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1.
Am J Respir Crit Care Med ; 203(1): 54-66, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33119402

RESUMO

Rationale: Initial reports of case fatality rates (CFRs) among adults with coronavirus disease (COVID-19) receiving invasive mechanical ventilation (IMV) are highly variable.Objectives: To examine the CFR of patients with COVID-19 receiving IMV.Methods: Two authors independently searched PubMed, Embase, medRxiv, bioRxiv, the COVID-19 living systematic review, and national registry databases. The primary outcome was the "reported CFR" for patients with confirmed COVID-19 requiring IMV. "Definitive hospital CFR" for patients with outcomes at hospital discharge was also investigated. Finally, CFR was analyzed by patient age, geographic region, and study quality on the basis of the Newcastle-Ottawa Scale.Measurements and Results: Sixty-nine studies were included, describing 57,420 adult patients with COVID-19 who received IMV. Overall reported CFR was estimated as 45% (95% confidence interval [CI], 39-52%). Fifty-four of 69 studies stated whether hospital outcomes were available but provided a definitive hospital outcome on only 13,120 (22.8%) of the total IMV patient population. Among studies in which age-stratified CFR was available, pooled CFR estimates ranged from 47.9% (95% CI, 46.4-49.4%) in younger patients (age ≤40 yr) to 84.4% (95% CI, 83.3-85.4%) in older patients (age >80 yr). CFR was also higher in early COVID-19 epicenters. Overall heterogeneity is high (I2 >90%), with nonsignificant Egger's regression test suggesting no publication bias.Conclusions: Almost half of patients with COVID-19 receiving IMV died based on the reported CFR, but variable CFR reporting methods resulted in a wide range of CFRs between studies. The reported CFR was higher in older patients and in early pandemic epicenters, which may be influenced by limited ICU resources. Reporting of definitive outcomes on all patients would facilitate comparisons between studies.Systematic review registered with PROSPERO (CRD42020186997).


Assuntos
Pandemias , Respiração Artificial/métodos , COVID-19/mortalidade , COVID-19/terapia , Saúde Global , Humanos , SARS-CoV-2 , Taxa de Sobrevida/tendências
2.
Intern Med J ; 52(5): 724-739, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35066970

RESUMO

BACKGROUND: Observational data during the pandemic have demonstrated mixed associations between frailty and mortality. AIM: To examine associations between frailty and short-term mortality in patients hospitalised with coronavirus disease 2019 (COVID-19). METHODS: In this systematic review and meta-analysis, we searched PubMed, Embase and the COVID-19 living systematic review from 1 December 2019 to 15 July 2021. Studies reporting mortality and frailty scores in hospitalised patients with COVID-19 (age ≥18 years) were included. Data on patient demographics, short-term mortality (in hospital or within 30 days), intensive care unit (ICU) admission and need for invasive mechanical ventilation (IMV) were extracted. The quality of studies was assessed using the Newcastle-Ottawa Scale. RESULTS: Twenty-five studies reporting 34 628 patients were included. Overall, 26.2% (n = 9061) died. Patients who died were older (76.7 ± 9.6 vs 69.2 ± 13.4), more likely male (risk ratio (RR) = 1.08; 95% confidence interval (CI): 1.06-1.11) and had more comorbidities. Fifty-eight percent of patients were frail. Adjusting for age, there was no difference in short-term mortality between frail and non-frail patients (RR = 1.04; 95% CI: 0.84-1.28). The non-frail patients were commonly admitted to ICU (27.2% (4256/15639) vs 29.1% (3567/12274); P = 0.011) and had a higher mortality risk (RR = 1.63; 95% CI: 1.30-2.03) than frail patients. Among patients receiving IMV, there was no difference in mortality between frail and non-frail (RR = 1.62; 95% CI 0.93-2.77). CONCLUSION: This systematic review did not demonstrate an independent association between frailty status and short-term mortality in patients with COVID-19. Patients with frailty were less commonly admitted to ICU and non-frail patients were more likely to receive IMV and had higher mortality risk. This finding may be related to allocation decisions for patients with frailty amidst the pandemic.


Assuntos
COVID-19 , Fragilidade , Adolescente , Idoso , Idoso Fragilizado , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Tempo de Internação , Masculino , Pandemias
3.
BMC Anesthesiol ; 22(1): 30, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-35062880

RESUMO

BACKGROUND: The use of sublingual buprenorphine (SLBup) for acute pain after major abdominal surgery may offer the potential advantages of unique analgesic properties and more reliable absorption during resolving ileus. We hypothesized that complete opioid transition to SLBup rather than oral oxycodone (OOxy) in the early postoperative period after major abdominal surgery would reduce hospital length of stay, and acute pain and total OMEDD (Oral Morphine Equivalent Daily Dose) requirements in the first 24 h from post-parenteral opioid transition. METHODS: We reviewed 146 patients who had undergone elective and emergency abdominal surgery under our quaternary referral centre's Upper Gastro-Intestinal and Colo-Rectal Surgical Units 6 months before and after the introduction of complete postoperative transition to sublingual buprenorphine, rather than oral oxycodone, in July 2017. Our primary endpoint was 24-hourly post-transition OMEDDs; secondary endpoints were 24-hourly post-transition Mean NRS-11 pain scores on movement (POM) and length of hospital stay (LOS). Univariate analysis and linear multivariate regression analyses were used to quantify effect size and identify surgical, patient & other analgesic factors associated with these outcome measures. RESULTS: Patients transitioning to SLBup had reduced 24-hourly post-transition OMEDD requirements on postoperative day 2 (POD) (26 mg less, p = 0.04) and NRS-11 POM at POD1 (0.7 NRS-11 units less, p = 0.01). When adjusting for patient, surgical and special analgesic factors, SLBup was associated with a similar reduction in OMEDDs (Unstandardised beta-coefficient -26 mg, p = 0.0001), but not NRS-11 POM (p = 0.47) or hospital LOS (p = 0.16). CONCLUSIONS: Our change of practice from use of OOxy to SLBup as primary transition opioid from patient-controlled analgesia delivered full opioid agonists was associated with a clinically significant decrease in 24-hourly post-parenteral opioid transition OMEDDs and improved NRS-11 POM, but without an association with hospital LOS after major abdominal surgery. Further prospective randomized work is required to confirm these observed associations and impact on other important patient-centred outcomes.


Assuntos
Abdome/cirurgia , Analgésicos Opioides/uso terapêutico , Buprenorfina/uso terapêutico , Tempo de Internação/estatística & dados numéricos , Administração Sublingual , Idoso , Analgésicos Opioides/administração & dosagem , Buprenorfina/administração & dosagem , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
4.
Aust Crit Care ; 35(1): 5-12, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33965312

RESUMO

BACKGROUND: Personal-protective equipment (PPE)-preparedness, defined as adherence to guidelines, healthcare worker (HCW) training, procuring PPE stocks and responding appropriately to suspected cases, is crucial to prevent HCW-infections. OBJECTIVES: To perform a follow-up survey to assess changes in PPE-preparedness across six Asia-Pacific countries during the COVID-19 pandemic. METHODS: A prospective follow-up cross-sectional, web-based survey was conducted between 10/08/2020 to 01/09/ 2020, five months after the initial Phase 1 survey. The survey was sent to the same 231 intensivists across the six Asia-Pacific countries (Australia, Hong Kong, India, New Zealand, Philippines, and Singapore) that participated in Phase 1. The main outcome measure was to identify any changes in PPE-preparedness between Phases 1 and 2. FINDINGS: Phase 2 had responses from 132 ICUs (57%). Compared to Phase 1 respondents reported increased use of PPE-based practices such as powered air-purifying respirator (40.2% vs. 6.1%), N95-masks at all times (86.4% vs. 53.7%) and double-gloving (87.9% vs. 42.9%). The reported awareness of PPE stocks (85.6% vs. 51.9%), mandatory showering policies following PPE-breach (31.1% vs. 6.9%) and safety perception amongst HCWs (60.6% vs. 28.4%) improved significantly during Phase 2. Despite reported statistically similar adoption rate of the buddy system in both phases (42.4% vs. 37.2%), there was a reported reduction in donning/doffing training in Phase 2 (44.3% vs. 60.2%). There were no reported differences HCW training in other areas, such as tracheal intubation, intra-hospital transport and safe waste disposal, between the 2 phases. CONCLUSIONS: Overall reported PPE-preparedness improved between the two survey periods, particularly in PPE use, PPE inventory and HCW perceptions of safety. However, the uptake of HCW training and implementation of low-cost safety measures continued to be low and the awareness of PPE breach management policies were suboptimal. Therefore, the key areas for improvement should focus on regular HCW training, implementing low-cost buddy-system and increasing awareness of PPE-breach management protocols.


Assuntos
COVID-19 , Equipamento de Proteção Individual , Estudos Transversais , Seguimentos , Hong Kong , Humanos , Unidades de Terapia Intensiva , Pandemias , Estudos Prospectivos , SARS-CoV-2 , Inquéritos e Questionários
5.
Aust Crit Care ; 35(4): 415-423, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34404579

RESUMO

BACKGROUND: Clinical guidelines on infection control strategies in healthcare workers (HCWs) play an important role in protecting them during the severe acute respiratory syndrome coronavirus 2 pandemic. Poorly constructed guidelines that are incomprehensive and/or ambiguous may compromise HCWs' safety. OBJECTIVE: The objective of this study was to develop and validate a tool to appraise guidelines on infection control strategies in HCWs based on the guidelines published early in the coronavirus disease 2019 pandemic. DESIGN, SETTING, AND OUTCOMES: A three-stage, web-based, Delphi consensus-building process among a panel of diverse HCWs and healthcare managers was performed. The tool was validated by appraising 40 international, specialty-specific, and procedure-specific guidelines along with national guidelines from countries with a wide range of gross national income. RESULTS: Overall consensus (≥75%) was reached at the end of three rounds for all six domains included in the tool. The Delphi panel recommended an ideal infection control guideline should encompass six domains: general characteristics (domain 1), engineering recommendations (domain 2), personal protective equipment (PPE) use (domain 3), and administrative aspects (domain 4-6) of infection control. The appraisal tool performed well across the six domains, and the inter-rater agreement was excellent for the 40 guidelines. All included guidelines performed relatively better in domains 1-3 than in domains 4-6, and this was more evident in guidelines originating from lower income countries. CONCLUSION: The guideline appraisal tool was robust and easy to use. Engineering recommendations aspects of infection control, administrative measures that promote optimal PPE use, and HCW wellbeing were generally lacking in assessed guidelines. This tool may enable health systems to adopt high-quality HCW infection control guidelines during the severe acute respiratory syndrome coronavirus 2 pandemic and may also provide a framework for future guideline development.


Assuntos
COVID-19 , Pessoal de Saúde , Humanos , Controle de Infecções , Transmissão de Doença Infecciosa do Paciente para o Profissional , Pandemias/prevenção & controle , SARS-CoV-2
6.
Crit Care Med ; 49(10): e1001-e1014, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33927120

RESUMO

OBJECTIVES: Several studies have reported prone positioning of nonintubated patients with coronavirus diseases 2019-related hypoxemic respiratory failure. This systematic review and meta-analysis evaluated the impact of prone positioning on oxygenation and clinical outcomes. DESIGN AND SETTING: We searched PubMed, Embase, and the coronavirus diseases 2019 living systematic review from December 1, 2019, to November 9, 2020. SUBJECTS AND INTERVENTION: Studies reporting prone positioning in hypoxemic, nonintubated adult patients with coronavirus diseases 2019 were included. MEASUREMENTS AND MAIN RESULTS: Data on prone positioning location (ICU vs non-ICU), prone positioning dose (total minutes/d), frequency (sessions/d), respiratory supports during prone positioning, relative changes in oxygenation variables (peripheral oxygen saturation, Pao2, and ratio of Pao2 to the Fio2), respiratory rate pre and post prone positioning, intubation rate, and mortality were extracted. Twenty-five observational studies reporting prone positioning in 758 patients were included. There was substantial heterogeneity in prone positioning location, dose and frequency, and respiratory supports provided. Significant improvements were seen in ratio of Pao2 to the Fio2 (mean difference, 39; 95% CI, 25-54), Pao2 (mean difference, 20 mm Hg; 95% CI, 14-25), and peripheral oxygen saturation (mean difference, 4.74%; 95% CI, 3-6%). Respiratory rate decreased post prone positioning (mean difference, -3.2 breaths/min; 95% CI, -4.6 to -1.9). Intubation and mortality rates were 24% (95% CI, 17-32%) and 13% (95% CI, 6-19%), respectively. There was no difference in intubation rate in those receiving prone positioning within and outside ICU (32% [69/214] vs 33% [107/320]; p = 0.84). No major adverse events were recorded in small subset of studies that reported them. CONCLUSIONS: Despite the significant variability in frequency and duration of prone positioning and respiratory supports applied, prone positioning was associated with improvement in oxygenation variables without any reported serious adverse events. The results are limited by a lack of controls and adjustments for confounders. Whether this improvement in oxygenation results in meaningful patient-centered outcomes such as reduced intubation or mortality rates requires testing in well-designed randomized clinical trials.


Assuntos
COVID-19/complicações , COVID-19/fisiopatologia , Decúbito Ventral/fisiologia , COVID-19/mortalidade , Humanos , Posicionamento do Paciente , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/fisiopatologia
7.
Crit Care Med ; 49(6): 901-911, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33710030

RESUMO

OBJECTIVES: To investigate the incidence, characteristics, and outcomes of in-hospital cardiac arrest in patients with coronavirus disease 2019 and to describe the characteristics and outcomes for patients with in-hospital cardiac arrest within the ICU, compared with non-ICU patients with in-hospital cardiac arrest. Finally, we evaluated outcomes stratified by age. DATA SOURCES: A systematic review of PubMed, EMBASE, and preprint websites was conducted between January 1, 2020, and December 10, 2020. Prospective Register of Systematic Reviews identification: CRD42020203369. STUDY SELECTION: Studies reporting on consecutive in-hospital cardiac arrest with a resuscitation attempt among patients with coronavirus disease 2019. DATA EXTRACTION: Two authors independently performed study selection and data extraction. Study quality was assessed with the Newcastle-Ottawa Scale. Data were synthesized according to the Preferred Reporting Items for Systematic Reviews guidelines. Discrepancies were resolved by consensus or through an independent third reviewer. DATA SYNTHESIS: Eight studies reporting on 847 in-hospital cardiac arrest were included. In-hospital cardiac arrest incidence varied between 1.5% and 5.8% among hospitalized patients and 8.0-11.4% among patients in ICU. In-hospital cardiac arrest occurred more commonly in older male patients. Most initial rhythms were nonshockable (83.9%, [asystole = 36.4% and pulseless electrical activity = 47.6%]). Return of spontaneous circulation occurred in 33.3%, with a 91.7% in-hospital mortality. In-hospital cardiac arrest events in ICU had higher incidence of return of spontaneous circulation (36.6% vs 18.7%; p < 0.001) and relatively lower mortality (88.7% vs 98.1%; p < 0.001) compared with in-hospital cardiac arrest in non-ICU locations. Patients greater than or equal to 60 years old had significantly higher in-hospital mortality than those less than 60 years (93.1% vs 87.9%; p = 0.019). CONCLUSIONS: Approximately, one in 20 patients hospitalized with coronavirus disease 2019 received resuscitation for an in-hospital cardiac arrest. Hospital survival after in-hospital cardiac arrest within the ICU was higher than non-ICU locations and seems comparable with prepandemic survival for nonshockable rhythms. Although the data provide guidance surrounding prognosis after in-hospital cardiac arrest, it should be interpreted cautiously given the paucity of information surrounding treatment limitations and resource constraints during the pandemic. Further research is into actual causative mechanisms is needed.


Assuntos
COVID-19/mortalidade , COVID-19/terapia , Parada Cardíaca/mortalidade , Parada Cardíaca/terapia , Mortalidade Hospitalar , Resultado do Tratamento , Causas de Morte , Humanos , Incidência
8.
Intern Med J ; 51(11): 1773-1780, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34487424

RESUMO

The objective of the present study is to investigate the incidence, characteristics and outcomes of patients who were readmitted to hospital emergency departments or required re-hospitalisation following an index hospitalisation with a diagnosis of COVID-19. A systematic review of PubMed, EMBASE and pre-print websites was conducted between 1 January and 31 December 2020. Studies reporting on the incidence, characteristics and outcomes of patients with COVID-19 who represent or require hospital admission were included. Two authors independently performed study selection and data extraction. Study quality was assessed with the Newcastle-Ottawa Scale. Discrepancies were resolved by consensus or through an independent third reviewer. Data were synthesised according to the Preferred Reporting Items for Systematic Reviews guidelines. Six studies reporting on 547 readmitted patients were included. The overall incidence was 4.4%, most common in males (57.2%), and due to respiratory distress or prolonged COVID-19. Readmitted patients had a shorter initial hospital length of stay (LOS) compared with those with a single hospitalisation (8.1 ± 10.6 vs 13.9 ± 10.2 days). The mean time to readmission was 7.6 ± 6.0 days; the mean LOS on re-hospitalisation was 6.3 ± 5.6 days. Hypertension (odds ratio (OR) = 2.08; 95% confidence interval (CI) 1.69-2.55; P < 0.001; I2 = 0%), diabetes mellitus (OR = 1.77; 95% CI 1.38-2.27; P < 0.001; I2 = 0%) and chronic renal failure (OR = 2.37; 95% CI 1.09-5.14; P < 0.001; I2 = 0%) were more common in these patients. Intensive care admission rates were similar between the two groups; 12.8% (22/172) of readmitted patients died. In summary, readmitted patients following an index hospitalisation for COVID-19 were more commonly males with multiple comorbidities. Shorter initial hospital LOS and unresolved primary illness may have contributed to readmission.


Assuntos
COVID-19 , Humanos , Tempo de Internação , Masculino , Readmissão do Paciente , Fatores de Risco , SARS-CoV-2 , Sobreviventes
9.
Emerg Med J ; 37(7): 444-449, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32414709

RESUMO

INTRODUCTION: Multimodal interventions (MMI) are frequently used in various healthcare settings to encourage change in healthcare personnel practices and improve patient safety. In 2013, an MMI conducted in an Australian metropolitan ED used clinician champions, guidelines, education sessions and promotional materials to encourage a reduction in unused and inappropriate peripheral intravenous cannulas (PIVC). A 60-day postintervention demonstrated a successful reduction in the number of unused PIVCs without changes in appropriate insertions. We aimed to investigate if this MMI produced a sustained effect in reducing the frequency of unused PIVCs inserted in this ED. METHODS: A single-centre retrospective cohort study of adult patients presenting to the above ED in Victoria, Australia, was conducted in April 2018. A random sample of 380 patients with a PIVC inserted in ED was assessed to determine if the PIVC was used (termed 'Long-term follow-up'). The appropriateness of unused PIVCs was assessed. Our findings were compared with previously collected data in 2013 ('Pre-Intervention' and 'Immediately Post-Intervention') to determine a sustained reduction in the frequency of unused PIVC insertions was achieved. Long-term analysis of the MMI, including the overall frequency of PIVC insertions in ED before and after the MMI, was also collected. RESULTS: In our Long-term follow-up cohort, 101 of 373 (27.1%, 95% CI 22.6% to 31.9%) PIVCs were unused (seven cases excluded). This was significantly lower than the Pre-Intervention cohort (139/376, 37.0%, 95% CI 32.1% to 42.1%). While not significant, the frequency of unused PIVCs in the Post-Intervention cohort was lower in comparison (73/378, 19.3%, 95% CI 15.4% to 23.7%). No significant change in the appropriateness of unused PIVCs was observed between the Post-Intervention and Long-term follow-up. The overall proportion of patients receiving a PIVC has remained low since the MMI. CONCLUSION: An MMI aimed at reducing unused PIVC insertions in ED has been effective in eliciting sustained change. Unused but appropriately inserted PIVCs seem unaffected by the intervention.


Assuntos
Cateterismo Periférico/normas , Serviço Hospitalar de Emergência/normas , Melhoria de Qualidade , Adulto , Idoso , Estudos Controlados Antes e Depois , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Vitória
10.
Molecules ; 25(22)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33228061

RESUMO

Brucea javanica oil (BJO) is widely used in traditional Chinese medicine to treat various types of cancer and inflammatory diseases. There is significant interest in understanding the medicinal activities of BJO and its molecular components, especially quassinoids, and in exploring how they can be incorporated into nanomedicine delivery strategies for improved application prospects. Herein, we cover the latest progress in developing different classes of drug delivery vehicles, including nanoemulsions, liposomes, nanostructured lipid carriers, and spongosomes, to encapsulate BJO and purified quassinoids. An introduction to the composition and medicinal activities of BJO and its molecular components, including quassinoids and fatty acids, is first provided. Application examples involving each type of drug delivery vehicle are then critically presented. Future opportunities for nanomedicine delivery strategies in the field are also discussed and considered within the context of translational medicine needs and drug development processes.


Assuntos
Brucea/química , Sistemas de Liberação de Medicamentos , Nanomedicina , Óleos de Plantas/uso terapêutico , Animais , Portadores de Fármacos/química , Humanos , Lipídeos/química , Óleos de Plantas/química , Óleos de Plantas/farmacologia
11.
Chemistry ; 24(9): 2232-2241, 2018 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-29218746

RESUMO

Two stable boron dipyrromethene (BODIPY)-based antiaromatic macrocycles, Mc-Fur and Mc-Th, were synthesized through a one-pot Knoevenagel condensation reaction between a BODIPY precursor and furan-2,5-dicarboxaldehyde or thiophene-2,5-dicarboxaldehyde, respectively. 1 H NMR spectroscopic characterization of the two macrocycles supported their highly antiaromatic character. The oxidation properties of the two macrocycles were studied through electron spin resonance spectroscopy and UV/Vis absorption spectrophotometry, which suggested the formation of a stable monoradical cation species on first oxidation followed by an aromatic dicationic species on subsequent oxidation. Both molecules have a nearly planar π-conjugated backbone and show a strong tendency to aggregate in solution due to efficient stacking of the antiaromatic macrocycles. Transient absorption and two-photon absorption (TPA) measurements in solution and aggregated states of the macrocycles revealed that aggregation resulted in large enhancement of TPA cross sections and increased excited-state lifetimes, in accordance with the decrease in the antiaromatic character in the aggregated state.

12.
Australas Psychiatry ; 26(4): 401-404, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29577734

RESUMO

OBJECTIVES: To determine the frequency and quality of religious history taking of patients by clinicians working in an old age psychiatry service. METHODS: A retrospective audit of 80 randomised patient files from the Koropiko Mental Health Services for Older People (MHSOP) in Middlemore Hospital, Auckland, New Zealand. RESULTS: A total of 66 clinical records were available for analysis. A religious history was taken in 33/66 (50%) patients. However, when such histories were evaluated using the FICA assessment tool, only 10/33 (30.3%) histories contained detailed information regarding the patient's religiousness. CONCLUSIONS: The infrequency and low quality of religious histories discovered in this audit suggest that clinicians need more training in taking a religious history from patients.


Assuntos
Psiquiatria Geriátrica/normas , Entrevista Psicológica/normas , Transtornos Mentais/diagnóstico , Serviços de Saúde Mental/normas , Religião , Idoso , Auditoria Clínica , Psiquiatria Geriátrica/métodos , Humanos , Entrevista Psicológica/métodos , Estudos Retrospectivos
13.
Chemistry ; 23(32): 7698-7702, 2017 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-28452090

RESUMO

Tri(4-iodo-2,3,5,6-tetrachlorophenyl)methane (2) is reported as a general building block for the synthesis of various π-conjugated polychlorotriphenylmethyl (PTM) radicals. Three push-pull-type triphenylamine-substituted PTM radicals with different substitution patterns were prepared and all exhibited intense inter-valence charge-transfer bands and large two-photon absorption (TPA) cross sections. Moreover, increase of solvent polarity also resulted in improved TPA response. The charge-transfer character of the relevant excited states provoked the efficient photo-generation of charges, anions in the PTM and cations in the amine arms, driven by the amphoteric redox character and the small coupling between donor and acceptor.

14.
Org Biomol Chem ; 15(15): 3188-3191, 2017 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-28362454

RESUMO

Two BODIPY-substituted anthroxyl radicals were investigated. The one with two ethyl substituents (2Et-BO-An-O) is sensitive to air and silica gel due to the lack of sufficient kinetic blocking, while another one with four methyl substituents (4Me-BO-An-O) shows high stability. The structure of the latter was fully characterized by X-ray crystallographic analysis and electron-spin resonance spectra. 4Me-BO-An-O was subjected to react with various reactive oxygen/nitrogen species (ROS/RNS) and selective fluorescence turn-on detection of a hydroxyl radical was achieved, validating the concept of "using stable radicals to detect ROS/RNS".

15.
Malays J Med Sci ; 24(4): 47-54, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28951689

RESUMO

INTRODUCTION: Oral cancer is a life-threatening disease. Lack of public awareness is a potent barrier for the early detection of oral cancer, especially for high-risk populations. OBJECTIVE: This study aimed to determine the awareness and knowledge of the signs, symptoms and risk factors of oral cancer among a Siamese ethnic group in Tumpat, Kelantan. METHODS: A cross-sectional study was conducted, using a guided questionnaire on sociodemography, habits, awareness and knowledge of the signs, symptoms and risk factors of oral cancer. Individuals under 18 years old and who had been diagnosed with oral cancer were excluded from this study. RESULTS: A total of 195 respondents participated, 61.5% were female and the mean age was 46 (1.64). About 41% of the respondents had received secondary education and 35.4% were illiterate. Most respondents were self-employed (21.5%), followed by farmers (19.5%) and housewives (20%). The majority of them had a monthly income that fell below the poverty level of RM 830 (76.9%). Among the respondents, 22.6% had the habit of smoking, 25.6% consumed alcohol, 8.2% were betel quid chewers and 2.6% chewed tobacco. Out of 195 respondents, only 6.7% were aware of oral cancer. About 16.9% of the respondents correctly answered all of the questions regarding the signs and symptoms of oral cancer and only 4.1% knew the risk factors of oral cancer. CONCLUSION: The awareness and knowledge of oral cancer in this targeted population were unsatisfactory. Future effective health promotion programs and education should be emphasised.

17.
Angew Chem Int Ed Engl ; 55(32): 9316-20, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27356244

RESUMO

Extended bis(benzothia)quinodimethanes and their dications were synthesized as stable species. The neutral compounds mainly have a quinoidal structure in the ground state but show increased diradical character with extension of the central quinodimethane unit. The dications exhibit similar electronic absorption spectra, NMR spectra, NICS values, and diatropic ring currents to their aromatic all-carbon acene analogues and thus can be regarded as genuine isoelectronic structures of pentacene, hexacene, and heptacene, respectively. Our research gave some insights into the design and synthesis of stable longer acene analogues.

18.
Cogn Sci ; 48(1): e13402, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38226686

RESUMO

Distinctive aspects of a culture are often reflected in the meaning and usage of words in the language spoken by bearers of that culture. Keywords such as душа (soul) in Russian, hati (heart) in Indonesian and Malay, and gezellig (convivial/cosy/fun) in Dutch are held to be especially culturally revealing, and scholars have identified a number of such keywords using careful linguistic analyses (Peeters, 2020b; Wierzbicka, 1990). Because keywords are expected to have different statistical properties than related words in other languages, we argue that a quantitative comparison of word usage across languages can help to identify cultural keywords. To support this claim, we describe a computational method that compares word frequencies across languages, and apply it to both linguistic corpora and word association data. The method identifies culturally specific words that range from "obvious" examples, such as Amsterdam in Dutch, to non-obvious yet independently proposed examples, such as hati (heart) in Indonesian. We show in addition that linguistic corpora and word association data provide converging evidence about culturally specific words. Our results therefore show how computational analyses and behavioral experiments can supplement the methods previously used by linguists to identify culturally salient words across languages.


Assuntos
Idioma , Linguística , Humanos
19.
PLoS One ; 19(8): e0304655, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39137226

RESUMO

Recognising human activities using smart devices has led to countless inventions in various domains like healthcare, security, sports, etc. Sensor-based human activity recognition (HAR), especially smartphone-based HAR, has become popular among the research community due to lightweight computation and user privacy protection. Deep learning models are the most preferred solutions in developing smartphone-based HAR as they can automatically capture salient and distinctive features from input signals and classify them into respective activity classes. However, in most cases, the architecture of these models needs to be deep and complex for better classification performance. Furthermore, training these models requires extensive computational resources. Hence, this research proposes a hybrid lightweight model that integrates an enhanced Temporal Convolutional Network (TCN) with Gated Recurrent Unit (GRU) layers for salient spatiotemporal feature extraction without tedious manual feature extraction. Essentially, dilations are incorporated into each convolutional kernel in the TCN-GRU model to extend the kernel's field of view without imposing additional model parameters. Moreover, fewer short filters are applied for each convolutional layer to alleviate excess parameters. Despite reducing computational cost, the proposed model utilises dilations, residual connections, and GRU layers for longer-term time dependency modelling by retaining longer implicit features of the input inertial sequences throughout training to provide sufficient information for future prediction. The performance of the TCN-GRU model is verified on two benchmark smartphone-based HAR databases, i.e., UCI HAR and UniMiB SHAR. The model attains promising accuracy in recognising human activities with 97.25% on UCI HAR and 93.51% on UniMiB SHAR. Since the current study exclusively works on the inertial signals captured by smartphones, future studies will explore the generalisation of the proposed TCN-GRU across diverse datasets, including various sensor types, to ensure its adaptability across different applications.


Assuntos
Atividades Humanas , Smartphone , Humanos , Redes Neurais de Computação , Aprendizado Profundo , Algoritmos
20.
Plants (Basel) ; 12(13)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37447097

RESUMO

Research has confirmed that the utilisation of Antarctic microorganisms, such as bacteria, yeasts and fungi, in the bioremediation of diesel may provide practical alternative approaches. However, to date there has been very little attention towards Antarctic microalgae as potential hydrocarbon degraders. Therefore, this study focused on the utilisation of an Antarctic microalga in the bioremediation of diesel. The studied microalgal strain was originally obtained from a freshwater ecosystem in Paradise Bay, western Antarctic Peninsula. When analysed in systems with and without aeration, this microalgal strain achieved a higher growth rate under aeration. To maintain the growth of this microalga optimally, a conventional one-factor-at a-time (OFAT) analysis was also conducted. Based on the optimized parameters, algal growth and diesel degradation performance was highest at pH 7.5 with 0.5 mg/L NaCl concentration and 0.5 g/L of NaNO3 as a nitrogen source. This currently unidentified microalga flourished in the presence of diesel, with maximum algal cell numbers on day 7 of incubation in the presence of 1% v/v diesel. Chlorophyll a, b and carotenoid contents of the culture were greatest on day 9 of incubation. The diesel degradation achieved was 64.5% of the original concentration after 9 days. Gas chromatography analysis showed the complete mineralisation of C7-C13 hydrocarbon chains. Fourier transform infrared spectroscopy analysis confirmed that strain WCY_AQ5_3 fully degraded the hydrocarbon with bioabsorption of the products. Morphological and molecular analyses suggested that this spherical, single-celled green microalga was a member of the genus Micractinium. The data obtained confirm that this microalga is a suitable candidate for further research into the degradation of diesel in Antarctica.

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