The thermodynamic properties of ionic liquids (ILs) bearing alkylsilane and alkylsiloxane chains, as well as their carbon-based analogs, were investigated. Effects such as the replacement of carbon ...atoms by silicon atoms, the introduction of a siloxane linkage, and the length of the alkylsilane chain were explored. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to study the thermal and phase behavior (glass transition temperature, melting point, enthalpy and entropy of fusion, and thermal stability). Heat capacity was obtained by high-precision drop calorimetry and differential scanning microcalorimetry. The volatility and cohesive energy of these ILs were investigated via the Knudsen effusion method coupled with a quartz crystal microbalance (KEQCM). Gas phase energetics and structure were also studied to obtain the gas phase heat capacity as well as the energy profile associated with the rotation of the IL side chain. The computational study suggested the existence of an intramolecular interaction in the alkylsiloxane-based IL. The obtained glass transition temperatures seem to follow the trend of chain flexibility. An increase of the alkylsilane chain leads to a seemingly linear increase in molar heat capacity. A regular increment of 30 J·K–1·mol–1 in the molar heat capacity was found for the replacement of carbon by silicon in the IL alkyl chain. The alkylsilane series was revealed to be slightly more volatile than its carbon-based analogs. A further increase in volatility was found for the alkylsiloxane-based IL, which is likely related to the decrease of the cohesive energy due to the existence of an intramolecular interaction between the siloxane linkage and the imidazolium headgroup. The use of Si in the IL structure is a suitable way to significantly reduce the IL’s viscosity while preserving its large liquid range (low melting point and high thermal stability) and low volatilities.
This study tested whether three different cement layer thicknesses (60, 120 and 180 μm) would provide the same bonding capacity between adhesively luted lithium disilicate and human dentin. Ceramic ...blocks were cut to 20 blocks with a low-speed diamond saw under cooling water and were then cemented to human flat dentin with an adhesive protocol. The assembly was sectioned into 1 mm2 cross-section beams composed of ceramic/cement/dentin. Cement layer thickness was measured, and three groups were formed. Half of the samples were immediately tested to evaluate the short-term bond strength and the other half were submitted to an aging simulation. The microtensile test was performed in a universal testing machine, and the bond strength (MPa) was calculated. The fractured specimens were examined under stereomicroscopy. Applying the finite element method, the residual stress of polymerization shrinkage according to cement layer thickness was also calculated using first principal stress as analysis criteria. Kruskal–Wallis tests showed that the ‘‘cement layer thickness’’ factor significantly influenced the bond strength results for the aged samples (p = 0.028); however, no statistically significant difference was found between the immediately tested groups (p = 0.569). The higher the cement layer thickness, the higher the residual stress generated at the adhesive interface due to cement polymerization shrinkage. In conclusion, the cement layer thickness does not affect the immediate bond strength in lithium disilicate restorations; however, thinner cement layers are most stable in the short term, showing constant bond strength and lower residual stress.
Familial colorectal cancer type X (FCCTX) is a heterogeneous colorectal cancer predisposition syndrome that, although displays a cancer pattern similar to Lynch syndrome, is mismatch repair ...proficient and does not exhibit microsatellite instability. Besides, its genetic etiology remains to be elucidated. In this study we performed germline exome sequencing of 39 cancer-affected patients from 34 families at risk for FCCTX. Variant classification followed the American College of Medical Genetics and Genomics (ACMG) guidelines. Pathogenic/likely pathogenic variants were identified in 17.65% of the families. Rare and potentially pathogenic alterations were identified in known hereditary cancer genes (CHEK2), in putative FCCTX candidate genes (OGG1 and FAN1) and in other cancer-related genes such as ATR, ASXL1, PARK2, SLX4 and TREX1. This study provides novel important clues that can contribute to the understanding of FCCTX genetic basis.
Summary Objective To evaluate and characterize macrophage populations (M1/M2) in the tumor microenvironment of oral cavity squamous cell carcinoma (OCSCC). The relationship between macrophages and ...clinicopathological factors, such as survival data, lymph node metastasis, tumoral proliferation, and WHO histological grading are also analyzed. Materials and methods The samples consisted of surgically excised specimens from patients with non-metastatic and metastatic OCSCC and normal oral mucosa (control). Immunohistochemistry, flow cytometry, and qRT-PCR were used to evaluate macrophage populations and the expression of pro- (IL-12, IL-23, and INF-γ) and anti-inflammatory (IL-10 and TGF-β) cytokines. The level required for statistical significance was defined as p < 0.05. Results The data showed a predominance of M2 phenotype (high percentage of IL-10+ TGF-β+ ) macrophages in the tumor microenvironment of OCSCC. A higher percentage of macrophages expressing TGF-β was seen in the OCSCC group when compared with healthy individuals. The assessment of mRNA expression also presented a greater expression of anti-inflammatory cytokines TGF β and IL10 in OCSCC when compared with the control group. The percentage of macrophages, demonstrated by immunohistochemistry, was significantly higher in the metastatic OCSCC group than in the non-metastatic and control groups. The log-rank test also showed that the mean survival time for patients with high levels of macrophages was less (44 months) when compared with patients with a low percentage of such cells (93 months). Conclusion A predominance of the M2 phenotype in the tumor microenvironment of OCSCC could contribute to local immunosuppression, via TGF-β production, and consequently greater lymph node involvement and reduced patient survival time.
Nowadays, neurodegenerative diseases (NDs), such as Parkinsons disease (PD), Alzheimers disease (AD), Huntingtons disease (HD), and amyotrophic lateral sclerosis (ALS), represent a great challenge in ...different scientific fields, such as neuropharmacology, medicinal chemistry, molecular biology and medicine, as all these pathologies remain incurable, with high socioeconomic impacts and high costs for governmental health services. Due to their severity and multifactorial pathophysiological complexity, the available approved drugs for clinic have not yet shown adequate effectiveness and exhibited very restricted options in the therapeutic arsenal; this highlights the need for continued drug discovery efforts in the academia and industry. In this context, natural products, such as curcumin (1), resveratrol (2) and cannabidiol (CBD, 3) have been recognized as important sources, with promising chemical entities, prototype models and starting materials for medicinal organic chemistry, as their molecular architecture, multifunctional properties and single chemical diversity could facilitate the discovery, optimization and development of innovative drug candidates with improved pharmacodynamics and pharmacokinetics compared to the known drugs and, perhaps, provide a chance for discovering novel effective drugs to combat NDs. In this review, we report the most recent efforts of medicinal chemists worldwide devoted to the exploration of curcumin (1), resveratrol (2) and cannabidiol (CBD, 3) as starting materials or privileged scaffolds in the design of multi-target directed ligands (MTDLs) with potential therapeutic properties against NDs, which have been published in the scientific literature during the last 10 years of research and are available in PubMed, SCOPUS and Web of Science databases.
The derivation of the piezoelectric equations requires only the Maxwell equations of electrostatics and the momentum equation with electric forces, together with the constitutive equations derived ...from the first principle of thermodynamics. In the non-isothermal case, the inclusion of thermal conduction requires also the second principle of thermodynamics and then the equation of energy becomes necessary. Furthermore, in the viscoelastic case, the viscous stresses modify the momentum and energy equations. The sequence outlined above provides the simplest derivation of the fundamental equation of anisothermal viscoelastic piezoelectricity including thermal and viscous dissipation. The equations of piezomagnetism are similar to those of piezoelectricity, replacing the electric by magnetic fields. The coupling of the unsteady electric and magnetic fields through electromagnetic waves interacts with both piezoelectricity and piezomagnetism leading to piezoelectromagnetism. In the general case of unsteady anisothermal piezoelectromagnetism, the energy, momentum and Maxwell equations specify the temperature, displacement vector, electric field and magnetic field. The coefficients involve constitutive and diffusion tensors specifying the properties of matter, generally anisotropic, such as crystals and orthotropic plates. They can also specify the properties of amorphous substances corresponding to the simplest isotropic case.
•The equations of piezoelectricity are extended to include thermal stresses and conduction and viscoelastic effects.•The extension to piezoelectromagnetism combines unsteady piezoelectricity and piezomagnetism with electromagnetic waves.•Dissipative effects include thermal conduction and relaxation, Ohmic electrical conductivity and viscosity.•The equations are valid for general anisotropic materials as crystals or orthotropic plates, with isotropy a particular case.•The constitutive and diffusive tensors are defined from thermodynamic relations.
The objective of this study is to propose a new post-treatment of effluents from Upflow Anaerobic Sludge Blanket (UASB) using rapid filtration, aiming at the production of water for potable reuse. ...The final quality of the effluent produced by the treatment using gravel, sand, clinoptilolite and activated carbon associated with disinfection was evaluated by physical chemical analysis, heavy metals and persistent organic contaminants. Experiments were carried out in jar test, filter operation time, evaluation of the efficiency using peracetic acid and free chlorine as disinfectant and all results were statistically analysed. The best conditions were those using 20 mg/L of ferric chloride and natural pH of the effluent (≈ 7.0), which resulted in less reagent consumption. The use of intermediate fund discharges made it possible to obtain approximately 91% of recovered water efficiency. The effluent treated under these conditions showed DOC <2.0 mg/L, COD <1.0 mg/L, BOD <1.0 mg/L, turbidity <1.0 NTU, TSS <1.0 mg/L, ammonia <0.1 mg/L, total phosphorus <0.1 mg/L and surfactants <0.1 mg/L. The disinfection process with free chlorine and PAA allowed the total inactivation of faecal coliforms and total coliforms. The treatment using rapid filtration with disinfection by chlorine reached the appropriate level for urban, environmental, industrial and indirect potable water reuse.
Proteins from microalgal biomass have become promising raw materials in several industrial segments. To evaluate growth performance and protein production under different nutritional conditions, ...Haematococcus pluvialis was grown in different culture media: BBM, RM, BG-11, and KM2. The cultures were inoculated at 105 cells mL-1, and submitted to a temperature of 24°C, in a continous photoperiod and irradiance of 40 µmol photons m-2 s-1. The highest cell density was observed when H. pluvialis was maintained in BG-11 medium (142 ± 30 × 104 cells mL-1), but no statistical difference was observed when comparing the results with those obtained when culturing this microalga in BBM (101 ± 14 × 104 cells mL-1) and RM (105 ± 5 × 104 cells mL-1) media. Also, the lowest cell density was found when cultivating H. pluvialis in KM2 medium (57 ± 9 × 104 cells mL-1), and there was no statistical difference for doubling time, growth rate and specific growth rate results between treatments. In addition, higher protein contents in H. pluvialis were reported for RM, BG-11, and KM2 culture media at 55.1 ± 5.6, 49.3 ± 3.6 and 58.4 ± 2.8%, respectively; and lower protein content was found using the BBM medium (31.1 ± 2.9%). The highest cell density and biomass were achieved at greater nitrogen availability and a higher nitrogen to phosphorus ratio. The results suggest that H. pluvialis is a potential species for protein production, and that BG-11 is the most suitable medium for growing this microalga as it allowed the achievement of highest biomass production and protein content among the media evaluated.
Alzheimer's disease (AD) is characterized by progressive cognitive decline associated with a featured neuropathology (neuritic plaques and neurofibrillary tangles). Several studies have implicated ...oxidative damage to DNA, DNA repair, and altered cell-cycle regulation in addition to cell death in AD post-mitotic neurons. However, there is a lack of studies that systematically assess those biological processes in patients with AD neuropathology but with no evidence of cognitive impairment. We evaluated markers of oxidative DNA damage (8-OHdG, H2AX), DNA repair (p53, BRCA1, PTEN), and cell-cycle (Cdk1, Cdk4, Cdk5, Cyclin B1, Cyclin D1, p27Kip1, phospho-Rb and E2F1) through immunohistochemistry and cell death through TUNEL in autopsy hippocampal tissue samples arrayed in a tissue microarray (TMA) composed of three groups: I) "clinical-pathological AD" (CP-AD)--subjects with neuropathological AD (Braak ≥ IV and CERAD = B or C) and clinical dementia (CDR ≥ 2, IQCODE>3.8); II) "pathological AD" (P-AD)--subjects with neuropathological AD (Braak ≥ IV and CERAD = B or C) and without cognitive impairment (CDR 0, IQCODE<3.2); and III) "normal aging" (N)--subjects without neuropathological AD (Braak ≤ II and CERAD 0 or A) and with normal cognitive function (CDR 0, IQCODE<3.2). Our results show that high levels of oxidative DNA damage are present in all groups. However, significant reductions in DNA repair and cell-cycle inhibition markers and increases in cell-cycle progression and cell death markers in subjects with CP-AD were detected when compared to both P-AD and N groups, whereas there were no significant differences in the studied markers between P-AD individuals and N subjects. This study indicates that, even in the setting of pathological AD, healthy cognition may be associated with a preserved repair to DNA damage, cell-cycle regulation, and cell death in post-mitotic neurons.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Malaria cases in Brazil are concentrated in the Amazon region. In the state of Pará, malaria is considered an endemic disease, and the population has different levels of exposure, which contributes ...to different types of occurrence in the municipalities.
A descriptive, cross-sectional, and ecological study was conducted using data from the Malaria Epidemiological Surveillance System of the municipalities of Cametá and Tucuruí, PA, Brazil, from 2014 to 2018; the Brazilian Institute of Geography and Statistics; and the National Registry of Health Institutions of the Ministry of Health. Statistical and spatial analyses of epidemiological, laboratory and public health service coverage variables were performed using the Bioestat 5.0 and ArcGis 10.5 software.
11,381 Malaria cases were reported in the two municipalities. The highest percentage of case notifications was reported in brown-skinned men aged from 19 and 59 years, and who had primary education levels. The predominant occupations were farming and livestock in Cametá and domestic activity in Tucuruí. The most common diagnostic examination used was a thick blood smear, and Plasmodium vivax was the species most often encountered. The percentage of primary care coverage increased during the study period. The spatial distribution of the disease was not homogeneous, and there were clusters of cases with different densities in Cametá and Tucuruí.
Malaria is a public health problem in the municipalities of Cametá and Tucuruí, because of its transmission dynamics and variable spatial distribution as well as the coexistence of factors that favor the exposure of resident populations to epidemiological situations, thus reflecting health inequities.
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