178 research outputs found
Self-Healing of Cracks in Concrete using Bacillus cibi with Different Encapsulation Techniques
One of the main challenges related to concrete is the formation of cracks, which can greatly diminish its strength and decrease its service life. Repair costs to mitigate these cracks can be high. This study investigated the use of Bacillus cibi to produce a self-healing bio-concrete capable of repairing cracks by itself through microbial activity. Bacteria were introduced into concrete by direct incorporation and encapsulating it in lightweight aggregates (LWA) and diatomaceous earth (DE). Samples of concrete cylinders were tested to quantify crack healing, compressive strength, and water permeability. The results showed that bio-concrete prepared with the LWA encapsulation method was able heal the largest crack width at 0.541 mm after 35 days of wet-dry cycle. Bio-concrete produced from bacteria with no encapsulation exhibited significant enhancement in 28-day compressive strength (57.28 MPa) compared to normal concrete (54.78 MPa) and produced the highest hydraulic conductivity recovery at 85.04% after 35 days of healing. The XRD analysis showed that the bacteria did not cause any major changes to the concrete
Self-Healing of Cracks in Concrete using Bacillus cibi with Different Encapsulation Techniques
One of the main challenges related to concrete is the formation of cracks, which can greatly diminish its strength and decrease its service life. Repair costs to mitigate these cracks can be high. This study investigated the use of Bacillus cibi to produce a self-healing bio-concrete capable of repairing cracks by itself through microbial activity. Bacteria were introduced into concrete by direct incorporation and encapsulating it in lightweight aggregates (LWA) and diatomaceous earth (DE). Samples of concrete cylinders were tested to quantify crack healing, compressive strength, and water permeability. The results showed that bio-concrete prepared with the LWA encapsulation method was able heal the largest crack width at 0.541 mm after 35 days of wet-dry cycle. Bio-concrete produced from bacteria with no encapsulation exhibited significant enhancement in 28-day compressive strength (57.28 MPa) compared to normal concrete (54.78 MPa) and produced the highest hydraulic conductivity recovery at 85.04% after 35 days of healing. The XRD analysis showed that the bacteria did not cause any major changes to the concrete
Characterization of begomoviruses sampled during severe epidemics in tomato cultivars carrying the Ty-1 gene
Tomato yellow leaf curl virus (TYLCV, genus Begomovirus, family Geminiviridae) is a major species that causes a tomato disease for which resistant tomato hybrids (mainly carriers of the Ty-1/Ty-3 gene) are being used widely. We have characterized begomoviruses severely affecting resistant tomato crops in Southeast Spain. Circular DNA was prepared from samples by rolling circle amplification, and sequenced by massive sequencing (2015) or cloning and Sanger sequencing (2016). Thus, 23 complete sequences were determined, all belonging to the TYLCV Israel strain (TYLCV-IL). Massive sequencing also revealed the absence of other geminiviral and beta-satellite sequences. A phylogenetic analysis showed that the Spanish isolates belonged to two groups, one related to early TYLCV-IL isolates in the area (Group 1), and another (Group 2) closely related to El Jadida (Morocco) isolates, suggesting a recent introduction. The most parsimonious evolutionary scenario suggested that the TYLCV isolates of Group 2 are back recombinant isolates derived from TYLCV-IS76, a recombinant virus currently predominating in Moroccan epidemics. Thus, an infectious Group 2 clone (TYLCV-Mu15) was constructed and used in in planta competition assays against TYLCV-IS76. TYLCV-Mu15 predominated in single infections, whereas TYLCV-IS76 did so in mixed infections, providing credibility to a scenario of co-occurrence of both types of isolates
Children with special health care needs attending emergency department in Italy: analysis of 3479 cases
Background Although children with special health care needs (CSHCN) represent a minority of the population, they go through more hospitalizations, more admissions to the Emergency Department (ED), and receive a major number of medical prescriptions, in comparison to general pediatric population. Objectives of the study were to determine the reasons for admission to the ED in Italian CSHCN, and to describe the association between patient's demographic data, clinical history, and health services requirements. Methods Ad hoc web site was created to collect retrospective data of 3479 visits of CSHCN to the ED in 58 Italian Hospitals. Results Seventy-two percent of patients admitted to ED were affected by a previously defined medical condition. Most of the ED admissions were children with syndromic conditions (54%). 44.2% of the ED admissions were registered during the night-time and/or at the weekends. The hospitalization rate was of 45.6% among patients admitted to the ED. The most common reason for admission to the ED was the presence of respiratory symptoms (26.6%), followed by gastrointestinal problems (21.3%) and neurological disorders (18.2%). 51.4% of the access were classified as 'urgent', with a red/yellow triage code. Considering the type of ED, 61.9% of the visits were conducted at the Pediatric EDs (PedEDs), 33.5% at the Functional EDs (FunEDs) and 4.6% at the Dedicated EDs (DedEDs). Patients with more complex clinical presentation were more likely to be evaluated at the PedEDs. CSHCN underwent to a higher number of medical procedures at the PedEDs, more in comparison to other EDs. Children with medical devices were directed to a PedED quite exclusively when in need for medical attention. Subjects under multiple anti-epileptic drug therapy attended to PedEDs or FunEDs generally. Patients affected by metabolic diseases were more likely to look for medical attention at FunEDs. Syndromic patients mostly required medical attention at the DedEDs. Conclusions Access of CSHCN to an ED is not infrequent. For this reason, it is fundamental for pediatricians working in any kind of ED to increase their general knowledge about CHSCN and to gain expertise in the management of such patients and their related medical complexity
Accuracy of Plateau Pressure and Stress Index to Identify Injurious Ventilation in Patients with Acute Respiratory Distress Syndrome.
BACKGROUND:
Guidelines suggest a plateau pressure (PPLAT) of 30 cm H(2)O or less for patients with acute respiratory distress syndrome, but ventilation may still be injurious despite adhering to this guideline. The shape of the curve plotting airway pressure versus time (STRESS INDEX) may identify injurious ventilation. The authors assessed accuracy of PPLAT and STRESS INDEX to identify morphological indexes of injurious ventilation.
METHODS:
Indexes of lung aeration (computerized tomography) associated with injurious ventilation were used as a "reference standard." Threshold values of PPLAT and STRESS INDEX were determined assessing the receiver-operating characteristics ("training set," N = 30). Accuracy of these values was assessed in a second group of patients ("validation set," N = 20). PPLAT and STRESS INDEX were partitioned between respiratory system (Pplat,Rs and STRESS INDEX,RS) and lung (PPLAT,L and STRESS INDEX,L; esophageal pressure; "physiological set," N = 50).
RESULTS:
Sensitivity and specificity of PPLAT of greater than 30 cm H(2)O were 0.06 (95% CI, 0.002-0.30) and 1.0 (95% CI, 0.87-1.00). PPLAT of greater than 25 cm H(2)O and a STRESS INDEX of greater than 1.05 best identified morphological markers of injurious ventilation. Sensitivity and specificity of these values were 0.75 (95% CI, 0.35-0.97) and 0.75 (95% CI, 0.43-0.95) for PPLAT greater than 25 cm H(2)O versus 0.88 (95% CI, 0.47-1.00) and 0.50 (95% CI, 0.21-0.79) for STRESS INDEX greater than 1.05. Pplat,Rs did not correlate with PPLAT,L (R(2) = 0.0099); STRESS INDEX,RS and STRESS INDEX,L were correlated (R(2) = 0.762).
CONCLUSIONS:
The best threshold values for discriminating morphological indexes associated with injurious ventilation were Pplat,Rs greater than 25 cm H(2)O and STRESS INDEX,RS greater than 1.05. Although a substantial discrepancy between Pplat,Rs and PPLAT,L occurs, STRESS INDEX,RS reflects STRESS INDEX,L
COnsensus on Pediatric Pain in the Emergency Room: The COPPER project, issued by 17 Italian scientific societies
Inter-society consensus document on treatment and prevention of bronchiolitis in newborns and infants
Acute bronchiolitis is the leading cause of lower respiratory tract infection and hospitalization in children less than 1 year of age worldwide. It is usually a mild disease, but some children may develop severe symptoms, requiring hospital admission and ventilatory support in the ICU. Infants with pre-existing risk factors (prematurity, bronchopulmonary dysplasia, congenital heart diseases and immunodeficiency) may be predisposed to a severe form of the disease.
Clinical diagnosis of bronchiolitis is manly based on medical history and physical examination (rhinorrhea, cough, crackles, wheezing and signs of respiratory distress). Etiological diagnosis, with antigen or genome detection to identify viruses involved, may have a role in reducing hospital transmission of the infection.
Criteria for hospitalization include low oxygen saturation (<90-92%), moderate-to-severe respiratory distress, dehydration and presence of apnea. Children with pre-existing risk factors should be carefully assessed.
To date, there is no specific treatment for viral bronchiolitis, and the mainstay of therapy is supportive care. This consists of nasal suctioning and nebulized 3% hypertonic saline, assisted feeding and hydration, humidified O2 delivery. The possible role of any pharmacological approach is still debated, and till now there is no evidence to support the use of bronchodilators, corticosteroids, chest physiotherapy, antibiotics or antivirals. Nebulized adrenaline may be sometimes useful in the emergency room. Nebulized adrenaline can be useful in the hospital setting for treatment as needed. Lacking a specific etiological treatment, prophylaxis and prevention, especially in children at high risk of severe infection, have a fundamental role. Environmental preventive measures minimize viral transmission in hospital, in the outpatient setting and at home. Pharmacological prophylaxis with palivizumab for RSV bronchiolitis is indicated in specific categories of children at risk during the epidemic period.
Viral bronchiolitis, especially in the case of severe form, may correlate with an increased incidence of recurrent wheezing in pre-schooled children and with asthma at school age.
The aim of this document is to provide a multidisciplinary update on the current recommendations for the management and prevention of bronchiolitis, in order to share useful indications, identify gaps in knowledge and drive future research
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