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1.
Nutrients ; 16(6)2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38542756

RESUMEN

Obesity is a global health concern. Recent research has suggested that the development of anti-obesity ingredients and functional foods should focus on natural products without side effects. We examined the effectiveness and underlying mechanisms of Brassica juncea extract (BJE) in combating obesity via experiments conducted in both in vitro and in vivo obesity models. In in vitro experiments conducted in a controlled environment, the application of BJE demonstrated the ability to suppress the accumulation of lipids induced by MDI in 3T3-L1 adipocytes. Additionally, it downregulated adipogenic-related proteins peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein-α (C/EBP-α), adipocyte protein 2 (aP2), and lipid synthesis-related protein acetyl-CoA carboxylase (ACC). It also upregulated the heat generation protein peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and fatty acid oxidation protein carnitine palmitoyltransferase-1 (CPT-1). The oral administration of BJE decreased body weight, alleviated liver damage, and inhibited the accumulation of lipids in mice with diet-induced obesity resulting from a high-fat diet. The inhibition of lipid accumulation by BJE in vivo was associated with a decreased expression of adipogenic and lipid synthesis proteins and an increased expression of heat generation and fatty acid oxidation proteins. BJE administration improved obesity by decreasing adipogenesis and activating heat generation and fatty acid oxidation in 3T3-L1 cells and in HFD-induced obese C57BL/6J mice. These results suggest that BJE shows potential as a natural method for preventing metabolic diseases associated with obesity.


Asunto(s)
Fármacos Antiobesidad , Planta de la Mostaza , Ratones , Animales , Células 3T3-L1 , Planta de la Mostaza/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones Endogámicos C57BL , Ratones Obesos , Fármacos Antiobesidad/uso terapéutico , Obesidad/metabolismo , Adipogénesis , Lípidos/farmacología , Ácidos Grasos/farmacología , PPAR gamma/metabolismo
2.
Food Sci Biotechnol ; 33(3): 539-556, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38274178

RESUMEN

Sulforaphane (SFN) is an isothiocyanate commonly found in cruciferous vegetables. It is formed via the enzymatic hydrolysis of glucoraphanin by myrosinase. SFN exerts various biological effects, including anti-cancer, anti-oxidation, anti-obesity, and anti-inflammatory effects, and is widely used in functional foods and clinical medicine. However, the structure of SFN is unstable and easily degradable, and its production is easily affected by temperature, pH, and enzyme activity, which limit its application. Hence, several studies are investigating its physicochemical properties, stability, and biological activity to identify methods to increase its content. This article provides a comprehensive review of the plant sources, extraction and analysis techniques, in vitro and in vivo biological activities, and bioavailability of SFN. This article highlights the importance and provides a reference for the research and application of SFN in the future.

3.
Sci Rep ; 14(1): 922, 2024 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-38195717

RESUMEN

This study focused on a novel strategy that combines deep learning and radiomics to predict epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC) using computed tomography (CT). A total of 1280 patients with NSCLC who underwent contrast-enhanced CT scans and EGFR mutation testing before treatment were selected for the final study. Regions of interest were segmented from the CT images to extract radiomics features and obtain tumor images. These tumor images were input into a convolutional neural network model to extract 512 image features, which were combined with radiographic features and clinical data to predict the EGFR mutation. The generalization performance of the model was evaluated using external institutional data. The internal and external datasets contained 324 and 130 EGFR mutants, respectively. Sex, height, weight, smoking history, and clinical stage were significantly different between the EGFR-mutant patient groups. The EGFR mutations were predicted by combining the radiomics and clinical features, and an external validation dataset yielded an area under the curve (AUC) value of 0.7038. The model utilized 1280 tumor images, radiomics features, and clinical characteristics as input data and exhibited an AUC of approximately 0.81 and 0.78 during the primary cohort and external validation, respectively. These results indicate the feasibility of integrating radiomics analysis with deep learning for predicting EGFR mutations. CT-image-based genetic testing is a simple EGFR mutation prediction method, which can improve the prognosis of NSCLC patients and help establish personalized treatment strategies.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Aprendizaje Profundo , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/genética , Receptores ErbB/genética , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/genética , Mutación , Radiómica
4.
Nat Commun ; 14(1): 8460, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38123571

RESUMEN

Three-dimensional (3D) microprinting is considered a next-generation manufacturing process for the production of microscale components; however, the narrow range of suitable materials, which include mainly polymers, is a critical issue that limits the application of this process to functional inorganic materials. Herein, we develop a generalised microscale 3D printing method for the production of purely inorganic nanocrystal-based porous materials. Our process is designed to solidify all-inorganic nanocrystals via immediate dispersibility control and surface linking-induced interconnection in the nonsolvent linker bath and thereby creates multibranched gel networks. The process works with various inorganic materials, including metals, semiconductors, magnets, oxides, and multi-materials, not requiring organic binders or stereolithographic equipment. Filaments with a diameter of sub-10 µm are printed into designed complex 3D microarchitectures, which exhibit full nanocrystal functionality and high specific surface areas as well as hierarchical porous structures. This approach provides the platform technology for designing functional inorganics-based porous materials.

5.
ACS Nano ; 17(23): 23936-23943, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-37991883

RESUMEN

The electrochemical production of H2O2 via the two-electron oxygen-reduction reaction (2e- ORR) has been actively studied using systems with atomically dispersed metal-nitrogen-carbon (M-N-C) structures. However, the development of well-defined M-N-C structures that restrict the migration and agglomeration of single-metal sites remains elusive. Herein, we demonstrate a Langmuir-Blodgett (LB) monolayer of cobalt phthalocyanine (CoPc) on monolayer graphene (LB CoPc/G) as a single-metal catalyst for the 2e- ORR. The as-prepared CoPc LB monolayer has a ß-form crystalline structure with a lattice space for the facile adsorption of oxygen molecules on the cobalt active sites. The CoPc LB monolayer system provides highly exposed Co atoms in a well-defined structure without agglomeration, resulting in significantly improved catalytic activity, which is manifested by a very high H2O2 production rate per catalyst (31.04 mol gcat-1 h-1) and TOF (36.5 s-1) with constant production stability for 24 hours. To the best of our knowledge, the CoPc LB monolayer system exhibits the highest H2O2 production rate per active site. This fundamental study suggests that an LB monolayer of molecules with single-metal atoms as a well-defined structure works for single-atom catalysts.

6.
Nanoscale ; 15(1): 195-203, 2022 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-36477469

RESUMEN

The electrochemical production of H2O2via the two-electron oxygen reduction reaction (2e- ORR) has recently attracted attention as a promising alternative to the current anthraquinone process. Identification of active sites in O-doped carbon materials, which exhibit high activities and selectivities for the 2e- ORR, is important for understanding the selective electrocatalytic process and achieving the rational design of active electrocatalysts. However, this is impeded by the heterogeneous distribution of various active sites on these catalysts. In this study, we exploited the molecular functionalisation approach to implant anthraquinone, benzoic acid, and phenol groups on carbon nanotubes and systematically compared the electrocatalytic activities and selectivities of these functional groups. Among these oxygen functional groups, the anthraquinone group showed the highest surface-area-normalised and active-site-normalised activities.

7.
Lupus ; 31(14): 1759-1769, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36218127

RESUMEN

OBJECTIVES: The Montreal Cognitive Assessment (MoCA) is an increasingly used screening tool for cognitive impairment. The aim of this study was to examine how MoCA performed in identifying cognitive impairment (CI) domains in SLE patients compared with formal standardized neuropsychological testing (NPT). Factors related to SLE disease, immunologic and psychological state associated with CI were also explored. METHODS: This cross-sectional study recruited 50 SLE patients without overt neuropsychiatric manifestations from April 2017 to May 2018. The patients were evaluated with MoCA, formal NPT and the Depression, Anxiety, and Stress Scales (DASS) 42-item self-report questionnaire. Values of sensitivity and specificity were computed for different cut-offs of MoCA within each cognitive domain of NPT and descriptive analysis was used to identify the factors affecting cognitive function. RESULTS: The median score for MoCA was 27.5 (range 22-30). Using a MoCA cutoff of <26, 18 (36%) were identified to have CI using NPT compared to 8 (16%) using MoCA. The most frequently affected cognitive domain was executive functioning with 15 affected patients. Sensitivities and specificities of the MoCA range from 50% to 100% and 5.7% to 16.7%, respectively, across cognitive domains. A lower MoCA cutoff of <25 improve sensitivity of identifying impairment in executive functioning from 60% to 80%. In univariate analysis, DASS scores, disease activity, presence of antiphospholipid antibodies, presence of concurrent autoimmune disease, current, and cumulative corticosteroid therapy did not predict cognitive performance. CONCLUSION: MoCA may be a useful screening tool to identify the most frequently affected cognitive domain which is executive functioning using a lower cutoff of <25 in SLE patients without overt neuropsychiatric manifestations.


Asunto(s)
Disfunción Cognitiva , Lupus Eritematoso Sistémico , Humanos , Estudios Transversales , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/psicología , Pruebas de Estado Mental y Demencia , Disfunción Cognitiva/etiología , Disfunción Cognitiva/complicaciones , Función Ejecutiva , Pruebas Neuropsicológicas
8.
Sci Rep ; 12(1): 6281, 2022 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-35428854

RESUMEN

In this study, we developed a deep learning model to identify patients with tongue cancer based on a validated dataset comprising oral endoscopic images. We retrospectively constructed a dataset of 12,400 verified endoscopic images from five university hospitals in South Korea, collected between 2010 and 2020 with the participation of otolaryngologists. To calculate the probability of malignancy using various convolutional neural network (CNN) architectures, several deep learning models were developed. Of the 12,400 total images, 5576 images related to the tongue were extracted. The CNN models showed a mean area under the receiver operating characteristic curve (AUROC) of 0.845 and a mean area under the precision-recall curve (AUPRC) of 0.892. The results indicate that the best model was DenseNet169 (AUROC 0.895 and AUPRC 0.918). The deep learning model, general physicians, and oncology specialists had sensitivities of 81.1%, 77.3%, and 91.7%; specificities of 86.8%, 75.0%, and 90.9%; and accuracies of 84.7%, 75.9%, and 91.2%, respectively. Meanwhile, fair agreement between the oncologist and the developed model was shown for cancer diagnosis (kappa value = 0.685). The deep learning model developed based on the verified endoscopic image dataset showed acceptable performance in tongue cancer diagnosis.


Asunto(s)
Aprendizaje Profundo , Neoplasias de la Lengua , Humanos , Redes Neurales de la Computación , Curva ROC , Estudios Retrospectivos , Lengua , Neoplasias de la Lengua/diagnóstico por imagen
9.
ACS Appl Mater Interfaces ; 13(50): 59904-59914, 2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-34882382

RESUMEN

H2O2 electrosynthesis is an emerging clean chemical technology, whose efficiency critically depends on the activity and selectivity of electrocatalysts for two-electron oxygen reduction reaction (2e- ORR). Here, we demonstrate that 2e- ORR activity of oxygen-doped carbons, which have been one of the most promising catalysts for this reaction, can be substantially influenced by the types and concentrations of cations in electrolytes. Heat-treated carbon comprising active oxygen functional groups exhibits cation-dependent 2e- ORR activity trends in alkaline media, following the order Cs+ > K+ > Li+. Importantly, an electrolyte with a high cation concentration (0.1 M KOH + 0.5 M KCl) afforded the highest 2e- ORR mass activity (250 ± 30 A gcat-1 at 0.70 V vs reversible hydrogen electrode) ever reported. We have established that the cation promotion effect correlates with cation-dependent electron-transfer kinetics, which regulates the rate-determining first electron transfer to O2.

10.
Chem Commun (Camb) ; 57(60): 7350-7361, 2021 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-34231572

RESUMEN

Oxygen reduction reaction (ORR) plays a pivotal role in electrochemical energy conversion and commodity chemical production. Oxygen reduction involving a complete four-electron (4e-) transfer is important for the efficient operation of polymer electrolyte fuel cells, whereas the ORR with a partial 2e- transfer can serve as a versatile method for producing industrially important hydrogen peroxide (H2O2). For both the 4e- and 2e- pathway ORR, platinum-group metals (PGMs) have been materials of prevalent choice owing to their high intrinsic activity, but they are costly and scarce. Hence, the development of highly active and selective non-precious metal catalysts is of crucial importance for advancing electrocatalysis of the ORR. Heteroatom-doped carbon-based electrocatalysts have emerged as promising alternatives to PGM catalysts owing to their appreciable activity, tunable selectivity, and facile preparation. This review provides an overview of the design of heteroatom-doped carbon ORR catalysts with tailored 4e- or 2e- selectivities. We highlight catalyst design strategies that promote 4e- or 2e- ORR activity. We also summarise the major active sites and activity descriptors of the respective ORR pathways and describe the catalyst properties controlling the ORR mechanisms. We conclude the review with a summary and suggestions for future research.

11.
Angew Chem Int Ed Engl ; 60(37): 20528-20534, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34263519

RESUMEN

Rational control of the coordination environment of atomically dispersed catalysts is pivotal to achieve desirable catalytic reactivity. We report the reversible control of coordination structure in atomically dispersed electrocatalysts via ligand exchange reactions to reversibly modulate their reactivity for oxygen reduction reaction (ORR). The CO-ligated atomically dispersed Rh catalyst exhibited ca. 30-fold higher ORR activity than the NHx -ligated catalyst, whereas the latter showed three times higher H2 O2 selectivity than the former. Post-treatments of the catalysts with CO or NH3 allowed the reversible exchange of CO and NHx ligands, which reversibly tuned oxidation state of metal centers and their ORR activity and selectivity. DFT calculations revealed that more reduced oxidation state of CO-ligated Rh site could further stabilize the *OOH intermediate, facilitating the two- and four-electron pathway ORR. The reversible ligand exchange reactions were generalized to Ir- and Pt-based catalysts.

12.
Angew Chem Int Ed Engl ; 60(3): 1441-1449, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33043551

RESUMEN

Ordered mesoporous carbons (OMCs) have attracted considerable interest owing to their broad utility. OMCs reported to date comprise amorphous rod-like or tubular or graphitic rod-like frameworks, which exhibit tradeoffs between conductivity and surface area. Here we report ordered mesoporous carbons constructed with graphitic tubular frameworks (OMGCs) with tunable pore sizes and mesostructures via dual templating, using mesoporous silica and molybdenum carbide as exo- and endo-templates, respectively. OMGCs simultaneously realize high electrical conductivity and large surface area and pore volume. Benefitting from these features, Ru nanoparticles (NPs) supported on OMGC exhibit superior catalytic activity for alkaline hydrogen evolution reaction and single-cell performance for anion exchange membrane water electrolysis compared to Ru NPs on other OMCs and commercial catalysts. Further, the OMGC-based full-carbon symmetric cell demonstrates excellent performances for Li-ion capacitors.

13.
Angle Orthod ; 91(2): 206-212, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33289837

RESUMEN

OBJECTIVES: To determine if the depth of corticotomy done with the piezoelectric knife could play a role in the intensity of the regional acceleratory phenomenon (RAP). MATERIALS AND METHODS: Eighteen Sprague-Dawley rats were divided into two groups: untreated (3 rats) and treatment (15 rats). In the treatment group, a split-model design was used. The right tibia received transcortical (deep) penetrations with the piezoelectric knife, while intracortical (shallow) penetrations were performed on the left tibia of the same animal. The rats were euthanized at day 1, 3, 7, 14, and 28. Cone-beam computed tomography scans were taken for each sample and then assessed by histological analysis. RESULTS: Higher amounts of osteoclastic activity and new collagen formation were observed in the deep penetration group when compared with the shallow penetration group. The former peaked at day 14 for both groups (1.53% ± 0.01% vs 0.03% ± 0.0004%, respectively), and the latter peaked at day 28 (0.65 × 106 ± 0.01 vs 0.08 × 106 ± 0.0008, respectively). CONCLUSIONS: Within the limitations of this study, it appears that the intensity of the RAP in the rat is corticotomy depth dependent. This is to be kept in mind when decorticating the bone during surgically facilitated orthodontic procedures.


Asunto(s)
Osteoclastos , Tibia , Animales , Huesos , Tomografía Computarizada de Haz Cónico , Ratas , Ratas Sprague-Dawley , Tibia/diagnóstico por imagen , Tibia/cirugía , Técnicas de Movimiento Dental
14.
Jpn J Clin Oncol ; 49(8): 789-792, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31671191

RESUMEN

A pilot study of biomarker-driven targeted therapy in patients with platinum-resistant recurrent ovarian cancer has been started in Korea. Archival tumor samples were tested for HRD and PD-L1 status. Treatment arms will be allocated according to the test results. For HRD+ patients, we tested the synergistic effects of olaparib and other agents; treatment arms will randomly be allocated. (Arm 1: olaparib and cediranib; Arm 2: olaparib and durvalumab). For HRD- patients, we tested the role of biomarker-driven immunotherapy according to PD-L1 expression (Arm 3: durvalumab and chemotherapy in patients with high PD-L1 expression; Arm 4: durvalumab, tremelimumab, and chemotherapy in patients with low PD-L1 expression). Sixty-eight patients will be included from three Korean institutions within 1 year. The primary endpoint is the response rate according to RECIST 1.1 (6 months after treatment initiation). This trial has been registered with clinicaltrials.gov, and the registration number is NCT03699449.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Resistencia a Antineoplásicos , Terapia Molecular Dirigida , Recurrencia Local de Neoplasia/tratamiento farmacológico , Neoplasias Ováricas/tratamiento farmacológico , Platino (Metal)/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Femenino , Humanos , Neoplasias Ováricas/patología , Proyectos Piloto , República de Corea
15.
Small ; 15(38): e1901793, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31379110

RESUMEN

Band-like transport behavior of H-doped transition metal dichalcogenide (TMD) channels in field effect transistors (FET) is studied by conducting low-temperature electrical measurements, where MoTe2 , WSe2 , and MoS2 are chosen for channels. Doped with H atoms through atomic layer deposition, those channels show strong n-type conduction and their mobility increases without losing on-state current as the measurement temperature decreases. In contrast, the mobility of unintentionally (naturally) doped TMD FETs always drops at low temperatures whether they are p- or n-type. Density functional theory calculations show that H-doped MoTe2 , WSe2 , and MoS2 have Fermi levels above conduction band edge. It is thus concluded that the charge transport behavior in H-doped TMD channels is metallic showing band-like transport rather than thermal hopping. These results indicate that H-doped TMD FETs are practically useful even at low-temperature ranges.

16.
Libyan J Med ; 14(1): 1597327, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30935302

RESUMEN

Many undergoing in vitro fertilization-embryo transfer (IVF-ET) procedures treatments have been tried for older infertile patients, but still can not reverse the aging effect on oocyte, and infertility treatment is expensive, even for people in developed countries. The study aimed to compare outcomes following the application of luteal phase ovulation induction (LPOI) and ultra-short gonadotropin-releasing hormone agonist (GnRH-a) protocols in patients aged more than 40 years undergoing IVF-ET and to examine the effectiveness and feasibility of LPOI. A total of 266 IVF-ET cycles in 155 patients aged 40 years and over were retrospectively analyzed. Of these patients, 105 underwent the ultra-short GnRH-a protocol (GnRH-a group) and 50 underwent LPOI (LPOI group). Various clinical outcomes were compared between these two groups using either t-tests or the chi-square test. The study showed patients in the LPOI group required a higher dosage of human menopausal gonadotropin and a lower dosage of recombinant follicle stimulating hormone than those in the GnRH-a group. Furthermore, though the total dosage of gonadotropin was higher in the LPOI, its cost was lower. Finally, fertilization rates were higher and high-quality embryo rates were lower in the LPOI group, and the live birth rate of LPOI group is higher than (GnRH-a group) . These between-group differences were all significant (P < 0.05). Compared with the ultra-short GnRH-a protocol, LPOI may enable higher 2-pronuclear embryo fertilization rates and lower gonadotropin costs to be achieved, indicating that LPOI might be an ideal choice for older patients undergoing IVF-ET.


Asunto(s)
Transferencia de Embrión/métodos , Fertilización In Vitro , Hormona Liberadora de Gonadotropina/agonistas , Fase Luteínica/fisiología , Inducción de la Ovulación/métodos , Adulto , Factores de Edad , Femenino , Humanos , Edad Materna , Estudios Retrospectivos
17.
Nano Lett ; 19(4): 2456-2463, 2019 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-30855970

RESUMEN

Since transition metal dichalcogenide (TMD) semiconductors are found as two-dimensional van der Waals materials with a discrete energy bandgap, many TMD based field effect transistors (FETs) are reported as prototype devices. However, overall reports indicate that threshold voltage ( Vth) of those FETs are located far away from 0 V whether the channel is p- or n-type. This definitely causes high switching voltage and unintended OFF-state leakage current. Here, a facile way to simultaneously modulate the Vth of both p- and n-channel FETs with TMDs is reported. The deposition of various organic small molecules on the channel results in charge transfer between the organic molecule and TMD channels. Especially, HAT-CN molecule is found to ideally work for both p- and n-channels, shifting their Vth toward 0 V concurrently. As a proof of concept, a complementary metal oxide semiconductor (CMOS) inverter with p-MoTe2 and n-MoS2 channels shows superior voltage gain and minimal power consumption after HAT-CN deposition, compared to its initial performance. When the same TMD FETs of the CMOS structure are integrated into an OLED pixel circuit for ambipolar switching, the circuit with HAT-CN film demonstrates complete ON/OFF switching of OLED pixel, which was not switched off without HAT-CN.

18.
Nano Lett ; 18(3): 1937-1945, 2018 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-29400979

RESUMEN

A van der Waals (vdW) Schottky junction between two-dimensional (2D) transition metal dichalcogenides (TMDs) is introduced here for both vertical and in-plane current devices: Schottky diodes and metal semiconductor field-effect transistors (MESFETs). The Schottky barrier between conducting NbS2 and semiconducting n-MoS2 appeared to be as large as ∼0.5 eV due to their work-function difference. While the Schottky diode shows an ideality factor of 1.8-4.0 with an on-to-off current ratio of 103-105, Schottky-effect MESFET displays little gate hysteresis and an ideal subthreshold swing of 60-80 mV/dec due to low-density traps at the vdW interface. All MESFETs operate with a low threshold gate voltage of -0.5 ∼ -1 V, exhibiting easy saturation. It was also found that the device mobility is significantly dependent on the condition of source/drain (S/D) contact for n-channel MoS2. The highest room temperature mobility in MESFET reaches to approximately more than 800 cm2/V s with graphene S/D contact. The NbS2/n-MoS2 MESFET with graphene was successfully integrated into an organic piezoelectric touch sensor circuit with green OLED indicator, exploiting its predictable small threshold voltage, while NbS2/n-MoS2 Schottky diodes with graphene were applied to extract doping concentrations in MoS2 channel.

19.
Adv Mater ; 29(30)2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28585272

RESUMEN

Recently, α-MoTe2 , a 2D transition-metal dichalcogenide (TMD), has shown outstanding properties, aiming at future electronic devices. Such TMD structures without surface dangling bonds make the 2D α-MoTe2 a more favorable candidate than conventional 3D Si on the scale of a few nanometers. The bandgap of thin α-MoTe2 appears close to that of Si and is quite smaller than those of other typical TMD semiconductors. Even though there have been a few attempts to control the charge-carrier polarity of MoTe2 , functional devices such as p-n junction or complementary metal-oxide-semiconductor (CMOS) inverters have not been reported. Here, we demonstrate a 2D CMOS inverter and p-n junction diode in a single α-MoTe2 nanosheet by a straightforward selective doping technique. In a single α-MoTe2 flake, an initially p-doped channel is selectively converted to an n-doped region with high electron mobility of 18 cm2 V-1 s-1 by atomic-layer-deposition-induced H-doping. The ultrathin CMOS inverter exhibits a high DC voltage gain of 29, an AC gain of 18 at 1 kHz, and a low static power consumption of a few nanowatts. The results show a great potential of α-MoTe2 for future electronic devices based on 2D semiconducting materials.

20.
Int J Med Robot ; 13(4)2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28371219

RESUMEN

BACKGROUND: Despite its evident clinical benefits, single-incision laparoscopic surgery (SILS) imposes inherent limitations of collision between external arms and inadequate triangulation because multiple instruments are inserted through a single port at the same time. METHODS: A robot platform appropriate for SILS was developed wherein an elbowed instrument can be equipped to easily create surgical triangulation without the interference of robot arms. A novel joint mechanism for a surgical instrument actuated by a rigid link was designed for high torque transmission capability. RESULTS: The feasibility and effectiveness of the robot was checked through three kinds of preliminary tests: payload, block transfer, and ex vivo test. Measurements showed that the proposed robot has a payload capability >15 N with 7 mm diameter. CONCLUSIONS: The proposed robot is effective and appropriate for SILS, overcoming inadequate triangulation and improving workspace and traction force capability.


Asunto(s)
Procedimientos Quirúrgicos Robotizados/instrumentación , Procedimientos Quirúrgicos Robotizados/métodos , Robótica/instrumentación , Fenómenos Biomecánicos , Diseño de Equipo , Mano/fisiología , Humanos , Laparoscopía/instrumentación , Acero Inoxidable
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