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1.
Eur Rev Med Pharmacol Sci ; 26(15): 5426-5435, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35993638

RESUMEN

OBJECTIVE: An otoacoustic emission (OAE) is a low-level sound emitted by the cochlea. OAEs are able to objectively evaluate the auditory perception and reflect the functional status of the auditory system. With the characteristics of non-invasiveness, high reliability, and easy manipulation, OAEs have gained wide popularity in clinical audiology and anesthesiology. This review aims to summarize the application of OAE in anesthesia. MATERIALS AND METHODS: This study collected data from the databases Web of Science-Clarivate Analytics, PubMed, and Google Scholar in English, covering research in the last 40 years. The keywords were defined as anesthesia, cochlea, OAEs, distortion product otoacoustic emissions, transient evoked otoacoustic emissions, bispectral index, auditory evoked potentials, and depth of anesthesia. Documents that matched defined keywords were selected and reviewed. RESULTS: Research showed that the types and doses of anesthetic drugs impacted OAEs. Ketamine-based anesthesia has a greater effect on OAE sensitivity over time compared to isoflurane. A higher dose of ketamine-xylazine significantly reduced the amplitude of OAEs. According to those characteristics, OAEs could be used as an objective evaluation method for the effect of anesthetics and have great potential to be applied for anesthetic drug dose control during surgery. OAEs also have been used to detect the cochlear function during anesthesia, which may cause irreversible damage to the cochlea. CONCLUSIONS: Studies reported that OAEs have been used in anesthesia. However, the existing studies have mainly focused on the influence of anesthetic types or dosages on OAEs. Considering the characteristics of OAEs, such as a convenient measurement, less susceptibility to interference, and fast detection speed, the application of OAE has a great potential in the anesthesia field.


Asunto(s)
Anestesia , Ketamina , Estimulación Acústica , Cóclea , Ketamina/farmacología , Emisiones Otoacústicas Espontáneas/fisiología , Reproducibilidad de los Resultados
3.
Artículo en Chino | MEDLINE | ID: mdl-34666442

RESUMEN

Objective: To investigate the variation regularity and influencing factors of cortical auditory evoked potential (CAEP) evoked by pure tone, syllable and tone stimuli in cochlear implant (CI) children. Methods: Cortical auditory evoked potential (CAEP) responses were collected from 46 CI children in the sound field. Pure tones with frequencies of 1 kHz and 2 kHz were used as the standard and the deviant respectively in the pure tone stimulation condition. The Chinese Mandarin tokens/ba/-/pa/and/ba1/-/ba4/pairs were used as the stimuli respectively in the syllable and tone stimulation condition. The latency, amplitude and presence rate of P1 and mismatch negative(MMN) were obtained and the correlation between the difficulty of auditory task, the age of hearing month, the duration of severe-profound hearing loss, the wearing history of hearing aid before CI, the hearing threshold of the better ear before CI and the latency and amplitude of P1 and MMN were analyzed. All statistical analyses and figures were conducted using SPSS 25.0. Results: The P1 presence rate of pure tone, syllable and tone group was 100% (17/17), 100% (13/13) and 75.0% (12/16), respectively, with significant difference (χ²=8.214, P=0.016). There was significant difference between pure tone group and tone group (χ²=4.836, P=0.028), but no significant difference between pure tone group and syllable group, syllable group and tone group. The MMN presence rate of pure tone, syllable and tone group was 94.1% (16/17), 84.6% (11/13) and 62.5% (10/16), respectively, but no significant difference among the three groups with different auditory tasks(χ²=0.066, P=0.066). No significant difference was observed among the three groups of different auditory tasks in the latency and amplitude of P1 and MMN. Multiple linear regression analysis showed that the latency of P1 was positively correlated with the difficulty of auditory task and the hearing threshold of the better ear before CI, and negatively correlated with hearing age and the history of hearing aid before CI. The latency of MMN was positively correlated with the difficulty of auditory task, and negatively correlated with hearing age. Conclusions: The P1 presence rate of pure tone auditory task is significantly higher than that of tone auditory task. The difficulty of auditory task, hearing age, the history of hearing aid before CI, and the hearing threshold of the better ear before CI has significant effects on the P1 latency. The difficulty of auditory task and hearing age has significant effects on the MMN latency.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Audífonos , Estimulación Acústica , Niño , Potenciales Evocados Auditivos , Audición , Humanos
4.
Nat Commun ; 12(1): 5741, 2021 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-34593793

RESUMEN

Twisted two-dimensional van der Waals (vdW) heterostructures have unlocked a new means for manipulating the properties of quantum materials. The resulting mesoscopic moiré superlattices are accessible to a wide variety of scanning probes. To date, spatially-resolved techniques have prioritized electronic structure visualization, with lattice response experiments only in their infancy. Here, we therefore investigate lattice dynamics in twisted layers of hexagonal boron nitride (hBN), formed by a minute twist angle between two hBN monolayers assembled on a graphite substrate. Nano-infrared (nano-IR) spectroscopy reveals systematic variations of the in-plane optical phonon frequencies amongst the triangular domains and domain walls in the hBN moiré superlattices. Our first-principles calculations unveil a local and stacking-dependent interaction with the underlying graphite, prompting symmetry-breaking between the otherwise identical neighboring moiré domains of twisted hBN.

5.
Nat Commun ; 12(1): 5266, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34489461

RESUMEN

The time-resolved magneto-optical (MO) Voigt effect can be utilized to study the Néel order dynamics in antiferromagnetic (AFM) materials, but it has been limited for collinear AFM spin configuration. Here, we have demonstrated that in Mn3Sn with an inverse triangular spin structure, the quench of AFM order by ultrafast laser pulses can result in a large Voigt effect modulation. The modulated Voigt angle is significantly larger than the polarization rotation due to the crystal-structure related linear dichroism effect and the modulated MO Kerr angle arising from the ferroic ordering of cluster magnetic octupole. The AFM order quench time shows negligible change with increasing temperature approaching the Néel temperature (TN), in markedly contrast with the pronounced slowing-down demagnetization typically observed in conventional magnetic materials. This atypical behavior can be explained by the influence of weakened Dzyaloshinskii-Moriya interaction rather than the smaller exchange splitting on the diminished AFM order near TN. The temperature-insensitive ultrafast spin manipulation can pave the way for high-speed spintronic devices either working at a wide range of temperature or demanding spin switching near TN.

6.
Nat Commun ; 10(1): 4780, 2019 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-31636265

RESUMEN

Photonic crystals are commonly implemented in media with periodically varying optical properties. Photonic crystals enable exquisite control of light propagation in integrated optical circuits, and also emulate advanced physical concepts. However, common photonic crystals are unfit for in-operando on/off controls. We overcome this limitation and demonstrate a broadly tunable two-dimensional photonic crystal for surface plasmon polaritons. Our platform consists of a continuous graphene monolayer integrated in a back-gated platform with nano-structured gate insulators. Infrared nano-imaging reveals the formation of a photonic bandgap and strong modulation of the local plasmonic density of states that can be turned on/off or gradually tuned by the applied gate voltage. We also implement an artificial domain wall which supports highly confined one-dimensional plasmonic modes. Our electrostatically-tunable photonic crystals are derived from standard metal oxide semiconductor field effect transistor technology and pave a way for practical on-chip light manipulation.

7.
Nat Commun ; 10(1): 4360, 2019 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-31554808

RESUMEN

Properties of atomic van der Waals heterostructures are profoundly influenced by interlayer coupling, which critically depends on stacking of the proximal layers. Rotational misalignment or lattice mismatch of the layers gives rise to a periodic modulation of the stacking, the moiré superlattice. Provided the superlattice period extends over many unit cells, the coupled layers undergo lattice relaxation, leading to the concentration of strain at line defects - solitons - separating large area commensurate domains. We visualize such long-range periodic superstructures in thin crystals of hexagonal boron nitride using atomic-force microscopy and nano-infrared spectroscopy. The solitons form sub-surface hexagonal networks with periods of a few hundred nanometers. We analyze the topography and infrared contrast of these networks to obtain spatial distribution of local strain and its effect on the infrared-active phonons of hBN.

8.
Br Poult Sci ; 60(5): 517-521, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31185729

RESUMEN

1. Generating a robust egg albumen is one of the major factors contributing to interior egg quality owing to its nutritive value and superior appearance. However, the genetic factors regulating the proportion of thick albumen are poorly understood. 2. In this study, 1330 eggs were collected from 450 Rhode Island White layers, aged 40 weeks, to measure egg compositional traits for three successive days. The restricted maximum likelihood method was applied to estimate genetic parameters for the thick-to-thin albumen ratio and other egg compositional traits. A univariate animal model was fitted to calculate heritability for each trait. 3. The heritabilities of egg weight, yolk weight, albumen height, Haugh units, percentages of yolk, thick albumen, thin albumen and the thick-to-thin albumen ratio were 0.32, 0.34, 0.28, 0.47, 0.61, 0.39, 0.31, and 0.45, respectively. The percentage of thick albumen was negatively correlated genetically with all traits, and percentage of thin albumen was negatively correlated genetically with all traits except for Haugh units. The thick-to-thin albumen ratio was positively correlated genetically with egg weight, albumen height and Haugh units, with correlations ranging from 0.21 to 0.54. 4. The results indicated that the percentage of thick albumen and the thick-to-thin albumen ratio were found to be moderately to highly heritable, and selection for the thick-to-thin albumen ratio could be conducive to the improvement of egg albumen quality.


Asunto(s)
Albúminas/análisis , Pollos/fisiología , Yema de Huevo/fisiología , Óvulo/fisiología , Albúminas/química , Animales , Pollos/genética , Femenino , Herencia , Óvulo/química
9.
Science ; 362(6419): 1153-1156, 2018 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-30523109

RESUMEN

Graphene is an atomically thin plasmonic medium that supports highly confined plasmon polaritons, or nano-light, with very low loss. Electronic properties of graphene can be drastically altered when it is laid upon another graphene layer, resulting in a moiré superlattice. The relative twist angle between the two layers is a key tuning parameter of the interlayer coupling in thus-obtained twisted bilayer graphene (TBG). We studied the propagation of plasmon polaritons in TBG by infrared nano-imaging. We discovered that the atomic reconstruction occurring at small twist angles transforms the TBG into a natural plasmon photonic crystal for propagating nano-light. This discovery points to a pathway for controlling nano-light by exploiting quantum properties of graphene and other atomically layered van der Waals materials, eliminating the need for arduous top-down nanofabrication.

10.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 53(10): 712-715, 2018 Oct 09.
Artículo en Chino | MEDLINE | ID: mdl-30392231

RESUMEN

Three dimentional printing is a new rapid prototyping technology based on digital model files, which developed through a combination of multi-disciplines such as information technology, precision machinery and materials science. With rapid development in recent years, three dimentional printing technology has been widely used in the medical fields, stomatology especially. It gradually penetrates into various parts of stomatology, such as education, practice and innovation, making stomatology clinical medicine more and more efficient, accurate and minimally invasive. Combined with basic research and clinical cases, this article describes the application and developent prospects of three dimentional printing technology in stomatology.


Asunto(s)
Medicina Oral , Impresión Tridimensional
11.
J Dairy Sci ; 101(10): 9108-9127, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30077450

RESUMEN

Cost-effective high-density (HD) genotypes of livestock species can be obtained by genotyping a proportion of the population using a HD panel and the remainder using a cheaper low-density panel, and then imputing the missing genotypes that are not directly assayed in the low-density panel. The efficacy of genotype imputation can largely be affected by the structure and history of the specific target population and it should be checked before incorporating imputation in routine genotyping practices. Here, we investigated the efficacy of imputation in crossbred dairy cattle populations of East Africa using 4 different commercial single nucleotide polymorphisms (SNP) panels, 3 reference populations, and 3 imputation algorithms. We found that Minimac and a reference population, which included a mixture of crossbred and ancestral purebred animals, provided the highest imputation accuracy compared with other scenarios of imputation. The accuracies of imputation, measured as the correlation between real and imputed genotypes averaged across SNP, were around 0.76 and 0.94 for 7K and 40K SNP, respectively, when imputed up to a 770K panel. We also presented a method to maximize the imputation accuracy of low-density panels, which relies on the pairwise (co)variances between SNP and the minor allele frequency of SNP. The performance of the developed method was tested in a 5-fold cross-validation process where various densities of SNP were selected using the (co)variance method and also by alternative SNP selection methods and then imputed up to the HD panel. The (co)variance method provided the highest imputation accuracies at almost all marker densities, with accuracies being up to 0.19 higher than the random selection of SNP. The accuracies of imputation from 7K and 40K panels selected using the (co)variance method were around 0.80 and 0.94, respectively. The presented method also achieved higher accuracy of genomic prediction at lower densities of selected SNP. The squared correlation between genomic breeding values estimated using imputed genotypes and those from the real 770K HD panel was 0.95 when the accuracy of imputation was 0.64. The presented method for SNP selection is straightforward in its application and can ensure high accuracies in genotype imputation of crossbred dairy populations in East Africa.


Asunto(s)
Bovinos/genética , Genómica , Genotipo , Polimorfismo de Nucleótido Simple , África Oriental , Animales , Cruzamiento , Genoma
12.
Nature ; 557(7706): 530-533, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29795255

RESUMEN

Plasmon polaritons are hybrid excitations of light and mobile electrons that can confine the energy of long-wavelength radiation at the nanoscale. Plasmon polaritons may enable many enigmatic quantum effects, including lasing 1 , topological protection2,3 and dipole-forbidden absorption 4 . A necessary condition for realizing such phenomena is a long plasmonic lifetime, which is notoriously difficult to achieve for highly confined modes 5 . Plasmon polaritons in graphene-hybrids of Dirac quasiparticles and infrared photons-provide a platform for exploring light-matter interaction at the nanoscale6,7. However, plasmonic dissipation in graphene is substantial 8 and its fundamental limits remain undetermined. Here we use nanometre-scale infrared imaging to investigate propagating plasmon polaritons in high-mobility encapsulated graphene at cryogenic temperatures. In this regime, the propagation of plasmon polaritons is primarily restricted by the dielectric losses of the encapsulated layers, with a minor contribution from electron-phonon interactions. At liquid-nitrogen temperatures, the intrinsic plasmonic propagation length can exceed 10 micrometres, or 50 plasmonic wavelengths, thus setting a record for highly confined and tunable polariton modes. Our nanoscale imaging results reveal the physics of plasmonic dissipation and will be instrumental in mitigating such losses in heterostructure engineering applications.

13.
Br J Biomed Sci ; 74(4): 187-192, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28745139

RESUMEN

BACKGROUND: Circulating miRNAs are potential biomarkers of the pathogenesis of certain diseases and in monitoring therapeutic responses. We hypothesized that serum miR-29 can determine risk of acute cardiac allograft rejection. METHODS: Peripheral vein blood was collected from 50 healthy volunteers and 506 patients during post-transplant surveillance. Serum cardiac troponin I (cTnI) and miR-29 was detected by ELISA and qRT-PCR assay respectively. Rejection risk was defined as International Society of Heart and Lung Transplant score from leukocyte infiltration of an endomyocardial biopsy. No evidence of rejection was defined as grade R0, mild as R1, moderate as 2R and severe as 3R. Specificity and sensitivity of miR-29 to discriminate rejection was determined by the area under the curve (AUC) of receiver operating characteristic curve analysis. Correlations between miR29 and rejection grade were compared. RESULTS: Serum miR-29 was 100.8 ± 42.4 copies/µl in R0 groups (P = 0.164 versus controls), 537.5 ± 84.3 copies/µl in R1 groups (P = 0.024) and 1478.4 ± 198.7 copies/µl in the joint R2/R3 groups (P = 0.001). MiR-29 was 1963.5 ± 214.7 six months after transplantation, 1242.5 ± 103.8 after a year, 825.6 ± 58.2 after 2 years, 413.8 ± 61.9 after 3 years and 270.6 ± 34.6 ng/mL after 4 years (P < 0.001). The level of miR-29 correlated positively with cTnI, NT-proBNP, white blood cell counts, and negatively with lymphocyte counts (all P < 0.001). The AUC values (95% CI) for discriminating R0 and R1 was 0.81 (0.75-0.89), and was 0.79 (0.72-0.86) for R0 and R2/R3 (both P < 0.01). CONCLUSION: miR-29 is a promising predictor of the risk of heart transplant rejection.


Asunto(s)
Rechazo de Injerto/etiología , Rechazo de Injerto/genética , Trasplante de Corazón/efectos adversos , MicroARNs/sangre , Enfermedad Aguda , Biomarcadores/sangre , Femenino , Humanos , Masculino , MicroARNs/genética , Persona de Mediana Edad , Curva ROC , Factores de Riesgo
14.
J Anim Breed Genet ; 134(3): 242-255, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28508487

RESUMEN

Selection decisions in genomic selection schemes are made based on genomic breeding values (GBV) of candidates. Thus, the accuracy of GBV is a relevant parameter, as it reflects the stability of prediction and the possibility that the GBV might change when more information becomes available. Accuracy of genomic prediction defined as the correlation between GBV and true breeding values (TBV), however, is difficult to assess, considering TBV of the candidates are not available in reality. In previous studies, several methods were proposed to assess the accuracy of GBV including methods using population parameters or parameters inferred from mixed-model equations. In practice, most approaches tended to overestimate the accuracy of genomic prediction. We thus tested approaches used in previous studies in order to assess the magnitude of bias. Analyses were performed based on simulated data under a variety of scenarios mimicking different livestock breeding programmes. Furthermore, we proposed a novel method and tested it both with simulated data and in a real Holstein data set. The new method provided a better prediction for the accuracy of GBV in the simulated scenarios.


Asunto(s)
Cruzamiento , Genómica/métodos , Modelos Genéticos , Carácter Cuantitativo Heredable , Animales , Bovinos , Simulación por Computador , Femenino , Frecuencia de los Genes , Variación Genética , Genética de Población , Masculino , Linaje
15.
Zhonghua Yi Xue Za Zhi ; 97(13): 1001-1005, 2017 Apr 04.
Artículo en Chino | MEDLINE | ID: mdl-28395418

RESUMEN

Objectives: To investigate the therapeutic effects of intravenous thrombolysis, intra-artery thrombolysis, mechanical thrombectomy on patients with acute vertebrobasilar occlusion. Methods: Retrospective analysis of clinical data of patients with acute vertebrobasilar occlusion, admitted to Huai'an First People's Hospital and Bingtuan Qishi Hospital from January 2014 to January 2016, was performed. According to different vascular recanalization, these patients were divided into intravenous thrombolysis group, intra-artery thrombolysis group and mechanical thrombectomy group. Clinical outcomes were compared among the three groups such as recanalization rates( modified thrombolysis in cerebral infarction[mTICI]≥2b), changes of NIHSS scores after 24 hours(scores decreased at least 4 points or complete resolution of symptoms), symptomatic cerebral hemorrhage rate(European Cooperative Acute Stroke Study Ⅱ standard) and modified Rankin scale(mRS) score improvement 3 months after treatment. Results: Among patients from mechanical thrombectomy group, the recanalization rate was 87.5%(28/32), 22 patients(68.8%)got good outcome according to the significant decrease of NIHSS scores, symptomatic intracranial hemorrhage occurred in 3 patient (9.4%), the rate of good prognosis(mRS≤2) at 3 months was 50.0% (16/32). In patients from intravenous thrombolysis group, the rate of recanalization was 34.8% (16/46), 12 patients(26.1%)got apparent decrease of NIHSS scores, symptomatic cerebral hemorrhage occurred in 14 patients(30.4%), the rate of good clinical outcome(mRS ≤2) at 3 months was 17.4%(8/46). Among patients from intra-arterial thrombolysis group, the recanalization rate was 53.3%(16/30), 12 patients(40.0%) got good outcome according to the significant decrease in NIHSS score, symptomatic intracranial hemorrhage occurred in 6 patients(20.0%), the rate of good prognosis(mRS≤2) at 3 months was 26.7%(8/30). The rate of complete recanalization and NIHSS score improvement at 24 hours were significantly higher in the mechanical thrombectomy group than the intravenous or intra-arterial thrombolysis group(χ(2)=21.324, P<0.001; χ(2)=14.162, P=0.001). The good outcome(mRS≤2) at 3 months was more frequent in the mechanical thrombectomy group than the intravenous or intra-arterial thrombolysis group (χ(2)=9.799, P=0.007). The differences of symptomatic intracranial hemorrhage rate among the three treatment groups were not statistically significant(χ(2)=5.035, P=0.081). Conclusion: As compared with the intravenous or intra-arterial thrombolysis, the mechanical thrombectomy has better efficiency and safety in the treatment of acute vertebrobasilar occlusion.


Asunto(s)
Arteriopatías Oclusivas/cirugía , Trombectomía , Humanos , Hemorragias Intracraneales , Estudios Retrospectivos , Accidente Cerebrovascular , Resultado del Tratamiento
16.
Eur Rev Med Pharmacol Sci ; 21(3): 470-478, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28239825

RESUMEN

OBJECTIVE: Bone formation/remodeling-associated biomarkers, such as osteocalcin, amino pro-peptide of type 1 collagen (P1NP) and CrossLaps (CTX) have been deregulated in type 2 diabetes mellitus (T2DM) patients. In particular, the T2DM-associated sclerostin markedly inhibits the bone formation, suppresses the osteoblast activity and downregulates the bone turnover. PATIENTS AND METHODS: In the present study, we examined the serum levels of sclerostin, osteocalcin, P1NP and CTX in the T2DM patients. We evaluated the regulation on osteocalcin, P1NP and CTX by sclerostin treatment in osteoblast hFOB 1.19 cells. Finally, we determined the mediation of Wnt signaling in the regulation by sclerostin on osteocalcin, P1NP and CTX in human osteoblast hFOB 1.19 cells. RESULTS: It was demonstrated that osteocalcin, P1NP and CTX were downregulated in the femur fracture of patients with T2DM, whereas the serum level of the sclerostin was markedly higher in the femur fracture of patients with T2DM. Moreover, the downregulated osteocalcin, P1NP or CTX was negatively associated with the upregulated sclerostin. In vitro results confirmed that sclerostin downregulated the expression of osteocalcin, P1NP and CTX in hFOB 1.19 cells. Also, our results demonstrated that Wnt/ß-catenin inhibition was associated with the sclerostin-mediated inhibition of osteocalcin, P1NP and CTX in hFOB 1.19 cells. The Wnt/ß-catenin level was markedly inhibited by sclerostin treatment, and the siRNA-mediated downregulation of ß-catenin reduced the levels of osteocalcin, P1NP and CTX. CONCLUSIONS: Our study demonstrated that the upregulated serum sclerostin level in the T2DM patients with fracture inhibited the expression of the bone formation/remodeling-associated biomarkers via antagonizing Wnt signaling. It suggests that sclerostin might be an effective target for T2DM-associated bone fracture and delayed fracture healing.


Asunto(s)
Proteínas Morfogenéticas Óseas/sangre , Remodelación Ósea , Diabetes Mellitus Tipo 2/sangre , Fracturas Óseas/sangre , Osteogénesis , Vía de Señalización Wnt , Proteínas Adaptadoras Transductoras de Señales , Adulto , Biomarcadores/sangre , Línea Celular , Colágeno/sangre , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Fémur/patología , Marcadores Genéticos , Humanos , Masculino , Persona de Mediana Edad , Osteocalcina/sangre , Fragmentos de Péptidos/sangre , Procolágeno/sangre , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
17.
Nano Lett ; 16(12): 7842-7848, 2016 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-27960518

RESUMEN

We report on a nanoinfrared (IR) imaging study of ultraconfined plasmonic hotspots inside graphene nanobubbles formed in graphene/hexagonal boron nitride (hBN) heterostructures. The volume of these plasmonic hotspots is more than one-million-times smaller than what could be achieved by free-space IR photons, and their real-space distributions are controlled by the sizes and shapes of the nanobubbles. Theoretical analysis indicates that the observed plasmonic hotspots are formed due to a significant increase of the local plasmon wavelength in the nanobubble regions. Such an increase is attributed to the high sensitivity of graphene plasmons to its dielectric environment. Our work presents a novel scheme for plasmonic hotspot formation and sheds light on future applications of graphene nanobubbles for plasmon-enhanced IR spectroscopy.

18.
Phys Rev Lett ; 117(8): 086801, 2016 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-27588873

RESUMEN

We show that the surface plasmons of a two-dimensional Dirac metal such as graphene can be reflected by linelike perturbations hosting one-dimensional electron states. The reflection originates from a strong enhancement of the local optical conductivity caused by optical transitions involving these bound states. We propose that the bound states can be systematically created, controlled, and liquidated by an ultranarrow electrostatic gate. Using infrared nanoimaging, we obtain experimental evidence for the locally enhanced conductivity of graphene induced by a carbon nanotube gate, which supports this theoretical concept.

19.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 5961-5964, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28269610

RESUMEN

We present finite element (FE) modeling approaches of ear mechanics including 3-dimensional (3D) reconstruction of the human middle and inner ear. Specifically, we demonstrate a semi-automatic methodology for the 3D reconstruction of the inner ear structures, a FE harmonic response model of the middle ear to predict the stapes footplate frequency response, a 2D FE slice model of the cochlea for the coupled response at the micromechanical level for either acoustic or electrical excitation and a coupled FE middle ear model with a simplified cochlea box model to simulate the basilar membrane velocity in response to acoustic excitation. The proposed methodologies are validated against experimental and literature data and the results are in good agreement.


Asunto(s)
Cóclea/ultraestructura , Oído Interno/ultraestructura , Oído Medio/ultraestructura , Microtomografía por Rayos X/métodos , Membrana Basilar , Cóclea/anatomía & histología , Oído Interno/anatomía & histología , Oído Medio/anatomía & histología , Análisis de Elementos Finitos , Humanos , Modelos Biológicos
20.
J Hazard Mater ; 303: 41-7, 2016 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-26513562

RESUMEN

The excess sludge from Up-flow anaerobic sludge bed (UASB) reactor operated on source separated toilet wastewater is a potential source of nutrients and organic matter. It can be further stabilized and dried by composting and applied as a soil amendment. Presence of pathogens, heavy metals and micropollutants in the compost derived from anaerobic sludge is thus undesirable. This paper focuses on removal of micropollutants, typically present in domestic wastewater, via composting of UASB sludge with waste wood. Estrone, diclofenac, ibuprofen, metoprolol, carbamazepine, galaxolide and triclosan were spiked to a mixture of UASB sludge and waste wood. Their concentrations were monitored during 92 days of composting at controlled temperature conditions. All studied micropollutants were removed at various rates with overall removal ranging from 99.9% for ibuprofen, diclofenac and estrone to 87.8% for carbamazepine. Accumulation of methyltriclosan as by-product of triclosan degradation was observed. The prospects and limitations of the integration of a composting process into Source Separated Sanitation concepts are discussed.


Asunto(s)
Agricultura , Aguas del Alcantarillado/análisis , Suelo , Contaminantes Químicos del Agua/análisis , Anaerobiosis , Biodegradación Ambiental , Dióxido de Carbono/análisis , Oxígeno/análisis , Eliminación de Residuos Líquidos , Aguas Residuales , Contaminantes Químicos del Agua/aislamiento & purificación
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