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1.
Nano Lett ; 23(16): 7633-7641, 2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37558214

RESUMEN

Assembling plasmonic nanocrystals in regular superlattices can produce effective optical properties not found in homogeneous materials. However, the range of these metamaterial properties is limited when a single nanocrystal composition is selected for the constituent meta-atoms. Here, we show how continuously varying doping at two length scales, the atomic and nanocrystal scales, enables tuning of both the frequency and bandwidth of the collective plasmon resonance in nanocrystal-based metasurfaces, while these features are inextricably linked in single-component superlattices. Varying the mixing ratio of indium tin oxide nanocrystals with different dopant concentrations, we use large-scale simulations to predict the emergence of a broad infrared spectral region with near-zero permittivity. Experimentally, tunable reflectance and absorption bands are observed, owing to in- and out-of-plane collective resonances. These spectral features and the predicted strong near-field enhancement establish this multiscale doping strategy as a powerful new approach to designing metamaterials for optical applications.

2.
Nano Lett ; 23(7): 3030-3037, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-36989531

RESUMEN

Optical properties of nanoparticle assemblies reflect distinctive characteristics of their building blocks and spatial organization, giving rise to emergent phenomena. Integrated experimental and computational studies have established design principles connecting the structure to properties for assembled clusters and superlattices. However, conventional electromagnetic simulations are too computationally expensive to treat more complex assemblies. Here we establish a fast, materials agnostic method to simulate the optical response of large nanoparticle assemblies incorporating both structural and compositional complexity. This many-bodied, mutual polarization method resolves limitations of established approaches, achieving rapid, accurate convergence for configurations including thousands of nanoparticles, with some overlapping. We demonstrate these capabilities by reproducing experimental trends and uncovering far- and near-field mechanisms governing the optical response of plasmonic semiconductor nanocrystal assemblies including structurally complex gel networks and compositionally complex mixed binary superlattices. This broadly applicable framework will facilitate the design of complex, hierarchically structured, and dynamic assemblies for desired optical characteristics.

3.
J Am Chem Soc ; 144(50): 22941-22949, 2022 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-36472892

RESUMEN

Crystallographic defects are essential to the functional properties of semiconductors, controlling everything from conductivity to optical properties and catalytic activity. In nanocrystals, too, defect engineering with extrinsic dopants has been fruitful. Although intrinsic defects like vacancies can be equally useful, synthetic strategies for controlling their generation are comparatively underdeveloped. Here, we show that intrinsic defect concentration can be tuned during the synthesis of colloidal metal oxide nanocrystals by the addition of metal salts. Although not incorporated in the nanocrystals, the metal salts dissociate at high temperatures, promoting the dissociation of carboxylate ligands from metal precursors, leading to the introduction of oxygen vacancies. For example, the concentration of oxygen vacancies can be controlled up to 9% in indium oxide nanocrystals. This method is broadly applicable as we demonstrate by generating intrinsic defects in metal oxide nanocrystals of various morphologies and compositions.


Asunto(s)
Nanopartículas del Metal , Sales (Química) , Óxidos , Metales , Oxígeno
4.
Sensors (Basel) ; 22(19)2022 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-36236667

RESUMEN

This paper presents a fast design optimization using an effective characteristic analysis for linear permanent magnet motors (LPMMs) with techniques for improving motor performance such as using an auxiliary tooth, permanent magnet (PM) skew, and overhang structures. These techniques have different effects on the characteristics of the LPMM depending on the combinations of each other, resulting in complexity in the design optimization process. In particular, the three-dimensional (3-D) effect of the PM skew and overhang structure takes a lot of time to be analyzed. To deal with this problem, an effective magnetic field analysis method and a novel optimization algorithm are proposed. Preferentially, the field reconstruction method is used for a fast and accurate evaluation of the magnetic field of the LPMM. In the proposed magnetic field analysis method, the change of magnetic field distribution due to the addition of an auxiliary tooth is predicted, and the 3-D magnetic field effect of PM skew and overhang structure is considered. By reducing the computational burden in the magnetic field analysis, the electromagnetic characteristics of LPMMs can be calculated quickly, such as detent force, end force, thrust force, and back-EMF. The effect of the auxiliary tooth and overhang structure on the optimal PM skew length is investigated with comparative study results. Subsequently, the proposed optimization algorithm has the advantage of reducing time cost by providing multimodal optimization and robustness evaluation of local peaks at the same time. The proposed method is verified via comparison with finite element analysis and experimental results.


Asunto(s)
Algoritmos , Imanes , Fenómenos Electromagnéticos , Análisis de Elementos Finitos , Campos Magnéticos
5.
J Chem Phys ; 152(1): 014709, 2020 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-31914766

RESUMEN

A synthetic challenge in faceted metal oxide nanocrystals (NCs) is realizing tunable localized surface plasmon resonance (LSPR) near-field response in the infrared (IR). Cube-shaped nanoparticles of noble metals exhibit LSPR spectral tunability limited to visible spectral range. Here, we describe the colloidal synthesis of fluorine, tin codoped indium oxide (F,Sn:In2O3) NC cubes with tunable IR range LSPR for around 10 nm particle sizes. Free carrier concentration is tuned through controlled Sn dopant incorporation, where Sn is an aliovalent n-type dopant in the In2O3 lattice. F shapes the NC morphology into cubes by functioning as a surfactant on the {100} crystallographic facets. Cube shaped F,Sn:In2O3 NCs exhibit narrow, shape-dependent multimodal LSPR due to corner, edge, and face centered modes. Monolayer NC arrays are fabricated through a liquid-air interface assembly, further demonstrating tunable LSPR response as NC film nanocavities that can heighten near-field enhancement (NFE). The tunable F,Sn:In2O3 NC near-field is coupled with PbS quantum dots, via the Purcell effect. The detuning frequency between the nanocavity and exciton is varied, resulting in IR near-field dependent enhanced exciton lifetime decay. LSPR near-field tunability is directly visualized through IR range scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS). STEM-EELS mapping of the spatially confined near-field in the F,Sn:In2O3 NC array interparticle gap demonstrates elevated NFE tunability in the arrays.

6.
Bioorg Med Chem Lett ; 28(16): 2741-2745, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-29510880

RESUMEN

Surgical methods guided by exogenous fluorescent markers have the potential to define tissue types in real time. Small molecule dyes with efficient and selective renal clearance could enable visualization of the ureter during surgical procedures involving the abdomen and pelvis. These studies report the design and synthesis of a water soluble, net neutral C4'-O-alkyl heptamethine cyanine, Ureter-Label (UL)-766, with excellent properties for ureter visualization. This compound is accessed through a concise synthetic sequence involving an N- to O-transposition reaction that provides other inaccessible C4'-O-alkyl heptamethine cyanines. Unlike molecules containing a C4'-O-aryl substituent, which have also been used for ureter visualization, UL-766 is not reactive towards glutathione and the cellular proteome. In addition, rat models of abdominal surgery reveal that UL-766 undergoes efficient and nearly exclusive renal clearance in vivo. In total, this molecule represents a promising candidate for visualizing the ureter during a variety of surgical interventions.


Asunto(s)
Colorantes Fluorescentes/química , Uréter/química , Animales , Biomarcadores/química , Relación Dosis-Respuesta a Droga , Colorantes Fluorescentes/administración & dosificación , Colorantes Fluorescentes/farmacocinética , Células HEK293 , Humanos , Inyecciones Intravenosas , Estructura Molecular , Ratas , Relación Estructura-Actividad , Distribución Tisular
7.
Korean J Physiol Pharmacol ; 18(3): 211-6, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24976760

RESUMEN

Endoplasmic reticulum (ER) stress, unfolded protein response (UPR), and mitochondrial biogenesis were assessed following varying intensities of exercise training. The animals were randomly assigned to receive either low- (LIT, n=7) or high intensity training (HIT, n=7), or were assigned to a control group (n=7). Over 5 weeks, the animals in the LIT were exercised on a treadmill with a 10° incline for 60 min at a speed of 20 m/min group, and in the HIT group at a speed of 34 m/min for 5 days a week. No statistically significant differences were found in the body weight, plasma triglyceride, and total cholesterol levels across the three groups, but fasting glucose and insulin levels were significantly lower in the exercise-trained groups. Additionally, no statistically significant differences were observed in the levels of PERK phosphorylation in skeletal muscles between the three groups. However, compared to the control and LIT groups, the level of BiP was lower in the HIT group. Compared to the control group, the levels of ATF4 in skeletal muscles and CHOP were significantly lower in the HIT group. The HIT group also showed increased PGC-1α mRNA expression in comparison with the control group. Furthermore, both of the trained groups showed higher levels of mitochondrial UCP3 than the control group. In summary, we found that a 5-week high-intensity exercise training routine resulted in increased mitochondrial biogenesis and decreased ER stress and apoptotic signaling in the skeletal muscle tissue of rats.

8.
Front Vet Sci ; 11: 1400139, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38840642

RESUMEN

Introduction: Intramedullary cord tumors present diagnostic and therapeutic challenges. Furthermore, spinal cord tumors can move across compartments, making antemortem diagnosis difficult, even with advanced imaging. This report presents a rare case of a cranial cervical spinal glioma, confirmed by surgical histopathology, with postoperative improvement in a dog. Case description: A 9-year-old female Maltese dog presented with kyphotic posture, progressive left hemiparesis, and decreased appetite. Neurological examination revealed neck pain and decreased proprioception in the left limbs along with intact deep pain perception. Two days later, the patient developed non-ambulatory tetraparesis. Magnetic resonance imaging (MRI) revealed an ovoid, well-defined mass with homogeneously marked contrast enhancement in the second cervical spinal cord that severely compressed the spinal cord. This mass was heterogeneously hyperintense on T2-weighted images and iso-to-hypointense on T1-weighted images, showing an appearance resembling the "golf-tee" and "dural tail" signs. The MRI findings suggested an intradural extramedullary tumor. Intraoperatively, a well-demarcated mass which was locally adherent to the spinal meninges was removed. Both histopathological and genomic tumor tests were indicative of a glioma. Approximately 2 weeks postoperatively, the patient's neurological signs returned to normal. Conclusion: This case report describes an atypical cervical glioma with complicated MR characteristics in a dog, where MRI helped guide surgical intervention.

9.
ACS Nano ; 18(1): 972-982, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38117550

RESUMEN

The ability to efficiently absorb light in ultrathin (subwavelength) layers is essential for modern electro-optic devices, including detectors, sensors, and nonlinear modulators. Tailoring these ultrathin films' spectral, spatial, and polarimetric properties is highly desirable for many, if not all, of the above applications. Doing so, however, often requires costly lithographic techniques or exotic materials, limiting scalability. Here we propose, demonstrate, and analyze a mid-infrared absorber architecture leveraging monolayer films of nanoplasmonic colloidal tin-doped indium oxide nanocrystals (ITO NCs). We fabricate a series of ITO NC monolayer films using the liquid-air interface method; by synthetically varying the Sn dopant concentration in the NCs, we achieve spectrally selective perfect absorption tunable between wavelengths of two and five micrometers. We achieve monolayer thickness-controlled coupling strength tuning by varying NC size, allowing access to different coupling regimes. Furthermore, we synthesize a bilayer film that enables broadband absorption covering the entire midwave IR region (λ = 3-5 µm). We demonstrate a scalable platform, with perfect absorption in monolayer films only hundredths of a wavelength in thickness, enabling strong light-matter interaction, with potential applications for molecular detection and ultrafast nonlinear optical applications.

10.
Nano Lett ; 12(5): 2436-40, 2012 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-22506531

RESUMEN

Owing to their novel optical properties, three-dimensional plasmonic nanostructures with reduced symmetry such as a nanocrescent and a nanocup have attracted considerable current interest in biophotonic imaging and sensing. However, their practical applications have been still limited since the colloidal synthesis of such structures that allows, in principle, for in vivo application and large-scale production has not been explored yet. To date, these structures have been fabricated only on two-dimensional substrates using micro/nanofabrication techniques. Here we demonstrate an innovative way of breaking symmetry of colloidal plasmonic nanoparticles. Our strategy exploits the direct overgrowth of Au on a hybrid colloidal dimer consisting of Au and polystyrene (PS) nanoparticles without the self-nucleation of Au in an aqueous solution. Upon the overgrowth reaction, the steric crowding of PS leads to morphological evolution of the Au part in the dimer ranging from half-shell, nanocrescent to nanoshell associated with the appearance of the second plasmon absorption band in near IR. Surface-enhanced Raman scattering signal is obtained directly from the symmetry-broken nanoparticles solution as an example showing the viability of the present approach. We believe our concept represents an important step toward a wide range of biophotonic applications for optical nanoplasmonics such as targeting, sensing/imaging, gene delivery, and optical gene regulations.


Asunto(s)
Coloides , Nanopartículas , Microscopía Electrónica de Transmisión
11.
Front Vet Sci ; 10: 1323088, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38169649

RESUMEN

A 6-year-old castrated, mixed breed cat presented with vomiting, anorexia, and lethargy. Ultrasonography and computed tomography revealed a round, well-marginated structure closely associated with the ileum proximal to the ileocolic junction. Exploratory laparotomy revealed a mass originating from the distal end of the ileum, close to the ileocolic junction. The mass did not interact with the intestinal lumen. Excisional biopsy with omentalization was performed without small intestinal resection to preserve the ileocolic junctions. Histopathological examination confirmed the presence of an enteric duplication cyst. The cat recovered uneventfully from surgery and remained asymptomatic postoperatively. No recurrence was identified 4 months after surgery. Enteric duplication cysts are uncommon congenital anomalies that originate in the gastrointestinal tract. They could either be communicating or non-communicating with the intestinal lumen. Enteric duplication cysts can be symptomatic or asymptomatic. Enteric duplication cysts associated with the esophagus, duodenum, and jejunum have also been reported in cats. However, to the best of our knowledge, this is the first reported case of an enteric duplication cyst in the feline ileum. Thus, enteric duplication should be considered a differential diagnosis in cystic masses of the ileum.

12.
Polymers (Basel) ; 15(10)2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37242888

RESUMEN

Tendons are responsible for transmitting mechanical forces from muscles to bones for body locomotion and joint stability. However, tendons are frequently damaged with high mechanical forces. Various methods have been utilized for repairing damaged tendons, including sutures, soft tissue anchors, and biological grafts. However, tendons experience a higher rate of retear post-surgery due to their low cellularity and vascularity. Surgically sutured tendons are vulnerable to reinjury due to their inferior functionality when compared with native tendons. Surgical treatment using biological grafts also has complications such as joint stiffness, re-rupture, and donor-site morbidity. Therefore, current research is focused on developing novel materials that can facilitate the regeneration of tendons with histological and mechanical characteristics similar to those of intact tendons. With respect to the complications in association with the surgical treatment of tendon injuries, electrospinning may be an alternative for tendon tissue engineering. Electrospinning is an effective method for fabrication of polymeric fibers with diameters ranging from nanometers to micrometers. Thus, this method produces nanofibrous membranes with an extremely high surface area-to-volume ratio, which is similar to the extracellular matrix structure, making them suitable candidates for application in tissue engineering. Moreover, it is possible to fabricate nanofibers with specific orientations that are similar to those of the native tendon tissue using an adequate collector. To increase the hydrophilicity of the electrospun nanofibers, natural polymers in addition to synthetic polymers are used concurrently. Therefore, in this study, aligned nanofibers composed of poly-d,l-lactide-co-glycolide (PLGA) and small intestine submucosa (SIS) were fabricated using electrospinning with rotating mandrel. The diameter of aligned PLGA/SIS nanofibers was 568.44 ± 135.594 nm, which closely resembles that of native collagen fibrils. Compared to the results of the control group, the mechanical strength exhibited by the aligned nanofibers was anisotropic in terms of break strain, ultimate tensile strength, and elastic modulus. Elongated cellular behavior was observed in the aligned PLGA/SIS nanofibers using confocal laser scanning microscopy, indicating that the aligned nanofibers were highly effective with regard to tendon tissue engineering. In conclusion, considering its mechanical properties and cellular behavior, aligned PLGA/SIS is a promising candidate for tendon tissue engineering.

13.
J Vet Med Sci ; 85(10): 1116-1120, 2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37661431

RESUMEN

A 15-year-old, spayed female, Scottish Straight cat without any traumatic history was presented with swollen abdomen and diagnosed as an abdominal wall hernia. Abdominal ultrasound revealed thickened, irregular, and hypoechoic change of abdominal wall muscle adjacent to defect. During the herniorrhaphy, multiple nodules were identified in the subcutaneous tissue around the defect. Histological examination of the nodular tissue was performed, and it was confirmed as mammary gland tumor. After the surgery, metastatic changes of the pancreas were identified, and pleural effusion and ascites were also confirmed. The patient deteriorated rapidly and died 78 days after the surgery. This is the first case presenting abdominal wall hernia induced by malignant tumor in veterinary medicine.


Asunto(s)
Pared Abdominal , Carcinoma , Enfermedades de los Gatos , Hernia Abdominal , Hernia Ventral , Glándulas Mamarias Humanas , Gatos , Animales , Femenino , Humanos , Hernia Abdominal/diagnóstico por imagen , Hernia Abdominal/cirugía , Hernia Abdominal/veterinaria , Hernia Ventral/cirugía , Hernia Ventral/veterinaria , Pared Abdominal/cirugía , Herniorrafia/veterinaria , Carcinoma/cirugía , Carcinoma/veterinaria , Enfermedades de los Gatos/diagnóstico por imagen , Enfermedades de los Gatos/cirugía
14.
PLoS One ; 18(11): e0294554, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37983215

RESUMEN

Numerous studies make extensive use of healthcare data, including human materials and clinical information, and acknowledge its significance. However, limitations in data collection methods can impact the quality of healthcare data obtained from multiple institutions. In order to secure high-quality data related to human materials, research focused on data quality is necessary. This study validated the quality of data collected in 2020 from 16 institutions constituting the Korea Biobank Network using 104 validation rules. The validation rules were developed based on the DQ4HEALTH model and were divided into four dimensions: completeness, validity, accuracy, and uniqueness. Korea Biobank Network collects and manages human materials and clinical information from multiple biobanks, and is in the process of developing a common data model for data integration. The results of the data quality verification revealed an error rate of 0.74%. Furthermore, an analysis of the data from each institution was performed to examine the relationship between the institution's characteristics and error count. The results from a chi-square test indicated that there was an independent correlation between each institution and its error count. To confirm this correlation between error counts and the characteristics of each institution, a correlation analysis was conducted. The results, shown in a graph, revealed the relationship between factors that had high correlation coefficients and the error count. The findings suggest that the data quality was impacted by biases in the evaluation system, including the institution's IT environment, infrastructure, and the number of collected samples. These results highlight the need to consider the scalability of research quality when evaluating clinical epidemiological information linked to human materials in future validation studies of data quality.


Asunto(s)
Bancos de Muestras Biológicas , Exactitud de los Datos , Humanos , Manejo de Especímenes/métodos , Atención a la Salud , República de Corea
15.
ACS Nano ; 17(23): 23649-23658, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-38039345

RESUMEN

The high explosiveness of hydrogen gas in the air necessitates prompt detection in settings where hydrogen is used. For this reason, hydrogen sensors are required to offer rapid detection and possess superior sensing characteristics in terms of measurement range, linearity, selectivity, lifetime, and environment insensitivity according to the publicized protocol. However, previous approaches have only partially achieved the standardized requirements and have been limited in their capability to develop reliable materials for spatially accessible systems. Here, an electrical hydrogen sensor with an ultrafast response (∼0.6 s) satisfying all demands for hydrogen detection is demonstrated. Tailoring structural engineering based on the reaction kinetics of hydrogen and palladium, an optimized heating architecture that thermally activates fully suspended palladium (Pd) nanowires at a uniform temperature is designed. The developed Pd nanostructure, at a designated temperature distribution, rapidly reacts with hydrogen, enabling a hysteresis-free response from 0.1% to 10% and durable characteristics in mechanical shock and repetitive operation (>10,000 cycles). Moreover, the device selectively detects hydrogen without performance degradation in humid or carbon-based interfering gas circumstances. Finally, to verify spatial accessibility, the wireless hydrogen detection system has been demonstrated, detecting and reporting hydrogen leakage in real-time within just 1 s.

16.
J Biol Chem ; 286(1): 322-30, 2011 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-20980254

RESUMEN

Ribonuclease P (RNase P) complexed with external guide sequence (EGS) represents a novel nucleic acid-based gene interference approach to modulate gene expression. We have previously used an in vitro selection procedure to generate EGS variants that efficiently direct human RNase P to cleave a target mRNA in vitro. In this study, a variant was used to target the mRNA encoding the protease of human cytomegalovirus (HCMV), which is essential for viral capsid formation and replication. The EGS variant was about 35-fold more active in inducing human RNase P to cleave the mRNA in vitro than the EGS derived from a natural tRNA. Moreover, a reduction of 95% in the expression of the protease and a reduction of 4,000-fold in viral growth were observed in HCMV-infected cells that expressed the EGS variant, whereas a reduction of 80% in the protease expression and an inhibition of 150-fold in viral growth were detected in cells that expressed the EGS derived from a natural tRNA sequence. No significant reduction in viral protease expression or viral growth was observed in cells that either did not express an EGS or produced a "disabled" EGS, which carried nucleotide mutations that precluded RNase P recognition. Our results provide direct evidence that engineered EGS variant is highly effective in blocking HCMV expression and growth by targeting the viral protease. Furthermore, these results demonstrate the utility of engineered EGS RNAs in gene targeting applications, including the inhibition of HCMV infection by blocking the expression of virus-encoded essential proteins.


Asunto(s)
Citomegalovirus/genética , Citomegalovirus/fisiología , Regulación Viral de la Expresión Génica/genética , Ingeniería Genética/métodos , Interferencia de ARN , Replicación Viral/genética , Secuencia de Bases , Cápside/enzimología , Cápside/metabolismo , Citomegalovirus/enzimología , Citomegalovirus/crecimiento & desarrollo , Replicación del ADN/genética , Estudios de Factibilidad , Genes Virales/genética , Células HeLa , Humanos , Péptido Hidrolasas/deficiencia , Péptido Hidrolasas/genética , ARN Mensajero/genética , Ribonucleasa P/metabolismo
17.
Sci Rep ; 12(1): 22401, 2022 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-36575249

RESUMEN

Urban climate influences economic activities and the health and safety of urban residents. Therefore, monitoring temperature in urban areas is important. However, owing to the lack of space for an appropriate observation site, an automatic weather station (AWS) was installed on a building rooftop. The rooftop installation can indicate temperature differences depending on the intensity of strong solar radiation and radiant heat of the building, and wind speed. Therefore, in this study, we aimed to provide observation standards for measuring rooftop temperature according to the optimal rooftop material and observation height. Specifically, an AWS was installed on the rooftop of the Gochang Standard Weather Station (GSWO), Jeollabuk-do Province, to observe the urban climate in South Korea and establish suitable weather standards. Different temperatures, optimum surface materials, and optimum heights for measuring the temperature at the rooftop of GSWO were investigated and compared over 1 year. The temperature recorded after installing a palm mat on the rooftop was more similar to that observed in the grassland. Furthermore, the installation height of the temperature sensor of 2.5-3.0 m for the palm mat and 3.5-4.0 m for concrete was found to be the optimal height for observing temperature at the rooftop.


Asunto(s)
Clima , Tiempo (Meteorología) , Temperatura , Viento , República de Corea , Calor , Monitoreo del Ambiente
18.
Vet Sci ; 9(11)2022 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-36356071

RESUMEN

A 7-year-old spayed female domestic shorthair cat presented with a swollen right forelimb and mild lameness. On physical examination, the mass was palpable in the right humeral region, and the cat exhibited pain on palpation. Radiography revealed an expansile osteolytic lesion at the proximal end of the right humerus. Computed tomography (CT) revealed an expansile bony mass on the proximal end of the right humerus and a mild periosteal reaction around the acromion of the scapula. Amputation of the right forelimb, including the scapula and removal of the axillary lymph node, were strongly recommended to the owner, but were declined. Four months after the initial presentation, the cat presented with a dramatically swollen right forelimb and progressive lameness. CT was performed again. In addition to osteolytic changes in the mass, vascular development had occurred at the cranioproximal region. The right forelimb, including the scapula and ipsilateral lymph nodes, was removed. The cat died during the postoperative recovery period. Based on clinical, diagnostic imaging, and histological findings, the final diagnosis was aneurysmal bone cyst. To the best of our knowledge, this is the first case of an aneurysmal bone cyst in the humerus of a cat.

19.
Vet Sci ; 9(12)2022 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-36548841

RESUMEN

An 11-year-old castrated male Shih Tzu was referred for lethargy and melena. The hematocrit level was 18.8% (normal range: 36-56%), indicating severe anemia. Abdominal ultrasound revealed a round-to-oval-shaped mass in the stomach. Computed tomography (CT) revealed an intraluminal mass (17 × 12 × 15 mm) cranial to the pyloric antrum. After obtaining informed consent from the owner, exploratory laparotomy and subsequent gastrostomy were performed, showing an ulcerated mass potentially responsible for the severe anemia. A lump of hair was firmly attached to the ulcerated surface of the mass. After complete removal of the mass, the anemia resolved spontaneously. Histological examination revealed that the mass was a gastric hyperplastic polyp. At the 6-month follow-up, the dog was healthy with a normal hematocrit level. Gastric hyperplastic polyps are tumor-like lesions arising from the mucosal surface of the stomach, and projecting into the lumen. They can appear in any part of the stomach, and are usually found incidentally during gastric endoscopy or necropsy. The clinical signs include chronic occult blood loss, abdominal pain, and gastric tract obstruction. Gastric polyps causing acute blood loss anemia have rarely been reported in human medicine. To our knowledge, this is the first report describing a gastric hyperplastic polyp that caused severe anemia because of acute blood loss in a dog.

20.
ACS Nano ; 16(8): 11957-11967, 2022 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-35621510

RESUMEN

Palladium (Pd) has been drawing increasing attention as a hydrogen (H2) detecting material due to its highly selective sensitivity to H2. However, at H2 concentrations above 2%, Pd undergoes an inevitable phase transition, causing undesirable electrical and mechanical alterations. In particular, nonlinear gas response (ΔR/R0) that accompanies phase transition has been a great bottleneck for detecting H2 in high concentrations, which is especially important as there is a risk of explosion over 4% H2. Here, we propose a phase-transition-inhibited Pd nanowire H2 sensor that can detect up to 4% H2 with high linearity and high sensitivity. Based on the calculation of the change in free energy, we designed Pd nanowires that are highly adhered to the substrate to withstand the stress that leads to phase transition. We theoretically optimized the Pd nanowire dimensions using a finite element method simulation and then experimentally fabricated the proposed sensor by exploiting a developed nanofabrication method. The proposed sensor exhibits a high sensing linearity (98.9%) with high and stable sensitivity (ΔR/R0/[H2] = 875%·bar-1) over a full range of H2 concentrations (0.1-4%). Using the fabricated Pd sensors, we have successfully demonstrated a wireless sensor module that can detect H2 with high linearity, notifying real-time H2 leakage through remote communication. Overall, our work suggests a nanostructuring strategy for detecting H2 with a phase-transition-inhibited pure Pd H2 sensor with rigorous scientific exploration.

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