分光光度法测定黄瓜籽粉中盐酸小檗碱的含量

采用超声波法在2种条件下即(1)先超声处理,后放置过夜;(2)先放置过夜,后超声处理,对黄瓜籽粉中盐酸小檗碱进行提取,利用分光光度法测定盐酸小檗碱的含量,检测波长为426nm。回归方程y=0.00393+1.28929x(mg/10mL),r=0.9999;盐酸小檗碱浓度在0.099—0.796mg/10mL范围内与吸光度呈线性关系。2种方法的平均含量分别为2.4043、1.4797mg/g。平均回收率分别为94.96%、107.32%。实验结果表明,方法(1)较方法(2)提取率高。分光光度法用于黄瓜籽粉中盐酸小檗碱的含量测定,简便,可靠,快捷。     

用OPD-H 2 O 2-HRP伏安酶联免疫法检测植物病毒ArMV、C MV、SBMV和TuMV*

首次将邻苯二胺（ＯＰＤ）－Ｈ２Ｏ２－辣根过氧化物酶（ＨＲＰ）伏安酶联免疫分析体系,应用于植物病毒南芥菜花叶病毒（ＡｒＭＶ）,黄瓜花叶病毒（ＣＭＶ）,南方菜豆花叶病毒（ＳＢＭＶ）和芜箐花叶病毒的血清学检测。该法测定以上植物病毒感染病叶澄清液的最高稀释比（体积比）分别为１：５００００００,１：５０００００;１：２５０００００和１：２５００００,而酶联免疫吸附分析（ＥＬＩＳＡ）测定的最高稀释比分别为１：     

In Situ Spectroscopic Detection of Large-Scale Reorientations of Transmembrane Helices During Influenza A M2 Channel Opening**

Viroporins are small ion channels in membranes of enveloped viruses that play key roles during viral life cycles. To use viroporins as drug targets against viral infection requires in-depth mechanistic understanding and, with that, methods that enable investigations under in situ conditions. Here, we apply surface-enhanced infrared absorption (SEIRA) spectroscopy to Influenza A M2 reconstituted within a solid-supported membrane, to shed light on the mechanics of its viroporin function. M2 is a paradigm of pH-activated proton channels and controls the proton flux into the viral interior during viral infection. We use SEIRA to track the large-scale reorientation of M2’s transmembrane α-helices in situ during pH-activated channel opening. We quantify this event as a helical tilt from 26° to 40° by correlating the experimental results with solid-state nuclear magnetic resonance-informed computational spectroscopy. This mechanical motion is impeded upon addition of the inhibitor rimantadine, giving a direct spectroscopic marker to test antiviral activity. The presented approach provides a spectroscopic tool to quantify large-scale structural changes and to track the function and inhibition of the growing number of viroporins from pathogenic viruses in future studies.     

A Duplex Polymerization Strategy for General,Programmable and High-Resolution Nanopore-Based Sensing

Nanopore sensing is highly promising in single molecular analysis but their broad applications have been challenged by the limited strategies that can transduce a target-of-interest into a specific and anti-false/inference signal, especially for solid-state nanopores with relatively lower resolution and higher noise. Here we report a high-resolution signal-production concept named target-induced duplex polymerization strategy (DPS). Through linking the same or different duplex substrates (DSs) with a special linker (L) and an optional structure tag (ST), the DPS can generate target-specific DS polymers with highly controllable duration times, duration intervals and even distinguished secondary tagging currents. Experimentally, DPS mono-polymerization of single DS and co-polymerization of multiple DSs has verified the duration time of a DPS product is the sum of those for each DS monomer. Tetrahedron-DNA structures with different sizes are used as the STs to provide needle-like secondary peaks for further resolution enhancement and multiplex assay. With these examples DPS represents a general, programmable and advanced strategy that may simultaneously provide size-amplification, concentration amplification, and signal-specificity for molecular recognition. It is also promisingly in various applications regarding to single molecular investigation, such as polymerization degree, structure/side chain conformation, programmable multiplex decoding and information index.     

Inactivation of the enveloped virus phi6 with hydrodynamic cavitation

The COVID −19 pandemic reminded us that we need better contingency plans to prevent the spread of infectious agents and the occurrence of epidemics or pandemics. Although the transmissibility of SARS-CoV-2 in water has not been confirmed, there are studies that have reported on the presence of infectious coronaviruses in water and wastewater samples. Since standard water treatments are not designed to eliminate viruses, it is of utmost importance to explore advanced treatment processes that can improve water treatment and help inactivate viruses when needed. This is the first study to investigate the effects of hydrodynamic cavitation on the inactivation of bacteriophage phi6, an enveloped virus used as a SARS-CoV-2 surrogate in many studies. In two series of experiments with increasing and constant sample temperature, virus reduction of up to 6.3 logs was achieved. Inactivation of phi6 at temperatures of 10 and 20 °C occurs predominantly by the mechanical effect of cavitation and results in a reduction of up to 4.5 logs. At 30 °C, the reduction increases to up to 6 logs, where the temperature-induced increased susceptibility of the viral lipid envelope makes the virus more prone to inactivation. Furthermore, the control experiments without cavitation showed that the increased temperature alone is not sufficient to cause inactivation, but that additional mechanical stress is still required. The RNA degradation results confirmed that virus inactivation was due to the disrupted lipid bilayer and not to RNA damage. Hydrodynamic cavitation, therefore, has the potential to inactivate current and potentially emerging enveloped pathogenic viruses in water at lower, environmentally relevant temperatures.