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1.
Nan Fang Yi Ke Da Xue Xue Bao ; 43(4): 516-526, 2023 Apr 20.
Article Dans Chinois | MEDLINE | ID: covidwho-20239030

Résumé

OBJECTIVE: To establish a rapid detection and genotyping method for SARS-CoV-2 Omicron BA.4/5 variants using CRISPPR-Cas12a gene editing technology. METHODS: We combined reverse transcription-polymerase chain reaction (RT-PCR) and CRISPR gene editing technology and designed a specific CRISPPR RNA (crRNA) with suboptimal protospacer adjacent motifs (PAM) for rapid detection and genotyping of SARS- CoV-2 Omicron BA.4/5 variants. The performance of this RT- PCR/ CRISPPR-Cas12a assay was evaluated using 43 clinical samples of patients infected by wild-type SARS-CoV-2 and the Alpha, Beta, Delta, Omicron BA. 1 and BA. 4/5 variants and 20 SARS- CoV- 2-negative clinical samples infected with 11 respiratory pathogens. With Sanger sequencing method as the gold standard, the specificity, sensitivity, concordance (Kappa) and area under the ROC curve (AUC) of RT-PCR/CRISPPR-Cas12a assay were calculated. RESULTS: This assay was capable of rapid and specific detection of SARS- CoV-2 Omicron BA.4/5 variant within 30 min with the lowest detection limit of 10 copies/µL, and no cross-reaction was observed in SARS-CoV-2-negative clinical samples infected with 11 common respiratory pathogens. The two Omicron BA.4/5 specific crRNAs (crRNA-1 and crRNA-2) allowed the assay to accurately distinguish Omicron BA.4/5 from BA.1 sublineage and other major SARS-CoV-2 variants of concern. For detection of SARS-CoV-2 Omicron BA.4/5 variants, the sensitivity of the established assay using crRNA-1 and crRNA-2 was 97.83% and 100% with specificity of 100% and AUC of 0.998 and 1.000, respectively, and their concordance rate with Sanger sequencing method was 92.83% and 96.41%, respectively. CONCLUSION: By combining RT-PCR and CRISPPR-Cas12a gene editing technology, we successfully developed a new method for rapid detection and identification of SARS-CoV-2 Omicron BA.4/5 variants with a high sensitivity, specificity and reproducibility, which allows rapid detection and genotyping of SARS- CoV-2 variants and monitoring of the emerging variants and their dissemination.


Sujets)
COVID-19 , Humains , Systèmes CRISPR-Cas , Génotype , Reproductibilité des résultats , RT-PCR , SARS-CoV-2/génétique , ARN , Dépistage de la COVID-19
2.
2022 IEEE International Conference on Big Data, Big Data 2022 ; : 4513-4519, 2022.
Article Dans Anglais | Scopus | ID: covidwho-2266329

Résumé

The primary goals of this study are to determine if the datasets of positive COVID-19 test cases and CO2 emissions from Connecticut over the span of March 24th, 2020-October 31, 2021 are in any ways correlated. With climate change a prominent issue facing the entire world today, it is important to explore methods of providing records of past patterns of greenhouse gas emissions in order to inform decision making that could reduce future ones. Autoregressive integrated moving average (ARIMA) modeling is also implemented in this paper to provide forecasting based on CO2 emissions in CT starting from 2019. The most significant results from this paper are as follows: the CO2 emission data of transportation sectors including ground transportation, domestics aviation, and international aviation and weekly COVID-19 positive test cases data has a strong relationship during the first 28 weeks of the pandemic with a correlation of -86.34%. The CO2 emissions experienced on average a -22.96% change of pre-pandemic vs during initial quarantine conditions and at most a - 44.48% change when comparing the pre-pandemic mean to the during initial quarantine minimum value. Lastly, the ARIMA model found to have the lowest Akaike information criterion (AIC) was ARIMA (4,0,4). In conclusion, in the event of a collective global pandemic and lockdown conditions, less traveling resulting in a correlated decrease of CO2 emissions. This means that perhaps concentrated efforts on reducing unnecessary travel could help mitigate the levels of carbon dioxide emissions as a more long-term solution to climate change opposed to the pandemic's short-term example. © 2022 IEEE.

3.
European Respiratory Journal Conference: European Respiratory Society International Congress, ERS ; 60(Supplement 66), 2022.
Article Dans Anglais | EMBASE | ID: covidwho-2254255

Résumé

Introduction: Chronic respiratory diseases (CRDs) are growing problems worldwide. Pulmonary rehabilitation (PR) has proven benefits for patients with CRDs, but programmes need to be adapted to low resource settings, in the context of the recent COVID-19, to home-based delivery. Aim(s): To evaluate the feasibility of delivering home-based PR for patients with CRDs in Malaysia. Method(s): We recruited people with CRD from two hospitals in Klang Valley, Malaysia to home-based PR programme. Patients were provided education sessions, and assessments [functional exercise capacity {6-Minutes walking test (6MWT)}] and [Health-Related Quality of Life (HRQOL) {COPD Assessment Test (CAT)}] were made at centres prior to the start of programme. They performed exercise at least 5 sessions per week for 8 weeks at home and were supervised weekly via phone calls. Post PR, we assessed the attendance and retention rate and measured 6MWT and CAT at centre. Result(s): We recruited 30 patients. The retention rate was 93.3%;2 dropped out due to hospitalization. However, only 11(36.7%) attended post PR assessment at centres, of these 9 (81.8%) had performed all 40 sessions of home exercises. The attendance for post- PR assessment was limited due to COVD-19 restrictions that forbade travel in Malaysia at that time. Data from the 11 patients showed significant change in CAT scores, 5.09;pre: 22.45, post: 17.36(95% confidence interval (CI) 1.48, 8.70, p=0.01) but no significant change in 6MWT distance -24.36;pre: 276.36, post: 300.72(95% CI -80.52,-31.79, p=0.356). Conclusion(s): Home-based PR is feasible and can be a valuable method to deliver PR remotely.

4.
European Respiratory Journal Conference: European Respiratory Society International Congress, ERS ; 60(Supplement 66), 2022.
Article Dans Anglais | EMBASE | ID: covidwho-2281344

Résumé

Background: The evidence for management of severe COVID-19 with persistent respiratory failure (PRF) after acute treatment is scarce, despite some authors reported a good response to corticosteroid in histological proven secondary organising pneumonia (OP). Objective(s): This study aimed to study the disease course of COVID-19 patients with persistent respiratory failure, and its radiological pattern. Method(s): A single centre retrospective cohort study on severe COVID-19 patients was conducted from January 2021 to June 2021. All radiological imaging and data were retrieved from electronic database. Result(s): Severe COVID-19 pneumonia had a 78% (584/750) survival in our cohort. Among the survival, 48% (279/584) had PRF beyond 14 days of illness and 10% of them required oxygen therapy upon discharge. Eighty-six percent (240/279) of patients with PRF had a HRCT performed. Eighty percent (187/240) of them attended clinic follow up with 81% had a radiological pattern consistent with OP. The mean severity CT score was 10 (SD+/-3). [Jin C et al. Front Public Heal.2020;8] Seventy-eight percent of patients were perceived with WHO functional class of 1-2. Sixty-eight percent of patients (128/187) were given short course of prednisolone during admission with tapering doses. The mean prednisolone dose was 0.69mg/kg/day with a mean duration of 47 days (SD+/-18). Seventy-eight percent (146/187) had a follow up chest x-ray (CXR) at 12+/-8 weeks. Only 6.4% (12/187) of them had abnormal CXR findings whereby two patients were later confirmed to have pulmonary tuberculosis. Conclusion(s): Radiological pattern of OP is common in COVID-19 with PRF. HRCT is a non-invasive tool to assess this entity.

5.
Neuroscience ; 491: 43-64, 2022 05 21.
Article Dans Anglais | MEDLINE | ID: covidwho-2269494

Résumé

Under normal conditions, dopamine (DA) clearance after release largely depends on uptake by the DA transporter (DAT). DAT expression/activity is reduced in some neuropsychiatric and neurological disorders. Our aim was to characterize the behavioral, neurochemical and electrophysiological effects of eliminating DAT in a novel knockout rat model we generated using CRISPR/Cas9. Consistent with existing DAT-KO models, our DAT-KO rats displayed increased locomotion, paradoxical calming by amphetamine, and reduced kinetics of DA clearance after stimulated release. Reduced DA kinetics were demonstrated using fast-scan cyclic voltammetry in brain slices containing the striatum or substantia nigra pars compacta (SNc) and in the dorsal striatum in vivo. Cocaine enhanced DA release in wild-type (WT) but not DAT-KO rats. Basal extracellular DA concentration measured with fast-scan controlled-adsorption voltammetry was higher in DAT-KO rats both in the striatum and SNc and was enhanced by L-DOPA (particularly after pharmacological block of monoamine oxidase), confirming that DA release after L-DOPA is not due to DAT reversal. The baseline firing frequency of SNc neurons was similar in both genotypes. However, D2 receptor-mediated inhibition of firing (by quinpirole or L-DOPA) was blunted in DAT-KO rats, while GABAB-mediated inhibition was preserved. We have also provided new data for the DAT-KO rat regarding the effects of slowing DA diffusion with dextran and blocking organic cation transporter 3 with corticosterone. Together, our results validate our DAT-KO rat and provide new insights into the mechanisms of chronic dysregulation of the DA system by addressing several unresolved issues in previous studies with other DAT-KO models.


Sujets)
Transporteurs de la dopamine , Dopamine , Amfétamine/pharmacologie , Animaux , Corps strié/métabolisme , Dopamine/pharmacologie , Transporteurs de la dopamine/métabolisme , Lévodopa/pharmacologie , Rats
6.
5th International Conference on Information Management and Management Science, IMMS 2022 ; : 208-215, 2022.
Article Dans Anglais | Scopus | ID: covidwho-2194117

Résumé

As the epidemic normaliztion continues, more and more enterprises chose telecommuting as their working mode. However, telecommuting has greatly reduced the opportunities and time for employees to socialize in the workplace. In that case, the workplace loneliness may induced by the lack of quantity and quality of employees' social contact, which would seriously affect the job satisfaction, organizational commitment and even the physical and mental health of employees. Based on the self-determination theory and the theory of Maslow's hierarchy of needs, this study explored the impact of self-efficacy on workplace loneliness, with professional identity and social support for mediation. The results showed that self-efficacy has a negative influence on the workplace loneliness, and professional identity and social support in the relationship between self-efficacy and workplace loneliness the chain intermediary role. Corporate managers should pay more attention to the harm of workplace loneliness. According to these findings, suggestions for organization managers and department of human resources, especially on alleviate workplace loneliness, were proposed and discussed. © 2022 ACM.

7.
IOP Conference Series Materials Science and Engineering ; 1257(1):012040, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-2087703

Résumé

The demand for ZnO significantly increased over the past decades. Extraction and refinement of zinc ores results in the release of hazardous wastes to the environment. In particular, the tremendous demand for disposable nitrile gloves during the Covid-19 pandemic has spiked superior demand for ZnO used as a crosslinking agent in the manufacturing process and leads to the generation of zinc containing wastewater traditionally removed via chemical precipitation. This paper focuses on the application of adsorption for zinc removal which opens an opportunity to recycle zinc to synthesize secondary zinc oxide. This study evaluated the feasibility of zinc oxide synthesis via the adsorption-desorption-chemical precipitation pathway. Palm shell activated carbon (PSAC), a low-cost adsorbent, was used for the removal of zinc from the synthetic and industrial wastewaters. Subsequently, zinc desorption was carried out using 0.3 M HCl. Then ZnO was synthesized from the desorption solutions via chemical precipitation using potassium hydroxide. Average zinc conversion rate of 98 % was achieved in this study. The synthesized ZnO exhibited high surface area of 97.4 m2/g after calcination (400 °C, 3 hr), high purity and crystallinity. The results confirmed the feasibility of zinc ions recovery for recycling to produce secondary good quality zinc oxide.

10.
Journal of AAPOS ; 25(4):e37, 2021.
Article Dans Anglais | EMBASE | ID: covidwho-1415484

Résumé

Introduction: The aim of this study was to evaluate the impact of COVID-19 pandemic on mental health in eye care professionals, staff, and optometry students. Methods: A 23-question survey was sent through social media and email to ophthalmologists, optometrists, staff, and optometry students. Demographics, stress level before and during COVID-19, positive and negative factors which impact mental health and screening questions for depression and anxiety were collected. Results: A total of 2,134 individuals from 50 USA states and Canada responded to the survey, including 887 optometrists, 252 ophthalmologists, 794 optometry students, and 185 eye care staff (16 had missing job information). There were 1319 participants (61.8%) stated that COVID 19 had a negative impact on their mental health, vs 25.4% stating no impact and 12.6% stating a positive impact. Participants reported significantly higher stress during COVID-19 compared to before, 3.49 ( ± 1.12) vs 2.86 ( ± 1.02) on a scale of 1-5 (P < 0.0001). The top 3 self-reported factors that have negatively impacted mental health were: worries about family /friends being infected with COVID-19, worry about being infected with COVID-19 myself, and social isolation. The top 3 activities that helped maintain mental health were: outdoor activities, family time, and exercise. Conclusion/Relevance: Overall, 38.4% of the respondent reported symptoms of depression, anxiety, or both and 61.8% reported worsening mental health during COVID-19. Female, young people, and minority (Asians) were the risk factors for depression, anxiety, and psychological stress. This study warrants further monitoring and specific interventions for eye care practitioners during the COVID-19 pandemic to prevent mental health disorders.

11.
Neurology ; 96(15 SUPPL 1), 2021.
Article Dans Anglais | EMBASE | ID: covidwho-1407850

Résumé

Objective: To describe the neurological disorders associated with COVID-19 in Singapore. Background: Various neurological disorders have been reported in COVID-19 patients. Postulated mechanisms include hypercoagulopathy, dysimmunity, inflammation and direct viral invasion. The incidence and relationship to SARS-CoV-2, considering the confounding effect of a surge in COVID-19 cases on healthcare systems, are unclear. Design/Methods: This was a prospective, nation-wide, multi-centre, cohort study of patients with microbiologically-confirmed COVID-19 referred for any neurological complaints With in 3 months of infection. Neurological diagnoses and relationship to COVID-19 were made by consensus guided by contemporaneous published case definitions. Results: Between March-July 2020, 47,572 patients [median age 34 (1-102) years, 98% males] were diagnosed with COVID-19 in Singapore. Of 90 patients referred for neurological disorders, 39 [median age 41 (27-73) years, 97% males] were deemed related to COVID-19 and categorised as: i) Central nervous system syndromes - 3 encephalitis, 1 acute disseminated encephalomyelitis;ii) Cerebrovascular disorders - 19 acute ischemic stroke/transient ischemic attack (AIS/TIA), 4 cerebral venous thrombosis (CVT) and 2 intracerebral haemorrhage;iii) Peripheral nervous system - 7 mono/polyneuropathy;iv) Autonomic nervous system - 4 limited dysautonomia. Fifty-one other patients had pre/co-existent neurological conditions (headache, seizure, mononeuropathies and functional neurological disorders) unrelated to COVID-19. Encephalitis is delayed, occurring in critical COVID-19, while CVT and dysautonomia occurred relatively early and largely in mild infections. AIS/TIA was variable in onset;remarkably 63.2% had asymptomatic COVID-19. CVT was more frequent than expected and occurred in patients with mild/asymptomatic COVID-19. The pathophysiology of COVID-19 neurology appeared to be dysimmunity and/or prothrombotic tendency. There were no neurological complications in all 81 paediatric COVID-19 cases. Conclusions: COVID-19 neurology has a wide spectrum of dysimmune-thrombotic disorders. The relatively few cases recorded was probably because our outbreak affected mainly healthy young men with mild/asymptomatic COVID-19 and the pandemic did not unduly affect the Singapore healthcare system.

12.
Diabetic Medicine ; 38(SUPPL 1):47, 2021.
Article Dans Anglais | EMBASE | ID: covidwho-1238403

Résumé

Background: We aim to examine the prevalence and management of hyperglycaemia in non-diabetic and diabetic ICU patients with covid-19. Methods: Retrospective study of 27 ICU patients with covid- 19 treated with dexamethasone. Results: Mean age 58yrs and 74% male: 26% female. Prevalence of pre-existing diabetes was 44% (12) while 56% (15) had no known history of diabetes. Type 2 diabetes accounted for all cases of pre-existing diabetes. In preceding 6 months 67% had no HbA1c check and 11.1% had an HbA1c on admission (all people with known diabetes). Ninety-three percent became hyperglycaemic (glucose >12 mmol/l) while in ICU. Mean peak glucose throughout admission for patients with pre-existing diabetes and those with no prior history were 18.5 mmol/l and 15.1 mmol/l, respectively. Of those with hyperglycaemia, 76% received insulin treatment: 92% of patients with pre-existing diabetes had some form of insulin treatment compared to 53% of patients with no prior history. Treatment regimens: actrapid infusion (73.7%), actrapid infusion with long-acting insulin (15.8%) and novorapid as required doses (10.5%). A third of patients required input from the diabetes team while on ICU. Conclusion: Our data shows that the majority of covid-19 patients treated with dexamethasone, regardless of diabetes history, develop hyperglycaemia and subsequently require insulin. HbA1c is not routinely performed on admission onto intensive care;however it is a useful tool in detecting undiagnosed diabetes at presentation, assessment of prior glycaemic control and degree of insulin resistance in patients with known diabetes. HbA1c measurement has implications for appropriate on-going management and long-term specialist input/follow-up.

13.
Vaccines (Basel) ; 9(4):05, 2021.
Article Dans Anglais | MEDLINE | ID: covidwho-1208799

Résumé

The highly infectious coronavirus disease 2019 (COVID-19) associated with the pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to become a global pandemic. At present, the world is relying mainly on containment and hygiene-related measures, as well as repurposed drugs to control the outbreak. The development of COVID-19 vaccines is crucial for the world to return to pre-pandemic normalcy, and a collective global effort has been invested into protection against SARS-CoV-2. As of March 2021, thirteen vaccines have been approved for application whilst over 90 vaccine candidates are under clinical trials. This review focuses on the development of COVID-19 vaccines and highlights the efficacy and vaccination reactions of the authorised vaccines. The mechanisms, storage, and dosage specification of vaccine candidates at the advanced stage of development are also critically reviewed together with considerations for potential challenges. Whilst the development of a vaccine is, in general, in its infancy, current progress is promising. However, the world population will have to continue to adapt to the "new normal" and practice social distancing and hygienic measures, at least until effective vaccines are available to the general public.

14.
Biophysical Journal ; 120(3):15A-16A, 2021.
Article Dans Anglais | Web of Science | ID: covidwho-1187562
15.
Annals of the Academy of Medicine, Singapore ; 50(2):188-190, 2021.
Article Dans Anglais | MEDLINE | ID: covidwho-1139099
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