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1.
Adv Sci (Weinh) ; 11(11): e2307509, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38161227

RESUMO

Topological insulators have recently received attention in optoelectronic devices because of their high mobility and broadband absorption resulting from their topological surface states. In particular, theoretical and experimental studies have emerged that can improve the spin generation efficiency in a topological insulator-based p-n junction structure called a TPNJ, drawing attention in optospintronics. Recently, research on implementing the TPNJ structure is conducted; however, studies on the device characteristics of the TPNJ structure are still insufficient. In this study, the TPNJ structure is effectively implemented without intermixing by controlling the annealing temperature, and the photocharacteristics appearing in the TPNJ structure are investigated using a cross-pattern that can compare the characteristics in a single device. Enhanced photo characteristics are observed for the TPNJ structure. An optical pump Terahertz probe and a physical property measurement system are used to confirm the cause of improved photoresponsivity. Consequently, the photocharacteristics are improved owing to the change in the absorption mechanism and surface transport channel caused by the Fermi level shift in the TPNJ structure.

2.
PLoS One ; 18(10): e0293222, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37906609

RESUMO

The aim of the present study was to find acoustic correlates of perceived personality from the speech produced in a formal communicative setting-that of Korean customer service employees in particular. This work extended previous research on voice personality impressions to a different sociocultural and linguistic context in which speakers are expected to speak politely in a formal register. To use naturally produced speech rather than read speech, we devised a new method that successfully elicited spontaneous speech from speakers who were role-playing as customer service employees, while controlling for the words and sentence structures they used. We then examined a wide range of acoustic properties in the utterances, including voice quality and global acoustic and segmental properties using Principal Component Analysis. Subjects of the personality rating task listened to the utterances and rated perceived personality in terms of the Big-Five personality traits. While replicating some previous findings, we discovered several acoustic variables that exclusively accounted for the personality judgments of female speakers; a more modal voice quality increased perceived conscientiousness and neuroticism, and less dispersed formants reflecting a larger body size increased the perceived levels of extraversion and openness. These biases in personality perception likely reflect gender and occupation-related stereotypes that exist in South Korea. Our findings can also serve as a basis for developing and evaluating synthetic speech for Voice Assistant applications in future studies.


Assuntos
Fala , Voz , Humanos , Feminino , Acústica , Personalidade , Idioma
4.
Tissue Eng Regen Med ; 20(5): 767-778, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37079199

RESUMO

BACKGROUND: In guided bone regeneration (GBR), there are various problems that occur in the bone defect after the wound healing period. This study aimed to investigate the enhancement of the osteogenic ability of the dual scaffold complex and identify the appropriate concentration of growth factors (GF) for new bone formation based on the novel GBR concept that is applying rapid bone forming GFs to the membrane outside of the bone defect. METHODS: Four bone defects with a diameter of 8 mm were formed in the calvaria of New Zealand white rabbits each to perform GBR. Collagen membrane and biphasic calcium phosphate (BCP) were applied to the bone defects with the four different concetration of BMP-2 or FGF-2. After 2, 4, and 8 weeks of healing, histological, histomorphometric, and immunohistochemical analyses were conducted. RESULTS: In the histological analysis, continuous forms of new bones were observed in the upper part of bone defect in the experimental groups, whereas no continuous forms were observed in the control group. In the histomorphometry, The group to which BMP-2 0.5 mg/ml and FGF-2 1.0 mg/ml was applied showed statistically significantly higher new bone formation. Also, the new bone formation according to the healing period was statistically significantly higher at 8 weeks than at 2, 4 weeks. CONCLUSION: The novel GBR method in which BMP-2, newly proposed in this study, is applied to the membrane is effective for bone regeneration. In addition, the dual scaffold complex is quantitatively and qualitatively advantageous for bone regeneration and bone maintenance over time.


Assuntos
Fator 2 de Crescimento de Fibroblastos , Osteogênese , Animais , Coelhos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Regeneração Óssea , Crânio/patologia , Colágeno
5.
J Funct Biomater ; 14(3)2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36976094

RESUMO

We examined whether recombinant human bone morphogenetic protein-2 (rhBMP-2) when applied to collagen membranes, would reinforce them during guided bone regeneration. Four critical cranial bone defects were created and treated in 30 New Zealand white rabbits, including a control group, critical defect only; group 1, collagen membrane only; group 2, biphasic calcium phosphate (BCP) only; group 3, collagen membrane + BCP; group 4, collagen membrane with rhBMP-2 (1.0 mg/mL); group 5, collagen membrane with rhBMP-2 (0.5 mg/mL); group 6, collagen membrane with rhBMP-2 (1.0 mg/mL) + BCP; and group 7, collagen membrane with rhBMP-2 (0.5 mg/mL) + BCP. After a 2-, 4-, or 8-week healing period, the animals were sacrificed. The combination of collagen membranes with rhBMP-2 and BCP yielded significantly higher bone formation rates compared to the other groups (control group and groups 1-5 < groups 6 and 7; p < 0.05). A 2-week healing period yielded significantly lower bone formation than that at 4 and 8 weeks (2 < 4 = 8 weeks; p < 0.05). This study proposes a novel GBR concept in which rhBMP-2 is applied to collagen membranes outside instead of inside the grafted area, thereby inducing quantitatively and qualitatively enhanced bone regeneration in critical bone defects.

6.
J Craniofac Surg ; 34(5): e442-e444, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36917036

RESUMO

Mandibular asymmetry has a variety of patterns because they are affected the position and the shape of mandible in addition to the overlying soft tissue. This study aimed to assess the factor in mandibular asymmetry, focusing on each mandibular functional units and the soft tissue thickness in the mandibular angle area. Forty patients who were diagnosed with facial asymmetry and undergone the orthognathic surgery without genioplasty were enrolled in this study. The skeletal patterns of the patients were analyzed by using cone-beam computed tomography data and 3D virtual images divided into 2 categories; the mandibular functional unit length and the soft tissue depth. All difference in bilateral mandibular functional unit lengths had a statistically significant with chin top deviation ( P <0.05). The greatest correlation was the condylar unit length compared with other functional units. The soft tissue thickness in the mandibular angle area was not statistically related to chin top deviation ( P >0.05), and the soft tissue did not change remarkably after orthognathic surgery ( P >0.05). This study suggests that the considerations of a surgical plan for treatment based on the mandibular asymmetry.


Assuntos
Assimetria Facial , Mandíbula , Humanos , Assimetria Facial/diagnóstico por imagem , Assimetria Facial/cirurgia , Estudos Retrospectivos , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Queixo/cirurgia , Ossos Faciais , Imageamento Tridimensional/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Cefalometria/métodos
7.
Sci Rep ; 13(1): 2942, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-36807586

RESUMO

Coronavirus disease secondary to infection by SARS-CoV-2 (COVID19 or C19) causes respiratory illness, as well as severe neurological symptoms that have not been fully characterized. In a previous study, we developed a computational pipeline for the automated, rapid, high-throughput and objective analysis of electroencephalography (EEG) rhythms. In this retrospective study, we used this pipeline to define the quantitative EEG changes in patients with a PCR-positive diagnosis of C19 (n = 31) in the intensive care unit (ICU) of Cleveland Clinic, compared to a group of age-matched PCR-negative (n = 38) control patients in the same ICU setting. Qualitative assessment of EEG by two independent teams of electroencephalographers confirmed prior reports with regards to the high prevalence of diffuse encephalopathy in C19 patients, although the diagnosis of encephalopathy was inconsistent between teams. Quantitative analysis of EEG showed distinct slowing of brain rhythms in C19 patients compared to control (enhanced delta power and attenuated alpha-beta power). Surprisingly, these C19-related changes in EEG power were more prominent in patients below age 70. Moreover, machine learning algorithms showed consistently higher accuracy in the binary classification of patients as C19 versus control using EEG power for subjects below age 70 compared to older ones, providing further evidence for the more severe impact of SARS-CoV-2 on brain rhythms in younger individuals irrespective of PCR diagnosis or symptomatology, and raising concerns over potential long-term effects of C19 on brain physiology in the adult population and the utility of EEG monitoring in C19 patients.


Assuntos
Encefalopatias , COVID-19 , Adulto , Humanos , Idoso , SARS-CoV-2 , Estudos Retrospectivos , Eletroencefalografia , Encéfalo
8.
Front Bioeng Biotechnol ; 11: 1332138, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38173870

RESUMO

Introduction: Synthetic hydroxyapatite (HAp) scaffolds have shown promising therapeutic outcomes in both animals and patients. In this study, we aim to evaluate the chemical and physical phenotype, biocompatibility, and bone repair effects of hydrothermally treated coral with natural coral and synthetic HAp. Methods: The phase composition, surface pattern, 3D structures, and porosity of the scaffolds were characterized, and cell viability, proliferation, and osteogenic differentiation of mesenchymal stem cells (MSCs) after seeding onto the scaffold were determined. The scaffolds were implanted into rats to assess their bone repair effects using micro-CT analysis, mechanical testing, and histological staining. Results: The results showed that the phase composition, porous structure, and porosity of hydrothermally treated coral were comparable to pure HAp scaffold. While only the natural coral happens to be dominantly calcium carbonate. Higher cell proliferation and osteogenic differentiation potential were observed in the hydrothermally treated coral scaffold compared to natural coral and pure HAp. Histological results also showed increased new bone formation in the hydrothermally treated coral group. Discussion: Overall, our study suggests that hydrothermal modification enhances the cytocompatibility and therapeutic capacity of coral without altering its physical properties, showing superior effectiveness in bone repair to synthetic HAp.

9.
Sensors (Basel) ; 22(19)2022 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-36236366

RESUMO

Reinforcement learning (RL) trains an agent by maximizing the sum of a discounted reward. Since the discount factor has a critical effect on the learning performance of the RL agent, it is important to choose the discount factor properly. When uncertainties are involved in the training, the learning performance with a constant discount factor can be limited. For the purpose of obtaining acceptable learning performance consistently, this paper proposes an adaptive rule for the discount factor based on the advantage function. Additionally, how to use the advantage function in both on-policy and off-policy algorithms is presented. To demonstrate the performance of the proposed adaptive rule, it is applied to PPO (Proximal Policy Optimization) for Tetris in order to validate the on-policy case, and to SAC (Soft Actor-Critic) for the motion planning of a robot manipulator to validate the off-policy case. In both cases, the proposed method results in a better or similar performance compared with cases using the best constant discount factors found by exhaustive search. Hence, the proposed adaptive discount factor automatically finds a discount factor that leads to comparable training performance, and that can be applied to representative deep reinforcement learning problems.


Assuntos
Algoritmos , Reforço Psicológico , Aprendizagem , Recompensa , Incerteza
10.
Nanomaterials (Basel) ; 11(11)2021 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-34835753

RESUMO

Seawater splitting represents an inexpensive and attractive route for producing hydrogen, which does not require a desalination process. Highly active and durable electrocatalysts are required to sustain seawater splitting. Herein we report the phosphidation-based synthesis of a cobalt-iron-phosphate ((Co,Fe)PO4) electrocatalyst for hydrogen evolution reaction (HER) toward alkaline seawater splitting. (Co,Fe)PO4 demonstrates high HER activity and durability in alkaline natural seawater (1 M KOH + seawater), delivering a current density of 10 mA/cm2 at an overpotential of 137 mV. Furthermore, the measured potential of the electrocatalyst ((Co,Fe)PO4) at a constant current density of -100 mA/cm2 remains very stable without noticeable degradation for 72 h during the continuous operation in alkaline natural seawater, demonstrating its suitability for seawater applications. Furthermore, an alkaline seawater electrolyzer employing the non-precious-metal catalysts demonstrates better performance (1.625 V at 10 mA/cm2) than one employing precious metal ones (1.653 V at 10 mA/cm2). The non-precious-metal-based alkaline seawater electrolyzer exhibits a high solar-to-hydrogen (STH) efficiency (12.8%) in a commercial silicon solar cell.

11.
J Neurol ; 268(5): 2001, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33620561
12.
Nanoscale Adv ; 3(22): 6386-6394, 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36133497

RESUMO

The design and fabrication of highly cost-effective electrocatalysts with high activity, and stability to enhance the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been considered to be one of the most promising approaches toward overall water splitting. In this study, sulfur-incorporated cobalt-iron (oxy)hydroxide (S-(Co,Fe)OOH) nanosheets were directly grown on commercial iron foam via galvanic corrosion and hydrothermal methods. The incorporation of sulfur into (Co,Fe)OOH results in superior catalytic performance and high stability in both the HER and OER conducted in 1 M KOH. The incorporation of sulfur enhanced the electrocatalytic activity by modifying the electronic structure and chemical states of (Co,Fe)OOH. An alkaline water electrolyzer for overall water splitting was fabricated using a two-electrode configuration utilizing the S-(Co,Fe)OOH bifunctional electrocatalyst in both the HER and OER. The fabricated electrolyzer outperformed a precious metal-based electrolyzer using Pt/C as the HER electrocatalyst and IrO2 as the OER electrocatalyst, which are the benchmark catalysts. This electrolyzer provides a lower potential of 1.641 V at 10 mA cm-2 and maintains 98.4% of its performance after 50 h of durability testing. In addition, the S-(Co,Fe)OOH-based electrolyzer successfully generated hydrogen under natural illumination upon its combination with a commercial silicon solar cell and exhibited a solar to hydrogen (STH) efficiency of up to 13.0%. This study shows that S-(Co,Fe)OOH is a promising candidate for application in the future renewable energy industry due to its high cost-effectiveness, activity, and stability during overall water splitting. In addition, the combination of a commercial silicon solar cell with an alkaline water electrolyzer has great potential for the production of hydrogen.

13.
J Neurol ; 268(5): 1995-2000, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33231724

RESUMO

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo worldwide. This review considers recent advances in the diagnosis and management of BPPV including the use of web-based technology and artificial intelligence as well as the evidence supporting the use of vitamin D supplements for patients with BPPV and subnormal serum vitamin D.


Assuntos
Inteligência Artificial , Vertigem Posicional Paroxística Benigna , Vertigem Posicional Paroxística Benigna/diagnóstico , Vertigem Posicional Paroxística Benigna/terapia , Suplementos Nutricionais , Humanos , Vitamina D
14.
Sensors (Basel) ; 20(20)2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33086774

RESUMO

Since path planning for multi-arm manipulators is a complicated high-dimensional problem, effective and fast path generation is not easy for the arbitrarily given start and goal locations of the end effector. Especially, when it comes to deep reinforcement learning-based path planning, high-dimensionality makes it difficult for existing reinforcement learning-based methods to have efficient exploration which is crucial for successful training. The recently proposed soft actor-critic (SAC) is well known to have good exploration ability due to the use of the entropy term in the objective function. Motivated by this, in this paper, a SAC-based path planning algorithm is proposed. The hindsight experience replay (HER) is also employed for sample efficiency and configuration space augmentation is used in order to deal with complicated configuration space of the multi-arms. To show the effectiveness of the proposed algorithm, both simulation and experiment results are given. By comparing with existing results, it is demonstrated that the proposed method outperforms the existing results.

15.
J Shoulder Elbow Surg ; 24(6): 875-81, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25547855

RESUMO

BACKGROUND: The purpose of this study was to compare clinical outcomes and structural integrity of arthroscopic repair by either transtendon repair or tear completion for a significant (>50%) partial-thickness articular-side subscapularis tear associated with a full-thickness supraspinatus tear. METHODS: The study population comprised 109 patients who underwent arthroscopic repair for partial-thickness subscapularis tears associated with full-thickness supraspinatus tears with either a transtendon technique (81 patients, group T) or tear completion (28 patients, group C). Pain on a visual analog scale; the Subjective Shoulder Value; the American Shoulder and Elbow Surgeons score; and the University of California, Los Angeles shoulder score were used to compare clinical outcomes between the 2 groups. At 6 months after surgery, magnetic resonance arthrography or computed tomographic arthrography was performed to assess structural integrity. RESULTS: At the 2-year follow-up, there were no significant differences in functional outcomes between groups. In group T, external rotation was reduced significantly from 55° to 51° (P < .001). The subscapularis and overall retear rates were 8% and 19%, respectively, in group T and 12% and 23%, respectively, in group C. There were no significant differences in retear rates between groups. CONCLUSIONS: Arthroscopic repair of partial-thickness subscapularis tears associated with full-thickness supraspinatus tears using either the transtendon technique or tear completion resulted in significant functional improvements in both groups except for postoperative external rotation in group T, and there were no significant differences between groups. The retear rates were also not significantly different between groups. However, after subscapularis repair using the transtendon technique, some patients may have decreased external rotation.


Assuntos
Artroscopia/métodos , Manguito Rotador/cirurgia , Articulação do Ombro/fisiopatologia , Articulação do Ombro/cirurgia , Traumatismos dos Tendões/cirurgia , Idoso , Artrografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Recidiva , Estudos Retrospectivos , Rotação , Lesões do Manguito Rotador , Ruptura/cirurgia , Articulação do Ombro/diagnóstico por imagem , Tomografia por Raios X , Resultado do Tratamento
16.
J Korean Neurosurg Soc ; 56(4): 356-60, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25371789

RESUMO

The coexistence of moyamoya disease (MMD) with an arteriovenous malformation (AVM) is exceedingly rare. We report two cases of AVM associated with MMD. The first case was an incidental AVM diagnosed simultaneously with MMD. This AVM was managed expectantly after encephalo-duro-arterio-synangiosis (EDAS) as the main feeders stemmed from the internal carotid artery, which we believed would be obliterated with the progression of MMD. However, the AVM persisted with replacement of the internal carotid artery feeders by new external carotid artery feeders from the EDAS site. The AVM was eventually treated with gamma knife radiosurgery considering an increasing steal effect. The second case was a de novo AVM case. The patient was initially diagnosed with MMD, and acquired an AVM eight years later that was slowly fed by the reconstituted anterior cerebral artery. Because the patient remained asymptomatic, the AVM is currently being closely followed for more than 2 years without further surgical intervention. Possible differences in the pathogenesis and the radiologic presentation of these AVMs are discussed with a literature review. No solid consensus exists on the optimal treatment of MMD-associated AVMs. Gamma knife radiosurgery appears to be an effective treatment option for an incidental AVM. However, a de novo AVM may be managed expectantly considering the possible risks of damaging established collaterals, low flow characteristics, and probably low risks of rupture.

17.
Nat Commun ; 5: 5317, 2014 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-25354725

RESUMO

Here, we demonstrate that electroporation-enhanced immunization with a rationally designed HPV DNA vaccine (GX-188E), preferentially targeting HPV antigens to dendritic cells, elicits a significant E6/E7-specific IFN-γ-producing T-cell response in all nine cervical intraepithelial neoplasia 3 (CIN3) patients. Importantly, eight out of nine patients exhibit an enhanced polyfunctional HPV-specific CD8 T-cell response as shown by an increase in cytolytic activity, proliferative capacity and secretion of effector molecules. Notably, seven out of nine patients display complete regression of their lesions and viral clearance within 36 weeks of follow up. GX-188E administration does not elicit serious vaccine-associated adverse events at all administered doses. These findings indicate that the magnitude of systemic polyfunctional CD8 T-cell response is the main contributing factor for histological, cytological and virological responses, providing valuable insights into the design of therapeutic vaccines for effectively treating persistent infections and cancers in humans.


Assuntos
Infecções por Papillomavirus/terapia , Vacinas contra Papillomavirus/uso terapêutico , Displasia do Colo do Útero/terapia , Neoplasias do Colo do Útero/terapia , Vacinas de DNA/uso terapêutico , Adulto , Formação de Anticorpos , Linfócitos T CD8-Positivos/imunologia , Feminino , Humanos , Imunidade Celular , Pessoa de Meia-Idade , Proteínas Oncogênicas Virais/imunologia , Neoplasias do Colo do Útero/virologia , Adulto Jovem , Displasia do Colo do Útero/virologia
20.
J Vestib Res ; 24(5-6): 443-51, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25564087

RESUMO

Diagnosis of central vestibulopathy remains a challenge when it is associated with peripheral vestibular dysfunction because neurotological findings from peripheral vestibulopathy may overshadow those from central vestibular involvements. To define the characteristics of disorders involving both peripheral and central vestibular structures, we classified the combined vestibulopathies into four types according to their vestibular manifestations, and describe a typical case in each subtype. Infarction involving the territory of anterior inferior cerebellar artery is the most common cause of acute unilateral cases, whereas tumors involving the cerebellopontine angle should be of prime suspicion in patients with chronic unilateral ones. Wernicke encephalopathy was most common in patients with acute bilateral combined vestibulopathy while degenerative disorders should be considered in chronic bilateral ones. Since the head impulse test (HIT) is mostly positive in combined vestibulopathy, signs of central vestibular dysfunction other than negative HIT should be sought carefully even in patients with obvious clinical or laboratory features of peripheral vestibulopathy.


Assuntos
Doenças do Sistema Nervoso Central/complicações , Perda Auditiva/etiologia , Infarto da Artéria Cerebral Anterior/complicações , Doenças do Sistema Nervoso Periférico/complicações , Doenças Vestibulares/complicações , Adulto , Idoso de 80 Anos ou mais , Neoplasias do Tronco Encefálico/complicações , Neoplasias do Tronco Encefálico/diagnóstico , Doenças do Sistema Nervoso Central/diagnóstico , Ataxia Cerebelar/complicações , Ataxia Cerebelar/diagnóstico , Feminino , Perda Auditiva Neurossensorial/complicações , Perda Auditiva Neurossensorial/diagnóstico , Hemossiderose/complicações , Hemossiderose/diagnóstico , Humanos , Infarto da Artéria Cerebral Anterior/diagnóstico , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças Vestibulares/classificação , Doenças Vestibulares/diagnóstico , Encefalopatia de Wernicke/complicações , Encefalopatia de Wernicke/diagnóstico
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