quantification were also tested by an ORTHO VISION automated anti-D indirect antiglobulin test (IAT) serial dilution and then converted to TS. CFA results and history of anti-D prophylaxis were used to categorise samples as passive or immune, with the aim of determining a potential TS cut-off for CFA referral of at risk patients. RESULTS: Five UK National Health Service (NHS) trusts generated a total of 196 anti-D TS results, of which 128 were classified as passive and 68 as immune. Diagnostic testing of CFA and TS values indicated a TS cut-off of 35 to assist in distinguishing the nature of anti-D. Using this cut-off, 175 (89%) results were correctly assigned into the passive or immune range, giving a specificity of 92.19% and a negative predictive value of 91.47%. CONCLUSION: TS in conjunction with clinical and anti-D prophylaxis history can be used as a viable and cost-effective alternative to CFA in a hospital laboratory setting.


Assuntos
Teste de Coombs , Eritroblastose Fetal , Sistema do Grupo Sanguíneo Rh-Hr , Imunoglobulina rho(D) , Adulto , Teste de Coombs/economia , Teste de Coombs/instrumentação , Teste de Coombs/métodos , Análise Custo-Benefício , Eritroblastose Fetal/sangue , Eritroblastose Fetal/economia , Feminino , Humanos , Gravidez , Sistema do Grupo Sanguíneo Rh-Hr/sangue , Sistema do Grupo Sanguíneo Rh-Hr/economia , Imunoglobulina rho(D)/sangue , Imunoglobulina rho(D)/economia
17.
Nutrients ; 12(11)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33212933

RESUMO

Multivitamin and mineral (MVM) supplements are frequently used amongst older populations to improve adequacy of micronutrients, including B-vitamins, but evidence for improved health outcomes are limited and deficiencies remain prevalent. Although this may indicate poor efficacy of supplements, this could also suggest the possibility for altered B-vitamin bioavailability and metabolism in older people. This open-label, single-arm acute parallel study, conducted at the Liggins Institute Clinical Research Unit in Auckland, compared circulatory and urinary B-vitamer responses to MVM supplementation in older (70.1 ± 2.7 y, n = 10 male, n = 10 female) compared to younger (24.2 ± 2.8 y, n = 10 male, n = 10 female) participants for 4 h after the ingestion of a single dose of a commercial MVM supplement and standardized breakfast. Older adults had a lower area under the curve (AUC) of postprandial plasma pyridoxine (p = 0.02) and pyridoxal-5'phosphate (p = 0.03) forms of vitamin B6 but greater 4-pyridoxic acid AUC (p = 0.009). Urinary pyridoxine and pyridoxal excretion were higher in younger females than in older females (time × age × sex interaction, p < 0.05). Older adults had a greater AUC increase in plasma thiamine (p = 0.01), riboflavin (p = 0.009), and pantothenic acid (p = 0.027). In older adults, there was decreased plasma responsiveness of the ingested (pyridoxine) and active (pyridoxal-5'phosphate) forms of vitamin B6, which indicated a previously undescribed alteration in either absorption or subsequent metabolic interconversion. While these findings cannot determine whether acute B6 responsiveness is adequate, this difference may have potential implications for B6 function in older adults. Although this may imply higher B vitamin substrate requirements for older people, further work is required to understand the implications of postprandial differences in availability.


Assuntos
Envelhecimento , Desjejum , Período Pós-Prandial , Complexo Vitamínico B/sangue , Complexo Vitamínico B/urina , Adulto , Idoso , Registros de Dieta , Ingestão de Energia , Feminino , Humanos , Masculino , Nutrientes , Complexo Vitamínico B/administração & dosagem , Adulto Jovem
18.
BMC Gastroenterol ; 20(1): 204, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600320

RESUMO

BACKGROUND: Adult lactase non-persistence (LNP) is due to low lactase expression, resulting in lactose malabsorption (LM). LNP is a genetic trait, but is typically determined by LM markers including breath H2, blood glucose, and urinary galactose after a lactose tolerance test. Known validity of these markers using milk is limited, despite being common practice. Compositional variation, such as ß-casein variants, in milk may impact diagnostic efficacy. This study aimed to evaluate the diagnostic accuracy to detect LNP using these commonly measured LM markers after both lactose and milk challenges. METHODS: Fourty healthy young women were challenged with 50 g lactose then randomized for separate cross-over visits to ingest 750 mL milk (37.5 g lactose) as conventional (both A1 and A2 ß-casein) and A1 ß-casein-free (a2 Milk™) milk. Blood, breath and urine were collected prior to and up to 3 h following each challenge. The presence of C/T13910 and G/A22018 polymorphisms, determined by restriction fragment length polymorphism, was used as the diagnostic reference for LNP. RESULTS: Genetic testing identified 14 out of 40 subjects as having LNP (C/C13910 and G/G22018). All three LM markers (breath H2, plasma glucose and urinary galactose/creatinine) discriminated between lactase persistence (LP) and LNP following lactose challenge with an area under the receiver operating characteristic (ROC) curve (AUC) of 1.00, 0.75 and 0.73, respectively. Plasma glucose and urinary galactose/creatinine were unreliable (AUC < 0.70) after milk ingestion. The specificity of breath H2 remained high (100%) when milk was used, but sensitivity was reduced with conventional (92.9%) and a2 Milk™ (78.6%) compared to lactose (sensitivities adjusted for lactose content). The breath H2 optimal cut-off value was lower with a2 Milk™ (13 ppm) than conventional milk (21 ppm). Using existing literature cut-off values the sensitivity and specificity of breath H2 was greater than plasma glucose to detect LNP following lactose challenge whereas values obtained for urinary galactose/creatinine were lower than the existing literature cut-offs. CONCLUSION: This study showed accurate diagnosis of LNP by breath H2 irrespective of the substrate used, although the diagnostic threshold may vary depending on the lactose substrate or the composition of the milk. TRIAL REGISTRATION: ACTRN12616001694404 . Registered prospectively on December 9, 2016.


Assuntos
Intolerância à Lactose , Lactose , Adulto , Animais , Testes Respiratórios , Ingestão de Alimentos , Feminino , Humanos , Hidrogênio/análise , Lactase/genética , Intolerância à Lactose/diagnóstico , Intolerância à Lactose/genética , Leite/química
19.
Sci Total Environ ; 712: 136489, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32050377

RESUMO

Communities across the Western United States face the growing challenge of managing water resources in the face of rapid population growth and climate change. There are two contrasting approaches to understanding and managing residential water demand in this context. Many scientists and water managers see water use as a reflection of individual attitudes and decisions where people are assumed to have the agency to act independently of structural constraints. Conversely, other scientists and policymakers focus on the importance of the built environment and the broader social, economic, and policy contexts within which households make water decisions. Using multilevel models, we compared attitudinal, demographic, and structural drivers of indoor and outdoor residential water use for a sample of households in Northern Utah. We estimated multilevel mixed-effect Poisson models with robust standard errors using matched household survey data with metered residential water use records. Outdoor water use had a substantially greater amount of neighborhood-level variation than indoor water use. Structural factors generally eclipsed individual agency in our analysis. While indoor use was most strongly predicted by household size, tenure status, and length of residence, outdoor water use was most associated with the built environment (lot size and the presence of vegetable gardens and underground sprinklers), socioeconomic status (household income, rental status), and residents' sensitivity to lawn watering norms. Higher water prices were associated with lower water use, with lower-income households being more responsive to prices than higher-income households. Our findings have important implications for water managers and policymakers.

20.
Nutrients ; 12(2)2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32023931

RESUMO

Cooking changes the texture and tenderness of red meat, which may influence its digestibility, circulatory amino acids (AA) and gastrointestinal (GI) hormonal responses in consumers. In a randomised crossover intervention, healthy males (n = 12) consumed a beef steak sandwich, in which the beef was cooked by either a pan-fried (PF) or sous-vide (SV) method. Plasma AA were measured by ultrahigh performance liquid chromatography (UPLC), while plasma GI hormones were measured using a flow cytometric multiplex array. Following meat ingestion, the circulatory concentrations of some of the essential AA (all the branched-chain AA: leucine, isoleucine and valine; and threonine), some of the nonessential AA (glycine, alanine, tyrosine and proline) and some of the nonproteogenic AA (taurine, citrulline and ornithine) were increased from fasting levels by 120 or 180 min (p < 0.05). There were no differences in circulating AA concentrations between cooking methods. Likewise, of the measured GI hormones, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) concentrations increased from fasting levels after consumption of the steak sandwich (p < 0.05), with no differences between the cooking methods. In the healthy male adults, protein digestion and circulating GI hormone responses to a beef-steak breakfast were unaltered by the different cooking methods.


Assuntos
Aminoácidos/sangue , Culinária/métodos , Proteínas Alimentares/sangue , Hormônios Gastrointestinais/sangue , Carne Vermelha , Adolescente , Adulto , Estudos Cross-Over , Ingestão de Alimentos , Jejum/sangue , Voluntários Saudáveis , Humanos , Masculino , Período Pós-Prandial , Adulto Jovem
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