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1.
Int J Mol Sci ; 25(15)2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39125585

RESUMO

Acute respiratory distress syndrome (ARDS) occurs as an acute onset condition, and patients present with diffuse alveolar damage, refractory hypoxemia, and non-cardiac pulmonary edema. ARDS progresses through an initial exudative phase, an inflammatory phase, and a final fibrotic phase. Pirfenidone, a powerful anti-fibrotic agent, is known as an agent that inhibits the progression of fibrosis in idiopathic pulmonary fibrosis. In this study, we studied the treatment efficiency of pirfenidone on lipopolysaccharide (LPS) and bleomycin-induced ARDS using rats. The ARDS rat model was created by the intratracheal administration of 3 mg/kg LPS of and 3 mg/kg of bleomycin dissolved in 0.2 mL of normal saline. The pirfenidone treatment group was administered 100 or 200 mg/kg of pirfenidone dissolved in 0.5 mL distilled water orally 10 times every 2 days for 20 days. The administration of LPS and bleomycin intratracheally increased lung injury scores and significantly produced pro-inflammatory cytokines. ARDS induction increased the expressions of transforming growth factor (TGF)-ß1/Smad-2 signaling factors. Additionally, matrix metalloproteinase (MMP)-9/tissue inhibitor of metalloproteinase (TIMP)-1 imbalance occurred, resulting in enhanced fibrosis-related factors. Treatment with pirfenidone strongly suppressed the expressions of TGF-ß1/Smad-2 signaling factors and improved the imbalance of MMP-9/TIMP-1 compared to the untreated group. These effects led to a decrease in fibrosis factors and pro-inflammatory cytokines, promoting the recovery of damaged lung tissue. These results of this study showed that pirfenidone administration suppressed inflammation and fibrosis in the ARDS animal model. Therefore, pirfenidone can be considered a new early treatment for ARDS.


Assuntos
Bleomicina , Lipopolissacarídeos , Piridonas , Síndrome do Desconforto Respiratório , Transdução de Sinais , Animais , Piridonas/farmacologia , Piridonas/uso terapêutico , Síndrome do Desconforto Respiratório/tratamento farmacológico , Síndrome do Desconforto Respiratório/metabolismo , Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/induzido quimicamente , Transdução de Sinais/efeitos dos fármacos , Ratos , Masculino , Bleomicina/efeitos adversos , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Proteína Smad2/metabolismo , Ratos Sprague-Dawley , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Modelos Animais de Doenças , Metaloproteinase 9 da Matriz/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Pulmão/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Proteínas Smad/metabolismo
2.
Small ; 19(33): e2300223, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37093184

RESUMO

Memristors are drawing attention as neuromorphic hardware components because of their non-volatility and analog programmability. In particular, electrochemical metallization (ECM) memristors are extensively researched because of their linear conductance controllability. Two-dimensional materials as switching medium of ECM memristors give advantages of fast speed, low power consumption, and high switching uniformity. However, the multistate retention in the switching conductance range for the long-term reliable neuromorphic system has not been achieved using two-dimensional materials-based ECM memristors. In this study, the copper migration-controlled ECM memristor showing excellent multistate retention characteristics in the switching conductance range using molybdenum disulfide (MoS2 ) and aluminum oxide (Al2 O3 ) is proposed. The fabricated device exhibits gradual resistive switching with low switching voltage (<0.5 V), uniform switching (σ/µ âˆ¼ 0.07), and a wide switching range (>12). Importantly, excellent reliabilities with robustness to cycling stress and retention over 104 s for more than 5-bit states in the switching conductance range are achieved. Moreover, the contribution of the Al2 O3 layer to the retention characteristic is investigated through filament morphology observation using transmission electron microscopy (TEM) and copper migration component analysis. This study provides a practical approach to developing highly reliable memristors with exceptional switching performance.

3.
Medicina (Kaunas) ; 57(11)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34833384

RESUMO

Background and Objectives: When performing the jump inside kick in Wushu, it is important to understand the rotation technique while in mid-air. This is because the score varies according to the mid-air rotation, and when landing after the mid-air rotation, it causes considerable injury to the knee. This study aimed to compare the differences in kinematic and kinetic variables between experienced and less experienced knee injuries in the Wushu players who perform 360°, 540°, and 720° jump inside kicks in self-taolu. Materials and Methods: The participants' mean (SD) age was 26.12 (2.84) years old. All of them had suffered knee injuries and were all recovering and returning to training. The group was classified into a group with less than 20 months of injury experience (LESS IG, n = 6) and a group with more than 20 months of injury experience (MORE IG, n = 6). For kinematic measurements, jump inside kicks at three rotations were assessed by using high-speed cameras. For kinetic measurements, the contraction time and maximal displacement of tensiomyography were assessed in the vastus lateralis, vastus medialis, rectus femoris, biceps femoris, gastrocnemius lateralis, gastrocnemius medialis, and tibialis anterior. The peak torque, work per repetition, fatigue index, and total work of isokinetic moments were assessed using knee extension/flexion, ankle inversion/eversion, and ankle plantarflexion/dorsiflexion tests. Results: Although there was no difference at the low difficulty level (360°), there were significant differences at the higher difficulty levels (540° and 720°) between the LESS IG and the MORE IG. For distance and time, the LESS IG had a shorter jump distance, but a faster rotation time compared to those in the MORE IG. Due to the characteristics of the jump inside kick's rotation to the left, the static and dynamic muscle contractility properties were mainly found to be higher in the left lower extremity than in the right lower extremity, and higher in the LESS IG than in the MORE IG. In addition, this study observed that the ankle plantarflexor in the LESS IG was significantly higher than that in the MORE IG. Conclusion: To become a world-class self-taolu athlete while avoiding knee injuries, it is necessary to develop the static and dynamic myofunctions of the lower extremities required for jumping. Moreover, it is considered desirable to train by focusing on the vertical height and the amount of rotation during jumping.


Assuntos
Traumatismos do Joelho , Artes Marciais , Adulto , Fenômenos Biomecânicos , Humanos , Articulação do Joelho , Músculo Esquelético
4.
Acta Anaesthesiol Scand ; 64(10): 1431-1437, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32659862

RESUMO

BACKGROUND: A variety of rapid response systems (RRSs) based on the systematic assessment of vital signs and laboratory tests have been developed to reduce hospital mortality through the early detection of alarm signs, while deterioration may still be reversible. This study aimed to determine the association between alarm signs and post-operative hospital mortality during post-operative days (POD) 0-3 in patients undergoing non-cardiac surgery. METHODS: This retrospective observational study used data from the registry of a single tertiary academic hospital. The study population included patients who were ≥18 years old, admitted between 1 January 2013 and 30 June 2018 for non-cardiac surgery, and subsequently transferred to the general ward. RESULTS: A total of 116 329 patients were included in the analysis. Among them, 10 099 patients (8.7%) showed positive alarm criteria and triggered the RRS in the post-operative ward during POD 0-3. In the multivariate logistic regression model, PaO2 <55 mm Hg, SpO2 <90%, and total CO2 <15 mmol/L were associated with a 3.57-, 3.46-, and 12.53-fold increase in post-operative hospital mortality, respectively. Moreover, when compared to the no alarm signs group, patients with 1, 2, 3, and ≥4 alarm signs showed a 2.79-, 2.76-, 6.54-, and 20.02-fold increase in hospital mortality, respectively. CONCLUSION: Increased post-operative hospital mortality was found to be associated with alarm signs detected by the RRS during POD 0-3. The post-operative alarm signs detected by the RRS may therefore be useful in determining high-risk patients who require medical interventions in the surgical ward.


Assuntos
Hospitais , Sinais Vitais , Mortalidade Hospitalar , Humanos , Período Pós-Operatório , Estudos Retrospectivos
5.
Nano Lett ; 19(2): 839-849, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30608706

RESUMO

With the advent of artificial intelligence (AI), memristors have received significant interest as a synaptic building block for neuromorphic systems, where each synaptic memristor should operate in an analog fashion, exhibiting multilevel accessible conductance states. Here, we demonstrate that the transition of the operation mode in poly(1,3,5-trivinyl-1,3,5-trimethyl cyclotrisiloxane) (pV3D3)-based flexible memristor from conventional binary to synaptic analog switching can be achieved simply by reducing the size of the formed filament. With the quantized conductance states observed in the flexible pV3D3 memristor, analog potentiation and depression characteristics of the memristive synapse are obtained through the growth of atomically thin Cu filament and lateral dissolution of the filament via dominant electric field effect, respectively. The face classification capability of our memristor is evaluated via simulation using an artificial neural network consisting of pV3D3 memristor synapses. These results will encourage the development of soft neuromorphic intelligent systems.


Assuntos
Cobre/química , Nanoestruturas/química , Nanotecnologia/instrumentação , Redes Neurais de Computação , Siloxanas/química , Inteligência Artificial , Condutividade Elétrica , Desenho de Equipamento , Face/anatomia & histologia , Humanos , Nanotecnologia/métodos
6.
J Environ Manage ; 239: 103-113, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30897476

RESUMO

This study aimed to investigate the comparative effects of oxygenates such as ethanol (EA), methyl tertiary-butyl ether (MTBE), and ethyl tertiary butyl ether (ETBE) by fixing the oxygen contents as 0.82 wt% 1.65 wt%, and 2.74 wt% of the fuels on the regulated (CO, NMHC and NOx) and unregulated (formaldehyde, acetaldehyde and BTEX) exhaust emissions in gasoline-powered vehicles. The most widely used type of vehicles (light-duty, medium-duty, heavy-duty) in Korea were tested on a chassis dynamometer under the CVS-75 Cycle. When EA, MTBE and ETBE percentage increased, the CO and NMHC concentration decreased. The NOx emission decreased at 1.65 wt% and 2.74 wt% oxygen content of MTBE and ETBE. The emissions of CO decreased by 0.363 g/km, 0.266 g/km and 0.356 g/km for light-duty vehicle when EA, MTBE and ETBE oxygenates blending ratio increased. Increased EA, MTBE and ETBE oxygenates blending ratio demonstrated no specific reducing effect on CO emissions from low-mileage vehicle, but NMHC emissions decreased by 0.011 g/km (medium-duty), 0.015 g/km (light-duty) and 0.018 g/km (heavy-duty). More CO was emitted from MTBE among three oxygenates at same oxygen content. The emitted concentrations of NMHC from three oxygenates at same oxygen content were almost similar, but reduced NOx emissions from EA (10%) to MTBE (20.4%) and ETBE (23.6%) were observed at 2.74 wt% oxygen content. Reducing effect on CO emissions was order of EA > ETBE > MTBE. Formaldehyde emissions increased up to 54.3% as MTBE ratio increased. When oxygen content of ETBE, EA, and MTBE increased from 0.82 wt% to 2.74 wt%, the acetaldehyde emissions increased up to 177.4%, 39.5% and 31.0%, respectively. There was significant formaldehyde concentration difference between high emission vehicle type (light-duty and medium-duty) and low emission vehicle type (heavy-duty and low-mileage) for three oxygenates. Reduction effect of MTBE and ETBE on BTEX was the order of toluene > benzene > ethylbenzene > xylene, and MTBE showed more reduction effect than ETBE at same oxygen content.


Assuntos
Poluentes Atmosféricos , Éteres Metílicos , Éteres , Gasolina , República da Coreia , Emissões de Veículos
7.
Anal Chem ; 90(15): 8769-8775, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-29790330

RESUMO

Lead(II) acetate [Pb(Ac)2] reacts with hydrogen sulfide to form colored brownish precipitates of lead sulfide. Thus far, in order to detect leakage of H2S gas in industrial sectors, Pb(Ac)2 has been used as an indicator in the form of test papers with a detection limit only as low as 5 ppm. Diagnosis of halitosis by exhaled breath needs sensors able to detect down to 1 ppm of H2S gas. In this work, high surface area and porous Pb(Ac)2 anchored nanofibers (NFs) that overcome limitations of the conventional Pb(Ac)2-based H2S sensor are successfully achieved. First, lead(II) acetate, which melts at 75 °C, and polyacrylonitrile (PAN) polymer are mixed and stirred in dimethylformamide (DMF) solvent at 85 °C, enabling uniform dispersion of fine liquid droplets in the electrospinning solution. During the subsequent electrospinning, Pb(Ac)2 anchored NFs are obtained, providing an ideal nanostructure with high thermal stability against particle aggregation, numerous reactions sites, and enhanced diffusion of H2S into the three-dimensional (3D)-networked NF web. This newly obtained sensing material can detect down to 400 ppb of H2S at a relative humidity of 90%, exhibiting high potential feasibility as a high-performance colorimetric sensor platform for diagnosis of halitosis.


Assuntos
Colorimetria/métodos , Sulfeto de Hidrogênio/análise , Nanofibras/química , Compostos Organometálicos/química , Resinas Acrílicas/química , Testes Respiratórios/métodos , Halitose/diagnóstico , Humanos , Limite de Detecção , Nanofibras/ultraestrutura , Porosidade
8.
J Environ Manage ; 206: 291-303, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29096143

RESUMO

Concentration levels and seasonal variation of odorous gases at landfill site and in surrounding areas within the city of Incheon, South Korea were investigated. Sampling was conducted at 11 points (5 at landfill site and 6 in surrounding areas). The highest concentrations of odorous gases (complex odor, ammonia, acetaldehyde, and VOCs) at landfill site were found in summer, probably due to fast decomposition of waste in high temperature related with more release of ammonia. In addition, specific weather condition of dominant wind direction, humidity and higher atmospheric pressure with no or lower wind speed caused positive effect of higher aldehyde compounds and VOCs concentration. Similar to other studies, sludge-related sampling site S-2, where a couple of odor generating facilities including sludge mixing and drying treatment process are located, showed the highest concentration levels of odorous gases compared to other sites. Odor generation frequency was in the order of acetaldehyde (68.8%) > ammonia (39.4%) > propionaldehyde (21.9%), which means the main substances generating the unpleasant odor at landfill site was recognized as aldehydes and ammonia due to combined effect of sludge-related facilities and meteorological conditions. Offensive odor was not a big pollution issue in most surrounding areas which are located within a circle of 5 km radius of the landfill except high odor generation frequency of acetaldehyde and propionaldehyde. Relative percentage differences (RPD) of odorous gases between day and night times at landfill site were below 10%, which indicates that the concentration differences in day and night were not severe. The relationship between concentrations of complex odor and designated offensive odor substances was analyzed statistically. At landfill site, the analysis shows that the correlation coefficient between the concentration of complex odor and ammonia was quite high (0.833), but it was much lower (0.129) in the surrounding areas due to considerably lower concentrations of these substances.


Assuntos
Poluentes Atmosféricos , Odorantes , Instalações de Eliminação de Resíduos , Cidades , Monitoramento Ambiental , Gases , Eliminação de Resíduos , República da Coreia
9.
J Sports Sci ; 34(21): 2114-20, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26930152

RESUMO

There are few studies on the relationship between skeletal muscle mass and balance in the young ages. We investigated the relationship between appendicular skeletal muscle mass, isokinetic muscle strength of lower extremity, and balance among healthy young men using relative skeletal muscle index. Thirty men were grouped according to relative appendicular skeletal muscle mass index: higher skeletal muscle group (n = 15) and lower skeletal muscle group (n = 15). Static and dynamic balance abilities were measured using the following: a test where participants stood on one leg with eyes closed, a modified Clinical Test of Sensory Interaction on Balance (mCTSIB) with eyes open and eyes closed, a stability test, and limits of stability test. The muscle strength of lower extremities was measured with an isokinetic analyser in hip, knee, and ankle joints. Participants with higher appendicular skeletal muscle mass were significantly more stable in maintaining dynamic balance than those with lower appendicular skeletal muscle mass. Moreover, appendicular skeletal muscle mass index was positively correlated with dynamic balance ability. Participants with higher appendicular skeletal muscle mass had stronger strength in the lower extremity, and there were significant differences in the isokinetic torque ratios between groups. From these results, it can be inferred that higher appendicular skeletal muscle mass relates to muscle strength and the alteration in the peak torque ratio of the lower extremity, contributing to the maintenance of balance.


Assuntos
Extremidade Inferior , Força Muscular , Músculo Esquelético/anatomia & histologia , Equilíbrio Postural , Adulto , Fenômenos Biomecânicos , Humanos , Masculino , Movimento , Músculo Esquelético/fisiologia , Tamanho do Órgão , Aptidão Física , Valores de Referência , Torque , Adulto Jovem
10.
Adv Sci (Weinh) ; 11(23): e2308847, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38566434

RESUMO

Electrolyte-gated synaptic transistors (EGSTs) have attracted considerable attention as synaptic devices owing to their adjustable conductance, low power consumption, and multi-state storage capabilities. To demonstrate high-density EGST arrays, 2D materials are recommended owing to their excellent electrical properties and ultrathin profile. However, widespread implementation of 2D-based EGSTs has challenges in achieving large-area channel growth and finding compatible nanoscale solid electrolytes. This study demonstrates large-scale process-compatible, all-solid-state EGSTs utilizing molybdenum disulfide (MoS2) channels grown through chemical vapor deposition (CVD) and sub-30 nm organic-inorganic hybrid electrolyte polymers synthesized via initiated chemical vapor deposition (iCVD). The iCVD technique enables precise modulation of the hydroxyl group density in the hybrid matrix, allowing the modulation of proton conduction, resulting in adjustable synaptic performance. By leveraging the tunable iCVD-based hybrid electrolyte, the fabricated EGSTs achieve remarkable attributes: a wide on/off ratio of 109, state retention exceeding 103, and linear conductance updates. Additionally, the device exhibits endurance surpassing 5 × 104 cycles, while maintaining a low energy consumption of 200 fJ/spike. To evaluate the practicality of these EGSTs, a subset of devices is employed in system-level simulations of MNIST handwritten digit recognition, yielding a recognition rate of 93.2%.

11.
Med Intensiva (Engl Ed) ; 47(7): 383-390, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36243630

RESUMO

OBJECTIVE: To determine which method of Positive End-expiratory Pressure (PEEP) titration is more useful, and to establish an evidence base for the clinical impact of Electrical Impedance Tomography (EIT) based individual PEEP setting which appears to be a promising method to optimize PEEP in Acute Respiratory Distress Syndrome (ARDS) patients. DESIGN: A systematic review and meta-analysis. SETTING: 4 databases (PUBMED, EMBASE, Web Of Science, and the Cochrane Library) from 1980 to December 2020 were performed. PARTICIPANTS: Randomized clinical trials patients with ARDS. MAIN VARIABLES: PaO2/FiO2-ratio and respiratory system compliance. INTERVENSION: The quality of the studies was assessed with the Cochrane risk and bias tool. RESULTS: 8 trials, including a total of 222 participants, were eligible for analysis. Meta-analysis demonstrates a significantly EIT-based individual PEEP setting for patients receiving higher PaO2/FiO2 ratio as compared to other PEEP titration strategies [5 trials, 202 patients, SMD 0.636, (95% CI 0.364-0.908)]. EIT-drived PEEP titration strategy did not significantly increase respiratory system compliance when compared to other peep titration strategies, [7 trials, 202 patients, SMD -0.085, (95% CI -0.342 to 0.172)]. CONCLUSIONS: The benefits of PEEP titration with EIT on clinical outcomes of ARDS in placebo-controlled trials probably result from the visible regional ventilation of EIT. These findings offer clinicians and stakeholders a comprehensive assessment and high-quality evidence for the safety and efficacy of the EIT-based individual PEEP setting as a superior option for patients who undergo ARDS.


Assuntos
Síndrome do Desconforto Respiratório , Tomografia Computadorizada por Raios X , Humanos , Síndrome do Desconforto Respiratório/terapia , Pulmão , Respiração com Pressão Positiva/métodos , Fenômenos Fisiológicos Respiratórios
12.
Adv Mater ; 35(46): e2305222, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37607534

RESUMO

High-entropy alloys (HEAs) provide unprecedented physicochemical properties over unary nanoparticles (NPs). According to the conventional alloying guideline (Hume-Rothery rule), however, only size-and-structure similar elements can be mixed, limiting the possible combinations of alloying elements. Recently, it has been reported that based on carbon thermal shocks (CTS) in a vacuum atmosphere at high temperature, ultrafast heating/cooling rates and high-entropy environment play a critical role in the synthesis of HEAs, ruling out the possibility of phase separation. Since the CTS requires conducting supports, the Joule-heating efficiencies rely on the carbon qualities, featuring difficulties in uniform heating along the large area. This work proposes a photo-thermal approach as an alternative and innovative synthetic method that is compatible with ambient air, large-area, remote process, and free of materials selection. Single flash irradiation on carbon nanofibers induced momentary high-temperature annealing (>1800 °C within 20 ms duration, and ramping/cooling rates >104 K s-1 ) to successfully decorate HEA NPs up to nine elements with excellent compatibility for large-scale synthesis (6.0 × 6.0 cm2 of carbon nanofiber paper). To demonstrate their feasibility toward applications, senary HEA NPs (PtIrFeNiCoCe) are designed and screened, showing high activity (ηoverall = 777 mV) and excellent stability (>5000 cycles) at the water splitting, including hydrogen evolution reactions and oxygen evolution reactions.

13.
Adv Mater ; 35(24): e2300023, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36938884

RESUMO

With advances in artificial intelligent services, brain-inspired neuromorphic systems with synaptic devices are recently attracting significant interest to circumvent the von Neumann bottleneck. However, the increasing trend of deep neural network parameters causes huge power consumption and large area overhead of a nonlinear neuron electronic circuit, and it incurs a vanishing gradient problem. Here, a memristor-based compact and energy-efficient neuron device is presented to implement a rectifying linear unit (ReLU) activation function. To emulate the volatile and gradual switching of the ReLU function, a copolymer memristor with a hybrid structure is proposed using a copolymer/inorganic bilayer. The functional copolymer film developed by introducing imidazole functional groups enables the formation of nanocluster-type pseudo-conductive filaments by boosting the nucleation of Cu nanoclusters, causing gradual switching. The ReLU neuron device is successfully demonstrated by integrating the memristor with amorphous InGaZnO thin-film transistors, and achieves 0.5 pJ of energy consumption based on sub-10 µA operation current and high-speed switching of 650 ns. Furthermore, device-to-system-level simulation using neuron devices on the MNIST dataset demonstrates that the vanishing gradient problem is effectively resolved by five-layer deep neural networks. The proposed neuron device will enable the implementation of high-density and energy-efficient hardware neuromorphic systems.

14.
Mater Horiz ; 10(6): 2035-2046, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37039721

RESUMO

Memristive synapses based on conductive bridging RAMs (CBRAMs) utilize a switching layer having low binding energy with active metals for excellent analog conductance modulation, but the resulting unstable conductive filaments cause fluctuation and drift of the conductance. This tunability-stability dilemma makes it difficult to implement practical neuromorphic computing. A novel method is proposed to enhance the stability and controllability of conductive filaments by introducing imidazole groups that boost the nucleation of Cu nanoclusters in the ultrathin polymer switching layer through the initiated chemical vapor deposition (iCVD) process. It is confirmed that conductive filaments based on nanoclusters with specific gaps are generated in the copolymer medium using this method. Furthermore, by modulating the tunneling gaps, an ultra-wide conductance range of analog tunable conductive filaments is achieved from several hundreds of nS to a few mS with a sub-1 V driving voltage. Through this, both reliable and stable analog switching are achieved with low cycle-to-cycle and device-to-device weight update variations and separable state retention with 32 states. This approach paves the way for the extension of state availability in synaptic devices to overcome the tunability-stability dilemma, which is essential for the synaptic elements in neuromorphic systems.

15.
ACS Nano ; 17(23): 23347-23358, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37801574

RESUMO

Single-atom catalysts feature interesting catalytic activity toward applications that rely on surface reactions such as electrochemical energy storage, catalysis, and gas sensors. However, conventional synthetic approaches for such catalysts require extended periods of high-temperature annealing in vacuum systems, limiting their throughput and increasing their production cost. Herein, we report an ultrafast flash-thermal shock (FTS)-induced annealing technique (temperature > 2850 °C, <10 ms duration, and ramping/cooling rates of ∼105 K/s) that operates in an ambient-air environment to prepare single-atom-stabilized N-doped graphene. Melamine is utilized as an N-doping source to provide thermodynamically favorable metal-nitrogen bonding sites, resulting in a uniform and high-density atomic distribution of single metal atoms. To demonstrate the practical utility of the single-atom-stabilized N-doped graphene produced by the FTS method, we showcased their chemiresistive gas sensing capabilities and electrocatalytic activities. Overall, the air-ambient, ultrafast, and versatile (e.g., Co, Ni, Pt, and Co-Ni dual metal) FTS method provides a general route for high-throughput, large area, and vacuum-free manufacturing of single-atom catalysts.

16.
N Am Spine Soc J ; 11: 100133, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35800731

RESUMO

Background: Synovial cysts are benign fluid-filled sacs commonly found in the degenerative lumbar spine. Few studies have reported the detailed epidemiology and standardized therapy for this disease. Conservative treatment is recommended if synovial cysts are asymptomatic or show mild clinical symptoms. If percutaneous facet joint steroid injections are ineffective or neurologic symptoms are aggravated, the open decompression with additional fusion is the reasonable surgical strategy to remove the pain generator. Furthermore, the synovial cysts that occur at the cervicothoracic spine are infrequently, especially accompanied by hemorrhagic radiographic evidence. Therefore, we describe the efficacy and safety of the full-endoscopy surgical procedure assisted by intraoperative O-arm navigation guidance to manage C7/T1 spinal synovial cysts. Case description: We describe a 71-year-old male patient diagnosed with cervicothoracic hemorrhagic synovial cysts. The pathologic site is located at the posterior side of the C7 vertebral body to the medial side of the C7-T1 left facet joint. Herein is described a step-by-step protocol for the full-endoscopic procedure via the posterior approach to remove the lesions under intraoperative O-arm navigation guidance. Outcome: The patient was successfully treated via full-endoscopic removal of the synovial cysts guided by intraoperative O-arm navigation. Intraoperative bleeding of 30 mL occurred, and the operative time was 150 minutes. The patient's sensory strength improved, and no opioid medicine was required with no complications postoperatively. One-year follow-up magnetic resonance imaging (MRI) and computed tomography (CT) scans showed no synovial cyst recurrence. Conclusions: Full-endoscopy assisted with intraoperative O-arm navigation guidance improves precision and safety in treating patients with synovial cysts of the cervicothoracic spine. The O-arm navigation system improves the efficiency and safety of intraoperative positioning at the cervicothoracic lesion and reduces radiation exposure to the surgeons. Meanwhile, this technique preserves the range of cervicothoracic motion and facilitates the patient return to normal life.

17.
Nutrients ; 14(11)2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35684117

RESUMO

The initial nutritional delivery policy for patients with sepsis admitted to the intensive care unit (ICU) has not been fully elucidated. We aimed to determine whether an initial adequate nutrition supply and route of nutrition delivery during the first week of sepsis onset improve clinical outcomes of critically ill patients with sepsis. We reviewed adult patients with sepsis and septic shock in the ICU in a single tertiary teaching hospital between 31 November 2013 and 20 May 2017. Poisson log-linear and Cox regressions were performed to assess the relationships between clinical outcomes and sex, modified nutrition risk in the critically ill score, sequential organ failure assessment score, route of nutrition delivery, acute physiology and chronic health evaluation score, and daily energy and protein delivery during the first week of sepsis onset. In total, 834 patients were included. Patients who had a higher protein intake during the first week of sepsis onset had a lower in-hospital mortality (adjusted hazard ratio (HR), 0.55; 95% confidence interval (CI), 0.39−0.78; p = 0.001). A higher energy intake was associated with a lower 30-day mortality (adjusted HR, 0.94; 95% CI, 0.90−0.98; p = 0.003). The route of nutrition delivery was not associated with 1-year mortality in the group which was underfed; however, in patients who met > 70% of their nutritional requirement, enteral feeding (EN) with supplemental parenteral nutrition (PN) was superior to only EN (p = 0.016) or PN (p = 0.042). In patients with sepsis and septic shock, a high daily average protein intake may lower in-hospital mortality, and a high energy intake may lower the 30-day mortality, especially in those with a high modified nutrition risk in the critically ill scores. In patients who receive adequate energy, EN with supplemental PN may be better than only EN or PN, but not in underfed patients.


Assuntos
Desnutrição , Sepse , Choque Séptico , Adulto , Estado Terminal/terapia , Humanos , Tempo de Internação , Apoio Nutricional , Estudos Retrospectivos , Sepse/terapia , Choque Séptico/terapia
18.
Nanoscale ; 14(11): 4304-4311, 2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35244667

RESUMO

In spite of having a large exciton binding energy, two-dimensional (2D) transition metal dichalcogenides (TMDs) are limited as light-emitting materials because the spectral weight of neutral excitons decreases exponentially with increasing the excitation density. That is, neutral excitons easily transfer to trions, and exciton-exciton annihilation (EEA) occurs due to the strengthening of exciton kinetic energy in the layered structure. In here, we come up with an isolated neutral exciton system, maintaining its high spectral weight when the carrier density increased, which is achieved via MoS2 clusters on a MoS2 trilayer directly synthesized by metal-organic chemical vapor deposition (MOCVD). While increasing the excitation density, trions are decomposed by spatial confinement at the saturation level of its full width at half maximum (FWHM), and simultaneously the spectral weight of neutral excitons restarts to increase. Furthermore, we reveal the causality relationship between trions and B excitons, providing a keen insight into organic interactions among radiative recombination processes in 2D TMDs.

19.
ACS Nano ; 16(11): 18133-18142, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36108309

RESUMO

The process of exsolution for the synthesis of strongly anchored metal nanoparticles (NPs) on host oxide lattices has been proposed as a promising strategy for designing robust catalyst-support composite systems. However, because conventional exsolution processes occur in harsh reducing environments at high temperatures for long periods of time, the choice of support materials and dopant metals are limited to those with inherently high thermal and chemical stability. Herein, we report the exsolution of a series of noble metal catalysts (Pt, Rh, and Ir) from metal oxide nanofibers (WO3 NFs) supports in an entirely ambient environment induced by intense pulsed light (IPL)-derived momentary photothermal treatment (>1000 °C). Since the exsolution process spans an extremely short period of time (<20 ms), unwanted structural artifacts such as decreased surface area and phase transition of the support materials are effectively suppressed. At the same time, exsolved NPs (<5 nm) with uniform size distributions could successfully be formed. To prove the practical utility of exsolved catalytic NPs functionalized on WO3 NFs, the chemiresistive gas sensing characteristics of exsolved Pt-decorated WO3 NFs were analyzed, exhibiting high durability (>200 cyclic exposures), enhanced response (Rair/Rgas > 800 @ 1 ppm/350 °C), and selectivity toward H2S target gas. Altogether, we successfully demonstrated that ultrafast exsolution within a few milliseconds could be induced in ambient conditions using the IPL-derived momentary photothermal treatment and contributed to expanding the practical viability of the exsolution-based synthetic approaches for the production of highly stable catalyst systems.

20.
J Clin Med ; 10(5)2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33801384

RESUMO

Determining the peri-implant marginal bone level on radiographs is challenging because the boundaries of the bones around implants are often unclear or the heights of the buccal and lingual bone levels are different. Therefore, a deep convolutional neural network (CNN) was evaluated for detecting the marginal bone level, top, and apex of implants on dental periapical radiographs. An automated assistant system was proposed for calculating the bone loss percentage and classifying the bone resorption severity. A modified region-based CNN (R-CNN) was trained using transfer learning based on Microsoft Common Objects in Context dataset. Overall, 708 periapical radiographic images were divided into training (n = 508), validation (n = 100), and test (n = 100) datasets. The training dataset was randomly enriched by data augmentation. For evaluation, average precision, average recall, and mean object keypoint similarity (OKS) were calculated, and the mean OKS values of the model and a dental clinician were compared. Using detected keypoints, radiographic bone loss was measured and classified. No statistically significant difference was found between the modified R-CNN model and dental clinician for detecting landmarks around dental implants. The modified R-CNN model can be utilized to measure the radiographic peri-implant bone loss ratio to assess the severity of peri-implantitis.

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