Objectives: . This study aimed to investigate the regulatory functions of gamma-aminobutyric acid (GABA)ergic neural circuits from the inferior colliculus (IC) to the medial geniculate body (MGB) in salicylate-induced tinnitus. Methods: . Mice were treated with salicylate to induce tinnitus, and tinnitus-like behaviors were evaluated via gap prepulse inhibition of acoustic startle. Using combined viral tracing methodologies, we identified and mapped the pathways and connections from the IC to the MGB. Furthermore, we employed Gq-coupled human M3 designer receptors exclusively activated by designer drugs (DREADDs) and Gi-coupled human M4 DREADDs to achieve targeted excitation or suppression of GABAergic neurons in the IC and MGB. Following the administration of clozapine N-oxide, which binds to these receptors, we modulated these neural circuits to assess their impact on tinnitus severity in a mouse model. Results: . Our findings demonstrated that mice exposed to salicylate exhibited tinnitus-like behaviors. GABAergic neurons projecting retrogradely from the MGB to the IC were primarily concentrated in the external nucleus of the IC. After clozapine N-oxide administration, chemogenetic activation of IC-MGB GABAergic neurons aggravated salicylate-induced tinnitus. Additionally, activation of GABAergic neurons between the IC and MGB induced the perception of tinnitus even without salicylate. However, chemogenetic inhibition of the IC-MGB GABAergic circuit did not reverse salicylate-induced tinnitus. Conclusion . These findings suggest that activation of the IC-MGB GABAergic neural circuit may contribute to tinnitus generation through a mechanism distinct from that of salicylate-induced tinnitus. This study provides novel insights into the mechanisms underlying tinnitus.

The functional realization of proteins and other biological macromolecules depends on conformational dynamics and allosteric regulation, and elucidating their molecular mechanisms is an important foundation for understanding life processes. Molecular dynamics simulations are a powerful tool for investigating conformational evolution at the atomic level. However, traditional methods are limited by simulation timescales and high free-energy barriers, making it difficult to effectively capture rare conformations and their transition pathways. As a result, the development of enhanced sampling techniques has become key to overcoming this bottleneck. As a classical enhanced sampling technique, metadynamics suffers from several shortcomings, including strong dependence on collective variables and significant errors caused by bias potential accumulation. This article reviews three major improvement strategies. The first combines stochastic resetting with metadynamics, using trajectory-resetting mechanisms to improve sampling efficiency while avoiding the difficulty of optimizing collective variables. The second, SinkMeta, employs a “sinking” bias effect to enable efficient exploration of specific regions and paths. The third, OPES-based hybrid methods, improve the stability of free-energy estimation by optimizing the target distribution or the way the bias is constructed. These methods provide new ideas for characterizing free-energy landscapes and studying conformational transitions in complex biological systems, while also promoting the continued development of enhanced sampling methodologies.

Background: s/Aims: Sarcomatoid hepatocellular carcinoma (HCC) is a rare histological subtype of HCC characterized by extremely poor prognosis; however, its molecular characterization has not been elucidated. Methods: In this study, we conducted an integrated multiomics study of whole-exome sequencing, RNA-seq, spatial transcriptome, and immunohistochemical analyses of 28 paired sarcomatoid tumor components and conventional HCC components from 10 patients with sarcomatoid HCC, in order to identify frequently altered genes, infer the tumor subclonal architectures, track the genomic evolution, and delineate the transcriptional characteristics of sarcomatoid HCCs. Results: Our results showed that the sarcomatoid HCCs had poor prognosis. The sarcomatoid tumor components and the conventional HCC components were derived from common ancestors, mostly accessing similar mutational processes. Clonal phylogenies demonstrated branched tumor evolution during sarcomatoid HCC development and progression. TP53 mutation commonly occurred at tumor initiation, whereas ARID2 mutation often occurred later. Transcriptome analyses revealed the epithelial–mesenchymal transition (EMT) and hypoxic phenotype in sarcomatoid tumor components, which were confirmed by immunohistochemical staining. Moreover, we identified ARID2 mutations in 70% (7/10) of patients with sarcomatoid HCC but only 1–5% of patients with non-sarcomatoid HCC. Biofunctional investigations revealed that inactivating mutation of ARID2 contributes to HCC growth and metastasis and induces EMT in a hypoxic microenvironment. Conclusions We offer a comprehensive description of the molecular basis for sarcomatoid HCC, and identify genomic alteration (ARID2 mutation) together with the tumor microenvironment (hypoxic microenvironment), that may contribute to the formation of the sarcomatoid tumor component through EMT, leading to sarcomatoid HCC development and progression.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Background: s/Aims: Sarcomatoid hepatocellular carcinoma (HCC) is a rare histological subtype of HCC characterized by extremely poor prognosis; however, its molecular characterization has not been elucidated. Methods: In this study, we conducted an integrated multiomics study of whole-exome sequencing, RNA-seq, spatial transcriptome, and immunohistochemical analyses of 28 paired sarcomatoid tumor components and conventional HCC components from 10 patients with sarcomatoid HCC, in order to identify frequently altered genes, infer the tumor subclonal architectures, track the genomic evolution, and delineate the transcriptional characteristics of sarcomatoid HCCs. Results: Our results showed that the sarcomatoid HCCs had poor prognosis. The sarcomatoid tumor components and the conventional HCC components were derived from common ancestors, mostly accessing similar mutational processes. Clonal phylogenies demonstrated branched tumor evolution during sarcomatoid HCC development and progression. TP53 mutation commonly occurred at tumor initiation, whereas ARID2 mutation often occurred later. Transcriptome analyses revealed the epithelial–mesenchymal transition (EMT) and hypoxic phenotype in sarcomatoid tumor components, which were confirmed by immunohistochemical staining. Moreover, we identified ARID2 mutations in 70% (7/10) of patients with sarcomatoid HCC but only 1–5% of patients with non-sarcomatoid HCC. Biofunctional investigations revealed that inactivating mutation of ARID2 contributes to HCC growth and metastasis and induces EMT in a hypoxic microenvironment. Conclusions We offer a comprehensive description of the molecular basis for sarcomatoid HCC, and identify genomic alteration (ARID2 mutation) together with the tumor microenvironment (hypoxic microenvironment), that may contribute to the formation of the sarcomatoid tumor component through EMT, leading to sarcomatoid HCC development and progression.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective To explore the mechanism of Cistanche phenylethanoid glycosides(CPhGs)in treating osteoporosis by regu-lating osteogenic differentiation via SIRT2-C/EBPβ-AREG axis.Methods An osteoporosis mouse model was established using ova-riectomy.Trabecular number/thickness,bone formation rate,and tissue morphology were evaluated using micro-computed tomography,calcein double labeling,and hematoxylin and eosin staining,respectively.SIRT2,C/EBPβ,AREG,proteins related to the SIRT2-C/EBPβ-AREG axis,were analyzed by Western blotting and co-immunoprecipitation.The mRNA expression of osteogenic differentiation marker genes OCN,OPN,RUNX2,C/EBPβ,and AREG were detected by real-time quantitative PCR.Results CPhGs intervention significantly improved the trabecular microarchitecture and promoted bone formation in mice undergoing ovariectomy,and the mechanism involved the activation of SIRT2-mediated deacetylation of C/EBPβ,which in turn upregulated AREG expression.Cell experiments confirmed that CPhGs significantly increased the activity of alkaline phosphatase and the expression of osteogenic genes such as OCN,OPN,and RUNX2 in MC3T3-E1 cells by enhancing the interaction between SIRT2 and C/EBPβ.Notably,this effect could be reversed by SIRT2 knockdown.Conclusion CPhGs regulate the osteogenic differentiation process through the SIRT2-C/EBPβ-AREG axis,providing a new molecular target and theoretical basis for the treatment of osteoporosis with the active ingredients of traditional Chinese medicine.

The ocean plays a critical role in the global carbon cycle,and base on the"dual carbon"goals,ocean carbon sinks have received widespread attention.Shellfish aquaculture is one of the most important sources of carbon sinks in fisheries,which has an important impact on the offshore carbon cy-cle.As global temperature rises and ocean acidification intensifies,the capacity of the ocean to absorb CO2 will change.However,the effects of high temperature on the physiology and transcriptome related to carbon metabolism in Mytilus coruscus are not clear enough.This study investigated the effects of high temperatures on the total carbon content,carbon metabolism,antioxidant-related enzyme activities,and the transcriptome of Mytilus coruscus.The results showed that high temperature significantly inhibited the activities of hexokinase and pyruvate kinase,increased carbonic anhydrase activity(P＜0.05),de-creased the ATP content of digestive glands(P＜0.05),and affected glycolysis and the tricarboxylic acid cycle,leading to a significant decrease in the mussel's ability to sequester carbon.High temperature re-sulted in significant(P＜0.05)increases in the levels of reactive oxygen species and malondialdehyde,and enhanced the activities of superoxide dismutase and catalase.Observations by transmission electron microscopy showed that high temperatures damaged the subcellular structure of the digestive gland in Mytilus coruscus,resulting in the shrinkage of the nucleolus,swelling of the endoplasmic reticulum,and a significant reduction in the mitochondrial cristae.Comparative transcriptomic analysis showed that the upregulated DEGs were mainly enriched in protein processing in the endoplasmic reticulum,antigen pro-cessing and presentation,and MAPK signaling pathway.The downregulated DEGs were mainly enriched in necroptosis,DNA replication,and the NF-kappa B signaling pathway.In antioxidant-related DEGs,the upregulated DEGs include vitamin K epoxide reductase,peroxidases,heat shock protein 105 kD,heat shock protein 70 kD,and superoxide dismutase;The downregulated DEGs mainly included NADPH oxidase,glutathione reductase,cytochrome b-245,cytochrome P450,and quinone reductase.The up-regulated genes enriched in the carbon metabolism pathway included chitinase,phosphatidylinositol 4,5-bisphosphate 3-kinase,phosphoenolpyruvate carboxykinase,galactokinase,and inositol trisphosphate 3-kinase.The downregulated genes included aldose-1-epimerase,carbonic anhydrase,galactose mutaro-tase,acyl-CoA synthetase,alcohol dehydrogenase,and hexokinase.In conclusion,high temperature has an inhibitory effect on the activities of enzymes and the expression of genes related to carbon metabolism in Mytilus coruscus.The results of this study are intended to provide a scientific basis for the healthy de-velopment of mussel aquaculture and the assessment of carbon sinks.

Objective:To explore and compare the clinical application value of 8-channel head phased-array coil, an 8-channel temporomandibular joint (TMJ)-specific surface coil, and a single-channel surface coil in TMJ MRI examinations.Methods:A total of 600 temporomandibular disorders (TMD) patients (1 200 joints) who underwent TMJ MRI examination in the First People′s Hospital of Jinzhong from June 2020 to January 2025 were retrospectively screened. Based on inclusion/exclusion criteria, 120 TMD patients (240 joints) with closed-mouth oblique sagittal proton density weighted imaging (OSag PDWI), coronal T2 fat-suppression weighted imaging (OCor fs T2WI) and open-mouth oblique sagittal proton density weighted imaging (OSag PDWI) were included. Patients were divided into groups A, B, and C, with 40 cases in each group. Group A (31female, 9male, median age 24 years old), underwent 8-channel head phased-array coil imaging. Group B (29 female, 11male, median age 23.5 years old) underwent TMJ imaging with an 8-channel surface coil. Group C (29 female, 11male, median age 22.5 years old) underwent single-channel surface coil imaging. There were no significant differences in age, gender, type or disease types among groups ( P>0.05). Six healthy volunteers without TMD (4 female, 2 male, range 19 to 45 years old) underwent imaging with all three coils as self-control. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image quality were compared for five regions of interest (ROI) in both patients and volunteers. Results:Under the same sequence and the same parameters, SNR and CNR in group B were higher than those in group A, and SNR and CNR in group C were also higher than those in group A, the differences were statistically significant ( P<0.05). However, there were significant differences in SNR and CNR between group B and group C in the closed and open positions of ROI1, the open positions of ROI3 and the open positions of ROI5 ( P<0.05), and there were no significant differences in other positions ( P>0.05). Group B had the best image quality, followed by group C and group A had the worst image quality. There were significant differences in the visualization of OSag PDWI in the closed mouth position, OCor T2WI in the coronal position, and OSag PDWI in the open mouth position, such as condyle, anterior attachment, joint disc, double lamina area, joint cavity and lateral pterygoid muscle ( P<0.05). There were significant differences between group B and group C in showing the joint cavity in the closed mouth position and showing the structure of the bilaminar area in the open mouth position ( P<0.05). There was no significant difference in other regions of interest ( P>0.05). The subjective scores of condyle, anterior attachment, articular disc, bilaminar area, articular cavity, lateral pterygos muscle and other structures were medium to high in group A, high in group B, and high or high in group C by two radiologists independently. In the five rois, the 8-channel TMJ surface coil showed more details, especially in the articular disc, condyle and lateral pterygoid muscle regions, and had more advantages in both volunteers and patients. Conclusions:The 8-channel TMJ-specific surface coil provides significantly clearer visualization of critical anatomical details within the ROIs, demonstrating the highest clinical application value and is recommended as the preferred choice.