New Modular Relations for the Göllnitz-Gordon Functions

We attempt to obtain new modular relations for the Göllnitz-Gordon functions by techniques which have been used by L. J. Rogers, G. N. Watson, and D. Bressoud to prove some of Ramanujan's 40 identities. Also, we give new proofs for some modular relations for the Göllnitz-Gordon functions which have been previously established by using results from L. Rogers and D. Bressoud. Finally, we give applications of those new modular relations to the theory of partitions.     

Analysis by raman spectroscopy and XRF of glass beads from excavations in the harbor area of rio de janeiro,Brazil

In this paper, nine beads from excavations in the Valongo Wharf, located in the harbor area of Rio de Janeiro, Brazil that were utilized as ornaments by Africans and Afrodescendants during the 19th century were analyzed by Raman and X-Ray Fluorescence (XRF) spectroscopy. All samples in the analysis showed Raman spectra with two bands of maximum intensity around 1000 and 500 cm⁻¹ related to the maximum stretching (ν_max) and bending mode (δ), respectively, of the tetrahedral network of the SiO₄ present in the glass matrix. However, there is variation in the intensity and position of the bands that are directly associated with the burning process and the raw material utilized in the manufacture of the beads. Based on the polymerization index (I_p = A₅₀₀/A₁₀₀₀), it is possible to relate these two parameters. By establishing a correlation among the I_p and the ν_max band, the beads were classified into groups. The results reveal that the beads’ base paste exhibits differences, allowing their classification into groups according to the manufacturing process. Based on the combination of the elemental characterization and Raman spectroscopy results, it was also possible to conclude that European and Asian countries are the possible origins of the beads.     

Pathogen detection in complex samples by quartz crystal microbalance sensor coupled to aptamer functionalized core–shell type magnetic separation

A quartz crystal microbalance sensor (QCM) was developed for sensitive and specific detection of Salmonella enterica serovar typhimurium cells in food samples by integrating a magnetic bead purification system. Although many sensor formats based on bioaffinity agents have been developed for sensitive and specific detection of bacterial cells, the development of robust sensor applications for food samples remained a challenging issue. A viable strategy would be to integrate QCM to a pre-purification system. Here, we report a novel and sensitive high throughput strategy which combines an aptamer-based magnetic separation system for rapid enrichment of target pathogens and a QCM analysis for specific and real-time monitoring. As a proof-of-concept study, the integration of Salmonella binding aptamer immobilized magnetic beads to the aptamer-based QCM system was reported in order to develop a method for selective detection of Salmonella. Since our magnetic separation system can efficiently capture cells in a relatively short processing time (less than 10 min), feeding captured bacteria to a QCM flow cell system showed specific detection of Salmonella cells at 100 CFU mL⁻¹ from model food sample (i.e., milk). Subsequent treatment of the QCM crystal surface with NaOH solution regenerated the aptamer-sensor allowing each crystal to be used several times.     

Development of Flow Cytometric Assay for Detecting Papillary Thyroid Carcinoma Related hsa-miR-146b-5p through Toehold-Mediated Strand Displacement Reaction on Magnetic Beads

In this work, a simple enzyme-free flow cytometric assay (termed as TSDR-based flow cytometric assay) has been developed for the detection of papillary thyroid carcinoma (PTC)-related microRNA (miRNA), hsa-miR-146b-5p with high performance through the toehold-mediated strand displacement reaction (TSDR) on magnetic beads (MBs). The complementary single-stranded DNA (ssDNA) probe of hsa-miR-146b-5p was first immobilized on the surface of MB, which can partly hybridize with the carboxy-fluorescein (FAM)-modified ssDNA, resulting in strong fluorescence emission. In the presence of hsa-miR-146b-5p, the TSDR is trigged, and the FAM-modified ssDNA is released form the MB surface due to the formation of DNA/RNA heteroduplexes on the MB surface. The fluorescence emission change of MBs can be easily read by flow cytometry and is strongly dependent on the concentration of hsa-miR-146b-5p. Under optimal conditions, the TSDR-based flow cytometric assay exhibits good specificity, a wide linear range from 5 to 5000 pM and a relatively low detection limit (LOD, 3σ) of 4.21 pM. Moreover, the practicability of the assay was demonstrated by the analysis of hsa-miR-146b-5p amounts in different PTC cells and clinical PTC tissues.     

有色噪声激励下双稳态电磁式振动能量捕获器动力学特性研究

随着微机电科技的进步,利用环境振动进行系统自供电已经成为目前非线性动力学研究的热点.以附加线性振子的双稳态电磁式振动能量捕获器为研究对象,建立系统的动力学方程,通过数值仿真研究了有色噪声激励作用下双稳态能量捕获系统的动力学行为,分别从有色噪声强度、质量比和调频比3个方面研究了双稳态系统动力学响应,获得了上述参数对双稳态能量捕获系统动力学特性的影响规律,上述研究结果为双稳态电磁式振动能量捕获系统的相关研究提供理论基础.     

Gelatin scaffolds functionalized by silver nanoparticle‐containing calcium alginate beads for wound care applications

The embedding of silver nanoparticle (nAg)‐containing calcium alginate (CaAlg) beads in gelatin scaffolds was aimed to reduce the burst release and prolong the release of silver (Ag⁺) ions for a long period of time. The reduced sizes of the nAg‐containing CaAlg beads were prepared by an emulsification/external gelation method. The diameter of these beads was ~2 µm. The nAg‐containing CaAlg beads were then embedded into gelatin scaffolds by a freeze‐drying method for evaluating the potential of these scaffolds as wound dressings. The compressive modulus of these scaffolds embedded with nAg‐containing CaAlg beads ranged between 7 and 9 kPa. For release study, the cumulative released amounts of Ag⁺ ions from the nAg‐containing CaAlg beads embedded in gelatin scaffolds were lower than those from the nAg‐containing CaAlg beads. Moreover, the nAg‐containing CaAlg beads embedded in gelatin scaffolds had great antibacterial activity and low cytotoxicity. Thus, these scaffolds had potential for sustaining the release and use in wound care applications, especially chronic wound. Copyright © 2016 John Wiley & Sons, Ltd.     

Enhanced biodegradation of thiocyanate by immobilized Bacillus brevis

Biodegradation of Thiocyanate by Free and Immobilized Bacillus brevis was explored. Lignite carbon and Alginate beads have been used as immobilization matrices to study the degradation of thiocyanate with immobilized cells. The rate of thiocyanate degradation is found to be higher by immobilized cells. Cells on lignite carbon matrix are more efficient than cells on alginate beads. The tolerance of the bacteria to the toxic chemical increases by immobilization. Degradation of 100 ppm of thiocyanate was achieved in 20 h by immobilized Bacillus brevis onto lignite carbon. Reduced cost and simplicity make this technique very useful for wastewater treatment.     

Polymer entanglement loss in extensional flow: Evidence from electrospun short nanofibers

High strain rate extensional flow of a semidilute polymer solution can result in fragmentation caused by polymer entanglement loss, evidenced by appearance of short nanofibers during electrospinning. The typically desired outcome of electrospinning is long continuous fibers or beads, but, under certain material and process conditions, short nanofibers can be obtained, a morphology that has scarcely been studied. Here we study the conditions that lead to the creation of short nanofibers, and find a distinct parametric space in which they are likely to appear, requiring a combination of low entanglement of the polymer chains and high strain rate of the electrospinning jet. Measurements of the length and diameter of short nanofibers, electrospun from PMMA dissolved in a blend of CHCl₃ and DMF, confirm the theoretical prediction that the fragmentation of the jet into short fibers is brought about by elastic stretching and loss of entanglement of the polymer network. The ability to tune nanofiber length, diameter and nanostructure, by modifying variables such as the molar mass, concentration, solvent quality, electric field intensity, and flow rate, can be exploited for improving their mechanical and thermodynamic properties, leading to novel applications in engineering and life sciences. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1377–1391     

Implementation of splitter-less SPLITT fractionation and its application to large scale-fractionation of sea sediment

The split-flow thin cell fractionation (SF) is a useful tool for separating colloidal particles or macromolecules into two or more fractions in a preparative scale. In a conventional design, the SF channel is equipped with flow stream-splitters at the inlet and the outlet of the channel, which may cause deterioration of the resolution due to the disturbance in the flow stream by the imperfection of the splitter geometry. In this study, a new splitter-less SF channel was implemented, which was designed to operate only in the full-feed depletion (FFD) mode (FFD-SF). Without the splitters, it was possible to make the channel much larger than conventional ones (about 25 times larger in the channel volume), and thus obtain a much higher sample throughput (TP, amount of the sample that can be processed in a unit time period). The new splitter-less FFD-SF system was tested and optimized using polyurethane (PU) latex spheres, and then applied successfully to a large scale separation of sea sediment. A series of three steps of FFD-SF operations (with each step repeated, and there were 6 steps in total) yielded separation of the sea sediment into four fractions having diameter ranges of larger than 10 µm, between 5 and 10 µm, between 2 and 5 µm, and smaller than 2 µm. TP of the three FFD-SF operations were 37.3, 22.1, and 17.9 kg/h, and the fractionation efficiencies (FE) of the four size fractions were 80.5, 73.7, 79.1 and 86.1%. Results suggest the new splitter-less FFD-SF system could be a useful tool for large scale separation of complex particulates such as environmental particles.     

磁珠快速核酸提取法在南美白对虾病原检测中的应用及其性能评价

为实现南美白对虾相关病原核酸快速、便捷提取,并实现原材料国产化,降低成本,建立了一种基于国产磁珠的核酸快速提取方法(以下简称磁珠法).以携带虾肝肠胞虫的南美白对虾为实验样本,通过微流控芯片对3种磁珠提取的核酸进行测试,并对裂解液中盐酸胍浓度及洗涤液2中乙醇浓度进行了优化.通过优选实验确定:奥润磁珠提取效果优于其他两种磁珠;裂解液中盐酸胍的最佳浓度为4 mol·L^-1;洗涤液2中乙醇的最佳质量分数为75%.在此基础上,分析评价了优化后的磁珠法核酸提取线性范围、灵敏度、精密度、特异性及抗干扰能力等技术性能.结果显示:稀释10⁴倍后的低浓度病原核酸仍保持较好的扩增效果,变异系数为2.03%,表明建立的磁珠法具有较宽的检测范围,灵敏度高,特异性和抗干扰能力强.本文建立的磁珠法可实现快捷、通用、高纯度、低成本的南美白对虾主要病原的核酸提取.