Superelastic Hybrid CNT/Graphene Fibers for Wearable Energy Storage

The demands for wearable technologies continue to grow and novel approaches for powering these devices are being enabled by the advent of new electromaterials and novel fabrication strategies. Herein, a novel approach is reported to develop superelastic wet-spun hybrid carbon nanotube graphene fibers followed by electrodeposition of polyaniline to achieve a high-performance fiber-based supercapacitor. It is found that the specific capacitance of hybrid carbon nanotube (CNT)/graphene fiber is enhanced up to ≈39% using a graphene to CNT fiber ratio of 1:3. Fabrication of spring-like coiled fiber coated with an elastic polymer shows an extraordinary elasticity capable of 800% strain while affording a specific capacitance of ≈138 F g -1 . The elastic rubber coating enables extreme stretchability and enabling cycles with up to 500% strain for thousands of cycles with no significant change in its performance. Multiple supercapacitors can be easily assembled in series or parallel to meet specific energy and power needs

A Polymorphic Microdeletion in the RGS9 Gene Suppresses PTB Binding and Associates with Obesity

Objective: RGS9 is a member of the family of Regulators of G-Protein Signaling (RGS) proteins defined by the presence of an RGS domain which can accelerate the GTPase-activity of G protein Gα subunits. An insertion/deletion (I/D) polymorphism of the nucleotide sequence TTTCT (rs3215227) has been identified in the human RGS9 gene, which matches the consensus high affinity binding motif for the ubiquitously expressed RNA binding Polypyrimidine Tract Binding Protein (PTB). In this study, we evaluate the genetic association and functional relevance of this polymorphism in type 2 diabetes and obesity. Subjects and methods: We genotyped a larger population of 9272 Chinese and Malaysian individuals for the RGS9 I/D polymorphism using TaqMan allelic discrimination protocols. We found that the D allele of the RGS9 polymorphism was associated with a decreased prevalence of obesity in women (P=0.003, OR=0.753 95%CI 0.625-0.906) and girls (P=0.002, OR=0.604 95%CI 0.437-0.835). The association was moderate in boys (P=0.038, OR=0.724 95%CI 0.533-0.983) and not significant in men. Furthermore, we found that the transcript deletion variant exhibited a 10-fold reduction in PTB binding in vitro and that the splicing of the deletion variant was less affected by PTB co-expression. Conclusions: We provide genetic and biochemical data to support a genetic role of RGS9 in obesity but unlikely in T2D. The RGS9 I/D polymorphism influence the post-transcriptional processing of the gene through an altered affinity for the splicing factor PTB and are associated with obesity

Scanning range extension by combining arrays with lenses

Array antennas, and more specifically phased array antennas, are widely used in radar detection and communication systems because of their excellent beam scanning ability and simple control. Generally speaking, the scanning function can be realized in two ways: mechanically or electronically. Mechanical steering is done by rotating the whole structure, so there is a certain delay. The electronic scanning is done by controlling the relative relationship between the input signals of different array elements. Electronical scanning is then faster and easy to integrate with other circuits, which makes it an interesting solution to these applications. However, the disadvantage of electronic steering is that the scanning angle range is limited, which is generally within the range of ±60° . Beyond this range, the performance of the antenna will decrease considerably. One way to improve the antenna gain or expand the scanning range of the array antenna is to combine the array antenna with a dielectric radome. This thesis mainly studies how to adjust the shape of the dielectric radome with a center frequency of 28GHz to expand the beam scanning range of the two-dimensional array composed of rectangular waveguide ports. The inner and outer profiles of the dielectric lens follows the conics equation, and the shape of the lens can be controlled by adjusting different parameters. In this thesis, I adjust the lens shape according to three different objectives: 1. Increase the gain of the array antenna at the small scanning angle (0° ∼ 30°). The adjusted lens model increases the gain in this range by about 0.5 dBi; 2. Improve the gain of the array antenna at the large scanning angle (60° ∼ 80°). The final lens model increases the gain of the array antenna at the scanning angle of 70° and 80° by about 0.5 dBi and 1 dBi respectively; and 3. Improve the directivity of the array antenna in the range of 0° ∼ 70° . The final dielectric lens model improves the directivity in the broadside direction by about 1 dBi, and increases about 0.6 dBi when the scanning angle is 60° ;Arrayantenner, och mer specifikt fasantenner, används ofta i radardetekterings- och kommunikationssystem på grund av deras utmärkta strålskanningsförmåga och enkla kontroll. Generellt kan skanningsfunktionen realiseras på två sätt: mekaniskt eller elektroniskt. Mekanisk styrning görs genom att rotera hela strukturen, så det finns en viss fördröjning. Den elektroniska skanningen görs genom att styra det relativa förhållandet mellan ingångssignalerna för olika arrayelement. Elektronisk skanning är då snabbare och lätt att integrera med andra kretsar, vilket gör det till en intressant lösning för dessa applikationer. Nackdelen med elektronisk styrning är dock att skanningsvinkeln är begränsad, vanligtvis mindre än ±60°. Utöver detta område kommer antennens prestanda att minska avsevärt. Ett sätt att förbättra antennförstärkningen eller utöka antennens skanningsområde är att kombinera arrayantennen med en dielektrisk radom. Denna avhandling studerar huvudsakligen hur man justerar formen på den dielektriska radomen med en centerfrekvens på 28GHz för att utöka strålskanningsområdet för den tvådimensionella array bestående av rektangulära vågledarportar. Den dielektriska linsens inre och yttre form följer konekvationen, och linsens form kan kontrolleras genom att justera olika parametrar. I denna avhandling justerar jag linsens form enligt tre olika mål: 1. Öka förstärkningen av antennen vid den lilla skanningsvinkeln (0° ∼ 30°). Den justerade linsmodellen ökar förstärkningen i detta område med cirka 0.5 dBi; 2. Förbättra förstärkningen av antennen vid den stora skanningsvinkeln (60° ∼ 80° ). Den slutliga modellen på linsen ökar förstärkningen av antennen i skanningsvinkeln 70° och 80° med cirka 0.5 dBi respektive 1 dBi; och 3. Förbättra riktigheten hos antennen i intervallet 0° ∼ 70°. Den slutliga dielektriska linsmodellen förbättrar riktningen i breddriktningen med ca 1 dBi, och ökar ca 0.6 dBi när skanningsvinkeln är 60°

Scanning range extension by combining arrays with lenses

Array antennas, and more specifically phased array antennas, are widely used in radar detection and communication systems because of their excellent beam scanning ability and simple control. Generally speaking, the scanning function can be realized in two ways: mechanically or electronically. Mechanical steering is done by rotating the whole structure, so there is a certain delay. The electronic scanning is done by controlling the relative relationship between the input signals of different array elements. Electronical scanning is then faster and easy to integrate with other circuits, which makes it an interesting solution to these applications. However, the disadvantage of electronic steering is that the scanning angle range is limited, which is generally within the range of ±60° . Beyond this range, the performance of the antenna will decrease considerably. One way to improve the antenna gain or expand the scanning range of the array antenna is to combine the array antenna with a dielectric radome. This thesis mainly studies how to adjust the shape of the dielectric radome with a center frequency of 28GHz to expand the beam scanning range of the two-dimensional array composed of rectangular waveguide ports. The inner and outer profiles of the dielectric lens follows the conics equation, and the shape of the lens can be controlled by adjusting different parameters. In this thesis, I adjust the lens shape according to three different objectives: 1. Increase the gain of the array antenna at the small scanning angle (0° ∼ 30°). The adjusted lens model increases the gain in this range by about 0.5 dBi; 2. Improve the gain of the array antenna at the large scanning angle (60° ∼ 80°). The final lens model increases the gain of the array antenna at the scanning angle of 70° and 80° by about 0.5 dBi and 1 dBi respectively; and 3. Improve the directivity of the array antenna in the range of 0° ∼ 70° . The final dielectric lens model improves the directivity in the broadside direction by about 1 dBi, and increases about 0.6 dBi when the scanning angle is 60° ;Arrayantenner, och mer specifikt fasantenner, används ofta i radardetekterings- och kommunikationssystem på grund av deras utmärkta strålskanningsförmåga och enkla kontroll. Generellt kan skanningsfunktionen realiseras på två sätt: mekaniskt eller elektroniskt. Mekanisk styrning görs genom att rotera hela strukturen, så det finns en viss fördröjning. Den elektroniska skanningen görs genom att styra det relativa förhållandet mellan ingångssignalerna för olika arrayelement. Elektronisk skanning är då snabbare och lätt att integrera med andra kretsar, vilket gör det till en intressant lösning för dessa applikationer. Nackdelen med elektronisk styrning är dock att skanningsvinkeln är begränsad, vanligtvis mindre än ±60°. Utöver detta område kommer antennens prestanda att minska avsevärt. Ett sätt att förbättra antennförstärkningen eller utöka antennens skanningsområde är att kombinera arrayantennen med en dielektrisk radom. Denna avhandling studerar huvudsakligen hur man justerar formen på den dielektriska radomen med en centerfrekvens på 28GHz för att utöka strålskanningsområdet för den tvådimensionella array bestående av rektangulära vågledarportar. Den dielektriska linsens inre och yttre form följer konekvationen, och linsens form kan kontrolleras genom att justera olika parametrar. I denna avhandling justerar jag linsens form enligt tre olika mål: 1. Öka förstärkningen av antennen vid den lilla skanningsvinkeln (0° ∼ 30°). Den justerade linsmodellen ökar förstärkningen i detta område med cirka 0.5 dBi; 2. Förbättra förstärkningen av antennen vid den stora skanningsvinkeln (60° ∼ 80° ). Den slutliga modellen på linsen ökar förstärkningen av antennen i skanningsvinkeln 70° och 80° med cirka 0.5 dBi respektive 1 dBi; och 3. Förbättra riktigheten hos antennen i intervallet 0° ∼ 70°. Den slutliga dielektriska linsmodellen förbättrar riktningen i breddriktningen med ca 1 dBi, och ökar ca 0.6 dBi när skanningsvinkeln är 60°

The hydrochemical and isotopic data in Poyang Lake Basin

<p>Groundwater hydrochemical and isotopic data in Poyang Lake Basin.</p&gt

Superelastic Hybrid CNT/Graphene Fibers for Wearable Energy Storage

The demands for wearable technologies continue to grow and novel approaches for powering these devices are being enabled by the advent of new electromaterials and novel fabrication strategies. Herein, a novel approach is reported to develop superelastic wet-spun hybrid carbon nanotube graphene fibers followed by electrodeposition of polyaniline to achieve a high-performance fiber-based supercapacitor. It is found that the specific capacitance of hybrid carbon nanotube (CNT)/graphene fiber is enhanced up to ≈39% using a graphene to CNT fiber ratio of 1:3. Fabrication of spring-like coiled fiber coated with an elastic polymer shows an extraordinary elasticity capable of 800% strain while affording a specific capacitance of ≈138 F g -1 . The elastic rubber coating enables extreme stretchability and enabling cycles with up to 500% strain for thousands of cycles with no significant change in its performance. Multiple supercapacitors can be easily assembled in series or parallel to meet specific energy and power needs

Three-Dimensional Broadband and Isotropic Double-Mesh Twin-Wire Media for Meta-Lenses

Lenses are used for multiple applications, including communications, surveillance and security, and medical instruments. In homogeneous lenses, the contour is used to control the electromagnetic propagation. Differently, graded-index lenses make use of inhomogeneous materials, which is an extra degree of freedom. This extra degree of freedom enables the design of devices with a high performance. For instance, rotationally symmetric lenses without spherical aberrations, e.g., the Luneburg lens, can be designed. However, the manufacturing of such lenses is more complex. One possible approach to implement these lenses is using metamaterials, which are able to produce equivalent refractive indices. Here, we propose a new type of three-dimensional metamaterial formed with two independent sets of wires. The double-mesh twin-wire structure permits the propagation of a first mode without cut-off frequency and with low dispersion and high isotropy. These properties are similar to periodic structures with higher symmetries, such as glide symmetry. The variations of the equivalent refractive index are achieved with the dimension of the meandered wires. The potential of this new metamaterial is demonstrated with simulated results of a Luneburg meta-lens

Dynamical analysis of almost periodic solution for a multispecies predator-prey model with mutual interference and time delays

Abstract In this paper, we build a multispecies predator-prey model with mutual interference and time delays. By means of the comparison theorem, Ascoli theorem and Lebesgue dominated convergence theorem, we establish the sufficient conditions of permanence and investigate the existence of a unique almost periodic solution. By constructing a suitable Lyapunov function, we obtain that the positive almost periodic solution is globally attractive. Finally, we give numerical simulations to indicate the complex dynamical behaviors of this system

Drug susceptibility and molecular epidemiology of Escherichia coli in bloodstream infections in Shanxi, China

Objectives We carried out a retrospective study to investigate the drug susceptibility and genetic relationship of clinical Escherichia coli isolates from patients with BSIs in Shanxi, China. Methods E. coli isolates causing BSIs were consecutively collected from June 2019 to March 2020. Antimicrobial susceptibility testing was performed by broth microdilution method. PCR was used to detect antimicrobial resistance genes coding for extended-spectrum β-lactamases (ESBLs), phylogenetic groups and seven housekeeping genes of E. coli. Results A total of 76 E. coli were collected. Antimicrobial susceptibility testing revealed that the top six E. coli resistant antibiotics were ampicillin (90.7%), ciprofloxacin (69.7%), cefazolin (65.7%), levofloxacin (63.1%), ceftriaxone and cefotaxime (56.5%). Among the 76 isolates, 43 produced ESBLs. Molecular analysis showed that CTX-M-14 was the most common ESBLs, followed by CTX-M-15 and CTX-M-55. Phylogenetic group D (42.2%) predominated, followed by group B2 (34.2%), group A (18.4%) and group B1 (5.2%). The most prevalent sequence types (STs) were ST131 (15/76), ST69 (12/76) and ST38 (6/76). Conclusions This study is the first to report the phenotypic and molecular characteristics of E. coli isolated from BSIs in Shanxi, China. Our results indicated a high prevalence of MDR in E. coli strains isolated from BSIs and a serious spread of ESBL genes in Shanxi, especially the epidemiological blaCTX-M. Phylogenetic analysis indicated genetic diversity among E. coli BSIs isolates