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1.
BMC Med Educ ; 23(1): 761, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37828485

RESUMO

BACKGROUND: Life expectancy in recent decades has increased the prevalence of chronic diseases in the population, requiring an approach to new health topics, such as discussions on quality of life and expectations about death and dying. The concept of advance directives (ADs) gives individuals the opportunity to make known their decisions about the treatments they would like to receive at the end of life. Despite the recognition of relevance in clinical practice, the applicability of the concept presents challenges, including establishing the appropriate prognosis for each patient and the ideal time to approach the patient. Some prognostic tools were developed, such as the surprise question (SQ): "Would you be surprised if your patient died in 12 months?", which is used in some clinical settings to predict patient deaths and to make decisions regarding ADs. The main objective of the present study was to evaluate the behavior of second-year resident physicians (PGY-2) when the SQ was applied. METHOD: In our observational study, from July 1, 2016, to February 28, 2017, (PGY-2) in the Internal Medicine Residency Program (IMRP) applied SQ to all patients with multiple and varied chronic no communicable comorbidities, who were followed up at the general medicine outpatient clinic (GMOC) of a tertiary university hospital in São Paulo- Brazil. The frequency of the outcome (death or non-death within 12 months) was analyzed by correlating it with the clinical data (impact of the studied variables). RESULTS: Eight hundred forty patients entered the study. Fitfty-two of them (6.2%) died within one year. PGY-2 predicted that two hundred and fourteen patients (25.5% of total) would die within a year (answer No to SQ), of which, 32 (14.9%) did so. The correct residents' prognosis for the subgroup of 626 patients (answer "Yes" to SQ) was NPV = 96.8% (CI = 95.4%-98.2%) and PPV = 14.9% (CI 10.1%-19, 6%). Answering "Yes" to SQ correlated negatively to addressing AD while the outcomes death and the answer No to SQ were positively correlated, according to the number of comorbidities. CONCLUSION: The SQ, in addition to care, contributed to health education, communication and care planning shared by the doctor and patient.


Assuntos
Pacientes Ambulatoriais , Cuidados Paliativos , Humanos , Prognóstico , Qualidade de Vida , Estudos Prospectivos , Brasil/epidemiologia
2.
Phys Rev Lett ; 129(24): 242502, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36563237

RESUMO

ß decay of proton-rich nuclei plays an important role in exploring isospin mixing. The ß decay of ^{26}P at the proton drip line is studied using double-sided silicon strip detectors operating in conjunction with high-purity germanium detectors. The T=2 isobaric analog state (IAS) at 13 055 keV and two new high-lying states at 13 380 and 11 912 keV in ^{26}Si are unambiguously identified through ß-delayed two-proton emission (ß2p). Angular correlations of two protons emitted from ^{26}Si excited states populated by ^{26}P ß decay are measured, which suggests that the two protons are emitted mainly sequentially. We report the first observation of a strongly isospin-mixed doublet that deexcites mainly via two-proton decay. The isospin mixing matrix element between the ^{26}Si IAS and the nearby 13 380-keV state is determined to be 130(21) keV, and this result represents the strongest mixing, highest excitation energy, and largest level spacing of a doublet ever observed in ß-decay experiments.

3.
Nat Commun ; 13(1): 7193, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36424384

RESUMO

The dynamics of a nuclear open quantum system could be revealed in the correlations between the breakup fragments of halo nuclei. The breakup mechanism of a proton halo nuclear system is of particular interest as the Coulomb polarization may play an important role, which, however, remains an open question. Here we use a highly efficient silicon detector array and measure the correlations between the breakup fragments of 8B incident on 120Sn at near-barrier energies. The energy and angular correlations can be explained by a fully quantum mechanical method based on the state-of-the-art continuum discretized coupled channel calculations. The results indicate that, compared to the neutron halo nucleus 6He, 8B presents distinctive reaction dynamics: the dominance of the elastic breakup. This breakup occurs mainly via the short-lived continuum states, almost exhausts the 7Be yield, indicating the effect of Coulomb polarization on the proton halo state. The correlation information reveals that the prompt breakup mechanism dominates, occurring predominantly on the outgoing trajectory. We also show that, as a large environment, the continuum of 8B breakup may not significantly influence elastic scattering and complete fusion.

4.
Hum Reprod Open ; 2021(4): hoab034, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34532597

RESUMO

STUDY QUESTION: Is it possible to develop a simplified physiological in vitro system representing the key cell-types associated with a receptive endometrial phenotype? SUMMARY ANSWER: We present a new concept to investigate endometrial receptivity, with a 3D organotypic co-culture model to simulate an early and transient acute autoinflammatory decidual status that resolves in the induction of a receptive endometrial phenotype. WHAT IS KNOWN ALREADY: Embryo implantation is dependent on a receptive uterine environment. Ovarian steroids drive post-ovulation structural and functional changes in the endometrium, which becomes transiently receptive for an implanting conceptus, termed the 'window of implantation', and dysregulation of endometrial receptivity is implicated in a range of reproductive, obstetric, and gynaecological disorders and malignancies. The interactions that take place within the uterine microenvironment during this time are not fully understood, and human studies are constrained by a lack of access to uterine tissue from specific time-points during the menstrual cycle. Physiologically relevant in vitro model systems are therefore fundamental for conducting investigations to better understand the cellular and molecular mechanisms controlling endometrial receptivity. STUDY DESIGN SIZE DURATION: We conducted an in vitro cell culture study using human cell lines and primary human cells isolated from endometrial biopsy tissue. The biopsy tissue samples were obtained from three women attending gynaecological outpatient departments in NHS Lothian. The work was carried out between December 2016 and April 2019, at the MRC Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh. PARTICIPANTS/MATERIALS SETTING METHODS: An endometrial stromal cell (ESC) line, and endometrial epithelial cells (EECs) isolated from endometrial biopsy tissue and expanded in vitro by conditional reprogramming, were used throughout the study. Immunocytochemical and flow cytometric analyses were used to confirm epithelial phenotype following conditional reprogramming of EECs. To construct an endometrial organotypic co-culture model, ESCs were embedded within a 3D growth factor-reduced Matrigel structure, with a single layer of conditionally reprogrammed EECs seeded on top. Cells were stimulated with increasing doses of medroxyprogesterone acetate, cAMP and oestradiol, in order to induce ESC decidual transformation and endometrial receptivity. Decidual response and the induction of a receptive epithelial phenotype were assessed by immunocytochemical detection and quantitative in-cell western analyses, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: A transient up-regulation of the interleukin-33 receptor protein, ST2L, was observed in ESCs, indicating a transient autoinflammatory decidual response to the hormonal stimulation, known to induce receptivity gene expression in the overlying epithelium. Hormonal stimulation increased the EEC protein levels of the key marker of endometrial receptivity, integrin αVß3 (n = 8; *P < 0.05; ***P < 0.0001). To our knowledge, this is the first demonstration of a dedicated endometrial organotypic model, which has been developed to investigate endometrial receptivity, via the recapitulation of an early decidual transitory acute autoinflammatory phase and induction of an epithelial phenotypic change, to represent a receptive endometrial status. LIMITATIONS REASONS FOR CAUTION: This simplified in vitro ESC-EEC co-culture system may be only partly representative of more complex in vivo conditions. WIDER IMPLICATIONS OF THE FINDINGS: The 3D endometrial organotypic model presented here may offer a valuable tool for investigating a range of reproductive, obstetric, and gynaecological disorders, to improve outcomes for assisted reproductive technologies, and for the development of advances in contraceptive methods. STUDY FUNDING/COMPETING INTERESTS: This work was supported in part by a Medical Research Council Centre Grant (project reference MR/N022556/1). R.F. was the recipient of a Moray Endowment award and a Barbour Watson Trust award. C.-J.L. is a Royal Society of Edinburgh Personal Research Fellow, funded by the Scottish Government. The authors have no conflicts of interest to declare.

5.
Phys Rev Lett ; 125(19): 192503, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33216609

RESUMO

ß-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of ß-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror ß decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.

6.
Zhonghua Yi Xue Za Zhi ; 100(32): 2503-2506, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32829596

RESUMO

Objective: To compare the effects of vestibular rehabilitation training and drug therapy on the symptoms of vertigo and disability in patients with vestibular peripheral vertigo. Methods: This prospective study was enrolled 43 patients with vestibular peripheral vertigo who admitted to the outpatient department of Eye & ENT Hospital of Fudan University from January 2018 to December 2018. They were randomly divided into two groups: control group (drug treatment group) and experimental group (drug treatment combined rehabilitation training group). All patients filled in the first vertigo disability rating scale (DHI), specific activity balance confidence scale (ABC) and anxiety self-rating scale (SAS) on the day of treatment and at two, four and eight weeks after treatment intervention, and the data were statistically analyzed. Results: There was no significant difference in gender, age and body weight between the two groups (P>0.05). After treatment (Control group (4w) : DHI (45.5±30.6) , ABC (86.9±12.4) , SAS (37.9±8.2) Experimental group (8w) : DHI (34.8±28.5) , SAS (35.7±7.9) ) , the three scales of the two groups were better than before treatment (Control group: DHI (59.2±25.9) , ABC (79.7±16.7) ,SAS (41.1±6.8) ; Experimental group: DHI (55.2±20.5) , ABC (80.3±18.3) , SAS (41.9±9.1) ) . The comparison of data before and after treatment in each group according to treatment time indicated that DHI and ABC scores in the experimental group showed that the DHI and ABC scores of the experimental group changed significantly at 2 weeks after treatment, and the SAS scores changed at 4 weeks after treatment. The difference was statistically significant (P<0.05). However, there was a statistically significant difference between the control group DHI score 4 weeks after treatment and SAS score 8 weeks after treatment (P<0.05). ABC score did not show statistical difference (P>0.05). Conclusion: The subjective symptoms and anxiety of vertigo and disability in the two groups improved obviously after treatment. Compared with drug therapy alone, drug therapy combined with vestibular rehabilitation training can significantly improve patients' subjective symptoms of vertigo and disability, as well as their anxiety and depression, so as to improve their overall quality of life.


Assuntos
Tontura , Qualidade de Vida , Vertigem , Ansiedade , Humanos , Estudos Prospectivos , Vertigem/terapia
7.
Sci Rep ; 10(1): 4503, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144355

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

8.
Osteoporos Int ; 31(1): 193-201, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31642977

RESUMO

Following 150 mg of oral ibandronate, Taiwanese females have greater serum and urine levels of this drug and bone resorption marker suppression than Caucasian women. These inter-ethnic differences seems to be partly explained by a 2.48-fold higher bioavailability of ibandronate in Taiwanese postmenopausal women. INTRODUCTION: Interethnic differences in the pharmacokinetics of oral ibandronate for osteoporosis are unknown. We compared the disposition of oral ibandronate between Caucasian and Taiwanese postmenopausal women. METHODS: Ibandronate 150 mg was administered to 35 Caucasian and 16 Taiwanese postmenopausal women in two separate phase 1 studies. Interethnic comparisons were performed to assess pharmacokinetic properties, including the area under the concentration-time curve (AUC), peak concentration (Cmax), elimination half-life, urinary drug recovery (Ae%), renal clearance (CLr), apparent total clearance (CL/F), and apparent volume of distribution (Vd/F). RESULTS: The mean AUC, Cmax, and Ae% were 2.41-, 1.69-, and 2.95-fold greater in the Taiwanese than in the Caucasian subjects, and the average CL/F and Vd/F were 2.48- and 2.46-fold smaller. There were no significant differences in mean CLr and half-life between both groups. As bisphosphonates are not biotransformed but are mainly excreted in the urine, the total body clearance is close to the CLr. These results suggested a larger bioavailability in the Taiwanese group which resulted in the differences in the CL/F and Vd/F. Multiple linear regression analysis demonstrated ethnicity influences of the pharmacokinetic properties after adjusting for the other variables. CONCLUSIONS: Bioavailability was largely responsible for the interethnic pharmacokinetic differences following oral administration of 150 mg ibandronate and seemed greater in the Taiwanese compared with the Caucasian subjects. Further dose-ranging studies are warranted to determine the optimal dosages of oral ibandronate in patients of Asian or Taiwanese ethnicity.


Assuntos
Conservadores da Densidade Óssea , Ácido Ibandrônico , Osteoporose Pós-Menopausa , Pós-Menopausa , Administração Oral , Idoso , Povo Asiático , Disponibilidade Biológica , Conservadores da Densidade Óssea/farmacocinética , Difosfonatos/uso terapêutico , Feminino , Humanos , Ácido Ibandrônico/farmacocinética , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/tratamento farmacológico , Fatores Raciais , População Branca
9.
Osteoporos Int ; 30(9): 1855-1864, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31201481

RESUMO

Upper limb fractures (including wrist, forearm, and humerus) represent a significant burden among postmenopausal women with osteoporosis. Up to 7 years of treatment with denosumab resulted in an increase in bone mineral density and decrease in fractures in upper limb sites. INTRODUCTION: Upper limb (wrist, forearm, and humerus) fractures are a significant burden in osteoporosis, associated with significant morbidity and mortality. Denosumab, a monoclonal antibody against RANK ligand, increases bone mineral density (BMD) and decreases vertebral, nonvertebral, and hip fractures. Here, we evaluated the long-term effect of denosumab treatment on upper limb fracture risk and BMD. METHODS: In the FREEDOM trial, subjects were randomized 1:1 to receive every-6-month denosumab 60 mg or placebo subcutaneously for 3 years, after which all subjects could receive denosumab for up to 7 years (Extension). Among placebo subjects who completed FREEDOM and enrolled in the Extension, wrist, forearm, humerus, and upper limb fracture rates and rate ratios between different time periods (FREEDOM years 1-3, Extension years 1-3, and Extension years 4-7) were computed. BMD at the ultradistal radius, 1/3 radius, and total radius was analyzed in a subset of subjects in a BMD substudy. RESULTS: This analysis included 2207 subjects (116 in the BMD substudy). Fracture rates decreased over the 7-year Extension; fracture rate ratios between Extension years 4-7 (denosumab) and FREEDOM years 1-3 (placebo) reduced significantly for the wrist (0.57), forearm (0.57), humerus (0.42), and upper limb (0.52; p < 0.05 for all). Percentage increase in BMD from Extension baseline at the ultradistal radius, 1/3 radius, and total radius was significant by Extension year 7 (p < 0.05 for all). CONCLUSIONS: Long-term treatment with denosumab decreases upper limb fracture risk and increases forearm BMD, suggesting beneficial effects on both cortical and trabecular bone accruing over time.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Denosumab/uso terapêutico , Fraturas do Úmero/prevenção & controle , Osteoporose Pós-Menopausa/tratamento farmacológico , Fraturas por Osteoporose/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/efeitos dos fármacos , Conservadores da Densidade Óssea/administração & dosagem , Osso Cortical/efeitos dos fármacos , Estudos Cross-Over , Denosumab/administração & dosagem , Método Duplo-Cego , Esquema de Medicação , Feminino , Seguimentos , Traumatismos do Antebraço/prevenção & controle , Humanos , Injeções Subcutâneas , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/fisiopatologia , Rádio (Anatomia)/fisiopatologia , Traumatismos do Punho/prevenção & controle
10.
J Endocrinol Invest ; 42(11): 1307-1317, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31079353

RESUMO

OBJECTIVE: To investigate the expression of miR-217 and HIF-1α/VEGF pathway in patients with diabetic foot ulcer (DFU) and its effect on angiogenesis in DFU rats. METHODS: The serum levels of miR-217, HIF-1α and VEGF were detected in DFU and simple diabetes mellitus (DM) patients, and healthy controls. DFU rat models were established and treated with miR-217 inhibitors and/or HIF-1α siRNA. The ulcer healing of DFU rats was observed. Besides, ELISA method was performed to detect the serum level of HIF-1α, VEGF and inflammatory factors, immunohistochemical (IHC) method to test the micro-vessel density (MVD), as well as qRT-PCR and Western blot to determine expressions of miR-217, HIF-1α, VEGF, VEGFR2, eNOS, MMP-2, and MMP-9 in tissues. RESULTS: The serum levels of miR-217 were up-regulated while HIF-1α and VEGF were down-regulated in DFU patients and rats when compared with DM and healthy controls (all P < 0.05). Dual-luciferase reporter gene assay confirmed that HIF-1α was the direct target gene of miR-217. DFU rats treated with miR-217 inhibitors had decreased foot ulcer area and accelerated ulcer healing, with significantly reduced inflammatory factors (IL-1ß, TNF-α and IL-6), as well as elevated HIF-1α and VEGF (all P < 0.05); meanwhile, they remarkably increased the MVD in foot dorsum wound tissues and the protein expressions of HIF-1α, VEGF, VEGFR2, eNOS, MMP-2, and MMP-9 (all P < 0.05). CONCLUSION: Inhibiting miR-217 could up-regulate HIF-1α/VEGF pathway to promote angiogenesis and ameliorate inflammation of DFU rats, thereby effectively advancing the healing of ulcerated area.


Assuntos
Diabetes Mellitus/fisiopatologia , Pé Diabético/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , MicroRNAs/genética , Neovascularização Patológica/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Biomarcadores/análise , Estudos de Casos e Controles , Pé Diabético/epidemiologia , Pé Diabético/genética , Pé Diabético/metabolismo , Feminino , Seguimentos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Prognóstico , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/genética , Cicatrização
11.
J Intellect Disabil Res ; 63(9): 1125-1136, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31016807

RESUMO

BACKGROUND: To promote sexual health in adults with an intellectual disability (ID) in Taiwan, sexual health programmes were provided to adults with ID, their parents and service workers. This study evaluates the impact of these programmes that involved the parents and service workers. METHODS: Intervention and participatory research paradigms were applied to develop, implement and evaluate programmes that address the challenges that relate to the sexual rights of adults with ID. Additionally, the programmes fostered open dialogue among the participants concerning the sexual health of people with ID. In total, 57 parents and 164 service workers were involved in the programmes. A quasi-experimental design and standardised questionnaires (Attitudes to Sexuality Questionnaire - Individuals with an Intellectual Disability), as well as in-depth interviews, were used to collect both quantitative and qualitative data on the programmes' effectiveness and participants' experiences between April 2012 and July 2015. RESULTS: The findings revealed that after the programmes were implemented, attitudes towards the sexual rights of people with ID were significantly more positive among both the parents and service workers. Participation in the sexual health programmes facilitated constructive dialogue by revealing hidden concerns and by transforming the perspectives of the parents and service workers from viewing sexuality as a social problem to understanding the sexual rights of adults with ID. CONCLUSIONS: Both the quantitative and qualitative results demonstrate that the programmes had a positive impact on the parents and service workers in terms of their attitudes towards the sexual rights of people with ID. Open dialogue and reciprocal interaction strategies caused transformations in the perspectives of parents and service workers on sexual health.


Assuntos
Atitude do Pessoal de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Direitos Humanos , Deficiência Intelectual , Pais , Pessoas com Deficiência Mental , Avaliação de Programas e Projetos de Saúde , Saúde Sexual , Sexualidade , Adulto , Idoso , Feminino , Pessoal de Saúde , Direitos Humanos/legislação & jurisprudência , Humanos , Masculino , Pessoa de Meia-Idade , Pessoas com Deficiência Mental/legislação & jurisprudência , Pesquisa Qualitativa , Saúde Sexual/legislação & jurisprudência , Taiwan
12.
AJNR Am J Neuroradiol ; 40(3): 540-542, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30679218

RESUMO

Time-density curve analysis of DSA provides useful blood flow information. However, manually selecting the ROI is time-consuming. We developed an automatic technique to provide arterial, capillary, and venous vasculatures with corresponding time-density curves. This study retrospectively analyzed the data of 36 patients with unilateral carotid stenosis. We found that the full width at half maximum of the time-density curve for the automatically segmented capillary vasculature is a suitable representation of the cerebral circulation time.


Assuntos
Angiografia Digital/métodos , Estenose das Carótidas/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
13.
Neuropathol Appl Neurobiol ; 45(2): 157-173, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29679389

RESUMO

AIMS: The accumulation of α-synuclein is a hallmark in the pathogenesis of Parkinson's disease (PD). Natural resistance-associated macrophage protein-1 (Nramp1) was previously shown to contribute to the degradation of extracellular α-synuclein in microglia under conditions of iron overload. This study was aimed at investigating the role of Nramp1 in α-synuclein pathology in the neurone under 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)/1-methyl-4-phenylpyridinium (MPP+ ) treatment. METHODS: The expression of Nramp1 and pathological features (including iron and α-synuclein accumulation) were examined in the dopaminergic neurones of humans (with and without PD) and of mice [with and without receiving chronic MPTP intoxication]. The effects of Nramp1 expression on low-dose MPP+ -induced α-synuclein expression and neurotoxicity were determined in human dopaminergic neuroblastoma SH-SY5Y cells. RESULTS: Similar to the findings in the substantia nigra of human PD, lower expression of Nramp1 but higher levels of iron and α-synuclein were identified in the dopaminergic neurones of mice receiving chronic MPTP intoxication, compared to controls. In parallel to the loss of dopaminergic neurones, the numbers of glial fibrillary acidic protein- and ionized calcium-binding adapter molecule-1-positive cells were significantly increased in the substantia nigra of MPTP-treated mice. Likewise, in human neuroblastoma SH-SY5Y cells exposed to low-dose MPP+ , Nramp1 expression and cathepsin D activity were decreased, along with an increase in α-synuclein protein expression and aggregation. Overexpression of functional Nramp1 restored cathepsin D activity and attenuated α-synuclein up-regulation and neuronal cell death caused by MPP+ treatment. CONCLUSIONS: These data suggest that the neuronal expression of Nramp1 is important for protecting against the development of MPTP/MPP+ -induced α-synuclein pathology and neurotoxicity.


Assuntos
1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Proteínas de Transporte de Cátions/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , alfa-Sinucleína/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Animais , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular Tumoral , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Masculino , Camundongos , Microglia/efeitos dos fármacos , Microglia/metabolismo , Doença de Parkinson/patologia , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , alfa-Sinucleína/metabolismo
14.
Sci Rep ; 7(1): 14473, 2017 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-29101360

RESUMO

Recently a new diluted magnetic semiconductor, (Ba,K)(Zn,Mn)2As2 (BZA), with high Curie temperature was discovered, showing an independent spin and charge-doping mechanism. This makes BZA a promising material for spintronics devices. We report the successful growth of a BZA single crystal for the first time in this study. An Andreev reflection junction, which can be used to evaluate spin polarization, was fabricated based on the BZA single crystal. A 66% spin polarization of the BZA single crystal was obtained by Andreev reflection spectroscopy analysis.

15.
J Chem Phys ; 146(22): 224701, 2017 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-29166063

RESUMO

We proposed a single-molecule magnetic junction (SMMJ), composed of a dissociated amine-ended benzene sandwiched between two Co tip-like nanowires. To better simulate the break junction technique for real SMMJs, the first-principles calculation associated with the hard-hard coupling between a amine-linker and Co tip-atom is carried out for SMMJs with mechanical strain and under an external bias. We predict an anomalous magnetoresistance (MR) effect, including strain-induced sign reversal and bias-induced enhancement of the MR value, which is in sharp contrast to the normal MR effect in conventional magnetic tunnel junctions. The underlying mechanism is the interplay between four spin-polarized currents in parallel and anti-parallel magnetic configurations, originated from the pronounced spin-up transmission feature in the parallel case and spiky transmission peaks in other three spin-polarized channels. These intriguing findings may open a new arena in which magnetotransport and hard-hard coupling are closely coupled in SMMJs and can be dually controlled either via mechanical strain or by an external bias.

16.
Eur Phys J C Part Fields ; 77(2): 112, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29033670

RESUMO

We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor [Formula: see text], arising in the semileptonic [Formula: see text] transition at zero momentum transfer, as well as the decay constant ratio [Formula: see text] and its consequences for the CKM matrix elements [Formula: see text] and [Formula: see text]. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of [Formula: see text] and [Formula: see text] Chiral Perturbation Theory. We review the determination of the [Formula: see text] parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for [Formula: see text] and [Formula: see text] (also new compared to the previous review), as well as those for D- and B-meson-decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant [Formula: see text].

17.
Rev Sci Instrum ; 88(5): 056105, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28571430

RESUMO

Tagging of neutrons (2.45 MeV) with their associated 3He particles from deuterium-deuterium (D-D) fusion reactions has been demonstrated in a compact neutron generator setup enabled by a high brightness, microwave-driven ion source with a high fraction of deuterons. Energy spectra with well separated peaks of the D-D fusion reaction products, 3He, tritons, and protons, were measured with a silicon PIN diode. The neutrons were detected using a liquid scintillator detector with pulse shape discrimination. By correlating the 3He detection events with the neutron detection in time, we demonstrated the tagging of emitted neutrons with 3He particles detected with a Si PIN diode detector mounted inside the neutron generator vacuum vessel.

18.
AJNR Am J Neuroradiol ; 38(4): 740-746, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28126751

RESUMO

BACKGROUND AND PURPOSE: Time-resolved 3D-DSA (4D-DSA) enables viewing vasculature from any desired angle and time frame. We investigated whether these advantages may facilitate treatment planning and the feasibility of using 4D-DSA as a single imaging technique in AVM/dural arteriovenous fistula radiosurgery. MATERIALS AND METHODS: Twenty consecutive patients (8 dural arteriovenous fistulas and 12 AVMs; 13 men and 7 women; mean age, 45 years; range, 18-64 years) who were scheduled for gamma knife radiosurgery were recruited (November 2014 to October 2015). An optimal volume of reconstructed time-resolved 3D volumes that defines the AVM nidus/dural arteriovenous fistula was sliced into 2D-CT-like images. The original radiosurgery treatment plan was overlaid retrospectively. The registration errors of stereotactic 4D-DSA were compared with those of integrated stereotactic imaging. AVM/dural arteriovenous fistula volumes were contoured, and disjoint and conjoint components were identified. The Wilcoxon signed rank test and the Wilcoxon rank sum test were adopted to evaluate registration errors and contoured volumes of stereotactic 4D-DSA and integration of stereotactic MR imaging and stereotactic 2D-DSA. RESULTS: Sixteen of 20 patients were successfully registered in Advanced Leksell GammaPlan Program. The registration error of stereotactic 4D-DSA was smaller than that of integrated stereotactic imaging (P = .0009). The contoured AVM volume of 4D-DSA was smaller than that contoured on the integration of MR imaging and 2D-DSA, while major inconsistencies existed in cases of dural arteriovenous fistula (P = .042 and 0.039, respectively, for measurements conducted by 2 authors). CONCLUSIONS: Implementation of stereotactic 4D-DSA data for gamma knife radiosurgery for brain AVM/dural arteriovenous fistula is feasible. The ability of 4D-DSA to demonstrate vascular morphology and hemodynamics in 4 dimensions potentially reduces the target volumes of irradiation in vascular radiosurgery.


Assuntos
Angiografia Digital/métodos , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Malformações Arteriovenosas Intracranianas/cirurgia , Radiocirurgia/métodos , Adolescente , Adulto , Idoso , Malformações Vasculares do Sistema Nervoso Central/diagnóstico por imagem , Malformações Vasculares do Sistema Nervoso Central/cirurgia , Circulação Cerebrovascular , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
19.
Phys Rev Lett ; 119(4): 042503, 2017 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-29341746

RESUMO

The threshold anomaly of the phenomenological potential has been known for a long time in nuclear reactions at energies around the Coulomb barrier, where the connection between the real and imaginary potentials is well described by the dispersion relation. However, this connection is not clear yet for some weakly bound nuclear systems, especially for reactions induced by exotic radioactive nuclei. In this study, precise optical potentials of the halo nuclear system ^{6}He+^{209}Bi were extracted via ^{208}Pb(^{7}Li,^{6}He) transfer reactions with energies measured downward to the extremely sub-barrier region. The real potential presents a bell-like shape around the barrier as a normal threshold anomaly in tightly bound nuclear systems. However, the imaginary potential shows an abnormal behavior: it increases first with energy decreasing below the barrier and then falls quickly down to 0. It is the first time the threshold of the imaginary potential has been determined in an exotic nuclear system. Moreover, experimental results show the dispersion relation is not applicable for this system, which may be a common phenomenon for exotic nuclear systems. We discuss possible explanations for such a peculiar behavior, but further study is still desired for the underlying physics.

20.
AJNR Am J Neuroradiol ; 38(1): 132-138, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27765737

RESUMO

BACKGROUND AND PURPOSE: Sinus stenosis occasionally occurs in dural arteriovenous fistulas. Sinus stenosis impedes venous outflow and aggravates intracranial hypertension by reversing cortical venous drainage. This study aimed to analyze the likelihood of sinus stenosis and its impact on cerebral hemodynamics of various types of dural arteriovenous fistulas. MATERIALS AND METHODS: Forty-three cases of dural arteriovenous fistula in the transverse-sigmoid sinus were reviewed and divided into 3 groups: Cognard type I, type IIa, and types with cortical venous drainage. Sinus stenosis and the double peak sign (occurrence of 2 peaks in the time-density curve of the ipsilateral drainage of the internal jugular vein) in dural arteriovenous fistula were evaluated. "TTP" was defined as the time at which a selected angiographic point reached maximum concentration. TTP of the vein of Labbé, TTP of the ipsilateral normal transverse sinus, trans-fistula time, and trans-stenotic time were compared across the 3 groups. RESULTS: Thirty-six percent of type I, 100% of type IIa, and 84% of types with cortical venous drainage had sinus stenosis. All sinus stenosis cases demonstrated loss of the double peak sign that occurs in dural arteriovenous fistula. Trans-fistula time (2.09 seconds) and trans-stenotic time (0.67 seconds) in types with cortical venous drainage were the most prolonged, followed by those in type IIa and type I. TTP of the vein of Labbé was significantly shorter in types with cortical venous drainage. Six patients with types with cortical venous drainage underwent venoplasty and stent placement, and 4 were downgraded to type IIa. CONCLUSIONS: Sinus stenosis indicated dysfunction of venous drainage and is more often encountered in dural arteriovenous fistula with more aggressive types. Venoplasty ameliorates cortical venous drainage in dural arteriovenous fistulas and serves as a bridge treatment to stereotactic radiosurgery in most cases.


Assuntos
Malformações Vasculares do Sistema Nervoso Central/patologia , Malformações Vasculares do Sistema Nervoso Central/fisiopatologia , Hemodinâmica/fisiologia , Seios Transversos/patologia , Seios Transversos/fisiopatologia , Adulto , Malformações Vasculares do Sistema Nervoso Central/cirurgia , Angiografia Cerebral , Constrição Patológica/patologia , Constrição Patológica/fisiopatologia , Feminino , Humanos , Hipertensão Intracraniana/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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