Construction and characterization of nitrate reductase-based amperometric electrode and nitrate assay of fertilizers and drinking water

The construction and characterization of a nitrate reductase-based amperometric electrode for determination of nitrate ion is described. The electrode consisted of nitrate reductase held by dialysis membrane onto a Nafion-coated glassy carbon electrode. Methyl viologen was allowed to absorb into the Nafion layer, which acted as a reservoir for the electron mediator. The utility of the electrode to assay fertilizer and water sample for nitrate was demonstrated. The assays conducted with this electrode compared well with colorimetric and potentiometric assays of the same samples.     

热带钢轧机板形板厚抗干扰全解耦控制研究

宽带钢热连轧过程是一个多变量过程控制系统,除了系统有用输入和输出之间具有耦合作用之外,干扰输入也会和系统输出产生耦合作用,影响板形板厚控制质量.设计了前向通道解耦控制器和前馈补偿环节,实现了板形板厚输入输出解耦的同时使得带钢来料厚度波动对板形板厚输出的耦合性得以抑制和消除.生产实践表明,解耦策略的应用,有效地降低了板形板厚的耦合作用,尤其是板厚调节对带钢板形的干扰影响,为进一步提高带钢出口板形板厚综合质量奠定了基础.     

线材减定径关键工艺装备技术的研究与开发

分析了高速线材及减定径技术现状,对减定径工艺装备相关的孔型设计、微张力控制、控制冷却模型、速比配置及换挡技术、模态分析等重要问题进行了研究。开发了先进的SRSCD线材减定径机组及水冷控温模型系统,可实现750 ℃低温轧制和40%～45%大压下,产品精度达到±0.1 mm,并在某不锈钢线材生产线上进行了定径机的高精度轧制验证,其产品精度达到研发目标,开发的SRSCD机组为线材生产技术升级提供了良好的手段。     

Kinetics and mechanisms of synthesis and sintering of ferrites

Conclusions Data yielded by x-ray diffraction, magnetic, metallographic, pycnometric, gravimetric, and dilatometric investigations into the kinetics of formation and sintering of ferrites with various crystal structures have enabled the mechanisms of these processes to be established. It is shown that the formation of a new (ferrite) phase is effected on the basis of the lattice of a more stable oxide, with preferential diffusion of cations of the other oxide. The processes of formation and sintering of ferrites taking place under nonequilibrium conditions are satisfactorily described by a nonequilibrium thermodynamics equation. The ferrite synthesis and sintering processes have comparatively small energies of activation, which is due to the high degree of defectiveness of the ferrite crystal lattice.Translated from Poroshkovaya Metallurgiya, No. 1(277), pp. 18–23, January, 1986.     

Identification and characterization of the glycoprotein E and I genes of canine herpesvirus

We have determined the sequence of the gE and gI genes of canine herpesvirus (CHV), DFD-6 strain. The gE ORF codes for a 522 a.a. polypeptide with a signal sequence at the amino-terminus and a trans-membrane domain at the carboxy-terminus. The gI ORF codes for a 259 a.a. polypeptide with a signal sequence but no trans-membrane domain. Comparison with another line of CHV indicated that the DFD-6 gI gene underwent a frame-shift mutation which caused the loss of the trans-membrane domain. Antibodies against the gE and gI polypeptides detected a 94 kDa gE and a broad band of gI (55-62 kDa) in DFD-6 infected cells, respectively. The precursor of DFD-6 gE is modified to the mature form by N-linked glycosylation only in the presence of gI. Together with the fact that the gI- mutant of DFD-6 produced smaller plaques, it is suggested that the truncated DFD-6 gI is functional. The precursor of DFD-6 gI is modified to the mature form by N-linked glycosylation only in the presence of gE.     

The variation and covariation of cup and disc diameters

The variation and covariation of cup and disc diameters were studied in a material derived from a population survey and consisting of 2,334 fundus photographs from as many eyes in 1,322 subjects. A simple device was used to facilitate focusing of the camera. The colour slides were projected on to a screen at a fixed distance and measured on ruled paper. The effect of refraction on the magnification in the eye-camera system was compensated by the use of a simple correcting factor. Some apparently quite normal discs, nevertheless, had an area more than four times larger than that of other equally normal ones. The sizes of discs and cups covaried, however, to a suprisingly great extent (r = 0.8) and changes in disc diameter were in general parallelled by similar changes in cup diameter. The amount of tissue in the optic nerve head therefore varied somewhat less than the disc size. Cup diameters were widely dispersed, unevenly distributed and heavily dependent on disc size. The "average rim breadths", on the other hand, were much less dispersed, normally distributed and independent on the disc diameter. By taking the covariation of cup and disc diameters into account the detection of any enlargement or diminution of the optic cup ought to be facilitated.     

Method and technique of experimental autotransplantation of a lung and a lung lobe

The authors have accumulated an experience of 350 canine autotransplantations of a lung and its lobe. The peculiarities of the operative technique are described, and special emphasis is laid on its technical details that largely determine the success of a lung autotransplantation. The described method and technique permit the performance of orthotopic autotransplantation of a whole lung and of its lobe, and of heterotopic autotransplantation of the lower lobe of the right lung into the left pleural cavity in place of a removed lower lobe or whole lung. The first stage of autotransplantation of a lung or its lobe consists in applying an atrio-venous or venous anastomosis and that of the pulmonary artery with continuous U-shaped eversion sutures, with a re-establishment of the circulation, thus reducing the period of lung ischaemia. Upon restoring the blood flow in the lung, a bronchial anastomosis is applied with interrupted or continuous sutures, and the ventilation is restored. The vascular and bronchial anastomoses are applied with synthetic suture material (Orsylon) on atraumatic needles. The extensive experience of the authors in long-term follow-up of the animals after transplantation (up to 5 years) demonstrates that the described technique and method of lung autotransplantation ensures good competence and patency of the vascular and bronchial anastomoses, without any stenoses observed in the late postoperative period. As shown by histological examinations, the inflammatory reaction around the suture material is minimal.     

Male and female alcoholics'' attributions regarding the onset and termination of relapses and the maintenance of abstinence

The application of a knowledge-based segmentation method to the problem of automatically detecting the outer follicle wall boundary in ultrasonographic images of ovaries is presented. A combination of computer detection and interactive adjustment was used to define an approximate inner follicle-wall boundary, which was then used by the computer algorithm as a priori knowledge to automatically find the outer follicle-wall border. The segmentation algorithm was tested on ultrasonographic images of women's ovaries that were imaged in vivo. The semiautomatic segmentations were compared to segmentations by an expert human observer in terms of border placement differences and in terms of quantitative parameters relevant to the physiologic status of the follicles. These physiological parameters include total and specific signal intensity from the follicle and from the follicle wall. The computer-detected outer follicle wall boundaries correlated well with the human observer-defined wall boundaries, in terms of enclosed follicle area, specific and total follicle signal, enclosed wall area, and specific and total wall signal. The actual border placement differences were also small, with a maximum placement difference of 1.47 +/- 0.83 mm and a root mean square (r.m.s.) placement difference of 0.59 +/- 0.28 mm.     

Preparation of TIC-WC and NBC-WC solid solutions and study of their superconductivity

Summary TiC-WC and NbC-WC carbide solid solutions were prepared in this work by simultaneous synthesis from a mixture of the metals with carbon black in a hot-compaction press.The results obtained for the region of solubility of WC in TiC and NbC and for the variation of the lattice parameter with solid solution composition are in good agreement with literature data.The temperature of transition into the superconducting state in the region of existence of the solid solution with a NaCl type lattice in both systems rises with increasing tungsten carbide content. The maximum critical temperature for the compositions with the limiting solubility of WC is about 7° K for the system TiC-WC and 13° K for the system NbC-WC. The critical temperature in both systems may be raised by extending the limits of solubility of WC; this may be achieved by increasing the temperature of solid solution formation.Extrapolation of data on superconductivity in the systems investigated leads to the conclusion that the tungsten carbide with a cubic NaCl type lattice must be a superconductor with a temperature of transition into the superconducting state above 10° K.Translated from Poroshkovaya Metallurgiya, No. 6(54), pp. 16–20, June, 1967.     

纳米锰方硼石的合成与结构性能表征

通过溶胶?凝胶（Sol?Gel）法成功合成了纳米锰方硼石并对其进行了稀土Eu3+掺杂。使用X射线衍射、透射电子显微镜和高分辨透射电子显微镜等表征了锰方硼石晶体结构,并通过荧光光谱测试对其发光性能进行了研究。结果表明:合成纳米锰方硼石为粒径小于50 nm的球状颗粒,与天然锰方硼石的物相结构相同,属于斜方晶系,与尖晶石类似,（010）晶面的晶面间距为0.8565 nm。在490 nm激发光激发下,天然锰方硼石、合成锰方硼石和稀土Eu3+掺杂锰方硼石晶体中的Mn2+发光,其中发绿光的Mn2+在晶体中占据四面体格位中心,发红光的Mn2+在晶体占据八面体格位中心。合成的锰方硼石随激发波长变长,产生发射光谱的红移现象,有利于实现冷暖发光转换;在稀土Eu3+掺杂的纳米锰方硼石光谱的发光强度得到了提升。      

Expression of vimentin and GFAP and development of the retina in the trout

The glial cell development was studied during the edification of the retina and the optic tract, in a teleost, the rainbow trout. The intermediate filament proteins, vimentin and glial fibrillary acidic protein (GFAP) were visualized by an indirect immunohistochemical method. Results show that both vimentin and GFAP are early expressed in the developing retina and, particularly in the Müller cells, a coexpression of vimentin and GFAP is observed from embryonic to adult stages. The ganglion cell layer and the optic fiber layer both exhibit GFAP-positive structures. The deep staining for GFAP is also seen in the optic nerve and induces us to credit astrocyte-like cells with a leading role in the pattern formation of this tract.     

Consumption of foods and micronutrients and the risk of cancer of the biliary tract

BACKGROUND: Gallstones and obesity have been suggested as risk factors for cancer of the biliary tract. Since both factors are related to diet, we studied the relationship between dietary intake and the cancer of interest in a population-based case-control study. METHODS: The study population comprised 111 patients and 480 controls. Food intake was assessed by means of a semiquantitative food frequency questionnaire. Estimates of the intake of foods and micronutrients were obtained from cases and controls themselves (direct respondents) or from relatives (indirect respondents). Participants were categorized into tertiles of intake. Risk ratios were estimated by logistic regression analysis. RESULTS: The major findings are a monotonic decrease in risk associated with the consumption of vegetables (ORs 1.0, 0.7, 0.4, P value trend < 0.01) and a monotonic increase in risk associated with sugar added to drinks and desserts (ORs 1.0, 1.3, 2.5; P value trend < 0.01). CONCLUSIONS: The finding on added sugar corresponds to our earlier report that the group monosaccharides and disaccharides is a potential risk factor for this cancer. Sugar may influence bile composition through lipoprotein metabolism. The protective effect of vegetables is in accordance with the reported inverse relationship between vegetables and many epithelial cancers of the alimentary tract.     

Behavior of various blood parameters of carbohydrate and fat metabolism of light and heavy-weight rats of varying age and different diet groups]

The bone mineral content of the femoral neck of 61 autopsy specimens was assayed by x-ray spectrophotometry. The mechanical strength of the specimens was also determined experimentally by applying a compressive force perpendicularly to the shaft. The ultimate force at fracture was obtained from force/displacement plots. A coefficient of correlation of 0.89 between bone mineral content of the femoral neck and the ultimate force at fracture was found. Even when limited to a group of women aged 67-80 a fairly close correlation was found. This indicates that the bone mineral level, measured in vivo, can be used as a criterion of the risk of fracture in elderly women.     

Stability and Strength of Rigid and Semirigid Plane Frameworks

A computational technique for incorporating stability and strength into the analysis of plane frameworks is presented. The procedure for computing critical and/or collapse loads and for identifying the corresponding failure mode is outlined. The analysis is based on nonlinear kinematic relations and linearly elastic material behavior except at the plastic hinges—concentrated plasticity. The connections can be treated either as rigid or as flexible. The supports, in general, contain rotational restraints. The developed solution methodology is applicable to all multistory‐multibay orthogonal frames. The examples analyzed in the paper include: (1) A single‐story‐two‐bay frame with rigid joint connections; (2) a single‐story‐three‐bay frame with flexible joint connections; (3) a two‐story‐single‐bay frame with both rigid and flexible joint connections; and (4) a three‐story‐two‐bay frame with rigid joint connections. In all cases the loading consists of a symmetric distribution of concentrated loads on the beams, applied at the midspan positions and at or near the beam‐to‐column joints. The effect of several geometric and structural parameters is assessed.     

Synthesis and pharmacological comparison of dimethylheptyl and pentyl analogs of anandamide

(Dimethylheptyl)anandamide [(16,16-dimethyldocosa-cis-5,8,11,14-tetraenoyl)ethanolamine ] (17a) and its amide analogs were synthesized by Wittig coupling of a ylide derived from a fragment of arachidonic acid. These amides were compared to the endogenous cannabinoid receptor ligand arachidonylethanolamide (anandamide, 2a) and its amide analogs in pharmacological assays for potential enhancement of cannabimimetic activities. The receptor affinity to rat brain membranes of the dimethylheptyl (DMH) analogs increased by an order of magnitude in most comparisons to the corresponding anandamides in displacement assays versus the cannabinoid agonist [3H]CP 55,940 or antagonist [3H]SR141716A, for which rank order differences in affinity were observed. An order of magnitude enhancement of potency with comparable or higher efficacy in behavioral assays in the mouse tetrad of tests of cannabinoid activity was observed in 17a versus 2a. In contrast, no enhancement in potency for the pentyl to DMH side chain exchange was seen in the mouse vas deferens assay. The data indicate a structural equivalence between classical plant cannabinoids and 2a as well as different receptor-ligand interactions that characterize multiple receptor sites or binding modes.     

Disinfection of medical and surgical equipment: efficacy of chemical disinfectants and water and soap

In this experimental study we compared the previous descontamination efficacy of the medical surgical materials by the use of chemical disinfectants and the mechanical cleaning with water and soap, as well as verified the organic material interference in these procedures. To carry out this study, we used surgical pincers under contamination with: Staphylococcus aureus ATCC-6538, Salmonella cholerae suis ATCC-10708, and Pseudomonas aeruginosa ATCC-15442 in presence and absence of organic matter (fetal bovine serum). The following treatments: glutaraldehyde 2%, sodium hypochlorite 1%, hydrogen peroxide 6%, alcohol 70% and the mechanical cleaning with water and soap were compared with eight repetitions in a total of 480 observations. In the described conditions, the disinfectants had a good efficacy in the previous descontamination of the medical surgical materials and a less inactivation by the organic material. The mechanical cleaning with water and soap showed a reduction of the microrganism to safe levels, considered adequate for previous descontamination.     

复杂破碎巷道支护效果分析与评价

金川集团龙首矿为高应力复杂破碎岩体,矿区岩体流变特性显著,巷道围岩变形量大,变形持续时间长;为有效控制巷道收敛变形,矿山采用了双层喷锚网支护的支护加固措施。为探究矿山当前的巷道支护效果,进行了现场锚杆应力和巷道收敛变形监测,结果表明:巷道锚杆整体托锚力较低,一般为锚杆锚固能力的6.67%～23.33%,为此提出了增强支护效果的建议措施;巷道围岩变形量呈现缓慢增加趋势,变形速率有减缓趋势,水平方向收敛大于垂直方向收敛,平均收敛速率0.09～0.19mm/d,处于减速变形阶段,巷道整体稳定状态良好,取得了相对较好的支护加固效果。     

Investigation of Tribological Properties and Characterization of Borided AISI 420 and AISI 5120 Steels

In the present study, tribological and characterization properties of borides formed on AISI 420 martensitic stainless and AISI 5120 cementation steels have been investigated. The boride layer was characterized by optical microscopy, X-ray diffraction technique and the micro-Vickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe₂B and CrB compounds. The wear tests were carried out in a ball-disc arrangement under a dry friction condition at room temperature with an applied load of 10 N and with a sliding speed of 0.3 m/s at a sliding distance of 1,000 m. The wear surfaces of the steels were analyzed using a SEM microscopy and X-ray energy dispersive spectroscopy EDS. The results were compared with each other. It was observed that the friction coefficient of unborided and borided steels ranged from 0.42 to 0.63. The wear rate of the borided steels was found to be approximately five times lower the wear rate of the unborided steels.     

改性高水材料抗压、抗剪强度特征及对比分析

以高水充填材料为载体,用聚乙烯塑料（PE）对其进行改性,研究了改性高水材料的抗压、抗剪强度特征,并对结果进行了对比分析。结果表明:随PE粉掺量的增加,改性高水材料的抗压、抗剪强度均呈现降低的趋势,改性高水材料各应力应变曲线与纯高水材料有明显区别,纯高水材料的残余强度更高,改性高水材料的残余强度普遍较低,而剪切位移曲线变化不明显;PE粉的加入明显改变了材料的生成物形貌以及微观结构,随掺量的增加逐渐由纤维网状结构向絮凝块状结构变化,而且生成物之间更容易形成尺寸较大的贯穿孔洞;改性高水材料的抗剪强度明显低于抗压强度,表明改性类高水充填材料不宜用于倾角较大的煤层。      

Comparison of the structures and properties of binary and ternary melt-quenched Al-Ni-Cr alloys

Foils of melt-quenched binary Al-0.6 at % Ni and Al-0.8 at % Cr and ternary Al-0.6 at % Ni-0.6 at % Cr alloys are analyzed. The alloys exhibit cellular morphology of the free surface, a microcrystalline coarse-blocked structure, and a (111) texture. The microhardness of the foils is higher than that of the corresponding bulk samples. The study of the thermal stability in the ternary alloy reveals a multistage aging process caused by successive precipitation of the intermetallic Al₃Ni and A₇Cr phases.