bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of Methylene Blue Using Ni-Al/Magnetite Biochar Layered Double Hydroxides Composite by Adsorption
Authors: Zahara Zaqiya Artha , Royani Idha , Palapa Neza Rahayu , Mohadi Risfidian , Lesbani Aldes
Published: November 2023

Methylene blue dye is hard to degrade and requires treatment using Ni-Al Layered double hydroxides (LDHs) modified with magnetite biochar (MBC) to form Ni-Al/magnetite biochar composite in overcoming environmental pollution. Material attainment was identified by characterization using X-Ray Diffraction (XRD), Fourier Transform – Infra Red (FT-IR), Branuer Emmet Teller (BET), Scanning Electron Microscopy – Energy Dispersive X-Ray (SEM-EDX) and Vibration Sample Magnetometer (VSM). XRD characterization displays angle 2θ at 11°, 60° is a typical angle of LDH, and angles 22° and 35° of magnetite biochar. FT-IR characterization analysis at wavelength 1381 cm-1 for NO3- group and M-O group at wave number 700 cm-1. C-H group on biochar at 1404 cm-1 and wave number 586 cm-1 for Fe-O group. BET characterization analysis of Ni-Al/MBC has a large surface area and pore volume of 127.310 m²/g and 0.1950 cm³/g. SEM characterization analysis of Ni-Al/MBC has large, coarse pores and non-uniform shape, EDX data shows that there are forming elements such as Ni, Al from LDH and, Fe, C elements from magnetite biochar. pH, kinetics, isotherms, and thermodynamics become influential in adsorption processes. The adsorption capacity of the composite reaches 68.493 mg/g by following the Langmuir equation and adsorption kinetics refers to the Pseudo Second Order (PSO) equation. Adsorption continuity is spontaneous and endothermic. Ni-Al/MBC has stability in the process of adsorbent regeneration up to five adsorption cycles and, therefore can be used as a potential adsorbent in the treatment of methylene blue dye in aqueous environmental pollution. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Theoretical analysis of a monopole antenna with conducting flat disk above the earth
Authors: Yuasa Aki , Itatsu Daisuke , Inagaki Naoki , Kikuma Nobuyoshi
Published: November 2023

The monopole antenna with a conductive ground above the earth is analyzed by means of an equivalent circuit. The current distribution, input impedance, directivity, and antenna efficiency corrected for the effect of the electrical characteristics of the earth are derived in terms of parameters such as the antenna length, the radius of the grounding disk, and the frequency. First, by means of the plane wave expansion, the system is represented by an equivalent circuit in the spectral domain and Green's function is obtained by solving the circuit equation. From the numerical results by the method of moments, the input impedance and the antenna efficiency are found to depend on the size of the radius of the grounding disk. In the absence of the grounding disk, the antenna efficiency is higher for a larger antenna length. On the other hand, in the presence of the grounding disk, the antenna efficiency decreases as the antenna length is increased, and increases as the antenna length is decreased. As regards the radiation pattern, the maximum direction of radiation approaches the horizontal plane as the antenna length is increased, and the beam width increases as the radius of the grounding disk is increased. The effect of frequency is found to be small. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(7): 27–36, 2001
Variable mux/demux time division photonic switching network using optical time jumper
Authors: Yasui Tadahiko , Nakano Yoshiaki
Published: November 2023

A pulse can be viewed as a kind of memory with faster processing elements, because the information carried by the pulse can be read out at any time by the faster processing elements. Taking this into consideration, one of the authors proposed a TDM switching system which in principle requires no random access memories, but rather only logical gates. This is very much suited to the photonic TDM switching system, as optical RAMs are not as yet available.

This paper newly proposes a photonic TDM switching system in which a time jumper is placed on a highway link connecting multistage variable multiplexer and multistage variable demultiplexer. It discusses the system concept, jumpering algorithm, jumper configuration, traffic characterization of the system, optimal system configuration, and finally applications of the system. The characteristics in terms of cost/erl are better than those of the system proposed before. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(9): 1–15, 2001
Exact analysis of delay performance of Go‐Back‐N ARQ scheme over multiple parallel channels
Authors: Fujii Shumji , Hayashida Yukuo , Komatsu Masaharu
Published: November 2023

The Go‐Back‐N ARQ scheme, which is one of the typical error control methods for data transmission, has been widely used because of its good performance and easier implementation. Most analyses of the throughput and delay performances of the ARQ scheme (including the Go‐Back‐N) have been carried out for a single channel connecting a pair of a sender and a receiver.

This paper gives an exact analysis of the delay performance of a Go‐Back‐N ARQ scheme, for a simultaneous transmission of multiple frames using multiple parallel channels between a pair of a sender and a receiver. In a discrete‐time queueing model, the state of the system is described at each successful slot of frame transmission by using variables (which show the frame queue length and the existence of retransmitting frame) so that the distribution of the frame queue length is obtained from the solutions of the state equations. By using the results of the analysis, the distribution of the transmission delay of frames is obtained. The average delay characteristics are examined by using numerical examples. The results show that the delay performance can be improved by increasing the number of parallel channels. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(9): 27–41, 2001
Nonvolatile method of semiconductor disk device for the memory database recovery
Authors: Kawase Katsuyuki , Yamasaki Mikio , Hirano Masanori , Masuda Etsuo , Imagawa Hitoshi , Kinouchi Yasuo
Published: November 2023

To accelerate database processing, advanced intelligent networks and on‐line transaction processing systems employ memory databases in which all databases reside in main memory. Nonvolatile methods for the semiconductor disk devices backing up the memory databases have been proposed for these systems. Specifically, the methods adopted were a nonvolatile method using directly connected batteries and a method to transfer the contents of the semiconductor disk device to a magnetic disk drive which is a nonvolatile medium. An examination of the required nonvolatile time and the database capacity clearly demonstrated the application ranges of these two techniques by evaluating the battery capacity and the amount of hardware. Consequently, for a database capacity from 512 MB to 2 GB, the required nonvolatile time is about 10 hours. In the semiconductor disk device for an advanced intelligent network, the nonvolatile method using directly connected batteries was shown to be effective. To effectively maintain the batteries, a method to automatically decide whether to replace the batteries was proposed. Finally, the prototype battery structure based on these results and the structure for a service control node in the advanced intelligent network incorporating this battery structure were illustrated. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(9): 42–53, 2001
Performance analysis of indoor infrared wireless systems using OOK CDMA on a diffuse channel
Authors: Matsuo Ryoko , Matsuo Michihito , Ohtsuki Tomoaki , Sasase Iwao , Udagawa Tomoyuki
Published: November 2023

We analyze the bit error rate (BER) performance of indoor infrared wireless systems using on–off keying (OOK) code division multiple access (CDMA) on diffuse channels by taking the effects of intersymbol interference (ISI) for more than ten chips into account. We show how much the transmitted power should be increased on multipath channels to compensate the performance degradation due to the ISI, and demonstrate that this analysis evaluates the effects of ISI more correctly than does the conventional analysis. We also show that the bit rate is limited because of ISI and eye safety, when we use OOK CDMA on multipath channels. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(10): 1–9, 2001
Wireless packet transmission with variable processing gain control in packet‐switched and circuit‐switched mode integrated DS‐CDMA systems
Authors: Ito Takumi , Sampei Seiichi , Morinaga Norihiko
Published: November 2023

A DS‐CDMA system with both a circuit‐switching scheme for voice transmission and a packet‐switching scheme for data transmission is effective in multimedia communication required to transmit a variety of media. Although the Slotted‐ALOHA system is believed to be an effective packet‐switched system from the perspectives of transmission efficiency and interference power, only open loop transmit power control is used because of the difficulty in using closed loop transmit power control in the ALOHA system. In this paper, we analyze the performance of open loop transmit power control that uses a power margin to obtain the quality required even in packet‐switched terminals, and propose wireless packet transmission with variable processing gain control as the method to achieve high‐speed transmission by more effectively using the free channels. The results of computer simulations showed that the system capacity of circuit‐switched terminals is not damaged when an appropriate power margin is set, and the additional effect of the packet‐switched terminals is increased. In addition, the proposed system can greatly shorten the average delay time of packet‐switched terminals. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(10): 16–26, 2001
Experiments on satellite TDMA system for multimedia communications
Authors: Kazama Hiroshi , Sugiyama Takatoshi , Fukuda Hideki
Published: November 2023

As a new form of communications, computer networks represented by the Internet have become widespread. In these networks, multimedia information such as static and dynamic images, audio, data file, and so on are handled. In such multimedia communications, the access circuits of the users are low‐speed ones while the return links to the users are large‐capacity, high‐speed circuits and, therefore, the configuration has an asymmetric bidirectional form. In this paper, as a highly efficient method of transmission of asymmetric bidirectional multimedia communications with different speeds, which can be adopted only to satellite systems, the TDMA signals of variable transmission speeds are used in the return links of multiple connected transmitting stations. The multiplexed SSMA signals are superposed on TDMA signals of the low‐speed forward links. Such a multimedia satellite TDMA communication system is proposed and a fabricated prototype is used in the satellite connections of the NTT Yokosuka and Musashino Research Centers. In this prototype, the actual TDMA capacity is 42.24 Mbits/s while 20 circuits of 32 kbits/s are accommodated in the SSMA signal. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(10): 55–65, 2001
An end‐to‐end bit error ratio monitoring method for digital backbone networks
Authors: Kawashima Makoto , Miyagawa Yuuzou , Matsushita Masahiko
Published: November 2023

In the evaluation of the QoS (quality of service) of digital networks, not only the management and operation of the network, but also the development of a new service menu must be considered important factors. Among them, the user information error ratio is the most essential item. This paper considers QoS monitoring of a digital backbone network that will support future communication services, and proposes a new method for determining the user information error ratio. The proposed method performs error monitoring by transmitting the error‐detecting code generated by the sending side to the receiving side through a channel which is different from the channel used for user information, and realizes highly accurate in‐service end‐to‐end error monitoring for any kind of user link. This paper analyzes the requirements for user information error monitoring. The operating principles and a characteristics analysis of the proposed method are presented, revealing the monitoring performance of the system. Finally, the method is applied and design examples are presented, demonstrating the usefulness of the proposed method. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(9): 1–10, 2001
Current sensing device for micro‐IDDQ test
Authors: Nose Koichi , Sakurai Takayasu
Published: November 2023

In LSIs with more than 1 million gates, detection of the defective locations becomes difficult. In particular, in the case of an abnormality in the standby current, excessive power is consumed even if operation is successful. Hence, it is necessary to identify the error location in order to reduce power consumption. The IDDQ test detects the error by measuring the static current in standby for each circuit block. A typical implementation is the BICS (Built‐In Current Sensor). However, the conventional method has the problems of reduction of the noise margin and degradation of the circuit speed. In this paper, two types of current sensors, the Lorentz force MOSFET (LMOS) and Hall effect MOSFET (HEMOS), based on a magnetic sensor circuit using CMOS technology, are proposed. These sensors are capable of non‐contacting and non‐disturbing current measurement. A circuit for applications to the IDDQ test is described. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(9): 21–27, 2001
Correction factor for four‐probe resistivity measurements on resistive sheets with parallel electrodes
Authors: Kanagawa Makoto
Published: November 2023

This article discusses the use of the four‐probe method for direct measurements of the resistance per square of a resistive sheet with parallel electrodes. These measurements must be adjusted by a correction factor, which is calculated in this work by modeling the resistive sheet as a two‐dimensional square with opposing cylindrical electrodes and setting the resistance of the electrodes equal to zero. The correction factor is then computed by postulating the boundary condition that the potentials on the two sides are constant. Although it is the resistive sheet with parallel electrodes that controls the performance of the resistive‐sheet pressure response type of digitizer, this performance has been evaluated only by indirect methods. Nevertheless, the simulations and experiments described in this paper confirm that the resistance per square of a resistive sheet with parallel electrodes can be measured by the four‐probe method when the correction factor derived here is used. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(9): 36–45, 2001
Frequency‐range widening of three‐transformer CATV divider using a bead‐type ferrite core
Authors: Kanie Tomohiko , Takeo Takashi , Itoh Haruhiko , Hashimoto Reiji , Azakami Takashi
Published: November 2023

This paper describes the frequency‐range widening of a three‐transformer CATV divider consisting of one divider transformer and two matching transformers, all of which use a bead‐type ferrite core. For frequency‐range widening, the shape and material of the ferrite core, transformer windings, and transformer packaging are theoretically studied by means of a newly proposed high‐frequency transformer equivalent circuit. For the divider designed based on the theoretical study, excellent measurement results are obtained in the frequency range of 20 to 3000 MHz, including a divider loss of 3.6 to 4.6 dB and more than 20 dB of coupling loss between terminals. In the design emphasizing a flat frequency characteristic at some expense of divider loss from a low to intermediate frequency range, the flatness is found to increase to about ±0.3 dB. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(9): 46–55, 2001
Three‐dimensional FDTD analysis of light scattering from a phase‐change optical disk structure
Authors: Fukai Shin‐ichiro , Kojima Toshitaka , Wei Yi‐
Published: November 2023

In this article, we discuss simulations of the scattering characteristics of models of a phase‐change optical disk illuminated by a laser beam, using the three‐dimensional finite‐difference time domain (FDTD) method. We first analyzed a three‐dimensional conducting pit and a rewritable optical disk model, using the boundary element method (BEM) together with FDTD code that we wrote, and demonstrated that the results of using these two methods are in satisfactory agreement. Next, based on a four‐layer three‐dimensional structural model of a phase‐change optical disk, we investigated visualization images of the near‐field distribution, including the recording layer, as well as examples of far‐field scattering patterns calculated in the planes perpendicular and parallel to the guide groove, in order to determine how these patterns change before and after recording. We then made visualizations of the intensity distribution of light focused by the objective lens, and investigated how the regenerated sum and tracking error signal characteristics differ before and after recording. Finally, for the case in which the optical spot tracks without leaving the guiding groove, we can identify when the spot is in the space between adjacent recording marks. We conclude that a comparative analysis of light scattering by a complicated multilayer optical disk structure can easily be carried out by the 3D FDTD analysis discussed in this article. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(9): 56–66, 2001
Semen Characteristics of the Captive Indian Leopard, Panthera pardus
Authors: JAYAPRAKASH D. , PATIL SURESH B. , KUMAR M. NAVIN , MAJUMDAR K. C. , SHIVAJI S.
Published: November 2023

ABSTRACT: Semen samples from 11 Indian leopards (Panthera pardus) from 3 different zoos in India were collected by electroejaculation. A computer‐aided semen analyzer (CASA) was used for assessing the quality of the semen vis‐à‐vis sperm motility. The volume of the ejaculate, sperm density, and the number of motile and morphologically normal spermatozoa were found to be 1.57 ± 1.26 mL, 55.78 million ± 38.67 million per mL, 57.05% ± 16.96%. and 71.92% ± 15.32%, respectively. Although the spermatology varied between individuals in the study, Box‐Whisker‐plot analysis suggested that the distribution was normal (P < .05). The ejaculated sperm were cryopreserved after diluting in test‐yolk buffer. The post‐thaw motility was 32.14% and did not differ at 30 or 60 days after cryopreservation. CASA indicated that the progressive velocity (VSL) of cryopreserved spermatozoa was decreased and, as a consequence, they moved more slowly than the neat (VSL 76.3 μm/sec in neat vs 53.8 μm/sec in cryopreserved spermatozoa) and the trajectories were less planar. However, both cryopreserved and neat spermatozoa penetrated the zona‐free hamster oocyte with equal efficiency (79% neat vs 80% cryopreserved). The study also reports application of CASA for feline spermatozoa and provides information for the first time on the spermatology of the Indian leopard. This baseline data could be used in captive breeding programs. The results are compared and discussed with the available information on other felines.
Nitric Oxide Induces Oxidative Stress and Mediates Cytotoxicity to Human Cavernosal Cells in Culture
Authors: RAJASEKARAN MAHADEVAN , HELLSTROM WAYNE J. G. , SIKKA SURESH C.
Published: November 2023

ABSTRACT: Nitric oxide (NO) is a product of nitric oxide synthase (NOS) activity and is recognized as the main mediator of penile erection by induction of cavernosal smooth muscle relaxation. Although excessive NO can be generated via inducible NOS activation under certain inflammatory and noninflammatory conditions, for example, in response to TGF‐β and γ‐IFN (the proinflammatory cytokines), the effect of excessive NO produced as reactive nitrogen radical (NO) in the corpora cavernosa is not known. The present study was designed to evaluate whether the effect of NO on human cavernosal cells in primary culture is via oxidative stress. Cell growth was monitored by DNA synthesis, and mitochondrial function was evaluated by adenosine triphosphate (ATP) production. Primary culture was initiated with explants from human corpora cavernosa, and the monolayer cavernosal cells (passage 2–3) were plated on 12‐well tissue culture plates. At 70%‐80% confluency, the cells were incubated with varying concentrations of sodium nitroprusside(SNP) for 16 hours. The cell growth (DNA synthesis) was monitored by measuring [3H] thymidine incorporation, ATP levels (nanomoles per 104 cells) were measured by chemiluminescence assay using a lu‐minometer, the total oxidative stress was monitored by measuring the levels of 8‐iso PGF2α (picograms per milliliter) by using an enzyme‐linked immunosorbent assay kit, and NO production was monitored by accumulation of nitrite levels (micrometer per 104 cells). Human cavernosal smooth muscle cells (HCSMC) exposed to SNP (0 to 0.8 mM) exhibited a dose‐dependent (two‐ to fivefold) decrease in DNA and ATP synthesis, accompanied by a two‐ to threefold increase in the levels of 8‐iso PGF2α and about an eightfold increase in nitrite accumulation. These findings suggest that the NO released by SNP (>0.8 mM) exhibited a significant cytotoxicity to HCSMC, mediated by increased oxidative stress to these cells.
Have Sperm Counts Deteriorated Over the Past 20 Years in Healthy, Young Japanese Men? Results From the Sapporo Area
Authors: ITOH NAOKI , KAYAMA FUJIO , TATSUKI JIRO , TSUKAMOTO TAIJI
Published: November 2023

ABSTRACT: Changes in semen quality of healthy men is a controversial issue throughout the world. It is suspected that many chemical endocrine disrupters may affect the quality of semen. Although exposure to them may be extensive in Japan, no evidence of changes in semen quality has been reported. In this study, changes in semen volume and sperm counts were analyzed over 20 years in the Sapporo area of Japan. Semen volume and sperm counts were measured in 254 and 457 normal, healthy volunteers who lived in the Sapporo area in 1975–1980 and 1998, respectively. Posters and handbills were used to recruit participants in both studies. Semen samples were collected by masturbation after 3 days or more of abstinence. There was no change in semen volume between 1975–1980 and 1998. Mean sperm counts were 70.9 ± 47.3 × 106/mL in 1975–1980 and 79.6 ± 49.3 × 106/mL in 1998. Sperm counts did not decline over about 20 years. No significant correlation between age and sperm counts was recognized in either study. The rates of subjects with oligozoospermia and azoospermia were the same in both studies. In the 1975–1980 study, 34 of 254 (13.4%) participants had a child, and in the 1998 study, 51 of 457 (11.2%) participants had a child. Mean sperm count was significantly (P < .02) lower in the earlier study (66.0 ± 44.9 × 106/mL) than in the 1998 study (98.7 ± 60.2 × 106/mL). This is the first reliable report in which changes in sperm counts in Japan were studied. We conclude that there was no evidence of deterioration in sperm counts of normal healthy men who lived in the Sapporo area of Japan over 20 years. However, selection bias in the recruitment of volunteers and the issue of variable abstinence might have affected the results of these studies. Therefore, well‐designed prospective studies should be performed in several different regions to extrapolate our results on sperm counts to healthy, young Japanese men in general.
Detection of the Mouse Acrosome Reaction by Acid Phosphatase. Comparison With Chlortetracycline and Electron Microscopy
Authors: PIETROBON ELISA O. , DOMÍNGUEZ LUIS A. , VINCENTI AMANDA E. , BURGOS MARIO H. , FORNÉS MIGUEL W.
Published: November 2023

ABSTRACT: The sperm acrosome is a uniquely regulated secretory vesicle containing several hydrolase enzymes, including acid phosphatase (AP). The exocytotic event that releases these enzymes, the acrosome reaction, is required for fertilization in mammals. Different methods have been described in the scientific literature for detection of the acrosome reaction: double and triple stains, fluorescent‐lectin stains, monoclonal antibodies against acrosomal antigens (immunodetection techniques), Coomassie blue, differential interference contrast or phase contrast, flow cytometry, and chlortetracycline (CTC). In contrast, only 1 method to detect AP released by live and reacted sperm has been described in the literature thus far. In this work we compare 2 classical methods, CTC and transmission electron microscopy (TEM), with the assay of AP released from the acrosome. AP released during the acrosome reaction was measured in the culture medium. Enzyme remaining in nonreacted sperm cells was released by Triton X‐100 treatment. This enzyme‐based methodology shows an increase of AP in the culture media after the acrosome reaction and a corresponding decrease in the detergent‐releasable enzyme. The AP assay thus permits the detection of the mouse acrosome reaction and compares well with the CTC and TEM methods. This method is performed on the whole sperm population and so avoids the observer error that is inherent in light microscopic methods.
Objectively Measured Sperm Motility and Sperm Head Morphometry in Boars (Sus scrofa): Relation to Fertility and Seminal Plasma Growth Factors
Authors: HIRAI MIYAKO , BOERSMA AUKE , HOEFLICH ANDREAS , WOLF ECKHARD , FÖLL JÜRGEN , AUMÜLLER ROLAND , BRAUN JOACHIM
Published: November 2023

ABSTRACT: This study was conducted to investigate the relationships between results of computer‐assisted semen analysis (spermatozoal motility and sperm head morphometry) and fertility of boars. In addition, concentrations of insulin‐like growth factor (IGF)‐I and IGF‐II in seminal plasma were determined. The nonreturn rate (NRR) and the number of live‐born piglets were compatible with the requirements of artificial insemination for all boars included in this study. Semen samples of 12 boars (Pietrain; 3 ejaculates each) were evaluated for spermatozoal motility and sperm head dimensions using computer‐assisted methods. Native semen samples were centrifuged, and seminal plasma was frozen at −20°C until assayed for IGF‐I and IGF‐II by specific radioimmunoassays. Spermatozoa of boars with a higher NRR (>86%) had a significantly slower average velocity of motile spermatozoa when compared with that of boars with an NRR below 86%. High‐fertility boars (NRR > 86%) had significantly smaller sperm heads than did boars with an NRR below 86%, and their sperm heads were less elongated. Substantial concentrations of IGF‐I (8.4–22.2 ng/mL) and IGF‐II (12.1–19.8 ng/mL) could be measured in porcine seminal plasma; however, there was no correlation between IGF levels and semen parameters or individual fertility.
Effects of Methyl‐Beta‐Cyclodextrin on Cryosurvival of Boar Spermatozoa
Authors: ZENG WEN‐XIAN , TERADA TAKATO
Published: November 2023

ABSTRACT: Methyl‐beta‐cyclodextrin (MBCD), which leads to the stimulation of cholesterol efflux from the cell membrane, was examined for its ability to increase the cryosurvival of spermatozoa from Göttingen miniature pigs. The intactness of the acrosome and various motion parameters of spermatozoa after freezing and thawing were used to monitor cryosurvival. Spermatozoa were exposed to MBCD or a combination of MBCD and cholesterol‐3‐sulfate over a period of 3 hours while being cooled slowly from 25°C to 5°C, and were subsequently cryopreserved by the pellet method. After freezing and thawing, the acrosomal status was monitored by fluorescein isothiocyanate‐labeled peanut agglutinin, and the motion parameters were assessed with a computer‐assisted sperm motility analysis system. In post‐thaw spermatozoa the values of the intact acrosome, motility, progressive motility, progressive velocity, straightness, and linearity of the cell path increased greatly with the concentration of MBCD (P < .05). In contrast, the lateral head displacement amplitude and the beat cross‐frequency of post‐thaw spermatozoa were not different among all treatments. On the contrary, the addition of cholesterol‐3‐sulfate to the diluent containing MBCD abolished the protective effect against freeze‐thaw injury that MBCD provides to spermatozoa. These results indicate that cryosurvival of boar spermatozoa is enhanced by exposure to MBCD before freezing. This protective effect of MBCD may be due to active depletion of sperm membrane cholesterol.
Androgen‐Dependent Transcriptional Regulation of the Prostate‐Specific Antigen Gene by Thyroid Hormone 3,5,3′‐L‐triiodothyronine
Authors: ZHU WEN , YOUNG CHARLES Y. F.
Published: November 2023

ABSTRACT: Prostate‐specific antigen (PSA) is the most useful bio‐marker for human prostate cancer and may play a role in prostate tumor biology. Androgens, via their receptors, are the major positive regulators of PSA expression. Recently, we showed that thyroid hormone 3,5,3′‐L‐triiodothyronine (T3) also increases androgen‐depen‐dent PSA expression, even though androgen receptor expression is not affected. This report demonstrates for the first time that there is a functional T3‐responsive element (TRE) in the 5′‐promoter region of the PSA gene. Mutation of this TRE reduced the T3‐enhanced androgenic activation of the PSA promoter. Our study provides direct evidence that the PSA gene is regulated by T3 at the transcriptional level.
Leydig Cell Aging: Steroidogenic Acute Regulatory Protein (StAR) and Cholesterol Side‐Chain Cleavage Enzyme
Authors: LUO LINDI , CHEN HAOLIN , ZIRKIN BARRY R.
Published: November 2023

ABSTRACT: Primary points of control in steroidogenesis are the transport of cholesterol from intracellular stores to the inner mitochondrial membrane, and the subsequent conversion of cholesterol to pregnenolone by the cholesterol side‐chain cleavage enzyme (P450scc). Testosterone production has been shown to decline in Brown Norway rat Leydig cells as the rats age. To better understand the mechanism by which aging Leydig cells lose steroidogenic function, we examined the effect of aging on steroidogenic acute regulatory protein (StAR), an important Leydig cell cholesterol transfer protein, and on P450scc. Leydig cells isolated from middle‐aged (14 months) and old (24 months) rats produced significantly less testosterone than cells from young (4 months) rats. StAR mRNA (1.7 kilobase [kb]) was significantly reduced in Leydig cells from middle‐aged and old rats, by 26% and 52%, respectively. Significant reductions also were seen in the steady‐state levels of mRNA for P450scc, of 29% and 50%, respectively. Western blots revealed significant reductions in StAR protein, by 47% and 74%, respectively, and in P450scc protein, by 38% and 54%, respectively. In response to LH stimulation in vitro, testosterone production by Leydig cells in young, middle‐aged, and old rats increased by 30‐, 40‐, and 33‐fold, respectively, although the amounts of testosterone produced by the young cells significantly exceeded that produced by the middle‐aged and old cells. StAR protein also increased in response to LH by 1.4‐, 3‐, and 11‐fold, respectively, whereas P450scc protein remained unchanged. These results are consistent with the conclusion that compromise of StAR‐mediated cholesterol transport may play a key role in age‐related reductions in Leydig cell steroidogenesis. However, because P450scc is reduced in old Leydig cells, the reaction catalyzed by this enzyme would be rate‐limiting under circumstances in which saturating amounts of cholesterol entered the mitochondria.
Expression of Crisp‐1 mRNA Splice Variants in the Rat Epididymis, and Comparative Analysis of the Rat and Mouse Crisp‐1 Gene Regulatory Regions
Authors: ROBERTS KENNETH P. , HOFFMAN LAURA B. , ENSRUD KATHY M. , HAMILTON DAVID W.
Published: November 2023

ABSTRACT: The rat Crisp‐1 gene encodes Protein DE (acidic epididymal glycoprotein; AEG), a glycoprotein secreted by the epididymal epithelium that associates with maturing sperm and has been implicated in the process of sperm‐egg fusion. Previous characterization of the Crisp‐1 messenger RNA in the rat epididymis has demonstrated the presence of 3 splice variants (Klemme et al, 1999). This study was undertaken to determine if expression of the Crisp‐1 splice variants in the rat epididymis is region‐specific and correlates with the region‐specific pattern of synthesis of the D and E forms of the Crisp‐1 protein. Expression of each of the splice variants was shown by RNase protection assays to be under the control of androgens, but they are not differentially regulated either within the epididymal segments or along the length of the organ. The reported structure of the mouse Crisp‐1 gene does not include an exon that is equivalent to the rat exon 1, suggesting that the rat splice variants cannot exist in the mouse and may be specific to the rat. Furthermore, the mouse transcription start site is situated in a different region of the gene than in the rat. In this study, a comparison of the mouse and rat genes in the region flanking the mouse exon 1 and the rat exon 2 (within the rat intron 1) shows greater than 80% sequence identity, including the conservation of several putative androgen receptor binding sites. In addition, the rat gene is shown to have a corrupted TATA box in intron 1 that corresponds to the TATA box located in the mouse gene. These observations explain the preferential transcription for the mouse gene in this region, while the predominant start site for the rat gene is 5′ of the upstream exon 1. Although an exon corresponding to the rat exon 1 has not been found in the mouse gene, reverse transcription—polymerase chain reaction experiments using mouse epididymal RNA suggest that such an exon exists in the mouse gene and is transcribed at low frequency.
Book Review
Authors: Lamb Dolores J.
Published: November 2023

Handbook of the Assisted Reproduction Laboratory, edited by Brooks A. Keel, Jeffrey V. May, and Christopher J. De Jonge
Melatonin Inhibits the Expression of Steroidogenic Acute Regulatory Protein and Steroidogenesis in MA‐10 Cells
Authors: WU CHING‐SHYI , LEU SEW‐FEN , YANG HSI‐YUAN , HUANG BU‐MIIN
Published: November 2023

ABSTRACT: The effects of melatonin on steroidogenesis and steroidogenic acute regulatory (StAR) protein expression were investigated in MA‐10 mouse Leydig tumor cells. MA‐10 cells were treated with human chorionic gonadotropin/cyclic adenosine monophosphate (hCG/cAMP) analogue alone or with hCG/cAMP analogue plus melatonin in different dosages (0.1 nM to 10 μM). Steroid production and the expression of StAR protein were measured. Melatonin directly inhibited hCG‐ or dbcAMP‐stimulated progesterone production in MA‐10 cells within 3 hours. The inhibitory effects of melatonin on hCG‐ or dbcAMP‐stimulated stroid production in MA‐10 cells were abolished by a comparative melatonin receptor antagonist, luzindole. 22R‐hydroxycholesterol reversed melatonin's inhibitory effects, which illustrated that melatonin did not suppress P450scc enzyme activity. Moreover, StAR protein expression stimulated by hCG and dbcAMP was maximally reduced by 10 nM of melatonin treatment for 3 hours. The effects of prolonged exposure (12 h) to melatonin with dbcAMP stimulation in MA‐10 cells were also examined. The expression of StAR protein and steroid production were reduced by melatonin concentrations from 1 nM to 10 μM. However, melatonin at a dose of 1 nM had no effect in 3‐hour treatment. Our results indicate that melatonin suppressed MA‐10 mouse Leydig cell steroidogenesis through specific binding sites by blocking StAR protein expression without altering the activity of P450scc enzyme.
The Effect of Cardiac Arrest on the Blood‐Testis Barrier to Albumin, Tumor Necrosis Factor‐Alpha, Pituitary Adenylate Cyclase Activating Polypeptide, Sucrose, and Verapamil in the Mouse
Authors: MIZUSHIMA HIDEKATSU , NAKAMURA YOSHINORI , MATSUMOTO HIROAKI , DOHI KENJI , MATSUMOTO KIYOSHI , SHIODA SEIJI , BANKS WILLIAM A.
Published: November 2023

ABSTRACT: Impotence commonly occurs after events such as acute myocardial infarction, coronary bypass, head trauma, and cerebral bleeding, including subarachnoid hemorrhage. We hypothesize that the hypoxia accompanying these events could damage the blood‐testis barrier (BTB) and so cause testicular dysfunction, a possible cause of impotence. We examined the effect of cardiac arrest in mice on testis weight and various aspects of BTB function. Testis weight was decreased by about 24% 12 hours after cardiac arrest but had recovered fully by day 7. The testis/serum ratio for albumin was increased 12 hours after arrest, showing a disruption in the vascular BTB with recovery by 24 hours. The testis/serum ratio for sucrose was not consistently elevated, showing that the Sertoli cell BTB remained intact. The testis/serum ratio for verapamil was increased on day 3 of cardiac arrest, suggesting impaired function of the BTB's p‐glycoprotein efflux transporter. Transporters for pituitary adenylate cyclase activating polypeptide and tumor necrosis factor‐α were not affected by cardiac arrest. These results show that cardiac arrest affects testis weight and some aspects of BTB function. Such changes might have long‐term effects on testicular function.
Regulation of Sertoli Cell Myotubularin (rMTM) Expression by Germ Cells In Vitro
Authors: LI JONATHAN C. H. , LEE WILL M. , MRUK DOLORES , CHENG C. YAN
Published: November 2023

ABSTRACT: Recent studies have shown that rat myotubularin (rMTM), the homolog of human myotubularin, which is a putative protein tyrosine phosphatase (PTP), is expressed by Sertoli cells in the rat testis. In addition, a significant increase in its steady‐state mRNA level was detected in Sertoli cells at the time of inter‐Sertoli tight junction (TJ) assembly in vitro. Since the interplay of protein kinases and phosphatases that determines the intracellular phosphoprotein content can, in turn, regulate the assembly and maintenance of TJ and anchoring junctions (AJ) in vitro, as demonstrated in different cell types, such as Madin‐Darby canine kidney (MDCK) cells, endothelial cells, and Sertoli cells, rMTM may be an important molecule in regulating the assembly and maintenance of inter‐Sertoli TJs during spermatogenesis. We thus sought to characterize its regulation. During testicular maturation, it was shown that the rMTM steady‐state mRNA level increased drastically with aging. The expression of rMTM increased by as much as 2–4‐fold in the rat testis at 45–60 days of age versus 20 days of age, coinciding with the onset of spermiation. This result seemingly suggests that rMTM may participate in the release of spermatids by disassembling the Sertoli‐spermatid AJs, since PTP inhibitor was shown to perturb the inter‐Sertoli TJ permeability barrier in vitro. Unexpectedly, when Sertoli cells were isolated from 20‐, 45‐, and 90‐day‐old rats and the steady‐state rMTM level was quantified, it was shown that there is a drastic reduction in rMTM expression in adult Sertoli cells. Studies that used Sertoli‐germ cell cocultures and Sertoli cells incubated with increasing germ cell—derived proteins have shown that the high level of testicular rMTM expression in the testis might be maintained by germ cells. Although work remains to be done to delineate the role of rMTM in the testis, these results illustrate that germ cells play a very active role in regulation testicular function by altering the phosphoprotein content.
Thyroid Hormone Receptors in Neonatal, Prepubertal, and Adult Rat Testis
Authors: CANALE DOMENICO , AGOSTINI MAURA , GIORGILLI GIANFRANCO , CAGLIERESI CAROLINA , SCARTABELLI GIOVANNA , NARDINI VINCENZO , JANNINI EMMANUELE A. , MARTINO ENIO , PINCHERA ALDO , MACCHIA ENRICO
Published: November 2023

ABSTRACT: Thyroid hormone (TH) is involved in the differentiation and development of rat testis, whereas its role in adult testis function is still undefined. The aim of our work has been to further analyze the presence in the testis of rats of various ages of messenger RNA (mRNA) coding the different TH receptor (TR) subtypes using a sensitive assay, such as reverse transcriptase‐polymerase chain reaction (RT‐PCR). To rule out the possibility of an “illegitimate transcription,” we have analyzed both T3‐binding capacity of adult rat testis and the presence in the same organ of TR proteins by immunohistochemistry, using specific antibodies directed against the various TR isoforms. Messenger RNA coding for TR α1 and α2 isoforms was clearly visible in gels prepared from RT‐PCR samples obtained from the testis of rats of all ages, including adults, whereas mRNA for the TRβ1‐β2 was absent. The T3 maximal binding capacity (Cmax) by nuclear extracts of testicular homogenates gradually decreased from birth to adulthood, still remaining significantly detectable in adult testis, and represented approximately 1 % of the Cmax observed in the liver. The immunostaining technique revealed an intense nuclear staining along the basement membrane of testicular tubules prepared from rats of all ages and incubated with an antipeptide antibody specific for TRα1 (α1–403). Staining with an antipeptide antibody specific for TRβ1 (β‐62) was never present. Our data show that mRNAs coding for the functional TRα1, and also for the still undefined α2, are present in the testis of rats of all ages. T3‐binding activity and immunohistochemical studies confirmed that the message is translated into proteins. The transcriptional activity clearly decreased from birth to adulthood, but it still remained significantly present. The presence of a TRα1 message indicates that the adult rat testis may be directly responsive to T3 and, therefore, suggests an action of TH on rat testis that is not only developmental, but also metabolic.
Ecto‐ATPase mRNA Is Regulated by FSH in Sertoli Cells
Authors: LU QINGXIAN , PORTER L. DAVID , CUI XIAOMING , SANBORN BARBARA M.
Published: November 2023

ABSTRACT: A putative messenger RNA (mRNA) sequence, designated C8, that was up‐regulated in Sertoli cells prepared from hypophysectomized rats treated with testosterone, was isolated from a Sertoli cell complementary DNA (cDNA) library. The coding region of C8 exhibited 99% identity with rat brain ecto‐ATPase and expressed a 60‐kilodalton protein following in vitro transcription/translation. Transfection of COS7 cells with C8 cDNA resulted in a marked increase in Ca2+‐ and Mg2+‐dependent ATPase activity in both whole cells and cell homogenates, which is consistent with localization of this enzyme in the plasma membrane. C8 ecto‐ATPase steady state mRNA levels were increased within 6 hours and for 3 days by follicle‐stimulating hormone (FSH) in Sertoli cells but not in peritubular cells. In contrast, dibutyrylcyclic adenosine monophosphate (cAMP) increased ecto‐ATPase in both Sertoli and peritubular cells. Testosterone had no significant effect under these conditions. These data indicate that ecto‐ATPase mRNA is positively regulated by FSH in Sertoli cells and by cAMP in both Sertoli and peritubular cells. This enzyme may play a role in the control of extracellular signaling by ATP, adenosine, or both in the cells of the seminiferous epithelium.
Dialysis Addition of Trehalose/Glycerol Cryoprotectant Allows Recovery of Cryopreserved Mouse Spermatozoa With Satisfactory Fertilizing Ability as Assessed by Yield of Live Young
Authors: THOMPSON KATHLEEN A. , RICHA JEAN , LIEBHABER STEPHEN A. , STOREY BAYARD T.
Published: November 2023

ABSTRACT: Mouse sperm cryopreservation provides a means for storing the genetic information in genetically modified mice (mutants, transgenics, and “knockouts”) in a cost‐ and space‐effective manner. Sperm from this species are highly sensitive to cryodamage, which has impeded their cryopreservation in the past. The cryoprotectant used in this study was 6% glycerol (0.65 M) plus 7.5% trehalose (0.22 M), which was added to a concentrated suspension of sperm from B6SJLF1/J mice in bicarbonate‐free buffer by dialysis to minimize osmotic stress on the cells. Sperm suspensions were frozen in 0.25 mL straws and stored in liquid N2. Eggs were obtained from B6SJLF1/J superovulated females. For in vitro fertilization (IVF), 15–25 μL of sperm suspension post‐thaw from one straw was added directly to each of three 1.5 mL drops of fertilization medium containing 30 eggs each, for 3 replicates per experiment. The fertilized eggs were scored for blastocyst formation, after which 12 blastocysts from each drop were implanted into pseudopregnant CD‐1 females. The number of live pups were then scored at birth. Ten experiments yielded 21.7 ± 1.4 (SD) blastocysts per 30 eggs inseminated (72%) and 7.3 ± 0.4 (SD) live pups per 12 blastocysts implanted (61%). The overall yield of live pups was 44 per 100 eggs inseminated (44%). This yield should be satisfactory for maintaining a mouse strain through sperm cryostorage, with restart of the strain through IVF and embryo transfer. The method should also provide improvement in human sperm cryopreservation, as human sperm are less sensitive to cryodamage than are mouse sperm.
Great Paragraphs
Authors: Boyd Cristin A.
Published: November 2023

Keith S. Folse, April Muchmore‐Vokoun, and Elena Vestri Solomon. Boston: Houghton Mifflin, 1999
Dynamic stiffness for piecewise non‐uniform Timoshenko column by power series—part II: Follower force
Authors: Leung A. Y. T. , Zhou W. E. , Lim C. W. , Yuen R. K. K. , Lee U.
Published: November 2023

A follower force is an applied force whose direction changes according to the deformed shape during the course of deformation. The dynamic stiffness matrix of a non‐uniform Timoshenko column under follower force is formed by the power‐series method. The dynamic stiffness matrix is unsymmetrical due to the non‐conservative nature of the follower force. The frequency‐dependent mass matrix is still symmetrical and positive definite according to the extended Leung theorem. An arc length continuation method is introduced to find the influence of a concentrated follower force, distributed follower force, end mass and stiffness, slenderness, and taper ratio on the natural frequency and stability. It is found that the power‐series method can handle a very wide class of dynamic stiffness problem. Copyright © 2001 John Wiley & Sons, Ltd.
Dynamic stiffness for piecewise non‐uniform Timoshenko column by power series—part I: Conservative axial force
Authors: Leung A. Y. T. , Zhou W. E. , Lim C. W. , Yuen R. K. K. , Lee U.
Published: November 2023

The dynamic stiffness method uses the solutions of the governing equations as shape functions in a harmonic vibration analysis. One element can predict many modes exactly in the classical sense. The disadvantages lie in the transcendental nature and in the need to solve a non‐linear eigenproblem for the natural modes, which can be solved by the Wittrick–William algorithm and the Leung theorem. Another practical problem is to solve the governing equations exactly for the shape functions, non‐uniform members in particular. It is proposed to use power series for the purpose. Dynamic stiffness matrices for non‐uniform Timoshenko column are taken as examples. The shape functions can be found easily by symbolic programming. Step beam structures can be treated without difficulty. The new contributions of the paper include a general formulation, an extended Leung's theorem and its application to parametric study. Copyright © 2001 John Wiley & Sons, Ltd.
A parallel advancing front grid generation scheme
Authors: Löhner Rainald
Published: November 2023

A parallel advancing front scheme has been developed. The domain to be gridded is first subdivided spatially using a relatively coarse octree. Boxes are then identified and gridded in parallel. A scheme that resembles closely the advancing front technique on scalar machines is recovered by only considering the boxes of the active front that generate small elements. The procedure has been implemented on the SGI origin class of machines using the shared memory paradigm. Timings for a variety of cases show speedups similar to those obtained for flow codes. The procedure has been used to generate grids with tens of millions of elements. Copyright © 2001 John Wiley & Sons, Ltd.