亚花松萝多糖的提取与分离工艺的优化

本文研究亚花松萝多糖的提取与分离工艺的优化。亚花松萝多糖提取工艺各因素的最佳水平为热水体积200ml（每4g松萝）、70～80℃提取三次，每次2h。其中对亚花松萝多糖含量影响最显著的因素是提取次数，然而提取温度在一定范围内无显著影响。乙醇沉淀多糖的最佳浓度为80％一倍，Sevage试剂除游离蛋白时的体积比为3：1，反复脱蛋白五次，每次振荡30min。多糖的最佳得率为6．86％，总糖含量为76％。     

Systematic linearisation of a microfluidic gradient network with unequal solution inlet viscosities demonstrated using glycerol

This paper presents a mathematical and experimental study of the effect of inlet concentration (and therefore viscosity) of glycerol solutions on the performance of a microfluidic network. This was achieved with analytical modelling, implemented in MATLAB, and optical measurement of the entire concentration distribution of the network. A mathematical proposal to improve the linearity of the outlet profile is also implemented and successfully verified experimentally. The concentration gradients of a two inlet–six outlet (2–6) microfluidic network device were obtained with inlet solutions of 10–40 wt% glycerol and flow rates of up to 5 μl/s per inlet. The mathematical model developed gave a good agreement with the experimental results obtained. ‘S’ shaped outlet profiles were obtained for the four glycerol cases studied and the closest results to the model were achieved at an optimised flow rate of 1μl/s for 10 wt% glycerol, 5 μl/s for both 20 and 30 wt% glycerol and 1.5 μl/s for 40 wt% glycerol. The linearity of the outlet profiles for the 20, 30 and 40 wt% inlet glycerol experiments were improved from R ² of 0.977, 0.946 and 0.966, respectively (before linearisation) to their new values of 0.997, 0.995 and 0.974, respectively (after the linearisation). This was performed by application of the mathematical model, at controlled inlet flow rate ratios of 0.77, 0.63 and 0.52 with respect to the viscous inlet, for 20, 30 and 40 wt% glycerol experiments, again with very good agreement of the outlet performance between the experimental and the mathematical results.     

Exploration of the multiparameter space of nanosecond-laser damage growth in fused silica optics

Historically, the rate at which laser-induced damage sites grow on the exit surface of SiO2 optics under subsequent illumination with nanosecond-laser pulses of any wavelength was believed to depend solely on laser fluence. We demonstrate here that much of the scatter in previous growth observations was due to additional parameters that were not previously known to affect growth rate, namely the temporal pulse shape and the size of a site. Furthermore, the remaining variability observed in the rate at which sites grow is well described in terms of Weibull statistics. The effects of site size and laser fluence may both be expressed orthogonally in terms of Weibull coefficients. In addition, we employ a clustering algorithm to explore the multiparameter growth space and expose average growth trends. Conversely, this analysis approach also identifies sites likely to exhibit growth rates outside the norm. The ability to identify which sites are likely to grow abnormally fast in advance of the manifestation of such behavior will significantly enhance the accuracy of predictive models over those based on average growth behaviors.     

Correlation of central and peripheral corneal thickness in healthy corneas

Purpose

To study the thickness profile of the normal cornea in order to establish any correlation between central and peripheral points.

Methods

Sixty-seven eyes of 40 patients were subjected to central corneal thickness measurement (CCT) with an ultrasound pachymeter (UP) and corneal thickness mapping with the Oculus Pentacam. The corneal apex thickness (CAT), pupil centre thickness (recorded as CCT and corresponded to CCT of UP) and thickness at the thinnest location (CTL) were obtained and compared with each other. Corneal thickness data at 3 mm and 7 mm temporally, nasally, superiorly and inferiorly from the corneal apex were obtained. The mean corneal thickness values along the 2, 4, 6, 8 and 10 mm diameter concentric circles, with the CTL as the centre, were also obtained. The above data at different points were statistically correlated.

Results

There was no significant difference between CCT readings measured by UP and Pentacam (P = 0.721). There was high positive correlation between the CAT values and the thickness at 3 mm (R ≥ 0.845, P < 0.001) and at 7 mm points (R ≥ 0.654, P < 0.001). A gradual increase in thickness was noted from the centre to the periphery with a high positive correlation between the CTL values and the mean thickness at the circles of 2, 4, 6, 8 and 10 mm (R ≥ 0.635, P < 0.001).

Conclusion

The results suggest that central corneal thickness can serve as a good guide for predicting peripheral thickness. For surgical procedures specifically undertaken at mid-peripheral and peripheral zones, the actual measurements at the site of surgery may confer some advantage.     

TFRC-CR: An equation-based transport protocol for cognitive radio networks

Reliable and high throughput data delivery in cognitive radio networks remains an open challenge owing to the inability of the source to quickly identify and react to changes in spectrum availability. The window-based rate adaptation in TCP relies on acknowledgments (ACKs) to self trigger the sending rate, which are often delayed or lost owing to intermittent primary user (PU) activity, resulting in an incorrect inference of congestion by the source node. This paper proposes the first equation-based transport protocol based on TCP Friendly Rate Control for Cognitive Radio, called as TFRC-CR, which allows immediate changes in the transmission rate based on the spectrum-related changes in the network environment. TFRC-CR has the following unique features: (i) it leverages the recent FCC mandated spectrum databases with minimum querying overhead, (ii) it enables fine adjustment of the transmission rate by identifying the instances of true network congestion, as well as (iii) provides guidelines on when to re-start the source transmission after a pause due to PU activity. TFRC-CR is evaluated through an extensive set of module additions to the ns-2 simulator which is also released for further investigation by the research community.     

The Functions of the Demethylase JMJD3 in Cancer

Cancer is a major cause of death worldwide. Epigenetic changes in response to external (diet, sports activities, etc.) and internal events are increasingly implicated in tumor initiation and progression. In this review, we focused on post-translational changes in histones and, more particularly, the tri methylation of lysine from histone 3 (H3K27me3) mark, a repressive epigenetic mark often under- or overexpressed in a wide range of cancers. Two actors regulate H3K27 methylation: Jumonji Domain-Containing Protein 3 demethylase (JMJD3) and Enhancer of zeste homolog 2 (EZH2) methyltransferase. A number of studies have highlighted the deregulation of these actors, which is why this scientific review will focus on the role of JMJD3 and, consequently, H3K27me3 in cancer development. Data on JMJD3’s involvement in cancer are classified by cancer type: nervous system, prostate, blood, colorectal, breast, lung, liver, ovarian, and gastric cancers.     

Investigation of Oil and Protein Contents of Eight Sudanese Lagenaria siceraria Varieties

The composition of the oil and protein contents of eight Lagenaria siceraria varieties was characterized in order to evaluate their suitability as a source of edible oil and protein. The physicochemical properties and fatty acids of seed oils were determined. The oil yield ranged from 24.11 to 26.32 %. The refractive indices and relative densities of the oils fell within the narrow ranges of 1.464–1.468 and 0.857–0.907 g/cm³, respectively. The saponification value ranged from 158.48 to 179.52 mg KOH/g, unsaponifiable matter was between 0.749 and 0.937 %, and the peroxide values were lower than Codex values for vegetable oils. The principal fatty acids were linoleic (62.1–67.9 %), oleic (11.54–15.46 %), palmitic (12.13–14.03 %), and stearic (6.71–7.71 %) acids. Low linolenic acid levels were also observed (<1 %) within the range of 0.32–0.44 %. The major essential amino acids were arginine (2.04–3.77 g/100 g), leucine (1.245–1.726 g/100 g), phenylalanine (0.803–1.396 g/100 g), and lysine (0.921–1.383 g/100 g). The non‐essential amino acids were glutamic acid (2.5–4.37 g/100 g), aspartic acid (1.39–2.36 g/100 g), serine (0.69–1.19 g/100 g), glycine (0.79–1.37 g/100 g), alanine (0.72–1.37 g/100 g), and proline (0.63–1.02 g/100 g). Nine minerals (Na, Ca, Mg, K, Cu, Fe, Mn, Zn, and P) were determined with significant (p < 0.05) differences. The studied oils showed promising results and can be used in the food, cosmetics, and pharmaceutical industries. This is the first study on the eight L. siceraria seed varieties grown in Sudan, opening the way for further studies on these seeds.     

小檗饮料的研制

介绍了小檗饮料的生产工艺过程。通过正交试验,对影响饮料品质的几个因素进行了研究和讨论,确定了最佳配方,得到了风味、色泽均佳的一种新型饮料。     

On the convergence of real-time active noise control systems

Available convergence analyses of adaptive active noise control systems apply to only theoretical cases with broad-band white noise or pure delay secondary paths. In order to investigate convergence behaviors of these systems in more practical conditions, this paper conducts a new convergence analysis for filtered-x LMS-based active noise control systems with band-limited white noise and moving average secondary paths. A linear model for the adaptation process is developed. Based on this model, the upper-bound of the adaptation step-size is derived. Also, the adaptation step-size leading to the fastest convergence rate is derived. In addition to the computer simulation, a fully implemented real time active noise control system is used to verify the validity of the analytical results.