Paper-Based Strip for Ultrasensitive Detection of OSCC-Associated Salivary MicroRNA via CRISPR/Cas12a Coupling with IS-Primer Amplification Reaction.

As the most common malignancy in humans, oral squamous cell carcinoma (OSCC) not only harms the people's health but also undermines their confidence after facial surgery. Early detection and treatment can effectively reduce these damages. The unique collateral trans-cleavage nuclease activity of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system was utilized to realize the detection of nucleic acid with high sensitivity. So, in this work, we designed a point-of-care testing (POCT) platform for the detection of OSCC-associated salivary hsa-miRNA 31-5p (miR-31) via the cascade signal amplification of "invading stacking primer" (IS-primer) amplification reaction (ISAR), CRISPR/Cas12a, and dual-mode paper-based strip (dm-Strip). To amplify the detection signal of trace miR-31, the cascade signal amplification of CRISPR/Cas12a system coupling with ISAR was designed in a one-pot reaction at a constant temperature. The target miR-31 could activate the ISAR to generate numerous DNAs, which would further trigger the trans-cleavage effect of Cas12a to catalyze the nonspecific single-stranded DNA (ssDNA) cleavage. This ssDNA was labeled with digoxin and biotin at the 5' and 3' termini (digoxin/ssDNA/biotin), respectively, which led to generate the naked-eye signal and fluorescent signal of the designed dm-Strip. The whole detection time was 90 min with limit-of-detection (LOD) down to aM level. This ISAR/Cas12a-based dm-Strip (ISAR/Cas12a-dmStrip) allowed for the portable and ultrasensitive detection of miRNA, an important step in early diagnosis of OSCC and biomedical research.

[Design and application of a new transoral gastric tube for extraction and storage of gastric contents].

Difficulty in swallowing is a common symptom in stroke patients, and nasogastric tubes are routinely used to solve the nutritional support problem of these patients. The existing nasogastric tube have the disadvantages of causing aspiration pneumonia and patient discomfort. The traditional transoral gastric tube has no one-way valve switch and gastric content storage device, and cannot be fixed in the stomach, resulting in reflux of gastric contents, inability to fully understand the digestion and absorption of gastric contents, and accidental dislocation of the gastric tube, affecting further feeding and gastric content detection. For these reasons, the medical staff of the department of gastroenterology and colorectal surgery of Jilin University China-Japan Union Hospital designed a new transoral gastric tube that can extract and store gastric contents, and was granted a national utility model patent of China (ZL 2020 2 1704393.1). The device consists of collection, cannula and fixation modules. The collection module includes three parts. Gastric contents storage capsule, which can clearly visualize the gastric contents; three-way switch, which can be controlled by rotating the pathway, makes the pathway exist in different states, which is convenient for medical personnel to extract gastric juice, as well as perform intermittent oral tube feeding on the patient or close the pipeline, and reduce contamination and prolong the service life of the gastric tube; one-way valve, which can effectively avoid the contents of the reflux back into the stomach. The tube insertion module includes three parts. A graduated tube, which can enable the medical staff to effectively identify the insertion depth; a solid guide head, which makes the insertion of the tube through the mouth more smoothly; the gourd-shaped passageway, which effectively avoids the blockage of the tube. The fixation module is a water-filled balloon, which is properly filled with water and air. After the pipe is inserted through the mouth, it can be injected with water and gas properly to avoid accidental withdrawal of the gastric tube. Intermittent oroesophageal tube feeding of patients with dysphagia after stroke through a transoral gastric tube that can extract and store gastric contents can not only accelerate the recovery process of patients and shorten the hospitalization time, but also transoral enteral nutrition can effectively promote the recovery of patients' systemic systems, which has certain clinical use value.

Designing single-site alloy catalysts using a degree-of-isolation descriptor.

Geometrically isolated metal atoms in alloy catalysts can target efficient and selective catalysis. However, the geometric and electronic disturbance between the active atom and its neighbouring atoms, that is, diverse microenvironments, makes the active site ambiguous. Herein, we demonstrate a methodology to describe the microenvironment and determine the effectiveness of active sites in single-site alloys. A simple descriptor, degree-of-isolation, is proposed, considering both electronic regulation and geometric modulation within a PtM ensemble (M = transition metal). The catalytic performance of PtM single-site alloy is examined thoroughly using this descriptor for an industrially important reaction, propane dehydrogenation. The volcano-shaped isolation-selectivity plot reveals a Sabatier-type principle for designing selective single-site alloys. Specifically, for a single-site alloy with a high degree-of-isolation, alternation of the active centre has a great impact on tuning selectivity, validated by the outstanding consistency between experimental propylene selectivity and the computational descriptor.

Noninvasive monitoring of early antiangiogenic therapy response in human nasopharyngeal carcinoma xenograft model using MRI with RGD-conjugated ultrasmall superparamagnetic iron oxide nanoparticles.

PURPOSE: Arginine-glycine-aspartic acid (RGD)-based nanoprobes allow specific imaging of integrin αvß3, a protein overexpressed during angiogenesis. Therefore, this study applied a novel RGD-coupled, polyacrylic acid (PAA)-coated ultrasmall superparamagnetic iron oxide (USPIO) (referred to as RGD-PAA-USPIO) in order to detect tumor angiogenesis and assess the early response to antiangiogenic treatment in human nasopharyngeal carcinoma (NPC) xenograft model by magnetic resonance imaging (MRI). MATERIALS AND METHODS: The binding specificity of RGD-PAA-USPIO with human umbilical vein endothelial cells (HUVECs) was confirmed by Prussian blue staining and transmission electron microscopy in vitro. The tumor targeting of RGD-PAA-USPIO was evaluated in the NPC xenograft model. Later, mice bearing NPC underwent MRI at baseline and after 4 and 14 days of consecutive treatment with Endostar or phosphate-buffered saline (n=10 per group). RESULTS: The specific uptake of the RGD-PAA-USPIO nanoparticles was mainly dependent on the interaction between RGD and integrin αvß3 of HUVECs. The tumor targeting of RGD-PAA-USPIO was observed in the NPC xenograft model. Moreover, the T2 relaxation time of mice in the Endostar-treated group decreased significantly compared with those in the control group both on days 4 and 14, consistent with the immunofluorescence results of CD31 and CD61 (P<0.05). CONCLUSION: This study demonstrated that the magnetic resonance molecular nanoprobes, RGD-PAA-USPIOs, allow noninvasive in vivo imaging of tumor angiogenesis and assessment of the early response to antiangiogenic treatment in NPC xenograft model, favoring its potential clinical translation.