6 research outputs found
Optimal Dual Active Bridge DC-DC Converter Operation with Minimal Reactive Power for Battery Electric Vehicles Using Model Predictive Control
The dual active bridge DC-DC converter is a promising power converter used in several applications. Much research has been focusing on the study of such a converter from different angles. In this paper, an optimal design of the DAB converter is proposed to provide minimal reactive power in addition to reduced weight and size for the converter magnetic components in order to assure the DC-DC conversion stage of battery electric vehicles’ powertrains. Two modes of operation are considered in order to fulfill such a requirement and minimize reactive power of the converter (circulating current/conduction losses): an optimal extended phase shift (EPS) modulation along with an optimal triangular phase shift (TrgPS) modulation. The operation of the DAB converter under the two modes is being driven using a model predictive controller. Simulation results using MATLAB/Simulink presented in the paper show that the operation of the DAB converter for such an application is optimal when operating under optimal TrgPS modulation. In addition to the aforementioned features, it also solves many other concerns, such as transient load fluctuation and input voltage disturbance effects, and provides ease of control
Agreement between two real-time commercial PCR kits and an in-house real-time PCR for diagnosis of mucormycosis
ABSTRACT Mucormycosis is a severe and emerging invasive fungal infection associated with high mortality rates. Early diagnosis is crucial for initiating specific antifungal treatment, with molecular tools currently representing the most efficient diagnostic approach. Presently, a standardized in-house real-time PCR method is widely employed for diagnosing mucormycosis. Our study aimed to evaluate the agreement for the Mucorales DNA detection between two commercial real-time PCR assays—the Fungiplex Mucorales Real-Time PCR Kit and the MycoGENIE Aspergillus-Mucorales spp. Real-Time PCR Kit—in comparison with the in-house PCR. We retrospectively analyzed 58 samples previously identified as positive for Mucorales using the in-house PCR. These samples, obtained from 22 patients with proven or probable mucormycosis, were tested with both commercial kits. Additionally, samples from 40 patients without mucormycosis served as negative controls. Our findings revealed that the MycoGENIE Kit demonstrated superior performance in detecting Mucorales DNA in samples identified as positive by the in-house PCR. Notably, we observed minimal variability in cycle threshold (CT) values when comparing the results of the MycoGENIE Kit with those of the in-house PCR, with an average difference of 1.8 cycles. In contrast, the Fungiplex Kit exhibited a larger discrepancy in CT values compared to the in-house PCR, with an average difference of 4.1 cycles. The MycoGENIE Kit exhibited very good agreement (kappa of 0.82) with the in-house PCR for detecting Mucorales DNA across various sample types. These findings are important for the choice of kits that could be used to diagnose mucormycosis in clinical microbiology laboratories.IMPORTANCEEarly diagnosis of mucormycosis is crucial for initiating effective treatment. The detection of Mucorales DNA by PCR in serum has revolutionized the diagnosis of this infection. However, the use of in-house methods can be time consuming. The availability of a commercial kit eliminates the need for in-house assay development, reducing laboratory workload and ensuring consistent performance across different healthcare settings. Currently, there are several commercial assays available, but many have limited evaluation. In this study, we compared two commercial kits and found that the MycoGENIE Kit offers a promising alternative to the in-house method
Estimating the global prevalence of chronic obstructive pulmonary disease (COPD): a systematic review and meta-analysis
Abstract Background Chronic obstructive pulmonary disease (COPD) is a major public health problem. The present study aims to provide a global and regional estimate of the prevalence of COPD based on spirometry according to the two most widely used diagnostic criteria of COPD: fixed ratio (FR) and lower limit of normal (LLN). Methods We conducted a systematic review of the literature according to PRISMA guidelines. MEDLINE, Web of Sciences, and Scopus databases were searched to identify studies on the spirometry-based prevalence of COPD in individuals aged 40 years and older. The meta-analysis was performed using MedCalc 19 software. Results In total, 42 of the 3393 studies reviewed were eligible for inclusion. The overall prevalence of COPD in people aged 40 years and older was 12.64% (95% CI 10.75%-14.65%) and 7.38% (95% CI 5.47% − 9.55%) based on FR and LLN criteria, respectively. By gender, men had a higher prevalence of COPD compared to women (15.47%; 95% CI 12.22%-19.02% for men versus 8.79%; 95% CI 6.94%-10.82% for women). Using the LLN criteria, the prevalence of COPD in both sexes was almost identical (8.67%; 95% CI 8.44%- 8.90% for men and 8.00%; 95% CI 6.42% − 9.73% for women). We reported a high prevalence of COPD among smokers and the elderly by both definitions of airway obstruction. Regional prevalence estimates using the FR definition indicate that the highest COPD prevalence was recorded in the Americas and the lowest was recorded in the Eastern Mediterranean region. Using the LLN definition, the highest prevalence was recorded in the Southeast Asian region and the lowest prevalence was recorded in the American region. The most common COPD stage was stage II, with a prevalence of 50.46%. The results indicate a huge lack of prevalence data in the African and Eastern Mediterranean region. The results were given using a random-effect model due to the high heterogeneity between studies. Conclusion Results show that the prevalence of COPD differs according to the diagnostic criteria used. In addition, management and prevention strategies targeting risk factors for COPD are certainly needed to reduce the global burden of this chronic respiratory disease
COVID-19-Associated Pulmonary Aspergillosis, Fungemia, and Pneumocystosis in the Intensive Care Unit: a Retrospective Multicenter Observational Cohort during the First French Pandemic Wave
International audienceThe aim of this study was to evaluate diagnostic means, host factors, delay of occurrence, and outcome of patients with COVID-19 pneumonia and fungal coinfections in the intensive care unit (ICU). From 1 February to 31 May 2020, we anonymously recorded COVID-19-associated pulmonary aspergillosis (CAPA), fungemia (CA-fungemia), and pneumocystosis (CA-PCP) from 36 centers, including results on fungal biomarkers in respiratory specimens and serum. We collected data from 154 episodes of CAPA, 81 of CA-fungemia, 17 of CA-PCP, and 5 of other mold infections from 244 patients (male/female [M/F] ratio = 3.5; mean age, 64.7 ± 10.8 years). CA-PCP occurred first after ICU admission (median, 1 day; interquartile range [IQR], 0 to 3 days), followed by CAPA (9 days; IQR, 5 to 13 days), and then CA-fungemia (16 days; IQR, 12 to 23 days) (P < 10-4). For CAPA, the presence of several mycological criteria was associated with death (P < 10-4). Serum galactomannan was rarely positive (<20%). The mortality rates were 76.7% (23/30) in patients with host factors for invasive fungal disease, 45.2% (14/31) in those with a preexisting pulmonary condition, and 36.6% (34/93) in the remaining patients (P = 0.001). Antimold treatment did not alter prognosis (P = 0.370). Candida albicans was responsible for 59.3% of CA-fungemias, with a global mortality of 45.7%. For CA-PCP, 58.8% of the episodes occurred in patients with known host factors of PCP, and the mortality rate was 29.5%. CAPA may be in part hospital acquired and could benefit from antifungal prescription at the first positive biomarker result. CA-fungemia appeared linked to ICU stay without COVID-19 specificity, while CA-PCP may not really be a concern in the ICU. Improved diagnostic strategy for fungal markers in ICU patients with COVID-19 should support these hypotheses. IMPORTANCE To diagnose fungal coinfections in patients with COVID-19 in the intensive care unit, it is necessary to implement the correct treatment and to prevent them if possible. For COVID-19-associated pulmonary aspergillosis (CAPA), respiratory specimens remain the best approach since serum biomarkers are rarely positive. Timing of occurrence suggests that CAPA could be hospital acquired. The associated mortality varies from 36.6% to 76.7% when no host factors or host factors of invasive fungal diseases are present, respectively. Fungemias occurred after 2 weeks in ICUs and are associated with a mortality rate of 45.7%. Candida albicans is the first yeast species recovered, with no specificity linked to COVID-19. Pneumocystosis was mainly found in patients with known immunodepression. The diagnosis occurred at the entry in ICUs and not afterwards, suggesting that if Pneumocystis jirovecii plays a role, it is upstream of the hospitalization in the ICU
Plasmodium ovale spp dhfr mutations associated with reduced susceptibility to pyrimethamine in sub-Saharan Africa: a retrospective genetic epidemiology and functional study
International audienc
Active Surveillance Program to Increase Awareness on Invasive Fungal Diseases: the French RESSIF Network (2012 to 2018)
International audienceThe French National Reference Center for Invasive Mycoses and Antifungals leads an active and sustained nationwide surveillance program on probable and proven invasive fungal diseases (IFDs) to determine their epidemiology in France. Between 2012 and 2018, a total of 10,886 IFDs were recorded. The incidence increased slightly over time (2.16 to 2.36/10,000 hospitalization days, P = 0.0562) in relation with an increase of fungemia incidence (1.03 to 1.19/10,000, P = 0.0023), while that of other IFDs remained stable. The proportion of ≥65-year-old patients increased from 38.4% to 45.3% (P 60% of the cases) with a global mortality rate of 42.5% and 59.3%, respectively, at 3 months and significant changes in diagnosis procedure over time. More concurrent infections were also diagnosed over time (from 5.4% to 9.4% for mold IFDs, P = 0.0115). In conclusion, we observed an aging of patients with IFD with a significant increase in incidence only for yeast fungemia, a trend toward more concurrent infections, which raises diagnostic and therapeutic issues. Overall, global survival associated with IFDs has not improved despite updated guidelines and new diagnostic tools.IMPORTANCE The epidemiology of invasive fungal diseases (IFDs) is hard to delineate given the difficulties in ascertaining the diagnosis that is often based on the confrontation of clinical and microbiological criteria. The present report underlines the interest of active surveillance involving mycologists and clinicians to describe the global incidence and that of the main IFDs. Globally, although the incidence of Pneumocystis pneumonia, invasive aspergillosis, and mucormycosis remained stable over the study period (2012 to 2018), that of yeast fungemia increased slightly. We also show here that IFDs seem to affect older people more frequently. The most worrisome observation is the lack of improvement in the global survival rate associated with IFDs despite the increasing use of more sensitive diagnostic tools, the availability of new antifungal drugs very active in clinical trials, and a still low/marginal rate of acquired in vitro resistance in France. Therefore, other tracks of improvement should be investigated actively