Heterocyclic Anticancer Compounds: Recent Advances and the Paradigm Shift towards the Use of Nanomedicine's Tool Box.

The majority of heterocycle compounds and typically common heterocycle fragments present in most pharmaceuticals currently marketed, alongside with their intrinsic versatility and unique physicochemical properties, have poised them as true cornerstones of medicinal chemistry. Apart from the already marketed drugs, there are many other being investigated for their promising activity against several malignancies. In particular, anticancer research has been capitalizing on the intrinsic versatility and dynamic core scaffold of these compounds. Nevertheless, as for any other promising anticancer drugs, heterocyclic compounds do not come without shortcomings. In this review, we provide for a concise overview of heterocyclic active compounds and families and their main applications in medicine. We shall focus on those suitable for cancer therapy while simultaneously addressing main biochemical modes of action, biological targets, structure-activity relationships as well as intrinsic limitation issues in the use of these compounds. Finally, considering the advent of nanotechnology for effective selective targeting of drugs, we shall discuss fundamental aspects and considerations on nanovectorization of such compounds that may improve pharmacokinetic/pharmacodynamic properties of heterocycles.

Effect of gamma irradiation on the nutritional quality of Agaricus bisporus strains cultivated in different composts.

The effect of irradiation doses (0, 125, 250 and 500 Gy) on the nutritional quality of A. bisporus mushrooms (strains ABI-07/06, ABI-05/03 and PB-1) cultivated in composts based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) was evaluated. The experimental design was 4 x 3 x 2 factorial scheme (irradiation doses x strains x composts), with 24 treatments, consisting of two repetitions each, totaling 48 experimental units (samples of mushrooms). The samples were irradiated in Cobalt-60 irradiator, model Gammacell 220 kGy, with dose rate of 0.740 kGy h-1, according to the treatments proposed. Subsequently, the control (unirradiated) and the other treatments were maintained at 4±1°C and 90% RH in a climatic chamber for carrying out the chemical analysis of the mushrooms on the 1st and 14th day of storage. It was found that all A. bisporus strains evaluated were food with excellent nutritional value, because they presented high protein and fiber contents and low ethereal extract content; the chemical characterization of the mushrooms was influenced by the compost type in which they were cultivated; gamma irradiation influenced the chemical composition of mushrooms.

Effects of surgical masks on the responses to constant work-rate cycling performed at different intensity domains.

We aimed at examining the impact of wearing surgical face masks on exercise performance. Thirty-two healthy adults (16 males and 16 females) completed a graded exercise test to measure peak oxygen uptake (VO2peak ) and the ventilatory threshold (VT). Then, on separate days, all participants performed resting and standardized protocols (moderate intensity: 25% infra-VT; severe intensity: 25% supra-VT) on two different conditions (with and without a surgical mask). The use of masks reduced both VO2 and minute ventilation during moderate and severe exercise (p < 0.0001), and this effect was particularly pronounced during severe exercise. Time to exhaustion was also shortened by ~10% on the face mask condition (p = 0.014). In contrast, neither heart rate nor the respiratory exchange ratio was affected by masking. The submaximal VO2 was similar between the two epochs of analysis obtained during moderate cycling (i.e. 3-6 min vs. 7-10 min) and this occurred similarly between conditions. In conclusion, the impact of the surgical masks on exercise capacity is particularly pronounced during severe exercise performed at constant work rate. Ultimately, this may implicate a considerable impairment of structured or even unstructured strenuous physical activity. Clinical Trials registration number: NCT04963049.

Effect of drug metabolism in the treatment of SARS-CoV-2 from an entirely computational perspective.

Understanding the effects of metabolism on the rational design of novel and more effective drugs is still a considerable challenge. To the best of our knowledge, there are no entirely computational strategies that make it possible to predict these effects. From this perspective, the development of such methodologies could contribute to significantly reduce the side effects of medicines, leading to the emergence of more effective and safer drugs. Thereby, in this study, our strategy is based on simulating the electron ionization mass spectrometry (EI-MS) fragmentation of the drug molecules and combined with molecular docking and ADMET models in two different situations. In the first model, the drug is docked without considering the possible metabolic effects. In the second model, each of the intermediates from the EI-MS results is docked, and metabolism occurs before the drug accesses the biological target. As a proof of concept, in this work, we investigate the main antiviral drugs used in clinical research to treat COVID-19. As a result, our strategy made it possible to assess the biological activity and toxicity of all potential by-products. We believed that our findings provide new chemical insights that can benefit the rational development of novel drugs in the future.

Theoretical insights into the effect of halogenated substituent on the electronic structure and spectroscopic properties of the favipiravir tautomeric forms and its implications for the treatment of COVID-19.

In this study, we systematically investigated the electronic structure, spectroscopic (nuclear magnetic resonance, infrared, Raman, electron ionization mass spectrometry, UV-Vis, circular dichroism, and emission) properties, and tautomerism of halogenated favipiravir compounds (fluorine, chlorine, and bromine) from a computational perspective. Additionally, the effects of hydration on the proton transfer mechanism of the tautomeric forms of the halogenated favipiravir compounds are discussed. Our results suggest that spectroscopic properties allow for the elucidation of such tautomeric forms. As is well-known, the favipiravir compound has excellent antiviral properties and hence was recently tested for the treatment of new coronavirus (SARS-CoV-2). Through in silico modeling, in the current study, we evaluate the role of such tautomeric forms in order to consider the effect of drug-metabolism in the inhibition process of the main protease (Mpro) and RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 virus. According to the molecular docking, all halogenated compounds presented a better interaction energy than the co-crystallized active ligand (-3.5 kcal mol-1) in the viral RdRp, in both wild-type (-6.3 to -6.5 kcal mol-1) and variant (-5.4 to -5.6 kcal mol-1) models. The variant analyzed for RdRp (Y176C) decreases the affinity of the keto form of the compounds in the active site, and prevented the ligands from interacting with RNA. These findings clearly indicated that all these compounds are promising as drug candidates for this molecular target.

Computational evidence for nitro derivatives of quinoline and quinoline N-oxide as low-cost alternative for the treatment of SARS-CoV-2 infection.

A new and more aggressive strain of coronavirus, known as SARS-CoV-2, which is highly contagious, has rapidly spread across the planet within a short period of time. Due to its high transmission rate and the significant time-space between infection and manifestation of symptoms, the WHO recently declared this a pandemic. Because of the exponentially growing number of new cases of both infections and deaths, development of new therapeutic options to help fight this pandemic is urgently needed. The target molecules of this study were the nitro derivatives of quinoline and quinoline N-oxide. Computational design at the DFT level, docking studies, and molecular dynamics methods as a well-reasoned strategy will aid in elucidating the fundamental physicochemical properties and molecular functions of a diversity of compounds, directly accelerating the process of discovering new drugs. In this study, we discovered isomers based on the nitro derivatives of quinoline and quinoline N-oxide, which are biologically active compounds and may be low-cost alternatives for the treatment of infections induced by SARS-CoV-2.

TGFß2-induced formation of lipid droplets supports acidosis-driven EMT and the metastatic spreading of cancer cells.

Acidosis, a common characteristic of the tumor microenvironment, is associated with alterations in metabolic preferences of cancer cells and progression of the disease. Here we identify the TGF-ß2 isoform at the interface between these observations. We document that acidic pH promotes autocrine TGF-ß2 signaling, which in turn favors the formation of lipid droplets (LD) that represent energy stores readily available to support anoikis resistance and cancer cell invasiveness. We find that, in cancer cells of various origins, acidosis-induced TGF-ß2 activation promotes both partial epithelial-to-mesenchymal transition (EMT) and fatty acid metabolism, the latter supporting Smad2 acetylation. We show that upon TGF-ß2 stimulation, PKC-zeta-mediated translocation of CD36 facilitates the uptake of fatty acids that are either stored as triglycerides in LD through DGAT1 or oxidized to generate ATP to fulfill immediate cellular needs. We also address how, by preventing fatty acid mobilization from LD, distant metastatic spreading may be inhibited.

Effect of plants in constructed wetlands for organic carbon and nutrient removal: a review of experimental factors contributing to higher impact and suggestions for future guidelines.

Constructed wetland is a proven technology for water pollution removal, but process mechanisms and their respective contribution are not fully understood. The present review details the effect of plants on removal efficiency of constructed wetlands by focusing on literature that includes experiments with unplanted controls for organic carbon and nutrient (N and P) removal. The contribution of plant direct uptake is also assessed. Although it was found that several studies, mostly at laboratory or pilot scales, showed no statistical differences between planted and unplanted controls, some factors were found that help maximize the effect of plants. This study intends to contribute to a better understanding of the significance of the effect of plants in a constructed wetland, as well as to suggest a set of experimental guidelines in this field.

Doação de sangue durante a pandemia da Covid-19: conhecimentos, práticas e atitudes dos estudantes de medicina / Blood donation during the Covid-19 pandemic: knowledge, practices and attitudes of medical students

Doação voluntária de sangue é um ato desafiador, em especial, durante períodos de crise sanitária. O propósito deste estudo transversal foi analisar os conhecimentos, práticas e atitudes dos estudantes de medicina, do ciclo básico ao internato, quanto à doação de sangue durante a pandemia da Covid-19. O trabalho foi realizado entre maio e dezembro de 2021, via Google forms. Para motivo de comparação, a amostra (n=327) foi dividida em do-adores (n=183) e não doadores (n=144) de sangue e utilizado teste qui-quadrado e teste exato de Fisher, sendo considerado estatisticamente significantes perguntas que obtiveram valores com p<0,05. Os resultados indicam que, mesmo sendo a minoria de ambos os grupos, ainda há uma quantidade significativa de estudantes de medicina que apresentam pouco domínio sobre o processo de doação de sangue, além de estarem permeados por medo e desinformação sobre a segurança da coleta. Fatos estes, ainda mais perceptíveis durante o período da pandemia, no qual o percentual de doadores foi de 30,6%. Desta forma, ressalta-se a necessidade de estratégias educacionais criativas e contextualizadas para esclarecer e sensibilizar melhor os jovens para este ato de solidariedade (AU).

Voluntary blood donation is a challenging act, especially during a health crisis. The purpose of this cross-sectional study was to analyze the knowledge, practices, and attitudes of medical students, from the basic cycle to the internship, regarding blood donation during the Covid-19 pandemic. The work was carried out between May and December 2021 via Google Forms. For comparison, the sample (n=327) was divided into blood donors (n=183) and non-donors (n=144). The chi-square and Fisher's exact tests were used, considering statistically significant questions with p<0.05 p-value. The results indicate that, even though they are a minority of both groups, there is still a significant number of medical students who do not know much about the blood donation process and are permeated by fear and misinformation about blood collection safety. These facts were even more noticeable during the pandemic, in which the percentage of donors was 30.6%. In this way, the need for creative and contextualized educational strategies is highlighted to clarify and better sensitize young people to this act of solidarity (AU).

Extensive review of shale gas environmental impacts from scientific literature (2010-2015).

Extensive reviews and meta-analyses are essential to summarize emerging developments in a specific field and offering information on the current trends in the scientific literature. Shale gas exploration and exploitation has been extensively debated in literature, but a comprehensive review of recent studies on the environmental impacts has yet to be carried out. Therefore, the goal of this article is to systematically examine scientific articles published between 2010 and 2015 and identify recent advances and existing data gaps. The examined articles were classified into six main categories (water resources, atmospheric emissions, land use, induced seismicity, occupational and public health and safety, and other impacts). These categories are analyzed separately to identify specific challenges, possibly existing consensus and data gaps yet remained in the literature.

Role of three different plants on simultaneous salt and nutrient reduction from saline synthetic wastewater in lab-scale constructed wetlands.

Constructed Wetlands (CWs) can be a valuable technology to treat high salinity wastewaters but it is not known their potential for removal of both nutrients and salt, and the type of plants to use. This study evaluated the effect of three plants on salt reduction and simultaneous nutrient removal in CWs microcosms with expanded clay and in hydroponic conditions. Initial values of the synthetic wastewater tested were EC=15dSm-1, SAR=151; NH4+-N=24mgL-1; PO43--P=30mgL-1 and NO3--N=34mgL-1. With expanded clay CW removal efficiency for NH4+-N was 21, 88 and 85%, while for NO3--N, it was 4, 56 and 68% for Spartina maritima, Juncus maritimus and Arundo donax, respectively. PO43--P was adsorbed completely in the expanded clay. However, in hydroponic system, removal efficiencies for NH4+-N were 53 and 50%, while PO43--P removal was 89 and -14% for Spartina maritima and Juncus maritimus, respectively. Nutrient removal in planted microcosms was statistically higher than unplanted controls for NH4+-N and PO43--P. However, salt removal was apparent in the hydroponic system only after 23days of HRT, despite clear salt excretion visible in both Spartina maritima and Juncus maritimus. This study demonstrates the potential of two halophytic plants for saline wastewater treatment. However, salt removal in such a scenario could not be well documented and might prove to be impractical in future work.

Multifunctional gold-nanoparticles: A nanovectorization tool for the targeted delivery of novel chemotherapeutic agents.

Due to their small size and unique properties, multifunctional nanoparticles arise as versatile delivery systems easily grafted with a vast array of functional moieties, such as anticancer cytotoxic chemotherapeutics and targeting agents. Here, we formulated a multifunctional gold-nanoparticle (AuNP) system composed of a monoclonal antibody against epidermal growth factor receptor (EGFR) (anti-EGFR D-11) for active targeting and a Co(II) coordination compound [CoCl(H2O)(phendione)2][BF4] (phendione=1,10-phenanthroline-5,6-dione) (TS265) with proven antiproliferative activity towards cancer cells (designated as TargetNanoTS265). The efficacy of this nanoformulation, and the non-targeted counterpart (NanoTS265), were evaluated in vitro using cancer cell models and in vivo using mice xenografts. Compared to the free compound, both nanoformulations (TargetNanoTS265 and NanoTS265) efficiently delivered the cytotoxic cargo in a controlled selective manner due to the active targeting, boosting tumor cytotoxicity. Treatment of HCT116-derived xenografts tumors with TargetNanoTS265 led to 93% tumor reduction. This simple conceptual nanoformulation demonstrates the potential of nanovectorization of chemotherapeutics via simple assembly onto AuNPs of BSA/HAS-drug conjugates that may easily be expanded to suit other cargo of novel compounds that require optimized controlled delivery to cancer target.

Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided.

Acidosis Drives the Reprogramming of Fatty Acid Metabolism in Cancer Cells through Changes in Mitochondrial and Histone Acetylation.

Bioenergetic preferences of cancer cells foster tumor acidosis that in turn leads to dramatic reduction in glycolysis and glucose-derived acetyl-coenzyme A (acetyl-CoA). Here, we show that the main source of this critical two-carbon intermediate becomes fatty acid (FA) oxidation in acidic pH-adapted cancer cells. FA-derived acetyl-CoA not only fuels the tricarboxylic acid (TCA) cycle and supports tumor cell respiration under acidosis, but also contributes to non-enzymatic mitochondrial protein hyperacetylation, thereby restraining complex I activity and ROS production. Also, while oxidative metabolism of glutamine supports the canonical TCA cycle in acidic conditions, reductive carboxylation of glutamine-derived α-ketoglutarate sustains FA synthesis. Concomitance of FA oxidation and synthesis is enabled upon sirtuin-mediated histone deacetylation and consecutive downregulation of acetyl-CoA carboxylase ACC2 making mitochondrial fatty acyl-CoA degradation compatible with cytosolic lipogenesis. Perturbations of these regulatory processes lead to tumor growth inhibitory effects further identifying FA metabolism as a critical determinant of tumor cell proliferation under acidosis.

Phytoremediation of salt-affected soils: a review of processes, applicability, and the impact of climate change.

Soil salinization affects 1-10 billion ha worldwide, threatening the agricultural production needed to feed the ever increasing world population. Phytoremediation may be a cost-effective option for the remediation of these soils. This review analyzes the viability of using phytoremediation for salt-affected soils and explores the remedial mechanisms involved. In addition, it specifically addresses the debate over plant indirect (via soil cation exchange enhancement) or direct (via uptake) role in salt remediation. Analysis of experimental data for electrical conductivity (ECe) + sodium adsorption ratio (SAR) reduction and plant salt uptake showed a similar removal efficiency between salt phytoremediation and other treatment options, with the added potential for phytoextraction under non-leaching conditions. A focus is also given on recent studies that indicate potential pathways for increased salt phytoextraction, co-treatment with other contaminants, and phytoremediation applicability for salt flow control. Finally, this work also details the predicted effects of climate change on soil salinization and on treatment options. The synergetic effects of extreme climate events and salinization are a challenging obstacle for future phytoremediation applications, which will require additional and multi-disciplinary research efforts.

Dynamics of the chemical composition and productivity of composts for the cultivation of Agaricus bisporus strains.

Two compost formulations based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) were tested for the cultivation of three Agaricus bisporus strains (ABI-07/06, ABI-05/03, and PB-1). The experimental design was a 2 × 3 factorial scheme (composts × strains) with 6 treatments and 8 repetitions (boxes containing 12 kg of compost). The chemical characterization of the compost (humidity, organic matter, carbon, nitrogen, pH, raw protein, ethereal extract, fibers, ash, cellulose, hemicellulose, and lignin) before and after the cultivation of A. bisporus and the production (basidiomata mass, productivity, and biological efficiency) were evaluated. Data were submitted to variance analysis, and averages were compared by means of the Tukey's test. According to the results obtained, the chemical and production characteristics showed that the best performances for the cultivation of A. bisporus were presented by the compost based on oat and the strain ABI-07/06.

Estimating functions and the generalized method of moments.

Estimating functions provide a very general framework for statistical inference, and are particularly useful when one is either unable or unwilling to specify a likelihood function. This paper aims to provide an accessible review of estimating function theory that has potential for application to the analysis and modelling of a wide range of complex systems. Assumptions are given in terms that can be checked relatively easily in practice, and some of the more technical derivations are relegated to an online supplement for clarity of exposition. The special case of the generalized method of moments is considered in some detail. The main points are illustrated by considering the problem of inference for a class of stochastic rainfall models based on point processes, with simulations used to demonstrate the performance of the methods.