Special Issue on “Synthesis and Characterization of Nanomaterials”

Nanomaterial is defined a natural, incidental or manufactured material containing particles, in an unbound state, as an aggregate, or as an agglomerate, and where, for 50% or more of the particles in the number size distribution, one or more external dimensions is in the size range 1–100 nm [...]

Measurement report: Particle-size-dependent fluorescence properties of water-soluble organic compounds (WSOCs) and their atmospheric implications for the aging of WSOCs

Water-soluble organic compounds (WSOCs) play important roles in atmospheric particle formation, migration, and transformation processes. Size-segregated atmospheric particles were collected in a rural area of Beijing. Three-dimensional fluorescence spectroscopy was used to investigate the optical properties of WSOCs as a means of inferring information about their atmospheric sources. Sophisticated analysis on fluorescence data was performed to characteristically estimate the connections among particles of different sizes. WSOC concentrations and the average fluorescence intensity (AFI) showed a monomodal distribution in winter and a bimodal distribution in summer, with the dominant mode in the 0.26–0.44 µm size range in both seasons. The excitation–emission matrix (EEM) spectra of WSOCs varied with particle size, likely due to changing sources and/or the chemical transformation of organics. Size distributions of the fluorescence regional integration (regions III and V) and humification index (HIX) indicate that the humification degree or aromaticity of WSOCs was the highest in the particle size range of 0.26–0.44 µm. The Stokes shift (SS) and the harmonic mean of the excitation and emission wavelengths (WH) reflected that π-conjugated systems were high in the same particle size range. The parallel factor analysis (PARAFAC) results showed that humic-like substances were abundant in fine particles (< 1 µm) and peaked at 0.26–0.44 µm. All evidence supported the fact that the humification degree of WSOCs increased with particle size in the submicron mode (< 0.44 µm) and then decreased gradually with particle size, which implied that the condensation of organics occurred in submicron particles, resulting in the highest degree of humification in the particle size range of 0.26–0.44 µm rather than in the < 0.26 µm range. Synthetically analyzing three-dimensional fluorescence data could efficiently reveal the secondary transformation processes of WSOCs.

Development of Three-Stage Bioaerosol Sampler for Size-Selective Sampling

In this study, a three-stage bioaerosol sampler with a sampling flow rate of 170 L/min was designed and fabricated for sampling the bioaerosols released during human breathing and coughing, and its performance was evaluated. The sampler was constructed using a cyclone separator with a cutoff size of 2.5 µm as a preseparator, a multi-nozzle virtual impactor with a cutoff size of 0.34 µm as an aerosol concentrator, and a BioSampler, which is a commercial product, for collecting bioaerosols in a collection fluid. The collection efficiency of the sampler was evaluated through simulations and experiments. Only particles with sizes of 0.1-4 µm were selectively collected in the collection fluid. Bacteriophage bioaerosols were sampled using the developed sampler and ACD-200 Bobcat sampler, which is a commercial product. The amounts of collected bacteriophages were compared using the polymerase chain reaction (PCR) technique. The sampling performance of the developed sampler was similar to that of the ACD-200 Bobcat sampler. Moreover, the developed sampler showed its ability to sample bioaerosols of a specific size-range and collect them directly in a collection fluid for the PCR analysis. Therefore, the developed sampler is expected to be useful for indoor environmental monitoring by effectively sampling the bioaerosols released indoors during human breathing and coughing.

Evaluating the Efficacy of the MedicAir Air Purifier in Reducing Ambient Air Pollution in Classrooms

In light of the novel coronavirus and transmission in schools, increased scrutiny has been placed on airborne viral and particulate contamination, and efforts to mitigate this have been suggested, including the use of air purification. The importance of this is increased given the relationship between increased airborne particulates and increased coronavirus transmission, as well as the significance of removing particulates in the size range of bacteria and viruses from the air. Ambient levels of pm2.5 and pm1 in the absence of purification were recorded in two classrooms of similar size using medical grade data loggers, which then measured the change in these levels with use MedicAir air purifiers. It was found that baseline levels at times doubled the WHO limits for safe IAQ- MedicAir units were able to rapidly reduce levels of particulates to significantly below guidelines. We propose that the use of these units is an effective and rapid solution for the mitigation of coronavirus transmission, as well as the improvement of IAQ in schools.

Influence of Particle Size of River Sand on the Decontamination Process in the Slow Sand Filter Treatment of Micro-Polluted Water

Slow sand filters (SSFs) have been widely used in the construction of water plants in rural areas. It is necessary to find river sand of suitable particle size to improve SSF treatment of micro-polluted water so as to ensure the effective and long-term operation of these plants. In this study, SSF1# (particle size of 0.1–0.5 mm), SSF2# (particle size of 0.5–1 mm), and SSF3# (particle size of 1–1.5 mm) were selected. The physical absorption, CODMn and NH4+-N removal effect, and microbial community were analyzed. According to Langmuir and Freundlich adsorption model fitting, the smaller the particle size of the river sand, the more pollutants are adsorbed under the same conditions. SSF1# has the shortest membrane-forming time, highest CODMn and NH4+-N removal rate, and highest Shannon estimator, indicating that there are more abundant microbial species in the biofilm. Mesorhizobium, Pannonibacter, Pseudoxanthomonas, Aquabacterium, Devosia, and other bacteria have different proportions in each system, each forming its own stable biological chain system. The effluent quality of the three SSFs can meet drinking water standards. However, river sand with a particle size range of 0.1–0.5 mm is easily blocked, and thus the recommended size range for SSF is 0.5–1 mm.

An Inquiry into Gradable Zero-Waste Apparel Design

The implementation of standardized grading production practices within the mass market has been challenging for scholars experimenting with zero-waste apparel design. The purpose of this research was to test the efficacy of the Carrico Zero-waste Banded Grading (CZWBG) technique, which utilizes bands inserted in strategic locations as a method of grading zero-waste patterns across various consumer categories. An additional purpose was to evaluate the ways in which this grading approach affected the aesthetic outcomes of garments across a size run, and to determine whether this method affected the overall design process of the designers involved. Through experimental research design, six design scholars successfully tested and incorporated the CZWBG technique in zero-waste one or two-piece apparel item(s), subsequently developing three sizes in an industry-specified size range for their product category. Each design was cut from zero-waste patterns in a mid-range size and graded up and down one–two sizes using an industry-standardized grading scale. The grading was achieved by varying the widths and lengths of strategically inserted bands of fabric or trim. The designers utilized various grading methods, textiles, pattern development methods, and size runs, showing that the CZWBG technique can successfully be applied across multiple consumer categories in the apparel industry.

Engineered Dutasteride-Lipid Based Nanoparticle (DST-LNP) System Using Oleic and Stearic Acid for Topical Delivery

Male pattern baldness (MPB) is a common condition that has a negative impact on the psycho-social health of many men. This study aims to engineer an alcohol-free formulation to cater for individuals who may have had allergic reactions to alcohol-based preparations. A lipid-based nanoparticle system composed of stearic and oleic acid (solid and liquid lipid) was used to deliver dutasteride (DST) for topical application. Two compositions, with oleic acid (Formulation A) and without (Formulation B), were compared to analyse the role of oleic acid as a potential active ingredient in addition to DST. DST-loaded LNP were prepared using the emulsification–ultrasonication method. All of the prepared formulations were spherical in shape in the nanometric size range (150–300 nm), with entrapment efficiencies of >75%. X-ray diffractograms revealed that DST exists in an amorphous form within the NLP matrices. The drug release behaviour from both LNP preparations displayed slow release of DST. Permeation studies through pig ear skin demonstrated that DST-LNP with oleic acid produced significantly lower permeation into the dermis compared to the formulation without oleic acid. These results suggest that the proposed formulation presents several characteristics which are novel, indicating its suitability for the dermal delivery of anti-androgenic molecules.

Study of Tribological Properties of Fullerenol and Nanodiamonds as Additives in Water-Based Lubricants for Amorphous Carbon (a-C) Coatings

The tribological performances of fullerenol and nanodiamonds (NDs) as additives in water-based lubricants for amorphous carbon (a-C) coatings are investigated to avoid disadvantage factors, such as chemical reactions and deformation of particles. The effects of size and additive amount on tribological properties of nanoparticles are studied by rigid nanoparticles within the dot size range. The results show that owing to its small particle size (1–2 nm), fullerenol cannot prevent direct contact of the friction pair at low concentration conditions. Only when the quantity of fullerenol increased to support the asperity contact loads in sufficient concentration did nano-bearings perform well in anti-friction and anti-wear effects. Unlike fullerenol, nanodiamond particles with a diameter of about 5–10 nm show friction-reducing effect based on the nano-bearing effects at ultra-low concentration (0.01 wt.%), whereas particles at higher concentration block the rolling movement, hence increasing the coefficient of friction (COF) and wear. As a result of the effect of difference in size, fullerenol provides a better overall lubrication, but it is hard to reach a friction coefficient as low as NDs even under the optimal conditions.

The Emerging Role of Nanosuspensions for Drug Delivery and Stability

: Poor solubility of some medicinal compounds is a serious challenge that can be addressed by using a nano-suspension for improved delivery. The nanoparticles enhance the bioavailability along with the aqueous solubility of the drug, which is accomplished by increasing the active surface area of the drug. The gained attention of the nanosuspension is due to its stabilization facility, which is achieved by polymers, such as polyethylene glycol (PEG), having a particular size range of 10 - 100 nm. Hence, these nanoparticles have the capacity of binding to the targeted with very low damage to the healthy tissues. These are prepared by various methods, such as milling, high-pressure homogenization, and emulsification, along with melt emulsification. Moreover, surface modification and solidification have been used to add specific properties to the advanced therapies as post-processing techniques. For many decades, it has been known that water solubility hampers the bioavailability and not all drugs are water-soluble. In order to combat this obstacle, nanotechnology has been found to be of specific interest. For elevating the bioavailability by increasing the dissolution rate, the methodology of reduction of the associated drug particles into their subsequent submicron range is incorporated. For oral and non-oral administration, these nanosuspension formulations are used for the delivery of drugs.

Assessment of the level of allelic polymorphism of SSR markers and genetic distances of some grape varieties of the South of Russia of different ecological-geographical groups

Представлены результаты оценки генетического разнообразия 24 местных сортов юга России, поддерживаемых на ампелографической коллекции ФГБУН «ВННИИВиВ «Магарач». ДНК-типирование сортов и оценка аллельного разнообразия выполнено с использованием 9 ядерных (nSSR) и 3 хлоропластных (cpSSR) микросателлитных локусов. Уровень полиморфизма nSSR локусов составил 100 %. Всего было идентифицировано 73 аллеля, в среднем 9.1 аллеля /локус. Минимальное количество аллелей идентифицировано в локусах ssrVrZAG64 и ssrZag83. Наибольшее количество аллелей выявлено в локусе ssrVvUCH29 (13 аллелей), диапазон размера которых составил 203 п.н. - 309 п.н. В результате анализа полиморфизма сpSSR-локусов идентифицировано 4 хлоротипа: А, В, С, D. Наиболее распростанен в группе изученных сортов хлоротип D (58 %). В статье обсуждается происхождение сортов на основе анализа их гаплотипов. По результатами анализа аллельного полиморфизма nSSR-локусов рассчитана матрица генетических дистанций, значения которой находились в диапазоне 0,33-0,94, построена дендрограмма, отражающая взаимоотношения между образцами. По степени генетического сходства выделились 3 основных кластера, в которых наблюдалась дифференциация или тенденция к дифференциации по эколого-географическим группам. The assessment results of genetic diversity of 24 local varieties of the South of Russia, maintained in the ampelographic collection of the FSBSI Institute Magarach are presented. DNA typing of cultivars and assessment of allelic diversity was performed using 9 nuclear (nSSR) and 3 chloroplast (cpSSR) microsatellite loci. The level of polymorphism of nSSR loci was 100%. A total of 73 alleles were identified with an average of 9.1 alleles per locus. The minimal number of alleles was observed in the ssrVrZAG64 and ssrZag83 loci. The biggest number of alleles was found in the ssrVvUCH29 locus (13 alleles), the size range of which was 203 bp-309 bp. As a result of polymorphism analysis of cpSSR loci, 4 chlorotypes were identified: A, B, C, D. Chlorotype D is the most widespread in the group of the studied cultivars (58%). The article discusses the origin of varieties based on the analysis of their haplotypes. Based on the results of the analysis of allelic polymorphism of nSSR loci, a matrix of genetic distances was calculated, the values of which were in the range of 0.33-0.94, and a dendrogram, reflecting the relationship between the samples, was constructed. According to the degree of genetic similarity, 3 main clusters were distinguished, in which differentiation or a tendency towards differentiation by ecological-geographical groups was observed.