A catalog of 13,591 papers published by the Japan Academy in three phases over a century in the Proceedings of the Imperial Academy (1913–1945), the Proceedings of the Japan Academy (1945–1977), and Proceedings of the Japan Academy, divided in Series A and B (1977–2022), is made available for public access. The catalog contains information about the authors, the title of the paper, published year, volume, issue, start page, end page, the field of sciences, and the academy member who introduced the paper in the monthly academy meeting. This article reports some analyses of the catalog and discusses the trends and background of the academies’ publications during the past century.

Magnetron production and use far exceed that of other microwave tubes due to their high operational efficiency, power efficiency, and cost-effectiveness in production. The magnetron was named by A. W. Hull; however, the device invented by Hull differs from the magnetron utilized as a microwave tube. The magnetron widely used today is based on the split-anode magnetron invented by K. Okabe. This overview introduces two papers published by Okabe in the Proceedings of the Imperial Academy and discusses the events that led to the discovery of the split-anode magnetron. In addition, the operation mechanisms of magnetrons are explained.

Rikō Majima published seven papers in this journal, and seeing these papers and their surrounding contexts allows us to glance at the birth of a galaxy of scientists.

In 1932, Mizushima and Higasi reported the dependence of the dipole moments of 1,2-dichloroethane on both temperature and solvent in the Proceedings of the Imperial Academy, Japan. This report was followed by their first proposal of the existence of conformers that exchanged by internal rotation about a C–C single bond based on experimental data. Their monumental work marked the beginning of the essential concept of conformation in modern stereochemistry. Their proposal was later confirmed by the direct observation of the anti and gauche conformers of 1,2-dichloroethane by Raman spectroscopy, and further supported by other experimental and theoretical methods. The relative stabilities of the anti and gauche conformers of 1,2-dichloroethane and other 1,2-disubstituted ethanes were discussed in terms of steric, electrostatic, and stereoelectronic effects based on analysis of calculated data. Those studies influenced the development of subsequent research in organic chemistry, such as the conformational analysis of cyclohexane derivatives and the isolation of chiral gauche conformers.

Kimura’s discovery of z-term in the polar motion (Astron. J. 22, 107 (1902) and Astron. Nachr. 158, 233 (1902)) was recognized as an epoch-making scientific achievement for modern Japan, opening its doors to the world in 1868. Although Kimura served as the chair of the International Latitude Service during 1922–1934 and made efforts to interpret the z-term, it was unsuccessful. The physical interpretation of the z-term was given decades later by Wako (PASJ, 22, 525 (1970)). This article highlights Kimura’s additional contributions that led to the interpretation by Wako.

This review seeks to highlight and celebrate Professor Tomizo Yoshida’s famous work on “Establishment and characterization of a rat ascites sarcoma, later named “Yoshida ascites sarcoma”. Considering the tremendous contribution of this ascites tumor system to the subsequent promotion of research on cancer biology and cancer chemotherapy, his paper should be regarded as a monumental one in the cancer field. The research was carried out during 1943 and the results were submitted to this Journal in October 1944, when Japan was approaching a debilitating defeat in World War II in August 1945. In 1947, when “Research on Ascites sarcoma” was first comprehensively introduced to researchers in a special lecture at the Annual Meeting of the Japanese Society of Pathology, the whole audience was deeply impressed and was encouraged to resume scientific activity in Japan.

A paper titled “On the Synthesis of Hinokitiol” appeared in this journal in 1950 and marked the beginning of a new research field of novel aromatics.

Catalase, a heme-containing antioxidant enzyme, was once considered essential for human survival. It is widely distributed in the human body and is particularly abundant in red blood cells. The term “acatalasemia” first appeared in the Proceedings of the Japan Academy in 1951, drawing global attention to families genetically deficient in catalase. This deficiency not only altered the significance of catalase but also played a pioneering role in human genetics during an era of limited genetic methodology. In this article, we examine the discovery of acatalasemia by an otolaryngologist during surgery on an 11-year-old girl. This remarkable journey led to epoch-making research spanning biochemistry, hematology, and human genetics.

I. Watanabe et al. isolated approximately 30 strains of RNA phages from various parts of Japan. To isolate RNA phages, they assessed the infection specificity of male Escherichia coli and RNase sensitivity. They found that the isolated strains of RNA phages could be serologically separated into three groups. Furthermore, most of them were serologically related, and the antiphage rabbit serum prepared by one of these phages neutralized most of the other phages. The only serologically unrelated phage was the RNA phage Qβ, which was isolated at the Institute for Virus Research, Kyoto University, in 1961.

Calcium ions (Ca²⁺) play critical roles in various biological phenomena. The free Ca²⁺ concentration in the cytoplasm of a resting cell is at the 10^-7 M level, whereas that outside the cell is 10^-3 M, creating a 10,000-fold gradient of Ca²⁺ concentrations across the cell membrane, separating the intracellular and extracellular solutions.^1),2) When a cell is activated by external stimuli, the intracellular Ca²⁺ concentration increases to levels of 10^-6–10^-5 M through Ca²⁺ entry from the extracellular solution via plasma membrane Ca²⁺ channels and/or Ca²⁺ release from intracellular stores. This transient increase in Ca²⁺ functions as an important signal mediated by Ca²⁺ sensors. Thus, Ca²⁺ signals are transmitted to intracellular loci such as distinct, localized targets of Ca²⁺ sensors. Among numerous Ca²⁺ sensors present in cells, calmodulin is a highly conserved and ubiquitous Ca²⁺ sensor.³⁾

Since the large-volume press with a double-stage multianvil system was created by the late Professor Naoto Kawai, this apparatus (Kawai-type multianvil apparatus or KMA) has been developed for higher-pressure generation, in situ X-ray and neutron observations, deformation experiments, measurements of physical properties, synthesis of high-pressure phases, etc., utilizing its large sample volume and capacity in stable and homogeneous high temperature generation compared to those of competitive diamond anvil cells. These advancements in KMA technology have been made primarily by Japanese scientists and engineers, which yielded a wealth of new experimental data on phase transitions, melting relations, and physical characteristics of minerals and rocks, leading to significant constraints on the structures, chemical compositions, and dynamics of the deep Earth. KMA technology has also been used for synthesis of novel functional materials such as nano-polycrystalline diamond and transparent nano-ceramics, opening a new research field of ultrahigh-pressure materials science.

In the late 1970s, crude interferon samples were found to exhibit anti-tumour activity. This discovery led to the interferon as a “magic drug” for cancer patients. Many groups, including those in Tokyo, Zürich, and San Francisco, attempted to identify human interferon cDNAs. Tadatsugu Taniguchi was the first to announce the cloning of human interferon-β cDNA in the December 1979 issue of Proc. Jpn. Acad. Ser. B. This was followed by the cloning of human interferon-α by a Zürich group and interferon-γ by a group in Genentech in San Francisco. Recombinant interferon proteins were produced on a large scale, and interferon-α was widely used to treat C-type hepatitis patients. The biological functions of interferons were quickly elucidated with the purified recombinant interferons. The molecular mechanisms underlying virus-induced interferon gene expression were also examined using cloned chromosomal genes. The background that led to interferon gene cloning and its impact on cytokine gene hunting is described herein.