miRNome Profiling and Functional Analysis Reveal Involvement of hsa-miR-1246 in Colon Adenoma-Carcinoma Transition by Targeting AXIN2 and CFTR

Regulatory changes occurring early in colorectal cancer development remain poorly investigated. Since the majority of cases develop from polyps in the adenoma-carcinoma transition, a search of early molecular features, such as aberrations in miRNA expression occurring prior to cancer development, would enable identification of potentially causal, rather than consequential, candidates in the progression of polyp to cancer. In the current study, by employing small RNA-seq profiling of colon biopsy samples, we described differentially expressed miRNAs and their isoforms in the adenoma-carcinoma transition. Analysis of healthy-adenoma-carcinoma sequence in an independent validation group enabled us to identify early deregulated miRNAs including hsa-miR-1246 and hsa-miR-215-5p, the expressions of which are, respectively, gradually increasing and decreasing. Loss-of-function experiments revealed that inhibition of hsa-miR-1246 lead to reduced cell viability, colony formation, and migration rate, thereby indicating an oncogenic effect of this miRNA in vitro. Subsequent western blot and luciferase reporter assay provided evidence of hsa-miR-1246 being involved in the regulation of target AXIN2 and CFTR genes’ expression. To conclude, the present study revealed possible involvement of hsa-miR-1246 in early colorectal cancer development and regulation of tumor suppressors AXIN2 and CFTR.     

Design and Collection Efficiency of a New Electrostatic Precipitator for Bioaerosol Collection

We have developed and tested a new bioaerosol sampler in which airborne microorganisms are collected by electrostatic means. In this sampler, 2 ionizers charge the incoming particles if they carry insufficient electric charge for efficient collection. The organisms are then subjected to a precipitating electric field and are collected onto 2 square agar plates positioned along the flow axis. Tests with nonbiological NaCl particles versus B. subtilis var. niger (BG) spores and vegetative cells have shown that airborne microorganisms are collected more efficiently than nonbiological particles, even when the microorganisms have first passed through an electric charge neutralizer with no additional charging applied. The difference was attributed to the natural charges contained in cell membranes or spore coats of the microorganisms. Charge-neutralized BG spores and vegetative cells were collected at 4 L/min with efficiencies close to 80%, depending on the precipitation voltage, versus 50-60% for NaCl test particles. When incoming BG spores were charged with positive ions and then collected by a precipitating voltage of + 1,300 V, about 80% of the incoming spores were collected and more than 70% of incoming spores formed colonies. These experiments with BG spores have also indicated that there were no significant particle losses inside the sampler. The collection efficiency of biological and nonbiological particles increased to 90-100% when the particles were externally charged and the precipitating voltage was increased to more than - 4,000 V. It has also been shown that the aerosolized BG spores (used as anthrax simulants for bioaerosol sensors) carry a net negative electric charge. Thus the collection efficiency depends on the polarity of the electric field applied across the agar plates. These findings indicate that the collection of airborne microorganisms is possible by electrostatic precipitation without prior electric charging if the microorganisms already carry electric charges. These are usually high immediately after their release into the air.     

A comparative Raman spectroelectrochemical study of selected polyaniline derivatives in a pH-neutral solution

Selected conducting polymers (polyaniline and poly-N-methylaniline), and copolymers of aniline with o-, m-, and p-phenylenediamines, as well as with metanilic acid, have been electropolymerized at a gold electrode, and studied with Raman spectroscopy (532 nm excitation) in a pH-neutral solution. Characteristic Raman features have been obtained and analysed for (co)polymers within electrode potential range of ?0.4 to 0.2 V vs. Ag/AgCl. Changes in Raman spectra depending on electrode potential have been analysed and assigned to different redox forms of (co)polymers. It has been shown that both oxidised and reduced forms of (co)polymers can exist, depending on electrode potential, even in a pH-neutral solution, where most of the polymers studied show no clearly defined electrochemical redox processes.     

Evaluation of a high-volume portable bioaerosol sampler in laboratory and field environments

This study investigated the physical and biological performances of a portable centrifugal sampler for viable bioaerosols, RCS High Flow. The performance of the test sampler in the laboratory and field environments was compared with that of a reference sampler, BioSampler. The laboratory experiments with non-biological particles of KCl, oleic acid, and polystyrene latex showed that the test sampler's collection efficiency is about 22% for 0.5-microm particles, 48% for 1.0-microm particles, and approximately 100% for particles of 2.5 microm and larger. These tests indicated that the sampler's cut-off size (d50) was 1.1 microm. The test sampler's physical performance when collecting the spores and vegetative cells of Bacillus subtilis var. niger (BG) was similar to that when collecting non-biological particles of the same size. In the laboratory tests, the RCS High Flow sampler was found to enumerate approximately 40% of BG spores and cells relative to the reference sampler, BioSampler. A similar ratio was found during testing in an indoor environment. This ratio decreased to below 10% when testing was performed in an outdoor environment. We hypothesize that the test sampler's underperformance compared with the BioSampler could be caused by the damage to sensitive microorganisms during the collection process, test sampler's sensitivity to wind direction and speed as well as break-up of particle aggregates during the impingement process in BioSampler, which resulted in more colony-forming units (CFUs) being counted by the reference sampler than by the test sampler. Overall, when the RCS High Plus is used to sample culturable airborne microorganisms, the results obtained may have to be adjusted to avoid potential underestimation of microorganism concentration in the air. PRACTICAL IMPLICATIONS: The laboratory testing of the RCS High Flow bioaerosol sampler showed that the sampler collects 1 microm particles and larger with an efficiency of 50% and higher; the efficiency reaches approximately 100% for particles of 2.5 microm and larger. When considering this result, most of the airborne fungal spores would be collected with an efficiency between 50 and 100%. The field testing, however, indicated that the RCS High Flow sampler recovered from 41 to 71% of microorganisms collected relative to the reference sampler, Biosampler, and this ratio dropped to below 5% during outdoor testing. Thus, while the RCS High Flow sampler offers certain advantages over other samplers for viable bioaerosols--it is lightweight, battery operated, and collects viable microorganisms at a high flow rate directly on agar media, the results obtained may have to be adjusted to avoid potential underestimation of microorganism concentration in the air, especially if sampling is performed outdoors.     

Investigation of inherent and latent internal losses in liquid-based bioaerosol samplers

Previous studies have analyzed collection efficiencies and reaerosolization rates of liquid-based bioaerosol collectors. However, these studies did not analyze latent internal losses in the samplers, i.e., the fraction of the particles that is aerosolized from the collection liquid, attach to the samplers’ inner surfaces and do not leave the sampler via outlet. Here, we investigated the internal losses and reaerosolization rates in BioSampler (SKC Inc., Eighty Four, PA) and AGI-30 (Ace Glass Inc., Vineland, NJ) bioaerosol collectors operated with different amounts of liquid as a function of particle type (polystyrene latex particles of 0.9 and 3.2 μm, B. subtilis bacteria and C. cladosporioides fungal spores), particle concentration (“low” and “high” differing by a factor of 100) and operating time (15 and 30 min). The samplers were filled with sterile deionized water containing known (reference) particle concentrations and were operated in a particle-free atmosphere for 15 or 30 min. The overall particle loss was determined by comparing the concentration of particles remaining in the collection liquid with the reference concentration. The reaerosolization rates were estimated by comparing the concentration of particles collected at each sampler's outlet with the reference concentration. The internal loss was determined as a fraction of particles remaining attached to the inner walls of a sampler, i.e., particles not in the collection liquid and not reaerosolized. All the investigated variables had a statistically significant effect on the overall particle loss, the reaerosolization rate and the internal loss. Averaged for all test conditions, the internal loss for BioSampler with 5 mL liquid, BioSampler with 20 mL liquid and AGI-30 was 37.7%, 29.6% and 22.5%, respectively. The observed reaerosolization rates were rather low and ranged from 0.2% to 6.9%. This study shows that depending on a particular set of sampling conditions a substantial fraction of already collected particles could leave the collection fluid, attach to the inner surfaces of the samplers and not be available for sample analysis thus affecting the accuracy of bioaerosol investigations.     

Technology roles and paths of influence in an ecosystem model of technology evolution

We propose a new conceptual model for understanding technology evolution that highlights dynamic and highly interdependent relationships among multiple technologies. We argue that, instead of considering technologies in isolation, technology evolution is best viewed as a dynamic system or ecosystem that includes a variety of interrelated technologies. By considering the interdependent nature of technology evolution, we identify three roles that technologies play within a technology ecosystem. These roles are components, products and applications, and support and infrastructure. Technologies within an ecosystem interact through these roles and impact each others’ evolution. We also classify types of interactions between technology roles, which we term paths of influence. We demonstrate the use of our proposed model through examples of wireless networking (Wi-Fi) technologies and a business mini-case on the digital music industry.

Neutronic characterization of the MEGAPIE target

The MEGAPIE project aimed to design, build and operate a liquid metal spallation neutron target of about 1 MW beam power in the SINQ facility at the Paul Scherrer Institut (Villigen, Switzerland). This project is an important step in the roadmap towards the demonstration of the accelerator driven system (ADS) concept and high power liquid metal targets in general. Following the design phase, an experimental program was defined to provide a complete characterization of the facility by performing a “mapping” of the neutron flux at different points, from the center of the target to the beam lines. The neutronic performance of the target was studied using different experimental techniques with the goals of validating the Monte Carlo codes used in the design of the target; additionally, the performance was compared with the solid lead targets used before and after the MEGAPIE experiment.     

Estimation of ambient temperature impact on vertical dynamic behaviour of passenger rail vehicle with damaged wheels

Maintenance and repair specialists of rolling stock face the problem related to accurate and reliable assessment of the vibrations of the car body of passenger rail vehicle, caused by wheel damage, and its impact on passengers. Another important aspect is to deter-mine the permissible speed at which the passenger car with wheel damage could move to the nearest station or depot without badly damaging the rails. The purpose of this research is to examine the dynamic processes of the interaction of the passenger car chassis with the railway track using a newly developed mathematical models called the “Passenger Car - Track” system. During the simulation, the dynamic characteristics of the track, bogies and car body in different season temperature were estimated. The validation of theoretical results was obtained based on the field tests of the test train as well as the results of measurements of changes in track stiffness temperatures. Finally, conclusions and suggestions are presented.     

Use of a robotic sampling platform to assess young children's exposure to indoor bioaerosols

Indoor exposures to allergens, mold spores, and endotoxin have been suggested as etiological agents of asthma; therefore, accurate determination of those exposures, especially in young children (6-36 months), is important for understanding the development of asthma. Because use of personal sampling equipment in this population is difficult, and in children <1 year of age impossible, we developed a personal sampling surrogate: the Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler to better estimate their exposures. During sampling, PIPER simulates the activity patterns, speed of motion, and the height of the breathing zones of young children, and mechanically resuspends the deposited dust just as a young child does during running and crawling. The concentrations of allergens, mold spores, and endotoxin measured by PIPER were compared to those measured using traditional stationary air sampling method in 75 homes in central New Jersey, United States. Endotoxin was detected in all homes with median concentrations of 1.0 and 0.55 EU/m(3) for PIPER and stationary sampler, respectively. The difference in median concentrations obtained using the two methods was statistically significant for homes with carpeted floors (P = 0.0001) in the heating season. For such homes, the average ratio of endotoxin concentration measured by PIPER to the stationary sampler was 2.96 (95% CI 2.29-3.63). Fungal spores were detected in all homes, with median fungal concentrations of 316 and 380 spores/m(3) for PIPER and stationary sampler, respectively. For fungi, the difference between the two sampling methods was not statistically significant. For both sampling methods, the total airborne mold levels were statistically significantly higher in the non-heating season than in the heating season. Allergens were detected in ~15% of investigated homes. The data indicate that the traditional stationary air-sampling methods may substantially underestimate personal exposures to endotoxin, especially due to resuspension of dust from carpeted floor surfaces. A personal sampling surrogate, such as PIPER, is a feasible approach to estimate personal exposures in young children. PIPER should be seriously considered as the sampling platform for future exposure studies in young children. PRACTICAL IMPLICATIONS: This study investigated potential indoor bioaerosol exposure of young children using a Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler platform. The results show that the traditional stationary air-sampling methods can substantially underestimate personal exposures to resuspended material, and that a personal sampling surrogate, such as PIPER, offers a feasible surrogate for measuring personal inhalation exposures of young children.