Display omitted
•We presented an enhancing strategy for adenosine detection via target-triggering strand displacement cycle and Au NPs.•The method exhibited a low detection limit of 0.21pM.•High ...specificity of aptamers to target much favors for the selectivity improvement of the SPR assays.
Herein, we combine the advantage of aptamer technique with the amplifying effect of an enzyme-free signal-amplification and Au nanoparticles (NPs) to design a sensitive surface plasmon resonance (SPR) aptasensor for detecting small molecules. This detection system consists of aptamer, detection probe (c-DNA1) partially hybridizing to the aptamer strand, Au NPs-linked hairpin DNA (Au-H-DNA1), and thiolated hairpin DNA (H-DNA2) previously immobilized on SPR gold chip. In the absence of target, the H-DNA1 possessing hairpin structure cannot hybridize with H-DNA2 and thereby Au NPs will not be captured on the SPR gold chip surface. Upon addition of target, the detection probe c-DNA1 is forced to dissociate from the c-DNA1/aptamer duplex by the specific recognition of the target to its aptamer. The released c-DNA1 hybridizes with Au-H-DNA1 and opens the hairpin structure, which accelerate the hybridization between Au-H-DNA1 and H-DNA2, leading to the displacement of the c-DNA1 through a branch migration process. The released c-DNA1 then hybridizes with another Au-H-DNA1 probe, and the cycle starts anew, resulting in the continuous immobilization of Au-H-DNA1 probes on the SPR chip, generating a significant change of SPR signal due to the electronic coupling interaction between the localized surface plasma of the Au NPs and the surface plasma wave. With the use of adenosine as a proof-of-principle analyte, this sensing platform can detect adenosine specifically with a detection limit as low as 0.21pM, providing a simple, sensitive and selective protocol for small target molecules detection.
Bananas are susceptible to the effects of endogenous enzymatic, leading to their rapid decay and deterioration. In order to mitigate economic losses and prolong the shelf life of bananas, the ...objective of this study was to develop a new and green gas-regulating packaging film. In this study, an active gas-regulating packaging film was prepared by extrusion, with mobil composition of matter (MCM)-41 loaded with salicylic acid (SA) as the active agent and poly (lactic acid) (PLA), poly (butylene adipate-co-terephthalate) (PBAT), and thermoplastic starch (TPS) as the base materials. The obtained films included PLA/PBAT/TPS, PLA/PBAT/TPS-SA, and PLA/PBAT/TPS-MCSA. These films were subsequently applied to banana preservation. The study focused on the variations in soluble solid content (SSC), rate of weight loss (RWL), malondialdehyde (MDA) content, and polyphenol oxidase (PPO) activity of bananas during the preservation process. The results showed that, compared with the PLA/PBAT/TPS film, the oxygen transmission rate of the PLA/PBAT/TPS-MCSA film increased from 384.36 ± 22.06 cm3·m−2·24 h−1·0.1 MPa−1 to 543.10 ± 3.47 cm3·m−2·24 h−1·0.1 MPa−1. Throughout the preservation period, the PLA/PBAT/TPS-MCSA film exhibited superior performance, effectively retarding the increase in banana SSC, RWL, and MDA while inhibiting the elevation of PPO activity and prolonging the shelf life of bananas by 4–5 days. However, this study needs to further investigate the mechanism of function of MCM-41 loaded with SA in banana preservation.
(-)-5-Methylmellein (1) and its new dimer (2) were isolated from cultures of the basidiomycete Inonotus sinensis. Their structures were elucidated on the basis of extensive spectroscopic methods ...including UV, IR, HR-EI-MS, 1D NMR and 2D NMR. The structure of Compound 2 was determined by single-crystal X-ray crystallographic analysis. Compound 2 was tested for the cytotoxicities against five human cancer cell lines.
Triptolide is a bioactive ingredient in traditional Chinese medicine that exhibits diverse biologic properties, including anticancer properties. Among its many putative targets, this compound has ...been reported to bind to XPB, the largest subunit of general transcription factor TFIIH, and to cause degradation of the largest subunit Rpb1 of RNA polymerase II (RNAPII). In this study, we clarify multiple important questions concerning the significance and basis for triptolide action at this core target. Triptolide decreased Rpb1 levels in cancer cells in a manner that was correlated tightly with its cytotoxic activity. Compound exposure blocked RNAPII at promoters and decreased chromatin-bound RNAPII, both upstream and within all genes that were examined, also leading to Ser-5 hyperphosphorylation and increased ubiqutination within the Rbp1 carboxy-terminal domain. Notably, cotreatment with inhibitors of the proteasome or the cyclin-dependent kinase CDK7 inhibitors abolished the ability of triptolide to ablate Rpb1. Together, our results show that triptolide triggers a CDK7-mediated degradation of RNAPII that may offer an explanation to many of its therapeutic properties, including its robust and promising anticancer properties.
Herein, a novel electrochemiluminescence resonance energy transfer (ECL-RET) biosensor using graphene quantum dots (GQDs) as donor and graphene oxide (GO) as acceptor for monitoring the activity of ...protein kinase was presented for the first time. Anti-phosphoserine antibody conjugated graphene oxide (Ab-GO) nonocomposite could be captured onto the phosphorylated peptide/GQDs modified electrode surface through antibody–antigen interaction in the presence of casein kinase II (CK2) and adenosine 5′-triphosphate (ATP), resulting in ECL from the GQDs quenching by closely contacting GO. This ECL quenching degree was positively correlated with CK2 activity. Therefore, on the basis of ECL-RET between GQDs and GO, the activity of protein kinase can be detected sensitively. This biosensor can also be used for quantitative analysis CK2 activity in serum samples and qualitative screening kinase inhibition, indicating the potential application of the developed method in biochemical fundamental research and clinical diagnosis.
Display omitted
•We reported a novel ECL-RET biosensor for sensitive analysis of casein kinase II activity.•The successful ECL-RET between GQDs and GO could be established.•GQDs was employed for casein kinase II activity monitoring and inhibition assay.•Highly sensitive detection of CK2 activity and inhibition was achieved.
Face detection is important for computer vision. Until now, the Viola and Jones algorithm is still the most popular face detector embedded in digital cameras. Although it has good performance in ...frontal face detection, it may not perform well in detecting rotated, head-up, and head-down faces. In this paper, we propose a more robust face detector based on prominent feature extraction. We find that, in addition to using eyes and mouth, which have been adopted by other algorithms, noses and ears are also important clues for face detection. Particularly, for a profile face, only a single eye can be detected. For head-up or head-down faces, eyes and mouth may not be well detected. However, in these cases, noses and ears can still be detected well and we can apply these features to improve the accuracy of rotated, head-up, and head-down face detection. To well detect these prominent features, in addition to the Viola–Jones detector, we also apply edge and color information and use the refocus algorithm based on the convolutional neural network. Simulations conducted on several popular multi-view face databases show that the proposed face detector can attain higher detection rates and is robust to rotated, head-up, and head-down cases.
Pheromones are environmentally friendly alternatives to traditional pesticides for pest control. They are widely applied for insect monitoring, mating disruption and mass trapping.
Nicotiana ...benthamiana
and
N. tabacum
are potential green biomass production platforms of moth sex pheromones. Using these two
Nicotiana
species as plant factories, we expressed biosynthetic genes of plant and insect origin in leaf tissue. Moth sex pheromone precursors (
E
)-11-tetradecenoic acid, (
Z
)-11-tetradecenoic acid and (
Z
)-11-hexadecenoic acid were produced by introducing the acyl-ACP thioesterases
CpuFatB1
from
Cuphea pulcherrima
or
CpaFatB2
from
C. palustris
and the fatty acyl desaturases
Ave∆11
from
Argyrotaenia velutinana
,
CpaE11
from
Choristoneura parallela
or
Atr∆11
from
Amyelois transitella
, under the control of CaMV-35S promoter. Among the
Nicotiana
spp. transformants, the best line produced (
Z
)-11-hexadecenoic acid at 17.6% of total fatty acids in leaves, during flowering stage, corresponding to 335 µg of (
Z
)-11-hexadecenoic acid per gram of fresh leaf. The (
Z
)-11-hexadecenoic acid production lines from
N. benthamiana
were selected for further propagation to obtain homozygous lines. In the
N. benthamiana
T2 generation, the production quantity of (
Z
)-11-hexadecenoic acid was stable. Our study demonstrates the feasibility of stable transformation of
N. benthamiana
for production of moth pheromone precursors in vegetative tissue.
This work focuses on exponential synchronization for a class of partially coupled heterogeneous networks with time-delays and heterogeneous impulses. The synchronization targets are selected as the ...common equilibrium solution and the average trajectory, respectively. Some synchronization criteria are deduced by using Lyapunov function and comparison principle.
Introduction
To investigate the characteristics of β7high CD4+ T cells during HIV‐1 infection and the relationship between β7high CD4+ T cells and HIV‐1 disease progress.
Methods
This study enrolled ...124 HIV‐1‐infected patients, including 80 treatment naïve patients (TNs), 41 patients who underwent antiretroviral therapy (ARTs), and three long‐term no progression patients (LTNPs). Nineteen matched healthy subjects were included as controls (HCs). The characteristics and frequency of β7high CD4+ T cells were analyzed using flow cytometry. An in vitro culture experiment was used to study HIV‐1 infection of β7high CD4+ T cells. Real‐time polymerase chain reaction was performed to quantify HIV‐1 DNA and CA‐RNA levels.
Results
The frequency of β7high CD4+ T in the peripheral blood was significantly decreased and negatively correlated with disease progression during chronic HIV‐1 infection. A large proportion of β7high CD4+ T cells showed Th17 phenotype. Furthermore, β7high CD4+ T cells were preferentially infected by HIV‐1 in vitro and in vivo. There were no significant differences of HIV‐1 DNA, and CA‐RNA levels between β7high CD4+ T and β7low CD4+ T subsets in HIV‐1 infected individuals after antiviral treatment.
Conclusion
The β7high CD4+ T cells were negatively correlated with disease progression during chronic HIV‐1 infection. β7high CD4+ T cells are susceptible to infection with HIV‐1 and HIV‐1 latent cells.
PDF
