Design of an electroflotation system for the concentration and harvesting of freshwater microalgae

Microalgae are considered as one of the most promising alternatives for the integrated use of agro-industrial water residues and the production of metabolites of high industrial interest. This is due to algae can grow on wastewater which in turn can reduce the emission of nutrients to rivers and lakes. However, the greatest scientific-technological barrier is the concentration and separation of the biomass produced. There are several processes used at different levels (from laboratory to industrial scale) such as flocculation, centrifugation, flotation, etc. These can be very expensive or can (possibly) contaminate the biomass. Unlike the previous ones, electroflotation has been proposed as a cost-efficient method, nevertheless its final efficiency will depend heavily on the type of alga and culture medium. Taking into account the above, the present project aims to design an electroflotation system for the concentration and harvest of microalgae biomass. The effect of several factors (pH, time, voltage and distance between the electrodes) and for types of materials (Copper, Aluminium, Iron and Steel) on biomass recovery efficiency from a culture of Chlorella vulgaris UTEX 1803 was evaluated by the implementation of a Design of experiments (43 non-factorial design) using STATISTICA 7.0. Results show that, the materials with higher concentration efficiency were cooper and aluminium with 40 and 80% respectively, and the most relevant factors were distance between electrodes (1-2 cm), time (>20 min) and Voltage (>15V). In order to increase the efficiency of the overall process a new 43 experimental factorial design was proposed using as factors distance between electrodes, time, voltage and agitation. Results show that agitation positively affects the total efficiency until reaching a total concentration of the biomass (100%). It was found that a voltage close to 50V and a time greater than 25 min positively affect the final efficiency of the copper and aluminium electrodes, however aluminium has the highest efficiency (> 95%) compared to copper (<85%)

Removal of nutrients and pesticides from agricultural runoff using microalgae and cyanobacteria

The use of pesticides in agriculture has ensured the production of different crops. However, pesticides have become an emerging public health problem for Latin American countries due to their excessive use, inadequate application, toxic characteristics, and minimal residue control. The current project evaluates the ability of two strains of algae (Chlorella and Scenedesmus sp.) and one cyanobacteria (Hapalosyphon sp.) to remove excess pesticides and other nutrients present in runoff water from rice production. Different concentrations of wastewater and carbon sources (Na2CO3 and NaHCO3 ) were evaluated. According to the results, all three strains can be grown in wastewater without dilution (100%), with a biomass concentration comparable to a synthetic medium. All three strains significantly reduced the concentration of NO3 and PO4 (95 and 85%, respectively), with no difference between Na2CO3 or NaHCO3 . Finally, Chlorella sp. obtained the highest removal efficiency of the pesticide (Chlorpyrifos), followed by Scenedesmus and Hapalosyphon sp. (100, 75, and 50%, respectively). This work shows that it is possible to use this type of waste as an alternative source of nutrients to obtain biomass and metabolites of interest, such as lipids and carbohydrates, to produce biofuels

Cranio-spinal migration of a metallic clip placed during arteriovenous malformation resection - A case report, review of the literature, and management strategies

<p>Abstract</p> <p>Background</p> <p>Microclip placement during AVM resection is generally accepted to be a safe practice in neurosurgery. Here, we describe an unusual complication involving cranio-spinal clip migration discovered five years after the initial AVM surgery.</p> <p>Case Presentation</p> <p>A 53-year-old man underwent resection of a superior vermian AVM that required the placement of two microclips during the procedure. Five years after surgery, the patient suffered from descending sensory radiculopathy that resolved spontaneously. The workup revealed cranio-spinal migration of one of the previously placed microclips.</p> <p>Conclusions</p> <p>AVM clip migration is a rare phenomenon; however, the diagnosis should be entertained in patients with posterior fossa instrumentation who suffer from unusual neurologic symptoms.</p

A scalable monitoring for the CMS Filter Farm based on elasticsearch

A flexible monitoring system has been designed for the CMS File-based Filter Farm making use of modern data mining and analytics components. All the metadata and monitoring information concerning data flow and execution of the HLT are generated locally in the form of small documents using the JSON encoding. These documents are indexed into a hierarchy of elasticsearch (es) clusters along with process and system log information. Elasticsearch is a search server based on Apache Lucene. It provides a distributed, multitenant-capable search and aggregation engine. Since es is schema-free, any new information can be added seamlessly and the unstructured information can be queried in non-predetermined ways. The leaf es clusters consist of the very same nodes that form the Filter Farm thus providing natural horizontal scaling. A separate central" es cluster is used to collect and index aggregated information. The fine-grained information, all the way to individual processes, remains available in the leaf clusters. The central es cluster provides quasi-real-time high-level monitoring information to any kind of client. Historical data can be retrieved to analyse past problems or correlate them with external information. We discuss the design and performance of this system in the context of the CMS DAQ commissioning for LHC Run 2

Poverty, social exclusion and dental caries of 12-year-old children: a cross-sectional study in Lima, Peru

Background: Socioeconomic differences in oral health have been reported in many countries. Poverty and social exclusion are two commonly used indicators of socioeconomic position in Latin America. The aim of this study was to explore the associations of poverty and social exclusion with dental caries experience in 12-year-old children. Methods: Ninety families, with a child aged 12 years, were selected from 11 underserved communities in Lima (Peru), using a two-stage cluster sampling. Head of households were interviewed with regard to indicators of poverty and social exclusion and their children were clinically examined for dental caries. The associations of poverty and social exclusion with dental caries prevalence were tested in binary logistic regression models. Results: Among children in the sample, 84.5% lived in poor households and 30.0% in socially excluded families. Out of all the children, 83.3% had dental caries. Poverty and social exclusion were significantly associated with dental caries in the unadjusted models (p = 0.013 and 0.047 respectively). In the adjusted model, poverty remained significantly related to dental caries (p = 0.008), but the association between social exclusion and dental caries was no longer significant (p = 0.077). Children living in poor households were 2.25 times more likely to have dental caries (95% confidence interval: 1.24; 4.09), compared to those living in non-poor households. Conclusion: There was support for an association between poverty and dental caries, but not for an association between social exclusion and dental caries in these children. Some potential explanations for these findings are discussed

Nucleoside Hydrolase From Crithidia Fasciculata: Metabolic Role, Purification, Specificity, and Kinetic Mechanism

Crithidia fasciculata cells grown on complex medium with added [8-14C,5\u27-3H]inosine or [8-14C,5\u27-3H]adenosine metabolize \u3e50% of the salvaged nucleosides through a pathway involving N-glycoside bond cleavage. Cell extracts contain a substantial nucleoside hydrolase activity but an insignificant purine nucleoside phosphorylase. The nucleoside hydrolase has been purified 1000-fold to \u3e99% homogeneity from kilogram quantities of C. fasciculata. The enzyme is a tetramer of M(r) 34,000 subunits to give an apparent holoenzyme M(r) of 143,000 by gel filtration. All of the commonly occurring nucleosides are substrates. The K(m) values vary from 0.38 to 4.7 mM with purine nucleosides binding more tightly than the pyrimidines. Values of V(max)/K(m) vary from 3.4 x 103 M-1 s-1 to 1.7 x 105 M-1 s-1 with the pyrimidine nucleosides giving the larger values. The turnover rate for inosine is 32 s-1 at 30 °C. The kinetic mechanism with inosine as substrate is rapid equilibrium with random product release. The hydrolytic reaction can be reversed to given an experimental K(eq) of 106 M with H2O taken as unity. The product dissociation constants for ribose and hypoxanthine are 0.7 and 6.2 mM, respectively. Deoxynucleosides or 5\u27-substituted nucleosides are poor substrates or do not react, and are poor inhibitors of the enzyme. The enzyme discriminates against methanol attack from solvent during steady-state catalysis, indicating the participation of an enzyme-directed water nucleophile. The pH profile for inosine hydrolysis gives two apparent pK(a) values of 6.1 with decreasing V(max)/K(m) values below the pK(a) and a plateau at higher pH values. These effects are due to the pH sensitivity of the V(max) values, since K(m) is independent of pH. The pH profile implicates two negatively charged groups which stabilize a transition state with oxycarbonium character

薜荔抗腸病毒活性及其免疫調節作用之研究

Outbreak of enterovirus occurred annually in Taiwan. The major isolats were enterovirus 71 (EV71), coxsackievirus B3 (CVB3), and coxsackievirus A16, which caused severe manifestations such as aseptic meningitis, cardiopulmonary edema, foot and mouth disease, meningitis, and viral myocarditis;and even death. Ficus pumila L. grows commonly in Taiwan traditionally for the treatment of kidney storing essence, antioncotic, detoxication, and blood-stanching. The aim of this study was to investigate anti-EV71 and CVB3 activity of the Ficus pumila 95% ethanol extracts and its relevant immunomodulation. The Ficus pumila 95% ethanol extract exhibited high anti-EV71 and CVB3 activity with 3.38～10.4 and 34.1～39.1 μg/mL, respectively, of 50% inhibitory concentrations (IC50). The anti-EV71 activity of the extrcet was better than that of CVB3. The Ficus pumila 95% ethanol extract had high selectivity index (SI, 23.5～72.7) against EV71. Prophylactic viral infection (inhibition rate : 0.21～5.39% and 18.1～50.4%), direct virucidal action (inhibition rate : 12.5～54.3% and 21.9～74.7%), and anti-viral replication (inhibition rate : 16.5～89.5% and 24.3～89.3%) for the extract were observed in both EV71 and CVB3 infections. The Ficus pumila 95% ethanol extract significantly increased the IL-6 and decreaced the IL-8, IL-2 and IL-1β (only effective on RD infected cells) levels in the EV71-or CVB3-infected cells. A high correlation was observed between the extract and the IL-6 increasing. The IL-8 and IL-1β reduction is able to retard the EV71 or CVB3-induced inflammation. To summarize, the Ficus pumila 95% ethanol extract exhibited high anti-EV71 and CVB3 activity, in which the IL-6 plays an important role in antivirus.台灣每年春夏季節均會爆發腸病毒感染，分離之病毒株主要為腸病毒71型 (enterovirus 71, EV71)、克沙奇B3型 (coxsackievirusB3, CVB3) 及克沙奇A16型 (coxsackievirusA16, CVA16)，臨床症狀包括無菌性腦膜炎、心肺水腫、手足口症及腦膜炎、病毒性心肌炎等，皆具嚴重之致命性。薜荔 (Ficus pumila L.) 為台灣野生資源極為豐富之藤本植物，傳統上具有固精消腫散毒止血之功效。本研究探討薜荔95%乙醇萃取物抗EV71及CVB3之活性及其對宿主細胞之免疫調節作用。結果顯示出，薜荔95%乙醇萃取物具有非常優異的抗EV71及CVB3活性，50%抑制濃度分別為3.38～10.4 μg/mL及34.1～39.1 μg/mL，對EV71之作用優於CVB3。薜荔萃取物對EV71具有高選擇指數 (selectivity index, SI；23.5～72.7)。萃取物對EV71及CVB3之抑制作用包括預防病毒感染 (抑制率：0.2～5.3%及18.1～50.4%)、使病毒失活 (抑制率：12.5～54.3%及25.5～74.7%) 及抑制病毒之複製 (抑制率：44.1～69.3%及10.6～85.6%)。宿主細胞免疫調節結果顯示出，薜荔95%乙醇萃取物會誘導被EV71及CVB3感染之宿主細胞顯著的增加IL-6及降低IL-8、IL-2、IL-1β (僅對感染之RD細胞) 之生成量。薜荔95%乙醇萃取物對EV71及CVB3之抑制作用與IL-6的增加有高度的相關性，IL-8、IL-1β的降低可減緩EV71及CVB3誘發之發炎反應。綜合本研究之結果，薜荔95%乙醇萃取物對EV71及CVB3顯示出高度抑制活性，其中IL-6扮演抗病毒重要角色。目 次 圖表目次 III 附圖表目次 IV 中文摘要 1 英文摘要 2 縮寫表 4 壹、前言 5 貳、文獻整理 6 一、腸病毒 6 (一) 腸病毒的種類與特性 6 (二) 腸病毒71型 6 (三) 克沙奇B3型 9 二、抗腸病毒藥物之探討 12 三、細胞激素 13 (一) 促發炎細胞激素 13 四、薜荔 16 (一) 薜荔之介紹 16 (二) 薜荔的營養成分 17 (三) 薜荔之化學成分 19 (四) 薜荔之生理活性 20 (五) 薜荔於食品工業之應用 21 參、研究目的 24 肆、實驗架構 25 伍、材料與方法 26 一、材料 26 (一) 薜荔 26 (二) 細胞株及病毒 26 (三) 儀器設備 26 二、方法 27 (一) 薜荔萃取物製備 27 (二) 細胞培養 27 (三) 病毒增殖及效價測定 29 (四) 50%細胞毒性濃度測定 31 (五) 50%抑制濃度測定 32 (六) 病毒感染時間效應 34 (七) 細胞激素含量測定 36 (八) 統計分析 38 陸、結果與討論 39 一、薜荔抗病毒之活性 39 (一) 50%細胞毒性濃度 39 (二) 50%抑制濃度 39 (三) 選擇指數 40 (四) 病毒感染時間效應 42 二、感染EV71及CVB3宿主細胞之免疫反應 47 (一) 萃取物對感染EV71宿主細胞之細胞激素生成量 48 (二) 萃取物對感染CVB3宿主細胞之細胞激素生成量 51 柒、結論 56 捌、參考文獻 57 玖、附錄 (藥品配置) 6