Development of a Glassy Carbon Electrode Modified with Graphene/Au Nanoparticles for Determination of Acetaminophen in Pharmaceutical Preparation

Russian Journal of Electrochemistry - A graphene/Au nanoparticles composite modified glassy carbon electrode (GR/AuNPs/GCE) was developed. Electrochemical behavior of acetaminophen (ACOP) at this...     

Quick stabilization of capillary for rapid determination of potassium ions in the blood of epilepsy patients by capillary electrophoresis without sample pretreatment

Mutations in the potassium channel genes may be linked to the development of epilepsy and affect the blood potassium levels. Therefore, accurate determination of potassium in the blood will be critical to diagnose the cause of epilepsy. CE is a competent technique for the fast detection of multiple ions, but complicated matrices of a blood sample may cause significant variation of migration times and the peak shape. In this work, a procedure for rapid stabilization of the capillary inner surface through preflushing of a blood sample was employed. The process takes only 40 min for a capillary and then it can be used for more than 2 weeks. No pretreatment of the blood sample or other surface modification of the capillary is needed for the analysis. The RSDs of the migration time and peak area were reduced to 1.5 and 5.1% from 12.6 and 14.5%, respectively. The proposed method has been successfully applied to the determination of the potassium contents in the blood sample of patients with epilepsy at different stages. The recoveries of potassium ions in these blood samples are in a range from 86.5 to 104.5%.     

-switched Yb Doped Fiber Ring Laser with a M-Z Interferometer

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｑ ｓｗｉｔｃｈｅｄｌａｓｅｒｓａｒｅａｔｔｒａｃｔｉｖｅｌａｓｅｒｓｏｕｒｃｅｓｆｏｒｒａｎｇｉｎｇ ,ａｌｔｉｍｅｔｒｙ ,ｌｉｄａｒ,ａｎｄｏｔｈｅｒａｐｐｌｉｃａｔｉｏｎｓｒｅｑｕｉｒｉｎｇｈｉｇｈｅｎｅｒｇｉｃ ｐｕｌｓｅｓ .Ｑ ｓｗｉｔｃｈｅｄｆｉｂｅｒｌａｓｅｒｓｙｓｔｅｍｓｂａｓｅｄｏｎｓｉｎｇｌｅ ｍｏｄｅｒａｒｅ ｅａｒｔｈｄｏｐｅｄｆｉｂｅｒｓｈａｖｅａｔｔｒａｃｔｅｄｇｒｅａｔｉｎｔｅｒｅｓｔｂｅｃａｕｓｅｔｈｅｙｃａｎｂｅｕｓｅｄａｓｃｏｍｐａｃｔ,…     

Effective SNR improvement using a high-power pulsed pump in an ytterbium-doped fiber amplifier

A high-power pulsed pump method is proposed to obtain a high-energy output with an improved signal- to-noise ratio （SNR） during pulse amplification. Based on numerical analysis, the ytterbium-doped fiber amplifiers are compared under different pumping conditions. At the same signal gain, the output using the high-power pulsed pump shows great SNR improvement and reduced output signal distortion, compared with a continuous-wave pump and a low-power pulsed pump. By adjusting the pump parameters, the amplifier can achieve the optimal output SNR without sacrificing the signal gain. We believe that the high-power pulsed pump scheme is very suitable for the high-energy nanosecond pulse amplification, which has a high SNR requirement.     

CO2激光对熔石英表面小尺寸损伤的修复

利用10.6 μm的CO2激光对不同直径的点状损伤和不同宽度的划痕进行了修复。经过波长351 nm的紫外激光考核发现,对于直径小于80 μm的点状损伤和对于宽度小于40 μm的划痕,随着损伤点尺寸和划痕宽度的增加,修复后阈值提高程度逐渐降低。划痕的宽度在达到40 μm以后修复效果非常微弱。修复过程中,由于作用时间较短及温度分布不均产生了热应力导致样片损伤以后产生径向裂痕,后续的紫外激光会使裂痕明显扩展。当样品被置于高温退火炉内退火3 h以后,应力导致开裂的现象得到了解决。     

Engineering Polymer‐Binding Bispecific Antibodies for Enhanced Pretargeted Delivery of Nanoparticles to Mucus‐Covered Epithelium

Mucus represents a major barrier to sustained and targeted drug delivery to mucosal epithelium. Ideal drug carriers should not only rapidly diffuse across mucus, but also bind the epithelium. Unfortunately, ligand‐conjugated particles often exhibit poor penetration across mucus. In this work, we explored a two‐step “pretargeting” approach through engineering a bispecific antibody that binds both cell‐surface ICAM‐1 and polyethylene glycol (PEG) on the surface of nanoparticles, thereby effectively decoupling cell targeting from particle design and formulation. When tested in a mucus‐coated Caco‐2 culture model that mimics the physiological process of mucus clearance, pretargeting increased the amount of PEGylated particles binding to cells by around 2‐fold or more compared to either non‐targeted or actively targeted PEGylated particles. Pretargeting also markedly enhanced particle retention in mouse intestinal tissues. Our work underscores pretargeting as a promising strategy to improve the delivery of therapeutics to mucosal surfaces.     

仪器分析课程教学改革调查及对策分析

根据调查结果,分析了仪器分析课程教学改革的现状及存在的问题,并针对问题提出了改革措施及实施计划。     

A novel 852-nm tunable fiber laser

We report a novel fiber laser operating at 850-nm band by using semiconductor optical amplifier and fiber grating. The laser system is stable, compact, and the operating wavelength can be tuned continuously from about 851 to 854 nm for Cs atomic clock system by stretching the fiber grating. An output power up to 20 mW is obtained with a signal-to-background ratio beyond 20 dB.     

Low-threshold single-wavelength all-fiber laser generating cylindrical vector beams using a few-mode fiber Bragg grating

We propose and demonstrate a low-threshold single-wavelength all-fiber laser generating cylindrical vector beams using a few-mode fiber Bragg grating. Both radially and azimuthally polarized beams have been generated with very good modal symmetry and polarization purity higher than 94%. The radially and azimuthally polarized modes can be switched by simply adjusting the polarization controllers built in the fiber laser cavity. This fiber laser operates at a single wavelength of 1053 nm with a 3 dB linewidth of less than 0.02 nm, signal-to-background ratio of more than 55 dB, and a threshold as low as 16 mW. A new method for the polarization purity measurement is also proposed.