Scale-up Method Research Articles

A scalable human islet 3D-culture platform maintains cell mass and function long-term for transplantation

Present-day islet culture methods provide short-term maintenance of cell viability and function, limiting access to islet transplantation. Attempts to lengthen culture intervals remain unsuccessful. A new method was developed to permit the long-term culture of islets. Human islets were embedded in polysaccharide 3D-hydrogel in cell culture inserts or gas-permeable chambers with serum-free CMRL 1066 supplemented media for up to 8 weeks. The long-term cultured islets maintained better morphology, cell mass, and viability at 4 weeks than islets in conventional suspension culture. In fact, islets cultured in the 3D-hydrogel retained β cell mass and function on par with freshly isolated islets in vitro and, when transplanted into diabetic mice, restored glucose balance similar to fresh islets. Using gas-permeable chambers, the 3D-hydrogel culture method was scaled up over 10-fold and maintained islet viability and function, although the cell mass recovery rate was 50%. Additional optimization of scale-up methods continues. If successful, this technology could afford flexibility and expand access to islet transplantation, especially single-donor islet-after-kidney transplantation.

Exploring the Comprehensive Kozak Sequence Landscape for AAV Production in Sf9 System.

The widespread successful use of recombinant Adeno-associated virus (rAAV) in gene therapy has driven the demand for scale-up manufacturing methods of vectors with optimized yield and transduction efficiency. The Baculovirus/Sf9 system is a promising platform for high yield production; however, a major drawback to using an invertebrate cell line compared to a mammalian system is a generally altered AAV capsid stoichiometry resulting in lower biological potency. Here, we introduce a term of the structural and biological "fitness" of an AAV capsid as a function of two interdependent parameters: (1) packaging efficiency (yield), and (2) transduction efficiency (infectivity). Both parameters are critically dependent on AAV capsid structural proteins VP1/2/3 stoichiometry. To identify an optimal AAV capsid composition, we developed a novel Directed Evolution (DE) protocol for assessing the structural and biological fitness of Sf9-manufactured rAAV for any given serotype. The approach involves the packaging of a combinatorial capsid library in insect Sf9 cells, followed by a library screening for high infectivity in human Cre-recombinase-expressing C12 cells. One single DE selection round, complemented by Next-Generation Sequencing (NGS) and guided by in silico analysis, identifies a small subset of VP1 translation initiation sites (known as Kozak sequence) encoding "fit" AAV capsids characterized by a high production yield and superior transduction efficiencies.

Self-reported abortion experiences in Ethiopia and Uganda, new evidence from cross-sectional community-based surveys.

Unsafe abortion is a major contributor to maternal morbidity and mortality. To gain insight into the ways in which abortion restrictions and stigma may shape reproductive health outcomes, we present self-reported data on abortions in Ethiopia and Uganda and compare these findings across the two varying legal contexts. W investigate differences in sociodemographic characteristics by whether or not a woman self-reported an abortion, and we describe the characteristics of women's most recent self-reported abortion. In Ethiopia only, we classified abortions as being either safe, less safe, or least safe. Finally, we estimate minimum one-year induced abortion incidence rates using the Network Scale-Up Method (NSUM). We find that women who self-reported abortions were more commonly older, formerly married, or had any children compared to women who did not report an abortion. While three-quarters of women in both settings accessed their abortion in a health facility, women in Ethiopia more commonly used public facilities as compared to in Uganda (23.0% vs 12.6%). In Ethiopia, 62.4% of self-reported abortions were classified as safe, and treated complications were more commonly reported among least and less safe abortions compared to safe abortions (21.4% and 23.1% vs. 12.4%, respectively). Self-reported postabortion complications were more common in Uganda (37.2% vs 16.0%). The NSUM estimate for the minimum one-year abortion incidence rate was 4.7 per 1000 in Ethiopia (95% CI 3.9-5.6) and 19.4 per 1000 in Uganda (95% C 16.2-22.8). The frequency of abortions and low levels of contraception use at the time women became pregnant suggest a need for increased investments in family planning services in both settings. Further, it is likely that the broadly accessible nature of abortion in Ethiopia has made abortions safer and less likely to result in complications in Ethiopia as compared to Uganda.

Feasibility Study and Assessment of Chitosan-Based Bioflocculant Harvesting Method for Scale-up of Microalgae Micractinium sp.

Feasibility Study and Assessment of Chitosan-Based Bioflocculant Harvesting Method for Scale-up of Microalgae Micractinium sp.

Thermal Equivalent Circuit Model and Parameter Estimation for High-Capacity Li-Ion Cell

The equivalent circuit model (ECM) has gained popularity as a simplified and computationally efficient battery model. However, an appropriate model is required to accurately calculate terminal voltage, state of charge (SOC), and temperature for high-capacity Li-ion batteries used in hybrid electric and electric vehicles. In this study, we integrate the ECM with an energy balance model to calculate the cell temperature. Furthermore, we propose improved model structures and parameter estimation strategies to effectively characterize high-capacity batteries. First, the actual SOC is calculated considering the actual discharge capacity. Second, as the current increases, the overcalculated resistance is corrected. Finally, ECM parameters are estimated using experimental data and the genetic algorithm (GA). To facilitate the parameter-search process for GA, we employ the dimensionless scale-up method and the Pareto optimal concept. The thermal ECM is validated using experimental data from 57.6 Ah batteries, demonstrating voltage and temperature calculation errors of less than 1.71% and 3.51%, respectively.

Environment-Adaptable Rotational Energy Harvesters Based on Nylon-core Coiled Carbon Nanotube Yarns.

Owing to increasing amount of research on energy harvesting, studies on harvesters for practical application and their performance are attracting attention. Therefore, studies on the use of continuous energy as an energy source for energy-harvesting devices are being conducted, and fluid flows, e.g., wind, river flow, and sea wave, are widely used as input energy sources for continuous energy harvesting. A new energy-harvesting technology has emerged based on the mechanical stretch and release of coiled carbon nanotube (CNT) yarns, which generate energy based on the change in the electrochemical double-layer capacitance. First, this CNT yarn-based mechanical energy harvester is demonstrated, which is applicable to various environments where fluid flow exists. This environment-adaptable harvester uses rotational energy as the mechanical energy source and is tested in river and ocean environments. Moreover, an attachable-type harvester for the application of the existing rotational system is devised. In the case of a slow rotational environment, a square-wave strain-applying harvester has been implemented, which can convert sinusoidal strain motion into square-wave strain motion for high output voltages. To achieve high performance of practical harvesting applications, a scale-up method for powering signal-transmitting devices has been implemented.

PC@PPy porous membrane prepared by breath figure method with superior mechanical property for efficient solar interfacial evaporation

Solar interfacial evaporation (SIE) is one of the most prospective solar energy harvesting technologies for solving the scarcity of freshwater resources. Herein, we report a novel photothermal membrane polycarbonate (PC)@polypyrrole (PPy) (PC@PPy) adopting to breath figure method followed by surface chemistry modification, and assemble a double-layer solar interfacial evaporator consisting of PC@PPy photothermal membrane as the upper layer and plant fiber-wrapped expanded polyethylene (EPE) foam as the bottom layer for SIE. Due to the abundant porous structure and strong light absorption of the PC@PPy membrane, excellent insulation of the EPE sponge, the as-prepared PC@PPy-EPE evaporator exhibits a high evaporation of 1.78 kg m-2h−1 and photothermal conversion efficiency of 93.57%, and outstanding evaporation stability and resistance in 16% wt NaCl with an evaporation of 1.58 kg m-2h−1 under 1 sun irradiation. Moreover, the PC@PPy photothermal possess superior flexibility and strong mechanical properties. Coupling with cost-effective, environment-friendly, simple and easily scale-up breath figure preparation method, the PC@PPy-EPE generator has broad application prospects in SIE.

Electrical Energy Consumption of Multiscale UV-AOP Reactors for Micropollutant Removal in Drinking Water: Facilitated Prediction by Reaction Rate Constants Measured on a Mini-Fluidic Photoreaction System.

Electrical energy consumption per order (EEO) is an important figure-of-merit for the selection and optimization of ultraviolet (UV)-based advanced oxidation processes (UV-AOPs). However, EEO applications are limited by the lack of an accurate and facilitative evaluation method because EEO presents reactor property dependence. In this study, we developed an EEO prediction method for multiscale UV-AOP reactors for micropollutant removal in water. The method utilized the reaction rate constants determined in a reference reactor (e.g., mini-fluidic photoreaction system), complemented by a scale-up method that clarified the dependence of EEO on reactor properties. The predicted results of various UV-AOPs were verified experimentally in four bench/pilot-scale reactors in laboratory and a full-scale flow-through reactor (FFR) in field using sulfamethazine as a model micropollutant. For example, EEO values of 0.105 and 0.058 kWh m-3 order-1 were predicted in the FFR at H2O2 doses of 5 and 10 mg L-1, respectively, which generally agreed with verification results. Additionally, the developed method could assist the identification of appropriate reactors in the laboratory for EEO measurements, providing a valuable supplement for the EEO prediction in practice. The developed method presents acceptable accuracy, convenience, and low cost, which would significantly facilitate EEO evaluations for practical UV-AOP applications.

Relation between Scale-Up and Life Cycle Assessment for Wet Grinding Process of Pumice

This study examines the grinding process of pumice based on the dry and wet laboratory measurements, scale-up method, and life cycle assessment. This research’s main goal was to set up the relation between scale-up and life cycle assessment results for the wet grinding process with the help of mathematical equations. Within the first research works, basic grinding testing in a laboratory dry Bond mill was accomplished. This step allowed the description of the estimated particle size distribution, median particle size, specific grinding work, and grindability index number of pumice. The second step was the determination of power consumption and scale-up in a laboratory stirred media mill, and it involved the assessment of resources, primary energies, and environmental impacts of wet grinding using GaBi 8.0 software. According to the results, we obtain life cycle emission factors by introducing five coefficients for grinding in laboratory and industrial conditions. These constants depend on the external dimensions of the mill and can be expressed by a derived scale constant from the scale-up. Research results enable the industry to make a prognosis for industrial plants based on the integration between life cycle assessment and scale-up of the pilot grinding processes.

Scaled-up production and quality controlling techniques of energetic cocrystals: challenges and prospects

Cocrystallization techniques have become extremely important methods for obtaining novel high-energy insensitive energetic materials, and it has attracted great attention for the development of high-energy explosives and propellants, etc. in recent years. Several scale-up cocrystallization techniques including solvent-nonsolvent, semibatch reaction, bead milling, and spray drying methods et al. have been applied for obtaining the energetic cocrystals, and the preparation processes of these methods were also shown. The types and quality of raw materials and solvents, the synthetic times, morphology, and size of these cocrystals were described and compared by using different synthetic techniques in the review. Moreover, the principle, advantages and disadvantages of scale-up preparation methods were shown. More importantly, the preparation efficiency, the ratio between the quality of raw materials and the volume of solvent, and yield of different methods were also exhibited and discussed, which can provide key information and experiences for the future application of the materials. Finally, future research trends are suggested from different perspectives involving the formation mechanisms in the preparation process by using intermolecular interaction simulation, experimental study, and thermodynamic calculations, the optimization of traditional scale-up techniques, and the exploitation of novel methods for the energetic cocrystals.

Nanobioremediation: a bacterial consortium-zinc oxide nanoparticle-based approach for the removal of methylene blue dye from wastewater.

Industrial effluents carrying dyes are considered a major environmental threat in the present era. Methylene blue (MB) dye is one of the key dyes of the thiazine group of dyes. It is broadly used in medical, textile, and various fields and is well known for its carcinogenicity and methemoglobin nature. Bacterial and other microbes-mediated bioremediation is becoming an emerging and significant section for the treatment of wastewater. Isolated bacteria were used for the bioremediation and nanobioremediation of methylene blue dye under varying conditions and parameters. A comparative study was conducted for the remediation of methylene blue dye using bacterial consortium, potential bacteria (isolated by scale-up method), and potential bacteria within zinc oxide nanoparticles. The decolorizing ability of bacteria was analyzed by UV visible spectrophotometer after stirring and static incubation in different time intervals of the isolates. Growth parameters and environmental parameters which include pH, initial dye concentration, and dose of nanoparticles were optimized with the minimal salt medium. An enzyme assay study was also done to check the effect of dye and nanoparticles on bacterial growth and the mode of action of degradation. The authors found that potential bacteria within ZnO nanoparticles showed enhanced decolorization efficiency (95.46% at pH 8) due to the properties of nanoparticles. On the other hand, the decolorization of MB dye by potential bacteria and the bacterial consortium was about 89.08 and 76.3%, respectively, for a 10-ppm dye concentration. During the enzyme assays study, the highest activity was observed for phenol oxidase, nicotinamide adenine dinucleotide (NADH), 2,6-Dichloroindophenol(DCIP), and laccase for nutrient broth having MB dye, MB dye, and ZnO NPs, while no such change was observed for manganese peroxidase enzyme activity. Nanobioremediation is a promising approach to removing such pollutants from the environment.

Rationally Designed Eco-Friendly Solvent System for High-Performance, Large-Area Perovskite Solar Cells and Modules.

The important but remained issue to be addressed to achieve the mass production of perovskite solar modules include a large-area fabrication of high-quality perovskite film with eco-friendly, viable production methods. Although several efforts are made to achieve large-area fabrication of perovskite, the development of eco-friendly solvent system, which is precisely designed to be fit to scale-up methods are still challenging. Herein, this work develops the eco-friendly solvent/co-solvent system to produce a high-quality perovskite layer with a bathing in eco-friendly antisolvent. The new co-solvent/additive, methylsulfonylmethane (MSM), efficiently improves the overall solubility and has a suitable binding strength to the perovskite precursor, resulting in a high-quality perovskite film with antisolvent bathing method in large area. The resultant perovskite solar cells showed high power conversion efficiency of over 24% (in reverse scan), with a good long-term stability under continuous light illumination or damp-heat condition. MSM is also beneficial to produce a perovskite layer at low-temperature or high-humidity. MSM-based solvent system is finally applied to large-area, resulting in highly efficiency perovskite solar modules with PCE of 19.9% (by aperture) or 21.2% (by active area) in reverse scan. These findings contribute to step forward to a mass production of perovskite solar modules with eco-friendly way.

An Empirical Comparison of a Traditional Strategy and Network Scale-Up Method for Prevalence Estimation of Child Trafficking in Sierra Leone

The goal of this paper is to compare a traditional survey method with the network scale-up method (NSUM) for the prevalence estimation of child trafficking in Sierra Leone in 2020. The traditional survey method involved a probability-based, stratified, and clustered multistage sampling design in which adult respondents in 3,070 households were interviewed about trafficking of children who reside in their household in three selected districts. This paper details the first attempt to estimate the prevalence of child trafficking using NSUM, which entailed questioning the same adult respondents about the trafficking-related activities of children in their personal networks. Findings and interpretation of these results are presented, along with implications and recommendations for future studies.

Introduction to bio-based packaging materials

Abstract Bio-based materials must be studied to replace polymers from petrochemical sources in packaging applications. However, using polymers from petrochemical sources has caused consumer and environmental concerns. Therefore, synthetic and non-synthetic materials that can be used for packaging applications, scale-up methods, industrial uses, sustainability assessments, and end-of-life alternatives will all be included in this study. Synthetic polymers, e.g., polylactic acid (PLA), polyethylene furanoate (PEF), polybutylene succinate (PBS), and non-synthetic polymers, including waxes, lipids, proteins, starch, cellulose, and polyhydrodialkanoate (PHAs), are some of the bio-based compounds that will be covered in this work. Besides that, more attention is paid to surface modification techniques and coatings, multilayers, biocomposites, and additives used to modify material characteristics, particularly gas and moisture barriers and biodegradability. In sum, this research offers a comprehensive analysis of bio-based packaging materials, including processing, and an assessment of sustainability and available alternatives.

Further Exploring the Public Health Implications of the Network Scale-Up Method: Cross-Sectional Survey Study.

The decline in the number of new HIV infections among adults has slowed down, gradually becoming the biggest obstacle to achieving the 2030 target of ending the HIV/AIDS epidemic. Thus, a political declaration to ensure that 90% of people at high risk of HIV infection can access comprehensive prevention services was proposed by the United Nations General Assembly. Therefore, obtaining an accurate estimated size of high-risk populations is required as a prior condition to plan and implement HIV prevention services. The network scale-up method (NSUM) was recommended by the United Nations Programme on HIV/AIDS and the World Health Organization to estimate the sizes of populations at high risk of HIV infection; however, we found that the NSUM also revealed underlying population characteristics of female sex workers in addition to being used to estimate the population size. Such information on underlying population characteristics is very useful in improving the planning and implementation of HIV prevention services. This is especially relevant for people who inject drugs, where in addition to stigma and discrimination, criminalization further hinders access to HIV prevention services. We aimed to conduct a further exploration of the public health implications of the NSUM by using it to estimate the population size, popularity ratio, and information transmission rate among people who inject drugs. A stratified 2-stage cluster survey of the general population and a respondent-driven sampling survey of people who inject drugs were conducted in the urban district of Taiyuan, China, in 2021. The estimated size of the population of people who inject drugs in Taiyuan was 1241.9 (95% CI 1009.2-1474.9), corresponding to 4.4×10-2% (95% CI 3.6×10-2% to 5.2×10-2%) of the adult population aged 15-64 years. The estimated popularity ratio of people who inject drugs was 53.6% (95% CI 47.2%-60.1%), and the estimated information transmission rate was 87.9% (95% CI 86.5%-89.3%). In addition to being used to estimate the size of the population of people who inject drugs, the NSUM revealed that they have smaller-sized personal social networks while concealing their drug use, and these underlying population characteristics are extremely useful for planning appropriate service delivery approaches with the fewest barriers for people who inject drugs to access HIV prevention services. Therefore, more cost-effectiveness brings new public health implications for the NSUM, which makes it even more promising for its application.

Prevalence of Domestic Violence against Women and Its Visibility in Southeast Iran.

We aimed to estimate the prevalence of domestic violence against women at Reproductive Age (WARA) and its visibility in southeast of Iran. Adopting a modified time-location sampling, we recruited 933 WARA in the city of Kerman, Iran from Aug to Dec 2019. Domestic violence (DV) was divided into three main categories: Physical, psychological, and sexual. Data were obtained by direct and Network Scale-Up (NSU) methods through self-administered questionnaires. Generalized Estimating Equations (GEE) was used to determine the association between socioeconomic variables and the violence experience. Visibility was defined as the ratio of NSU over direct estimates. Using the direct method, the annual prevalence of psychological violence was estimated at 60.9%. Corresponding figures for physical and sexual violence were 34.7% and 37.7%, respectively. NSU estimates were about one-third of the direct estimates. Divorced and widowed, self-employed, and less educated women were more likely to experience DV. While the average DV was as high as 44%, its visibility was as low as 33%. Nearly two-thirds of domestic violence against women remains undisclosed. This indicates a high level of stigma perceived around this type of violence.

Solid Lipid Nanoparticles: Multitasking Nano-Carriers for Cancer Treatment.

Despite all the advances seen in recent years, the severe adverse effects and low specificity of conventional chemotherapy are still challenging problems regarding cancer treatment. Nanotechnology has helped to address these questions, making important contributions in the oncological field. The use of nanoparticles has allowed the improvement of the therapeutic index of several conventional drugs and facilitates the tumoral accumulation and intracellular delivery of complex biomolecules, such as genetic material. Among the wide range of nanotechnology-based drug delivery systems (nanoDDS), solid lipid nanoparticles (SLNs) have emerged as promising systems for delivering different types of cargo. Their solid lipid core, at room and body temperature, provides SLNs with higher stability than other formulations. Moreover, SLNs offer other important features, namely the possibility to perform active targeting, sustained and controlled release, and multifunctional therapy. Furthermore, with the possibility to use biocompatible and physiologic materials and easy scale-up and low-cost production methods, SLNs meet the principal requirements of an ideal nanoDDS. The present work aims to summarize the main aspects related to SLNs, including composition, production methods, and administration routes, as well as to show the most recent studies about the use of SLNs for cancer treatment.

Controlling Surface of Rods With Entrained Particle as Asperities

Abstract Changing the surface properties (i.e., roughness or friction) can be instrumental for many applications but can be a complex and resource-intensive process. In this paper, we demonstrate a novel process of controlling the friction of a continuous rod by delivering inorganic microparticles. A standardized continuous particle transfer protocol has been developed in our laboratory for depositing particles from a liquid carrier system (LCS) to the cylindrical rod substrate. The particle transfer process can produce controllable and tunable surface properties. Polymeric binder is used to deliver the particles as asperities over the rod substrate and by controlling their size, shape, and distribution, the coefficient of friction of the rod is determined. Tabletop experiments are designed and performed to measure the friction coefficient following the Capstan equation. The entrained particles on the substrate will create size- and shape-based asperities, which will alter the surface morphology toward the desired direction. Both oblique and direct quantitative measurements are performed at different particles and binder concentrations. A systematic variation in the friction coefficient is observed and reported in the result section. It is observed from the capstan experiment that adding only 1% irregular shaped particles in the suspension changes the friction coefficient of the rods by almost 115%. The proposed friction control technique is a simple scale-up, low-cost, low-waste, and low-energy manufacturing method for controlling the surface morphology.

Application of the network scale-up method to estimate the sizes of key populations for HIV in Singapore using online surveys.

Singapore lacks robust data on the sizes of the key populations that are most at risk for HIV. Using the network scale-up method for hidden or hard-to-reach populations, we estimate the sizes of five key populations-male clients of female sex workers (MCFSW), men who have sex with men (MSM), female sex workers (FSW), people who inject drugs (PWID) and transgender people-and profile the ages and ethnicities of respondents with the high-risk contacts they report knowing. We conducted a cross-sectional online survey between March and May 2019 (n = 2802) using a network scale-up instrument previously developed for Singapore. Participants were recruited using an existing panel and online advertising, and the sample reweighted by age, sex, ethnicity and education attained to represent the general adult population. We built a Bayesian hierarchical model to estimate the sizes of the five key populations for HIV in Singapore. After adjustment, the sizes of the at-risk populations are estimated to be: 76,800 (95% credible interval [CI]: 64,200-91,800) MCFSW; 139,000 (95% CI: 120,000-160,000) MSM; 8030 (95% CI: 3980-16,200) FSW; 3470 (95% CI: 1540-7830) PWID and 18,000 (95% CI: 14,000-23,200) transgender people. Generally, men reported knowing more people in all the high-risk groups; older people reported knowing more MCFSW, FSW and transgender people; and younger people reported knowing more MSM. There was a bimodal effect of age on those who reported knowing more PWIDs: people in their 20s and 60s reported more contacts. This study demonstrates that a size estimation study of hidden populations is quickly and efficiently scalable through using online surveys in a socially conservative society, like Singapore, where key populations are stigmatized or criminalized. The approach may be suitable in other countries where stigma is prevalent and where barriers to surveillance and data collection are numerous.

Constructing a Hierarchical Hydrophilic Crosslink Network on the Surface of a Polyvinylidene Fluoride Membrane for Efficient Oil/Water Emulsion Separation

Oil/water mixtures from industrial and domestic wastewater adversely affect the environment and human beings. In this context, the development of a facile and improved separation method is crucial. Herein, dopamine was used as a bioadhesive to bind tea polyphenol (TP) onto the surface of a polyvinylidene fluoride (PVDF) membrane to form the first hydrophilic polymer network. Sodium periodate (NaIO4) is considered an oxidising agent for triggering self-polymerisation and can be used to introduce hydrophilic groups via surface manipulation to form the second hydrophilic network. In contrast to the individual polydopamine (PDA) and TP/NaIO4 composite coatings for a hydrophobic PVDF microfiltration membrane, a combination of PDA, TP, and NaIO4 has achieved the most facile treatment process for transforming the hydrophobic membrane into the hydrophilic state. The hierarchical superhydrophilic network structure with a simultaneous underwater superoleophobic membrane exhibited excellent performance in separating various oil-in-water emulsions, with a high water flux (1530 L.m-2 h-1.bar) and improved rejection (98%). The water contact angle of the modified membrane was 0° in 1 s. Moreover, the steady polyphenol coating was applied onto the surface, which endowed the membrane with an adequate antifouling and recovery capability and a robust durability against immersion in an acid, alkali, or salt solution. This facile scale-up method depends on in situ plant-inspired chemistry and has remarkable potential for practical applications.