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1.
Nano Lett ; 24(35): 10957-10963, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39171725

RESUMO

Logic-in-memory (LIM) architecture holds great potential to break the von Neumann bottleneck. Despite the extensive research on novel devices, challenges persist in developing suitable engineering building blocks for such designs. Herein, we propose a reconfigurable strategy for efficient implementation of Boolean logics based on a hafnium oxide-based ferroelectric field effect transistor (HfO2-based FeFET). The logic results are stored within the device itself (in situ) during the computation process, featuring the key characteristics of LIM. The fast switching speed and low power consumption of a HfO2-based FeFET enable the execution of Boolean logics with an ultralow energy of lower than 8 attojoule (aJ). This represents a significant milestone in achieving aJ-level computing energy consumption. Furthermore, the system demonstrates exceptional reliability with computing endurance exceeding 108 cycles and retention properties exceeding 1000 s. These results highlight the remarkable potential of a FeFET for the realization of high performance beyond the von Neumann LIM computing architectures.

2.
Nano Lett ; 24(35): 11067-11074, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39162290

RESUMO

The generation of ultrashort electron wavepackets is crucial for the development of ultrafast electron microscopes. Recent studies on Coulomb-correlated few-electron number states, photoemitted from sharp metallic tapers, have shown emission nonlinearities in the multiphoton photoemission regime which scale with the electron number. Here, we study few-electron photoemission from gold nanotapers triggered by few-cycle near-infrared pulses, demonstrating extreme 20th-order nonlinearities for electron triplets. We report interferometric autocorrelation traces of the electron yield that are quenched to a single emission peak with subfemtosecond duration due to these high nonlinearities. The modulation of the emission yield by the carrier-envelope phase suggests that electron emission predominantly occurs during a single half cycle of the driving laser field. When applying a bias voltage to the tip, recollisions in the electron trajectories are suppressed and coherent subcycle electron beams are generated with promising prospects for ultrafast electron microscopy with subcycle time resolution.

3.
Diabetologia ; 67(7): 1399-1412, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38656372

RESUMO

AIMS/HYPOTHESIS: Obesity surgery (OS) and diet-induced weight loss rapidly improve insulin resistance. We aim to investigate the impact of either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery compared with a diet low in energy (low-calorie diet; LCD) on body composition, glucose control and insulin sensitivity, assessed both at the global and tissue-specific level in individuals with obesity but not diabetes. METHODS: In this parallel group randomised controlled trial, patients on a waiting list for OS were randomised (no blinding, sealed envelopes) to either undergo surgery directly or undergo an LCD before surgery. At baseline and 4 weeks after surgery (n=15, 11 RYGB and 4 SG) or 4 weeks after the start of LCD (n=9), investigations were carried out, including an OGTT and hyperinsulinaemic-euglycaemic clamps during which concomitant simultaneous whole-body [18F]fluorodeoxyglucose-positron emission tomography (PET)/MRI was performed. The primary outcome was HOMA-IR change. RESULTS: One month after bariatric surgery and initiation of LCD, both treatments induced similar reductions in body weight (mean ± SD: -7.7±1.4 kg and -7.4±2.2 kg, respectively), adipose tissue volume (7%) and liver fat content (2% units). HOMA-IR, a main endpoint, was significantly reduced following OS (-26.3% [95% CI -49.5, -3.0], p=0.009) and non-significantly following LCD (-20.9% [95% CI -58.2, 16.5). For both groups, there were similar reductions in triglycerides and LDL-cholesterol. Fasting plasma glucose and insulin were also significantly reduced only following OS. There was an increase in glucose AUC in response to an OGTT in the OS group (by 20%) but not in the LCD group. During hyperinsulinaemia, only the OS group showed a significantly increased PET-derived glucose uptake rate in skeletal muscle but a reduced uptake in the heart and abdominal adipose tissue. Both liver and brain glucose uptake rates were unchanged after surgery or LCD. Whole-body glucose disposal and endogenous glucose production were not significantly affected. CONCLUSIONS/INTERPRETATION: The short-term metabolic effects seen 4 weeks after OS are not explained by loss of body fat alone. Thus OS, but not LCD, led to reductions in fasting plasma glucose and insulin resistance as well as to distinct changes in insulin-stimulated glucose fluxes to different tissues. Such effects may contribute to the prevention or reversal of type 2 diabetes following OS. Moreover, the full effects on whole-body insulin resistance and plasma glucose require a longer time than 4 weeks. TRIAL REGISTRATION: ClinicalTrials.gov NCT02988011 FUNDING: This work was supported by AstraZeneca R&D, the Swedish Diabetes Foundation, the European Union's Horizon Europe Research project PAS GRAS, the European Commission via the Marie Sklodowska Curie Innovative Training Network TREATMENT, EXODIAB, the Family Ernfors Foundation, the P.O. Zetterling Foundation, Novo Nordisk Foundation, the Agnes and Mac Rudberg Foundation and the Uppsala University Hospital ALF grants.


Assuntos
Composição Corporal , Restrição Calórica , Fluordesoxiglucose F18 , Resistência à Insulina , Imageamento por Ressonância Magnética , Obesidade , Tomografia por Emissão de Pósitrons , Humanos , Masculino , Feminino , Composição Corporal/fisiologia , Adulto , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , Resistência à Insulina/fisiologia , Restrição Calórica/métodos , Obesidade/cirurgia , Obesidade/metabolismo , Glucose/metabolismo , Cirurgia Bariátrica , Redução de Peso/fisiologia , Derivação Gástrica , Glicemia/metabolismo , Gastrectomia/métodos
4.
Plant J ; 115(3): 627-641, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37077033

RESUMO

Plants need to integrate internal and environmental signals to mount adequate stress responses. The NUCLEAR PORE COMPLEX (NPC) component HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1 (HOS1) is emerging as such an integrator, affecting responses to cold, heat, light, and salinity. Stress conditions often converge in a low-energy signal that activates SUCROSE NON-FERMENTING 1-RELATED KINASE 1 (SnRK1) to promote stress tolerance and survival. Here, we explored the role of HOS1 in the SnRK1-dependent response to low-energy stress in Arabidopsis thaliana, using darkness as a treatment and a combination of genetic, biochemical, and phenotypic assays. We show that the induction of starvation genes and plant tolerance to prolonged darkness are defective in the hos1 mutant. HOS1 interacts physically with the SnRK1α1 catalytic subunit in yeast two-hybrid assays and in planta, and the nuclear accumulation of SnRK1α1 is reduced in the hos1 mutant. Likewise, another NPC mutant, nup160, exhibits lower activation of starvation genes and decreased tolerance to prolonged darkness. Importantly, defects in low-energy responses in the hos1 background are rescued by fusing SnRK1α1 to a potent nuclear localization signal or by sugar supplementation during the dark treatment. Altogether, this work demonstrates the importance of HOS1 for the nuclear accumulation of SnRK1α1, which is key for plant tolerance to low-energy conditions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Quinases/genética , Proteínas Nucleares/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
5.
BMC Genomics ; 25(1): 252, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448813

RESUMO

The SnRK (sucrose non-fermentation-related protein kinase) plays an important role in regulating various signals in plants. However, as an important bamboo shoot and wood species, the response mechanism of PheSnRK in Phyllostachys edulis to hormones, low energy and stress remains unclear. In this paper, we focused on the structure, expression, and response of SnRK to hormones and sugars. In this study, we identified 75 PheSnRK genes from the Moso bamboo genome, which can be divided into three groups according to the evolutionary relationship. Cis-element analysis has shown that the PheSnRK gene can respond to various hormones, light, and stress. The PheSnRK2.9 proteins were localized in the nucleus and cytoplasm. Transgenic experiments showed that overexpression of PheSnRK2.9 inhibited root development, the plants were salt-tolerant and exhibited slowed starch consumption in Arabidopsis in the dark. The results of yeast one-hybrid and dual luciferase assay showed that PheIAAs and PheNACs can regulate PheSnRK2.9 gene expression by binding to the promoter of PheSnRK2.9. This study provided a comprehensive understanding of PheSnRK genes of Moso bamboo, which provides valuable information for further research on energy regulation mechanism and stress response during the growth and development of Moso bamboo.


Assuntos
Arabidopsis , Poaceae , Poaceae/genética , Evolução Biológica , Bioensaio , Saccharomyces cerevisiae , Hormônios
6.
Small ; 20(27): e2310908, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38279585

RESUMO

The high potassization/depotassization energy barriers and lack of efficient ion diffusion pathways are two serious obstacles for carbon-based materials to achieve satisfactory potassium ion storage performance. Herein, a facile and controllable one-step exfoliation-doping-etching strategy is proposed to construct heteroatoms (N, O, and S)-doped mesoporous few-layer carbon nanosheets (NOS-C). The mixed molten salts of KCl/K2SO4 are innovatively used as the exfoliators, dopants, and etching agents, which enable NOS-C with expanded interlayer spacing and uniformly distributed mesopores with the adjusted electronic structure of surrounding carbon atoms, contributing efficient dual (vertical and horizontal) K-ion diffusion pathways, low potassization/depotassization energy barriers and abundant active sites. Thus, the NOS anodes achieve a high reversible capacity of 516.8 mAh g-1 at 0.05 A g-1, superior rate capability of 202.8 mAh g-1 at 5 A g-1 and excellent long-term cyclic stability, and their practical application potential is demonstrated by the assembled potassium-ion full batteries. Moreover, a surface-interlayer synergetic K+ storage mechanism is revealed by a combined theoretical and experimental approach including in situ EIS, in situ Raman, ex situ XPS, and SEM analysis. The proposed K+ storage mechanism and unique structural engineering provide a new pathway for potassium-ion storage devices and even beyond.

7.
Photosynth Res ; 161(3): 203-212, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38935195

RESUMO

Acaryochloris species belong to a special category of cyanobacteria possessing chlorophyll (Chl) d. One of the photosynthetic characteristics of Acaryochloris marina MBIC11017 is that the absorption spectra of photosystem I (PSI) showed almost no bands and shoulders of low-energy Chls d over 740 nm. In contrast, the absorption spectra of other Acaryochloris species showed a shoulder around 740 nm, suggesting that low-energy Chls d within PSI are diversified among Acaryochloris species. In this study, we purified PSI trimer and monomer cores from Acaryochloris sp. NBRC 102871 and examined their protein and pigment compositions and spectral properties. The protein bands and pigment compositions of the PSI trimer and monomer of NBRC102871 were virtually identical to those of MBIC11017. The absorption spectra of the NBRC102871 PSIs exhibited a shoulder around 740 nm, whereas the fluorescence spectra of PSI trimer and monomer displayed maximum peaks at 754 and 767 nm, respectively. These spectral properties were different from those of MBIC11017, indicating the presence of low-energy Chls d within the NBRC102871 PSIs. Moreover, we analyzed the NBRC102871 genome to identify amino acid sequences of PSI proteins and compared them with those of the A. marina MBIC11017 and MBIC10699 strains whose genomes are available. The results showed that some of the sequences in NBRC102871 were distinct from those in MBIC11017 and MBIC10699. These findings provide insights into the variety of low-energy Chls d with respect to the protein environments of PSI cores among the three Acaryochloris strains.


Assuntos
Clorofila , Cianobactérias , Complexo de Proteína do Fotossistema I , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema I/química , Clorofila/metabolismo , Cianobactérias/metabolismo , Cianobactérias/genética , Espectrometria de Fluorescência
8.
Osteoporos Int ; 35(10): 1759-1766, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38890177

RESUMO

Evidence regarding the risk factors and characteristics of those with foot fragility fractures compared to non-foot fragility fractures is limited. Foot fragility fracture patients are more likely to be younger female with a higher BMI. A foot fragility fracture is strongly predictive of a subsequent foot fragility fracture. PURPOSE: Osteoporosis can clinically result in fragility fractures. Evidence regarding the risk factors and characteristics of foot fragility fractures compared to non-foot fragility fractures is limited. The American Orthopaedic Association's Own the Bone (OTB) is a bone health initiative with a substantial dataset. The purpose of this study was to examine and compare characteristics of patients presenting with isolated foot fragility fracture to those with a non-foot fragility fracture. METHODS: Between January 2009 and March of 2022, 58,001 fragility fractures occurred that were included in this cohort. A total of 750 patients had foot fragility fracture(s) and 57,251 patients had a non-foot fragility fracture that included shoulder, arm, elbow, forearm, wrist, spine, ribs, pelvis, hip, thigh, knee, tibia/fibula, and ankle. Demographics, fracture history, bone health factors, medication history, and medication use for each patient were reported in the OTB database. This data was utilized in our secondary cohort comparative analysis of characteristics and the risk of future fractures between foot fragility fracture and non-foot fragility fracture groups. RESULTS: Foot fragility fracture patients have a significantly higher probability to be younger (66.9 years old), female (91.5%), and have a higher BMI (28.3 kg/m2) compared to non-foot fragility fracture (p < 0.0001) patients. Patients with a foot fragility fracture are nine times (OR = 9.119, CI = 7.44-11.18, p < 0.001) more likely to have had a prior foot fragility fracture. Young, female patients with a prior foot fragility fracture are at higher risk of a future foot fragility fracture, and this risk increased as BMI increased. CONCLUSIONS: Foot fragility fracture patients are more likely to be female and younger compared to patients with a non-foot fragility fracture. A foot fragility fracture is a sentinel event considering that a prior foot fragility fracture is strongly predictive of a subsequent foot fragility fracture. LEVEL OF EVIDENCE: 3 (retrospective cohort).


Assuntos
Bases de Dados Factuais , Fraturas por Osteoporose , Humanos , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Fraturas por Osteoporose/fisiopatologia , Idoso , Fatores de Risco , Feminino , Estados Unidos/epidemiologia , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Fatores Etários , Masculino , Traumatismos do Pé/epidemiologia , Traumatismos do Pé/complicações , Traumatismos do Pé/fisiopatologia , Índice de Massa Corporal , Osteoporose/complicações , Osteoporose/fisiopatologia , Osteoporose/epidemiologia , Fatores Sexuais
9.
Strahlenther Onkol ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748213

RESUMO

We present the rare case of a 42-year-old woman with oligometastatic lung adenocarcinoma in her first trimester of pregnancy who was treated for brain metastases with metastasectomy and intraoperative radiation therapy (IORT) using the INTRABEAM® system (Zeiss AG, Jena, Germany). This case underscores the potential of IORT in optimizing cancer treatment while safeguarding fetal health in pregnant patients.

10.
J Surg Res ; 300: 63-70, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38795674

RESUMO

INTRODUCTION: Clinical implications of screening for blunt cerebrovascular injury (BCVI) after low-energy mechanisms of injury (LEMI) remain unclear. We assessed BCVI incidence and outcomes in LEMI versus high-energy mechanisms of injury (HEMI) patients. METHODS: In this retrospective cohort study, blunt trauma adults admitted between July 2015 and June 2021 with cervical spine fractures, excluding single spinous process, osteophyte, and chronic fractures were included. Demographics, comorbidities, injuries, screening and treatment data, iatrogenic complications, and mortality were collected. Our primary end point was to compare BCVI rates between LEMI and HEMI patients. RESULTS: Eight hundred sixty patients (78%) were screened for BCVI; 120 were positive for BCVI. LEMI and HEMI groups presented similar BCVI rates (12.6% versus 14.4%; P = 0.640). Compared to HEMI patients (n = 95), LEMI patients (n = 25) were significantly older (79 ± 14.9 versus 54.3 ± 17.4, P < 0.001), more likely to be on anticoagulants before admission (64% versus 23.2%, P < 0.001), and less severely injured (LEMI injury severity score 10.9 ± 6.6 versus HEMI injury severity score 18.7 ± 11.4, P = 0.001). All but one LEMI and 90.5% of the HEMI patients had vertebral artery injuries with no significant difference in BCVI grades. One HEMI patient developed acute kidney injury because of BCVI screening. Eleven HEMI patients developed BCVI-related stroke with two related mortalities. One LEMI patient died of a BCVI-related stroke. CONCLUSIONS: BCVI rates were similar between HEMI and LEMI groups when screening based on cervical spine fractures. The LEMI group exhibited no screening or treatment complications, suggesting that benefits may outweigh the risks of screening and potential bleeding complications from treatment.


Assuntos
Traumatismo Cerebrovascular , Vértebras Cervicais , Fraturas da Coluna Vertebral , Ferimentos não Penetrantes , Humanos , Estudos Retrospectivos , Feminino , Masculino , Vértebras Cervicais/lesões , Pessoa de Meia-Idade , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/etiologia , Fraturas da Coluna Vertebral/diagnóstico , Idoso , Ferimentos não Penetrantes/diagnóstico , Ferimentos não Penetrantes/complicações , Ferimentos não Penetrantes/terapia , Ferimentos não Penetrantes/mortalidade , Ferimentos não Penetrantes/epidemiologia , Adulto , Traumatismo Cerebrovascular/diagnóstico , Traumatismo Cerebrovascular/complicações , Traumatismo Cerebrovascular/epidemiologia , Traumatismo Cerebrovascular/etiologia , Idoso de 80 Anos ou mais , Incidência , Medição de Risco/estatística & dados numéricos , Medição de Risco/métodos
11.
Eur J Nutr ; 63(3): 919-926, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38243136

RESUMO

PURPOSE: Stable isotope ratios of nitrogen (δ15N) have previously been shown to increase in human hair during periods of catabolism. The goal of this study was to assess changes in δ15N in urinary urea (δ15Nurea) and Δ15N during a short-term controlled energy deficit. METHODS: We analyzed samples from 6 recreationally active men (25 ± 1 years, BMI: 23.5 ± 0.6 kg/m2) who participated in a repeated measures cross-over study involving 4 days of energy deficit (ED, ~ 15 kcal/kg FFM) without and with exercise (ED-EX, ED + EX) and control conditions in energy balance (CON-EX, CON + EX). δ15Nurea was analyzed from urine samples, and Δ15N was calculated as δ15Nurea-δ15Ndiet, with δ15Ndiet obtained from diet prescriptions. RESULTS: δ15Nurea was significantly elevated in ED-EX (4.4 ± 0.2‰) when compared to CON-EX (3.7 ± 0.1‰; p = 0.026) and CON + EX (3.34 ± 0.13‰, p = 0.001). As a consequence, Δ15N was positive in ED-EX (0.2 ± 0.2‰) and remained negative in ED + EX (- 0.6 ± 0.5‰), CON-EX (- 1.0 ± 0.2) and CON + EX (- 1.1 ± 0.2). Differences in Δ15N were significant between ED-EX and CON-EX (p = 0.005) and ED-EX and CON + EX (p = 0.006). CONCLUSION: Our results suggest that δ15Nurea and subsequently Δ15N are responsive to a short-term energy deficit, likely due to increased amino acid oxidation to meet energy demands and preferable elimination of 14N.


Assuntos
Dieta , Nitrogênio , Masculino , Humanos , Isótopos de Nitrogênio/análise , Isótopos de Nitrogênio/metabolismo , Estudos Cross-Over , Ureia , Isótopos de Carbono/análise , Isótopos de Carbono/metabolismo
12.
Climacteric ; 27(2): 210-214, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38251861

RESUMO

OBJECTIVE: A randomized controlled study was conducted to evaluate the safety and efficacy of radiofrequency treatment in postmenopausal women not willing to use or presenting a contraindication for menopause hormone therapy (MHT) and suffering from genitourinary syndrome of menopause (GSM). METHODS: A prospective randomized open study evaluated the effect of radiofrequency treatment versus a gel (control group) in postmenopausal women suffering from GSM. Patients were assessed at baseline and after 10-12 weeks of treatment for severity of vulvovaginal atrophy, dyspareunia, pH, vaginal smear maturation index, Vaginal Health Index and Female Sexual Function Index. The difference at baseline and after 10-12 weeks of treatment and the difference in improvement were tested between groups by a two-sample t-test and the Mann-Whitney test. RESULTS: Due to the COVID-19 pandemic, we were only able to treat 48 patients (24 patients using radiofrequency and 24 patients using a gel). Globally, at the end of the study, there were no differences in changes of the measured outcomes between the group of women treated with radiofrequency and the control group. CONCLUSION: Radiofrequency treatment was found to be safe, but was not superior to a gel, although the study lacked power. The study was registered at ClinicalTrials.gov (NCT03857893).


Assuntos
Doenças dos Genitais Femininos , Doenças Vaginais , Feminino , Humanos , Doenças Vaginais/terapia , Estudos Prospectivos , Pandemias , Vagina/patologia , Menopausa , Resultado do Tratamento , Atrofia
13.
Scand J Med Sci Sports ; 34(1): e14551, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38093477

RESUMO

PURPOSE: The purpose of the study was to investigate whether carbohydrate utilization is altered during exercise in overreached endurance athletes and examine the utility of continuous glucose monitors (CGM) to detect overreaching status. METHODS: Eleven endurance athletes (M:8, F:3) completed a 5-week training block consisting of 1 week of reduced training (PRE), 3 weeks of high-intensity overload training (POST), and 1 week of recovery training (REC). Participants completed a Lamberts and Lambert Submaximal Cycling Test (LSCT) and 5 km time-trial at PRE, POST, and REC time points, 15 min following the ingestion of a 50 g glucose beverage with glucose recorded each minute via CGM. RESULTS: Performance in the 5 km time-trial was reduced at POST (∆-7 ± 10 W, p = 0.04, η p 2 = 0.35) and improved at REC (∆12 ± 9 W from PRE, p = 0.01, η p 2 = 0.66), with reductions in peak lactate (∆-3.0 ± 2.0 mmol/L, p = 0.001, η p 2 = 0.71), peak HR (∆-6 ± 3 bpm, p < 0.001, η p 2 = 0.86), and Hooper-Mackinnon well-being scores (∆10 ± 5 a.u., p < 0.001, η p 2 = 0.79), indicating athletes were functionally overreached. The respiratory exchange ratio was suppressed at POST relative to REC during the 60% (POST: 0.80 ± 0.05, REC: 0.87 ± 0.05, p < 0.001, η p 2 = 0.74), and 80% (POST: 0.93 ± 0.05, REC: 1.00 ± 0.05, p = 0.003, η p 2 = 0.68) of HR-matched submaximal stages of the LSCT. CGM glucose was reduced during HR-matched submaximal exercise in the LSCT at POST (p = 0.047, η p 2 = 0.36), but not the 5 km time-trial (p = 0.07, η p 2 = 0.28) in overreached athletes. CONCLUSION: This preliminary investigation demonstrates a reduction in CGM-derived glucose and carbohydrate oxidation during submaximal exercise in overreached athletes. The use of CGM during submaximal exercise following standardized nutrition could be employed as a monitoring tool to detect overreaching in endurance athletes.


Assuntos
Exercício Físico , Resistência Física , Humanos , Glicemia , Glucose , Atletas
14.
Scand J Med Sci Sports ; 34(1): e14553, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38268074

RESUMO

Low energy availability (LEA) is a health concern for athletes, although it may paradoxically lead to improved cardiometabolic health in the general population. We investigated the associations between LEA, body composition, and serum cardiometabolic profile in 23 physique athletes (DIET) and 21 controls (CONT) during a 5-month pre-competition diet (MID), followed by 1 week of increased energy availability (COMP) and a 5-month weight regain period (POST). Quantification of 250 serum metabolome variables was conducted by NMR spectroscopy, body composition by dual-energy x-ray absorptiometry, dietary intake by food diaries, and exercise levels by training logs. Body fat percentage decreased from 19.5 ± 7.0% to 8.3 ± 5.3% (p < 0.001) in DIET through increased exercise levels and decreased energy intake, while CONT maintained those constant. In MID, DIET had increased (FDR < 0.01) HDL cholesterol, HDL particle size and number, and decreased (FDR < 0.05) VLDL lipids, serum triglycerides, and low-grade inflammation (glycoprotein acetyls) compared to baseline and CONT. The changes were associated with reduced android fat mass (-78 ± 13%) and energy intake (-28 ± 10%). In COMP, most of the metabolic changes found in MID persisted, except for altered triglycerides in all lipoprotein classes. After weight regain in POST, serum metabolome, body composition, energy intake, and exercise levels had reverted to baseline levels. In conclusion, fat loss and LEA may have beneficial yet transient effects on the serum cardiometabolic profile of lean individuals. Especially the HDL lipidome and lipoprotein triglycerides offer potential novel biomarkers for detecting LEA in athletes.


Assuntos
Atletas , Doenças Cardiovasculares , Humanos , HDL-Colesterol , Triglicerídeos , Aumento de Peso
15.
J Hum Nutr Diet ; 37(4): 995-1006, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38798236

RESUMO

BACKGROUND: The Manchester Intermittent versus Daily Diet App Study (MIDDAS) tested the feasibility and potential efficacy of two remotely delivered low-energy diet (LED) programmes (800 kcal/day) to support weight loss and remission of type 2 diabetes: continuous [CLED] (8 weeks of daily LED) and intermittent [ILED] (2 days of LED/week for 28 weeks). Understanding participant experiences can help us to understand the acceptability of LED programmes to people with type 2 diabetes, informing future programme development and implementation. METHODS: Twenty participants (10 CLED; 10 ILED) took part in interviews conducted at the end of the active weight loss phase (CLED week 12, ILED week 28). Interviews were transcribed and analysed thematically using the template analysis approach, with an a priori focus on acceptability. Four themes are presented: prospective acceptability, intervention coherence and perceived effectiveness, opportunity costs and self-efficacy. RESULTS: Both remotely supported CLED and ILED interventions appeared acceptable to participants. CLED participants found the rapid initial weight loss phase comparatively easy and highly motivating but expressed more concerns around weight maintenance. ILED participants found the more gradual weight loss initially frustrating but expressed greater confidence in their longer-term adherence. The importance of continued individualised support from healthcare professionals was emphasised, and evidence of weight loss and improvement in other medical markers through monitoring via the mobile phone app was useful. CONCLUSION: Different approaches to remotely delivered LEDs appear acceptable; therefore asking patients which approach may be more acceptable to them may be a useful way to offer individualised and tailored support.


Assuntos
Restrição Calórica , Diabetes Mellitus Tipo 2 , Redução de Peso , Humanos , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/terapia , Masculino , Feminino , Pessoa de Meia-Idade , Restrição Calórica/métodos , Idoso , Aceitação pelo Paciente de Cuidados de Saúde , Programas de Redução de Peso/métodos , Dieta Redutora/métodos , Autoeficácia , Estudos de Viabilidade , Indução de Remissão , Adulto , Aplicativos Móveis , Resultado do Tratamento , Estudos Prospectivos
16.
Proc Natl Acad Sci U S A ; 118(51)2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34911762

RESUMO

Imaging of proteins at the single-molecule level can reveal conformational variability, which is essential for the understanding of biomolecules. To this end, a biologically relevant state of the sample must be retained during both sample preparation and imaging. Native electrospray ionization (ESI) can transfer even the largest protein complexes into the gas phase while preserving their stoichiometry and overall shape. High-resolution imaging of protein structures following native ESI is thus of fundamental interest for establishing the relation between gas phase and solution structure. Taking advantage of low-energy electron holography's (LEEH) unique capability of imaging individual proteins with subnanometer resolution, we investigate the conformational flexibility of Herceptin, a monoclonal IgG antibody, deposited by native electrospray mass-selected ion beam deposition (ES-IBD) on graphene. Images reconstructed from holograms reveal a large variety of conformers. Some of these conformations can be mapped to the crystallographic structure of IgG, while others suggest that a compact, gas-phase-related conformation, adopted by the molecules during ES-IBD, is retained. We can steer the ratio of those two types of conformations by changing the landing energy of the protein on the single-layer graphene surface. Overall, we show that LEEH can elucidate the conformational heterogeneity of inherently flexible proteins, exemplified here by IgG antibodies, and thereby distinguish gas-phase collapse from rearrangement on surfaces.


Assuntos
Holografia/métodos , Imunoglobulina G/química , Imagem Individual de Molécula/métodos , Conformação Proteica , Espectrometria de Massas por Ionização por Electrospray
17.
J Hum Nutr Diet ; 37(4): 919-926, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38536127

RESUMO

BACKGROUND: Neurological impairment (NI) relates to disorders of the central nervous system. The specific aetiology of NI varies but includes genetic, congenital abnormalities or brain injury. In children with severe NI, feeding impairments can lead to undernutrition, and some children require a feeding tube. Although tube feeding improves overall nutritional status, it has also been associated with excess body fat. Commercially available enteral formulas that are low in energy, hydrolysed and nutritionally adequate for protein and micronutrients are available to mitigate gastrointestinal symptoms and obesity. METHODS: This is a retrospective multicentre study of children who attended NI clinics between January 2022 and July 2023. Data were collected before and 1 month after receiving a low-energy, partially hydrolysed enteral formula (0.6 kcal/mL) on demographic data (age, sex, ethnicity and NI diagnosis), anthropometric measurements (weight, height, weight-for-age Z-score, height-for-age Z-score, body mass index [BMI] Z-score) and feed regimen (feed volume, total fluids and type of formula/supplements). RESULTS: Dietitians collected data on 28 children, the median age was 7 years (interquartile range [IQR] 3, 8). The most frequently recorded NI was cerebral palsy, in 13 of 28 children (48%). Before the formula switch, the most frequently reported gastrointestinal symptom was constipation, in 13 of 28 children. Within 1 month of switching to a low-energy, hydrolysed formula, 10 of the 13 (77%) children reported an improvement in constipation. Before the formula switch, all 28 children were experiencing excessive weight gain. After the formula was switched to low-energy, hydrolysed formula, dietitians reported that 20 of the 28 (76%) children's weight either stabilised or reduced after 1 month. There was no statistically significant difference in weight-for-age Z-score or BMI Z-scores postswitch of formula (p-value 0.1 and 0.09, respectively). Fibre intake increased significantly from 3.3 to 8.1 g/day (p-value < 0.01) after formula switch. The number of children whose feed regimens were simplified after switching to a low-energy, partially hydrolysed formula was 24 of 28 (91%). CONCLUSIONS: Children with an NI who have gastrointestinal symptoms may benefit from a low-energy, hydrolysed enteral formula to maximise feed tolerance and promote healthy weight gain. In addition, changing to a low-energy, hydrolysed formula may simplify feed regimens by eliminating the need for additional electrolytes, multivitamins and fluid boluses. Healthcare professionals should be knowledgeable about the effectiveness and availability of a low-energy, hydrolysed formula.


Assuntos
Nutrição Enteral , Alimentos Formulados , Doenças do Sistema Nervoso , Humanos , Estudos Retrospectivos , Criança , Masculino , Feminino , Nutrição Enteral/métodos , Pré-Escolar , Doenças do Sistema Nervoso/dietoterapia , Gastroenteropatias/etiologia , Peso Corporal , Ingestão de Energia , Estado Nutricional
18.
J Ren Nutr ; 34(2): 141-153, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37769751

RESUMO

OBJECTIVES: Obesity is a modifiable risk factor for chronic kidney disease (CKD) progression. Low energy diets (LEDs) have not been adequately studied in people with CKD. This study aimed to explore acceptability, adherence, safety, and experiences of two LED prescriptions in adults living with obesity and CKD. DESIGN AND METHODS: In a mixed-methods study, obese adults with CKD were prescribed two LEDs (∼800 to 1000 kcal/day each), in a randomised order for 2 weeks each. One diet consisted of four meal replacement products daily (Optifast®, Nestlé Health Science) and the other two pre-prepared frozen meals (Lite n' Easy®, Mitchell's Quality Foods). Participants received weekly dietitian support, completed daily adherence checklists (converted to % of provided meals/replacements consumed) and participated in post-intervention semi-structured interviews to capture their experience. RESULTS: Nine participants were included (mean age 46.5 ± 14.3 years, estimated glomerular filtration rate 64 ± 26 mL/min/1.73 m2, 4/9 male). Mean self-reported adherence was 88 ± 11% and mean 4-week weight change was -7.3 ± 5.6 kg. Two participants withdrew at week two. Most frequently reported side effects were hunger and headaches. Adverse events of interest included one episode each of hyperkalaemia and hypoglycaemia. No serious adverse events occurred. Four overarching themes of patient experiences were identified: strategies used to adapt, disruption to the norm, individual preferences, and influences on acceptability. CONCLUSIONS: LEDs were found to be acceptable and safe with high self-reported adherence rates. Future LED trials should include specialist diabetes management, close monitoring for hyperkalaemia and adequate support to assist with managing side effects and dietary and social adjustments.


Assuntos
Hiperpotassemia , Insuficiência Renal Crônica , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico
19.
J Appl Clin Med Phys ; : e14531, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39259853

RESUMO

PURPOSE: To characterize the dose-response, energy dependence, postexposure changes, orientation dependence, and spatial capabilities of LD-V1, a new low-dose Gafchromic film for low-energy x-ray dosimetry. METHODS: A single sheet of LD-V1 Gafchromic film was cut into 15 × 20 mm2 rectangles with a notch to track orientation. Eight different doses between 5 and 320 mGy were delivered by an MXR-160/22 x-ray tube using x-ray beams of 90, 100, and 120 kVp filtered with 3 mm of Al and 2 mm of Ti. The 120 kVp films were scanned at 1, 1.5, 2, 3, 12, 24, 48, 72, and 168 h postexposure in portrait orientation and additionally scanned in landscape orientation at 24 h. The 90 and 100 kVp films were scanned at 24 h postexposure in portrait orientation. Lastly, a 20 × 200 mm2 strip of film was irradiated using a thin-slit imaging collimator and scanned 24 h postexposure to test the film performance in an x-ray imaging application. RESULTS: Of the three color channels, the red channel was found to produce a dose-response curve with a large range of net optical density (netOD) values across the considered dose range. A prominent energy dependence was discovered, resulting in dose discrepancies on the scale of 17 mGy between 90 and 120 kVp for a dose of 80 mGy. The measured postexposure changes suggest that the calibration irradiation-to-scan time should be longer than 12 h with a ± 4 h scanning time window for dose errors of <0.5%. An average dose difference of 3.4% was found between the two scanning orientations. Lastly, noise of 4% was measured in the thin slit collimator film for a dose of 30 mGy. CONCLUSIONS: We have characterized the LD-V1 film for low-energy, low-dose x-ray dosimetry. Energy, scan-time, and orientation dependencies should be considered when using this film.

20.
Int J Sport Nutr Exerc Metab ; 34(5): 253-257, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38796175

RESUMO

Despite the increased popularity of female elite road cycling, research to inform the fueling requirements of these endurance athletes is lacking. In this case study, we report for the first time the energetics of a female world-tour cyclist competing in the 2023 Tour de France Femmes, an 8-day race of the Union Cycliste Internationale. The 29-year-old athlete presented with oligomenorrhea and low T3 before the race. Total daily energy expenditure assessed with the doubly labeled water technique was 7,572 kcal/day (∼4.3 physical activity levels), among the highest reported in the literature to date for a female. Crank-based mean maximal power was consistent with female world-tour cyclists (5 min, mean 342 W, 4.8 W/kg; 20 min 289 W, 4.1 W/kg). The average daily energy intake measured with the remote food photography method (Stage Days 1-7) was 5,246 kcal and carbohydrate intake was 13.7 g/kg (range 9.7-15.9 g/kg), and 84 g/hr during stages, and an average fat intake of 15% of daily energy intake. An estimated 2,326 kcal/day energy deficit was evidenced in a 2.2 kg decrease in body mass. Notwithstanding the high carbohydrate intake, the athlete was unable to match the energy requirements of the competition. Despite signs of energy deficiency preexisting (oligomenorrhea and low T3), and other further developing during the race (weight loss), performance was in line with that of other world-tour cyclists and a best personal performance was recorded for the last stage. This case study emphasizes the need for further research to inform energy requirements for female athletes' optimal performance and health.


Assuntos
Atletas , Ciclismo , Ingestão de Energia , Metabolismo Energético , Humanos , Feminino , Ciclismo/fisiologia , Adulto , Resistência Física/fisiologia , Fenômenos Fisiológicos da Nutrição Esportiva , França , Carboidratos da Dieta/administração & dosagem
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