Μm In Diameter Research Articles

Plasma-based etching approach for GEM detector microfabrication at FBK for X-ray polarimetry in space

Gas Electron Multiplier (GEM) detectors are crucial for enabling high-resolution X-ray polarization of astrophysical sources when coupled to custom pixel readout ASIC in Gas Pixel Detectors (GPD), as in the Imaging X-ray Polarimetry Explorer (IXPE), the Polarlight cubesat pathfinder and the PFA telescope onboard the future large enhanced X-ray Timing and Polarimetry (eXTP) Chinese mission. The R&D efforts of the IXPE collaboration have resulted in mature GPD technology. However, limitations in the classical wet-etch or laser-drilled fabrication process of GEMs motivated our exploration of alternative methods. This work focuses on investigating a plasma-based etching approach for fabricating GEM patterns at Fondazione Bruno Kessler (FBK). The objective is to improve the aspect ratio of the GEM holes, to mitigate the charging of the GEM dielectric which generates rate-dependent gain changes. Unlike the traditional wet-etch process, Reactive Ion Etching (RIE) enables more vertical etching profiles and thus better aspect ratios. Moreover, the RIE process promises to overcome non-uniformities in the GEM hole patterns which are believed to cause systemic effects in the azimuthal response of GPDs equipped with either laser-drilled or wet-etch GEMs. We present a GEM geometry with 20 μm in diameter and 50 μm pitch, accompanied by extensive characterization (SEM and PFIB) of the structural features and aspect ratios. The collaboration with INFN Pisa and Turin enabled us to compare the electrical properties of these detectors and test their performance in their use as electron multipliers in GPDs. Although this R&D work is in its initial stages, it holds promise for enhancing the sensitivity of the IXPE mission in X-ray polarimetry measurements through GEM pattern with more vertical hole profiles. The outcomes of this study have the potential to advance the current technological platforms and improve the capabilities of future space-based X-ray polarimetry missions.

First report of Rhizopus stolonifer causing flower rot of yellow passion fruit (Passiflora edulis f. flavicarpa Deg.) in China.

The genus Passiflora, commonly known as passion fruit, originated in South America, is an economically important horticulture crop and widely distributed in the tropics and subtropics. Yellow passion fruit (Passiflora edulis f. flavicarpa) and purple passion fruit (Passiflora edulis f. edulis) are the two most planted species (Santos-Jiménez et al., 2022), which have been largely cultivated in southern China. The average annual production reaches 600,000 tons, of which yellow fruit accounts for more than 70% (Zhou et al., 2022). In 2022 to 2023, a disease caused flower rot severely in passion fruit plantations. The incidence rate was generally 10% in purple passion fruit, with an incidence up to 60% in yellow passion fruit 'Qinmi No. 9'. Flower rot occurs mainly in the rainy season, especially during periods of prolonged rain. Infected flowers had black patches that were water-soaked on the interior of the flower bud. The patches covered the entire flower bud, and fluffy mycelium and sporangia developed, which caused the flower bud rotten and abscised easily. Five symptomatic flowers from Wuhua, Guangdong (23°23'N, 115°18'E) and 8 symptomatic flowers from Shangsi, Guangxi (21°15'N, 107°98'E) of 'Qinmi No. 9' were collected during flowering period in 2022 and 2023. Diseased flower pieces were surface-sterilized with 70% ethanol for 2 to 3 min, rinsed with sterile distilled water 3 times, and placed on PDA medium at 25℃ in darkness. Four and 6 fungal isolates with similar morphology were isolated from the infected samples of Wuhua and Shangsi, respectively. Two isolates, PRFJ01 from Wuhua and PRGX02 from Shangsi, were randomly selected for further study. Purified fungal colonies at the age of 3 days accompany with diffuse cottony mycelia, turned white to gray later. The mycelia were hyaline and aseptate. Sporangiophores with 0.56 (0.22~1.10) mm in length and 6.1 (3.18~10.87) μm in width (n=100) were erect, light brown, and had rhizoids and stolons at their bases. Sporangia with 48.0 (23.45~92.85) μm in diameter (n=100) were dark-colored, near spherical and having dark ovoid sporangiospores with 3.56 (2.34~6.39) μm × 2.82 (1.73~4.70) μm (n=100). The morphology of the fungus were identical to Rhizopus stolonifer (Ehrenb.) Vuill (Haque et al. 2023). The two isolates were molecularly identified using genomic regions of 28S large ribosomal subunit (LSU) with NL1 and LR3 primers (Cruz-Lachica et al., 2018). The phylogenetic trees revealed the sequences of PRFJ01 (OR801560.1) and PRGX02 (OR801561.1) were 100% and 99% identical to R. stolonifer (MK705761.1 and KC412868.1), respectively. Pathogenicity tests were conducted on healthy flowers and leaves of 5-month-old grafted 'Qinmi No. 9' plants. Mycelial plugs with 5-mm diameter were placed on the flowers and leaves. Three plants were performed for each of the isolates, and the test was repeated twice. The inoculated plants were moisturized with plastic bags. Healthy flowers and leaves inoculated with sterile PDA plugs were used as control. Typical symptoms were observed on inoculated plants after 2 days. The dark grey mycelia and sporangia covered the entire flower after 4 days inoculation. The flower bud became putrid and the flower stalk split off. Lesions on leaves expanded accompany with numerous aerial mycelium. However, the controls were symptomless. R. stolonifer was reisolated from inoculated tissues. Previously, flower rot on passion fruit caused by R. stolonifer has only been recorded in Brazil (Ploetz, 2003). To our knowledge, this is the first report of R. stolonifer causing flower rot on passion fruit in China.

Effects of hatch spacing on pore segregation and mechanical properties during blue laser directed energy deposition of AlSi10Mg

Hatch spacing is a crucial parameter for achieving superior mechanical properties during the process of laser directed energy deposition (L-DED) process. However, the optimum hatch spacing is based on trial and error approaches using pre-existing experience. In this paper, we have systematically compared the porosity characteristics, microstructure evolution, and thermal gradients in double tracks of AlSi10Mg under various hatch spacings during blue laser directed energy deposition (BL-DED). A peculiar phenomenon of pore segregation is observed at the boundary of the overlapping zone of adjacent deposited tracks, where the porosity is almost 8 times that of other areas in the molten zone. Pore segregation consistently exists under different hatch spacings, with 90 % of the pores being below 10 μm in diameter. As the hatch spacing increases, the occurrence of pore segregation reduces significantly within the double tracks. Pore segregation tends to occur more frequently at the boundaries of Si eutectic networks due to the cellular growth pattern of α-Al in the solidification process, which pushes the pores towards the Si-based eutectics. The electron backscatter diffraction results reveal that the grain orientations of the double tracks are closely aligned with the <101> direction, and the overlapping area exhibits a mixing characteristic of fine equiaxed and columnar grain structures along the building direction. The BL-DED AlSi10Mg parts exhibited an ultimate tensile strength of 400±4 MPa with minimum pore segregation under the hatch spacing of 1.6 mm (80 % of the width of the single track). This study provides a novel insight into the hatch spacing during BL-DED and the relationship among pore defects, developed Si eutectic networks, and solidification structures. It also challenges the conventional selection strategies for hatch spacing and suggests potential enhancements in the quality and mechanical characteristics of BL-DED fabricated parts.

First Report of Powdery Mildew on Viburnum chinshanense Caused by Erysiphe pseudoviburni in China.

Viburnum chinshanense, a deciduous shrub in the family Caprifoliaceae, is a dominant tree distributed mainly in the North-Central and South-Central regions of China (Zhu et al. 2023). Because of its lush white flowers and vibrant red fruits, V. chinshanense is used widely as ornamental tree in China. In May 2022, severe powdery mildew symptoms were observed on V. chinshanense on the Huaxi Campus of Guizhou Normal University, Guiyang, China. The incidence was approximately 75% among 80 V. chinshanense plants observed. White mycelia were present on both adaxial and abaxial leaf sides, but not on fruits, petioles, or stems. Infected leaves showed slight chlorosis and twisting. The mycelia were amphigenous, forming small-to-large patches, often sparse on the upper leaf surface, but mostly confluent on the lower leaf surface. Hyphae were hyaline, 4-7 μm wide. Hyphal appressoria were lobed to multilobed, in opposite pairs or solitary. Conidiophores were erect, straight, or somewhat flexuous, 60-130 µm long (n = 30). Foot cells were subcylindrical to slightly curved-sinuous at the base, 20-40 × 6-10 µm (n = 30) in size, followed by 1-3 shorter cells. Conidia formed singly, occasionally two to three in a chain. Conidia were ellipsoid to ovoid, cylindrical, and 24-40 × 16-20 µm (n = 50). No fibrosin bodies were observed on the conidia. Chasmothecia were subglobose, 56-115 µm in diameter. The appendages were 35-70 µm long. Based on these morphological characteristics, the powdery mildew fungus was identified as Erysiphe pseudoviburni (Bradshaw et al. 2020). To confirm the identification, the ribosomal DNA internal transcribed spacer (ITS) and the ribosomal large subunit (LSU) region were amplified and sequenced using the ITS1/ITS4 primer pair (White et al. 1990) and the NL1/NL4 primer pair (Ziemiecki et al. 1990), respectively. The obtained 643-bp ITS sequence (GenBank accession no. ON729292) had 99.84% identity with E. pseudoviburni strains KUS-F27310 (MN431595) and MUMH0001 (LC009904). The obtained 593-bp LSU sequence (ON729293) had 99.83% identity with E. pseudoviburni (LC009904 and MN431595). Based on the phylogenetic analysis of the combined ITS and LSU dataset (Bradshaw et al. 2020), the isolate (GZVD-1) was grouped in a clade with the E. pseudoviburni strains KUS-F27319, KUS-F27310, and MUMH0001. To fulfill Koch's postulates, leaves of three healthy potted V. chinshanense plants were inoculated by gently pressing with diseased leaves. Non-contact plants were used as controls. All plants were incubated in a greenhouse at 25 ± 2°C, 80% relative humidity. Similar powdery mildew symptoms were observed on the inoculated plants 12 days after inoculation, whereas the control plants remained symptomless. The reisolated fungus from the inoculated plants was morphologically identical to that on originally diseased plants. ITS and LSU sequences of the reisolated fungus showed 100% identity with ON729292 and ON729293, respectively. E. pseudoviburni has previously been reported to infect some Viburnum species, including V. sieboldii in Japan (Takamatsu et al. 2015) and V. odoratissimum in South Korea (Bradshaw et al. 2020). To the best of our knowledge, this is the first report of powdery mildew caused by E. pseudoviburni on V. chinshanense in China. This work expands the known host range of E. pseudoviburni in the Viburnum genus.

Перебіг гаметогенезу у вузькопалих річкових раків (Astacus leptodactylus Eschscholtz, 1823) в умовах водойм Придніпров’я

Purpose. Detailed study of the stages of reproductive development (oogenesis and spermatogenesis) of crayfish using the example of the narrow-clawed crayfish Astacus leptodactylus Eschscholtz, 1823 in reservoirs of the Dnieper region. Methodology. The study was conducted during the period of 2022-2023. The material for the study were individuals of the narrow-clayed crayfish A. leptodactilus. A morphometric analysis was performed, after which the crayfish were preserved in an alcohol solution (70% ethanol and 2% glycerol) for the slide of histological cross-sections. Histological slides of crayfish gonads were made in accordance with generally accepted histological methods. The analysis of the cross-sections was carried out using a microscope and a digital camera. Descriptions of the slides were made using atlases of histology of decapods. Findings. It has been found that the gonads exhibited an asynchronous development and were in stages C, D, E, F, with a significant number of oocytes in stage C. The diameter of oocytes in phase D mainly ranged from 195.72 ± 12.43 μm with an area of 38,21 μm². The nucleus had a diameter of 48.14 ± 1.44 μm. In phases E, the size of oocytes reached a diameter of 259.24 ± 76.18 μm and an area of 52,850 ± 5,760 μm². Throughout phase D, the diameter of vacuoles was 18.45 ± 0.86 μm. In phase E, the diameter of vacuoles increased to 26.55 ± 1.24 μm, and as soon as in the transitional phase E–F, vacuoles merged massively with individual non-merging vacuoles having a diameter of 25.22 ± 1.12 μm. At the terminal stage F, oocytes reached definitive sizes and were ready for ovulation. The average size of larvae was 2600 ± 0.093 μm in diameter. The course of spermatogenesis in crayfish males was characterized by synchronous development of gametes. The analysis of sections showed that the area of spermatocytes was 43.14 ± 0.74 μm with a diameter of 7.14 ± 0.23 μm². In turn, the nuclei of spermatocytes had dimensions of 21.64 ± 0.35 μm² and 5.24 ± 0.02 μm in diameter. Originality. A comprehensive analysis of crayfish gametogenesis was conducted for the first time in the zones of the reproductive range of the Dnieper reservoirs. Some features of the stages of oogenesis and spermatogenesis were identified and the impact of the ecological regime on the reproduction of crayfish was studied. Keywords: narrow-clawed crayfish, water bodies, reproduction, ecological state of water bodies, reservoir, eggs, gametogenesis.

Prenatal air pollution exposure is associated with inflammatory, cardiovascular, and metabolic biomarkers in mothers and newborns

BackgroundPrenatal air pollution exposure has been associated with individual inflammatory, cardiovascular, and metabolic biomarkers in mothers and neonates. However, studies of air pollution and a comprehensive panel of biomarkers across maternal and cord blood samples remain limited. Few studies used data-driven methods to identify biomarker groupings that converge biomarkers from multiple biological pathways. This study aims to investigate the impacts of prenatal air pollution on groups of biomarkers in maternal and cord blood samples. MethodsIn the Maternal And Developmental Risks from Environmental and Social Stressors (MADRES) cohort, 87 biomarkers were quantified from 45 trimester 1 maternal blood and 55 cord blood samples. Pregnancy and trimester 1-averaged concentrations of particulate matter ≤2.5 μm and ≤10 μm in diameter (PM2.5 and PM10), nitrogen dioxide (NO2), and ozone (O3) were estimated, using inverse distance squared weighted spatial interpolation from regulatory air monitoring stations. Traffic-related NOx was assessed using California Line Source Dispersion Model: freeway/highway roads, non-freeway major roads, non-freeway minor roads, and their sum as total NOx. Elastic Net (EN) regression within the rexposome R package was used to group biomarkers and assess their associations with air pollution. ResultsIn maternal samples, trimester 1-averaged PM10 was associated with elevated inflammation biomarkers and lowered cardiovascular biomarkers. NO2 exhibited positive associations with cardiovascular and inflammation markers. O3 was inversely associated with inflammation, metabolic, and cardiovascular biomarkers. In cord blood, pregnancy-averaged PM2.5 was associated with higher cardiovascular biomarkers and lower metabolic biomarkers. PM10 was associated with lower inflammation and higher cardiovascular biomarkers. Total and major road NOx was associated with lower cardiovascular biomarkers. ConclusionPrenatal air pollution exposure was associated with changes in biomarkers related to inflammation, cardiovascular, metabolic, cancer, and neurological function in both mothers and neonates. This study shed light on mechanisms by which air pollution can influence biological function during pregnancy.

First Report of Phytophthora ramorum Causing Leaf Spots on Cornus capitata (Evergreen Dogwood) in United States.

Cornus capitata Wall. ex Roxb. (evergreen dogwood) is a bushy evergreen tree or shrub native to East Asia grown for its showy creamy bracts in late spring followed by attractive red fruit. In Feb 2023, a sample of foliage with leaf spots and tip dieback from C. capitata 'Mountain Moon' was submitted from a Humboldt Co. nursery as part of a CDFA inspection program for Phytophthora ramorum. The leaf spots were medium to dark brown, irregularly shaped, and ranged from 5 to 8 mm in diameter. They were located primarily along the leaf midrib and covered up to 1/4 of the leaf surface. Six 6-mm-diameter leaf discs taken from the margins of brown lesions and tip dieback were plated on Phytophthora selective CMA-PARP (PARP) media (Jeffers and Martin 1986). After 6 to 10 days, colonies resembling P. ramorum, with coralloid coenocytic hyphae, chlamydospores, ellipsoidal semi-papillate and caducous sporangia, and a relatively slow growth rate were recovered. Abundant sporangia formed on agar singly or in clusters on sympodially branched sporangiophores (n = 50), varying in size from 35 to 60 μm × 20 to 30 μm (mean 45.6 × 24.8 μm) with a length/breadth ratio ranging from 1.3 to 2.3 (mean 1.8). Chlamydospores (n = 50) ranged from 35 to 62 μm in diameter (mean 51.9 μm) on 14-day-old PARP cultures. The internal transcribed spacer region (ITS) using primers ITS5/ITS4 (White et al. 1990; accession no. OR636225) and cytochrome oxidase subunit 1 region (cox1) using primers OomCox1Levup/Fm85mod (Robideau et al. 2011; OR635665) of one isolate (0254-32A) were amplified and sequenced. BLAST analysis showed 100% identity of both regions to P. ramorum ex-type strain (MG865581 and MH136973). Microsatellite loci placed the P. ramorum isolate in the NA2 clonal lineage (Goss et al, 2011). Pathogenicity of P. ramorum isolate 0254-32A was tested using five C. capitata plants (2.5-year-old, 28-cm-tall, 3.78-liter pot). Zoospore inoculum was produced as described in Blomquist et al. (2021). Above ground parts of each plant were sprayed with inoculum (15 ml, 1.3 × 105 zoospores/ml). Inoculated plants were incubated in a dew chamber in the dark at 23°C for 72 h and then placed in a 23±1°C growth chamber with a 12-h photoperiod. Five control plants were treated as above but with sterile water instead of the zoospore suspension. Two days after inoculation, brown spots were visible on leaves on all inoculated plants, initiating from where the drops of inoculum had persisted. After 3 days, brown lesions, from water drop- to majority of entire leaf-sized, were observed on approximately 75% of inoculated leaves. After 6 days, lesions expanded to the edges of leaves, causing leaf curling and defoliation. Lesions stopped expanding after 3 weeks, and by 4 weeks, most infected leaves had abscised, with no new infections observed. Phytophthora ramorum was consistently isolated from foliar lesions of inoculated plants on PARP. It was not isolated from leaf or stem tissues of control plants, which remained asymptomatic during the 4-week experiment period. Phytophthora ramorum was detected on C. capitata in the UK in 2015 (DEFRA 2015). To our knowledge, this is the first report of P. ramorum infecting C. capitata in the United States and the completion of Koch's postulates on any Cornus spp. Incidence on C. capitata in the California nursery was low. However, their proximity to other infected foliar hosts suggests Cornus spp. may present a potential risk for the spread of P. ramorum.

3D porous ZnO microspheres sensitized by Ag quantum dots for highly responsive TEA sensors

The study aims to create a highly responsive gas sensor for TEA. In order to achieve this goal, spherical ZnO with layered structure was synthesized by a simple hydrothermal method. Subsequently, Ag quantum dots (QDs) are precipitated onto the surface of the ZnO microspheres. The ZnO microspheres were analyzed to demonstrate that they are comprised of porous nanosheets measuring roughly 10 μm in diameter. The composite with the optimal mass percentage displayed outstanding sensitivity to triethylamine (TEA), yielding a response of 1223, approximately 90 times higher than that of the pure ZnO sensor. Furthermore, this composite also demonstrated remarkable selectivity towards TEA. The exceptional detection results were achieved due to the catalytic influence of Ag as a precious metal, coupled with the distinctive structure of quantum dots and ZnO materials.

The fabrication method impacts biological properties of microfibrous three-dimensional in vitro cell culture scaffolds and their applications in drug screening

Two-dimensional (2D) cell culture models cannot accurately emulate the three-dimensional (3D) in vivo microenvironment; hence, the shift from compound screening in traditional 2D well plates to 3D cell culture models is forthcoming. New scaffold designs must comply with the 3Rs principle to reduce the use of animal-derived products, such as natural proteins. In line with this motivation, we engineered and compared various fibrous scaffolds featuring diverse fibre networks (coarse and fine fibres) and fibre surface properties (porous vs. smooth fibres), and tested them in in vitro cell culture. We fabricated coarse solid fibre scaffolds via a melt-based electrohydrodynamic process, which resulted in fibres with a diameter of 10.6 ± 1.9 µm and a porosity of 87.1 ± 0.9%. Using solution-based cryo-electrohydrodynamic process, we fabricated fine porous fibre and fine solid fibre scaffolds that exhibited fibres of 2.01 ± 0.5 µm and 1.72 ± 0.6 µm in diameter, with porosities of 96.5 ± 0.3% and 94.4 ± 0.5%, respectively. The scaffolds underwent only chemical modification via an alkaline treatment to enhance their hydrophilicity. We used mouse fibroblast L929 cells and human triple-negative breast cancer MDA-MB-231 cells as cell models, and used the MTT assay to measure their viability. After seven days of cell culture, all scaffolds were thoroughly penetrated. However, the coarse scaffolds created by the melt-based electrohydrodynamic process and the porous fibre scaffolds produced by the solution-based cryo-electrohydrodynamic process outperformed the simpler morphology of smooth fine fibres. Furthermore, the 50% half-maximum effective concentration (EC50) of doxorubicin tested in human glioblastoma (U87-MG) and human triple-negative breast cancer (MDA-MB-231) cell lines in 3D cell culture models was approximately twice as high as that achieved in conventional 2D cell cultures. Therefore, we infer that poly (ɛ-caprolactone) (PCL) microfibre scaffolds, devoid of animal-derived product surface treatment, may provide a favourable 3D milieu for various cell types for in vitro studies.

Abstract 833: No association between air pollution and lung cancer incidence in a 2 million South Korean cohort

Abstract Background: Accumulating evidence has consistently suggested long-term exposure to air pollution as a risk factor of lung cancer incidence. Our previous study of long-term exposure to particulate matter air pollution and lung cancer incidence in a South Korean cohort showed no association with hazard ratios greater than one. This inconsistent finding with those from previous cohort studies could be due to limited exposure assessment relying on district averages and a relatively small sample size of 80 thousand people. The present study aimed to overcome the two major limitations and re-analyzed the association for long-term exposure to particulate matter ≤ 10 µm and 2.5 µm in diameter (PM10 and PM2.5), nitrogen dioxide (NO2), and ozone. Specifically, we improved our exposure assessment for individual exposure using 100-meter grid addresses, and increased the population size to 2 million people based on the National Health Insurance Database (NHID) composed of the entire South Korean population. Methods: Our study population included 1,976,265 people who aged 30 years or older, had no history of cancer for 2002-2006, underwent health screening for 2005-2007, and resided in the Seoul Metropolitan Area. We defined lung cancer incidence as the first diagnosis based on the International Classification of Diseases 10th revision code and identified the incidence for 10 years of follow-up from 2007 through 2016. We estimated individual long-term exposure to PM10, PM2.5, NO2, and ozone as five-year average concentrations on each year at 100-meter grid addresses of participants’ homes by using previously-validated exposure prediction models. Finally, we applied time-varying Cox proportional hazard model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for a 10 µg/m3 or 10 ppb increase of each of the four pollutants after adjusting for individual- and area-level characteristics. Results: Out of 1,976,265 people, 15,707 people (0.79%) developed new cases of lung cancer for 10 years of follow-up. In all analyses for long-term exposure to four pollutants and lung cancer incidence, we did not find an association (PM10: HR= 0.999 [95% CI=0.956 - 1.044]; PM2.5: 0.890 [0.787 - 1.006]; NO2: 1.002 [0.967 - 1.037]; ozone: 1.027 [0.978 - 1.077]). Our stratified analyses by individual and area-level characteristics as well as 79 districts showed that the null findings in the total population were not derived by specific subpopulations. Conclusion: Despites the considerable improvement in exposure assessment and population size, our findings are contradictory to previous evidence. In addition to the possibility of no association, our null findings could be due to a relatively short period of exposure, the lack of histological information, and exposure measurement error resulting from indoor-outdoor difference and time activity. Future studies should overcome these limitations and re-examine the association. Citation Format: Sun-Young Kim, Jeongho Park, Ok-Jin Kim, Miyoun Shin, Sungchan Kang, Seung-sik Hwang, Youngwook Kim, Young-Jae Cho. No association between air pollution and lung cancer incidence in a 2 million South Korean cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 833.

Synthesis and characterization of hydroxy propyl methyl Cellulose/Copper nanobiocomposites for antibacterial and antioxidant smart materials

The synthesis of hydroxy propyl methyl cellulose (HPMC)/copper nanobiocomposites adopting a microwave treatment. In this study, HPMC and copper nitrate at various concentration were mixed and subjected to varying microwave treatment times (10, 20, 30, 40, 50 and 60 s). UV–Vis spectroscopy was employed to analyse the physicochemical characteristics of HPMC/copper nanobiocomposites, with a maximal absorbance at 380 nm, indicating the formation of copper nanoparticles within the HPMC matrix. The interaction between copper nanoparticles and HPMC was further confirmed through FT-IR analysis. The SEM analysis displayed microporous structures ranging from 5 to 14 µm in diameter, with an average pore size of 7.0 ± 2.0 nm. The compositional analysis was done with EDS mapping. TEM analysis revealed spherical shaped copper nanoparticles with an average particle size about 2.5 nm in HPMC matrix. Remarkably, these nanobiocomposites exhibited a broad-spectrum antibacterial activity, displaying minimal inhibitory concentrations against both Gram-negative and Gram-positive bacterium. Significantly, the assessment of antibacterial activity in HPMC/copper nanobiocomposites demonstrated their efficacy against both Escherichia coli and Staphylococcus aureus. In addition to the antioxidant property, the antibacterial properties holds significant implications for their potential applications of HPMC/ copper nanobiocomposites in the fields of food packaging and biomedicine.

DISTRIBUTION AND CHARACTERISTICS OF MESENTERIC MILK SPOTS IN HEALTHY RATS AND THOSE WITH ADHESION DISEASE

Introduction. The adhesion process occurs in more than 80% of cases after all abdominal operations. The process of adhesion formation and, as a consequence, chronic inflammation involve the lymphoid elements (Peyer's spots, solitary follicles) present in the peritoneum and submucosa of the intestine, causing a pathological immune response. Fat-associated lymphoid clusters (FALCs), known as mammary structures, are also found in other fat reservoirs, such as the pericardium, mediastinum, and pleural cavity. The problem of visualizing milk spots in various structures of the peritoneum remains open. Relevance. Despite the fact that as early as 1921, scientists emphasized the presence of milk spots in the abdominal cavity and their great biological significance, the results of experimental studies related to milk spots are still relatively few. The novelty consists in investigating the peculiarities of the distribution of milk spots in the mesentery of the intestine with adhesion disease in rats in comparison with the health animals.&#x0D; Objective of this study is to detect milk spots, to investigate their topography and structure in the mesentery of the intestine in the health and in adhesion disease.&#x0D; Materials and methods: The experiment involved tissue preparation, macroscopic examination, histological analysis of hematoxylin and eosin-stained film preparations.&#x0D; Results. Milk spots of the intestinal mesentery in rats from the intact group are represented by round formations, 1-2 μm in diameter, white in color, uniformly and diffusely located on the area of the mesentery of the small and large intestine. Microscopically, they are characterized as a cluster of lymphocytes, plasma cells, and macrophages belonging to FALC lymphoid tissue. The area of milk spots of the peritoneum in the experimental groups varies depending on the course of the process of adhesion formation. Individual small white and gray granulations were observed in the animals of the II experimental group on the 7th day. On the 14th day of observation in the III group, the diameter of the milk spots reached 2-2.5 mm, they appeared as white granular clusters. On the 21st day, the animals of the IV group demonstrated an abundant accumulation of elliptical whitish structures, 3-4 mm in diameter near the blood vessels that differed significantly from the indicators of the other groups.&#x0D; Conclusion. The study has expanded knowledge regarding the distribution and composition of milk spots in the normal mesentery compared to those observed in adhesion disease. According to data obtained, milk spots are lymphoid tissue, represented by various types of lymphocytes, macrophages and plasma cells. The question of whether the lymphocytes found in the milk spots belong to different subpopulations, the dynamics of their number during the main stages of adhesion formation, remains an open question requiring further scientific research.

Bronchiolitis recovery and the use of High Efficiency Particulate Air (HEPA) Filters (The BREATHE Study): study protocol for a multi-center, parallel, double-blind, randomized controlled clinical trial

BackgroundAcute viral bronchiolitis is the most common reason for hospitalization of infants in the USA. Infants hospitalized for bronchiolitis are at high risk for recurrent respiratory symptoms and wheeze in the subsequent year, and longer-term adverse respiratory outcomes such as persistent childhood asthma. There are no effective secondary prevention strategies. Multiple factors, including air pollutant exposure, contribute to risk of adverse respiratory outcomes in these infants. Improvement in indoor air quality following hospitalization for bronchiolitis may be a prevention opportunity to reduce symptom burden. Use of stand-alone high efficiency particulate air (HEPA) filtration units is a simple method to reduce particulate matter ≤ 2.5 µm in diameter (PM2.5), a common component of household air pollution that is strongly linked to health effects.MethodsBREATHE is a multi-center, parallel, double-blind, randomized controlled clinical trial. Two hundred twenty-eight children < 12 months of age hospitalized for the first time with bronchiolitis will participate. Children will be randomized 1:1 to receive a 24-week home intervention with filtration units containing HEPA and carbon filters (in the child’s sleep space and a common room) or to a control group with units that do not contain HEPA and carbon filters. The primary objective is to determine if use of HEPA filtration units reduces respiratory symptom burden for 24 weeks compared to use of control units. Secondary objectives are to assess the efficacy of the HEPA intervention relative to control on (1) number of unscheduled healthcare visits for respiratory complaints, (2) child quality of life, and (3) average PM2.5 levels in the home.DiscussionWe propose to test the use of HEPA filtration to improve indoor air quality as a strategy to reduce post-bronchiolitis respiratory symptom burden in at-risk infants with severe bronchiolitis. If the intervention proves successful, this trial will support use of HEPA filtration for children with bronchiolitis to reduce respiratory symptom burden following hospitalization.Trial registrationNCT05615870. Registered on November 14, 2022.

Fine Particulate Matter, Noise Pollution, and Greenspace and Prostate Cancer Risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Cohort.

Greenspace is hypothesized as being protective against cancer, whereas noise pollution and fine particulate matter (<2.5 μm in diameter, PM2.5) are both potential risk factors. Findings from recent studies of greenspace and PM2.5 with prostate cancer are not conclusive and the association between noise exposure and cancer has not been evaluated in a U.S. study. We assessed PM2.5, noise, and greenspace exposure using spatiotemporal models and satellite-based estimates at enrollment addresses for N = 43,184 male participants of the prospective Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial cohort (enrolled 1994-2001). We used Cox regression models adjusted for age, race and ethnicity, study center, family history of prostate cancer, and Area Deprivation Index to estimate associations between ambient PM2.5 (μg/m3), greenspace (index range from -1 to 1), and noise pollution (loudest 10% of total existing sound, decibels) and incident prostate cancer risk through December 2017. A total of 6,327 cases of prostate cancer were diagnosed among male participants during follow-up. PM2.5 and noise exposures were moderately positively correlated (Spearman ρ = 0.46), and PM2.5 and greenspace were not correlated (ρ = 0.10); greenspace and noise were inversely correlated (ρ = -0.32). In single-pollutant and multipollutant models mutually adjusted for coexposures, we found no associations with prostate cancer risk. We did not find evidence that PM2.5, greenspace, and noise pollution were associated with prostate cancer risk in this large, geographically spread cohort. This study contributes to a small body of existing literature investigating these biologically plausible associations.

Risk of dementia due to Co-exposure to air pollution and neighborhood disadvantage

BackgroundCo-exposure to air pollution and neighborhood disadvantage may influence cognition decline. We tested these associations in the context of dementia risk. MethodsWe leveraged a cohort of adults ≥65 years (n = 5397) enrolled from 2011 to 2018 in the National Health and Aging Trends Study (NHATS). Particulate matter (PM) ≤ 10 μm in diameter, PM ≤ 2.5 μm in diameter, carbon monoxide, nitric oxide, and nitrogen dioxide - and neighborhood disadvantage were tested for joint associations with dementia risk. Pollutant concentrations at the 2010 census tract level were assigned using the US Environmental Protection Agency's Community Multiscale Air Quality Modeling System. Neighborhood disadvantage was defined using the tract Social Deprivation Index (SDI). Dementia was determined through self- or proxy-report or scores indicative of “probable dementia” according to NHATS screening tools. Joint effects of air pollutants and SDI were tested using quantile g-computation Cox proportional hazards models. We also stratified joint air pollution effects across SDI tertiles. Analyses adjusted for age at enrollment, sex, education, partner status, urbanicity, income, race and ethnicity, years at residence, census segregation, and census region. ResultsSDI score (aHR = 1.08; 95% CI 0.96, 1.22), joint air pollution (aHR = 1.03, 95% CI 0.92, 1.16) and joint SDI with air pollution (aHR = 1.04, 95% CI 0.89, 1.22) were not associated with dementia risk. After accounting for competing risk of death, joint SDI with air pollution was not associated with dementia risk (aHR = 1.06; 95% CI 0.87, 1.29). In stratified models, joint air pollution was associated with greater risk of dementia at high (aHR = 1.19; 95% CI 0.87, 1.63), but not at medium or low SDI. ConclusionAir pollution was associated with greater dementia risk in disadvantaged areas after accounting for competing risks. Air pollution associations with dementia incidence may be attenuated when other risk factors are more prominent in disadvantaged neighborhoods.

Ultra-high-Q free-space coupling to microtoroid resonators

Whispering gallery mode (WGM) microtoroid resonators are one of the most sensitive biochemical sensors in existence, capable of detecting single molecules. The main barrier for translating these devices out of the laboratory is that light is evanescently coupled into these devices though a tapered optical fiber. This hinders translation of these devices as the taper is fragile, suffers from mechanical vibration, and requires precise positioning. Here, we eliminate the need for an optical fiber by coupling light into and out from a toroid via free-space coupling and monitoring the scattered resonant light. A single long working distance objective lens combined with a digital micromirror device (DMD) was used for light injection, scattered light collection, and imaging. We obtain Q-factors as high as 1.6×108\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1.6\ imes {10}^{8}$$\\end{document} with this approach. Electromagnetically induced transparency (EIT)-like and Fano resonances were observed in a single cavity due to indirect coupling in free space. This enables improved sensing sensitivity. The large effective coupling area (~10 μm in diameter for numerical aperture = 0.14) removes the need for precise positioning. Sensing performance was verified by combining the system with the frequency locked whispering evanescent resonator (FLOWER) approach to perform temperature sensing experiments. A thermal nonlinear optical effect was examined by tracking the resonance through FLOWER while adjusting the input power. We believe that this work will be a foundation for expanding the implementation of WGM microtoroid resonators to real-world applications.

Direct electrospinning of short polymer fibers: factors affecting size and quality

The growing demand for lightweight and robust materials drives the development of polymer-based and fiber-reinforced composites. Here, using short fibers offers several advantages; however, currently employed methods for producing short fibers, such as homogenization, result in a wide dispersion of dimensions in the produced fibers, which is an undesirable effect in composite materials. In this study, electrospinning is used to produce polymer short fibers directly. This research highlights, for the first time, the differences in the electrospinning process dynamics between short and continuous fibers. By adjusting parameters: voltage and distance, we control dimensions of short fibers below 1 µm in diameter and around 4 µm in length to a few microns in diameter and approximately 14 µm in length. Direct electrospinning of short fibers offers significant advantages, including a narrow size distribution and reproducibility compared to chopped continuous fibers with homogenization.

Antibacterial effect of novel dental resin composites containing rod-like zinc oxide

Abstract Dental resin composite materials are widely used as dental fillings; however, the accumulation of microbes and the resulting secondary caries often leads to filling failure. ZnO, an inorganic antibacterial material, exhibits effective antibacterial properties and is considered safe for use. In this study, rod-like ZnO was prepared by using the atmospheric-pressure hydrothermal method, and its microstructure and antibacterial effects on Streptococcus mutans were studied. Subsequently, we created modified resins by incorporating rod-like ZnO at varying mass fractions and analyzed their morphological characteristics and elemental distributions. The antibacterial effectiveness, biocompatibility, and mechanical properties of these materials were examined using in vitro experiments. The results indicated that the rod-like ZnO exhibited a complete hexagonal wurtzite structure, with columnar dimensions of approximately 2.5 μm in length, 0.8 μm in diameter, and a lattice spacing of 0.2544 nm. The growth, biofilm formation, and biofilm destruction of S. mutans were significantly inhibited at 1/4, 1/2, 3/4, and 1 times the minimum inhibitory concentration. The rod-like modified resin, with mass fractions of 2.5, 5, and 7.5 wt%, exhibited evident inhibitory effects on S. mutans biofilm formation. These modified resins demonstrated no cytotoxicity toward HGF-1 cells and exhibited enhanced compressive strength. Therefore, rod-like ZnO modified resin has promising potential for the treatment of dental caries.

Intra-articular injection of gold micro-particles with hyaluronic acid for painful knee osteoarthritis

BackgroundRecently, in an open pilot study, we found up to two years, a potential pain-relieving effect of intra-articular gold micro-particles using the patient’s synovial fluid for patients with knee osteoarthritis (KOA). During the study the excluded group of patients, due to multisite pain, co-morbidities, and other exclusion criteria., received intra-articular gold micro-particles using hyaluronic acid,. We aimed to identify if pre-treatment characteristics influence the global outcome two years after intra-articular treatment for painful KOA with gold microparticles using hyaluronic acid.MethodsUsing hyaluronic acid as the carrier, 136 patients with KOA received intraarticular injections with 20 mg gold microparticles (72.000 particles, 20–40 μm in diameter). In the analysis, we included the Global Rating of Change Scale, Pain Detect Questionnaire (PDQ), Body Mass Index (BMI), and Kellgren & Lawrence score at the inclusion, Western Ontario, and McMaster Universities Osteoarthritis Index (WOMAC) sub-scores for pain, stiffness, and function at inclusion and two years.ResultsOn the Global Rating Change Scale, 69.1% of patients reported a positive effect, 28.7% no effect, and 2.2% worse. PDQ and the three WOMAC subscores all improved at two years of follow-up. PDQ ≥ 13 (P = 0.028), BMI (P = 0.022) and Kellgren & Lawrence grade 4 (P = 0.028) at inclusion reduced the effect with a minor odds ratio compared to the baseline effect of treatment (P = 0.025). WOMAC subscores at inclusion did not influence the outcome (P > 0.5).ConclusionsSevere osteoarthritis, obesity, and neuropathic pain, reduced the effect of intra-articular gold microparticles for knee OA.Trial registrationThe study followed the principles of the Declaration of Helsinki and was approved by the local ethics committee of the North Denmark Region by 27/07/2016 (N-20,160,045). The regional data protection agency approved the project by 06/07/2016 (2008-58-0028, ID 2016 − 116) and registered in ClinicalTrial.Gov by 04/01/2018 (NCT03389906).

Oil Droplet Capture and Ingestion by Filter-Feeding Sabellid and Serpulid Polychaetes

Benthic filter-feeders form an essential role in marine food chains as they constitute the bridge between the microscopic primary producers and the consumers. Although filter-feeders mainly feed on solid particles, they also capture and ingest oil droplets. Usually, these microdroplets come from the decomposition of animals or algae or from petroleum oils that enter water via spills and leakages. Here, we used videography, TRITC fluorescence microscopy, and fluid mechanics to study the capture mechanisms of canola, fish, and four petroleum motor oil droplets by the filter feeding sabellid and a serpulid polychaetes. Schizobranchia insignis, Eudistylia vancouveri, Myxicola infundibulum and Serpula columbiana actively feed on waste motor oil droplets in seawater. A further experiment found that S. insignis fed on all types of oil droplets, demonstrating no selectivity based on type. The oil droplet capture mechanism of S. insignis were direct interception and sieving, like that of solid particles. The size range of droplets ingested was 10 to 300 µm in diameter, but these ranges differed depending on the density and viscosity of the oils. Higher density and viscous oils were captured at smaller droplet sizes. These results are the first to characterize the mechanics of oil droplet capture, transport and ingestion by benthic ciliary filter feeders, and contribute to understanding the behavior of animals in response to oil emulsions, and how oils enter marine food webs.