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Subwavelength terahertz (THz) imaging methods are highly desirable for biochemical sensing as well as materials sciences, yet sensitive spectral fingerprinting is still challenging in the frequency domain due to weak light-matter interactions. Here, we demonstrate subwavelength THz resonance imaging (STRING) that overcomes this limitation to achieve ultrasensitive molecular fingerprinting. STRING combines individual ring-shaped coaxial single resonators with near-field spectroscopy, yielding considerable sensitivity gains from both local field enhancement and the near-field effect. As an initial demonstration, we obtained spectral fingerprints from isomers of α-lactose and maltose monohydrates, achieving sensitivity that was enhanced by up to 10 orders of magnitude compared to far-field THz measurements with pelletized samples. Our results show that the STRING platform could enable the development of THz spectroscopy as a practical and sensitive tool for the fingerprinting and spectral imaging of molecules and nanoparticles.
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Nanopartículas , Espectroscopía de Terahertz , Análisis Espectral , Espectroscopía de Terahertz/métodosRESUMEN
Detection of terahertz (THz) radiation has many potential applications, but presently available detectors are limited in many aspects of their performance, including sensitivity, speed, bandwidth and operating temperature. Most do not allow the characterization of THz polarization states. Recent observation of THz-driven luminescence in quantum dots offers a possible detection mechanism via field-driven interdot charge transfer. We demonstrate a room-temperature complementary metal-oxide-semiconductor THz camera and polarimeter based on quantum-dot-enhanced THz-to-visible upconversion mechanism with optimized luminophore geometries and fabrication designs. Besides broadband and fast responses, the nanoslit-based sensor can detect THz pulses with peak fields as low as 10 kV cm-1. A related coaxial nanoaperture-type device shows a to-date-unexplored capability to simultaneously record the THz polarization state and field strength with similar sensitivity.
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Puntos Cuánticos , Temperatura , Fotones , Semiconductores , LuminiscenciaRESUMEN
Background: Biliary cystadenoma is a rare cystic neoplasm of the liver. The clinical signs and symptoms are nonspecific, and treatment strategy is variable. Case presentation: In this study, we presented a case of a 32-year-old female with multilocular biliary cystadenoma. The patient underwent partial removal of the hepatic cyst two times in two different hospitals for two years and that the histopathological results were biliary cystic adenoma but was successfully treated by radical resection after the second recurrence. The patient underwent a J-shaped laparotomy. The giant cystic mass measuring 20 cm × 15 cm was below the position of the right anterior segment. This lesion pushed the liver parenchyma to both sides and compressed the hepatic hilum, causing dilatation of the intrahepatic bile ducts. The patient underwent complete resection of cystic mass. During the dissection, a 0.5mm-diameter fistula of left hepatic duct with the cyst was found. It was sutured using absorbable polydioxanone (PDS 6.0) and the cystic duct tube (C tube) (6 Fr) was inserted via the cystic duct into the left hepatic duct due to drain the bile fluid. Discussion: A biliary cystadenoma (BCA) primary origin is occasionally rare. Although imaging modalities such as ultrasound, computed tomography and magnetic resonance imaging could be suggestive, however, the definitive diagnosis is depended on the histological examination. Despite of being a benign tumor, it has a high risk of recurrence after conservative treatment. The potential risk for malignant is also present. Therefore, complete resection of the tumors is the treatment of choice. Conclusion: We herein present a report of a rare case with had a giant biliary cystadenoma (BCA) primary origin. This report aims to improve the understanding of the diagnosis and management of this uncommon disease.
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INTRODUCTION: Hepatic lymphorrhea (HL) is an uncommon but potentially life-threatening type of postoperative lymphatic leakage, especially following pancreaticoduodenectomy. CASE PRESENTATION: We herein report a case series of four patients with HL following pancreaticoduodenectomy that presented to the department with a severe clinical picture with the discovery in imaging and intraperitoneal fluid's tests. All our patients presented with a condition of Hepatic lymphorrhea secondary to pancreaticoduodenectomy, which were treated successfully with percutaneous hepatic lymphangiography (HLG). DISCUSSION: Hepatic lymphorrhea is an uncommon but potentially life-threatening complication following pancreaticoduodenectomy. Periportal lymphatic vessels, which was often isolated and dissected especially with extended lymphadenectomy, is potentially damaged and caused resistant chylous leakage. Newly techniques are updated and applied in diagnosis and treatment for this difficult-to-treat complication, one of them is percutaneous Hepatic Lymphangiography (HLG). CONCLUSION: HLG with percutaneous access could be effective to identify and terminate the chylous fistula from periportal lymphatic vessels after pancreaticoduodenectomy.
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Stridor is a sign of vital emergency that immediately orientates towards a laryngeal or tracheal obstruction. This case report focuses on the management of stridor, which comprises emergency securing of airways and parallel aetiological investigations. https://bit.ly/39CTjOg.
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INTRODUCTION: Chylous ascites is an uncommon but potentially life-threatening type of postoperative lymphatic leakage, especially following pancreaticoduodenectomy. CASE PRESENTATION: A 59-year-old man underwent pancreaticoduodenectomy (PD) with extended lymphadenectomy and segmental Superior Mesenteric Vein (SMV) resection for SMV-involved pancreatic ductal adenocarcinoma (PDAC). After 20th postoperative day, patient had a drain output with a milky appearance, and with a triglyceride level was 1.6 mmol/L, and the daily output volume was up to 1500 mL per day. She has been performed Conventional Lymphangiography (CLAG) to identify the broken lymphatic vessels as well as close the leakage. Following two consecutive lymphangiography, the source of chylous leakage was identified from hilar lymphatic system, and injection of Aetoxisclerol 2% into lymphatic vessels to close the leakage was performed. Partial parenteral nutrition with limited fat components or medium-chain triglyceride (MCT) was administered, and the amount of ascites decreased particularly. The drain was removed in 20th day after the second CLAG. He had no symptoms of abdominal distention after drain removal and had been discharged after 37 postoperative days (PODs). DISCUSSION: Chylous ascites is an uncommon but potentially life-threatening complication following pancreaticoduodenectomy. Portal lymphatic plexus, which was often isolated and dissected especially with extended lymphadenectomy, is potentially damaged and caused resistant chylous leakage. Newly techniques are updated and applied in diagnosis and treatment for this difficult-to-treat complication, one of them is percutaneous transhepatic Conventional Lymphangiography (CLAG). CONCLUSION: CLAG with percutaneous transhepatic access could be effective to identify and terminate the chylous fistula from portal lymphatic plexus after pancreaticoduodenectomy.
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Postoperative hepatic lymphorrhea is extremely rare and there is no standard treatment for this condition. We report the cases of 3 men, 32-, 56-, and 37-year-old, with postoperative hepatic lymphorrhea, which was refractory to conservative treatment. Transhepatic lymphangiography allowed locating the lymphatic leak and treating it with hepatic lymphatic vessels injection of foam sclerotic agent. This technique seems efficient and safe.
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With advances in nanofabrication techniques, extreme-scale nanophotonic devices with critical gap dimensions of just 1-2 nm have been realized. The plasmonic response in these extreme-scale gaps is significantly affected by nonlocal electrodynamics, quenching field enhancement and blue-shifting the resonance with respect to a purely local behavior. The extreme mismatch in lengthscales, ranging from millimeter-long wavelengths to atomic-scale charge distributions, poses a daunting computational challenge. In this paper, we perform computations of a single nanoslit using the hybridizable discontinuous Galerkin method to solve Maxwell's equations augmented with the hydrodynamic model for the conduction-band electrons in noble metals. This method enables the efficient simulation of the slit while accounting for the nonlocal interactions between electrons and the incident light. We study the impact of gap width, film thickness and electron motion model on the plasmon resonances of the slit for two different frequency regimes: (1) terahertz frequencies, which lead to 1000-fold field amplitude enhancements that saturate as the gap shrinks; and (2) the near- and mid-infrared regime, where we show that narrow gaps and thick films cluster Fabry-Pérot (FP) resonances towards lower frequencies, derive a dispersion relation for the first FP resonance, in addition to observing that nonlocality boosts transmittance and reduces enhancement.
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Can you diagnose this challenging cause of pleural effusion? http://bit.ly/2VVwZv3.
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With advances in nanofabrication techniques, extreme-scale nanophotonic devices with critical gap dimensions of just 1-2 nm have been realized. Plasmons in such ultranarrow gaps can exhibit nonlocal response, which was previously shown to limit the field enhancement and cause optical properties to deviate from the local description. Using atomic layer lithography, we create mid-infrared-resonant coaxial apertures with gap sizes as small as 1 nm and observe strong evidence of nonlocality, including spectral shifts and boosted transmittance of the cutoff epsilon-near-zero mode. Experiments are supported by full-wave 3-D nonlocal simulations performed with the hybridizable discontinuous Galerkin method. This numerical method captures atomic-scale variations of the electromagnetic fields while efficiently handling extreme-scale size mismatch. Combining atomic-layer-based fabrication techniques with fast and accurate numerical simulations provides practical routes to design and fabricate highly-efficient large-area mid-infrared sensors, antennas, and metasurfaces.
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We present a wafer-scale array of resonant coaxial nanoapertures as a practical platform for surface-enhanced infrared absorption spectroscopy (SEIRA). Coaxial nanoapertures with sub-10 nm gaps are fabricated via photolithography, atomic layer deposition of a sacrificial Al2O3 layer to define the nanogaps, and planarization via glancing-angle ion milling. At the zeroth-order Fabry-Pérot resonance condition, our coaxial apertures act as a "zero-mode resonator (ZMR)", efficiently funneling as much as 34% of incident infrared (IR) light along 10 nm annular gaps. After removing Al2O3 in the gaps and inserting silk protein, we can couple the intense optical fields of the annular nanogap into the vibrational modes of protein molecules. From 7 nm gap ZMR devices coated with a 5 nm thick silk protein film, we observe high-contrast IR absorbance signals drastically suppressing 58% of the transmitted light and infer a strong IR absorption enhancement factor of 104â¼105. These single nanometer gap ZMR devices can be mass-produced via batch processing and offer promising routes for broad applications of SEIRA.
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We combine atomic layer lithography and glancing-angle ion polishing to create wafer-scale metamaterials composed of dense arrays of ultrasmall coaxial nanocavities in gold films. This new fabrication scheme makes it possible to shrink the diameter and increase the packing density of 2 nm-gap coaxial resonators, an extreme subwavelength structure first manufactured via atomic layer lithography, both by a factor of 100 with respect to previous studies. We demonstrate that the nonpropagating zeroth-order Fabry-Pérot mode, which possesses slow light-like properties at the cutoff resonance, traps infrared light inside 2 nm gaps (gap volume â¼ λ(3)/10(6)). Notably, the annular gaps cover only 3% or less of the metal surface, while open-area normalized transmission is as high as 1700% at the epsilon-near-zero (ENZ) condition. The resulting energy accumulation alongside extraordinary optical transmission can benefit applications in nonlinear optics, optical trapping, and surface-enhanced spectroscopies. Furthermore, because the resonance wavelength is independent of the cavity length and dramatically red shifts as the gap size is reduced, large-area arrays can be constructed with λresonance â« period, making this fabrication method ideal for manufacturing resonant metamaterials.