Nutrient Dynamics in a Highly Weathered Soil Under No-Till and Heavy Metal Phytoavailability as Affected by Biochar Amendment

The nutrient dynamics in soils are affected by cropping systems, soil properties and environmental conditions. A field experiment under NT has been conducted in an Oxisol, which assesses rates of inorganic P and K fertilizers for soybean production in conjunction with liming since 1995. The objectives were to evaluate the effect of rates of P and K fertilizers on soybean yields, and to access the P species in solid state by X-ray fluorescence (P-XANES). The optimum amounts of P and K fertilizers were revealed, which will help farmers improve their crop yields while minimize the impact of fertilization on soil and water quality. The long-term mineral phosphate fertilizer application led to P stabilization in soils under more thermodynamically stable forms, such as P-Fe and P-Al, in spite of the effects that soil organic matter (SOM) might have on P reactivity. A second project studied the heavy metal (HM: Zn, Pb and Cd) dynamics in a contaminated soil of NE Oklahoma. High concentrations of HM in soils have negative impacts on plants, human health and the environmental quality. The purpose was to evaluate the effects of biochars on the Zn, Pb and Cd phytoavailability in Tar Creek contaminated soils, as well as on the growth and uptake of these elements by perennial ryegrass (Lolium perenne). Biochars produced from switchgrass (SGB) and poultry litter (PLB) feedstocks at 350 and 700 °C (pyrolysis temperatures) were characterized as their potential use as soil amendment. Those pyrolyzed at 700 oC were used to investigate their effect on ryegrass dry matter yield and the accumulation of HM in shoots and roots. Biochars were applied to the soil at 0, 0.5, 1, 2 and 4% (w/w) and the soils were extracted by DTPA to estimate the available HM contents. Soils amended with low amounts of biochars reduced HM phytoavailability thus reduced plant metal uptake. Biochar also increased plant biomass but reduced metal transfer from roots to shoots. It is effective using readily available bioproducts to remediate HM contaminated soils and to enhance ryegrass forage yield with acceptable amount of HM in the shoots

Ultrasonic-assisted removal of cationic and anionic dyes residues from wastewater using functionalized triptycene-based polymers of intrinsic microporosity (PIMs)

In this work, a series of hypercrosslinked polymers of intrinsic microporosity (HCP-PIMs), namely nitro-triptycene (TRIP-NO2), amino-triptycene (TRIP-NH2), sulfonated-triptycene (TRIP-SO3H) and hydrocarbon-triptycene (TRIP-HC), are employed for the adsorption of organic dyes from wastewater. The materials show the efficient removal of cationic (malachite green, MG) and anionic (methyl orange, MO) dyes. The adsorption parameters herein investigated include the initial pH, the adsorbate concentration and the contact time, with the aim to elucidate their effect on the adsorption process. Furthermore, the adsorption kinetic and isotherms are studied, and the findings suggest the results fit well with pseudo-second-order kinetics and Langmuir model. The reported maximum adsorption capacity is competitive for all the tested polymers. More specifically, TRIP-SO3H and TRIP-HC exhibit adsorptions of ~ 303 and ~ 270 mg g−1 for MG and MO, respectively. The selectivity toward cationic and anionic dyes is assessed by mixing the two dyes, and showing that TRIP-HC completely removes both species, whereas TRIP-NO2, TRIP-NH2 and TRIP-SO3H show an enhanced selectivity toward the cationic MG, compared to the anionic MO. The effect of the type of water is assessed by performing ultrasonic-assisted adsorption experiments, using TRIP-SO3H and TRIP-HC in the presence of either tap or seawater. The presence of competing ions and their concentrations is evaluated by ICP-MS. Our study shows that tap water does not have a detrimental effect on the adsorption of both polymers, whereas, in the presence of seawater, the performance of TRIP-HC toward MO proved to be more stable than MG with TRIP-SO3H, which is probably due to a larger concentration of competing ions. Comparison between ultrasonic-assisted and magnetic stirring adsorption demonstrates that the former exhibits a greater efficiency. This seems due to a more rapid mass transfer, driven by the formation of high velocity micro-jets, acoustic microstreaming and shock waves, at the polymer surface. Reusability studies show a good stability up to five adsorption–desorption cycles

Use of biochar as a soil amendment to reduce potentially toxic metals (PTMs) phytoavailability

The contamination of potentially toxic metals (PTMs) is widespread in the world and has negatively affected plants, humans, soil health, and environmental quality. Some metals are essential plant nutrients but they are also toxic to vegetation and aquatic live when present in high concentrations, such as Cu, Mn and Zn. Others (e.g., Pb, Cd, Cr, and As) are potential toxic metals for all organisms, and are not needed (or are toxic) for plant growth. This chapter summarizes the use of readily available biochars (BCs) to reduce PTMs phytoavailability in soils thus improving crop yields and to minimize its impact on the environment. The physicochemical and morphological properties of BCs as affected by feedstock sources and pyrolysis temperatures are discussed. The effectiveness of biochar rates on plant growth and metal fractions are also highlighted. Biochar has the potential to be used as a viable bioproduct for the remediation of contaminated soils since it reduces the phytoavailability of PTMs pollutants. Biochars produced from different feedstocks and at different pyrolysis temperatures present highly heterogeneous physicochemical and morphological properties, which can affect the effectiveness in the remediation of PTMs contaminated soils. Therefore, potential technologies need to be developed and research gaps still need to be overcome to optimize the use of BCs as a feasible alternative for remediation of metal contaminated soils.Plant and Soil Science

José de Alencar, identity and image: analysis of the image age as an expansion element of the author's identity project

O objetivo deste estudo é avaliar de que maneira o advento da televisão e do cinema, ao longo do século XX, serviram como elementos de consolidação do projeto identitário iniciado pelos românticos após a independência do Brasil, sobretudo na figura de José de Alencar. O estudo terá como elemento central de análise as particularidades sociopolíticas dos principais contextos brasileiros do século XX em que a produção cinematográfica e televisiva de suas obras teve crescimento expressivo.The aim of this study is to evaluate how the advent of television and cinema, throughout the 20th century, served as elements of consolidation of the identity project initiated by the romantics after Brazil's independence, especially in the figure of José de Alencar. The study will have as a central element of analysis the socio-political particularities of the main Brazilian contexts of the twentieth century in which the cinematographic and television production of his works had an expressive growth

Síntese e investigação da atividade catalítica de estruturas poliméricas baseadas em metaloporfirinas

Orientador : Shirley NakagakiCoorientador : Sônia Faria ZawadzkiCoorientador : Neil B. McKeown (The University of Edinburgh)Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Química. Defesa: Curitiba, 20/09/2016Inclui referências : f. 114-127Área de concentração : Química inorgânicaResumo: Porfirinas são compostos macrociclos, aromáticos, altamente conjugados, que estão presentes em diversos sistemas biológicos. Esses compostos podem ser sintetizados com grande versatilidade estrutural e possuem aplicação em diversas áreas do conhecimento. Metaloporifinas (MP) sintéticas têm sido amplamente investigadas como catalisadores em reações de oxidação, principalmente para mimetização das enzimas do citocromo P-450, tanto em estudos de catálise homogênea como heterogênea, apresentando resultados promissores. A catálise heterogênea possui vantagens em relação à homogênea, citando-se principalmente a possibilidade de reuso do catalisador em diversos ciclos catalíticos. Nesse sentido, MP têm sido imobilizadas em diferentes tipos de suportes, tais como sílicas, zeólitas, materiais lamelares e polímeros orgânicos. Além disso, MP têm sido utilizadas como blocos construtores na formação de sólidos poliméricos porosos tais como MOFs (Metal Organic Framework), COFs (Covalent Organic Framework) e PIMs (Polymer of Intrinsic Microporosity). PIMs são materiais altamente rígidos, não cristalinos, no qual a microporosidade se deve a rigidez dos monômeros empregados em sua síntese. PIMs insulúveis contendo porfirinas em suas estruturas foram previamente preparados. A elevada área superficial (~ 1000 m2 g-1) e a estabilidade química destes materiais estimulam a síntese de novos PIMs para uso em catálise heterogênea. Assim, no presente trabalho, porfirinas e metaloporfirinas (simétricas e não simétricas) foram sintetizadas, caracterizadas e empregadas como monômeros na formação de treze novos PIMs, os quais foram caracterizados por diferentes técnicas. A microporosidade dos sólidos poliméricos foi confirmada por meio de medidas de adsorção de nitrogênio utilizando-se o método BET (Brunauer-Emmett-Teller), apresentando valores de área superficial entre 300 a 1270 m2g-1. Estudos catalíticos com estes polímeros, em reações de oxidação do cicloocteno e cicloexano e na presença de PhIO revelou resultados surpreendentes e interessantes. Os polímeros apresentaram atividade catalítica similar, ou superior, ao obtido empregando-se a metaloporfirina MnP1 em solução. Tais polímeros também apresentaram capacidade de reuso e mantiveram excelente atividade catalítica e seletividade para o álcool em pelo menos quatro ciclos catalíticos frente à oxidação do cicloexano. Além disso, um dos PIMs sintetizados foi selecionado para testes iniciais para a oxidação do cicloocteno na presença de peróxido de hidrogênio e os resultados indicam que estes polímeros podem ser bons candidatos na presença deste oxidante, proporcionando assim uma tecnologia mais limpa aos processos catalíticos. Porém, estudos para o aprimoramento da atividade catalítica do polímero na presença de peróxido de hidrogênio ainda devem ser conduzidos. Palavras-Chaves: Porfirina, Polímeros de Intrínseca Microporosidade (PIM), Catálise Homogênea, Catálise Heterogênea, Oxidação.Abstract: Porphyrins are highly conjugated aromatic macrocyclic compounds that are present in many biological systems. These compounds can be synthesized with great structural versatility leading to a wide range of applications in different fields. Synthetic metalloporphyrins (MP) have been widely used as catalysts in many oxidation processes as models for cytochrome P-450 enzymes, in both homogeneous and heterogeneous catalysis showing promising catalytic results. Heterogeneous catalysis has a number of advantages when compared to its homogeneous analogue, especially regarding the possibility of catalyst recovery and reuse in many catalytic cycles. Hence, seeking heterogeneous catalysts, MP have been immobilized on a wide range of supports, such as silica, zeolites, lamellar materials and organic polymers. Moreover, these macrocyclic compounds have been used as building blocks for the design of porous polymers, such as MOFs (Metal Organic Frameworks), COFS (Covalent Organic Frameworks) and PIMs (Polymers of Intrinsic Microporosity). PIMs are highly rigid amorphous materials for which the microporosity is generated from the rigidity of the monomers used in their synthesis. Insoluble networks PIMs have been prepared previously using porphyrins as monomers. The high surface area (up to 1000 m2g-1) and the chemical stability of these materials encourage the synthesis of new network PIMs and their assessment for heterogeneous catalysis. Then, in the present work, porphyrins and metalloporphyrins (symmetric and unsymmetric) were synthesized, characterized and used as monomers to prepare thirteen new PIMs, which were characterized by different techniques. The microporosity of the prepared PIMs was confirmed by nitrogen adsorption, with the calculated Brunauer-Emmett-Teller (BET) surface areas showing values from 300 to 1270 m2 g-1. Catalytic studies showed surprising and interesting results for the oxidation reactions of the substrates cyclooctene and cyclohexane using PhIO as oxidant. The catalytic activity of these polymers were similar or better compared to the ones obtained using the metalloporphyrin MnP1 in solution. The polymers also showed reuse capacity and preserved their excellent catalytic activity and alcohol selectivity in at least four catalytic cycles on cyclohexane oxidation reaction. Furthermore, one of the synthesized PIMs has been selected for initial tests on cyclooctene oxidation reactions using hydrogen peroxide as the oxidant. The results showed that these polymers can also be good catalysts when employing this oxidant, thus providing a cleaner technology process in catalytic reactions. However, studies still should be conducted to improve the catalytic activity of the polymer using hydrogen peroxide. Keywords: Porphyrin, Polymers of Intrinsc Microporosity (PIMs), Homogeneous Catalysis, Heterogeneous Catalysis, Oxidation

Uso do acetato de deslorelina em protocolos de inseminação artificial em tempo fixo (IATF) em vacas leiteiras.

Resumo: o objetivo do experimento foi testar os efeitos do acetato de deslorelina sobre o aumento dos níveis séricos de FSH, para melhorar o desenvolvimento folicular durante o ciclo estral de vacas com média de 45 dias pós-parto (DPP), bem como, reduzir o período voluntário de espera (PVE) e buscar o aumento das taxas de prenhez. O presente estudo, foi dividido em dois experimentos (A e B). Dois protocolos de sincronização de estro foram comparados em vacas (n=72) da raça Holandesa Preto e Branca no período de março a setembro de 2010, em dois municípios pertencentes à região oeste do Paraná - PR. No experimento A, todos os animais (n = 20), receberam no dia 0 do protocolo, um dispositivo intravaginal contendo 558 mg de progesterona natural e 2 mg de benzoato de estradiol (BE) pela via intramuscular (IM). Após a remoção do implante no dia 8 (D 8), aplicou-se pela via IM em todos os animais, 0,150 mg de d-cloprostenol e após este procedimento, as vacas foram separadas aleatoriamente em dois grupos: Grupo controle (G1), sem tratamento ao D 8 do protocolo, e o grupo tratamento (G2), no qual se administrou 100 µg de acetato de deslorelina (veículo de liberação rápida) via IM ao D 8. No dia 10, apenas o G1 recebeu a 2ª dose do acetato de deslorelina por via IM, já que os animais G 2 ovularam 24 horas após a primeira aplicação da deslorelina, decidindo-se então, não inseminá-las. Apenas o G1 foi submetido à inseminação artificial em tempo fixo, no dia 11 do protocolo com uma taxa de prenhez de 40% (4-10). No experimento B, vacas (n=52), receberam o mesmo protocolo utilizado para o experimento A citado acima, porém a dose aplicada de acetato de deslorelina no D 8 foi de 150 µg, e em veículo de liberação lenta. Avaliações ultrassonográficas foram realizadas dos dias 0 a 11 do protocolo e amostras de sangue foram coletadas todos os dias em 5 animais de cada grupo para ambos os experimentos. No experimento A, ficou evidente que o acetato de deslorelina foi capaz de promover aumento significativo nas concentrações plasmáticas de FSH (G2=3,4047 ± 0,7943; G1=1,5324 ± 1,1405) e (P=0,0001), porém, ao mesmo tempo, as concentrações plasmáticas de LH aumentaram significativamente (G2=14,2870 ± 6,3588; G1=1,4510 ± 0,3753) e (P=0,001), fazendo com que as vacas do G2 ovulassem precocemente. No experimento B, o diâmetro do folículo pré-ovulatório apresentou diferenças significativas (G2=1,7222 ± 0,1095; G1=1,5785 ± 0,0896) e (P=0,0001). A taxa de prenhez no experimento B, foi maior no grupo tratamento (57,7 %) em relação ao grupo controle (34,61 %). As concentrações plasmáticas de LH diferiram significativamente entre os tratamentos (G2=15,9065 ± 4,3902; G1=1,5103 ± 0,5750) e (P= 0,02830). Concluímos que no presente trabalho, a dose de 150µg de acetato de deslorelina administrada nos animais do G2, foi capaz de estimular o desenvolvimento folicular, formando folículos pré-ovulatórios maiores e por consequência, melhorando a função lútea uma vez que as concentrações plasmáticas de progesterona foram maiores nos dias 3 e 7 pós-inseminação artificial para o grupo G2 em relação ao G1 (D3 G1=0,8217 ± 0,5000; G2=2,4654 ± 2,7300) e (D7 G1=3,1860 ± 0,8400; G2=4,1833 ± 4,1700) com P=0,0283

'Candidatus Mycoplasma haematoalbiventris' e patógenos transmitidos por carrapatos em Didelphis albiventris de Curitiba e Foz do Iguaçu, Paraná, Brasil

Orientador: Prof. Dr. Rafael Felipe da Costa VieiraCo-orientadora: Dra. Thállitha Samih Wischral Jayme VieiraTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Programa de Pós-Graduação em Ciências Veterinárias. Defesa : Curitiba, 06/08/2021Inclui referênciasResumo: Gambás são reconhecidos como possíveis reservatórios para patógenos de importância na Saúde Única. Sendo assim, o monitoramento destes marsupiais é crucial para estabelecer o controle de doenças emergentes e re-emergentes. Assim como outras espécies, os gambás são infestados por ectoparasitas, carrapatos e pulgas, vetores de patógenos como Ehrlichia sp., Anaplasma sp., Babesia sp., Rickettsia sp., entre outros. Estes animais podem ser peça chave para a permanência de ciclos das bactérias e protozoários e, por este motivo o presente estudo visa investigar a ocorrência e a diversidade genética de patógenos transmitidos por carrapatos e micoplasmas hemotrópicos que infectam gambás e ectoparasitas associados nas cidades de Curitiba e Foz do Iguaçu, Paraná, Brasil. No total, 30 gambás-de-orelha-branca (Didelphis albiventris) foram avaliados entre junho de 2018 e dezembro de 2020, sendo 13 deles capturados em Foz do Iguaçu e 17 em Curitiba. Para a avaliação, os animais foram contidos quimicamente, identificados e inspecionados para a presença de ectoparasitos. Foi coletado sangue por punção venosa da cauda ou jugular dos animais para posterior análise molecular. O DNA foi extraído utilizando-se kit comercialmente disponível. Em todas as amostras foi realizada uma PCR para o gene endógeno de mamífero gliceraldeído-3-fosfato desidrogenase (gapdh) e, posteriormente, as amostras foram triadas para Mycoplasma sp. hemotrópicos, usando PCR convencional para um fragmento do gene 16S rRNA de hemoplasmas. Amostras de DNA de gambás de orelha branca que testaram positivas para hemoplasmas foram submetidas a uma PCR gênero-específica para um fragmento (~800 pb) do gene 23S rRNA de hemoplasmas. Além disso, as amostras de DNA também foram testadas por PCR para um fragmento (551 pb) do gene 18S rRNA de Theileria/Babesia spp. e um fragmento (349 pb) do gene 16S rRNA de Ehrlichia/Anaplasma spp. Todos os gambás de orelha branca de ambas as localidades não estavam infestados por ectoparasitas no momento da coleta e todas as amostras amplificaram consistentemente o gene gapdh. Dois dos 13 (15,38%; IC 95%: 4,33-42,23%) gambás de orelha branca do município de Foz do Iguaçu foram positivos para hemoplasmas, enquanto os animais de Curitiba testaram-se negativos. Amplicons (~900 bp) dos genes 16S rRNA e 23S rRNA obtidos das amostras positivas para hemoplasmas foram sequenciadas em ambas as direções pelo método de Sanger. As sequências de nucleotídeos dos genes 16S rRNA e 23S rRNA dos hemoplasmas amplificados neste estudo foram submetidos ao banco de dados genéticos GenBank® (números de acesso: MW703800, MW703801, e MW694786, MW694787, respectivamente). O sequenciamento do fragmento do gene 16S rRNA mostrou 100% de identidade com ‘Candidatus Mycoplasma haemoalbiventris’ e, do fragmento do gene 23S rRNA mostrou identidade variando de 99,74-100% com ‘Ca. M. haemoalbiventris’ detectado em gambás-de-orelha-branca de duas regiões do Brasil. Todos os gambás, de ambas as localidades, foram negativos para Theileria/Babesia spp. e Ehrlichia/Anaplasma spp. Pela PCR. A presença de ‘Ca. M. haemoalbiventris’ em gambás-de-orelha-branca na cidade de Foz do Iguaçu-PR, indica que estes animais podem albergar uma ampla diversidade de hemoplasmas sendo necessário o desenvolvimento de estratégias de controle e dispersão de patógenos associado ao gênero Didelphis sp.Abstract: Opossums are recognized as possible reservoirs for diseases of importance in One Health. Therefore, monitoring these animals is crucial to establish control of emerging diseases. Like other species, opossums are infected by ectoparasites, which are vectors of agents such as Ehrlichia sp., Anaplasma sp., Babesia sp., and hemoplasmas. These animals may be a key element for the permanence of bacterial cycles, and, for this reason, the present study aims to investigate the occurrence and genetic diversity of pathogens transmitted by ticks that infect opossums and, associated ectoparasites in the cities of Curitiba and Foz do Iguaçu, Paraná, Brazil. Thirty white-eared opossums (Didephis albiventris) were evaluated in the period between June 2018 to December 2020. Thirteen of them were captured in Foz do Iguaçu and, 17 in Curitiba. After chemical restraint, animals were individually identified and visually inspected for ticks and fleas. Blood samples were collected for posterior molecular analysis. The DNA was extracted using a commercially available kit. To monitor DNA extraction, a PCR for the mammal endogenous gene glyceraldehyde-3-phosphate dehydrogenase (gapdh) was performed in all samples and, after, the samples were selected for homotropic Mycoplasma sp., using conventional PCR with genus-specific primers targeting a fragment of the 16S rRNA gene of Mycoplasma spp. Opossum DNA samples that tested positive in the PCR assay based on the 16S rRNA gene were subjected to a genus-specific PCR assay targeting a fragment (800 pb) of the 23S rRNA gene of hemoplasmas. ). Additionally, DNA samples were also tested by PCR assays targeting a fragment (551 bp) of the 18S rRNA gene of Theileria/Babesia spp. (Almeida et al., 2012) and a fragment (349 bp) of 16S rRNA gene of Ehrlichia/Anaplasma spp. Amplicons (900 bp) of two16S rRNA and three 23S rRNA Mycoplasma spp.-positive samples from Foz do Iguaçu City were sequenced in both directions by Sanger method. Nucleotide sequences of the 16S rRNA and 23S rRNA genes of hemotropic Mycoplasma sp. amplified herein were submitted to the GenBank® database (accession numbers: MW703800, MW703801, MW703802, and MW694786, MW694787, respectively). Opossums from both cities were not infested by ectoparasites (ticks and fleas) at the time of sampling and, all samples consistently amplified the mammal endogenous gapdh gene. All opossums tested negative for Theileria/Babesia spp. and Ehrlichia/Anaplasma spp. by PCR. Two animals from Foz do Iguaçu were positive for hemotropic Mycoplasma spp. by PCR. Sequencing of the 16S rRNA fragment showed 100% identity with ‘Ca. M. haemoalbiventris’ and, sequencing of the 23S rRNA fragment showed 99.74-100% identity with ‘Ca. M. haemoalbiventris’ detected in whiteeared opossums from Brazil. All opossums were negative for Theileria/Babesia spp. and Ehrlichia/Anaplasma spp. by PCR. The presence of ‘Candidatus Mycoplasma haemoalbiventris’ in white-eared opossums in Foz do Iguaçu city indicates these animals may carry a wide range of hemoplasms, requiring the development of strategies for the control and dispersion of pathogens associated with the genus Didelphis sp

Adjustable Functionalization of Hyper-Cross-Linked Polymers of Intrinsic Microporosity for Enhanced CO2 Adsorption and Selectivity over N2 and CH4

In this paper, we report the design, synthesis, and characterization of a series of hyper-cross-linked polymers of intrinsic microporosity (PIMs), with high CO2 uptake and good CO2/N2 and CO2/CH4 selectivity, which makes them competitive for carbon capture and biogas upgrading. The starting hydrocarbon polymers’ backbones were functionalized with groups such as −NO2, −NH2, and −HSO3, with the aim of tuning their adsorption selectivity toward CO2 over nitrogen and methane. This led to a significant improvement in the performance in the potential separation of these gases. All polymers were characterized via Fourier transform infrared (FTIR) spectroscopy and 13C solid-state NMR to confirm their molecular structures and isothermal gas adsorption to assess their porosity, pore size distribution, and selectivity. The insertion of the functional groups resulted in an overall decrease in the porosity of the starting polymers, which was compensated with an improvement in the final CO2 uptake and selectivity over the chosen gases. The best uptakes were achieved with the sulfonated polymers, which reached up to 298 mg g–1 (6.77 mmol g–1), whereas the best CO2/N2 selectivities were recorded by the aminated polymers, which reached 26.5. Regarding CH4, the most interesting selectivities over CO2 were also obtained with the aminated PIMs, with values up to 8.6. The reason for the improvements was ascribed to a synergetic contribution of porosity, choice of the functional group, and optimal isosteric heat of adsorption of the materials

The Use of Biochar as a Soil Amendment to Reduce Potentially Toxic Metals (PTMs) Phytoavailability

The contamination of potentially toxic metals (PTMs) is widespread in the world and has negatively affected plants, humans, soil health, and environmental quality. Some metals are essential plant nutrients but they are also toxic to vegetation and aquatic live when present in high concentrations, such as Cu, Mn and Zn. Others (e.g., Pb, Cd, Cr, and As) are potential toxic metals for all organisms, and are not needed (or are toxic) for plant growth. This chapter summarizes the use of readily available biochars (BCs) to reduce PTMs phytoavailability in soils thus improving crop yields and to minimize its impact on the environment. The physicochemical and morphological properties of BCs as affected by feedstock sources and pyrolysis temperatures are discussed. The effectiveness of biochar rates on plant growth and metal fractions are also highlighted. Biochar has the potential to be used as a viable bioproduct for the remediation of contaminated soils since it reduces the phytoavailability of PTMs pollutants. Biochars produced from different feedstocks and at different pyrolysis temperatures present highly heterogeneous physicochemical and morphological properties, which can affect the effectiveness in the remediation of PTMs contaminated soils. Therefore, potential technologies need to be developed and research gaps still need to be overcome to optimize the use of BCs as a feasible alternative for remediation of metal contaminated soils

Effect of a Single High-Dose Vitamin D3 on the Length of Hospital Stay of Severely 25-Hydroxyvitamin D-Deficient Patients with COVID-19

OBJECTIVES: In this ancillary analysis of a multicenter, double-blinded, randomized, placebo-controlled trial, we investigated the effect of a single high dose of vitamin D3 on the length of hospital stay of patients with severe 25-hydroxyvitamin D deficiency and COVID-19. METHODS: The primary outcome was length of hospital stay, defined as the total number of days that patients remained hospitalized from the date of randomization until the date of hospital discharge. Secondary outcomes included serum levels of 25-hydroxyvitamin D, mortality during hospitalization, number of patients admitted to the intensive care unit, and number of patients who required mechanical ventilation. ClinicalTrials.gov: NCT04449718. RESULTS: Thirty-two patients were included in the study. The mean (SD) age was 58.5 (15.6) years, body mass index was 30.8 (8.6) kg/m2, and 25-hydroxyvitamin D level was 7.8 (1.6) ng/mL. No significant difference was observed in the median interquartile range of length of hospital stay between the vitamin D3 group (6.0 [4.0-18.0] days) versus placebo (9.5 [6.3-15.5] days) (log-rank p=0.74; hazard ratio, 1.13 [95% confidence interval (CI), 0.53-2.40]; p=0.76). Vitamin D3 significantly increased serum 25-hydroxyvitamin D levels in the vitamin D3 group compared with that in the placebo group (between-group difference, 23.9 ng/mL [95% CI, 17.7-30.1]; p<0.001). CONCLUSIONS: A dose of 200.000 IU of vitamin D3 did not significantly reduce the length of hospital stay of patients with severe 25-hydroxyvitamin D deficiency and COVID-19