We have studied the possible reaction pathways operating in the Pd-catalyzed remote C–H functionalization of N-(2-haloaryl)acrylamides from an organometallic approach. We have isolated and ...characterized several proposed reaction intermediates, such as σ-alkyl-Pd complexes and spiro C,C-palladacycles, and evaluated the role of the base and the auxiliary ligands coordinated to Pd in the remote C–H activation process. In addition, the reactivity of these intermediates toward different unsaturated species such as benzyne, alkynes, and isocyanides has been studied in order to gain further insight into the reaction mechanism leading to functionalized spiro-oxoindoles.
•CO2 EERC for low-temperature refrigeration in warm climates is studied.•The triple point inside the two-phase flow ejector is analyzed.•The operating envelope of commercial compressors is ...considered.•A thermoeconomic optimization using NPV as objective function is conducted.•Better COPs and lower investment costs are achieved compared to the basic transcritical cycle.
Refrigeration industry is adopting a proactive strategy to phase out fluorinated greenhouse gases by more sustainable working fluids. R744 is a natural refrigerant widely proposed for commercial refrigeration. Its use in cascade and booster cycles allows a combined cooling and freezing production. However, when single-stage evaporation at low temperature is required, the adoption of R744 in transcritical cycles is scarce. The main reasons are due to the low Coefficient of Performance (COP) achieved, as well as the technical limitations to reach extreme pressure ratios using commercial compressors. In light of this, this paper proposes to use the CO2 Ejector-Expansion Refrigeration Cycle (EERC) to overcome these drawbacks. To assess the feasibility of the proposal, a thermoeconomic optimization is conducted for low-temperature refrigeration in warm climates. The analysis has been conducted considering a two-phase flow ejector, a commercial double-stage compressor, and evaporating conditions ranging from −10 °C to −38.11 °C, which was revealed the minimum temperature to avoid the triple point inside the ejector. The results showed that the EERC allows using smaller commercial compressors within a broader operating envelope, improving the annual average COP about 5.5% compared to the reference cycle, besides reducing investment and yearly energy consumption costs.
Prostate cancer (PCa) is the most commonly diagnosed cancer in men. The diagnosis is currently based on PSA levels, which are associated with overdiagnosis and overtreatment. Moreover, most PCas are ...localized tumours; hence, many patients with low-/very low-risk PCa could benefit from active surveillance (AS) programs instead of more aggressive, active treatments. Heterogeneity within inclusion criteria and follow-up strategies are the main controversial issues that AS presently faces. Many biomarkers are currently under investigation in this setting; however, none has yet demonstrated enough diagnostic ability as an independent predictor of pathological or clinical progression. This work aims to review the currently available literature on tissue, blood and urine biomarkers validated in clinical practice for the management of AS patients.
The order Mucorales is a group of ancient fungi with limited tools for gene manipulation. The main consequence of this manipulation unwillingness is the limited knowledge about its biology compared ...to other fungal groups. However, the emerging of mucormycosis, a fungal infection caused by Mucorales, is attracting the medical spotlight in recent years because the treatments available are not efficient in reducing the high mortality associated with this disease. The result of this renewed interest in Mucorales and mucormycosis is an extraordinarily productive effort to unveil their secrets during the last decade. In this review, we describe the most compelling advances related to the genetic study of virulence factors, pathways, and molecular mechanisms developed in these years. The use of a few genetic study models has allowed the characterization of virulence factors in Mucorales that were previously described in other pathogens, such as the uptake iron systems, the mechanisms of dimorphism, and azole resistances. More importantly, recent studies are identifying new genes and mechanisms controlling the pathogenic potential of Mucorales and their interactions with the host, offering new alternatives to develop specific strategies against mucormycosis.
All metazoans depend on the consumption of O
by the mitochondrial oxidative phosphorylation system (OXPHOS) to produce energy. In addition, the OXPHOS uses O
to produce reactive oxygen species that ...can drive cell adaptations
, a phenomenon that occurs in hypoxia
and whose precise mechanism remains unknown. Ca
is the best known ion that acts as a second messenger
, yet the role ascribed to Na
is to serve as a mere mediator of membrane potential
. Here we show that Na
acts as a second messenger that regulates OXPHOS function and the production of reactive oxygen species by modulating the fluidity of the inner mitochondrial membrane. A conformational shift in mitochondrial complex I during acute hypoxia
drives acidification of the matrix and the release of free Ca
from calcium phosphate (CaP) precipitates. The concomitant activation of the mitochondrial Na
/Ca
exchanger promotes the import of Na
into the matrix. Na
interacts with phospholipids, reducing inner mitochondrial membrane fluidity and the mobility of free ubiquinone between complex II and complex III, but not inside supercomplexes. As a consequence, superoxide is produced at complex III. The inhibition of Na
import through the Na
/Ca
exchanger is sufficient to block this pathway, preventing adaptation to hypoxia. These results reveal that Na
controls OXPHOS function and redox signalling through an unexpected interaction with phospholipids, with profound consequences for cellular metabolism.
Reduction of sludge production is one of the most desired goals in the wastewater treatment plants operation. Alternatives like the enhancement of metabolism uncoupling or the increase of endogenous ...respiration by different chemicals have been reported in the bibliography. In this work, two folic acid concentrations (0.8 and 1.6 mg L−1) added to a laboratory sequencing batch reactor were tested in order to assess the effect of this vitamin on the biological treatment. For this purpose, in addition to study sludge reduction and organic matter removal, an exhaustive biomass characterization including soluble microbial products, cellular viability, adenosine triphosphate (ATP), microbial hydrolytic enzymatic activities and bacterial community analysis have been performed. Results indicated that a concentration of 0.8 mg L−1 led to the greatest sludge reduction (44.7%), due to the increase of endogenous respiration. In the reactor with folic acid addition, higher soluble microbial products, enzymatic activities, cellular viability and lower cellular ATP was observed. Regarding the microbial community, folic acid addition did not affect nitrifying bacteria although it did reduce the abundance of denitrifying, increased the amount of filamentous bacteria (Caldilineacaeae and Haliscomenobacter) and enhanced Bacteriodetes and Chloroflexi phyla. A continuous addition of folic acid drove to biomass adaptation that caused a diminution of folic acid activity after 40 days.
•Addition of 0.8 mg L−1 of folic acid (FA) reduced the sludge production by 44.7%.•Mechanism of sludge reduction was the enhancement of the endogenous respiration.•FA addition increased SRT due to decrease on sludge production.•FA addition increased SMP(=soluble microbial products), enzymatic activities, cellular viability and Bacteriodetes and Chloroflexi phyla.•Once biomass adapted to FA (44 days) the sludge production rose again.
Skeletonization algorithms are used as basic methods to solve tracking problems, pose estimation, or predict animal group behavior. Traditional skeletonization techniques, based on image processing ...algorithms, are very sensitive to the shapes of the connected components in the initial segmented image, especially when these are low-resolution images. Currently, neural networks are an alternative providing more robust results in the presence of image-based noise. However, training a deep neural network requires a very large and balanced dataset, which is sometimes too expensive or impossible to obtain. This work proposes a new training method based on a custom-generated dataset with a synthetic image simulator. This training method was applied to different U-Net neural networks architectures to solve the problem of skeletonization using low-resolution images of multiple
Caenorhabditis elegans
contained in Petri dishes measuring 55 mm in diameter. These U-Net models had only been trained and validated with a synthetic image; however, they were successfully tested with a dataset of real images. All the U-Net models presented a good generalization of the real dataset, endorsing the proposed learning method, and also gave good skeletonization results in the presence of image-based noise. The best U-Net model presented a significant improvement of 3.32% with respect to previous work using traditional image processing techniques.
Recurrent disease outbreaks caused by different viruses, including the novel respiratory virus SARS-CoV-2, are challenging our society at a global scale; so versatile virus detection methods would ...enable a calculated and faster response. Here, we present a novel nucleic acid detection strategy based on CRISPR-Cas9, whose mode of action relies on strand displacement rather than on collateral catalysis, using the Streptococcus pyogenes Cas9 nuclease. Given a preamplification process, a suitable molecular beacon interacts with the ternary CRISPR complex upon targeting to produce a fluorescent signal. We show that SARS-CoV-2 DNA amplicons generated from patient samples can be detected with CRISPR-Cas9. We also show that CRISPR-Cas9 allows the simultaneous detection of different DNA amplicons with the same nuclease, either to detect different SARS-CoV-2 regions or different respiratory viruses. Furthermore, we demonstrate that engineered DNA logic circuits can process different SARS-CoV-2 signals detected by the CRISPR complexes. Collectively, this CRISPR-Cas9 R-loop usage for the molecular beacon opening (COLUMBO) platform allows a multiplexed detection in a single tube, complements the existing CRISPR-based methods, and displays diagnostic and biocomputing potential.
Diabetes and metabolic syndrome are associated with the typical American high glycemia diet and result in accumulation of high levels of advanced glycation end products (AGEs), particularly upon ...aging. AGEs form when sugars or their metabolites react with proteins. Associated with a myriad of age‐related diseases, AGEs accumulate in many tissues and are cytotoxic. To date, efforts to limit glycation pharmacologically have failed in human trials. Thus, it is crucial to identify systems that remove AGEs, but such research is scanty. Here, we determined if and how AGEs might be cleared by autophagy. Our in vivo mouse and C. elegans models, in which we altered proteolysis or glycative burden, as well as experiments in five types of cells, revealed more than six criteria indicating that p62‐dependent autophagy is a conserved pathway that plays a critical role in the removal of AGEs. Activation of autophagic removal of AGEs requires p62, and blocking this pathway results in accumulation of AGEs and compromised viability. Deficiency of p62 accelerates accumulation of AGEs in soluble and insoluble fractions. p62 itself is subject to glycative inactivation and accumulates as high mass species. Accumulation of p62 in retinal pigment epithelium is reversed by switching to a lower glycemia diet. Since diminution of glycative damage is associated with reduced risk for age‐related diseases, including age‐related macular degeneration, cardiovascular disease, diabetes, Alzheimer's, and Parkinson's, discovery of methods to limit AGEs or enhance p62‐dependent autophagy offers novel potential therapeutic targets to treat AGEs‐related pathologies.
AGEs are toxic compounds formed by non‐enzymatic reactions between sugars and proteins. AGEs are prone to aggregate. Insoluble AGEs are efficiently removed via p62‐selective autophagy. The autophagic removal of AGEs is a conserved pathway, and the lack of p62 leads to accumulation of toxic AGEs in mouse and worms. Enhanced autophagy is protective against glycation‐derived damage. p62‐dependent autophagy offers novel potential therapeutic targets to treat AGEs‐related pathologies.
This paper presents a new multiobjective Tabu search (NMTS) algorithm to solve a multiobjective fuzzy model for optimal planning of distribution systems. This algorithm obtains multiobjective ...nondominated solutions to three objective functions: fuzzy economic cost, level of fuzzy reliability, and exposure (maximization of robustness), also including optimal size and location of reserve feeders to be built for maximizing the level of reliability at the lowest economic cost (for a given level of robustness). The main characteristics of the NMTS algorithm are: search of planning solutions using several objective functions simultaneously; partition of the space of solutions to diversify the search; intensification of the search by ranking lists of the best network nodes of the distribution system; and an elaborated Tabu list that stores visited network nodes, avoiding unwanted movements. The NMTS algorithm has been intensively tested in real distribution systems, proving its practical application in large power distribution systems.
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