Optimal Selection of Sampling Points within Sewer Networks for Wastewater-Based Epidemiology Applications.

Wastewater-based epidemiology (WBE) has great potential to monitor community public health, especially during pandemics. However, it faces substantial hurdles in pathogen surveillance through WBE, encompassing data representativeness, spatiotemporal variability, population estimates, pathogen decay, and environmental factors. This paper aims to enhance the reliability of WBE data, especially for early outbreak detection and improved sampling strategies within sewer networks. The tool implemented in this paper combines a monitoring model and an optimization model to facilitate the optimal selection of sampling points within sewer networks. The monitoring model utilizes parameters such as feces density and average water consumption to define the detectability of the virus that needs to be monitored. This allows for standardization and simplicity in the process of moving from the analysis of wastewater samples to the identification of infection in the source area. The entropy-based model can select optimal sampling points in a sewer network to obtain the most specific information at a minimum cost. The practicality of our tool is validated using data from Hildesheim, Germany, employing SARS-CoV-2 as a pilot pathogen. It is important to note that the tool's versatility empowers its extension to monitor other pathogens in the future.

Molecular docking and metagenomics assisted mitigation of microplastic pollution.

Microplastics, tiny, flimsy, and direct progenitors of principal and subsidiary plastics, cause environmental degradation in aquatic and terrestrial entities. Contamination concerns include irrevocable impacts, potential cytotoxicity, and negative health effects on mortals. The detection, recovery, and degradation strategies of these pollutants in various biota and ecosystems, as well as their impact on plants, animals, and humans, have been a topic of significant interest. But the natural environment is infested with several types of plastics, all having different chemical makeup, structure, shape, and origin. Plastic trash acts as a substrate for microbial growth, creating biofilms on the plastisphere surface. This colonizing microbial diversity can be glimpsed with meta-genomics, a culture-independent approach. Owing to its comprehensive description of microbial communities, genealogical evidence on unconventional biocatalysts or enzymes, genomic correlations, evolutionary profile, and function, it is being touted as one of the promising tools in identifying novel enzymes for the degradation of polymers. Additionally, computational tools such as molecular docking can predict the binding of these novel enzymes to the polymer substrate, which can be validated through in vitro conditions for its environmentally feasible applications. This review mainly deals with the exploration of metagenomics along with computational tools to provide a clearer perspective into the microbial potential in the biodegradation of microplastics. The computational tools due to their polymathic nature will be quintessential in identifying the enzyme structure, binding affinities of the prospective enzymes to the substrates, and foretelling of degradation pathways involved which can be quite instrumental in the furtherance of the plastic degradation studies.

Contribution of rooftop rainwater harvesting to climate adaptation in the city of Hannover: Water quality and health issues of rainwater storage in cisterns and ponds.

Rooftop rainwater harvesting systems and blue-green infrastructure are becoming important resilience alternatives for urban climate adaptation. This study sheds light on the largely unreported physicochemical and microbiological quality of private roof-harvested rainwater (RHRW). We aimed to identify the physicochemical and microbiological characteristics of RHRW, explore potential correlations between them and assess probable health risks associated with recreational interactions of children with the water. RHRW was collected from cisterns and ponds located in an inner courtyard in Hanover, Germany. Physicochemical parameters were measured on site and samples were collected once a month in two campaigns in 2020 and 2021. Escherichia coli concentrations ranged from 1 × 10° to 24.1 × 102 MPN/100 mL, Enterococci from 1 × 10° to 19.7 × 102 MPN/100 mL, Salmonella from 1 × 102 to 39 × 103 CFU/100 mL and Pseudomonas aeruginosa from 1 × 10° to 3 × 103 MPN/100 mL. Correlation analysis indicated potential relationships between bacteria, oxygen, and water temperature. The results of the health risk assessment indicated a potential risk of gastrointestinal illnesses due to exposure to Enterococci and Salmonella spp. present in the cisterns and ponds, highlighting the need for appropriate regulations and guidelines for RHRW aimed for non-potable uses. Blue-green infrastructure, when effectively managed and maintained, can offer benefits both by enhancing urban climate resilience and promoting citizens well-being.

Microbiological water quality and derived health risks from exposure to ornamental water fountains in the city of Hannover.

Ornamental fountains are attractive urban infrastructures helping cities to cope with global warming, as water sprays have great cooling effects due to evaporative properties; however, exposure to microbiologically impaired water from ornamental fountains during recreational activities may result in adverse health outcomes for the exposed population. This study assesses the microbial water quality of four ornamental water fountains (Blätterbrunnen, Körtingbrunnen, Klaus-Bahlsen-Brunnen, and Marstallbrunnen) and performs a quantitative microbial risk assessment (QMRA) for children using Escherichia coli, Enterococci, and Salmonella to quantify the probability of gastrointestinal illnesses and Pseudomonas aeruginosa to quantify the risk of dermal infections. Samples were collected fortnightly in two campaigns in 2020 and 2021 and processed to determine bacterial concentrations. Data on exposure time were obtained during field observations on the selected fountains; a total of 499 people were observed of which 30% were children. Mean bacterial concentrations ranged from 1.6 × 101 to 6.1 × 102 most probable number (MPN)/100 mL for E. coli, 1.2 × 101 -1.2 × 103  MPN/100 mL for Enterococci, 8.6 × 103 -3.1 × 105  CFU/100 mL for Salmonella, and 2.5 × 103 -3.2 × 104  MPN/100 mL for P. aeruginosa. The results of the QMRA study showed that the USEPA illness rate of 36 NEEAR-gastrointestinal illnesses/1000 was exceeded for Enterococci at the Körtingbrunnen, Klaus-Bahlsen-Brunnen, and Marstallbrunnen fountains and for Salmonella and P. aeruginosa at the Körtingbrunnen fountain, suggesting that exposure to microbiologically contaminated water from ornamental fountains may pose a health risk to children. The scenario analysis shows the importance of keeping low bacterial concentrations in ornamental fountains so that the risk of illness/infection to children does not exceed the USEPA illness rate benchmark.

Bacterial diversity of biofilms on polyhydroxybutyrate exposed to marine conditions: Ex-situ vs. in-situ tests.

Biofilms form on any available surface and, depending on the characteristics of the material and the environmental conditions, biodegradation can take place. We compared the bacterial composition of polyhydroxybutyrate (PHB)-related biofilm communities from marine ex-situ and in-situ tests to assess the differences in diversity and abundance between these two biofilms. This comparison will help to better assess the transferability of tank tests to real-life scenarios. The in-situ tests were set up in the Mediterranean Sea on the Island of Elba, Italy where PHB-tensile bars were lodged in the sediments. This created a water-exposed aerobic and mud-planted anaerobic scenario. The ex-situ tests were modeled after in-situ tests and performed in temperature-controlled tanks. The PHB-related biofilms were harvested after 240 days of exposure along with planktonic bacteria, and particle- and sediment-related biofilm. The bacterial composition was elucidated using 16S rDNA sequencing. Biofilms harvested from the in-situ test were more diverse, less even, and contained more rare species compared to biofilms from the ex-situ test. The PHB-related biofilm was characterized by a higher abundance of the bacterial order Desulfobacterales. The composition of PHB-related biofilm varied significantly between the two tests and between aerobic and anaerobic conditions. The composition of PHB-related biofilm was significantly different from planktonic bacteria, particle, and sediment-related biofilm, showing the influence of PHB on the biofilm composition. Thus, the ex-situ tank test for PHB degradation cannot, in terms of bacterial composition, simulate the in-situ conditions to their full extent.

Systematizing Microbial Bioplastic Production for Developing Sustainable Bioeconomy: Metabolic Nexus Modeling, Economic and Environmental Technologies Assessment.

The excessive usage of non-renewable resources to produce plastic commodities has incongruously influenced the environment's health. Especially in the times of COVID-19, the need for plastic-based health products has increased predominantly. Given the rise in global warming and greenhouse gas emissions, the lifecycle of plastic has been established to contribute to it significantly. Bioplastics such as polyhydroxy alkanoates, polylactic acid, etc. derived from renewable energy origin have been a magnificent alternative to conventional plastics and reconnoitered exclusively for combating the environmental footprint of petrochemical plastic. However, the economically reasonable and environmentally friendly procedure of microbial bioplastic production has been a hard nut to crack due to less scouted and inefficient process optimization and downstream processing methodologies. Thereby, meticulous employment of computational tools such as genome-scale metabolic modeling and flux balance analysis has been practiced in recent times to understand the effect of genomic and environmental perturbations on the phenotype of the microorganism. In-silico results not only aid us in determining the biorefinery abilities of the model microorganism but also curb our reliance on equipment, raw materials, and capital investment for optimizing the best conditions. Additionally, to accomplish sustainable large-scale production of microbial bioplastic in a circular bioeconomy, extraction, and refinement of bioplastic needs to be investigated extensively by practicing techno-economic analysis and life cycle assessment. This review put forth state-of-the-art know-how on the proficiency of these computational techniques in laying the foundation of an efficient bioplastic manufacturing blueprint, chiefly focusing on microbial polyhydroxy alkanoates (PHA) production and its efficacy in outplacing fossil based plastic products.

Valorisation of waste cooking oil using mixed culture into short- and medium-chain length polyhydroxyalkanoates: Effect of concentration, temperature and ammonium.

The production of polyhydroxyalkanoates (PHAs) from waste cooking oil (WCO) by a mixed culture was investigated in the present study at increasing WCO concentrations, temperature and ammonium availability. The PHA production was done in two steps: in the first step, a mixed culture was enriched in PHA-accumulating bacteria from activated sludge in a sequencing batch reactor operated in a feast-famine mode and in the second step the PHA accumulation by the enriched mixed culture was assessed in a batch reactor. In the enrichment step, two substrates, WCO and nonanoic acid were used for enrichment and in the PHA accumulation step only WCO was used. It was not possible to enrich a mixed culture in PHA-accumulating bacteria using WCO as substrate due to the development of filamentous bacteria causing foam formation and bulking in the reactor. However, our results showed that the mixed culture continuously fed with nonanoic acid was enriched in PHA-accumulating bacteria. This enriched culture accumulated both scl- and mcl-PHA using WCO as substrate. The maximum PHA accumulation capacity of this mixed culture from WCO was 38.2% cdw. Increasing the temperature (30-40 â„ƒ) or WCO concentrations (5-20 g/l) increased the PHA accumulation capacity of the mixed culture and the ratios of scl-PHA to mcl-PHA. The presence of ammonium increased PHA accumulation (21.9% cdw) compared to the complete absence of ammonium (5.8% cdw). The thermal characterization of the PHA exhibited the advantageous properties of both scl- and mcl-PHA, i.e., higher melting temperature (152-172 â„ƒ) similar to scl-PHA and a lower degree of crystallinity (12%) similar to mcl-PHA. This is the first study to report the potential of open mixed culture to produce scl- and mcl-PHA from WCO and thus contributing to the understanding of sustainable polymer production.

Impact of juçara (Euterpe edulis) fruit waste extracts on the quality of conventional and antibiotic-free broiler meat.

Juçara (Euterpe edulis) is a native Brazilian palm tree from the Atlantic Forest, whose fruit-processing waste can present high concentration of antioxidant compounds. This research was assessed to determine the antioxidant potential of juçara waste extracts aiming to reduce the lipid and protein oxidation processes on conventional and antibiotic-free broiler meat throughout 9 d during refrigerated storage. The juçara waste extracts were obtained by microwave-assisted extraction. Two different extracts were tested based on the optimum point obtained when checking total phenolic (TPC) contents (Extract P) and antioxidant activity (Extract A) based on a previous study. The treatments using conventional and antibiotic-free broiler meat included: chicken patties without antioxidant addition (AFBNC and CBNC), with synthetic antioxidant (BHT) (AFBPC and CBPC), with Extract P (AFBEP and CBEP) and with Extract A (AFBEA and CBEA), totaling 8 treatments. Antioxidant activity of extracts along with TPC, flavonoid, anthocyanin, and tannin contents of extracts and patties were assessed. Proximate composition, fatty acid profile, lipid and protein oxidation process, and instrumental color were analyzed in patty treatments. Although both extracts had similar content of TPC and tannin, extract A presented the highest anthocyanin, while extract P exhibited the highest flavonoid. While extract A exhibited the highest antioxidant activity, extract P was highly influential in the stability of lipid oxidative degradation in both types of broiler meat (AFBEP and CBEP), and as successful as BHT (AFBPC and CBPC). In addition, extract P was also able to stabilize protein oxidation in conventional broiler meat (CBEP) from the third day, until the end of the storage period. Therefore, the fruit waste extract P of juçara can be a promising source of natural antioxidants to prevent the oxidative process in conventional and antibiotic-free broiler meat.

Modeling of Symbiotic Bacterial Biofilm Growth with an Example of the Streptococcus-Veillonella sp. System.

We present a multi-dimensional continuum mathematical model for modeling the growth of a symbiotic biofilm system. We take a dual-species namely, the Streptococcus-Veillonella sp. biofilm system as an example for numerical investigations. The presented model describes both the cooperation and competition between these species of bacteria. The coupled partial differential equations are solved by using an integrative finite element numerical strategy. Numerical examples are carried out for studying the evolution and distribution of the bio-components. The results demonstrate that the presented model is capable of describing the symbiotic behavior of the biofilm system. However, homogenized numerical solutions are observed locally. To study the homogenization behavior of the model, numerical investigations regarding on how random initial biomass distribution influences the homogenization process are carried out. We found that a smaller correlation length of the initial biomass distribution leads to faster homogenization of the solution globally, however, shows more fluctuated biomass profiles along the biofilm thickness direction. More realistic scenarios with bacteria in patches are also investigated numerically in this study.

Calcium carbonate deposits and microbial assemblages on microplastics in oligotrophic freshwaters.

Microplastics are solid polymer particles with a wide variety of surface properties, found in most waterbodies, and known as carriers of distinct microbial communities affecting the fate of the particles in the environment. Little is known about the formation of mineral deposits on microplastics and how these deposits connect to microbial assemblages and affect the physicochemical properties of the particles. In addition, most of the available research on this topic is based on large microplastics with sizes between 100 µm and up to 5 mm, rather than the small microplastics often found in drinking water sources. To narrow this gap in our understanding of environmental effects on small microplastics, two types of small microplastics made of two distinct polymers, poly(methyl methacrylate) (PMMA) and poly(tetrafluoroethylene) (PTFE) with sizes ranging from 15 to 150 µm, were incubated for six months in unprocessed and processed drinking water with increasing ionic concentration to allow for the formation of mineral deposits and microbial assemblages. Spatially resolved analysis with fluorescent in situ hybridization and confocal Raman microscopic imaging revealed deposits of calcium carbonates and scattered microbial assemblages on all microplastics, with structure, extend, and microbial association with the carbonates depending on the respective microplastic. Notably, PTFE floatation was overcome after three months in unprocessed drinking water but remained unchanged in processed drinking water, whereas PMMA appeared unaffected, indicating that the fate of microplastics in the environment may depend on polymer type and the encountered aquatic conditions forming mineral and microbial attachments to the particle surface.

Insightful Advancement and Opportunities for Microbial Bioplastic Production.

Impetuous urbanization and population growth are driving increased demand for plastics to formulate impeccable industrial and biomedical commodities. The everlasting nature and excruciating waste management of petroleum-based plastics have catered to numerous challenges for the environment. However, just implementing various end-of-life management techniques for assimilation and recycling plastics is not a comprehensive remedy; instead, the extensive reliance on finite resources needs to be reduced for sustainable production and plastic product utilization. Microorganisms, such as bacteria and algae, are explored substantially for their bioplastic production repertoire, thus replacing fossil-based plastics sooner or later. Nevertheless, the utilization of pure microbial cultures has led to various operational and economical complications, opening the ventures for the usage of mixed microbial cultures (MMCs) consisting of bacteria and algae for sustainable production of bioplastic. The current review is primarily focuses on elaborating the bioplastic production capabilities of different bacterial and algal strains, followed by discussing the quintessence of MMCs. The present state-of-the-art of bioplastic, different types of bacterial bioplastic, microalgal biocomposites, operational factors influencing the quality and quantity of bioplastic precursors, embracing the potential of bacteria-algae consortia, and the current global status quo of bioplastic production has been summarized extensively.

Small Sample Stress: Probing Oxygen-Deprived Ammonia-Oxidizing Bacteria with Raman Spectroscopy In Vivo.

The stress response of ammonia-oxidizing bacteria (AOB) to oxygen deprivation limits AOB growth and leads to different nitrification pathways that cause the release of greenhouse gases. Measuring the stress response of AOB has proven to be a challenge due to the low growth rates of stressed AOB, making the sample volumes required to monitor the internal stress response of AOB prohibitive to repeated analysis. In a proof-of-concept study, confocal Raman microscopy with excitation resonant to the heme c moiety of cytochrome c was used to compare the cytochrome c content and activity of stressed and unstressed Nitrosomonas europaea (Nm 50), Nitrosomonas eutropha (Nm 57), Nitrosospira briensis (Nsp 10), and Nitrosospira sp. (Nsp 02) in vivo. Each analysis required no more than 1000 individual cells per sampling; thus, the monitoring of cultures with low cell concentrations was possible. The identified spectral marker delivered reproducible results within the signal-to-noise ratio of the underlying Raman spectra. Cytochrome c content was found to be elevated in oxygen-deprived and previously oxygen-deprived samples. In addition, cells with predominantly ferrous cytochrome c content were found in deprived Nitrosomonas eutropha and Nitrosospira samples, which may be indicative of ongoing electron storage at the time of measurement.

Continuous cultivation strategy for yeast industrial wastewater-based polyhydroxyalkanoate production.

Polyhydroxyalkanoates (PHAs) present an eco-friendly alternative for conventional plastics. Industrial wastewater from the food industry is a copious source of organic carbon that can be recovered in the form of PHA. However, the wastewater composition varies considerably among the different industries demanding for an industry-specific investigation of the PHA production process. Wastewater from the yeast industry, besides its high concentration in organic carbon, also contains a high ammonium concentration which might decrease the PHA production. Thus, this study aims to investigate PHA production using yeast industry wastewater via an enriched mixed microbial culture (MMC). A less explored cultivation strategy, i.e., continuous cultivation for PHA production was evaluated and compared to the widely used batch cultivation. PHA accumulating MMC was enriched using a sequencing batch reactor (SBR) operated under aerobic dynamic feeding. An MMC dominated by the Thauera species was successfully enriched in the SBR. Experimental results showed that ammonium is indeed required for PHA accumulation and the complete absence of ammonium negatively affects the accumulation process. Using wastewater, batch and continuous feeding strategies, respectively, yielded the PHA accumulation of 72 % and 65 % per dry cell weight. Despite the slightly lower PHA accumulation with continuous cultivation, four times more biomass growth was produced. Consequently, higher theoretical PHA production (270 t/year) can be expected using continuous cultivation in half of the reactor volume (45 m3). Therefore, this study asserts the viability of continuous cultivation as a feasible investigatory tool and PHA production strategy.

Comparative study of polyhydroxyalkanoates production from acidified and anaerobically treated brewery wastewater using enriched mixed microbial culture.

The production of polyhydroxyalkanoates (PHA) from wastewaters using microbial mixed cultures (MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight (CDW) with pulse addition of acetate controlled by the dissolved oxygen (DO) concentration in the reactor. In a batch accumulation experiment with acetate, the PHA content achieved (28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate (~2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters (45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content (39% CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.

Sinks and sources of anammox bacteria in a wastewater treatment plant - screening with qPCR.

The deammonification process, which includes nitritation and anammox bacteria, is an energy-efficient nitrogen removal process. Starting up an anammox process in a wastewater treatment plant (WWTP) is still widely believed to require external seeding of anammox bacteria. To demonstrate the principle of a non-seeded anammox start-up, anammox bacteria in potential sources must be quantified. In this study, seven digesters, their substrates and reject water were sampled and quantitative polymerase chain reaction (qPCR) was used to quantify both total and viable anammox bacteria. The results show that mesophilic digesters fed with nitrifying sludge (with high sludge ages) can be classified as a reliable source of anammox bacteria. Sludge hygienization and dewatering of digestate reduce the amount of anammox bacteria by one to two orders of magnitude and can be considered as a sink. The sampled reject waters contained on average >4.0 × 104 copies mL-1 and the majority of these cells (>87%) were viable cells. Furthermore, plants with side-stream anammox treatment appear to have higher overall quantities of anammox bacteria than those without such treatment. The present study contributes to the development of sustainable strategies for both start-up of anammox reactors and the possibility of improving microbial management in WWTPs.

Characterization of PVA/glutaraldehyde hydrogels obtained using Central Composite Rotatable Design (CCRD).

Hydrogels are made from natural or synthetic polymers and, currently, they have many biomedical applications. In this work, the conditions for obtaining a hydrogel with similar physicochemical characteristics to the vitreous humor were defined using polyvinyl alcohol (PVA) and glutaraldehyde (GLUT) as cross-linker. The concentration of PVA and GLUT were modified, and their effect was analyzed in terms of the refractive index, density, and dynamic viscosity. The hydrogel which was obtained using 3.98% (w/V) of PVA, 3.13 mL (1.57 g) of GLUT in 100 mL, and the initial pH of 7.2 showed similar characteristics to the vitreous humor (density = 1.0174 ± 0.0050 g mL-1 , dynamic viscosity = 3.7425 ± 0.1800 mPa s and refractive index = 1.3410 ± 0.0010). The hydrogels were further investigated by rheological measurements, infrared spectroscopy, differential scanning calorimetry, X-ray diffraction and determination of swelling degree. The reticulation with GLUT promoted an increase in viscosity and glass transition temperature. On the other hand, it stimulated a decrease in the swelling degree, crystallinity, melting temperature, and intensity of the band related to the -OH bond, compared with the PVA without reticulation. The reticulated hydrogel displayed Newtonian behavior and a higher apparent viscosity than the PVA. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1558-1566, 2018.

Heat and Bleach: A Cost-Efficient Method for Extracting Microplastics from Return Activated Sludge.

The extraction of plastic microparticles, so-called microplastics, from sludge is a challenging task due to the complex, highly organic material often interspersed with other benign microparticles. The current procedures for microplastic extraction from sludge are time consuming and require expensive reagents for density separation as well as large volumes of oxidizing agents for organic removal, often resulting in tiny sample sizes and thus a disproportional risk of sample bias. In this work, we present an improved extraction method tested on return activated sludge (RAS). The treatment of 100 ml of RAS requires only 6% hydrogen peroxide (H2O2) for bleaching at 70 °C, followed by density separation with sodium nitrate/sodium thiosulfate (SNT) solution, and is completed within 24 h. Extracted particles of all sizes were chemically analyzed with confocal Raman microscopy. An extraction efficiency of 78 ± 8% for plastic particle sizes 20 µm and up was confirmed in a recovery experiment. However, glass shards with a diameter of less than 20 µm remained in the sample despite the density of glass exceeding the density of the separating SNT solution by 1.1 g/cm3. This indicates that density separation may be unreliable for particle sizes in the lower micrometer range.

Characterization of Rabbit Corneas Subjected to Stromal Stiffening by the Açaí Extract (Euterpe oleracea).

PURPOSE: In this study, we characterized rabbit corneas subjected to corneal cross-linking (CXL) with açaí extract compared with a riboflavin photo-stimulated procedure. MATERIALS AND METHODS: The corneas of the slaughterhouse rabbits were divided into three groups: control, consisting of untreated corneal samples; riboflavin/UVA, where corneas were treated with 0.1% riboflavin photo-stimulated at 365 nm as the standard protocol; and açaí, where the samples were subjected to 4% açaí extract for 0.5-2 h. After the CXL procedure, corneas of the three groups were characterized by analyzing their elastic modulus and thermal denaturation profile. RESULTS: The elastic modulus at 3% strain showed an approximately threefold increase in the riboflavin/UVA group and 10.5 times in the corneas treated with 4% açaí extract for 2 h, compared with the control group (p < 0.01). The denaturation temperature values of the two groups of crosslinked corneas increased significantly (p < 0.05) and were more pronounced in the açaí group. CONCLUSIONS: The açaí extract was effective in promoting CXL in rabbit corneas as characterized by the different techniques.

Sphygmomanometer test to evaluate muscle strength in individuals with lower limb amputation: validity and reliability / Teste do esfigmomanômetro para avaliação da força muscular em indivíduos com amputações de membros inferiores: validade e confiabilidade

Abstract Introduction: The sphygmomanometer test is an alternative and inexpensive method for assessment of muscle strength. This instrument was considered valid and reliable to measure the isometric strength in different health conditions, however, in individuals with limb amputations the properties of this instrument for this purpose, have not been investigated. Objective: To investigate the concurrent criterion validity, test-retest and inter-rater reliabilities of the aneroid sphygmomanometer test (AST) without modification, for assessment of the strength of subjects with lower limb amputations. Methods: Twenty-two subjects (57.6 ± 15.2 years) with lower limb amputations were included in this study. Maximum isometric force was assessed with a handheld dynamometer (microFet2®) and the AST. To identify differences between trials, one-way ANOVA was applied. To assess the concurrent criterion validity, test-retest and inter-rater reliabilities of the AST, Pearson's correlation coefficients of determination and intra-class correlation coefficient (ICC) were calculated. Results: For all muscle groups, no differences were observed between the trials (0.00001 ≤ F ≤ 0.10; 0.90 ≤ p ≤ 0.99). Significant, positive, and high to very high correlations were found between the HHD and the AST measures for the different numbers of trials for all assessed muscles (0.76 ≤ r ≤ 0.93; p ≤ 0.02). Test-retest (0.67 ≤ ICC ≤ 0.97) and inter-rater reliabilities (0.78 ≤ ICC ≤ 0.97) were adequate. The values obtained with the AST were good predictors of those obtained with HHD (0.58 ≤ r2 ≤ 0.85). Conclusion: For individuals with lower limb amputation, the AST showed adequate concurrent criterion validity, test-retest reliability and inter-rater reliability for the assessment of lower limbs muscle strength.

Resumo Introdução: O teste do esfigmomanômetro é um método alternativo e de baixo custo para se avaliar a força muscular. Esse instrumento já foi considerado válido e confiável para mensurar a força isométrica em diversas condições de saúde. No entanto, em indivíduos com amputações de membros as propriedades desse instrumento para esse fim, ainda não foram investigadas. Objetivo: Investigar a validade de critério concorrente, a confiabilidade teste-reteste e entre examinadores, do teste do esfigmomanômetro aneroide (TEA) sem modificação, para a avaliação da força muscular de indivíduos com amputações de membros inferiores (MMII). Métodos: Participaram 22 indivíduos (57,6 ± 15,2 anos) com amputações de MMII. A força isométrica máxima foi avaliada através de um dinamômetro portátil (microFet2®) e do TEA. Para identificar diferenças entre as repetições, ANOVA one-way foi utilizada. Para avaliar a validade do critério concorrente, confiabilidade teste-reteste e entre examinadores do TEA, os coeficientes de correlação de Pearson, de determinação e coeficiente de correlação intra-classe (CCI) foram calculados. Resultados: Para todos os grupos musculares, não foram observadas diferenças nas repetições (0,00001 ≤ F ≤ 0,10; 0,90 ≤ p ≤ 0,99). Os resultados apresentaram correlação positiva elevada e muito elevada para as diferentes medidas e grupos musculares dos MMII (0,76 ≤ r ≤ 0,93; p ≤ 0,02). E confiabilidade teste-reteste (0,67 ≤ ICC ≤ 0,97) e entre examinadores (0,78 ≤ ICC ≤ 0,97) consideráveis. Os valores obtidos com o TEA foram bons preditores daqueles obtidos com o dinamômetro manual (0,58 ≤ r2 ≤ 0,85). Conclusão: Para indivíduos com amputações de membros, o TEA apresentou valores adequados de validade de critério concorrente, confiabilidade teste-reteste e entre examinadores, para a avaliação de força muscular de MMII.

Confocal Raman microscopy and fluorescent in situ hybridization - A complementary approach for biofilm analysis.

We combine confocal Raman microscopy (CRM) of wet samples with subsequent Fluorescent in situ hybridization (FISH) without significant limitations to either technique for analyzing the same sample of a microbial community on a cell-to-cell basis. This combination of techniques allows a much deeper, more complete understanding of complex environmental samples than provided by either technique alone. The minimalistic approach is based on laboratory glassware with micro-engravings for reproducible localization of the sample at cell scale combined with a fixation and de- and rehydration protocol for the respective techniques. As proof of concept, we analyzed a floc of nitrifying activated sludge, demonstrating that the sample can be tracked with cell-scale precision over different measurements and instruments. The collected information includes the microbial content, spatial shape, variant chemical compositions of the floc matrix and the mineral microparticles embedded within. In addition, the direct comparison of CRM and FISH revealed a difference in reported cell size due to the different cell components targeted by the respective technique. To the best of our knowledge, this is the first report of a direct cell-to-cell comparison of confocal Raman microscopy and Fluorescent in situ hybridization analysis performed on the same sample. An adaptation of the method to include native samples as a starting point is planned for the near future. The micro-engraving approach itself also opens up the possibility of combining other, functionally incompatible techniques as required for further in-depth investigations of low-volume samples.