Study on the Compressive and Flexural Properties of Coconut Fiber Magnesium Phosphate Cement Curing at Different Low Temperatures.

The incorporation of coconut fiber (CF) into magnesium phosphate cement (MPC) can effectively improve upon its high brittleness and ease of cracking. In practical engineering, coconut fiber-reinforced magnesium phosphate cement (CF-MPC) will likely work in cold environments. Therefore, it is essential to understand the effects of various types of low-temperature curing on CF-MPC performances, but there are very few studies in this area. In this study, the static compression and three-point bending test were utilized to examine the compressive and flexural characteristics of CF-MPC with various CF contents and different negative curing temperatures. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were conducted to observe the impact of low-temperature maintenance on the structure and hydration reaction of the specimens. The results indicate that CF-MPC curing at low temperatures was more prone to cracks during compression and bending, while the appropriate amount of CF could enhance its plastic deformation capability. The CF-MPC's compressive and flexural strength declined as the curing temperature dropped. Moreover, with the rise in CF content, the samples' compressive strength also tended to fall, and there was a critical point for the change in flexural strength. In addition, MPC's primary hydration product (MgKPO4·6H2O) decreased with a drop in curing temperature, and more holes and fractures appeared in CF-MPC.

Effect of Water Immersion on Compressive Properties of Coir Fiber Magnesium Phosphate Cement.

Magnesium phosphate cement (MPC) is a new type of inorganic cementitious rapid repair material, but it has poor toughness and is easy to crack. According to our previous research, these problems can be ameliorated by adding natural coir fiber (CF) into MPC. As coir fiber magnesium phosphate cement (CF-MPC) may be used in humid or rainy areas, its water resistance is an important property in consideration. However, at present, little research has focused on this aspect to provide a good theoretical and experimental basis for the practical application of CF-MPC. In this paper, static compression test and solubility test were used to study the mechanical properties and solubility of CF-MPC under water. At the same time, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to test the changes of hydration composition and microstructure of the test specimen, so as to understand the deterioration mechanism of CF-MPC in water. The results suggested that, when compared with CF-MPC cured in air, CF-MPC cured in water is more prone to encounter oblique cracks and through cracks in the compression process. Moreover, with the extension of curing time, the compressive strength and elastic modulus of CF-MPC cured in water will continue to decrease, the concentrations of PH, K+, and Mg2+ in the curing solution will change significantly, resulting in the gradual decrease in the mass ratio of MgO and MgKPO4·6H2O in CF-MPC matrix, cracks and pores, and looseness in the microstructure.

A Review on the Prediction of Health State and Serving Life of Lithium-Ion Batteries.

The monitoring and prediction of the health status and the end of life of batteries during the actual operation plays a key role in the battery safety management. However, although many related studies have achieved exciting results, there are few systematic and comprehensive reviews on these prediction methods. In this paper, the current prediction models of remaining useful life of lithium-ion batteries are divided into mechanism-based models, semi-empirical models and data-driven models. Their advantages, technical obstacles, improvement methods and prediction performance are summarized, and the latest research results are shown by comparison. We highlight that the fusion models of convolution neural network, long short term memory network and so on, which have great practical application prospects because of their outstanding computing efficiency and strong modeling ability. Finally, we look forward to the future work in simplifying the model and improving its interpretability.

Human polyomavirus type six in respiratory samples from hospitalized children with respiratory tract infections in Beijing, China.

BACKGROUND: HPyV6 is a novel human polyomavirus (HPyV), and neither its natural history nor its prevalence in human disease is well known. Therefore, the epidemiology and phylogenetic status of HPyV6 must be systematically characterized. METHODS: The VP1 gene of HPyV6 was detected with an established TaqMan real-time PCR from nasopharyngeal aspirate specimens collected from hospitalized children with respiratory tract infections. The HPyV6-positive specimens were screened for other common respiratory viruses with real-time PCR assays. RESULTS: The prevalence of HPyV6 was 1.7 % (15/887), and children ≤ 5 years of age accounted for 80 % (12/15) of cases. All 15 HPyV6-positive patients were coinfected with other respiratory viruses, of which influenza virus A (IFVA) (8/15, 53.3 %) and respiratory syncytial virus (7/15, 46.7 %) were most common. All 15 HPyV6-positive patients were diagnosed with lower respiratory tract infections, and their viral loads ranged from 1.38 to 182.42 copies/µl nasopharyngeal aspirate specimen. The most common symptoms were cough (100 %) and fever (86.7 %). The complete 4926-bp genome (BJ376 strain, GenBank accession number KM387421) was amplified and showed 100 % identity to HPyV6 strain 607a. CONCLUSIONS: The prevalence of HPyV6 was 1.7 % in nasopharyngeal aspirate specimens from hospitalized children with respiratory tract infections, as analyzed by real-time PCR. Because the coinfection rate was high and the viral load low, it was not possible to establish a correlation between HPyV6 and respiratory diseases.

[The expression of interferon-lambda1 in CHO cell].

OBJECTIVE: To construct the eukaryotic expression vector PCI-dhfr-lambda1 and PCI-dhfr-SP163-lambda1 which linked the enhancer SP163 with interferon lambda1. Then express the interferon lambda1 in CHO (dhfr-) cells. METHODS: Using PCR method to introduce the restriction enzyme sites and through the fusion PCR binding the enhancer with the interferon Lambda1. After sequenced, lambda1 and SP163-lambda1 was inserted into PCI-dhfr forming the expression vector PCI-dhfr-lambda1 and PCI-dhfr-SP163-lambda1 which was constructed successfully confirming by sequencing. Then the expressing vectors were transfected into CHO (dhfr-) cells using liposome transfection method and interferon lambda1 protein was assayed with indirect immunofluorescence and Western Blot. Using cytopathic effect inhibition evaluated the antiviral activity of interferon lambda1. RESULTS: Successfully constructing the eukaryotic expression vectors of interferon lambda and the vectors could express interferon lambda1. The result of immunofluorescence showed the enhancer developed the expression of interferon lambda1. Detecting the interferon lambda1 in CHO (dhfr-) cells after transfecting 48 hour using Western Blot. The cytopathic effect inhibition showed the expressed interferon lambda1 has the antiviral activity. CONCLUSION: Successfully expressed the interferon lambda1 in CHO (dhfr-) cells and the protein possesses antiviral activity, which may supply a valuable basis for building the stable cell line of interferon lambda1.

Functional roles of glycogene and N-glycan in multidrug resistance of human breast cancer cells.

Drug resistance is a major problem in cancer chemotherapy. Aberrant glycosylation has been known to be associated with cancer chemoresistance. Aim of this work is to investigate the alterations of glycogene and N-glycan involved in multidrug resistance (MDR) in human breast cancer cell lines. Using real-time polymerase chain reaction (PCR) for quantification of glycogenes, fluorescein isothiocyanate (FITC)-lectin binding for glycan profiling, and mass spectrometry for N-glycan composition, the expression of glycogenes, glycan profiling, and N-glycan composition differed between drug-resistant MCF/ADR cells and the parental MCF-7 line. Further analysis of the N-glycan regulation by tunicamycin (TM) application or PNGase F treatment in MCF/ADR cells showed partial inhibition of the N-glycan biosynthesis and increased sensitivity to chemotherapeutic drugs dramatically both in vitro and in vivo. Using an RNA interference strategy, we showed that the downregulation of MGAT5 in MCF/ADR cells could enhance the chemosensitivity to antitumor drugs both in vitro and in vivo. Conversely, a stable high expression of MGAT5 in MCF-7 cells could increase resistance to chemotherapeutic drugs both in vitro and in vivo. In conclusion, the alterations of glycogene and N-glycan in human breast cancer cells correlate with tumor sensitivity to chemotherapeutic drug and have significant implications for the development of new treatment strategies. © 2013 IUBMB Life, 65(5):409-422, 2013.

[Preparation of the monoclonal antibody against human Bocavirus VP2 protein].

OBJECTIVE: To express and purify HBoV VP2 protein, and the monoclonal antibody against HBoV VP2 protein was prepared with hybridoma technique. METHODS: The HBoV VP2 cloned into vector pET-30a was expressed in E. coil. After purified by immobilized metal affinity chromatography, the BALB/c mouse was immunized with purified protein as antigen. The positive hybridoma cells were screened with hybridoma technique and ELISA assay. Isotype and titer of the monoclonal antibody were detected. RESULTS: The recombinant HBoV VP2 protein was expressed and purified, and then the monoclonal antibody was obtained with hybridoma technique. The titer of the IgG monoclonal antibody was up to 1:4 x 10(5). CONCLUSION: Monoclonal antibody against recombinant HBoV VP2 protein was prepared and the antibody titer was high. This work may provide a new method in rapid diagnosis and study of HBoV.

Visual detection of the human metapneumovirus using reverse transcription loop-mediated isothermal amplification with hydroxynaphthol blue dye.

BACKGROUND: Human metapneumovirus (hMPV) is a major cause of acute respiratory infections ranging from wheezing to bronchiolitis and pneumonia in children worldwide. The objective of this study is to develop a visual reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of hMPV and applied to the clinical samples. RESULTS: In this study, visual RT-LAMP assay for hMPV was performed in one step with the addition of hydroxynaphthol blue (HNB), and were used to detect respiratory samples. Six primers, including two outer primers (F3 and B3), two inner primers (FIP, BIP) and two loop primers (LF and LB), were designed for hMPV N gene by the online software. Moreover, the RT-LAMP assay showed good specificity and no cross-reactivity was observed with human rhinovirus (HRV), human respiratory syncytial Virus (RSV), or influenza virus A/PR/8/34 (H1N1). The detection limit of the RT-LAMP assay was approximately ten viral RNA copies, lower than that of traditional reverse transcriptase polymerase chain reaction (RT-PCR) 100 RNA copies. In the 176 nasopharyngeal samples, 23 (13.1%) were conformed as hMPV positive by RT-LAMP, but 18 (10.2%) positive by RT-PCR. CONCLUSION: Compared with conventional RT-PCR, the visual hMPV RT-LAMP assay performed well in the aspect of detect time, sensitivity, specificity and visibility. It is anticipated that the RT-LAMP will be used for clinical tests in hospital or field testing during outbreaks and in emergency.

Detection of enterovirus 71 using reverse transcription loop-mediated isothermal amplification (RT-LAMP).

Reverse transcription loop-mediated isothermal amplification (RT-LAMP), which is a visual assay for nucleic acids, is performed in a single step using one tube at 65 °C for 1.5 h. In this study, RT-LAMP was established as a method for the detection of enterovirus 71 (EV71). The detection limit of the assay was approximately 10 copies, and no cross-reactivity was noted with Coxsackievirus A16, echovirus, human rotavirus (HRV) or norovirus. This assay, which offers greater sensitivity at a lower cost compared with the conventional reverse transcription polymerase chain reaction (RT-PCR), was validated using 252 clinical specimens that had been confirmed by laboratory diagnosis using RT-PCR. Both methods produced the same results with 52 positive samples. The RT-LAMP-based assay does not require specialised equipment, and therefore, it can be performed conveniently during an outbreak or under field conditions. In brief, the RT-LAMP-based assay provided a simple, rapid and efficient method for the detection of EV71 nucleic acid under field conditions.

[Study on determining the composition of ternary complex (AI-CAS-CTMAB) with the ratio of double peak values at double wavelengths by UV spectrophotometry].

In the present paper, the composition of complex Al-CAS-CTMAB was studied with the ratio of double peak values at dual-wavelengths by UV spectrophotometry. First, the composition of complex of Al-CAS was determined in this method, Al:CAS = 1:2. The absorption of ternary complex(Al-CAS-CTMAB) was determined with reference reagent of the complex Al-CAS. The epsilon values of Al-CAS and Al-CAS-CTMAB were determined with water reference. The composition of complex Al (CAS)n1 (CTMAB)n2 was calculated with the formula: [formula: see text] CAS:CTMAB = 1:1; Al:CAS:CTMAB = 1:2:2. The calculated value and that obtained by traditional method are agreeable. The method is reliable for determining composition of ternary complexes.