23 research outputs found
Benthic foraminiferal assemblage turnover during intensification of the Northern Hemisphere glaciation in the Piacenzian Punta Piccola section (Southern Italy).
We present the results of a high-resolution analysis of the benthic foraminiferal assemblages at the Punta Piccola section (Stratotype for the Piacenzian Stage), which spans the gradual climate transition of the intensification of the Northern Hemisphere glaciation (3.6–2.6 Ma). This study highlighted a major benthic foraminiferal fauna turnover, which started at about 3.05 Ma with LO of Cibicidoides italicus, registered the gradual decline of Stilostomella spp. and culminated at about 2.7–2.75 Ma, when the dominant Siphonina reticulata was replaced by Cibicidoides pachyderma, costate Bulimine, spinose Bulimine, spinose Uvigerine and the Bolivina dilatata group. Four compositional zones, identified by constrained cluster analysis, are indicative of palaeoenvironmental changes and document the transition from stable and mainly oligotrophic conditions to unstable, mesotrophic and more fluctuating bottom conditions. Two intervals of deposition of sapropelite clusters coded as O and A, investigated using both benthic and planktic assemblages, reveal that anoxia conditions were never reached. Planktic foraminifera in the sapropelite layers of cluster O indicate deep mixing and benthic foraminifera suggest an increase in export productivity to the sea floor. By contrast, planktic foraminifera in the uppermost sapropelite layers of cluster A indicate oligotrophic surface water conditions, stratification and more eutrophic subsurface water conditions, without deep mixing. The benthic foraminifera indicate hypoxic and eutrophic bottom conditions, and evidence the first episode of down-slope transport, which testifies to a strengthening of runoff and stratification of superficial waters, but not true stagnation
Current Status of Polysaccharides-Based Drug Delivery Systems for Nervous Tissue Injuries Repair
Neurological disorders affecting both CNS and PNS still represent one of the most critical and challenging pathologies, therefore many researchers have been focusing on this field in recent decades. Spinal cord injury (SCI) and peripheral nerve injury (PNI) are severely disabling diseases leading to dramatic and, in most cases, irreversible sensory, motor, and autonomic impairments. The challenging pathophysiologic consequences involved in SCI and PNI are demanding the development of more effective therapeutic strategies since, as yet, a therapeutic strategy that can effectively lead to a complete recovery from such pathologies is not available. Drug delivery systems (DDSs) based on polysaccharides have been receiving more and more attention for a wide range of applications, due to their outstanding physical-chemical properties. This review aims at providing an overview of the most studied polysaccharides used for the development of DDSs intended for the repair and regeneration of a damaged nervous system, with particular attention to spinal cord and peripheral nerve injury treatments. In particular, DDSs based on chitosan and their association with alginate, dextran, agarose, cellulose, and gellan were thoroughly revised
Current Status of Polysaccharides-Based Drug Delivery Systems for Nervous Tissue Injuries Repair
Neurological disorders affecting both CNS and PNS still represent one of the most critical and challenging pathologies, therefore many researchers have been focusing on this field in recent decades. Spinal cord injury (SCI) and peripheral nerve injury (PNI) are severely disabling diseases leading to dramatic and, in most cases, irreversible sensory, motor, and autonomic impairments. The challenging pathophysiologic consequences involved in SCI and PNI are demanding the development of more effective therapeutic strategies since, as yet, a therapeutic strategy that can effectively lead to a complete recovery from such pathologies is not available. Drug delivery systems (DDSs) based on polysaccharides have been receiving more and more attention for a wide range of applications, due to their outstanding physical-chemical properties. This review aims at providing an overview of the most studied polysaccharides used for the development of DDSs intended for the repair and regeneration of a damaged nervous system, with particular attention to spinal cord and peripheral nerve injury treatments. In particular, DDSs based on chitosan and their association with alginate, dextran, agarose, cellulose, and gellan were thoroughly revised
Hydrolyzable and fermentable carbohydrates in North Italian pasture for horses
Digestive and metabolic disorders in the
horse were previously associated with
hydrolyzable and nonhydrolyzable but rapidly
fermentable components of nonstructural carbohydrates,
particularly fructans. Aim of the
study was to assess the contribution of the carbohydrate
fractions to the composition of pastures
in specific areas of Italy ordinarily
designed for horses feeding. Seventy-seven
samples from 11 pastures differing for floristic
composition were collected across two growing
seasons from April 18th 2008 to May 10th 2009 in
the foothills (380 m a.s.l.) of the province of
Parma (Italy). All samples were collected during
the vegetative growth phase. To identify
the bioclimatologic conditions of the growth,
the average fortnightly thermohygrometric
index (THI) was used. Slow fermentable carbohydrates
mean concentration (NDF: 510.6,
ADF: 274.7, ADL: 31.5 g/kg DM) reflected the
typical chemical composition of high-quality
grass and grass-legume mixtures. Among the
nonstructual carbohydrates (NSC: 199.9 g/kg
DM), hydrlolyzable carbohydrates content
accounted for about the 18%. Nonhydrolyzable
but rapidly fermentable carbohydrates were
constituted for about the 23% by fructans (37.7
g/kg DM, range 15.5 to 138.2). The environmental
conditions significantly affected the
carbohydrate concentration in forages. Among
NSC, fructans concentration in pastures was
affected by bioclimatologic conditions
(P<0.05). The floristic composition influenced
the fructans content at a lesser extent. These
results indicate a high variability of fructans
concentration and reflect what previously
observed in other areas. In any case the high
levels observed for fructans in some geographic
areas are not been achieved. Further interdisciplinary
studies in this area between veterinarians
and forage researchers are clearly
warranted
Hydrolyzable and fermentable carbohydrates in North Italian pastures for horses
Digestive and metabolic disorders in the horse were previously associated with hydrolyzable and nonhydrolyzable but rapidly fermentable components of nonstructural carbohydrates, particularly fructans. Aim of the study was to assess the contribution of the carbohydrate fractions to the composition of pastures in specific areas of Italy ordinarily designed for horses feeding. Seventy-seven samples from 11 pastures differing for floristic composition were collected across two growing seasons from April 18th 2008 to May 10th 2009 in the foothills (380 m a.s.l.) of the province of Parma (Italy). All samples were collected during the vegetative growth phase. To identify the bioclimatologic conditions of the growth, the average fortnightly thermohygrometric index (THI) was used. Slow fermentable carbohydrates mean concentration (NDF: 510.6, ADF: 274.7, ADL: 31.5 g/kg DM) reflected the typical chemical composition of high-quality grass and grass-legume mixtures. Among the nonstructual carbohydrates (NSC 199.9 g/kg DM), hydrlolyzable carbohydrates content accounted for about the 18%. Nonhydrolyzable but rapidly fermentable carbohydrates were constituted for about the 23% by fructans (37.7 g/kg DM, range 15.5 to 138.2). The environmental conditions significantly affected the carbohydrate concentration in forages. Between NSC, fructans concentration in pastures was affected by bioclimatologic conditions (P<0.05). The floristic composition influenced the fructans content at a lesser extent. These results indicate a high variability of fructans concentration and reflect what previously observed in other areas. In any case the high levels observed for fructans in some geographic areas are not been achieved. Further interdisciplinary studies in this area between veterinarians and forage researchers is clearly warranted.</p
Development of alginate-spermidine micro/nanogels as potential antioxidant and anti-inflammatory tool in peripheral nerve injuries. Formulation studies and physico-chemical characterization
The development of a successful strategy to ensure a full recovery in patients affected by peripheral nerve injury (PNI), one of the most debilitating pathologies, is, still today, a major clinical challenge. Herein, spermidine (SP), an endogenous polyamine, is employed with a dual role: as cross-linking agent for alginate (ALG) and as antioxidant and anti-inflammatory compound. In particular, micro/nanogels based on the ionic interaction between ALG and SP were obtained via ionotropic gelation. Different ALG concentrations and viscosity grades and different SP concentrations were considered. The influence of such variables on micro/nanogels size was investigated by means of a Design of Experiments (DoE) approach (full factorial design). The formation of micro/ nanogels was proved by Scanning Electron Microscope (SEM) analysis and by rheological and profilometry measurements. Fourier Transform Infrared (FTIR) measurements performed on nanogels of optimal composition confirmed SP-ALG interaction. The addition of trehalose as cryoprotectant agent to nanogel dispersion was considered in view of the employment of freeze-drying process to obtain a stable product. Moreover, in vitro studies on Schwann cells proved the ability of SP of expressing antioxidant and antiinflammatory properties, even if involved in the formation of nanogels
Peep titration based on the open lung approach during one lung ventilation in thoracic surgery: a physiological study
Abstract
Background
During thoracic surgery in lateral decubitus, one lung ventilation (OLV) may impair respiratory mechanics and gas exchange. We tested a strategy based on an open lung approach (OLA) consisting in lung recruitment immediately followed by a decremental positive-end expiratory pressure (PEEP) titration to the best respiratory system compliance (CRS) and separately quantified the elastic properties of the lung and the chest wall. Our hypothesis was that this approach would improve gas exchange. Further, we were interested in documenting the impact of the OLA on partitioned respiratory system mechanics.
Methods
In thirteen patients undergoing upper left lobectomy we studied lung and chest wall mechanics, transpulmonary pressure (PL), respiratory system and transpulmonary driving pressure (ΔPRS and ΔPL), gas exchange and hemodynamics at two time-points (a) during OLV at zero end-expiratory pressure (OLVpre-OLA) and (b) after the application of the open-lung strategy (OLVpost-OLA).
Results
The external PEEP selected through the OLA was 6 ± 0.8 cmH2O. As compared to OLVpre-OLA, the PaO2/FiO2 ratio went from 205 ± 73 to 313 ± 86 (p = .05) and CL increased from 56 ± 18 ml/cmH2O to 71 ± 12 ml/cmH2O (p = .0013), without changes in CCW.
Both ΔPRS and ΔPL decreased from 9.2 ± 0.4 cmH2O to 6.8 ± 0.6 cmH2O and from 8.1 ± 0.5 cmH2O to 5.7 ± 0.5 cmH2O, (p = .001 and p = .015 vs OLVpre-OLA), respectively. Hemodynamic parameters remained stable throughout the study period.
Conclusions
In our patients, the OLA strategy performed during OLV improved oxygenation and increased CL and had no clinically significant hemodynamic effects. Although our study was not specifically designed to study ΔPRS and ΔPL, we observed a parallel reduction of both after the OLA.
Trial registration
TRN:
ClinicalTrials.gov
,
NCT03435523
, retrospectively registered, Feb 14 2018