23 research outputs found

    Introducing Semi-Interpenetrating Networks of Chitosan and Ammonium-Quaternary Polymers for the Effective Removal of Waterborne Pathogens from Wastewaters

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    The present work aims to study the influence of ammonium-quaternary monomers and chitosan, obtained from different sources, upon the effect of semi-interpenetrating polymer network (semi-IPN) hydrogels upon the removal of waterborne pathogens and bacteria from wastewater. To this end, the study was focused on using vinyl benzyl trimethylammonium chloride (VBTAC), a water-soluble monomer with known antibacterial properties, and mineral-enriched chitosan extracted from shrimp shells, to prepare the semi-IPNs. By using chitosan, which still contains the native minerals (mainly calcium carbonate), the study intends to justify that the stability and efficiency of the semi-IPN bactericidal devices can be modified and better improved. The new semi-IPNs were characterized for composition, thermal stability and morphology using well-known methods. Swelling degree (SD%) and the bactericidal effect assessed using molecular methods revealed that hydrogels made of chitosan derived from shrimp shell demonstrated the most competitive and promising potential for wastewater (WW) treatment.Introducing Semi-Interpenetrating Networks of Chitosan and Ammonium-Quaternary Polymers for the Effective Removal of Waterborne Pathogens from WastewaterspublishedVersio

    Mechanical Performances of Lightweight Sandwich Structures Produced by Material Extrusion-Based Additive Manufacturing

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    Material Extrusion-Based Additive Manufacturing Process (ME-AMP) via Fused Filament Fabrication (FFF) offers a higher geometric flexibility than conventional technologies to fabricate thermoplastic lightweight sandwich structures. This study used polylactic acid/polyhydroxyalkanoate (PLA/PHA) biodegradable material and a 3D printer to manufacture lightweight sandwich structures with honeycomb, diamond-celled and corrugated core shapes as a single part. In this paper, compression, three-point bending and tensile tests were performed to evaluate the performance of lightweight sandwich structures with different core topologies. In addition, the main failure modes of the sandwich structures subjected to mechanical tests were evaluated. The main failure modes that were observed from mechanical tests of the sandwich structure were the following: face yielding, face wrinkling, core/skin debonding. Elasto-plastic finite element analysis allowed predicting the global behavior of the structure and stressing distribution in the elements of lightweight sandwich structures. The comparison between the results of bending experiments and finite element analyses indicated acceptable similarity in terms of failure behavior and force reactions. Finally, the three honeycomb, diamond-celled and corrugated core typologies were used in the leading edge of the wing and were impact tested and the results created favorable premises for using such structures on aircraft models and helicopter blade structures

    Evaluating Romanian Eco-Innovation Performances in European Context

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    The field of eco-innovation is included in the area of sustainable development being closely related with ecological planning. In this context, this paper aims to evaluate Romanian eco-innovation performance during the period 2003–2013 by constructing a composite index and to also identify the main eco-innovation poles at the European level using multidimensional analysis techniques based on the eco-innovation specific indicators for the year 2013. This approach used the methodology of constructing composite indices proposed by Organization for Economic Co-operation and Development (OECD) in 2008. The index measured the eco-innovation dimensions in 27 countries over the period 2003–2013. The empirical analysis revealed the conclusion that in Romania, the eco-innovation level is low compared with other countries, thus Romania cannot emphasize its eco-innovation performance. The empirical results of the study highlighted that eco-innovation represents a phenomenon leading to significant progress in achieving the objective of sustainable development in Romania, and also at the European level, only if the importance of this area is awarded and eco-innovation measures are enforced through adequate policies, leading to economic growth

    Heterocycles 52: The Drug-Likeness Analysis of Anti-Inflammatory Thiazolo[3,2-b][1,2,4]triazole and Imidazo[2,1-b][1,3,4]thiadiazole Derivatives

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    Lipophilicity, a significant physicochemical parameter of bioactive molecules, along with absorption, distribution, metabolism, excretion parameters and toxicity risk, was investigated for 32 thiazolo[3,2-b][1,2,4]triazole and imidazo[2,1-b][1,3,4]thiadiazole derivatives with anti-inflammatory potential. The experimental lipophilicity study was carried out by reversed-phase thin-layer chromatography in a binary isopropanol-water mobile phase, and the obtained results were compared with the theoretical lipophilicity parameters estimated by various computational methods. Strong correlations were found between the experimental retention factors and calculated partition coefficients. A modified Petra/Osiris/Molinspiration analysis was performed on the previously synthesized compounds, using SwissADME, Osiris and Molinspiration web tools. The predicted in silico parameters highlighted the most promising compounds as potential drug candidates. The compounds showed good gastrointestinal absorption, moderate activity according to the bioactivity score (values situated between −1.25 and −0.06), and a safe toxicity profile. The results obtained in this study will contribute to lipophilicity studies and other future studies focused on modulating new drug candidates starting from thiazolo[3,2-b][1,2,4]triazole and imidazo[2,1-b][1,3,4]thiadiazole derivatives, which are important heterocycles in medicinal chemistry

    Cervicomedullary junction intramedullary hemangioblastoma: A 10 years report of cases and review of literature

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    Hemangioblastoma is a rare, benign, highly vascularized tumour, that usually presents a muriform nodule. The most frequent localization is the posterior cranial fossa. The frequency of this spinal lesion is very low, representing less than 5% of spinal cord tumours. The presentation of hemangioblastoma can widely vary, from a solid tumour to a lesion with a cystic component. We present the case of a 43 years old patient, admitted to our clinic for left hemiparesis, swallowing disorders, and dysphonia. An MRI is performed and it showed a cervicomedullary junction tumour with a solid nodule and an anterior cystic cavity pushing towards the 4th ventricle. The patient underwent surgery for the total removal of the tumour. Post-operative CT confirmed the total ablation of the tumour. The patient is discharged with improved symptomatology. In the last 10 years, in our clinic were admitted 23 cases of hemangioblastoma, 14 males (61% of the patients) and 9 females (39%) with an age at presentation varied from 14 to 78 years (mean 48,2 years). Only 3 patients (13%) out of the 23 had associated von Hippel–Lindau syndrome, with hemangioblastomas also present in other locations. The most common location was the posterior fossa, in 13 cases (56,6%). Headache (69,5%), ataxia (56%) and balance disorders (52%) were the most common symptoms accused by patients. The follow-up varied from 6 to 84 months (mean 20 months). Only one patient died during hospitalization and one tumour recurrence was noted. Most patients improved or remained clinically stable postoperatively

    Multimodal treatment of glomus jugular tumours: Case series and literature review

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    Glomus jugulare tumours are extremely rare, slow-growing, hypervascular tumours that arise within the jugular foramen of the temporal bone and frequently involve the lower cranial nerves. We performed a retrospective study for patients treated between January 2005 and December 2019, reviewing clinical and radiological data for 91 cases of glomus jugulare tumours. Data were available for 91 patients presenting with 96 tumours. Surgery was 1st intention of treatment for 13 cases, the endovascular approach was 1st intention for 6 cases and GKRS was primarily performed in 72 cases. Combined treatment options were used in 19 cases. The median age at the time of treatment was of 57 years. The tumour volume varied between 0.5 and 73.4 cm3 with a median value of 8.3 cm3. For the cases treated with GKRS, the peripheral dose ranged between 8 and 35 Gy on the 35% to 65% isodose, with a median of 14 Gy on the 45% isodose. The average follow-up was 38 months with a maximum of 94 and consisted of contrast-enhanced MRI every six months in the first year after the procedure and every 1 to 2 years afterwards. Overall tumour control rate was of 95.6% using multimodal treatment options for glomus jugulare tumours. Multimodal treatment for glomus jugulare tumours offers the patient the chance for the best possible outcome and long-term survivability. Individual treatment approach for this kind of very rare head and neck tumour (0,6% of all head and neck tumours) is recommended to choose the best risk-versus-benefit treatment option

    Multimodal treatment of glomus jugular tumours: Case series and literature review

    No full text
    Glomus jugulare tumours are extremely rare, slow-growing, hypervascular tumours that arise within the jugular foramen of the temporal bone and frequently involve the lower cranial nerves. We performed a retrospective study for patients treated between January 2005 and December 2019, reviewing clinical and radiological data for 91 cases of glomus jugulare tumours. Data were available for 91 patients presenting with 96 tumours. Surgery was 1st intention of treatment for 13 cases, the endovascular approach was 1st intention for 6 cases and GKRS was primarily performed in 72 cases. Combined treatment options were used in 19 cases. The median age at the time of treatment was of 57 years. The tumour volume varied between 0.5 and 73.4 cm3 with a median value of 8.3 cm3. For the cases treated with GKRS, the peripheral dose ranged between 8 and 35 Gy on the 35% to 65% isodose, with a median of 14 Gy on the 45% isodose. The average follow-up was 38 months with a maximum of 94 and consisted of contrast-enhanced MRI every six months in the first year after the procedure and every 1 to 2 years afterwards. The overall tumour control rate was 95.6% using multimodal treatment options for glomus jugulare tumours. Multimodal treatment for glomus jugulare tumours offers the patient the chance for the best possible outcome and long-term survivability. An individual treatment approach for this kind of very rare head and neck tumour (0,6% of all head and neck tumours) is recommended to choose the best risk-versus-benefit treatment option

    Heterocycles 48. Synthesis, Characterization and Biological Evaluation of Imidazo[2,1-b][1,3,4]Thiadiazole Derivatives as Anti-Inflammatory Agents

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    Non-steroidal anti-inflammatory drugs (NSAIDs) are an important pharmacological class of drugs used for the treatment of inflammatory diseases. They are also characterized by severe side effects, such as gastrointestinal damage, increased cardiovascular risk and renal function abnormalities. In order to synthesize new anti-inflammatory and analgesic compounds with a safer profile of side effects, a series of 2,6-diaryl-imidazo[2,1-b][1,3,4]thiadiazole derivatives 5a–l were synthesized and evaluated in vivo for their anti-inflammatory and analgesic activities in carrageenan-induced rat paw edema. Among all compounds, 5c showed better anti-inflammatory activity compared to diclofenac, the standard drug, and compounds 5g, 5i, 5j presented a comparable antinociceptive activity to diclofenac. None of the compounds showed ulcerogenic activity. Molecular docking studies were carried out to investigate the theoretical bond interactions between the compounds and target, the cyclooxygenases (COX-1/COX-2). The compound 5c exhibited a higher inhibition of COX-2 compared to diclofenac

    Novel Thermoreversible Injectable Hydrogel Formulations Based on Sodium Alginate and Poly(N-Isopropylacrylamide)

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    <div><p>Novel injectable thermoreversible hydrogel compositions with semi-interpenetrating network structure were prepared through the addition of sodium alginate (SA) to poly(N-isopropylacrylamide) (PNIPAM) aqueous solutions. The addition of the hydrophilic alginate strongly improved the stability against syneresis of the 15 wt% PNIPAM hydrogels formed at 37°C from less than 15 min in the absence of alginate to more than 7 days in the presence of 4 wt% SA. Besides the SA concentration, the hydrogel stability depended on the molecular weight and polydispersity of PNIPAM, being lower when a high molecular weight fraction was present. The phase transition temperature (T<sub>ph</sub>) of the PNIPAM aqueous solutions decreased with alginate concentration, while the dynamic viscosity and elastic modulus of the hydrogels increased. By decreasing the PNIPAM molecular weight and polydispersity, the dynamic viscosity and elastic modulus of the PNIPAM–alginate hydrogels formed above T<sub>ph</sub> diminished, while their viscoelastic behavior changed from predominantly elastic to predominantly viscous.</p></div
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