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In recent years, hypervirulent Klebsiella pneumoniae (hvKp) has received greater attention. It mainly infects diabetic patients and typically causes a hepatic abscess. Here, we report a case of hvKp that caused forearm muscle and soft tissue infection in addition to bacteremia, hepatic and pulmonary abscess, and hyperglycemia. The patient’s condition stabilized after comprehensive treatment. She eventually recovered and was discharged after several debridement and flap operations. At 9 months of follow-up, no signs of infectious recurrence were noted, and the hyperglycemia resolved. Here, we detail important clinical features of a severe hvKp case diagnosed in an otherwise healthy individual. This report underscores the potential of hvKp to cause deep tissue infection and present with clinical symptoms similar to gas gangrene. Symptom onset in the setting of hvKp infection is usually gradual and misdiagnosis is common. The diagnosis of hvKp should be routinely considered in the clinical setting, and be strongly suspected when presenting with characteristic epidemiological, clinical and laboratory features. Although diabetes is a predisposing factor to hvKp infection, hyperglycemia appeared to manifest as a consequence of hvKp infection in this patient.

Poly(propylene carbonate) (PPC) has aroused extensive attention in the biomaterial field because of its excellent biocompatibility and appropriate degradability, but surface hydrophobicity and bioinertness limit its applications for bone repair and tissue engineering. In this study, a bioactive PPC/laponite (LAP) nanocomposite (PL) was prepared by a melt-blending method, and a microporous surface on PPC and PL (PT and PLT) was created by sodium hydroxide (NaOH) treatment. The results demonstrated that the surface roughness, hydrophilicity, surface energy, and degradability as well as protein adsorption of PLT were obviously improved compared with PPC. Moreover, the degradability of PLT was remarkably enhanced with a slight increase of pH values in Tris-HCl solution. Furthermore, adhesion and proliferation as well as osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) to PLT were significantly promoted compared with PPC. The results suggested that incorporating LAP into PPC obviously improved the surface performance of PL (with nanotopography), and surface treatment with NaOH further enhanced surface properties of PLT (with micronanotopography and hydrophilic groups), which significantly promoted responses of rBMSCs. In short, PLT displayed excellent cytocompatibility, which would have great potential for bone regeneration.

We propose a new method to estimate the directions-of-arrival (DOA) of target for passive bistatic radar (PBR) system in coherent environment. Since the illuminators of PBR is non-cooperative, the performance of the DOA estimation suffers from limited snapshots and low signal-to-noise ratio (SNR) In addition, the interferences of strong direct wave and multipath signals are also intractable to deal with. In this method a sparse representation of the signals is firstly established, and the iterative adaptive approach (IAA) is applied to spatial spectrum estimation. Then we can eliminate the direct wave in the airspace and obtain the DOA estimation of the scattered signal of target by searching for peaks. Compared with the previous works, the proposed method achieves improved DOA estimation accuracy. Simulation results validate the better performance of the proposed method.

The effect of extracellular matrix stiffness on cell growth and the underlying molecular mechanism was investigated using an in situ single-cell imaging of gene expression method based on rolling circle amplification., Cell behaviors are known to be regulated by the cellular microenvironment. Traditional cell-population based analysis methods need to separate cells from their extracellular matrix (ECM) and cannot resolve the heterogeneity of cell behaviors. Herein, an in situ single-cell analysis method based on rolling circle amplification was exploited to image gene expression in single cells for investigating the effect of ECM stiffness on cell growth. This method enables the simultaneous quantifying of the cell phenotype and gene expression at the single-cell level, which can help in understanding the underlying molecular mechanism of cell growth. It is found that ECM stiffness could affect cell growth via regulating the expression level of the cytoskeleton-assembly associated genes PFN1 and CFL1 and their co-expression pattern. Therefore, this single-cell analysis platform may facilitate us to tap into the study of “single-cell phenotypes” and elucidate the disease association of ECMs.

The epidermis and dermis of human skin have randomly distributed microstructures, so we can sense external stimuli with high sensitivity and a low detection limit. Herein, a biomimetic microstructure sensor was fabricated using sandpaper as a template. The finite element simulation results show that the strain sensing property of the sensor can be improved by introducing a biomimetic microstructure, which is consistent with the experimental results. The gauge factor of the microstructure sensor (20.64) is 4.81 times that of the planar structure sensor (4.29) in the linear strain range from 0.1% to 1.0%. The microstructure sensor has a very low detection limit (0.1% strain), fast response (53.6 ms), and good cycling durability (3000 cycles). In addition, the microstructure sensor can achieve real-time monitoring of human motion and physiological signals, such as finger bending, knee bending, and breathing frequency. The proposed microstructure sensor is expected to have broad application prospects in motion monitoring and health-care fields.

DNA nano-spring multivalent ligands for reversibly controlling the nanoscale distribution of cell binding ligands and regulating the cell behavior., Chemically functionalized and nanostructured materials, which mimic the features of the natural extracellular matrix, provide a tool to organize cell surface receptors into nanoscale clusters and manipulate cell functions. However, the existing materials are mainly based on static structures. Herein, we developed a DNA based structure-switchable and multivalent material that acts as a ‘nano-spring’, enabling reversible control of membrane receptor function at the cell surface. This ‘nano-spring’ can be easily synthesized by rolling circle amplification and finely tuned by changing the circular template design. Using this ‘nano-spring’ to interact with cells, we have demonstrated that the movement of the DNA nanostructure is sufficient to direct a cell morphology change from the normal morphology to having numerous cell protrusions and affect the mRNA expression level of integrin related genes. This DNA nano-spring structure can be a competitive material for actively manipulating cell receptor function and may help us to understand the role of receptor mediated signalling cascades.

We report a robust method for the efficient imaging of mRNA with single-nucleotide and near-single-molecule resolution in single cells., Detection of single-cell gene expression with high spatial and sequence resolution is a key challenge in single cell biology. Herein, we propose a robust method for the direct detection of mRNA, termed target RNA-initiated rolling circle amplification, which enables imaging of mRNA with single-nucleotide and near-single-molecule resolution in single cells. By utilizing a Splint R ligase capable of efficiently catalyzing the ligation of a padlock probe by the target RNA, the method can enable the efficient detection of mRNA without reverse transcription (detection efficiency over 20%). Meanwhile, attributed to the ligation-based recognition process, the method confers specificity sufficient to genotype mRNAs with one-nucleotide variations. The method has enabled the spatial mapping and correlation analysis of gene expression in single cells which could help us to elucidate the gene functions and regulatory mechanisms. This method offers an mRNA profiling ability with high spatial resolution and sequence specificity, thus is expected to be a single-cell analysis platform for not only investigating gene expression, but also potentially for analyzing single-nucleotide variants or mRNA alternative splicing at single-cell level.