108 research outputs found
Salinity induced anatomical and morphological changes in Chloris gayana Kunth roots
Chloris gayana Kunth is a grass species valuable as forage which was introduced into Argentina to be used as pasture in saline soils of subtropical and warm-temperate zones, given its good adaptability to drought, salinity and mild freezing. However, its tolerance varies according to the cultivar. In tetraploid cultivars, important reductions in yield have been observed. Here, a study of the variations produced on the root and stem system by salinity at different NaCl concentrations (0, 150 y 250 mM) was performed in the Boma cultivar, with the aim of determining the anatomical and morphological alterations produced by the salt excess. Plants cultivated with the highest level of salinity showed, in the whole, significant differences in the measured variables. A diminution in absolute values of the variables and a major reduction in vascular tissue dimensions were observed, which suggests that the lack of tolerance to salt stress could be related to a deficient adaptation to absorb and transport water and nutrients from the roots.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Ceccoli, Gabriel. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ramos, Julio C. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ortega, Leandro Ismael. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales (ex IFFIVE); ArgentinaFil: Acosta, Juan M. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perreta, Mariel Gladis. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Brief comments on three existing approaches for managing neonates at risk of early-onset sepsis
Background: Growing concerns regarding the adverse effects of antibiotics during the first days of life and the marked reduction in the incidence of early-onset sepsis (EOS) are changing the clinical practice for managing neonates at risk of EOS. Strategies avoiding unnecessary antibiotics while promoting mother-infant bonding and breastfeeding deserve to be considered. Main body: We compare strategies for managing newborns at risk of EOS recommended by the American Academy of Pediatrics, which are among the most followed recommendations worldwide. Currently three different approaches are suggested in asymptomatic full-term or late preterm neonates: i) the conventional management, based on standard perinatal risk factors for EOS alone, ii) the neonatal sepsis calculator, a multivariate risk assessment based on individualized, quantitative risk estimates (relying on maternal risk factors for EOS) combined with physical examination findings at birth and in the following hours and iii) an approach entirely based on newborn clinical condition (serial clinical observation) during the first 48 h of life. We discuss advantages and limitations of these approaches, by analyzing studies supporting each strategy. Approximately 40% of infants who develop EOS cannot be identified on the basis of maternal RFs or laboratory tests, therefore close monitoring of the asymptomatic but at-risk infant remains crucial. A key question is to know what proportion of babies with mild, unspecific symptoms at birth can be managed safely without giving antibiotics. Conclusions: Both neonatal sepsis calculator and serial clinical observation may miss cases of EOS, and clinical vigilance for all neonates is essential There is a need to assess which symptoms at birth are more predictive of EOS, and therefore require immediate interventions, or symptoms that can be carefully reevaluated without necessarily treat immediately the neonate with antibiotics. Studies comparing strategies for managing neonates are recommended
Born with a solitary kidney : at risk of hypertension
Background: Subjects with a congenital solitary kidney (CSK) are believed to be at risk of hypertension due to their low number of nephrons. However, as CSK is a congenital abnormality of the kidney or urinary tract (CAKUT), subtle dysplastic changes contributing to hypertension cannot be excluded. Methods: We retrospectively compared office blood pressure (OBP) and ambulatory blood pressure monitoring (ABPM) between two groups of children with CAKUT, aged 6\u201318 years: Group A with a CSK and Group B with two kidneys. All had normal renal parenchyma on scintigraphy and normal renal function. OBP and mean systolic and diastolic 24-h, daytime and nighttime ambulatory BP records were analyzed. The distribution of OBP and APBM as continuous values and the prevalence of hypertension (ambulatory/severe ambulatory or masked hypertension) in the two groups were compared. Results: There were 81 patients in Group A and 45 in Group B. Median OBP standard deviation scores were normal in both groups, without significant differences. Median ABPM standard deviation scores, although normal, were significantly higher in Group A and the prevalence of hypertension was higher (ambulatory/severe ambulatory or masked) (33.3 vs. 13.3%, p = 0.019), mainly because of the greater occurrence of masked hypertension. Conclusions: Our data show that a CSK per se can be associated with an increased risk of hypertension from the pediatric age. Therefore, ABPM, which has proved valuable in the screening of hypertension, is warranted in children with a CSK, even if laboratory and imaging assessment is otherwise normal
Retrospective 8-year study on the antibiotic resistance of uropathogens in children hospitalised for urinary tract infection in the emilia-romagna region, italy
The development and spread of antibiotic resistance is an increasingly important global public health problem, even in paediatric urinary tract infection (UTI). In light of the variability in the data, it is necessary to conduct surveillance studies to determine the prevalence of antibiotic resistance in specific geographical areas to optimize therapeutic management. In this observational, retrospective, multicentre study, the medical records of 1801 paediatric patients who were hospital-ised for UTI between January 1st, 2012, and June 30th, 2020, in Emilia-Romagna, Italy, were analysed. Escherichia coli was the most frequently detected pathogen (75.6%), followed by Klebsiella pneumoniae (6.9%) and Pseudomonas aeruginosa (2.5%). Overall, 840 cases (46.7%) were due to anti-microbial-resistant uropathogens: 83 (4.7%) extended spectrum beta-lactamase (ESBL)-producing, 119 (6.7%) multidrug resistant (MDR) and 4 (0.2%) extensively drug resistant (XDR) bacteria. Empirical antibiotic therapy failed in 172 cases (9.6%). Having ESBL or MDR/XDR uropathogens, a history of recurrent UTI, antibiotic therapy in the preceding 30 days, and empirical treatment with amoxicillin or amoxicillin/clavulanate were significantly associated with treatment failure, whereas first-line therapy with third-generation cephalosporins was associated with protection against negative outcomes. In conclusion, the increase in the resistance of uropathogens to commonly used antibiotics requires continuous monitoring, and recommendations for antibiotic choice need updating. In our epidemiological context, amoxicillin/clavulanate no longer seems to be the appropriate first-line therapy for children hospitalised for UTI, whereas third-generation cephalosporins continue to be useful. To further limit the emergence of resistance, every effort to reduce and ration-alise antibiotic consumption must be implemented
Clinical Outcome of Discordant Empirical Therapy and Risk Factors Associated to Treatment Failure in Children Hospitalized for Urinary Tract Infections
With the spread of antibiotic resistance in pediatric urinary tract infections (UTIs), more patients are likely to be started empirically on antibiotics to which pathogens are later found to be resistant (discordant therapy). However, in-vivo effectiveness may be different from in-vitro susceptibility. Aims of this study were to describe clinical outcomes of discordant empirical treatments in pediatric UTIs and to investigate risk factors associated to treatment failure. This observational, retrospective study was conducted on children hospitalized for febrile UTIs with positive urine culture and started on discordant empirical therapy. Failure rates of discordant treatments and associated risk factors were investigated. A total of 142/1600 (8.9%) patients were treated with inadequate empirical antibiotics. Clinical failure was observed in 67/142 (47.2%) patients, with no fatal events. Higher failure rates were observed for combinations of penicillin and beta-lactamase inhibitors (57.1%). Significant risk factors for failure of discordant treatment were history of recurrent UTIs (95% CI: 1.13–9.98, OR: 3.23, p < 0.05), recent use of antibiotics (95% CI: 1.46–21.82, OR: 5.02, p < 0.01), infections caused by Pseudomonas aeruginosa (95% CI: 1.85–62.10, OR: 7.30, p < 0.05), and empirical treatment with combinations of penicillin and beta-lactamase inhibitors (95% CI: 0.94–4.03, OR: 1.94, p = 0.05). This study showed that discordant empirical treatments may still be effective in more than half of pediatric UTIs. Clinical effectiveness varies between different discordant antibiotics in pediatric UTIs, and patients presenting risk factors for treatment failure may need a differentiated empirical approach
Analysis of Antibiotic Exposure and Early-Onset Neonatal Sepsis in Europe, North America, and Australia
IMPORTANCE Appropriate use of antibiotics is life-saving in neonatal early-onset sepsis (EOS), but overuse of antibiotics is associated with antimicrobial resistance and long-term adverse outcomes. Large international studies quantifying early-life antibiotic exposure along with EOS incidence are needed to provide a basis for future interventions aimed at safely reducing neonatal antibiotic exposure.OBJECTIVE To compare early postnatal exposure to antibiotics, incidence of EOS, and mortality among different networks in high-income countries.DESIGN, SETTING, AND PARTICIPANTS This is a retrospective, cross-sectional study of late preterm and full-term neonates born between January 1, 2014, and December 31, 2018, in 13 hospital-based or population-based networks from 11 countries in Europe and North America and Australia. The study included all infants born alive at a gestational age greater than or equal to 34 weeks in the participating networks. Data were analyzed from October 2021 to March 2022.EXPOSURES Exposure to antibiotics started in the first postnatal week.MAIN OUTCOMES AND MEASURES The main outcomes were the proportion of late-preterm and full-term neonates receiving intravenous antibiotics, the duration of antibiotic treatment, the incidence of culture-proven EOS, and all-cause and EOS-associated mortality.RESULTS A total of 757 979 late-preterm and full-term neonates were born in the participating networks during the study period; 21703 neonates (2.86%; 95% CI, 2.83%-2.90%), including 12 886 boys (59.4%) with a median (IQR) gestational age of 39 (36-40) weeks and median (IQR) birth weight of 3250 (2750-3750) g, received i ntra venous antibiotics during the first postnatal week. The proportion of neonates started on antibiotics ranged from 1.18% to 12.45% among networks. The median (IQR) duration of treatment was 9 (7-14) days for neonates with EOS and 4(3-6)days for those without EOS. This led to an antibiotic exposure of 135 days per 1000 live births (range across networks, 54-491 days per 1000 live births). The incidence of EOS was 0.49 cases per 1000 live births (range, 0.18-1.45 cases per 1000 live births). EOS-associated mortality was 3.20% (12 of 375 neonates; range, 0.00%-12.00%). For each case of EOS, 58 neonates were started on antibiotics and 273 antibiotic days were administered.CONCLUSIONS AND RELEVANCE The findings of this study suggest that antibiotic exposure during the first postnatal week is disproportionate compared with the burden of EOS and that there are wide (up to 9-fold) variations internationally. This study defined a set of indicators reporting on both dimensions to facilitate benchmarking and future interventions aimed at safely reducing antibiotic exposure in early life
Antibiotic exposure for culture-negative early-onset sepsis in late-preterm and term newborns: an international study
Background - Early-life antibiotic exposure is disproportionately high compared to the burden of culture-proven early-onset sepsis (CP-EOS). We assessed the contribution of culture-negative cases to the overall antibiotic exposure in the first postnatal week.
Methods - We conducted a retrospective analysis across eleven countries in Europe, North America, and Australia. All late-preterm and term infants born between 2014 and 2018 who received intravenous antibiotics during the first postnatal week were classified as culture-negative cases treated for ≥5 days (CN ≥ 5d), culture-negative cases treated for
Results - Out of 757,979 infants, 21,703 (2.9%) received intravenous antibiotics. The number of infants classified as CN ≥ 5d, CN
Conclusions - CN ≥ 5d substantially contributed to the overall antibiotic exposure, and was 21-fold more frequent than CP-EOS. Antimicrobial stewardship programs should focus on shortening antibiotic treatment for culture-negative cases
Development and Applications of Transplastomic Plants; A Way Towards Eco-Friendly Agriculture
With distribution of genetic materials and advance molecular characteristics, the chloroplast is prokaryotic compartments within the eukaryotic plants that have turned into a crucial source for the genetic engineering and transplastomic plants are becoming more popular means of agricultural development with elevated crop yield. To address global agricultural problems, genetic modification of crop plants is a rapid and promising solution to adapt the environment-friendly and well-controlled farming system. The transplastomic plant with high accumulation of foreign proteins (up to 45-46% TSP) and stable transgene expression with gene containment can be a unique choice for the agricultural innovation of coming centuries. Although the transplastomic plants still facing encumber to ensure the full potential exploitation and expansion as an economical means, the removal of hardness and obstacles of this technology and commercialization can contribute for the sustainable development of future agriculture. In this book chapter, we intend to recapitulate the up to date development and achievement of transplastomic plant including gene transfer procedures in plastid genomes, regulable expression of plastid transgenes, plant trait improvement by foreign gene expression, biopharmaceuticals production, engineering of metabolic pathways in plant, study of transformation mediated RNA editing technologies, bio-safety issues and public concerns on transplastomic plants and overall beneficial aspects. We believe that the utilization of transplastomic plants will ensure an eco-friendly approach in agriculture with minimized hazards and public concerns. © Springer Nature Switzerland AG 2020
Analisi del comportamento torsionale di travi realizzate in materiale composito
In questa nota si studia il comportamento torsionale di travi composite aventi sezione generica e costituite da materiali ortotropi. Il problema della torsione uniforme viene affrontato in termini della funzione delle tensioni di Prandtl. Viene fornita una soluzione approssimata per il problema della torsione di sezioni tubolari di spessore sottile con strati disposti in serie, per le quali si ricava l’espressione della rigidezza torsionale e della tensione tangenziale media. In un lavoro precedente gli autori hanno ottenuto la soluzione esatta per sezioni multistrato di forma rettangolare; tale soluzione è qui utilizzata per lo studio di travi in legno placcate per mezzo di lamine in composito fibro-rinforzato. Si mostra ad esempio come, placcando la trave con due lamine sottili di composito con fibre di carbonio o di vetro, sia possibile aumentare la rigidezza torsionale della trave anche di 15 volte. Infine si presenta un modello per lo studio della torsione non uniforme di travi composite. Tale modello consente di valutare l’effetto di irrigidimento qualora una base della trave sia perfettamente incastrata, nonchè la distanza di estinzione degli effetti di bordo. Gli esempi studiati evidenziano che nel caso di travi in materiale composito fibrorinforzato, per le quali il rapporto tra i moduli di elasticità longitudinale e tangenziale può assumere valori elevati, tale distanza può risultare molto maggiore che per travi in materiale isotropo
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