Edaphic properties as pieces of evidence of tailings deposit on soils.

Mine tailings are one of the primary contaminant sources of heavy metals and metalloids in the soil. Besides increasing the concentration of potentially toxic elements (PTEs), tailings may modify the edaphic conditions and decrease the buffer capacity of impacted soils. The influence of tailings may reach distances far from the impoundments depending on the transport path and the specific transport mean: air, rain (runoff and infiltration), or acid mine drainage. In this study, soil samples from various horizons were collected in trial pits along a transect, at different distances from sulfide tailings. Soil analysis included texture, organic matter, alkalinity, porous space, carbonates, pH, electrical conductivity, real density, apparent density, total sulfur, main mineralogy, and total concentrations of As, Cd, Pb, Fe, and Zn. Graphical and statistical interpretation of the results showed that real density and porous space are the leading indicators of the tailings dispersion and accumulation and that pH is not a significant parameter (all values were above the neutrality) due to the limestone abundance in the area. However, Zn and Cd concentrations had an inverse relation with pH. Differences in the concentrations of PTEs between the superficial and deep layers that increased toward the tailings were also observed. Gypsum was only present in the closest samples to the tailings and may also be an indicator of tailings' influence on soils. This study allowed us to identify general edaphic parameters as a first and quick means to determine the tailings contamination of soils.

Acute infection with Platynosomum illiciens (Trematoda: Dicrocoeliidae) as a clinically relevant and potentially fatal disease in Falco sparverius (Aves: Falconidae) in Brazil.

Platynosomum illiciens is a dicrocoeliid trematode from the biliary tract of warm-blooded vertebrates (felines, primates, marsupials, and birds) reported in different parts of the world. Although the veterinary relevance of platynosomosis in mammals, especially in domestic felines, has been increasingly evidenced in the scientific literature, studies involving avian disease caused by P. illiciens are comparatively scarce. In the present study, a female specimen of the American kestrel, Falco sparverius L., found dead, in November 2019, in Brazil, was necropsied. Parietal biliary effusion in the celomatic cavity was observed, suggesting biliary transudation and gallbladder stasis, which possibily preceded the distension and rupture of gallbladder noted during necropsy. In the microscopic analysis of the bile content, small trematodes were found and characterized as immature stages of Platynosomum after the morphological study. Partial sequences of the cox-1 gene enabled the identification of P. illiciens, with 100% similarity with previously sequenced sympatric isolates from mammals. The finding of immature specimens in a ruptured gallbladder strongly suggests a role for the parasite in biliary flow dysfunction, indicating acute platynosomosis as a clinically relevant and potentially fatal condition that has not yet been discussed.

NEW RECORDS OF NEMATODES IN THE YELLOW-BILLED CUCKOO COCCYZUS AMERICANUS (CUCULIFORMES: CUCULIDAE) BASED ON A MIGRANT SPECIMEN FOUND IN BRAZIL.

The yellow-billed cuckoo, Coccyzus americanus, is a threatened passerine bird native to North America that migrates to overwinter in South America. Although migratory birds have drawn broad attention, given their assumed role in the long-distance dispersal of parasites, studies on the helminth fauna of this cuculid are scarce. In the present study, nematodes found in the gastrointestinal tract of a specimen of C. americanus found in Belo Horizonte, State of Minas Gerais, southeastern Brazil, were characterized morphologically. Five species of gastrointestinal nematodes belonging to 4 families were identified: Synhimantus (Dispharynx) nasuta (Rudolphi, 1819) and Synhimantus (Dispharynx) resticulaCanavan, 1929 (Acuariidae), Microtetrameres sp. (Tetrameridae), and Cyrnea piayaeSandground, 1929 (Habronematidae) and Subulura halli Barreto, 1918 (Subuluridae). Except for Microtetrameres sp., all other nematodes are reported in this host for the first time. Although it is difficult to accurately determine the geographical origin of infections, it is important to note that Sy. (D.) resticula and Su. halli are reported for the first time in Brazil. Additionally, the absence of the former species infecting hosts where the widespread and generalist Sy. (D.) nasuta was found may indicate that Sy. (D.) resticula have either been overlooked in previous studies or that this nematode is rare indeed. Finally, the geographical distribution of Su. halli is greatly expanded and now includes the Americas. Aspects related to the dispersion of these parasites, both in migrating and native hosts, are briefly discussed.

Evaluation of the interactions of arsenic (As), boron (B), and lead (Pb) from geothermal production wells with agricultural soils.

Geothermal energy is a low-pollution energy source. However, air, soil, and water near geothermal plants may be affected by their operation. One of the largest geothermal energy sources in the world, Cerro Prieto, has a capacity of 720 MW and is located in northwest Mexico near an agricultural area. The abstracted geothermal fluids, which are enriched with arsenic (As), boron (B), lead (Pb), cadmium (Cd), and other heavy metals, are either reinjected into the aquifer or sent to an evaporation pond located in the geothermal plant. Because spills have occurred in other geothermal zones, it is important to evaluate the effect of those contaminants on the soils of the surrounding area and their possible infiltration into shallow groundwater. To that aim, soils (one chromic Vertisol and two calcic Regosols) from three sites near the Cerro Prieto Geothermal Plant were sampled to evaluate their behavior regarding As, Pb, and B retention. Batch experiments were carried out using the soils as the sorbent and geothermal water from three geothermal production wells as the sorbate. Raw water concentrations in each well were as follows: As: 0.2442 mg/L, 0.2774 mg/L, and mg/L; B: 18.409 mg/L, 13.5075 mg/L, and 16.646 mg/L; and Pb: 0.22 mg/L, 0.13 mg/L, and 0.26 mg/L. The physicochemical characteristics of the soils were determined and compared to the experimental results. A good adjustment of the chromic Vertisol sample to Freundlich isotherms was observed for As (r2 > 0.9), followed by Pb (r2 = 0.61), and B (r2 > 0.5). As retention also showed a good adjustment to the Langmuir model (r2 > 0.9). The retention followed the order Pb >As ≫B in one of the two calcic Regosols, while the other only retained Pb ≫ As. Cationic exchange capacity; clay minerals; carbonate; organic matter; and iron, aluminum, and manganese amorphous and crystalline oxides influenced the soils' retention capacities. Irrigation with geothermal water could not imply a toxicity risk to plants grown in the chromic Vertisol soil due to its high Pb and As sorption capacity. Pb concentration could not be a toxicity issue in the calcic Regosols for the same reason, but As and B could be. B would be a hazard to vegetables and water due to its low or lack of retention in the three soils and also for its possible infiltration into shallow groundwater used for irrigation in the area. This study highlights the importance of maintaining adequate operation and control of the disposal of geothermal fluids in geothermal plants.

Natural Biomaterials for Cardiac Tissue Engineering: A Highly Biocompatible Solution.

Cardiovascular diseases (CVD) constitute a major fraction of the current major global diseases and lead to about 30% of the deaths, i.e., 17.9 million deaths per year. CVD include coronary artery disease (CAD), myocardial infarction (MI), arrhythmias, heart failure, heart valve diseases, congenital heart disease, and cardiomyopathy. Cardiac Tissue Engineering (CTE) aims to address these conditions, the overall goal being the efficient regeneration of diseased cardiac tissue using an ideal combination of biomaterials and cells. Various cells have thus far been utilized in pre-clinical studies for CTE. These include adult stem cell populations (mesenchymal stem cells) and pluripotent stem cells (including autologous human induced pluripotent stem cells or allogenic human embryonic stem cells) with the latter undergoing differentiation to form functional cardiac cells. The ideal biomaterial for cardiac tissue engineering needs to have suitable material properties with the ability to support efficient attachment, growth, and differentiation of the cardiac cells, leading to the formation of functional cardiac tissue. In this review, we have focused on the use of biomaterials of natural origin for CTE. Natural biomaterials are generally known to be highly biocompatible and in addition are sustainable in nature. We have focused on those that have been widely explored in CTE and describe the original work and the current state of art. These include fibrinogen (in the context of Engineered Heart Tissue, EHT), collagen, alginate, silk, and Polyhydroxyalkanoates (PHAs). Amongst these, fibrinogen, collagen, alginate, and silk are isolated from natural sources whereas PHAs are produced via bacterial fermentation. Overall, these biomaterials have proven to be highly promising, displaying robust biocompatibility and, when combined with cells, an ability to enhance post-MI cardiac function in pre-clinical models. As such, CTE has great potential for future clinical solutions and hence can lead to a considerable reduction in mortality rates due to CVD.

Angiostrongylus minasensis n. sp.: new species found parasitizing coatis (Nasua nasua) in an urban protected area in Brazil.

Currently, there are 21 species of Angiostrongylus that parasitize the pulmonary or mesenteric arteries of wild and domestic rodents, felids, canids and human. Species of Angiostrongylus have cosmopolitan distribution covering tropical, subtropical and temperate regions. The procyonid Nasua nasua (coati) is a reservoir host for a wide variety of parasites that may be harmful to its populations or may contain etiological agents with zoonotic potential. In urban areas, coatis are usually found in close association with humans and domestic animals. We morphologically and molecularly characterized a new species of Angiostrongylus found in N. nasua in a protected area within Belo Horizonte, Brazil. The new species of Angiostrongylus differs from other species of the same genus in terms of the length and bifurcation level of the lateral and ventral rays, the length of spicules and female tail morphology. Molecular phylogenetic results based on the mitochondrial cytochrome c oxidase subunit 1 gene suggest that the newly identified species belongs to a genetic lineage that is separate from other species of Angiostrongylus. This new species was collected from the mesenteric arteries of N. nasua. It was named Angiostrongylus minasensis n. sp..

Angiostrongylus minasensis n. sp.: new species found parasitizing coatis (Nasua nasua) in an urban protected area in Brazil / Angiostrongylus minasensis n. sp.: nova espécie encontrada parasitando quatis (Nasua nasua) em área de proteção urbana no Brasil

Abstract Currently, there are 21 species of Angiostrongylus that parasitize the pulmonary or mesenteric arteries of wild and domestic rodents, felids, canids and human. Species of Angiostrongylus have cosmopolitan distribution covering tropical, subtropical and temperate regions. The procyonid Nasua nasua (coati) is a reservoir host for a wide variety of parasites that may be harmful to its populations or may contain etiological agents with zoonotic potential. In urban areas, coatis are usually found in close association with humans and domestic animals. We morphologically and molecularly characterized a new species of Angiostrongylus found in N. nasua in a protected area within Belo Horizonte, Brazil. The new species of Angiostrongylus differs from other species of the same genus in terms of the length and bifurcation level of the lateral and ventral rays, the length of spicules and female tail morphology. Molecular phylogenetic results based on the mitochondrial cytochrome c oxidase subunit 1 gene suggest that the newly identified species belongs to a genetic lineage that is separate from other species of Angiostrongylus. This new species was collected from the mesenteric arteries of N. nasua. It was named Angiostrongylus minasensis n. sp..

Resumo Existem 21 espécies de Angiostrongylus que parasitam as artérias pulmonares ou mesentéricas de roedores silvestres e domésticos, felídeos, canídeos e homem. Espécies de Angiostrongylus têm uma distribuição cosmopolita que abrange regiões tropicais, subtropicais e temperadas. O procionídeo Nasua nasua (quati) é hospedeiro de vários parasitos que podem ser prejudiciais para suas populações ou conter agentes etiológicos com potencial zoonótico. Nas áreas urbanas, os quatis podem ser encontrados em estreita associação com seres humanos e animais domésticos. Nós caracterizamos morfológica e molecularmente uma nova espécie de Angiostrongylus encontrada em N. nasua de uma área protegida na cidade de Belo Horizonte, Brasil. A nova espécie de Angiostrongylus difere de outras espécies do mesmo gênero pelo comprimento e nível de bifurcação dos raios lateral e ventral, o comprimento dos espículos e a morfologia da cauda da fêmea. Resultados moleculares e filogenéticos baseados no gene mitocondrial citocromo c oxidase subunidade 1 indicam que a espécie recém-identificada pertence a uma linhagem genética separada de outras espécies de Angiostrongylus. O presente relato descreve uma nova espécie de Angistrongylus coletada das artérias mesentéricas de N. nasua, denominada Angiostrongylus minasensis n. sp..

Prominence of fusion temperature and engineering heteroatoms on multifarious emissive shifts in carbon dots.

We present a simple but robust strategy to engineering heteroatoms (N, S) on carbon dots (CDs) surface that results in a collection of enhanced photoluminescence (PL) emissions. The use of citric acid (CA) and 2-Imidazolidinethione (2-IZT) as precursors was envisioned to study the impact of thermolysis process on the PL properties. The proposed strategy, implemented at two different temperatures (180 °C and 200 °C), is suitable to produce CDs with tunable PL and quantum yield (QY) up to ∼32%. Similar to earlier reports of CA-based CDs, the self-assembling of fluorophores integrated into the CDs edge is hypothesized, however, in our CDs a double intriguing effect of blue- and red-shifting can be observed for PL as the wavelength of excitation is increased in the range 280-480 nm. Through a comprehensive characterization and evaluation of these CDs in water suspensions, the mechanisms that lead to PL multifarious emissions are proposed.

Spontaneous, Solvent-Free, Polymer-Templated, Solid-Solid Transformation of Thin Metal Films into Nanoparticles.

Metal nanoparticles have unusual optical, electronic, sensing, recognition, catalytic, and therapeutic properties. They are expected to form the basis of many of the technological and biological innovations of this century. A prerequisite for future applications using nanoparticles as functional entities is control of the shape, size, and homogeneity of these nanoparticles and of their interparticle spacing and arrangement on surfaces, between electrodes, or in devices. Here, we demonstrate that thin films of gold, silver, and copper sputter-deposited onto the surface of an organic polymer poly[[1,1':4',1″-terphenyl]-4,4″-diyl(2-bromo-1-carboxyethylidene)] (PTBC) undergo spontaneous solid-solid transformation into nanoparticles. Furthermore, we show that, by varying the thickness of the films, the volume-to-surface ratio of the polymer substrate, and the amount of plasticizer, it is possible to control the rate of transformation and the morphology of the nanoparticles formed. PTBC containing Au nanoparticles was found to enhance the cell adhesion and proliferation. To the best of our knowledge, our findings constitute the first experimental evidence of spontaneous, room-temperature, solid-solid transformation of metal films sputtered onto the surface of an organic polymeric substrate into nanoparticles (crystals).

Linear, Single-Strand Heteroaromatic Polymers from Superacid-Catalyzed Step-Growth Polymerization of Ketones with Bisphenols.

Novel, linear, high-molecular-weight single-strand heteroaromatic polymers and copolymers containing 9H-xanthene moieties in the backbone were synthesized by metal-free superacid-catalyzed stoichiometric and nonstoichiometric step-growth polymerizations of carbonyl compounds bearing electron-withdrawing substituents with bisphenols. The electrophilic aromatic substitution reactions of ketones with phenol fragments occur exclusively in ortho-positions to the hydroxy phenol group and followed by highly efficient cyclodehydration reaction of hydroxyl-containing intermediates to give corresponding substituted 9H-xanthene-2,7-diyl polymers. The polymerizations were performed at room temperature in the Brønsted superacid trifluoromethanesulfonic acid (CF3SO3H, TFSA) and in a mixture of TFSA with methylene chloride and nitrobenzene.

Mechanistic aspects of superacid mediated condensation of polyphenols with ketones. Implications for polymer synthesis.

A detailed computational study of possible reaction paths for methanesulfonic and triflic acid mediated polyhydroxyalkylation reaction between resorcinol and trifluoracetone accompanied by cyclodehydration to give 9H-xanthene containing polymers has been carried out at M06-2X/6-311+G level of theory. A cluster solvation model was used for the calculations. The calculations revealed that the most kinetically favorable reaction path involves the cyclodehydration occurring during the polymer forming step. In this case 9H-xanthene formation is promoted by the activated phenyl ring in Wheland intermediate assisting the aromatic nucleophilic substitution of OH group which leads to the cyclization. It has been demonstrated that the inability of methanesulfonic acid to catalyze the formation of 9H-xanthene containing polymers is due to the very high barrier of the rate limiting step of the polymer forming reaction and not the cyclodehydration process.

O uso da ultra-sonografia no diagnóstico e evolução da apendicite aguda / Ultrasonography in the diagnosis and evolution of acute appendicitis

OBJETIVO: Aproximadamente 35 por cento das apendicites agudas têm diagnóstico clínico pré-operatório duvidoso ou incorreto, particularmente grávidas e crianças. A ultra-sonografia, em virtude do seu baixo custo e facilidade de acesso, tem-se mostrado um método diagnóstico importante. Este estudo propôs-se a demonstrar os principais achados de imagem das diversas fases da apendicite, com o objetivo de auxiliar o ultra-sonografista no diagnóstico precoce desta afecção. MATERIAIS E MÉTODOS: São relatados 14 casos de ultra-sonografias abdominais realizadas no período de janeiro a julho de 2001, em pacientes que se apresentavam com quadro de abdome agudo. O exame foi realizado com transdutores de 3,5 MHz e 7,5 MHz. RESULTADOS: O estudo ultra-sonográfico antes da perfuração demonstra apêndice não compressível, com espessamento e perda focal da definição das paredes. Após a perfuração, o apêndice pode não ser visualizado ao exame de ultra-sonografia, sendo evidenciadas alterações secundárias como efeito de massa, formação de plastrão, liquefação e formação de abscesso, além de ar dentro da coleção. CONCLUSÃO: O diagnóstico precoce da apendicite é essencial para minimizar a morbidade, que se mantém elevada se ocorrer perfuração. Apresentações atípicas resultam em confusão diagnóstica e retarde no tratamento. As principais dificuldades e erros são apendicite retrocecal, apendicite focal ou perfurada

OBJECTIVE: Approximately 35% of the patients with acute appendicitis have a doubtful or incorrect preoperatory diagnosis, particularly in pregnant women and children. Ultrasonography has demonstrated to be an important means of diagnosis due to its low cost and easy access. This study is intended to show the main imaging findings of the many phases of appendicitis, thus helping the ultrasonographist to establish an early diagnosis. MATERIALS AND METHODS: From January to June 2001, 14 patients with acute abdominal pain were submitted to abdominal ultrasound using 3.5 MHz and 7.5 MHz transducers. RESULTS: The ultrasound findings when perforation had not occurred demonstrated a noncompressible appendix, thickening and focal lack of definition of the walls. After perforation had occurred the appendix could no longer be visualized at ultrasonography. Secondary changes such as mass effect, phlegmous changes, liquefaction and abscess formation, and gas bubbles within a collection were identified. CONCLUSION: An early diagnosis of appendicitis is essential in order to minimize morbidity that is high when perforation occurs. Atypical presentations result in misdiagnosis and treatment delay. The main diagnostic challenges are retrocecal, focal or perforated appendicitis.

[Hpv cofactors in cervical carcinogenesis]. / Co-fatores do HPV na oncogênese cervical.

Human papillomavirus (HPV) plays a central rule in uterine cervix carcinogenesis. Other factors direct or indirectly influence the installation of this mechanism in cervical squamous epithelium. Investigations regarding mechanisms of interaction of these factors with viral elements are found in the literature of the last 20 years. The present review article discusses possible co-factors of HPV in the genesis of the squamous carcinoma of uterine cervix, taking into account only the factors whose association with the virus or cervical cancer has been documented by experimental studies, and not based just on clinical or epidemiological data. Among the approached parameters are immunological factors (local and humoral immune response), the association with Acquired Immune Deficiency Syndrome, genetic factors as protein p53 polymorphism, tabagism and the use of oral contraceptives. All these factors interact in variable intensity with oncoproteins and other HPV elements, increasing and facilitating the virus action in host cells, leading to the development of immortalization and carcinogenesis.

Co-fatores do HPV na oncogênese cervical / HPV Cofactors in cervical carcinogenesis

O papilomavírus humano (HPV) exerce um papel central na carcinogênese do colo uterino. Em torno a ele orbitam outros fatores que influenciam direta ou indiretamente a instalaçäo deste mecanismo no epitélio escamoso cervical. Investigaçöes a respeito dos mecanismos de atuaçäo e interaçäo desses co-fatores com os elementos virais encontram-se na literatura dos últimos 20 anos. O presente artigo de revisäo explora os possíveis co-fatores do HPV na gênese do carcinoma escamoso do colo uterino, levando em conta apenas os fatores cuja associaçäo com o vírus ou câncer cervical tenha sido documentada experimentalmente, e näo apenas clínica ou epidemiologicamente. Dentre os parâmetros abordados estäo os fatores imunológicos (resposta imune local e humoral), a associaçäo com a Síndrome da Imunodeficiência Adquirida Humana, fatores genéticos como o polimorfismo da proteína p53, o tabagismo e o uso de contraceptivos orais. Todos estes fatores interagem em menor ou maior intensidade com oncoproteínas e outros elementos do HPV, potencializando a açäo do vírus na célula hospedeira e facilitando o desenvolvimento dos processos de imortalizaçäo e carcinogênese