Investigação sobre a captação e acúmulo de chumbo e zinco por stipa hohenackeriana trin. & rupr. em experimentos de campo e em vaso

13 páginas.-- 8 tablas.-- 40 referencias.-- the articles are free to use, with proper attribution, in educational and non- commercial applications.[EN]: This study was conducted to evaluate Pb and Zn uptake, mobility, and accumulation in Stipa hohenackeriana using field soil in pot and field experiments. Moreover, the effects of Municipal Solid Waste Compost (MSWC) (0, 1, and 2%) and Nano-Silica (NS) (0, 250, and 500 mg/kg) on Stipa biomass, Pb and Zn availability in the soil, and Pb and Zn uptake and accumulation were studied using pot experiments. Samples of soil, root, and shoots of Stipa were collected from field and greenhouse and after drying, extraction of Pb and Zn was done by acid digestion. Bio-Concentration Factor (BCF) and Translocation Factor (TF) were calculated to determine Pb and Zn phytoremediation efficiency. The amount of Zn and Pb remediation by Stipa from soil was determined by remediation factor (RF). The results of field experiments showed the Pb and Zn level decreased in the order of: soil >shoot>root. Results of the pot experiments also showed that plants grown in NS500-amended pots had 33% and 32% higher Pb in roots and shoots compared to control pots, respectively. In comparison, roots Pb concentration in pots amended with MSWC1% and MSWC2% decreased 22.4% and 1.7%, respectively. Roots and shoots Zn concentration in NS500-amended pots was 5.6% and 6.5% higher, respectively. However, root Zn concentration in treatments of MSWC1% and MSWC2% decreased 52.3% and 39.4%, respectively. Shoots Zn concentration decreased 52.5% and 40.0%, respectively. Although MSWC decreased the uptake and accumulation of Pb and Zn in Stipa roots and shoots, it improved the plant growth and consequently increased RF and soil remediation compared to the NS. Thus, it seems that applying MSWC and NS simultaneously can be a suitable strategy for the purpose of improving phytoremediation capability of Stipa in the Pb and Zn contaminated soils. In general, Stipa can be a suitable candidate for the accumulation of heavy metals, especially for Pb and Zn contaminated soils.[PO]: Este estudo foi conduzido para avaliar a absorção, mobilidade e acumulação de Pb e Zn em Stipa hohenackeriana em experiências usando solo de campo em vaso e em campo. Além disso, os efeitos do Composto Municipal de Resíduos Sólidos (MSWC) (0, 1 e 2%) e de nanopartículas de sílica (NS) (0, 250 e 500 mg/kg) na biomassa de Stipa, na disponibilidade de Pb e Zn no solo, e na absorção e acúmulo de Pb e Zn foram estudados usando experiências em vaso. Amostras de solo, raiz e brotos de Stipa foram coletadas do campo e da estufa e, após a secagem, a extração de Pb e Zn foi feita por digestão ácida. O Fator de Bioconcentração (BCF) e o Fator de Translocação (TF) foram calculados para determinar a eficiência de fitorremediação de Pb e Zn. A quantidade de remediação de Zn e Pb pela Stipa a partir do solo foi determinada pelo Fator de Remediação (RF). Os resultados das experiências de campo mostraram que o nível de Pb e Zn diminuiu na seguinte ordem: solo > broto > raiz. Os resultados das experiências em vaso também mostraram que as plantas cultivadas em vasos corrigidos com NS500 apresentaram teores de Pb 33% e 32% maiores em raízes e brotos em comparação com vasos de controle, respectivamente. Em comparação, a concentração de Pb em raízes em vasos corrigidos com MSWC1% e MSWC2% diminuiu 22,4% e 1,7%, respectivamente. A concentração de Zn em raízes e brotos em vasos corrigidos com NS500 foi de 5,6% e 6,5% maior, respectivamente. No entanto, a concentração de Zn da raiz nos tratamentos de MSWC1% e MSWC2% diminuiu 52,3% e 39,4%, respectivamente. A concentração de Zn nos brotos diminuiu 52,5% e 40,0%, respectivamente. Embora o MSWC tenha diminuído a absorção e acumulação de Pb e Zn nas raízes e brotos de Stipa, melhorou o crescimento da planta e consequentemente aumentou o RF e a remediação do solo em relação ao NS. Assim, parece que aplicar MSWC e NS simultaneamente pode ser uma estratégia adequada com o objetivo de melhorar a capacidade de fitorremediação de Stipa nos solos contaminados com Pb e Zn. Em geral, a Stipa pode ser um candidato adequado para a acumulação de metais pesados, especialmente para solos contaminados com Pb e Zn.Peer reviewe

Meta-analysis of the prevalence of depression among breast cancer survivors in Iran: an urgent need for community supportive care programs

OBJECTIVES: Depression, which is the most common comorbidity in breast cancer (BC) patients, has adverse effects on patients' quality of life, disease progress, and survival. METHODS: The protocol of this study was registered in PROSPERO (registration No. CRD42019121494). We electronically searched published studies through January 2019 with the aim of finding articles that investigated the prevalence of depression among BC survivors. Web of Science, Scopus, PubMed/MEDLINE, Science Direct, and Google Scholar were searched to obtain relevant published studies. This review included 14 cross-sectional and 4 cohort studies published from 2000 to 2018. We used a random-effects model to conduct the meta-analysis and generated a summary estimate for the pooled prevalence with 95 confidence intervals (CIs). A subgroup analysis was also conducted based on the depression assessment tool used and the study design. RESULTS: The total sample size of the studies contained 2,799 women with BC, including 1,228 women who were diagnosed with depression. The pooled prevalence of depression among Iranian women with BC was 46.83 (95 CI, 33.77 to 59.88) with significant heterogeneity (I-2 = 98.5; p<0.001). The prevalence of depression ranged from 14.00 (95 CI, 4.91 to 23.09) to 95.90 (95 CI, 91.97 to 99.83). The results of the subgroup analyses suggested that the depression assessment tool, year of publication, and study design were sources of heterogeneity. CONCLUSIONS: Our findings indicate a high prevalence of depression among BC patients, underscoring the urgent need for clinicians and health authorities to provide well-defined social and psychological supportive care programs for these patients

Analysis and Simulation of Blood Cells Separation in a Polymeric Serpentine Microchannel under Dielectrophoresis Effect

The current work presents a novel microfluidic approach, allowing a full separation of blood cells. The approach relies on using a polydimethylsiloxane serpentine microchannel equipped with a series of electrodes, providing two separation zones. The proposed design exploits the unique configuration of the channel along with the inherent difference in dielectric properties of the three kinds of blood cells to achieve a size-based sorting. The platelets (PLTs) are subjected to a larger dielectrophoretic force than red blood cells (RBCs) and white blood cells (WBCs), forcing them to be separated in the first zone. This leaves RBCs and WBCs to be separated in the second zone. The model developed in this work has been used intensively to examine the feasibility of the proposed approach. The model results showed a full separation of blood content can be achieved over a range of phase flow rates and AC frequencies

Simulation Study of the Liquid–Solid Multistage Adsorption Process

In the present study, a computational model to simulate the separation of the multi-stage device is developed and used to verify an arbitrary-shaped adsorption isotherm and a limited mass transfer rate. The model’s governing equations are solved numerically by the MATLAB computing platform. For a specific separation, a suitable design must take into account the concentration record of the effluent solutions in the separation device. Further, since the experimental investigation has many limitations, an accurate mathematical description of a system could be viewed as an alternative approach to understanding it comprehensively. The usefulness of the simulation code depends heavily on how well it matches the experimental results and predicts them with minor adjustments and improvements. Here, the model is validated and used to investigate how changing the system’s parameters can affect its performance. The study found that increasing the size of the system (unit number and pore volume of the adsorbent) resulted in more solutions. Adsorption effectiveness was also investigated and it was found to be relatively unaffected by dividing the total amount of solution adsorption over many units, as long as slurrying was maintained at an adequate level. The model not only provides the prediction of the discharge concentration record but also the evaluation of the separation effectiveness attained by the multistage device

In Silico Investigation of the Impact of Reaction Kinetics on the Physico-Mechanical Properties of Coconut-Oil-Based Rigid Polyurethane Foam

Conventionally, designing rigid polyurethane foams (RPUFs) with improved physico-mechanical properties from new, bio-based polyols is performed by modifying foam formulations via experimentation. However, experimental endeavors are very resource-dependent, costly, cumbersome, time-intensive, waste-producing, and present higher health risks. In this study, an RPUF formulation utilizing a coconut-oil (CO)-based polyol with improved physico-mechanical properties was approximated through a computational alternative in the lens of the gel time of the RPUF formation. In the RPUF formation of most bio-based polyols, their very fast gel times negatively impact foam robustness. The computational alternative functioned by finding a CO-based RPUF formulation with a gel time in good agreement with a formulation based on commercial petroleum-derived polyol (control). The CO-based RPUF formulation with the best-fit catalyst loading was approximated by simulating temperature profiles using a range of formulations with modified catalyst loadings iteratively. The computational approach in designing RPUF with improved properties was found to effectively negate foam collapse (with a shrinkage decrease of >60%) and enhance foam strength (with a compressive strength increase of >300%). This study presents an economically and environmentally sustainable approach to designing RPUFs by enabling minimized utilization of material sources for experimentation and analysis and minimized dependence on waste-producing methods