Chaperone Copolymer-Assisted Catalytic Hairpin Assembly for Highly Sensitive Detection of Adenosine.

Adenosine is an endogenous molecule that plays a vital role in biological processes. Research indicates that abnormal adenosine levels are associated with a range of diseases. The development of sensors capable of detecting adenosine is pivotal for early diagnosis of disease. For example, elevated adenosine levels are closely associated with the onset and progression of cancer. In this study, we designed a novel DNA biosensor utilizing chaperone copolymer-assisted catalytic hairpin assembly for highly sensitive detection of adenosine. The functional probe comprises streptavidin magnetic beads, an aptamer, and a catalytic chain. In the presence of adenosine, it selectively binds to the aptamer, displacing the catalytic chain into the solution. The cyclic portion of H1 hybridizes with the catalytic strand, while H2 hybridizes with the exposed H1 fragment to form an H1/H2 complex containing a G-quadruplex. Thioflavin T binds specifically to the G-quadruplex, generating a fluorescent signal. As a nucleic acid chaperone, PLL-g-Dex expedites the strand exchange reaction, enhancing the efficiency of catalytic hairpin assembly, thus amplifying the signal and reducing detection time. The optimal detection conditions were determined to be a temperature of 25 °C and a reaction time of 10 min. Demonstrating remarkable sensitivity and selectivity, the sensor achieved a lowest limit of detection of 9.82 nM. Furthermore, it exhibited resilience to interference in complex environments such as serum, presenting an effective approach for rapid and sensitive adenosine detection.

Gas-Solid Reaction Synthesis and Electrocatalytic Oxygen Reduction of Pt-Skin L10-PtFe/C.

Compared to Pt/C, the atomic ordered Pt-based intermetallic compounds can deliver higher efficiency and reliable stability, and they are considered one of the ideal cathode catalysts for the next generation of fuel cells. This work proposed a simple ferrocene atmosphere annealing method to improve commercial Pt/C and convert Pt to L10-PtFe. After further acid etching treatment, the obtained carbon-supported Pt-skin L10-PtFe (Pt-skin L10-PtFe/C) with superfine particle size (∼3.3 nm) not only was highly dispersed on the carbon but possesses a thin Pt skin, like the armor of L10-PtFe. As excepted, the ORR activity of Pt-skin L10-PtFe/C (0.375 A mg-1; 0.921 mA cm-2) is far better than that of commercial Pt/C (0.121 A mg-1; 0.260 mA cm-2), and its stability is also greatly improved. Our proposed gas-solid reaction is straightforward and has great potential in producing Pt-based intermetallic catalysts on a large scale.

Efficient production of l-glutathione by whole-cell catalysis with ATP regeneration from adenosine.

l-glutathione (GSH) is an important tripeptide compound with extensive applications in medicine, food additives, and cosmetics industries. In this work, an innovative whole-cell catalytic strategy was developed to enhance GSH production by combining metabolic engineering of GSH biosynthetic pathways with an adenosine-based adenosine triphosphate (ATP) regeneration system in Escherichia coli. Concretely, to enhance GSH production in E. coli, several genes associated with GSH and  l-cysteine degradation, as well as the branched metabolic flow, were deleted. Additionally, the GSH bifunctional synthase (GshFSA) and GSH ATP-binding cassette exporter (CydDC) were overexpressed. Moreover, an adenosine-based ATP regeneration system was first introduced into E. coli to enhance GSH biosynthesis without exogenous ATP additions. Through the optimization of whole-cell catalytic conditions, the engineered strain GSH17-FDC achieved an impressive GSH titer of 24.19 g/L only after 2 h reaction, with a nearly 100% (98.39%) conversion rate from the added  l-Cys. This work not only unveils a new platform for GSH production but also provides valuable insights for the production of other high-value metabolites that rely on ATP consumption.

Accuracy of dual-energy computed tomography for bone marrow edema in the sacroiliac joint: A systematic review and meta-analysis.

BACKGROUND: This systematic literature review and meta-analysis aimed to assess the accuracy, sensitivity, and specificity of dual-energy computed tomography (DECT) of the sacroiliac joint. Bone marrow edema (BME) of the sacroiliac joint is an early manifestation of some diseases, such as ankylosing spondylitis, and is usually examined by nuclear magnetic resonance imaging (MRI); however, MRI can be intolerable for some patients; hence, numerous studies have analyzed DECT examinations. METHODS: We searched PUBMED, CNKI, and EMBASE in 2023 for articles containing the following terms (DECT) or (DE-CT) or (dual-energy CT) or "dual-energy CT" or (dual-energy computed tomography) and ((sacroiliac joint) or (ankylosing spondylitis) or (sacroiliac arthritis) or (sacroiliitis)). An initial search identified 444 articles, of which 7 met the criteria. Data were extracted to calculate the sensitivity, specificity, and diagnostic odds for analysis using R software. RESULTS: Out of 291 patients and 577 sacroiliac joints, 429 (74.35%) exhibited BME. All studies used magnetic resonance as the control group. The overall sensitivity and specificity of DECT were 79%, and 92%, respectively, with positive prediction rate of 92.55% and negative prediction rate of 83.73%. CONCLUSION: DECT appears to be a promising diagnostic tool for detecting BME in the sacroiliac joint and can be used as an alternative examination method for patients in whom MRI is contraindicated.