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1.
Phys Rev Lett ; 133(7): 072501, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39213556

RESUMO

Isomer spectroscopy of heavy neutron-rich nuclei beyond the N=126 closed shell has been performed for the first time at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. New millisecond isomers have been identified at low excitation energies, 985.3(19) keV in ^{213}Tl and 874(5) keV in ^{215}Tl. The measured half-lives of 1.34(5) ms in ^{213}Tl and 3.0(3) ms in ^{215}Tl suggest spins and parities 11/2^{-} with the single proton-hole configuration πh_{11/2} as leading component. They are populated via E1 transitions by the decay of higher-lying isomeric states with proposed spin and parity 17/2^{+}, interpreted as arising from a single πs_{1/2} proton hole coupled to the 8^{+} seniority isomer in the ^{A+1}Pb cores. The lowering of the 11/2^{-} states is ascribed to an increase of the πh_{11/2} proton effective single-particle energy as the second νg_{9/2} orbital is filled by neutrons, owing to a significant reduction of the proton-neutron monopole interaction between the πh_{11/2} and νg_{9/2} orbitals. The new ms isomers provide the first experimental observation of shell evolution in the almost unexplored N>126 nuclear region below doubly magic ^{208}Pb.

2.
East Asian Arch Psychiatry ; 32(3): 57-61, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36172723

RESUMO

OBJECTIVES: To evaluate the Mental Health Youth Ambassador Programme between 2016 and 2019 in terms of participants' improvement in attitudes towards individuals with depression or psychosis. METHODS: This anti-stigma programme was provided to secondary students (form 3 and above) and comprised three levels. Level 1 involved attending lectures about mental health; level 2 and level 3 involved social contact with persons-in-recovery. Students' attitudes towards those with depression and those with psychosis were assessed at baseline and after completion of each level of programme using the Chinese version of the Social Distance Scale. RESULTS: Only 25 students who were assessed at all four time points were included in analysis. The mean Social Distance Scale scores for attitudes towards depression and psychosis improved significantly across all time points. Specifically, significant improvement occurred after completion of level 2 and level 2 but not after completion of level 1. CONCLUSION: Social contact with people with mental illness (rather than attending lectures about mental health) contributed significantly to the improvement in students' attitude towards depression and psychosis. With the positive preliminary results, the Mental Health Youth Ambassador Programme should be extended to more students.


Assuntos
Transtornos Mentais , Saúde Mental , Adolescente , Atitude do Pessoal de Saúde , Hong Kong , Humanos , Transtornos Mentais/psicologia , Projetos Piloto , Estigma Social , Estudantes/psicologia , Inquéritos e Questionários
3.
Can J Microbiol ; 57(1): 33-41, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21217795

RESUMO

When lodgepole pines (Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson) that are killed by the mountain pine beetle (Dendroctonus ponderosae) and its fungal associates are not harvested, fungal decay can affect wood and fibre properties. Ophiostomatoids stain sapwood but do not affect the structural properties of wood. In contrast, white or brown decay basidiomycetes degrade wood. We isolated both staining and decay fungi from 300 lodgepole pine trees killed by mountain pine beetle at green, red, and grey stages at 10 sites across British Columbia. We retained 224 basidiomycete isolates that we classified into 34 species using morphological and physiological characteristics and rDNA large subunit sequences. The number of basidiomycete species varied from 4 to 14 species per site. We assessed the ability of these fungi to degrade both pine sapwood and heartwood using the soil jar decay test. The highest wood mass losses for both sapwood and heartwood were measured for the brown rot species Fomitopsis pinicola and the white rot Metulodontia and Ganoderma species. The sap rot species Trichaptum abietinum was more damaging for sapwood than for heartwood. A number of species caused more than 50% wood mass losses after 12 weeks at room temperature, suggesting that beetle-killed trees can rapidly lose market value due to degradation of wood structural components.


Assuntos
Basidiomycota/classificação , Basidiomycota/genética , Biodiversidade , Besouros/microbiologia , Pinus/metabolismo , Pinus/microbiologia , Animais , Basidiomycota/metabolismo , Colúmbia Britânica , DNA Ribossômico/genética , Temperatura , Fatores de Tempo , Madeira/microbiologia
4.
Oncogene ; 35(2): 218-27, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25893297

RESUMO

Reactivation of telomerase reverse transcriptase (TERT) expression is found in more than 85% of human cancers. The remaining cancers rely on the alternative lengthening of telomeres (ALT), a recombination-based mechanism for telomere-length maintenance. Prevalence of TERT reactivation over the ALT mechanism was linked to secondary TERT function unrelated to telomere length maintenance. To characterize this non-canonical function, we created a panel of ALT cells with recombinant expression of TERT and TERT variants: TERT-positive ALT cells showed higher tolerance to genotoxic insults compared with their TERT-negative counterparts. We identified telomere synthesis-defective TERT variants that bestowed similar genotoxic stress tolerance, indicating that telomere synthesis activity is dispensable for this survival phenotype. TERT expression improved the kinetics of double-strand chromosome break repair and reduced DNA damage-related nuclear division abnormalities, a phenotype associated with ALT tumors. Despite this reduction in cytological abnormalities, surviving TERT-positive ALT cells were found to have gross chromosomal instabilities. We sorted TERT-positive cells with cytogenetic changes and followed their growth. We found that the chromosome-number changes persisted, and TERT-positive ALT cells surviving genotoxic events propagated through subsequent generations with new chromosome numbers. Our data confirm that telomerase expression protects against double-strand DNA (dsDNA)-damaging events, and show that this protective function is uncoupled from its role in telomere synthesis. TERT expression promotes oncogene-transformed cell growth by reducing the inhibitory effects of cell-intrinsic (telomere attrition) and cell-extrinsic (chemical- or metabolism-induced genotoxic stress) challenges. These data provide the impetus to develop new therapeutic interventions for telomerase-positive cancers through simultaneous targeting of multiple telomerase activities.


Assuntos
Instabilidade Cromossômica , Dano ao DNA/efeitos dos fármacos , Telomerase/metabolismo , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Linhagem Celular Transformada/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Etoposídeo/farmacologia , Humanos , Irinotecano , Mitose , Mutação , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Telomerase/genética , Telômero
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