650 research outputs found
Float-Ram: A Sustainable Machine for Buildings Made by Compressed Earth Blocks
This article describes a sequence of research, design, prototyping and utilization of a new manually operated press, which has the purpose of facilitating a construction technology that uses compressed earth blocks, CEB. Buildings and houses made of CEB have better quality than traditional in poor region. They are also economical, robust, aesthetically pleasing, and sustainable from an environmental point of view. The research is addressed to some targets of the SDG 11, Sustainable Cities and Communities: (i) âensure access for all to adequate, safe and affordable housing and basic services and upgrade slumsâ; (ii) âsupport least developed countries, including through financial and technical assistance, in building sustainable and resilient buildings utilizing local materialsâ. The paper presents the project path, the results and finally the impact in a specific context, the rural areas in Tanzania
Decentralization and fuel subsidies
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordThis paper explores the role of decentralization in explaining variation in fuel subsidies across countries. Using panel data over the period 1998-2008 and for 108 countries, it emerges that the effect of âdecentralizationâ (taken to be an increase in the number of government levels) broadly decreases both diesel and gasoline subsidies, with this effect being more pronounced when the level of political accountability is low. For developing countries, for which political accountability is low, decentralization decreases gasoline and diesel subsidies by at least 6.98% and 12.99%, respectively. For developed countries, for which political accountability is high, decentralization does not have any impact on both gasoline and diesel. What this evidence points to is that in developing economies, where voters are poorly informed and accountability is low, decentralization appears to be associated with lower fuel subsidies.Leonzio Rizzo thankfully acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (ECO2012-37873) and also from FIR 2016
PRUDENT USE OF FLUOROQUINOLONES IN AVIAN SPECIES: PHARMACOKINETICS OF FLUMEQUINE AND ENROFLOXACIN FOR PK/PD MODELLING IN TURKEY.
The importance of prudent and rational use of antimicrobial is important, not only to safeguard the efficacy of these drugs in humans and veterinary medicine but, even more so, to prevent the emergence and spread of undesirable resistance phenotypes in zoonotic pathogens as well as in commensal bacteria that can be transmitted between animals and humans.
Even more importance and attention is now given to the prudent use of medically important antimicrobial drugs, referring to those drugs for human therapeutic use.
The fluoroquinolones belong to this category. These are very potent antimicrobials and active against a wide range of pathogenic organisms and are well distributed in the body after administration. This class of antimicrobials has a therapeutic effect on most infections in different organs or tissues. Although it is rare that fluoroquinolones are the only available agent for treatment of a specific infectious disease, fluoroquinolones are important alternative medicinal products for a veterinarian to have as option for treatment. Fluoroquinolones have a unique mechanism of action not related to conventional antimicrobials, and therefore their efficacy should be retained as long as possible.
The avian production increased enormously in the last 50 years and the European Union (EU) is one of the world's top producers in poultry meat and a net exporter of poultry products. In this production, turkeys that is considered a \u201cminor species\u201d, but it is important in the livestock production of Italy. Scarce data exist about the usage of antimicrobial drugs in turkey and even less is known about their efficacy. As the limited number of medicinal products authorized in this species, antimicrobial therapy is frequently carried out with the few products authorized or with drugs \u201cextra-label\u201d used with the consequence of increases of selective pressure and also with the possibility of cross-resistance within the same pharmacological group of compounds.
The studies reported in this thesis aimed to revise the use of fluoroquinolones in turkey to maintain the efficacy and reduce the spread of resistance against E.Coli, the most common zoonotic avian pathogen. Pharmacokinetic(PK)/pharmacodynamics (PD) models are the best tool in order to select optimal dosage regimen. To confirm dosages used at farms and allow the integration of PK/PD data, the plasma concentrations in blood from healthy animals collected during treatment with flumequine and enrofloxacin, were determined.
The first step was to optimize and validate a fast, simple, sensitive, and specific liquid chromatography-mass spectrometry (LC-MS)/MS/MS method suitable for the detection of a wide range of concentrations of fluoroquinolones as those occurring in pharmacokinetic and residue depletion studies from several matrices. The first trial presents a sensitive and reliable confirmatory method for the extraction, identification, quantification of five fluoroquinolones . For the extraction and matrix clean-up of fluoroquinolones residues from all biological matrices, the Quick Easy Cheap Effective Rugged Safe (QuEChERS) methodology was adopted; only for plasma samples acetonitrile was used. The analyses were performed by (LC-MS. LC separation was performed on a C18 Kinetex column (100x2.1 mm, 2.6 \ub5m, Phenomenex, CA, USA) with gradient elution using ammonium acetate solution (10 mM, pH 2.5) and methanol containing 0.1% formic acid. Mass spectrometric identification was done using an LTQ XL ion trap (Thermo Fisher Scientific, CA, USA), with a heated electrospray ionization probe, in positive ion mode. The method was validated according to the European Legislation (decision 2002/657/EC) and EMA guideline (EMA/CVMP/VICH/463202/2009); selectivity, linearity response, trueness (in terms of recovery), precision (within-day repeatability and within-laboratory reproducibility), limit of detection, limit of quantification, decision limits, detection capability, absolute recovery and robustness were evaluated using turkey blank matrices. All data were within the required limits established for confirmatory methods except for flumequine which presented a recovery value slightly higher than 110% in muscle and intestinal content. For all fluoroquinolones, all the extraction rates were greater than 70% and limits of quantification ranged from 1.2 \ub5g/kg to 118.8 \ub5g/kg. This method was suitable for the identification and quantification of fluoroquinolones in plasma samples of turkeys treated for the purpose of second and third trials.
In the second trial, the PK behavior of flumequine administered to 32 healthy turkeys as an oral bolus via gavage or as 5 days of 10-hours pulsed administration in drinking water were compared, using the EU authorized dose of 15 mg/kg and the double dose of 30 mg/kg. The MIC of 235 Escherichia coli field strains isolated from poultry were determined for PD to develop a PK/PD model. Blood samples were collected at established times over 24 h, and the obtained plasma was analyzed using the LC-MS/MS/MS method previously described. A monocompartmental model and a noncompartmental model were applied to the data to obtain the PK results. The maximum concentration (Cmax)/MIC50 and the plasma concentration-time curve from 0 to 24 hours (AUC0\u201324)/MIC50 ratios were, respectively, 0.67 \ub1 0.09 and 4.76 \ub1 0.48 and 1.18 \ub1 0.35 and 7.05 \ub1 2.40 for the 15 and 30 mg/kg bolus doses, respectively. After 10-hours pulsed administration of 15 mg/kg, values of Cmax/MIC50, 0.19 \ub1 0.02 on day 1 and 0.30 \ub1 0.08 on day 5 of therapy were obtained, the AUC/MIC50 ratios were 2.09 \ub1 0.29 and 3.22 \ub1 0.93 on d 1 and 5, respectively. Higher values were obtained with the doubled dose of 30 mg/kg: the Cmax/MIC50 ratios were 0.49 \ub1 0.11 on day 1 and 0.69 \ub1 0.18 on day 5; the AUC/MIC50 ratios were 5.15 \ub1 1.15 and 6.57 \ub1 1.92 on d 1 and 5, respectively. For both types of administration and both dosages, the Cmax/MIC50 and the AUC/MIC50 ratios achieved were significantly lower than the fluoroquinolones breakpoints usually considered for efficacy.
The last trial involving 50 healthy turkeys, was conducted to evaluate the efficacy of enrofloxacin. As in the previous study, the effectiveness of different treatment schemes against E. coli was evaluated by a PK/PD approach, correlating the PK results with the MIC determined for 235 E. coli strains.
In this study, 3 different oral treatments (a single oral gavage, 5 days of 10-hours pulsed water medication, and 5 days of 24-hours continuous water medication) and single parenteral (subcutaneous; SC) treatment using 2 different doses of enrofloxacin (i.e., the EU authorized dose, 10 mg/kg, and double the EU recommended dose, 20 mg/kg) were evaluated. Blood samples were collected at established times over 24 h. Plasma was analyzed using a LC-MS/MS/MS that was validated in house. A monocompartmental and a noncompartmental model were applied to the data to obtain the PK results. After gavage administration, the mean maximum concentration Cmax/MIC50 and area under the curve AUC0\u201324/MIC50 ratios were, respectively, 3.07 \ub1 0.62 and 7.01 \ub1 1.03 and 25.48\ub1 3.04 and 57.2 \ub1 3.73 for the 10 and 20 mg/kg doses, respectively. After SC administration of 10 mg/kg, Cmax/MIC50 and AUC0\u201324/MIC50 ratios were 3.45 \ub1 0.75 and 33.96 \ub1 7.46, respectively. After the administration of 10-h pulsed or 24-h continuous medicated water at 20 mg/kg, lower values of Cmax/MIC50 (10-h pulsed: 3.45 \ub1 0.7; 24-h continuous: 3.05 \ub10.48) and AUC0\u201324/MIC50 (10-h pulsed: 42.42 \ub1 6.17; 24-h continuous: 53.32 \ub1 5.55) were obtained. Based on these results, the European Union-recommended dosage of 10 mg/kg seems ineffective to achieve adequate drug plasma concentrations and even the 20 mg/kg by 10 h pulsed or continuous medicated water administration did not reach completely efficacious concentrations in plasma against colibacillosis. Although the results obtained were not completely encouraging, the medicated water should preferably be provided continuously. To conclude about the efficacy of enrofloxacin treatment against colibacillosis, target tissue concentration should be extensively considered
Venous pulse wave velocity
Central venous pressure and volume status are relevant parameters for the characterization of the patient's haemodynamic condition and for the management of fluid therapy however, their invasive assessment is affected by various risks and complications while non-invasive approaches provide only imprecise and subjective indications. Aim of the present study is to explore the possibility to assess changes in venous pressure from changes in the venous pulse wave velocity (vPWV). In 9 healthy subjects, pressure pulses were generated artificially in the veins by a PC-driven rapid inflation of a pneumatic cuff (300mmHg in <1sec) placed around a foot. Passage of the pulse wave in the superficial femoral vein distally to the inguinal ligament was detected by Doppler flowmeter and the latency from the pressure stimulus was measured. The vPWV was then calculated as the ratio between traveling distance and latency. Changes in leg venous pressure were obtained by raising the trunk of the subject from the initial supine position by 30 and 60 deg. In each position 15 pressure pulses were delivered every 30 s, at the end-expiratory phase for vPWV assessment. Venous pressure in the leg was non-invasively estimated by assessing the point of collapse of the jugular or axillary vein. The vPWV increased from 1.64±0.06(supine) to 2.13±0.26 (60 deg) (Studentâs t- test, p<.01) and exhibited a very strong correlation with leg venous pressure (overall r=0.76). Differences in vPWV among the three positions were statistically significant also on an individual basis in 8/9 subjects (ANOVA + Tukey's HSD post-hoc, p<.01). These preliminary results show that vPWV may be easily assessed in healthy subjects and may constitute a good non-invasive indicator of venous pressurechanges
A Portable Device for the Measurement of Venous Pulse Wave Velocity
Pulse wave velocity in veins (vPWV) has recently been reconsidered as a potential index of vascular filling, which may be valuable in the clinic for fluid therapy. The measurement requires that an exogenous pressure pulse is generated in the venous blood stream by external pneumatic compression. To obtain optimal measure repeatability, the compression is delivered synchronously with the heart and respiratory activity. We present a portable prototype for the assessment of vPWV based on the PC board Raspberry Pi and equipped with an A/D board. It acquires respiratory and ECG signals, and the Doppler shift from the ultrasound monitoring of blood velocity from the relevant vein, drives the pneumatic cuff inflation, and returns multiple measurements of vPWV. The device was tested on four healthy volunteers (2 males, 2 females, age 33 & PLUSMN;13 years), subjected to the passive leg raising (PLR) manoeuvre simulating a transient increase in blood volume. Measurement of vPWV in the basilic vein exhibited a low coefficient of variation (3.6 & PLUSMN;1.1%), a significant increase during PLR in all subjects, which is consistent with previous findings. This device allows for carrying out investigations in hospital wards on different patient populations as necessary to assess the actual clinical potential of vPWV
Surgical site infections in treatment of musculoskeletal tumors: experience from a single oncologic orthopedic institution
Objective: Limb-sparing surgery is the mainstay treatment for musculoskeletal tumors thanks to advances in surgical techniques, imaging modalities and multimodal therapies. As patients survive longer, plastic reconstructive procedures and revision surgery are increasingly required after tumor excision. Infection rate is reported to be up to 20% after prosthetic replacement and 30-44% after pelvic resection. The purpose of this study was to investigate the incidence of surgical site infections (SSIs), identifying the causative microrganisms related to specific surgical procedures and significant risk factors for SSIs. Methods: We retrospectively reviewed 723 interventions performed between 2009 and 2015 for oncological conditions. Non neoplastic lesions, aseptic wound complications, non-skeletally mature patients were excluded. Standardised antibiotic prophylaxis was used for different surgical procedures and maintained until removal of surgical drains. Results: Without considering tumor types and surgical sites, the overall infection rate was 8.7% (63/724). Infection occurred in prosthetic reconstruction with an incidence rate of 7.8%, whereas almost half of patients having undergone pelvic surgery got infected and about 20% of patients with spinal surgery and amputations were infected. Pelvic location, malignancy and radiotherapy were related to a major risk of SSI. The causative pathogens were detected in all examined cases. The most frequent pathogens detected by culture included Staphylococcus aureus (27 cases, 47.4%) and S. epidermidis (10 cases, 17.5%). Among the S. aureus cases, 10/27 cases (37%) were methicillin-resistant S. aureus (MRSA). Sixty-three out of 130 microbial isolations (47.7%) were nosocomial ALERT organisms. Conclusion: Oncologic orthopedic surgery is burdened by frequent and challenging SSIs because of extensive soft tissues dissection, long operative times and poor skin conditions. Patients are immunosuppressed and often have concomitant comorbidities predisposing to SSIs. Monitoring of local bacterial aetiology of SSIs could help orthopedic oncologic specialized centres in achieving the optimisation of antibiotic prophylactic regimens
Venous Pulse Wave Velocity variation in response to a simulated fluid challenge in healthy subjects
Purpose: The evaluation of a mini or simulated fluid challenge is still a complex and open issue in the clinical setting and it is of paramount significance for the fluid therapy optimization. We here investigated the capacity of a new hemodynamic parameter, the venous Pulse Wave Velocity (vPWV), to detect the effect of passive leg raising (PLR).
Materials and methods: In 15 healthy volunteers (7 M, 8 F, age 26 ± 3) venous pressure pulses were elicited by pneumatic compressions of the left hand and proximally detected by ultrasound for calculation of the vPWV. We also non-invasively measured the basilic vein (BV) cross-sectional perimeter, and peripheral venous pressure (PVP). The PLR manoeuvre was performed twice to evaluate reliability of the assessment.
Results: The PLR had an overall statistically significant effect on the entire set of variables (MANOVA, p < 0.05): vPWV increased from 2.11 ± 0.46 to 2.30 ± 0.47 m/s (p = 0.01; average increase: 10%). This effect was transient and dropped below 5% after about 3 min. A significant increase was also exhibited by BV size and PVP. In consecutive measurements vPWV showed little intra-subject variability (CoV = 8%) and good reliability (ICC = 0.87). Finally, the vPWV responses to the two PLRs exhibited good agreement (paired T-test: p = 0.96), and moderate reliability (ICC = 0.57).
Conclusion: These results demonstrated that vPWV can be non-invasively, objectively and reliably measured in healthy subjects and that it is adequate to detect small pressure/volume variations, as induced by PLR-from-supine. These characteristics make it suitable for clinical applications
A methodology for the development of a Hinged Ankle-Foot Orthosis compatible with natural joint kinematics
This work presents a new concept to design Hinged Ankle-Foot Orthoses (HAFOs), based on the definition of a special mechanical articulation able to mimic the physiological behavior of the human ankle joint. Current commercial braces typically do not take into account the natural variability of the ankle joint axis. As the hinge location as well as the rotation axis variability are both relevant for the overall function of the device, and strongly depend on the subject-specific characteristics, a methodology for the development of a HAFO with a floating axis of rotation, based on the in-vivo kinematic analysis of the ankle joint, is here proposed. The kinematic analysis was performed by calculation of the instantaneous and mean helical axes over the collected stereo-photogrammetric data of joint motion. This procedure was tested on a healthy subject, leading to the design and fabrication of a first customized prototype of the orthosis. The performance of this HAFO was experimentally verified by motion analysis. All relevant results are presented, and further possible future improvements of the procedure are discussed
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