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1.
Angew Chem Int Ed Engl ; 63(21): e202401987, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38526053

RESUMO

The in-depth understanding of the composition-property-performance relationship of solid electrolyte interphase (SEI) is the basis of developing a reliable SEI to stablize the Zn anode-electrolyte interface, but it remains unclear in rechargeable aqueous zinc ion batteries. Herein, a well-designed electrolyte based on 2 M Zn(CF3SO3)2-0.2 M acrylamide-0.2 M ZnSO4 is proposed. A robust polymer (polyacrylamide)-inorganic (Zn4SO4(OH)6.xH2O) hybrid SEI is in situ constructed on Zn anodes through controllable polymerization of acrylamide and coprecipitation of SO4 2- with Zn2+ and OH-. For the first time, the underlying SEI composition-property-performance relationship is systematically investigated and correlated. The results showed that the polymer-inorganic hybrid SEI, which integrates the high modulus of the inorganic component with the high toughness of the polymer ingredient, can realize high reversibility and long-term interfacial stability, even under ultrahigh areal current density and capacity (30 mA cm-2~30 mAh cm-2). The resultant Zn||NH4V4O10 cell also exhibits excellent cycling stability. This work will provide a guidance for the rational design of SEI layers in rechargeable aqueous zinc ion batteries.

4.
J Subst Use Addict Treat ; 159: 209259, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38103833

RESUMO

INTRODUCTION: Deaths caused by alcohol are increasing in England and 80 % of people with alcohol use disorders (AUDs) are not in treatment. The Blue Light approach (Alcohol Change UK) is an initiative to support people with AUDs who are not in treatment. This study aimed to tailor the Blue Light approach (combined with alcohol identification and alcohol brief interventions [ABI] training) for police officers and homeless service staff in North West England, and to qualitatively evaluate the feasibility and acceptability of the training. METHODS: The Blue Light approach was tailored using co-production activities, based on Transdisciplinary Action Research. Full-day and half-day training sessions were delivered to the police (full-day N = 14, half-day N = 54) and homeless service staff (full-day N = 11, half-day N = 32), in local police stations and online (four half-day sessions). Semi-structured interviews (N = 23) were conducted to evaluate implementation and integration, analysing the qualitative data in line with Normalisation Process Theory. RESULTS: Four themes were identified, each with two to three sub-themes, reflecting: (i) the importance of training for working practice, (ii) implementation of the interventions, (iii) changes to relationships within and between organizations, and (iv) recommendations for further changes to the training. Differences in findings across the organizations (police versus homeless services) and by training type attended (full-day versus half-day, in-person versus online) are presented. CONCLUSIONS: There is evidence to suggest that the training has provided worthwhile knowledge and intervention techniques that can become embedded into working practices. Nevertheless, structural barriers were apparent, primarily within the police service, with clear disparities between recognising the value of the training and what is achievable in practice, given the competing demands.


Assuntos
Alcoolismo , Polícia , Humanos , Estudos de Viabilidade , Alcoolismo/epidemiologia , Luz Azul , Inglaterra
5.
Nat Commun ; 14(1): 8066, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38052834

RESUMO

Understanding the degradation mechanism of organic light-emitting diodes (OLED) is essential to improve device performance and stability. OLED failure, if not process-related, arises mostly from chemical instability. However, the challenges of sampling from nanoscale organic layers and interfaces with enough analytical information has hampered identification of degradation products and mechanisms. Here, we present a high-resolution diagnostic method of OLED degradation using an Orbitrap mass spectrometer equipped with a gas cluster ion beam to gently desorb nanometre levels of materials, providing unambiguous molecular information with 7-nm depth resolution. We chemically depth profile and analyse blue phosphorescent and thermally-activated delayed fluorescent (TADF) OLED devices at different degradation levels. For OLED devices with short operational lifetimes, dominant chemical degradation mainly relate to oxygen loss of molecules that occur at the interface between emission and electron transport layers (EML/ETL) where exciton distribution is maximised, confirmed by emission zone measurements. We also show approximately one order of magnitude increase in lifetime of devices with slightly modified host materials, which present minimal EML/ETL interfacial degradation and show the method can provide insight for future material and device architecture development.

6.
Anal Chem ; 95(49): 18287-18294, 2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38044628

RESUMO

Bacterial biofilms are structured communities consisting of cells enmeshed in a self-generated extracellular matrix usually attached to a surface. They contain diverse classes of molecules including polysaccharides, lipids, proteins, nucleic acids, and diverse small organic molecules (primary and secondary metabolites) which are organized to optimize survival and facilitate dispersal to new colonization sites. In situ characterization of the chemical composition and structure of bacterial biofilms is necessary to fully understand their development on surfaces relevant to biofouling in health, industry, and the environment. Biofilm development has been extensively studied using confocal microscopy using targeted fluorescent labels providing important insights into the architecture of biofilms. Recently, cryopreparation has been used to undertake targeted in situ chemical characterization using Orbitrap secondary ion mass spectrometry (OrbiSIMS), providing a label-free method for imaging biofilms in their native state. Although the high mass resolution of OrbiSIMS enables more confident peak assignments, it is still very challenging to assign most of the peaks in the spectra due to complexity of SIMS spectra and lack of automatic peak assignment methods. Here, we analyze the same OrbiSIMS depth profile data generated from the frozen-hydrated biofilm, but employ a new untargeted chemical filtering process utilizing mass spectral databases to assign secondary ions to decipher the large number of fragments present in the SIMS spectra. To move towards comprehensive analysis of different chemistries in the sample, we apply a molecular formula prediction approach which putatively assigns 81% of peaks in the 3D OrbiSIMS depth profile analysis. This enables us to catalog over 1000 lipids and their fragments, 3500 protein fragments, 71 quorum sensing-related molecules (2-alkyl-4-quinolones and N-acylhomoserine lactones), 150 polysaccharide fragments, and glycolipids simultaneously from one data set and map these separated molecular classes spatially through a Pseudomonas aeruginosa biofilm. Assignment of different chemistries in this sample facilitates identification of differences between biofilms grown on biofilm-promoting and biofilm-resistant polymers.


Assuntos
Biofilmes , Pseudomonas aeruginosa , Pseudomonas aeruginosa/química , Percepção de Quorum , Espectrometria de Massa de Íon Secundário/métodos , Glicolipídeos
7.
J Control Release ; 364: 79-89, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37858627

RESUMO

A correlative methodology for label-free chemical imaging of soft tissue has been developed, combining non-linear optical spectroscopies and mass spectrometry to achieve sub-micron spatial resolution and critically improved drug detection sensitivity. The approach was applied to visualise the kinetics of drug reservoir formation within human skin following in vitro topical treatment with a commercial diclofenac gel. Non-destructive optical spectroscopic techniques, namely stimulated Raman scattering, second harmonic generation and two photon fluorescence microscopies, were used to provide chemical and structural contrast. The same tissue sections were subsequently analysed by secondary ion mass spectrometry, which offered higher sensitivity for diclofenac detection throughout the epidermis and dermis. A method was developed to combine the optical and mass spectrometric datasets using image registration techniques. The label-free, high-resolution visualisation of tissue structure coupled with sensitive chemical detection offers a powerful method for drug biodistribution studies in the skin that impact directly on topical pharmaceutical product development.


Assuntos
Diclofenaco , Pele , Humanos , Distribuição Tecidual , Análise Espectral Raman/métodos , Espectrometria de Massas
8.
Anal Chem ; 95(40): 15078-15085, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37715701

RESUMO

Quantitative analysis of binary mixtures of tris(2-phenylpyridinato)iridium(III) (Ir(ppy)3) and tris(8-hydroxyquinolinato)aluminum (Alq3) by using an artificial neural network (ANN) system to mass spectra was attempted based on the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study (TW2 A31) to evaluate matrix-effect correction and to investigate interface determination. Monolayers of binary mixtures having different Ir(ppy)3 ratios (0, 0.25, 0.50, 0.75, and 1.00), and the multilayers containing these mixtures and pure samples were measured using time-of-flight secondary ion mass spectrometry (ToF-SIMS) with different primary ion beams, OrbiSIMS (SIMS with both Orbitrap and ToF mass spectrometers), laser desorption ionization (LDI), desorption/ionization induced by neutral clusters (DINeC), and X-ray photoelectron spectroscopy (XPS). The mass spectra were analyzed using a simple ANN with one hidden layer. The Ir(ppy)3 ratios of the unknown samples and the interfaces of the multilayers were predicted using the simple ANN system, even though the mass spectra of binary mixtures exhibited matrix effects. The Ir(ppy)3 ratios at the interfaces indicated by the simple ANN were consistent with the XPS results and the ToF-SIMS depth profiles. The simple ANN system not only provided quantitative information on unknown samples, but also indicated important mass peaks related to each molecule in the samples without a priori information. The important mass peaks indicated by the simple ANN depended on the ionization process. The simple ANN results of the spectra sets obtained by a softer ionization method, such as LDI and DINeC, suggested large ions such as trimers. From the first step of the investigation to build an ANN model for evaluating mixture samples influenced by matrix effects, it was indicated that the simple ANN method is useful for obtaining candidate mass peaks for identification and for assuming mixture conditions that are helpful for further analysis.

10.
ACS Appl Mater Interfaces ; 15(21): 26047-26059, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37204772

RESUMO

Composite polymer electrolytes (CPEs) are attractive materials for solid-state lithium metal batteries, owing to their high ionic conductivity from ceramic ionic conductors and flexibility from polymer components. As with all lithium metal batteries, however, CPEs face the challenge of dendrite formation and propagation. Not only does this lower the critical current density (CCD) before cell shorting, but the uncontrolled growth of lithium deposits may limit Coulombic efficiency (CE) by creating dead lithium. Here, we present a fundamental study on how the ceramic components of CPEs influence these characteristics. CPE membranes based on poly(ethylene oxide) and lithium bis(trifluoromethanesulfonyl)imide (PEO-LiTFSI) with Li7La3Zr2O12 (LLZO) nanofibers were fabricated with industrially relevant roll-to-roll manufacturing techniques. Galvanostatic cycling with lithium symmetric cells shows that the CCD can be tripled by including 50 wt % LLZO, but half-cell cycling reveals that this comes at the cost of CE. Varying the LLZO loading shows that even a small amount of LLZO drastically lowers the CE, from 88% at 0 wt % LLZO to 77% at just 2 wt % LLZO. Mesoscale modeling reveals that the increase in CCD cannot be explained by an increase in the macroscopic or microscopic stiffness of the electrolyte; only the microstructure of the LLZO nanofibers in the PEO-LiTFSI matrix slows dendrite growth by presenting physical barriers that the dendrites must push or grow around. This tortuous lithium growth mechanism around the LLZO is corroborated with mass spectrometry imaging. This work highlights important elements to consider in the design of CPEs for high-efficiency lithium metal batteries.

11.
Nature ; 615(7953): 705-711, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36922598

RESUMO

Artificial sweeteners are used as calorie-free sugar substitutes in many food products and their consumption has increased substantially over the past years1. Although generally regarded as safe, some concerns have been raised about the long-term safety of the consumption of certain sweeteners2-5. In this study, we show that the intake of high doses of sucralose in mice results in immunomodulatory effects by limiting T cell proliferation and T cell differentiation. Mechanistically, sucralose affects the membrane order of T cells, accompanied by a reduced efficiency of T cell receptor signalling and intracellular calcium mobilization. Mice given sucralose show decreased CD8+ T cell antigen-specific responses in subcutaneous cancer models and bacterial infection models, and reduced T cell function in models of T cell-mediated autoimmunity. Overall, these findings suggest that a high intake of sucralose can dampen T cell-mediated responses, an effect that could be used in therapy to mitigate T cell-dependent autoimmune disorders.


Assuntos
Sacarose , Edulcorantes , Linfócitos T , Animais , Camundongos , Sacarose/análogos & derivados , Edulcorantes/administração & dosagem , Edulcorantes/efeitos adversos , Edulcorantes/farmacologia , Edulcorantes/uso terapêutico , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/patologia , Inocuidade dos Alimentos , Sinalização do Cálcio/efeitos dos fármacos , Receptores de Antígenos de Linfócitos T/efeitos dos fármacos , Receptores de Antígenos de Linfócitos T/imunologia , Infecções Bacterianas/imunologia , Neoplasias/imunologia , Autoimunidade/efeitos dos fármacos , Autoimunidade/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia
12.
PLoS One ; 18(2): e0280749, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36753517

RESUMO

BACKGROUND: Early detection and diagnosis of alcohol-related cognitive impairment (ARCI) among heavy drinkers is crucial to facilitating appropriate referral and treatment. However, there is lack of consensus in defining diagnostic criteria for ARCI. Uncertainty in attributing a diagnosis of suspected ARCI commonly arises in clinical practice and opportunities to intervene are missed. A systematic scoping review approach was taken to (i) summarise evidence relating to screening or diagnostic criteria used in clinical studies to detect ARCI; and (ii) to determine the extent of the research available about cognitive assessment tools used in 'point-of-care' screening or assessment of patients with suspected non-Korsakoff Syndrome forms of ARCI. METHODS: We searched Medline, PsycINFO, Cinahl and the Web of Science, screened reference lists and carried out forward and backwards citation searching to identify clinical studies about screening, diagnosis or assessment of patients with suspected ARCI. RESULTS: In total, only 7 studies met our primary objective and reported on modifications to existing definitions or diagnostic criteria for ARCI. These studies revealed a lack of coordinated research and progress towards the development and standardisation of diagnostic criteria for ARCI. Cognitive screening tools are commonly used in practice to support a diagnosis of ARCI, and as a secondary objective we included an additional 12 studies, which covered a range of settings and patient populations relevant to screening, diagnosis or assessment in acute, secondary or community 'point-of-care' settings. Across two studies with a defined ARCI patient sample and a further four studies with an alcohol use disorder patient sample, the accuracy, validity and/or reliability of seven different cognitive assessment tools were examined. The remaining seven studies reported descriptive findings, demonstrating the lack of evidence available to draw conclusions about which tools are most appropriate for screening patients with suspected ARCI. CONCLUSION: This review confirms the scarcity of evidence available on the screening, diagnosis or assessment of patients with suspected ARCI. The lack of evidence is an important barrier to the development of clear guidelines for diagnosing ARCI, which would ultimately improve the real-world management and treatment of patients with ARCI.


Assuntos
Intoxicação Alcoólica , Disfunção Cognitiva , Demência , Humanos , Demência/diagnóstico , Diagnóstico Diferencial , Reprodutibilidade dos Testes , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/complicações , Intoxicação Alcoólica/complicações , Sensibilidade e Especificidade
13.
BMC Psychiatry ; 23(1): 89, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36747152

RESUMO

BACKGROUND: There is strong evidence for the co-occurrence of mental health conditions and alcohol problems, yet physical health outcomes among this group are not well characterised. This study aimed to identify clusters of physical health conditions and their associations with mental health and problematic alcohol use in England's general population. METHODS: Cross-sectional analysis of the 2014 Adult Psychiatric Morbidity Survey (N = 7546) was conducted. The survey used standardised measures of problematic alcohol use and mental health conditions, including the Alcohol Use Disorders Identification Test (AUDIT) and the Clinical Interview Schedule-Revised. Participants self-reported any lifetime physical health conditions. Latent class analysis considered 12 common physical illnesses to identify clusters of multimorbidity. Multinomial logistic regression (adjusting for age, gender, ethnicity, education, and occupational grade) was used to explore associations between mental health, hazardous drinking (AUDIT 8 +), and co-occurring physical illnesses. RESULTS: Five clusters were identified with statistically distinct and clinically meaningful disease patterns: 'Physically Healthy' (76.62%), 'Emerging Multimorbidity' (3.12%), 'Hypertension & Arthritis' (14.28%), 'Digestive & Bowel Problems'' (3.17%), and 'Complex Multimorbidity' (2.8%). Having a mental health problem was associated with increased odds of 'Digestive & Bowel Problems' (adjusted multinomial odds ratio (AMOR) = 1.58; 95% CI [1.15-2.17]) and 'Complex Multimorbidity' (AMOR = 2.02; 95% CI [1.49-2.74]). Individuals with co-occurring mental health conditions and problematic alcohol use also had higher odds of 'Digestive & Bowel Problems' (AMOR = 2.64; 95% CI [1.68-4.15]) and 'Complex Multimorbidity' (AMOR = 2.62; 95% CI [1.61-4.23]). CONCLUSIONS: Individuals with a mental health condition concurrent with problematic alcohol use experience a greater burden of physical illnesses, highlighting the need for timely treatment which is likely to include better integration of alcohol and mental health services.


Assuntos
Alcoolismo , Saúde Mental , Adulto , Humanos , Estudos Transversais , Alcoolismo/epidemiologia , Análise por Conglomerados
15.
ACS Appl Mater Interfaces ; 14(47): 52779-52793, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36382786

RESUMO

Lithium-ion batteries are the most ubiquitous energy storage devices in our everyday lives. However, their energy storage capacity fades over time due to chemical and structural changes in their components, via different degradation mechanisms. Understanding and mitigating these degradation mechanisms is key to reducing capacity fade, thereby enabling improvement in the performance and lifetime of Li-ion batteries, supporting the energy transition to renewables and electrification. In this endeavor, surface analysis techniques are commonly employed to characterize the chemistry and structure at reactive interfaces, where most changes are observed as batteries age. However, battery electrodes are complex systems containing unstable compounds, with large heterogeneities in material properties. Moreover, different degradation mechanisms can affect multiple material properties and occur simultaneously, meaning that a range of complementary techniques must be utilized to obtain a complete picture of electrode degradation. The combination of these issues and the lack of standard measurement protocols and guidelines for data interpretation can lead to a lack of trust in data. Herein, we discuss measurement challenges that affect several key surface analysis techniques being used for Li-ion battery degradation studies: focused ion beam scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and time-of-flight secondary ion mass spectrometry. We provide recommendations for each technique to improve reproducibility and reduce uncertainty in the analysis of NMC/graphite Li-ion battery electrodes. We also highlight some key measurement issues that should be addressed in future investigations.

16.
Int J Pharm ; 628: 122191, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36191816

RESUMO

Amorphous solid dispersions (ASDs) are formulations with enhanced drug solubility and dissolution rate compared to their crystalline counterparts, however, they can be inherently thermodynamically unstable. This can lead to amorphous phase separation and drug re-crystallisation, phenomena that are typically faster and more dominant at the product's surfaces. This study investigates the use of high-resolution time of flight-secondary ion mass spectrometry (ToF-SIMS) imaging as a surface analysis technique combined with image-analysis for the early detection, monitoring and quantification of surface amorphous phase separation in ASDs. Its capabilities are demonstrated for two pharmaceutically relevant ASD systems with distinct re-crystallisation behaviours, prepared using hot melt extrusion (HME) followed by pelletisation or grinding: (1) paracetamol-hydroxypropyl methylcellulose (PCM-HPMC) pellets with drug loadings of 10%-50% w/w and (2) indomethacin-polyvinylpyrrolidone (IND-PVP) ground material with drug loadings of 20%-85% w/w. PCM-HPMC pellets showed intense phase separation, reaching 100% PCM surface coverage within 1-5 months. In direct comparison, IND-PVP HME ground material was more stable with only a moderate formation of isolated IND-rich clusters. Image analysis allowed the reliable detection and quantification of local drug-rich clusters. An Avrami model was applied to determine and compare phase separation kinetics. The combination of chemical sensitivity and high spatial resolution afforded by SIMS was crucial to enable the study of early phase separation and re-crystallisation at the surface. Compared with traditional methods used to detect crystalline material, such as XRPD, we show that ToF-SIMS enabled detection of surface physical instability already at early stages of drug cluster formation in the first days of storage.


Assuntos
Povidona , Espectrometria de Massa de Íon Secundário , Solubilidade , Composição de Medicamentos/métodos , Povidona/química , Derivados da Hipromelose/química , Indometacina/química , Estabilidade de Medicamentos
17.
Metabolomics ; 18(10): 77, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36181583

RESUMO

Single cell metabolomics is an emerging and rapidly developing field that complements developments in single cell analysis by genomics and proteomics. Major goals include mapping and quantifying the metabolome in sufficient detail to provide useful information about cellular function in highly heterogeneous systems such as tissue, ultimately with spatial resolution at the individual cell level. The chemical diversity and dynamic range of metabolites poses particular challenges for detection, identification and quantification. In this review we discuss both significant technical issues of measurement and interpretation, and progress toward addressing them, with recent examples from diverse biological systems. We provide a framework for further directions aimed at improving workflow and robustness so that such analyses may become commonly applied, especially in combination with metabolic imaging and single cell transcriptomics and proteomics.


Assuntos
Metaboloma , Metabolômica , Metabolômica/métodos , Proteômica , Fluxo de Trabalho
18.
Anal Chem ; 94(28): 10035-10044, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35786855

RESUMO

In this study, we examine the suitability of desorption electro-flow focusing ionization (DEFFI) for mass spectrometry imaging (MSI) of biological tissue. We also compare the performance of desorption electrospray ionization (DESI) with and without the flow focusing setup. The main potential advantages of applying the flow focusing mechanism in DESI is its rotationally symmetric electrospray jet, higher intensity, more controllable parameters, and better portability due to the robustness of the sprayer. The parameters for DEFFI have therefore been thoroughly optimized, primarily for spatial resolution but also for intensity. Once the parameters have been optimized, DEFFI produces similar images to the existing DESI. MS images for mouse brain samples, acquired at a nominal pixel size of 50 µm, are comparable for both DESI setups, albeit the new sprayer design yields better sensitivity. Furthermore, the two methods are compared with regard to spectral intensity as well as the area of the desorbed crater on rhodamine-coated slides. Overall, the implementation of a flow focusing mechanism in DESI is shown to be highly suitable for imaging biological tissue and has potential to overcome some of the shortcomings experienced with the current geometrical design of DESI.


Assuntos
Diagnóstico por Imagem , Espectrometria de Massas , Espectrometria de Massas por Ionização por Electrospray , Animais , Encéfalo/diagnóstico por imagem , Camundongos , Espectrometria de Massas por Ionização por Electrospray/métodos
19.
Health Technol Assess ; 25(58): 1-86, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34663491

RESUMO

BACKGROUND: Tranexamic acid reduces blood loss in surgery and the risk of death in trauma patients. Meta-analyses of small trials suggest that tranexamic acid decreases the number of deaths from gastrointestinal bleeding, but these meta-analyses are prone to selection bias. OBJECTIVE: The trial provides reliable evidence of the effect of tranexamic acid on mortality, rebleeding and complications in significant acute gastrointestinal bleeding. DESIGN: A multicentre, randomised, placebo-controlled trial and economic analysis. Patients were assigned by selecting one treatment pack from a box of eight, which were identical apart from the pack number. Patients, caregivers and outcome assessors were masked to allocation. The main analyses were by intention to treat. SETTING: The setting was 164 hospitals in 15 countries, co-ordinated from the London School of Hygiene & Tropical Medicine. PARTICIPANTS: Adults with significant upper or lower gastrointestinal bleeding (n = 12,009) were eligible if the responsible clinician was substantially uncertain about whether or not to use tranexamic acid. The clinical diagnosis of significant bleeding implied a risk of bleeding to death, including hypotension, tachycardia or signs of shock, or urgent transfusion, endoscopy or surgery. INTERVENTION: Tranexamic acid (a 1-g loading dose over 10 minutes, then a 3-g maintenance dose over 24 hours) or matching placebo. MAIN OUTCOME MEASURES: The primary outcome was death due to bleeding within 5 days of randomisation. Secondary outcomes were all-cause and cause-specific mortality; rebleeding; need for endoscopy, surgery or radiological intervention; blood product transfusion; complications; disability; and days spent in intensive care or a high-dependency unit. RESULTS: A total of 12,009 patients were allocated to receive tranexamic acid (n = 5994, 49.9%) or the matching placebo (n = 6015, 50.1%), of whom 11,952 (99.5%) received the first dose. Death due to bleeding within 5 days of randomisation occurred in 222 (3.7%) patients in the tranexamic acid group and in 226 (3.8%) patients in the placebo group (risk ratio 0.99, 95% confidence interval 0.82 to 1.18). Thromboembolic events occurred in 86 (1.4%) patients in the tranexamic acid group and 72 (1.2%) patients in the placebo group (risk ratio 1.20, 95% confidence interval 0.88 to 1.64). The risk of arterial thromboembolic events (myocardial infarction or stroke) was similar in both groups (0.7% in the tranexamic acid group vs. 0.8% in the placebo group; risk ratio 0.92, 95% confidence interval 0.60 to 1.39), but the risk of venous thromboembolic events (deep-vein thrombosis or pulmonary embolism) was higher in tranexamic acid-treated patients than in placebo-treated patients (0.8% vs. 0.4%; risk ratio 1.85, 95% confidence interval 1.15 to 2.98). Seizures occurred in 38 patients who received tranexamic acid and in 22 patients who received placebo (0.6% vs. 0.4%, respectively; risk ratio 1.73, 95% confidence interval 1.03 to 2.93). In the base-case economic analysis, tranexamic acid was not cost-effective and resulted in slightly poorer health outcomes than no tranexamic acid. CONCLUSIONS: Tranexamic acid did not reduce death from gastrointestinal bleeding and, although inexpensive, it is not cost-effective in adults with acute gastrointestinal bleeding. FUTURE WORK: These results caution against a uniform approach to the management of patients with major haemorrhage and highlight the need for randomised trials targeted at specific pathophysiological processes. LIMITATIONS: Although this is one of the largest randomised trials in gastrointestinal bleeding, we cannot rule out a modest increase or decrease in death due to bleeding with tranexamic acid. TRIAL REGISTRATION: Current Controlled Trials ISRCTN11225767, ClinicalTrials.gov NCT01658124 and EudraCT 2012-003192-19. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 58. See the NIHR Journals Library website for further project information.


Acute gastrointestinal bleeding (bleeding from the gut) is a common emergency and an important cause of death and illness worldwide. In the UK, more than 65,000 people each year are admitted to hospital because of acute gastrointestinal bleeding; approximately 10% of them die within 30 days. Gastrointestinal bleeding is also common in low- and middle-income countries. The care of patients with gastrointestinal bleeding has improved in recent decades, but death rates remain high. Gastrointestinal bleeding is often caused by stomach ulcers, but also by liver damage owing to alcohol or hepatitis C infection. An effective and affordable treatment for gastrointestinal bleeding could save many lives and may reduce the need for blood transfusions, which is important because blood is a scarce resource in some health-care settings. Tranexamic acid, also known as TXA, is a cheap drug that reduces bleeding in other conditions. It helps blood to clot, thereby decreasing bleeding. A trial in bleeding accident victims found that tranexamic acid reduced the chances of bleeding to death, without any increase in side effects. We wanted to find out if tranexamic acid safely improves outcomes in patients with gastrointestinal bleeding, particularly to prevent deaths. To investigate this, the HALT-IT (Haemorrhage ALleviation with Tranexamic acid ­ Intestinal system) trial studied 12,009 patients with significant gastrointestinal bleeding in 164 hospitals across 15 countries. Half of the patients received tranexamic acid and the other half received a dummy drug, called a placebo. The treatments were assigned randomly and given in addition to all other treatments needed. Neither the patient nor the doctor knew which treatment a patient received. The trial showed that tranexamic acid did not reduce deaths from gastrointestinal bleeding. Instead, tranexamic acid was linked to an increased risk of complications, including unwanted blood clots (such as deep-vein thrombosis) and seizures. The economic analysis indicated that giving tranexamic acid to patients with gastrointestinal bleeding does not represent value for money for the NHS.


Assuntos
Antifibrinolíticos , Acidente Vascular Cerebral , Ácido Tranexâmico , Adulto , Antifibrinolíticos/uso terapêutico , Transfusão de Sangue , Análise Custo-Benefício , Hemorragia Gastrointestinal/tratamento farmacológico , Humanos
20.
Analyst ; 146(10): 3378-3390, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-33876155

RESUMO

Controlled-release formulations, in the form of micro- or nanoparticles, are increasingly attractive to the pharmaceutical industry for drug delivery. For respiratory illnesses, controlled-release microparticle formulations provide an opportunity to deliver a higher percentage of an inhaled medicament dose to the lung, thus potentially reducing the therapeutic dose, frequency of dosing, and minimising side-effects. We describe the use of a multimodal approach consisting of MALDI MS imaging, 3D depth profiling TOF-SIMS analysis, and histopathology to monitor the distribution of drug and excipients in sections taken from excised rat lungs following an inhaled administration of drug-laden microparticles. Following a single dose, the administered drug was detected in the lung via both MALDI MS and TOF-SIMS over a range of time points. Both imaging techniques enabled the characterisation of the distribution and retention of drug particles and identified differences in the capabilities of both imaging modalities. Histochemical staining of consecutive sections was used to provide biological context to the findings and will also be discussed in this presentation. We demonstrate how this multimodal approach could be used to help increase our understanding of the use of controlled release microparticles.


Assuntos
Excipientes , Pulmão , Animais , Preparações de Ação Retardada , Pulmão/diagnóstico por imagem , Imagem Multimodal , Tamanho da Partícula , Ratos
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