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

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

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

Long term deflection of reinforced SCC beams

Long-term structural behavior of reinforced Self Compacting Concrete beams has been investigated, according to the four point bending scheme. Time evolution of midspan deflection as well as compressive and tensile strains have been recorded. Experimental data have been then compared with predictions by analytical models, where, as far as rheological properties are concerned, both international codes provisions and experimental data have been used. Model predictions fit quite accurately experimental behavior, even though tension stiffening effect should be improved. Creep-flexural strength interaction has been also investigated by performing failure tests on control beams before and after long-term tests, and on beams subject to long-term loading. Small flexural strength variation has been observed, if the growth of compressive strength due to concrete ageing is taken into account

A comparison between long term properties of self compacting concrete of different strength

In the present paper, results of an experimental campaign concerning rheological properties of hardened self-compacting concrete are presented. Two mixes of self-compacting concrete have been employed, with different compressive strength. Stress levels have been selected to cover the range of application from cast-in-place to prestressed structures. For each mix, compressive strength and elastic modulus evolution with time have been monitored along a period of time of about one year. Creep tests have been also performed at two different stress level, 35% and 55% of compressive strength and with two different ages at loading (7 and 28 days). Influence on delayed deformation of concrete strength, stress level and aging have been observed. Experimental data have been finally compared with international standard provision

Sull'interazione dinamica di strutture per sili col suolo

Viene presentato un modello per l'analisi dell'interazione dinamica col suolo, nel dominio delle frequenze, di alcune tipiche strutture per sili. La struttura è schematizzata come un insieme rigido di celle pensili su un insieme di colonne deformabili elasticamente. La fondazione è schematizzata come una piastra rigida su un semispazio elastico. Sulla base del teorema di reciprocità di Graffi, il comportamento dinamico del semispazio è descritto in termini di spostamenti di superficie e di pressioni di contatto all'interfaccia con la fondazione. Lo smorzamento isteretico del suolo viene messo in conto introducendo valori complessi dei moduli di Lamè per il materiale. Il metodo adottato consente di valutare sia la deviazione delle frequenze di risonanza da quelle della struttura su base fissa sia gli effetti dello smorzamento per irraggiamento dovuti alla presenza del semispazio elastico