Biofouling represents an important limitation in photobioreactor cultures. The biofouling propensity of different materials (polystyrene, borosilicate glass, polymethyl methacrylate, and polyethylene ...terephthalate glycol‐modified) and coatings (two spray‐applied and nanoparticle‐based superhydrophobic coatings and a hydrogel‐based fouling release coating) was evaluated by means of a short‐term protein test, using bovine serum albumin (BSA) as a model protein, and by the long‐term culture of the marine microalga Nannochloropsis gaditana under practical conditions. The results from both methods were similar, confirming that the BSA test predicts microalgal biofouling on surfaces exposed to microalgae cultures whose cells secrete macromolecules, such as proteins, with a high capacity for forming a conditioning film before cell adhesion. The hydrogel‐based coating showed significantly reduced BSA and N. gaditana adhesion, whereas the other surfaces failed to control biofouling. Microalgal biofouling was associated with an increased concentration of sticky extracellular proteins at low N/P ratios (below 15).
Full RNA-Seq is a fundamental research tool for whole transcriptome analysis. However, it is too costly and time consuming to be used in routine clinical practice. We evaluated the transcript ...quantification agreement between RNA-Seq and a digital multiplexed gene expression platform, and the subtype call after running the PAM50 assay in a series of breast cancer patients classified as triple negative by IHC/FISH. The goal of this study is to analyze the concordance between both expression platforms overall, and for calling PAM50 triple negative breast cancer intrinsic subtypes in particular.
The analyses were performed in paraffin-embedded tissues from 96 patients recruited in a multicenter, prospective, non-randomized neoadjuvant triple negative breast cancer trial (NCT01560663). Pre-treatment core biopsies were obtained following clinical practice guidelines and conserved as FFPE for further RNA extraction. PAM50 was performed on both digital multiplexed gene expression and RNA-Seq platforms. Subtype assignment was based on the nearest centroid classification following this procedure for both platforms and it was concordant on 96% of the cases (N = 96). In four cases, digital multiplexed gene expression analysis and RNA-Seq were discordant. The Spearman correlation to each of the centroids and the risk of recurrence were above 0.89 in both platforms while the agreement on Proliferation Score reached up to 0.97. In addition, 82% of the individual PAM50 genes showed a correlation coefficient > 0.80.
In our analysis, the subtype calling in most of the samples was concordant in both platforms and the potential discordances had reduced clinical implications in terms of prognosis. If speed and cost are the main driving forces then the preferred technique is the digital multiplexed platform, while if whole genome patterns and subtype are the driving forces, then RNA-Seq is the preferred method.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Preventing biofouling in microalgal photobioreactors Soriano-Jerez, Y.; Gallardo-Rodríguez, J.J.; López-Rosales, L. ...
Bioresource technology,
September 2024, 2024-09-00, 20240901, Letnik:
407
Journal Article
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Odprti dostop
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•Biofouling issue, possible solutions and their efficacy under operational conditions.•Fouling necessitates frequent operation shutdowns to clean the photobioreactor.•Transparent ...amphiphilic coatings are successful in avoiding microalgae cell adhesion.•PEG/PDMS-based coatings seem the best option to obtain efficient photobioreactors.
Photobioreactors (PBRs) are used to grow the light-requiring microalgae in diverse commercial processes. Often, they are operated as continuous culture over months period. However, with time, biofouling layer develops on the inner surfaces of their walls. The fouling layer formation deteriorates the PBR performance as foulants reduce light penetration in it. Light is essential for photosynthetic cultures, and a deterioration in lighting adversely impacts algae growth and biomass productivity. Fouling requires a frequent shutdown to clean the PBR and add to the environmental impact of the operation by generating many wastewaters contaminated with the cleaning chemicals. Antibiofouling coatings could be used to modify the surfaces of existing and future PBRs. Therefore, transparent and non-toxic fouling-release coatings, produced using hydrogel technology, could transform the existing PBRs into efficient and enduring microalgae culture systems, requiring only the application of the coating to the inner walls, without additional investments in new PBRs.
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•Microalga and free feeds degraded in percentages of 1.5 and 24% respectively.•No antioxidant treatment is necessary for feed storage during 1.5 year period.•First time evaluated the ...price of microalgae feeds in a viable manner.
The rising prices of fishery derivatives limits their use in aquafeeds. Therefore, other alternatives are used to replace those ingredients. Among them, microalgae are of great interest both as an ingredient and as a potential stabilising agent against lipid oxidation. This study evaluates on the use of Nannochloropsis gaditana to prevent lipid oxidation in a set of 12 aquafeeds over 540 days of storage. Aquafeeds were formulated with/without 15 % N. gaditana combined with two antioxidants −butylhydroxytoluene (25–150 mg·kg-1) or vitamin E (500–3000 mg·kg-1). The effect of i) storage period, ii) presence of microalgae and iii) antioxidant addition on lipid oxidation was assessed. Results showed higher fatty acid degradation in diets lacking microalgae. The microalgae supplemented diets is enough for preserving feeds presenting the highest antioxidant effect at the end, without significant differences with the microalgae-supplemented feeds and those including antioxidants after 540 days of storage.
Adhesion of microalgal cells to photobioreactor walls reduces productivity resulting in significant economic losses. The physico-chemical surface properties and the fluid dynamics present in the ...photobioreactor during cultivation are relevant. However, to date, no multiphysical model has been able to predict biofouling formation in these systems. In this work, to model the microalgal adhesion, a Computational Fluid Dynamic simulation was performed using a Eulerian-Lagrangian particle-tracking model. The adhesion criterion was based on the balance of forces and moments included in the XDLVO model. A cell suspension of the marine microalga Nannochloropsis gaditana was fed into a commercial flow cell composed of poly-methyl-methacrylate coupons for validation. Overall, the simulated adhesion criterion qualitatively predicted the initial distribution of adhered cells on the coupons. In conclusion, the combined Computational Fluid Dynamics-Discrete Phase Model (CFD-DPM) approach can be used to overcome the challenge of predicting microalgal cell adhesion in photobioreactors.
The implementation of industrial-scale facilities for microalgae cultivation is limited due to the high operation costs. One of the main problems in obtaining an efficient and long-lasting microalgae ...culture system is biofouling. The particular issue when developing antibiofouling surfaces for microalgae cultures is that the material must be transparent. The main purpose of this work was to evaluate the antibiofouling efficiency of a non-toxic polydimethylsiloxane-based coating prepared with polyethylene glycol-based copolymer on different photobioreactors at the pilot-plant scale. The antifouling properties result from the development of a fouling-release coating utilizing hydrogel technology. Nannochloropsis gaditana and Chlorella sorokiniana were cultured outdoors for 3 months over the summer, when biofouling formation is at its highest due to environmental conditions, to test the coating's antibiofouling efficiency. Although biofouling was not completely prevented in either photobioreactor, the coating significantly reduced cell adhesion compared to the polydimethylsiloxane control (70% less adhesion). Therefore, this coating was shown to be a good alternative for constructing efficient closed-photobioreactors at the pilot-plant scale, at least for cultures lasting 3 months.
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•Antibiofouling DBE-311 additive improves productivity of outdoor microalgae cultures.•Bio-remediable ions influence on biofouling formation in microalgae cultures.•DBE-311-based coating reduced N. gaditana adhesion by 74%.•DBE-311-based coating reduced C. sorokiniana adhesion by 62%.•DBE-311 -based coating is a good option to increase the bioremediation efficiency.
Marine microalgae have potential to be low-cost raw materials. This depends on the exploitation of different biomass fractions for high-value products, including unique compounds. Chrysochromulina ...rotalis, an under-explored haptophyte with promising properties, was the focus of this study. For the first time, C. rotalis was successfully cultivated in an 80 L tubular photobioreactor, illuminated by an easy-to-use light-emitting-diode-based system. C. rotalis grew without certain trace elements and showed adaptability to different phosphorus sources, allowing a significant reduction in the N:P ratio without compromising biomass yield and productivity. The design features of the photobioreactor provided a protective environment that ensured consistent biomass production from this shear-sensitive microalgae. Carotenoid analysis showed fucoxanthin and its derivatives as major components, with essential fatty acids making up a significant proportion of the total. The study emphasizes the tubular photobioreactor's role in sustainable biomass production for biorefineries, with C. rotalis as a valuable bioactive feedstock.
Abstract
The purpose of this study is to assess the levels of Technological Knowledge and Content Knowledge on Acid-Base Concepts and relationship between the Technological Knowledge and Content ...Knowledge on Acid-Base Concepts among the Senior High School STEM students in Iligan City. The study utilized two (2) Public High Schools in Iligan City schools division that offer STEM Strand. The respondents are the Senior High School STEM students that are taking up a Chemistry subject in the School Year 2018-2019. Questionnaires for Technological Knowledge and Content Knowledge on Acid-Base concepts were used. The collected data were analyzed using mean, frequency distribution, percentage, p-test, t-test, pearson correlation and levene’s test. The level of Technological Knowledge of Grade 11 STEM students in Iligan City National High School is very good. The level of Technological Knowledge of Grade 12 STEM students is also very good. The level of Technological Knowledge of Senior High School STEM students in Iligan City National High School is very good. The level of Content Knowledge on Acid- Base Concepts of Grade 11 students in Iligan City National High School is satisfactory. On the other hand, the result shows that the level of Content Knowledge on Acid- Base Concepts of Grade 12 STEM students one the same school is poor. Moreover, the level of Content Knowledge on Acid- Base Concepts of Senior High School STEM students in Iligan City National High School is poor. The level of Content Knowledge on Acid- Base Concepts of Senior High School STEM students in Iligan City East National High School is poor. The result shows that the difference and relationship of the technological knowledge and the content knowledge of Senior High School STEM students in Iligan City is not significant. Since the level of Technological Knowledge of the students were very good, teachers may make use the available technologies in teaching Acid- Base Concepts. Future researchers may utilize a larger population like different Schools Division in this region to validate this findings.
Background
Persistent alopecia (PA) after docetaxel has been recently described. The aim of our study is to establish the incidence and characteristics of PA following adjuvant docetaxel for breast ...cancer (BC) and to test the ability of scalp cooling in prevention.
Patients and methods
BC patients receiving adjuvant chemotherapy followed or not by endocrine therapy (and a control group receiving only endocrine therapy) were interviewed in a single institution at 1.5 to 5 years following primary diagnosis searching for PA. A confirmatory prevalence study was later performed in other two institutions. Finally, a prevention study using prophylactic scalp cooling (PSC) with ELASTO-GEL hypothermia caps in patients receiving adjuvant docetaxel was performed.
Results
In the initial prevalence study (492 patients), minor forms of PA (grade 1) were recorded with all chemotherapy regimens and aromatase inhibitors. Patients receiving docetaxel regimens at cumulative dose (CD) ≥ 400 mmg/m
2
presented a significantly higher prevalence of grades 1 PA (33–52%) and 2 PA (5–12%). Prevalence of grade 2 PA with docetaxel CD ≥ 400 mmg/m
2
was confirmed in two other institutions. Overall, grade 2 PA was seen in 10.06% (95% CI 7.36–13.61) of 358 patients with docetaxel regimens reaching CD ≥ 400 mmg/m
2
, but not in patients with lower docetaxel CD, other chemotherapy regimens, or endocrine therapy alone. In prevention trial, no grade 2 PA occurred among 116 patients receiving adjuvant docetaxel (≥ 400 mmg/m
2
) and PSC followed-up after a 96 months median time. PSC was well tolerated. No scalp relapses were seen among 30 patients (22% of all inclusions) having disease relapse.
Conclusion
Adjuvant treatment with docetaxel (CD ≥ 400 mmg/m
2
) is associated with a significant rate of grade 2 PA, leading to wearing a wig, in around 10% of patients. This toxicity was completely prevented with scalp cooling. Clinical Trial Reference: NCT00515762.
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