Recent studies have indicated that the expression of ubiquitin-specific protease 51 (USP51), a novel deubiquitinating enzyme (DUB) that mediates protein degradation as part of the ubiquitin‒proteasome system (UPS), is associated with tumor progression and therapeutic resistance in multiple malignancies. However, the underlying mechanisms and signaling networks involved in USP51-mediated regulation of malignant phenotypes remain largely unknown. The present study provides evidence of USP51's functions as the prominent DUB in chemoresistant triple-negative breast cancer (TNBC) cells. At the molecular level, ectopic expression of USP51 stabilized the 78 kDa Glucose-Regulated Protein (GRP78) protein through deubiquitination, thereby increasing its expression and localization on the cell surface. Furthermore, the upregulation of cell surface GRP78 increased the activity of ATP binding cassette subfamily B member 1 (ABCB1), the main efflux pump of doxorubicin (DOX), ultimately decreasing its accumulation in TNBC cells and promoting the development of drug resistance both in vitro and in vivo. Clinically, we found significant correlations among USP51, GRP78, and ABCB1 expression in TNBC patients with chemoresistance. Elevated USP51, GRP78, and ABCB1 levels were also strongly associated with a poor patient prognosis. Importantly, we revealed an alternative intervention for specific pharmacological targeting of USP51 for TNBC cell chemosensitization. In conclusion, these findings collectively indicate that the USP51/GRP78/ABCB1 network is a key contributor to the malignant progression and chemotherapeutic resistance of TNBC cells, underscoring the pivotal role of USP51 as a novel therapeutic target for cancer management.

An ideal dermal filler should integrate filling, repair, and anti-aging effects, with immediate tissue augmentation, slow degradation, and progressive stimulation of collagen regeneration. However, commonly used hyaluronic acid (HA) hydrogels, while effective for rapid filling, suffer from limited duration of support, weak cell adhesion, and an inability to promote collagen regeneration. Silk fibroin (SF), a natural protein from silkworm cocoons, is known for its excellent cell adhesion and collagen-stimulating abilities. However, its limited gelation capability restricts its potential application as a standalone injectable hydrogel. Based on a complementary strategy, this study combines the rapid gelling properties of HA with the collagen regenerative properties of SF to create a co-crosslinked HA-SF hydrogel. The composite hydrogel merges HA's rapid filling effect with SF's strong tissue adhesion and collagen-stimulating abilities. The formulation, physicochemical properties, degradation, biocompatibility, and filling effects of the HA-SF hydrogel were systematically investigated. HA-SF hydrogel exhibits excellent mechanical properties and ensures long-term support while maintaining injectability. Interestingly, after intradermal injection in the UVB-induced photoaging model, HA-SF hydrogel not only enhances hydrogel-cell interaction but also continues to stimulate collagen regeneration, especially type III collagen. This dual action achieves the biological effects of repair and anti-aging while maintaining the filling effect. Proteomic analysis confirms that repair and anti-aging effects are enhanced by the regulation of skin fibroblasts and modulation of amino acid and lipid metabolism. This composite hydrogel holds strong promise for clinical applications, offering a safer, long-lasting, and more natural injectable filler that combines filling, repair, and anti-aging into one system.

Numerous c-mesenchymal-epithelial transition (c-MET) inhibitors have been reported as potential anticancer agents. However, most fail to enter clinical trials owing to poor efficacy or drug resistance. To date, the scaffold-based chemical space of small-molecule c-MET inhibitors has not been analyzed. In this study, we constructed the largest c-MET dataset, which included 2,278 molecules with different structures, by inhibiting the half maximal inhibitory concentration (IC₅₀) of kinase activity. No significant differences in drug-like properties were observed between active molecules (1,228) and inactive molecules (1,050), including chemical space coverage, physicochemical properties, and absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles. The higher chemical diversity of the active molecules was downscaled using t-distributed stochastic neighbor embedding (t-SNE) high-dimensional data. Further clustering and chemical space networks (CSNs) analyses revealed commonly used scaffolds for c-MET inhibitors, such as M5, M7, and M8. Activity cliffs and structural alerts were used to reveal "dead ends" and "safe bets" for c-MET, as well as dominant structural fragments consisting of pyridazinones, triazoles, and pyrazines. Finally, the decision tree model precisely indicated the key structural features required to constitute active c-MET inhibitor molecules, including at least three aromatic heterocycles, five aromatic nitrogen atoms, and eight nitrogen-oxygen atoms. Overall, our analyses revealed potential structure-activity relationship (SAR) patterns for c-MET inhibitors, which can inform the screening of new compounds and guide future optimization efforts.

Numerous c-mesenchymal-epithelial transition(c-MET)inhibitors have been reported as potential anticancer agents.However,most fail to enter clinical trials owing to poor efficacy or drug resistance.To date,the scaffold-based chemical space of small-molecule c-MET inhibitors has not been analyzed.In this study,we constructed the largest c-MET dataset,which included 2,278 molecules with different struc-tures,by inhibiting the half maximal inhibitory concentration(IC50)of kinase activity.No significant differences in drug-like properties were observed between active molecules(1,228)and inactive mol-ecules(1,050),including chemical space coverage,physicochemical properties,and absorption,distri-bution,metabolism,excretion,and toxicity(ADMET)profiles.The higher chemical diversity of the active molecules was downscaled using t-distributed stochastic neighbor embedding(t-SNE)high-dimensional data.Further clustering and chemical space networks(CSNs)analyses revealed commonly used scaffolds for c-MET inhibitors,such as M5,M7,and M8.Activity cliffs and structural alerts were used to reveal"dead ends"and"safe bets"for c-MET,as well as dominant structural fragments consisting of pyr-idazinones,triazoles,and pyrazines.Finally,the decision tree model precisely indicated the key structural features required to constitute active c-MET inhibitor molecules,including at least three aromatic het-erocycles,five aromatic nitrogen atoms,and eight nitrogen-oxygen atoms.Overall,our analyses revealed potential structure-activity relationship(SAR)patterns for c-MET inhibitors,which can inform the screening of new compounds and guide future optimization efforts.

Objective·To explore the mechanism at the atomic level by which the KRASG12D/R68G mutation induces tumor cell resistance to MRTX1133.Methods·The crystal structure data of the KRASG12D-MRTX1133 complex were obtained from the RCSB Protein Data Bank(PDB).PyMOL software was used to mutate arginine at position 68 of KRAS to glycine(R68G),constructing the initial conformations of the KRASG12D-MRTX1133 and KRASG12D/R68G-MRTX1133 complexes.The LEaP module was used to build simulation systems under periodic boundary conditions.The ff19SB force field was applied to standard amino acids in KRAS,GAFF(general AMBER force field)to MRTX1133,and TIP3P(intermolecular potential three point)to water molecules.Energy minimization was performed using the Amber software suite.The systems were then heated to 300 K,followed by NVT(constant volume and temperature)equilibration and NPT(constant pressure and temperature)production.Root mean square deviation(RMSD),root mean square fluctuation(RMSF),principal component analysis(PCA)and solvent-accessible surface area(SASA)of MRTX1133 and GDP were analyzed using cpptraj.The number of hydrogen bonds between regions and the dynamic cross-correlation matrix(DCCM)of amino acid movements were also calculated.Results·RMSD analysis showed greater structural variation in KRAS in the KRASG12D/R68G system compared to the KRASG12D system.RMSF analysis revealed significantly higher fluctuations in the Switch Ⅰ and Switch Ⅱ regions of the KRASG12D/R68G system.PCA indicated that Switch Ⅰ and Switch Ⅱ in the KRASG12D/R68G system were more frequently in an open conformation.The distances between Switch Ⅰ and the P-loop,and between Switch Ⅱ and the P-loop,were larger in the KRASG12D/R68G system,indicating an expanded binding pocket for GDP and MRTX1133 compared to the KRASG12D system.SASA analysis indicated that both GDP and MRTX1133 had increased solvent exposure in the KRASG12D/R68G system.DCCM analysis revealed more decoupled movements among the Switch Ⅰ,Switch Ⅱ and P-loop regions in the KRASG12D/R68G system.Conclusion·The KRASG12D/R68G mutation disrupts the interactions between the Switch Ⅰ and Switch Ⅱregions,leading to their separation and the opening of the MRTX1133 binding pocket.This increases the solvent exposure of MRTX1133,accelerates its dissociation,and ultimately results in KRASG12D/R68G resistance to MRTX1133.

Objective To develop Tibetan nasalance test materials,and to determine the normal range of na-salance in Tibetan-speaking children,and to investigate the characteristics of nasalance in Tibetan schoolchildren in different Chinese and Tibetan corpora.Methods Three corpora,including three Chinese test sentences,three Ti-betan test materials,and three Tibetan rhymes,were selected to test the nasalance of 50 children(7～12 years old)in the context of Tibetan as their mother tongue in the Tibetan region during pronunciation.Results Differences in nasalance between Chinese and Tibetan nasal sentences were statistically significant(P＜0.01)and lower in Tibetan than in Chinese among Tibetan schoolchildren.The mean nasalance of Tibetan rhymes showed/i/＞/u/＞/a/.Na-sal sentences of Tibetan corpus,oral sentences,oral-nasal sentences and Tibetan rhyming/i/had statistically signif-icant differences in nasalance between genders(P＜0.05 or P＜0.01).Conclusion When assessing the nasalance of Tibetan schoolchildren with Tibetan,a special dialect of Tibetan,as their mother tongue and main language of com-munication in Tibet,the choice of corpus is one of the important factors influencing the nasalance in addition to age and gender,and the application of the Tibetan corpus provides important reference information for the phonological assessment of Tibetan children with nasal resonance disorders.

OBJECTIVE To establish a closed-loop management system for the whole-process traceability of outpatient drugs based on internet of things(IoT)and blockchain technology,and evaluate its implementation effects.METHODS A closed-loop management system for the whole-process traceability of outpatient drugs covering the entire drug lifecycle was designed using drug traceability codes integrated with IoT and blockchain technology.System effectiveness was evaluated from three dimensions:work efficiency,medication management quality and data safety by comparing indicators such as the acceptance time of incoming drugs and the number of collected drug traceability codes before the system implementation(October to December 2024)and after the system implementation(January to March 2025).RESULTS A closed-loop management system for the whole-process traceability of outpatient drugs,centered around the drug traceability code management system,was successfully established.The acceptance time for incoming drugs was shortened from(4.65±0.26)h before implementation to(0.34±0.08)h after implementation(P＜0.05).The number of collected drug traceability codes increased from 419 018 to 1 236 522,and the coverage rate of traceability codes rose from 28.36%to 89.88%(P＜0.05).The time pharmacists spent on drug expiry management per week decreased from(128.40±19.20)min to(0.56±0.13)min(P＜0.05),and the dispensing time for a single prescription(excluding a part of injections and repackaged drugs)was reduced from(143.25±17.67)s to(15.24±10.08)s(P＜0.05).The time for drug return was reduced from 129.90(122.32,137.00)s to 104.36(89.91,117.33)s(P＜0.05);the number of drug dispensing errors decreased from 2 cases to 0 cases.After the system was launched,there were no data security incidents in our outpatient pharmacy.CONCLUSIONS The constructed closed-loop management system for the whole-process traceability of outpatient drugs can significantly enhance drug traceability accuracy and drug management quality,improve pharmacist work efficiency,and reduce drug management risks,thus providing a feasible solution for the digital transformation of hospital pharmaceutical services.

Objective·To explore the mechanism at the atomic level by which the KRASG12D/R68G mutation induces tumor cell resistance to MRTX1133.Methods·The crystal structure data of the KRASG12D-MRTX1133 complex were obtained from the RCSB Protein Data Bank(PDB).PyMOL software was used to mutate arginine at position 68 of KRAS to glycine(R68G),constructing the initial conformations of the KRASG12D-MRTX1133 and KRASG12D/R68G-MRTX1133 complexes.The LEaP module was used to build simulation systems under periodic boundary conditions.The ff19SB force field was applied to standard amino acids in KRAS,GAFF(general AMBER force field)to MRTX1133,and TIP3P(intermolecular potential three point)to water molecules.Energy minimization was performed using the Amber software suite.The systems were then heated to 300 K,followed by NVT(constant volume and temperature)equilibration and NPT(constant pressure and temperature)production.Root mean square deviation(RMSD),root mean square fluctuation(RMSF),principal component analysis(PCA)and solvent-accessible surface area(SASA)of MRTX1133 and GDP were analyzed using cpptraj.The number of hydrogen bonds between regions and the dynamic cross-correlation matrix(DCCM)of amino acid movements were also calculated.Results·RMSD analysis showed greater structural variation in KRAS in the KRASG12D/R68G system compared to the KRASG12D system.RMSF analysis revealed significantly higher fluctuations in the Switch Ⅰ and Switch Ⅱ regions of the KRASG12D/R68G system.PCA indicated that Switch Ⅰ and Switch Ⅱ in the KRASG12D/R68G system were more frequently in an open conformation.The distances between Switch Ⅰ and the P-loop,and between Switch Ⅱ and the P-loop,were larger in the KRASG12D/R68G system,indicating an expanded binding pocket for GDP and MRTX1133 compared to the KRASG12D system.SASA analysis indicated that both GDP and MRTX1133 had increased solvent exposure in the KRASG12D/R68G system.DCCM analysis revealed more decoupled movements among the Switch Ⅰ,Switch Ⅱ and P-loop regions in the KRASG12D/R68G system.Conclusion·The KRASG12D/R68G mutation disrupts the interactions between the Switch Ⅰ and Switch Ⅱregions,leading to their separation and the opening of the MRTX1133 binding pocket.This increases the solvent exposure of MRTX1133,accelerates its dissociation,and ultimately results in KRASG12D/R68G resistance to MRTX1133.

Objective To develop Tibetan nasalance test materials,and to determine the normal range of na-salance in Tibetan-speaking children,and to investigate the characteristics of nasalance in Tibetan schoolchildren in different Chinese and Tibetan corpora.Methods Three corpora,including three Chinese test sentences,three Ti-betan test materials,and three Tibetan rhymes,were selected to test the nasalance of 50 children(7～12 years old)in the context of Tibetan as their mother tongue in the Tibetan region during pronunciation.Results Differences in nasalance between Chinese and Tibetan nasal sentences were statistically significant(P＜0.01)and lower in Tibetan than in Chinese among Tibetan schoolchildren.The mean nasalance of Tibetan rhymes showed/i/＞/u/＞/a/.Na-sal sentences of Tibetan corpus,oral sentences,oral-nasal sentences and Tibetan rhyming/i/had statistically signif-icant differences in nasalance between genders(P＜0.05 or P＜0.01).Conclusion When assessing the nasalance of Tibetan schoolchildren with Tibetan,a special dialect of Tibetan,as their mother tongue and main language of com-munication in Tibet,the choice of corpus is one of the important factors influencing the nasalance in addition to age and gender,and the application of the Tibetan corpus provides important reference information for the phonological assessment of Tibetan children with nasal resonance disorders.