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1.
Artigo em Inglês | MEDLINE | ID: mdl-38615071

RESUMO

BACKGROUND: The surgical landscape for Lower Urinary Tract Symptoms (LUTS) and Benign Prostatic Hyperplasia (BPH) has evolved with the introduction of Minimally Invasive Surgical Therapies (MISTs), recognizing the impact of sexual function on patients' well-being, and prioritizing ejaculation-sparing approaches. METHODS: This systematic review explored ejaculation sparing after classic endoscopic procedures and MISTs (iTind, Rezum, Urolift, Aquablation, and TPLA) and a literature search yielded 41 studies. RESULTS: While all procedures demonstrated efficacy in improving LUTS/BPH symptoms (IPSS, QoL, Qmax), a subset of studies evaluated ejaculatory function. Positive outcomes were noted, challenging the historical association of BPH surgeries with ejaculatory dysfunction. Variations in study design, patient cohorts, and limited long-term data present challenges. Notably, the lack of baseline specificity, use of alpha-blockers, and non-specific sexual function assessments underscore potential biases. CONCLUSIONS: Despite limitations, the review tentatively concluded that MISTs, including iTind, Rezum, Urolift, Aquablation, and TPLA, appear comparable in sparing ejaculation. Long-term studies are essential to validate sustainability, and comparative research should assess trade-offs between MISTs and traditional surgeries. Incorporating patient-reported outcomes and quality of life assessments will enhance future investigations, refining MISTs as standard therapeutic options for LUTS/BPH.

2.
Int J Mol Sci ; 24(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37834001

RESUMO

The extensive use of agricultural pesticides to improve crop quality and yield significantly increased the risk to the public of exposure to small but repeated doses of pesticides over time through various routes, including skin, by increasing the risk of disease outbreaks. Although much work was conducted to reduce the use of pesticides in agriculture, little attention was paid to prevention, which could reduce the toxicity of pesticide exposure by reducing its impact on human health. Extra virgin olive oil (EVOO), a major component of the Mediterranean diet, exerts numerous health-promoting properties, many of which are attributed to oleuropein aglycone (OleA), the deglycosylated form of oleuropein, which is the main polyphenolic component of EVOO. In this work, three pesticides with different physicochemical and biological properties, namely oxadiazon (OXA), imidacloprid (IMID), and glyphosate (GLYPHO), were compared in terms of metabolic activity, mitochondrial function and epigenetic modulation in an in vitro cellular model of human HaCaT keratinocytes to mimic the pathway of dermal exposure. The potential protective effect of OleA against pesticide-induced cellular toxicity was then evaluated in a cell pre-treatment condition. This study showed that sub-lethal doses of OXA and IMID reduced the metabolic activity and mitochondrial functionality of HaCaT cells by inducing oxidative stress and altering intracellular calcium flux and caused epigenetic modification by reducing histone acetylation H3 and H4. GLYPHO, on the other hand, showed no evidence of cellular toxicity at the doses tested. Pretreatment of cells with OleA was able to protect cells from the damaging effects of the pesticides OXA and IMID by maintaining metabolic activity and mitochondrial function at a controlled level and preventing acetylation reduction, particularly of histone H3. In conclusion, the bioactive properties of OleA reported here could be of great pharmaceutical and health interest, as they could be further studied to design new formulations for the prevention of toxicity from exposure to pesticide use.


Assuntos
Olea , Praguicidas , Humanos , Piranos/farmacologia , Monoterpenos Ciclopentânicos , Azeite de Oliva , Queratinócitos , Praguicidas/toxicidade , Olea/química
3.
Healthcare (Basel) ; 11(20)2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37893879

RESUMO

BACKGROUND: Fall represents one of the highest concerns in the healthcare system, especially in medical rehabilitation settings. However, there is a lack of instruments for the assessment of risk falls in the context of musculoskeletal rehabilitation. METHODS: This retrospective multisite study aimed to assess the sensitivity and specificity of four fall risk assessment tools (the Functional Independence Measure, the Fall Risk Assessment, the Schmid Fall Risk Assessment Tool, and the ePA-AC) in predicting falls in patients admitted to musculoskeletal rehabilitation in Swiss inpatient facilities. RESULTS: The data relative to 6970 individuals (61.5% females) were analyzed and 685 (9.83% of patients) fall events were registered. The area under the curve (AUC) relative to the Functional Independence Measure was 0.689, 0.66 for the Fall Risk Assessment, 0.641 for the Schmid Fall Risk Assessment Tool, and 0.675 for the ePA-AC. Among the four tools, the Functional Independence Measure had an acceptable discriminatory power in distinguishing between significant events (i.e., patients' falls) and non-events (no falls). CONCLUSION: None of the assessed tools showed highly satisfying levels of statistical sensitivity or sensibility. However, the Functional Independence Measure could be used to assess the fall risk assessment in musculoskeletal rehabilitation settings, although with some caution, since this questionnaire was not designed for this diagnostic purpose. We strongly suggest urgently designing a tool for risk assessment that is specific to this population and the rehabilitative setting.

4.
Cancer Lett ; 571: 216338, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37549770

RESUMO

Gastric cancer (GC) is the fifth most frequent malignancy and the fourth leading cause of worldwide cancer-related death. Despite the usage of multimodal perioperative chemotherapy (pCT), GC progressively gains chemoresistance, thereby, the identification of suitable targets to overcome drug resistance is fundamental. Amongst the potential biomarkers, carbonic anhydrase IX (CAIX) - associated with a poor prognosis of several solid cancers - has gained the most attention. In a cohort of GC patients who received perioperative FLOT (i.e., Leucovorin, 5-Fluouracil, Docetaxel, and Oxaliplatin) or FOLFOX (i.e., Leucovorin, 5-Fluouracil, and Oxaliplatin), non-responder patients showed an increased expression of tumor CAIX compared to responder group. Moreover, GC cell lines induced to be resistant to 5-Fluouracil, Paclitaxel, Cisplatin, or the combination of 5-Fluorouracil, Oxaliplatin, and Docetaxel, overexpressed CAIX compared to the control. Accordingly, CAIX-high-expressing GC cells showed increased therapy resistance compared to low-expressing cells. Notably, SLC0111 significantly improved the therapy response of both wild-type and resistant GC cells. Overall, these data suggest a correlation between CAIX and GC drug resistance highlighting the potential of SLC-0111 in re-sensitizing GC cells to pCT.


Assuntos
Antineoplásicos , Inibidores da Anidrase Carbônica , Neoplasias Gástricas , Humanos , Antígenos de Neoplasias/metabolismo , Antineoplásicos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrase Carbônica IX/genética , Anidrase Carbônica IX/metabolismo , Linhagem Celular , Docetaxel/farmacologia , Fluoruracila/farmacologia , Leucovorina/farmacologia , Oxaliplatina/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Taxoides/farmacologia , Taxoides/uso terapêutico , Linhagem Celular Tumoral
5.
Materials (Basel) ; 16(6)2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36984120

RESUMO

Extrusion and hot compressing molding processes were used to create bio-polyethylene (BioPE) composites reinforced with argan byproducts (shell, pulp, and argan cake) as bio-fillers. The thermal stability of the composites wass analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Dynamical mechanical analysis and rheological testing were used to investigate their mechanical properties. The morphological results showed a good adhesion between the argan and BioPE matrix. More efficient mechanical properties have been distinguished in the case of argan byproduct-based composite. A higher Young's modulus was noted for all the biocomposites compared to pure BioPE. Thermal analysis revealed that the addition of bio-filler to polymer reduced decomposition temperatures. This study provides an ecological alternative for upgrading the valorization of abundant and underutilized Moroccan biomass. Furthermore, the possibility of using argan byproducts in composite manufacturing will help open up new markets for what is currently considered waste.

6.
Materials (Basel) ; 15(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36363169

RESUMO

Fused deposition modelling is a rapidly growing additive manufacturing technology due to its ability to build functional parts with complex geometries. The mechanical properties of a built part depend on several process parameters. The effect of wood content on the properties of 3D printed parts has been studied. Four types of filaments using poly(butylene succinate-co-adipate) (PBSA) with different reinforcement levels of Typha stem powder 0%, 5%, 10%, and 15% by weight were used for 3D printing. The density of the filaments and parts printed in this study increased with the Typha stem powder content. The thermal stability, mechanical performance, and viscoelastic properties of the different biocomposite filaments and 3D printed objects were analysed. The results show an increase in the crystallisation kinetics and a slight decrease in the thermal stability of the biomaterials. Compared to virgin PBSA FDM filaments, the PBSA biocomposite filament filled with Typha stem powder showed an increase in the tensile strength of the parts and specimens from 2.5 MPa to 8 MPa and in the modulus of elasticity from 160 MPa to 375 MPa, respectively, with additions of 5%, 10%, and 15% by mass. The addition of Typha stem fibres generated an increase in the elastic behaviour and relaxation time of the biomaterial structure, visualised by increases in the values of the viscosity components. The surface morphology reveals a decrease in the porosity of the printed samples.

7.
J Int Med Res ; 50(11): 3000605221138843, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36448484

RESUMO

OBJECTIVE: Functional impairments after coronavirus disease 2019 (COVID-19) constitute a major concern in rehabilitative settings; however, evidence assessing the efficacy of rehabilitation programs is lacking. The aim of this study was to verify the clinical characteristics that may represent useful predictors of the short-term effectiveness of multidisciplinary rehabilitation. METHODS: In this real-practice retrospective pre-post intervention cohort study, the short-term effectiveness of a multidisciplinary patient-tailored rehabilitation program was assessed through normalized variations in the Functional Independence Measure in post-acute care patients who had overcome severe COVID-19. Biochemical markers, motor and nutritional characteristics, and the level of comorbidity were evaluated as predictors of functional outcome. Length of stay in the rehabilitation ward was also considered. RESULTS: Following rehabilitation, all participants (n = 53) reported a significant decrease in the level of disability in both motor and cognitive functioning. However, neither motor and nutritional characteristics nor comorbidities played a significant role in predicting the overall positive change registered after rehabilitation. CONCLUSIONS: The results support the existing sparse evidence addressing the importance of an early rehabilitation program for patients who received intensive care and post-acute care due to severe COVID-19.


Assuntos
COVID-19 , Humanos , Estudos de Coortes , Estudos Retrospectivos , Sobreviventes , Cuidados Críticos
10.
Int J Mol Sci ; 22(14)2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34299320

RESUMO

Chemotherapy is still widely used as a coadjutant in gastric cancer when surgery is not possible or in presence of metastasis. During tumor evolution, gatekeeper mutations provide a selective growth advantage to a subpopulation of cancer cells that become resistant to chemotherapy. When this phenomenon happens, patients experience tumor recurrence and treatment failure. Even if many chemoresistance mechanisms are known, such as expression of ATP-binding cassette (ABC) transporters, aldehyde dehydrogenase (ALDH1) activity and activation of peculiar intracellular signaling pathways, a common and universal marker for chemoresistant cancer cells has not been identified yet. In this study we subjected the gastric cancer cell line AGS to chronic exposure of 5-fluorouracil, cisplatin or paclitaxel, thus selecting cell subpopulations showing resistance to the different drugs. Such cells showed biological changes; among them, we observed that the acquired chemoresistance to 5-fluorouracil induced an endothelial-like phenotype and increased the capacity to form vessel-like structures. We identified the upregulation of thymidine phosphorylase (TYMP), which is one of the most commonly reported mutated genes leading to 5-fluorouracil resistance, as the cause of such enhanced vasculogenic ability.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Fluoruracila/farmacologia , Neovascularização Patológica/induzido quimicamente , Neoplasias Gástricas/irrigação sanguínea , Neoplasias Gástricas/tratamento farmacológico , Antineoplásicos/metabolismo , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Fluoruracila/metabolismo , Humanos , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Paclitaxel/farmacologia , Neoplasias Gástricas/patologia , Talidomida/farmacologia , Timidina Fosforilase/genética , Regulação para Cima/efeitos dos fármacos
11.
Polymers (Basel) ; 13(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201232

RESUMO

An eco-friendly solution to produce new material for the material extrusion process is to use quarry waste as filler for biopolymer composites. A quarry waste that is still studied little as a filler for polymer composites is pozzolan. In this study, the optimization of the formulations and processing parameters of composites produced with pozzolan and bio-based polyethylene for 3D printing technology was performed. Furthermore, a precision irrigation system in the form of a drip watering cup was designed, printed, and characterized. The results showed that the presence of the pozzolan acted as a reinforcement for the composite material and improved the cohesion between the layers of the 3D printed objects. Furthermore, the optimization of the process conditions made it possible to print pieces of complex geometry and permeable parts for the control of the water flow rates with an order of magnitude in the range from mL/h to mL/day.

12.
Eur J Pharm Biopharm ; 160: 100-124, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33497794

RESUMO

Present study addresses the challenge of incorporating hydrophilic streptomycin sulphate (STRS; log P -6.4) with high dose (1 g/day) into a lipid matrix of SLNs. Cold high-pressure homogenization technique used for SLN preparation achieved 30% drug loading and 51.17 ± 0.95% entrapment efficiency. Polyethylene glycol 600 as a supporting-surfactant assigned small size (218.1 ± 15.46 nm) and mucus-penetrating property. It was conceived to administer STRS-SLNs orally rather than intramuscularly. STRS-SLNs remained stable on incubation for varying times in SGF or SIF. STRS-SLNs were extensively characterised for microscopic (TEM and AFM), thermal (DSC), diffraction (XRD) and spectroscopic (NMR and FTIR) properties and showed zero-order controlled release. Enhanced (60 times) intracellular uptake was observed in THP-1 and Pgp expressing LoVo and DLD-1 cell lines, using fluorescein-SLNs. Presence of SLNs in LoVo cells was also revealed by TEM studies. STRS-SLNs showed 3 times reduction in MIC against Mycobacterium tuberculosis H37RV (256182) in comparison to free STRS. It also showed better activity against both M. bovis BCG and Mycobacterium tuberculosis H37RV (272994) in comparison to free STRS. Cytotoxicity and acute toxicity studies (OECD 425 guidelines) confirmed in vitro and in vivo safety of STRS-SLNs. Single-dose oral pharmacokinetic studies in rat plasma using validated LCMS/MS technique or the microbioassay showed significant oral absorption and bioavailability (160% - 710% increase than free drug).


Assuntos
Antituberculosos/administração & dosagem , Portadores de Fármacos/química , Mycobacterium bovis/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Estreptomicina/administração & dosagem , Administração Oral , Animais , Antituberculosos/química , Antituberculosos/farmacocinética , Antituberculosos/toxicidade , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lipídeos/química , Macrófagos/metabolismo , Masculino , Testes de Sensibilidade Microbiana , Nanopartículas/química , Tamanho da Partícula , Ratos , Solubilidade , Estreptomicina/química , Estreptomicina/farmacocinética , Estreptomicina/toxicidade , Células THP-1 , Testes de Toxicidade Aguda
13.
J Drug Target ; 29(6): 631-650, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33410357

RESUMO

The present study describes a special lipid-polyethylene glycol matrix solid lipid nanoparticles (SLNs; 138 nm; -2.07 mV) for ocular delivery. Success of this matrix to encapsulate (entrapment efficiency - 62.09%) a hydrophilic drug, fluconazole (FCZ-SLNs), with no burst release (67% release in 24 h) usually observed with most water-soluble drugs, is described presently. The system showed 164.64% higher flux than the marketed drops (Zocon®) through porcine cornea. Encapsulation within SLNs and slow release did not compromise efficacy of FCZ-SLNs. Latter showed in vitro and in vivo antifungal effects, including antibiofilm effects comparable to free FCZ solution. Developed system was safe and stable (even to sterilisation by autoclaving); and showed optimal viscosity, refractive index and osmotic pressure. These SLNs could reach up to retina following application as drops. The mechanism of transport via corneal and non-corneal transcellular pathways is described by fluorescent and TEM images of mice eye cross sections. Particles streamed through the vitreous, crossed inner limiting membrane and reached the outer retinal layers.


Assuntos
Antifúngicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Fluconazol/administração & dosagem , Lipossomos , Nanopartículas , Animais , Antifúngicos/farmacocinética , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Linhagem Celular , Química Farmacêutica/métodos , Córnea/metabolismo , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Feminino , Fluconazol/farmacocinética , Fluconazol/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Polietilenoglicóis/química , Segmento Posterior do Olho/metabolismo , Coelhos , Ratos , Suínos , Distribuição Tecidual
14.
Materials (Basel) ; 14(1)2020 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-33374306

RESUMO

A new eco-composite polymer for material extrusion fabrication based on fine fraction pozzolan waste was developed. In addition, the composite materials obtained were used to produce a self-watering pot with complex geometry and a permeable porous part to regulate the passage of water from the storage area to the roots of the plant. Moreover, the system was devised with a cover characterized by a UV-B barrier film. The results have shown the possibility of the 3D printing of complex geometric parts as microporous structures or thin films using a composite based on poly lactic acid (PLA) and pozzolan. The pozzolan has an effect of reinforcement for the composite and at the same time improves the cohesion between the layers of the part during printing.

15.
Biology (Basel) ; 9(9)2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32887417

RESUMO

To date, 5-Fluorouracil (5FU) is a major component of several chemotherapy regimens, thus its study is of fundamental importance to better understand all the causes that may lead to chemoresistance and treatment failure. Given the evident differences between prognosis in Asian and Caucasian populations, triggered by clear genetic discordances and given the extreme genetic heterogeneity of gastric cancer (GC), the evaluation of the most frequent mutations in every single member of the 5FU conversion and activation pathway might reveal several important results. Here, we exploited the cBioPortal analysis software to query a large databank of clinical and wide-genome studies to evaluate the components of the three major 5FU transformation pathways. We demonstrated that mutations in such ways were associated with a poor prognosis and reduced overall survival, often caused by a deletion in the TYMP gene and amplification in TYMS. The use of prodrugs and dihydropyrimidine dehydrogenase (DPD) inhibitors, which normally catabolizes 5FU into inactive metabolites, improved such chemotherapies, but several steps forward still need to be taken to select better therapies to target the chemoresistant pools of cells with high anaplastic features and genomic instability.

17.
Int J Mol Sci ; 21(8)2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32326163

RESUMO

Gastric cancer (GC) is turning out today to be one of the most important welfare issues for both Asian and European countries. Indeed, while the vast majority of the disease burden is located in China and in Pacific and East Asia, GC in European countries still account for about 100,000 deaths per year. With this review article, we aim to focus the attention on one of the most complex cellular pathways involved in GC proliferation, invasion, migration, and metastasis: the MAP kinases. Such large kinases family is to date constantly studied, since their discovery more than 30 years ago, due to the important role that it plays in the regulation of physiological and pathological processes. Interactions with other cellular proteins as well as miRNAs and lncRNAs may modulate their expression influencing the cellular biological features. Here, we summarize the most important and recent studies involving MAPK in GC. At the same time, we need to underly that, differently from cancers arising from other tissues, where MAPK pathways seems to be a gold target for anticancer therapies, GC seems to be unique in any aspect. Our aim is to review the current knowledge in MAPK pathways alterations leading to GC, including H. pylori MAPK-triggering to derail from gastric normal epithelium to GC and to encourage researches involved in MAPK signal transduction, that seems to definitely sustain GC development.


Assuntos
Sistema de Sinalização das MAP Quinases , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neoplasias Gástricas/metabolismo , Animais , Biomarcadores , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Suscetibilidade a Doenças , Epigênese Genética , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter pylori , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , MicroRNAs/genética , Metástase Neoplásica , Estadiamento de Neoplasias , RNA Longo não Codificante/genética , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/patologia
18.
Drug Deliv Transl Res ; 10(4): 919-944, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32270439

RESUMO

Statins, widely prescribed for cardiovascular diseases, are also being eyed for management of age-related macular degeneration (AMD). Poor bioavailability and blood-aqueous barrier may however limit significant ocular concentration of statins following oral administration. We for the first time propose and investigate local application of atorvastatin (ATS; representative statin) loaded into solid lipid nanoparticles (SLNs), as self-administrable eye drops. Insolubility, instability, and high molecular weight > 500 of ATS, and ensuring that SLNs reach posterior eye were the challenges to be met. ATS-SLNs, developed (2339/DEL/2014) using suitable components, quality-by-design (QBD) approach, and scalable hot high-pressure homogenization, were characterized and evaluated comprehensively for ocular suitability. ATS-SLNs were 8 and 12 times more bioavailable (AUC) in aqueous and vitreous humor, respectively, than free ATS. Three-tier (in vitro, ex vivo, and in vivo) ocular safety, higher corneal flux (2.5-fold), and improved stability (13.62 times) including photostability of ATS on incorporation in ATS-SLNs were established. Autoclavability and aqueous nature are the other highlights of ATS-SLNs. Presence of intact fluorescein-labeled SLNs (F-SLNs) in internal eye tissues post-in vivo application as eye drops provides direct evidence of successful delivery. Perinuclear fluorescence in ARPE-19 cells confirms the effective uptake of F-SLNs. Prolonged residence, up to 7 h, was attributed to the mucus-penetrating nature of ATS-SLNs. Graphical abstract.


Assuntos
Atorvastatina/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Lipídeos/administração & dosagem , Nanopartículas/administração & dosagem , Soluções Oftálmicas/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Atorvastatina/química , Atorvastatina/farmacocinética , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Córnea/metabolismo , Liberação Controlada de Fármacos , Células Epiteliais/efeitos dos fármacos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Lipídeos/química , Lipídeos/farmacocinética , Degeneração Macular/tratamento farmacológico , Masculino , Nanopartículas/química , Soluções Oftálmicas/química , Soluções Oftálmicas/farmacocinética , Permeabilidade , Coelhos , Ratos , Suínos
19.
3D Print Addit Manuf ; 7(6): 311-325, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36654669

RESUMO

This article presents the effect analysis of the printing time sequences on the mechanical properties in correlation with the crystallization kinetics and rheological behavior. For this purpose, two printing order of 3D printed samples (printed simultaneously or in sequence) were chosen. In addition, two different infill patterns (line and gyroid) and building directions (horizontal and vertical) have been used. Concerning the polymer filaments, two commercial polylactic acid (PLA 3D870 and PLA 3D850) having different crystallization kinetics were used. The effect of the printing time delay between each layer on the temperature profile and the crystallization evolution was studied using a finite element analysis method simulation. The simulation results show a greater thermal excursion for longer delay times between the layers and with a crystallization degree evolution characterized by a step pattern. Moreover, a major density of crystals appears in the center of the final part. A new approach was adapted to measure the volumetric contraction of the material as a function of the temperature; it was performed with a gap test using a rotational rheometer under static conditions (without external deformation). The normal force measured from the test has shown a faster and higher increase of the contraction for the material with faster crystallization kinetics and with a higher degree of crystallinity. The results concerning the tensile properties show better rigidity for the samples printed in sequence due to the minor time of delay between the deposited layers. The mesostructure of the printed parts was analyzed with an X-ray tomography and a scanning electron microscope. The highest difference is presented from the PLA 3D870 characterized by the highest rate of crystallization resulting in more microvoids compared with the PLA 3D850, due to the less welding cohesion between the layers.

20.
Cell Mol Life Sci ; 77(6): 965-976, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31563996

RESUMO

Crystallins were firstly found as structural proteins of the eye lens. To this family belong proteins, such as ζ-crystallin, expressed ubiquitously, and endowed with enzyme activity. ζ-crystallin is a moonlighting protein endowed with two main different functions: (1) mRNA binding with stabilizing activity; (2) NADPH:quinone oxidoreductase. ζ-crystallin has been clearly demonstrated to stabilize mRNAs encoding proteins involved in renal glutamine catabolism during metabolic acidosis resulting in ammoniagenesis and bicarbonate ion production that concur to compensate such condition. ζ-crystallin binds also mRNAs encoding for antiapoptotic proteins, such as Bcl-2 in leukemia cells. On the other hand, the physiological role of its enzymatic activity is still elusive. Gathering research evidences and data mined from public databases, we provide a framework where all the known ζ-crystallin properties are called into question, making it a hypothetical pivotal player in cancer, allowing cells to hijack or subjugate the acidity response mechanism to increase their ability to resist oxidative stress and apoptosis, while fueling their glutamine addicted metabolism.


Assuntos
Neoplasias/metabolismo , zeta-Cristalinas/metabolismo , Acidose/metabolismo , Amônia/metabolismo , Animais , Apoptose , Glutamina/metabolismo , Humanos , Estresse Oxidativo , Ligação Proteica , RNA Mensageiro/metabolismo
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