Search

Despite the progress on the analysis of proteins either in vitro or in vivo, detection and imaging of low-abundance proteins in living cells still remains challenging. Herein, a novel biodegradable and cofactor self-sufficient DNAzyme nanoprobe has been deve-loped for catalytic imaging of protein in living cells with signal amplification capacity. This DNAzyme nanoprobe is constructed by assembling a DNAzyme subunit-containing aptamer hairpin (HP), another DNAzyme subunit strand (DS), and the molecular beacon (MB) substrate strand onto pH-sensitive ZnO@polydopamine nanorods (ZnO@PDA NRs) that work as DNAzyme cofactor suppliers. Such a nanoprobe can facilitate cellular uptake of DNA molecules and protection of them from nuclease degradation as well as release of them in cells by lysosomal acid-triggered dissolution of ZnO@PDA NRs into Zn

In this paper, the azeotropic mixture of CO2/R170 (0.78/0.22, mass fraction) is presented as a refrigerant to replace R134a in an ASHPWH system. On the basis of the first and second laws of thermodynamics, system performance and the exergy efficiency analysis are carried out for the system using both refrigerants. The results show that both the COPheat (coefficient of heating performance) and exergy efficiency of the system using the CO2/R170 mixture refrigerant are higher than that using the R134a, and the values can be increased by 31.3% and 30.6%, respectively. Moreover, the compressor discharge temperature for CO2/R170 is about 34.3–49.8 °C lower and the compression ratio of compressor also has a significant reduction (from 12.0417 to 3.2734), which leads to a higher lifetime for the compressors. So, the CO2/R170 mixture may be a good choice to substitute for R134a in ASHPWH systems. Also, a CO2/R170 ASHPWH system may be more suitable in cold region.

Simple, rapid and selective methods for simultaneous determination of ultralow amount of multiple protein biomarkers in complicated biological samples are in great demand for early-stage diagnostics and biomedical research. Herein, we present a novel polydopamine nanoparticle (PDANP)-based multicolor fluorescent proximity immunoassay for ultrasensitive and multiplexed analysis of proteins in a single solu- tion using isothermal quadratic amplification (IQA). The assay system consists of DNA tethered-antibody pairs for different protein targets, different fluorophore-labeled DNA hairpin probes, DNA polymerase, T7 exonuclease and PDANPs. The DNA tethered- antibodies and fluorophore-labeled hairpin probes can coexist stably, and fluorophore- labeled DNA hairpin probes are adsorbed onto the PDANPs, leading to the significant quenching of the fluorescence of all fluorophores. When target proteins enter into the system, each pair of DNA tethered-antibodies simultaneously binds to a specific pro- tein target and forms the proximate complexes via proximity-dependent DNA hybridi- zation. The formed proximate complexes can then unfold the hairpin structures of the respective probes, leading to DNA polymerase/T7 exonuclease-catalyzed recycling of both proximate complexes and DNA strands to achieve IQA. This IQA results in the di- gestion of many fluorophore-labeled hairpin probes, causing a substantial increase in the fluorescence of corresponding fluorophores for detection of target proteins. As a proof of concept, we demonstrate that a three-color proximity immunoassay can si- multaneously detect prostate-specific antigen (PSA), carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) with ultralow attomolar detection limits, high specificity and 6-log dynamic range. Furthermore, the application of this assay for direct and simulta- neous determination of multiple proteins in clinical sera has also been demonstrated. Our newly proposed assay can be expected to provide a generic method platform for multiplexed analysis of a variety of low-abundance proteins.

It is universally acknowledged that the accumulation of frost on the evaporator surface will reduce the cooling capacity and performance of the cold storage. Therefore defrosting must be periodically and effectively carried out to avoid the evaporator blockage. The electric heater defrosting (EHD) and reversed cycle defrosting (RCD) methods are usually used in cold storages. However, no matter what method is adopted, there will be extra thermal load distributed to the compartments which lead to an unfavorable storage temperature fluctuation and then cause quality loss of the stored food. In order to solve the above-mentioned problems, a novel cold storage defrosting device based on EHD and RCD was proposed in this paper. Experiment was performed on the device to investigate its effect on several aspects including energy saving, reduction of cold storage temperature fluctuation and improvement of compressor operational stability etc. The results showed that this novel device could remarkably increase energy utilization and reduce temperature fluctuation of the cold storage, which was beneficial for long-term storage of products in the cold storage. Moreover, it was able to increase the operational stability of the compressor.

High mobility group AT-hook 2 (HMGA2) is involved in a wide spectrum of biological processes and is upregulated in several tumors. Here, we collected 273 breast cancer (BC) specimens as a training set and 310 specimens as a validation set to examine the expression of HMGA2 by immunohistochemical staining. It was found that HMGA2 expression was significantly positively correlated with advanced tumor grade and poor survival. Subgroup analysis indicated that high level of HMGA2 was significantly correlated with poor prognosis, especially in the subgroups of stage II-III, low pathological grade and non-triple negative breast cancer cases. Gene set enrichment analysis (GSEA) demonstrated a significant positive correlation between HMGA2 level and the gene expression signature of metaplastic and mesenchymal phenotype. Importantly, we also observed that ectopic expression of HMGA2 promoted the migration and invasion of breast cancer cells, and protected cancer cells against genotoxic stress from agents stimulating P53 (Ser15) phosphorylation. As a conclusion, expression of HMGA2 might indicate more advanced malignancy of breast cancer. Thus we believe HMGA2 could serve as a biomarker of poor prognosis and a novel target in treating BC tumors.