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Journal of Visualized Experiments : JoVE Jul 2023The mustard aphid (L. erysimi) is a pest that infests various cruciferous crops and transmits plant viruses. To achieve eco-friendly pest management, entomopathogenic...
The mustard aphid (L. erysimi) is a pest that infests various cruciferous crops and transmits plant viruses. To achieve eco-friendly pest management, entomopathogenic fungi (EPF) are potential microbial control agents for controlling this pest. Therefore, virulence screening of EPF isolates under Petri dish conditions is necessary before field application. However, the mustard aphid is a parthenogenetic insect, making it difficult to record data during Petri dish experiments. A modified system for detached-leaf bioassays was developed to address this issue, using a micro-sprayer to inoculate conidia onto aphids and prevent drowning by facilitating air-drying after spore suspension. The system maintained high relative humidity throughout the observation period, and the leaf disc remained fresh for over ten days, allowing parthenogenetic reproduction of the aphids. To prevent offspring buildup, a process of daily removal using a painting brush was implemented. This protocol demonstrates a stable system for evaluating the virulence of EPF isolates against mustard aphids or other aphids, enabling the selection of potential isolates for aphid control.
Topics: Animals; Aphids; Mustard Plant; Fungi; Spores, Fungal; Insecta
PubMed: 37677031
DOI: 10.3791/65312 -
Pharmaceutics Mar 2022Orodispersible films (ODFs) have been widely used in paediatric, geriatric and dysphagic patients due to ease of administration and precise and flexible dose...
Orodispersible films (ODFs) have been widely used in paediatric, geriatric and dysphagic patients due to ease of administration and precise and flexible dose adjustments. ODF fabrication has seen significant advancements with the move towards more technologically advanced production methods. The acceptability of ODFs is dependent upon film composition and process of formation, which affects disintegration, taste, texture and mouthfeel. There is currently a lack of testing to accurately assess ODFs for these important acceptability sensory perceptions. This study produced four ODFs formed of polyvinyl alcohol and sodium carboxymethylcellulose using 3D printing. These were assessed using three in vitro methods: Petri dish and oral cavity model (OCM) methods for disintegration and bio-tribology for disintegration and oral perception. Increasing polymer molecular weight (MW) exponentially increased disintegration time in the Petri dish and OCM methods. Higher MW films adhered to the OCM upper palate. Bio-tribology analysis showed that films of higher MW disintegrated quickest and had lower coefficient of friction, perhaps demonstrating good oral perception but also stickiness, with higher viscosity. These techniques, part of a toolbox, may enable formulators to design, test and reformulate ODFs that both disintegrate rapidly and may be better perceived when consumed, improving overall treatment acceptability.
PubMed: 35456566
DOI: 10.3390/pharmaceutics14040732 -
IEEE Transactions on Bio-medical... Jul 2021Embryo manipulation is a fundamental task in assisted reproductive technology (ART). Nevertheless, conventional pick-place techniques often require proper alignment to...
UNLABELLED
Embryo manipulation is a fundamental task in assisted reproductive technology (ART). Nevertheless, conventional pick-place techniques often require proper alignment to avoid causing damage to the embryo and further, the tools have limited capability to orient the embryo being handled.
OBJECTIVE
This paper presents a novel and non-invasive technique that can easily manipulate mouse embryos on a polyvinyl chloride (PVC) Petri dish.
METHODS
An inverted microchip with quadrupole electrodes was attached to a micromanipulator to become a robotic dielectrophoresis (DEP) tweezers, and a motorized platform provided additional mobility to the embryos lying on a Petri dish. Vision-based algorithms were developed to evaluate relevant information of the embryos from the image, and to provide feedback signals for precise position and orientation control of the embryo.
RESULTS
A series of experiments was conducted to examine the system performance, and the embryo can be successfully manipulated to a specified location with the desired orientation for subsequent processing.
CONCLUSION
This system offers a non-contact, low cost, and flexible method for rapid cell handling.
SIGNIFICANCE
As the DEP tweezers can grasp the embryo without the need for precise alignment, the overall time required to process a large number of embryos can be shortened.
Topics: Algorithms; Animals; Embryo, Mammalian; Mice; Micromanipulation; Robotic Surgical Procedures; Rotation
PubMed: 33052848
DOI: 10.1109/TBME.2020.3031043 -
Experimental Parasitology Nov 2022The fall webworm (FWW), Hyphantria cunea Drury (Lepidoptera: Erebidae), is an invasive and polyphagous insect pest of many economically important crops such as...
Insecticidal activities of the local entomopathogenic nematodes and cell-free supernatants from their symbiotic bacteria against the larvae of fall webworm, Hyphantriacunea.
The fall webworm (FWW), Hyphantria cunea Drury (Lepidoptera: Erebidae), is an invasive and polyphagous insect pest of many economically important crops such as hazelnuts, apple, and mulberry. Recently, there have been an increasing number of reports about the damaging activities of FWW from hazelnut growing areas of Turkey indicating that currently existing control methods fail to satisfy the expectations of growers. Entomopathogenic nematodes (EPNs) in the Steinernematidae and Heterorhabditidae (Nematoda: Rhabditida) families and the symbiotic bacteria they carry in their intestine have a great potential for the management of many agriculturally important pests. In this study, the symbiotic bacteria of local EPN species (Heterorhabditis bacteriophora AVB-15, Steinernema feltiae KCS-4S, and Steinernema bicornotum MGZ-4S) recovered from the central Anatolia region was characterized using recA gene region as Photorhabdus luminescens, Xenorhabdus bovienii and Xenorhabdus budapestensis. The contact (25, 50, 100, 200 IJs/Petri) and oral efficacies of the infective juveniles (IJs) (25, 50, 100, 200 IJs/leaf) of these EPN isolates determined on 3rd/4th instar larvae, and cell-free supernatants from the identified symbiotic bacteria were evaluated separately on the 3rd and 4th larval instars of FWW in Petri dish environment under laboratory conditions (25 ± 1 °C, 60% of RH). In the Petri dish bioassays of EPN species, the most pathogenic isolate at the 1st DAT and 4th DAT was S. feltiae which caused 50% mortality at the highest concentration (200 IJs/Petri) and the highest mortality rate (97.5%) were achieved at 4th DAT by H. bacteriophora AVB-15 isolate. Surprisingly, the mortality rates were generally higher at the lowest concentrations and 82.5% mortality were reached 4th DAT by S. bicornotum at the lowest concentration (25 IJs/leaf) in the leaf bioassays. Mortality rates were higher in both Petri dish and filter paper efficacies of cell-free supernatants at the 2nd DAT and the highest mortality (87.5%) was reached in the contact efficacy studies when applied X. bovienii KCS-4S strain. The results suggest that the tested EPN species and CFSs have good potential for biological control of the larvae of FWW and can contribute to the IPM programs of FWW. However, the efficacy of both IJs of EPNs and CFSs of their symbiotic bacteria on larvae of FWW requires further studies to verify their efficiency in the field.
Topics: Humans; Animals; Larva; Insecticides; Rhabditida; Photorhabdus; Moths; Pest Control, Biological
PubMed: 36116520
DOI: 10.1016/j.exppara.2022.108380 -
ACS Applied Materials & Interfaces Aug 2014Recently, we have developed a semidirect breath figure (sDBF) method for direct fabrication of large-area and ordered honeycomb structures on commercial polystyrene (PS)...
Recently, we have developed a semidirect breath figure (sDBF) method for direct fabrication of large-area and ordered honeycomb structures on commercial polystyrene (PS) Petri dishes without the use of an external polymer solution. In this work, we showed that both the pore size and the pore uniformity of the breath figure patterns were controllable by solvent amount. The cross-sectional image shows that only one layer of pores was formed on the BF figure patterns. By combing the sDBF method and Pickering emulsion and using the modular building blocks, we endowed the honeycomb-structured Petri dish with molecular recognition capability via the decoration of molecularly imprinted polymer (MIP) nanoparticles into the honeycomb pores. The radioligand binding experiments show that the MIP nanoparticles on the resultant honeycomb structures maintained high molecular binding selectivity. The reusability study indicates that MIP-BF patterns had excellent mechanical stability during the radioligand binding process. We believe that the modular approach demonstrated in this work will open up further opportunities for honeycomb structure-based chemical sensors for drug analysis, substrates for catalysts, and scaffold for cell growth.
Topics: Humidity; Hydrophobic and Hydrophilic Interactions; Ligands; Light; Molecular Imprinting; Nanoparticles; Particle Size; Polystyrenes; Porosity; Propranolol; Recycling; Scattering, Radiation; Solvents; Spectroscopy, Fourier Transform Infrared; Toluene; Water
PubMed: 24941125
DOI: 10.1021/am502871t -
Journal of Colloid and Interface Science Apr 2019The traditional Petri dish, which has not been changed in almost 60 years, has clear limitations when it is applied to cell cultures in a modern biological laboratory....
The traditional Petri dish, which has not been changed in almost 60 years, has clear limitations when it is applied to cell cultures in a modern biological laboratory. In this work, by integrating the advantages of both the semidirect breath figure (sDBF) method and the traditional breath figure (BF) method, we proposed for the first time a novel hybrid BF method for the fabrication of honeycomb-patterned Petri dishes with mPEG self-assembly in the pores. Due to the amphiphilic structure of mPEG, the active OH groups of mPEG were located inside the pores of the dishes, which could covalently couple with other functional materials. For instance, in this work, an antibacterial agent was immobilized onto the dish surface via a typical coupling reaction. Because of the size difference between the bacteria and cells, the prepared dishes had selective antibacterial activity but noncytotoxicity against mammalian cells. The present hybrid BF method provides a new insight for endowing commercial PS Petri dishes or other membranes with special topographical structures and functions, which could solve the long-term challenges of cell cultures in the future.
Topics: Anti-Bacterial Agents; Cell Culture Techniques; Cell Proliferation; Escherichia coli; Hep G2 Cells; Humans; Surface-Active Agents
PubMed: 30684750
DOI: 10.1016/j.jcis.2019.01.074 -
Environmental Entomology Feb 2023Beauveria bassiana (Balsamo) Vuillemin infects a wide variety of insects, including the green peach aphid, Myzus persicae (Sulzer). Volatiles emitted from B. bassiana...
Beauveria bassiana (Balsamo) Vuillemin infects a wide variety of insects, including the green peach aphid, Myzus persicae (Sulzer). Volatiles emitted from B. bassiana can act as semiochemical attractants or repellents, with most responses reported to date resulting in insects avoiding B. bassiana. Since insects can detect 'enemy-specific volatile compounds', we hypothesized the preference behavior of M. persicae would be influenced by volatile emissions from B. bassiana. We conducted Petri dish and Y-tube olfactometer bioassays to characterize the preference of M. persicae to B. bassiana strain GHA. During Petri dish bioassays, more apterous and alate M. persicae were recorded in the vicinity of agar colonized by B. bassiana compared to agar, or Fusarium proliferatum (Matsushima) Nirenberg and Ambrosiella grosmanniae Mayers, McNew, & Harrington as representatives of nonentomopathogenic fungi. Petri dish bioassays also determined that apterous and alate M. persicae preferred filter paper saturated with 1 × 107, 1 × 106, and 1 × 105B. bassiana conidia/ml compared to Tween 80. Y-tube bioassays documented that more apterous and alate M. persicae oriented upwind to volatiles from B. bassiana mycelia compared to agar. Apterous and alate Myzus persicae were also preferentially attracted to 1 × 107 and 1 × 106B. bassiana conidia/ml compared to Tween-80 during Y-tube bioassays. These results complement a previous finding that the mosquito Anopheles stephensi (Diptera: Culicidae) Liston is attracted to volatiles from B. bassiana. Future studies aimed at characterizing the olfactory mechanism leading to the attraction of M. persicae to B. bassiana could aid in optimizing lure-and-kill strategies.
Topics: Animals; Beauveria; Aphids; Agar; Spores, Fungal; Pest Control, Biological
PubMed: 36421055
DOI: 10.1093/ee/nvac100 -
Cell Aug 2008With the growing cost of using animals to test the safety of new chemicals and an increasing backlog of chemicals awaiting testing, the quest for cell-based in vitro...
With the growing cost of using animals to test the safety of new chemicals and an increasing backlog of chemicals awaiting testing, the quest for cell-based in vitro alternatives for toxicity testing is gaining momentum.
Topics: Animal Testing Alternatives; Animals; Europe; Government Agencies; Humans; Models, Animal; Toxicity Tests; United States; United States Environmental Protection Agency
PubMed: 18724925
DOI: 10.1016/j.cell.2008.08.011 -
Gene Therapy Sep 1999The nonreplicating vaccinia virus MVA/T7 RNA polymerase hybrid system was tested with Petri dish electroporation for ectopic gene expression in human umbilical vein...
The nonreplicating vaccinia virus MVA/T7 RNA polymerase hybrid system was tested with Petri dish electroporation for ectopic gene expression in human umbilical vein endothelial cells (HUVECs). A range of voltages (150-450 V), pulse times (10-40 ms), DNA concentrations (0-20 microg/ml) and infection levels (0-15 multiplicities of infection) were tested for effects on T7 promoter-directed chloramphenicol acetyltransferase (CAT) activity after MVA/T7RP infection. MVA/T7RP-directed expression was transient and at least 10 000-fold in excess of nonviral, cytomegalovirus enhancer-directed expression. Use of a Petri dish electrode with the MVA/T7RP system showed increased viability compared with a cuvette electrode. Overexpression of interleukin-2 alpha subunit (IL2Ralpha) pro- tein followed by anti-IL2Ralpha-directed magnetic immunoaffinity cell sorting allowed isolation of the transfected population. The high fidelity of cellular sorting was shown by segregation of CAT activity in the IL2Ralpha-sorted population after transfection of T7 promoter-directed bicistronic IL2Ralpha/CAT DNA. Expression of a panel of proteins including the fluorophore green fluorescent protein as detected by fluorescence microscopy and p21cip1, p27kip1, pp60c-src, FGF-1, pRb, p107 and pRb2/p130 proteins was also achieved. Thus, use of the nonreplicating vaccinia virus/T7 RNA polymerase expression system with Petri dish electroporation is feasible for certain applications for the manipulation of HUVECs by gene transfer.
Topics: Bacteriophage T7; Chloramphenicol O-Acetyltransferase; DNA-Directed RNA Polymerases; Electroporation; Endothelium, Vascular; Gene Expression; Gene Transfer Techniques; Green Fluorescent Proteins; Humans; Immunoblotting; Luminescent Proteins; Microscopy, Fluorescence; Receptors, Interleukin-2; Umbilical Veins; Vaccinia virus; Viral Proteins
PubMed: 10490772
DOI: 10.1038/sj.gt.3300977 -
Monthly Bulletin of the Ministry of... Jan 1955
Topics: Bacteriology; Manufactured Materials
PubMed: 13235702
DOI: No ID Found