Rice is the world's largest food crop, and its yield and quality are directly related to food security and human health. Grain size, as one of the important factors determining the rice yield, has been widely concerned by breeders and researchers for a long time. To decipher the regulatory mechanism of rice grain size, we obtained a multi-tiller, dwarf, and small-grain mutant htd1 by ethyl methanesulfonate (EMS) mutation from the Japonica rice cultivar 'Zhonghua 11' ('ZH11'). Genetic analysis indicated that the phenotype of htd1 was controlled by a single recessive gene. Using the mutation site map (Mutmap) method, we identified the candidate gene OsHTD1, which encoded a carotenoid cleavage dioxygenase involved in the biosynthesis of strigolactone (SL). The SL content in htd1 was significantly lower than that in 'ZH11'. Cytological analysis showed that the grain size of the mutant decreased due to the reductions in the length and width of glume cells. The function of htd1 was further verified by the CRISPR/cas9 gene editing technology. The plants with the gene knockout exhibited similar grain size to the mutant. In addition, gene expression analysis showed that the expression levels of multiple grain size-related genes in the mutant changed significantly, suggesting that HTD1 may interact with other genes regulating grain size. This study provides a new theoretical basis for research on the regulatory mechanism of rice grain size and potential genetic resources for breeding the rice cultivars with high yields.
Oryza/growth & development* ; Mutation ; Edible Grain/growth & development* ; Alleles ; Plant Proteins/genetics* ; Dioxygenases/genetics* ; Lactones/metabolism* ; Gene Expression Regulation, Plant ; Genes, Plant ; Gene Editing ; CRISPR-Cas Systems ; Phenotype

Rice (Oryza sativa L.), as a thermophilic crop, is highly susceptible to cold stress during its growth process. Chilling injury at the plumule stage and seedling stage often affects the morphological development and leads to yield reduction of rice. The exploration and utilization of cold tolerance genes are among the most direct and effective approaches to address cold stress in rice. To identify quantitative trait loci (QTLs) associated with cold tolerance at plumule and seedling stages, in this study, we measured the seedling rates and survived seedling rates of the indica rice cultivar 'HZ', the japonica cultivar 'Nekken2', and their 120 recombinant inbred lines (RILs) under cold stress. A previously constructed high-density genetic linkage map was used for the mapping of the QTLs conferring cold tolerance at the plumule and seedling stages. A total of 4 QTLs for plumule-stage cold tolerance and 9 QTLs for seedling-stage cold tolerance were detected, with the maximum limit of detection reaching 5.20. Notably, a genetically overlapping QTL for both plumule and seedling stages was identified on chromosome 8, spanning a physical interval of 24 432 953-25 295 129 bp. Candidate genes within the detected QTL intervals were screened, and quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze the gene expression during the plumule and seedling stages. The results revealed that LOC_Os03g06570, LOC_Os03g07100, LOC_Os06g08280, LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540 exhibited significantly differential expression between the parental lines. These genes were either significantly downregulated or upregulated under cold stress. Among them, the first three gene (LOC_Os03g06570, LOC_Os03g07100, and LOC_Os06g08280) were hypothesized to be key candidates regulating the cold tolerance of rice seedlings, while the latter three genes (LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540) were identified as comprehensive regulators of cold tolerance during both plumule and seedling stages. These findings lay a foundation for the fine mapping and cloning of cold tolerance genes at the plumule and seedling stages, providing valuable insights for breeding cold-tolerant rice varieties.
Quantitative Trait Loci/genetics* ; Oryza/growth & development* ; Seedlings/growth & development* ; Cold Temperature ; Chromosome Mapping ; Gene Expression Regulation, Plant

Objective:To examine the relationship between college students'core self-evaluation and academic burnout,and to provide empirical support for intervention strategies.Methods:A two-point longitudinal study was conducted with 245 medical students over a period of 18 months(T1:May 2023,T2:November 2024)to assess participants'core self-evaluation level using the Core Self-Evaluation Scale(CSES),and the overall burnout level u-sing the Academic Study Burnout Inventory(ASBI).Cross-lagged panel model was applied to examine the bidirec-tional causal relationship.Results:The cross-lagged results showed that core self-evaluation score in T1 negatively predicted academic burnout score inT2(β=-0.21,P＜0.01),and academic burnout score in T1 also negatively predicted core self-evaluation score in T2(β=-0.20,P＜0.05).Conclusion:Core self-evaluations and academic burnout exhibit a reciprocal predictive relationship over time.

Objective:To examine the relationship between college students'core self-evaluation and academic burnout,and to provide empirical support for intervention strategies.Methods:A two-point longitudinal study was conducted with 245 medical students over a period of 18 months(T1:May 2023,T2:November 2024)to assess participants'core self-evaluation level using the Core Self-Evaluation Scale(CSES),and the overall burnout level u-sing the Academic Study Burnout Inventory(ASBI).Cross-lagged panel model was applied to examine the bidirec-tional causal relationship.Results:The cross-lagged results showed that core self-evaluation score in T1 negatively predicted academic burnout score inT2(β=-0.21,P＜0.01),and academic burnout score in T1 also negatively predicted core self-evaluation score in T2(β=-0.20,P＜0.05).Conclusion:Core self-evaluations and academic burnout exhibit a reciprocal predictive relationship over time.

Background::Homoharringtonine (HHT) is an effective anti-inflammatory, anti-viral, and anti-tumor protein synthesis inhibitor that has been applied clinically. Here, we explored the therapeutic effects of HHT in a mouse heart transplant model.Methods::Healthy C57BL/6 mice were used to observe the toxicity of HHT in the liver, kidney, and hematology. A mouse heart transplantation model was constructed, and the potential mechanism of HHT prolonging allograft survival was evaluated using Kaplan–Meier analysis, immunostaining, and bulk RNA sequencing analysis. The HHT-T cell crosstalk was modeled ex vivo to further verify the molecular mechanism of HHT-induced regulatory T cells (Tregs) differentiation. Results::HHT inhibited the activation and proliferation of T cells and promoted their apoptosis ex vivo. Treatment of 0.5 mg/kg HHT for 10 days significantly prolonged the mean graft survival time of the allografts from 7 days to 48 days ( P <0.001) without non-immune toxicity. The allografts had long-term survival after continuous HHT treatment for 28 days. HHT significantly reduced lymphocyte infiltration in the graft, and interferon-γ-secreting CD4 + and CD8 + T cells in the spleen ( P <0.01). HHT significantly increased the number of peripheral Tregs (about 20%, P <0.001) and serum interleukin (IL)-10 levels. HHT downregulated the expression of T cell receptor (TCR) signaling pathway-related genes ( CD4, H2-Eb1, TRAT1, and CD74) and upregulated the expression of IL-10 and transforming growth factor (TGF) -β pathway-related genes and Treg signature genes ( CTLA4, Foxp3, CD74, and ICOS). HHT increased CD4 + Foxp3 + cells and Foxp3 expression ex vivo, and it enhanced the inhibitory function of inducible Tregs. Conclusions::HHT promotes Treg cell differentiation and enhances Treg suppressive function by attenuating the TCR signaling pathway and upregulating the expression of Treg signature genes and IL-10 levels, thereby promoting mouse heart allograft acceptance. These findings may have therapeutic implications for organ transplant recipients, particularly those with viral infections and malignancies, which require a more suitable anti-rejection medication.

Objective To investigate the antigen presentation characteristics of dendritic cells(DC)and B cells in cardiac grafts.Methods The heart of BALB/c mice was transplanted into the abdominal cavity of C57BL/6J mice.CD45+cells in the heart graft were extracted and sorted by flow cytometry at postoperative 5 d,and single cell RNA sequencing was performed.Taking DC and B cell subsets in cardiac grafts as the main study cells,the changing trend,antigen presenting ability and intercellular communication with T cells after heart transplantation were analyzed by bioinformatics analysis and flow cytometry.Gene ontology(GO)function enrichment difference analysis was adopted to prove the specific function and the reliability annotation of cell subsets.Results Germinal center-like B cell(GC-L B)was the B cell subset with the largest increase in quantity during the acute rejection phase,accounting for 87％.Classical DC(cDC)2 was the only DC subset with a significant increase in quantity during acute rejection of heart transplantation,accounting for 44％of DC subset,and it occupied the highest communication intensity with T cells after heart transplantation.Mononucleated DC(moDC)and memory B cell(MBC)were the main transmitters of T cell input signals in non-transplanted hearts,whereas transformed into cDC2 and GC-L B during the acute rejection phase.Among them,MBC and GC-L B were the main sources of T cell input signals in non-transplanted hearts and heart grafts.Conclusions Compared with DC,B cells occupy a higher number and weight in the intercellular communication with T cells in non-transplanted hearts and heart grafts,prompting that the antigen presenting activity of B cells is more active and stronger than DC in the early stage of acute rejection of heart transplantation.

Objective:To investigate the clinical, endoscopic and pathological characteristics of synchronous multiple early gastric cancer (SMEGC), and to reduce the rate of missed diagnosis.Methods:Clinical data of 227 early gastric cancer patients treated by endoscopic submucosal dissection (ESD) and/or surgery in Songjiang Hospital, Shanghai Jiaotong University School of Medicine from January 2017 to December 2019 were retrospectively analyzed. The differences of clinical, endoscopic and pathological characteristics between solitary early gastric cancer (SEGC) group (200 cases) and SMEGC group (27 cases) were compared. The relevance of endoscopic and pathological features of major and minor lesions of SMEGC was also analyzed.Results:Among the 227 early gastric cancer patients, 27 (11.9%) were SMEGC (58 lesions), of which 25 cases were detected preoperatively, and 2 cases were reexamined within 6 months after surgery with another lesion found at a different site from the previous lesion. In the SMEGC group, the percentages of male and atrophy and intestinal metaplasia in surrounding mucosa were significantly higher than those of the SEGC group [85.2% (23/27) VS 61.5% (123/200), χ2=5.815, P=0.016; 96.3% (26/27) VS 81.0% (162/200), χ2=3.912, P=0.048]. The mean age of the SMEGC group was significantly higher than that of the SEGC group (68.7±6.7 years VS 63.8±9.8 years, t=-2.561, P=0.011). The correlation analysis showed a significant correlation between the major and minor lesions of SMEGC in the size of lesion ( r=0.640, P<0.001), vertical location ( r=0.518, P=0.006), macroscopic type ( r=0.904, P<0.001) and depth of invasion ( r=0.470, P=0.013). Conclusion:SMEGC is prevalent in elderly males with atrophic gastritis and intestinal metaplasia. It is necessary to be alert to the possibility of multiple cancer lesions, if an early cancer lesion is found under endoscopy, especially those that may have the same or similar shape and invasion depth in the same vertical distribution range.

Idiopathic hypoparathyroidism is a rare endocrine disease. It is often manifested as neuropsychiatric symptoms, especially epileptic seizures. Thus, it is easy to be misdiagnosed as primary epilepsy. The following case report details the diagnosis of a 17-year-old girl who had been misdiagnosed as primary epilepsy for a long time. She was found hypoparathyroidism during the hospitalization for the operation of ovarian mixed germ cell tumor. After whole exome sequencing, she was ultimately diagnosed as 22q11.2 deletion syndrome. This case suggested that clinicians should be aware of the possibility of hypoparathyroidism in adolescent epilepsy, especially hereditary hypoparathyroidism. At the same time, the possible high risk of tumors should also be considered in hereditary hypoparathyroidism.

Objective:To study the production of 24Na in major organs and tissues of Chinese reference human phantom following the instantaneous exposure to fission neutrons, so as to provide basic data for the estimation of neutron exposure dose. Methods:252Cf fission neutron source was used to irradiate Chinese reference human phantom to measure the interval count of 24Na in equivalent liquid of different organs and tissues. The 24Na activity and neutron fluence were analyzed and calculated by multiple mathematical methods, and the results were obtained after normalization. Results:The specific activities of 24Na in heart, liver, lungs, brain, and the upper, the middle, and the lower section tissues of human body were obtained under the instantaneous irradiation of 252Cf fission neutron source, and the results were within the range of (0.739~3.191)×10 -7(Bq·cm 2)·g Na-1. Conclusion:According to the 24Na specific activity of human blood under neutron irradiation reported in the literature, the method established in this study is feasible and the results are reliable.

Objective:To study the production of 24Na in major organs and tissues of Chinese reference human phantom following the instantaneous exposure to fission neutrons, so as to provide basic data for the estimation of neutron exposure dose. Methods:252Cf fission neutron source was used to irradiate Chinese reference human phantom to measure the interval count of 24Na in equivalent liquid of different organs and tissues. The 24Na activity and neutron fluence were analyzed and calculated by multiple mathematical methods, and the results were obtained after normalization. Results:The specific activities of 24Na in heart, liver, lungs, brain, and the upper, the middle, and the lower section tissues of human body were obtained under the instantaneous irradiation of 252Cf fission neutron source, and the results were within the range of (0.739~3.191)×10 -7(Bq·cm 2)·g Na-1. Conclusion:According to the 24Na specific activity of human blood under neutron irradiation reported in the literature, the method established in this study is feasible and the results are reliable.