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BackgroundBronchial rupture in children is a rare but dangerous complication after chest trauma that has been associated with increased mortality. Veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) is reported as one of the treatments for this life-threatening complication.Case presentationA 4-year-old boy who suffered from bronchial rupture and traumatic wet lung complicated by cardiac arrest after chest trauma was admitted to an adult ECMO center. He had two cardiac arrests-one before and one during the operation. The total duration of cardiac arrest was 30 minutes. V-V ECMO was initiated because of severe hypoxia and carbon dioxide retention during the operation. ECMO was performed for 6 days, and mechanical ventilation lasted 11 days. On the 31st day after the operation, he recovered completely and discharged without neurological deficit.ConclusionV-V ECMO can be considered for support in children with severe acute respiratory failure after bronchial rupture. In an emergency, V-V ECMO can be carried out effectively in a qualified and experienced adult ECMO center. But the application of ECMO in children is different from that in adults and requires more refined management.

Background Bronchial rupture in children is a rare but dangerous complication after chest trauma and is associated with increased mortality. Veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) is reported as one of the treatments for this life-threatening complication. Case presentation A 4-year-old boy with bronchial rupture and traumatic wet lung complicated by cardiac arrest after chest trauma was admitted to an adult ECMO centre. He experienced two cardiac arrests, one before and one during the operation. The total duration of cardiac arrest was 30 min. V-V ECMO was initiated because of severe hypoxia and hypercapnia during the operation. ECMO was performed for 6 days, and mechanical ventilation lasted 11 days. On the 31st day after surgery, he had recovered completely and was discharged without neurological deficit. Conclusion V-V ECMO can be considered for supportive care in children with severe acute respiratory failure after bronchial rupture. In an emergency, V-V ECMO can be carried out effectively in a qualified and experienced adult ECMO centre. However, the application of ECMO in children is different from that in adults and requires more refined management.

The rapid and cost-effective detection of bacteria is of great importance to ensuring food safety, preventing food poisoning. Herein, we developed a sensitive detection of Escherichia coli (E. coli) using bacteria-specific aptamer in conjunction with microchip capillary electrophoresis-coupled laser-induced fluorescence (MCE-LIF). Based on the differences between charge to mass ratios of free aptamer and bacteria-aptamer complex, which influence their electrophoretic mobilities, the separation of free aptamers and complex peaks by MCE could be achieved. Under optimal conditions, the sensitive detection of E. coli was achieved with a detection limit of 3.7 × 102 CFU mL−1, at a fast response of 135 s and a short detection length of 2.3 cm. The spiked recovery experiment showed that E. coli could be recovered from spiked drinking water and milk samples with recovery rates of 94.7% and 92.8%, respectively. This work demonstrates that the established detection strategy can be a useful tool for the detection and/or monitoring of E. coli in food and environment.

Polypeptides serve as a bridge between natural macromolecules and synthetic polymers, leading to the development of biocompatible and biodegradable materials with diverse and complex structures. Here, nucleobase modified polylysine (PLL-co-PTLL) was synthesized via post-polymerization modification of polylysine with thymine (T). Then, melamine (M) with three thymine-like faces was taken as a molecular chaperone analogue to drive the self-assembly of PLL-co-PTLL. It was observed that 7M–1T (M : T = 7 : 1) was the appropriate molar ratio for the pronounced self-assembly, resulting in regular and uniform fibers with an extremely high aspect ratio when the substitution degree of T was relatively low (around 27%). Furthermore, the morphological transformation from fibrous to spherical could be achieved by simply increasing the substitution degree of T. We proposed that melamine and thymine could assemble into a tetrameric structure, which enabled the accumulation of polypeptide chains in a cooperative nucleation-growth polymerization mechanism. Therefore, multiple H-bonding faces created between designable substitution polypeptides and complementary molecules would promote synergistic and hierarchical self-assembly processes.

The detection of Staphylococcus aureus (S. aureus) is very important as it is responsible for bacterial infectious diseases and food poisoning. In this paper we explored the application of fluorescently labelled vancomycin to specifically bind and detect S. aureus. In view of the specificity of vancomycin towards bacterial cell surfaces, we utilized Cy5 to label vancomycin (Cy5-Van) for the identification of S. aureus. Our experiments were designed to examine in greater detail the specificity of the reaction between Cy5-Van and S. aureus. Detection parameters such as the derivatization conditions, concentrations of buffer, pH value, response performance of Cy5-Van to bacterial surface, injection time and reversed-polarity time have been investigated and optimized. To develop a simple and quick assay for the detection of S. aureus at low concentrations, we propose to use the Cy5-Van for labeling the S. aureus coupled with an on-line multiple-concentration in microchip electrophoresis. Under the optimized conditions, the detection of S. aureus was achieved within 150 s with limit of detection (S/N = 3) of 981 CFU/mL, and 350-fold enhancement was obtained for S. aureus as compared to using the no concentration step. It is self-evident that this approach has great potential in the future for the analysis of S. aureus.

The detection of Salmonella enterica serovar Typhimurium (S. Typhimurium) is very important for the prevention of food poisoning and other infectious diseases. Here we reported a simple and sensitive strategy to test S. Typhimurium by microchip capillary electrophoresis couple with laser-induced fluorescence (MCE-LIF) based on the specific reaction between the bacterium and corresponding aptamers. Based on the differences in charge to mass ratio between bacteria-aptamer complexes and free aptamers, a separation of the complexes and free aptamers could be obtained by MCE. The optimal parameters of the specific reaction including fluorescent dye concentration, Mg2+ concentration, incubation time, and pH of incubation solution were carefully investigated. Meanwhile, a non-specific DNA was exploited as a contrast for the detection of S. Typhimurium. Under the optimal conditions, a rapid separation of the bacteria-aptamer complex and free aptamers was achieved within 135 s with a limit of detection (S/N = 3) of 3.37 × 102 CFU mL−1. This method was applied for the detection of S. Typhimurium in fresh milk samples and a recovery rate of 95.8% was obtained. The experimental results indicated that the specific aptamers are of enough biostability and the established method could be used to analyze S. Typhimurium in foods.

Based on hourly precipitation from national surface stations, persistent heavy rainfall events (PHREs) over the Sichuan Basin (SCB) are explored during the warm season (May to September) from 2000 to 2015 to compare synoptic circulations and maintenance mechanisms between different PHRE types. There are two main types of PHREs: one is characterized by a rain belt west of 106°E over the SCB (WSB-PHREs), and the other features a rain belt east of 106°E over the SCB (ESB-PHREs). In total, there are 18 ESB-PHREs and 10 WSB-PHREs during the study period. Overall, the rain belts of WSB-PHREs are along the terrain distribution east of the Tibetan Plateau, while the precipitation intensity of ESB-PHREs is stronger. For the two types of PHREs, the shortwave trough over the SCB and the western Pacific subtropical high act as their favorable background environments, particularly for ESB-PHREs. The water vapor of WSB-PHREs is mainly transported from the South China Sea, whereas for ESB-PHREs the South China Sea and Bay of Bengal are their main moisture sources. The composite vorticity budgets of southwest vortices during their mature stage indicate that the convergence effect is a dominant factor for maintaining the two types of PHREs, and the strong vertical vorticity advection is also favorable, but the relative contribution of vertical advection is larger for WSB-PHREs. 摘要 本文筛选出四川盆地西部 (盆西型) 和盆地东部 (盆东型) 持续性暴雨个例, 深入对比两类持续性暴雨的大气环流特征和直接造成持续性暴雨的西南低涡维持的机理. 四川盆地的短波槽和西太平洋副热带高压的配置有利于持续性暴雨的维持, 盆东型的降水强度较盆西型个例强, 高空急流位置偏南, 南亚高压的强度更强, 高层辐散更强, 对流层中层副热带高压偏东偏南. 盆西型的水汽输送主要来自南海, 而盆东型的水汽输送主要来自南海和孟加拉湾. 合成涡度收支的结果表明散度项是两类持续暴雨中西南涡维持的主要原因, 但盆西型中, 垂直平流的作用更强.

Nowadays, distributed storage systems have been widely used in the world, e.g, Google Drive, OneDrive, DropBox, Baidu PCS, etc.. Although these cloud storage services significantly facilitate the file storage for users, the performance of them varies widely when using in different countries. For example, Google Drive has high upload/download speed in America while it has very low upload/download speed in China. Therefore, to enhance the reliability and security of the cloud storage, in this paper, we firstly design a multi-cloud based distributed storage platform, named as, Normal Drive, by utilizing random linear coding and APIs provided by multiple cloud disks. We then implement the Normal Drive and conduct extensive evaluation from different aspects in five different locations around the world to test the performance of it. The experimental results show that the proposed Normal Drive can significantly improve the transmission performance and enhance the reliability of file storage when comparing with single-cloud based distributed storage system.

A new method of capillary electrophoresis (CE) using laser induced fluorescence (LIF) detection via online pre-concentration techniques including transient trapping combined with the dynamic pH junction mode was developed for the sensitive determination of glutathione in biological samples. The mechanism together with the important parameters governing the pre-concentration and separation were investigated in order to obtain maximum resolution and sensitivity. The analytes were compressed into a narrow zone due to the effect of the dynamic pH junction mode, and then transiently trapped by SDS micelles at the interface of the sample and micellar areas. Under the optimal conditions, the limits of detection for reduced glutathione, glycine, oxidized glutathione, cysteine, and glutamic acid were 0.01, 0.01, 0.5, 0.7, and 0.1 nM (S/N = 3), respectively. The enhancement factors obtained when using the transient trapping combined with the dynamic pH junction mode as a pre-concentration process were enhanced from 87 to 430 when compared to the results obtained by the classical capillary zone electrophoresis (CZE) mode. Moreover, this optimized method was successfully applied to bacteria (Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus) and HaCaT cell samples for the determination of reduced glutathione with satisfactory recoveries.

We reported the use of polydopamine/Au nanoparticles/DNA (PDA/Au NPs/DNA) as a stationary phase for the separation of tryptophan enantiomers by microchip capillary electrophoresis (MCE). The stationary phase was formed by sequentially immobilizing PDA/Au NPs and DNA to the glass microfluidic channel surface using layer-by-layer assembly. The formation of PDA/Au NPs as a functional film involved the use of HAuCl4 as an oxidant to trigger DA self-polymerization. DA was then used as a reductant to reduce HAuCl4 to Au NPs. All these Au NPs were simultaneously deposited on the microchip surface by the adhesive PDA, and the thiolated DNA was strongly adsorbed onto the glass microfluidic channel surface through covalent gold–sulfur bonding. The functional film of the PDA/Au NPs/DNA was characterized by scanning electron microscopy, UV-vis spectra and ATR-FT-IR. The influence of separation voltage and the concentration and pH value of the running buffer were found to significantly influence separation. Successful baseline separation of tryptophan enantiomers was achieved within 65 s utilizing an effective separation length of 33 mm, and coupling with laser-induced fluorescence detection resulted in a resolution factor of 2.95. All these evaluation parameters, including stability and reproducibility, were considered satisfactory. The method outlined here, using the PDA/Au NPs/DNA-coated microfluidic channel as a versatile platform, may offer a processing strategy to prepare a functional surface on microfluidic chips.

The release of cytochrome C (Cyt C) plays an important role in apoptosis. In this study, selective and sensitive detection of Cyt C based on an aptamer strategy coupled with MCE was developed. Following the binding of a specific aptamer to Cyt C, the aptamer exhibited an irregular state, reducing the binding affinity of a fluorescent probe, and thus preventing the aptamer-Cyt C complexes from detection within the MCE. The height of the detection peak of the residual aptamer linearly decreased, and therefore, the difference in peak height of residual aptamer compared to that of the initial aptamer was used to quantify the captured protein concentration. Experimental conditions such as incubation time, pH, temperature, and ionic strength were optimized. A measurement of Cyt C concentration by MCE was achieved within 135 s, with a limit of detection as low as 0.4 nM. The proposed method has high selectivity and good stability for the detection of Cyt C. The experimental results demonstrate that this method is quick, consumes only a small quantity of sample, is highly selectivity and exhibits high sensitivity.

Foodborne bacteria are some of the most important human pathogens and can cause many diseases. In this study, multiplex PCR amplification combined with microchip electrophoresis (MCE) was studied to simultaneously and sensitively detect Staphylococcus aureus, Proteus mirabilis, and Enterobacter sakazakii. In order to simultaneously and accurately detect the aim bacteria, three pairs of primers were specially designed for the multiplex PCR amplification of the target genes of three bacteria, which were the specific genes corresponding to these bacteria respectively. After the DNA fragments of three bacteria were simultaneously extracted, the multiplex PCR amplification was performed by adding the three pairs of specific primers in the mixed DNA fragments solution. The multiplex PCR products of the three food-borne pathogens were analyzed by MCE and the limits of detection of target DNA fragments were 1.2-2.2ngμL-1, (S/N=3). The limits of detection of the aim bacteria were calculated as 53CFUmL-1 for Enterobacter sakazakii, 32CFUmL-1 for Proteus mirabilis, 28CFUmL-1 for Staphylococcus aureus, respectively. Satisfactory results were obtained when this method was applied to detect the three foodborne bacteria in milk samples. The experimental results show that this method has the advantages of quickness, less sample consumption, high selectivity and high sensitivity.

A rapid and sensitive PCR based strategy in combination with microchip capillary electrophoresis (MCE) was employed to simultaneously detect three foodborne pathogenic bacteria. Three pairs of primers were specially designed for the amplification of target genes from Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella enterica serovar Typhimurium (S. Typhimurium). The PCR products along with standard DNA fragments were employed to optimize the separation conditions in MCE. Under optimal conditions, detectable separation of the PCR products (1.6–3.5 ng μL−1) from the three foodborne pathogenic bacteria was achieved within 135 s. The limits of detection of the three bacteria were concluded to be as low as 45 CFU mL−1 for E. coli, 62 CFU mL−1 for S. aureus and 42 CFU mL−1 for S. Typhimurium. The RSD of migration time was in the range of 0.5–0.8%. We conclude that MCE along with PCR holds real potential for rapid analysis and detection of nucleic acids from routine foodborne pathogenic bacteria.

In this paper, polydopamine/gold nanoparticles (PDA/Au NPs) were used to construct a functional film on a glass microfluidic channel surface in microchip electrophoresis (MCE) for the separation of reduced glutathione (GSH) and oxidized glutathione (GSSH). The formation of the PDA/Au NPs was characterized by scanning electron microscopy, transmission electron microscope, UV–Vis spectra and ATR-FTIR. An online pre-concentration strategy involving field-amplified sample stacking was used to determine the sensitivity of the assay for measuring GSH and GSSH in bacteria (Escherichia coli, Staphylococcus aureus and Salmonella enterica serovar Typhimurium) and HaCaT cells samples by MCE with laser-induced fluorescence detection. The influences of the separation voltage, the concentration of the running buffer and the pH value of running buffer, were carefully investigated. Using this studied method, GSH and GSSH could be simultaneously pre-concentrated and separated within 70 s. The limits of detection of GSH and GSSH were as low as 0.81 and 0.91 nM, respectively (S/N = 3), which corresponded to approximately 180–301-fold improvements in peak height. Moreover, this method was successfully applied to the analysis of bacteria (E. coli, S. aureus and S. typhimurium) and HaCaT cell samples with a satisfactory recovery rate.