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1.
Front Oncol ; 14: 1358888, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38887232

RESUMO

Background: Rapid diagnostic clinics (RDCs) provide a streamlined holistic pathway for patients presenting with non-site specific (NSS) symptoms concerning of malignancy. The current study aimed to: 1) assess the prevalence of anxiety and depression, and 2) identify a combination of patient characteristics and symptoms associated with severe anxiety and depression at Guy's and St Thomas' Foundation Trust (GSTT) RDC in Southeast London. Additionally, we compared standard statistical methods with machine learning algorithms for predicting severe anxiety and depression. Methods: Patients seen at GSTT RDC between June 2019 and January 2023 completed the General Anxiety Disorder Questionnaire (GAD-7) and Patient Health Questionnaire (PHQ-8) questionnaires, at baseline. We used logistic regression (LR) and 2 machine learning (ML) algorithms (random forest (RF), support vector machine (SVM)) to predict risk of severe anxiety and severe depression. The models were constructed using a set of sociodemographic and clinical variables. Results: A total of 1734 patients completed GAD-7 and PHQ-8 questionnaires. Of these, the mean age was 59 years (Standard Deviation: 15.5), and 61.5% (n:1067) were female. Prevalence of severe anxiety (GAD-7 score ≥15) was 13.8% and severe depression (PHQ-8 score≥20) was 9.3%. LR showed that a combination of previous mental health condition (PMH, Adjusted Odds Rario (AOR) 3.28; 95% confidence interval (CI) 2.36-4.56), symptom duration >6 months (AOR 2.20; 95%CI 1.28-3.77), weight loss (AOR 1.88; 95% CI 1.36-2.61), progressive pain (AOR 1.71; 95%CI 1.26-2.32), and fatigue (AOR 1.36; 95%CI 1.01-1.84), was positively associated with severe anxiety. Likewise, a combination PMH condition (AOR 3.95; 95%CI 2.17-5.75), fatigue (AOR 2.11; 95%CI 1.47-3.01), symptom duration >6 months (AOR 1.98; 95%CI 1.06-3.68), weight loss (AOR 1.66; 95%CI 1.13-2.44), and progressive pain (AOR 1.50; 95%CI 1.04-2.16), was positively associated with severe depression. LR and SVM had highest accuracy levels for severe anxiety (LR: 86%, SVM: 85%) and severe depression (SVM: 89%, LR: 86%). Conclusion: High prevalence of severe anxiety and severe depression was found. PMH, fatigue, weight loss, progressive pain, and symptoms >6 months emerged as combined risk factors for both these psychological comorbidities. RDCs offer an opportunity to alleviate distress in patients with concerning symptoms by expediting diagnostic evaluations.

2.
BMJ Open ; 14(4): e080285, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38626962

RESUMO

OBJECTIVE: To analyse the effectiveness of rapid diagnostic clinics (RDCs) as an alternative pathway for patients with concerning symptoms and a faecal immunochemical test (FIT) result <10. Our primary endpoint was rate of colorectal cancer (CRC) detection. Second endpoints were rates of other cancers and gastrointestinal (GI) serious benign conditions. Finally, we analysed the specific pathway followed by FIT <10 patients with cancer at Guy's and St Thomas NHS Foundation Trust (GSTT) RDC. DESIGN: A retrospective and prospective cohort study. SETTING: GSTT RDC, one of England's largest single-centre RDCs. Sociodemographic and clinical characteristics of FIT <10 patients were analysed descriptively. PARTICIPANTS: Patients with an FIT result <10, seen at GSTT RDC between 1 January 2020 and 5 May 2023. RESULTS: A total of 1299 patients with an FIT<10 were seen at GSTT RDC between January 2020 and May 2023. Of these, 66% (n=861) reported weight loss, 62% (n=805) pain, 37% (n=481) fatigue, 34% (n=444) were anaemic and 23% (n=301) had nausea and vomiting. Among these patients, 7% (n=88) received a cancer diagnosis, 36% (n=462) were identified as having a serious benign condition. Within the patients with cancer, 9% (n=8) were diagnosed with CRC. Among patients with serious benign conditions, 7% (n=31) were referred to colorectal, hepatopancreatobiliary, or upper GI specialists. CONCLUSION: This study demonstrates the effectiveness of RDCs as an alternate pathway for FIT <10 patients with ongoing clinical concerns. These results contribute to enhancing patient care and optimising resource allocation within the healthcare system.


Assuntos
Neoplasias Colorretais , Humanos , Sensibilidade e Especificidade , Neoplasias Colorretais/diagnóstico , Estudos Retrospectivos , Estudos Prospectivos , Testes de Diagnóstico Rápido , Sangue Oculto , Detecção Precoce de Câncer/métodos , Colonoscopia , Fezes/química , Hemoglobinas/análise
3.
Health Expect ; 27(2): e14037, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38634418

RESUMO

BACKGROUND AND AIM: Long Covid is often stigmatised, particularly in people who are disadvantaged within society. This may prevent them from seeking help and could lead to widening health inequalities. This coproduced study with a Community Advisory Board (CAB) of people with Long Covid aimed to understand healthcare and wider barriers and stigma experienced by people with probable Long Covid. METHODS: An active case finding approach was employed to find adults with probable, but not yet clinically diagnosed, Long Covid in two localities in London (Camden and Merton) and Derbyshire, England. Interviews explored the barriers to care and the stigma faced by participants and were analysed thematically. This study forms part of the STIMULATE-ICP Collaboration. FINDINGS: Twenty-three interviews were completed. Participants reported limited awareness of what Long Covid is and the available pathways to management. There was considerable self-doubt among participants, sometimes reinforced by interactions with healthcare professionals (HCPs). Participants questioned their deservedness in seeking healthcare support for their symptoms. Hesitancy to engage with healthcare services was motivated by fear of needing more investigation and concerns regarding judgement about the ability to carry out caregiving responsibilities. It was also motivated by the complexity of the clinical presentation and fear of all symptoms being attributed to poor mental health. Participants also reported trying to avoid overburdening the health system. These difficulties were compounded by experiences of stigma and discrimination. The emerging themes reaffirmed a framework of epistemic injustice in relation to Long Covid, where creating, interpreting and conveying knowledge has varied credibility based on the teller's identity characteristics and/or the level of their interpretive resources. CONCLUSION: We have codeveloped recommendations based on the findings. These include early signposting to services, dedicating protected time to listening to people with Long Covid, providing a holistic approach in care pathways, and working to mitigate stigma. Regardless of the diagnosis, people experiencing new symptoms must be encouraged to seek timely medical help. Clear public health messaging is needed among communities already disadvantaged by epistemic injustice to raise awareness of Long Covid, and to share stories that encourage seeking care and to illustrate the adverse effects of stigma. PATIENT OR PUBLIC CONTRIBUTION: This study was coproduced with a CAB made up of 23 members including HCPs, people with lived experience of Long Covid and other stakeholders.


Assuntos
COVID-19 , Síndrome de COVID-19 Pós-Aguda , Adulto , Humanos , Estigma Social , Saúde Mental , Acessibilidade aos Serviços de Saúde
4.
Space Sci Rev ; 220(1): 9, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38282745

RESUMO

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA's F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms-1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes - B1, provided by the Japanese space agency, JAXA, and B2 - that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission's science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.

5.
Space Sci Rev ; 219(7): 53, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37744214

RESUMO

ESA's Jupiter Icy Moons Explorer (JUICE) will provide a detailed investigation of the Jovian system in the 2030s, combining a suite of state-of-the-art instruments with an orbital tour tailored to maximise observing opportunities. We review the Jupiter science enabled by the JUICE mission, building on the legacy of discoveries from the Galileo, Cassini, and Juno missions, alongside ground- and space-based observatories. We focus on remote sensing of the climate, meteorology, and chemistry of the atmosphere and auroras from the cloud-forming weather layer, through the upper troposphere, into the stratosphere and ionosphere. The Jupiter orbital tour provides a wealth of opportunities for atmospheric and auroral science: global perspectives with its near-equatorial and inclined phases, sampling all phase angles from dayside to nightside, and investigating phenomena evolving on timescales from minutes to months. The remote sensing payload spans far-UV spectroscopy (50-210 nm), visible imaging (340-1080 nm), visible/near-infrared spectroscopy (0.49-5.56 µm), and sub-millimetre sounding (near 530-625 GHz and 1067-1275 GHz). This is coupled to radio, stellar, and solar occultation opportunities to explore the atmosphere at high vertical resolution; and radio and plasma wave measurements of electric discharges in the Jovian atmosphere and auroras. Cross-disciplinary scientific investigations enable JUICE to explore coupling processes in giant planet atmospheres, to show how the atmosphere is connected to (i) the deep circulation and composition of the hydrogen-dominated interior; and (ii) to the currents and charged particle environments of the external magnetosphere. JUICE will provide a comprehensive characterisation of the atmosphere and auroras of this archetypal giant planet.

6.
PLoS One ; 18(7): e0284297, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37471432

RESUMO

BACKGROUND AND AIM: Long Covid is a significant public health concern with potentially negative implications for health inequalities. We know that those who are already socially disadvantaged in society are more exposed to COVID-19, experience the worst health outcomes and are more likely to suffer economically. We also know that these groups are more likely to experience stigma and have negative healthcare experiences even before the pandemic. However, little is known about disadvantaged groups' experiences of Long Covid, and preliminary evidence suggests they may be under-represented in those who access formal care. We will conduct a pilot study in a defined geographical area in London, United Kingdom to test the feasibility of a community-based approach of identifying Long Covid cases that have not been clinically diagnosed and have not been referred to Long Covid specialist services. We will explore the barriers to accessing recognition, care, and support, as well as experiences of stigma and perceived discrimination. METHODS: This protocol and study materials were co-produced with a Community Advisory Board (CAB) made up primarily of people living with Long Covid. Working with voluntary organisations, a study leaflet will be distributed in the local community to highlight Long Covid symptoms and invite those experiencing them to participate in the study if they are not formally diagnosed. Potential participants will be assessed according to the study's inclusion criteria and offered the opportunity to participate if they fit them. Awareness of Long Covid and associated symptoms, experiences of trying to access care, as well as stigma and discrimination will be explored through qualitative interviews with participants. Upon completion of the interviews, participants will be offered a referral to the local social prescribing team to receive support that is personalised to them potentially including, but not restricted to, liaising with their primary care provider and the regional Long Covid clinic.


Assuntos
COVID-19 , Prestação Integrada de Cuidados de Saúde , Humanos , COVID-19/epidemiologia , Síndrome de COVID-19 Pós-Aguda , Projetos Piloto , Reino Unido
7.
Hemasphere ; 7(4): e864, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37008165

RESUMO

Lymphoma is the most common hematological malignancy and is among the 10 most prevalent cancers worldwide. Although survival has been improved by modern immunochemotherapeutic regimens, there remains a significant need for novel targeted agents to treat both B-cell and T-cell malignancies. Cytidine triphosphate synthase 1 (CTPS1), which catalyzes the rate-limiting step in pyrimidine synthesis, plays an essential and nonredundant role in B-cell and T-cell proliferation but is complemented by the homologous CTPS2 isoform outside the hemopoietic system. This report describes the identification and characterization of CTPS1 as a novel target in B- and T-cell cancers. A series of small molecules have been developed which show potent and highly selective inhibition of CTPS1. Site-directed mutagenesis studies identified the adenosine triphosphate pocket of CTPS1 as the binding site for this small molecule series. In preclinical studies, a potent and highly selective small molecule inhibitor of CTPS1 blocked the in vitro proliferation of human neoplastic cells, showing the highest potency against lymphoid neoplasms. Importantly, pharmacological CTPS1 inhibition induced cell death by apoptosis in the majority of lymphoid cell lines tested, thus demonstrating a cytotoxic mechanism of action. Selective CTPS1 inhibition also inhibited the growth of neoplastic human B- and T- cells in vivo. These findings identify CTPS1 as a novel therapeutic target in lymphoid malignancy. A compound from this series is in phase 1/2 clinical studies for the treatment of relapsed/refractory B- and T-cell lymphoma (NCT05463263).

8.
J Med Chem ; 65(24): 16640-16650, 2022 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-36449304

RESUMO

Herein, we report the discovery of a first-in-class chemotype 2-(alkylsulfonamido)thiazol-4-yl)acetamides that act as pan-selective inhibitors of cytidine 5'-triphosphate synthetase (CTPS1/2), critical enzymes in the de novo pyrimidine synthesis pathway. Weak inhibitors identified from a high-throughput screening of 240K compounds have been optimized to a potent, orally active agent, compound 27, which has shown significant pharmacological responses at 10 mg/kg dose BID in a well-established animal model of inflammation.


Assuntos
Carbono-Nitrogênio Ligases , Inibidores Enzimáticos , Animais , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Carbono-Nitrogênio Ligases/metabolismo , Proliferação de Células , Ensaios de Triagem em Larga Escala
9.
Space Sci Rev ; 218(8): 65, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36397966

RESUMO

The environment of a comet is a fascinating and unique laboratory to study plasma processes and the formation of structures such as shocks and discontinuities from electron scales to ion scales and above. The European Space Agency's Rosetta mission collected data for more than two years, from the rendezvous with comet 67P/Churyumov-Gerasimenko in August 2014 until the final touch-down of the spacecraft end of September 2016. This escort phase spanned a large arc of the comet's orbit around the Sun, including its perihelion and corresponding to heliocentric distances between 3.8 AU and 1.24 AU. The length of the active mission together with this span in heliocentric and cometocentric distances make the Rosetta data set unique and much richer than sets obtained with previous cometary probes. Here, we review the results from the Rosetta mission that pertain to the plasma environment. We detail all known sources and losses of the plasma and typical processes within it. The findings from in-situ plasma measurements are complemented by remote observations of emissions from the plasma. Overviews of the methods and instruments used in the study are given as well as a short review of the Rosetta mission. The long duration of the Rosetta mission provides the opportunity to better understand how the importance of these processes changes depending on parameters like the outgassing rate and the solar wind conditions. We discuss how the shape and existence of large scale structures depend on these parameters and how the plasma within different regions of the plasma environment can be characterised. We end with a non-exhaustive list of still open questions, as well as suggestions on how to answer them in the future.

10.
Exp Astron (Dordr) ; 54(2-3): 713-744, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36915624

RESUMO

The goal of Project GAUSS (Genesis of Asteroids and evolUtion of the Solar System) is to return samples from the dwarf planet Ceres. Ceres is the most accessible candidate of ocean worlds and the largest reservoir of water in the inner Solar System. It shows active volcanism and hydrothermal activities in recent history. Recent evidence for the existence of a subsurface ocean on Ceres and the complex geochemistry suggest past habitability and even the potential for ongoing habitability. GAUSS will return samples from Ceres with the aim of answering the following top-level scientific questions: What is the origin of Ceres and what does this imply for the origin of water and other volatiles in the inner Solar System?What are the physical properties and internal structure of Ceres? What do they tell us about the evolutionary and aqueous alteration history of dwarf planets?What are the astrobiological implications of Ceres? Is it still habitable today?What are the mineralogical connections between Ceres and our current collections of carbonaceous meteorites?

12.
Br J Cancer ; 124(6): 1079-1087, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33402736

RESUMO

BACKGROUND: Rapid Diagnostic Clinics (RDC) are being expanded nationally by NHS England. Guy's RDC established a pathway for GPs and internal referrals for patients with symptoms concerning for malignancy not suitable for a site-specific 2WW referral. However, little data assessing the effectiveness of RDC models are available in an English population. METHODS: We evaluated all patients referred to Guy's RDC between December 2016 and June 2019 (n = 1341) to assess the rate of cancer diagnoses, frequency of benign conditions and effectiveness of the service. RESULTS: There were 96 new cancer diagnoses (7.2%): lung (16%), haematological (13%) and colorectal (12%)-with stage IV being most frequent (40%). Median time to definitive cancer diagnosis was 28 days (IQR 15-47) and treatment 56 days (IQR 32-84). In all, 75% were suitable for treatment: surgery (26%), systemic (24%) and radiotherapy (14%). Over 180 serious non-neoplastic conditions were diagnosed (35.8%) of patients with no significant findings in two-third of patients (57.0%). CONCLUSIONS: RDCs provide GPs with a streamlined pathway for patients with complex non-site-specific symptoms that can be challenging for primary care. The 7% rate of cancer diagnosis exceeds many 2WW pathways and a third of patients presented with significant non-cancer diagnoses, which justifies the need for rapid diagnostics. Rapid Diagnostic Centres (RDCs) are being rolled out nationally by NHS England and NHS Improvement as part of the NHS long-term plan. The aim is for a primary care referral pathway that streamlines diagnostics, patient journey, clinical outcomes and patient experience. This pilot study of 1341 patients provides an in-depth analysis of the largest single RDC in England. Cancer was diagnosed in 7% of patients and serious non-cancer conditions in 36%-justifying the RDC approach in vague symptom patients.


Assuntos
Detecção Precoce de Câncer/métodos , Auditoria Médica/estatística & dados numéricos , Neoplasias/diagnóstico , Atenção Primária à Saúde/organização & administração , Avaliação de Sintomas/métodos , Idoso , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico , Estudos Prospectivos , Encaminhamento e Consulta , Estudos Retrospectivos , Fatores de Tempo
13.
Nat Commun ; 10(1): 5418, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31780664
14.
JMIR Ment Health ; 6(7): e12853, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31322125

RESUMO

BACKGROUND: Engagement in activities that promote the dissipation of work stress is essential for post work recovery and consequently for well-being. Previous research suggests that activities that are immersive, active, and engaging are especially effective at promoting recovery. Therefore, digital games may be able to promote recovery, but little is known about how they compare with other popular mobile activities, such as mindfulness apps that are specifically designed to support well-being. OBJECTIVE: The aim of this study was to investigate and compare the effectiveness of a digital game and mindfulness app in promoting post work recovery, first in a laboratory setting and then in a field study. METHODS: Study 1 was a laboratory experiment (n=45) in which participants' need for recovery was induced by a work task, before undertaking 1 of 3 interventions: a digital game (Block! Hexa Puzzle), a mindfulness app (Headspace), or a nonmedia control with a fidget spinner (a physical toy). Recovery in the form of how energized participants felt (energetic arousal) was compared before and after the intervention and how recovered participants felt (recovery experience) was compared across the conditions. Study 2 was a field study with working professionals (n=20), for which participants either played the digital game or used the mindfulness app once they arrived home after work for a period of 5 working days. Measures of energetic arousal were taken before and after the intervention, and the recovery experience was measured after the intervention along with measures of enjoyment and job strain. RESULTS: A 3×2 mixed analysis of variance identified that, in study 1, the digital game condition increased energetic arousal (indicative of improved recovery) whereas the other 2 conditions decreased energetic arousal (F2,42=3.76; P=.03). However, there were no differences between the conditions in recovery experience (F2,42=.01; P=.99). In study 2, multilevel model comparisons identified that neither the intervention nor day of the week had a significant main effect on how energized participants felt. However, for those in the digital game condition, daily recovery experience increased during the course of the study, whereas for those in the mindfulness condition, it decreased (F1,18=9.97; P=.01). Follow-up interviews with participants identified 3 core themes: detachment and restoration, fluctuations and differences, and routine and scheduling. CONCLUSIONS: This study suggests that digital games may be effective in promoting post work recovery in laboratory contexts (study 1) and in the real world, although the effect in this case may be cumulative rather than instant (study 2).

15.
Medchemcomm ; 10(8): 1379-1390, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32952998

RESUMO

Parthenolide is a natural product that exhibits anti-leukaemic activity, however, its clinical use is limited by its poor bioavailability. It may be extracted from feverfew and protocols for growing, extracting and derivatising it are reported. A novel parthenolide derivative with good bioavailability and pharmacological properties was identified through a screening cascade based on in vitro anti-leukaemic activity and calculated "drug-likeness" properties, in vitro and in vivo pharmacokinetics studies and hERG liability testing. In vitro studies showed the most promising derivative to have comparable anti-leukaemic activity to DMAPT, a previously described parthenolide derivative. The newly identified compound was shown to have pro-oxidant activity and in silico molecular docking studies indicate a prodrug mode of action. A synthesis scheme is presented for the production of amine 7 used in the generation of 5f.

16.
Science ; 362(6410)2018 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-30287635

RESUMO

Saturn's main rings are composed of >95% water ice, and the nature of the remaining few percent has remained unclear. The Cassini spacecraft's traversals between Saturn and its innermost D ring allowed its cosmic dust analyzer (CDA) to collect material released from the main rings and to characterize the ring material infall into Saturn. We report the direct in situ detection of material from Saturn's dense rings by the CDA impact mass spectrometer. Most detected grains are a few tens of nanometers in size and dynamically associated with the previously inferred "ring rain." Silicate and water-ice grains were identified, in proportions that vary with latitude. Silicate grains constitute up to 30% of infalling grains, a higher percentage than the bulk silicate content of the rings.

17.
Phys Rev Lett ; 121(10): 106801, 2018 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-30240231

RESUMO

The existence of Wigner crystallization, one of the most significant hallmarks of strong electron correlations, has to date only been definitively observed in two-dimensional systems. In one-dimensional (1D) quantum wires Wigner crystals correspond to regularly spaced electrons; however, weakening the confinement and allowing the electrons to relax in a second dimension is predicted to lead to the formation of a new ground state constituting a zigzag chain with nontrivial spin phases and properties. Here we report the observation of such zigzag Wigner crystals by use of on-chip charge and spin detectors employing electron focusing to image the charge density distribution and probe their spin properties. This experiment demonstrates both the structural and spin phase diagrams of the 1D Wigner crystallization. The existence of zigzag spin chains and phases which can be electrically controlled in semiconductor systems may open avenues for experimental studies of Wigner crystals and their technological applications in spintronics and quantum information.

18.
Phys Rev Lett ; 120(13): 137701, 2018 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-29694224

RESUMO

We report spin amplification using a capacitive beam splitter in n-type GaAs where the spin polarization is monitored via a transverse electron focusing measurement. It is shown that partially spin-polarized current injected by the emitter can be precisely controlled, and the spin polarization associated with it can be amplified by the beam splitter, such that a considerably high spin polarization of around 50% can be obtained. Additionally, the spin remains coherent as shown by the observation of quantum interference. Our results illustrate that spin-polarization amplification can be achieved in materials without strong spin-orbit interaction.

19.
Bioorg Med Chem ; 26(4): 791-797, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29366687

RESUMO

A spirocyclic, sp3-atom rich oxetane-containing scaffold was synthesised in just two steps via a gold catalysed propargylic alcohol rearrangement. The key gold cyclisation can be undertaken on a 40 g scale allowing the preparation of 419 lead-like compounds based on the scaffold for the European Lead Factory.


Assuntos
Desenho de Fármacos , Éteres Cíclicos/química , Piperidinas/química , Bibliotecas de Moléculas Pequenas/química , Catálise , Ciclização , Ouro/química , Bibliotecas de Moléculas Pequenas/síntese química
20.
Nanoscale Res Lett ; 12(1): 553, 2017 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-28952141

RESUMO

We present experimental results of transverse electron-focusing measurements performed using n-type GaAs. In the presence of a small transverse magnetic field (B⊥), electrons are focused from the injector to detector leading to focusing peaks periodic in B⊥. We show that the odd-focusing peaks exhibit a split, where each sub-peak represents a population of a particular spin branch emanating from the injector. The temperature dependence reveals that the peak splitting is well defined at low temperature whereas it smears out at high temperature indicating the exchange-driven spin polarisation in the injector is dominant at low temperatures.

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