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Prophylactic intestinal resection following carbon-ion radiotherapy for locally recurrent rectal cancer: a case report.
No full textTreatment of locally recurrent rectal cancer (LRRC) after surgery is often complex and challenging. A 52-year-old man received emergency surgery (Hartmann's procedure) for bowel perforation caused by a huge sigmoid colon cancer, followed by treatment for concurrent advanced lower rectal cancer with neoadjuvant chemoradiotherapy and abdominoperineal resection. A solitary lung metastasis emerged afterwards, and was surgically removed. However, the patient developed LRRC in front of the sacrum. As surgical resection for the local recurrence was considered too invasive, carbon-ion radiotherapy (CIRT) was performed as radical local therapy. Because the surrounding intestine was highly adherent to the tumor and there was a high risk of developing an ulcer, the intestine was prophylactically resected. The patient has remained relapse-free for 2 years and 6 months since the most recent surgery. CIRT for LRRC appears to represent a useful therapeutic option in combination with prophylactic intestinal resection.journal articl
Shielding design to mitigate neutron-induced single event upsets in space
No full textWe evaluated charged particle and neutron environments in space modules constructed from various structural materials using Monte Carlo simulations. Error rates due to single event upsets (SEU) in silicon devices were also assessed. Charged particle environments in modules constructed from organic composite materials closely resemble those in conventional aluminum structures, whereas neutron environments showed notable differences. Compared to aluminum, organic composites reduced SEU rates by up to 55%. Under a human habitat assumption with an additional water structure, thermal neutrons below 100 meV contribute approximately 10% of the SEU rates through the 10B(n, α) reaction. This contribution from thermal neutrons could be effectively eliminated using a 100-μm-thick thermal neutron absorption coating enriched with Gd2O3. These results suggest that organic composite materials, in combination with thermal neutron absorption paint, offer potential advantages for radiation safety in space by protecting both humans and electronic devices.journal articl
JT-60SAの運転状況と研究計画
No full text日本が推進する核融合エネルギーの早期実現をめざして，ITER 計画，ならびに原型炉をめざすさまざまな研究開発が進む中1)，2023年からプラズマ実験を開始したJT-60SA 装置2)(図1)の役割は，国内のみならず，世界的にみても重要になっている。JT-60SA 装置の研究計画の策定では，各研究フェーズでのプラズマ性能の達成目標や研究項目を設定すると共に，必要な装置増強を計画し，進捗ごとにITERや原型炉に成果を反映するようにしている。本稿では，現在までの運転状況，次のプラズマ実験フェーズに向けた装置の増強計画，ならびに研究計画の概要を報告する。journal articl
Oral Lentinula edodes mycelia extract enhances the antitumor effect of radiotherapy via gut-associated activation of dendritic and cytotoxic T cells.
No full textOral administration of Lentinula edodes mycelia extract (L.E.M.) has been shown to stimulate systemic T cell-mediated antitumor immunity and inhibit tumor growth in mice, suggesting its potential to modulate host immune responses. However, the route of this systemic antitumor effect remains unclear. This study focused on gut-associated immune mechanisms by analyzing mesenteric lymph nodes (MLNs), a major component of the gut-associated lymphoid tissue (GALT), and examined whether oral L.E.M. enhances the antitumor efficacy of radiation therapy (RT) in a B16F10-OVA melanoma model. L.E.M. administration upregulated MHC class II and CD86 expression on CD11c dendritic cells (DCs) in MLNs and significantly increased the proportion of CD103 subsets, indicating DC maturation within the GALT. In a B16F10-OVA melanoma model treated with X-ray irradiation, L.E.M. further enhanced DC maturation and increased CD8α DCs in the spleen, accompanied by elevated effector and central memory fractions of CD8 T cells in peripheral blood. Antigen-specific CD8 T cells (OVA tetramer) were significantly enriched within tumors, and L.E.M. combined with RT achieved greater tumor growth inhibition than RT alone. These findings demonstrate that oral L.E.M. activates GALT-mediated DC and CD8 T-cell responses, thereby augmenting the antitumor immune effects of RT.journal articl
Facial Emotional Expression in Reaction to Internet Gaming Videos Among Young Adults: A Preliminary and Exploratory Study
No full textThe surge in online gaming's popularity has raised concerns regarding excessive engagement particularly among younger generations. Internet gaming disorder (IGD) is increasingly recognized as a clinical concern, underscoring the necessity for early detection and intervention. Although facial expressions provide key emotional insights, their link to symptoms associated with internet gaming addiction remains largely unexplored. In this preliminary study, we investigated facial emotional expressions in response to internet gaming videos among 28 young adults who casually play online games, utilizing the automated facial expression recognition system for analysis. Participants watched internet gaming and neutral (nongaming) videos while their facial expressions were recorded. We measured the intensity of each facial expression (happy, sad, angry, surprised, scared, disgusted, and neutral) and explored their correlation with symptoms related to internet gaming addiction. Participants exhibited a higher intensity of neutral expression and a lower intensity of sad expression in internet gaming videos compared to neutral ones; however, the findings were only nominally significant and did not survive correction for multiple comparisons. Moreover, participants with higher symptoms of internet gaming addiction displayed reduced facial intensity of sadness in response to internet gaming videos. Additionally, we noted a positive correlation between the facial intensity of surprise and levels of gaming desire. Furthermore, the intensity of disgusted facial expressions showed a negative correlation with participants' familiarity levels with the online games. These preliminary and exploratory findings hold promise for deepening our understanding of individualsjournal articl
Identification of the causal gene for the high seed protein content mutant hp1 and its application in soybean breeding
No full textSoybean seeds accumulate approximately 40% protein and are widely used as a raw material in the food and feed industries. Historically, soybean breeding has been constrained by a negative correlation between seed protein concentration and yield. This trade-off has been attributed to limitations in assimilate supply during seed filling, whereby an increase in seed number per unit area dilutes the carbon and nitrogen available per seed, resulting in reduced seed protein concentration. To elucidate the underlying mechanisms, a high seed protein content mutant, hp1, identified from an EMS-induced mutant library, was subjected to next-generation sequencing (NGS)–based bulk DNA analysis. This analysis led to the identification of the causal gene, GmSWEET10b, which encodes a sugar transporter that facilitates sugar allocation to the embryo. The hp1 mutant harbors a mutation at the splice site between the third intron and the fourth exon of GmSWEET10b, resulting in retention of the third intron and a consequent frameshift mutation. Using amplicon sequencing methods, two additional nonsense mutants and one splice-site mutant were identified from the soybean mutant library, all of which exhibited elevated seed protein content. While the seed protein content of the wild-type cultivar ‘Enrei’ was 46%, that of hp1 reached 52%, and the other mutants also showed significantly higher seed protein content than ‘Enrei’, accompanied by a reduction in seed size. Introgression of the hp1 mutation into the ultra–high–protein soybean cultivar ‘Tomutan’ further increased seed protein content despite a reduction in seed size, demonstrating that the hp1 mutation can be utilized to enhance protein accumulation in soybean seeds.Advancing Soybean Breeding: Genetics, Genomics, Biotechnology and Agronomyconference poste
核融合エネルギー講座
No full text核融合エネルギーは軽い原子核同士が融合して別の原子核に変わる際に放出されるエネルギーであり、カーボンニュートラル方針への適合や豊富にある燃料、固有の安全性などからエネルギー問題と地球環境問題を同時に解決する次世代のエネルギーとして期待されています。ここでは、核融合に関する最新の研究成果とともに、核融合エネルギーを新たな産業と捉え、実用化に向け加速化が図られている状況をご紹介します。朝日カルチャーセンターconference presentatio
Electron recollisional excitation of OCS+ in phase-locked ω + 2ω intense laser fields
No full textPhotoelectron-photoion coincidence momentum imaging has been performed to investigate excitation processes on dissociative ionization of OCS, OCS → OCS+ + e− → OC + S+ + e−, in phase-locked ω + 2ω intense laser fields. The electron kinetic energy spectra depend on coincidentally produced ion species, OCS+ or S+. The observed electron momentum distribution shows a clear asymmetry along the laser polarization direction with a 2π-oscillation period as a function of the phase difference in ω + 2ω laser fields. The asymmetry of the electron emission in the OCS+ channel flips at the electron kinetic energy of 8.2 eV where the dominant scattering direction switches from forward to backward. In the S+ channel, the asymmetry flip occurs at the lower kinetic energy of 4.2 eV, and this shift corresponds to an inelastic scattering process. In comparison with a classical trajectory Monte-Carlo simulation, it has been clarified that the shift of the electron kinetic energy at which the asymmetry flip occurs corresponds to the excitation energy of the parent ion and indicates contributions of electron recollisional excitation to form the fragment ion in intense laser fields.journal articl
Mutational profiles of spontaneous and radiation-related mammary carcinomas in a rat model of Brca1 haploinsufficiency
No full textFemale carriers of a heterozygous germline mutation in BRCA1/2 have a high risk of breast cancer. Although recent research has suggested that genomic instability via BRCA1/2 haploinsufficiency contributes to the early phase of BRCA-associated carcinogenesis, insights into the role of BRCA haploinsufficiency in carcinogenesis are lacking. We previously reported that the Brca1L63X/+ rat, a model of Brca1 haploinsufficiency carcinogenesis, exhibits a significantly higher incidence of mammary carcinomas than wild-type rats exposed to ionizing radiation; notably, the carcinomas retained a wild-type Brca1 allele. To explore the mutation spectrum underlying Brca1 haploinsufficiency, we performed whole-exome sequencing of spontaneous and radiation-associated mammary carcinomas in wild-type and Brca1L63X/+ rats. Mammary tumors from wild-type and Brca1L63X/+ rats did not differ significantly regarding the number of somatic single-nucleotide variants (SNVs), small insertions/deletions (InDels), or frequency of copy-number variants (CNVs). The radiation-associated carcinomas of Brca1L63X/+ rats had significantly fewer identifiable cancer-driver mutations induced by SNVs and InDels than those of wild-type rats; moreover, irradiated Brca1L63X/+ rats tended to have more carcinomas with no detectable cancer-driver mutations via SNVs, InDels or CNVs. Thus, Brca1 haploinsufficiency contributes to breast carcinogenesis by bypassing the generation of cancer-driver mutations that would otherwise occur via accumulation of nonsynonymous mutations and CNVs.journal articl
Estimating in-air micro-PIXE beam conditions from element concentrations in plant obtained by inductively coupled plasma mass spectrometry
No full textKnowledge of elemental localization in plants is essential for understanding nutrients and toxic element transport. In-air micro–particle induced X-ray emission (micro-PIXE) enables multi-elemental mapping of living tissues by detecting characteristic X-rays from trace elements. Unlike electron beam–based methods, micro-PIXE is conducted in air and allows non-destructive analysis of living cells. However, optimizing beam exposure time in advance remains difficult and often increases analysis time. In this study, we estimated optimal observation conditions for in-air micro-PIXE using element concentrations measured by inductively coupled plasma mass spectrometry (ICP-MS). Lotus japonicus stems were cultured in solutions containing 0.01–100 mM Cs, Na, Fe, or Zn, and elemental distributions were analyzed by both methods. Fe, Zn, and Cs showed clear concentration-dependent distributions and were successfully mapped by micro-PIXE, whereas Na could not be mapped due to X-ray absorption by the beryllium window. X-ray detection counts showed strong correlations with ICP-MS values, enabling estimation of appropriate irradiation conditions. These results provide practical guidelines for predicting exposure time or element accumulation required for successful mapping, improving the efficiency and accessibility of micro-PIXE for plant element studies.conference pape