PCR-Based Analytical Methods for Quantification and Quality Control of Recombinant Adeno-Associated Viral Vector Preparations

Recombinant adeno-associated viral vectors (rAAV) represent a gene therapy tool of ever-increasing importance. Their utilization as a delivery vehicle for gene replacement, silencing and editing, among other purposes, demonstrate considerable versatility. Emerging vector utilization in various experimental, preclinical and clinical applications establishes the necessity of producing and characterizing a wide variety of rAAV preparations. Critically important characteristics concerning quality control are rAAV titer quantification and the detection of impurities. Differences in rAAV constructs necessitate the development of highly standardized quantification assays to make direct comparisons of different preparations in terms of assembly or purification efficiency, as well as experimental or therapeutic dosages. The development of universal methods for impurities quantification is rather complicated, since variable production platforms are utilized for rAAV assembly. However, general agreements also should be achieved to address this issue. The majority of methods for rAAV quantification and quality control are based on PCR techniques. Despite the progress made, increasing evidence concerning high variability in titration assays indicates poor standardization of the methods undertaken to date. This review summarizes successes in the field of rAAV quality control and emphasizes ongoing challenges in PCR applications for rAAV characterization. General considerations regarding possible solutions are also provided.

Synthesis and Properties of SrTiO3 Ceramic Doped with Sm2O3

The aim of this work was to study the effect of samarium oxide doping on a SrTiO3 perovskite ceramic. After analyzing the data obtained on the morphological features of the synthesized structures, it was found that an increase in the dopant concentration led not only to a change in the morphological features, but also in the density of the ferroelectrics. Using the X-ray diffraction method, it was found that doping with Sm2O3 led to the formation of a multiphase system of two cubic phases of SrTiO3 and Sm2O3. At the same time, an increase in the concentration of Sm2O3 dopant led to a change in the crystallinity degree, as well as deformation of the structure. Evaluation of the efficiency of use of synthesized ferroelectrics as catalysts for purification of aqueous media from manganese showed that an increase in the concentration of Sm2O3 dopant led to an increase in purification efficiency by 50–70%.

Purification efficiency of eight aquatic plant species in an artificial floating island system in relation to extracellular enzyme activity and microbial community

The floating island system exploits the combination of aquatic plants, microorganisms, and extracellular enzymes to purify wastewater. We investigated the purification efficiency of eight aquatic plant species cultured in wastewater. The relationships of plant purification capacity with extracellular enzyme activity and microbial community were analyzed to explore the crucial factors that affect the plant purification capacity and the mechanism of pollutants removal in different plant systems. Three plant species, namely Oenanthe javanica, Thalia dealbata, and lris pseudacorus, were most effective for purification of ammonium-nitrogen (NH4⁺-N), total phosphate (TP), and chemical oxygen demand (COD) with maximum efficiencies of 76.09, 85.87, and 89.10%, respectively. Urease, alkaline phosphatase (AP), and β-glucosidase activities were significantly and positively correlated with root system development (P < 0.05). Activities of urease and AP were positively correlated with NH4⁺-N and TP removal, respectively. The magnitude of urease and AP activity was generally consistent with the plant’s capacity to remove NH4⁺-N and TP. β-Glucosidase activity and COD removal were not significantly correlated. The dominant microbial phylum in each species treatment was Proteobacteria. Alphaproteobacteria and Bacteroidia showed > 1% relative abundance and greater involvement in degradation of pollutants in the experimental system.

Advanced hemodialysis equipment for more eco-friendly dialysis

Healthcare in general and dialysis care in particular are contributing to resource consumption and, thus, have a notable environmental footprint. Dialysis is a life-saving therapy but it entails the use of a broad range of consumables generating waste, and consumption of water and energy for the dialysis process. Various stakeholders in the healthcare sector are called upon to develop and to take measures to save resources and to make healthcare and dialysis more sustainable. Among these stakeholders are manufacturers of dialysis equipment and water purification systems. Dialysis equipment and consumables, together with care processes need to be advanced to reduce waste generation, enhance recyclability, optimize water purification efficiency and water use. Joint efforts should thus pave the way to enable delivering green dialysis and to contribute to environmentally sustainable health care.

Under the dynamic environment of normal diagnosis and treatment in the bronchoscope room, the study of the removal efficiency of the new air purifier on microbial aerosols

Background The SARS-CoV-2 can spread through droplets, aerosols, etc. In the case of a severe outbreak of the SARS-CoV-2, the use of new air purifiers in work and living places has a certain effect on reducing the spread of the SARS-CoV-2. There are abundant microbial aerosols in the indoor medical environment. The innovation of this experiment lies in the use of long-term, large-volume sampling methods under the multi-factor dynamic conditions of normal diagnosis and treatment in the bronchoscope room, and the use of two microbial detection methods at the same time to study the removal efficiency of the new air purifier on microbial aerosols ; The innovation of the new air purifier lies in outdoor fresh air and steady-state displacement flow technology. Methods In this experiment, the test group and the control group were set up. Gelatin filtration membrane and PTFE filtration membrane were used to sample the microbial aerosols in the bronchoscope room. Long time (39.5h) and large sampling volume (70590L) was used. A total of 16 days of pure working time sampling was carried out for a period of 1 month. The collected specimens were tested by two methods: next-generation sequencing (mNGS) and microbial culture identification. The researcher retrieved and recorded the microbiological test results of related patients, and compared them with the results of this experiment. Results The result of next-generation sequencing (mNGS): The total purification efficiency was 88.0%. Microbial culture counting and identification results: the total purification efficiency is 87.5%. The results are statistically significant. There is a certain correlation between the experimental results and the clinical microbiological test results of patients. Conclusions 1. The new type of air purifier has a good effect on the removal of microbial aerosols in the bronchoscope room; 2. A variety of microorganisms involved in the experiment can be transmitted through aerosols. Discussion The new air purifier has a total removal efficiency of more than 85% of microorganisms under the dynamic environment of the hospital's normal diagnosis and treatment, and the purification efficiency of a single microorganism ranges 50%-100%. Such removal efficiency may have a positive effect for the control of the SARS-CoV-2 epidemic.

INFLUENCE OF THE SIDE VENTILATION ON THE DURABILITY OF THE FUNCTIONING OF DRYING BEDS WITH NON-SATURATED FLOW IN TREATEMENT OF SEPTIC TANK SLUDGE

The non-saturated Flow Drying Beds allow efficient treatment of septic tank sludge. However, they are vulnerable to clogging. To ensure the sustainability of this technology, through an additional supply of oxygen from the lateral surface, a flow model coupled with the variation of the biofilm has been developed. The calibration, validation and comparison of the simulated and experimental results were made from the NASH criterion. The simulations focused on two types of reactors. A reactor with pores on its side surface is called a ventilated reactor (VR). The second is then called an unventilated reactor (UVR). The results show that the maximum applicable organic load is 43.3 mgO2 / cm2 / d at the UVR level and 51.8 mgO2 / cm2 / d at the VR level. In addition, the reduction in free flow porosity is 93.33% at the UVR level and 81% at the AR level. In addition, the results show that when the hydraulic head is less than 5 cm / d, the COD removal efficiency is 96.19% at the UVR level and 95.64% at the VR level. But, when the load is greater than 5 cm / d, the yield is 92.65% at the level of the UVR and of 94.95% at the level of the VR. Thus, in the context of a large-scale operation, lateral ventilation is essential. It guarantees good purification efficiency, slows down internal clogging of beds and accelerates its reversibility when it occurs.

Purification Efficiency of Three Combinations of Native Aquatic Macrophytes in Artificial Wastewater in Autumn

Water pollution caused by excessive nutrient and biological invasion is increasingly widespread in China, which can lead to problems with drinking water as well as serious damage to the ecosystem if not be properly treated. Aquatic plant restoration (phytoremediation) has become a promising and increasingly popular solution. In this study, eight native species of low-temperature-tolerant aquatic macrophytes were chosen to construct three combinations of aquatic macrophytes to study their purification efficiency on eutrophic water in large open tanks during autumn in Guangzhou City. The total nitrogen (TN) removal rates of group A (Vallisneria natans + Ludwigia adscendens + Monochoria vaginalis + Saururus chinensis), group B (V. natans + Ipomoea aquatica + Acorus calamus + Typha orientalis), and group C (V. natans + L. adscendens + Schoenoplectus juncoides + T. orientalis) were 79.10%, 46.39%, and 67.46%, respectively. The total phosphorus (TP) removal rates were 89.39%, 88.37%, and 91.96% in groups A, B, and C, respectively, while the chemical oxygen demand (COD) removal rates were 93.91%, 96.48%, and 92.78%, respectively. In the control group (CK), the removal rates of TN, TP, and COD were 70.42%, 86.59%, and 87.94%, respectively. The overall removal rates of TN, TP, and COD in the plant groups were only slightly higher than that in CK group, which did not show a significant advantage. This may be related to the leaf decay of some aquatic plants during the experiment, whereby the decay of V. natans was the most obvious. The results suggest that a proper amount of plant residue will not lead to a significant deterioration of water quality.