89 research outputs found
Quantitative evaluation of iPP nucleation in the presence of carbon fibres: Induction time approach
Crystallization and nucleation behavior in model composites based on iPP and differently sized carbon fibres have been analyzed in this work. The investigations were performed in the isothermal regime (120?127 ?C) using PLM and DSC. The results were analyzed by applying the Avrami and Muchova-Lednicky methods. It was shown that the carbon fibre surface acts as a nucleating agent during the crystallization of the iPP matrix. The highest effect was obtained with the fibres of PP-compatible size (C-T) related to unsized carbon fibres (C-U). The induction time, ti, and half-time of crystallization decreased with increasing carbon fibre content. The energy effect on the thickness of the critical nucleus decreased in the presence of C-fibres, a fact confirmed by a decrease in the nucleation parameter Q and the difference energy parameter ?? (Q decreased from ? 4.96 for iPP to ?21.32 for C/iPP model composites, and ?? decreased from 6.14x10-7 J/cm2 for iPP to 1.63x10-7 J/cm2 for model composites). The results of the model composites and their comparison with published data confirmed that the Muchova-Lednicky method could be successfully applied for the quantitative evaluation of the nucleation parameters not only in the temperature range previously suggested (130?138?C), but also at lower crystallization temperatures (Tc=121?127?C)
Microporous Hyper-Crosslinked Polystyrenes and Nanocomposites with High Adsorption Properties: A Review
Hyper-crosslinked (HCL) polystyrenes show outstanding properties, such as high specific
surface area and adsorption capability. Several researches have been recently focused on tailoring
their performance for specific applications, such as gas adsorption and separation, energy storage,
air and water purification processes, and catalysis. In this review, main strategies for the realization
of HCL polystyrene-based materials with advanced properties are reported, including a summary of
the synthetic routes that are adopted for their realization and the chemical modification approaches
that are used to impart them specific functionalities. Moreover, the most up to date results on the
synthesis of HCL polystyrene-based nanocomposites that are realized by embedding these high
surface area polymers with metal, metal oxide, and carbon-based nanofillers are discussed in detail,
underlining the high potential applicability of these systems in different fields
ANTI-OBESITY EFFECT OF CANNABIS SATIVA SEED FLOUR FROM KHLALFA OF TAOUNATE REGION (NORTHERN OF MOROCCO) IN HIGH CALORIC DIET-INDUCED OBESE MICE
Objective: The objective of the present study was to evaluate the anti-obesity activity of Cannabis sativa seed Flour (CSSF) on obese mice.
Methods: The experiment process was carried out in 8 weeks. In this time, three groups of animals were adopted: High caloric diet control group (HCD), group treated with 100 mg/kg of CSSF, group treated with 200 mg/kg of CSSF, and normal diet control group (ND). Then, the histopathological and biochemical parameters analysis has been realized at the end of the experiment.
Results: As a result, body weight gain, epididymal, and perirenal adipose tissue decreased in the CSSF (Cannabis sativa seed Flour) group in both doses (100 mg/kg and 200 mg/kg) compared to the HCD. CSSF lowered serum glucose level elevated by HCD. For lipid profiles, total cholesterol (TC), HDL-cholesterol, LDL-cholesterol, and triglycerides (TG) significantly decreased in the CSSF group. The histopathological results of this study showed a regenerative effect of CSSF on the kidney and liver tissues.
Conclusion: It is concluded from the present study that CSSF can be used as a natural anti-obesity agent
Marketing and legal status of phytomedicines and food supplements in Morocco
Publisher Copyright: © 2020 Walter de Gruyter GmbH, Berlin/Boston.The Phytomedicine (PM) and Food supplements (FS) Market is considerably growing in Morocco a review of state is necessarily to structure and improve it. Information was collected directly from the pharmacist through a questionnaire-based survey who was conducted in 284 pharmacies in the region of Fez-Meknes in Morocco. Data were analyzed and classified using relative frequency of citations (RFC). More than 98% of the pharmacies commercialized the PM and FS, 80% of the pharmacists deny the existence of a real area dedicated to them, the majority (94%) of them prefer phytomedicine rather than classic drugs. This study reported about 64 products as the most used by the population of the region of Fez-Meknes among them 48 FS (75%) and 16 PM (25%) and the most marketed products are used for Transit Disorders (28.34%), then Anxiety (22.17%) and ENT Disease (20.18%). Despite the fact that Morocco is a country where people use medicinal plants daily, the commercialization of the PM and FS is still unstructured. Due to legal problem the PM Sold in the market are mainly exported. To assure development and also valorization of this sector the regulation of this market is highly required.Peer reviewe
Topical treatment of experimental cutaneous leishmaniasis in golden hamster (Mesocricetus auratus) with formulations containing pentamidine
Current treatment of cutaneous leishmaniasis (CL) relies mainly on pentavalent antimonials salts and second-line drugs include pentamidine and amphotericin B, but these therapies have side effects and require parenteral administration. The aim of this work was to evaluate the topical formulations containing pentamidine isethionate (PI) in the experimental treatment of cutaneous leishmaniasis (CL). Golden hamsters (Mesocricetus auratus) were infected in the nose with Leishmania (Leishmania) amazonensis. Six treatment groups received different topical treatments of anhydrous or hydrating emulsions, for a maximum of 10 days, with an application of 50 mg day(-1). After treatment tissue samples of lesions were evaluated by histology, transmission electron microscopy and biopsy cultivation. Compared with untreated group, topical treatment with hydrating emulsion with 10% PI and usnic acid (ACE5AU) showed significantly decrease in volume lesion (P= 0.028) on 20th day after the end of the treatment with reduction of 27.37%. Topical treatment with anhydrous emulsion with 10% PI and usnic acid (ACPU) reduces parasite burden in Golden hamsters. This study demonstrated the potential of topical treatment to reduce the number of parasites that could be combined with others drugs and to have a faster and more effective treatment of cutaneous leishmaniasis.Peer reviewe
Preparation and properties of novel binary and ternary highly amorphous poly(vinyl alcohol)-based composites with hybrid nanofillers
Smart protective coatings and devices are currently of great interest. In particular, they can absorb or reflect harmful waves of electromagnetic interference (EMI). In this work, novel binary and ternary composites with highly amorphous poly(vinyl alcohol) (HAVOH) as a matrix and single-walled carbon nanotubes (SWCNTs) and MXenes as nanofillers were prepared. HAVOH is a recently patented kind of poly(vinyl alcohol) (PVOH) that was modified with diol monomers. MXenes are a new type of inorganic two-dimensional (2D) nanoparticle consisting of carbides, nitrides and carbonitrides. Three series of composites, HAVOH/SWCNTs, HAVOH/MXenes and HAVOH/SWCNTs/MXenes, were prepared using the solvent casting method. Samples were tested with various methods to study their structure, electrical properties, thermal behavior and EMI-shielding properties. HAVOH/3.0 wt.% SWCNTs/3.0 wt.% MXene specimens revealed a shielding effectiveness of 55 dB, which is 122 times better than that of the neat matrix. These results are promising for the fabrication of films with protective effects against EMI.Drexel University; Horizon 2020 Framework Programme, H2020; H2020 Marie Skłodowska-Curie Actions, MSCA, (777810, APVV 19–0465, VEGA 02/0006/22); European Cooperation in Science and Technology, COST, (CA19118)Authors greatly appreciate Prof. Yury Gogotsi and Dr. Christopher Shuck (Drexel University, USA) for providing the MXene paste
Synthesis and characterization of nanocomposites based on PANI and carbon nanostructures prepared by electropolymerization
Nanocomposites based on polyaniline (PANI) and carbon nanostructures (CNSs) (graphene (G) and multiwall carbon nanotubes (MWCNTs)) were prepared by in situ electrochemical polymerization. CNSs were inserted into the PANI matrix by dispersing them into the electrolyte before the electropolymerization. Electrochemical characterization by means of cyclic voltammetry and steady state polarization were performed in order to determine conditions for electro- polymerization. Electro-polymerization of the PANI based nanocomposites was carried out at 0.75 V vs. saturated calomel electrode (SCE) for 40 and 60 minutes. The morphology and structural characteristics of the obtained nanocomposites were studied by scanning electron microscopy (SEM) and Raman spectroscopy, while thermal stability was determined using thermal gravimetric analysis (TGA). According to the morphological and structural study, fibrous and porous structure of PANI based nanocomposites was detected well embedding both G and MWCNTs. Also, strong interaction between quinoidal structure of PANI with carbon nanostructures via π–π stacking was detected by Raman spectroscopy. TGA showed the increased thermal stability of composites reinforced with CNSs, especially those reinforced with graphene
Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign
Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come
Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study
: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI
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