Small Fragments Research Articles

Unveiling microplastics pollution in a subtropical rural recreational lake: A novel insight

While global attention has been primarily focused on the occurrence and persistence of microplastics (MP) in urban lakes, relatively little attention has been paid to the problem of MP pollution in rural recreational lakes. This pioneering study aims to shed light on MP size, composition, abundance, spatial distribution, and contributing factors in a rural recreational lake, ‘Nikli Lake’ in Kishoreganj, Bangladesh. Using density separation, MPs were extracted from 30 water and 30 sediment samples taken from ten different locations in the lake. Subsequent characterization was carried out using a combination of techniques, including a stereomicroscope, Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FE-SEM). The results showed a significant prevalence of MPs in all samples, with an average amount of 109.667 ± 10.892 pieces/kg3 (dw) in the sediment and 98.167 ± 12.849 pieces/m3 in the water. Small MPs (<0.5 mm), fragments and transparent colored particles formed the majority, accounting for 80.2%, 64.5% and 55.3% in water and 78.9%, 66.4% and 64.3% in sediment, respectively. In line with global trends, polypropylene (PP) (53%) and polyethylene (PE) (43%) emerged as the predominant polymers within the MPs. MP contents in water and sediment showed positive correlations with outflow, while they correlated negatively with inflow and lake depth (p > 0.05). Local activities such as the discharge of domestic sewage, fishing waste and agricultural runoff significantly influence the distribution of polypropylene. Assessment of pollution factor, pollution risk index and pollution load index values at the sampling sites confirmed the presence of MPs, with values above 1. This study is a baseline database that provides a comprehensive understanding of MP pollution in the freshwater ecosystem of Bangladesh, particularly in a rural recreational lake. A crucial next step is to explore ecotoxicological mechanisms, legislative measures and future research challenges triggered by MP pollution.

Resonant Acoustic Vibration-Assisted Cathode Stripping for Efficient Recycling of Spent Li-Ion Batteries

Abstract The emerging field of direct recycling for spent Li-ion batteries offers significant advantages, such as reduced energy expenses and minimized secondary pollution, when compared to traditional pyrometallurgical and hydrometallurgical methods. This is due to its direct utilization of the spent cathodes as raw materials. However, efficient harvesting of spent cathode particles remains a challenge. To address this issue, this technical brief is the first to incorporate resonant acoustic vibration technology (RAV) as an efficient method for stripping cathode powders from spent Li-ion batteries. Our findings indicate that RAV-based techniques can achieve a stripping efficiency of up to 92%. A comparative analysis with conventional stripping methods, such as magnetic stirring, sonication, and curling–uncurling, reveals that RAV coupled with heat treatment provides unparalleled scalability and efficiency, eliminating the need for post-processing. Furthermore, the resulting cathode powders retain their original polycrystalline particle structures, with no impurities, such as carbon black or small aluminum fragments detected. These findings highlight the promise of RAV technology for large-scale recovery of electrode powders and its potential role in direct recycling of spent Li-ion batteries.

Extracellular Vesicles Slow Down Aβ(1-42) Aggregation by Interfering with the Amyloid Fibril Elongation Step.

Formation of amyloid-β (Aβ) fibrils is a central pathogenic feature of Alzheimer's disease. Cell-secreted extracellular vesicles (EVs) have been suggested as disease modulators, although their exact roles and relations to Aβ pathology remain unclear. We combined kinetics assays and biophysical analyses to explore how small (<220 nm) EVs from neuronal and non-neuronal human cell lines affected the aggregation of the disease-associated Aβ variant Aβ(1-42) into amyloid fibrils. Using thioflavin-T monitored kinetics and seeding assays, we found that EVs reduced Aβ(1-42) aggregation by inhibiting fibril elongation. Morphological analyses revealed this to result in the formation of short fibril fragments with increased thicknesses and less apparent twists. We suggest that EVs may have protective roles by reducing Aβ(1-42) amyloid loads, but also note that the formation of small amyloid fragments could be problematic from a neurotoxicity perspective. EVs may therefore have double-edged roles in the regulation of Aβ pathology in Alzheimer's disease.

Activation of peroxymonosulfate by sustainable biomass-based carbon nanotubes for controlling the spread of plant viruses in water environments

With the increasing demand for water in hydroponic systems and agricultural irrigation, viral diseases have seriously affected the yield and quality of crops. By removing plant viruses in water environments, virus transmission can be prevented and agricultural production and ecosystems can be protected. But so far, there have been few reports on the removal of plant viruses in water environments. Herein, in this study, easily recyclable biomass-based carbon nanotubes catalysts were synthesized with varying metal activities to activate peroxymonosulfate (PMS). Among them, the magnetic 0.125Fe@NCNTs-1/PMS system showed the best overall removal performance against pepper mild mottle virus, with a 5.9 log10 removal within 1 min. Notably, the key reactive species in the 0.125Fe@NCNTs-1/PMS system is 1O2, which can maintain good removal effect in real water matrices (river water and tap water). Through RNA fragment analyses and label free analysis, it was found that this system could effectively cleave virus particles, destroy viral proteins and expose their genome. The capsid protein of pepper mild mottle virus was effectively decomposed where serine may be the main attacking sites by 1O2. Long viral RNA fragments (3349 and 1642 nt) were cut into smaller fragments (∼160 nt) and caused their degradation. In summary, this study contributes to controlling the spread of plant viruses in real water environment, which will potentially help protect agricultural production and food safety, and improve the health and sustainability of ecosystems.

Pseudomonas environmental strain produces a DegQ-derived and PDZ domain containing peptide with protease activity.

In the search of new enzymatic activities with a possible industrial application, we focused on those microorganisms and their molecular mechanisms that allow them to succeed in the environment, particularly in the proteolytic activity and its central role in the microorganisms' successful permanence. The use of highly active serine proteases for industrial applications is a modern need, especially for the formulation of detergents, protein processing, and hair removal from animal skins. This report provides the isolation and identification of a highly proteolytic fragment derived from DegQ produced by a Pseudomonas fluorescens environmental strain isolated from a frog carcass. Zymograms demonstrate that a 10kDa protein mainly generates the total proteolytic activity of this strain, which is enhanced by the detergent SDS. Mass spectroscopy analysis revealed that the protein derived a couple of peptides, the ones showing the highest coverage belonging to DegQ. Interestingly, this small protein fragment contains a PDZ domain but no obvious residues indicating that it is a protease. Protein model analysis shows that this fragment corresponds to the main PDZ domain from DegQ, and its unique sequence and structure render a proteolytic peptide. The results presented here indicate that a novel DegQ fragment is sufficient for obtaining high protease activity highlighting that the analysis of environmental microorganisms can render new strains or enzymes with helpful biotechnological characteristics.

First Report of Cercospora Leaf Spot Caused by Cercospora cf. flagellaris on Lonicera japonica Thunb. in Henan, China.

Honeysuckle flower (Lonicera japonica Thunb.) is a traditional Chinese medicinal plant. It is perennial and widely cultivated in China, Japan and Korea. From late August to October in 2021 and 2022, leaf spots symptoms were observed on L. japonica in different planting fields in Yuzhou, Yuanyang and Fenqiu districts, Henan province, China. The disease incidence was above 85% which reduce photosynthesis. Early disease symptoms appeared as small, circular to elliptical, brown spots on the leaves and later the lesions (1 to 5 mm × 1 to 4 mm) slowly developed yellow haloes. The different brown lesions seldom merge and form larger irregular lesions. Small fragments (3 to 5 mm) of leave tissue were excised from the lesion margins and surface-sterilized in 3% NaClO for 3 min, followed by three washes with sterile distilled water, and then placed on potato dextrose agar (PDA) and incubated at 25°C in the dark for 5 days. A total number of 8 cultures were obtained and purified by single-spore subcultures on PDA for morphological identification. The colonies on PDA were whitish to gray, with cottony aerial mycelium. Conidiophores were fasciculate, olivaceous brown, straight or geniculate, uniform in width, multiseptate, and ranged from 290 to 700 μm (560 μm on average, n = 20). Conidia were hyaline, slightly curved or straight, needle shaped, truncate at the base, and terminal at the tip, 3 to 17-septate, and measuring 150 to 240 μm (180 μm on average, n = 20). The morphological features were consistent with Cercospora cf. flagellaris Ellis & G. Martin (Groenewald et al. 2013). The genomic DNA was extracted using CTAB method. The nuclear ribosomal internal transcribed spacer region (ITS), portions of the actin (ACT), histone H3 (HIS3), and translation elongation factor 1-α (TEF1) genes were amplified using primers ITS1/ITS4 (Groenewald et al. 2013), ACT-512F/ACT-783R (Carbone and Kohn 1999), CYLH3F/CYLH3R (Crous et al. 2006), and EF1-728F/EF1-986R (Carbone and Kohn 1999). The resulting 537-bp ITS, 226-bp ACT, 410-bp HIS3, and 306-bp TEF1 sequences of isolate JDJ002 were deposited in GenBank (accession nos. OR492367, OR548247, OR548248 and OR548248, respectively). Sequence analysis revealed that ITS, ACT, HIS3 and TEF1α sequences exhibited ≥99% of identity with the ITS (KP896013), ACT(KP895965), HIS3(MK991295) and TEF1 (MN180408) sequences of C. cf. flagellaris, respectively. A pathogenicity test was conducted on healthy of L. japonica leaves. The healthy leaves pricked from L. japonica plants, rinsed in autoclaved distilled water three times and dried with distilled filter paper. Then twelve healthy leave were inoculated with a mycelial plug (0.4 cm diameter) harvested from the periphery of two week-old colony. As negative control, leaves inoculated with PDA medium plugs. Inoculated leaves were covered with plastic bags to maintain high relative humidity and incubated at 25°C in growth chamber. After 7 days, the inoculated leaves showed symptoms identical to those observed in the field under natural conditions, whereas negative control remained symptom-free. Re-isolation of the fungus from lesions on inoculated leaves confirmed that the causal agent was C. cf. flagellaris. Pathogenicity tests were repeated three times by the same methods with the same results. To our knowledge, this is the first report of C. cf. flagellaris except Cercospora rhamni Fack., Alternaria alternata, Corynespora cassiicola or Phomopsis sp. causing leave spots on L. japonica in China.

Ligandability assessment of the C-terminal Rel-homology domain of NFAT1.

Transcription factors are generally considered challenging, if not "undruggable", targets but they promise new therapeutic options due to their fundamental involvement in many diseases. In this study, we aim to assess the ligandability of the C-terminal Rel-homology domain of nuclear factor of activated T cells 1 (NFAT1), a TF implicated in T-cell regulation. Using a combination of experimental and computational approaches, we demonstrate that small molecule fragments can indeed bind to this protein domain. The newly identified binder is the first small molecule binder to NFAT1 validated with biophysical methods and an elucidated binding mode by X-ray crystallography. The reported eutomer/distomer pair provides a strong basis for potential exploration of higher potency binders on the path toward degrader or glue modalities.

Exposure of Hoffa Fractures Is Improved by Posterolateral and Posteromedial Extensile Approaches: A Qualitative and Quantitative Anatomical Study.

The current literature lacks recommendations regarding surgical approaches to best visualize and reduce Hoffa fractures. The aims of this study were to (1) define surgical corridors to the posterior portions of the lateral and medial femoral condyles and (2) compare the articular surface areas visible with different approaches. Eight fresh-frozen human cadaveric knees (6 male and 2 female donors; mean age, 68.2 ± 10.2 years) underwent dissection simulating 6 surgical approaches to the distal femur. The visible articular surface areas for each approach were marked using an electrocautery device and subsequently analyzed using image-processing software. The labeled areas of each femoral condyle were statistically compared. At 30° of flexion, visualization of the posterior portions of the lateral and medial femoral condyles was not possible by lateral and medial parapatellar approaches, as only the anterior 29.4% ± 2.1% of the lateral femoral condyle and 25.6% ± 2.8% of the medial condyle were exposed. Visualization of the lateral femoral condyle was limited by the posterolateral ligamentous structures, hence a posterolateral approach only exposed its central (13.1% ± 1.3%) and posterior (12.4% ± 1.1%) portions. Posterolateral extension by an osteotomy of the lateral femoral epicondyle significantly improved the exposure to 53.4% ± 2.7% and, when combined with a Gerdy's tubercle osteotomy, to 70.9% ± 4.1% (p < 0.001). For the posteromedial approach, an arthrotomy between the anteromedial retinaculum and the superficial medial collateral ligament, and one between the posterior oblique ligament and the medial gastrocnemius tendon, allowed visualization of the central (13.5% ± 2.2%) and the posterior (14.6% ± 2.3%) portions of the medial femoral condyle, while a medial femoral epicondyle osteotomy significantly improved visualization to 66.1% ± 5.5% (p < 0.001). Visualization of the posterior portions of the femoral condyles is limited by the specific anatomy of each surgical corridor. Extension by osteotomy of the femoral epicondyles and Gerdy's tubercle significantly improved articular surface exposure of the femoral condyles. Knowledge of the surgical approach-specific visualization of the articular surface of the femoral condyles might be helpful to properly reduce small Hoffa fragments.

Laboratory Measurements of Pyrene and Acenaphthene Partition into Microplastics

Microplastics are a major environmental issue. In marine systems, these break down into small fragments that may lodge within organisms, but they behave as vectors for chemicals when pollutants such as metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, and pharmaceuticals are absorbed by the particles. The rate and extent of uptake of organic compounds onto microplastics is dependent on a range of factors such as the sites available on the surface, the type of plastic, and the compound being sorbed, with hydrophobicity an important property. Laboratory experiments determined the uptake of pyrene and acenaphthene (and sometimes phenanthrene) onto pellets of polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyoxymethylene (POM), polypropylene (PP) and polystyrene (PS). The kinetics of uptake in the experiments reveals half-lives ~10 h. The extent of partition onto the plastic pellets was similar for pyrene and phenanthrene, though lower for acenaphthene. This was not surprising because the octanol-water distribution coefficient of acenaphthene is about an order of magnitude smaller than that of pyrene, suggesting it is less hydrophobic. The PAHs are distributed most strongly into PP but only weakly into PVC. The fragmentation and oxidation of microplastics means that they sorb increasing amounts of organic material as they age.

Novel plasma-polymerized coating facilitates HeLa cell spheroid formation, exerting necroptosis via β-cyclodextrin-encapsulated resveratrol

Beta-cyclodextrins (β-CDs) comprise a pore for accommodating resveratrol (Res), thereby boosting its bioavailability. Res-incorporated β -CD (Res/CD) may be cytotoxic against both normal and cancer cells. Herein, we examined whether Res/CD exhibits anticancer activity against tumor spheroids, similar to in vivo tumor mass. To prepare three-dimensional spheroids, 1,1,1,3,5,7,7,7 octamethyl-3,5-bis(trimethylsiloxyl) tetrasiloxane (OMBTSTS) was deposited to the surface of the culture dish via plasma polymerization. We observed that HeLa cells grew as spheroids on the OMBTSTS-deposited surface at 20 W plasma power. Res/CD was delivered to the hypoxic core of the spheroid, inducing necrosis, whereas Res was not. Consistently, 10 μM Res alone was not cytotoxic to two-dimensional HeLa cells grown on a culture dish and three-dimensional spheroids. However, Res/CD promoted the necroptosis of spheroids, which were split into small fragments, ultimately inducing cell spheroid death. Collectively, our data suggest that nontoxic levels of Res/CD were efficiently delivered to the hypoxic core of tumor spheroids, promoting cell death. Therefore, Res/CD can be used as an effective anticancer drug. Moreover, the plasma-polymerized OMBTSTS modification technique provides insights into the efficient formation of spheroids in various cancer cell lines.

Differential 5'-tRNA Fragment Expression in Circulating Preeclampsia Syncytiotrophoblast Vesicles Drives Macrophage Inflammation.

The relationship between placental pathology and the maternal syndrome of preeclampsia is incompletely characterized. Mismatch between placental nutrient supply and fetal demands induces stress in the syncytiotrophoblast, the layer of placenta in direct contact with maternal blood. Such stress alters the content and increases the release of syncytiotrophoblast extracellular vesicles (STB-EVs) into the maternal circulation. We have previously shown 5'-tRNA fragments (5'-tRFs) constitute the majority of small RNA in STB-EVs in healthy pregnancy. 5'-tRFs are produced in response to stress. We hypothesized STB-EV 5'-tRF release might change in preeclampsia. We perfused placentas from 8 women with early-onset preeclampsia and 6 controls, comparing small RNA expression in STB-EVs. We used membrane-affinity columns to isolate maternal plasma vesicles and investigate placental 5'-tRFs in vivo. We quantified 5'-tRFs from circulating STB-EVs using a placental alkaline phosphatase immunoassay. 5'-tRFs and scrambled RNA controls were added to monocyte, macrophage and endothelial cells in culture to investigate transcriptional responses. 5'-tRFs constitute the majority of small RNA in STB-EVs from both preeclampsia and normal pregnancies. More than 900 small RNA fragments are differentially expressed in preeclampsia STB-EVs. Preeclampsia-dysregulated 5'-tRFs are detectable in maternal plasma, where we identified a placentally derived load. 5'-tRF-Glu-CTC, the most abundant preeclampsia-upregulated 5'-tRF in perfusion STB-EVs, is also increased in preeclampsia STB-EVs from maternal plasma. 5'-tRF-Glu-CTC induced inflammation in macrophages but not monocytes. The conditioned media from 5'-tRF-Glu-CTC-activated macrophages reduced eNOS (endothelial NO synthase) expression in endothelial cells. Increased release of syncytiotrophoblast-derived vesicle-bound 5'-tRF-Glu-CTC contributes to preeclampsia pathophysiology.

Ankle fractures with Chaput fragment: A new classification system with insights into morphology and relation to surgical treatment

BackgroundThe Chaput fragment, a bony avulsion of the anterolateral margin of the distal tibia, is a less commonly discussed fracture pattern in ankle injuries. Its significance in ankle fractures and the optimal fixation technique remains unclear due to limited literature. This study aims to describe the morphology of ankle fractures with Chaput fragment and introduce a new classification system. Materials and methodsWe retrospectively analyzed 33 patients with ankle fractures with associated Chaput fragment treated at our institute over a 3-year period. Data on patient demographics, fracture classification, surgical approach, and fixation method were collected, and a novel classification system for Chaput fragments was proposed. ResultsFour distinct morphological types of Chaput fragment were identified (types 1–4), and three newer variants of trimalleolar fractures were identified (anterior, lateral, and medial variants). Type 1 refers to a small avulsion fragment attached to the anterior-inferior tibiofibular ligament; Type 2 is an anterolateral oblique type; Type 3 refers to an anterolateral fragment with extension into the medial malleolus and Type 4 is a comminuted Chaput fragment. Type 1 Chaput fragment was the most prevalent (60.6%), followed by Type 2 (24.3%), Type 4 (9.1%), and Type 3 (6.1%). The fixation methods ranged from screw fixation, plate fixation, and suture fixation to combinations of these techniques or even indirect stabilization with syndesmotic screws. ConclusionOur new classification system based on morphology includes all possible variants of Chaput fracture. This preliminary data needs to be corroborated by more studies and validated by a larger number of observers

The significance of clinically insignificant residual fragments after percutaneous nephrolithotomy: an analysis into the relevance of complete stone clearance

PurposeAfter treatment for kidney stones, residual fragments with a diameter of ≤ 4 mm are traditionally referred to as ‘clinically insignificant residual fragments’. We hypothesize that patients with these fragments are at an increased risk for stone-related morbidity, such as complaints, hydronephrosis, and stone regrowth, when compared to stone-free patients. This study aimed to investigate the relevance of complete stone clearance in surgical treatment of urolithiasis.MethodsWe conducted a single-center retrospective cohort study. Patients who underwent percutaneous nephrolithotomy between 2015 and 2020 were included if a CT-scan was available within 6 months after the procedure, and the follow-up duration was at least 1 year. The stone-free status at the end of the first stone episode during the study period was categorized as fully stone-free, not stone-free with small residual fragments (≤ 4 mm) and not stone-free with large residual fragments (> 4 mm). Follow-up data were collected, including stone-related events and re-intervention rates.ResultsA total of 103 subjects were included with a median follow-up of 21.4 months. Stone-related events occurred in 10 (29.4%) of the fully stone-free subjects, 20 (58.8%) of the subjects with small residual fragments and 25 (71.4%) of the subjects with large residual fragments. The stone-related event-free survival per subgroup resulted in a significantly different survival distribution in a log rank test (p = 0.008).ConclusionA complete stone-free status seems to be of fundamental importance for decreasing stone-related morbidity. Further developments and research should focus on optimizing the full clearance of stone material during PCNL.

Drivers of functional diversity in small-bodied mammals across a deforestation frontier in the Southern Brazilian Amazon

Deforestation remains the most pervasive driver of biodiversity erosion across tropical forests. Understanding how species can cope with such habitat changes is particularly important along the rapidly expanding agricultural frontiers. To do so, we used a functional perspective examining small mammal responses to habitat loss, fragmentation, and degradation across the ‘Arc of Deforestation’ in the Southern Brazilian Amazon. Small mammals were surveyed using a combination of conventional and pitfall traps across 20 forest fragments—ranging from 42 to 4743 ha—in addition to two relatively continuous forest sites (> 7000 ha). These fragments lie isolated by a cattle pasture matrix of varying grazing intensity. We then analysed taxonomic and functional diversity patterns—represented by Simpson Diversity and Rao Quadratic entropy indices—in Generalised Linear Models containing local- to landscape-scale predictors of variation. Further, we used a functional trait composition approach based on community-weighted mean trait values to depict and predict small mammal functional variations across this degradation gradient. From a total of 847 individuals recorded belonging to 24 taxa, functional responses tended to follow the taxonomic diversity, both increasing with fragment area. The functional dimension further was promoted by low fire-related disturbance. Functional trait composition was mainly driven by habitat quality, represented by tree density, arthropod biomass, and fire-related disturbance. Our results reinforce that small forest fragments sustain depauperate small mammal assemblages both taxonomically and functionally. Accounting for habitat quality further allows for boosting the persistence across functional groups. Our findings can be used to improve the efficiency of management practices thereby maximising the multiple dimensions of small mammal diversity and their associated ecosystem services across tropical deforestation frontiers.

Mechanism of improving the digestibility of coconut globulin by atmospheric cold plasma treatment: The perspective of protein structure

As a natural emulsifier in coconut milk, coconut globulin (CG) is a potential plant-based protein source to replace animal protein. However, due to its poor solubility and poor digestive properties, CG is not sufficiently utilized. The aim of this study was to improve the digestibility of CG by employing atmospheric cold plasma (ACP) technology. The influence of ACP treatment on the digestive properties of coconut globulin was evaluated by measurements of digestibility, degree of hydrolysis, free amino acids (FAAs), and polypeptide distribution after gastrointestinal digestion. These results implied that application of ACP treatment facilitated the digestion of CG, resulting in the hydrolysis of the compound into numerous smaller peptides (<1000 Da) and FAAs. The quartz crystal microbalance with dissipation technique was utilized to monitor the dynamic digestion process of CG. The results observed that ACP-treated CG had increased affinity for pepsin and trypsin, especially at 60 kV (the adsorbed mass was 7.60 μg/cm2). Various analytical techniques, including circular dichroism spectroscopy, Fourier transform infrared spectroscopy, fluorescence spectroscopy, and particle size distribution, demonstrated that ACP treatment facilitated the structural unfold of CG, resulting in increased exposure of enzyme binding sites and hydrolysis into smaller fragments. In addition, in vitro and cell-based antioxidant experiments provided evidence of the significant antioxidant activity of the hydrolysate derived from ACP-treated CG. Hence, the utilization of ACP treatment at 60 kV emerged as the optimal approach for enhancing the digestibility of CG (from 71.65% to 78.65%). This finding provides a theoretical basis for the use of ACP treatment in protein-rich foods, thereby providing insights for expanding the application of ACP treatment in the field of food processing.

Impact of breech geometry and propellant flow on the release of large pellets for the ITER disruption mitigation system

Studies have been performed on the release mechanism for large pellets using high pressure gas in a shattered pellet injector. Typically, pellets are dislodged from the cryogenic surface and accelerated down a barrel using high pressure gas delivered by a fast-acting propellant valve. The pellets impact an angled surface which shatters the pellet into many small fragments before entering the plasma. This technique was initially demonstrated on DIII-D (Commaux et al 2016 Nucl. Fusion 56 046007) and is now deployed on JET, KSTAR, ASDEX-Upgrade, and other tokamaks around the world in support of ITER’s disruption mitigation system design and physics basis. The large hydrogen, 28.5 mm diameter, 2 length-to-diameter ratio, pellets foreseen for ITER SPI operation have low material strength and low heat of sublimation, which cause the pellets to be fragile and highly reactive to the impact of warm propellant gas. Due to the size of the pellets, significantly more propellant gas is required to dislodge and accelerate them. This creates a potentially significant propellant gas removal issue as 2–6 bar-L of gas is expected to be required for release and speed control. The research presented in this paper is an in-depth exploration of the parameters that are keys to reliable pellet release and speed control. Computational fluid dynamics (CFD) modeling of propellant flows through various breech designs was conducted to determine the force generated on the back surface of a pellet. These simulations assumed the use of the ORNL designed flyer plate valve. CFD modeling combined with experimental measurements provide adequate insight to determine a path to an optimal valve and breech design for ITER SPI pellet release and speed control while minimizing propellant gas usage.

In vivo evaluation of a polyester and fiberglass composite intramedullary nail for femoral osteosynthesis in calves.

The objective of this study was to test a composite of polyester resin and fiberglass in the form of an intramedullary nail for osteosynthesis of femoral fractures in calves. The methodology was established based on a previous study that used a bovine femur finite element model to simulate fractures, which were then stabilized by the same nails as proposed in this study. General anesthesia was induced in six calves followed by fracture creation via an oblique incision in the middle third of the femoral diaphysis, and osteosynthesis was immediately performed by retrograde insertion of the composite nail. Locking was achieved by drilling the bone and nail without using a jig and introducing two stainless steel screws proximal and two distal to the fracture line. Five of the six calves achieved complete fracture healing after 60 days. No signs of incompatibility or toxicity of the composite were observed. However, limitations were observed during the surgery, such as difficulty in drilling the nail and trimming the remainder portion of the nail that extended beyond the length of the bone. Small fragments produced by these maneuvers were considered irritating to soft tissues during the postoperative period. It was also found that small cracks in the nail tended to propagate in the form of longitudinal fractures. In conclusion, an intramedullary nail made of polyester resin and fiberglass (a low-cost and easy-to-acquire material) was considered biocompatible and capable of allowing bone healing of femoral fractures in young cattle. However, the development of solutions for the reported limitations is crucial prior to recommending the proposed composite for clinical use.

A Simple High Yield Technique for Isolation of Wharton's Jelly-derived Mesenchymal Stem Cell.

The isolation of Mesenchymal Stem Cells (MSCs) from various tissues is possible, with the umbilical cord emerging as a competitive alternative to bone marrow. In order to fulfill the demands of cell therapy, it is essential to generate stem cells on a clinical scale while minimizing time, cost, and contamination. Here is a simple and effective protocol for isolating MSC from Wharton's Jelly (WJ-MSC) using the explant method with various supplements. Utilizing the explant method, small fragments of Wharton's jelly from the human umbilical cord were cultured in a flask. The multipotency of the isolated cells, were confirmed by their differentiation ability to osteocyte and adipocyte. Additionally, the immunophenotyping of WJ-MSCs showed positive expression of CD73, CD90, and CD105, while remaining negative for hematopoietic markers CD34 and CD45, meeting the criteria for WJ-MSC identification. Following that, to evaluate cells' proliferative capacity, various supplements, including basic Fibroblast Growth Factor (bFGF), Non-Essential amino acids (NEA), and L-Glutamine (L-Gln) were added to either alpha-Minimal Essential Medium (α-MEM) or Dulbecco's Modified Eagle's Medium-F12 (DMEM-F12), as the basic culture media. WJ-MSCs isolated by the explant method were removed from the tissue after seven days and transferred to the culture medium. These cells differentiated into adipocyte and osteocyte lineages, expressing CD73, CD90, and CD105 positively and CD34 and CD45 negatively. The results revealed that addition of bFGF to α-MEM or DMEMF12 media significantly increased the proliferation of MSCs when compared to the control group. However, there were no significant differences observed when NEA or LGln were added. Although bFGF considerably enhances cell proliferation, our study demonstrates that MSCs can grow and expand when properly prepared Wharton's jelly tissues of the human umbilical cord.

Photocatalytic degradation of reactive dyes over Ni[sbnd]Al layered double hydroxide

Due to the uncontrolled discharge of textile effluents, the extent of reactive dyes in wastewater is rising. Due to their toxicity, efficient removal becomes quite essential. In this report, NiAl layered double hydroxide (LDH) has been prepared using the coprecipitation methodology for the photocatalytic degradation of reactive dyes. The as-prepared materials were characterized by different techniques, such as DRS, XRD, FESEM, HRTEM, and XPS etc. The XRD pattern of the LDH confirms the formation of the rhombohedral (R3m) phase. The FESEM analysis reveals the irregular hexagon-like shape of the prepared LDH. The NiAl LDH has 98(1) and 87(1)% photodegradation efficiencies towards the removal of reactive blue 19 and reactive Red 120, respectively. The control experiments in the presence of different scavengers confirm that hydroxyl radicals and superoxide anions participate in photocatalytic degradation. The HRMS studies confirm the formation of different smaller fragments, thereby providing a deeper insight into the photodegradation mechanism. Moreover, the demineralization efficiency (88.9%) is quite close to the degradation efficiency for reactive blue 19, signifying practically complete demineralization of the pollutants. The recyclability studies ascertain the high stability of the photocatalyst. Therefore, the as-prepared NiAl LDHs can be considered a promising photocatalyst for the removal of reactive dyes from wastewater.

Particle aerosol generation and potential altering in airflow used for acute/repeated inhalation toxicity testing

Reproducible aerosol generation in combination with stable aerosol properties are essential prerequisites for compliant performance of acute or repeated inhalation toxicity tests of particulate materials according to OECD TG 403, 436, 412, or 413. A frequent problem of powder aerosol generation is the formation of coarse agglomerates with low shear resistance, which are beyond the tolerable size range but not detected by the prescribed aerodynamic measurement techniques by cascade impactor as the measurement conditions cause a disintegration into smaller fragments. But such agglomerates are observed during the transport to the inhalation chambers. These effects particularly apply to high mass concentrations and low-density powders, i.e., pyrogenic oxides. This study describes the transport influence in the airflow on the change of powder aerosols and on their respirability.A simplified short tube set-up was developed for the aerosol transport pre-tests, which allows the determination of the optimal aerosol formation conditions for the inhalation tests. The particles were measured with low shear using laser diffraction measurement or optical particle counters. The calculation of the aerodynamic particle sizes prescribed in the guidelines requires knowledge of the effective particle density of the porous aerosol particles. A practicable method for determining these is presented and described. In the outlook, first low concentration measurements show that clear agglomeration effects can also occur at particle concentrations around 20 mg/m³.