Biomedical subjects

Tujin Shi

Publications and source records attributed to Tujin Shi.

5 recordsLinked to original sources

PubMed2026

Proteogenomic analysis of pediatric and AYA high-grade glioma reveals age-dependent biology, female-male differences, and kinase targets.

High-grade gliomas (HGGs) in children and adolescents and young adults (AYA) exhibit distinct biology across the neurodevelopmental spectrum. To dissect tumor-intrinsic molecular characteristics independent of developmental variation, we perform comprehensive proteogenomic analyses of tumors from 112 HGG patients aged 0-40 years. Our multi-omics analysis identifies two AYA subgroups-adolescents (aged 15-26 years) and young adults (aged 26-40 years)-with distinct molecular profiles and survival outcomes. Tumor-normal comparisons and survival modeling highlight roles of oxidative phosphorylation and neuronal system biology in glioma progression. Causal network analysis and cell line studies provide a rationale for personalized therapies targeting candidate kinases, such as CDK8. Survival modeling, clustering, and immune-landscape analyses identify proteins, post-translational modifications, and immune signatures linked to outcomes and reveal clinically relevant differences between male and female patients.

adolescent and young adult glioma↗

PubMed2007

Coordination of triply charged lanthanum in the gas phase: theory and experiment.

Ion-molecule reactions between complexes [La(CH3CN)n]3+ (n=6-9) or [La(NC(CH2)4CN)n]3+ (n=3-4) and water were studied at low collision energies in the second quadrupole of a tandem mass spectrometer. The products [La(CH3CN)p(H2O)8-p]3+ (p=6-8) and [La(NC(CH2)4CN)q(H2O)8-2q]3+ (q=3-4) had the highest relative abundances. This strongly suggests that the preferred coordination number of La3+ is eight. Similarly, the coordination number of Ca2+ was re-examined both experimentally and theoretically, and was found to be six, in good agreement with previous observations. Density functional calculations provide strong evidence that the primary solvation shell of [La(L)n]3+ consists of eight ligands; additional ligands reside in a second solvation shell and are hydrogen bonded to one or two water molecules in the first shell.

Journal Article↗

PubMed2005

Formation of abundant [Pb(H2O)]2+ by ligand-exchange reaction between [Pb(N2)n]2+ (n = 1-3) and H2O.

Doubly charged lead monohydrate, [Pb(H2O)]2+, was predicted to be unstable in the gas phase, but it has recently been observed to form in low yield via ligand change between [Pb(CH3CN)]2+ and H2O [Shi, T.; Orlova, G.; Guo, J.; Bohme, D. K.; Hopkinson, A. C.; Siu, K. W. M. J. Am. Chem. Soc. 2004, 126, 7975-7980]. Here we report that abundant [Pb(H2O)]2+ is formed in the gas phase by ligand-exchange reaction between [Pb(N2)n]2+ (n = 1-3) and water after collisional activation. Density functional theory has been used to examine the ligand-exchange reaction profile. A comparison of the potential-energy surfaces between [Pb(N2)]2+ and [Pb(CH3CN)]2+ reacting with H2O provides strong evidence that the ligand-exchange reaction of [Pb(N2)]2+ with H2O to form [Pb(H2O)]2+ is more efficient than that of [Pb(CH3CN)]2+ with H2O.

Journal Article↗

PubMed2004

Existence of doubly charged lead monohydrate: experimental evidence and theoretical examination.

Despite reports to the contrary, doubly charged lead monohydrate is a stable species against both proton and charge transfers. [Pb(H(2)O)](2+) has been observed as a minor product in the ligand-exchange reaction of [Pb(CH(3)CN)](2+) with H(2)O after collisional activation. Density functional theory has been used to examine reaction profiles of [Pb(H(2)O)(n)](2+) where n = 1, 2, and 3.

Journal Article↗

PubMed2004

Hydrogen bonds in 1,4-dioxane/ammonia binary clusters.

With synchrotron radiation, we have studied the photoionization and dissociation of 1,4-dioxane/ammonia clusters in a supersonic expansion. The observed major product ions are the 1,4-dioxane cation M(+) and protonated cluster ions M(NH(3))(n)H(+) (where M=1,4-dioxane), and the intensities of the unprotonated cluster ions M(NH(3))(n) (+) are much lower. Fully optimized geometries and energies of the neutral cluster M(NH(3))(2) and related cluster ions have been obtained using the ab initio molecular orbital method and density functional theory. The potential energy surface of the excited state of M(NH(3))(2) (+) was also calculated. With these results, the mechanisms of different photoionization-dissociation channels have been suggested. The most probable channel is electron ejection from the highest occupied molecular orbital, followed by the dissociation into M(+) and (NH(3))(2). For another main channel, after removing an electron from the second highest occupied molecular orbital, the intracluster proton transfer process takes place to form the stable unprotonated cluster ion M(NH(3))H(+)-NH(2), which usually leads to the dissociated protonated cluster ion M(NH(3))H(+) and a radical NH(2).

Journal Article↗