Aspergillus flavus and Aflatoxins in grain crops give rise to a serious threat to food security and cause huge economic losses. In particular, aflatoxin Bsub.1 has been identified as a Class I ...carcinogen to humans by the International Agency for Research on Cancer (IARC). Compared with conventional methods, Surface-Enhanced Raman Scattering (SERS) has paved the way for the detection of Aspergillus flavus and Aflatoxins in grain crops as it is a rapid, nondestructive, and sensitive analytical method. In this work, the rapid detection of Aspergillus flavus and quantification of Aflatoxin Bsub.1 in grain crops were performed by using a portable Raman spectrometer combined with colloidal Au nanoparticles (AuNPs). With the increase of the concentration of Aspergillus flavus spore suspension in the range of 10sup.2-10sup.8 CFU/mL, the better the combination of Aspergillus flavus spores and AuNPs, the better the enhancement effect of AuNPs solution on the Aspergillus flavus. A series of different concentrations of aflatoxin Bsub.1 methanol solution combined with AuNPs were determined based on SERS and their spectra were similar to that of solid powder. Moreover, the characteristic peak increased gradually with the increase of concentration in the range of 0.0005-0.01 mg/L and the determination limit was 0.0005 mg/L, which was verified by HPLC in ppM concentration. This rapid detection method can greatly shorten the detection time from several hours or even tens of hours to a few minutes, which can help to take effective measures to avoid causing large economic losses.
Keywords: Intestinal epithelial cells; Candida albicans; Commensal fungi; Cytokine secretion; Mucosal immunity Intestinal epithelial cells (IECs) are the first to encounter luminal antigens and play ...an active role in intestinal immune responses. We previously reported that beta-glucans, major fungal cell-wall glycans, induced chemokine secretion by IEC lines in a Dectin-1- and Syk-dependent manner. Here, we show that in contrast to beta-glucans, stimulation of IEC lines with Candida albicans and Saccharomyces cerevisiae did not induce secretion of any of the proinflammatory cytokines IL-8, CCL2, CXCL1, and GM-CSF. Commensal fungi and beta-glucans activated Syk and ERK in IEC lines. However, only beta-glucans activated p38, JNK, and the transcription factors NF-PHIB p65 and c-JUN, which were necessary for cytokine secretion. Furthermore, costimulation of IEC lines with beta-glucans and C. albicans yielded decreased cytokine secretion compared to stimulation with beta-glucans alone. Finally, ex vivo stimulation of human colonic mucosal explants with zymosan and C. albicans, leads to epithelial Syk and ERK phosphorylation, implying recognition of fungi and similar initial signaling pathways as in IEC lines. Lack of cytokine secretion in response to commensal fungi may reflect IECs' response to fungal glycans, other than beta-glucans, that contribute to mucosal tolerance. Skewed epithelial response to commensal fungi may impair homeostasis and contribute to intestinal inflammation. CAPTION(S): Supporting information Byline: Sarit Cohen-Kedar, Danielle Keizer, Suzana Schwartz, Keren M. Rabinowitz, Kawsar Kaboub, Efrat Shaham Barda, Eran Sadot, Meirav Wolff-Bar, Tali Shaltiel, Iris Dotan
This study demonstrates the use of photopolymerization to create semi-crystalline linear polymers suitable for thermally reversible materials in dental cast moldings produced from 3D printing.
An ...aromatic diallyl, aliphatic dithiol chain extender, and monofunctional thiol were used in a photoinitiated system. The photopolymerization and crystallization kinetics as a function of chemistry and temperature were investigated using spectroscopy and calorimetry. These insights were used to realize vat photopolymerization-based 3D printing of functional objects that could be remotely melted and thereby removed using induction heating.
The addition of monothiol was shown to decrease the polymer molecular weight which correspondingly increased the crystallization rate. Photopolymerization kinetics are independent of temperature while crystallization was slowed as the temperature approaches the melting point of the materials. Through inclusion of chromium oxide, semicrystalline materials could be melted through induction heating. These materials were implemented in vat photopolymerization 3D printing to realize high-resolution objects that could be used as releasable dental molds following printing and induction heating.
This work demonstrates a proof-of-concept methodology to realize directly printable, thermally reversible semicrystalline materials for potential use as dental molding materials.
Abstract The permanent mold was made of Ferro Casting Ductile as a result of sand casting. Permanent mold is mold that can be used repeatedly. This permanent mold is used to produce tensile test ...specimens. Tensile test specimens are made of gray cast iron. This study aims to determine and analyze the effect of spheroidal graphite on the hardness and toughness of Ferro Casting Ductile in permanent molds to make tensile test specimens. The casting process starts by making patterns using Styrofoam, making molds with green-sand sand molds, followed by pouring molten cast iron into the molds. The next process is dismantling the castings and machining to get a permanent mold according to the dimensions. Specimens for testing the chemical composition were obtained from the results of castings into spherical dies. Meanwhile, the impact, hardness, and microstructure specimens were taken from the permanent molded product. The results of the chemical composition test showed that Ferro Casting Ductile contained several main elements, namely 92.14 %Fe, 3.681 %C, 3.715 %Si, 0.182 %Mn, 0.050 %Ni, and 0.034 %Mg which affected the percentage of nodular graphite. Nodular graphite will affect the hardness of the permanent mold. Validation was carried out by testing the hardness at 3 different points 167.70 VHN, 162.77 VHN, and 155.77 VHN. Toughness was obtained from the impact test using the Charpy method, the impact values were 0.048 Joule/mm 2 0.046 Joule/mm 2 0.037 Joule/mm 2 on 3 different specimens. From the test results, the specimen has met the FCD 400 standard.
•Botrytis cinerea develops most serious postharvest fungal disease in tomato plants.•Management of postharvest fungal diseases are important for quantitative yields.•Bacillus subtilis L1-21 was used ...to control gray mold on tomato fruits.•The gfp-tagged strain of L1-21 was used for colonization in harvested tomatoes.•Significant disease control effect was investigated through this endophytic strain.
Gray mold (Botrytis cinerea) is a serious disease causing considerable losses to harvested tomato during storage and transportation. Extensive and unjudicial use of fungicides has certain deleterious effects such as evolved resistance in pathogen and environmental pollution. The ice cold chain transportation is the most commonly used method, but the results are not satisfactory. Currently, the trend is shifting towards prevention and control measures which ensures environmental protection, therefore, the biological control of postharvest diseases has become a hot spot. In this study, Bacillus subtilis L1-21 was used to control gray mold on tomato fruits, by adopting plate confrontation and fruit acupuncture method. To evaluate the preservative effect of biocontrol agent L1-21 on tomato, the gfp-tagged L1-21 was used to study colonization potential in harvested tomatoes assay. Colonization of L1-21-gfp in postharvest tomatoes was stable at 103 cfu/g by soaking and fluorescence method. Whereas inhibition rate of B. cinerea was 39.63% ± 4.73% in plate confrontation. Culture suspension of L1-21 at a concentration of 108 cfu/ml displayed the best control effect: 86.57% ± 2.55% against tomato gray mold. In addition, different components exhibited different results such as cell pellet + saline (72.94% ± 8.49%), supernatant (41.18% ± 16.22%), sterilized culture (28.56% ± 6.54%). Further, suspension of B. cinerea and Bacillus L1-21 injected in tested tomatoes led to maximum control effect (81.40% ± 2.74%) after 4 h. Injection of L1-21 culture into tomato followed by pathogen B. cinerea spore solution resulted in 100%±0% control effect after 48 h. There was no significant difference in fruit quality between treated and untreated tomatoes. Taken together, B. subtilis L1-21 may lay theoretical foundation to be used in prevention of gray mold and other postharvest diseases during storage time.
The currently growing demand for metallic and polymeric products has undoubtedly changed the rules of manufacturing, enabling customers to more functionally define their products based on their ...needs. Nowadays, a new technique for rapid tooling, Additive Manufacturing (AM), can create customized products with more complex geometries and short life cycles (flexibility) in order to keep up with the new variables imposed by the manufacturing environment. In the last two decades, the migration from subtractive manufacturing to AM has materialized such products with reduced costs and cycle times. AM has been recently promoted to develop polymer molds for product manufacturing. This paper reviews the main findings in the literature concerning polymer molds created by AM compared to conventional (metal) molds obtained by subtractive manufacturing. Information about specific topics is scarce or nonexistent, for example, about the characterization of the most commonly injected materials and molds used in this type of technology, their mechanical properties (part and mold), designs for all types of geometries, and costs. These aspects are addressed in this literature review, highlighting the advantages of this alternative manufacturing process, which is considered a desirable technology worldwide.
During mould design phase different approaches are envisaged to materialize part production and they must be evaluated not only in technological criteria, but also in an economical perspective. ...However, the comparison of such alternative approaches is not always evident for the mould designer. The solution proposed in this paper, based on the development of a life cycle cost model, fosters its application as a methodology to compare two mould manufacturing alternatives: a spray metal shell mould backfilled with a resin and aluminium powder resin and a conventional machined aluminium mould. A better mould or a better alternative is the one that incurs in fewer life cycle costs, assuming that the injected part is produced within a conformed quality.
Abstract
Micro/nanostructured components play an important role in micro-optics and optical engineering, tribology and surface engineering, and biological and biomedical engineering, among other ...fields. Precision glass molding technology is the most efficient method of manufacturing micro/nanostructured glass components, the premise of which is meld manufacturing with complementary micro/nanostructures. Numerous mold manufacturing methods have been developed to fabricate extremely small and high-quality micro/nanostructures to satisfy the demands of functional micro/nanostructured glass components for various applications. Moreover, the service performance of the mold should also be carefully considered. This paper reviews a variety of technologies for manufacturing micro/nanostructured molds. The authors begin with an introduction of the extreme requirements of mold materials. The following section provides a detailed survey of the existing micro/nanostructured mold manufacturing techniques and their corresponding mold materials, including nonmechanical and mechanical methods. This paper concludes with a detailed discussion of the authors recent research on nickel-phosphorus (Ni-P) mold manufacturing and its service performance.
•A newly designed copper disc mold simulator (CDMS) is introduced.•The interfacial thermal resistance between the copper mold and the flux surface is obtained.•The interfacial thermal resistance is ...evaluated with the waviness of surface and the crystallinity.
The new modified pouring method (copper disc mold simulator, CDMS) to investigate the interfacial thermal resistance and crystallinity for the mold fluxes was introduced. To make sure the formation of the air gap, the surface waviness was measured with the crystallinity. The interfacial thermal resistance increased with higher average waviness, which means the average height of air gap. However, the average waviness did not increase with the higher crystallinity. This result came from the different crystallization mechanisms and the contraction of the flux during the solidification and crystallization was varied based on the crystallization mechanism. Therefore, it is important to apply the mold flux which has optimum crystallization behavior because applying the strong crystallized mold flux to increase the interfacial thermal resistance does not always bring the high interfacial thermal resistance.
Mold infestations in buildings pose significant challenges to human health, affecting both private residences and hospitals. While molds commonly trigger asthma and allergies in the immunocompetent, ...they can cause life-threatening diseases in the immunocompromised. Currently, there is an unmet need for new strategies to reduce or prevent mold infestations. Far-UVC technology can inactivate microorganisms while remaining safe for humans. This study investigates the inhibitory efficacy of far-UVC light at 222 nm on the growth of common mold-producing fungi, specifically Penicillium candidum , when delivered in low-dose on-off duty cycles, a configuration consistent with its use in real-world settings. The inhibitory effect of the low-dose duty cycles was assessed on growth induced by i) an adjacent spore-producing P . candidum donor and ii) P . candidum spores seeded directly onto agar plates. In both setups, the far-UVC light significantly inhibited both vertical and horizontal growth of P . candidum , even when the UV doses were below the Threshold Value Limit of 23 mJ/cm 2 . These results suggest that far-UVC light holds the potential to improve indoor air quality by reducing or preventing mold growth, also when people are present.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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