Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

Development of a filtration system with high-frequency flow reversal

ABSTRACT The aim of this study was to develop a filtration system with high-frequency flow reversal and minimum requirement of water for cleaning routines. The system was developed in the period from 2011 to 2013 and consists of three screen filters and eleven solenoid valves electronically controlled by a controller that operates based on head loss measurements. The following evaluations were carried out: head loss curve as a function of flow rate; filtrating efficiency as a function of solids concentration, frequency of flow reversal and increment in head loss. The experimental design was completely randomized in a factorial scheme with three replicates and two treatment levels for each factor. The filtration efficiency was equal to 98.6% for particles larger than 50 µm. The minimum volume of water for each cleaning of the filters was 5.39 L. The head loss increment in the filtration system with flow reversal at frequencies of 11.11 and 22.22 mHz was smaller compared with the filtration system without flow reversal. The developed filtration system has potential for filtering low-quality irrigation water, but requires periodic maintenance to clean the filter element

Development of a system for control of water pH for microirrigation

O objetivo deste trabalho foi desenvolver um sistema eletrônico de controle do pH da água para microirrigação. O trabalho foi realizado no Laboratório de Hidráulica do Departamento de Engenharia de Biossistemas (LEB) da Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP). O sistema de controle consta de um sensor de pH, um circuito eletrônico programado para manter o pH da água em 5,5 e um dispositivo de injeção de ácido controlado por uma válvula solenóide comandada por pulsos elétricos enviados pelo circuito eletrônico. O sistema foi testado em águas de diferentes valores iniciais de pH (variando de 6,2 a 9,2) sob vazão constante (264 L h-1) e variável, sendo efetuada a medição do pH imediatamente à jusante do sistema e ao longo da linha lateral, nos pontos situados a 1, 14, 29 e 44 m do início e em diferentes intervalos de tempo a partir do início dos ensaios. Os resultados obtidos comprovam a eficiência do sistema para manter o pH da água na faixa desejada, tanto para a condição de vazão constante quanto para a variável. Não foram verificadas variações temporais nem espaciais significativas na linha lateral de irrigação.The aim of this work was to develop an electronic system for control of water pH in microirrigation. The study was accomplished in the Hydraulics Laboratory of Biossystems Engineering Department, Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP). The water pH control system has a device for acid injection controlled by a solenoid valve. This valve is switched on by electric pulses from a microcontroller. The system was evaluated for different water pH values (ranging from 6.2 to 9.2) under constant (264 L h-1) and variable flow. The pH was measured immediately on system downstream, and along the lateral line at 1, 14, 29, and 44 m from the lateral inlet, tests were also accomplished for different intervals of time. The obtained results proved the efficiency of the system on maintaining water pH in desired range for constant and variable flow conditions. Meaningful temporal or spatial variations along lateral irrigation line were not observed

Flow rate dynamics of pressure-compensating drippers under clogging effect

ABSTRACT The clogging dynamics of pressure-compensating drippers is still poorly addressed, and its understanding is quite important to control clogging. The aim of this study was to evaluate the flow performance of pressure-compensating drippers under clogging effect. Eight pressure-compensating emitters, model J-SC Jain PC-PLUS with nominal flow rate of 2.2 L h-1 were evaluated. The tests were run for 8 h d-1 for 4 weeks, a total of 160 h. Every 40 h, the concentration and granulometry of suspended particles were increased, by adding 125 mg L-1 of solids, composed of sand. The flow rate of the emitters was determined using a weight measurement system. Flow rate variations of the emitters did not follow a defined pattern. Clogging seems to occur randomly and abruptly. Sometimes the flow rate exceeded the nominal value (maximum relative flow rate of 182%) and other times it was lower than the nominal value (minimum relative flow rate of 0%)