No abstract

No abstract

No abstract

T helper 17 cells (Th17) constitute a distinct subset of helper T cells with a unique transcriptional profile (STAT3, RORγ, and RORα), cytokine production pattern (IL17 family), and requirement of specific cytokines for their differentiation (TGF-β, IL6, IL21, and IL23). Recent studies involving experimental animals and humans have shown that Th17/IL17 plays a crucial role in host defense against a variety of pathogens, including bacteria and viruses. The underlying mechanisms by which Th17 performs include dendritic cell (DC) regulation, neutrophil recruitment, Th1 modulation, and T regulatory cell (Treg) balance. In recent years, researchers have generated an accumulating wealth of evidence on the role of Th17/IL17 in protective immunity to intracellular bacterial pathogens, such as Mycobacterium tuberculosis and Chlamydia trachomatis, which are one of the most important pathogens that inflict significant socioeconomic burden across the globe. In this article, we reviewed the current literature on the functions and mechanisms by which Th17/IL17 responds to intracellular bacterial infections. A better understanding of Th17/IL17 immunity to pathogens would be crucial for developing effective prophylactics and therapeutics.

No abstract

No abstract

A facile one-step approach to fabricate substrates for surface-enhanced Raman scattering (SERS) detection of polycyclic aromatic hydrocarbons (PAHs) was explored by reduction of silver nitrate with humic acids (HAs). This simple process readily delivers silver nanoparticles (Ag NPs) decorated with HAs (HAs-Ag NPs), and an average diameter of 50 nm. More importantly, it compares favorably to Ag NPs prepared by the usual sodium citrate method, HAs-Ag NPs show excellent SERS activity for PAHs and display a remarkable capacity to absorb aromatic molecules through presumed π-π stacking interactions. Furthermore, the HAs-Ag NPs displayed good SERS stability, possibly due to the fact that HAs form loose coils or networks around the nanoparticles thus preventing aggregation. The investigation of qualitative and quantitative detection of PAHs on HAs-Ag NPs indicate that different PAHs can be distinguished easily from their discriminant SERS peaks, and the SERS responses exhibited a linear dependence on PAH concentrations over two orders of magnitude, with tens of nM detection limits. In addition, the HAs-Ag NPs performed well in the multicomponent analysis of PAH mixtures by the SERS technique without pre-separation.

A disposable electrode, modified with multiwalled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs), was developed to serve as a sensor for the simultaneous determination of dihydroxybenzene isomers (hydroquinone, catechol and resorcinol). The modified electrode was fabricated by electrodepositing AuNPs on a MWCNTs decorated screen-printed electrode (SPE), then it was characterized in morphology and electrochemical properties and utilized to determine the isomers of dihydroxybenzene in water samples. Compared with bare SPE, AuNPs-modified SPE, and MWCNTs-modified SPE, the fabricated SPE has much stronger electrocatalytic activity for the oxidation of dihydroxybenzenes with the increase of the peak current and the decrease of the potential difference (OE p ) between the anodic and cathodic peaks. By using differential pulse voltammetry (DPV), the three isomers can be determined simultaneously and sensitively at the modified SPE. For hydroquinone, catechol and resorcinol, the oxidation peak currents are linear to the concentrations at the range of 2.0 Â 10 À6 $7.3 Â 10 À4 M, 2.0 Â 10 À6 $7.3 Â 10 À4 M and 3.0 Â 10 À6 $9.6 Â 10 À4 M with the detection limits of 3.9 Â 10 À7 M, 2.6 Â 10 À7 M and 7.2 Â 10 À7 M, respectively. Moreover, a rapid onfiled determination is convenient to be performed at this disposable modified SPE incorporated in a portable electrochemical system. These results reveal that the presented sensor can be used for the simultaneous and sensitive on-field determination of dihydroxybenzene isomers.