1,277 research outputs found
genetic optimization for economic feasibility of refurbishment in buildings
Abstract This paper investigates the possibility to enhance the thermal characteristics of a building fabric taking into account the economic feasibility in order to avoid useless expensive interventions. The problem consists in realizing an internal insulation system for a single apartment located in Trieste. A genetic optimization has been implemented in order to search a large number of solutions with multiple objects and constraints. EnergyPlus has been used for dynamic building and plant simulation and modeFRONTIER for optimization loop setup. The objectives are the used heating energy consumption and the life cycle refurbishment cost, using a net present value approach. An additional objective has been added in order to guarantee the maximization of the interior useful floor area, which is directly influenced by the internal insulation thickness. Different approaches have been compared, considering actions dealing with opaque surfaces only or considering the replacement of existing windows. The paper demonstrates that an automatic optimization approach can help designers to identify the best suited intervention for building refurbishment
Family's History Based on the CDH1 Germline Variant (c.360delG) and a Suspected Hereditary Gastric Cancer Form
Hereditary diffuse gastric cancer (HDGC) is a cancer susceptibility syndrome caused by germline pathogenic variant in CDH1, the gene encoding E-cadherin. The germline loss-of-function variants are the only proven cause of the cancer syndrome HDGC, occurring in approximately 10-18% of cases and representing a helpful tool in genetic counseling. The current case reports the family history based on a CDH1 gene variant, c.360delG, p.His121Thr in a suspected family for hereditary gastric cancer form. This frameshift deletion generates a premature stop codon at the amino acid 214, which leads to a truncated E-cadherin protein detecting it as a deleterious variant. The present study expands the mutational spectra of the family with the CDH1 variant. Our results highlight the clinical impact of the reported CDH1 variant running in gastric cancer families
Polymorphisms in Pepsinogen C and miRNA Genes Associate with High Serum Pepsinogen II in Gastric Cancer Patients
Background: Pepsinogen (PG) II (PGII) is a serological marker used to estimate the risk of
gastric cancer but how PGII expression is regulated is largely unknown. It has been suggested that
PGII expression, from the PGC (Progastricsin) gene, is regulated by microRNAs (miRNA), but how
PGII levels vary with Helicobacter pylori (H. pylori) infection and miRNAs genotype remains unclear.
Methods: Serum levels of PGI and PGII were determined in 80 patients with gastric cancer and
persons at risk for gastric cancer (74 first-degree relatives of patients, 62 patients with autoimmune
chronic atrophic gastritis, and 2 patients with dysplasia), with and without H. pylori infection. As
control from the general population, 52 blood donors were added to the analyses. Associations
between PGII levels and genetic variants in PGC and miRNA genes in these groups were explored
based on H. pylori seropositivity and the risk for gastric cancer. The two-dimensional difference
in gel electrophoresis (2D-DIGE) and the NanoString analysis of messenger RNA (mRNAs) from
gastric cancer tissue were used to determine the pathways associated with increased PGII levels.
Results: PGII levels were significantly higher in patients with gastric cancer, and in those with H.
pylori infection, than in other patients or controls. A PGI/PGII ratio 3 was found better than
PGI < 25 ng/mL to identify patients with gastric cancer (15.0% vs. 8.8%). For two genetic variants,
namely rs8111742 in miR-Let-7e and rs121224 in miR-365b, there were significant differences in
PGII levels between genotype groups among patients with gastric cancer (p = 0.02 and p = 0.01,
respectively), but not among other study subjects. Moreover, a strict relation between rs9471643
C-allele with H. pylori infection and gastric cancer was underlined. Fold change in gene expression of
mRNA isolated from gastric cancer tissue correlated well with polymorphism, H. pylori infection,
increased PGII level, and pathway for bacteria cell entry into the host. Conclusions: Serum PGII
levels depend in part on an interaction between H. pylori and host miRNA genotypes, which may
interfere with the cut-off of PGI/PGII ratio used to identify persons at risk of gastric cancer. Results
reported new findings regarding the relation among H. pylori, PGII-related host polymorphism, and
genes involved in this interaction in the gastric cancer setting
Characterization of the multidrug efflux transporter styMdtMfrom Salmonella enterica serovar Typhi
Salmonellae are foodborne pathogens and the major cause of gastroenteritis in humans. Salmonellae express multidrug efflux transporters that play a key role in their drug resistance, which is becoming an increasing problem for therapeutic intervention. Despite their biomedical importance, the mechanisms underlying substrate transport by multidrug efflux transporters remain poorly understood. Here, we describe the first characterization of a multidrug transporter belonging to the major facilitator superfamily from the genus Salmonella. We show that several clinical Salmonella Typhi (S. Typhi) isolates constitutively express the styMdtM (STY4874) gene, which encodes a known multidrug-resistance (MDR) transporter. Guided by the structure of the Escherichia coli (E. coli) homolog, we studied two residues critical for substrate transport, Asp25 and Arg111. Mutation of Asp25 to glutamate did not affect the transport function of styMdtM, whereas mutation to alanine reduced its transport activity, suggesting that a negative charge at this position is critical for substrate translocation across the membrane. Substrate-affinity measurements by intrinsic fluorescence spectroscopy showed that the Asp25Ala mutant retained its capacity to bind substrate, albeit at a lower level. Mutation of Arg111 to alanine resulted in a decrease in secondary structure content of the transporter, and mutation to lysine completely destabilized the structure of the transporter. A homology model of styMdtM suggests that Arg111 is important for stabilizing the transmembrane domain by mediating necessary interactions between neighboring helices. Together, our studies provide new structural and mechanistic insights into the Salmonella MDR transporter styMdtM
Higher ventricular-arterial coupling derived from three-dimensional echocardiography is associated with a worse clinical outcome in systemic sclerosis
Primary myocardial involvement is common in systemic sclerosis (SSc). Ventricular-arterial coupling (VAC) reflecting the interplay between ventricular performance and arterial load, is a key determinant of cardiovascular (CV) performance. We aimed to investigate VAC, VAC-derived indices, and the potential association between altered VAC and survival free from death/hospitalization for major adverse CV events (MACE) in scleroderma. Only SSc patients without any anamnes-tic and echocardiographic evidence of primary myocardial involvement who underwent three-dimensional echocardiography (3DE) were included in this cross-sectional study and compared with healthy matched controls. 3DE was used for noninvasive measurements of end-systolic elastance (Ees), arterial elastance (Ea), VAC (Ea/Ees) and end-diastolic elastance (Eed); the occurrence of death/hospitalization for MACE was recorded during follow-up. Sixty-five SSc patients (54 female; aged 56 ± 14 years) were included. Ees (p = 0.04), Ea (p = 0.04) and Eed (p = 0.01) were higher in patients vs. controls. Thus, VAC was similar in both groups. Ees was lower and VAC was higher in patients with diffuse cutaneous form (dcSSc) vs. patients with limited form (lcSSc) (p = 0.001 and p = 0.02, respectively). Over a median follow-up of 4 years, four patients died for heart failure and 34 were hospitalized for CV events. In patients with VAC >0.63 the risk of MACE was higher (HR 2.5; 95% CI 1.13–5.7; p = 0.01) and survival free from death/hospitalization was lower (p = 0.005) than in those with VAC < 0.63. Our study suggests that VAC may be impaired in SSc patients without signs and symptoms of primary myocardial involvement. Moreover, VAC appears to have a prognostic role in SSc
Níveis de metano e perdas energéticas em bovinos de corte, suplementados ou não, em pastagem de capim mombaça (Panicum maximum cv. Mombaça).
Objetivou-se avaliar o impacto da suplementação protéico-energética na emissão de metano (CH4) de novilhos, durante a recria, em pastagem de capim-mombaça. Os tratamentos avaliados foram: T0 ? Apenas suplementação mineral; T1 ? Suplementação protéico-energética. Utilizou-se a técnica do gás traçador interno hexafluoreto de enxofre (SF6) para estimar a emissão diária de CH4. Foram utilizados 20 animais, sendo dez de cada tratamento, em dois ensaios, com medição de CH4 em cinco dias consecutivos. Na análise estatística dos dados de emissão de CH4 , utilizou-se a metodologia de modelos mistos para medidas repetidas do SAS. Os animais foram também avaliados quanto à eficiência de utilização do alimento, utilizando-se como critério o consumo alimentar residual (CAR). Animais suplementados e não suplementados não diferiram (P>0,05) quanto à produção diária de metano e quanto à perda total diária de energia na forma de CH4. Entretanto, quando a perda de energia foi expressa em g/kg de matéria seca consumida (21,51 vs. 29,76 g/kg) e como porcentagem da energia bruta (EB) ingerida (6,36 versus 8,59 %), os animais suplementados tiveram menores perdas (P0,05) quanto aos níveis de emissão de metano (total ou por kg de matéria seca ? MS ingerida). Assim, conclui-se que: a suplementação com concentrado age de forma efetiva na mitigação da emissão de metano; diferenças no CAR não podem ser atribuídas a diferenças nos níveis de emissão de metano
Nanoscale Assembly of Functional Peptides with Divergent Programming Elements
Self-assembling peptides are being applied both in the biomedical area and as building blocks in nanotechnology. Their applications are closely linked to their modes of self-assembly, which determine the functional nanostructures that they form. This work brings together two structural elements that direct nanoscale self-association in divergent directions: proline as a β-breaker and the β-structure-associated diphenylalanine motif, into a single tripeptide sequence. Amino acid chirality was found to resolve the tension inherent to these conflicting self-assembly instructions. Stereoconfiguration determined the ability of each of the eight possible Pro-Phe-Phe stereoisomers to self-associate into diverse nanostructures, including nanoparticles, nanotapes, or fibrils, which yielded hydrogels with gel-to-sol transition at a physiologically relevant temperature. Three single-crystal structures and all-atom molecular dynamics simulations elucidated the ability of each peptide to establish key interactions to form long-range assemblies (i,e., stacks leading to gelling fibrils), medium-range assemblies (i.e., stacks yielding nanotapes), or short-range assemblies (i.e., dimers or trimers that further associated into nanoparticles). Importantly, diphenylalanine is known to serve as a binding site for pathological amyloids, potentially allowing these heterochiral systems to influence the fibrillization of other biologically relevant peptides. To probe this hypothesis, all eight Pro-Phe-Phe stereoisomers were tested in vitro on the Alzheimer's disease-associated Aβ(1-42) peptide. Indeed, one nonfibril-forming stereoisomer effectively inhibited Aβ fibrillization through multivalent binding between diphenylalanine motifs. This work thus defined heterochirality as a useful feature to strategically develop future therapeutics to interfere with pathological processes, with the additional value of resistance to protease-mediated degradation and biocompatibility
Bisecting the mental number line in near and far space
Much evidence suggests that common posterior parietal mechanisms underlie the orientation of attention in physical space and along the mental number line. For example, the small leftward bias (pseudoneglect) found in paper-and-pencil line bisection is also found when participants "bisect" number pairs, estimating (without calculating) the number midway between two others. For bisection of physical lines, pseudoneglect has been found to shift rightward as lines are moved from near space (immediately surrounding the body) to far space. We investigated whether the presentation of stimuli in near or far space also modulated spatial attention for the mental number line. Participants bisected physical lines or number pairs presented at four distances (60, 120, 180, 240 cm). Clear rightward shifts in bias were observed for both tasks. Furthermore, the rate at which this shift occurred in the two tasks, as measured by least squares regression slopes, was significantly correlated across participants, suggesting that the transition from near to far distances induced a common modulation of lateral attention in physical and numerical space. These results demonstrate a tight coupling between number and physical space, and show that even such prototypically abstract concepts as number are modulated by our on-line interactions with the world
Heterochirality and Halogenation Control Phe-Phe Hierarchical Assembly
Diphenylalanine is an amyloidogenic building block that can form a versatile array of supramolecular materials. Its shortcomings, however, include the uncontrolled hierarchical assembly into microtubes of heterogeneous size distribution and well-known cytotoxicity. This study rationalized heterochirality as a successful strategy to address both of these pitfalls and it provided an unprotected heterochiral dipeptide that self-organized into a homogeneous and optically clear hydrogel with excellent ability to sustain fibroblast cell proliferation and viability. Substitution of one l-amino acid with its d-enantiomer preserved the ability of the dipeptide to self-organize into nanotubes, as shown by single-crystal XRD analysis, whereby the pattern of electrostatic and hydrogen bonding interactions of the backbone was unaltered. The effect of heterochirality was manifested in subtle changes in the positioning of the aromatic side chains, which resulted in weaker intermolecular interactions between nanotubes. As a result, d-Phe-l-Phe self-organized into homogeneous nanofibrils with a diameter of 4 nm, corresponding to two layers of peptides around a water channel, and yielded a transparent hydrogel. In contrast with homochiral Phe-Phe stereoisomer, it formed stable hydrogels thermoreversibly. d-Phe-l-Phe displayed no amyloid toxicity in cell cultures with fibroblast cells proliferating in high numbers and viability on this biomaterial, marking it as a preferred substrate over tissue-culture plastic. Halogenation also enabled the tailoring of d-Phe-l-Phe self-organization. Fluorination allowed analogous supramolecular packing as confirmed by XRD, thus nanotube formation, and gave intermediate levels of bundling. In contrast, iodination was the most effective strategy to augment the stability of the resulting hydrogel, although at the expense of optical transparency and biocompatibility. Interestingly, iodine presence hindered the supramolecular packing into nanotubes, resulting instead into amphipathic layers of stacked peptides without the occurrence of halogen bonding. By unravelling fine details to control these materials at the meso- A nd macro-scale, this study significantly advanced our understanding of these systems
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