アンテイドウイタイヲモチイタカセンセイタイケイニオケルショウカオヨビダツチツノケントウ

博士（農学)東京農工大

Testicular Histopathology and Spermatogenesis in Mice with Scrotal Heat Stress

Chronic heat stress-induced testicular damage and function therefore adversely affect their reproduction. Some research shows that heat stress has a negative effect on histopathological features of testicular tissue structure and spermatogenesis. An animal model was used to evaluate the effect of heat stress on testicular histology changes and spermatogenesis. The mouse model of heat stress was established by submerged in a pre-warmed incubator. The testes’ tissue was fixed and stained with hematoxylin–eosin (H&E) for quantitative analysis of histopathological alterations and spermatogenesis according to Johnson scoring system. Mice exposed to heat stress exhibited degenerated and disorganized features of spermatogenic epithelium and reduced spermatogenic cells. Heat stress exposure shows a significantly reduced Johnson score compared to the control condition. The percentage of high Johnsen score points was decreased in heat-stress exposure mice, while the ratio of low Johnsen score points was gradually increased. This chapter describes a mouse model for studying the male reproductive system and applies the Johnsen scores system to assess testicular histopathology in the seminiferous tubule cross-section. Collectively, this chapter indicated a negative impact of heat stress on mouse spermatogenesis as well as the human reproductive system

A Design of Similar High-gain and Dual-band Frequency/Polarization Reconfigurable Antenna for ISM Band Applications

This paper proposes a frequency/polarization reconfigurable antenna (RA) incorporating with Frequency Selective Surface (FSS) to achieve dual-band and similar high-gain characteristics. The proposed RA-FSS design using 4 PIN Diodes can switch between circular polarization (CP) at 1.8 GHz and linear polarization at 2.45 GHz. The fabricated prototype shows good CP performance at 1.8 GHz while the measured peak broadside gains are about 7.2 dBi at 1.8 GHz and 8.5 dBi at 2.45 GHz when PIN diode ON and OFF, respectively

A FLEXIBLE HIGH-BANDWIDTH LOW-LATENCY MULTI-PORT MEMORY CONTROLLER

Multi-port memory controllers (MPMCs) have become increasingly important in many modern applications due to the tremendous growth in bandwidth requirement. Many approaches so far have focused on improving either the memory access latency or the bandwidth utilization for specific applications. Moreover, the application systems are likely to require certain adjustments to connect with an MPMC, since the MPMC interface is limited to a single-clock and single-data-width domain. In this paper, we propose efficient techniques to improve the flexibility, latency, and bandwidth of an MPMC. Firstly, MPMC interfaces employ a pair of dual-clock dualport FIFOs at each port, so any multi-clock multi-data-width application system can connect to an MPMC without requiring extra resources. Secondly, memory access latency is significantly reduced because parallel FIFOs temporarily keep the data transfer between the application system and memory. Lastly, a proposed arbitration scheme, namely window-based first-come-first-serve, considerably enhances the bandwidth utilization. Depending on the applications, MPMC can be properly configured by updating several internal configuration registers. The experimental results in an Altera Cyclone V FPGA prove that MPMC is fully operational at 150 MHz and supports up to 32 concurrent connections at various clocks and data widths. More significantly, achieved bandwidth utilization is approximately 93.2% of the theoretical bandwidth, and the access latency is minimized as compared to previous designs

Detailed investigation of factors affecting the synthesis of SiO2@Au for the enhancement of Raman spectroscopy

The reaction time, temperature, ratio of precursors, and concentration of sodium citrate are known as the main factors that affect the direct synthesis process of SiO2@Au based on the chemical reaction of HAuCl4 and sodium citrate. Hence, we investigated, in detail, and observed that these factors played a crucial role in determining the shape and size of synthesized nanoparticles. The significant enhancement of the SERS signal corresponding to the fabrication conditions is an existing challenge. Our study results show that the optimal reaction conditions for the fabrication of SiO2@Au are a 1:21 ratio of HAuCl4 to sodium citrate, with an initial concentration of sodium citrate of 4.2 mM, and a reaction time lasting longer than 6 h at a temperature of 80 degrees C. Under optimal conditions, our synthesis process result is SiO2@Au nanoparticles with a diameter of approximately 350 nm. In particular, the considerable enhancement of Raman intensities of SiO2@Au compared to SiO2 particles was examined.Web of Science1217art. no. 308