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1.
J Phys Condens Matter ; 36(31)2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38663418

RESUMO

Topological insulator (TI) surface states exert strong spin-orbit torques. When the magnetization is in the plane its interaction with the TI conduction electrons is non-trivial, and is influenced by extrinsic spin-orbit scattering. This is expected to be strong in TIs but is difficult to calculate and to measure unambiguously. Here we show that extrinsic spin-orbit scattering sizably renormalizes the surface state spin-orbit torque resulting in a strong density dependence. The magnitude of the renormalization of the spin torque and the effect of spin-orbit scattering on the relative sizes of the in-plane and out-of-plane field-like torques have strong implications for experiment: We propose two separate experimental signatures for the measurement of its presence.

2.
Sci Rep ; 13(1): 8900, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37264062

RESUMO

This study examined the effects of maternal and/or post-weaning Bacillus altitudinis supplementation on the microbiota in sow colostrum and faeces, and offspring digesta and faeces. Sows (n = 12/group) were assigned to: (1) standard diet (CON), or (2) CON supplemented with probiotic B. altitudinis spores (PRO) from day (d)100 of gestation to weaning (d26 of lactation). At weaning, offspring were assigned to CON or PRO for 28d, resulting in: (1) CON/CON, (2) CON/PRO, (3) PRO/CON, and (4) PRO/PRO, after which all received CON. Samples were collected from sows and selected offspring (n = 10/group) for 16S rRNA gene sequencing. Rothia was more abundant in PRO sow colostrum. Sow faeces were not impacted but differences were identified in offspring faeces and digesta. Most were in the ileal digesta between PRO/CON and CON/CON on d8 post-weaning; i.e. Bacteroidota, Alloprevotella, Prevotella, Prevotellaceae, Turicibacter, Catenibacterium and Blautia were more abundant in PRO/CON, with Firmicutes and Blautia more abundant in PRO/PRO compared with CON/CON. Lactobacillus was more abundant in PRO/CON faeces on d118 post-weaning. This increased abundance of polysaccharide-fermenters (Prevotella, Alloprevotella, Prevotellaceae), butyrate-producers (Blautia) and Lactobacillus likely contributed to previously reported improvements in growth performance. Overall, maternal, rather than post-weaning, probiotic supplementation had the greatest impact on intestinal microbiota.


Assuntos
Colostro , Dieta , Gravidez , Suínos , Animais , Feminino , Dieta/veterinária , Desmame , RNA Ribossômico 16S/genética , Esporos Bacterianos , Lactação , Suplementos Nutricionais , Fezes/microbiologia , Ração Animal/análise
3.
Nanoscale ; 15(18): 8437-8446, 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37096561

RESUMO

Spin torques at topological insulator (TI)/ferromagnet interfaces have received considerable attention in recent years with a view towards achieving full electrical manipulation of magnetic degrees of freedom. The most important question in this field concerns the relative contributions of bulk and surface states to the spin torque, a matter that remains incompletely understood. Whereas the surface state contribution has been extensively studied, the contribution due to the bulk states has received comparatively little attention. Here we study spin torques due to TI bulk states and show that: (i) there is no spin-orbit torque due to the bulk states on a homogeneous magnetisation, in contrast to the surface states, which give rise to a spin-orbit torque via the well-known Edelstein effect. (ii) The bulk states give rise to a spin transfer torque (STT) due to the inhomogeneity of the magnetisation in the vicinity of the interface. This spin transfer torque, which has not been considered in TIs in the past, is somewhat unconventional since it arises from the interplay of the bulk TI spin-orbit coupling and the gradient of the monotonically decaying magnetisation inside the TI. Whereas we consider an idealised model in which the magnetisation gradient is small and the spin transfer torque is correspondingly small, we argue that in real samples the spin transfer torque should be sizable and may provide the dominant contribution due to the bulk states. We show that an experimental smoking gun for identifying the bulk states is the fact that the field-like component of the spin transfer torque generates a spin density with the same size but opposite sign for in-plane and out-of-plane magnetisations. This distinguishes them from the surface states, which are expected to give a spin density of a similar size and the same sign for both an in-plane and out-of-plane magnetisations.

4.
Catheter Cardiovasc Interv ; 100(4): 585-592, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36104863

RESUMO

INTRODUCTION: Left main stem percutaneous coronary intervention (LMS-PCI) is a complex high-risk procedure which can be performed as an alternative to coronary artery bypass graft (CABG) procedure in surgical turn-down patients or where there is equipoise in percutaneous versus surgical strategies. Current guidelines suggest that PCI is an appropriate alternative to CABG in patients with unprotected LMS disease and low SYNTAX score. However, "real world" data on outcomes of LMS-PCI remain limited. This study aims to quantify and determine predictors of mortality following LMS-PCI. METHODS: Using local coronary angioplasty registries from two UK centers, all LMS-PCI cases were identified from 2016 to 2020. Descriptive statistics and multivariate logistic regressions were used to examine the association between baseline and procedural characteristics with 30-day and 12-month mortality. RESULTS: We identified 484 cases of LMS-PCI between 2016 and 2020. There was a year-on-year increase in the number of LMS-PCI, the highest being in 2020. Covariates associated with higher 30-day mortality were age (OR 1.07, 95% CI: 1.02-1.12) and shock preprocedure (OR 23.88, 95% CI: 7.90-72.20). Covariates associated with higher 12-month mortality were age (OR 1.04, 95% CI: 1.01-1.08), acute coronary syndrome (ACS) (OR 2.50, 95% CI: 1.08-5.80), renal disease (OR 5.24, 95% CI: 1.47-18.68), and shock preprocedure (OR 7.93, 95% CI: 3.30-19.05). Overall, 30-day and 12-month mortality in this contemporary data set were 9.5% and 16.7%, respectively, with significantly lower rates in elective cases (p < 0.01). CONCLUSIONS: Older age and cardiogenic shock preprocedure were associated with increased 30-day mortality after LMS-PCI. Twelve-month mortality was associated with older age, ACS presentation, preexisting renal disease, and cardiogenic shock preprocedure.


Assuntos
Síndrome Coronariana Aguda , Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Fatores de Risco , Choque Cardiogênico , Resultado do Tratamento , Reino Unido/epidemiologia
5.
Animals (Basel) ; 11(10)2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34680002

RESUMO

There is evidence that spontaneous fermentation frequently occurs in liquid pig feed that is intended to be delivered as fresh liquid feed, often with a resultant deterioration in the microbial and nutritional quality of the feed, which can negatively affect pig health and growth. Strategies including controlled fermentation with microbial inoculants, pre-fermentation or soaking of the cereal fraction of the diet, enzyme supplementation and dietary acidification have been employed to inhibit pathogens and prevent deterioration of feed nutritional quality, with promising results obtained in many cases. This review evaluates the impact of these strategies on the microbial quality of liquid feed and discusses how they can be further improved. It also investigates if/how these strategies impact the pig gut microbiota and growth performance of liquid-fed pigs. Finally, we review liquid feed system sanitisation practices, which are highly variable from farm to farm and discuss the impact of these practices and whether they are beneficial or detrimental to liquid feed microbial quality. Overall, we provide a comprehensive review of the current state of knowledge on liquid feed for pigs, focusing on factors affecting microbial quality and strategies for its optimisation, as well as its impact on the pig gut microbiome.

6.
Phys Rev Lett ; 126(25): 256601, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34241516

RESUMO

We demonstrate that the Berry curvature monopole of nonmagnetic two-dimensional spin-3/2 holes leads to a novel Hall effect linear in an applied in-plane magnetic field B_{∥}. Remarkably, all scalar and spin-dependent disorder contributions vanish to leading order in B_{∥}, while there is no Lorentz force and hence no ordinary Hall effect. This purely intrinsic phenomenon, which we term the anomalous planar Hall effect (APHE), provides a direct transport probe of the Berry curvature accessible in all p-type semiconductors. We discuss experimental setups for its measurement.

7.
Surg Neurol Int ; 11: 297, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33093974

RESUMO

BACKGROUND: Myxopapillary ependymoma occurs more frequently in adults, but is found in the first two decades of life in around 8-20% of patients. Tumors are usually benign with low likelihood for dissemination. CASE DESCRIPTION: We describe a case of a 13-year-old boy who presented with progressive kyphosis and bilateral weakness of the lower limbs. MRI shows a thoracolumbosacral intradural tumor with invasion of sacral neural foramina and dissemination to the cervicothoracic region. The patient received T10-L5 laminectomy with subtotal tumor resection. Pathological examination revealed myxopapillary ependymoma. After surgical resection, the patient underwent physical therapy with whole spinal radiotherapy for disease control. CONCLUSION: Spinal myxopapillary ependymomas are usually benign and slow-growing tumors. This case illustrates an extensive and disseminated myxopapillary ependymoma.

8.
J Invasive Cardiol ; 32(9): E244-E245, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32865513

RESUMO

Interventional cardiologists should maintain awareness of extracardiac structures when undertaking cardiac catheterization, as pathology outside of the coronary arteries may be identified.


Assuntos
Cateterismo Cardíaco , Vasos Coronários , Idoso , Angiografia , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos
9.
Sci Rep ; 10(1): 13716, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792575

RESUMO

This study aimed to determine the impact of fermenting the cereal fraction of the diet (Cferm) and enzyme supplementation (ENZ) on the bacterial composition of the feed, nutrient digestibility, pig growth, feed efficiency (FE), intestinal volatile fatty acid (VFA) concentrations and intestinal microbiota composition. A total of 252 grow-finisher pigs (~ 40.4 kg; 7 pigs/pen) were randomly allocated to 4 diets in a 2 × 2 factorial arrangement for 55d. The diets were: (1) fresh liquid feed (Fresh); (2) Cferm liquid feed (Ferm); (3) Fresh + ENZ and (4) Ferm + ENZ. Cferm increased total tract nutrient digestibility, reduced caecal butyrate and propionate concentrations, and increased average daily gain (ADG). ENZ increased ileal and total tract nutrient digestibility, reduced caecal isobutyrate and propionate concentrations, and improved FE. Bacterial taxa positively correlated with pig growth (Lactobacillus kisonensis in the ileum and Roseburia faecis in the caecum) were more abundant in pigs fed ENZ diets, whereas most of the ileal bacterial taxa negatively correlated with growth (Megasphaera, Bifidobacterium and Streptococcus) had lower abundance in pigs fed Cferm diets. In conclusion, Cferm increased ADG and ENZ improved FE, with these improvements possibly mediated by increased nutrient digestibility, and beneficial modulation of the intestinal microbiota.


Assuntos
Ração Animal/análise , Suplementos Nutricionais , Microbioma Gastrointestinal , Glicosídeo Hidrolases/administração & dosagem , Nutrientes/metabolismo , Suínos/crescimento & desenvolvimento , Suínos/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Digestão , Grão Comestível/química , Grão Comestível/metabolismo , Fermentação , Trato Gastrointestinal/microbiologia , Glicosídeo Hidrolases/metabolismo , Masculino
11.
J Alzheimers Dis ; 75(4): 1211-1218, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32417786

RESUMO

BACKGROUND: Alzheimer's disease (AD) begins decades before the onset of dementia. There is a need to investigate biomarkers of early AD for use in clinical trials and to facilitate early intervention. OBJECTIVE: We aimed to determine whether changes in hippocampal subfield volumes in healthy middle-aged adults were associated with risk of future dementia. METHODS: We included 150 participants from the PREVENT-Dementia cohort, which recruited subjects aged 40-59 with or without a family history of dementia (FHD; included here were 81 with FHD and 69 without). Hippocampal subfield volumes were segmented from high resolution T2-weighted 3T MRI images taken at baseline and 2-year follow-up. RESULTS: FHD and greater 20 year-risk of dementia due to cardiovascular risk factors were both associated with lower CA1 volume. FHD was also associated with a relative increase in combined CA3, CA4, and dentate gyrus volume between baseline and follow-up. CONCLUSION: CA1 atrophy may commence as early as middle-age in those with a high risk of future dementia, while increases in CA3, CA4, and dentate gyrus volume may be a response to early AD in the form of inflammation or neurogenesis.


Assuntos
Demência/patologia , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Adulto , Atrofia/diagnóstico por imagem , Demência/diagnóstico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Fatores de Risco
12.
Acta Neurochir (Wien) ; 161(11): 2397-2401, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31489531

RESUMO

BACKGROUND: Specific procedural complications in aneurysm surgery are broadly related to vascular territory compromise and brain/nerve retraction; vascular complications account for about half of this. Intraoperative indocyanine green video angiography (ICG-VA) provides real-time high spatial resolution imaging of the cerebrovascular architecture, allowing immediate quality assurance of aneurysm occlusion and vessel integrity. The aim of this study was to examine whether the routine use of ICG-VA reduced early procedural complications related to vascular compromise or injury during micro-neurosurgical clipping of ruptured cerebral aneurysms. METHODS: Retrospective comparative observational study of 412 adult good-grade (WFNS 1 or 2) SAH patients who had undergone microsurgical clipping without (n = 200, 2001-2004) or with (n = 212, 2009-2015) ICG-VA in a high-volume neurosurgical centre. RESULTS: The ICG-VA group had a significantly lower incidence of procedural vascular complications (7/212; 3.3%) compared with the non-ICG-VA group (19/200; 9.5%) (Fisher's exact test p = 0.0137). CONCLUSIONS: ICG-VA is a straightforward, easy-to-use, intraoperative adjunct which significantly reduces avoidable 'technical error' related morbidity.


Assuntos
Aneurisma Roto/cirurgia , Angiografia Cerebral/métodos , Aneurisma Intracraniano/cirurgia , Complicações Intraoperatórias/prevenção & controle , Microcirurgia/métodos , Monitorização Intraoperatória/métodos , Procedimentos Cirúrgicos Vasculares/métodos , Adulto , Idoso , Feminino , Corantes Fluorescentes , Humanos , Verde de Indocianina , Masculino , Microcirurgia/efeitos adversos , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Vasculares/efeitos adversos
18.
J Endod ; 41(6): 920-4, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25791075

RESUMO

INTRODUCTION: The purpose of this study was to evaluate the effect of various concentrations of sodium hypochlorite (NaOCl), including 8.25%, on dental pulp dissolution and dentin flexural strength and modulus. METHODS: Sixty dental pulp samples and 55 plane parallel dentin bars were retrieved from extracted human teeth. Five test groups (n = 10) were formed consisting of a pulp sample and dentin bar immersed in various NaOCl solutions. The negative control group (n = 5) consisted of pulp samples and dentin bars immersed in saline. The positive control group (n = 5) consisted of pulp samples immersed in 8.25% NaOCl without a dentin bar. Every 6 minutes for 1 hour, the solutions were refreshed. The dentin bars were tested for flexural strength and modulus with a 3-point bend test. The time until total pulp dissolution and any changes in dentin bar flexural strength and modulus for the different NaOCl solutions were statistically analyzed. RESULTS: An increase in NaOCl concentration showed a highly significant decrease in pulp dissolution time. The pulp dissolution property of 8.25% NaOCl was significantly faster than any other tested concentration of NaOCl. The presence of dentin did not have a significant effect on the dissolution capacity of NaOCl if the solutions were refreshed. NaOCl concentration did not have a statistically significant effect on dentin flexural strength or modulus. CONCLUSIONS: Dilution of NaOCl decreases its pulp dissolution capacity. Refreshing the solution is essential to counteract the effects of dentin. In this study, NaOCl did not have a significant effect on dentin flexural strength or modulus.


Assuntos
Polpa Dentária/efeitos dos fármacos , Dentina/efeitos dos fármacos , Irrigantes do Canal Radicular/administração & dosagem , Hipoclorito de Sódio/administração & dosagem , Análise do Estresse Dentário , Dentina/fisiologia , Elasticidade , Humanos , Dente Molar , Estresse Mecânico
19.
Singapore Med J ; 55(9): 473-5, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25273931

RESUMO

We report five cases of non-arteritic anterior ischaemic optic neuropathy (NA-AION) where spontaneous resolution of the optic disc swelling occurred, and all relevant visual modalities were normal at presentation and remained so until resolution of the process after a median time of 9.6 weeks. This condition, which can be termed 'incipient NA­AION' or 'threatened NA-AION', should be recognised so that unnecessary investigations for other and more serious causes of optic disc swelling can be prevented.


Assuntos
Neuropatia Óptica Isquêmica/diagnóstico , Agonistas de Receptores Adrenérgicos alfa 2/uso terapêutico , Adulto , Tartarato de Brimonidina/uso terapêutico , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Soluções Oftálmicas , Disco Óptico/patologia , Singapura , Fatores de Tempo , Visão Ocular , Acuidade Visual
20.
Transl Oncol ; 7(1): 55-64, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24772208

RESUMO

BACKGROUND: Preclinical data have indicated the anti-epidermal growth factor receptor (EGFR) agent cetuximab (Erbitux) as a radiosensitizer in pancreatic cancer, but this has not been specifically addressed in a clinical study. We report the results of an original study initiated in 2007, where cetuximab was tested with radiotherapy (RT) alone in locally advanced pancreatic cancer in a phase II trial (PACER). METHODS: Patients (n = 21) received cetuximab loading dose (400 mg/m(2)) and weekly dose (250 mg/m(2)) during RT (50.4 Gy in 28 fractions). Toxicity and disease response end point data were prospectively assessed. A feasibility study of on-trial patient blood and skin sampling was incorporated. RESULTS: Treatment was well tolerated, and toxicity was low; most patients (71%) experienced acute toxicities of grade 2 or less. Six months posttreatment, stable local disease was achieved in 90% of evaluable patients, but only 33% were free from metastatic progression. Median overall survival was 7.5 months, and actuarial survival was 33% at 1 year and 11% at 3 years, reflecting swift metastatic progression in some patients but good long-term control of localized disease in others. High-grade acneiform rash (P = .0027), posttreatment stable disease (P = .0059), and pretreatment cancer antigen 19.9 (CA19.9) level (P = .0042) associated with extended survival. Patient skin and blood samples yielded sufficient RNA and good quality protein, respectively. CONCLUSIONS: The results indicate that cetuximab inhibits EGFR-mediated radioresistance to achieve excellent local control with minimal toxicity but does not sufficiently control metastatic progression in all patients. Translational studies of patient tissue samples may yield molecular information that may enable individual treatment response prediction.

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