PV System Linked to an Electrical Network with an Active Power Filter Using DPC Modified Method Under Distorted Grid Voltage Conditions

This article presents an energy system that enhances the quality of electrical energy by injecting photovoltaic (PV) renewable energy into the electrical network in the presence of a polluting load. This system is based on a new control approach known as Zero Direct Power Command (ZDPC). The innovative aspect of the proposed work is the addition of clean energy while simultaneously removing the unsettling harmonics produced by the nonlinear loads provided by distorted voltages. This approach combines a traditional Proportional Integrator (PI) controller for regulating the DC bus voltage with a clever technique (fuzzy logic) for tracking the Maximum Power Point Tracking (MPPT). The current has a harmonic distortion rate of about 1% with unity power factor due to the suppression of undesirable harmonics from the source currents. A PV panel connected in series with a chopper and managed by fuzzy logic via a two-state inverter ensures the injection of PV energy into the electrical network. Software called MATLAB/Simulink is used to model this system. The outcomes demonstrate the reliability and viability of the ZDPC control, which concurrently ensures harmonic current compensation, power factor correction, and the introduction of solar power into the electrical network despite distorted source voltages

The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Active Power Filtering Using the ZDPC Method under Unbalanced and Distorted Grid Voltage Conditions

In this paper, we propose a new Zero Direct Power Control (ZDPC) technique for active compensation of harmonics and reactive power, using shunt active power filter (SAPF), based on cancellation of instantaneous active and reactive power disturbances by comparison with their zero references. To separate harmonic and fundamental components of the line voltage and current a highly selective filter (HSF) has been used. Depending on the power errors and line voltage vector position, a switching table produces the appropriate control vectors leading to the active and reactive power variation required to reach the zero power references, even under grid voltage unbalanced and distorted conditions. The experimental validation of the proposed ZDPC has been performed. The results are compared to other recent techniques to demonstrate the superiority and feasibility of the proposed strategy

Water relations, photosynthesis, xylem embolism and accumulation of carbohydrates and cyclitols in two Eucalyptus species (E. camaldulensis and E. torquata) subjected to dehydration-rehydration cycle

International audienceKey message Resilience to xylem embolism and the accumulation of cyclitols are promising criteria for the selection of drought-resilient Eucalyptus species. Abstract Due to the aridity of the climate in the southern Mediterranean region, the choice of suitable species for afforestation projects is crucial. The present study aims to compare resilience mechanisms against drought in two frequently used Euca-lyptus species (E. camaldulensis and E. torquata). Two-year-old self-rooted cuttings of the two species were grown in sand-filled pots and subjected to a dehydration period followed by rehydration. At regular intervals, water relations, gas exchange, chlorophyll fluorescence and xylem embolism were measured on these plants. In addition, carbohydrates and cyclitols were quantified in their leaves. The results revealed that E. camaldulensis was more resilient to drought than E. torquata. During the dehydration phase, plant water status, cell turgor, net photosynthetic rate (P n) and photosynthetic machinery integrity were less affected in E. camaldulensis than E. torquata. After rehydration, these variables were at levels similar to those of control plants in the case of E. camaldulensis, but not in the case of E. torquata. The restoration rate was 96% and 88% for predawn leaf water potential (Ψ pd), and it was 98% and 77% for P n in E. camaldulensis and E. torquata, respectively. The resilience of E. camaldulensis against drought may be due to the efficiency of two determinant survival mechanisms: osmotic adjustment and resistance to xylem embolism. Indeed, E. camaldulensis was less vulnerable to drought-induced xylem embolism and more able to repair embolized xylem vessels than E. torquata. Xylem refilling reduced embolism rate (percent loss of conductivity) to 15% in E. camaldulensis, compared to 22% in E. torquata. Furthermore, E. camaldulensis was found capable of efficient osmotic adjustment than E. torquata by accumulating soluble carbohydrates, especially cyclitols. Indeed, under severe drought (Ψ pd of − 7 MPa), E. camaldulensis accumulated 9.27 mg g − 1 DW of quercitol and 3.81 mg g − 1 DW of pinitol; it also had three times more myo-inositol in its leaves than E. torquata. We suggest the use of resilience to xylem embolism and the accumulation of cyclitols to screen Eucalyptus germplasm for drought resistance

Design of ophthalmic micelles loaded with diclofenac sodium: effect of chitosan and temperature on the block-copolymer micellization behaviour

Diclofenac sodium 0.1% is a commonly used NSAID with well-documented clinical efficacy in reducing postoperative inflammation; however, its corneal tolerability and ophthalmic tissue bioavailability require further improvement. Advanced micellar delivery systems composed of block-copolymers and chitosan showing fine balance between the mucoadhesion and mucus permeation, capable to slip through the mucus barrier and adhere to the epithelial ocular surface, may be used to tackle both challenges. The aggregation behaviour of the block-copolymers in the presence of different additives will dramatically influence the quality attributes like particle size, particle size distribution, drug-polymer interaction, zeta potential, drug incorporation, important for the delicate balance among mucoadhesion and permeation, as well as safety and efficacy of the ophthalmic micelles. Therefore, quality by design approach and D-optimal experimental design model were used to create a pool of useful data for the influence of chitosan and the formulation factors on the block copolymer’s aggregation behaviour during the development and optimization of Diclofenac loaded Chitosan/Lutrol F127 or F68 micelles. Particle size, polydispersity index, dissolution rate, FTIR and DSC studies, NMR spectroscopy, cytotoxicity, mucoadhesivity, mucus permeation studies, and bioadhesivity were assessed as critical quality attributes. FTIR and DSC studies pointed to the chaotropic effect of chitosan during the micelle aggregation. Mainly, Pluronic F68 micellization behaviour was more dramatically affected by the presence of chitosan, and self-aggregation into larger micelles with high polydispersity index was favoured at higher chitosan concentration. The optimized formulation with highest potential for ophthalmic delivery of diclofenac sodium, good cytotoxicity profile, delicate balance of the mucoadhesivity, and mucus permeation was in the design space of Chitosan/Lutrol F127 micelles. Graphical abstract: [Figure not available: see fulltext.]The authors received financial support from the project Drug delivery systems for improved ophthalmic delivery, QUST-1-CPH2020-8, Qatar University

Haplotype Map of Sickle Cell Anemia in Tunisia

-Globin haplotypes are important to establish the ethnic origin and predict the clinical development of sickle cell disease patients (SCD). To determine the chromosomal background of Tunisian sickle cell patients, in this first study in Tunisia, we have explored four polymorphic regions of -globin cluster on chromosome 11. It is the 5 region of -LCR-HS2 site, the intervening sequence II (IVSII) region of two fetal ( G and A ) genes and the 5 region of -globin gene. The results reveal a high molecular diversity of a microsatellite configuration describing the sequences haplotypes. The linkage disequilibrium analysis showed various haplotype combinations giving 22 "extended haplotypes". These results confirm the utility of the -globin haplotypes for population studies and contribute to knowledge of the Tunisian gene pool, as well as establishing the role of genetic markers in physiopathology of SCD

Association between TLR2, TLR4, and TLR5 genetic variants and the risk of hepatocellular carcinoma in Moroccan population

International audienceHepatocellular carcinoma (HCC) is the fifth most common human malignancy and the fourth most frequent cause of cancer-related deaths worldwide. Toll-like receptors (TLRs), are known to play a key role in hepatocarcinogenesis through induction of inflammation. We aimed to investigate the association between TLR2 rs3804099, TLR4 rs4986790, rs4986791, and rs11536889 and TLR5 rs5744174 and HCC risk in a total of 306 Moroccan subjects, including 152 HCC patient and 154 controls using a TaqMan allelic discrimination assay. Our result showed that the frequency of TLR4 rs11536889 C allele was higher in control group than in HCC patients (OR = 0.52, 95% CI = 0.30-0.88, p = 0.01). Moreover, under the dominant model, we observed that CG/CC genotypes were protective factors against HCC risk (OR = 0.51, 95% CI = 0.28-0.91, p = 0.02). However, no significant differences were found in the allele and genotype frequencies of TLR4 rs4986790 and rs4986791, between HCC patients and controls. Similarly, genotypic frequencies of TLR2 and TLR5 polymorphisms did not differ significantly between HCC patients and controls. However, TLR4 haplotype analysis revealed that ACC haplotype may be protective of HCC risk in patients with HCC (OR = 0.53, 95% CI = 0.31-0.92, p = 0.02). In conclusion, our result suggest that TLR4 rs11536889 polymorphism and ACC haplotype may decrease risk of hepatocellular carcinoma in Moroccan populatio