303 research outputs found

    Development of an empirical wall-friction model for 2D simulations of pseudo-2D bubbling fluidized beds

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    Pseudo-2D fluidized beds have been crucial for the understanding of the dynamics of gas-particle systems. In these systems the distance between the front and back walls is narrow, which restricts and creates a resistance to the solids motion, leading to a different flow behaviour compared to fully 3D systems. This interaction of the particle motion with the walls can be significant and should not be neglected in numerical simulations. The present work develops a new model to easily account for the friction effect between the walls and the particles in a pseudo-2D bed. The model is based on experimental results combined with simplifications of the shear force on a wall provided by the kinetic theory of granular flows. The dependence on the particle diameter and bed thickness is directly introduced in the model through the use of a straightforward expression that is easy to code and does not lead to numerical divergence. To test the model two beds of different thickness were simulated, and the resulting time-averaged solids concentration and velocity as well as bubble properties were compared with experiments. It is shown that the numerical results with the new wall-friction model improve the prediction of the standard 2D-simulations

    A questionnaire-based survey in Spain provides relevant information to improve the control of ovine coccidiosis

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    Ovine coccidiosis is a widespread intestinal parasitic disease caused by Eimeria spp. Lambs are infected by the ingestion of sporulated oocysts, experiencing diarrhea and low growth rates. Control should be based on measures to reduce infection pressure and stress on the animals as well as on appropriate diagnosis and strategic treatment. To obtain information on how control measures are implemented in the ovine sector in Spain, a questionnaire-based survey was completed in 2022 by 154 veterinarians and 173 farmers working in this sector. Coccidiosis was highlighted as a relevant disease by 34% of the respondents. The period of greatest risk seemed to differ between production systems, being mainly early after weaning (7–15 days after weaning) in meat flocks and feedlots and later (1–2 months after weaning) in dairy flocks. The absence of cleaning and disinfection measures was identified as a risk factor by 51% of the veterinarians, with 22% mentioning overcrowding of animals and 22% indicating that coccidiosis has more incidence in flocks with large number of animals. The use of laboratory diagnosis methods (fecal oocyst count) was unusual in 70 and 84% of the veterinarians and farmers, respectively. Regarding control, dairy flocks usually housed a larger number of animals under intensive conditions, and they implemented more frequently control measures for coccidiosis than meat flocks. Anticoccidial drugs were used in 79% of the flocks, and in 74–82% of them, they were applied based on clinical criteria. Comparing protocols for anticoccidial treatment among different production systems, in meat flocks, anticoccidial drugs were applied more frequently when clinical signs were observed, and coccidiostats were used for less than 28 days compared to dairy flocks. These results highlight the need for improvement in the use of anticoccidial treatments adjusted to the new regulatory framework in the EU, which in turn will rationalize the use of antimicrobial compounds and may help to mitigate the impact of coccidiosis in flocks

    Prevention of road crashes in older adults: perspectives on facilitators, barriers and the role of the family doctor

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    This work was supported by the SEMERGEN-UGR Chair of Teaching and Research in Family Medicine (Catedra de Docencia e Investigacion en Medicina de Familia SEMERGEN-UGR), University of Granada, Spain.Background: People over 64 years have a high fatality rate when they are involved in traffic accidents. Besides, older victims of road crashes are expected to rise in the future due to population aging. The purpose of the study was to document their perception on the role of the family doctor, the main facilitating factors, and the perceived barriers to the temporary or permanent restriction of their driving. Methods: This qualitative study used focus group methodology. A sample of 16 people over 65 years old was obtained through a series of segmentation criteria at an active participation centre for older adults in a small town in Jaén province (Spain). All were invited to participate in a discussion during which they were asked to express their opinions and subjective experiences concerning the role of their family doctor. The group conversation was taped, fully transcribed and analysed, and codes were generated with both deductive and inductive methods. Results: After merging the codes to generate themes, we identified 9 relevant categories: perception of age-related risk, road safety, role of public authorities, driver assessment centre, role of the family doctor, role of the family, proposals for addressing traffic accidents in older adults, consequences of the driving prohibition, and public transport. All categories help to explain the subjective driving and traffic safety experiences of older road users. Conclusions: Although family doctors do not usually ask their older patients about road driving, they are highly valued by these patients. Thus, family doctors have a great potential to act, along with the family members, for the benefit of older patients’ traffic safety, in ways that can prevent their involvement in road crashes and reduce the negative consequences of having to stop driving if necessary.SEMERGEN-UGR Chair of Teaching and Research in Family Medicine (Catedra de Docencia e Investigacion en Medicina de Familia SEMERGEN-UGR), University of Granada, Spai

    Trochoidal Milling Path with Variable Feed. Application to the Machining of a Ti-6Al-4V Part

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    Trochoidal milling is a well-stablished machining strategy which still allows for the introduction of new approaches. This strategy can be applied to any kind of material, although it is usually associated to advanced materials, such as titanium and nickel alloys. This study is based on the adaptation of the feed speed of a milling tool with Ti-6Al-4V, so the chip width can be maintained constant without modifying the path geometry. A singularity in the experimental stage was to mill an Archimedes spiral groove instead of the conventional straight grooves. This made it possible to obtain a concave wall as well as a convex one and to optimize the amount of material used. The time efficiency compared to a constant feed, was slightly superior to 20%, reducing tool wear also. These techniques require milling machines with high mechanical and kinematic performance, as well as the absence of clearance between joints and a high acceleration capacity

    MKP1 mediates chemosensitizer effects of E1a in response to cisplatin in non-small cell lung carcinoma cells

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    The adenoviral gene E1a is known to enhance the antitumor effect of cisplatin, one of the cornerstones of the current cancer chemotherapy. Here we study the molecular basis of E1a mediated sensitivity to cisplatin in an experimental model of Non-small cell lung cancer. Our data show how E1a blocks the induction of autophagy triggered by cisplatin and promotes the apoptotic response in resistant cells. Interestingly, at the molecular level, we present evidences showing how the phosphatase MKP1 is a major determinant of cisplatin sensitivity and its upregulation is strictly required for the induction of chemosensitivity mediated by E1a. Indeed, E1a is almost unable to promote sensitivity in H460, in which the high expression of MKP1 remains unaffected by E1a. However, in resistant cell as H1299, H23 or H661, which display low levels of MKP1, E1a expression promotes a dramatic increase in the amount of MKP1 correlating with cisplatin sensitivity. Furthermore, effective knock down of MKP1 in H1299 E1a expressing cells restores resistance to a similar extent than parental cells. stores resistance to a similar extent than parental cells. In summary, the present work reinforce the critical role of MKP1 in the cellular response to cisplatin highlighting the importance of this phosphatase in future gene therapy approach based on E1a gene

    ERK5/BMK1 is a novel target of the tumor suppressor VHL: implication in clear cell renal carcinoma

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    Hi ha quatre pàgines de material suplementari sense numeracióExtracellular signal-regulated kinase 5 (ERK5), also known as big mitogen-activated protein kinase (MAPK) 1, is implicated in a wide range of biologic processes, which include proliferation or vascularization. Here, we show that ERK5 is degraded through the ubiquitin-proteasome system, in a process mediated by the tumor suppressor von Hippel-Lindau (VHL) gene, through a prolyl hydroxylation-dependent mechanism. Our conclusions derive from transient transfection assays in Cos7 cells, as well as the study of endogenous ERK5 in different experimental systems such as MCF7, HMEC, or Caki-2 cell lines. In fact, the specific knockdown of ERK5 in pVHL-negative cell lines promotes a decrease in proliferation and migration, supporting the role of this MAPK in cellular transformation. Furthermore, in a short series of fresh samples from human clear cell renal cell carcinoma, high levels of ERK5 correlate with more aggressive and metastatic stages of the disease. Therefore, our results provide new biochemical data suggesting that ERK5 is a novel target of the tumor suppressor VHL, opening a new field of research on the role of ERK5 in renal carcinomas

    Differential clinicopathological and molecular features within late-onset colorectal cancer according to tumor location

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    Background: Since there is a predilection of some clinical and molecular features for a given tumor location, we assessed whether this can be confirmed in late-onset colorectal cancer (LOCRC). Results: Right colon cancers showed features associated with sporadic Microsatellite Instability: predominance of female cases and BRAF mutations, and an important mucinous component. Left colon cancers developed a higher number of polyps and multiple primary CRCs, showed the strongest familial component, and had better prognosis. Rectal cancers showed a predominantly sporadic phenotype, with worse prognosis and a CpG Island Methylator Phenotype (CIMP)-High. No copy number alterations (CNAs) greater than or equal to 50% were observed in this LOCRC group, and the most recurrent alterations were losses at 5q13 and 14q11, and gains at 7q11, 7q21-q22, 19p13-p12, 19q13 and 20p11-q11. KRAS and PIK3CA were the only mutated genes showing differences according to the tumor location, mainly for right colon cancers. Materials and Methods: We analyzed clinical and molecular characteristics of LOCRC at different tumor locations in order to determine if there are differential phenotypes related with the location in the colon. Conclusions: Categorizing LOCRC according to tumor location appears to be an adequate first step to resolving the heterogeneity of this subset of CRCThis work was funded by Projects PI10/0683, PI13/01741, PI13/0127 and PI14/00459 from the Spanish Ministry of Health and Consumer Affairs and FEDER, and was approved by the Ethics Committee of our Institutio

    Construcción y obras públicas [glosario]

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    En el libro Glosario General de Tecnología, el profesor D. Enrique Alarcón Álvarez coordina el área destinada a la Construcción y obras públicas, en la que también participa como autor

    Rational engineering of a human GFP-like protein scaffold for humanized targeted nanomedicines

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    Green fluorescent protein (GFP) is a widely used scaffold for protein-based targeted nanomedicines because of its high biocompatibility, biological neutrality and outstanding structural stability. However, being immunogenicity a major concern in the development of drug carriers, the use of exogenous proteins such as GFP in clinics might be inadequate. Here we report a human nidogen-derived protein (HSNBT), rationally designed to mimic the structural and functional properties of GFP as a scaffold for nanomedicine. For that, a GFP-like β-barrel, containing the G2 domain of the human nidogen, has been rationally engineered to obtain a biologically neutral protein that self-assembles as 10nm-nanoparticles. This scaffold is the basis of a humanized nanoconjugate, where GFP, from the well-characterized protein T22-GFP-H6, has been substituted by the nidogen-derived GFP-like HSNBT protein. The resulting construct T22-HSNBT-H6, is a humanized CXCR4-targeted nanoparticle that selectively delivers conjugated genotoxic Floxuridine into cancer CXCR4+ cells. Indeed, the administration of T22-HSNBT-H6-FdU in a CXCR4-overexpressing colorectal cancer mouse model results in an even more efficient selective antitumoral effect than that shown by its GFP-counterpart, in absence of systemic toxicity. Therefore, the newly developed GFP-like protein scaffold appears as an ideal candidate for the development of humanized protein nanomaterials and successfully supports the tumor-targeted nanoscale drug T22-HSNBT-H6-FdU.Patricia Álamo and Juan Cedano contributed equally to this work. The authors are indebted to Agencia Estatal de Investigación (AEI) and to Fondo Europeo de Desarrollo Regional (FEDER) (grant BIO2016-76063-R, AEI/FEDER, UE), to AGAUR (2017SGR-229) and CIBER-BBN (project NANOPROTHER), granted to AV, to CIBER-BBN (project NANOSCAPE and NANOLINK) and ISCIII (PI20/00400 co-funding FEDER) granted to UU, to ISCIII (PI15/00272 co-founding FEDER) granted to EV and to ISCIII (PIE15/00028 and PI18/00650, co-funding FEDER) and AGAUR (2017 SGR 865 GRC) granted to RM. We are also indebted to CERCA programme (Generalitat de Catalunya) and to the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) that is an initiative funded by the VI National R&D&I Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III, with assistance from the European Regional Development Fund. We also appreciate the support from the COST-Action Nano2Clinics. Protein production has been partially performed by the ICTS “NANBIOSIS”, more specifically by the Protein Production Platform of CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN)/ IBB, at the UAB sePBioEs scientific-technical service (http://www.nanbiosis.es/portfolio/u1-protein-production-platform-ppp/), and the nanoparticle size analysis by the Biomaterial Processing and Nanostructuring Unit. Synthesis of thiolated oligo-FdU was performed by the ICTS NANBIOSIS Oligonucleotide Synthesis Platform (CIBER-BBN). The in vivo work was performed by the ICTS NANBIOSIS of the CIBER-BBN Nanotoxicology Unit (http://www.nanbiosis.es/portfolio/u18-nanotoxicology-unit/). We are indebted to Servei de Microscopia from UAB for their excellent confocal and electronic microscopy services. We are also indebted to Servei de Cultius Celulars i Anticossos (SCAC) form UAB for their excellent cell culture and flow cytometry facilities and especially to Fran Cortes for his excellent technical support. We are thankful to Dra. Marta Taulés from CCiT-UB for her help in SPR experiments and analysis. We are also thankful to Luis Carlos Navas from Institut d'Investigacions biomèdiques Sant Pau (IIB Sant Pau) for his technical support in immunohistochemistry experiments. UU and LMCD were supported by Miguel Servet (CP19/00028) and PFIS (FI19/00148) contracts respectively from ISCIII co-funded by European Social Fund (ESF investing in your future). NS was supported by a pre-doctoral fellowship from the Government of Navarra and LAC was supported by AECC Scientific Foundation grant postdoctoral fellow. AV received an ICREA ACADEMIA award.Peer reviewe
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