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INTRODUCTION: Intrahepatic cholelithiasis is a common disease for which laparoscopic liver resection is one of the treatment options. Here is a case of a patient who developed atypical complications after liver resection. CASE PRESENTATION: A 59-year-old patient with intrahepatic cholelithiasis underwent laparoscopic left hemihepatectomy in our hospital. However, the patient developed recurrent fever and jaundice after surgery. And with multiple treatments, the symptoms improved and the diagnosis was finally confirmed. DISCUSSION: This case has some educational value as it shows that post-operative hepatic stones can lead to biliary hemorrhage due to infection and that imaging and signs can be deceptive to some extent. CONCLUSION: In patients with intrahepatic cholelithiasis who present with symptoms of fever and jaundice after hepatectomy, hemobilia cannot be completely ruled out, even if the fecal occult blood test is negative.
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Liquid crystal elastomers (LCEs) are a kind of polymer network that combines the entropic elasticity of polymer networks and the mesogenic unit by means of mild cross-linking. LCEs have been extensively investigated in various fields, including artificial muscles, actuators, and microrobots. However, LCEs are characterized by the poor mechanical properties of the light polymers themselves. In this study, we propose to prepare a carbon nanotube/liquid crystal elastomer (CNT/LCE) composite yarn by electrospinning technology and a two-step cross-linking strategy. The CNT/LCE composite yarn exhibits a reversible shrinkage ratio of nearly 70%, a tensile strength of 16.45 MPa, and a relatively sensitive response speed of â¼3 s, enabling a fast response by photothermal actuation. The research disclosed in this article may provide new insights for the development of artificial muscles and next-generation smart robots.
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Pre-meal immersion is a common process for both the consumption of dried noodles and development of takeaway noodles, but its impact on the structure and digestibility of dried noodles is still unclear. In this study, dried noodles cooked for the optimal time were immersed at 80 °C for different time durations. Multi-scale structural changes, including texture, molecular structure, microstructure, and in vitro starch digestibility were studied using a combination of kinetic (first-order exponential decay function, the Peleg model, and LOS plots), physicochemical, and microscopic analysis. The relationship between multi-scale structural changes and starch digestibility was derived. As the immersion progressed, the hardness first rapidly decayed and then reached equilibrium. The decay rate in the initial stage depended on the gluten content. In most cases, the immersion process caused depolymerization of gluten proteins and further gelatinization of starch granules, which was observed from an increase in the free -SH content and decrease in the short-range ordered structure, although there were fluctuations over immersion time. Structural changes resulted in the corresponding changes in substance migration. However, a high gluten content (â¼15% w/w) imparted a denser microstructure to the noodles, weakening the deterioration effects compared with a low gluten content (â¼10% w/w). In vitro digestion experiments proved that samples with higher gluten content had higher starch digestion rates and lower starch digestion extent during immersion. Correlation analysis revealed that there was a negative correlation between k1 and the tightness of the gel. This study helps to reveal the structural mechanisms of starch digestibility in cooked noodles during immersion.
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Inmersión , Almidón , Almidón/química , Culinaria , Glútenes , Harina/análisisRESUMEN
Flammability and poor toughness of unmodified PLA limit its applications in various fields. Though ammonium polyphosphate (APP) is a green and effective flame retardant, it has poor compatibility with the matrix, leading to a decrease in mechanical properties. Stereo-complexation greatly improves the strength and heat resistance of traditional PLA. However, the effect of flame retardants on the formation of stereo-complexed crystals and the impact of stereo-complexation on flame retardancy have not been studied previously. In this research, PDLA chains were first in-situ reacted with APP particles for improved interfacial compatibility. By utilizing the characteristic of PLA enantiomers that can form stereo-complexed crystals, near-complete stereo-complexed PLA fibers with flame retardancy were produced via clean and continuous melt spinning. The compatibility between PDLA-g-APP and PLLA matrix was studied by SEM, rheological analyses and DSC. Strength and flexibility of the fibers were simultaneously enhanced compared to traditional PLA due to the synergistic effect of interfacial compatibility and stereo-complexation. Compared to traditional PLA, the peak heat release rate and total heat release in microcalorimetry test were reduced by 33 % and 22 %, respectively. The flame-retardant fibers achieved a V-0 rating in the UL-94 test, and an increase in LOI value from 19.4 % to 28.2 %.
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Retardadores de Llama , Calorimetría , Poliésteres , PolifosfatosRESUMEN
Liquid crystal elastomer (LCE) fibers exhibit large deformation and reversibility, making them an ideal candidate for soft actuators. It is still challenging to develop a scalable strategy and endow fiber actuators with photoelectric functions to achieve tailorable photo-electro-thermal responsiveness and rapid large actuation deformation. Herein, we fabricated a multiresponsive actuator that consists of LCE long fibers obtained by continuous dry spinning and further coated it with polydopamine (PDA)-modified MXene ink. The designed PDA@MXene-integrated LCE fiber is used for shape-deformable and multi-trigger actuators that can be photo- and electro-thermally actuated. The proposed LCE fiber actuator combines an excellent photothermal and long-term electrically conductive PDA@MXene and a shape-morphing LCE fiber, enabling their robust mechanical flexibility, multiple fast responses (â¼0.4 s), and stable and large actuation deformation (â¼60%). As a proof-of-concept, we present near-infrared light-driven artificial muscle that can lift 1000 times the weight and an intelligent circuit switch with stable controllability and fast responsiveness (â¼0.1 s). Importantly, an adaptive smart window system that integrates light-driven energy harvesting/conversion functions is ingeniously constructed by the integration of a propellable curtain woven by the designed fiber and solar cells. This work can provide insights into the development of advanced intelligent materials toward soft robotics, sustainable energy savings and beyond.
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Enzyme membrane systems (EMS) have generated considerable interest because of their advantages of accelerating reactions, eliminating product inhibition, and enhancing conversion rates. However, there are deficiencies in the efficient fabrication of affinity carrier membranes and dynamic catalytic separation properties. Herein, a strong and highly flexible spunlaced viscose/bacterial cellulose (BC) composite membrane in situ embedded with graphene oxide (GO) was developed by combining a scalable bio-synthesis method with atom transfer radical polymerization technology. Notably, the layer-by-layer growth of BC on composite film and the addition of GO resulted in an entangled network with strong hydrogen bonding, endowing the resulting membrane with superior mechanical properties and flexibility, while facilitating a gradient structure and porous transport channels. Subsequently, a novel and highly efficient EMS was constructed by using abundant molecular brushes on composite membrane as immobilized enzyme carrier. The resulting EMS exhibited a high throughput (2.17 L/min*m2) and an interception rate (98.64%) in dynamic catalytic sulfonamide antibiotic wastewater activated with syringaldehyde mediator. Meanwhile, the removal rates of sulphapyridine and sulfamethazine were 97.20% and 94.78% under 0.14 MPa and 15 min, respectively. This efficient and scalable manufacturing strategy is of great significance and may pave a novel pathway for antibiotics wastewater treatment and recycling.
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Antibacterianos , Celulosa , Antibacterianos/farmacología , Bacterias , Celulosa/química , Grafito , Porosidad , Sulfanilamida , SulfonamidasRESUMEN
Laccase is a promising biocatalyst for pollutant degradation and water purification. However, laccase can only improve the stability of enzyme activity and achieve its significant catalytic effect after effective immobilization. Herein, we report a general strategy to integrate nanocellulose aerogel and laccase for high-efficiency degradation of organic pollutants. Biomass-derived functional bacterial cellulose (BC) aerogel with a nanonetwork structure and high porosity was prepared by biosynthesis, solvent replacement, and atom transfer radical polymerization (ATRP) procedures. Subsequently, a biocatalyst platform was fabricated by "coupling" ATRP-modified BC aerogel with abundant active sites with laccase through ion coordination. The results demonstrated the biocatalyst platform not only has good biological affinity, but also has high enzyme load and structural stability. Meanwhile, the degradation rates of reactive red X-3B and 2, 4-dichlorophenol reached 94.5% and 85.2% within 4 h, respectively. The strategy disclosed herein could provide a practical method for the degradation of organic pollutants.
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Contaminantes Ambientales , Purificación del Agua , Biomasa , Enzimas Inmovilizadas/química , Lacasa/metabolismoRESUMEN
This paper proposes a star-bus topology optic fiber sensor network with an efficient mechanism for network communication to accomplish monitoring and protection operations. The master node scans each channel for its healthy conditions with an N * M optical switch, just as in time-division multiplexing, accomplishing a comprehensive monitoring of the whole sensor network. In addition, we analyze the impact of structural parameters on network robustness, then obtain a basic design principle of network topology. We also demonstrate the proposed network's feasibility by multiplexing different fiber sensor systems simultaneously; in addition, an optimized structure is proposed to accomplish the measurement in extreme environments and proved to be effective.
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The polarization-maintaining performance of the traditional Panda-type polarization-maintaining fiber (PMF) coil is significantly affected by winding stress and temperature. Here, we present an elliptical core Panda-type PMF coil based on a fiber that employs both geometric and stress birefringence. The extinction ratio of the elliptical core PMF coil was found to be 20.13 dB at a temperature of 20°C, corresponding to an increase of 3.71 dB compared to the traditional Panda-type PMF coil. In addition, results from distributed polarization cross talk and gyroscope output tests also revealed a low sensitivity of the fiber to stress caused by the winding process and temperature. In summary, the proposed fiber coil has better polarization-maintaining ability compared to conventional coil and is promising for applications in high-precision optical fiber sensors.
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The development and maturation of simultaneous localization and mapping (SLAM) in robotics opens the door to the application of a visual inertial odometry (VIO) to the robot navigation system. For a patrol robot with no available Global Positioning System (GPS) support, the embedded VIO components, which are generally composed of an Inertial Measurement Unit (IMU) and a camera, fuse the inertial recursion with SLAM calculation tasks, and enable the robot to estimate its location within a map. The highlights of the optimized VIO design lie in the simplified VIO initialization strategy as well as the fused point and line feature-matching based method for efficient pose estimates in the front-end. With a tightly-coupled VIO anatomy, the system state is explicitly expressed in a vector and further estimated by the state estimator. The consequent problems associated with the data association, state optimization, sliding window and timestamp alignment in the back-end are discussed in detail. The dataset tests and real substation scene tests are conducted, and the experimental results indicate that the proposed VIO can realize the accurate pose estimation with a favorable initializing efficiency and eminent map representations as expected in concerned environments. The proposed VIO design can therefore be recognized as a preferred tool reference for a class of visual and inertial SLAM application domains preceded by no external location reference support hypothesis.
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Two kinds of photonic crystal fiber (PCF) sensors based on surface plasmon resonance (SPR) with silver nano-continuous gratings (i) and (ii) are designed. The coupling characteristics and sensing properties are analyzed numerically by the finite element method (FEM). The results show that the proposed sensor based on silver nano-continuous grating (i) can achieve better performance than that of the sensors based on silver nano-continuous grating (ii) and plane silver film structures. When the segmented number is 50 and segmented angle is 0.5°, a wavelength sensitivity of the proposed sensor with silver nano-continuous grating (i) is obtained as high as 13,600 nm/RIU in the refractive index (RI) range from 1.330 to 1.365, corresponding to a maximum RI resolution of 7.35×10-6 RIU, which can have promising applications in medical and environmental monitoring and biochemical detection.
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The geomagnetic field is as fundamental a constituent of passive navigation as Earth's gravity. In cases where no other external attitude reference is available, for the direct heading angle estimation by a typical magnetic compass, a two-step optimized correction algorithm is proposed to correct the model coefficients caused by hard and soft iron nearby. Specifically, in Step 1, a Levenberg-Marquardt (L-M) fitting estimator with an ellipsoid constraint is applied to solve the hard magnetic coefficients. In Step 2, a Lagrange multiplier estimator is used to deal with the soft magnetic iron circumstance. The essential attribute of "the two-step" lies in its eliminating the coupling effects of hard and soft magnetic fields, and their mutual interferences on the pure geomagnetic field. Under the conditions of non-deterministic magnetic interference sources with noise, the numerical simulation by referring to International Geomagnetic Reference Field (IGRF), and the laboratory tests based upon the turntable experiments with Honeywell HMR3000 compass (Honeywell, Morristown, NJ, USA) conducted, the experimental results indicate that, in the presence of the variation of multi-magnetic interferences, the RMSE (Root Mean Square Error) value of the estimated total magnetic flux density by the proposed two-step estimator falls to 0.125 µT from its initial 2.503 µT, and the mean values of the heading angle error estimates are less than 1°. The proposed solution therefore, exhibits ideal convergent properties, fairly meeting the accuracy requirements of non-tactical level navigation applications.
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A facile synthetic approach for total synthesis of tanshinone I has been accomplished. The key precursor is a novel compound, epoxy phenanthraquinone. And this synthesis of tanshinone I is achieved in only three simple stages, which include Diels-Alder reaction, Δ(2)-Weitz-Scheffer-type epoxidation, and Feist-Bénary reaction from commercially available styrene.