Rapid weaning from mechanical ventilation and bronchial thermoplasty for near-fatal asthma: A case report.

Background: The action mechanism of bronchial thermoplasty (BT) is poorly understood. Generally, patients with severe asthma who are in desperate need of treatment have relatively low baseline values. In this paper, we describe the case of an asthmatic patient who was saved by a combination of therapy and bronchial thermoplasty. Case information: A patient with near-fatal asthma was initially treated in our hospital with conventional medication, but his condition did not improve. The patient was next subjected to invasive mechanical ventilation, which did not provide significant relief. Additionally, he was treated with BT in conjunction with mechanical ventilation, which promptly reversed his status asthmaticus and stabilized his condition. Conclusion: Patients with near-fatal asthma who do not react effectively to aggressive therapy may benefit from BT.

Design and construction strategies to improve covalent organic frameworks photocatalyst's performance for degradation of organic pollutants.

Covalent organic frameworks (COFs) are a class of crystalline porous organic polymers. In recent years, COFs have received extensive attention in the field of photocatalytic degradation due to their large specific surface area, good thermal and solvent stability, and diverse structures. This review studies the progress of COF in the field of photocatalytic degradation, and summarizes the strategies to improve the photocatalytic activity of covalent organic frameworks, including the designs of ligands and structures. In particular, the design and construction of the COF composites (COF/MOF, COF/g-C3N4, COF/metal semiconductor) are discussed. The photocatalytic mechanism is described in detail, and the prospect of COFs in photocatalytic degradation is prospected.

A microfluidic system for precisely reproducing physiological blood pressure and wall shear stress to endothelial cells.

To reproduce hemodynamic stress microenvironments of endothelial cells in vitro is of vital significance, by which one could exploit the quantitative impact of hemodynamic stresses on endothelial function and seek innovative approaches to prevent circulatory system diseases. Although microfluidic technology has been regarded as an effective method to create physiological microenvironments, a microfluidic system to precisely reproduce physiological arterial hemodynamic stress microenvironments has not been reported yet. In this paper, a novel microfluidic chip consisting of a cell culture chamber with on-chip afterload components designed by the principle of input impedance to mimic the global hemodynamic behaviors is proposed. An external feedback control system is developed to accurately generate the input pressure waveform. A lumped parameter hemodynamic model (LPHM) is built to represent the input impedance to mimic the on-chip global hemodynamic behaviors. Sensitivity analysis of the model parameters is also elaborated. The performance of reproducing physiological blood pressure and wall shear stress is validated by both numerical characterization and flow experiment. Investigation of intracellular calcium ion dynamics in human umbilical vein endothelial cells is finally conducted to demonstrate the biological applicability of the proposed microfluidic system.

Reconfigurable logic in nanosecond Cu/GeTe/TiN filamentary memristors for energy-efficient in-memory computing.

Owing to the capability of integrating the information storage and computing in the same physical location, in-memory computing with memristors has become a research hotspot as a promising route for non von Neumann architecture. However, it is still a challenge to develop high performance devices as well as optimized logic methodologies to realize energy-efficient computing. Herein, filamentary Cu/GeTe/TiN memristor is reported to show satisfactory properties with nanosecond switching speed (<60 ns), low voltage operation (<2 V), high endurance (>104 cycles) and good retention (>104 s @85 °C). It is revealed that the charge carrier conduction mechanisms in high resistance and low resistance states are Schottky emission and hopping transport between the adjacent Cu clusters, respectively, based on the analysis of current-voltage behaviors and resistance-temperature characteristics. An intuitive picture is given to describe the dynamic processes of resistive switching. Moreover, based on the basic material implication (IMP) logic circuit, we proposed a reconfigurable logic method and experimentally implemented IMP, NOT, OR, and COPY logic functions. Design of a one-bit full adder with reduction in computational sequences and its validation in simulation further demonstrate the potential practical application. The results provide important progress towards understanding of resistive switching mechanism and realization of energy-efficient in-memory computing architecture.

[A rapid screening program on the resistance to streptomycin and ethambutol in Mycobacterium tuberculosis isolates by PCR melting curve analysis].

OBJECTIVE: To evaluate the effects of PCR melting curve analysis assay on a rapid screening program regarding the resistance of Mycobacterium tuberculosis (MTB) clinical isolates to streptomycin and ethambutol. METHODS: A total of 331 clinical isolates of MTB had been collected since 2007-2009 in Shenzhen. Mutations at codon 306, 378-380, 406 and 497 of embB gene, codon 43, 88 of rpsL gene, and 513-517, 905-908 region of rrs gene were detected by PCR melting curve analysis. Results were compared with that of conventional drug susceptibility test. RESULTS: Compared to drug susceptibility test, sensitivity, specificity and accuracy for streptomycin resistance were 78.6%, 90.1% and 86.7%, respectively while 83.0%, 93.3% and 91.8%, respectively for ethambutol resistance detected by PCR melting curve analysis. PCR melting curve method was in good agreement with drug susceptibility test. CONCLUSION: PCR melting curve analysis on genetic regions associated with resistance to streptomycin and ethambutol seemed to be a rapid, specific and closed-tube method so it could be used for detection of streptomycin and ethambutol resistance in MTB.

[Analyzing the mutations of rpoB gene in Mycobacterium tuberculosis clinical isolates by probe melting analysis assay].

OBJECTIVE: To evaluate the clinical performance of a probe melting analysis (PMA)-based real-time PCR detection kit in rapid detection of rifampin-resistant mutations in Mycobacterium tuberculosis (MTB). METHODS: The specificity of the assay was evaluated by detecting 37 non-tuberculous mycobacteria (NTM), and the detection limit of the method was evaluated by genomic DNA of a standard strain H37Rv. Finally, 962 clinical isolates were analyzed with the PMA assay by detecting mutations in rifampin resistance-determining region (RRDR) of rpoB gene, and results were verified with DNA sequencing. RESULTS: Among 37 NTM strains, three strains showed drug resistant mutation signals. The PMA method could detect down to 30 bacteria per reaction. Sample analysis showed that 186 of 962 isolates were mutants, 751 isolates were wild type and 25 isolates failed to give amplification signals. Among the mutant samples detected, 112 samples from November 2009 to April 2010 were further analyzed by sequencing, as well as 200 wild-type samples. The results showed a complete agreement with the PMA assay except for 5 samples failed in sequence analysis. CONCLUSION: The PMA assay is rapid, accurate and easy-to-use, and thus can be used for detection of rifampin-resistant in clinical isolate samples.

[Rapid detection of rifampin- and isoniazid-resistant Mycobacterium tuberculosis using real-time PCR and melting curve analysis].

OBJECTIVE: To evaluate the application of a real-time PCR and melting curve analysis assay for rapid detection of rifampin and isoniazid resistance in Mycobacterium tuberculosis (M. tuberculosis). METHODS: A total of 311 clinical isolates of M. tuberculosis obtained from Shenzhen Center for Chronic Disease Control (SZCCC) were included in the study. These isolates were collected originally from national baseline survey on drug-resistant tuberculosis, project for drug resistance surveillance in Shenzhen and clinical patients in SZCCC between 2007 and 2009. rpoB gene resistance-determining region, ahpC promoter (-44 to -30 and -15 to -3), inhA promoter (-17 to -8), inhA 94 and katG 315 were detected by melting curve analysis after real-time PCR, and the results were compared with that of proportion method and DNA sequencing. The performances of the assay in detecting the resistance of rifampin and isoniazid were compared to that of reference proportion method drug susceptibility test. RESULTS: Real-time PCR and melting analysis was a closed-tube assay that could be completed within 2 - 3 h. Compared to the results of the proportion method, the sensitivity, specificity and accuracy of the assay for rifampin resistance were 97.8%, 97.1% and 97.4% respectively, and for isoniazid resistance were 86.6%, 98.7% and 92.6% respectively. CONCLUSIONS: Real-time PCR and melting analysis is a rapid, accurate and closed-tube method that can be used as a screening test for rapid identification of Multidrug-resistant tuberculosis.