Long-Term Maintenance and Meiotic Entry of Early Germ Cells in Murine Testicular Organoids Functionalized by 3D Printed Scaffolds and Air-Medium Interface Cultivation

Short-term germ cell survival and central tissue degeneration limit organoid cultures. Here, testicular organoids (TOs) were generated from two different mouse strains in 3D printed one-layer scaffolds (1LS) at the air-medium interface displaying tubule-like structures and Leydig cell functionality supporting long-term survival and differentiation of germ cells to the meiotic phase. Chimeric TOs, consisting of a mixture of primary testicular cells and EGFP+ germline stem (GS) cells, were cultured in two-layer scaffolds (2LSs) for better entrapment. They showed an improved spheroidal morphology consisting of one intact tubule-like structure and surrounding interstitium, representing the functional unit of a testis. However, GS cells did not survive long-term culture. Consequently, further optimization of the culture medium is required to enhance the maintenance and differentiation of germ cells. The opportunities TOs offer to manipulate somatic and germ cells are essential for the study of male infertility and the search for potential therapies.

Research on Acoustic Transfer Performance of Power Cabin of Underwater Craft

In order to study the acoustic performance of underwater vehicle including vibration and noise, two kinds of structure models of an underwater craft cabin in the air medium and in the water medium were analyzed separately by finite element method. Through modal analysis, the impedance ratios of the two kinds of models were calculated. The influence of the thickness of the pressure hull on the impedance ratio of the structure was studied, and the acoustic transfer performance was analyzed and compared between the two kinds of models.

Do It Yourself: Air Drag Force Experiment Using Paper and Scraper Sheet

Free fall motion in air medium is only influenced by gravitation acceleration. However, there are several variables that caused the observations to be different with the concept. Variables, such as air drag and terminal velocity, are often teachers not presented in detail, causing misconceptions. This study aims to develop a simple experiment on free fall motion by identifying air drag and terminal velocity. The data in this study is the video of free fall motion of paper and scraper analyzed using Tracker video analyze. From the video analyzed, information is obtained in the form of time (t), track (l, θ), and velocity (v) of the object. This study shows that the air drag force increase unto the terminal velocity. The calculation of the drag coefficient giving the number of the paper 2,16 and the scraper 2,10. According to data analyzed, the air drag force is affected by the mass (m), area (A), and the air drag force (F_D) with the linear correlation until it reaches the terminal velocity. The result of this study may use as references of free fall motion experiment with other objects and analyze.

P–799 Long-term maintenance and meiotic entry of early germ cells in functionalized murine testicular organoids mediated by 3D printed scaffolds and air-medium interphase cultivation

Study question Can improved culture conditions advance the functionality of murine testicular organoids (TOs)? Summary answer Testicular cells formed spheroidal TOs resembling the functional unit of the testis and supporting meiotic entry of germ cells during long-term culture in printed macropores. What is known already Organ cultures at the air-medium interphase have traditionally been used for in-vitro spermatogenesis (IVS) in rodents because they best preserve the testicular architecture, which is pivotal in achieving IVS. However, organ cultures do not offer the ability to access and manipulate single cells, making it an inefficient model for mechanistic studies. Culturing testicular cell suspensions into organoids offer these features. Previously, testicular organoids in immersion culture resulted in testicular architecture, but only supported short-term survival of germ cells. Moreover, millimeter-sized organoids show signs of degeneration due to insufficient nutrient and oxygen supply. Study design, size, duration First, we focused on recreating the testicular architecture at air-medium interphase and determined whether higher cell densities could improve our previously developed 3D printed culture model during long-term culture using different mouse strains. Afterwards, the focus was put on improving TO morphology by adapting the scaffold design. Moreover, to expand the potential of TOs, the possibility to cultivate chimeric mixtures of testicular cells and germ line stem cells expressing a reporter transgene (EGFP) was assessed. Participants/materials, setting, methods Prepubertal testicular cells from C57BL/6J (n = 5) or CBAB6F1 (n = 3) mice were cultured in the macropores of 3D printed squared 1-layered scaffolds (1LSs) composed of Cellink-RGD (8x104 cells/mm²). Next, 1LS was modified with an additional layer of alginate (2LS) to culture a chimeric mixture of testicular cells of prepubertal C57BL/6J mice and EGFP-expressing germline stem cells (2:1). Cell reorganization and differentiation were characterized by immunohistochemistry and testosterone was quantified by electrochemiluminescence. Main results and the role of chance During long-term cultures in 1LSs, testicular cells reorganized into organoids with restoration of testicular architecture and Leydig cell functionality supporting the differentiation of germ cells to the meiotic phase, regardless of the mouse strain. However, pore overgrowth and fusion of adjacent aggregates, resulted in irregularly shaped TOs. Based on these results, the design of 1LS was modified with an additional layer of alginate to entrap reorganizing cells (2LS). To non-invasively evaluate germ cell behavior, EGFP-expressing germline stem cells were mixed with testicular cells of prepubertal C57BL/6J mice in 2LS. This approach resulted in the formation of chimeric organoids with a more regular and spheroidal morphology. These improved TOs consisted typically of 1 tubule-like structure and surrounding interstitium, representing the functional unit of a testis. in contrast to primary germ cells, germline stem cells were not observed after the 3rd week of culture. Limitations, reasons for caution Candidate factors have to be tested in their ability to elevate the meiotic blockage of germ cells in TOs. In addition, the culture medium needs further optimization to enhance maintenance of germline stem cells in chimeric models. Finally, results obtained with rodents remain to be confirmed in further human studies. Wider implications of the findings: The opportunities testicular organoids offer to manipulate cells through genetic modification, inclusion and exclusion, are essential for the study of male infertility and the search for potential therapies. Moreover, they permit high-throughput screening of chemicals, thereby substantially reducing the number of animals for the high demanding reproductive toxicity studies. Trial registration number Not applicable

Fixture for the High-Frequency Transfer Path Analysis for Relative Comparison of Fluids of an Electric Motor

In a previous paper, it was determined that coolant fluids can have a significant influence on the acoustic emission of an electric motor. There is no appliance that can investigate and compare the transfer path analysis of isolated fluids. For this case, a new fixture is introduced and its suitability is evaluated. Furthermore, the appliance is used to measure and compare different media and their frequency response functions. The results indicate that the fixture and its repeatability are suitable to measure and compare fluids and media. A comparison of different media shows how the air medium has the lowest amplitudes for the transfer path analysis, in relation to incompressible fluids. Furthermore, differences in the transfer path analysis between both considered gearbox oils are marginal. While the utilization of air as a coolant medium is not always possible, due to thermal issues, the presented fixture can help find an acoustically suitable coolant medium for future applications in electric motors. Additionally, it is possible to investigate the influence of temperature and pressure conditions on the transfer path analysis of fluids.

Air 100 UAV for Law and Enforcement Applications

In India the crime increased with a percentage of 1.3% as per the NCRB data, in number, there are around50.74 lakh crimes under the Indian Penal Code and around 20 lakh crimes under local laws. There are many ways to detect where crimes are committed but those locations needed frequent monitoring. During an emergency call foran incident quicker response is required. The cops may/may not reach the location in time because of road transportation.But with UAV, the reaction for the call can be made better .UAV make an incredible time in reaching the exact location through the air medium. So the people in Law and enforcement sometimes use COTS (Commercial off the self) drones. They are not purposely made for it .The purpose of the paper is to make a custom UAV with the perfect specification to handle various critical situations.