Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
Inorg Chem ; 62(30): 12027-12037, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37466301

RESUMO

A new reduced phase derived from the excitonic insulator candidate Ta2NiSe5 has been synthesized via the intercalation of lithium. LiTa2NiSe5 crystallizes in the orthorhombic space group Pmnb (no. 62) with lattice parameters a = 3.50247(3) Å, b = 13.4053(4) Å, c = 15.7396(2) Å, and Z = 4, with an increase of the unit cell volume by 5.44(1)% compared with Ta2NiSe5. Significant rearrangement of the Ta-Ni-Se layers is observed, in particular a very significant relative displacement of the layers compared to the parent phase, similar to that which occurs under hydrostatic pressure. Neutron powder diffraction experiments and computational analysis confirm that Li occupies a distorted triangular prismatic site formed by Se atoms of adjacent Ta2NiSe5 layers with an average Li-Se bond length of 2.724(2) Å. Li-NMR experiments show a single Li environment at ambient temperature. Intercalation suppresses the distortion to monoclinic symmetry that occurs in Ta2NiSe5 at 328 K and that is believed to be driven by the formation of an excitonic insulating state. Magnetometry data show that the reduced phase has a smaller net diamagnetic susceptibility than Ta2NiSe5 due to the enhancement of the temperature-independent Pauli paramagnetism caused by the increased density of states at the Fermi level evident also from the calculations, consistent with the injection of electrons during intercalation and formation of a metallic phase.

2.
Resuscitation ; 118: 82-88, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28689046

RESUMO

BACKGROUND: The PARAMEDIC cluster randomised trial evaluated the LUCAS mechanical chest compression device, and did not find evidence that use of mechanical chest compression led to an improvement in survival at 30 days. This paper reports patient outcomes from admission to hospital to 12 months after randomisation. METHODS: Information about hospital length of stay and intensive care management was obtained through linkage with Hospital Episode Statistics and the Intensive Care National Audit and Research Centre. Patients surviving to hospital discharge were approached to complete questionnaires (SF-12v2, EQ-5D, MMSE, HADS and PTSD-CL) at 90days and 12 months. The study is registered with Current Controlled Trials, number ISRCTN08233942. RESULTS: 377 patients in the LUCAS arm and 658 patients in the manual chest compression were admitted to hospital. Hospital and intensive care length of stay were similar. Long term follow-up assessments were limited by poor response rates (53.7% at 3 months and 55.6% at 12 months). Follow-up rates were lower in those with worse neurological function. Among respondents, long term health related quality of life outcomes and emotional well-being was similar between groups. Cognitive function, measured by MMSE, was marginally lower in the LUCAS arm mean 26.9 (SD 3.7) compared to control mean 28.0 (SD 2.3), adjusted mean difference -1.5 (95% CI -2.6 to -0.4). CONCLUSION: There were no clinically important differences identified in outcomes at long term follow-up between those allocated to the mechanical chest compression compared to those receiving manual chest compression.


Assuntos
Reanimação Cardiopulmonar/métodos , Massagem Cardíaca/métodos , Parada Cardíaca Extra-Hospitalar/terapia , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Reanimação Cardiopulmonar/instrumentação , Estudos de Casos e Controles , Massagem Cardíaca/instrumentação , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Razão de Chances , Parada Cardíaca Extra-Hospitalar/mortalidade , Estudos Prospectivos , Inquéritos e Questionários , Sobreviventes/estatística & dados numéricos
3.
Int J Law Psychiatry ; 50: 61-67, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27237959

RESUMO

The UK has one of the highest rates of self harm (SH) in Europe, and almost four times more people die by suicide than in road traffic collisions. Emergency ambulance paramedics are often the first health professionals involved in the care of people who have self-harmed, yet little is known about the care provided or issues raised in these encounters. The aim of this study is to explore paramedics' perceptions and experiences of caring for people who SH, to inform education and policy. Semi structured interviews were conducted with paramedics, and themes generated by constant comparison coding. This paper reports two emerging themes: Firstly, professional, legal, clinical and ethical tensions, linked to limited decision support, referral options and education. The second theme of relationships with police, revealed practices and surreptitious strategies related to care and detention, aimed at overcoming complexities of care. In the absence of tailored education, guidance or support for self-harm care, 'ways and means' have evolved which may negatively influence care and challenge ethical and legal frameworks. There is an urgent need to include evidence from this study in revised guidance and educational materials for paramedics working with people who self-harm in the prehospital emergency setting.


Assuntos
Atitude do Pessoal de Saúde , Auxiliares de Emergência/psicologia , Comportamento Autodestrutivo/psicologia , Comportamento Autodestrutivo/terapia , Tentativa de Suicídio/psicologia , Suicídio/psicologia , Internação Compulsória de Doente Mental/legislação & jurisprudência , Estudos Transversais , Tomada de Decisões/ética , Auxiliares de Emergência/ética , Auxiliares de Emergência/legislação & jurisprudência , Ética Médica , Feminino , Teoria Fundamentada , Humanos , Intenção , Comunicação Interdisciplinar , Colaboração Intersetorial , Masculino , Polícia/ética , Polícia/legislação & jurisprudência , Polícia/psicologia , Comportamento Autodestrutivo/epidemiologia , Suicídio/ética , Suicídio/estatística & dados numéricos , Tentativa de Suicídio/prevenção & controle , Tentativa de Suicídio/estatística & dados numéricos , Reino Unido , Prevenção do Suicídio
4.
Resuscitation ; 109: 110-115, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27886777

RESUMO

AIM: This study explores why resuscitation is withheld when emergency medical staff arrive at the scene of a cardiac arrest and identifies modifiable factors associated with this decision. METHODS: This is a secondary analysis of unselected patients who sustained an out of hospital cardiac arrest attended by ambulance vehicles participating in a randomized controlled trial of a mechanical chest compression device (PARAMEDIC trial). Patients were categorized as 'non-resuscitation' patients if there was a do-not-attempt-cardiopulmonary-resuscitation (DNACPR) order, signs unequivocally associated with death or resuscitation was deemed futile (15min had elapsed since collapse with no bystander-CPR and asystole recorded on EMS arrival). RESULTS: Emergency Medical Services attended 11,451 cardiac arrests. Resuscitation was attempted or continued by Emergency Medical Service staff in 4805 (42%) of cases. Resuscitation was withheld in 6646 cases (58%). 711 (6.2%) had a do not attempt resuscitation decision, 4439 (38.8%) had signs unequivocally associated with death and in 1496 cases (13.1%) CPR was considered futile. Those where resuscitation was withheld due to futility were characterised by low bystander CPR rates (7.2%) and by being female. CONCLUSIONS: Resuscitation was withheld by ambulance staff in over one in ten (13.1%) victims of out of hospital cardiac arrest on the basis of futility. These cases were associated with a very low rate of bystander CPR. Future studies should explore strengthening the 'Chain of Survival' to increase the community bystander CPR response and evaluate the effect on the numbers of survivors from out of hospital cardiac arrest.


Assuntos
Reanimação Cardiopulmonar/estatística & dados numéricos , Serviços Médicos de Emergência/métodos , Futilidade Médica , Parada Cardíaca Extra-Hospitalar/mortalidade , Ordens quanto à Conduta (Ética Médica) , Suspensão de Tratamento/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Morte , Serviços Médicos de Emergência/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tempo para o Tratamento
5.
Biotechnol Lett ; 38(11): 1903-1910, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27502834

RESUMO

OBJECTIVE: Palladised cells of Desulfovibrio desulfuricans and Shewanella oneidensis have been reported as fuel cell electrocatalysts but growth at scale may be unattractive/costly; we have evaluated the potential of using E. coli, using H2/formate for Pd-nanoparticle manufacture. RESULTS: Using 'bio-Pd' made under H2 (20 wt%) cyclic voltammograms suggested electrochemical activity of bio-NPs in a native state, attributed to proton adsorption/desorption. Bio-Pd prepared using formate as the electron donor gave smaller, well separated NPs; this material showed no electrochemical properties, and hence little potential for fuel cell use using a simple preparation technique. Bio-Pd on S. oneidensis gave similar results to those obtained using E. coli. CONCLUSION: Bio-Pd is sufficiently conductive to make an E. coli-derived electrochemically active material on intact, unprocessed bacterial cells if prepared at the expense of H2, showing potential for fuel cell applications using a simple one-step preparation method.


Assuntos
Escherichia coli/crescimento & desenvolvimento , Formiatos/química , Hidrogênio/química , Paládio/química , Fontes de Energia Bioelétrica , Desulfovibrio desulfuricans/metabolismo , Eletroquímica , Elétrons , Escherichia coli/metabolismo , Formiatos/metabolismo , Hidrogênio/metabolismo , Nanoestruturas/química , Paládio/metabolismo , Shewanella/metabolismo
6.
Phys Chem Chem Phys ; 16(23): 11435-46, 2014 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-24802981

RESUMO

Platinum (Pt) nanoparticles were prepared in aqueous dispersion using the non-ionic surfactant nonylphenolethoxylate (NP9) and the cationic surfactant tetradecyltrimethylammonium bromide (TTAB). The surfactants were added to give colloidal stability. Such species are generally considered to block electrochemical active sites and to be undesirable for the oxygen reduction reaction (ORR). However, the procedures used to remove them are likely to cause particle aggregation. The purpose of this work was to investigate the effect of surfactants on Pt ORR performance. The nanoparticles prepared using NP9 showed good oxygen reduction performance when compared with the commercial Pt/C catalyst TKK, without removing the surfactant. In contrast, Pt nanoparticles prepared using the cationic surfactant TTAB showed very poor ORR performance, exemplifying the importance of careful surfactant selection in catalyst synthesis.

7.
Nanoscale ; 5(1): 174-7, 2013 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-23187950

RESUMO

We report proof-of-concept measurements relating to the impact of nanoparticles with an electrode potentiostatted at a value corresponding to the diffusion controlled oxidation of silver nanoparticles in authentic seawater media. The charge associated with the oxidation reveals the number of atoms in the nanoparticle and thus its size and state of aggregation.


Assuntos
Condutometria/instrumentação , Eletrodos , Nanopartículas Metálicas/análise , Água do Mar/análise , Água do Mar/química , Prata/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Nanopartículas Metálicas/química , Prata/química
8.
Bone Marrow Transplant ; 48(6): 803-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23178547

RESUMO

While pre-emptive rituximab therapy for EBV has substantially reduced the incidence of post-transplant lymphoproliferative disorder, following allogeneic haematopoietic SCT (HSCT), cytomegalovirus (CMV) and adenovirus (ADV) still contribute to significant morbidity and mortality after HSCT. We therefore aimed to identify high-risk children who could benefit from recent advances in virus-specific immunotherapy, define the impact of viral reactivations on survival and estimate the economic burden of pre-emptive antiviral drug therapy. Between 2005 and 2010, prospective monitoring of 291 paediatric HSCT procedures revealed that reactivation of CMV (16%), ADV (15%) and EBV (11%) was frequent during period of CD4 T-cell lymphopenia (0.15 × 10(9) L(-1); P<0.05). We report significant risk factors for reactivation, most notably the use of serotherapy and development of GVHD (grade II) in the presence of pre-existing infection (ADV) or donor and/or recipient seropositivity (CMV, EBV). Most interestingly, CMV and ADV viraemia were the major independent predictors of mortality (P<0.05). CMV, ADV or EBV viral reactivation caused prolonged hospitalization (P<0.05), accounted for 15% of all mortality and substantially increased the cost of transplantation by ∼£22 500 ($34 000). This provides an economic rationale for targeting high-risk HSCT recipients with interventions such as virus-specific cell therapy.


Assuntos
Infecções por Vírus de DNA/mortalidade , Vírus de DNA , Transplante de Células-Tronco Hematopoéticas , Linfopenia/mortalidade , Adolescente , Aloenxertos , Linfócitos T CD4-Positivos/imunologia , Criança , Pré-Escolar , Infecções por Vírus de DNA/imunologia , Feminino , Doenças Genéticas Inatas/imunologia , Doenças Genéticas Inatas/mortalidade , Doenças Genéticas Inatas/terapia , Doenças Hematológicas/imunologia , Doenças Hematológicas/mortalidade , Doenças Hematológicas/terapia , Humanos , Lactente , Tempo de Internação , Linfopenia/imunologia , Masculino , Estudos Retrospectivos , Fatores de Risco
9.
Commun Med ; 6(2): 165-76, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20635553

RESUMO

The therapeutic relationship is the greatest predictor of treatment outcome, yet its relationship to communication is largely unevaluated. This study explored how psychiatrists and people with a diagnosis of schizophrenia establish mutual understanding in naturalistic communication, and associations with the therapeutic relationship, patient satisfaction and symptoms. In conversation analysis, the concept of repair focuses on how participants in interaction create mutual understanding and address misunderstanding. A standardized protocol measuring the frequency of repair was applied to 15 outpatient consultations. Correlations between repair and the therapeutic relationship, patients' experience of the consultation and symptoms were explored. Patients made most effort to make their contribution understandable, whereas psychiatrists made most effort to repair misunderstandings. The more positively psychiatrists rated the relationship, the more effort they made to understand patients. Although psychiatrists' efforts were not associated with patients' overall view of the relationship, patients felt better emotionally, despite, feeling less understood. Psychiatrists used fewer repairs when patients were more symptomatic. Both parties prioritized understanding similar topics but psychiatrists focused more on medication and patients on voices. Quantifying repair offers a new way of analyzing how mutual understanding is established in interaction, and links communication processes with treatment outcomes.


Assuntos
Comunicação , Relações Médico-Paciente , Processos Psicoterapêuticos , Psicoterapia , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicolinguística
10.
Br J Haematol ; 130(4): 595-603, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16098075

RESUMO

Adenovirus (AdV) infections are a frequent cause of morbidity and mortality following allogeneic stem cell transplantation (SCT), and disseminated infection is associated with high mortality, particularly in paediatric SCT. Here, we describe an approach to reduce mortality from adenoviraemia by combining prospective monitoring for the occurrence of adenoviraemia using a sensitive polymerase chain reaction method, early antiviral therapy and prompt withdrawal of immunosuppression. A total of 155 consecutive paediatric SCT procedures were prospectively monitored, of which 113 (73%) transplants involved donors other than matched siblings and 126 (83%) employed T-cell depletion. Adenoviraemia was detected in 26/155 (17%) transplants and developed exclusively in patients who had received T-cell-depleted grafts. Withdrawal of immunosuppression coupled with early antiviral therapy led to resolution of adenoviraemia in 19/26 (81%) patients with only five patients succumbing to disseminate AdV infection. Survival from adenoviraemia was associated with lymphocyte recovery to above 0.3x10(9)/l. Mortality was closely linked with the absence of lymphocyte recovery because of profound T-cell depletion of the graft with CD34+ magnetic-activated cell sorting. Mortality from disseminated AdV infection was 5/26 (19%) in this study, which is significantly lower than previously reported.


Assuntos
Infecções por Adenoviridae/complicações , Adenoviridae , Doenças Hematológicas/cirurgia , Transplante de Células-Tronco/efeitos adversos , Adenoviridae/genética , Adolescente , Antivirais/uso terapêutico , Criança , Pré-Escolar , DNA Viral/análise , DNA Viral/sangue , Fezes/virologia , Ganciclovir/uso terapêutico , Doenças Hematológicas/virologia , Humanos , Imunossupressores/uso terapêutico , Lactente , Modelos Logísticos , Nasofaringe/virologia , Nariz/virologia , Reação em Cadeia da Polimerase/métodos , Prognóstico , Estudos Prospectivos , Fatores de Risco , Condicionamento Pré-Transplante/métodos , Transplante Homólogo , Resultado do Tratamento
11.
Chemistry ; 7(6): 1194-201, 2001 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-11322545

RESUMO

The reactions of Pd(II) ions with a series of chelate-tethered derivatives of adenine and guanine have been studied and reveal a difference in the reactivity of the purine bases. Reactions of [PdCl2(MeCN)2] and A-alkyl-enH x Cl (alkyl = propyl or ethyl, A adenine, en = ethylenediamine) yield the monocationic species [PdCl(A-N3-Et-en)]+ (1) and [PdCl(A-N3-Pr-en)]+ (2). Both involve co-ordination at the minor groove site N3 of the nucleobase as confirmed by single-crystal X-ray analysis. Reactions with the analogous G-alkyl-enH x Cl derivatives (G=guanine, alkyl = ethyl or propyl) were more complex with a mixture of species being observed. For G-Et-en HCI a product was isolated which was identified as [PdCl(G-C8-Et-en)]+ (3). This compound contains a biomolecular metal-carbon bond involving C8 of the purine base. Crystallography of a product obtained from reaction of G-Pr-enH x Cl and [Pd(MeCN)4][NO3]2 reveals an octacationic tetrameric complex (4), in which each ligand acts to bridge two metal ions through a combination of a tridentate binding mode involving the diamine and N3 and monodentate coordination at N7.


Assuntos
Adenina/metabolismo , Guanina/metabolismo , Paládio/metabolismo , Adenina/química , Pareamento de Bases , Sítios de Ligação , DNA/metabolismo , DNA/ultraestrutura , Guanina/química , Ligação de Hidrogênio , Ligantes , Modelos Moleculares , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Paládio/química
12.
Health Bull (Edinb) ; 59(4): 268-75, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12664738

RESUMO

The White Paper Towards a Healthier Scotland pledged 15 million Pounds to support four national health demonstration projects to lead the way in achieving sustained improvement in child health, young people's sexual health, coronary heart disease and cancer. The Starting Well project aims to demonstrate that child health in Glasgow can be improved by a programme of activities which both supports families and provides them with access to enhanced community-based resources. The Healthy Respect project aims to help young people in Lothian develop a positive attitude to their own sexuality and that of others, and a healthy respect for their partners, in order to reduce unplanned teenage pregnancies and sexually transmitted infections. The Have a Heart Paisley project is targeting coronary heart disease among the population of Scotland's largest town. The Cancer Challenge project is piloting a screening programme in the North East of Scotland for the detection of colorectal cancer. Though each project has specific objectives, appropriate to its own topic, all share underlying principles. The projects will act as test beds for action and a learning resource for the rest of Scotland.


Assuntos
Promoção da Saúde/métodos , Programas Nacionais de Saúde/organização & administração , Doenças Cardiovasculares/prevenção & controle , Criança , Proteção da Criança , Humanos , Neoplasias/prevenção & controle , Escócia , Educação Sexual
13.
Opt Lett ; 26(23): 1840-2, 2001 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-18059711

RESUMO

The fabrication of an optical cavity at the distal end of an optical fiber has been achieved by Langmuir-Blodgett (LB) deposition of tricosanoic acid. This technique allows nanometer-scale control over the cavity length to a total thickness of ~0.5 microm . The cavity has been shown to act interferometrically and, thus, has potential sensing applications.

14.
Artigo em Inglês | MEDLINE | ID: mdl-18244845

RESUMO

A new kind of dynamical fuzzy model is proposed to represent discrete-time complex systems which include both linguistic information and system uncertainties. A new stability analysis and control system design approach is then developed for this kind of dynamical fuzzy model. Furthermore, a constructive algorithm is developed to obtain the H(infinity) feedback control law. An example is given to illustrate the application of the method.

15.
Food Addit Contam ; 17(7): 575-81, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10983581

RESUMO

Consumption data can be expressed in different ways although it should be comparable to what is known about the toxicological property of the chemical in question and the likely pattern of consumer exposure. For example if the chemical has an acute toxic effect the consumption data should ideally be based on a single eating occasion or consumption over a single day and be based on the population of concern. This paper describes five UK dietary surveys and consumption data, specifically relevant to acute exposure assessment, from adult and pre-schoolchildren surveys. The acute consumption data are taken from the first day of the dietary regime. Closer examination of the dietary survey information suggests that either picking a random survey day or selecting all consuming days give 97.5 percentile values which are not significantly different. Consumption data are given for whole commodities and a few fruit juices. Examination of the dietary survey information shows that the consumption patterns are very different between whole commodities (e.g. apples), ingredients (e.g. apple in a dish or recipe) and juices and between adults and young children.


Assuntos
Bases de Dados Factuais , Inquéritos sobre Dietas , Contaminação de Alimentos/análise , Resíduos de Praguicidas , Adolescente , Adulto , Pré-Escolar , Alimentos , Humanos , Lactente , Concentração Máxima Permitida , Pessoa de Meia-Idade , Inquéritos Nutricionais , Reino Unido
16.
Food Addit Contam ; 13(4): 411-6, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8792131

RESUMO

The UK has developed considerable experience in the estimating additive intake over the past 20 years. The earliest approach involved collecting large amounts of detailed information on additive concentrations and aimed to provide accurate estimates of intake for all additives in a given class. This has been replaced in recent times by a hierarchical approach which is applied to selected additives following an initial prioritization. Initial intake estimates are made using readily available data and conservative assumptions about additive occurrence and food consumption. More refined calculations are not necessary if the initial estimate shows that intake is well below the Acceptable Daily Intake. Once the level of intake has been established, it is only necessary to repeat the estimation if market information shows that there have been substantial changes in additive usage or food consumption. A similar approach is recommended for adoption across the European Union.


Assuntos
Aditivos Alimentares/administração & dosagem , Alimentos , Aditivos Alimentares/análise , Análise de Alimentos , Humanos , Legislação sobre Alimentos , Edulcorantes/administração & dosagem , Reino Unido
17.
Artigo em Inglês | MEDLINE | ID: mdl-18263023

RESUMO

A discrete-time fuzzy control system which is composed of a dynamic fuzzy model and a fuzzy state feedback controller is proposed. Stability of the fuzzy control system is discussed and a sufficient condition to guarantee the stability of the system is given in terms of uncertain linear system theory. The results in this paper improve our previous stability results. An example is used to show the proposed method.

18.
J Chem Technol Biotechnol ; 55(1): 73-8, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1384563

RESUMO

Aqueous two-phase systems formed from PEG and dextran have been applied to the synthesis of oligosaccharide by Jack bean alpha-mannosidase in reverse. Whilst rates of synthesis and percentage yields were similar in two-phase systems and one-phase aqueous buffer systems, a ten-fold increase in yield of product per unit of enzyme was seen. In addition, the use of aqueous two-phase systems offers potential process advantages over one-phase systems for the synthesis of oligosaccharides.


Assuntos
Manosidases/metabolismo , Oligossacarídeos/síntese química , Sequência de Carboidratos , Dextranos/química , Estudos de Avaliação como Assunto , Glicosídeos/síntese química , Cinética , Dados de Sequência Molecular , Polietilenoglicóis/química , Solubilidade , Água/química , alfa-Manosidase
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA