ABSTRACT
Transferring the high strength of individual carbon nanotubes (CNTs) to macroscopic fibers is still a major technical challenge. In this study, CNT fibers are wound from a hollow cylindrical assembly. In particular, atomized catalytic pyrolysis is utilized to produce the fiber and control its purity. The pristine fiber is then continuously prestrained to have a highly aligned structure for subsequent full densification. Experimental measurements show that the final fiber possesses a high tensile strength (8.0 GPa), specific strength (5.54 N tex-1 (tex: the weight (g) of a fiber of 1 km long)), Young's modulus (350 GPa), and elongation at break (4%). Such an excellent combination is superior to that of any other existing fiber and attributed to the efficient stress transfer among the highly aligned and packed CNTs. Our study provides a new strategy involving atomized catalysis for developing superstrong CNT assemblies such as fibers and films for practical applications.
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To explore the autoimmune response and outcome in the central nervous system (CNS) at the onset of viral infection and correlation between autoantibodies and viruses. METHODS: A retrospective observational study was conducted in 121 patients (2016-2021) with a CNS viral infection confirmed via cerebrospinal fluid (CSF) next-generation sequencing (cohort A). Their clinical information was analysed and CSF samples were screened for autoantibodies against monkey cerebellum by tissue-based assay. In situ hybridisation was used to detect Epstein-Barr virus (EBV) in brain tissue of 8 patients with glial fibrillar acidic protein (GFAP)-IgG and nasopharyngeal carcinoma tissue of 2 patients with GFAP-IgG as control (cohort B). RESULTS: Among cohort A (male:female=79:42; median age: 42 (14-78) years old), 61 (50.4%) participants had detectable autoantibodies in CSF. Compared with other viruses, EBV increased the odds of having GFAP-IgG (OR 18.22, 95% CI 6.54 to 50.77, p<0.001). In cohort B, EBV was found in the brain tissue from two of eight (25.0%) patients with GFAP-IgG. Autoantibody-positive patients had a higher CSF protein level (median: 1126.00 (281.00-5352.00) vs 700.00 (76.70-2899.00), p<0.001), lower CSF chloride level (mean: 119.80±6.24 vs 122.84±5.26, p=0.005), lower ratios of CSF-glucose/serum-glucose (median: 0.50[0.13-0.94] vs 0.60[0.26-1.23], p=0.003), more meningitis (26/61 (42.6%) vs 12/60 (20.0%), p=0.007) and higher follow-up modified Rankin Scale scores (1 (0-6) vs 0 (0-3), p=0.037) compared with antibody-negative patients. A Kaplan-Meier analysis revealed that autoantibody-positive patients experienced significantly worse outcomes (p=0.031). CONCLUSIONS: Autoimmune responses are found at the onset of viral encephalitis. EBV in the CNS increases the risk for autoimmunity to GFAP.
Subject(s)
Encephalitis , Epstein-Barr Virus Infections , Male , Humans , Female , Autoimmunity , Retrospective Studies , Herpesvirus 4, Human , Autoantibodies , Immunoglobulin GABSTRACT
Carbon nanotube (CNT) materials show large degradation in tensile strength when they are exposed in chemically active environments due to the loss of inter-tube bonding. Here, we report the suppression of such degradation by chemical vapor infiltration of amorphous carbon into CNT films. The amorphous carbon generated by the thermal decomposition of the gaseous hydrocarbon of acetylene is firmly bonded on the CNT sidewalls and intersections. Based on the improved inter-tube bonding and restriction of inter-tube sliding, the tensile strength of the film is improved to be 3 times of the original level. More importantly, the bonding is so strong and stable that the high tensile strength remains with little loss even in harsh wet environments such as boiling alcoholic, acidic, alkaline solutions and seawater. Such harsh environments-tolerant properties, which were rarely observed before, could open new windows for the CNT/C composite material to be applied from functional devices to structural components under extreme corrosive conditions.
ABSTRACT
BACKGROUND: Paroxysmal kinesigenic dyskinesia (PKD) is the most common type of paroxysmal dyskinesias. Only one-third of PKD patients are attributed to proline-rich transmembrane protein 2 (PRRT2) mutations. OBJECTIVE: We aimed to explore the potential causative gene for PKD. METHODS: A cohort of 196 PRRT2-negative PKD probands were enrolled for whole-exome sequencing (WES). Gene Ranking, Identification and Prediction Tool, a method of case-control analysis, was applied to identify the candidate genes. Another 325 PRRT2-negative PKD probands were subsequently screened with Sanger sequencing. RESULTS: Transmembrane Protein 151 (TMEM151A) variants were mainly clustered in PKD patients compared with the control groups. 24 heterozygous variants were detected in 25 of 521 probands (frequency = 4.80%), including 18 missense and 6 nonsense mutations. In 29 patients with TMEM151A variants, the ratio of male to female was 2.63:1 and the mean age of onset was 12.93 ± 3.15 years. Compared with PRRT2 mutation carriers, TMEM151A-related PKD were more common in sporadic PKD patients with pure phenotype. There was no significant difference in types of attack and treatment outcome between TMEM151A-positive and PRRT2-positive groups. CONCLUSIONS: We consolidated mutations in TMEM151A causing PKD with the aid of case-control analysis of a large-scale WES data, which broadens the genotypic spectrum of PKD. TMEM151A-related PKD were more common in sporadic cases and tended to present as pure phenotype with a late onset. Extensive functional studies are needed to enhance our understanding of the pathogenesis of TMEM151A-related PKD. © 2021 International Parkinson and Movement Disorder Society.
Subject(s)
Chorea , Dystonia , Membrane Proteins , Adolescent , Child , Female , Humans , Male , Chorea/genetics , Dystonia/genetics , Membrane Proteins/metabolism , Mutation/genetics , PhenotypeABSTRACT
Tetraphenylethylene (TPE) related (supra)molecules have been intensively investigated due to their aggregation-induced emission (AIE) effect based on the restriction of intramolecular rotation (RIR). Meanwhile, boron-dipyrromethene (BODIPY) tends to emit intense fluorescence with high quantum yields. Herein, we combined TPE, BODIPY and terpyridine (TPY) into one system to study the emissive behaviour of organic building block as well as a self-assembled metallo-supramolecule. The TPY and BODIPY substituents with bulky sizes provide strong hindrance to restrict the rotation of the phenyl groups on TPE, leading to enhancement of emissive properties in both solution and aggregation states. Furthermore, the BODIPY-TPE-TPY ligand (L) was assembled with Zn (II) through coordination-driven self-assembly to form a cyclic dimer (D) with typical AIE characteristics.
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A new method is reported for preparing carbon nanotube (CNT) films. This method involves the continuous production of a hollow cylindrical CNT assembly and its condensation on a winding drum. The alignment and densification of CNTs in the film are improved by controlling the winding rate and imposition of mechanical rolling, respectively. The prepared film has a strength of 9.6 GPa, which is well above those for all other man-made films and fibers.
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In lower-limb rehabilitation, human action recognition (HAR) technology can be introduced to analyze the surface electromyography (sEMG) signal generated by movements, which can provide an objective and accurate evaluation of the patient's action. To balance the long cycle required for rehabilitation and the inconvenient factors brought by wearing sEMG devices, a portable sEMG signal acquisition device was developed that can be used under daily scenarios. Additionally, a mobile application was developed to meet the demand for real-time monitoring and analysis of sEMG signals. This application can monitor data in real time and has functions such as plotting, filtering, storage, and action capture and recognition. To build the dataset required for the recognition model, six lower-limb motions were developed for rehabilitation (kick, toe off, heel off, toe off and heel up, step back and kick, and full gait). The sEMG segment and action label were combined for training a convolutional neural network (CNN) to achieve high-precision recognition performance for human lower-limb actions (with a maximum accuracy of 97.96% and recognition accuracy for all actions reaching over 97%). The results show that the smartphone-based sEMG analysis system proposed in this paper can provide reliable information for the clinical evaluation of lower-limb rehabilitation.
Subject(s)
Mobile Applications , Smartphone , Humans , Electromyography , Pattern Recognition, Automated , Exercise TherapyABSTRACT
Vertically aligned carbon nanotubes (VACNTs), a unique group of highly aligned CNTs normal to a substrate, have been extensively studied during the past decades. However, it is a long-standing challenge to improve the height of VACNTs due to the incidental deactivation of catalysts during growth. Herein, we demonstrate a facile strategy toward synthesizing high-density and well-aligned CNT arrays from in situ formed Fe-based catalysts on a stainless steel (SS) mesh. These catalysts were generated by direct oxidation-reduction treatment to the SS, which had excellent adhesion on the mesh substrate, and thus suppressed catalyst aggregation and promoted CNT growth under the flow of C2H2. In particular, by feeding additional CO2 at an optimal rate, the height of CNT arrays could be boosted from ca. 15 µm to ca. 80.0 µm, one of the highest heights observed for VACNTs on SS-based substrates so far. This is attributed to the prolonged activity of the catalysts by CO2 induced removal of extra carbon. Our study might provide an insight into the development of efficient strategies for VACNT growth on conductive substrates.
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The proliferation of the biomarker Ki67 has been extensively studied in colorectal cancer (CRC). Although numerous Ki67 cut-off values have previously been reported, the optimal cut-off value remains unclear with previous studies providing contrasting results. The present retrospective cohort study aimed to determine the optimal cut-off value for CRC. Ki67 levels and the prognosis of patients with non-metastatic CRC were obtained from the Electronic Health Information System of a tertiary hospital in Kunming City. The Restricted Cubic Spline (RCS) model was used to analyze the non-linear association between Ki67 levels and the risk of patient death and metastasis. Moreover, the RCS model was used to determine the optimal cut-off value of Ki67. Cox proportional hazards models were used to verify the effects of the cut-off value. In total, 210 patients with CRC and a median age of 62.5 years (age range, 23.0-88.0 years) were studied. Results of the present study demonstrated a non-linear association between Ki67 levels and the risk of patient death based on the RCS model, and at Ki67 levels ≥60%, the hazard ratio (HR) of patient death gradually increased. Using multivariate-adjusted Cox proportional hazards models, the results of the present study demonstrated that Ki67 ≥60% indicated a high-risk ratio for both distant metastasis and death [HR, 2.640; 95% confidence interval (CI), 1.066-6.539], compared with Ki67 <60% (HR, 2.558; 95% CI, 1.079-6.064). Therefore, Ki67 ≥60% may be the optimal cut-off value for the prediction of death and metastasis in patients with CRC. Thus, Ki67 may act as a biomarker for predicting the prognosis of patients with CRC, and the optimal cut-off value for the prediction of both death and metastasis of patients with CRC is 60%.
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Thermally insulating materials (TIMs) with ultra-low thermal conductivity, fire-retardancy, and mechanical stability are demanded to improve energy efficiency in many fields, such as petrochemical plants, energy-saving buildings, and aerospace. However, traditional polymer-based TIMs could not meet these demands. Herein, we propose a direct foaming strategy for obtaining carbon nanotube (CNT) aerogels by the gradual expansion of CNT films with H2O2 as a foaming agent at room temperature. The obtained CNT aerogels have hierarchical cellular structures and possess an ultra-low density (4.6 mg cm-3) and thermal conductivity (16.5 mW m-1 K-1) as well as excellent mechanical robustness and fire-resistance. Our results show that such CNT aerogels have promising applications in the field of thermal insulation and present a facile pathway for the design of thermally insulating, fire-retardant materials based on CNTs.
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Carbon nanotubes (CNTs) have been considered as promising electrode materials for energy storage devices, especially flexible electronics owing to their excellent electrical, physicochemical and mechanical properties. However, the severe aggregation between CNTs significantly reduces the electrochemically active surface areas and thus degrades the electrochemical properties. In this study, we demonstrate a facile layer-by-layer strategy toward preparing a CNT/hollow carbon nanocage (HCNC) hybrid film. Through electrochemically removing the impurities in CNT films and optimizing the concentrations of HCNC, the hybrid film exhibits a high specific capacitance of 183.7 F g-1 at 10 mV s-1 and good cycling stability of 85% retention after 5000 cycles at 1 A g-1. Our study provides potential scale-up synthesis of free-standing CNT electrode materials for high-performance supercapacitors.
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Antireflective (AR) materials are required to possess high optical antireflection and mechanical stability for their practical applications in optical, opto-electronic, and electron-optical devices. However, the AR materials developed so far can hardly meet these requirements. Here, we report the construction of a highly porous and sponge-like material based on carbon nanotubes (CNTs). This is achieved by continuous winding of a hollow cylindrical CNT assembly and subsequent modification with amorphous carbon (AC). The resultant material is shown to have very low optical reflectance at the visible and infra-red wavelengths over a wide range of incident angles and undergoes little degradation even after long-lasting compressive cycling between 0 and 90% strains or a large change of environmental temperature from -196 to 300 °C. Besides, the AR sponge material can recover fast after bending, stretching, and compression from high elastic strains. Such an excellent combination of broadband and omnidirectional antireflection, mechanical stability, and elastic flexibility results from the strong light absorption by the highly porous CNT structures strengthened by AC deposition on CNT surfaces and junctions, and the new AR material has potential applications in the renewable energy and military fields.
ABSTRACT
For applications in energy-saving buildings, aerospace industry, and wearable electronic devices, thermally insulating materials (TIMs) are required to possess not only low thermal conductivity but also light weight, mechanical robustness, and environmental stability. However, conventional TIMs can rarely meet these requirements. To overcome this shortcoming, we propose a new strategy for preparing TIMs. This is based on the design of a highly porous structure from carbon nanotubes (CNTs). The CNT structure is constructed by continuous winding of a hollow cylindrical CNT assembly from a high-temperature furnace and subsequent modification by the deposition of amorphous carbon (AC). The resultant sponge-like material is shown to have a record-low density of 2-4 mg cm-3 and a record-low thermal conductivity of 10-14 mW m-1 K-1. Combined with this thermal property, the sponge material also possesses fire-retardancy during burning, mechanical robustness after repeated loading and unloading to a high strain of 90%, and environmental stability from 535 to -196 °C. Such a combination of physical and mechanical properties results from the strengthening of the porous structure by virtue of AC deposition on CNT surfaces and junctions. The high performance of the new TIM constitutes the foundation for it to be used in wide areas, especially under the harsh conditions requiring multifunctionality.
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BACKGROUND: Refractory mycoplasma pneumonia (RMPP) is one of the important pathogens of community-acquired pneumonia (CAP) in children. Its treatment is difficult. The aims of this study were to analyze the clinical manifestations, diagnosis, and treatment of 20 cases of RMPP in children in order to provide a reference for the diagnosis and treatment of RMPP. METHODS: The clinical data of 20 patients with RMPP admitted to the Pediatrics Department of the First Affiliated Hospital of Guangzhou Medical University in the recent three years were retrospectively analyzed. The clinical data of 36 patients with common mycoplasma pneumonia in the same period were compared. The clinical manifestations, laboratory examinations, and imaging characteristics of RMPP were discussed. Intrapulmonary and extrapulmonary complications and treatment were also analyzed in order to provide assistance in the diagnosis and treatment of RMPP. RESULTS: There were significant differences between the refractory group and the general group in terms of heat duration, hospitalization time, hypoxemia, lung rales, CRP, ESR, PCT, LDH, ALT, PLT, WBC, D dimer and other laboratory examinations, intrapulmonary and extrapulmonary complications, and treatment (all P<0.05). There was no significant difference in the age, sex, and wheezing between the two groups (P>0.05). CONCLUSIONS: Long duration of fever, tachycardia, and lung rale protrusion may be the clinical characteristics of RMPP. Unilateral pulmonary shadow and atelectasis should be paid more attention, which may be a high-risk factor for the development of RMPP. The inflammation index of RMPP cases increased and there were many complications inside and outside the patients' lungs. It was necessary to give enough macrolides to fight the infection by using Glucocorticoid and Intravenous immunoglobulin reasonably while liver, heart, and fiberoptic bronchoscopy was completed to improve the effectiveness of the diagnosis and treatment.
Subject(s)
Pneumonia, Mycoplasma , Child , Fever , Humans , Lung , Mycoplasma pneumoniae , Pneumonia, Mycoplasma/diagnosis , Pneumonia, Mycoplasma/drug therapy , Retrospective StudiesABSTRACT
So far, preparation of high-performance carbon nanotube (CNT)/polymer composites still faces big challenges mainly due to the limited control of CNT dispersion, fraction, and alignment in polymers. Here, a new "layer-by-layer deposition" method is put forward for preparing CNT/polymer composite fibers using poly(vinyl alcohol) (PVA) as an exemplary polymer. This is based on the continuous production of a hollow cylindrical CNT assembly from a high temperature reactor and its shrinking by a PVA-containing solution and deposition on a removable substrate wire. The in situ mixing of the two composite components at the molecular level allows CNTs to disperse and PVA to infiltrate into the fiber efficiently. As a result, remarkable effects of the CNT reinforcement on the PVA matrix are observed, including a strength improvement from â¼50 to 1255 MPa and electrical conductivity from â¼0 to 1948 S cm(-1). The new method offers good controllability of CNT dispersion and fraction in the polymer matrix, variability for making composite fibers using different polymers, and suitability for scaled up production. This study thus provides a new research direction for preparing CNT-reinforced composites and future performance maximization.
Subject(s)
Blindness/prevention & control , Cataract Extraction , Cataract/prevention & control , Delivery of Health Care/organization & administration , Models, Organizational , Ophthalmology/organization & administration , Blindness/epidemiology , Cataract/epidemiology , China/epidemiology , Health Services Accessibility , Healthcare Disparities/statistics & numerical data , Humans , Pilot Projects , Rural Population , Urban PopulationABSTRACT
OBJECTIVE: To investigate the distribution of translocation between chromosomes 4q35 and 10q26 in facioscapulohumeral muscular dystrophy (FSHD) patients and normal individuals. METHODS: The Bgl II-Bln I dosage test was performed to study the distribution of translocation between chromosomes 4q35 and 10q26 in 70 cases of FSHD patients, 55 cases of kindred with FSHD, and 52 cases of normal controls. RESULTS: (1) In normal individuals, the frequency of translocation between chromosomes 4q35 and 10q26 is 19.23%. The frequency of translocation from chromosome 4q35 to 10q26 and that from chromosome 10q26 to 4q35 are both 9.62%. (2) In the FSHD patients, the frequency of translocation between chromosomes 4q35 and 10q26 is 18.57%. The frequency of translocation from chromosome 4q35 to 10q26 and that from chromosome 10q26 to 4q35 are 12.86% and 5.71% respectively. CONCLUSIONS: The translocation between chromosomes 4q35 and 10q26 was frequently observed in both normal Chinese population and FSHD patients. No significant difference was observed between them.