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1.
Phys Rev Lett ; 132(22): 222501, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38877923

RESUMO

The known I^{π}=8_{1}^{+}, E_{x}=2129-keV isomer in the semimagic nucleus ^{130}Cd_{82} was populated in the projectile fission of a ^{238}U beam at the Radioactive Isotope Beam Factory at RIKEN. The high counting statistics of the accumulated data allowed us to determine the excitation energy, E_{x}=2001.2(7) keV, and half-life, T_{1/2}=57(3) ns, of the I^{π}=6_{1}^{+} state based on γγ coincidence information. Furthermore, the half-life of the 8_{1}^{+} state, T_{1/2}=224(4) ns, was remeasured with high precision. The new experimental information, combined with available data for ^{134}Sn and large-scale shell model calculations, allowed us to extract proton and neutron effective charges for ^{132}Sn, a doubly magic nucleus far-off stability. A comparison to analogous information for ^{100}Sn provides first reliable information regarding the isospin dependence of the isoscalar and isovector effective charges in heavy nuclei.

2.
Osteoporos Int ; 32(2): 293-299, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32876712

RESUMO

A better understanding of the features of subsequent fractures after distal radius fracture (DRF) is important for the prevention of further osteoporotic fractures. This study found that the cumulative incidence of subsequent osteoporotic fractures in South Korea increased over time and that the mortality rates of subsequent DRFs were lower than those of first-time DRFs. INTRODUCTION: We examined the incidence of osteoporotic fractures following distal radius fractures (DRFs) and the mortality rate after subsequent DRFs using claims data from the Korea National Health Insurance (KNHI) Service. METHODS: We identified records for 41,417 patients with first-time DRFs in 2012. The occurrence of osteoporotic fractures of the spine, hip, wrist, and humerus at least 6 months after the index DRF was tracked through 2016. All fractures were identified by specific diagnosis and procedure codes. One-year mortality rates and standardized mortality ratios (SMRs) for initial and subsequent DRFs were calculated for all patients. RESULTS: The 4-year cumulative incidence of all subsequent osteoporotic fractures was 14.74% (6105/41,417; 9.47% in men, 15.9% in women). The number of associated subsequent fractures was 2850 for the spine (46.68%), 2271 for the wrist (37.2%), 708 for the hip (11.6%), and 276 for the humerus (4.52%). The cumulative mortality rate 1 year after the first-time and subsequent DRF was 1.47% and 0.71%, respectively, and the overall SMR was 1.48 (95% CI: 1.37-1.61) and 0.71 (95% CI: 0.42-1.21), respectively. CONCLUSION: The cumulative incidence of osteoporotic fractures following DRFs increased over the study period and was higher among women. The cumulative mortality rates and SMRs of subsequent DRFs were lower than those of first-time DRFs at the 1-year follow-up. Given the increasing incidence rate of DRFs, the incidence of subsequent osteoporotic fractures may also increase.


Assuntos
Fraturas por Osteoporose , Fraturas do Rádio , Feminino , Humanos , Incidência , Masculino , Programas Nacionais de Saúde , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Fraturas do Rádio/epidemiologia , República da Coreia/epidemiologia , Estudos Retrospectivos
3.
Osteoporos Int ; 31(3): 547-555, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31720711

RESUMO

Thyroid dysfunction is associated with the loss of bone density (osteoporosis). However, the connection between subclinical thyroid dysfunction and osteoporosis remains controversial. This study found no apparent association between subclinical hypothyroidism or subclinical hyperthyroidism and bone mineral density (BMD) in the lumbar spine and femur. INTRODUCTION: The present study examined the relationship between subclinical thyroid dysfunction and BMD in healthy middle-aged adults. METHODS: A total of 25,510 healthy Koreans with normal free thyroxine levels were enrolled from January 2011 to December 2016, and 91% of subjects visited only once. The average age of the 15,761 women was 45, and the average age of the 9749 men was 48. Levels of thyroid-stimulating hormone (TSH) and BMD were recorded in all subjects. BMD was measured using dual-energy X-ray absorptiometry. RESULTS: No apparent association was found between subclinical thyroid dysfunction and BMD in the lumbar spine, femur-neck, and proximal femur sites compared with a euthyroid group. Age, body mass index (BMI), and postmenopausal status affected BMD in women, and only BMI affected BMD in men. Subclinical hypothyroidism was independently associated with a lower risk of osteoporosis (odds ratio 0.657, 95% confidence interval 0.464-0.930) in 4710 postmenopausal women. CONCLUSIONS: No apparent association was found between subclinical hypothyroidism or subclinical hyperthyroidism defined on single TSH measurement and BMD at the lumbar spine and femur in a large cohort of middle-aged men and women. Subclinical hypothyroidism was independently associated with a lower risk of osteoporosis in postmenopausal women.


Assuntos
Densidade Óssea , Osteoporose , Absorciometria de Fóton , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Osteoporose/etiologia , República da Coreia/epidemiologia
4.
Inflamm Res ; 69(11): 1157, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32918568

RESUMO

After the publication of our article [1] we were made aware that in Fig. 2D the images for PMA 2.5 ng/ml and PMA 25 ng/ml are identical.

5.
Phys Rev Lett ; 122(21): 212502, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31283301

RESUMO

The ß-delayed γ-ray spectroscopy of neutron-rich ^{123,125}Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2^{-} ß-emitting isomers in ^{123,125}Ag are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2^{+} and 1/2^{-} levels is extended in Ag isotopes up to N=78, providing a clear signal for the reduction of the Z=40 subshell gap in Ag towards N=82. Shell-model calculations with the state-of-the-art V_{MU} plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in ^{123,125}Ag. The tensor force is found to play a crucial role in the evolution of the size of the Z=40 subshell gap. The observed inversion of the single-particle levels around ^{123}Ag can be well interpreted in terms of the monopole shift of the π1g_{9/2} orbitals mainly caused by the increasing occupation of ν1h_{11/2} orbitals.

6.
Phys Rev Lett ; 118(24): 242502, 2017 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-28665637

RESUMO

The level structure of the neutron-rich ^{77}Cu nucleus is investigated through ß-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of ^{77}Ni are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in ^{77}Cu are identified for the first time by correlating γ rays with the ß decay of ^{77}Ni, and a level scheme is constructed by utilizing their coincidence relationships. The good agreement between large-scale Monte Carlo shell model calculations and experimental results allows for the evaluation of the single-particle structure near ^{78}Ni and suggests a single-particle nature for both the 5/2_{1}^{-} and 3/2_{1}^{-} states in ^{77}Cu, leading to doubly magic ^{78}Ni.

7.
J Endocrinol Invest ; 40(10): 1069-1076, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28391584

RESUMO

BACKGROUND: Although sodium glucose cotransporter 2 (SGLT2) inhibitors have many beneficial effects for type 2 diabetes, including decreased cardiovascular death, recent reports that they increased glucagon through SGLT2 inhibition raised some concern. Troglitazone, Peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, was reported to increase SGLT2 in renal proximal tubule cells, but its role on pancreatic alpha cells have not been reported. We investigated the effect of troglitazone on SGLT2 expression in alpha cells and subsequent glucagon regulation in hyperglycemia. METHODS: An Alpha TC1-6 cell line was cultured in control (5 mM) or hyperglycemia (HG, 15 mM) for 72 h. We applied troglitazone with or without PPARγ antagonist (GW9662 10 µM). To investigate the involvement of PI3K/Akt pathway, we applied troglitazone with or without Wortmanin. We measured sodium glucose transporter 2 (SGLT2) and glucagon (GCG) mRNA and protein expression. PPAR gamma, PI3K and Akt protein were also measured. RESULTS: Exposure of alpha TC cells to HG for 72 h increased glucagon mRNA and protein expression. HG decreased SGLT2 mRNA and protein expression. Troglitazone significantly reversed HG-induced reduction of SGLT2 expression and increase of glucagon secretion. PPARγ antagonist (GW9662 10 µM) decreased the expression of SGLT2 and increased glucagon as HG did. Hyperglycemia increased PI3K and pAkt expression in alpha cells. Wortmanin (PI3K inhibitor, 1 µM) reversed HG-induced SGLT2 decrease and glucagon increase. Troglitazone treatment decreased PI3K and pAkt expression in HG. CONCLUSION: In conclusion, PPARγ agonist, troglitazone improved glucose transport SGLT2 dysfunction and subsequent glucagon dysregulation in alpha cell under hyperglycemia. Those effects were through the involvement of PI3K/pAkt signaling pathway. This study may add one more reason for the ideal combination of PPARγ agonist and SGLT2 inhibitor in clinical practice.


Assuntos
Cromanos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células Secretoras de Glucagon/metabolismo , Glucagon/metabolismo , Hiperglicemia/fisiopatologia , PPAR gama/agonistas , Transportador 2 de Glucose-Sódio/metabolismo , Tiazolidinedionas/farmacologia , Animais , Células Cultivadas , Células Secretoras de Glucagon/efeitos dos fármacos , Células Secretoras de Glucagon/patologia , Glucose/farmacologia , Hipoglicemiantes/farmacologia , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Troglitazona
8.
NMR Biomed ; 29(6): 690-701, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27061076

RESUMO

The ability to visualize whole-brain vasculature is important for quantitative in vivo investigation of vascular malfunctions in cerebral small vessel diseases, including cancer, stroke and neurodegeneration. Transverse relaxation-based ΔR2 and ΔR2 * MR angiography (MRA) provides improved vessel-tissue contrast in animal deep brain with the aid of intravascular contrast agents; however, it is susceptible to orientation dependence, air-tissue interface artifacts and vessel size overestimation. Dual-mode MRA acquisition with superparamagnetic iron oxide nanoparticles (SPION) provides a unique opportunity to systematically compare and synergistically combine both longitudinal (R1 ) and transverse (ΔR2 and ΔR2 *) relaxation-based MRA. Through Monte Carlo (MC) simulation and MRA experiments in normal and tumor-bearing animals with intravascular SPION, we show that ultrashort TE (UTE) MRA acquires well-defined vascularization on the brain surface, minimizing air-tissue artifacts, and combined ΔR2 and ΔR2 * MRA simultaneously improves the sensitivity to intracortical penetrating vessels and reduces vessel size overestimation. Consequently, UTE-ΔR2 -ΔR2 * combined MRA complements the shortcomings of individual angiograms and provides a strategy to synergistically merge longitudinal and transverse relaxation effects to generate more robust in vivo whole-brain micro-MRA. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Dextranos , Angiografia por Ressonância Magnética/métodos , Nanopartículas de Magnetita , Neovascularização Patológica/diagnóstico por imagem , Animais , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Circulação Cerebrovascular , Meios de Contraste , Aumento da Imagem/métodos , Neovascularização Patológica/patologia , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Dis Esophagus ; 29(4): 326-32, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-25716873

RESUMO

The study aims to report the operative outcomes of robot-assisted thoracoscopic esophagectomy (RATE) with extensive mediastinal lymphadenectomy (ML) for intrathoracic esophageal cancer. We analyzed a prospective database of 114 consecutive patients who underwent RATE with lymph node dissection along recurrent laryngeal nerve (RLN) followed by cervical esophagogastrostomy. The study included 104 men with a mean age of 63.1 ± 0.8 years. Of these, 110 (96.5%) had squamous cell carcinoma, and the location of the tumor was upper esophagus in 7 (6.1%), middle in 62 (54.4%), and lower in 45 (39.5%). Preoperative concurrent chemoradiation was performed in 15 patients (13.2%). All but one patient underwent successful RATE, and R0 resection was achieved in 111 patients (97.4%). Extended ML and total ML were performed in 24 (21.1%) and 90 (78.9%) patients, respectively. Total operation time was 419.6 ± 7.9 minutes, and robot console time was 206.6 ± 5.2 minutes. The mean number of total, mediastinal, and RLN nodes was 43.5 ± 1.4, 24.5 ± 1.0, and 9.7 ± 0.7, respectively. The most common complication was RLN palsy (30, 26.3%), followed by anastomotic leakage (17, 14.9%) and pulmonary complications (11, 9.6%). Median hospital stay was 16 days, and 90-day mortality was observed in three patients (2.5%). On multivariate analysis, preoperative concurrent chemoradiation was a risk factor for pulmonary complications (odds ratio 7.42, 95% confidence interval 1.91-28.8, P = 0.004). RATE with extensive ML could be performed safely with acceptable postoperative outcomes. Long-term survival data should be followed in the future to verify the oncological outcome of the procedure.


Assuntos
Neoplasias Esofágicas , Esofagectomia , Excisão de Linfonodo , Linfonodos , Procedimentos Cirúrgicos Robóticos , Toracoscopia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Esofagectomia/efeitos adversos , Esofagectomia/métodos , Feminino , Humanos , Excisão de Linfonodo/efeitos adversos , Excisão de Linfonodo/métodos , Linfonodos/patologia , Linfonodos/cirurgia , Metástase Linfática , Masculino , Mediastino , Pessoa de Meia-Idade , Duração da Cirurgia , Avaliação de Processos e Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , República da Coreia/epidemiologia , Fatores de Risco , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/métodos , Toracoscopia/efeitos adversos , Toracoscopia/métodos
10.
Nano Lett ; 15(1): 372-7, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25483819

RESUMO

We demonstrate efficient terahertz (THz) modulation by coupling graphene strongly with a broadband THz metasurface device. This THz metasurface, made of periodic gold slit arrays, shows near unity broadband transmission, which arises from coherent radiation of the enhanced local-field in the slits. Utilizing graphene as an active load with tunable conductivity, we can significantly modify the local-field enhancement and strongly modulate the THz wave transmission. This hybrid device also provides a new platform for future nonlinear THz spectroscopy study of graphene.

11.
Neuroimage ; 112: 382-389, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25818683

RESUMO

Intravascular superparamagnetic iron oxide nanoparticles (SPION)-enhanced MR transverse relaxation rates (∆R2(⁎) and ∆R2) are widely used to investigate in vivo vascular parameters, such as the cerebral blood volume (CBV), microvascular volume (MVV), and mean vessel size index (mVSI, ∆R2(⁎)/∆R2). Although highly efficient, regional comparison of vascular parameters acquired using gradient-echo based ∆R2(⁎) is hampered by its high sensitivity to magnetic field perturbations arising from air-tissue interfaces and large vessels. To minimize such demerits, we took advantage of the dual contrast property of SPION and both theoretically and experimentally verified the direct benefit of replacing gradient-echo based ∆R2(⁎) measurement with ultra-short echo time (UTE)-based ∆R1 contrast to generate the robust CBV and mVSI maps. The UTE acquisition minimized the local measurement errors from susceptibility perturbations and enabled dose-independent CBV measurement using the vessel/tissue ∆R1 ratio, while independent spin-echo acquisition enabled simultaneous ∆R2 measurement and mVSI calculation of the cortex, cerebellum, and olfactory bulb, which are animal brain regions typified by significant susceptibility-associated measurement errors.


Assuntos
Vasos Sanguíneos/anatomia & histologia , Volume Sanguíneo/fisiologia , Circulação Cerebrovascular/fisiologia , Imagem Ecoplanar/métodos , Algoritmos , Animais , Simulação por Computador , Compostos Férricos , Processamento de Imagem Assistida por Computador , Masculino , Nanopartículas Metálicas , Camundongos , Camundongos Nus , Microcirculação/fisiologia , Método de Monte Carlo , Reprodutibilidade dos Testes
12.
Phys Rev Lett ; 115(17): 172503, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26551108

RESUMO

Absolute cross sections for isotopically identified products formed in multinucleon transfer in the (136)Xe+(198)Pt system at ∼8 MeV/nucleon are reported. The isotopic distributions obtained using a large acceptance spectrometer demonstrated the production of the "hard-to-reach" neutron-rich isotopes for Z<78 around the N=126 shell closure far from stability. The main contribution to the formation of these exotic nuclei is shown to arise in collisions with a small kinetic energy dissipation. The present experimental finding corroborates for the first time recent predictions that multinucleon transfer reactions would be the optimum method to populate and characterize neutron-rich isotopes around N=126 which are crucial for understanding both astrophysically relevant processes and the evolution of "magic" numbers far from stability.

13.
Phys Rev Lett ; 114(19): 192501, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26024165

RESUMO

The ß-decay half-lives of 110 neutron-rich isotopes of the elements from _{37}Rb to _{50}Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A≈130) and the rare-earth-element (A≈160) abundance peaks may result from the freeze-out of an (n,γ)⇄(γ,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r-process events.

14.
Oral Dis ; 21(5): 550-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25098817

RESUMO

Use of ceramics and polymers continues to dominate clinical procedures in modern dentistry. Polymers have provided the basis for adhesives, tissue void fillers, and artificial replacements for whole teeth. They have been remarkably effective in the clinic at restoration of major dental functions after damage or loss of teeth. With the rapid development of polymer science, dental materials science has significantly lagged behind in harnessing these advanced polymer products. What they offer is new and unique properties superior to traditional polymers and crucially a range of properties that more closely match natural biomaterials. Therefore, we should pursue more vigorously the benefits of advanced polymers in dentistry. In this review, we highlight how the latest generation of advanced polymers will enhance the application of materials in the dental clinic using numerous promising examples. Polymers have a broad range of applications in modern dentistry. Some major applications are to construct frameworks that mimic the precise structure of tissues, to restore tooth organ function, and to deliver bioactive agents to influence cell behavior from the inside. The future of polymers in dentistry must include all these new enhancements to increase biological and clinical effectiveness beyond what can be achieved with traditional biomaterials.


Assuntos
Materiais Dentários/uso terapêutico , Odontologia/métodos , Polímeros/uso terapêutico , Animais , Materiais Biocompatíveis/uso terapêutico , Cerâmica/uso terapêutico , Implantes Dentários , Humanos , Dente/transplante
15.
Phys Rev Lett ; 113(3): 032505, 2014 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-25083639

RESUMO

The half-lives of 20 neutron-rich nuclei with Z=27-30 have been measured at the RIBF, including five new half-lives of (76)Co(21.7(-4.9)(+6.5) ms), (77)Co(13.0(-4.3)(+7.2) ms), (79)Ni(43.0(-7.5)(+8.6) ms), (80)Ni(23.9(-17.2)(+26.0) ms), and (81)Cu(73.2 ± 6.8 ms). In addition, the half-lives of (73-75)Co, (74-78)Ni, (78-80)Cu, and (80-82)Zn were determined with higher precision than previous works. Based on these new results, a systematic study of the ß-decay half-lives has been carried out, which suggests a sizable magicity for both the proton number Z = 28 and the neutron number N=50 in (78)Ni.

16.
Phys Rev Lett ; 113(13): 132502, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25302883

RESUMO

Delayed γ-ray cascades, originating from the decay of (6⁺) isomeric states, in the very neutron-rich, semimagic isotopes (136,138)Sn have been observed following the projectile fission of a ²³8U beam at RIBF, RIKEN. The wave functions of these isomeric states are proposed to be predominantly a fully aligned pair of f(7/2) neutrons. Shell-model calculations, performed using a realistic effective interaction, reproduce well the energies of the excited states of these nuclei and the measured transition rates, with the exception of the B(E2;6⁺→4⁺) rate of ¹³6Sn, which deviates from a simple seniority scheme. Empirically reducing the νf(7/2)(2) orbit matrix elements produces a 41⁺ state with almost equal seniority 2 and 4 components, correctly reproducing the experimental B(E2;6⁺→4⁺) rate of ¹³6Sn. These data provide a key benchmark for shell-model interactions far from stability.

17.
Phys Rev Lett ; 113(4): 042502, 2014 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-25105611

RESUMO

A new isomer with a half-life of 23.0(8) ms has been identified at 2406 keV in (126)Pd and is proposed to have a spin and parity of 10(+) with a maximally aligned configuration comprising two neutron holes in the 1h(11/2) orbit. In addition to an internal-decay branch through a hindered electric octupole transition, ß decay from the long-lived isomer was observed to populate excited states at high spins in (126)Ag. The smaller energy difference between the 10(+) and 7(-) isomers in (126)Pd than in the heavier N=80 isotones can be interpreted as being ascribed to the monopole shift of the 1h(11/2) neutron orbit. The effects of the monopole interaction on the evolution of single-neutron energies below (132)Sn are discussed in terms of the central and tensor forces.

18.
Phys Rev Lett ; 112(13): 132501, 2014 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-24745408

RESUMO

A low-lying state in 131In82, the one-proton hole nucleus with respect to double magic 132Sn, was observed by its γ decay to the Iπ=1/2- ß-emitting isomer. We identify the new state at an excitation energy of Ex=1353 keV, which was populated both in the ß decay of 131Cd83 and after ß-delayed neutron emission from 132Cd84, as the previously unknown πp3/2 single-hole state with respect to the 132Sn core. Exploiting this crucial new experimental information, shell-model calculations were performed to study the structure of experimentally inaccessible N=82 isotones below 132Sn. The results evidence a surprising absence of proton subshell closures along the chain of N=82 isotones. The consequences of this finding for the evolution of the N=82 shell gap along the r-process path are discussed.

19.
Phys Rev Lett ; 111(15): 152501, 2013 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-24160593

RESUMO

The level structures of the very neutron-rich nuclei 128Pd and 126Pd have been investigated for the first time. In the r-process waiting-point nucleus 128Pd, a new isomer with a half-life of 5.8(8) µs is proposed to have a spin and parity of 8(+) and is associated with a maximally aligned configuration arising from the g(9/2) proton subshell with seniority υ=2. For 126Pd, two new isomers have been identified with half-lives of 0.33(4) and 0.44(3) µs. The yrast 2(+) energy is much higher in 128Pd than in 126Pd, while the level sequence below the 8(+) isomer in 128Pd is similar to that in the N=82 isotone 130Cd. The electric quadrupole transition that depopulates the 8(+) isomer in 128Pd is more hindered than the corresponding transition in 130Cd, as expected in the seniority scheme for a semimagic, spherical nucleus. These experimental findings indicate that the shell closure at the neutron number N=82 is fairly robust in the neutron-rich Pd isotopes.

20.
J Dent Res ; 102(7): 825-834, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37246809

RESUMO

The enamel knot (EK), located at the center of cap stage tooth germs, is a transitory cluster of nondividing epithelial cells. The EK acts as a signaling center that provides positional information for tooth morphogenesis and regulates the growth of tooth cusps. To identify species-specific cuspal patterns, this study analyzed the cellular mechanisms in the EK that were related to bone morphogenetic protein (Bmp), which plays a crucial role in cell proliferation and apoptosis. To understand the cellular mechanisms in the EK, the differences between 2 species showing different cuspal patterning, mouse (pointy bunodont cusp) and gerbil (flat lophodont cusp), were analyzed with quantitative reverse transcriptase polymerase chain reaction and immunofluorescent staining. Based on these, we performed protein-soaked bead implantation on tooth germs of the 2 different EK regions and compared the cellular behavior in the EKs of the 2 species. Many genes related with cell cycle, cell apoptosis, and cell proliferation were involved in BMP signaling in the EK during tooth development. A comparison of the cell proliferation and apoptosis associated with Bmp revealed distinctive patterns of the cellular mechanisms. Our findings indicate that the cellular mechanisms, such as cell proliferation and apoptosis, in the EK are related to Bmp4 and play an important role in tooth morphogenesis.


Assuntos
Dente , Animais , Camundongos , Esmalte Dentário/metabolismo , Odontogênese/genética , Germe de Dente , Proteínas Morfogenéticas Ósseas/metabolismo , Proliferação de Células , Apoptose , Proteína Morfogenética Óssea 4/metabolismo
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