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1.
Orthod Craniofac Res ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321788

RESUMO

OBJECTIVE: To investigate the accuracy of artificial intelligence-assisted growth prediction using a convolutional neural network (CNN) algorithm and longitudinal lateral cephalograms (Lat-cephs). MATERIALS AND METHODS: A total of 198 Japanese preadolescent children, who had skeletal Class I malocclusion and whose Lat-cephs were available at age 8 years (T0) and 10 years (T1), were allocated into the training, validation, and test phases (n = 161, n = 17, n = 20). Orthodontists and the CNN model identified 28 hard-tissue landmarks (HTL) and 19 soft-tissue landmarks (STL). The mean prediction error values were defined as 'excellent,' 'very good,' 'good,' 'acceptable,' and 'unsatisfactory' (criteria: 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm, respectively). The degree of accurate prediction percentage (APP) was defined as 'very high,' 'high,' 'medium,' and 'low' (criteria: 90%, 70%, and 50%, respectively) according to the percentage of subjects that showed the error range within 1.5 mm. RESULTS: All HTLs showed acceptable-to-excellent mean PE values, while the STLs Pog', Gn', and Me' showed unsatisfactory values, and the rest showed good-to-acceptable values. Regarding the degree of APP, HTLs Ba, ramus posterior, Pm, Pog, B-point, Me, and mandibular first molar root apex exhibited low APPs. The STLs labrale superius, lower embrasure, lower lip, point of lower profile, B', Pog,' Gn' and Me' also exhibited low APPs. The remainder of HTLs and STLs showed medium-to-very high APPs. CONCLUSION: Despite the possibility of using the CNN model to predict growth, further studies are needed to improve the prediction accuracy in HTLs and STLs of the chin area.

2.
Int Endod J ; 54(7): 1142-1154, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33641170

RESUMO

AIM: To identify odontogenesis-promoting compounds and examine the molecular mechanism underlying enhanced odontoblast differentiation and tooth formation. METHODOLOGY: Five different nymphaeols, nymphaeol B (NB), isonymphaeol B (INB), nymphaeol A (NA), 3'-geranyl-naringenin (GN) and nymphaeol C (NC) were isolated from the fruit of Macaranga tanarius. The cytotoxic effect of nymphaeols on human DPSCs was observed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effect of nymphaeols on odontoblast differentiation was analysed with Alizarin Red S staining and odontoblast marker expression was assessed using real-time polymerase chain reaction and Western blot analysis. The molecular mechanism was investigated with Western blot analysis. In order to examine the effect of INB on dentine formation in the developing tooth germ, INB-soaked beads were placed under the tooth bud explants in the collagen gel; thereafter, the tooth bud explant-bead complexes were implanted into the sub-renal capsules for 3 weeks. Tooth root formation was analysed using micro-computed tomography and histological analysis. Data are presented as mean ± standard error (SEM) values of three independent experiments, and results are compared using a two-tailed Student's t-test. The data were considered to have statistical significance when the P-value was less than 0.05. RESULTS: Three of the compounds, NB, INB, and GN, did not exert a cytotoxic effect on human DPSCs. However, INB was most effective in promoting the deposition of calcium minerals in vitro (P < 0.001) and induced the expression of odontogenic marker genes (P < 0.05). Moreover, this compound strongly induced the phosphorylation of mitogen-activated protein (MAP) kinases and protein kinase B (AKT) (P < 0.05). The inhibition of p38 MAP, c-Jun N-terminal kinase (JNK), and AKT substantially suppressed the INB-induced odontoblast differentiation (P < 0.001). In addition, isonymphaeol B significantly induced the formation of dentine and elongation of the tooth root in vivo (P < 0.05). CONCLUSIONS: Prenylflavonoids, including INB, exerted stimulatory effects on odontoblast differentiation and tooth root and dentine formation via the MAP kinase and AKT signalling pathways. These results suggest that nymphaeols could stimulate the repair processes for dentine defects or injuries.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Euphorbiaceae/química , Flavonoides/farmacologia , Odontoblastos/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células Cultivadas , Polpa Dentária/citologia , Humanos , Proteínas Quinases Ativadas por Mitógeno , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Raiz Dentária , Microtomografia por Raio-X
3.
Transplant Proc ; 50(10): 3113-3120, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30577176

RESUMO

BACKGROUND: To analyze our initial results of hand-assisted laparoscopic living donor nephrectomy, executed by a skilled gastrointestinal surgeon. METHODS: A total of 22 consecutive patients underwent the hand-assisted laparoscopic living donor nephrectomy between December 2014 and January 2017. We retrospectively analyze the patient's perioperative clinical data, which were collected prospectively. RESULTS: The right kidney was harvested in 12 patients. The mean operative time and intraoperative blood loss was 241.0 ± 43.4 minutes (range, 140-310 min) and 293.2 ± 203.1 mL (range, 50-700 mL), respectively. The mean warm ischemic time was 288.4 ± 103.4 seconds (range, 179-610 s). Postoperative complications included chyle leakage in 2 patients who were left kidney donors and oliguria in 1 patient who was a right kidney donor. All patients recovered with conservative care, and the mean hospital stay was 7.5 ± 1.7 days. The mean creatinine level was 0.7 ± 0.2 mg/dL before surgery, 1.1 ± 0.3 mg/dL at postoperative day (POD) 1, and 1.0 ± 0.2 mg/dL after discharge. The mean glomerular filtration rate was 97.9 ± 18.2 mL/min/1.73 m2 before surgery, 60.7 ± 10.4 at POD 1, and 67.3 ± 11.1 after discharge. Operation time was not associated with patient body mass index and case number. No significant differences, other than postoperative complications, were found in the perioperative data for the side of kidney donation. CONCLUSION: A skilled surgeon with experience in laparoscopic abdominal surgery (such as gastrectomy or colectomy) might safely perform hand-assisted donor nephrectomy. However, we could not identify a clear case number to complete the learning curve.


Assuntos
Cirurgia Geral/educação , Laparoscopia Assistida com a Mão/educação , Transplante de Rim/educação , Nefrectomia/educação , Coleta de Tecidos e Órgãos/educação , Adulto , Perda Sanguínea Cirúrgica , Feminino , Taxa de Filtração Glomerular , Laparoscopia Assistida com a Mão/efeitos adversos , Laparoscopia Assistida com a Mão/métodos , Humanos , Transplante de Rim/efeitos adversos , Transplante de Rim/métodos , Curva de Aprendizado , Tempo de Internação , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Nefrectomia/efeitos adversos , Nefrectomia/métodos , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Coleta de Tecidos e Órgãos/métodos , Isquemia Quente
4.
Nat Commun ; 9(1): 2139, 2018 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-29849096

RESUMO

Strong interplay of spin and charge/orbital degrees of freedom is the fundamental characteristic of the iron-based superconductors (FeSCs), which leads to the emergence of a nematic state as a rule in the vicinity of the antiferromagnetic state. Despite intense debate for many years, however, whether nematicity is driven by spin or orbital fluctuations remains unsettled. Here, by use of transport, magnetization, and 75As nuclear magnetic resonance (NMR) measurements, we show a striking transformation of the relationship between nematicity and spin fluctuations (SFs) in Na1-xLi x FeAs; For x ≤ 0.02, the nematic transition promotes SFs. In contrast, for x ≥ 0.03, the system undergoes a non-magnetic phase transition at a temperature T0 into a distinct nematic state that suppresses SFs. Such a drastic change of the spin fluctuation spectrum associated with nematicity by small doping is highly unusual, and provides insights into the origin and nature of nematicity in FeSCs.

5.
Nat Commun ; 8(1): 2167, 2017 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-29255140

RESUMO

A subtle balance between competing interactions in iron-based superconductors (FeSCs) can be tipped by additional interfacial interactions in a heterostructure, often inducing exotic phases with unprecedented properties. Particularly when the proximity-coupled layer is magnetically active, rich phase diagrams are expected in FeSCs, but this has not been explored yet. Here, using high-accuracy 75As and 51V nuclear magnetic resonance measurements, we investigate an electronic phase that emerges in the FeAs layer below T 0 ~ 155 K of Sr2VO3FeAs, a naturally assembled heterostructure of an FeSC and a Mott-insulating vanadium oxide. We find that frustration of the otherwise dominant Fe stripe and V Neel fluctuations via interfacial coupling induces a charge/orbital order in the FeAs layers, without either static magnetism or broken C 4 symmetry, while suppressing the Neel antiferromagnetism in the SrVO3 layers. These findings demonstrate that the magnetic proximity coupling stabilizes a hidden order in FeSCs, which may also apply to other strongly correlated heterostructures.

6.
Phys Rev Lett ; 119(3): 037201, 2017 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-28777603

RESUMO

We report a ^{35}Cl nuclear magnetic resonance study in the honeycomb lattice α-RuCl_{3}, a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that α-RuCl_{3} exhibits a magnetic-field-induced QSL. For fields larger than ∼10 T, a spin gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly with an increasing magnetic field, reaching ∼50 K at 15 T, and is nearly isotropic with respect to the field direction. The unusual rapid increase of the spin gap with increasing field and its isotropic nature are incompatible with conventional magnetic ordering and, in particular, exclude that the ground state is a fully polarized ferromagnet. The presence of such a field-induced gapped QSL phase has indeed been predicted in the Kitaev model.

7.
Nat Commun ; 7: 12775, 2016 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-27605152

RESUMO

Charge-stripe order has recently been established as an important aspect of cuprate high-Tc superconductors. However, owing to the complex interplay between competing phases and the influence of disorder, it is unclear how it emerges from the parent high-temperature state. Here we report on the discovery of an unconventional ordered phase between charge-stripe order and (pseudogapped) metal in the cuprate La1.8-xEu0.2SrxCuO4. We use three complementary experiments-nuclear quadrupole resonance, nonlinear conductivity and specific heat-to demonstrate that the order appears through a sharp phase transition and exists in a dome-shaped region of the phase diagram. Our results imply that the new phase is a state, which preserves translational symmetry: a charge nematic. We thus resolve the process of charge-stripe development in cuprates, show that this nematic phase is distinct from high-temperature pseudogap and establish a link with other strongly correlated electronic materials with prominent nematic order.

8.
J Phys Condens Matter ; 27(48): 485603, 2015 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-26571207

RESUMO

We report (23)Na nuclear magnetic resonance (NMR) and zero-field (ZF) and longitudinal-field (LF) muon spin relaxation (µSR) measurements of the depleted hyperkagome compounds Na(4-x)Ir3O8 (x = 0.3 and 0.7), which undergo an insulator-semimetal transition as a function of x. The (23)Na spin-lattice relaxation rates, T1(-1), follow a T(2.5) power law behavior at accessible temperatures of T = 120-350 K. A substantial temperature dependence of T1(-1) indicates the presence of gapped excitations at elevated temperatures through the transition to a semimetallic phase. ZF-µSR results reveal that hole-doping leads to a melting of quasi-static order to a dynamically fluctuating state. The very slow muon depolarization rate which varies hardly with temperature indicates that spins are close to an itinerant limit in the largest doping x = 0.7. The dynamic relaxation rates extracted from the LF-µSR spectra show a three-dimensional diffusive transport. Our combined NMR and µSR results suggest the occurrence of intriguing spin and charge excitations across the insulator-semimetal transition.

10.
Eye (Lond) ; 29(12): 1555-60, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26293140

RESUMO

UNLABELLED: Purpose: To evaluate and compare surgical outcomes with respect to refractive errors in strabismus surgery for the treatment of intermittent exotropia (IXT). METHODS: The medical records of patients with IXT who were treated by one surgeon from January 2005 and June 2011 were reviewed. Three hundred and thirty-three IXT patients were included and divided into three groups according to preoperative refractive error: IXT with hyperopia (group I), IXT with emmetropia (group II), and IXT with myopia (group III). The surgical outcomes with respect to sensory and motor criteria were compared among the three groups. RESULTS: The surgical success rates according to motor criteria and sensory and motor criteria combined were higher in groups I (29 patients) and III (124 patients) than in group II (180 patients) at postoperative 3 and 6 months and at the last follow-up. Stereopsis was significantly better in groups II and III than in group I preoperatively (P=0.002 by one-way analysis of variance test); however, the difference was not significant postoperatively. Twenty patients in group I (69.0%) were prescribed undercorrected hyperopic spectacles postoperatively, while only 22 patients in group III (17.7%) were prescribed spectacles with more myopic power than their refractive errors. CONCLUSION: In the surgical treatment of IXT, hyperopia was not an indicator of poor prognosis. Taking into consideration the age effect, follow-up period after IXT surgery, and stereopsis improvement, hyperopic refractive error is rather a good prognostic factor.


Assuntos
Exotropia/cirurgia , Hiperopia/diagnóstico , Hiperopia/etiologia , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos/efeitos adversos , Criança , Pré-Escolar , Percepção de Profundidade/fisiologia , Óculos , Feminino , Humanos , Hiperopia/terapia , Masculino , Prognóstico , Estudos Retrospectivos , Fatores de Risco
11.
Eye (Lond) ; 29(6): 776-82, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25853395

RESUMO

PURPOSE: To examine the clinical course of consecutive esotropia (ET) using conservative management, after intermittent exotropia (IXT) surgery. METHODS: This study included 149 out of 151 consecutive patients with ET after IXT surgery, who were managed conservatively. The clinical course of consecutive ET was examined and the patients were classified into two groups based on the duration of esodeviation: (1) >3 weeks (persistent ET group, n=56) and (2) <3 weeks (transient ET group, n=93). Patient characteristics and treatment outcomes, including the recurrence of exotropia and stereopsis, were compared between the two groups. RESULTS: All patients with ET were managed with full-time alternate occlusion and/or with a Fresnel prism. In 149 patients out of 151 consecutive patients, 82% of ET disappeared at 12-month follow-up and all at the last follow-up visit (31.4±23.5 months). At the final visit, a recurrence of exotropia of >10 prism dioptres was significantly less frequent in the persistent ET group than in the transient ET group (25% vs 62%, respectively; P=0.01). However, stereopsis outcome was not significantly different between the two groups, and stereopsis change was not affected by age. CONCLUSIONS: By using conservative management only, persistent consecutive ET after IXT surgery disappeared in most cases by the 1-year follow-up visit after surgery. Recurrence of exotropia was significantly less frequent in patients with persistent ET, yet the sensory outcome was not affected by the duration of consecutive ET or age.


Assuntos
Esotropia/terapia , Exotropia/cirurgia , Óculos , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos/efeitos adversos , Privação Sensorial , Criança , Pré-Escolar , Percepção de Profundidade/fisiologia , Esotropia/etiologia , Esotropia/fisiopatologia , Exotropia/diagnóstico , Feminino , Seguimentos , Humanos , Masculino , Recidiva , Estudos Retrospectivos , Resultado do Tratamento , Visão Binocular/fisiologia , Acuidade Visual/fisiologia
12.
Int J Oral Maxillofac Surg ; 44(1): 16-22, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25444479

RESUMO

The objective of this study was to analyze the oncological and functional outcomes after the surgical treatment of parotid cancer. We reviewed 80 primary parotid carcinomas retrospectively. A superficial parotidectomy was performed in 10 patients; 27 patients underwent total parotidectomy and 43 patients underwent radical parotidectomy. A facial-facial nerve anastomosis was chosen for the facial nerve reconstruction in eight patients, while an interpositional graft was selected in 24 patients. The overall N-positive rate of pathology was 21.3%. The rate of occult metastasis was 8.1%. High-grade carcinoma and lymphovascular emboli were independent factors for nodal metastasis. The 5-year disease-free survival and overall survival rates were 79.7% and 78.8%, respectively. Preoperative facial nerve palsy and extraparenchymal invasion were the independent factors associated with poor disease-free survival. Of the 41 patients in the facial nerve preservation group, 13 (31.7%) had transient facial nerve paresis. In the facial nerve sacrifice group of 39 cases, (sub)total recovery (House-Brackmann grade I/II) occurred in 14 (35.9%), partial recovery (House-Brackmann grade III/IV) in 13 (33.3%), and no recovery (House-Brackmann grade V) in 12 (30.8%). Facial nerve palsy upon presentation and extraparenchymal invasion indicate a grave prognosis. Facial nerve function after proper reconstruction is tolerable.


Assuntos
Neoplasias Parotídeas/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Paralisia Facial/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Procedimentos Cirúrgicos Bucais , Complicações Pós-Operatórias/epidemiologia , Prognóstico , Procedimentos de Cirurgia Plástica , Recuperação de Função Fisiológica , Estudos Retrospectivos , Taxa de Sobrevida
13.
Nat Mater ; 14(2): 210-4, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25384167

RESUMO

A fundamental and unconventional characteristic of superconductivity in iron-based materials is that it occurs in the vicinity of two other instabilities. In addition to a tendency towards magnetic order, these Fe-based systems have a propensity for nematic ordering: a lowering of the rotational symmetry while time-reversal invariance is preserved. Setting the stage for superconductivity, it is heavily debated whether the nematic symmetry breaking is driven by lattice, orbital or spin degrees of freedom. Here, we report a very clear splitting of NMR resonance lines in FeSe at Tnem = 91 K, far above the superconducting Tc of 9.3 K. The splitting occurs for magnetic fields perpendicular to the Fe planes and has the temperature dependence of a Landau-type order parameter. Spin-lattice relaxation rates are not affected at Tnem, which unequivocally establishes orbital degrees of freedom as driving the nematic order. We demonstrate that superconductivity competes with the emerging nematicity.

14.
Spinal Cord ; 52 Suppl 3: S16-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25376310

RESUMO

STUDY DESIGN: A case report. OBJECTIVES: This study discusses a case of spinal segmental myoclonus caused by thoracic myelopathy, mimicking hiccup spasms. Spinal myoclonus caused by thoracic myelopathy is extremely rare. It can be misdiagnosed as chronic intractable hiccups due to similar clinical manifestations. SETTING: Korea University Anam Hospital, Seoul, Republic of Korea. METHODS: A 42-year-old man presented with a history of involuntary jerky movement of the upper abdominal wall muscles that had been continuing for over 3 years. A neurological examination, brain computed tomography and electroencephalogram did not reveal a cause of the symptoms. Electromyography was performed on the abdominal muscles and the findings revealed were compatible with spinal myoclonus. The spinal myoclonus had started in the abdominal muscles, with a spinal magnetic resonance imaging revealing a disc protrusion compressing the anterior spinal cord. RESULTS: The cause of the spinal myoclonus was determined to be spinal myelopathy due to mild T7 disc protrusion. The patient refused surgical or invasive interventions and was conservatively treated with clonazepam. The symptoms were reported to be less frequent following the treatment. CONCLUSION: Compressive myelopathy developed from disc protrusion may cause spinal myoclonus mimicking as hiccup spasms.


Assuntos
Soluço/patologia , Soluço/fisiopatologia , Mioclonia/fisiopatologia , Compressão da Medula Espinal/patologia , Compressão da Medula Espinal/fisiopatologia , Doenças da Medula Espinal/complicações , Traumatismos da Medula Espinal/patologia , Adulto , Soluço/etiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Músculo Esquelético/patologia , Mioclonia/etiologia , Exame Neurológico/métodos , Compressão da Medula Espinal/complicações , Doenças da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/diagnóstico
15.
J Oral Rehabil ; 41(7): 523-31, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24717149

RESUMO

Dentin hypersensitivity (DH) is defined as pain derived from exposed dentin in response to chemical, thermal, tactile, or osmotic stimuli that cannot be explained as having arisen from any other dental defect or disease. The aim of this trial was to test the efficacy and the safety of a low-level laser-emitting toothbrush on management of DH. A prospective, double blind, randomised clinical trial was designed; 96 individuals with hypersensitive teeth without caries or fracture were selected as subjects. The subjects were randomly allocated to either the test group with the 635 nm per 6 mW laser-emitting toothbrush, or the control group with the 635 nm per 12.9 µW light-emitting diode (LED) toothbrush. An air blast was applied with a dental air syringe held 3 mm away from the selected tooth and a visual analogue scale (VAS: 0-10) was used to quantify subjective pain. Assessments were completed at a screening visit and after 2-week and 4-week of using a test/control toothbrush. Results demonstrated that the use of both control and test toothbrushes resulted in decreased discomfort after 4 weeks. In the test group, pain intensity scores decreased from 5.8 ± 1.2 to 2.3 ± 1.6, and in the control group, the scores decreased from 6.4 ± 1.3 to 5.5 ± 2.0 (P < 0.05). This decrease was significantly greater in the test group. There were no significant adverse events or side effects. It was concluded that the use of the low-level laser emitting toothbrush is a safe and effective treatment option for the management of DH.


Assuntos
Sensibilidade da Dentina/radioterapia , Dor Facial , Terapia com Luz de Baixa Intensidade/métodos , Escovação Dentária/instrumentação , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
16.
J Viral Hepat ; 21(10): e108-17, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24602294

RESUMO

Viruses exploit cellular SUMOylation machinery to favour their own propagation. We show that NS5A is a target protein of small ubiquitin-like modifier (SUMO) and is SUMOylated at lysine residue 348. We demonstrated that SUMOylation increased protein stability of NS5A by inhibiting ubiquitylation, and SUMOylation was also required for protein interaction with NS5B. These data imply that SUMO modification may contribute to HCV replication. Indeed, silencing of UBC9 impaired HCV replication in Jc1-infected cells, and HCV replication level was also significantly reduced in SUMO-defective subgenomic replicon cells. Taken together, these data indicate that HCV replication is regulated by SUMO modification of NS5A protein. We provide evidence for the first time that HCV exploits host cellular SUMO modification system to favour its own replication.


Assuntos
Hepacivirus/fisiologia , Interações Hospedeiro-Patógeno , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Sumoilação , Enzimas de Conjugação de Ubiquitina/metabolismo , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Inativação Gênica , Mapeamento de Interação de Proteínas , Estabilidade Proteica , Enzimas de Conjugação de Ubiquitina/genética
17.
J Phys Condens Matter ; 25(16): 162204, 2013 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-23553364

RESUMO

(75)As NMR investigation of a single crystal of superconducting LiFeAs is presented. The Knight shift and the in situ ac susceptibility measurements as a function of temperature and external field are indicative of two superconducting (SC) transition temperatures, each of which is associated with its own upper critical field. Strikingly, the Knight shift maintains its normal state value over a temperature range in the SC state before it drops abruptly, being consistent with spin-singlet pairing. Together with our previous NMR study, the anomalous SC state featuring the constant Knight shift is attributed to the extremely sensitive SC properties of LiFeAs, probably stemming from its proximity to a critical instability.

18.
Transplant Proc ; 45(1): 420-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23375332

RESUMO

Although cardiac stem cells (CSCs) have emerged in regeneration research, the number of isolated CSCs is low, making a sufficient supply of functional elements an important consideration in cardiovascular research. In this study, we established an efficient method for CSC isolation. We directly compared cultures of single cells to human cardiac-derived c-kit-positive progenitor cells (hCPCs(c-kit+)). The two protocols employed enzymatically digested hCPCs(c-kit+) (ED-hCPCs) with tissue-expanded hCPC(c-kit+) (TE-hCPCs). Using fluorescence-activated cell sorting, we showed the concentration of c-kit in TE-hCPCs to be higher than in ED-hCPCs, although the total number of c-kit positive cells resulting from ED-hCPCs was similar to that resulting from TE-hCPCs. The cardiomyocyte-associated proteins, GATA4 and Nkx2-5, which were expressed during hCPCs expansion, did not differ between the isolation methods. Importantly, the expression of the CSC stem cell marker, c-kit, was more efficiently preserved using the ED-hCPCs versus the TE-hCPCs method. In a cell proliferation assay, the ED-hCPCs method produced a significantly greater number of cells. Finally, hCPCs derived using both protocols differentiated into endothelial, smooth muscle, and cardiomyocyte lineages. In conclusion, the single-cell culture protocol using an enzymatic digestion method may be more useful to isolate human cardiac-derived c-kit-positive elements compared with the tissue expansion method.


Assuntos
Técnicas de Cultura de Células , Proteínas Proto-Oncogênicas c-kit/metabolismo , Células-Tronco/citologia , Diferenciação Celular , Linhagem da Célula , Separação Celular , Células Endoteliais/citologia , Citometria de Fluxo , Cardiopatias/metabolismo , Humanos , Miócitos Cardíacos/citologia , Miócitos de Músculo Liso/citologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Regeneração , Transplante de Células-Tronco
19.
Phys Rev Lett ; 110(24): 247202, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-25165956

RESUMO

The temperature (T) dependence of the optical conductivity spectra σ(ω) of a single crystal SrRuO(3) thin film is studied over a T range from 5 to 450 K. We observed significant T dependence of the spectral weights of the charge transfer and interband d-d transitions across the ferromagnetic Curie temperature (T(c) ∼ 150 K). Such T dependence was attributed to the increase in the Ru spin moment, which is consistent with the results of density functional theory calculations. T scans of σ(Ω,T) at fixed frequencies Ω reveal a clear T(2) dependence below T(c), demonstrating that the Stoner mechanism is involved in the evolution of the electronic structure. In addition, σ(Ω,T) continues to evolve at temperatures above T(c), indicating that the local spin moment persists in the paramagnetic state. This suggests that SrRuO(3) is an intriguing oxide system with itinerant ferromagnetism.

20.
Br J Pharmacol ; 168(6): 1401-11, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23072581

RESUMO

BACKGROUND AND PURPOSE: The present study assessed the effects of cilostazol on LPS-stimulated TLR4 signal pathways in synovial macrophages from patients with rheumatoid arthritis (RA). These effects were confirmed in collagen-induced arthritis (CIA) in mice. EXPERIMENTAL APPROACH: Expression of TLR4, PU.1, NF-κB p65 and IκBα on synovial fluid macrophages from RA patients was determined by Western blotting, and cytokines were measured by ELISA. Anti-arthritic effects were evaluated in CIA mice. KEY RESULTS: Intracellular cAMP was concentration-dependently raised by cilostazol (1-100 µM). Cilostazol significantly suppressed LPS-stimulated increase of TLR4 expression by blocking PU.1 transcriptional activity in RA macrophages. In addition, cilostazol decreased LPS-induced myeloid differentiation factor 88 (MyD88) expression, but not that of TNF receptor-associated factor 6 (TRAF6). Cilostazol also suppressed IkBα degradation and NF-κB p65 nuclear translocation. Moreover, LPS-induced increase of cytokine production (TNF-α, IL-1ß) was inhibited by cilostazol, an effect which was accompanied by suppression of IκBα degradation, and NF-κB p65 nuclear translocation. However, expression of anti-inflammatory IL-10 was elevated by cilostazol and forskolin/IBMX. In mice with CIA, post-treatment with cilostazol (30 mg kg⁻¹ day⁻¹) decreased expression of TLR4 in knee joints in association with decreased recruitment of macrophages. Consequently, synovial inflammation, proteoglycan depletion and bone erosion were significantly inhibited by cilostazol treatment. CONCLUSIONS AND IMPLICATIONS: Cilostazol down-regulated LPS-stimulated PU.1-linked TLR4 expression and TLR4/MyD88/NF-κB signal pathways, and then suppressed inflammatory cytokine production in synovial macrophages from RA patients. Also cilostazol markedly inhibited the severity of CIA in mice.


Assuntos
Antirreumáticos/farmacologia , Artrite Reumatoide/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Inibidores da Fosfodiesterase 3/farmacologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Tetrazóis/farmacologia , Receptor 4 Toll-Like/antagonistas & inibidores , Transativadores/antagonistas & inibidores , Animais , Antirreumáticos/uso terapêutico , Artrite Reumatoide/imunologia , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Células Cultivadas , Cilostazol , Citocinas/antagonistas & inibidores , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Articulação do Joelho/efeitos dos fármacos , Articulação do Joelho/imunologia , Articulação do Joelho/metabolismo , Articulação do Joelho/patologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos DBA , Inibidores da Fosfodiesterase 3/uso terapêutico , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Tetrazóis/uso terapêutico , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Transativadores/genética , Transativadores/metabolismo
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