1,200 research outputs found
Model anisotropic quantum Hall states
Model quantum Hall states including Laughlin, Moore-Read and Read-Rezayi
states are generalized into appropriate anisotropic form. The generalized
states are exact zero-energy eigenstates of corresponding anisotropic two- or
multi-body Hamiltonians, and explicitly illustrate the existence of geometric
degrees of in the fractional quantum Hall effect. These generalized model
quantum Hall states can provide a good description of the quantum Hall system
with anisotropic interactions. Some numeric results of these anisotropic
quantum Hall states are also presented.Comment: 10 pages, 5 figure
Reduced glutamine synthetase activity alters the fecundity of female Bactrocera dorsalis (Hendel)
Glutamine synthetase (GS) is a key enzyme in glutamine synthesis and is associated with multiple physiological processes in insects, such as embryonic development, heat shock response, and fecundity regulation. However, little is known about the influence of GS on female fecundity in the oriental fruit fly, Bactrocera dorsalis. Based on the cloning of BdGSs, mitochondrial BdGSm and cytoplasmic BdGSc, we determined their expressions in the tissues of adult B. dorsalis. BdGSm was highly expressed in the fat body, while BdGSc was highly expressed in the head and midgut. Gene silencing by RNA interference against two BdGSs isoforms suppressed target gene expression at the transcriptional level, leading to a reduced ovarian size and lower egg production. The specific inhibitor L-methionine S-sulfoximine suppressed enzyme activity, but only the gene expression of BdGSm was suppressed. A similar phenotype of delayed ovarian development occurred in the inhibitor bioassay. Significantly lower expression of vitellogenin and vitellogenin receptor was observed when GS enzyme activity was suppressed. These data illustrate the effects of two GS genes on adult fecundity by regulating vitellogenin synthesis in different ways
Kondo Signatures of a Quantum Magnetic Impurity in Topological Superconductors
We study the Kondo physics of a quantum magnetic impurity in two-dimensional topological superconductors (TSCs), either intrinsic or induced on the surface of a bulk topological insulator, using a numerical renormalization group technique. We show that, despite sharing the p+ip pairing symmetry, intrinsic and extrinsic TSCs host different physical processes that produce distinct Kondo signatures. Extrinsic TSCs harbor an unusual screening mechanism involving both electron and orbital degrees of freedom that produces rich and prominent Kondo phenomena, especially an intriguing pseudospin Kondo singlet state in the superconducting gap and a spatially anisotropic spin correlation. In sharp contrast, intrinsic TSCs support a robust impurity spin doublet ground state and an isotropic spin correlation. These findings advance fundamental knowledge of novel Kondo phenomena in TSCs and suggest experimental avenues for their detection and distinction
Recent Biosensors Technologies for Detection of Mycotoxin in Food Products
Mycotoxins are chemically diverse and capable of inducing a wide diversity of acute and chronic symptoms, ranging from feed refusal to rapid death. Accurate detection and monitoring of mycotoxins is an essential component of the prevention, diagnosis, and remediation of mycotoxin-related issues in livestock and human food. Current trends in food analysis are focusing on the application of fast, simple procedure needed, and low-cost biosensor technologies that can detect with high sensitivity and selectivity different compounds associated with food safety. This chapter discussed the recent analytical methods-based biosensor technology for quantification of mycotoxins in food products. Mainly focus on the biosensor technology based on the immobilization of antibodies onto various nanomaterials such as nanoparticles, graphite, carbon nanotubes, and quantum dots. The nanomaterials are able to be functionalized with various biomolecules such as enzymes, antibodies, nucleic acids, DNA/RNA aptamers, bio- or artificial receptors that make them suitable for detection of various substances such as food toxins, bacteria, and other compounds important in food analysis. All the nanomaterials provide an effective platform for achieving high sensitivity that is similar and, in some cases, even better than conventional analytical methods. We believe that future trends will be emphasized on improving biosensor properties toward practical application in the food industry
Topological superconductivity and large spin Hall effect in the kagome family Ti6X4 (X = Bi, Sb, Pb, Tl, In)
Topological superconductors (TSC) become a focus of research due to the
accompanying Majorana fermions. However, the experimentally reported TSC are
extremely rare. The recent experiments reported the kagome TSC AVSb
(A=K, Rb, Cs), which exhibit unique superconductivity, topological surface
states (TSS), and Majorana bound states. More recently, the first
titanium-based kagome superconductor CsTiBi with nontrivial
topology was successfully synthesized as a perspective TSC. Given that Cs
contributes little to the electronic structures of CsTiBi and
binary compounds may be easier to be synthesized, here, by density functional
theory calculations, we predict five stable non-magnetic kagome compounds TiX (X = Bi, Sb, Pb, Tl, In) which exhibit superconductivity with
critical temperature Tc = 3.85.1 K, nontrivial band
topology, and TSS close to the Fermi level. In addition, the large intrinsic
spin Hall effect is obtained in TiX, which is caused by gapped
Dirac nodes and nodal lines due to a strong spin-orbit coupling. This work
offers new platforms for TSC and spintronic devices
Efficacy of the Combination of Voriconazole and Caspofungin in Experimental Pulmonary Aspergillosis by Different Aspergillus Species
OBJECTIVES: Invasive pulmonary aspergillosis (IPA) caused by Aspergillus fumigatus, Aspergillus flavus, or Aspergillus niger is associated with high mortality. We evaluated the efficacy and compared the therapeutic effect differences of voriconazole (VRC) in combination with caspofungin (CAS) in transiently neutropenic rats infected by A. fumigatus, A. flavus, or A. niger. METHODS: Treatment groups consisted of VRC (10 mg/kg q12 h) monotherapy, CAS (1 mg/kg/day) monotherapy, combination of VRC (10 mg/kg q12 h) + CAS (1 mg/kg/day), and no drug for 10 consecutive days. The efficacy and the difference in the treatments were evaluated through prolongation of survival, reduction in serum galactomannan levels and residual fungal burden, and histological studies. RESULTS: For all the strains, the combination of VRC and CAS led to significant prolongation in survival (P < 0.05) and reduction in residual fungal burden (P < 0.05) compared with CAS alone, and decrease in serum galactomannan levels (P < 0.05) compared with either agent alone. The survival in the combined therapy groups was significantly improved compared to VRC monotherapy for the strains of A. flavus and A. niger (P < 0.05), but no significant difference for the strains of A. fumigatus (P > 0.05). CONCLUSIONS: Combination of VRC and CAS was synergistic in IPA by A. flavus and A. niger, but small efficacy benefits in IPA by A. fumigatus
Development of biodegradable hybrid polymer film for detection of formaldehyde in seafood products
Despite the enormous accomplishments of current sensing methods, portable and sensitive sensing materials remains a challenging issue. Herein, a novel of a biodegradable hybrid polymer film was developed for quantitative analysis of formaldehyde seafood, including Lutjanus erythropterus, Euthynnus affinis, Caranx indicus, and Penaeus monodon at Sabah, Malaysia. In this research, starch and chitosan were introduced as the substrate to entrap Nash colorimetric reagents for the fabrication of biodegradable films for detection of formaldehyde. Under optimal conditions, excellent linearity (R2 = 0.9918) of colorimetric response was obtained in formaldehyde concentration ranges of 100 to 0 ppm, with a limit of detection and quantification calculated to be 5 and 16.8 ppm, respectively. The developed film was successfully applied to the identification and quantification of formaldehyde in four different seafood samples with satisfactory recoveries, and RSD values obtained range between 98.80%–104.65% and 0.12%–1.21%, respectively. The present research demonstrated short response time (within 5 min) that provides reliable methods for application in biosensing, which exhibited the advantage of this well-performing platform for application in the food, environmental, and medical disciplines sensing
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