A New Fluorogenic Probe for the Detection of endo‐β‐N‐Acetylglucosaminidase

We developed a fluorescence‐quenching‐based assay system to determine the hydrolysis activity of endo‐β‐N‐acetylglucosaminidases (ENGases). The pentasaccharide derivative 1 was labeled with an N‐methylanthraniloyl group as a reporter dye at the non‐reducing end and with a 2,4‐dinitrophenyl group as a quencher molecule at the reducing end. This derivative is hydrolyzed by ENGase, resulting in an increase in fluorescence intensity. Thus, the fluorescence signal is directly proportional to the amount of the tetrasaccharide derivative, hence allowing ENGase activity to be evaluated easily and quantitatively. Using this system, we succeeded in measuring the hydrolysis activities of ENGases and thus the inhibitory activities of known inhibitors. We confirmed that this assay system is suitable for high‐throughput screening for potential inhibitors of human ENGase that might serve as therapeutic agents for the treatment of N‐glycanase 1 (NGLY1) deficiency.     

Temporal occurrence of immature skeletal muscle fibers in the sciatic nerve matrix regenerating within the silicone chamber after nerve transection in the normal rat

We examined by light and electron microscopy the immature skeletal muscle fibers in the rat sciatic nerve regenerating within the silicone chamber 14 days after nerve transection. Small myelinated and nonmyelinated nerve fibers associated with Schwann cells from the proximal stump began to approach the midportion of the interstump zone. In the middle segment, fibroblasts or fibroblast-like mesenchymal cells and macrophages were observed everywhere in the newly formed matrix filled with exuded erythrocytes and fibrin clots. In addition to some fibroblast-like mesenchymal cells were closely apposed to each other. However, the proximal and distal segments contained immature muscle fibers with various amount of myofilaments and one or plural centrally located nuclei, thus indicating various phases of the early differentiation of skeletal muscle fibers similar to those observed during an early stage of developing muscle fibers. However, the precise origin of these skeletal muscle fibers remains to be determined.     

Chain‐length Distribution Profiles of Amylopectin Isolated from Endosperm Starch of Waxy and Low‐amylose Bread Wheat (Triticum aestivum L.) Lines with Common Genetic Background

Large A‐type endosperm starch granules were isolated from near‐isogenic waxy and non‐waxy lines and low‐amylose mutant lines of bread wheat with a common genetic background. The amylose contents of A‐type starch ranged from 2.6% to 23.6%. Amylopectin was isolated by concanavalin A (Con A) precipitation from the isolated starch. The λ_max (range: 532‐538 nm) and blue values at 680 nm (range: 0.026‐0.037) of the iodine‐amylopectin complex were not significantly different among the isolated amylopectins, indicating that amylopectins from non‐waxy and low‐amylose lines did not contain such long chains as amylose or extra‐long chains of amylopectin affecting iodine complex properties. Chain‐length distribution profiles measured by both high‐performance size‐exclusion chromatography (HPSEC) and high‐performance anion‐exchange chromatography (HPAEC) showed that the amylopectin structures of these lines were indistinguishable from each other. Extra‐long chains were not detected in the amylopectins by HPSEC measurement. The side‐chains measured by HPAEC were classified into four groups according to their degree of polymerization (DP), and the proportion of each group were in the following ranges: DP 6‐12, 26.5‐27.5%; DP 13‐24, 43.6‐44.1%; DP 25‐36, 13.6‐14.2%, and DP 37‐60, 11.0‐11.7%. The alleles on the Wx‐D1 locus, i.e., Wx‐D1a, Wx‐D1d, Wx‐D1f, and Wx‐D1g, responsible for granule‐bound starch synthase (GBSS I) biosynthesis had no influence on the properties of iodine‐amylopectin complex and the chain‐length distribution profiles of amylopectin.     

Highly sensitive molecular detection with swift heavy ions

Various imaging techniques using microbeam have been applied in biology. Secondary ion mass spectrometry (SIMS) is one of the prominent tools for biological imaging; SIMS can provide data on molecular distribution in biological samples smaller than 1 μm. However, conventional SIMS has only low sensitivity for molecular ions; therefore there is a need for beams of more sensitive primary ions. Plasma desorption mass spectrometry (PDMS) is a method using high energy fission fragments from excitation of a ²⁵²Cf source, and it allows ionization of large molecules (typically up to 20 kDa) due to the dense electronic excitation. Although PDMS is not in use today because of the development of soft ionization methods, ionization induced by high energy ion collision still remains the only method which combines high spatial resolution and sensitive detection of large molecules. In this work, the secondary ion yield of amino acid and phospholipid was measured for 6 MeV Cu⁴⁺. The yields were compared to bismuth cluster ions, which achieve relatively high yield. It was confirmed that the swift heavy ion has a couple of hundred times higher yield for large molecules than bismuth cluster ions.     

An investigation on the heterogeneous nature of mineral matters in Assam (India) coal by CCSEM technique

This is a very first preliminary investigation on the distribution of heterogeneous nature of mineral matter in one of the industrially important Assam (India) pulverized coal using computer-controlled scanning electron microscopy (CCSEM). The results show that clay minerals, quartz, pyrite, and pyrrhotite form the bulk of the mineral matter. Minor minerals, such as calcite, dolomite, ankerite, barite, oxidized pyrrhotite, and gypsum, are also observed in the sample. The particle size distribution (PSD) of the included minerals is generally observed to be finer than that of the excluded ones in the coal. As a consequence, the coal rich in included minerals has more small mineral particles, which may affect its reactivity. Regarding the association of individual mineral species, the proportion of included to excluded is found to be higher in major cases. With regard to the modes of occurrence of major inorganic elements, it is found that Si mostly occurs as quartz and clay minerals, while Al mostly occurs as silicate minerals. Fe is primarily present as iron sulfides, iron oxide, and Fe-Al-silicate. S is partitioned into iron sulfides and gypsum. Most Ca occurs as carbonates and gypsum, with a minor fraction associated with clay minerals. Mg is mainly present as dolomite and clay minerals, with a very minor fraction present as ankerite. The majority of alkali elements are associated with aluminosilicates. P is mostly associated with kaolinite and/or present as more complex compounds containing Al, Si, and other elements as apatite is found to be absent in the coal studied. Ti is mainly present as rutile and kaolinite.     

Ripple compensation for torque sensors built into harmonic drives

Harmonic drives include a mechanically flexible component which transmits load torque, and therefore, a torque sensor can be built into harmonic drives by cementing strain gages on a flexible component of the gear. However, a periodic sensing error called ripple is generated by deformation of a flexible component during the gear operation. The ripple signal cannot be sufficiently compensated by pairs of strain gages that produce opposite phase signals, because the strain gages cannot be exactly positioned on the desired locations. In this paper, we present a method to compensate the ripple by a new approach of tuning the ripple amplitudes for separate strain gages. The ripple, caused by positioning errors of the strain gages, can be perfectly compensated, and, therefore, the requirement for accurate strain gage positioning is reduced. The method does not need any online calculations, and consequently, the torque signal is not delayed. The minimum number of strain gages needed to compensate a given number of frequency components of a ripple is derived. Some experimental results are shown     

基于PSO_GRNN网络的肺内静态压力值预测方法* .txt

摘要：为了实现机械通气辅助医疗中依据病人个体差异控制呼吸机通气参量，分析了基于广义回归神经网络（GRNN）的呼吸系统力学模型，通过结合PSO_GRNN网络、数值积分和递推最小二乘法等实现呼吸系统模型的参数辨识。采用直接计算法实现单周期呼吸样本的肺静态压力值计算，并利用二阶多项式拟合体积值误差，计算10个吸气周期静态数据点的平均绝对值误差为0169 3 mL，计算10个呼气周期静态数据点的平均绝对值误差为0372 8 mL。采用PSO_GRNN网络实现多周期呼吸样本集的肺静态压力值预测，10个呼吸周期样本集的训练集平均误差为0000 9 kPa，测试集平均误差为0040 7 kPa。仿真实验结果表明PSO_GRNN网络在收敛速度、平均误差、运算速度等方面均优于PSO_BP网络。所用方法在机械通气辅助治疗时可以为医生设置呼吸机通气参量提供有效的参考依据。 .txt     

Clinical efficacy of imipenem/cilastatin sodium for respiratory infections in patients with lung cancer

Imipenem/cilastatin sodium (IPM/CS) was administered to 102 patients with respiratory tract infections and lung cancer. Patients with other serious diseases were excluded and a total of 73 patients were enrolled. They were divided into 12 patients who underwent surgery (operated group) and 61 who did not (non-operated group); the latter group included 28 patients treated with anticancer agents or radiation therapy (treated group) and 33 untreated patients (untreated group). IPM/CS was effective in 75% of the patients, both with and without surgery. The drug was effective in 81% of the treated group, although many of the patients had Stage III or more advanced cancer, as well as bronchial occlusion. IPM/CS was also effective in 69% of the untreated group, although many of the patients have serious infections and a PS (Performance Status) of 3 or greater. Thus, IPM/CS treatment achieved good results. Bacteriological studies showed that 3 out of 4 strains in the operated group and 16 out of 18 in the non-operated group were eliminated. Safety was evaluated in all patients. Two patients (2%) experienced side effects and two others (2%) showed abnormal clinical findings, but the symptoms were mild and resolved after discontinuation or completion of therapy. In conclusion, IPM/CS was very effective for treating respiratory infections in patients with lung cancer.