Arabidopsis LFR, a SWI/SNF complex component, interacts with ICE1 and activates ICE1 and CBF3 expression in cold acclimation

Low temperatures restrict the growth and geographic distribution of plants, as well as crop yields. Appropriate transcriptional regulation is critical for cold acclimation in plants. In this study, we found that the mutation of Leaf and flower related (LFR), a component of SWI/SNF chromatin remodeling complex (CRC) important for transcriptional regulation in Arabidopsis (Arabidopsis thaliana), resulted in hypersensitivity to freezing stress in plants with or without cold acclimation, and this defect was successfully complemented by LFR. The expression levels of CBFs and COR genes in cold-treated lfr-1 mutant plants were lower than those in wild-type plants. Furthermore, LFR was found to interact directly with ICE1 in yeast and plants. Consistent with this, LFR was able to directly bind to the promoter region of CBF3, a direct target of ICE1. LFR was also able to bind to ICE1 chromatin and was required for ICE1 transcription. Together, these results demonstrate that LFR interacts directly with ICE1 and activates ICE1 and CBF3 gene expression in response to cold stress. Our work enhances our understanding of the epigenetic regulation of cold responses in plants

Validation of the Liverpool Elbow Score for evaluation of elbow stiffness

Abstract Background The Liverpool Elbow Score (LES) has been widely used to assess the outcomes of total elbow replacement in various conditions. However, there have been no published validation studies on LES for patients with stiff elbows undergoing arthrolysis. The purpose of this study was to find out whether LES could be equally applied to evaluate joint function in patients with elbow stiffness. Methods A total of 63 patients with elbow stiffness were included in this retrospective validation study. The LES combines a nine-item patient-answered questionnaire (PAQ) and a six-item clinical assessment score (CAS), and can also be divided to evaluate two different parameters: elbow motion capacity (EMC) and elbow-related symptoms (ERS). Construct validity was assessed by correlating LES with previously validated scoring systems, and Spearman correlation coefficients (SCCs) were calculated. Effect size (ES) and standardized response mean (SRM) were calculated to determine responsiveness. Results There were no ceiling or floor effects in the target population. Good-to-excellent validity was determined based on total score (0.45–0.89), PAQ (0.42–0.88), CAS (0.35–0.60), EMC (0.46–0.86), and ERS (0.36–0.59). High responsiveness (ES/SRM) was observed in total score (2.80/2.24), PAQ (2.34/1.78), CAS (2.90/2.34), EMC (2.92/2.35), and ERS (0.55/0.52). Conclusion Our results suggest that the LES is a valid elbow-specific scoring system that can be used to evaluate joint function in patients with elbow stiffness, though some items included had some weakness either

Determining the effective timing of an open arthrolysis for post-traumatic elbow stiffness: a retrospective cohort study

Abstract Background Following trauma, the elbow is the most susceptible to restricted motion among all joints. Open arthrolysis is often performed for post-traumatic elbow stiffness if that stiffness does not improve with non-operative management. However, the optimal timing for performing an open arthrolysis remains controversial. The purpose of this study was to compare the outcome (elbow motion and function) and the rate of complications among patients who had undergone early, median and late release procedures to establish an optimal time interval following the injury, after which, an effective open arthrolysis can be performed. Methods In this retrospective cohort study, we included total 133 patients, who had undergone open arthrolysis for post-traumatic elbow stiffness. The subjects were divided into 3 groups, with 31 patients in the early release group (arthrolysis performed at 6–10 months after injury), 78 patients in the median release group (at 11–20 months), and 24 patients in the late release group (at > 20 months). The release procedure in all patients was performed by the same surgeon, using the same technique. The general data, functional performance, and complications, if any, were retrospectively documented for all patients and statistically analysed. Results The demographic data and disease characteristics of all patients were comparable at baseline. Postoperatively, no significant differences were found among the three groups with respect to the range of motion (p = 0.067), Mayo Elbow Performance Score (p = 0.350) and its ratings (p = 0.329), visual analog scale score for pain (p = 0.227), Dellon classification for ulnar nerve symptoms (p = 0.497), and each discrete complication (all p values > 0.05). Conclusions At the final follow-up, our results showed no significant difference in the postoperative elbow motion capacities, functional scores and the rates of complications among patients who had undergone an early, median, and late release. Therefore, we have recommended that an early arthrolysis would be preferable due to its multiple advantages, and the conventionally observed interval of > 1 year after the injury, could be shortened. Level of evidence Level III; Retrospective Cohort Design; Therapeutic Study

Design and fabrication of a highly sensitive and naked-eye distinguishable colorimetric biosensor for chloramphenicol detection by using ELISA on nanofibrous membranes.

Enzyme-linked immunoassay (ELISA) is highly specific and selective towards target molecules and is convenient for on-site detection. However, in many cases, lack of high sensitivity makes it hard to reveal a significant colorimetric signal for detecting a trace amount of target molecules. Thus, analytical instruments are required for detection, which limits the application of ELISA for on-site detection. In the present study, a highly sensitive and naked-eyed detectable colorimetric biosensor for chloramphenicol (CAP) was prepared by incorporating ELISA onto surfaces of microporous and nanofibrous membranes. The high specific surface areas of the nanofibers significantly increased the number of antibodies covalently linked onto the fiber surfaces and binding capacity of the sensor with antigens present in a sample. With such an integration, the sensitivity of the ELISA sensor was dramatically increased, and a trace number of targets could reveal a naked-eye detectable color. The immunoassay sensor exhibited a significant naked-eye distinguishable color to chloramphenicol (CAP) at 0.3 ng/mL. The successful design and fabrication of the nanofibrous membrane immunoassay sensor provide new paths towards the development of on-site inspection sensors without the assistance from any instrument

Design and Synthesis of Core–Shell Carbon Polymer Dots with Highly Stable Fluorescence in Polymeric Materials

In recent years, fluorescent carbon dots have attracted great attention due to their good luminescence and low toxicity. Here, blue fluorescent core-shell structured carbon polymer dots (CPDs) with high stability under a wide range of pH values, long storage time and excellent fluorescence in various solvents and even in solid state were prepared by hydrothermal synthesis of dendritic tris(2-aminoethyl)amine (TAEA) and citric acid. The CPDs core structure provides strong fluorescent luminescence, a shell structure of the core possesses high amount of dendritic primary amino groups connected by ethylene groups to the core. This unique structure prevents aggregation of the cores and self-quenching effect of CPDs. As a result, the CPDs have high fluorescence in both aqueous and hydrophobic solutions and even as pure solid-state powder. In addition, the CPDs are also insensitive to pH of solutions, and the fluorescence intensity of the solution was stable in the pH range of 4-14. The CPDs embedded polymer films and fibers revealed excellent fluorescent properties

Long non-coding RNA HIF1A-AS2 facilitates adipose-derived stem cells (ASCs) osteogenic differentiation through miR-665/IL6 axis via PI3K/Akt signaling pathway

Abstract Background This study was aimed to investigate the role and specific molecular mechanism of HIF1A-AS2/miR-665/IL6 axis in regulating osteogenic differentiation of adipose-derived stem cells (ASCs) via the PI3K/Akt signaling pathway. Methods RNAs’ expression profile in normal/osteogenic differentiation-induced ASCs (osteogenic group) was from the Gene Expression Omnibus database. The analysis was carried out using Bioconductor of R. Gene Set Enrichment Analysis and Kyoto Encyclopedia of Genes and Genomes dataset were applied to identify up- and downregulated signaling pathways. Co-expression network of specific lncRNAs and mRNAs was structured by Cytoscape, while binding sites amongst lncRNA, mRNA, and miRNA were predicted by TargetScan and miRanda. ASCs were derived from human adipose tissue and were authenticated by flow cytometry. ASC cell function was surveyed by alizarin red and alkaline phosphatase (ALP) staining. Molecular mechanism of HIF1A-AS2/miR-665/IL6 axis was investigated by RNAi, cell transfection, western blot, and qRT-PCR. RNA target relationships were validated by dual-luciferase assay. Results HIF1A-AS2 and IL6 were highly expressed while miR-665 was lowly expressed in induced ASCs. HIF1A-AS2 and IL6 improved the expression level of osteoblast markers Runx2, Osterix, and Osteocalcin and also accelerated the formation of calcium nodule and ALP activity, yet miR-665 had opposite effects. HIF1A-AS2 directly targeted miR-665, whereas miR-665 repressed IL6 expression. Moreover, the HIF1A-AS2/miR-665/IL6 regulating axis activated the PI3K/Akt signaling pathway. Conclusions LncRNA HIF1A-AS2 could sponge miR-665 and hence upregulate IL6, activate the PI3K/Akt signaling pathway, and ultimately promote ASC osteogenic differentiation

Diffusion of Protein Molecules through Microporous Nanofibrous Polyacrylonitrile Membranes

Porous nanofibrous membranes have ultrahigh specific surface areas and could be broadly employed in protein purification, enzyme immobilization, and biosensors with enhanced selectivity, sensitivity, and efficiency. However, large biomolecules, such as proteins, have hindered diffusion behavior in the micro-porous media, significantly reducing the benefits provided by the nanofibrous membranes. The study of protein diffusion in polyacrylonitrile (PAN) nanofibrous membranes produced under varied humidity and polymer concentration of electrospinning revealed that heterogeneous structures of the nanofibrous membranes possess much smaller effective pore sizes than the measured pore sizes, which significantly affects the diffusion of large molecules through the system though sizes of proteins and pH conditions also have great impacts. Only when the measured membrane pore size is at least 1000 times higher than the protein size, the diffusion behavior of the protein is predictable in the system. The results provide insights into the design and applications of proper nanofibrous materials for improved applications in protein purification and immobilizations

Sample-to-Answer Robotic ELISA

Enzyme-linked immunosorbent assays (ELISA), as one of the most used immunoassays, have been conducted ubiquitously in hospitals, research laboratories, etc. However, the conventional ELISA procedure is usually laborious, occupies bulky instruments, consumes lengthy operation time, and relies considerably on the skills of technicians, and such limitations call for innovations to develop a fully automated ELISA platform. In this paper, we have presented a system incorporating a robotic-microfluidic interface (RoMI) and a modular hybrid microfluidic chip that embeds a highly sensitive nanofibrous membrane, referred to as the Robotic ELISA, to achieve human-free sample-to-answer ELISA tests in a fully programmable and automated manner. It carries out multiple bioanalytical procedures to replace the manual steps involved in classic ELISA operations, including the pneumatically driven high-precision pipetting, efficient mixing and enrichment enabled by back-and-forth flows, washing, and integrated machine vision for colorimetric readout. The Robotic ELISA platform has achieved a low limit of detection of 0.1 ng/mL in the detection of a low sample volume (15 μL) of chloramphenicol within 20 min without human intervention, which is significantly faster than that of the conventional ELISA procedure. Benefiting from its modular design and automated operations, the Robotic ELISA platform has great potential to be deployed for a broad range of detections in various resource-limited settings or high-risk environments, where human involvement needs to be minimized while the testing timeliness, consistency, and sensitivity are all desired

Discovery of Peptidic Ligands against the SARS-CoV-2 Spike Protein and Their Use in the Development of a Highly Sensitive Personal Use Colorimetric COVID-19 Biosensor.

In addition to efficacious vaccines and antiviral therapeutics, reliable and flexible in-home personal use diagnostics for the detection of viral antigens are needed for effective control of the COVID-19 pandemic. Despite the approval of several PCR-based and affinity-based in-home COVID-19 testing kits, many of them suffer from problems such as a high false-negative rate, long waiting time, and short storage period. Using the enabling one-bead-one-compound (OBOC) combinatorial technology, several peptidic ligands with a nanomolar binding affinity toward the SARS-CoV-2 spike protein (S-protein) were successfully discovered. Taking advantage of the high surface area of porous nanofibers, immobilization of these ligands on nanofibrous membranes allows the development of personal use sensors that can achieve low nanomolar sensitivity in the detection of the S-protein in saliva. This simple biosensor employing naked-eye reading exhibits detection sensitivity comparable to some of the current FDA-approved home detection kits. Furthermore, the ligand used in the biosensor was found to detect the S-protein derived from both the original strain and the Delta variant. The workflow reported here may enable us to rapidly respond to the development of home-based biosensors against future viral outbreaks