Simple, inexpensive, and rapid diagnostic tests in low-resource settings with limited laboratory equipment and technical expertise are instrumental in reducing morbidity and mortality from epidemic ...infectious diseases. We developed a smartphone-based fluorescent lateral flow immunoassay (LFIA) platform for the highly sensitive point-of-care detection of Zika virus nonstructural protein 1 (ZIKV NS1). An attachment was designed and 3D-printed to integrate the smartphone with external optical and electrical components, enabling the miniaturization of the instrument and reduction in cost and complexity. Quantum dot microspheres were utilized as probes in fluorescent LFIA because of their extremely bright fluorescence signal. This approach can achieve quantitative point-of-care detection of ZIKV NS1 within 20 min. Limits of detection (LODs) in buffer and serum were 0.045 and 0.15 ng mL−1, respectively. Despite the high structural similarity, a high-level Dengue virus NS1 as interferent showed limited cross-reactivity. Furthermore, this assay was successfully applied to detecte ZIKV NS1 and virions spiked in complex biological samples, indicating its practical application capability. Given its low cost, compact size, and excellent analytical performance, the proposed smartphone-based fluorescent LFIA platform holds considerable potential in rapid and accurate point-of-care detection of ZIKV NS1 and provides new insight into the design and application of molecular diagnostic methods in low-resource settings.
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•Portable and low-cost smartphone-based fluorescent lateral flow immunoassay platform.•Quantitative detection of ZIKV NS1 within 20 min with a low limit of detection of 0.045 ng mL−1 in buffer or 0.15 ng mL−1 in serum sample.•Low cross-reactivity with high-level DENV NS1 as interferent.•Point-of-care detection of ZIKV NS1 and virions in complex biological samples.
During the traditional channel noise modeling of nanoscale MOSFETs, neither the suppression of shot noise by Fermi and Coulomb effects nor the cross correlation noise between the source current noise ...and gate current noise is considered. However, they should not be ignored. In this study, the channel noise of a 22 nm MOSFET is tested experimentally, and the results show that the suppressed shot noise, the thermal noise, and the cross correlation noise are the main types of channel noises in nano-MOSFETs. Furthermore, according to the physical structure and characteristics of the MOSFET, a noise model, including the elements of shot noise, thermal noise, and cross correlation noise, is derived, which considers the influence of the shot noise suppressed by either the Fermi or Coulomb effects. Based on the model, the variation of noise with the channel length, temperature, source–drain voltage, and gate voltage is analyzed. The results are consistent with the experiments and theories in the literature.
With silicon solar cells as the research object, this paper takes their nondestructive character and analyzes their quality with noise-based technology. Through the stress aging of samples and the ...testing of various types of noise, including 1/f noise, microplasma noise, and G-R noise, in the cells in the laboratory, the noise characteristics are analyzed. The research results show that noise is correlated with defects in silicon solar cells. The different types of noise can be used to characterize different parts and types of defects in the cells according to the mechanism of generation of noise and the failure physics of photovoltaic devices, and thereby, the evaluation of the quality and analysis of the reliability of solar cells can be achieved.
Starting from the basic equations describing the evolution of the carriers and photons inside a semiconductor optical amplifier (SOA), the equation governing pulse propagation in the SOA is derived. ...By employing homotopy analysis method (HAM), a series solution for the output pulse by the SOA is obtained, which can effectively characterize the temporal features of the nonlinear process during the pulse propagation inside the SOA. Moreover, the analytical solution is compared with numerical simulations with a good agreement. The theoretical results will benefit the future analysis of other problems related to the pulse propagation in the SOA.
The reliability of through silicon via (TSV) in a 3-dimensional integrated circuit (3D IC) determines whether the electronic system can operate continuously and steadily. The finite element method ...was adopted to study the response of TSV to thermoelectric coupling, the effect of different dielectric layer materials and the filling degree of carbon nanotubes (CNT) on TSV reliability were investigated, respectively. Through orthogonal simulation experiments, the high reliability of a type of TSV with benzocyclobutene (BCB) dielectric layer and filling by a coaxial hybrid CNT bundle was verified, and its lifetime was predicted by the failure of the physical model. The simulation results show that the most important influence factor to TSV reliability is the depth-to-width ratio, the second important factor is the choice of dielectric material, and the least important factor is the filling degree of CNT. The parameter values with the optimum reliability are as follows: the depth-to-width ratio of copper column is 20, the dielectric material is BCB, and the CNT filling degree is 4–8%.
A chelation-assisted palladium-catalyzed ortho-cyanation of the sp2 C−H bond by CuCN provided aromatic nitriles in moderate to good yields. Notably, the reaction could be conducted on a 10 mmol ...scale. The key intermediate of the natural product of Menispermum dauricum DC was concisely synthesized by the procedure. This new approach represents an exceedingly practical method for the synthesis of aromatic nitriles and offers an attractive alternative to the traditional Sandmeyer reaction.
The HIV-1 protein Nef inhibits antigen presentation by class I major histocompatibility complex (MHC-I). We determined the mechanism of this activity by solving the crystal structure of a protein ...complex comprising Nef, the MHC-I cytoplasmic domain (MHC-I CD) and the μ1 subunit of the clathrin adaptor protein complex 1. A ternary, cooperative interaction clamps the MHC-I CD into a narrow binding groove at the Nef-μ1 interface, which encompasses the cargo-recognition site of μ1 and the proline-rich strand of Nef. The Nef C terminus induces a previously unobserved conformational change in μ1, whereas the N terminus binds the Nef core to position it optimally for complex formation. Positively charged patches on μ1 recognize acidic clusters in Nef and MHC-I. The structure shows how Nef functions as a clathrin-associated sorting protein to alter the specificity of host membrane trafficking and enable viral evasion of adaptive immunity.
Recent years have seen a heated discussion on what influences employees' recognition of enterprise brand equity among the psychological community. Some empirical evidence suggests that the brand ...equity of consumers and brand equity of sales are two categories that should be studied. However, more recent discussions have focused more on the former. In contrast, this study discusses the factors influencing brand equity based on the employee level. Moreover, this paper examines whether FinTech can help companies get out of financing difficulties and thus improve employees' brand equity recognition. This research illustrates how FinTech has become an essential driver of brand equity value. Based on micro panel data on enterprises from 2011 to 2019, we analyze the transmission mechanism between the two factors and the mediating role of financing constraints. FinTech's development promotes employees' recognition of corporate brand equity, and financing constraints are an essential transmission path between the two factors. Furthermore, the impact of financing constraints on employee brand equity identity is characterized by cross-regional economic heterogeneity. In contrast, the development of FinTech characterizes the cross-enterprise heterogeneity in employees' recognition of brand equity value. Altogether, this study demonstrates the promising application of FinTech in influencing the mechanisms of employee brand equity.
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